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6457 lines
160 KiB
6457 lines
160 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Routines having to do with the 'struct sk_buff' memory handlers. |
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* |
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* Authors: Alan Cox <[email protected]> |
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* Florian La Roche <[email protected]> |
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* |
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* Fixes: |
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* Alan Cox : Fixed the worst of the load |
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* balancer bugs. |
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* Dave Platt : Interrupt stacking fix. |
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* Richard Kooijman : Timestamp fixes. |
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* Alan Cox : Changed buffer format. |
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* Alan Cox : destructor hook for AF_UNIX etc. |
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* Linus Torvalds : Better skb_clone. |
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* Alan Cox : Added skb_copy. |
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* Alan Cox : Added all the changed routines Linus |
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* only put in the headers |
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* Ray VanTassle : Fixed --skb->lock in free |
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* Alan Cox : skb_copy copy arp field |
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* Andi Kleen : slabified it. |
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* Robert Olsson : Removed skb_head_pool |
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* |
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* NOTE: |
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* The __skb_ routines should be called with interrupts |
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* disabled, or you better be *real* sure that the operation is atomic |
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* with respect to whatever list is being frobbed (e.g. via lock_sock() |
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* or via disabling bottom half handlers, etc). |
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*/ |
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|
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/* |
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* The functions in this file will not compile correctly with gcc 2.4.x |
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*/ |
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|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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|
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/mm.h> |
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#include <linux/interrupt.h> |
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#include <linux/in.h> |
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#include <linux/inet.h> |
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#include <linux/slab.h> |
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#include <linux/tcp.h> |
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#include <linux/udp.h> |
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#include <linux/sctp.h> |
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#include <linux/netdevice.h> |
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#ifdef CONFIG_NET_CLS_ACT |
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#include <net/pkt_sched.h> |
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#endif |
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#include <linux/string.h> |
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#include <linux/skbuff.h> |
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#include <linux/splice.h> |
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#include <linux/cache.h> |
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#include <linux/rtnetlink.h> |
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#include <linux/init.h> |
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#include <linux/scatterlist.h> |
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#include <linux/errqueue.h> |
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#include <linux/prefetch.h> |
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#include <linux/if_vlan.h> |
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#include <linux/mpls.h> |
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#include <linux/kcov.h> |
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|
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#include <net/protocol.h> |
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#include <net/dst.h> |
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#include <net/sock.h> |
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#include <net/checksum.h> |
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#include <net/ip6_checksum.h> |
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#include <net/xfrm.h> |
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#include <net/mpls.h> |
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#include <net/mptcp.h> |
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#include <net/mctp.h> |
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#include <net/page_pool.h> |
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|
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#include <linux/uaccess.h> |
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#include <trace/events/skb.h> |
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#include <linux/highmem.h> |
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#include <linux/capability.h> |
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#include <linux/user_namespace.h> |
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#include <linux/indirect_call_wrapper.h> |
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|
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#include "datagram.h" |
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#include "sock_destructor.h" |
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|
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struct kmem_cache *skbuff_head_cache __ro_after_init; |
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static struct kmem_cache *skbuff_fclone_cache __ro_after_init; |
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#ifdef CONFIG_SKB_EXTENSIONS |
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static struct kmem_cache *skbuff_ext_cache __ro_after_init; |
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#endif |
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int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS; |
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EXPORT_SYMBOL(sysctl_max_skb_frags); |
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|
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/** |
|
* skb_panic - private function for out-of-line support |
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* @skb: buffer |
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* @sz: size |
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* @addr: address |
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* @msg: skb_over_panic or skb_under_panic |
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* |
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* Out-of-line support for skb_put() and skb_push(). |
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* Called via the wrapper skb_over_panic() or skb_under_panic(). |
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* Keep out of line to prevent kernel bloat. |
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* __builtin_return_address is not used because it is not always reliable. |
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*/ |
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static void skb_panic(struct sk_buff *skb, unsigned int sz, void *addr, |
|
const char msg[]) |
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{ |
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pr_emerg("%s: text:%px len:%d put:%d head:%px data:%px tail:%#lx end:%#lx dev:%s\n", |
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msg, addr, skb->len, sz, skb->head, skb->data, |
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(unsigned long)skb->tail, (unsigned long)skb->end, |
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skb->dev ? skb->dev->name : "<NULL>"); |
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BUG(); |
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} |
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|
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static void skb_over_panic(struct sk_buff *skb, unsigned int sz, void *addr) |
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{ |
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skb_panic(skb, sz, addr, __func__); |
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} |
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|
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static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr) |
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{ |
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skb_panic(skb, sz, addr, __func__); |
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} |
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|
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#define NAPI_SKB_CACHE_SIZE 64 |
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#define NAPI_SKB_CACHE_BULK 16 |
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#define NAPI_SKB_CACHE_HALF (NAPI_SKB_CACHE_SIZE / 2) |
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|
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struct napi_alloc_cache { |
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struct page_frag_cache page; |
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unsigned int skb_count; |
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void *skb_cache[NAPI_SKB_CACHE_SIZE]; |
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}; |
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|
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static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); |
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static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache); |
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|
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void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) |
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{ |
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struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); |
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|
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fragsz = SKB_DATA_ALIGN(fragsz); |
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|
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return page_frag_alloc_align(&nc->page, fragsz, GFP_ATOMIC, align_mask); |
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} |
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EXPORT_SYMBOL(__napi_alloc_frag_align); |
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|
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void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) |
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{ |
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void *data; |
|
|
|
fragsz = SKB_DATA_ALIGN(fragsz); |
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if (in_hardirq() || irqs_disabled()) { |
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struct page_frag_cache *nc = this_cpu_ptr(&netdev_alloc_cache); |
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|
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data = page_frag_alloc_align(nc, fragsz, GFP_ATOMIC, align_mask); |
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} else { |
|
struct napi_alloc_cache *nc; |
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|
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local_bh_disable(); |
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nc = this_cpu_ptr(&napi_alloc_cache); |
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data = page_frag_alloc_align(&nc->page, fragsz, GFP_ATOMIC, align_mask); |
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local_bh_enable(); |
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} |
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return data; |
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} |
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EXPORT_SYMBOL(__netdev_alloc_frag_align); |
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|
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static struct sk_buff *napi_skb_cache_get(void) |
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{ |
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struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); |
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struct sk_buff *skb; |
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|
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if (unlikely(!nc->skb_count)) |
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nc->skb_count = kmem_cache_alloc_bulk(skbuff_head_cache, |
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GFP_ATOMIC, |
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NAPI_SKB_CACHE_BULK, |
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nc->skb_cache); |
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if (unlikely(!nc->skb_count)) |
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return NULL; |
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|
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skb = nc->skb_cache[--nc->skb_count]; |
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kasan_unpoison_object_data(skbuff_head_cache, skb); |
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|
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return skb; |
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} |
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|
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/* Caller must provide SKB that is memset cleared */ |
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static void __build_skb_around(struct sk_buff *skb, void *data, |
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unsigned int frag_size) |
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{ |
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struct skb_shared_info *shinfo; |
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unsigned int size = frag_size ? : ksize(data); |
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|
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size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
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|
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/* Assumes caller memset cleared SKB */ |
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skb->truesize = SKB_TRUESIZE(size); |
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refcount_set(&skb->users, 1); |
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skb->head = data; |
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skb->data = data; |
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skb_reset_tail_pointer(skb); |
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skb->end = skb->tail + size; |
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skb->mac_header = (typeof(skb->mac_header))~0U; |
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skb->transport_header = (typeof(skb->transport_header))~0U; |
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|
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/* make sure we initialize shinfo sequentially */ |
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shinfo = skb_shinfo(skb); |
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); |
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atomic_set(&shinfo->dataref, 1); |
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|
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skb_set_kcov_handle(skb, kcov_common_handle()); |
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} |
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|
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/** |
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* __build_skb - build a network buffer |
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* @data: data buffer provided by caller |
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* @frag_size: size of data, or 0 if head was kmalloced |
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* |
|
* Allocate a new &sk_buff. Caller provides space holding head and |
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* skb_shared_info. @data must have been allocated by kmalloc() only if |
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* @frag_size is 0, otherwise data should come from the page allocator |
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* or vmalloc() |
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* The return is the new skb buffer. |
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* On a failure the return is %NULL, and @data is not freed. |
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* Notes : |
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* Before IO, driver allocates only data buffer where NIC put incoming frame |
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* Driver should add room at head (NET_SKB_PAD) and |
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* MUST add room at tail (SKB_DATA_ALIGN(skb_shared_info)) |
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* After IO, driver calls build_skb(), to allocate sk_buff and populate it |
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* before giving packet to stack. |
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* RX rings only contains data buffers, not full skbs. |
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*/ |
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struct sk_buff *__build_skb(void *data, unsigned int frag_size) |
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{ |
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struct sk_buff *skb; |
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|
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skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); |
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if (unlikely(!skb)) |
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return NULL; |
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|
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memset(skb, 0, offsetof(struct sk_buff, tail)); |
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__build_skb_around(skb, data, frag_size); |
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|
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return skb; |
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} |
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|
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/* build_skb() is wrapper over __build_skb(), that specifically |
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* takes care of skb->head and skb->pfmemalloc |
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* This means that if @frag_size is not zero, then @data must be backed |
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* by a page fragment, not kmalloc() or vmalloc() |
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*/ |
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struct sk_buff *build_skb(void *data, unsigned int frag_size) |
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{ |
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struct sk_buff *skb = __build_skb(data, frag_size); |
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|
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if (skb && frag_size) { |
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skb->head_frag = 1; |
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if (page_is_pfmemalloc(virt_to_head_page(data))) |
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skb->pfmemalloc = 1; |
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} |
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return skb; |
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} |
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EXPORT_SYMBOL(build_skb); |
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|
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/** |
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* build_skb_around - build a network buffer around provided skb |
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* @skb: sk_buff provide by caller, must be memset cleared |
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* @data: data buffer provided by caller |
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* @frag_size: size of data, or 0 if head was kmalloced |
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*/ |
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struct sk_buff *build_skb_around(struct sk_buff *skb, |
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void *data, unsigned int frag_size) |
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{ |
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if (unlikely(!skb)) |
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return NULL; |
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|
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__build_skb_around(skb, data, frag_size); |
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|
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if (frag_size) { |
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skb->head_frag = 1; |
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if (page_is_pfmemalloc(virt_to_head_page(data))) |
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skb->pfmemalloc = 1; |
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} |
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return skb; |
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} |
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EXPORT_SYMBOL(build_skb_around); |
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|
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/** |
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* __napi_build_skb - build a network buffer |
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* @data: data buffer provided by caller |
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* @frag_size: size of data, or 0 if head was kmalloced |
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* |
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* Version of __build_skb() that uses NAPI percpu caches to obtain |
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* skbuff_head instead of inplace allocation. |
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* |
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* Returns a new &sk_buff on success, %NULL on allocation failure. |
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*/ |
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static struct sk_buff *__napi_build_skb(void *data, unsigned int frag_size) |
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{ |
