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2909 lines
68 KiB
2909 lines
68 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* NETLINK Kernel-user communication protocol. |
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* |
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* Authors: Alan Cox <[email protected]> |
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* Alexey Kuznetsov <[email protected]> |
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* Patrick McHardy <[email protected]> |
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* |
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* Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
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* added netlink_proto_exit |
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* Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <[email protected]> |
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* use nlk_sk, as sk->protinfo is on a diet 8) |
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* Fri Jul 22 19:51:12 MEST 2005 Harald Welte <[email protected]> |
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* - inc module use count of module that owns |
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* the kernel socket in case userspace opens |
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* socket of same protocol |
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* - remove all module support, since netlink is |
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* mandatory if CONFIG_NET=y these days |
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*/ |
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|
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#include <linux/module.h> |
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|
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#include <linux/capability.h> |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/signal.h> |
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#include <linux/sched.h> |
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#include <linux/errno.h> |
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#include <linux/string.h> |
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#include <linux/stat.h> |
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#include <linux/socket.h> |
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#include <linux/un.h> |
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#include <linux/fcntl.h> |
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#include <linux/termios.h> |
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#include <linux/sockios.h> |
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#include <linux/net.h> |
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#include <linux/fs.h> |
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#include <linux/slab.h> |
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#include <linux/uaccess.h> |
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#include <linux/skbuff.h> |
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#include <linux/netdevice.h> |
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#include <linux/rtnetlink.h> |
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#include <linux/proc_fs.h> |
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#include <linux/seq_file.h> |
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#include <linux/notifier.h> |
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#include <linux/security.h> |
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#include <linux/jhash.h> |
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#include <linux/jiffies.h> |
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#include <linux/random.h> |
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#include <linux/bitops.h> |
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#include <linux/mm.h> |
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#include <linux/types.h> |
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#include <linux/audit.h> |
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#include <linux/mutex.h> |
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#include <linux/vmalloc.h> |
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#include <linux/if_arp.h> |
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#include <linux/rhashtable.h> |
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#include <asm/cacheflush.h> |
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#include <linux/hash.h> |
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#include <linux/genetlink.h> |
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#include <linux/net_namespace.h> |
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#include <linux/nospec.h> |
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#include <linux/btf_ids.h> |
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|
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#include <net/net_namespace.h> |
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#include <net/netns/generic.h> |
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#include <net/sock.h> |
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#include <net/scm.h> |
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#include <net/netlink.h> |
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#define CREATE_TRACE_POINTS |
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#include <trace/events/netlink.h> |
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|
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#include "af_netlink.h" |
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|
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struct listeners { |
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struct rcu_head rcu; |
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unsigned long masks[]; |
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}; |
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|
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/* state bits */ |
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#define NETLINK_S_CONGESTED 0x0 |
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|
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static inline int netlink_is_kernel(struct sock *sk) |
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{ |
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return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET; |
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} |
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|
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struct netlink_table *nl_table __read_mostly; |
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EXPORT_SYMBOL_GPL(nl_table); |
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|
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static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); |
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|
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static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; |
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|
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static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { |
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"nlk_cb_mutex-ROUTE", |
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"nlk_cb_mutex-1", |
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"nlk_cb_mutex-USERSOCK", |
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"nlk_cb_mutex-FIREWALL", |
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"nlk_cb_mutex-SOCK_DIAG", |
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"nlk_cb_mutex-NFLOG", |
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"nlk_cb_mutex-XFRM", |
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"nlk_cb_mutex-SELINUX", |
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"nlk_cb_mutex-ISCSI", |
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"nlk_cb_mutex-AUDIT", |
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"nlk_cb_mutex-FIB_LOOKUP", |
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"nlk_cb_mutex-CONNECTOR", |
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"nlk_cb_mutex-NETFILTER", |
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"nlk_cb_mutex-IP6_FW", |
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"nlk_cb_mutex-DNRTMSG", |
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"nlk_cb_mutex-KOBJECT_UEVENT", |
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"nlk_cb_mutex-GENERIC", |
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"nlk_cb_mutex-17", |
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"nlk_cb_mutex-SCSITRANSPORT", |
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"nlk_cb_mutex-ECRYPTFS", |
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"nlk_cb_mutex-RDMA", |
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"nlk_cb_mutex-CRYPTO", |
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"nlk_cb_mutex-SMC", |
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"nlk_cb_mutex-23", |
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"nlk_cb_mutex-24", |
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"nlk_cb_mutex-25", |
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"nlk_cb_mutex-26", |
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"nlk_cb_mutex-27", |
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"nlk_cb_mutex-28", |
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"nlk_cb_mutex-29", |
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"nlk_cb_mutex-30", |
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"nlk_cb_mutex-31", |
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"nlk_cb_mutex-MAX_LINKS" |
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}; |
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|
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static int netlink_dump(struct sock *sk); |
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|
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/* nl_table locking explained: |
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* Lookup and traversal are protected with an RCU read-side lock. Insertion |
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* and removal are protected with per bucket lock while using RCU list |
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* modification primitives and may run in parallel to RCU protected lookups. |
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* Destruction of the Netlink socket may only occur *after* nl_table_lock has |
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* been acquired * either during or after the socket has been removed from |
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* the list and after an RCU grace period. |
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*/ |
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DEFINE_RWLOCK(nl_table_lock); |
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EXPORT_SYMBOL_GPL(nl_table_lock); |
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static atomic_t nl_table_users = ATOMIC_INIT(0); |
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|
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#define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
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|
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static BLOCKING_NOTIFIER_HEAD(netlink_chain); |
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|
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static const struct rhashtable_params netlink_rhashtable_params; |
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|
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void do_trace_netlink_extack(const char *msg) |
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{ |
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trace_netlink_extack(msg); |
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} |
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EXPORT_SYMBOL(do_trace_netlink_extack); |
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|
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static inline u32 netlink_group_mask(u32 group) |
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{ |
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return group ? 1 << (group - 1) : 0; |