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struct sk_buff *skb; |
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|
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skb = napi_skb_cache_get(); |
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if (unlikely(!skb)) |
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return NULL; |
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|
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memset(skb, 0, offsetof(struct sk_buff, tail)); |
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__build_skb_around(skb, data, frag_size); |
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|
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return skb; |
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} |
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|
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/** |
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* napi_build_skb - build a network buffer |
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* @data: data buffer provided by caller |
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* @frag_size: size of data, or 0 if head was kmalloced |
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* |
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* Version of __napi_build_skb() that takes care of skb->head_frag |
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* and skb->pfmemalloc when the data is a page or page fragment. |
|
* |
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* Returns a new &sk_buff on success, %NULL on allocation failure. |
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*/ |
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struct sk_buff *napi_build_skb(void *data, unsigned int frag_size) |
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{ |
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struct sk_buff *skb = __napi_build_skb(data, frag_size); |
|
|
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if (likely(skb) && frag_size) { |
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skb->head_frag = 1; |
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skb_propagate_pfmemalloc(virt_to_head_page(data), skb); |
|
} |
|
|
|
return skb; |
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} |
|
EXPORT_SYMBOL(napi_build_skb); |
|
|
|
/* |
|
* kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells |
|
* the caller if emergency pfmemalloc reserves are being used. If it is and |
|
* the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves |
|
* may be used. Otherwise, the packet data may be discarded until enough |
|
* memory is free |
|
*/ |
|
static void *kmalloc_reserve(size_t size, gfp_t flags, int node, |
|
bool *pfmemalloc) |
|
{ |
|
void *obj; |
|
bool ret_pfmemalloc = false; |
|
|
|
/* |
|
* Try a regular allocation, when that fails and we're not entitled |
|
* to the reserves, fail. |
|
*/ |
|
obj = kmalloc_node_track_caller(size, |
|
flags | __GFP_NOMEMALLOC | __GFP_NOWARN, |
|
node); |
|
if (obj || !(gfp_pfmemalloc_allowed(flags))) |
|
goto out; |
|
|
|
/* Try again but now we are using pfmemalloc reserves */ |
|
ret_pfmemalloc = true; |
|
obj = kmalloc_node_track_caller(size, flags, node); |
|
|
|
out: |
|
if (pfmemalloc) |
|
*pfmemalloc = ret_pfmemalloc; |
|
|
|
return obj; |
|
} |
|
|
|
/* Allocate a new skbuff. We do this ourselves so we can fill in a few |
|
* 'private' fields and also do memory statistics to find all the |
|
* [BEEP] leaks. |
|
* |
|
*/ |
|
|
|
/** |
|
* __alloc_skb - allocate a network buffer |
|
* @size: size to allocate |
|
* @gfp_mask: allocation mask |
|
* @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache |
|
* instead of head cache and allocate a cloned (child) skb. |
|
* If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for |
|
* allocations in case the data is required for writeback |
|
* @node: numa node to allocate memory on |
|
* |
|
* Allocate a new &sk_buff. The returned buffer has no headroom and a |
|
* tail room of at least size bytes. The object has a reference count |
|
* of one. The return is the buffer. On a failure the return is %NULL. |
|
* |
|
* Buffers may only be allocated from interrupts using a @gfp_mask of |
|
* %GFP_ATOMIC. |
|
*/ |
|
struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, |
|
int flags, int node) |
|
{ |
|
struct kmem_cache *cache; |
|
struct sk_buff *skb; |
|
unsigned int osize; |
|
bool pfmemalloc; |
|
u8 *data; |
|
|
|
cache = (flags & SKB_ALLOC_FCLONE) |
|
? skbuff_fclone_cache : skbuff_head_cache; |
|
|
|
if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
|
|
/* Get the HEAD */ |
|
if ((flags & (SKB_ALLOC_FCLONE | SKB_ALLOC_NAPI)) == SKB_ALLOC_NAPI && |
|
likely(node == NUMA_NO_NODE || node == numa_mem_id())) |
|
skb = napi_skb_cache_get(); |
|
else |
|
skb = kmem_cache_alloc_node(cache, gfp_mask & ~GFP_DMA, node); |
|
if (unlikely(!skb)) |
|
return NULL; |
|
prefetchw(skb); |
|
|
|
/* We do our best to align skb_shared_info on a separate cache |
|
* line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives |
|
* aligned memory blocks, unless SLUB/SLAB debug is enabled. |
|
* Both skb->head and skb_shared_info are cache line aligned. |
|
*/ |
|
size = SKB_DATA_ALIGN(size); |
|
size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
|
data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); |
|
if (unlikely(!data)) |
|
goto nodata; |
|
/* kmalloc(size) might give us more room than requested. |
|
* Put skb_shared_info exactly at the end of allocated zone, |
|
* to allow max possible filling before reallocation. |
|
*/ |
|
osize = ksize(data); |
|
size = SKB_WITH_OVERHEAD(osize); |
|
prefetchw(data + size); |
|
|
|
/* |
|
* Only clear those fields we need to clear, not those that we will |
|
* actually initialise below. Hence, don't put any more fields after |
|
* the tail pointer in struct sk_buff! |
|
*/ |
|
memset(skb, 0, offsetof(struct sk_buff, tail)); |
|
__build_skb_around(skb, data, osize); |
|
skb->pfmemalloc = pfmemalloc; |
|
|
|
if (flags & SKB_ALLOC_FCLONE) { |
|
struct sk_buff_fclones *fclones; |
|
|
|
fclones = container_of(skb, struct sk_buff_fclones, skb1); |
|
|
|
skb->fclone = SKB_FCLONE_ORIG; |
|
refcount_set(&fclones->fclone_ref, 1); |
|
|
|
fclones->skb2.fclone = SKB_FCLONE_CLONE; |
|
} |
|
|
|
return skb; |
|
|
|
nodata: |
|
kmem_cache_free(cache, skb); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(__alloc_skb); |
|
|
|
/** |
|
* __netdev_alloc_skb - allocate an skbuff for rx on a specific device |
|
* @dev: network device to receive on |
|
* @len: length to allocate |
|
* @gfp_mask: get_free_pages mask, passed to alloc_skb |
|
* |
|
* Allocate a new &sk_buff and assign it a usage count of one. The |
|
* buffer has NET_SKB_PAD headroom built in. Users should allocate |
|
* the headroom they think they need without accounting for the |
|
* built in space. The built in space is used for optimisations. |
|
* |
|
* %NULL is returned if there is no free memory. |
|
*/ |
|
struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, |
|
gfp_t gfp_mask) |
|
{ |
|
struct page_frag_cache *nc; |
|
struct sk_buff *skb; |
|
bool pfmemalloc; |
|
void *data; |
|
|
|
len += NET_SKB_PAD; |
|
|
|
/* If requested length is either too small or too big, |
|
* we use kmalloc() for skb->head allocation. |
|
*/ |
|
if (len <= SKB_WITH_OVERHEAD(1024) || |
|
len > SKB_WITH_OVERHEAD(PAGE_SIZE) || |
|
(gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { |
|
skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); |
|
if (!skb) |
|
goto skb_fail; |
|
goto skb_success; |
|
} |
|
|
|
len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
|
len = SKB_DATA_ALIGN(len); |
|
|
|
if (sk_memalloc_socks()) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
|
|
if (in_hardirq() || irqs_disabled()) { |
|
nc = this_cpu_ptr(&netdev_alloc_cache); |
|
data = page_frag_alloc(nc, len, gfp_mask); |
|
pfmemalloc = nc->pfmemalloc; |
|
} else { |
|
local_bh_disable(); |
|
nc = this_cpu_ptr(&napi_alloc_cache.page); |
|
data = page_frag_alloc(nc, len, gfp_mask); |
|
pfmemalloc = nc->pfmemalloc; |
|
local_bh_enable(); |
|
} |
|
|
|
if (unlikely(!data)) |
|
return NULL; |
|
|
|
skb = __build_skb(data, len); |
|
if (unlikely(!skb)) { |
|
skb_free_frag(data); |
|
return NULL; |
|
} |
|
|
|
if (pfmemalloc) |
|
skb->pfmemalloc = 1; |
|
skb->head_frag = 1; |
|
|
|
skb_success: |
|
skb_reserve(skb, NET_SKB_PAD); |
|
skb->dev = dev; |
|
|
|
skb_fail: |
|
return skb; |
|
} |
|
EXPORT_SYMBOL(__netdev_alloc_skb); |
|
|
|
/** |
|
* __napi_alloc_skb - allocate skbuff for rx in a specific NAPI instance |
|
* @napi: napi instance this buffer was allocated for |
|
* @len: length to allocate |
|
* @gfp_mask: get_free_pages mask, passed to alloc_skb and alloc_pages |
|
* |
|
* Allocate a new sk_buff for use in NAPI receive. This buffer will |
|
* attempt to allocate the head from a special reserved region used |
|
* only for NAPI Rx allocation. By doing this we can save several |
|
* CPU cycles by avoiding having to disable and re-enable IRQs. |
|
* |
|
* %NULL is returned if there is no free memory. |
|
*/ |
|
struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, |
|
gfp_t gfp_mask) |
|
{ |
|
struct napi_alloc_cache *nc; |
|
struct sk_buff *skb; |
|
void *data; |
|
|
|
len += NET_SKB_PAD + NET_IP_ALIGN; |
|
|
|
/* If requested length is either too small or too big, |
|
* we use kmalloc() for skb->head allocation. |
|
*/ |
|
if (len <= SKB_WITH_OVERHEAD(1024) || |
|
len > SKB_WITH_OVERHEAD(PAGE_SIZE) || |
|
(gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { |
|
skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX | SKB_ALLOC_NAPI, |
|
NUMA_NO_NODE); |
|
if (!skb) |
|
goto skb_fail; |
|
goto skb_success; |
|
} |
|
|
|
nc = this_cpu_ptr(&napi_alloc_cache); |
|
len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
|
len = SKB_DATA_ALIGN(len); |
|
|
|
if (sk_memalloc_socks()) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
|
|
data = page_frag_alloc(&nc->page, len, gfp_mask); |
|
if (unlikely(!data)) |
|
return NULL; |
|
|
|
skb = __napi_build_skb(data, len); |
|
if (unlikely(!skb)) { |
|
skb_free_frag(data); |
|
return NULL; |
|
} |
|
|
|
if (nc->page.pfmemalloc) |
|
skb->pfmemalloc = 1; |
|
skb->head_frag = 1; |
|
|
|
skb_success: |
|
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); |
|
skb->dev = napi->dev; |
|
|
|
skb_fail: |
|
return skb; |
|
} |
|
EXPORT_SYMBOL(__napi_alloc_skb); |
|
|
|
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, |
|
int size, unsigned int truesize) |
|
{ |
|
skb_fill_page_desc(skb, i, page, off, size); |
|
skb->len += size; |
|
skb->data_len += size; |
|
skb->truesize += truesize; |
|
} |
|
EXPORT_SYMBOL(skb_add_rx_frag); |
|
|
|
void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, |
|
unsigned int truesize) |
|
{ |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
|
|
|
skb_frag_size_add(frag, size); |
|
skb->len += size; |
|
skb->data_len += size; |
|
skb->truesize += truesize; |
|
} |
|
EXPORT_SYMBOL(skb_coalesce_rx_frag); |
|
|
|
static void skb_drop_list(struct sk_buff **listp) |
|
{ |
|
kfree_skb_list(*listp); |
|
*listp = NULL; |
|
} |
|
|
|
static inline void skb_drop_fraglist(struct sk_buff *skb) |
|
{ |
|
skb_drop_list(&skb_shinfo(skb)->frag_list); |
|
} |
|
|
|
static void skb_clone_fraglist(struct sk_buff *skb) |
|
{ |
|
struct sk_buff *list; |
|
|
|
skb_walk_frags(skb, list) |
|
skb_get(list); |
|
} |
|
|
|
static void skb_free_head(struct sk_buff *skb) |
|
{ |
|
unsigned char *head = skb->head; |
|
|
|
if (skb->head_frag) { |
|
if (skb_pp_recycle(skb, head)) |
|
return; |
|
skb_free_frag(head); |
|
} else { |
|
kfree(head); |
|
} |
|
} |
|
|
|
static void skb_release_data(struct sk_buff *skb) |
|
{ |
|
struct skb_shared_info *shinfo = skb_shinfo(skb); |
|
int i; |
|
|
|
if (skb->cloned && |
|
atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1, |
|
&shinfo->dataref)) |
|
goto exit; |
|
|
|
skb_zcopy_clear(skb, true); |
|
|
|
for (i = 0; i < shinfo->nr_frags; i++) |
|
__skb_frag_unref(&shinfo->frags[i], skb->pp_recycle); |
|
|
|
if (shinfo->frag_list) |
|
kfree_skb_list(shinfo->frag_list); |
|
|
|
skb_free_head(skb); |
|
exit: |
|
/* When we clone an SKB we copy the reycling bit. The pp_recycle |
|
* bit is only set on the head though, so in order to avoid races |
|
* while trying to recycle fragments on __skb_frag_unref() we need |
|
* to make one SKB responsible for triggering the recycle path. |
|
* So disable the recycling bit if an SKB is cloned and we have |
|
* additional references to the fragmented part of the SKB. |
|
* Eventually the last SKB will have the recycling bit set and it's |
|
* dataref set to 0, which will trigger the recycling |
|
*/ |
|
skb->pp_recycle = 0; |
|
} |
|
|
|
/* |
|
* Free an skbuff by memory without cleaning the state. |
|
*/ |
|
static void kfree_skbmem(struct sk_buff *skb) |
|
{ |
|
struct sk_buff_fclones *fclones; |
|
|
|
switch (skb->fclone) { |
|
case SKB_FCLONE_UNAVAILABLE: |
|
kmem_cache_free(skbuff_head_cache, skb); |
|
return; |
|
|
|
case SKB_FCLONE_ORIG: |
|
fclones = container_of(skb, struct sk_buff_fclones, skb1); |
|
|
|
/* We usually free the clone (TX completion) before original skb |
|
* This test would have no chance to be true for the clone, |
|
* while here, branch prediction will be good. |
|
*/ |
|
if (refcount_read(&fclones->fclone_ref) == 1) |
|
goto fastpath; |
|
break; |
|
|
|
default: /* SKB_FCLONE_CLONE */ |
|
fclones = container_of(skb, struct sk_buff_fclones, skb2); |
|
break; |
|
} |
|
if (!refcount_dec_and_test(&fclones->fclone_ref)) |
|
return; |
|
fastpath: |
|
kmem_cache_free(skbuff_fclone_cache, fclones); |
|
} |
|
|
|
void skb_release_head_state(struct sk_buff *skb) |
|
{ |
|
skb_dst_drop(skb); |
|
if (skb->destructor) { |
|
WARN_ON(in_hardirq()); |
|
skb->destructor(skb); |
|
} |
|
#if IS_ENABLED(CONFIG_NF_CONNTRACK) |
|
nf_conntrack_put(skb_nfct(skb)); |
|
#endif |
|
skb_ext_put(skb); |
|
} |
|
|
|
/* Free everything but the sk_buff shell. */ |
|
static void skb_release_all(struct sk_buff *skb) |
|
{ |
|
skb_release_head_state(skb); |
|
if (likely(skb->head)) |
|
skb_release_data(skb); |
|
} |
|
|
|
/** |
|
* __kfree_skb - private function |
|
* @skb: buffer |
|
* |
|
* Free an sk_buff. Release anything attached to the buffer. |
|
* Clean the state. This is an internal helper function. Users should |
|
* always call kfree_skb |
|
*/ |
|
|
|
void __kfree_skb(struct sk_buff *skb) |
|
{ |
|
skb_release_all(skb); |
|
kfree_skbmem(skb); |
|
} |
|
EXPORT_SYMBOL(__kfree_skb); |
|
|
|
/** |
|
* kfree_skb_reason - free an sk_buff with special reason |
|
* @skb: buffer to free |
|
* @reason: reason why this skb is dropped |
|
* |
|
* Drop a reference to the buffer and free it if the usage count has |
|
* hit zero. Meanwhile, pass the drop reason to 'kfree_skb' |
|
* tracepoint. |
|
*/ |
|
void kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) |
|
{ |
|
if (!skb_unref(skb)) |
|
return; |
|
|
|
trace_kfree_skb(skb, __builtin_return_address(0), reason); |
|
__kfree_skb(skb); |
|
} |
|
EXPORT_SYMBOL(kfree_skb_reason); |
|
|
|
void kfree_skb_list(struct sk_buff *segs) |
|
{ |
|
while (segs) { |
|
struct sk_buff *next = segs->next; |
|
|
|
kfree_skb(segs); |
|
segs = next; |
|
} |
|
} |
|
EXPORT_SYMBOL(kfree_skb_list); |
|
|
|
/* Dump skb information and contents. |
|
* |
|
* Must only be called from net_ratelimit()-ed paths. |
|
* |
|
* Dumps whole packets if full_pkt, only headers otherwise. |
|
*/ |
|
void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt) |
|
{ |
|
struct skb_shared_info *sh = skb_shinfo(skb); |
|
struct net_device *dev = skb->dev; |
|
struct sock *sk = skb->sk; |
|
struct sk_buff *list_skb; |
|
bool has_mac, has_trans; |
|
int headroom, tailroom; |
|
int i, len, seg_len; |
|
|
|
if (full_pkt) |
|
len = skb->len; |
|
else |
|
len = min_t(int, skb->len, MAX_HEADER + 128); |
|
|
|
headroom = skb_headroom(skb); |
|
tailroom = skb_tailroom(skb); |
|
|
|
has_mac = skb_mac_header_was_set(skb); |
|
has_trans = skb_transport_header_was_set(skb); |
|
|
|
printk("%sskb len=%u headroom=%u headlen=%u tailroom=%u\n" |
|
"mac=(%d,%d) net=(%d,%d) trans=%d\n" |
|
"shinfo(txflags=%u nr_frags=%u gso(size=%hu type=%u segs=%hu))\n" |
|
"csum(0x%x ip_summed=%u complete_sw=%u valid=%u level=%u)\n" |
|
"hash(0x%x sw=%u l4=%u) proto=0x%04x pkttype=%u iif=%d\n", |
|
level, skb->len, headroom, skb_headlen(skb), tailroom, |
|
has_mac ? skb->mac_header : -1, |
|
has_mac ? skb_mac_header_len(skb) : -1, |
|
skb->network_header, |
|
has_trans ? skb_network_header_len(skb) : -1, |
|
has_trans ? skb->transport_header : -1, |
|
sh->tx_flags, sh->nr_frags, |
|
sh->gso_size, sh->gso_type, sh->gso_segs, |
|
skb->csum, skb->ip_summed, skb->csum_complete_sw, |
|
skb->csum_valid, skb->csum_level, |
|
skb->hash, skb->sw_hash, skb->l4_hash, |
|
ntohs(skb->protocol), skb->pkt_type, skb->skb_iif); |
|
|
|
if (dev) |
|
printk("%sdev name=%s feat=%pNF\n", |
|
level, dev->name, &dev->features); |
|
if (sk) |
|
printk("%ssk family=%hu type=%u proto=%u\n", |
|
level, sk->sk_family, sk->sk_type, sk->sk_protocol); |
|
|
|
if (full_pkt && headroom) |
|
print_hex_dump(level, "skb headroom: ", DUMP_PREFIX_OFFSET, |
|
16, 1, skb->head, headroom, false); |
|
|
|
seg_len = min_t(int, skb_headlen(skb), len); |
|
if (seg_len) |
|
print_hex_dump(level, "skb linear: ", DUMP_PREFIX_OFFSET, |
|
16, 1, skb->data, seg_len, false); |
|
len -= seg_len; |
|
|
|
if (full_pkt && tailroom) |
|
print_hex_dump(level, "skb tailroom: ", DUMP_PREFIX_OFFSET, |
|
16, 1, skb_tail_pointer(skb), tailroom, false); |
|
|
|
for (i = 0; len && i < skb_shinfo(skb)->nr_frags; i++) { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
|
u32 p_off, p_len, copied; |
|
struct page *p; |
|
u8 *vaddr; |
|
|
|
skb_frag_foreach_page(frag, skb_frag_off(frag), |
|
skb_frag_size(frag), p, p_off, p_len, |
|
copied) { |
|
seg_len = min_t(int, p_len, len); |
|
vaddr = kmap_atomic(p); |
|
print_hex_dump(level, "skb frag: ", |
|
DUMP_PREFIX_OFFSET, |
|
16, 1, vaddr + p_off, seg_len, false); |
|
kunmap_atomic(vaddr); |
|
len -= seg_len; |
|
if (!len) |
|
break; |
|
} |
|
} |
|
|
|
if (full_pkt && skb_has_frag_list(skb)) { |
|
printk("skb fraglist:\n"); |
|
skb_walk_frags(skb, list_skb) |
|
skb_dump(level, list_skb, true); |
|
} |
|
} |
|
EXPORT_SYMBOL(skb_dump); |
|
|
|
/** |
|
* skb_tx_error - report an sk_buff xmit error |
|
* @skb: buffer that triggered an error |
|
* |
|
* Report xmit error if a device callback is tracking this skb. |
|
* skb must be freed afterwards. |
|
*/ |
|
void skb_tx_error(struct sk_buff *skb) |
|
{ |
|
skb_zcopy_clear(skb, true); |
|
} |
|
EXPORT_SYMBOL(skb_tx_error); |
|
|
|
#ifdef CONFIG_TRACEPOINTS |
|
/** |
|
* consume_skb - free an skbuff |
|
* @skb: buffer to free |
|
* |
|
* Drop a ref to the buffer and free it if the usage count has hit zero |
|
* Functions identically to kfree_skb, but kfree_skb assumes that the frame |
|
* is being dropped after a failure and notes that |
|
*/ |
|
void consume_skb(struct sk_buff *skb) |
|
{ |
|
if (!skb_unref(skb)) |
|
return; |
|
|
|
trace_consume_skb(skb); |
|
__kfree_skb(skb); |
|
} |
|
EXPORT_SYMBOL(consume_skb); |
|
#endif |
|
|
|
/** |
|
* __consume_stateless_skb - free an skbuff, assuming it is stateless |
|
* @skb: buffer to free |
|
* |
|
* Alike consume_skb(), but this variant assumes that this is the last |
|
* skb reference and all the head states have been already dropped |
|
*/ |
|
void __consume_stateless_skb(struct sk_buff *skb) |
|
{ |
|
trace_consume_skb(skb); |
|
skb_release_data(skb); |
|
kfree_skbmem(skb); |
|
} |
|
|
|
static void napi_skb_cache_put(struct sk_buff *skb) |
|
{ |
|
struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); |
|
u32 i; |
|
|
|
kasan_poison_object_data(skbuff_head_cache, skb); |
|
nc->skb_cache[nc->skb_count++] = skb; |
|
|
|
if (unlikely(nc->skb_count == NAPI_SKB_CACHE_SIZE)) { |
|
for (i = NAPI_SKB_CACHE_HALF; i < NAPI_SKB_CACHE_SIZE; i++) |
|
kasan_unpoison_object_data(skbuff_head_cache, |
|
nc->skb_cache[i]); |
|
|
|
kmem_cache_free_bulk(skbuff_head_cache, NAPI_SKB_CACHE_HALF, |
|
nc->skb_cache + NAPI_SKB_CACHE_HALF); |
|
nc->skb_count = NAPI_SKB_CACHE_HALF; |
|
} |
|
} |
|
|
|
void __kfree_skb_defer(struct sk_buff *skb) |
|
{ |
|
skb_release_all(skb); |
|
napi_skb_cache_put(skb); |
|
} |
|
|
|
void napi_skb_free_stolen_head(struct sk_buff *skb) |
|
{ |
|
if (unlikely(skb->slow_gro)) { |
|
nf_reset_ct(skb); |
|
skb_dst_drop(skb); |
|
skb_ext_put(skb); |
|
skb_orphan(skb); |
|
skb->slow_gro = 0; |
|
} |
|
napi_skb_cache_put(skb); |
|
} |
|
|
|
void napi_consume_skb(struct sk_buff *skb, int budget) |
|
{ |
|
/* Zero budget indicate non-NAPI context called us, like netpoll */ |
|
if (unlikely(!budget)) { |
|
dev_consume_skb_any(skb); |
|
return; |
|
} |
|
|
|
lockdep_assert_in_softirq(); |
|
|
|
if (!skb_unref(skb)) |
|
return; |
|
|
|
/* if reaching here SKB is ready to free */ |
|
trace_consume_skb(skb); |
|
|
|
/* if SKB is a clone, don't handle this case */ |
|
if (skb->fclone != SKB_FCLONE_UNAVAILABLE) { |
|
__kfree_skb(skb); |
|
return; |
|
} |
|
|
|
skb_release_all(skb); |
|
napi_skb_cache_put(skb); |
|
} |
|
EXPORT_SYMBOL(napi_consume_skb); |
|
|
|
/* Make sure a field is contained by headers group */ |
|
#define CHECK_SKB_FIELD(field) \ |
|
BUILD_BUG_ON(offsetof(struct sk_buff, field) != \ |
|
offsetof(struct sk_buff, headers.field)); \ |
|
|
|
static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) |
|
{ |
|
new->tstamp = old->tstamp; |
|
/* We do not copy old->sk */ |
|
new->dev = old->dev; |
|
memcpy(new->cb, old->cb, sizeof(old->cb)); |
|
skb_dst_copy(new, old); |
|
__skb_ext_copy(new, old); |
|
__nf_copy(new, old, false); |
|
|
|
/* Note : this field could be in the headers group. |
|
* It is not yet because we do not want to have a 16 bit hole |
|
*/ |
|
new->queue_mapping = old->queue_mapping; |
|
|
|
memcpy(&new->headers, &old->headers, sizeof(new->headers)); |
|
CHECK_SKB_FIELD(protocol); |
|
CHECK_SKB_FIELD(csum); |
|
CHECK_SKB_FIELD(hash); |
|
CHECK_SKB_FIELD(priority); |
|
CHECK_SKB_FIELD(skb_iif); |
|
CHECK_SKB_FIELD(vlan_proto); |
|
CHECK_SKB_FIELD(vlan_tci); |
|
CHECK_SKB_FIELD(transport_header); |
|
CHECK_SKB_FIELD(network_header); |
|
CHECK_SKB_FIELD(mac_header); |
|
CHECK_SKB_FIELD(inner_protocol); |
|
CHECK_SKB_FIELD(inner_transport_header); |
|
CHECK_SKB_FIELD(inner_network_header); |
|
CHECK_SKB_FIELD(inner_mac_header); |
|
CHECK_SKB_FIELD(mark); |
|
#ifdef CONFIG_NETWORK_SECMARK |
|
CHECK_SKB_FIELD(secmark); |
|
#endif |
|
#ifdef CONFIG_NET_RX_BUSY_POLL |
|
CHECK_SKB_FIELD(napi_id); |
|
#endif |
|
#ifdef CONFIG_XPS |
|
CHECK_SKB_FIELD(sender_cpu); |
|
#endif |
|
#ifdef CONFIG_NET_SCHED |
|
CHECK_SKB_FIELD(tc_index); |
|
#endif |
|
|
|
} |
|
|
|
/* |
|
* You should not add any new code to this function. Add it to |
|
* __copy_skb_header above instead. |
|
*/ |
|
static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) |
|
{ |
|
#define C(x) n->x = skb->x |
|
|
|
n->next = n->prev = NULL; |
|
n->sk = NULL; |
|
__copy_skb_header(n, skb); |
|
|
|
C(len); |
|
C(data_len); |
|
C(mac_len); |
|
n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len; |
|
n->cloned = 1; |
|
n->nohdr = 0; |
|
n->peeked = 0; |
|
C(pfmemalloc); |
|
C(pp_recycle); |
|
n->destructor = NULL; |
|
C(tail); |
|
C(end); |
|
C(head); |
|
C(head_frag); |
|
C(data); |
|
C(truesize); |
|
refcount_set(&n->users, 1); |
|
|
|
atomic_inc(&(skb_shinfo(skb)->dataref)); |
|
skb->cloned = 1; |
|
|
|
return n; |
|
#undef C |
|
} |
|
|
|
/** |
|
* alloc_skb_for_msg() - allocate sk_buff to wrap frag list forming a msg |
|
* @first: first sk_buff of the msg |
|
*/ |
|
struct sk_buff *alloc_skb_for_msg(struct sk_buff *first) |
|
{ |
|
struct sk_buff *n; |
|
|
|
n = alloc_skb(0, GFP_ATOMIC); |
|
if (!n) |
|
return NULL; |
|
|
|
n->len = first->len; |
|
n->data_len = first->len; |
|
n->truesize = first->truesize; |
|
|
|
skb_shinfo(n)->frag_list = first; |
|
|
|
__copy_skb_header(n, first); |
|
n->destructor = NULL; |
|
|
|
return n; |
|
} |
|
EXPORT_SYMBOL_GPL(alloc_skb_for_msg); |
|
|
|
/** |
|
* skb_morph - morph one skb into another |
|
* @dst: the skb to receive the contents |