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} |
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|
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static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, |
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gfp_t gfp_mask) |
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{ |
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unsigned int len = skb_end_offset(skb); |
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struct sk_buff *new; |
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|
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new = alloc_skb(len, gfp_mask); |
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if (new == NULL) |
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return NULL; |
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NETLINK_CB(new).portid = NETLINK_CB(skb).portid; |
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NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; |
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NETLINK_CB(new).creds = NETLINK_CB(skb).creds; |
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|
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skb_put_data(new, skb->data, len); |
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return new; |
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} |
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|
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static unsigned int netlink_tap_net_id; |
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|
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struct netlink_tap_net { |
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struct list_head netlink_tap_all; |
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struct mutex netlink_tap_lock; |
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}; |
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|
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int netlink_add_tap(struct netlink_tap *nt) |
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{ |
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struct net *net = dev_net(nt->dev); |
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struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
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|
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if (unlikely(nt->dev->type != ARPHRD_NETLINK)) |
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return -EINVAL; |
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|
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mutex_lock(&nn->netlink_tap_lock); |
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list_add_rcu(&nt->list, &nn->netlink_tap_all); |
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mutex_unlock(&nn->netlink_tap_lock); |
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|
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__module_get(nt->module); |
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|
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(netlink_add_tap); |
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|
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static int __netlink_remove_tap(struct netlink_tap *nt) |
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{ |
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struct net *net = dev_net(nt->dev); |
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struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
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bool found = false; |
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struct netlink_tap *tmp; |
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|
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mutex_lock(&nn->netlink_tap_lock); |
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list_for_each_entry(tmp, &nn->netlink_tap_all, list) { |
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if (nt == tmp) { |
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list_del_rcu(&nt->list); |
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found = true; |
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goto out; |
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} |
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} |
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pr_warn("__netlink_remove_tap: %p not found\n", nt); |
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out: |
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mutex_unlock(&nn->netlink_tap_lock); |
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|
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if (found) |
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module_put(nt->module); |
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|
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return found ? 0 : -ENODEV; |
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} |
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int netlink_remove_tap(struct netlink_tap *nt) |
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{ |
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int ret; |
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|
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ret = __netlink_remove_tap(nt); |
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synchronize_net(); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(netlink_remove_tap); |
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|
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static __net_init int netlink_tap_init_net(struct net *net) |
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{ |
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struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
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INIT_LIST_HEAD(&nn->netlink_tap_all); |
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mutex_init(&nn->netlink_tap_lock); |
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return 0; |
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} |
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static struct pernet_operations netlink_tap_net_ops = { |
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.init = netlink_tap_init_net, |
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.id = &netlink_tap_net_id, |
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.size = sizeof(struct netlink_tap_net), |
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}; |
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|
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static bool netlink_filter_tap(const struct sk_buff *skb) |
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{ |
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struct sock *sk = skb->sk; |
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|
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/* We take the more conservative approach and |
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* whitelist socket protocols that may pass. |
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*/ |
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switch (sk->sk_protocol) { |
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case NETLINK_ROUTE: |
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case NETLINK_USERSOCK: |
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case NETLINK_SOCK_DIAG: |
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case NETLINK_NFLOG: |
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case NETLINK_XFRM: |
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case NETLINK_FIB_LOOKUP: |
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case NETLINK_NETFILTER: |
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case NETLINK_GENERIC: |
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return true; |
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} |
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return false; |
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} |
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static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
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struct net_device *dev) |
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{ |
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struct sk_buff *nskb; |
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struct sock *sk = skb->sk; |
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int ret = -ENOMEM; |
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if (!net_eq(dev_net(dev), sock_net(sk))) |
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return 0; |
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dev_hold(dev); |
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if (is_vmalloc_addr(skb->head)) |
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nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
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else |
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nskb = skb_clone(skb, GFP_ATOMIC); |
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if (nskb) { |
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nskb->dev = dev; |
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nskb->protocol = htons((u16) sk->sk_protocol); |
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nskb->pkt_type = netlink_is_kernel(sk) ? |
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PACKET_KERNEL : PACKET_USER; |
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skb_reset_network_header(nskb); |
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ret = dev_queue_xmit(nskb); |
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if (unlikely(ret > 0)) |
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ret = net_xmit_errno(ret); |
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} |
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dev_put(dev); |
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return ret; |
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} |
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static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn) |
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{ |
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int ret; |
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struct netlink_tap *tmp; |
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|
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if (!netlink_filter_tap(skb)) |
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return; |
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list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) { |
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ret = __netlink_deliver_tap_skb(skb, tmp->dev); |
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if (unlikely(ret)) |
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break; |
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} |
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} |
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static void netlink_deliver_tap(struct net *net, struct sk_buff *skb) |
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{ |
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struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
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rcu_read_lock(); |
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if (unlikely(!list_empty(&nn->netlink_tap_all))) |
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__netlink_deliver_tap(skb, nn); |
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|
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rcu_read_unlock(); |
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} |
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static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
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struct sk_buff *skb) |
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{ |
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if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) |
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netlink_deliver_tap(sock_net(dst), skb); |
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} |
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static void netlink_overrun(struct sock *sk) |
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{ |
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struct netlink_sock *nlk = nlk_sk(sk); |
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|
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if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { |
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if (!test_and_set_bit(NETLINK_S_CONGESTED, |
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&nlk_sk(sk)->state)) { |
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sk->sk_err = ENOBUFS; |
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sk->sk_error_report(sk); |
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} |
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} |
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atomic_inc(&sk->sk_drops); |
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} |
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static void netlink_rcv_wake(struct sock *sk) |
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{ |
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struct netlink_sock *nlk = nlk_sk(sk); |
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|
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if (skb_queue_empty_lockless(&sk->sk_receive_queue)) |
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clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
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if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) |
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wake_up_interruptible(&nlk->wait); |
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} |
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|
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static void netlink_skb_destructor(struct sk_buff *skb) |
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{ |
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if (is_vmalloc_addr(skb->head)) { |
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if (!skb->cloned || |
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!atomic_dec_return(&(skb_shinfo(skb)->dataref))) |
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vfree(skb->head); |
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|
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skb->head = NULL; |
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} |
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if (skb->sk != NULL) |
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sock_rfree(skb); |
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} |
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|
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static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) |
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{ |
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WARN_ON(skb->sk != NULL); |
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skb->sk = sk; |
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skb->destructor = netlink_skb_destructor; |
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atomic_add(skb->truesize, &sk->sk_rmem_alloc); |
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sk_mem_charge(sk, skb->truesize); |
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} |
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|
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static void netlink_sock_destruct(struct sock *sk) |
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{ |
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struct netlink_sock *nlk = nlk_sk(sk); |
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|
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if (nlk->cb_running) { |
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if (nlk->cb.done) |
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nlk->cb.done(&nlk->cb); |
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module_put(nlk->cb.module); |
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kfree_skb(nlk->cb.skb); |
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} |
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|
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skb_queue_purge(&sk->sk_receive_queue); |
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|
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if (!sock_flag(sk, SOCK_DEAD)) { |
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printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
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return; |
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} |
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|
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WARN_ON(atomic_read(&sk->sk_rmem_alloc)); |
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WARN_ON(refcount_read(&sk->sk_wmem_alloc)); |
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WARN_ON(nlk_sk(sk)->groups); |
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} |
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|
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static void netlink_sock_destruct_work(struct work_struct *work) |
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{ |
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struct netlink_sock *nlk = container_of(work, struct netlink_sock, |
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work); |
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|
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sk_free(&nlk->sk); |
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} |
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|
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/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
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* SMP. Look, when several writers sleep and reader wakes them up, all but one |
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* immediately hit write lock and grab all the cpus. Exclusive sleep solves |
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* this, _but_ remember, it adds useless work on UP machines. |
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*/ |
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|
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void netlink_table_grab(void) |
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__acquires(nl_table_lock) |
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{ |
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might_sleep(); |
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|
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write_lock_irq(&nl_table_lock); |
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|
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if (atomic_read(&nl_table_users)) { |
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DECLARE_WAITQUEUE(wait, current); |
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|
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add_wait_queue_exclusive(&nl_table_wait, &wait); |
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for (;;) { |
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set_current_state(TASK_UNINTERRUPTIBLE); |
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if (atomic_read(&nl_table_users) == 0) |
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break; |
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write_unlock_irq(&nl_table_lock); |
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schedule(); |
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write_lock_irq(&nl_table_lock); |
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} |
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|
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__set_current_state(TASK_RUNNING); |
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remove_wait_queue(&nl_table_wait, &wait); |
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} |
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} |
|
|
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void netlink_table_ungrab(void) |
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__releases(nl_table_lock) |
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{ |
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write_unlock_irq(&nl_table_lock); |
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wake_up(&nl_table_wait); |
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} |
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|
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static inline void |
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netlink_lock_table(void) |
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{ |
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/* read_lock() synchronizes us to netlink_table_grab */ |
|
|
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read_lock(&nl_table_lock); |
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atomic_inc(&nl_table_users); |
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read_unlock(&nl_table_lock); |
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} |
|
|
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static inline void |
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netlink_unlock_table(void) |
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{ |
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if (atomic_dec_and_test(&nl_table_users)) |
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wake_up(&nl_table_wait); |
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} |
|
|
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struct netlink_compare_arg |
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{ |
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possible_net_t pnet; |
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u32 portid; |
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}; |
|
|
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/* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
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#define netlink_compare_arg_len \ |
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(offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) |
|
|
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static inline int netlink_compare(struct rhashtable_compare_arg *arg, |
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const void *ptr) |
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{ |
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const struct netlink_compare_arg *x = arg->key; |
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const struct netlink_sock *nlk = ptr; |
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|
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return nlk->portid != x->portid || |
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!net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
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} |
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|
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static void netlink_compare_arg_init(struct netlink_compare_arg *arg, |
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struct net *net, u32 portid) |
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{ |
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memset(arg, 0, sizeof(*arg)); |
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write_pnet(&arg->pnet, net); |
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arg->portid = portid; |
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} |
|
|
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static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
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struct net *net) |
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{ |
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struct netlink_compare_arg arg; |
|
|
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netlink_compare_arg_init(&arg, net, portid); |
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return rhashtable_lookup_fast(&table->hash, &arg, |
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netlink_rhashtable_params); |
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} |
|
|
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static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
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{ |
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struct netlink_compare_arg arg; |