|
* @src: the skb to supply the contents |
|
* |
|
* This is identical to skb_clone except that the target skb is |
|
* supplied by the user. |
|
* |
|
* The target skb is returned upon exit. |
|
*/ |
|
struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src) |
|
{ |
|
skb_release_all(dst); |
|
return __skb_clone(dst, src); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_morph); |
|
|
|
int mm_account_pinned_pages(struct mmpin *mmp, size_t size) |
|
{ |
|
unsigned long max_pg, num_pg, new_pg, old_pg; |
|
struct user_struct *user; |
|
|
|
if (capable(CAP_IPC_LOCK) || !size) |
|
return 0; |
|
|
|
num_pg = (size >> PAGE_SHIFT) + 2; /* worst case */ |
|
max_pg = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; |
|
user = mmp->user ? : current_user(); |
|
|
|
do { |
|
old_pg = atomic_long_read(&user->locked_vm); |
|
new_pg = old_pg + num_pg; |
|
if (new_pg > max_pg) |
|
return -ENOBUFS; |
|
} while (atomic_long_cmpxchg(&user->locked_vm, old_pg, new_pg) != |
|
old_pg); |
|
|
|
if (!mmp->user) { |
|
mmp->user = get_uid(user); |
|
mmp->num_pg = num_pg; |
|
} else { |
|
mmp->num_pg += num_pg; |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(mm_account_pinned_pages); |
|
|
|
void mm_unaccount_pinned_pages(struct mmpin *mmp) |
|
{ |
|
if (mmp->user) { |
|
atomic_long_sub(mmp->num_pg, &mmp->user->locked_vm); |
|
free_uid(mmp->user); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(mm_unaccount_pinned_pages); |
|
|
|
struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size) |
|
{ |
|
struct ubuf_info *uarg; |
|
struct sk_buff *skb; |
|
|
|
WARN_ON_ONCE(!in_task()); |
|
|
|
skb = sock_omalloc(sk, 0, GFP_KERNEL); |
|
if (!skb) |
|
return NULL; |
|
|
|
BUILD_BUG_ON(sizeof(*uarg) > sizeof(skb->cb)); |
|
uarg = (void *)skb->cb; |
|
uarg->mmp.user = NULL; |
|
|
|
if (mm_account_pinned_pages(&uarg->mmp, size)) { |
|
kfree_skb(skb); |
|
return NULL; |
|
} |
|
|
|
uarg->callback = msg_zerocopy_callback; |
|
uarg->id = ((u32)atomic_inc_return(&sk->sk_zckey)) - 1; |
|
uarg->len = 1; |
|
uarg->bytelen = size; |
|
uarg->zerocopy = 1; |
|
uarg->flags = SKBFL_ZEROCOPY_FRAG; |
|
refcount_set(&uarg->refcnt, 1); |
|
sock_hold(sk); |
|
|
|
return uarg; |
|
} |
|
EXPORT_SYMBOL_GPL(msg_zerocopy_alloc); |
|
|
|
static inline struct sk_buff *skb_from_uarg(struct ubuf_info *uarg) |
|
{ |
|
return container_of((void *)uarg, struct sk_buff, cb); |
|
} |
|
|
|
struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size, |
|
struct ubuf_info *uarg) |
|
{ |
|
if (uarg) { |
|
const u32 byte_limit = 1 << 19; /* limit to a few TSO */ |
|
u32 bytelen, next; |
|
|
|
/* realloc only when socket is locked (TCP, UDP cork), |
|
* so uarg->len and sk_zckey access is serialized |
|
*/ |
|
if (!sock_owned_by_user(sk)) { |
|
WARN_ON_ONCE(1); |
|
return NULL; |
|
} |
|
|
|
bytelen = uarg->bytelen + size; |
|
if (uarg->len == USHRT_MAX - 1 || bytelen > byte_limit) { |
|
/* TCP can create new skb to attach new uarg */ |
|
if (sk->sk_type == SOCK_STREAM) |
|
goto new_alloc; |
|
return NULL; |
|
} |
|
|
|
next = (u32)atomic_read(&sk->sk_zckey); |
|
if ((u32)(uarg->id + uarg->len) == next) { |
|
if (mm_account_pinned_pages(&uarg->mmp, size)) |
|
return NULL; |
|
uarg->len++; |
|
uarg->bytelen = bytelen; |
|
atomic_set(&sk->sk_zckey, ++next); |
|
|
|
/* no extra ref when appending to datagram (MSG_MORE) */ |
|
if (sk->sk_type == SOCK_STREAM) |
|
net_zcopy_get(uarg); |
|
|
|
return uarg; |
|
} |
|
} |
|
|
|
new_alloc: |
|
return msg_zerocopy_alloc(sk, size); |
|
} |
|
EXPORT_SYMBOL_GPL(msg_zerocopy_realloc); |
|
|
|
static bool skb_zerocopy_notify_extend(struct sk_buff *skb, u32 lo, u16 len) |
|
{ |
|
struct sock_exterr_skb *serr = SKB_EXT_ERR(skb); |
|
u32 old_lo, old_hi; |
|
u64 sum_len; |
|
|
|
old_lo = serr->ee.ee_info; |
|
old_hi = serr->ee.ee_data; |
|
sum_len = old_hi - old_lo + 1ULL + len; |
|
|
|
if (sum_len >= (1ULL << 32)) |
|
return false; |
|
|
|
if (lo != old_hi + 1) |
|
return false; |
|
|
|
serr->ee.ee_data += len; |
|
return true; |
|
} |
|
|
|
static void __msg_zerocopy_callback(struct ubuf_info *uarg) |
|
{ |
|
struct sk_buff *tail, *skb = skb_from_uarg(uarg); |
|
struct sock_exterr_skb *serr; |
|
struct sock *sk = skb->sk; |
|
struct sk_buff_head *q; |
|
unsigned long flags; |
|
bool is_zerocopy; |
|
u32 lo, hi; |
|
u16 len; |
|
|
|
mm_unaccount_pinned_pages(&uarg->mmp); |
|
|
|
/* if !len, there was only 1 call, and it was aborted |
|
* so do not queue a completion notification |
|
*/ |
|
if (!uarg->len || sock_flag(sk, SOCK_DEAD)) |
|
goto release; |
|
|
|
len = uarg->len; |
|
lo = uarg->id; |
|
hi = uarg->id + len - 1; |
|
is_zerocopy = uarg->zerocopy; |
|
|
|
serr = SKB_EXT_ERR(skb); |
|
memset(serr, 0, sizeof(*serr)); |
|
serr->ee.ee_errno = 0; |
|
serr->ee.ee_origin = SO_EE_ORIGIN_ZEROCOPY; |
|
serr->ee.ee_data = hi; |
|
serr->ee.ee_info = lo; |
|
if (!is_zerocopy) |
|
serr->ee.ee_code |= SO_EE_CODE_ZEROCOPY_COPIED; |
|
|
|
q = &sk->sk_error_queue; |
|
spin_lock_irqsave(&q->lock, flags); |
|
tail = skb_peek_tail(q); |
|
if (!tail || SKB_EXT_ERR(tail)->ee.ee_origin != SO_EE_ORIGIN_ZEROCOPY || |
|
!skb_zerocopy_notify_extend(tail, lo, len)) { |
|
__skb_queue_tail(q, skb); |
|
skb = NULL; |
|
} |
|
spin_unlock_irqrestore(&q->lock, flags); |
|
|
|
sk_error_report(sk); |
|
|
|
release: |
|
consume_skb(skb); |
|
sock_put(sk); |
|
} |
|
|
|
void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg, |
|
bool success) |
|
{ |
|
uarg->zerocopy = uarg->zerocopy & success; |
|
|
|
if (refcount_dec_and_test(&uarg->refcnt)) |
|
__msg_zerocopy_callback(uarg); |
|
} |
|
EXPORT_SYMBOL_GPL(msg_zerocopy_callback); |
|
|
|
void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref) |
|
{ |
|
struct sock *sk = skb_from_uarg(uarg)->sk; |
|
|
|
atomic_dec(&sk->sk_zckey); |
|
uarg->len--; |
|
|
|
if (have_uref) |
|
msg_zerocopy_callback(NULL, uarg, true); |
|
} |
|
EXPORT_SYMBOL_GPL(msg_zerocopy_put_abort); |
|
|
|
int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len) |
|
{ |
|
return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_zerocopy_iter_dgram); |
|
|
|
int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, |
|
struct msghdr *msg, int len, |
|
struct ubuf_info *uarg) |
|
{ |
|
struct ubuf_info *orig_uarg = skb_zcopy(skb); |
|
struct iov_iter orig_iter = msg->msg_iter; |
|
int err, orig_len = skb->len; |
|
|
|
/* An skb can only point to one uarg. This edge case happens when |
|
* TCP appends to an skb, but zerocopy_realloc triggered a new alloc. |
|
*/ |
|
if (orig_uarg && uarg != orig_uarg) |
|
return -EEXIST; |
|
|
|
err = __zerocopy_sg_from_iter(sk, skb, &msg->msg_iter, len); |
|
if (err == -EFAULT || (err == -EMSGSIZE && skb->len == orig_len)) { |
|
struct sock *save_sk = skb->sk; |
|
|
|
/* Streams do not free skb on error. Reset to prev state. */ |
|
msg->msg_iter = orig_iter; |
|
skb->sk = sk; |
|
___pskb_trim(skb, orig_len); |
|
skb->sk = save_sk; |
|
return err; |
|
} |
|
|
|
skb_zcopy_set(skb, uarg, NULL); |
|
return skb->len - orig_len; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_zerocopy_iter_stream); |
|
|
|
static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig, |
|
gfp_t gfp_mask) |
|
{ |
|
if (skb_zcopy(orig)) { |
|
if (skb_zcopy(nskb)) { |
|
/* !gfp_mask callers are verified to !skb_zcopy(nskb) */ |
|
if (!gfp_mask) { |
|
WARN_ON_ONCE(1); |
|
return -ENOMEM; |
|
} |
|
if (skb_uarg(nskb) == skb_uarg(orig)) |
|
return 0; |
|
if (skb_copy_ubufs(nskb, GFP_ATOMIC)) |
|
return -EIO; |
|
} |
|
skb_zcopy_set(nskb, skb_uarg(orig), NULL); |
|
} |
|
return 0; |
|
} |
|
|
|
/** |
|
* skb_copy_ubufs - copy userspace skb frags buffers to kernel |
|
* @skb: the skb to modify |
|
* @gfp_mask: allocation priority |
|
* |
|
* This must be called on skb with SKBFL_ZEROCOPY_ENABLE. |
|
* It will copy all frags into kernel and drop the reference |
|
* to userspace pages. |
|
* |
|
* If this function is called from an interrupt gfp_mask() must be |
|
* %GFP_ATOMIC. |
|
* |
|
* Returns 0 on success or a negative error code on failure |
|
* to allocate kernel memory to copy to. |
|
*/ |
|
int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) |
|
{ |
|
int num_frags = skb_shinfo(skb)->nr_frags; |
|
struct page *page, *head = NULL; |
|
int i, new_frags; |
|
u32 d_off; |
|
|
|
if (skb_shared(skb) || skb_unclone(skb, gfp_mask)) |
|
return -EINVAL; |
|
|
|
if (!num_frags) |
|
goto release; |
|
|
|
new_frags = (__skb_pagelen(skb) + PAGE_SIZE - 1) >> PAGE_SHIFT; |
|
for (i = 0; i < new_frags; i++) { |
|
page = alloc_page(gfp_mask); |
|
if (!page) { |
|
while (head) { |
|
struct page *next = (struct page *)page_private(head); |
|
put_page(head); |
|
head = next; |
|
} |
|
return -ENOMEM; |
|
} |
|
set_page_private(page, (unsigned long)head); |
|
head = page; |
|
} |
|
|
|
page = head; |
|
d_off = 0; |
|
for (i = 0; i < num_frags; i++) { |
|
skb_frag_t *f = &skb_shinfo(skb)->frags[i]; |
|
u32 p_off, p_len, copied; |
|
struct page *p; |
|
u8 *vaddr; |
|
|
|
skb_frag_foreach_page(f, skb_frag_off(f), skb_frag_size(f), |
|
p, p_off, p_len, copied) { |
|
u32 copy, done = 0; |
|
vaddr = kmap_atomic(p); |
|
|
|
while (done < p_len) { |
|
if (d_off == PAGE_SIZE) { |
|
d_off = 0; |
|
page = (struct page *)page_private(page); |
|
} |
|
copy = min_t(u32, PAGE_SIZE - d_off, p_len - done); |
|
memcpy(page_address(page) + d_off, |
|
vaddr + p_off + done, copy); |
|
done += copy; |
|
d_off += copy; |
|
} |
|
kunmap_atomic(vaddr); |
|
} |
|
} |
|
|
|
/* skb frags release userspace buffers */ |
|
for (i = 0; i < num_frags; i++) |
|
skb_frag_unref(skb, i); |
|
|
|
/* skb frags point to kernel buffers */ |
|
for (i = 0; i < new_frags - 1; i++) { |
|
__skb_fill_page_desc(skb, i, head, 0, PAGE_SIZE); |
|
head = (struct page *)page_private(head); |
|
} |
|
__skb_fill_page_desc(skb, new_frags - 1, head, 0, d_off); |
|
skb_shinfo(skb)->nr_frags = new_frags; |
|
|
|
release: |
|
skb_zcopy_clear(skb, false); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_copy_ubufs); |
|
|
|
/** |
|
* skb_clone - duplicate an sk_buff |
|
* @skb: buffer to clone |
|
* @gfp_mask: allocation priority |
|
* |
|
* Duplicate an &sk_buff. The new one is not owned by a socket. Both |
|
* copies share the same packet data but not structure. The new |
|
* buffer has a reference count of 1. If the allocation fails the |
|
* function returns %NULL otherwise the new buffer is returned. |
|
* |
|
* If this function is called from an interrupt gfp_mask() must be |
|
* %GFP_ATOMIC. |
|
*/ |
|
|
|
struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) |
|
{ |
|
struct sk_buff_fclones *fclones = container_of(skb, |
|
struct sk_buff_fclones, |
|
skb1); |
|
struct sk_buff *n; |
|
|
|
if (skb_orphan_frags(skb, gfp_mask)) |
|
return NULL; |
|
|
|
if (skb->fclone == SKB_FCLONE_ORIG && |
|
refcount_read(&fclones->fclone_ref) == 1) { |
|
n = &fclones->skb2; |
|
refcount_set(&fclones->fclone_ref, 2); |
|
} else { |
|
if (skb_pfmemalloc(skb)) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
|
|
n = kmem_cache_alloc(skbuff_head_cache, gfp_mask); |
|
if (!n) |
|
return NULL; |
|
|
|
n->fclone = SKB_FCLONE_UNAVAILABLE; |
|
} |
|
|
|
return __skb_clone(n, skb); |
|
} |
|
EXPORT_SYMBOL(skb_clone); |
|
|
|
void skb_headers_offset_update(struct sk_buff *skb, int off) |
|
{ |
|
/* Only adjust this if it actually is csum_start rather than csum */ |
|
if (skb->ip_summed == CHECKSUM_PARTIAL) |
|
skb->csum_start += off; |
|
/* {transport,network,mac}_header and tail are relative to skb->head */ |
|
skb->transport_header += off; |
|
skb->network_header += off; |
|
if (skb_mac_header_was_set(skb)) |
|
skb->mac_header += off; |
|
skb->inner_transport_header += off; |
|
skb->inner_network_header += off; |
|
skb->inner_mac_header += off; |
|
} |
|
EXPORT_SYMBOL(skb_headers_offset_update); |
|
|
|
void skb_copy_header(struct sk_buff *new, const struct sk_buff *old) |
|
{ |
|
__copy_skb_header(new, old); |
|
|
|
skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size; |
|
skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs; |
|
skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type; |
|
} |
|
EXPORT_SYMBOL(skb_copy_header); |
|
|
|
static inline int skb_alloc_rx_flag(const struct sk_buff *skb) |
|
{ |
|
if (skb_pfmemalloc(skb)) |
|
return SKB_ALLOC_RX; |
|
return 0; |
|
} |
|
|
|
/** |
|
* skb_copy - create private copy of an sk_buff |
|
* @skb: buffer to copy |
|
* @gfp_mask: allocation priority |
|
* |
|
* Make a copy of both an &sk_buff and its data. This is used when the |
|
* caller wishes to modify the data and needs a private copy of the |
|
* data to alter. Returns %NULL on failure or the pointer to the buffer |
|
* on success. The returned buffer has a reference count of 1. |
|
* |
|
* As by-product this function converts non-linear &sk_buff to linear |
|
* one, so that &sk_buff becomes completely private and caller is allowed |
|
* to modify all the data of returned buffer. This means that this |
|
* function is not recommended for use in circumstances when only |
|
* header is going to be modified. Use pskb_copy() instead. |
|
*/ |
|
|
|
struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) |
|
{ |
|
int headerlen = skb_headroom(skb); |
|
unsigned int size = skb_end_offset(skb) + skb->data_len; |
|
struct sk_buff *n = __alloc_skb(size, gfp_mask, |
|
skb_alloc_rx_flag(skb), NUMA_NO_NODE); |
|
|
|
if (!n) |
|
return NULL; |
|
|
|
/* Set the data pointer */ |
|
skb_reserve(n, headerlen); |
|
/* Set the tail pointer and length */ |
|
skb_put(n, skb->len); |
|
|
|
BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)); |
|
|
|
skb_copy_header(n, skb); |
|
return n; |
|
} |
|
EXPORT_SYMBOL(skb_copy); |
|
|
|
/** |
|
* __pskb_copy_fclone - create copy of an sk_buff with private head. |
|
* @skb: buffer to copy |
|
* @headroom: headroom of new skb |
|
* @gfp_mask: allocation priority |
|
* @fclone: if true allocate the copy of the skb from the fclone |
|
* cache instead of the head cache; it is recommended to set this |
|
* to true for the cases where the copy will likely be cloned |
|
* |
|
* Make a copy of both an &sk_buff and part of its data, located |
|
* in header. Fragmented data remain shared. This is used when |
|
* the caller wishes to modify only header of &sk_buff and needs |
|
* private copy of the header to alter. Returns %NULL on failure |
|
* or the pointer to the buffer on success. |
|
* The returned buffer has a reference count of 1. |
|
*/ |
|
|
|
struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom, |
|
gfp_t gfp_mask, bool fclone) |
|
{ |
|
unsigned int size = skb_headlen(skb) + headroom; |
|
int flags = skb_alloc_rx_flag(skb) | (fclone ? SKB_ALLOC_FCLONE : 0); |
|
struct sk_buff *n = __alloc_skb(size, gfp_mask, flags, NUMA_NO_NODE); |
|
|
|
if (!n) |
|
goto out; |
|
|
|
/* Set the data pointer */ |
|
skb_reserve(n, headroom); |
|
/* Set the tail pointer and length */ |
|
skb_put(n, skb_headlen(skb)); |
|
/* Copy the bytes */ |
|
skb_copy_from_linear_data(skb, n->data, n->len); |
|
|
|
n->truesize += skb->data_len; |
|
n->data_len = skb->data_len; |
|
n->len = skb->len; |
|
|
|
if (skb_shinfo(skb)->nr_frags) { |
|
int i; |
|
|
|
if (skb_orphan_frags(skb, gfp_mask) || |
|
skb_zerocopy_clone(n, skb, gfp_mask)) { |
|
kfree_skb(n); |
|
n = NULL; |
|
goto out; |
|
} |
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i]; |
|
skb_frag_ref(skb, i); |
|
} |
|
skb_shinfo(n)->nr_frags = i; |
|
} |
|
|
|
if (skb_has_frag_list(skb)) { |
|
skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list; |
|
skb_clone_fraglist(n); |
|
} |
|
|
|
skb_copy_header(n, skb); |
|
out: |
|
return n; |
|
} |
|
EXPORT_SYMBOL(__pskb_copy_fclone); |
|
|
|
/** |
|
* pskb_expand_head - reallocate header of &sk_buff |
|
* @skb: buffer to reallocate |
|
* @nhead: room to add at head |
|
* @ntail: room to add at tail |
|
* @gfp_mask: allocation priority |
|
* |
|
* Expands (or creates identical copy, if @nhead and @ntail are zero) |
|
* header of @skb. &sk_buff itself is not changed. &sk_buff MUST have |
|
* reference count of 1. Returns zero in the case of success or error, |
|
* if expansion failed. In the last case, &sk_buff is not changed. |
|
* |
|
* All the pointers pointing into skb header may change and must be |
|
* reloaded after call to this function. |
|
*/ |
|
|
|
int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, |
|
gfp_t gfp_mask) |
|
{ |
|
int i, osize = skb_end_offset(skb); |
|
int size = osize + nhead + ntail; |
|
long off; |
|
u8 *data; |
|
|
|
BUG_ON(nhead < 0); |
|
|
|
BUG_ON(skb_shared(skb)); |
|
|
|
size = SKB_DATA_ALIGN(size); |
|
|
|
if (skb_pfmemalloc(skb)) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), |
|
gfp_mask, NUMA_NO_NODE, NULL); |
|
if (!data) |
|
goto nodata; |
|
size = SKB_WITH_OVERHEAD(ksize(data)); |
|
|
|
/* Copy only real data... and, alas, header. This should be |
|
* optimized for the cases when header is void. |
|
*/ |
|
memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head); |
|
|
|
memcpy((struct skb_shared_info *)(data + size), |
|
skb_shinfo(skb), |
|
offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags])); |
|
|
|
/* |
|
* if shinfo is shared we must drop the old head gracefully, but if it |
|
* is not we can just drop the old head and let the existing refcount |
|
* be since all we did is relocate the values |
|
*/ |
|
if (skb_cloned(skb)) { |
|
if (skb_orphan_frags(skb, gfp_mask)) |
|
goto nofrags; |
|
if (skb_zcopy(skb)) |
|
refcount_inc(&skb_uarg(skb)->refcnt); |
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
|
skb_frag_ref(skb, i); |
|
|
|
if (skb_has_frag_list(skb)) |
|
skb_clone_fraglist(skb); |
|
|
|
skb_release_data(skb); |
|
} else { |
|
skb_free_head(skb); |
|
} |
|
off = (data + nhead) - skb->head; |
|
|
|
skb->head = data; |
|
skb->head_frag = 0; |
|
skb->data += off; |
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET |
|
skb->end = size; |
|
off = nhead; |
|
#else |
|
skb->end = skb->head + size; |
|
#endif |
|
skb->tail += off; |
|
skb_headers_offset_update(skb, nhead); |
|
skb->cloned = 0; |
|
skb->hdr_len = 0; |
|
skb->nohdr = 0; |
|
atomic_set(&skb_shinfo(skb)->dataref, 1); |
|
|
|
skb_metadata_clear(skb); |
|
|
|
/* It is not generally safe to change skb->truesize. |
|
* For the moment, we really care of rx path, or |
|
* when skb is orphaned (not attached to a socket). |
|
*/ |
|
if (!skb->sk || skb->destructor == sock_edemux) |
|
skb->truesize += size - osize; |
|
|
|
return 0; |
|
|
|
nofrags: |
|
kfree(data); |
|
nodata: |
|
return -ENOMEM; |
|
} |
|
EXPORT_SYMBOL(pskb_expand_head); |
|
|
|
/* Make private copy of skb with writable head and some headroom */ |
|
|
|
struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) |
|
{ |
|
struct sk_buff *skb2; |
|
int delta = headroom - skb_headroom(skb); |
|
|
|
if (delta <= 0) |
|
skb2 = pskb_copy(skb, GFP_ATOMIC); |
|
else { |
|
skb2 = skb_clone(skb, GFP_ATOMIC); |
|
if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0, |
|
GFP_ATOMIC)) { |
|
kfree_skb(skb2); |
|
skb2 = NULL; |
|
} |
|
} |
|
return skb2; |
|
} |
|
EXPORT_SYMBOL(skb_realloc_headroom); |
|
|
|
/** |
|
* skb_expand_head - reallocate header of &sk_buff |
|
* @skb: buffer to reallocate |
|
* @headroom: needed headroom |
|
* |
|
* Unlike skb_realloc_headroom, this one does not allocate a new skb |
|
* if possible; copies skb->sk to new skb as needed |
|
* and frees original skb in case of failures. |
|
* |
|
* It expect increased headroom and generates warning otherwise. |
|
*/ |
|
|
|
struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom) |
|
{ |
|
int delta = headroom - skb_headroom(skb); |
|
int osize = skb_end_offset(skb); |
|
struct sock *sk = skb->sk; |
|
|
|
if (WARN_ONCE(delta <= 0, |
|
"%s is expecting an increase in the headroom", __func__)) |
|
return skb; |
|
|
|
delta = SKB_DATA_ALIGN(delta); |
|
/* pskb_expand_head() might crash, if skb is shared. */ |
|
if (skb_shared(skb) || !is_skb_wmem(skb)) { |
|
struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); |
|
|
|
if (unlikely(!nskb)) |
|
goto fail; |
|
|
|
if (sk) |
|
skb_set_owner_w(nskb, sk); |
|
consume_skb(skb); |
|
skb = nskb; |
|
} |
|
if (pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) |
|
goto fail; |
|
|
|
if (sk && is_skb_wmem(skb)) { |
|
delta = skb_end_offset(skb) - osize; |
|
refcount_add(delta, &sk->sk_wmem_alloc); |
|
skb->truesize += delta; |
|
} |
|
return skb; |
|
|
|
fail: |
|
kfree_skb(skb); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(skb_expand_head); |
|
|
|
/** |
|
* skb_copy_expand - copy and expand sk_buff |
|
* @skb: buffer to copy |
|
* @newheadroom: new free bytes at head |
|
* @newtailroom: new free bytes at tail |
|
* @gfp_mask: allocation priority |
|
* |
|
* Make a copy of both an &sk_buff and its data and while doing so |
|
* allocate additional space. |
|
* |
|
* This is used when the caller wishes to modify the data and needs a |
|
* private copy of the data to alter as well as more space for new fields. |
|
* Returns %NULL on failure or the pointer to the buffer |
|
* on success. The returned buffer has a reference count of 1. |
|
* |
|
* You must pass %GFP_ATOMIC as the allocation priority if this function |
|
* is called from an interrupt. |
|
*/ |
|
struct sk_buff *skb_copy_expand(const struct sk_buff *skb, |
|
int newheadroom, int newtailroom, |
|
gfp_t gfp_mask) |
|
{ |
|
/* |
|
* Allocate the copy buffer |
|
*/ |
|
struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom, |
|
gfp_mask, skb_alloc_rx_flag(skb), |
|
NUMA_NO_NODE); |
|
int oldheadroom = skb_headroom(skb); |
|
int head_copy_len, head_copy_off; |
|
|
|
if (!n) |
|
return NULL; |
|
|
|
skb_reserve(n, newheadroom); |
|
|
|
/* Set the tail pointer and length */ |
|
skb_put(n, skb->len); |
|
|
|
head_copy_len = oldheadroom; |
|
head_copy_off = 0; |
|
if (newheadroom <= head_copy_len) |
|
head_copy_len = newheadroom; |
|
else |
|
head_copy_off = newheadroom - head_copy_len; |
|
|
|
/* Copy the linear header and data. */ |
|
BUG_ON(skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off, |
|
skb->len + head_copy_len)); |
|
|
|
skb_copy_header(n, skb); |
|
|
|
skb_headers_offset_update(n, newheadroom - oldheadroom); |
|
|
|
return n; |
|
} |
|
EXPORT_SYMBOL(skb_copy_expand); |
|
|
|
/** |
|
* __skb_pad - zero pad the tail of an skb |
|
* @skb: buffer to pad |
|
* @pad: space to pad |
|
* @free_on_error: free buffer on error |
|
* |
|
* Ensure that a buffer is followed by a padding area that is zero |
|
* filled. Used by network drivers which may DMA or transfer data |
|
* beyond the buffer end onto the wire. |
|
* |
|
* May return error in out of memory cases. The skb is freed on error |
|
* if @free_on_error is true. |
|
*/ |
|
|
|
int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error) |
|
{ |
|
int err; |
|
int ntail; |
|
|
|
/* If the skbuff is non linear tailroom is always zero.. */ |
|
if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) { |
|
memset(skb->data+skb->len, 0, pad); |
|
return 0; |
|
} |
|
|
|
ntail = skb->data_len + pad - (skb->end - skb->tail); |
|
if (likely(skb_cloned(skb) || ntail > 0)) { |
|
err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC); |
|
if (unlikely(err)) |
|
goto free_skb; |
|
} |
|
|
|
/* FIXME: The use of this function with non-linear skb's really needs |
|
* to be audited. |
|
*/ |
|
err = skb_linearize(skb); |
|
if (unlikely(err)) |
|
goto free_skb; |
|
|
|
memset(skb->data + skb->len, 0, pad); |
|
return 0; |
|
|
|
free_skb: |
|
if (free_on_error) |
|
kfree_skb(skb); |
|
return err; |
|
} |
|
EXPORT_SYMBOL(__skb_pad); |
|
|
|
/** |
|
* pskb_put - add data to the tail of a potentially fragmented buffer |
|
* @skb: start of the buffer to use |
|
* @tail: tail fragment of the buffer to use |
|
* @len: amount of data to add |
|
* |
|
* This function extends the used data area of the potentially |
|
* fragmented buffer. @tail must be the last fragment of @skb -- or |
|
* @skb itself. If this would exceed the total buffer size the kernel |
|
* will panic. A pointer to the first byte of the extra data is |
|
* returned. |
|
*/ |
|
|
|
void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len) |
|
{ |
|
if (tail != skb) { |
|
skb->data_len += len; |
|
skb->len += len; |
|
} |
|
return skb_put(tail, len); |
|
} |
|