|
|
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netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
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return rhashtable_lookup_insert_key(&table->hash, &arg, |
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&nlk_sk(sk)->node, |
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netlink_rhashtable_params); |
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} |
|
|
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static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
|
{ |
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struct netlink_table *table = &nl_table[protocol]; |
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struct sock *sk; |
|
|
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rcu_read_lock(); |
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sk = __netlink_lookup(table, portid, net); |
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if (sk) |
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sock_hold(sk); |
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rcu_read_unlock(); |
|
|
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return sk; |
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} |
|
|
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static const struct proto_ops netlink_ops; |
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|
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static void |
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netlink_update_listeners(struct sock *sk) |
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{ |
|
struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
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unsigned long mask; |
|
unsigned int i; |
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struct listeners *listeners; |
|
|
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listeners = nl_deref_protected(tbl->listeners); |
|
if (!listeners) |
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return; |
|
|
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for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
|
mask = 0; |
|
sk_for_each_bound(sk, &tbl->mc_list) { |
|
if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
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mask |= nlk_sk(sk)->groups[i]; |
|
} |
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listeners->masks[i] = mask; |
|
} |
|
/* this function is only called with the netlink table "grabbed", which |
|
* makes sure updates are visible before bind or setsockopt return. */ |
|
} |
|
|
|
static int netlink_insert(struct sock *sk, u32 portid) |
|
{ |
|
struct netlink_table *table = &nl_table[sk->sk_protocol]; |
|
int err; |
|
|
|
lock_sock(sk); |
|
|
|
err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
|
if (nlk_sk(sk)->bound) |
|
goto err; |
|
|
|
nlk_sk(sk)->portid = portid; |
|
sock_hold(sk); |
|
|
|
err = __netlink_insert(table, sk); |
|
if (err) { |
|
/* In case the hashtable backend returns with -EBUSY |
|
* from here, it must not escape to the caller. |
|
*/ |
|
if (unlikely(err == -EBUSY)) |
|
err = -EOVERFLOW; |
|
if (err == -EEXIST) |
|
err = -EADDRINUSE; |
|
sock_put(sk); |
|
goto err; |
|
} |
|
|
|
/* We need to ensure that the socket is hashed and visible. */ |
|
smp_wmb(); |
|
nlk_sk(sk)->bound = portid; |
|
|
|
err: |
|
release_sock(sk); |
|
return err; |
|
} |
|
|
|
static void netlink_remove(struct sock *sk) |
|
{ |
|
struct netlink_table *table; |
|
|
|
table = &nl_table[sk->sk_protocol]; |
|
if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
|
netlink_rhashtable_params)) { |
|
WARN_ON(refcount_read(&sk->sk_refcnt) == 1); |
|
__sock_put(sk); |
|
} |
|
|
|
netlink_table_grab(); |
|
if (nlk_sk(sk)->subscriptions) { |
|
__sk_del_bind_node(sk); |
|
netlink_update_listeners(sk); |
|
} |
|
if (sk->sk_protocol == NETLINK_GENERIC) |
|
atomic_inc(&genl_sk_destructing_cnt); |
|
netlink_table_ungrab(); |
|
} |
|
|
|
static struct proto netlink_proto = { |
|
.name = "NETLINK", |
|
.owner = THIS_MODULE, |
|
.obj_size = sizeof(struct netlink_sock), |
|
}; |
|
|
|
static int __netlink_create(struct net *net, struct socket *sock, |
|
struct mutex *cb_mutex, int protocol, |
|
int kern) |
|
{ |
|
struct sock *sk; |
|
struct netlink_sock *nlk; |
|
|
|
sock->ops = &netlink_ops; |
|
|
|
sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
|
if (!sk) |
|
return -ENOMEM; |
|
|
|
sock_init_data(sock, sk); |
|
|
|
nlk = nlk_sk(sk); |
|
if (cb_mutex) { |
|
nlk->cb_mutex = cb_mutex; |
|
} else { |
|
nlk->cb_mutex = &nlk->cb_def_mutex; |
|
mutex_init(nlk->cb_mutex); |
|
lockdep_set_class_and_name(nlk->cb_mutex, |
|
nlk_cb_mutex_keys + protocol, |
|
nlk_cb_mutex_key_strings[protocol]); |
|
} |
|
init_waitqueue_head(&nlk->wait); |
|
|
|
sk->sk_destruct = netlink_sock_destruct; |
|
sk->sk_protocol = protocol; |
|
return 0; |
|
} |
|
|
|
static int netlink_create(struct net *net, struct socket *sock, int protocol, |
|
int kern) |
|
{ |
|
struct module *module = NULL; |
|
struct mutex *cb_mutex; |
|
struct netlink_sock *nlk; |
|
int (*bind)(struct net *net, int group); |
|
void (*unbind)(struct net *net, int group); |
|
int err = 0; |
|
|
|
sock->state = SS_UNCONNECTED; |
|
|
|
if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) |
|
return -ESOCKTNOSUPPORT; |
|
|
|
if (protocol < 0 || protocol >= MAX_LINKS) |
|
return -EPROTONOSUPPORT; |
|
protocol = array_index_nospec(protocol, MAX_LINKS); |
|
|
|
netlink_lock_table(); |
|
#ifdef CONFIG_MODULES |
|
if (!nl_table[protocol].registered) { |
|
netlink_unlock_table(); |
|
request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
|
netlink_lock_table(); |
|
} |
|
#endif |
|
if (nl_table[protocol].registered && |
|
try_module_get(nl_table[protocol].module)) |
|
module = nl_table[protocol].module; |
|
else |
|
err = -EPROTONOSUPPORT; |
|
cb_mutex = nl_table[protocol].cb_mutex; |
|
bind = nl_table[protocol].bind; |
|
unbind = nl_table[protocol].unbind; |
|
netlink_unlock_table(); |
|
|
|
if (err < 0) |
|
goto out; |
|
|
|
err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
|
if (err < 0) |
|
goto out_module; |
|
|
|
local_bh_disable(); |
|
sock_prot_inuse_add(net, &netlink_proto, 1); |
|
local_bh_enable(); |
|
|
|
nlk = nlk_sk(sock->sk); |
|
nlk->module = module; |
|
nlk->netlink_bind = bind; |
|
nlk->netlink_unbind = unbind; |
|
out: |
|
return err; |
|
|
|
out_module: |
|
module_put(module); |
|
goto out; |
|
} |
|
|
|
static void deferred_put_nlk_sk(struct rcu_head *head) |
|
{ |
|
struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); |
|
struct sock *sk = &nlk->sk; |
|
|
|
kfree(nlk->groups); |
|
nlk->groups = NULL; |
|
|
|
if (!refcount_dec_and_test(&sk->sk_refcnt)) |
|
return; |
|
|
|
if (nlk->cb_running && nlk->cb.done) { |
|
INIT_WORK(&nlk->work, netlink_sock_destruct_work); |
|
schedule_work(&nlk->work); |
|
return; |
|
} |
|
|
|
sk_free(sk); |
|
} |
|
|
|
static int netlink_release(struct socket *sock) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk; |
|
|
|
if (!sk) |
|
return 0; |
|
|
|
netlink_remove(sk); |
|
sock_orphan(sk); |
|
nlk = nlk_sk(sk); |
|
|
|
/* |
|
* OK. Socket is unlinked, any packets that arrive now |
|
* will be purged. |
|
*/ |
|
|
|
/* must not acquire netlink_table_lock in any way again before unbind |
|
* and notifying genetlink is done as otherwise it might deadlock |
|
*/ |
|
if (nlk->netlink_unbind) { |
|
int i; |
|
|
|
for (i = 0; i < nlk->ngroups; i++) |
|
if (test_bit(i, nlk->groups)) |
|
nlk->netlink_unbind(sock_net(sk), i + 1); |
|
} |
|
if (sk->sk_protocol == NETLINK_GENERIC && |
|
atomic_dec_return(&genl_sk_destructing_cnt) == 0) |
|
wake_up(&genl_sk_destructing_waitq); |
|
|
|
sock->sk = NULL; |
|
wake_up_interruptible_all(&nlk->wait); |
|
|
|
skb_queue_purge(&sk->sk_write_queue); |
|
|
|
if (nlk->portid && nlk->bound) { |
|
struct netlink_notify n = { |
|
.net = sock_net(sk), |
|
.protocol = sk->sk_protocol, |
|
.portid = nlk->portid, |
|
}; |
|
blocking_notifier_call_chain(&netlink_chain, |
|
NETLINK_URELEASE, &n); |
|
} |
|
|
|
module_put(nlk->module); |
|
|
|
if (netlink_is_kernel(sk)) { |
|
netlink_table_grab(); |
|
BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
|
if (--nl_table[sk->sk_protocol].registered == 0) { |
|
struct listeners *old; |
|
|
|
old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); |
|
RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); |
|
kfree_rcu(old, rcu); |
|
nl_table[sk->sk_protocol].module = NULL; |
|
nl_table[sk->sk_protocol].bind = NULL; |
|
nl_table[sk->sk_protocol].unbind = NULL; |
|
nl_table[sk->sk_protocol].flags = 0; |
|
nl_table[sk->sk_protocol].registered = 0; |
|
} |
|
netlink_table_ungrab(); |
|
} |
|
|
|
local_bh_disable(); |
|
sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
|
local_bh_enable(); |
|
call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
|
return 0; |
|
} |
|
|
|
static int netlink_autobind(struct socket *sock) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct net *net = sock_net(sk); |
|
struct netlink_table *table = &nl_table[sk->sk_protocol]; |
|
s32 portid = task_tgid_vnr(current); |
|
int err; |
|
s32 rover = -4096; |
|
bool ok; |
|
|
|
retry: |
|
cond_resched(); |
|
rcu_read_lock(); |
|
ok = !__netlink_lookup(table, portid, net); |
|
rcu_read_unlock(); |
|
if (!ok) { |
|
/* Bind collision, search negative portid values. */ |
|
if (rover == -4096) |
|
/* rover will be in range [S32_MIN, -4097] */ |
|
rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); |
|
else if (rover >= -4096) |
|
rover = -4097; |
|
portid = rover--; |
|
goto retry; |
|
} |
|
|
|
err = netlink_insert(sk, portid); |
|
if (err == -EADDRINUSE) |
|
goto retry; |
|
|
|
/* If 2 threads race to autobind, that is fine. */ |
|
if (err == -EBUSY) |
|
err = 0; |
|
|
|
return err; |
|
} |
|
|
|
/** |
|
* __netlink_ns_capable - General netlink message capability test |
|
* @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. |
|
* @user_ns: The user namespace of the capability to use |
|
* @cap: The capability to use |
|
* |
|
* Test to see if the opener of the socket we received the message |
|
* from had when the netlink socket was created and the sender of the |
|
* message has the capability @cap in the user namespace @user_ns. |
|
*/ |
|
bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, |
|
struct user_namespace *user_ns, int cap) |
|
{ |
|
return ((nsp->flags & NETLINK_SKB_DST) || |
|
file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && |
|
ns_capable(user_ns, cap); |
|
} |
|
EXPORT_SYMBOL(__netlink_ns_capable); |
|
|
|
/** |
|
* netlink_ns_capable - General netlink message capability test |
|
* @skb: socket buffer holding a netlink command from userspace |
|
* @user_ns: The user namespace of the capability to use |
|
* @cap: The capability to use |
|
* |
|
* Test to see if the opener of the socket we received the message |
|
* from had when the netlink socket was created and the sender of the |
|
* message has the capability @cap in the user namespace @user_ns. |
|
*/ |
|
bool netlink_ns_capable(const struct sk_buff *skb, |
|
struct user_namespace *user_ns, int cap) |
|
{ |
|
return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); |
|
} |
|
EXPORT_SYMBOL(netlink_ns_capable); |
|
|
|
/** |
|
* netlink_capable - Netlink global message capability test |
|
* @skb: socket buffer holding a netlink command from userspace |
|
* @cap: The capability to use |
|
* |
|
* Test to see if the opener of the socket we received the message |
|
* from had when the netlink socket was created and the sender of the |
|
* message has the capability @cap in all user namespaces. |
|
*/ |
|
bool netlink_capable(const struct sk_buff *skb, int cap) |
|
{ |
|
return netlink_ns_capable(skb, &init_user_ns, cap); |
|
} |
|
EXPORT_SYMBOL(netlink_capable); |
|
|
|
/** |
|
* netlink_net_capable - Netlink network namespace message capability test |
|
* @skb: socket buffer holding a netlink command from userspace |
|
* @cap: The capability to use |
|
* |
|
* Test to see if the opener of the socket we received the message |
|
* from had when the netlink socket was created and the sender of the |
|
* message has the capability @cap over the network namespace of |
|
* the socket we received the message from. |
|
*/ |
|
bool netlink_net_capable(const struct sk_buff *skb, int cap) |
|
{ |
|
return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); |
|
} |
|
EXPORT_SYMBOL(netlink_net_capable); |
|
|
|
static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
|
{ |
|
return (nl_table[sock->sk->sk_protocol].flags & flag) || |
|
ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
|
} |
|
|
|
static void |
|
netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
|
|
if (nlk->subscriptions && !subscriptions) |
|
__sk_del_bind_node(sk); |
|
else if (!nlk->subscriptions && subscriptions) |
|
sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); |
|
nlk->subscriptions = subscriptions; |
|
} |
|
|
|
static int netlink_realloc_groups(struct sock *sk) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
unsigned int groups; |
|
unsigned long *new_groups; |
|
int err = 0; |
|
|
|
netlink_table_grab(); |
|
|
|
groups = nl_table[sk->sk_protocol].groups; |
|
if (!nl_table[sk->sk_protocol].registered) { |
|
err = -ENOENT; |
|
goto out_unlock; |
|
} |
|
|
|
if (nlk->ngroups >= groups) |
|
goto out_unlock; |
|
|
|
new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
|
if (new_groups == NULL) { |
|
err = -ENOMEM; |
|
goto out_unlock; |
|
} |
|
memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
|
NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
|
|
|
nlk->groups = new_groups; |
|
nlk->ngroups = groups; |
|
out_unlock: |
|
netlink_table_ungrab(); |
|
return err; |
|
} |
|
|
|
static void netlink_undo_bind(int group, long unsigned int groups, |
|
struct sock *sk) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
int undo; |
|
|
|
if (!nlk->netlink_unbind) |
|
return; |
|
|
|
for (undo = 0; undo < group; undo++) |
|
if (test_bit(undo, &groups)) |
|
nlk->netlink_unbind(sock_net(sk), undo + 1); |
|
} |
|
|
|
static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
|
int addr_len) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct net *net = sock_net(sk); |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
|
int err = 0; |
|
unsigned long groups; |
|
bool bound; |
|
|
|
if (addr_len < sizeof(struct sockaddr_nl)) |
|
return -EINVAL; |
|
|
|
if (nladdr->nl_family != AF_NETLINK) |
|
return -EINVAL; |
|
groups = nladdr->nl_groups; |
|
|
|
/* Only superuser is allowed to listen multicasts */ |
|
if (groups) { |
|
if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
|
return -EPERM; |
|
err = netlink_realloc_groups(sk); |
|
if (err) |
|
return err; |
|
} |
|
|
|
if (nlk->ngroups < BITS_PER_LONG) |
|
groups &= (1UL << nlk->ngroups) - 1; |
|
|
|
bound = nlk->bound; |
|
if (bound) { |
|
/* Ensure nlk->portid is up-to-date. */ |
|
smp_rmb(); |
|
|
|
if (nladdr->nl_pid != nlk->portid) |
|
return -EINVAL; |
|
} |
|
|
|
if (nlk->netlink_bind && groups) { |
|
int group; |
|
|
|
/* nl_groups is a u32, so cap the maximum groups we can bind */ |
|
for (group = 0; group < BITS_PER_TYPE(u32); group++) { |
|
if (!test_bit(group, &groups)) |
|
continue; |
|
err = nlk->netlink_bind(net, group + 1); |
|
if (!err) |
|
continue; |
|
netlink_undo_bind(group, groups, sk); |
|
return err; |
|
} |
|
} |
|
|
|
/* No need for barriers here as we return to user-space without |
|
* using any of the bound attributes. |
|
*/ |
|
netlink_lock_table(); |
|
if (!bound) { |
|
err = nladdr->nl_pid ? |
|
netlink_insert(sk, nladdr->nl_pid) : |
|
netlink_autobind(sock); |
|
if (err) { |
|
netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk); |
|
goto unlock; |
|
} |
|
} |
|
|
|
if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
|
goto unlock; |
|
netlink_unlock_table(); |
|
|
|
netlink_table_grab(); |
|
netlink_update_subscriptions(sk, nlk->subscriptions + |
|
hweight32(groups) - |
|
hweight32(nlk->groups[0])); |
|
nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
|
netlink_update_listeners(sk); |
|
netlink_table_ungrab(); |
|
|
|
return 0; |
|
|
|
unlock: |
|
netlink_unlock_table(); |
|
return err; |
|
} |
|
|
|
static int netlink_connect(struct socket *sock, struct sockaddr *addr, |
|
int alen, int flags) |
|
{ |
|
int err = 0; |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
|
|
|
if (alen < sizeof(addr->sa_family)) |
|
return -EINVAL; |
|
|
|
if (addr->sa_family == AF_UNSPEC) { |
|
sk->sk_state = NETLINK_UNCONNECTED; |
|
nlk->dst_portid = 0; |
|
nlk->dst_group = 0; |
|
return 0; |
|
} |
|
if (addr->sa_family != AF_NETLINK) |
|
return -EINVAL; |
|
|
|
if (alen < sizeof(struct sockaddr_nl)) |
|
return -EINVAL; |
|
|
|
if ((nladdr->nl_groups || nladdr->nl_pid) && |
|
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
|
return -EPERM; |
|
|
|
/* No need for barriers here as we return to user-space without |
|
* using any of the bound attributes. |
|
*/ |
|
if (!nlk->bound) |
|
err = netlink_autobind(sock); |
|
|
|
if (err == 0) { |
|
sk->sk_state = NETLINK_CONNECTED; |
|
nlk->dst_portid = nladdr->nl_pid; |
|
nlk->dst_group = ffs(nladdr->nl_groups); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
|
int peer) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
|
|
|
nladdr->nl_family = AF_NETLINK; |
|
nladdr->nl_pad = 0; |
|
|
|
if (peer) { |
|
nladdr->nl_pid = nlk->dst_portid; |
|
nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
|
} else { |
|
nladdr->nl_pid = nlk->portid; |
|
netlink_lock_table(); |
|
nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
|
netlink_unlock_table(); |
|
} |
|
return sizeof(*nladdr); |
|
} |
|
|
|
static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
/* try to hand this ioctl down to the NIC drivers. |
|
*/ |
|
return -ENOIOCTLCMD; |
|
} |
|
|
|
static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
|
{ |
|
struct sock *sock; |
|
struct netlink_sock *nlk; |
|
|
|
sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
|
if (!sock) |
|
return ERR_PTR(-ECONNREFUSED); |
|
|
|
/* Don't bother queuing skb if kernel socket has no input function */ |
|
nlk = nlk_sk(sock); |
|
if (sock->sk_state == NETLINK_CONNECTED && |
|
nlk->dst_portid != nlk_sk(ssk)->portid) { |
|
sock_put(sock); |
|
return ERR_PTR(-ECONNREFUSED); |
|
} |
|
return sock; |
|
} |
|
|
|
struct sock *netlink_getsockbyfilp(struct file *filp) |
|
{ |
|
struct inode *inode = file_inode(filp); |
|
struct sock *sock; |
|
|
|
if (!S_ISSOCK(inode->i_mode)) |
|
return ERR_PTR(-ENOTSOCK); |
|
|
|
sock = SOCKET_I(inode)->sk; |
|
if (sock->sk_family != AF_NETLINK) |
|
return ERR_PTR(-EINVAL); |
|
|
|
sock_hold(sock); |
|
return sock; |
|
} |
|
|
|
static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
|
int broadcast) |
|
{ |
|
struct sk_buff *skb; |
|
void *data; |
|
|
|
if (size <= NLMSG_GOODSIZE || broadcast) |
|
return alloc_skb(size, GFP_KERNEL); |
|
|
|
size = SKB_DATA_ALIGN(size) + |
|
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
|
|
|
data = vmalloc(size); |
|
if (data == NULL) |
|
return NULL; |
|
|
|
skb = __build_skb(data, size); |
|
if (skb == NULL) |
|
vfree(data); |
|
else |
|
skb->destructor = netlink_skb_destructor; |
|
|
|
return skb; |
|
} |
|
|
|
/* |
|
* Attach a skb to a netlink socket. |
|
* The caller must hold a reference to the destination socket. On error, the |
|
* reference is dropped. The skb is not send to the destination, just all |
|
* all error checks are performed and memory in the queue is reserved. |
|
* Return values: |
|
* < 0: error. skb freed, reference to sock dropped. |
|
* 0: continue |
|
* 1: repeat lookup - reference dropped while waiting for socket memory. |
|
*/ |
|
int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
|
long *timeo, struct sock *ssk) |
|
{ |
|
struct netlink_sock *nlk; |
|
|
|
nlk = nlk_sk(sk); |
|
|
|
if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
|
test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
|
DECLARE_WAITQUEUE(wait, current); |
|
if (!*timeo) { |
|
if (!ssk || netlink_is_kernel(ssk)) |
|
netlink_overrun(sk); |
|
sock_put(sk); |
|
kfree_skb(skb); |
|
return -EAGAIN; |
|
} |
|
|
|
__set_current_state(TASK_INTERRUPTIBLE); |
|
add_wait_queue(&nlk->wait, &wait); |
|
|
|
if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
|
test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
|
!sock_flag(sk, SOCK_DEAD)) |
|
*timeo = schedule_timeout(*timeo); |
|
|
|
__set_current_state(TASK_RUNNING); |
|
remove_wait_queue(&nlk->wait, &wait); |
|
sock_put(sk); |
|
|
|
if (signal_pending(current)) { |
|
kfree_skb(skb); |
|
return sock_intr_errno(*timeo); |
|
} |
|
return 1; |
|
} |
|
netlink_skb_set_owner_r(skb, sk); |
|
return 0; |
|
} |
|
|
|
static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
int len = skb->len; |
|
|
|
netlink_deliver_tap(sock_net(sk), skb); |
|
|
|
skb_queue_tail(&sk->sk_receive_queue, skb); |
|
sk->sk_data_ready(sk); |
|
return len; |
|
} |
|
|
|
int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
int len = __netlink_sendskb(sk, skb); |
|
|
|
sock_put(sk); |
|
return len; |
|
} |
|
|
|
void netlink_detachskb(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
kfree_skb(skb); |
|
sock_put(sk); |
|
} |
|
|
|
static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
|
{ |
|
int delta; |
|
|
|
WARN_ON(skb->sk != NULL); |
|
delta = skb->end - skb->tail; |
|
if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
|
return skb; |
|
|
|
if (skb_shared(skb)) { |
|
struct sk_buff *nskb = skb_clone(skb, allocation); |
|
if (!nskb) |
|
return skb; |
|
consume_skb(skb); |
|
skb = nskb; |
|
} |
|
|
|
pskb_expand_head(skb, 0, -delta, |
|
(allocation & ~__GFP_DIRECT_RECLAIM) | |
|
__GFP_NOWARN | __GFP_NORETRY); |
|
return skb; |
|
} |
|
|
|
static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
|
struct sock *ssk) |
|
{ |
|
int ret; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
|
|
ret = -ECONNREFUSED; |
|
if (nlk->netlink_rcv != NULL) { |
|
ret = skb->len; |
|
netlink_skb_set_owner_r(skb, sk); |
|
NETLINK_CB(skb).sk = ssk; |
|
netlink_deliver_tap_kernel(sk, ssk, skb); |
|
nlk->netlink_rcv(skb); |
|
consume_skb(skb); |
|
} else { |
|
kfree_skb(skb); |
|
} |
|
sock_put(sk); |
|
return ret; |
|
} |
|
|
|
int netlink_unicast(struct sock *ssk, struct sk_buff *skb, |
|
u32 portid, int nonblock) |
|
{ |
|
struct sock *sk; |
|
int err; |
|
long timeo; |
|
|
|
skb = netlink_trim(skb, gfp_any()); |
|
|
|
timeo = sock_sndtimeo(ssk, nonblock); |
|
retry: |
|
sk = netlink_getsockbyportid(ssk, portid); |
|
if (IS_ERR(sk)) { |
|
kfree_skb(skb); |
|
return PTR_ERR(sk); |
|
} |
|
if (netlink_is_kernel(sk)) |
|
return netlink_unicast_kernel(sk, skb, ssk); |
|
|
|
if (sk_filter(sk, skb)) { |
|
err = skb->len; |
|
kfree_skb(skb); |
|
sock_put(sk); |
|
return err; |
|
} |
|
|
|
err = netlink_attachskb(sk, skb, &timeo, ssk); |
|
if (err == 1) |
|
goto retry; |
|
if (err) |
|
return err; |
|
|
|
return netlink_sendskb(sk, skb); |
|
} |
|
EXPORT_SYMBOL(netlink_unicast); |
|
|
|
int netlink_has_listeners(struct sock *sk, unsigned int group) |
|
{ |
|
int res = 0; |
|
struct listeners *listeners; |
|
|
|
BUG_ON(!netlink_is_kernel(sk)); |
|
|
|
rcu_read_lock(); |
|
listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); |
|
|
|
if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
|
res = test_bit(group - 1, listeners->masks); |
|
|
|
rcu_read_unlock(); |
|
|
|
return res; |
|
} |
|
EXPORT_SYMBOL_GPL(netlink_has_listeners); |
|
|
|
bool netlink_strict_get_check(struct sk_buff *skb) |
|
{ |
|
const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk); |
|
|
|
return nlk->flags & NETLINK_F_STRICT_CHK; |
|
} |
|
EXPORT_SYMBOL_GPL(netlink_strict_get_check); |
|
|
|
static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && |
|
!test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
|
netlink_skb_set_owner_r(skb, sk); |
|
__netlink_sendskb(sk, skb); |
|
return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
|
} |
|
return -1; |
|
} |
|
|
|
struct netlink_broadcast_data { |
|
struct sock *exclude_sk; |
|
struct net *net; |
|
u32 portid; |
|
u32 group; |
|
int failure; |
|
int delivery_failure; |
|
int congested; |
|
int delivered; |
|
gfp_t allocation; |
|
struct sk_buff *skb, *skb2; |
|
int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
|
void *tx_data; |
|
}; |
|
|
|
static void do_one_broadcast(struct sock *sk, |
|
struct netlink_broadcast_data *p) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
int val; |
|
|
|
if (p->exclude_sk == sk) |
|
return; |
|
|
|
if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
|
!test_bit(p->group - 1, nlk->groups)) |
|
return; |
|
|
|
if (!net_eq(sock_net(sk), p->net)) { |
|
if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) |
|
return; |
|
|
|
if (!peernet_has_id(sock_net(sk), p->net)) |
|
return; |
|
|
|
if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, |
|
CAP_NET_BROADCAST)) |
|
return; |
|
} |
|
|
|
if (p->failure) { |
|
netlink_overrun(sk); |
|
return; |
|
} |
|
|
|
sock_hold(sk); |
|
if (p->skb2 == NULL) { |
|
if (skb_shared(p->skb)) { |
|
p->skb2 = skb_clone(p->skb, p->allocation); |
|
} else { |
|
p->skb2 = skb_get(p->skb); |
|
/* |
|
* skb ownership may have been set when |
|
* delivered to a previous socket. |
|
*/ |
|
skb_orphan(p->skb2); |
|
} |