EXPORT_SYMBOL_GPL(pskb_put); |
|
|
|
/** |
|
* skb_put - add data to a buffer |
|
* @skb: buffer to use |
|
* @len: amount of data to add |
|
* |
|
* This function extends the used data area of the buffer. If this would |
|
* exceed the total buffer size the kernel will panic. A pointer to the |
|
* first byte of the extra data is returned. |
|
*/ |
|
void *skb_put(struct sk_buff *skb, unsigned int len) |
|
{ |
|
void *tmp = skb_tail_pointer(skb); |
|
SKB_LINEAR_ASSERT(skb); |
|
skb->tail += len; |
|
skb->len += len; |
|
if (unlikely(skb->tail > skb->end)) |
|
skb_over_panic(skb, len, __builtin_return_address(0)); |
|
return tmp; |
|
} |
|
EXPORT_SYMBOL(skb_put); |
|
|
|
/** |
|
* skb_push - add data to the start of a buffer |
|
* @skb: buffer to use |
|
* @len: amount of data to add |
|
* |
|
* This function extends the used data area of the buffer at the buffer |
|
* start. If this would exceed the total buffer headroom the kernel will |
|
* panic. A pointer to the first byte of the extra data is returned. |
|
*/ |
|
void *skb_push(struct sk_buff *skb, unsigned int len) |
|
{ |
|
skb->data -= len; |
|
skb->len += len; |
|
if (unlikely(skb->data < skb->head)) |
|
skb_under_panic(skb, len, __builtin_return_address(0)); |
|
return skb->data; |
|
} |
|
EXPORT_SYMBOL(skb_push); |
|
|
|
/** |
|
* skb_pull - remove data from the start of a buffer |
|
* @skb: buffer to use |
|
* @len: amount of data to remove |
|
* |
|
* This function removes data from the start of a buffer, returning |
|
* the memory to the headroom. A pointer to the next data in the buffer |
|
* is returned. Once the data has been pulled future pushes will overwrite |
|
* the old data. |
|
*/ |
|
void *skb_pull(struct sk_buff *skb, unsigned int len) |
|
{ |
|
return skb_pull_inline(skb, len); |
|
} |
|
EXPORT_SYMBOL(skb_pull); |
|
|
|
/** |
|
* skb_pull_data - remove data from the start of a buffer returning its |
|
* original position. |
|
* @skb: buffer to use |
|
* @len: amount of data to remove |
|
* |
|
* This function removes data from the start of a buffer, returning |
|
* the memory to the headroom. A pointer to the original data in the buffer |
|
* is returned after checking if there is enough data to pull. Once the |
|
* data has been pulled future pushes will overwrite the old data. |
|
*/ |
|
void *skb_pull_data(struct sk_buff *skb, size_t len) |
|
{ |
|
void *data = skb->data; |
|
|
|
if (skb->len < len) |
|
return NULL; |
|
|
|
skb_pull(skb, len); |
|
|
|
return data; |
|
} |
|
EXPORT_SYMBOL(skb_pull_data); |
|
|
|
/** |
|
* skb_trim - remove end from a buffer |
|
* @skb: buffer to alter |
|
* @len: new length |
|
* |
|
* Cut the length of a buffer down by removing data from the tail. If |
|
* the buffer is already under the length specified it is not modified. |
|
* The skb must be linear. |
|
*/ |
|
void skb_trim(struct sk_buff *skb, unsigned int len) |
|
{ |
|
if (skb->len > len) |
|
__skb_trim(skb, len); |
|
} |
|
EXPORT_SYMBOL(skb_trim); |
|
|
|
/* Trims skb to length len. It can change skb pointers. |
|
*/ |
|
|
|
int ___pskb_trim(struct sk_buff *skb, unsigned int len) |
|
{ |
|
struct sk_buff **fragp; |
|
struct sk_buff *frag; |
|
int offset = skb_headlen(skb); |
|
int nfrags = skb_shinfo(skb)->nr_frags; |
|
int i; |
|
int err; |
|
|
|
if (skb_cloned(skb) && |
|
unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))) |
|
return err; |
|
|
|
i = 0; |
|
if (offset >= len) |
|
goto drop_pages; |
|
|
|
for (; i < nfrags; i++) { |
|
int end = offset + skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
|
|
if (end < len) { |
|
offset = end; |
|
continue; |
|
} |
|
|
|
skb_frag_size_set(&skb_shinfo(skb)->frags[i++], len - offset); |
|
|
|
drop_pages: |
|
skb_shinfo(skb)->nr_frags = i; |
|
|
|
for (; i < nfrags; i++) |
|
skb_frag_unref(skb, i); |
|
|
|
if (skb_has_frag_list(skb)) |
|
skb_drop_fraglist(skb); |
|
goto done; |
|
} |
|
|
|
for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp); |
|
fragp = &frag->next) { |
|
int end = offset + frag->len; |
|
|
|
if (skb_shared(frag)) { |
|
struct sk_buff *nfrag; |
|
|
|
nfrag = skb_clone(frag, GFP_ATOMIC); |
|
if (unlikely(!nfrag)) |
|
return -ENOMEM; |
|
|
|
nfrag->next = frag->next; |
|
consume_skb(frag); |
|
frag = nfrag; |
|
*fragp = frag; |
|
} |
|
|
|
if (end < len) { |
|
offset = end; |
|
continue; |
|
} |
|
|
|
if (end > len && |
|
unlikely((err = pskb_trim(frag, len - offset)))) |
|
return err; |
|
|
|
if (frag->next) |
|
skb_drop_list(&frag->next); |
|
break; |
|
} |
|
|
|
done: |
|
if (len > skb_headlen(skb)) { |
|
skb->data_len -= skb->len - len; |
|
skb->len = len; |
|
} else { |
|
skb->len = len; |
|
skb->data_len = 0; |
|
skb_set_tail_pointer(skb, len); |
|
} |
|
|
|
if (!skb->sk || skb->destructor == sock_edemux) |
|
skb_condense(skb); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(___pskb_trim); |
|
|
|
/* Note : use pskb_trim_rcsum() instead of calling this directly |
|
*/ |
|
int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len) |
|
{ |
|
if (skb->ip_summed == CHECKSUM_COMPLETE) { |
|
int delta = skb->len - len; |
|
|
|
skb->csum = csum_block_sub(skb->csum, |
|
skb_checksum(skb, len, delta, 0), |
|
len); |
|
} else if (skb->ip_summed == CHECKSUM_PARTIAL) { |
|
int hdlen = (len > skb_headlen(skb)) ? skb_headlen(skb) : len; |
|
int offset = skb_checksum_start_offset(skb) + skb->csum_offset; |
|
|
|
if (offset + sizeof(__sum16) > hdlen) |
|
return -EINVAL; |
|
} |
|
return __pskb_trim(skb, len); |
|
} |
|
EXPORT_SYMBOL(pskb_trim_rcsum_slow); |
|
|
|
/** |
|
* __pskb_pull_tail - advance tail of skb header |
|
* @skb: buffer to reallocate |
|
* @delta: number of bytes to advance tail |
|
* |
|
* The function makes a sense only on a fragmented &sk_buff, |
|
* it expands header moving its tail forward and copying necessary |
|
* data from fragmented part. |
|
* |
|
* &sk_buff MUST have reference count of 1. |
|
* |
|
* Returns %NULL (and &sk_buff does not change) if pull failed |
|
* or value of new tail of skb in the case of success. |
|
* |
|
* All the pointers pointing into skb header may change and must be |
|
* reloaded after call to this function. |
|
*/ |
|
|
|
/* Moves tail of skb head forward, copying data from fragmented part, |
|
* when it is necessary. |
|
* 1. It may fail due to malloc failure. |
|
* 2. It may change skb pointers. |
|
* |
|
* It is pretty complicated. Luckily, it is called only in exceptional cases. |
|
*/ |
|
void *__pskb_pull_tail(struct sk_buff *skb, int delta) |
|
{ |
|
/* If skb has not enough free space at tail, get new one |
|
* plus 128 bytes for future expansions. If we have enough |
|
* room at tail, reallocate without expansion only if skb is cloned. |
|
*/ |
|
int i, k, eat = (skb->tail + delta) - skb->end; |
|
|
|
if (eat > 0 || skb_cloned(skb)) { |
|
if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0, |
|
GFP_ATOMIC)) |
|
return NULL; |
|
} |
|
|
|
BUG_ON(skb_copy_bits(skb, skb_headlen(skb), |
|
skb_tail_pointer(skb), delta)); |
|
|
|
/* Optimization: no fragments, no reasons to preestimate |
|
* size of pulled pages. Superb. |
|
*/ |
|
if (!skb_has_frag_list(skb)) |
|
goto pull_pages; |
|
|
|
/* Estimate size of pulled pages. */ |
|
eat = delta; |
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
|
|
if (size >= eat) |
|
goto pull_pages; |
|
eat -= size; |
|
} |
|
|
|
/* If we need update frag list, we are in troubles. |
|
* Certainly, it is possible to add an offset to skb data, |
|
* but taking into account that pulling is expected to |
|
* be very rare operation, it is worth to fight against |
|
* further bloating skb head and crucify ourselves here instead. |
|
* Pure masohism, indeed. 8)8) |
|
*/ |
|
if (eat) { |
|
struct sk_buff *list = skb_shinfo(skb)->frag_list; |
|
struct sk_buff *clone = NULL; |
|
struct sk_buff *insp = NULL; |
|
|
|
do { |
|
if (list->len <= eat) { |
|
/* Eaten as whole. */ |
|
eat -= list->len; |
|
list = list->next; |
|
insp = list; |
|
} else { |
|
/* Eaten partially. */ |
|
|
|
if (skb_shared(list)) { |
|
/* Sucks! We need to fork list. :-( */ |
|
clone = skb_clone(list, GFP_ATOMIC); |
|
if (!clone) |
|
return NULL; |
|
insp = list->next; |
|
list = clone; |
|
} else { |
|
/* This may be pulled without |
|
* problems. */ |
|
insp = list; |
|
} |
|
if (!pskb_pull(list, eat)) { |
|
kfree_skb(clone); |
|
return NULL; |
|
} |
|
break; |
|
} |
|
} while (eat); |
|
|
|
/* Free pulled out fragments. */ |
|
while ((list = skb_shinfo(skb)->frag_list) != insp) { |
|
skb_shinfo(skb)->frag_list = list->next; |
|
consume_skb(list); |
|
} |
|
/* And insert new clone at head. */ |
|
if (clone) { |
|
clone->next = list; |
|
skb_shinfo(skb)->frag_list = clone; |
|
} |
|
} |
|
/* Success! Now we may commit changes to skb data. */ |
|
|
|
pull_pages: |
|
eat = delta; |
|
k = 0; |
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
|
|
if (size <= eat) { |
|
skb_frag_unref(skb, i); |
|
eat -= size; |
|
} else { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[k]; |
|
|
|
*frag = skb_shinfo(skb)->frags[i]; |
|
if (eat) { |
|
skb_frag_off_add(frag, eat); |
|
skb_frag_size_sub(frag, eat); |
|
if (!i) |
|
goto end; |
|
eat = 0; |
|
} |
|
k++; |
|
} |
|
} |
|
skb_shinfo(skb)->nr_frags = k; |
|
|
|
end: |
|
skb->tail += delta; |
|
skb->data_len -= delta; |
|
|
|
if (!skb->data_len) |
|
skb_zcopy_clear(skb, false); |
|
|
|
return skb_tail_pointer(skb); |
|
} |
|
EXPORT_SYMBOL(__pskb_pull_tail); |
|
|
|
/** |
|
* skb_copy_bits - copy bits from skb to kernel buffer |
|
* @skb: source skb |
|
* @offset: offset in source |
|
* @to: destination buffer |
|
* @len: number of bytes to copy |
|
* |
|
* Copy the specified number of bytes from the source skb to the |
|
* destination buffer. |
|
* |
|
* CAUTION ! : |
|
* If its prototype is ever changed, |
|
* check arch/{*}/net/{*}.S files, |
|
* since it is called from BPF assembly code. |
|
*/ |
|
int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) |
|
{ |
|
int start = skb_headlen(skb); |
|
struct sk_buff *frag_iter; |
|
int i, copy; |
|
|
|
if (offset > (int)skb->len - len) |
|
goto fault; |
|
|
|
/* Copy header. */ |
|
if ((copy = start - offset) > 0) { |
|
if (copy > len) |
|
copy = len; |
|
skb_copy_from_linear_data_offset(skb, offset, to, copy); |
|
if ((len -= copy) == 0) |
|
return 0; |
|
offset += copy; |
|
to += copy; |
|
} |
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
int end; |
|
skb_frag_t *f = &skb_shinfo(skb)->frags[i]; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + skb_frag_size(f); |
|
if ((copy = end - offset) > 0) { |
|
u32 p_off, p_len, copied; |
|
struct page *p; |
|
u8 *vaddr; |
|
|
|
if (copy > len) |
|
copy = len; |
|
|
|
skb_frag_foreach_page(f, |
|
skb_frag_off(f) + offset - start, |
|
copy, p, p_off, p_len, copied) { |
|
vaddr = kmap_atomic(p); |
|
memcpy(to + copied, vaddr + p_off, p_len); |
|
kunmap_atomic(vaddr); |
|
} |
|
|
|
if ((len -= copy) == 0) |
|
return 0; |
|
offset += copy; |
|
to += copy; |
|
} |
|
start = end; |
|
} |
|
|
|
skb_walk_frags(skb, frag_iter) { |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + frag_iter->len; |
|
if ((copy = end - offset) > 0) { |
|
if (copy > len) |
|
copy = len; |
|
if (skb_copy_bits(frag_iter, offset - start, to, copy)) |
|
goto fault; |
|
if ((len -= copy) == 0) |
|
return 0; |
|
offset += copy; |
|
to += copy; |
|
} |
|
start = end; |
|
} |
|
|
|
if (!len) |
|
return 0; |
|
|
|
fault: |
|
return -EFAULT; |
|
} |
|
EXPORT_SYMBOL(skb_copy_bits); |
|
|
|
/* |
|
* Callback from splice_to_pipe(), if we need to release some pages |
|
* at the end of the spd in case we error'ed out in filling the pipe. |
|
*/ |
|
static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i) |
|
{ |
|
put_page(spd->pages[i]); |
|
} |
|
|
|
static struct page *linear_to_page(struct page *page, unsigned int *len, |
|
unsigned int *offset, |
|
struct sock *sk) |
|
{ |
|
struct page_frag *pfrag = sk_page_frag(sk); |
|
|
|
if (!sk_page_frag_refill(sk, pfrag)) |
|
return NULL; |
|
|
|
*len = min_t(unsigned int, *len, pfrag->size - pfrag->offset); |
|
|
|
memcpy(page_address(pfrag->page) + pfrag->offset, |
|
page_address(page) + *offset, *len); |
|
*offset = pfrag->offset; |
|
pfrag->offset += *len; |
|
|
|
return pfrag->page; |
|
} |
|
|
|
static bool spd_can_coalesce(const struct splice_pipe_desc *spd, |
|
struct page *page, |
|
unsigned int offset) |
|
{ |
|
return spd->nr_pages && |
|
spd->pages[spd->nr_pages - 1] == page && |
|
(spd->partial[spd->nr_pages - 1].offset + |
|
spd->partial[spd->nr_pages - 1].len == offset); |
|
} |
|
|
|
/* |
|
* Fill page/offset/length into spd, if it can hold more pages. |
|
*/ |
|
static bool spd_fill_page(struct splice_pipe_desc *spd, |
|
struct pipe_inode_info *pipe, struct page *page, |
|
unsigned int *len, unsigned int offset, |
|
bool linear, |
|
struct sock *sk) |
|
{ |
|
if (unlikely(spd->nr_pages == MAX_SKB_FRAGS)) |
|
return true; |
|
|
|
if (linear) { |
|
page = linear_to_page(page, len, &offset, sk); |
|
if (!page) |
|
return true; |
|
} |
|
if (spd_can_coalesce(spd, page, offset)) { |
|
spd->partial[spd->nr_pages - 1].len += *len; |
|
return false; |
|
} |
|
get_page(page); |
|
spd->pages[spd->nr_pages] = page; |
|
spd->partial[spd->nr_pages].len = *len; |
|
spd->partial[spd->nr_pages].offset = offset; |
|
spd->nr_pages++; |
|
|
|
return false; |
|
} |
|
|
|
static bool __splice_segment(struct page *page, unsigned int poff, |
|
unsigned int plen, unsigned int *off, |
|
unsigned int *len, |
|
struct splice_pipe_desc *spd, bool linear, |
|
struct sock *sk, |
|
struct pipe_inode_info *pipe) |
|
{ |
|
if (!*len) |
|
return true; |
|
|
|
/* skip this segment if already processed */ |
|
if (*off >= plen) { |
|
*off -= plen; |
|
return false; |
|
} |
|
|
|
/* ignore any bits we already processed */ |
|
poff += *off; |
|
plen -= *off; |
|
*off = 0; |
|
|
|
do { |
|
unsigned int flen = min(*len, plen); |
|
|
|
if (spd_fill_page(spd, pipe, page, &flen, poff, |
|
linear, sk)) |
|
return true; |
|
poff += flen; |
|
plen -= flen; |
|
*len -= flen; |
|
} while (*len && plen); |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* Map linear and fragment data from the skb to spd. It reports true if the |
|
* pipe is full or if we already spliced the requested length. |
|
*/ |
|
static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, |
|
unsigned int *offset, unsigned int *len, |
|
struct splice_pipe_desc *spd, struct sock *sk) |
|
{ |
|
int seg; |
|
struct sk_buff *iter; |
|
|
|
/* map the linear part : |
|
* If skb->head_frag is set, this 'linear' part is backed by a |
|
* fragment, and if the head is not shared with any clones then |
|
* we can avoid a copy since we own the head portion of this page. |
|
*/ |
|
if (__splice_segment(virt_to_page(skb->data), |
|
(unsigned long) skb->data & (PAGE_SIZE - 1), |
|
skb_headlen(skb), |
|
offset, len, spd, |
|
skb_head_is_locked(skb), |
|
sk, pipe)) |
|
return true; |
|
|
|
/* |
|
* then map the fragments |
|
*/ |
|
for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { |
|
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; |
|
|
|
if (__splice_segment(skb_frag_page(f), |
|
skb_frag_off(f), skb_frag_size(f), |
|
offset, len, spd, false, sk, pipe)) |
|
return true; |
|
} |
|
|
|
skb_walk_frags(skb, iter) { |
|
if (*offset >= iter->len) { |
|
*offset -= iter->len; |
|
continue; |
|
} |
|
/* __skb_splice_bits() only fails if the output has no room |
|
* left, so no point in going over the frag_list for the error |
|
* case. |
|
*/ |
|
if (__skb_splice_bits(iter, pipe, offset, len, spd, sk)) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* Map data from the skb to a pipe. Should handle both the linear part, |
|
* the fragments, and the frag list. |
|
*/ |
|
int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset, |
|
struct pipe_inode_info *pipe, unsigned int tlen, |
|
unsigned int flags) |
|
{ |
|
struct partial_page partial[MAX_SKB_FRAGS]; |
|
struct page *pages[MAX_SKB_FRAGS]; |
|
struct splice_pipe_desc spd = { |
|
.pages = pages, |
|
.partial = partial, |
|
.nr_pages_max = MAX_SKB_FRAGS, |
|
.ops = &nosteal_pipe_buf_ops, |
|
.spd_release = sock_spd_release, |
|
}; |
|
int ret = 0; |
|
|
|
__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk); |
|
|
|
if (spd.nr_pages) |
|
ret = splice_to_pipe(pipe, &spd); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_splice_bits); |
|
|
|
static int sendmsg_unlocked(struct sock *sk, struct msghdr *msg, |
|
struct kvec *vec, size_t num, size_t size) |
|
{ |
|
struct socket *sock = sk->sk_socket; |
|
|
|
if (!sock) |
|
return -EINVAL; |
|
return kernel_sendmsg(sock, msg, vec, num, size); |
|
} |
|
|
|
static int sendpage_unlocked(struct sock *sk, struct page *page, int offset, |
|
size_t size, int flags) |
|
{ |
|
struct socket *sock = sk->sk_socket; |
|
|
|
if (!sock) |
|
return -EINVAL; |
|
return kernel_sendpage(sock, page, offset, size, flags); |
|
} |
|
|
|
typedef int (*sendmsg_func)(struct sock *sk, struct msghdr *msg, |
|
struct kvec *vec, size_t num, size_t size); |
|
typedef int (*sendpage_func)(struct sock *sk, struct page *page, int offset, |
|
size_t size, int flags); |
|
static int __skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, |
|
int len, sendmsg_func sendmsg, sendpage_func sendpage) |
|
{ |
|
unsigned int orig_len = len; |
|
struct sk_buff *head = skb; |
|
unsigned short fragidx; |
|
int slen, ret; |
|
|
|
do_frag_list: |
|
|
|
/* Deal with head data */ |
|
while (offset < skb_headlen(skb) && len) { |
|
struct kvec kv; |
|
struct msghdr msg; |
|
|
|
slen = min_t(int, len, skb_headlen(skb) - offset); |
|
kv.iov_base = skb->data + offset; |
|
kv.iov_len = slen; |
|
memset(&msg, 0, sizeof(msg)); |
|
msg.msg_flags = MSG_DONTWAIT; |
|
|
|
ret = INDIRECT_CALL_2(sendmsg, kernel_sendmsg_locked, |
|
sendmsg_unlocked, sk, &msg, &kv, 1, slen); |
|
if (ret <= 0) |
|
goto error; |
|
|
|
offset += ret; |
|
len -= ret; |
|
} |
|
|
|
/* All the data was skb head? */ |
|
if (!len) |
|
goto out; |
|
|
|
/* Make offset relative to start of frags */ |
|
offset -= skb_headlen(skb); |
|
|
|
/* Find where we are in frag list */ |
|
for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx]; |
|
|
|
if (offset < skb_frag_size(frag)) |
|
break; |
|
|
|
offset -= skb_frag_size(frag); |
|
} |
|
|
|
for (; len && fragidx < skb_shinfo(skb)->nr_frags; fragidx++) { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[fragidx]; |
|
|
|
slen = min_t(size_t, len, skb_frag_size(frag) - offset); |
|
|
|
while (slen) { |
|
ret = INDIRECT_CALL_2(sendpage, kernel_sendpage_locked, |
|
sendpage_unlocked, sk, |
|
skb_frag_page(frag), |
|
skb_frag_off(frag) + offset, |
|
slen, MSG_DONTWAIT); |
|
if (ret <= 0) |
|
goto error; |
|
|
|
len -= ret; |
|
offset += ret; |
|
slen -= ret; |
|
} |
|
|
|
offset = 0; |
|
} |
|
|
|
if (len) { |
|
/* Process any frag lists */ |
|
|
|
if (skb == head) { |
|
if (skb_has_frag_list(skb)) { |
|
skb = skb_shinfo(skb)->frag_list; |
|
goto do_frag_list; |
|
} |
|
} else if (skb->next) { |
|
skb = skb->next; |
|
goto do_frag_list; |
|
} |
|
} |
|
|
|
out: |
|
return orig_len - len; |
|
|
|
error: |
|
return orig_len == len ? ret : orig_len - len; |
|
} |
|
|
|
/* Send skb data on a socket. Socket must be locked. */ |
|
int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset, |
|
int len) |
|
{ |
|
return __skb_send_sock(sk, skb, offset, len, kernel_sendmsg_locked, |
|
kernel_sendpage_locked); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_send_sock_locked); |
|
|
|
/* Send skb data on a socket. Socket must be unlocked. */ |
|
int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len) |
|
{ |
|
return __skb_send_sock(sk, skb, offset, len, sendmsg_unlocked, |
|
sendpage_unlocked); |
|
} |
|
|
|
/** |
|
* skb_store_bits - store bits from kernel buffer to skb |
|
* @skb: destination buffer |
|
* @offset: offset in destination |
|
* @from: source buffer |
|
* @len: number of bytes to copy |
|
* |
|
* Copy the specified number of bytes from the source buffer to the |
|
* destination skb. This function handles all the messy bits of |
|
* traversing fragment lists and such. |
|
*/ |
|
|
|
int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len) |
|
{ |
|
int start = skb_headlen(skb); |
|
struct sk_buff *frag_iter; |
|
int i, copy; |
|
|
|
if (offset > (int)skb->len - len) |
|
goto fault; |
|
|
|
if ((copy = start - offset) > 0) { |
|
if (copy > len) |
|
copy = len; |
|
skb_copy_to_linear_data_offset(skb, offset, from, copy); |
|
if ((len -= copy) == 0) |
|
return 0; |
|
offset += copy; |
|
from += copy; |
|
} |
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + skb_frag_size(frag); |
|
if ((copy = end - offset) > 0) { |
|
u32 p_off, p_len, copied; |
|
struct page *p; |
|
u8 *vaddr; |
|
|
|
if (copy > len) |
|
copy = len; |
|
|
|
skb_frag_foreach_page(frag, |
|
skb_frag_off(frag) + offset - start, |
|
copy, p, p_off, p_len, copied) { |
|
vaddr = kmap_atomic(p); |
|
memcpy(vaddr + p_off, from + copied, p_len); |
|
kunmap_atomic(vaddr); |
|
} |
|
|
|
if ((len -= copy) == 0) |
|
return 0; |
|
offset += copy; |
|
from += copy; |
|
} |
|
start = end; |
|
} |
|
|
|
skb_walk_frags(skb, frag_iter) { |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + frag_iter->len; |
|
if ((copy = end - offset) > 0) { |
|
if (copy > len) |
|
copy = len; |
|
if (skb_store_bits(frag_iter, offset - start, |
|
from, copy)) |
|
goto fault; |
|
if ((len -= copy) == 0) |
|
return 0; |
|
offset += copy; |
|
from += copy; |
|
} |
|
start = end; |
|
} |
|
if (!len) |
|
return 0; |
|
|
|
fault: |
|
return -EFAULT; |
|
} |
|
EXPORT_SYMBOL(skb_store_bits); |
|
|
|
/* Checksum skb data. */ |
|
__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len, |
|
__wsum csum, const struct skb_checksum_ops *ops) |
|
{ |
|
int start = skb_headlen(skb); |
|
int i, copy = start - offset; |
|
struct sk_buff *frag_iter; |
|
int pos = 0; |
|
|
|
/* Checksum header. */ |
|
if (copy > 0) { |
|
if (copy > len) |
|
copy = len; |
|
csum = INDIRECT_CALL_1(ops->update, csum_partial_ext, |
|
skb->data + offset, copy, csum); |
|
if ((len -= copy) == 0) |
|
return csum; |
|
offset += copy; |
|
pos = copy; |
|
} |
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
int end; |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + skb_frag_size(frag); |
|
if ((copy = end - offset) > 0) { |
|
u32 p_off, p_len, copied; |
|
struct page *p; |
|
__wsum csum2; |
|
u8 *vaddr; |
|
|
|
if (copy > len) |
|
copy = len; |
|
|
|
skb_frag_foreach_page(frag, |
|
skb_frag_off(frag) + offset - start, |
|
copy, p, p_off, p_len, copied) { |
|
vaddr = kmap_atomic(p); |
|
csum2 = INDIRECT_CALL_1(ops->update, |
|
csum_partial_ext, |
|
vaddr + p_off, p_len, 0); |
|
kunmap_atomic(vaddr); |
|
csum = INDIRECT_CALL_1(ops->combine, |
|
csum_block_add_ext, csum, |
|
csum2, pos, p_len); |
|
pos += p_len; |
|
} |
|
|
|
if (!(len -= copy)) |
|
return csum; |
|
offset += copy; |
|
} |
|
start = end; |
|
} |
|
|
|
skb_walk_frags(skb, frag_iter) { |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + frag_iter->len; |
|
if ((copy = end - offset) > 0) { |
|
__wsum csum2; |
|
if (copy > len) |
|
copy = len; |
|
csum2 = __skb_checksum(frag_iter, offset - start, |
|
copy, 0, ops); |
|
csum = INDIRECT_CALL_1(ops->combine, csum_block_add_ext, |
|
csum, csum2, pos, copy); |
|
if ((len -= copy) == 0) |
|
return csum; |
|
offset += copy; |
|
pos += copy; |
|
} |
|
start = end; |
|
} |
|
BUG_ON(len); |
|
|
|
return csum; |
|
} |
|
EXPORT_SYMBOL(__skb_checksum); |
|
|
|
__wsum skb_checksum(const struct sk_buff *skb, int offset, |
|
int len, __wsum csum) |
|
{ |
|
const struct skb_checksum_ops ops = { |
|
.update = csum_partial_ext, |
|
.combine = csum_block_add_ext, |
|
}; |
|
|
|
return __skb_checksum(skb, offset, len, csum, &ops); |
|
} |
|
EXPORT_SYMBOL(skb_checksum); |
|
|
|
/* Both of above in one bottle. */ |
|
|
|
__wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, |
|
u8 *to, int len) |
|
{ |
|
int start = skb_headlen(skb); |
|
int i, copy = start - offset; |
|
struct sk_buff *frag_iter; |
|
int pos = 0; |
|
__wsum csum = 0; |
|
|
|
/* Copy header. */ |
|
if (copy > 0) { |
|
if (copy > len) |
|
copy = len; |
|
csum = csum_partial_copy_nocheck(skb->data + offset, to, |
|
copy); |
|
if ((len -= copy) == 0) |
|
return csum; |
|
offset += copy; |
|
to += copy; |