|
} |
|
if (p->skb2 == NULL) { |
|
netlink_overrun(sk); |
|
/* Clone failed. Notify ALL listeners. */ |
|
p->failure = 1; |
|
if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
|
p->delivery_failure = 1; |
|
goto out; |
|
} |
|
if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { |
|
kfree_skb(p->skb2); |
|
p->skb2 = NULL; |
|
goto out; |
|
} |
|
if (sk_filter(sk, p->skb2)) { |
|
kfree_skb(p->skb2); |
|
p->skb2 = NULL; |
|
goto out; |
|
} |
|
NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); |
|
if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED) |
|
NETLINK_CB(p->skb2).nsid_is_set = true; |
|
val = netlink_broadcast_deliver(sk, p->skb2); |
|
if (val < 0) { |
|
netlink_overrun(sk); |
|
if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
|
p->delivery_failure = 1; |
|
} else { |
|
p->congested |= val; |
|
p->delivered = 1; |
|
p->skb2 = NULL; |
|
} |
|
out: |
|
sock_put(sk); |
|
} |
|
|
|
int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
|
u32 group, gfp_t allocation, |
|
int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), |
|
void *filter_data) |
|
{ |
|
struct net *net = sock_net(ssk); |
|
struct netlink_broadcast_data info; |
|
struct sock *sk; |
|
|
|
skb = netlink_trim(skb, allocation); |
|
|
|
info.exclude_sk = ssk; |
|
info.net = net; |
|
info.portid = portid; |
|
info.group = group; |
|
info.failure = 0; |
|
info.delivery_failure = 0; |
|
info.congested = 0; |
|
info.delivered = 0; |
|
info.allocation = allocation; |
|
info.skb = skb; |
|
info.skb2 = NULL; |
|
info.tx_filter = filter; |
|
info.tx_data = filter_data; |
|
|
|
/* While we sleep in clone, do not allow to change socket list */ |
|
|
|
netlink_lock_table(); |
|
|
|
sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
|
do_one_broadcast(sk, &info); |
|
|
|
consume_skb(skb); |
|
|
|
netlink_unlock_table(); |
|
|
|
if (info.delivery_failure) { |
|
kfree_skb(info.skb2); |
|
return -ENOBUFS; |
|
} |
|
consume_skb(info.skb2); |
|
|
|
if (info.delivered) { |
|
if (info.congested && gfpflags_allow_blocking(allocation)) |
|
yield(); |
|
return 0; |
|
} |
|
return -ESRCH; |
|
} |
|
EXPORT_SYMBOL(netlink_broadcast_filtered); |
|
|
|
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
|
u32 group, gfp_t allocation) |
|
{ |
|
return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
|
NULL, NULL); |
|
} |
|
EXPORT_SYMBOL(netlink_broadcast); |
|
|
|
struct netlink_set_err_data { |
|
struct sock *exclude_sk; |
|
u32 portid; |
|
u32 group; |
|
int code; |
|
}; |
|
|
|
static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
int ret = 0; |
|
|
|
if (sk == p->exclude_sk) |
|
goto out; |
|
|
|
if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
|
goto out; |
|
|
|
if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
|
!test_bit(p->group - 1, nlk->groups)) |
|
goto out; |
|
|
|
if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { |
|
ret = 1; |
|
goto out; |
|
} |
|
|
|
sk->sk_err = p->code; |
|
sk->sk_error_report(sk); |
|
out: |
|
return ret; |
|
} |
|
|
|
/** |
|
* netlink_set_err - report error to broadcast listeners |
|
* @ssk: the kernel netlink socket, as returned by netlink_kernel_create() |
|
* @portid: the PORTID of a process that we want to skip (if any) |
|
* @group: the broadcast group that will notice the error |
|
* @code: error code, must be negative (as usual in kernelspace) |
|
* |
|
* This function returns the number of broadcast listeners that have set the |
|
* NETLINK_NO_ENOBUFS socket option. |
|
*/ |
|
int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
|
{ |
|
struct netlink_set_err_data info; |
|
struct sock *sk; |
|
int ret = 0; |
|
|
|
info.exclude_sk = ssk; |
|
info.portid = portid; |
|
info.group = group; |
|
/* sk->sk_err wants a positive error value */ |
|
info.code = -code; |
|
|
|
read_lock(&nl_table_lock); |
|
|
|
sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
|
ret += do_one_set_err(sk, &info); |
|
|
|
read_unlock(&nl_table_lock); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL(netlink_set_err); |
|
|
|
/* must be called with netlink table grabbed */ |
|
static void netlink_update_socket_mc(struct netlink_sock *nlk, |
|
unsigned int group, |
|
int is_new) |
|
{ |
|
int old, new = !!is_new, subscriptions; |
|
|
|
old = test_bit(group - 1, nlk->groups); |
|
subscriptions = nlk->subscriptions - old + new; |
|
if (new) |
|
__set_bit(group - 1, nlk->groups); |
|
else |
|
__clear_bit(group - 1, nlk->groups); |
|
netlink_update_subscriptions(&nlk->sk, subscriptions); |
|
netlink_update_listeners(&nlk->sk); |
|
} |
|
|
|
static int netlink_setsockopt(struct socket *sock, int level, int optname, |
|
sockptr_t optval, unsigned int optlen) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
unsigned int val = 0; |
|
int err; |
|
|
|
if (level != SOL_NETLINK) |
|
return -ENOPROTOOPT; |
|
|
|
if (optlen >= sizeof(int) && |
|
copy_from_sockptr(&val, optval, sizeof(val))) |
|
return -EFAULT; |
|
|
|
switch (optname) { |
|
case NETLINK_PKTINFO: |
|
if (val) |
|
nlk->flags |= NETLINK_F_RECV_PKTINFO; |
|
else |
|
nlk->flags &= ~NETLINK_F_RECV_PKTINFO; |
|
err = 0; |
|
break; |
|
case NETLINK_ADD_MEMBERSHIP: |
|
case NETLINK_DROP_MEMBERSHIP: { |
|
if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
|
return -EPERM; |
|
err = netlink_realloc_groups(sk); |
|
if (err) |
|
return err; |
|
if (!val || val - 1 >= nlk->ngroups) |
|
return -EINVAL; |
|
if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
|
err = nlk->netlink_bind(sock_net(sk), val); |
|
if (err) |
|
return err; |
|
} |
|
netlink_table_grab(); |
|
netlink_update_socket_mc(nlk, val, |
|
optname == NETLINK_ADD_MEMBERSHIP); |
|
netlink_table_ungrab(); |
|
if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
|
nlk->netlink_unbind(sock_net(sk), val); |
|
|
|
err = 0; |
|
break; |
|
} |
|
case NETLINK_BROADCAST_ERROR: |
|
if (val) |
|
nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; |
|
else |
|
nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; |
|
err = 0; |
|
break; |
|
case NETLINK_NO_ENOBUFS: |
|
if (val) { |
|
nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; |
|
clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
|
wake_up_interruptible(&nlk->wait); |
|
} else { |
|
nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; |
|
} |
|
err = 0; |
|
break; |
|
case NETLINK_LISTEN_ALL_NSID: |
|
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) |
|
return -EPERM; |
|
|
|
if (val) |
|
nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; |
|
else |
|
nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; |
|
err = 0; |
|
break; |
|
case NETLINK_CAP_ACK: |
|
if (val) |
|
nlk->flags |= NETLINK_F_CAP_ACK; |
|
else |
|
nlk->flags &= ~NETLINK_F_CAP_ACK; |
|
err = 0; |
|
break; |
|
case NETLINK_EXT_ACK: |
|
if (val) |
|
nlk->flags |= NETLINK_F_EXT_ACK; |
|
else |
|
nlk->flags &= ~NETLINK_F_EXT_ACK; |
|
err = 0; |
|
break; |
|
case NETLINK_GET_STRICT_CHK: |
|
if (val) |
|
nlk->flags |= NETLINK_F_STRICT_CHK; |
|
else |
|
nlk->flags &= ~NETLINK_F_STRICT_CHK; |
|
err = 0; |
|
break; |
|
default: |
|
err = -ENOPROTOOPT; |
|
} |
|
return err; |
|
} |
|
|
|
static int netlink_getsockopt(struct socket *sock, int level, int optname, |
|
char __user *optval, int __user *optlen) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
int len, val, err; |
|
|
|
if (level != SOL_NETLINK) |
|
return -ENOPROTOOPT; |
|
|
|
if (get_user(len, optlen)) |
|
return -EFAULT; |
|
if (len < 0) |
|
return -EINVAL; |
|
|
|
switch (optname) { |
|
case NETLINK_PKTINFO: |
|
if (len < sizeof(int)) |
|
return -EINVAL; |
|
len = sizeof(int); |
|
val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; |
|
if (put_user(len, optlen) || |
|
put_user(val, optval)) |
|
return -EFAULT; |
|
err = 0; |
|
break; |
|
case NETLINK_BROADCAST_ERROR: |
|
if (len < sizeof(int)) |
|
return -EINVAL; |
|
len = sizeof(int); |
|
val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; |
|
if (put_user(len, optlen) || |
|
put_user(val, optval)) |
|
return -EFAULT; |
|
err = 0; |
|
break; |
|
case NETLINK_NO_ENOBUFS: |
|
if (len < sizeof(int)) |
|
return -EINVAL; |
|
len = sizeof(int); |
|
val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; |
|
if (put_user(len, optlen) || |
|
put_user(val, optval)) |
|
return -EFAULT; |
|
err = 0; |
|
break; |
|
case NETLINK_LIST_MEMBERSHIPS: { |
|
int pos, idx, shift; |
|
|
|
err = 0; |
|
netlink_lock_table(); |
|
for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
|
if (len - pos < sizeof(u32)) |
|
break; |
|
|
|
idx = pos / sizeof(unsigned long); |
|
shift = (pos % sizeof(unsigned long)) * 8; |
|
if (put_user((u32)(nlk->groups[idx] >> shift), |
|
(u32 __user *)(optval + pos))) { |
|
err = -EFAULT; |
|
break; |
|
} |
|
} |
|
if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) |
|
err = -EFAULT; |
|
netlink_unlock_table(); |
|
break; |
|
} |
|
case NETLINK_CAP_ACK: |
|
if (len < sizeof(int)) |
|
return -EINVAL; |
|
len = sizeof(int); |
|
val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; |
|
if (put_user(len, optlen) || |
|
put_user(val, optval)) |
|
return -EFAULT; |
|
err = 0; |
|
break; |
|
case NETLINK_EXT_ACK: |
|
if (len < sizeof(int)) |
|
return -EINVAL; |
|
len = sizeof(int); |
|
val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0; |
|
if (put_user(len, optlen) || put_user(val, optval)) |
|
return -EFAULT; |
|
err = 0; |
|
break; |
|
case NETLINK_GET_STRICT_CHK: |
|
if (len < sizeof(int)) |
|
return -EINVAL; |
|
len = sizeof(int); |
|
val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0; |
|
if (put_user(len, optlen) || put_user(val, optval)) |
|
return -EFAULT; |
|
err = 0; |
|
break; |
|
default: |
|
err = -ENOPROTOOPT; |
|
} |
|
return err; |
|
} |
|
|
|
static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) |
|
{ |
|
struct nl_pktinfo info; |
|
|
|
info.group = NETLINK_CB(skb).dst_group; |
|
put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); |
|
} |
|
|
|
static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
|
struct sk_buff *skb) |
|
{ |
|
if (!NETLINK_CB(skb).nsid_is_set) |
|
return; |
|
|
|
put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), |
|
&NETLINK_CB(skb).nsid); |
|
} |
|
|
|
static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
|
{ |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
|
u32 dst_portid; |
|
u32 dst_group; |
|
struct sk_buff *skb; |
|
int err; |
|
struct scm_cookie scm; |
|
u32 netlink_skb_flags = 0; |
|
|
|
if (msg->msg_flags & MSG_OOB) |
|
return -EOPNOTSUPP; |
|
|
|
err = scm_send(sock, msg, &scm, true); |
|
if (err < 0) |
|
return err; |
|
|
|
if (msg->msg_namelen) { |
|
err = -EINVAL; |
|
if (msg->msg_namelen < sizeof(struct sockaddr_nl)) |
|
goto out; |
|
if (addr->nl_family != AF_NETLINK) |
|
goto out; |
|
dst_portid = addr->nl_pid; |
|
dst_group = ffs(addr->nl_groups); |
|
err = -EPERM; |
|
if ((dst_group || dst_portid) && |
|
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
|
goto out; |
|
netlink_skb_flags |= NETLINK_SKB_DST; |
|
} else { |
|
dst_portid = nlk->dst_portid; |
|
dst_group = nlk->dst_group; |
|
} |
|
|
|
if (!nlk->bound) { |
|
err = netlink_autobind(sock); |
|
if (err) |
|
goto out; |
|
} else { |
|
/* Ensure nlk is hashed and visible. */ |
|
smp_rmb(); |
|
} |
|
|
|
err = -EMSGSIZE; |
|
if (len > sk->sk_sndbuf - 32) |
|
goto out; |
|
err = -ENOBUFS; |
|
skb = netlink_alloc_large_skb(len, dst_group); |
|
if (skb == NULL) |
|
goto out; |
|
|
|
NETLINK_CB(skb).portid = nlk->portid; |
|
NETLINK_CB(skb).dst_group = dst_group; |
|
NETLINK_CB(skb).creds = scm.creds; |
|
NETLINK_CB(skb).flags = netlink_skb_flags; |
|
|
|
err = -EFAULT; |
|
if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
|
kfree_skb(skb); |
|
goto out; |
|
} |
|
|
|
err = security_netlink_send(sk, skb); |
|
if (err) { |
|
kfree_skb(skb); |
|
goto out; |
|
} |
|
|
|
if (dst_group) { |
|
refcount_inc(&skb->users); |
|
netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
|
} |
|
err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags & MSG_DONTWAIT); |
|
|
|
out: |
|
scm_destroy(&scm); |
|
return err; |
|
} |
|
|
|
static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
|
int flags) |
|
{ |
|
struct scm_cookie scm; |
|
struct sock *sk = sock->sk; |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
int noblock = flags & MSG_DONTWAIT; |
|
size_t copied; |
|
struct sk_buff *skb, *data_skb; |
|
int err, ret; |
|
|
|
if (flags & MSG_OOB) |
|
return -EOPNOTSUPP; |
|
|
|
copied = 0; |
|
|
|
skb = skb_recv_datagram(sk, flags, noblock, &err); |
|
if (skb == NULL) |
|
goto out; |
|
|
|
data_skb = skb; |
|
|
|
#ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
|
if (unlikely(skb_shinfo(skb)->frag_list)) { |
|
/* |
|
* If this skb has a frag_list, then here that means that we |
|
* will have to use the frag_list skb's data for compat tasks |
|
* and the regular skb's data for normal (non-compat) tasks. |
|
* |
|
* If we need to send the compat skb, assign it to the |
|
* 'data_skb' variable so that it will be used below for data |
|
* copying. We keep 'skb' for everything else, including |
|
* freeing both later. |
|
*/ |
|
if (flags & MSG_CMSG_COMPAT) |
|
data_skb = skb_shinfo(skb)->frag_list; |
|
} |
|
#endif |
|
|
|
/* Record the max length of recvmsg() calls for future allocations */ |
|
nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); |
|
nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, |
|
SKB_WITH_OVERHEAD(32768)); |
|
|
|
copied = data_skb->len; |
|
if (len < copied) { |
|
msg->msg_flags |= MSG_TRUNC; |
|
copied = len; |
|
} |
|
|
|
skb_reset_transport_header(data_skb); |
|
err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
|
|
|
if (msg->msg_name) { |
|
DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
|
addr->nl_family = AF_NETLINK; |
|
addr->nl_pad = 0; |
|
addr->nl_pid = NETLINK_CB(skb).portid; |
|
addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
|
msg->msg_namelen = sizeof(*addr); |
|
} |
|
|
|
if (nlk->flags & NETLINK_F_RECV_PKTINFO) |
|
netlink_cmsg_recv_pktinfo(msg, skb); |
|
if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) |
|
netlink_cmsg_listen_all_nsid(sk, msg, skb); |
|
|
|
memset(&scm, 0, sizeof(scm)); |
|
scm.creds = *NETLINK_CREDS(skb); |
|
if (flags & MSG_TRUNC) |
|
copied = data_skb->len; |
|
|
|
skb_free_datagram(sk, skb); |
|
|
|
if (nlk->cb_running && |
|
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { |
|
ret = netlink_dump(sk); |
|
if (ret) { |
|
sk->sk_err = -ret; |
|
sk->sk_error_report(sk); |
|
} |
|
} |
|
|
|
scm_recv(sock, msg, &scm, flags); |
|
out: |
|
netlink_rcv_wake(sk); |
|
return err ? : copied; |
|
} |
|
|
|
static void netlink_data_ready(struct sock *sk) |
|
{ |
|
BUG(); |
|
} |
|
|
|
/* |
|
* We export these functions to other modules. They provide a |
|
* complete set of kernel non-blocking support for message |
|
* queueing. |
|
*/ |
|
|
|
struct sock * |
|
__netlink_kernel_create(struct net *net, int unit, struct module *module, |
|
struct netlink_kernel_cfg *cfg) |
|
{ |
|
struct socket *sock; |
|
struct sock *sk; |
|
struct netlink_sock *nlk; |
|
struct listeners *listeners = NULL; |
|
struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
|
unsigned int groups; |
|
|
|
BUG_ON(!nl_table); |
|
|
|
if (unit < 0 || unit >= MAX_LINKS) |
|
return NULL; |
|
|
|
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) |
|
return NULL; |
|
|
|
if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) |
|
goto out_sock_release_nosk; |
|
|
|
sk = sock->sk; |
|
|
|
if (!cfg || cfg->groups < 32) |
|
groups = 32; |
|
else |
|
groups = cfg->groups; |
|
|
|
listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
|
if (!listeners) |
|
goto out_sock_release; |
|
|
|
sk->sk_data_ready = netlink_data_ready; |
|
if (cfg && cfg->input) |
|
nlk_sk(sk)->netlink_rcv = cfg->input; |
|
|
|
if (netlink_insert(sk, 0)) |
|
goto out_sock_release; |
|
|
|
nlk = nlk_sk(sk); |
|
nlk->flags |= NETLINK_F_KERNEL_SOCKET; |
|
|
|
netlink_table_grab(); |
|
if (!nl_table[unit].registered) { |
|
nl_table[unit].groups = groups; |
|
rcu_assign_pointer(nl_table[unit].listeners, listeners); |
|
nl_table[unit].cb_mutex = cb_mutex; |
|
nl_table[unit].module = module; |
|
if (cfg) { |
|
nl_table[unit].bind = cfg->bind; |
|
nl_table[unit].unbind = cfg->unbind; |
|
nl_table[unit].flags = cfg->flags; |
|
if (cfg->compare) |
|
nl_table[unit].compare = cfg->compare; |
|
} |
|
nl_table[unit].registered = 1; |
|
} else { |
|
kfree(listeners); |
|
nl_table[unit].registered++; |
|
} |
|
netlink_table_ungrab(); |
|
return sk; |
|
|
|
out_sock_release: |
|
kfree(listeners); |
|
netlink_kernel_release(sk); |
|
return NULL; |
|
|
|
out_sock_release_nosk: |
|
sock_release(sock); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(__netlink_kernel_create); |
|
|
|
void |
|
netlink_kernel_release(struct sock *sk) |
|
{ |
|
if (sk == NULL || sk->sk_socket == NULL) |
|
return; |
|
|
|
sock_release(sk->sk_socket); |
|
} |
|
EXPORT_SYMBOL(netlink_kernel_release); |
|
|
|
int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
|
{ |
|
struct listeners *new, *old; |
|
struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
|
|
|
if (groups < 32) |
|
groups = 32; |
|
|
|
if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
|
new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
|
if (!new) |
|
return -ENOMEM; |
|
old = nl_deref_protected(tbl->listeners); |
|
memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
|
rcu_assign_pointer(tbl->listeners, new); |
|
|
|
kfree_rcu(old, rcu); |
|
} |
|
tbl->groups = groups; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* netlink_change_ngroups - change number of multicast groups |
|
* |
|
* This changes the number of multicast groups that are available |
|
* on a certain netlink family. Note that it is not possible to |
|
* change the number of groups to below 32. Also note that it does |
|
* not implicitly call netlink_clear_multicast_users() when the |
|
* number of groups is reduced. |
|
* |
|
* @sk: The kernel netlink socket, as returned by netlink_kernel_create(). |
|
* @groups: The new number of groups. |
|
*/ |
|
int netlink_change_ngroups(struct sock *sk, unsigned int groups) |
|
{ |
|
int err; |
|
|
|
netlink_table_grab(); |
|
err = __netlink_change_ngroups(sk, groups); |
|
netlink_table_ungrab(); |
|
|
|
return err; |
|
} |
|
|
|
void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
|
{ |
|
struct sock *sk; |
|
struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
|
|
|
sk_for_each_bound(sk, &tbl->mc_list) |
|
netlink_update_socket_mc(nlk_sk(sk), group, 0); |
|
} |
|
|
|
struct nlmsghdr * |
|
__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
|
{ |
|
struct nlmsghdr *nlh; |
|
int size = nlmsg_msg_size(len); |
|
|
|
nlh = skb_put(skb, NLMSG_ALIGN(size)); |
|
nlh->nlmsg_type = type; |
|
nlh->nlmsg_len = size; |
|
nlh->nlmsg_flags = flags; |
|
nlh->nlmsg_pid = portid; |
|
nlh->nlmsg_seq = seq; |
|
if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) |
|
memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
|
return nlh; |
|
} |
|
EXPORT_SYMBOL(__nlmsg_put); |
|
|
|
/* |
|
* It looks a bit ugly. |
|
* It would be better to create kernel thread. |
|
*/ |
|
|
|
static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb, |
|
struct netlink_callback *cb, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct nlmsghdr *nlh; |
|
|
|
nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno), |
|
NLM_F_MULTI | cb->answer_flags); |
|
if (WARN_ON(!nlh)) |
|
return -ENOBUFS; |
|
|
|
nl_dump_check_consistent(cb, nlh); |
|
memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); |
|
|
|
if (extack->_msg && nlk->flags & NETLINK_F_EXT_ACK) { |
|
nlh->nlmsg_flags |= NLM_F_ACK_TLVS; |
|
if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)) |
|
nlmsg_end(skb, nlh); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int netlink_dump(struct sock *sk) |
|
{ |
|
struct netlink_sock *nlk = nlk_sk(sk); |
|
struct netlink_ext_ack extack = {}; |
|
struct netlink_callback *cb; |
|
struct sk_buff *skb = NULL; |
|
struct module *module; |
|
int err = -ENOBUFS; |
|
int alloc_min_size; |
|
int alloc_size; |
|
|
|
mutex_lock(nlk->cb_mutex); |
|
if (!nlk->cb_running) { |
|
err = -EINVAL; |
|
goto errout_skb; |
|
} |
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
|
goto errout_skb; |
|
|
|
/* NLMSG_GOODSIZE is small to avoid high order allocations being |
|
* required, but it makes sense to _attempt_ a 16K bytes allocation |
|
* to reduce number of system calls on dump operations, if user |
|
* ever provided a big enough buffer. |
|
*/ |
|
cb = &nlk->cb; |
|
alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); |
|
|
|
if (alloc_min_size < nlk->max_recvmsg_len) { |
|
alloc_size = nlk->max_recvmsg_len; |
|
skb = alloc_skb(alloc_size, |
|
(GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | |
|
__GFP_NOWARN | __GFP_NORETRY); |
|
} |
|
if (!skb) { |
|
alloc_size = alloc_min_size; |
|
skb = alloc_skb(alloc_size, GFP_KERNEL); |
|
} |
|
if (!skb) |
|
goto errout_skb; |
|
|
|
/* Trim skb to allocated size. User is expected to provide buffer as |
|
* large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at |
|
* netlink_recvmsg())). dump will pack as many smaller messages as |
|
* could fit within the allocated skb. skb is typically allocated |
|
* with larger space than required (could be as much as near 2x the |
|
* requested size with align to next power of 2 approach). Allowing |
|
* dump to use the excess space makes it difficult for a user to have a |
|
* reasonable static buffer based on the expected largest dump of a |
|
* single netdev. The outcome is MSG_TRUNC error. |
|
*/ |
|
skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
|
netlink_skb_set_owner_r(skb, sk); |
|
|
|
if (nlk->dump_done_errno > 0) { |
|
cb->extack = &extack; |
|
nlk->dump_done_errno = cb->dump(skb, cb); |
|
cb->extack = NULL; |
|
} |
|
|
|
if (nlk->dump_done_errno > 0 || |
|
skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { |
|
mutex_unlock(nlk->cb_mutex); |
|
|
|
if (sk_filter(sk, skb)) |
|
kfree_skb(skb); |
|
else |
|
__netlink_sendskb(sk, skb); |
|
return 0; |
|
} |
|
|
|
if (netlink_dump_done(nlk, skb, cb, &extack)) |
|
goto errout_skb; |
|
|
|
#ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
|
/* frag_list skb's data is used for compat tasks |
|
* and the regular skb's data for normal (non-compat) tasks. |
|
* See netlink_recvmsg(). |
|
*/ |
|
if (unlikely(skb_shinfo(skb)->frag_list)) { |
|
if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, &extack)) |
|
goto errout_skb; |
|
} |
|
#endif |
|
|
|
if (sk_filter(sk, skb)) |
|
kfree_skb(skb); |
|
else |
|
__netlink_sendskb(sk, skb); |
|
|
|
if (cb->done) |
|
cb->done(cb); |
|
|
|
nlk->cb_running = false; |
|
module = cb->module; |
|
skb = cb->skb; |
|
mutex_unlock(nlk->cb_mutex); |
|
module_put(module); |
|
consume_skb(skb); |
|
return 0; |
|
|
|
errout_skb: |
|
mutex_unlock(nlk->cb_mutex); |
|
kfree_skb(skb); |
|
return err; |
|
} |
|
|
|
int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
|
const struct nlmsghdr *nlh, |
|
struct netlink_dump_control *control) |
|
{ |
|
struct netlink_sock *nlk, *nlk2; |
|
struct netlink_callback *cb; |
|
struct sock *sk; |
|
int ret; |
|
|
|
refcount_inc(&skb->users); |
|
|
|
sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
|
if (sk == NULL) { |
|
ret = -ECONNREFUSED; |
|
goto error_free; |
|
} |
|
|
|
nlk = nlk_sk(sk); |
|
mutex_lock(nlk->cb_mutex); |
|
/* A dump is in progress... */ |
|
if (nlk->cb_running) { |
|
ret = -EBUSY; |
|
goto error_unlock; |
|
} |
|
/* add reference of module which cb->dump belongs to */ |
|
if (!try_module_get(control->module)) { |
|
ret = -EPROTONOSUPPORT; |
|
goto error_unlock; |
|
} |
|
|
|
cb = &nlk->cb; |
|
memset(cb, 0, sizeof(*cb)); |
|
cb->dump = control->dump; |
|
cb->done = control->done; |
|
cb->nlh = nlh; |
|
cb->data = control->data; |
|
cb->module = control->module; |
|
cb->min_dump_alloc = control->min_dump_alloc; |
|
cb->skb = skb; |
|
|
|
nlk2 = nlk_sk(NETLINK_CB(skb).sk); |
|
cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK); |
|
|
|
if (control->start) { |
|
ret = control->start(cb); |
|
if (ret) |
|
goto error_put; |
|
} |
|
|
|
nlk->cb_running = true; |
|
nlk->dump_done_errno = INT_MAX; |
|
|
|
mutex_unlock(nlk->cb_mutex); |
|
|
|
ret = netlink_dump(sk); |
|
|
|
sock_put(sk); |
|
|
|
if (ret) |
|
return ret; |
|
|
|
/* We successfully started a dump, by returning -EINTR we |
|
* signal not to send ACK even if it was requested. |
|
*/ |
|
return -EINTR; |
|
|
|
error_put: |
|
module_put(control->module); |
|
error_unlock: |
|
sock_put(sk); |
|
mutex_unlock(nlk->cb_mutex); |
|
error_free: |
|
kfree_skb(skb); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL(__netlink_dump_start); |
|
|
|
void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, |
|
const struct netlink_ext_ack *extack) |
|
{ |
|
struct sk_buff *skb; |
|
struct nlmsghdr *rep; |
|
struct nlmsgerr *errmsg; |
|
size_t payload = sizeof(*errmsg); |
|
size_t tlvlen = 0; |
|
struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
|
unsigned int flags = 0; |
|
bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK; |
|
|
|
/* Error messages get the original request appened, unless the user |
|
* requests to cap the error message, and get extra error data if |
|
* requested. |
|
*/ |
|
if (nlk_has_extack && extack && extack->_msg) |
|