|
pos = copy; |
|
} |
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
if ((copy = end - offset) > 0) { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
|
u32 p_off, p_len, copied; |
|
struct page *p; |
|
__wsum csum2; |
|
u8 *vaddr; |
|
|
|
if (copy > len) |
|
copy = len; |
|
|
|
skb_frag_foreach_page(frag, |
|
skb_frag_off(frag) + offset - start, |
|
copy, p, p_off, p_len, copied) { |
|
vaddr = kmap_atomic(p); |
|
csum2 = csum_partial_copy_nocheck(vaddr + p_off, |
|
to + copied, |
|
p_len); |
|
kunmap_atomic(vaddr); |
|
csum = csum_block_add(csum, csum2, pos); |
|
pos += p_len; |
|
} |
|
|
|
if (!(len -= copy)) |
|
return csum; |
|
offset += copy; |
|
to += copy; |
|
} |
|
start = end; |
|
} |
|
|
|
skb_walk_frags(skb, frag_iter) { |
|
__wsum csum2; |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + frag_iter->len; |
|
if ((copy = end - offset) > 0) { |
|
if (copy > len) |
|
copy = len; |
|
csum2 = skb_copy_and_csum_bits(frag_iter, |
|
offset - start, |
|
to, copy); |
|
csum = csum_block_add(csum, csum2, pos); |
|
if ((len -= copy) == 0) |
|
return csum; |
|
offset += copy; |
|
to += copy; |
|
pos += copy; |
|
} |
|
start = end; |
|
} |
|
BUG_ON(len); |
|
return csum; |
|
} |
|
EXPORT_SYMBOL(skb_copy_and_csum_bits); |
|
|
|
__sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) |
|
{ |
|
__sum16 sum; |
|
|
|
sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); |
|
/* See comments in __skb_checksum_complete(). */ |
|
if (likely(!sum)) { |
|
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && |
|
!skb->csum_complete_sw) |
|
netdev_rx_csum_fault(skb->dev, skb); |
|
} |
|
if (!skb_shared(skb)) |
|
skb->csum_valid = !sum; |
|
return sum; |
|
} |
|
EXPORT_SYMBOL(__skb_checksum_complete_head); |
|
|
|
/* This function assumes skb->csum already holds pseudo header's checksum, |
|
* which has been changed from the hardware checksum, for example, by |
|
* __skb_checksum_validate_complete(). And, the original skb->csum must |
|
* have been validated unsuccessfully for CHECKSUM_COMPLETE case. |
|
* |
|
* It returns non-zero if the recomputed checksum is still invalid, otherwise |
|
* zero. The new checksum is stored back into skb->csum unless the skb is |
|
* shared. |
|
*/ |
|
__sum16 __skb_checksum_complete(struct sk_buff *skb) |
|
{ |
|
__wsum csum; |
|
__sum16 sum; |
|
|
|
csum = skb_checksum(skb, 0, skb->len, 0); |
|
|
|
sum = csum_fold(csum_add(skb->csum, csum)); |
|
/* This check is inverted, because we already knew the hardware |
|
* checksum is invalid before calling this function. So, if the |
|
* re-computed checksum is valid instead, then we have a mismatch |
|
* between the original skb->csum and skb_checksum(). This means either |
|
* the original hardware checksum is incorrect or we screw up skb->csum |
|
* when moving skb->data around. |
|
*/ |
|
if (likely(!sum)) { |
|
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && |
|
!skb->csum_complete_sw) |
|
netdev_rx_csum_fault(skb->dev, skb); |
|
} |
|
|
|
if (!skb_shared(skb)) { |
|
/* Save full packet checksum */ |
|
skb->csum = csum; |
|
skb->ip_summed = CHECKSUM_COMPLETE; |
|
skb->csum_complete_sw = 1; |
|
skb->csum_valid = !sum; |
|
} |
|
|
|
return sum; |
|
} |
|
EXPORT_SYMBOL(__skb_checksum_complete); |
|
|
|
static __wsum warn_crc32c_csum_update(const void *buff, int len, __wsum sum) |
|
{ |
|
net_warn_ratelimited( |
|
"%s: attempt to compute crc32c without libcrc32c.ko\n", |
|
__func__); |
|
return 0; |
|
} |
|
|
|
static __wsum warn_crc32c_csum_combine(__wsum csum, __wsum csum2, |
|
int offset, int len) |
|
{ |
|
net_warn_ratelimited( |
|
"%s: attempt to compute crc32c without libcrc32c.ko\n", |
|
__func__); |
|
return 0; |
|
} |
|
|
|
static const struct skb_checksum_ops default_crc32c_ops = { |
|
.update = warn_crc32c_csum_update, |
|
.combine = warn_crc32c_csum_combine, |
|
}; |
|
|
|
const struct skb_checksum_ops *crc32c_csum_stub __read_mostly = |
|
&default_crc32c_ops; |
|
EXPORT_SYMBOL(crc32c_csum_stub); |
|
|
|
/** |
|
* skb_zerocopy_headlen - Calculate headroom needed for skb_zerocopy() |
|
* @from: source buffer |
|
* |
|
* Calculates the amount of linear headroom needed in the 'to' skb passed |
|
* into skb_zerocopy(). |
|
*/ |
|
unsigned int |
|
skb_zerocopy_headlen(const struct sk_buff *from) |
|
{ |
|
unsigned int hlen = 0; |
|
|
|
if (!from->head_frag || |
|
skb_headlen(from) < L1_CACHE_BYTES || |
|
skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS) { |
|
hlen = skb_headlen(from); |
|
if (!hlen) |
|
hlen = from->len; |
|
} |
|
|
|
if (skb_has_frag_list(from)) |
|
hlen = from->len; |
|
|
|
return hlen; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_zerocopy_headlen); |
|
|
|
/** |
|
* skb_zerocopy - Zero copy skb to skb |
|
* @to: destination buffer |
|
* @from: source buffer |
|
* @len: number of bytes to copy from source buffer |
|
* @hlen: size of linear headroom in destination buffer |
|
* |
|
* Copies up to `len` bytes from `from` to `to` by creating references |
|
* to the frags in the source buffer. |
|
* |
|
* The `hlen` as calculated by skb_zerocopy_headlen() specifies the |
|
* headroom in the `to` buffer. |
|
* |
|
* Return value: |
|
* 0: everything is OK |
|
* -ENOMEM: couldn't orphan frags of @from due to lack of memory |
|
* -EFAULT: skb_copy_bits() found some problem with skb geometry |
|
*/ |
|
int |
|
skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) |
|
{ |
|
int i, j = 0; |
|
int plen = 0; /* length of skb->head fragment */ |
|
int ret; |
|
struct page *page; |
|
unsigned int offset; |
|
|
|
BUG_ON(!from->head_frag && !hlen); |
|
|
|
/* dont bother with small payloads */ |
|
if (len <= skb_tailroom(to)) |
|
return skb_copy_bits(from, 0, skb_put(to, len), len); |
|
|
|
if (hlen) { |
|
ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen); |
|
if (unlikely(ret)) |
|
return ret; |
|
len -= hlen; |
|
} else { |
|
plen = min_t(int, skb_headlen(from), len); |
|
if (plen) { |
|
page = virt_to_head_page(from->head); |
|
offset = from->data - (unsigned char *)page_address(page); |
|
__skb_fill_page_desc(to, 0, page, offset, plen); |
|
get_page(page); |
|
j = 1; |
|
len -= plen; |
|
} |
|
} |
|
|
|
to->truesize += len + plen; |
|
to->len += len + plen; |
|
to->data_len += len + plen; |
|
|
|
if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) { |
|
skb_tx_error(from); |
|
return -ENOMEM; |
|
} |
|
skb_zerocopy_clone(to, from, GFP_ATOMIC); |
|
|
|
for (i = 0; i < skb_shinfo(from)->nr_frags; i++) { |
|
int size; |
|
|
|
if (!len) |
|
break; |
|
skb_shinfo(to)->frags[j] = skb_shinfo(from)->frags[i]; |
|
size = min_t(int, skb_frag_size(&skb_shinfo(to)->frags[j]), |
|
len); |
|
skb_frag_size_set(&skb_shinfo(to)->frags[j], size); |
|
len -= size; |
|
skb_frag_ref(to, j); |
|
j++; |
|
} |
|
skb_shinfo(to)->nr_frags = j; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_zerocopy); |
|
|
|
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) |
|
{ |
|
__wsum csum; |
|
long csstart; |
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) |
|
csstart = skb_checksum_start_offset(skb); |
|
else |
|
csstart = skb_headlen(skb); |
|
|
|
BUG_ON(csstart > skb_headlen(skb)); |
|
|
|
skb_copy_from_linear_data(skb, to, csstart); |
|
|
|
csum = 0; |
|
if (csstart != skb->len) |
|
csum = skb_copy_and_csum_bits(skb, csstart, to + csstart, |
|
skb->len - csstart); |
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) { |
|
long csstuff = csstart + skb->csum_offset; |
|
|
|
*((__sum16 *)(to + csstuff)) = csum_fold(csum); |
|
} |
|
} |
|
EXPORT_SYMBOL(skb_copy_and_csum_dev); |
|
|
|
/** |
|
* skb_dequeue - remove from the head of the queue |
|
* @list: list to dequeue from |
|
* |
|
* Remove the head of the list. The list lock is taken so the function |
|
* may be used safely with other locking list functions. The head item is |
|
* returned or %NULL if the list is empty. |
|
*/ |
|
|
|
struct sk_buff *skb_dequeue(struct sk_buff_head *list) |
|
{ |
|
unsigned long flags; |
|
struct sk_buff *result; |
|
|
|
spin_lock_irqsave(&list->lock, flags); |
|
result = __skb_dequeue(list); |
|
spin_unlock_irqrestore(&list->lock, flags); |
|
return result; |
|
} |
|
EXPORT_SYMBOL(skb_dequeue); |
|
|
|
/** |
|
* skb_dequeue_tail - remove from the tail of the queue |
|
* @list: list to dequeue from |
|
* |
|
* Remove the tail of the list. The list lock is taken so the function |
|
* may be used safely with other locking list functions. The tail item is |
|
* returned or %NULL if the list is empty. |
|
*/ |
|
struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list) |
|
{ |
|
unsigned long flags; |
|
struct sk_buff *result; |
|
|
|
spin_lock_irqsave(&list->lock, flags); |
|
result = __skb_dequeue_tail(list); |
|
spin_unlock_irqrestore(&list->lock, flags); |
|
return result; |
|
} |
|
EXPORT_SYMBOL(skb_dequeue_tail); |
|
|
|
/** |
|
* skb_queue_purge - empty a list |
|
* @list: list to empty |
|
* |
|
* Delete all buffers on an &sk_buff list. Each buffer is removed from |
|
* the list and one reference dropped. This function takes the list |
|
* lock and is atomic with respect to other list locking functions. |
|
*/ |
|
void skb_queue_purge(struct sk_buff_head *list) |
|
{ |
|
struct sk_buff *skb; |
|
while ((skb = skb_dequeue(list)) != NULL) |
|
kfree_skb(skb); |
|
} |
|
EXPORT_SYMBOL(skb_queue_purge); |
|
|
|
/** |
|
* skb_rbtree_purge - empty a skb rbtree |
|
* @root: root of the rbtree to empty |
|
* Return value: the sum of truesizes of all purged skbs. |
|
* |
|
* Delete all buffers on an &sk_buff rbtree. Each buffer is removed from |
|
* the list and one reference dropped. This function does not take |
|
* any lock. Synchronization should be handled by the caller (e.g., TCP |
|
* out-of-order queue is protected by the socket lock). |
|
*/ |
|
unsigned int skb_rbtree_purge(struct rb_root *root) |
|
{ |
|
struct rb_node *p = rb_first(root); |
|
unsigned int sum = 0; |
|
|
|
while (p) { |
|
struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode); |
|
|
|
p = rb_next(p); |
|
rb_erase(&skb->rbnode, root); |
|
sum += skb->truesize; |
|
kfree_skb(skb); |
|
} |
|
return sum; |
|
} |
|
|
|
/** |
|
* skb_queue_head - queue a buffer at the list head |
|
* @list: list to use |
|
* @newsk: buffer to queue |
|
* |
|
* Queue a buffer at the start of the list. This function takes the |
|
* list lock and can be used safely with other locking &sk_buff functions |
|
* safely. |
|
* |
|
* A buffer cannot be placed on two lists at the same time. |
|
*/ |
|
void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&list->lock, flags); |
|
__skb_queue_head(list, newsk); |
|
spin_unlock_irqrestore(&list->lock, flags); |
|
} |
|
EXPORT_SYMBOL(skb_queue_head); |
|
|
|
/** |
|
* skb_queue_tail - queue a buffer at the list tail |
|
* @list: list to use |
|
* @newsk: buffer to queue |
|
* |
|
* Queue a buffer at the tail of the list. This function takes the |
|
* list lock and can be used safely with other locking &sk_buff functions |
|
* safely. |
|
* |
|
* A buffer cannot be placed on two lists at the same time. |
|
*/ |
|
void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&list->lock, flags); |
|
__skb_queue_tail(list, newsk); |
|
spin_unlock_irqrestore(&list->lock, flags); |
|
} |
|
EXPORT_SYMBOL(skb_queue_tail); |
|
|
|
/** |
|
* skb_unlink - remove a buffer from a list |
|
* @skb: buffer to remove |
|
* @list: list to use |
|
* |
|
* Remove a packet from a list. The list locks are taken and this |
|
* function is atomic with respect to other list locked calls |
|
* |
|
* You must know what list the SKB is on. |
|
*/ |
|
void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&list->lock, flags); |
|
__skb_unlink(skb, list); |
|
spin_unlock_irqrestore(&list->lock, flags); |
|
} |
|
EXPORT_SYMBOL(skb_unlink); |
|
|
|
/** |
|
* skb_append - append a buffer |
|
* @old: buffer to insert after |
|
* @newsk: buffer to insert |
|
* @list: list to use |
|
* |
|
* Place a packet after a given packet in a list. The list locks are taken |
|
* and this function is atomic with respect to other list locked calls. |
|
* A buffer cannot be placed on two lists at the same time. |
|
*/ |
|
void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&list->lock, flags); |
|
__skb_queue_after(list, old, newsk); |
|
spin_unlock_irqrestore(&list->lock, flags); |
|
} |
|
EXPORT_SYMBOL(skb_append); |
|
|
|
static inline void skb_split_inside_header(struct sk_buff *skb, |
|
struct sk_buff* skb1, |
|
const u32 len, const int pos) |
|
{ |
|
int i; |
|
|
|
skb_copy_from_linear_data_offset(skb, len, skb_put(skb1, pos - len), |
|
pos - len); |
|
/* And move data appendix as is. */ |
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
|
skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i]; |
|
|
|
skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags; |
|
skb_shinfo(skb)->nr_frags = 0; |
|
skb1->data_len = skb->data_len; |
|
skb1->len += skb1->data_len; |
|
skb->data_len = 0; |
|
skb->len = len; |
|
skb_set_tail_pointer(skb, len); |
|
} |
|
|
|
static inline void skb_split_no_header(struct sk_buff *skb, |
|
struct sk_buff* skb1, |
|
const u32 len, int pos) |
|
{ |
|
int i, k = 0; |
|
const int nfrags = skb_shinfo(skb)->nr_frags; |
|
|
|
skb_shinfo(skb)->nr_frags = 0; |
|
skb1->len = skb1->data_len = skb->len - len; |
|
skb->len = len; |
|
skb->data_len = len - pos; |
|
|
|
for (i = 0; i < nfrags; i++) { |
|
int size = skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
|
|
if (pos + size > len) { |
|
skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i]; |
|
|
|
if (pos < len) { |
|
/* Split frag. |
|
* We have two variants in this case: |
|
* 1. Move all the frag to the second |
|
* part, if it is possible. F.e. |
|
* this approach is mandatory for TUX, |
|
* where splitting is expensive. |
|
* 2. Split is accurately. We make this. |
|
*/ |
|
skb_frag_ref(skb, i); |
|
skb_frag_off_add(&skb_shinfo(skb1)->frags[0], len - pos); |
|
skb_frag_size_sub(&skb_shinfo(skb1)->frags[0], len - pos); |
|
skb_frag_size_set(&skb_shinfo(skb)->frags[i], len - pos); |
|
skb_shinfo(skb)->nr_frags++; |
|
} |
|
k++; |
|
} else |
|
skb_shinfo(skb)->nr_frags++; |
|
pos += size; |
|
} |
|
skb_shinfo(skb1)->nr_frags = k; |
|
} |
|
|
|
/** |
|
* skb_split - Split fragmented skb to two parts at length len. |
|
* @skb: the buffer to split |
|
* @skb1: the buffer to receive the second part |
|
* @len: new length for skb |
|
*/ |
|
void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) |
|
{ |
|
int pos = skb_headlen(skb); |
|
const int zc_flags = SKBFL_SHARED_FRAG | SKBFL_PURE_ZEROCOPY; |
|
|
|
skb_shinfo(skb1)->flags |= skb_shinfo(skb)->flags & zc_flags; |
|
skb_zerocopy_clone(skb1, skb, 0); |
|
if (len < pos) /* Split line is inside header. */ |
|
skb_split_inside_header(skb, skb1, len, pos); |
|
else /* Second chunk has no header, nothing to copy. */ |
|
skb_split_no_header(skb, skb1, len, pos); |
|
} |
|
EXPORT_SYMBOL(skb_split); |
|
|
|
/* Shifting from/to a cloned skb is a no-go. |
|
* |
|
* Caller cannot keep skb_shinfo related pointers past calling here! |
|
*/ |
|
static int skb_prepare_for_shift(struct sk_buff *skb) |
|
{ |
|
return skb_unclone_keeptruesize(skb, GFP_ATOMIC); |
|
} |
|
|
|
/** |
|
* skb_shift - Shifts paged data partially from skb to another |
|
* @tgt: buffer into which tail data gets added |
|
* @skb: buffer from which the paged data comes from |
|
* @shiftlen: shift up to this many bytes |
|
* |
|
* Attempts to shift up to shiftlen worth of bytes, which may be less than |
|
* the length of the skb, from skb to tgt. Returns number bytes shifted. |
|
* It's up to caller to free skb if everything was shifted. |
|
* |
|
* If @tgt runs out of frags, the whole operation is aborted. |
|
* |
|
* Skb cannot include anything else but paged data while tgt is allowed |
|
* to have non-paged data as well. |
|
* |
|
* TODO: full sized shift could be optimized but that would need |
|
* specialized skb free'er to handle frags without up-to-date nr_frags. |
|
*/ |
|
int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) |
|
{ |
|
int from, to, merge, todo; |
|
skb_frag_t *fragfrom, *fragto; |
|
|
|
BUG_ON(shiftlen > skb->len); |
|
|
|
if (skb_headlen(skb)) |
|
return 0; |
|
if (skb_zcopy(tgt) || skb_zcopy(skb)) |
|
return 0; |
|
|
|
todo = shiftlen; |
|
from = 0; |
|
to = skb_shinfo(tgt)->nr_frags; |
|
fragfrom = &skb_shinfo(skb)->frags[from]; |
|
|
|
/* Actual merge is delayed until the point when we know we can |
|
* commit all, so that we don't have to undo partial changes |
|
*/ |
|
if (!to || |
|
!skb_can_coalesce(tgt, to, skb_frag_page(fragfrom), |
|
skb_frag_off(fragfrom))) { |
|
merge = -1; |
|
} else { |
|
merge = to - 1; |
|
|
|
todo -= skb_frag_size(fragfrom); |
|
if (todo < 0) { |
|
if (skb_prepare_for_shift(skb) || |
|
skb_prepare_for_shift(tgt)) |
|
return 0; |
|
|
|
/* All previous frag pointers might be stale! */ |
|
fragfrom = &skb_shinfo(skb)->frags[from]; |
|
fragto = &skb_shinfo(tgt)->frags[merge]; |
|
|
|
skb_frag_size_add(fragto, shiftlen); |
|
skb_frag_size_sub(fragfrom, shiftlen); |
|
skb_frag_off_add(fragfrom, shiftlen); |
|
|
|
goto onlymerged; |
|
} |
|
|
|
from++; |
|
} |
|
|
|
/* Skip full, not-fitting skb to avoid expensive operations */ |
|
if ((shiftlen == skb->len) && |
|
(skb_shinfo(skb)->nr_frags - from) > (MAX_SKB_FRAGS - to)) |
|
return 0; |
|
|
|
if (skb_prepare_for_shift(skb) || skb_prepare_for_shift(tgt)) |
|
return 0; |
|
|
|
while ((todo > 0) && (from < skb_shinfo(skb)->nr_frags)) { |
|
if (to == MAX_SKB_FRAGS) |
|
return 0; |
|
|
|
fragfrom = &skb_shinfo(skb)->frags[from]; |
|
fragto = &skb_shinfo(tgt)->frags[to]; |
|
|
|
if (todo >= skb_frag_size(fragfrom)) { |
|
*fragto = *fragfrom; |
|
todo -= skb_frag_size(fragfrom); |
|
from++; |
|
to++; |
|
|
|
} else { |
|
__skb_frag_ref(fragfrom); |
|
skb_frag_page_copy(fragto, fragfrom); |
|
skb_frag_off_copy(fragto, fragfrom); |
|
skb_frag_size_set(fragto, todo); |
|
|
|
skb_frag_off_add(fragfrom, todo); |
|
skb_frag_size_sub(fragfrom, todo); |
|
todo = 0; |
|
|
|
to++; |
|
break; |
|
} |
|
} |
|
|
|
/* Ready to "commit" this state change to tgt */ |
|
skb_shinfo(tgt)->nr_frags = to; |
|
|
|
if (merge >= 0) { |
|
fragfrom = &skb_shinfo(skb)->frags[0]; |
|
fragto = &skb_shinfo(tgt)->frags[merge]; |
|
|
|
skb_frag_size_add(fragto, skb_frag_size(fragfrom)); |
|
__skb_frag_unref(fragfrom, skb->pp_recycle); |
|
} |
|
|
|
/* Reposition in the original skb */ |
|
to = 0; |
|
while (from < skb_shinfo(skb)->nr_frags) |
|
skb_shinfo(skb)->frags[to++] = skb_shinfo(skb)->frags[from++]; |
|
skb_shinfo(skb)->nr_frags = to; |
|
|
|
BUG_ON(todo > 0 && !skb_shinfo(skb)->nr_frags); |
|
|
|
onlymerged: |
|
/* Most likely the tgt won't ever need its checksum anymore, skb on |
|
* the other hand might need it if it needs to be resent |
|
*/ |
|
tgt->ip_summed = CHECKSUM_PARTIAL; |
|
skb->ip_summed = CHECKSUM_PARTIAL; |
|
|
|
/* Yak, is it really working this way? Some helper please? */ |
|
skb->len -= shiftlen; |
|
skb->data_len -= shiftlen; |
|
skb->truesize -= shiftlen; |
|
tgt->len += shiftlen; |
|
tgt->data_len += shiftlen; |
|
tgt->truesize += shiftlen; |
|
|
|
return shiftlen; |
|
} |
|
|
|
/** |
|
* skb_prepare_seq_read - Prepare a sequential read of skb data |
|
* @skb: the buffer to read |
|
* @from: lower offset of data to be read |
|
* @to: upper offset of data to be read |
|
* @st: state variable |
|
* |
|
* Initializes the specified state variable. Must be called before |
|
* invoking skb_seq_read() for the first time. |
|
*/ |
|
void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, |
|
unsigned int to, struct skb_seq_state *st) |
|
{ |
|
st->lower_offset = from; |
|
st->upper_offset = to; |
|
st->root_skb = st->cur_skb = skb; |
|
st->frag_idx = st->stepped_offset = 0; |
|
st->frag_data = NULL; |
|
st->frag_off = 0; |
|
} |
|
EXPORT_SYMBOL(skb_prepare_seq_read); |
|
|
|
/** |
|
* skb_seq_read - Sequentially read skb data |
|
* @consumed: number of bytes consumed by the caller so far |
|
* @data: destination pointer for data to be returned |
|
* @st: state variable |
|
* |
|
* Reads a block of skb data at @consumed relative to the |
|
* lower offset specified to skb_prepare_seq_read(). Assigns |
|
* the head of the data block to @data and returns the length |
|
* of the block or 0 if the end of the skb data or the upper |
|
* offset has been reached. |
|
* |
|
* The caller is not required to consume all of the data |
|
* returned, i.e. @consumed is typically set to the number |
|
* of bytes already consumed and the next call to |
|
* skb_seq_read() will return the remaining part of the block. |
|
* |
|
* Note 1: The size of each block of data returned can be arbitrary, |
|
* this limitation is the cost for zerocopy sequential |
|
* reads of potentially non linear data. |
|
* |
|
* Note 2: Fragment lists within fragments are not implemented |
|
* at the moment, state->root_skb could be replaced with |
|
* a stack for this purpose. |
|
*/ |
|
unsigned int skb_seq_read(unsigned int consumed, const u8 **data, |
|
struct skb_seq_state *st) |
|
{ |
|
unsigned int block_limit, abs_offset = consumed + st->lower_offset; |
|
skb_frag_t *frag; |
|
|
|
if (unlikely(abs_offset >= st->upper_offset)) { |
|
if (st->frag_data) { |
|
kunmap_atomic(st->frag_data); |
|
st->frag_data = NULL; |
|
} |
|
return 0; |
|
} |
|
|
|
next_skb: |
|
block_limit = skb_headlen(st->cur_skb) + st->stepped_offset; |
|
|
|
if (abs_offset < block_limit && !st->frag_data) { |
|
*data = st->cur_skb->data + (abs_offset - st->stepped_offset); |
|
return block_limit - abs_offset; |
|
} |
|
|
|
if (st->frag_idx == 0 && !st->frag_data) |
|
st->stepped_offset += skb_headlen(st->cur_skb); |
|
|
|
while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) { |
|
unsigned int pg_idx, pg_off, pg_sz; |
|
|
|
frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx]; |
|
|
|
pg_idx = 0; |
|
pg_off = skb_frag_off(frag); |
|
pg_sz = skb_frag_size(frag); |
|
|
|
if (skb_frag_must_loop(skb_frag_page(frag))) { |
|
pg_idx = (pg_off + st->frag_off) >> PAGE_SHIFT; |
|
pg_off = offset_in_page(pg_off + st->frag_off); |
|
pg_sz = min_t(unsigned int, pg_sz - st->frag_off, |
|
PAGE_SIZE - pg_off); |
|
} |
|
|
|
block_limit = pg_sz + st->stepped_offset; |
|
if (abs_offset < block_limit) { |
|
if (!st->frag_data) |
|
st->frag_data = kmap_atomic(skb_frag_page(frag) + pg_idx); |
|
|
|
*data = (u8 *)st->frag_data + pg_off + |
|
(abs_offset - st->stepped_offset); |
|
|
|
return block_limit - abs_offset; |
|
} |
|
|
|
if (st->frag_data) { |
|
kunmap_atomic(st->frag_data); |
|
st->frag_data = NULL; |
|
} |
|
|
|
st->stepped_offset += pg_sz; |
|
st->frag_off += pg_sz; |
|
if (st->frag_off == skb_frag_size(frag)) { |
|
st->frag_off = 0; |
|
st->frag_idx++; |
|
} |
|
} |
|
|
|
if (st->frag_data) { |
|
kunmap_atomic(st->frag_data); |
|
st->frag_data = NULL; |
|
} |
|
|
|
if (st->root_skb == st->cur_skb && skb_has_frag_list(st->root_skb)) { |
|
st->cur_skb = skb_shinfo(st->root_skb)->frag_list; |
|
st->frag_idx = 0; |
|
goto next_skb; |
|
} else if (st->cur_skb->next) { |
|
st->cur_skb = st->cur_skb->next; |
|
st->frag_idx = 0; |
|
goto next_skb; |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL(skb_seq_read); |
|
|
|
/** |
|
* skb_abort_seq_read - Abort a sequential read of skb data |
|
* @st: state variable |
|
* |
|
* Must be called if skb_seq_read() was not called until it |
|
* returned 0. |
|
*/ |
|
void skb_abort_seq_read(struct skb_seq_state *st) |
|
{ |
|
if (st->frag_data) |
|
kunmap_atomic(st->frag_data); |
|
} |
|
EXPORT_SYMBOL(skb_abort_seq_read); |
|
|
|
#define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb)) |
|
|
|
static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text, |
|
struct ts_config *conf, |
|
struct ts_state *state) |
|
{ |
|
return skb_seq_read(offset, text, TS_SKB_CB(state)); |
|
} |
|
|
|
static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) |
|
{ |
|
skb_abort_seq_read(TS_SKB_CB(state)); |
|
} |
|
|
|
/** |
|
* skb_find_text - Find a text pattern in skb data |
|
* @skb: the buffer to look in |
|
* @from: search offset |
|
* @to: search limit |
|
* @config: textsearch configuration |
|
* |
|
* Finds a pattern in the skb data according to the specified |
|
* textsearch configuration. Use textsearch_next() to retrieve |