tlvlen += nla_total_size(strlen(extack->_msg) + 1); |
|
|
|
if (err && !(nlk->flags & NETLINK_F_CAP_ACK)) |
|
payload += nlmsg_len(nlh); |
|
else |
|
flags |= NLM_F_CAPPED; |
|
if (err && nlk_has_extack && extack && extack->bad_attr) |
|
tlvlen += nla_total_size(sizeof(u32)); |
|
if (nlk_has_extack && extack && extack->cookie_len) |
|
tlvlen += nla_total_size(extack->cookie_len); |
|
if (err && nlk_has_extack && extack && extack->policy) |
|
tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); |
|
|
|
if (tlvlen) |
|
flags |= NLM_F_ACK_TLVS; |
|
|
|
skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); |
|
if (!skb) { |
|
NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; |
|
NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk); |
|
return; |
|
} |
|
|
|
rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
|
NLMSG_ERROR, payload, flags); |
|
errmsg = nlmsg_data(rep); |
|
errmsg->error = err; |
|
memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); |
|
|
|
if (nlk_has_extack && extack) { |
|
if (extack->_msg) { |
|
WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, |
|
extack->_msg)); |
|
} |
|
if (err && extack->bad_attr && |
|
!WARN_ON((u8 *)extack->bad_attr < in_skb->data || |
|
(u8 *)extack->bad_attr >= in_skb->data + |
|
in_skb->len)) |
|
WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, |
|
(u8 *)extack->bad_attr - |
|
(u8 *)nlh)); |
|
if (extack->cookie_len) |
|
WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, |
|
extack->cookie_len, extack->cookie)); |
|
if (extack->policy) |
|
netlink_policy_dump_write_attr(skb, extack->policy, |
|
NLMSGERR_ATTR_POLICY); |
|
} |
|
|
|
nlmsg_end(skb, rep); |
|
|
|
netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
|
} |
|
EXPORT_SYMBOL(netlink_ack); |
|
|
|
int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
|
struct nlmsghdr *, |
|
struct netlink_ext_ack *)) |
|
{ |
|
struct netlink_ext_ack extack; |
|
struct nlmsghdr *nlh; |
|
int err; |
|
|
|
while (skb->len >= nlmsg_total_size(0)) { |
|
int msglen; |
|
|
|
memset(&extack, 0, sizeof(extack)); |
|
nlh = nlmsg_hdr(skb); |
|
err = 0; |
|
|
|
if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
|
return 0; |
|
|
|
/* Only requests are handled by the kernel */ |
|
if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) |
|
goto ack; |
|
|
|
/* Skip control messages */ |
|
if (nlh->nlmsg_type < NLMSG_MIN_TYPE) |
|
goto ack; |
|
|
|
err = cb(skb, nlh, &extack); |
|
if (err == -EINTR) |
|
goto skip; |
|
|
|
ack: |
|
if (nlh->nlmsg_flags & NLM_F_ACK || err) |
|
netlink_ack(skb, nlh, err, &extack); |
|
|
|
skip: |
|
msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
|
if (msglen > skb->len) |
|
msglen = skb->len; |
|
skb_pull(skb, msglen); |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL(netlink_rcv_skb); |
|
|
|
/** |
|
* nlmsg_notify - send a notification netlink message |
|
* @sk: netlink socket to use |
|
* @skb: notification message |
|
* @portid: destination netlink portid for reports or 0 |
|
* @group: destination multicast group or 0 |
|
* @report: 1 to report back, 0 to disable |
|
* @flags: allocation flags |
|
*/ |
|
int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
|
unsigned int group, int report, gfp_t flags) |
|
{ |
|
int err = 0; |
|
|
|
if (group) { |
|
int exclude_portid = 0; |
|
|
|
if (report) { |
|
refcount_inc(&skb->users); |
|
exclude_portid = portid; |
|
} |
|
|
|
/* errors reported via destination sk->sk_err, but propagate |
|
* delivery errors if NETLINK_BROADCAST_ERROR flag is set */ |
|
err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
|
} |
|
|
|
if (report) { |
|
int err2; |
|
|
|
err2 = nlmsg_unicast(sk, skb, portid); |
|
if (!err || err == -ESRCH) |
|
err = err2; |
|
} |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL(nlmsg_notify); |
|
|
|
#ifdef CONFIG_PROC_FS |
|
struct nl_seq_iter { |
|
struct seq_net_private p; |
|
struct rhashtable_iter hti; |
|
int link; |
|
}; |
|
|
|
static void netlink_walk_start(struct nl_seq_iter *iter) |
|
{ |
|
rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti); |
|
rhashtable_walk_start(&iter->hti); |
|
} |
|
|
|
static void netlink_walk_stop(struct nl_seq_iter *iter) |
|
{ |
|
rhashtable_walk_stop(&iter->hti); |
|
rhashtable_walk_exit(&iter->hti); |
|
} |
|
|
|
static void *__netlink_seq_next(struct seq_file *seq) |
|
{ |
|
struct nl_seq_iter *iter = seq->private; |
|
struct netlink_sock *nlk; |
|
|
|
do { |
|
for (;;) { |
|
nlk = rhashtable_walk_next(&iter->hti); |
|
|
|
if (IS_ERR(nlk)) { |
|
if (PTR_ERR(nlk) == -EAGAIN) |
|
continue; |
|
|
|
return nlk; |
|
} |
|
|
|
if (nlk) |
|
break; |
|
|
|
netlink_walk_stop(iter); |
|
if (++iter->link >= MAX_LINKS) |
|
return NULL; |
|
|
|
netlink_walk_start(iter); |
|
} |
|
} while (sock_net(&nlk->sk) != seq_file_net(seq)); |
|
|
|
return nlk; |
|
} |
|
|
|
static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
|
__acquires(RCU) |
|
{ |
|
struct nl_seq_iter *iter = seq->private; |
|
void *obj = SEQ_START_TOKEN; |
|
loff_t pos; |
|
|
|
iter->link = 0; |
|
|
|
netlink_walk_start(iter); |
|
|
|
for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) |
|
obj = __netlink_seq_next(seq); |
|
|
|
return obj; |
|
} |
|
|
|
static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
|
{ |
|
++*pos; |
|
return __netlink_seq_next(seq); |
|
} |
|
|
|
static void netlink_native_seq_stop(struct seq_file *seq, void *v) |
|
{ |
|
struct nl_seq_iter *iter = seq->private; |
|
|
|
if (iter->link >= MAX_LINKS) |
|
return; |
|
|
|
netlink_walk_stop(iter); |
|
} |
|
|
|
|
|
static int netlink_native_seq_show(struct seq_file *seq, void *v) |
|
{ |
|
if (v == SEQ_START_TOKEN) { |
|
seq_puts(seq, |
|
"sk Eth Pid Groups " |
|
"Rmem Wmem Dump Locks Drops Inode\n"); |
|
} else { |
|
struct sock *s = v; |
|
struct netlink_sock *nlk = nlk_sk(s); |
|
|
|
seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n", |
|
s, |
|
s->sk_protocol, |
|
nlk->portid, |
|
nlk->groups ? (u32)nlk->groups[0] : 0, |
|
sk_rmem_alloc_get(s), |
|
sk_wmem_alloc_get(s), |
|
nlk->cb_running, |
|
refcount_read(&s->sk_refcnt), |
|
atomic_read(&s->sk_drops), |
|
sock_i_ino(s) |
|
); |
|
|
|
} |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_BPF_SYSCALL |
|
struct bpf_iter__netlink { |
|
__bpf_md_ptr(struct bpf_iter_meta *, meta); |
|
__bpf_md_ptr(struct netlink_sock *, sk); |
|
}; |
|
|
|
DEFINE_BPF_ITER_FUNC(netlink, struct bpf_iter_meta *meta, struct netlink_sock *sk) |
|
|
|
static int netlink_prog_seq_show(struct bpf_prog *prog, |
|
struct bpf_iter_meta *meta, |
|
void *v) |
|
{ |
|
struct bpf_iter__netlink ctx; |
|
|
|
meta->seq_num--; /* skip SEQ_START_TOKEN */ |
|
ctx.meta = meta; |
|
ctx.sk = nlk_sk((struct sock *)v); |
|
return bpf_iter_run_prog(prog, &ctx); |
|
} |
|
|
|
static int netlink_seq_show(struct seq_file *seq, void *v) |
|
{ |
|
struct bpf_iter_meta meta; |
|
struct bpf_prog *prog; |
|
|
|
meta.seq = seq; |
|
prog = bpf_iter_get_info(&meta, false); |
|
if (!prog) |
|
return netlink_native_seq_show(seq, v); |
|
|
|
if (v != SEQ_START_TOKEN) |
|
return netlink_prog_seq_show(prog, &meta, v); |
|
|
|
return 0; |
|
} |
|
|
|
static void netlink_seq_stop(struct seq_file *seq, void *v) |
|
{ |
|
struct bpf_iter_meta meta; |
|
struct bpf_prog *prog; |
|
|
|
if (!v) { |
|
meta.seq = seq; |
|
prog = bpf_iter_get_info(&meta, true); |
|
if (prog) |
|
(void)netlink_prog_seq_show(prog, &meta, v); |
|
} |
|
|
|
netlink_native_seq_stop(seq, v); |
|
} |
|
#else |
|
static int netlink_seq_show(struct seq_file *seq, void *v) |
|
{ |
|
return netlink_native_seq_show(seq, v); |
|
} |
|
|
|
static void netlink_seq_stop(struct seq_file *seq, void *v) |
|
{ |
|
netlink_native_seq_stop(seq, v); |
|
} |
|
#endif |
|
|
|
static const struct seq_operations netlink_seq_ops = { |
|
.start = netlink_seq_start, |
|
.next = netlink_seq_next, |
|
.stop = netlink_seq_stop, |
|
.show = netlink_seq_show, |
|
}; |
|
#endif |
|
|
|
int netlink_register_notifier(struct notifier_block *nb) |
|
{ |
|
return blocking_notifier_chain_register(&netlink_chain, nb); |
|
} |
|
EXPORT_SYMBOL(netlink_register_notifier); |
|
|
|
int netlink_unregister_notifier(struct notifier_block *nb) |
|
{ |
|
return blocking_notifier_chain_unregister(&netlink_chain, nb); |
|
} |
|
EXPORT_SYMBOL(netlink_unregister_notifier); |
|
|
|
static const struct proto_ops netlink_ops = { |
|
.family = PF_NETLINK, |
|
.owner = THIS_MODULE, |
|
.release = netlink_release, |
|
.bind = netlink_bind, |
|
.connect = netlink_connect, |
|
.socketpair = sock_no_socketpair, |
|
.accept = sock_no_accept, |
|
.getname = netlink_getname, |
|
.poll = datagram_poll, |
|
.ioctl = netlink_ioctl, |
|
.listen = sock_no_listen, |
|
.shutdown = sock_no_shutdown, |
|
.setsockopt = netlink_setsockopt, |
|
.getsockopt = netlink_getsockopt, |
|
.sendmsg = netlink_sendmsg, |
|
.recvmsg = netlink_recvmsg, |
|
.mmap = sock_no_mmap, |
|
.sendpage = sock_no_sendpage, |
|
}; |
|
|
|
static const struct net_proto_family netlink_family_ops = { |
|
.family = PF_NETLINK, |
|
.create = netlink_create, |
|
.owner = THIS_MODULE, /* for consistency 8) */ |
|
}; |
|
|
|
static int __net_init netlink_net_init(struct net *net) |
|
{ |
|
#ifdef CONFIG_PROC_FS |
|
if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops, |
|
sizeof(struct nl_seq_iter))) |
|
return -ENOMEM; |
|
#endif |
|
return 0; |
|
} |
|
|
|
static void __net_exit netlink_net_exit(struct net *net) |
|
{ |
|
#ifdef CONFIG_PROC_FS |
|
remove_proc_entry("netlink", net->proc_net); |
|
#endif |
|
} |
|
|
|
static void __init netlink_add_usersock_entry(void) |
|
{ |
|
struct listeners *listeners; |
|
int groups = 32; |
|
|
|
listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
|
if (!listeners) |
|
panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
|
|
|
netlink_table_grab(); |
|
|
|
nl_table[NETLINK_USERSOCK].groups = groups; |
|
rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
|
nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
|
nl_table[NETLINK_USERSOCK].registered = 1; |
|
nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
|
|
|
netlink_table_ungrab(); |
|
} |
|
|
|
static struct pernet_operations __net_initdata netlink_net_ops = { |
|
.init = netlink_net_init, |
|
.exit = netlink_net_exit, |
|
}; |
|
|
|
static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
|
{ |
|
const struct netlink_sock *nlk = data; |
|
struct netlink_compare_arg arg; |
|
|
|
netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
|
return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
|
} |
|
|
|
static const struct rhashtable_params netlink_rhashtable_params = { |
|
.head_offset = offsetof(struct netlink_sock, node), |
|
.key_len = netlink_compare_arg_len, |
|
.obj_hashfn = netlink_hash, |
|
.obj_cmpfn = netlink_compare, |
|
.automatic_shrinking = true, |
|
}; |
|
|
|
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
|
BTF_ID_LIST(btf_netlink_sock_id) |
|
BTF_ID(struct, netlink_sock) |
|
|
|
static const struct bpf_iter_seq_info netlink_seq_info = { |
|
.seq_ops = &netlink_seq_ops, |
|
.init_seq_private = bpf_iter_init_seq_net, |
|
.fini_seq_private = bpf_iter_fini_seq_net, |
|
.seq_priv_size = sizeof(struct nl_seq_iter), |
|
}; |
|
|
|
static struct bpf_iter_reg netlink_reg_info = { |
|
.target = "netlink", |
|
.ctx_arg_info_size = 1, |
|
.ctx_arg_info = { |
|
{ offsetof(struct bpf_iter__netlink, sk), |
|
PTR_TO_BTF_ID_OR_NULL }, |
|
}, |
|
.seq_info = &netlink_seq_info, |
|
}; |
|
|
|
static int __init bpf_iter_register(void) |
|
{ |
|
netlink_reg_info.ctx_arg_info[0].btf_id = *btf_netlink_sock_id; |
|
return bpf_iter_reg_target(&netlink_reg_info); |
|
} |
|
#endif |
|
|
|
static int __init netlink_proto_init(void) |
|
{ |
|
int i; |
|
int err = proto_register(&netlink_proto, 0); |
|
|
|
if (err != 0) |
|
goto out; |
|
|
|
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
|
err = bpf_iter_register(); |
|
if (err) |
|
goto out; |
|
#endif |
|
|
|
BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb)); |
|
|
|
nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
|
if (!nl_table) |
|
goto panic; |
|
|
|
for (i = 0; i < MAX_LINKS; i++) { |
|
if (rhashtable_init(&nl_table[i].hash, |
|
&netlink_rhashtable_params) < 0) { |
|
while (--i > 0) |
|
rhashtable_destroy(&nl_table[i].hash); |
|
kfree(nl_table); |
|
goto panic; |
|
} |
|
} |
|
|
|
netlink_add_usersock_entry(); |
|
|
|
sock_register(&netlink_family_ops); |
|
register_pernet_subsys(&netlink_net_ops); |
|
register_pernet_subsys(&netlink_tap_net_ops); |
|
/* The netlink device handler may be needed early. */ |
|
rtnetlink_init(); |
|
out: |
|
return err; |
|
panic: |
|
panic("netlink_init: Cannot allocate nl_table\n"); |
|
} |
|
|
|
core_initcall(netlink_proto_init);
|
|
|