|
* subsequent occurrences of the pattern. Returns the offset |
|
* to the first occurrence or UINT_MAX if no match was found. |
|
*/ |
|
unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, |
|
unsigned int to, struct ts_config *config) |
|
{ |
|
struct ts_state state; |
|
unsigned int ret; |
|
|
|
BUILD_BUG_ON(sizeof(struct skb_seq_state) > sizeof(state.cb)); |
|
|
|
config->get_next_block = skb_ts_get_next_block; |
|
config->finish = skb_ts_finish; |
|
|
|
skb_prepare_seq_read(skb, from, to, TS_SKB_CB(&state)); |
|
|
|
ret = textsearch_find(config, &state); |
|
return (ret <= to - from ? ret : UINT_MAX); |
|
} |
|
EXPORT_SYMBOL(skb_find_text); |
|
|
|
int skb_append_pagefrags(struct sk_buff *skb, struct page *page, |
|
int offset, size_t size) |
|
{ |
|
int i = skb_shinfo(skb)->nr_frags; |
|
|
|
if (skb_can_coalesce(skb, i, page, offset)) { |
|
skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); |
|
} else if (i < MAX_SKB_FRAGS) { |
|
get_page(page); |
|
skb_fill_page_desc(skb, i, page, offset, size); |
|
} else { |
|
return -EMSGSIZE; |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_append_pagefrags); |
|
|
|
/** |
|
* skb_pull_rcsum - pull skb and update receive checksum |
|
* @skb: buffer to update |
|
* @len: length of data pulled |
|
* |
|
* This function performs an skb_pull on the packet and updates |
|
* the CHECKSUM_COMPLETE checksum. It should be used on |
|
* receive path processing instead of skb_pull unless you know |
|
* that the checksum difference is zero (e.g., a valid IP header) |
|
* or you are setting ip_summed to CHECKSUM_NONE. |
|
*/ |
|
void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len) |
|
{ |
|
unsigned char *data = skb->data; |
|
|
|
BUG_ON(len > skb->len); |
|
__skb_pull(skb, len); |
|
skb_postpull_rcsum(skb, data, len); |
|
return skb->data; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_pull_rcsum); |
|
|
|
static inline skb_frag_t skb_head_frag_to_page_desc(struct sk_buff *frag_skb) |
|
{ |
|
skb_frag_t head_frag; |
|
struct page *page; |
|
|
|
page = virt_to_head_page(frag_skb->head); |
|
__skb_frag_set_page(&head_frag, page); |
|
skb_frag_off_set(&head_frag, frag_skb->data - |
|
(unsigned char *)page_address(page)); |
|
skb_frag_size_set(&head_frag, skb_headlen(frag_skb)); |
|
return head_frag; |
|
} |
|
|
|
struct sk_buff *skb_segment_list(struct sk_buff *skb, |
|
netdev_features_t features, |
|
unsigned int offset) |
|
{ |
|
struct sk_buff *list_skb = skb_shinfo(skb)->frag_list; |
|
unsigned int tnl_hlen = skb_tnl_header_len(skb); |
|
unsigned int delta_truesize = 0; |
|
unsigned int delta_len = 0; |
|
struct sk_buff *tail = NULL; |
|
struct sk_buff *nskb, *tmp; |
|
int err; |
|
|
|
skb_push(skb, -skb_network_offset(skb) + offset); |
|
|
|
skb_shinfo(skb)->frag_list = NULL; |
|
|
|
do { |
|
nskb = list_skb; |
|
list_skb = list_skb->next; |
|
|
|
err = 0; |
|
if (skb_shared(nskb)) { |
|
tmp = skb_clone(nskb, GFP_ATOMIC); |
|
if (tmp) { |
|
consume_skb(nskb); |
|
nskb = tmp; |
|
err = skb_unclone(nskb, GFP_ATOMIC); |
|
} else { |
|
err = -ENOMEM; |
|
} |
|
} |
|
|
|
if (!tail) |
|
skb->next = nskb; |
|
else |
|
tail->next = nskb; |
|
|
|
if (unlikely(err)) { |
|
nskb->next = list_skb; |
|
goto err_linearize; |
|
} |
|
|
|
tail = nskb; |
|
|
|
delta_len += nskb->len; |
|
delta_truesize += nskb->truesize; |
|
|
|
skb_push(nskb, -skb_network_offset(nskb) + offset); |
|
|
|
skb_release_head_state(nskb); |
|
__copy_skb_header(nskb, skb); |
|
|
|
skb_headers_offset_update(nskb, skb_headroom(nskb) - skb_headroom(skb)); |
|
skb_copy_from_linear_data_offset(skb, -tnl_hlen, |
|
nskb->data - tnl_hlen, |
|
offset + tnl_hlen); |
|
|
|
if (skb_needs_linearize(nskb, features) && |
|
__skb_linearize(nskb)) |
|
goto err_linearize; |
|
|
|
} while (list_skb); |
|
|
|
skb->truesize = skb->truesize - delta_truesize; |
|
skb->data_len = skb->data_len - delta_len; |
|
skb->len = skb->len - delta_len; |
|
|
|
skb_gso_reset(skb); |
|
|
|
skb->prev = tail; |
|
|
|
if (skb_needs_linearize(skb, features) && |
|
__skb_linearize(skb)) |
|
goto err_linearize; |
|
|
|
skb_get(skb); |
|
|
|
return skb; |
|
|
|
err_linearize: |
|
kfree_skb_list(skb->next); |
|
skb->next = NULL; |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_segment_list); |
|
|
|
/** |
|
* skb_segment - Perform protocol segmentation on skb. |
|
* @head_skb: buffer to segment |
|
* @features: features for the output path (see dev->features) |
|
* |
|
* This function performs segmentation on the given skb. It returns |
|
* a pointer to the first in a list of new skbs for the segments. |
|
* In case of error it returns ERR_PTR(err). |
|
*/ |
|
struct sk_buff *skb_segment(struct sk_buff *head_skb, |
|
netdev_features_t features) |
|
{ |
|
struct sk_buff *segs = NULL; |
|
struct sk_buff *tail = NULL; |
|
struct sk_buff *list_skb = skb_shinfo(head_skb)->frag_list; |
|
skb_frag_t *frag = skb_shinfo(head_skb)->frags; |
|
unsigned int mss = skb_shinfo(head_skb)->gso_size; |
|
unsigned int doffset = head_skb->data - skb_mac_header(head_skb); |
|
struct sk_buff *frag_skb = head_skb; |
|
unsigned int offset = doffset; |
|
unsigned int tnl_hlen = skb_tnl_header_len(head_skb); |
|
unsigned int partial_segs = 0; |
|
unsigned int headroom; |
|
unsigned int len = head_skb->len; |
|
__be16 proto; |
|
bool csum, sg; |
|
int nfrags = skb_shinfo(head_skb)->nr_frags; |
|
int err = -ENOMEM; |
|
int i = 0; |
|
int pos; |
|
|
|
if (list_skb && !list_skb->head_frag && skb_headlen(list_skb) && |
|
(skb_shinfo(head_skb)->gso_type & SKB_GSO_DODGY)) { |
|
/* gso_size is untrusted, and we have a frag_list with a linear |
|
* non head_frag head. |
|
* |
|
* (we assume checking the first list_skb member suffices; |
|
* i.e if either of the list_skb members have non head_frag |
|
* head, then the first one has too). |
|
* |
|
* If head_skb's headlen does not fit requested gso_size, it |
|
* means that the frag_list members do NOT terminate on exact |
|
* gso_size boundaries. Hence we cannot perform skb_frag_t page |
|
* sharing. Therefore we must fallback to copying the frag_list |
|
* skbs; we do so by disabling SG. |
|
*/ |
|
if (mss != GSO_BY_FRAGS && mss != skb_headlen(head_skb)) |
|
features &= ~NETIF_F_SG; |
|
} |
|
|
|
__skb_push(head_skb, doffset); |
|
proto = skb_network_protocol(head_skb, NULL); |
|
if (unlikely(!proto)) |
|
return ERR_PTR(-EINVAL); |
|
|
|
sg = !!(features & NETIF_F_SG); |
|
csum = !!can_checksum_protocol(features, proto); |
|
|
|
if (sg && csum && (mss != GSO_BY_FRAGS)) { |
|
if (!(features & NETIF_F_GSO_PARTIAL)) { |
|
struct sk_buff *iter; |
|
unsigned int frag_len; |
|
|
|
if (!list_skb || |
|
!net_gso_ok(features, skb_shinfo(head_skb)->gso_type)) |
|
goto normal; |
|
|
|
/* If we get here then all the required |
|
* GSO features except frag_list are supported. |
|
* Try to split the SKB to multiple GSO SKBs |
|
* with no frag_list. |
|
* Currently we can do that only when the buffers don't |
|
* have a linear part and all the buffers except |
|
* the last are of the same length. |
|
*/ |
|
frag_len = list_skb->len; |
|
skb_walk_frags(head_skb, iter) { |
|
if (frag_len != iter->len && iter->next) |
|
goto normal; |
|
if (skb_headlen(iter) && !iter->head_frag) |
|
goto normal; |
|
|
|
len -= iter->len; |
|
} |
|
|
|
if (len != frag_len) |
|
goto normal; |
|
} |
|
|
|
/* GSO partial only requires that we trim off any excess that |
|
* doesn't fit into an MSS sized block, so take care of that |
|
* now. |
|
*/ |
|
partial_segs = len / mss; |
|
if (partial_segs > 1) |
|
mss *= partial_segs; |
|
else |
|
partial_segs = 0; |
|
} |
|
|
|
normal: |
|
headroom = skb_headroom(head_skb); |
|
pos = skb_headlen(head_skb); |
|
|
|
do { |
|
struct sk_buff *nskb; |
|
skb_frag_t *nskb_frag; |
|
int hsize; |
|
int size; |
|
|
|
if (unlikely(mss == GSO_BY_FRAGS)) { |
|
len = list_skb->len; |
|
} else { |
|
len = head_skb->len - offset; |
|
if (len > mss) |
|
len = mss; |
|
} |
|
|
|
hsize = skb_headlen(head_skb) - offset; |
|
|
|
if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) && |
|
(skb_headlen(list_skb) == len || sg)) { |
|
BUG_ON(skb_headlen(list_skb) > len); |
|
|
|
i = 0; |
|
nfrags = skb_shinfo(list_skb)->nr_frags; |
|
frag = skb_shinfo(list_skb)->frags; |
|
frag_skb = list_skb; |
|
pos += skb_headlen(list_skb); |
|
|
|
while (pos < offset + len) { |
|
BUG_ON(i >= nfrags); |
|
|
|
size = skb_frag_size(frag); |
|
if (pos + size > offset + len) |
|
break; |
|
|
|
i++; |
|
pos += size; |
|
frag++; |
|
} |
|
|
|
nskb = skb_clone(list_skb, GFP_ATOMIC); |
|
list_skb = list_skb->next; |
|
|
|
if (unlikely(!nskb)) |
|
goto err; |
|
|
|
if (unlikely(pskb_trim(nskb, len))) { |
|
kfree_skb(nskb); |
|
goto err; |
|
} |
|
|
|
hsize = skb_end_offset(nskb); |
|
if (skb_cow_head(nskb, doffset + headroom)) { |
|
kfree_skb(nskb); |
|
goto err; |
|
} |
|
|
|
nskb->truesize += skb_end_offset(nskb) - hsize; |
|
skb_release_head_state(nskb); |
|
__skb_push(nskb, doffset); |
|
} else { |
|
if (hsize < 0) |
|
hsize = 0; |
|
if (hsize > len || !sg) |
|
hsize = len; |
|
|
|
nskb = __alloc_skb(hsize + doffset + headroom, |
|
GFP_ATOMIC, skb_alloc_rx_flag(head_skb), |
|
NUMA_NO_NODE); |
|
|
|
if (unlikely(!nskb)) |
|
goto err; |
|
|
|
skb_reserve(nskb, headroom); |
|
__skb_put(nskb, doffset); |
|
} |
|
|
|
if (segs) |
|
tail->next = nskb; |
|
else |
|
segs = nskb; |
|
tail = nskb; |
|
|
|
__copy_skb_header(nskb, head_skb); |
|
|
|
skb_headers_offset_update(nskb, skb_headroom(nskb) - headroom); |
|
skb_reset_mac_len(nskb); |
|
|
|
skb_copy_from_linear_data_offset(head_skb, -tnl_hlen, |
|
nskb->data - tnl_hlen, |
|
doffset + tnl_hlen); |
|
|
|
if (nskb->len == len + doffset) |
|
goto perform_csum_check; |
|
|
|
if (!sg) { |
|
if (!csum) { |
|
if (!nskb->remcsum_offload) |
|
nskb->ip_summed = CHECKSUM_NONE; |
|
SKB_GSO_CB(nskb)->csum = |
|
skb_copy_and_csum_bits(head_skb, offset, |
|
skb_put(nskb, |
|
len), |
|
len); |
|
SKB_GSO_CB(nskb)->csum_start = |
|
skb_headroom(nskb) + doffset; |
|
} else { |
|
skb_copy_bits(head_skb, offset, |
|
skb_put(nskb, len), |
|
len); |
|
} |
|
continue; |
|
} |
|
|
|
nskb_frag = skb_shinfo(nskb)->frags; |
|
|
|
skb_copy_from_linear_data_offset(head_skb, offset, |
|
skb_put(nskb, hsize), hsize); |
|
|
|
skb_shinfo(nskb)->flags |= skb_shinfo(head_skb)->flags & |
|
SKBFL_SHARED_FRAG; |
|
|
|
if (skb_orphan_frags(frag_skb, GFP_ATOMIC) || |
|
skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC)) |
|
goto err; |
|
|
|
while (pos < offset + len) { |
|
if (i >= nfrags) { |
|
i = 0; |
|
nfrags = skb_shinfo(list_skb)->nr_frags; |
|
frag = skb_shinfo(list_skb)->frags; |
|
frag_skb = list_skb; |
|
if (!skb_headlen(list_skb)) { |
|
BUG_ON(!nfrags); |
|
} else { |
|
BUG_ON(!list_skb->head_frag); |
|
|
|
/* to make room for head_frag. */ |
|
i--; |
|
frag--; |
|
} |
|
if (skb_orphan_frags(frag_skb, GFP_ATOMIC) || |
|
skb_zerocopy_clone(nskb, frag_skb, |
|
GFP_ATOMIC)) |
|
goto err; |
|
|
|
list_skb = list_skb->next; |
|
} |
|
|
|
if (unlikely(skb_shinfo(nskb)->nr_frags >= |
|
MAX_SKB_FRAGS)) { |
|
net_warn_ratelimited( |
|
"skb_segment: too many frags: %u %u\n", |
|
pos, mss); |
|
err = -EINVAL; |
|
goto err; |
|
} |
|
|
|
*nskb_frag = (i < 0) ? skb_head_frag_to_page_desc(frag_skb) : *frag; |
|
__skb_frag_ref(nskb_frag); |
|
size = skb_frag_size(nskb_frag); |
|
|
|
if (pos < offset) { |
|
skb_frag_off_add(nskb_frag, offset - pos); |
|
skb_frag_size_sub(nskb_frag, offset - pos); |
|
} |
|
|
|
skb_shinfo(nskb)->nr_frags++; |
|
|
|
if (pos + size <= offset + len) { |
|
i++; |
|
frag++; |
|
pos += size; |
|
} else { |
|
skb_frag_size_sub(nskb_frag, pos + size - (offset + len)); |
|
goto skip_fraglist; |
|
} |
|
|
|
nskb_frag++; |
|
} |
|
|
|
skip_fraglist: |
|
nskb->data_len = len - hsize; |
|
nskb->len += nskb->data_len; |
|
nskb->truesize += nskb->data_len; |
|
|
|
perform_csum_check: |
|
if (!csum) { |
|
if (skb_has_shared_frag(nskb) && |
|
__skb_linearize(nskb)) |
|
goto err; |
|
|
|
if (!nskb->remcsum_offload) |
|
nskb->ip_summed = CHECKSUM_NONE; |
|
SKB_GSO_CB(nskb)->csum = |
|
skb_checksum(nskb, doffset, |
|
nskb->len - doffset, 0); |
|
SKB_GSO_CB(nskb)->csum_start = |
|
skb_headroom(nskb) + doffset; |
|
} |
|
} while ((offset += len) < head_skb->len); |
|
|
|
/* Some callers want to get the end of the list. |
|
* Put it in segs->prev to avoid walking the list. |
|
* (see validate_xmit_skb_list() for example) |
|
*/ |
|
segs->prev = tail; |
|
|
|
if (partial_segs) { |
|
struct sk_buff *iter; |
|
int type = skb_shinfo(head_skb)->gso_type; |
|
unsigned short gso_size = skb_shinfo(head_skb)->gso_size; |
|
|
|
/* Update type to add partial and then remove dodgy if set */ |
|
type |= (features & NETIF_F_GSO_PARTIAL) / NETIF_F_GSO_PARTIAL * SKB_GSO_PARTIAL; |
|
type &= ~SKB_GSO_DODGY; |
|
|
|
/* Update GSO info and prepare to start updating headers on |
|
* our way back down the stack of protocols. |
|
*/ |
|
for (iter = segs; iter; iter = iter->next) { |
|
skb_shinfo(iter)->gso_size = gso_size; |
|
skb_shinfo(iter)->gso_segs = partial_segs; |
|
skb_shinfo(iter)->gso_type = type; |
|
SKB_GSO_CB(iter)->data_offset = skb_headroom(iter) + doffset; |
|
} |
|
|
|
if (tail->len - doffset <= gso_size) |
|
skb_shinfo(tail)->gso_size = 0; |
|
else if (tail != segs) |
|
skb_shinfo(tail)->gso_segs = DIV_ROUND_UP(tail->len - doffset, gso_size); |
|
} |
|
|
|
/* Following permits correct backpressure, for protocols |
|
* using skb_set_owner_w(). |
|
* Idea is to tranfert ownership from head_skb to last segment. |
|
*/ |
|
if (head_skb->destructor == sock_wfree) { |
|
swap(tail->truesize, head_skb->truesize); |
|
swap(tail->destructor, head_skb->destructor); |
|
swap(tail->sk, head_skb->sk); |
|
} |
|
return segs; |
|
|
|
err: |
|
kfree_skb_list(segs); |
|
return ERR_PTR(err); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_segment); |
|
|
|
#ifdef CONFIG_SKB_EXTENSIONS |
|
#define SKB_EXT_ALIGN_VALUE 8 |
|
#define SKB_EXT_CHUNKSIZEOF(x) (ALIGN((sizeof(x)), SKB_EXT_ALIGN_VALUE) / SKB_EXT_ALIGN_VALUE) |
|
|
|
static const u8 skb_ext_type_len[] = { |
|
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
|
[SKB_EXT_BRIDGE_NF] = SKB_EXT_CHUNKSIZEOF(struct nf_bridge_info), |
|
#endif |
|
#ifdef CONFIG_XFRM |
|
[SKB_EXT_SEC_PATH] = SKB_EXT_CHUNKSIZEOF(struct sec_path), |
|
#endif |
|
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) |
|
[TC_SKB_EXT] = SKB_EXT_CHUNKSIZEOF(struct tc_skb_ext), |
|
#endif |
|
#if IS_ENABLED(CONFIG_MPTCP) |
|
[SKB_EXT_MPTCP] = SKB_EXT_CHUNKSIZEOF(struct mptcp_ext), |
|
#endif |
|
#if IS_ENABLED(CONFIG_MCTP_FLOWS) |
|
[SKB_EXT_MCTP] = SKB_EXT_CHUNKSIZEOF(struct mctp_flow), |
|
#endif |
|
}; |
|
|
|
static __always_inline unsigned int skb_ext_total_length(void) |
|
{ |
|
return SKB_EXT_CHUNKSIZEOF(struct skb_ext) + |
|
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
|
skb_ext_type_len[SKB_EXT_BRIDGE_NF] + |
|
#endif |
|
#ifdef CONFIG_XFRM |
|
skb_ext_type_len[SKB_EXT_SEC_PATH] + |
|
#endif |
|
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) |
|
skb_ext_type_len[TC_SKB_EXT] + |
|
#endif |
|
#if IS_ENABLED(CONFIG_MPTCP) |
|
skb_ext_type_len[SKB_EXT_MPTCP] + |
|
#endif |
|
#if IS_ENABLED(CONFIG_MCTP_FLOWS) |
|
skb_ext_type_len[SKB_EXT_MCTP] + |
|
#endif |
|
0; |
|
} |
|
|
|
static void skb_extensions_init(void) |
|
{ |
|
BUILD_BUG_ON(SKB_EXT_NUM >= 8); |
|
BUILD_BUG_ON(skb_ext_total_length() > 255); |
|
|
|
skbuff_ext_cache = kmem_cache_create("skbuff_ext_cache", |
|
SKB_EXT_ALIGN_VALUE * skb_ext_total_length(), |
|
0, |
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC, |
|
NULL); |
|
} |
|
#else |
|
static void skb_extensions_init(void) {} |
|
#endif |
|
|
|
void __init skb_init(void) |
|
{ |
|
skbuff_head_cache = kmem_cache_create_usercopy("skbuff_head_cache", |
|
sizeof(struct sk_buff), |
|
0, |
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC, |
|
offsetof(struct sk_buff, cb), |
|
sizeof_field(struct sk_buff, cb), |
|
NULL); |
|
skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache", |
|
sizeof(struct sk_buff_fclones), |
|
0, |
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC, |
|
NULL); |
|
skb_extensions_init(); |
|
} |
|
|
|
static int |
|
__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len, |
|
unsigned int recursion_level) |
|
{ |
|
int start = skb_headlen(skb); |
|
int i, copy = start - offset; |
|
struct sk_buff *frag_iter; |
|
int elt = 0; |
|
|
|
if (unlikely(recursion_level >= 24)) |
|
return -EMSGSIZE; |
|
|
|
if (copy > 0) { |
|
if (copy > len) |
|
copy = len; |
|
sg_set_buf(sg, skb->data + offset, copy); |
|
elt++; |
|
if ((len -= copy) == 0) |
|
return elt; |
|
offset += copy; |
|
} |
|
|
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
|
int end; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
if ((copy = end - offset) > 0) { |
|
skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
|
if (unlikely(elt && sg_is_last(&sg[elt - 1]))) |
|
return -EMSGSIZE; |
|
|
|
if (copy > len) |
|
copy = len; |
|
sg_set_page(&sg[elt], skb_frag_page(frag), copy, |
|
skb_frag_off(frag) + offset - start); |
|
elt++; |
|
if (!(len -= copy)) |
|
return elt; |
|
offset += copy; |
|
} |
|
start = end; |
|
} |
|
|
|
skb_walk_frags(skb, frag_iter) { |
|
int end, ret; |
|
|
|
WARN_ON(start > offset + len); |
|
|
|
end = start + frag_iter->len; |
|
if ((copy = end - offset) > 0) { |
|
if (unlikely(elt && sg_is_last(&sg[elt - 1]))) |
|
return -EMSGSIZE; |
|
|
|
if (copy > len) |
|
copy = len; |
|
ret = __skb_to_sgvec(frag_iter, sg+elt, offset - start, |
|
copy, recursion_level + 1); |
|
if (unlikely(ret < 0)) |
|
return ret; |
|
elt += ret; |
|
if ((len -= copy) == 0) |
|
return elt; |
|
offset += copy; |
|
} |
|
start = end; |
|
} |
|
BUG_ON(len); |
|
return elt; |
|
} |
|
|
|
/** |
|
* skb_to_sgvec - Fill a scatter-gather list from a socket buffer |
|
* @skb: Socket buffer containing the buffers to be mapped |
|
* @sg: The scatter-gather list to map into |
|
* @offset: The offset into the buffer's contents to start mapping |
|
* @len: Length of buffer space to be mapped |
|
* |
|
* Fill the specified scatter-gather list with mappings/pointers into a |
|
* region of the buffer space attached to a socket buffer. Returns either |
|
* the number of scatterlist items used, or -EMSGSIZE if the contents |
|
* could not fit. |
|
*/ |
|
int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) |
|
{ |
|
int nsg = __skb_to_sgvec(skb, sg, offset, len, 0); |
|
|
|
if (nsg <= 0) |
|
return nsg; |
|
|
|
sg_mark_end(&sg[nsg - 1]); |
|
|
|
return nsg; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_to_sgvec); |
|
|
|
/* As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given |
|
* sglist without mark the sg which contain last skb data as the end. |
|
* So the caller can mannipulate sg list as will when padding new data after |
|
* the first call without calling sg_unmark_end to expend sg list. |
|
* |
|
* Scenario to use skb_to_sgvec_nomark: |
|
* 1. sg_init_table |
|
* 2. skb_to_sgvec_nomark(payload1) |
|
* 3. skb_to_sgvec_nomark(payload2) |
|
* |
|
* This is equivalent to: |
|
* 1. sg_init_table |
|
* 2. skb_to_sgvec(payload1) |
|
* 3. sg_unmark_end |
|
* 4. skb_to_sgvec(payload2) |
|
* |
|
* When mapping mutilple payload conditionally, skb_to_sgvec_nomark |
|
* is more preferable. |
|
*/ |
|
int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, |
|
int offset, int len) |
|
{ |
|
return __skb_to_sgvec(skb, sg, offset, len, 0); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_to_sgvec_nomark); |
|
|
|
|
|
|
|
/** |
|
* skb_cow_data - Check that a socket buffer's data buffers are writable |
|
* @skb: The socket buffer to check. |
|
* @tailbits: Amount of trailing space to be added |
|
* @trailer: Returned pointer to the skb where the @tailbits space begins |
|
* |
|
* Make sure that the data buffers attached to a socket buffer are |
|
* writable. If they are not, private copies are made of the data buffers |
|
* and the socket buffer is set to use these instead. |
|
* |
|
* If @tailbits is given, make sure that there is space to write @tailbits |
|
* bytes of data beyond current end of socket buffer. @trailer will be |
|
* set to point to the skb in which this space begins. |
|
* |
|
* The number of scatterlist elements required to completely map the |
|
* COW'd and extended socket buffer will be returned. |
|
*/ |
|
int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) |
|
{ |
|
int copyflag; |
|
int elt; |
|
struct sk_buff *skb1, **skb_p; |
|
|
|
/* If skb is cloned or its head is paged, reallocate |
|
* head pulling out all the pages (pages are considered not writable |
|
* at the moment even if they are anonymous). |
|
*/ |
|
if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) && |
|
!__pskb_pull_tail(skb, __skb_pagelen(skb))) |
|
return -ENOMEM; |
|
|
|
/* Easy case. Most of packets will go this way. */ |
|
if (!skb_has_frag_list(skb)) { |
|
/* A little of trouble, not enough of space for trailer. |
|
* This should not happen, when stack is tuned to generate |
|
* good frames. OK, on miss we reallocate and reserve even more |
|
* space, 128 bytes is fair. */ |
|
|
|
if (skb_tailroom(skb) < tailbits && |
|
pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC)) |
|
return -ENOMEM; |
|
|
|
/* Voila! */ |
|
*trailer = skb; |
|
return 1; |
|
} |
|
|
|
/* Misery. We are in troubles, going to mincer fragments... */ |
|
|
|
elt = 1; |
|
skb_p = &skb_shinfo(skb)->frag_list; |
|
copyflag = 0; |
|
|
|
while ((skb1 = *skb_p) != NULL) { |
|
int ntail = 0; |
|
|
|
/* The fragment is partially pulled by someone, |
|
* this can happen on input. Copy it and everything |
|
* after it. */ |
|
|
|
if (skb_shared(skb1)) |
|
copyflag = 1; |
|
|
|
/* If the skb is the last, worry about trailer. */ |
|
|
|
if (skb1->next == NULL && tailbits) { |
|
if (skb_shinfo(skb1)->nr_frags || |
|
skb_has_frag_list(skb1) || |
|
skb_tailroom(skb1) < tailbits) |
|
ntail = tailbits + 128; |
|
} |
|
|
|
if (copyflag || |
|
skb_cloned(skb1) || |
|
ntail || |
|
skb_shinfo(skb1)->nr_frags || |
|
skb_has_frag_list(skb1)) { |
|
struct sk_buff *skb2; |
|
|
|
/* Fuck, we are miserable poor guys... */ |
|
if (ntail == 0) |
|
skb2 = skb_copy(skb1, GFP_ATOMIC); |
|
else |
|
skb2 = skb_copy_expand(skb1, |
|
skb_headroom(skb1), |
|
ntail, |
|
GFP_ATOMIC); |
|
if (unlikely(skb2 == NULL)) |
|
return -ENOMEM; |
|
|
|
if (skb1->sk) |
|
skb_set_owner_w(skb2, skb1->sk); |
|
|
|
/* Looking around. Are we still alive? |
|
* OK, link new skb, drop old one */ |
|
|
|
skb2->next = skb1->next; |
|
*skb_p = skb2; |
|
kfree_skb(skb1); |
|
skb1 = skb2; |
|
} |
|
elt++; |
|
*trailer = skb1; |
|
skb_p = &skb1->next; |
|
} |
|
|
|
return elt; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_cow_data); |
|
|
|
static void sock_rmem_free(struct sk_buff *skb) |
|
{ |
|
struct sock *sk = skb->sk; |
|
|
|
atomic_sub(skb->truesize, &sk->sk_rmem_alloc); |
|
} |
|
|
|
static void skb_set_err_queue(struct sk_buff *skb) |
|
{ |
|
/* pkt_type of skbs received on local sockets is never PACKET_OUTGOING. |
|
* So, it is safe to (mis)use it to mark skbs on the error queue. |
|
*/ |
|
skb->pkt_type = PACKET_OUTGOING; |
|
BUILD_BUG_ON(PACKET_OUTGOING == 0); |
|
} |
|
|
|
/* |
|
* Note: We dont mem charge error packets (no sk_forward_alloc changes) |
|
*/ |
|
int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= |
|
(unsigned int)READ_ONCE(sk->sk_rcvbuf)) |
|
return -ENOMEM; |
|
|
|
skb_orphan(skb); |
|
skb->sk = sk; |
|
skb->destructor = sock_rmem_free; |
|
atomic_add(skb->truesize, &sk->sk_rmem_alloc); |
|
skb_set_err_queue(skb); |
|
|
|
/* before exiting rcu section, make sure dst is refcounted */ |
|
skb_dst_force(skb); |
|
|
|
skb_queue_tail(&sk->sk_error_queue, skb); |
|
if (!sock_flag(sk, SOCK_DEAD)) |
|
sk_error_report(sk); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(sock_queue_err_skb); |
|
|
|
static bool is_icmp_err_skb(const struct sk_buff *skb) |
|
{ |
|
return skb && (SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_ICMP || |
|
SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_ICMP6); |
|
} |
|
|
|
struct sk_buff *sock_dequeue_err_skb(struct sock *sk) |
|
{ |
|
struct sk_buff_head *q = &sk->sk_error_queue; |
|
struct sk_buff *skb, *skb_next = NULL; |
|
bool icmp_next = false; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&q->lock, flags); |
|
skb = __skb_dequeue(q); |
|
if (skb && (skb_next = skb_peek(q))) { |
|
icmp_next = is_icmp_err_skb(skb_next); |
|
if (icmp_next) |
|
sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_errno; |
|
} |
|
spin_unlock_irqrestore(&q->lock, flags); |
|
|
|
if (is_icmp_err_skb(skb) && !icmp_next) |
|
sk->sk_err = 0; |
|
|
|
if (skb_next) |
|
sk_error_report(sk); |
|
|
|
return skb; |
|
} |
|
EXPORT_SYMBOL(sock_dequeue_err_skb); |
|
|
|
/** |
|
* skb_clone_sk - create clone of skb, and take reference to socket |
|
* @skb: the skb to clone |
|
* |
|
* This function creates a clone of a buffer that holds a reference on |
|
* sk_refcnt. Buffers created via this function are meant to be |
|
* returned using sock_queue_err_skb, or free via kfree_skb. |
|
* |
|
* When passing buffers allocated with this function to sock_queue_err_skb |
|
* it is necessary to wrap the call with sock_hold/sock_put in order to |
|
* prevent the socket from being released prior to being enqueued on |
|
* the sk_error_queue. |
|
*/ |
|
struct sk_buff *skb_clone_sk(struct sk_buff *skb) |
|
{ |
|
struct sock *sk = skb->sk; |
|
struct sk_buff *clone; |
|
|
|
if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) |
|
return NULL; |
|
|
|
clone = skb_clone(skb, GFP_ATOMIC); |
|
if (!clone) { |
|
sock_put(sk); |
|
return NULL; |
|
} |
|
|
|
clone->sk = sk; |
|
clone->destructor = sock_efree; |
|
|
|
return clone; |
|
} |
|
EXPORT_SYMBOL(skb_clone_sk); |
|
|
|
static void __skb_complete_tx_timestamp(struct sk_buff *skb, |
|
struct sock *sk, |
|
int tstype, |
|
bool opt_stats) |
|
{ |
|
struct sock_exterr_skb *serr; |
|
int err; |
|
|
|
BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb)); |
|
|
|
serr = SKB_EXT_ERR(skb); |
|
memset(serr, 0, sizeof(*serr)); |
|
serr->ee.ee_errno = ENOMSG; |
|
serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; |
|
serr->ee.ee_info = tstype; |
|
serr->opt_stats = opt_stats; |
|
serr->header.h4.iif = skb->dev ? skb->dev->ifindex : 0; |
|
if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) { |
|
serr->ee.ee_data = skb_shinfo(skb)->tskey; |
|
if (sk_is_tcp(sk)) |
|
serr->ee.ee_data -= atomic_read(&sk->sk_tskey); |
|
} |
|
|
|
err = sock_queue_err_skb(sk, skb); |
|
|
|
if (err) |
|
kfree_skb(skb); |
|
} |
|
|
|
static bool skb_may_tx_timestamp(struct sock *sk, bool tsonly) |
|
{ |
|
bool ret; |
|
|
|
if (likely(sysctl_tstamp_allow_data || tsonly)) |
|
return true; |
|
|
|
read_lock_bh(&sk->sk_callback_lock); |
|
ret = sk->sk_socket && sk->sk_socket->file && |
|
file_ns_capable(sk->sk_socket->file, &init_user_ns, CAP_NET_RAW); |
|
read_unlock_bh(&sk->sk_callback_lock); |
|
return ret; |
|
} |
|
|
|
void skb_complete_tx_timestamp(struct sk_buff *skb, |
|
struct skb_shared_hwtstamps *hwtstamps) |
|
{ |
|
struct sock *sk = skb->sk; |
|
|
|
if (!skb_may_tx_timestamp(sk, false)) |
|
goto err; |
|
|
|
/* Take a reference to prevent skb_orphan() from freeing the socket, |
|
* but only if the socket refcount is not zero. |
|
*/ |
|
if (likely(refcount_inc_not_zero(&sk->sk_refcnt))) { |
|
*skb_hwtstamps(skb) = *hwtstamps; |
|
__skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND, false); |
|
sock_put(sk); |
|
return; |
|
} |
|
|
|
err: |
|
kfree_skb(skb); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp); |
|
|
|
void __skb_tstamp_tx(struct sk_buff *orig_skb, |
|
const struct sk_buff *ack_skb, |
|
struct skb_shared_hwtstamps *hwtstamps, |
|
struct sock *sk, int tstype) |
|
{ |
|
struct sk_buff *skb; |
|
bool tsonly, opt_stats = false; |
|
|
|
if (!sk) |
|
return; |
|
|
|
if (!hwtstamps && !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TX_SWHW) && |
|
skb_shinfo(orig_skb)->tx_flags & SKBTX_IN_PROGRESS) |
|
return; |
|
|
|
tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY; |
|
if (!skb_may_tx_timestamp(sk, tsonly)) |
|
return; |
|
|
|
if (tsonly) { |
|
#ifdef CONFIG_INET |
|
if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS) && |
|
sk_is_tcp(sk)) { |
|
skb = tcp_get_timestamping_opt_stats(sk, orig_skb, |
|
ack_skb); |
|
opt_stats = true; |
|
} else |
|
#endif |
|
skb = alloc_skb(0, GFP_ATOMIC); |
|
} else { |
|
skb = skb_clone(orig_skb, GFP_ATOMIC); |
|
} |
|
if (!skb) |
|
return; |
|
|
|
if (tsonly) { |
|
skb_shinfo(skb)->tx_flags |= skb_shinfo(orig_skb)->tx_flags & |
|
SKBTX_ANY_TSTAMP; |
|
skb_shinfo(skb)->tskey = skb_shinfo(orig_skb)->tskey; |
|
} |
|
|
|
if (hwtstamps) |
|
*skb_hwtstamps(skb) = *hwtstamps; |
|
else |
|
skb->tstamp = ktime_get_real(); |
|
|
|
__skb_complete_tx_timestamp(skb, sk, tstype, opt_stats); |
|
} |
|
EXPORT_SYMBOL_GPL(__skb_tstamp_tx); |
|
|
|
void skb_tstamp_tx(struct sk_buff *orig_skb, |
|
struct skb_shared_hwtstamps *hwtstamps) |
|
{ |
|
return __skb_tstamp_tx(orig_skb, NULL, hwtstamps, orig_skb->sk, |
|
SCM_TSTAMP_SND); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_tstamp_tx); |
|
|
|
void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) |
|
{ |
|
struct sock *sk = skb->sk; |
|
struct sock_exterr_skb *serr; |
|
int err = 1; |
|
|
|
skb->wifi_acked_valid = 1; |
|
skb->wifi_acked = acked; |
|
|
|
serr = SKB_EXT_ERR(skb); |
|
memset(serr, 0, sizeof(*serr)); |
|
serr->ee.ee_errno = ENOMSG; |
|
serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS; |
|
|
|
/* Take a reference to prevent skb_orphan() from freeing the socket, |
|
* but only if the socket refcount is not zero. |
|
*/ |
|
if (likely(refcount_inc_not_zero(&sk->sk_refcnt))) { |
|
err = sock_queue_err_skb(sk, skb); |
|
sock_put(sk); |
|
} |
|
if (err) |
|
kfree_skb(skb); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_complete_wifi_ack); |
|
|
|
/** |
|
* skb_partial_csum_set - set up and verify partial csum values for packet |
|
* @skb: the skb to set |
|
* @start: the number of bytes after skb->data to start checksumming. |
|
* @off: the offset from start to place the checksum. |
|
* |
|
* For untrusted partially-checksummed packets, we need to make sure the values |
|
* for skb->csum_start and skb->csum_offset are valid so we don't oops. |
|
* |
|
* This function checks and sets those values and skb->ip_summed: if this |
|
* returns false you should drop the packet. |
|
*/ |
|
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off) |
|
{ |
|
u32 csum_end = (u32)start + (u32)off + sizeof(__sum16); |
|
u32 csum_start = skb_headroom(skb) + (u32)start; |
|
|
|
if (unlikely(csum_start > U16_MAX || csum_end > skb_headlen(skb))) { |
|
net_warn_ratelimited("bad partial csum: csum=%u/%u headroom=%u headlen=%u\n", |
|
start, off, skb_headroom(skb), skb_headlen(skb)); |
|
return false; |
|
} |
|
skb->ip_summed = CHECKSUM_PARTIAL; |
|
skb->csum_start = csum_start; |
|
skb->csum_offset = off; |
|
skb_set_transport_header(skb, start); |
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_partial_csum_set); |
|
|
|
static int skb_maybe_pull_tail(struct sk_buff *skb, unsigned int len, |
|
unsigned int max) |
|
{ |
|
if (skb_headlen(skb) >= len) |
|
return 0; |
|
|
|
/* If we need to pullup then pullup to the max, so we |
|
* won't need to do it again. |
|
*/ |
|
if (max > skb->len) |
|
max = skb->len; |
|
|
|
if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL) |
|
return -ENOMEM; |
|
|
|
if (skb_headlen(skb) < len) |
|
return -EPROTO; |
|
|
|
return 0; |
|
} |
|
|
|
#define MAX_TCP_HDR_LEN (15 * 4) |
|
|
|
static __sum16 *skb_checksum_setup_ip(struct sk_buff *skb, |
|
typeof(IPPROTO_IP) proto, |
|
unsigned int off) |
|
{ |
|
int err; |
|
|
|
switch (proto) { |
|
case IPPROTO_TCP: |
|
err = skb_maybe_pull_tail(skb, off + sizeof(struct tcphdr), |
|
off + MAX_TCP_HDR_LEN); |
|
if (!err && !skb_partial_csum_set(skb, off, |
|
offsetof(struct tcphdr, |
|
check))) |
|
err = -EPROTO; |
|
return err ? ERR_PTR(err) : &tcp_hdr(skb)->check; |
|
|
|
case IPPROTO_UDP: |
|
err = skb_maybe_pull_tail(skb, off + sizeof(struct udphdr), |
|
off + sizeof(struct udphdr)); |
|
if (!err && !skb_partial_csum_set(skb, off, |
|
offsetof(struct udphdr, |
|
check))) |
|
err = -EPROTO; |
|
return err ? ERR_PTR(err) : &udp_hdr(skb)->check; |
|
} |
|
|
|
return ERR_PTR(-EPROTO); |
|
} |
|
|
|
/* This value should be large enough to cover a tagged ethernet header plus |
|
* maximally sized IP and TCP or UDP headers. |
|
*/ |
|
#define MAX_IP_HDR_LEN 128 |
|
|
|
static int skb_checksum_setup_ipv4(struct sk_buff *skb, bool recalculate) |
|
{ |
|
unsigned int off; |
|
bool fragment; |
|
__sum16 *csum; |
|
int err; |
|
|
|
fragment = false; |
|
|
|
err = skb_maybe_pull_tail(skb, |
|
sizeof(struct iphdr), |
|
MAX_IP_HDR_LEN); |
|
if (err < 0) |
|
goto out; |
|
|
|
if (ip_is_fragment(ip_hdr(skb))) |
|
fragment = true; |
|
|
|
off = ip_hdrlen(skb); |
|
|
|
err = -EPROTO; |
|
|
|
if (fragment) |
|
goto out; |
|
|
|
csum = skb_checksum_setup_ip(skb, ip_hdr(skb)->protocol, off); |
|
if (IS_ERR(csum)) |
|
return PTR_ERR(csum); |
|
|
|
if (recalculate) |
|
*csum = ~csum_tcpudp_magic(ip_hdr(skb)->saddr, |
|
ip_hdr(skb)->daddr, |
|
skb->len - off, |
|
ip_hdr(skb)->protocol, 0); |
|
err = 0; |
|
|
|
out: |
|
return err; |
|
} |
|
|
|
/* This value should be large enough to cover a tagged ethernet header plus |
|
* an IPv6 header, all options, and a maximal TCP or UDP header. |
|
*/ |
|
#define MAX_IPV6_HDR_LEN 256 |
|
|
|
#define OPT_HDR(type, skb, off) \ |
|
(type *)(skb_network_header(skb) + (off)) |
|
|
|
static int skb_checksum_setup_ipv6(struct sk_buff *skb, bool recalculate) |
|
{ |
|
int err; |
|
u8 nexthdr; |
|
unsigned int off; |
|
unsigned int len; |
|
bool fragment; |
|
bool done; |
|
__sum16 *csum; |
|
|
|
fragment = false; |
|
done = false; |
|
|
|
off = sizeof(struct ipv6hdr); |
|
|
|
err = skb_maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN); |
|
if (err < 0) |
|
goto out; |
|
|
|
nexthdr = ipv6_hdr(skb)->nexthdr; |
|
|
|
len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len); |
|
while (off <= len && !done) { |
|
switch (nexthdr) { |
|
case IPPROTO_DSTOPTS: |
|
case IPPROTO_HOPOPTS: |
|
case IPPROTO_ROUTING: { |
|
struct ipv6_opt_hdr *hp; |
|
|
|
err = skb_maybe_pull_tail(skb, |
|
off + |
|
sizeof(struct ipv6_opt_hdr), |
|
MAX_IPV6_HDR_LEN); |
|
if (err < 0) |
|
goto out; |
|
|
|
hp = OPT_HDR(struct ipv6_opt_hdr, skb, off); |
|
nexthdr = hp->nexthdr; |
|
off += ipv6_optlen(hp); |
|
break; |
|
} |
|
case IPPROTO_AH: { |
|
struct ip_auth_hdr *hp; |
|
|
|
err = skb_maybe_pull_tail(skb, |
|
off + |
|
sizeof(struct ip_auth_hdr), |
|
MAX_IPV6_HDR_LEN); |
|
if (err < 0) |
|
goto out; |
|
|
|
hp = OPT_HDR(struct ip_auth_hdr, skb, off); |
|
nexthdr = hp->nexthdr; |
|
off += ipv6_authlen(hp); |
|
break; |
|
} |
|
case IPPROTO_FRAGMENT: { |
|
struct frag_hdr *hp; |
|
|
|
err = skb_maybe_pull_tail(skb, |
|
off + |
|
sizeof(struct frag_hdr), |
|
MAX_IPV6_HDR_LEN); |
|
if (err < 0) |
|
goto out; |
|
|
|
hp = OPT_HDR(struct frag_hdr, skb, off); |
|
|
|
if (hp->frag_off & htons(IP6_OFFSET | IP6_MF)) |
|
fragment = true; |
|
|
|
nexthdr = hp->nexthdr; |
|
off += sizeof(struct frag_hdr); |
|
break; |
|
} |
|
default: |
|
done = true; |
|
break; |
|
} |
|
} |
|
|
|
err = -EPROTO; |
|
|
|
if (!done || fragment) |
|
goto out; |
|
|
|
csum = skb_checksum_setup_ip(skb, nexthdr, off); |
|
if (IS_ERR(csum)) |
|
return PTR_ERR(csum); |
|
|
|
if (recalculate) |
|
*csum = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
|
&ipv6_hdr(skb)->daddr, |
|
skb->len - off, nexthdr, 0); |
|
err = 0; |
|
|
|
out: |
|
return err; |
|
} |
|
|
|
/** |
|
* skb_checksum_setup - set up partial checksum offset |
|
* @skb: the skb to set up |
|
* @recalculate: if true the pseudo-header checksum will be recalculated |
|
*/ |
|
int skb_checksum_setup(struct sk_buff *skb, bool recalculate) |
|
{ |
|
int err; |
|
|
|
switch (skb->protocol) { |
|
case htons(ETH_P_IP): |
|
err = skb_checksum_setup_ipv4(skb, recalculate); |
|
break; |
|
|
|
case htons(ETH_P_IPV6): |
|
err = skb_checksum_setup_ipv6(skb, recalculate); |
|
break; |
|
|
|
default: |
|
err = -EPROTO; |
|
break; |
|
} |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL(skb_checksum_setup); |
|
|
|
/** |
|
* skb_checksum_maybe_trim - maybe trims the given skb |
|
* @skb: the skb to check |
|
* @transport_len: the data length beyond the network header |
|
* |
|
* Checks whether the given skb has data beyond the given transport length. |
|
* If so, returns a cloned skb trimmed to this transport length. |
|
* Otherwise returns the provided skb. Returns NULL in error cases |
|
* (e.g. transport_len exceeds skb length or out-of-memory). |
|
* |
|
* Caller needs to set the skb transport header and free any returned skb if it |
|
* differs from the provided skb. |
|
*/ |
|
static struct sk_buff *skb_checksum_maybe_trim(struct sk_buff *skb, |
|
unsigned int transport_len) |
|
{ |
|
struct sk_buff *skb_chk; |
|
unsigned int len = skb_transport_offset(skb) + transport_len; |
|
int ret; |
|
|
|
if (skb->len < len) |
|
return NULL; |
|
else if (skb->len == len) |
|
return skb; |
|
|
|
skb_chk = skb_clone(skb, GFP_ATOMIC); |
|
if (!skb_chk) |
|
return NULL; |
|
|
|
ret = pskb_trim_rcsum(skb_chk, len); |
|
if (ret) { |
|
kfree_skb(skb_chk); |
|
return NULL; |
|
} |
|
|
|
return skb_chk; |
|
} |
|
|
|
/** |
|
* skb_checksum_trimmed - validate checksum of an skb |
|
* @skb: the skb to check |
|
* @transport_len: the data length beyond the network header |
|
* @skb_chkf: checksum function to use |
|
* |
|
* Applies the given checksum function skb_chkf to the provided skb. |
|
* Returns a checked and maybe trimmed skb. Returns NULL on error. |
|
* |
|
* If the skb has data beyond the given transport length, then a |
|
* trimmed & cloned skb is checked and returned. |
|
* |
|
* Caller needs to set the skb transport header and free any returned skb if it |
|
* differs from the provided skb. |
|
*/ |
|
struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, |
|
unsigned int transport_len, |
|
__sum16(*skb_chkf)(struct sk_buff *skb)) |
|
{ |
|
struct sk_buff *skb_chk; |
|
unsigned int offset = skb_transport_offset(skb); |
|
__sum16 ret; |
|
|
|
skb_chk = skb_checksum_maybe_trim(skb, transport_len); |
|
if (!skb_chk) |
|
goto err; |
|
|
|
if (!pskb_may_pull(skb_chk, offset)) |
|
goto err; |
|
|
|
skb_pull_rcsum(skb_chk, offset); |
|
ret = skb_chkf(skb_chk); |
|
skb_push_rcsum(skb_chk, offset); |
|
|
|
if (ret) |
|
goto err; |
|
|
|
return skb_chk; |
|
|
|
err: |
|
if (skb_chk && skb_chk != skb) |
|
kfree_skb(skb_chk); |
|
|
|
return NULL; |
|
|
|
} |
|
EXPORT_SYMBOL(skb_checksum_trimmed); |
|
|
|
void __skb_warn_lro_forwarding(const struct sk_buff *skb) |
|
{ |
|
net_warn_ratelimited("%s: received packets cannot be forwarded while LRO is enabled\n", |
|
skb->dev->name); |
|
} |
|
EXPORT_SYMBOL(__skb_warn_lro_forwarding); |
|
|
|
void kfree_skb_partial(struct sk_buff *skb, bool head_stolen) |
|
{ |
|
if (head_stolen) { |
|
skb_release_head_state(skb); |
|
kmem_cache_free(skbuff_head_cache, skb); |
|
} else { |
|
__kfree_skb(skb); |
|
} |
|
} |
|
EXPORT_SYMBOL(kfree_skb_partial); |
|
|
|
/** |
|
* skb_try_coalesce - try to merge skb to prior one |
|
* @to: prior buffer |
|
* @from: buffer to add |
|
* @fragstolen: pointer to boolean |
|
* @delta_truesize: how much more was allocated than was requested |
|
*/ |
|
bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, |
|
bool *fragstolen, int *delta_truesize) |
|
{ |
|
struct skb_shared_info *to_shinfo, *from_shinfo; |
|
int i, delta, len = from->len; |
|
|
|
*fragstolen = false; |
|
|
|
if (skb_cloned(to)) |
|
return false; |
|
|
|
/* The page pool signature of struct page will eventually figure out |
|
* which pages can be recycled or not but for now let's prohibit slab |
|
* allocated and page_pool allocated SKBs from being coalesced. |
|
*/ |
|
if (to->pp_recycle != from->pp_recycle) |
|
return false; |
|
|
|
if (len <= skb_tailroom(to)) { |
|
if (len) |
|
BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len)); |
|
*delta_truesize = 0; |
|
return true; |
|
} |
|
|
|
to_shinfo = skb_shinfo(to); |
|
from_shinfo = skb_shinfo(from); |
|
if (to_shinfo->frag_list || from_shinfo->frag_list) |
|
return false; |
|
if (skb_zcopy(to) || skb_zcopy(from)) |
|
return false; |
|
|
|
if (skb_headlen(from) != 0) { |
|
struct page *page; |
|
unsigned int offset; |
|
|
|
if (to_shinfo->nr_frags + |
|
from_shinfo->nr_frags >= MAX_SKB_FRAGS) |
|
return false; |
|
|
|
if (skb_head_is_locked(from)) |
|
return false; |
|
|
|
delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); |
|
|
|
page = virt_to_head_page(from->head); |
|
offset = from->data - (unsigned char *)page_address(page); |
|
|
|
skb_fill_page_desc(to, to_shinfo->nr_frags, |
|
page, offset, skb_headlen(from)); |
|
*fragstolen = true; |
|
} else { |
|
if (to_shinfo->nr_frags + |
|
from_shinfo->nr_frags > MAX_SKB_FRAGS) |
|
return false; |
|
|
|
delta = from->truesize - SKB_TRUESIZE(skb_end_offset(from)); |
|
} |
|
|
|
WARN_ON_ONCE(delta < len); |
|
|
|
memcpy(to_shinfo->frags + to_shinfo->nr_frags, |
|
from_shinfo->frags, |
|
from_shinfo->nr_frags * sizeof(skb_frag_t)); |
|
to_shinfo->nr_frags += from_shinfo->nr_frags; |
|
|
|
if (!skb_cloned(from)) |
|
from_shinfo->nr_frags = 0; |
|
|
|
/* if the skb is not cloned this does nothing |
|
* since we set nr_frags to 0. |
|
*/ |
|
for (i = 0; i < from_shinfo->nr_frags; i++) |
|
__skb_frag_ref(&from_shinfo->frags[i]); |
|
|
|
to->truesize += delta; |
|
to->len += len; |
|
to->data_len += len; |
|
|
|
*delta_truesize = delta; |
|
return true; |
|
} |
|
EXPORT_SYMBOL(skb_try_coalesce); |
|
|
|
/** |
|
* skb_scrub_packet - scrub an skb |
|
* |
|
* @skb: buffer to clean |
|
* @xnet: packet is crossing netns |
|
* |
|
* skb_scrub_packet can be used after encapsulating or decapsulting a packet |
|
* into/from a tunnel. Some information have to be cleared during these |
|
* operations. |
|
* skb_scrub_packet can also be used to clean a skb before injecting it in |
|
* another namespace (@xnet == true). We have to clear all information in the |
|
* skb that could impact namespace isolation. |
|
*/ |
|
void skb_scrub_packet(struct sk_buff *skb, bool xnet) |
|
{ |
|
skb->pkt_type = PACKET_HOST; |
|
skb->skb_iif = 0; |
|
skb->ignore_df = 0; |
|
skb_dst_drop(skb); |
|
skb_ext_reset(skb); |
|
nf_reset_ct(skb); |
|
nf_reset_trace(skb); |
|
|
|
#ifdef CONFIG_NET_SWITCHDEV |
|
skb->offload_fwd_mark = 0; |
|
skb->offload_l3_fwd_mark = 0; |
|
#endif |
|
|
|
if (!xnet) |
|
return; |
|
|
|
ipvs_reset(skb); |
|
skb->mark = 0; |
|
skb->tstamp = 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_scrub_packet); |
|
|
|
/** |
|
* skb_gso_transport_seglen - Return length of individual segments of a gso packet |
|
* |
|
* @skb: GSO skb |
|
* |
|
* skb_gso_transport_seglen is used to determine the real size of the |
|
* individual segments, including Layer4 headers (TCP/UDP). |
|
* |
|
* The MAC/L2 or network (IP, IPv6) headers are not accounted for. |
|
*/ |
|
static unsigned int skb_gso_transport_seglen(const struct sk_buff *skb) |
|
{ |
|
const struct skb_shared_info *shinfo = skb_shinfo(skb); |
|
unsigned int thlen = 0; |
|
|
|
if (skb->encapsulation) { |
|
thlen = skb_inner_transport_header(skb) - |
|
skb_transport_header(skb); |
|
|
|
if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) |
|
thlen += inner_tcp_hdrlen(skb); |
|
} else if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) { |
|
thlen = tcp_hdrlen(skb); |
|
} else if (unlikely(skb_is_gso_sctp(skb))) { |
|
thlen = sizeof(struct sctphdr); |
|
} else if (shinfo->gso_type & SKB_GSO_UDP_L4) { |
|
thlen = sizeof(struct udphdr); |
|
} |
|
/* UFO sets gso_size to the size of the fragmentation |
|
* payload, i.e. the size of the L4 (UDP) header is already |
|
* accounted for. |
|
*/ |
|
return thlen + shinfo->gso_size; |
|
} |
|
|
|
/** |
|
* skb_gso_network_seglen - Return length of individual segments of a gso packet |
|
* |
|
* @skb: GSO skb |
|
* |
|
* skb_gso_network_seglen is used to determine the real size of the |
|
* individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP). |
|
* |
|
* The MAC/L2 header is not accounted for. |
|
*/ |
|
static unsigned int skb_gso_network_seglen(const struct sk_buff *skb) |
|
{ |
|
unsigned int hdr_len = skb_transport_header(skb) - |
|
skb_network_header(skb); |
|
|
|
return hdr_len + skb_gso_transport_seglen(skb); |
|
} |
|
|
|
/** |
|
* skb_gso_mac_seglen - Return length of individual segments of a gso packet |
|
* |
|
* @skb: GSO skb |
|
* |
|
* skb_gso_mac_seglen is used to determine the real size of the |
|
* individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4 |
|
* headers (TCP/UDP). |
|
*/ |
|
static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb) |
|
{ |
|
unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb); |
|
|
|
return hdr_len + skb_gso_transport_seglen(skb); |
|
} |
|
|
|
/** |
|
* skb_gso_size_check - check the skb size, considering GSO_BY_FRAGS |
|
* |
|
* There are a couple of instances where we have a GSO skb, and we |
|
* want to determine what size it would be after it is segmented. |
|
* |
|
* We might want to check: |
|
* - L3+L4+payload size (e.g. IP forwarding) |
|
* - L2+L3+L4+payload size (e.g. sanity check before passing to driver) |
|
* |
|
* This is a helper to do that correctly considering GSO_BY_FRAGS. |
|
* |
|
* @skb: GSO skb |
|
* |
|
* @seg_len: The segmented length (from skb_gso_*_seglen). In the |
|
* GSO_BY_FRAGS case this will be [header sizes + GSO_BY_FRAGS]. |
|
* |
|
* @max_len: The maximum permissible length. |
|
* |
|
* Returns true if the segmented length <= max length. |
|
*/ |
|
static inline bool skb_gso_size_check(const struct sk_buff *skb, |
|
unsigned int seg_len, |
|
unsigned int max_len) { |
|
const struct skb_shared_info *shinfo = skb_shinfo(skb); |
|
const struct sk_buff *iter; |
|
|
|
if (shinfo->gso_size != GSO_BY_FRAGS) |
|
return seg_len <= max_len; |
|
|
|
/* Undo this so we can re-use header sizes */ |
|
seg_len -= GSO_BY_FRAGS; |
|
|
|
skb_walk_frags(skb, iter) { |
|
if (seg_len + skb_headlen(iter) > max_len) |
|
return false; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
/** |
|
* skb_gso_validate_network_len - Will a split GSO skb fit into a given MTU? |
|
* |
|
* @skb: GSO skb |
|
* @mtu: MTU to validate against |
|
* |
|
* skb_gso_validate_network_len validates if a given skb will fit a |
|
* wanted MTU once split. It considers L3 headers, L4 headers, and the |
|
* payload. |
|
*/ |
|
bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu) |
|
{ |
|
return skb_gso_size_check(skb, skb_gso_network_seglen(skb), mtu); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_gso_validate_network_len); |
|
|
|
/** |
|
* skb_gso_validate_mac_len - Will a split GSO skb fit in a given length? |
|
* |
|
* @skb: GSO skb |
|
* @len: length to validate against |
|
* |
|
* skb_gso_validate_mac_len validates if a given skb will fit a wanted |
|
* length once split, including L2, L3 and L4 headers and the payload. |
|
*/ |
|
bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len) |
|
{ |
|
return skb_gso_size_check(skb, skb_gso_mac_seglen(skb), len); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_gso_validate_mac_len); |
|
|
|
static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb) |
|
{ |
|
int mac_len, meta_len; |
|
void *meta; |
|
|
|
if (skb_cow(skb, skb_headroom(skb)) < 0) { |
|
kfree_skb(skb); |
|
return NULL; |
|
} |
|
|
|
mac_len = skb->data - skb_mac_header(skb); |
|
if (likely(mac_len > VLAN_HLEN + ETH_TLEN)) { |
|
memmove(skb_mac_header(skb) + VLAN_HLEN, skb_mac_header(skb), |
|
mac_len - VLAN_HLEN - ETH_TLEN); |
|
} |
|
|
|
meta_len = skb_metadata_len(skb); |
|
if (meta_len) { |
|
meta = skb_metadata_end(skb) - meta_len; |
|
memmove(meta + VLAN_HLEN, meta, meta_len); |
|
} |
|
|
|
skb->mac_header += VLAN_HLEN; |
|
return skb; |
|
} |
|
|
|
struct sk_buff *skb_vlan_untag(struct sk_buff *skb) |
|
{ |
|
struct vlan_hdr *vhdr; |
|
u16 vlan_tci; |
|
|
|
if (unlikely(skb_vlan_tag_present(skb))) { |
|
/* vlan_tci is already set-up so leave this for another time */ |
|
return skb; |
|
} |
|
|
|
skb = skb_share_check(skb, GFP_ATOMIC); |
|
if (unlikely(!skb)) |
|
goto err_free; |
|
/* We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). */ |
|
if (unlikely(!pskb_may_pull(skb, VLAN_HLEN + sizeof(unsigned short)))) |
|
goto err_free; |
|
|
|
vhdr = (struct vlan_hdr *)skb->data; |
|
vlan_tci = ntohs(vhdr->h_vlan_TCI); |
|
__vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci); |
|
|
|
skb_pull_rcsum(skb, VLAN_HLEN); |
|
vlan_set_encap_proto(skb, vhdr); |
|
|
|
skb = skb_reorder_vlan_header(skb); |
|
if (unlikely(!skb)) |
|
goto err_free; |
|
|
|
skb_reset_network_header(skb); |
|
if (!skb_transport_header_was_set(skb)) |
|
skb_reset_transport_header(skb); |
|
skb_reset_mac_len(skb); |
|
|
|
return skb; |
|
|
|
err_free: |
|
kfree_skb(skb); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(skb_vlan_untag); |
|
|
|
int skb_ensure_writable(struct sk_buff *skb, int write_len) |
|
{ |
|
if (!pskb_may_pull(skb, write_len)) |
|
return -ENOMEM; |
|
|
|
if (!skb_cloned(skb) || skb_clone_writable(skb, write_len)) |
|
return 0; |
|
|
|
return pskb_expand_head(skb, 0, 0, GFP_ATOMIC); |
|
} |
|
EXPORT_SYMBOL(skb_ensure_writable); |
|
|
|
/* remove VLAN header from packet and update csum accordingly. |
|
* expects a non skb_vlan_tag_present skb with a vlan tag payload |
|
*/ |
|
int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci) |
|
{ |
|
struct vlan_hdr *vhdr; |
|
int offset = skb->data - skb_mac_header(skb); |
|
int err; |
|
|
|
if (WARN_ONCE(offset, |
|
"__skb_vlan_pop got skb with skb->data not at mac header (offset %d)\n", |
|
offset)) { |
|
return -EINVAL; |
|
} |
|
|
|
err = skb_ensure_writable(skb, VLAN_ETH_HLEN); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); |
|
|
|
vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN); |
|
*vlan_tci = ntohs(vhdr->h_vlan_TCI); |
|
|
|
memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN); |
|
__skb_pull(skb, VLAN_HLEN); |
|
|
|
vlan_set_encap_proto(skb, vhdr); |
|
skb->mac_header += VLAN_HLEN; |
|
|
|
if (skb_network_offset(skb) < ETH_HLEN) |
|
skb_set_network_header(skb, ETH_HLEN); |
|
|
|
skb_reset_mac_len(skb); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL(__skb_vlan_pop); |
|
|
|
/* Pop a vlan tag either from hwaccel or from payload. |
|
* Expects skb->data at mac header. |
|
*/ |
|
int skb_vlan_pop(struct sk_buff *skb) |
|
{ |
|
u16 vlan_tci; |
|
__be16 vlan_proto; |
|
int err; |
|
|
|
if (likely(skb_vlan_tag_present(skb))) { |
|
__vlan_hwaccel_clear_tag(skb); |
|
} else { |
|
if (unlikely(!eth_type_vlan(skb->protocol))) |
|
return 0; |
|
|
|
err = __skb_vlan_pop(skb, &vlan_tci); |
|
if (err) |
|
return err; |
|
} |
|
/* move next vlan tag to hw accel tag */ |
|
if (likely(!eth_type_vlan(skb->protocol))) |
|
return 0; |
|
|
|
vlan_proto = skb->protocol; |
|
err = __skb_vlan_pop(skb, &vlan_tci); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(skb_vlan_pop); |
|
|
|
/* Push a vlan tag either into hwaccel or into payload (if hwaccel tag present). |
|
* Expects skb->data at mac header. |
|
*/ |
|
int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) |
|
{ |
|
if (skb_vlan_tag_present(skb)) { |
|
int offset = skb->data - skb_mac_header(skb); |
|
int err; |
|
|
|
if (WARN_ONCE(offset, |
|
"skb_vlan_push got skb with skb->data not at mac header (offset %d)\n", |
|
offset)) { |
|
return -EINVAL; |
|
} |
|
|
|
err = __vlan_insert_tag(skb, skb->vlan_proto, |
|
skb_vlan_tag_get(skb)); |
|
if (err) |
|
return err; |
|
|
|
skb->protocol = skb->vlan_proto; |
|
skb->mac_len += VLAN_HLEN; |
|
|
|
skb_postpush_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); |
|
} |
|
__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(skb_vlan_push); |
|
|
|
/** |
|
* skb_eth_pop() - Drop the Ethernet header at the head of a packet |
|
* |
|
* @skb: Socket buffer to modify |
|
* |
|
* Drop the Ethernet header of @skb. |
|
* |
|
* Expects that skb->data points to the mac header and that no VLAN tags are |
|
* present. |
|
* |
|
* Returns 0 on success, -errno otherwise. |
|
*/ |
|
int skb_eth_pop(struct sk_buff *skb) |
|
{ |
|
if (!pskb_may_pull(skb, ETH_HLEN) || skb_vlan_tagged(skb) || |
|
skb_network_offset(skb) < ETH_HLEN) |
|
return -EPROTO; |
|
|
|
skb_pull_rcsum(skb, ETH_HLEN); |
|
skb_reset_mac_header(skb); |
|
skb_reset_mac_len(skb); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL(skb_eth_pop); |
|
|
|
/** |
|
* skb_eth_push() - Add a new Ethernet header at the head of a packet |
|
* |
|
* @skb: Socket buffer to modify |
|
* @dst: Destination MAC address of the new header |
|
* @src: Source MAC address of the new header |
|
* |
|
* Prepend @skb with a new Ethernet header. |
|
* |
|
* Expects that skb->data points to the mac header, which must be empty. |
|
* |
|
* Returns 0 on success, -errno otherwise. |
|
*/ |
|
int skb_eth_push(struct sk_buff *skb, const unsigned char *dst, |
|
const unsigned char *src) |
|
{ |
|
struct ethhdr *eth; |
|
int err; |
|
|
|
if (skb_network_offset(skb) || skb_vlan_tag_present(skb)) |
|
return -EPROTO; |
|
|
|
err = skb_cow_head(skb, sizeof(*eth)); |
|
if (err < 0) |
|
return err; |
|
|
|
skb_push(skb, sizeof(*eth)); |
|
skb_reset_mac_header(skb); |
|
skb_reset_mac_len(skb); |
|
|
|
eth = eth_hdr(skb); |
|
ether_addr_copy(eth->h_dest, dst); |
|
ether_addr_copy(eth->h_source, src); |
|
eth->h_proto = skb->protocol; |
|
|
|
skb_postpush_rcsum(skb, eth, sizeof(*eth)); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL(skb_eth_push); |
|
|
|
/* Update the ethertype of hdr and the skb csum value if required. */ |
|
static void skb_mod_eth_type(struct sk_buff *skb, struct ethhdr *hdr, |
|
__be16 ethertype) |
|
{ |
|
if (skb->ip_summed == CHECKSUM_COMPLETE) { |
|
__be16 diff[] = { ~hdr->h_proto, ethertype }; |
|
|
|
skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum); |
|
} |
|
|
|
hdr->h_proto = ethertype; |
|
} |
|
|
|
/** |
|
* skb_mpls_push() - push a new MPLS header after mac_len bytes from start of |
|
* the packet |
|
* |
|
* @skb: buffer |
|
* @mpls_lse: MPLS label stack entry to push |
|
* @mpls_proto: ethertype of the new MPLS header (expects 0x8847 or 0x8848) |
|
* @mac_len: length of the MAC header |
|
* @ethernet: flag to indicate if the resulting packet after skb_mpls_push is |
|
* ethernet |
|
* |
|
* Expects skb->data at mac header. |
|
* |
|
* Returns 0 on success, -errno otherwise. |
|
*/ |
|
int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto, |
|
int mac_len, bool ethernet) |
|
{ |
|
struct mpls_shim_hdr *lse; |
|
int err; |
|
|
|
if (unlikely(!eth_p_mpls(mpls_proto))) |
|
return -EINVAL; |
|
|
|
/* Networking stack does not allow simultaneous Tunnel and MPLS GSO. */ |
|
if (skb->encapsulation) |
|
return -EINVAL; |
|
|
|
err = skb_cow_head(skb, MPLS_HLEN); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
if (!skb->inner_protocol) { |
|
skb_set_inner_network_header(skb, skb_network_offset(skb)); |
|
skb_set_inner_protocol(skb, skb->protocol); |
|
} |
|
|
|
skb_push(skb, MPLS_HLEN); |
|
memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb), |
|
mac_len); |
|
skb_reset_mac_header(skb); |
|
skb_set_network_header(skb, mac_len); |
|
skb_reset_mac_len(skb); |
|
|
|
lse = mpls_hdr(skb); |
|
lse->label_stack_entry = mpls_lse; |
|
skb_postpush_rcsum(skb, lse, MPLS_HLEN); |
|
|
|
if (ethernet && mac_len >= ETH_HLEN) |
|
skb_mod_eth_type(skb, eth_hdr(skb), mpls_proto); |
|
skb->protocol = mpls_proto; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_mpls_push); |
|
|
|
/** |
|
* skb_mpls_pop() - pop the outermost MPLS header |
|
* |
|
* @skb: buffer |
|
* @next_proto: ethertype of header after popped MPLS header |
|
* @mac_len: length of the MAC header |
|
* @ethernet: flag to indicate if the packet is ethernet |
|
* |
|
* Expects skb->data at mac header. |
|
* |
|
* Returns 0 on success, -errno otherwise. |
|
*/ |
|
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len, |
|
bool ethernet) |
|
{ |
|
int err; |
|
|
|
if (unlikely(!eth_p_mpls(skb->protocol))) |
|
return 0; |
|
|
|
err = skb_ensure_writable(skb, mac_len + MPLS_HLEN); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN); |
|
memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb), |
|
mac_len); |
|
|
|
__skb_pull(skb, MPLS_HLEN); |
|
skb_reset_mac_header(skb); |
|
skb_set_network_header(skb, mac_len); |
|
|
|
if (ethernet && mac_len >= ETH_HLEN) { |
|
struct ethhdr *hdr; |
|
|
|
/* use mpls_hdr() to get ethertype to account for VLANs. */ |
|
hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN); |
|
skb_mod_eth_type(skb, hdr, next_proto); |
|
} |
|
skb->protocol = next_proto; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_mpls_pop); |
|
|
|
/** |
|
* skb_mpls_update_lse() - modify outermost MPLS header and update csum |
|
* |
|
* @skb: buffer |
|
* @mpls_lse: new MPLS label stack entry to update to |
|
* |
|
* Expects skb->data at mac header. |
|
* |
|
* Returns 0 on success, -errno otherwise. |
|
*/ |
|
int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse) |
|
{ |
|
int err; |
|
|
|
if (unlikely(!eth_p_mpls(skb->protocol))) |
|
return -EINVAL; |
|
|
|
err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE) { |
|
__be32 diff[] = { ~mpls_hdr(skb)->label_stack_entry, mpls_lse }; |
|
|
|
skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum); |
|
} |
|
|
|
mpls_hdr(skb)->label_stack_entry = mpls_lse; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(skb_mpls_update_lse); |
|
|
|
/** |
|
* skb_mpls_dec_ttl() - decrement the TTL of the outermost MPLS header |
|
* |
|
* @skb: buffer |
|
* |
|
* Expects skb->data at mac header. |
|
* |
|
* Returns 0 on success, -errno otherwise. |
|
*/ |
|
int skb_mpls_dec_ttl(struct sk_buff *skb) |
|
{ |
|
u32 lse; |
|
u8 ttl; |
|
|
|
if (unlikely(!eth_p_mpls(skb->protocol))) |
|
return -EINVAL; |
|
|
|
if (!pskb_may_pull(skb, skb_network_offset(skb) + MPLS_HLEN)) |
|
return -ENOMEM; |
|
|
|
lse = be32_to_cpu(mpls_hdr(skb)->label_stack_entry); |
|
ttl = (lse & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; |
|
if (!--ttl) |
|
return -EINVAL; |
|
|
|
lse &= ~MPLS_LS_TTL_MASK; |
|
lse |= ttl << MPLS_LS_TTL_SHIFT; |
|
|
|
return skb_mpls_update_lse(skb, cpu_to_be32(lse)); |
|
} |
|
EXPORT_SYMBOL_GPL(skb_mpls_dec_ttl); |
|
|
|
/** |
|
* alloc_skb_with_frags - allocate skb with page frags |
|
* |
|
* @header_len: size of linear part |
|
* @data_len: needed length in frags |
|
* @max_page_order: max page order desired. |
|
* @errcode: pointer to error code if any |
|
* @gfp_mask: allocation mask |
|
* |
|
* This can be used to allocate a paged skb, given a maximal order for frags. |
|
*/ |
|
struct sk_buff *alloc_skb_with_frags(unsigned long header_len, |
|
unsigned long data_len, |
|
int max_page_order, |
|
int *errcode, |
|
gfp_t gfp_mask) |
|
{ |
|
int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT; |
|
unsigned long chunk; |
|
struct sk_buff *skb; |
|
struct page *page; |
|
int i; |
|
|
|
*errcode = -EMSGSIZE; |
|
/* Note this test could be relaxed, if we succeed to allocate |
|
* high order pages... |
|
*/ |
|
if (npages > MAX_SKB_FRAGS) |
|
return NULL; |
|
|
|
*errcode = -ENOBUFS; |
|
skb = alloc_skb(header_len, gfp_mask); |
|
if (!skb) |
|
return NULL; |
|
|
|
skb->truesize += npages << PAGE_SHIFT; |
|
|
|
for (i = 0; npages > 0; i++) { |
|
int order = max_page_order; |
|
|
|
while (order) { |
|
if (npages >= 1 << order) { |
|
page = alloc_pages((gfp_mask & ~__GFP_DIRECT_RECLAIM) | |
|
__GFP_COMP | |
|
__GFP_NOWARN, |
|
order); |
|
if (page) |
|
goto fill_page; |
|
/* Do not retry other high order allocations */ |
|
order = 1; |
|
max_page_order = 0; |
|
} |
|
order--; |
|
} |
|
page = alloc_page(gfp_mask); |
|
if (!page) |
|
goto failure; |
|
fill_page: |
|
chunk = min_t(unsigned long, data_len, |
|
PAGE_SIZE << order); |
|
skb_fill_page_desc(skb, i, page, 0, chunk); |
|
data_len -= chunk; |
|
npages -= 1 << order; |
|
} |
|
return skb; |
|
|
|
failure: |
|
kfree_skb(skb); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(alloc_skb_with_frags); |
|
|
|
/* carve out the first off bytes from skb when off < headlen */ |
|
static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, |
|
const int headlen, gfp_t gfp_mask) |
|
{ |
|
int i; |
|
int size = skb_end_offset(skb); |
|
int new_hlen = headlen - off; |
|
u8 *data; |
|
|
|
size = SKB_DATA_ALIGN(size); |
|
|
|
if (skb_pfmemalloc(skb)) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
data = kmalloc_reserve(size + |
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), |
|
gfp_mask, NUMA_NO_NODE, NULL); |
|
if (!data) |
|
return -ENOMEM; |
|
|
|
size = SKB_WITH_OVERHEAD(ksize(data)); |
|
|
|
/* Copy real data, and all frags */ |
|
skb_copy_from_linear_data_offset(skb, off, data, new_hlen); |
|
skb->len -= off; |
|
|
|
memcpy((struct skb_shared_info *)(data + size), |
|
skb_shinfo(skb), |
|
offsetof(struct skb_shared_info, |
|
frags[skb_shinfo(skb)->nr_frags])); |
|
if (skb_cloned(skb)) { |
|
/* drop the old head gracefully */ |
|
if (skb_orphan_frags(skb, gfp_mask)) { |
|
kfree(data); |
|
return -ENOMEM; |
|
} |
|
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
|
skb_frag_ref(skb, i); |
|
if (skb_has_frag_list(skb)) |
|
skb_clone_fraglist(skb); |
|
skb_release_data(skb); |
|
} else { |
|
/* we can reuse existing recount- all we did was |
|
* relocate values |
|
*/ |
|
skb_free_head(skb); |
|
} |
|
|
|
skb->head = data; |
|
skb->data = data; |
|
skb->head_frag = 0; |
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET |
|
skb->end = size; |
|
#else |
|
skb->end = skb->head + size; |
|
#endif |
|
skb_set_tail_pointer(skb, skb_headlen(skb)); |
|
skb_headers_offset_update(skb, 0); |
|
skb->cloned = 0; |
|
skb->hdr_len = 0; |
|
skb->nohdr = 0; |
|
atomic_set(&skb_shinfo(skb)->dataref, 1); |
|
|
|
return 0; |
|
} |
|
|
|
static int pskb_carve(struct sk_buff *skb, const u32 off, gfp_t gfp); |
|
|
|
/* carve out the first eat bytes from skb's frag_list. May recurse into |
|
* pskb_carve() |
|
*/ |
|
static int pskb_carve_frag_list(struct sk_buff *skb, |
|
struct skb_shared_info *shinfo, int eat, |
|
gfp_t gfp_mask) |
|
{ |
|
struct sk_buff *list = shinfo->frag_list; |
|
struct sk_buff *clone = NULL; |
|
struct sk_buff *insp = NULL; |
|
|
|
do { |
|
if (!list) { |
|
pr_err("Not enough bytes to eat. Want %d\n", eat); |
|
return -EFAULT; |
|
} |
|
if (list->len <= eat) { |
|
/* Eaten as whole. */ |
|
eat -= list->len; |
|
list = list->next; |
|
insp = list; |
|
} else { |
|
/* Eaten partially. */ |
|
if (skb_shared(list)) { |
|
clone = skb_clone(list, gfp_mask); |
|
if (!clone) |
|
return -ENOMEM; |
|
insp = list->next; |
|
list = clone; |
|
} else { |
|
/* This may be pulled without problems. */ |
|
insp = list; |
|
} |
|
if (pskb_carve(list, eat, gfp_mask) < 0) { |
|
kfree_skb(clone); |
|
return -ENOMEM; |
|
} |
|
break; |
|
} |
|
} while (eat); |
|
|
|
/* Free pulled out fragments. */ |
|
while ((list = shinfo->frag_list) != insp) { |
|
shinfo->frag_list = list->next; |
|
consume_skb(list); |
|
} |
|
/* And insert new clone at head. */ |
|
if (clone) { |
|
clone->next = list; |
|
shinfo->frag_list = clone; |
|
} |
|
return 0; |
|
} |
|
|
|
/* carve off first len bytes from skb. Split line (off) is in the |
|
* non-linear part of skb |
|
*/ |
|
static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, |
|
int pos, gfp_t gfp_mask) |
|
{ |
|
int i, k = 0; |
|
int size = skb_end_offset(skb); |
|
u8 *data; |
|
const int nfrags = skb_shinfo(skb)->nr_frags; |
|
struct skb_shared_info *shinfo; |
|
|
|
size = SKB_DATA_ALIGN(size); |
|
|
|
if (skb_pfmemalloc(skb)) |
|
gfp_mask |= __GFP_MEMALLOC; |
|
data = kmalloc_reserve(size + |
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), |
|
gfp_mask, NUMA_NO_NODE, NULL); |
|
if (!data) |
|
return -ENOMEM; |
|
|
|
size = SKB_WITH_OVERHEAD(ksize(data)); |
|
|
|
memcpy((struct skb_shared_info *)(data + size), |
|
skb_shinfo(skb), offsetof(struct skb_shared_info, frags[0])); |
|
if (skb_orphan_frags(skb, gfp_mask)) { |
|
kfree(data); |
|
return -ENOMEM; |
|
} |
|
shinfo = (struct skb_shared_info *)(data + size); |
|
for (i = 0; i < nfrags; i++) { |
|
int fsize = skb_frag_size(&skb_shinfo(skb)->frags[i]); |
|
|
|
if (pos + fsize > off) { |
|
shinfo->frags[k] = skb_shinfo(skb)->frags[i]; |
|
|
|
if (pos < off) { |
|
/* Split frag. |
|
* We have two variants in this case: |
|
* 1. Move all the frag to the second |
|
* part, if it is possible. F.e. |
|
* this approach is mandatory for TUX, |
|
* where splitting is expensive. |
|
* 2. Split is accurately. We make this. |
|
*/ |
|
skb_frag_off_add(&shinfo->frags[0], off - pos); |
|
skb_frag_size_sub(&shinfo->frags[0], off - pos); |
|
} |
|
skb_frag_ref(skb, i); |
|
k++; |
|
} |
|
pos += fsize; |
|
} |
|
shinfo->nr_frags = k; |
|
if (skb_has_frag_list(skb)) |
|
skb_clone_fraglist(skb); |
|
|
|
/* split line is in frag list */ |
|
if (k == 0 && pskb_carve_frag_list(skb, shinfo, off - pos, gfp_mask)) { |
|
/* skb_frag_unref() is not needed here as shinfo->nr_frags = 0. */ |
|
if (skb_has_frag_list(skb)) |
|
kfree_skb_list(skb_shinfo(skb)->frag_list); |
|
kfree(data); |
|
return -ENOMEM; |
|
} |
|
skb_release_data(skb); |
|
|
|
skb->head = data; |
|
skb->head_frag = 0; |
|
skb->data = data; |
|
#ifdef NET_SKBUFF_DATA_USES_OFFSET |
|
skb->end = size; |
|
#else |
|
skb->end = skb->head + size; |
|
#endif |
|
skb_reset_tail_pointer(skb); |
|
skb_headers_offset_update(skb, 0); |
|
skb->cloned = 0; |
|
skb->hdr_len = 0; |
|
skb->nohdr = 0; |
|
skb->len -= off; |
|
skb->data_len = skb->len; |
|
atomic_set(&skb_shinfo(skb)->dataref, 1); |
|
return 0; |
|
} |
|
|
|
/* remove len bytes from the beginning of the skb */ |
|
static int pskb_carve(struct sk_buff *skb, const u32 len, gfp_t gfp) |
|
{ |
|
int headlen = skb_headlen(skb); |
|
|
|
if (len < headlen) |
|
return pskb_carve_inside_header(skb, len, headlen, gfp); |
|
else |
|
return pskb_carve_inside_nonlinear(skb, len, headlen, gfp); |
|
} |
|
|
|
/* Extract to_copy bytes starting at off from skb, and return this in |
|
* a new skb |
|
*/ |
|
struct sk_buff *pskb_extract(struct sk_buff *skb, int off, |
|
int to_copy, gfp_t gfp) |
|
{ |
|
struct sk_buff *clone = skb_clone(skb, gfp); |
|
|
|
if (!clone) |
|
return NULL; |
|
|
|
if (pskb_carve(clone, off, gfp) < 0 || |
|
pskb_trim(clone, to_copy)) { |
|
kfree_skb(clone); |
|
return NULL; |
|
} |
|
return clone; |
|
} |
|
EXPORT_SYMBOL(pskb_extract); |
|
|
|
/** |
|
* skb_condense - try to get rid of fragments/frag_list if possible |
|
* @skb: buffer |
|
* |
|
* Can be used to save memory before skb is added to a busy queue. |
|
* If packet has bytes in frags and enough tail room in skb->head, |
|
* pull all of them, so that we can free the frags right now and adjust |
|
* truesize. |
|
* Notes: |
|
* We do not reallocate skb->head thus can not fail. |
|
* Caller must re-evaluate skb->truesize if needed. |
|
*/ |
|
void skb_condense(struct sk_buff *skb) |
|
{ |
|
if (skb->data_len) { |
|
if (skb->data_len > skb->end - skb->tail || |
|
skb_cloned(skb)) |
|
return; |
|
|
|
/* Nice, we can free page frag(s) right now */ |
|
__pskb_pull_tail(skb, skb->data_len); |
|
} |
|
/* At this point, skb->truesize might be over estimated, |
|
* because skb had a fragment, and fragments do not tell |
|
* their truesize. |
|
* When we pulled its content into skb->head, fragment |
|
* was freed, but __pskb_pull_tail() could not possibly |
|
* adjust skb->truesize, not knowing the frag truesize. |
|
*/ |
|
skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); |
|
} |
|
|
|
#ifdef CONFIG_SKB_EXTENSIONS |
|
static void *skb_ext_get_ptr(struct skb_ext *ext, enum skb_ext_id id) |
|
{ |
|
return (void *)ext + (ext->offset[id] * SKB_EXT_ALIGN_VALUE); |
|
} |
|
|
|
/** |
|
* __skb_ext_alloc - allocate a new skb extensions storage |
|
* |
|
* @flags: See kmalloc(). |
|
* |
|
* Returns the newly allocated pointer. The pointer can later attached to a |
|
* skb via __skb_ext_set(). |
|
* Note: caller must handle the skb_ext as an opaque data. |
|
*/ |
|
struct skb_ext *__skb_ext_alloc(gfp_t flags) |
|
{ |
|
struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, flags); |
|
|
|
if (new) { |
|
memset(new->offset, 0, sizeof(new->offset)); |
|
refcount_set(&new->refcnt, 1); |
|
} |
|
|
|
return new; |
|
} |
|
|
|
static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old, |
|
unsigned int old_active) |
|
{ |
|
struct skb_ext *new; |
|
|
|
if (refcount_read(&old->refcnt) == 1) |
|
return old; |
|
|
|
new = kmem_cache_alloc(skbuff_ext_cache, GFP_ATOMIC); |
|
if (!new) |
|
return NULL; |
|
|
|
memcpy(new, old, old->chunks * SKB_EXT_ALIGN_VALUE); |
|
refcount_set(&new->refcnt, 1); |
|
|
|
#ifdef CONFIG_XFRM |
|
if (old_active & (1 << SKB_EXT_SEC_PATH)) { |
|
struct sec_path *sp = skb_ext_get_ptr(old, SKB_EXT_SEC_PATH); |
|
unsigned int i; |
|
|
|
for (i = 0; i < sp->len; i++) |
|
xfrm_state_hold(sp->xvec[i]); |
|
} |
|
#endif |
|
__skb_ext_put(old); |
|
return new; |
|
} |
|
|
|
/** |
|
* __skb_ext_set - attach the specified extension storage to this skb |
|
* @skb: buffer |
|
* @id: extension id |
|
* @ext: extension storage previously allocated via __skb_ext_alloc() |
|
* |
|
* Existing extensions, if any, are cleared. |
|
* |
|
* Returns the pointer to the extension. |
|
*/ |
|
void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, |
|
struct skb_ext *ext) |
|
{ |
|
unsigned int newlen, newoff = SKB_EXT_CHUNKSIZEOF(*ext); |
|
|
|
skb_ext_put(skb); |
|
newlen = newoff + skb_ext_type_len[id]; |
|
ext->chunks = newlen; |
|
ext->offset[id] = newoff; |
|
skb->extensions = ext; |
|
skb->active_extensions = 1 << id; |
|
return skb_ext_get_ptr(ext, id); |
|
} |
|
|
|
/** |
|
* skb_ext_add - allocate space for given extension, COW if needed |
|
* @skb: buffer |
|
* @id: extension to allocate space for |
|
* |
|
* Allocates enough space for the given extension. |
|
* If the extension is already present, a pointer to that extension |
|
* is returned. |
|
* |
|
* If the skb was cloned, COW applies and the returned memory can be |
|
* modified without changing the extension space of clones buffers. |
|
* |
|
* Returns pointer to the extension or NULL on allocation failure. |
|
*/ |
|
void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) |
|
{ |
|
struct skb_ext *new, *old = NULL; |
|
unsigned int newlen, newoff; |
|
|
|
if (skb->active_extensions) { |
|
old = skb->extensions; |
|
|
|
new = skb_ext_maybe_cow(old, skb->active_extensions); |
|
if (!new) |
|
return NULL; |
|
|
|
if (__skb_ext_exist(new, id)) |
|
goto set_active; |
|
|
|
newoff = new->chunks; |
|
} else { |
|
newoff = SKB_EXT_CHUNKSIZEOF(*new); |
|
|
|
new = __skb_ext_alloc(GFP_ATOMIC); |
|
if (!new) |
|
return NULL; |
|
} |
|
|
|
newlen = newoff + skb_ext_type_len[id]; |
|
new->chunks = newlen; |
|
new->offset[id] = newoff; |
|
set_active: |
|
skb->slow_gro = 1; |
|
skb->extensions = new; |
|
skb->active_extensions |= 1 << id; |
|
return skb_ext_get_ptr(new, id); |
|
} |
|
EXPORT_SYMBOL(skb_ext_add); |
|
|
|
#ifdef CONFIG_XFRM |
|
static void skb_ext_put_sp(struct sec_path *sp) |
|
{ |
|
unsigned int i; |
|
|
|
for (i = 0; i < sp->len; i++) |
|
xfrm_state_put(sp->xvec[i]); |
|
} |
|
#endif |
|
|
|
#ifdef CONFIG_MCTP_FLOWS |
|
static void skb_ext_put_mctp(struct mctp_flow *flow) |
|
{ |
|
if (flow->key) |
|
mctp_key_unref(flow->key); |
|
} |
|
#endif |
|
|
|
void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id) |
|
{ |
|
struct skb_ext *ext = skb->extensions; |
|
|
|
skb->active_extensions &= ~(1 << id); |
|
if (skb->active_extensions == 0) { |
|
skb->extensions = NULL; |
|
__skb_ext_put(ext); |
|
#ifdef CONFIG_XFRM |
|
} else if (id == SKB_EXT_SEC_PATH && |
|
refcount_read(&ext->refcnt) == 1) { |
|
struct sec_path *sp = skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH); |
|
|
|
skb_ext_put_sp(sp); |
|
sp->len = 0; |
|
#endif |
|
} |
|
} |
|
EXPORT_SYMBOL(__skb_ext_del); |
|
|
|
void __skb_ext_put(struct skb_ext *ext) |
|
{ |
|
/* If this is last clone, nothing can increment |
|
* it after check passes. Avoids one atomic op. |
|
*/ |
|
if (refcount_read(&ext->refcnt) == 1) |
|
goto free_now; |
|
|
|
if (!refcount_dec_and_test(&ext->refcnt)) |
|
return; |
|
free_now: |
|
#ifdef CONFIG_XFRM |
|
if (__skb_ext_exist(ext, SKB_EXT_SEC_PATH)) |
|
skb_ext_put_sp(skb_ext_get_ptr(ext, SKB_EXT_SEC_PATH)); |
|
#endif |
|
#ifdef CONFIG_MCTP_FLOWS |
|
if (__skb_ext_exist(ext, SKB_EXT_MCTP)) |
|
skb_ext_put_mctp(skb_ext_get_ptr(ext, SKB_EXT_MCTP)); |
|
#endif |
|
|
|
kmem_cache_free(skbuff_ext_cache, ext); |
|
} |
|
EXPORT_SYMBOL(__skb_ext_put); |
|
#endif /* CONFIG_SKB_EXTENSIONS */
|
|
|