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1457 lines
36 KiB
1457 lines
36 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* linux/net/ipv4/arp.c |
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* |
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* Copyright (C) 1994 by Florian La Roche |
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* |
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* This module implements the Address Resolution Protocol ARP (RFC 826), |
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* which is used to convert IP addresses (or in the future maybe other |
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* high-level addresses) into a low-level hardware address (like an Ethernet |
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* address). |
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* |
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* Fixes: |
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* Alan Cox : Removed the Ethernet assumptions in |
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* Florian's code |
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* Alan Cox : Fixed some small errors in the ARP |
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* logic |
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* Alan Cox : Allow >4K in /proc |
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* Alan Cox : Make ARP add its own protocol entry |
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* Ross Martin : Rewrote arp_rcv() and arp_get_info() |
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* Stephen Henson : Add AX25 support to arp_get_info() |
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* Alan Cox : Drop data when a device is downed. |
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* Alan Cox : Use init_timer(). |
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* Alan Cox : Double lock fixes. |
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* Martin Seine : Move the arphdr structure |
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* to if_arp.h for compatibility. |
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* with BSD based programs. |
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* Andrew Tridgell : Added ARP netmask code and |
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* re-arranged proxy handling. |
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* Alan Cox : Changed to use notifiers. |
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* Niibe Yutaka : Reply for this device or proxies only. |
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* Alan Cox : Don't proxy across hardware types! |
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* Jonathan Naylor : Added support for NET/ROM. |
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* Mike Shaver : RFC1122 checks. |
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* Jonathan Naylor : Only lookup the hardware address for |
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* the correct hardware type. |
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* Germano Caronni : Assorted subtle races. |
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* Craig Schlenter : Don't modify permanent entry |
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* during arp_rcv. |
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* Russ Nelson : Tidied up a few bits. |
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* Alexey Kuznetsov: Major changes to caching and behaviour, |
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* eg intelligent arp probing and |
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* generation |
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* of host down events. |
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* Alan Cox : Missing unlock in device events. |
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* Eckes : ARP ioctl control errors. |
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* Alexey Kuznetsov: Arp free fix. |
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* Manuel Rodriguez: Gratuitous ARP. |
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* Jonathan Layes : Added arpd support through kerneld |
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* message queue (960314) |
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* Mike Shaver : /proc/sys/net/ipv4/arp_* support |
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* Mike McLagan : Routing by source |
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* Stuart Cheshire : Metricom and grat arp fixes |
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* *** FOR 2.1 clean this up *** |
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* Lawrence V. Stefani: (08/12/96) Added FDDI support. |
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* Alan Cox : Took the AP1000 nasty FDDI hack and |
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* folded into the mainstream FDDI code. |
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* Ack spit, Linus how did you allow that |
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* one in... |
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* Jes Sorensen : Make FDDI work again in 2.1.x and |
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* clean up the APFDDI & gen. FDDI bits. |
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* Alexey Kuznetsov: new arp state machine; |
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* now it is in net/core/neighbour.c. |
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* Krzysztof Halasa: Added Frame Relay ARP support. |
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* Arnaldo C. Melo : convert /proc/net/arp to seq_file |
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* Shmulik Hen: Split arp_send to arp_create and |
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* arp_xmit so intermediate drivers like |
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* bonding can change the skb before |
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* sending (e.g. insert 8021q tag). |
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* Harald Welte : convert to make use of jenkins hash |
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* Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. |
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*/ |
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|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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|
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/string.h> |
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#include <linux/kernel.h> |
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#include <linux/capability.h> |
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#include <linux/socket.h> |
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#include <linux/sockios.h> |
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#include <linux/errno.h> |
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#include <linux/in.h> |
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#include <linux/mm.h> |
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#include <linux/inet.h> |
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#include <linux/inetdevice.h> |
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#include <linux/netdevice.h> |
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#include <linux/etherdevice.h> |
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#include <linux/fddidevice.h> |
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#include <linux/if_arp.h> |
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#include <linux/skbuff.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/stat.h> |
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#include <linux/init.h> |
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#include <linux/net.h> |
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#include <linux/rcupdate.h> |
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#include <linux/slab.h> |
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#ifdef CONFIG_SYSCTL |
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#include <linux/sysctl.h> |
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#endif |
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|
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#include <net/net_namespace.h> |
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#include <net/ip.h> |
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#include <net/icmp.h> |
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#include <net/route.h> |
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#include <net/protocol.h> |
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#include <net/tcp.h> |
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#include <net/sock.h> |
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#include <net/arp.h> |
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#include <net/ax25.h> |
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#include <net/netrom.h> |
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#include <net/dst_metadata.h> |
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#include <net/ip_tunnels.h> |
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|
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#include <linux/uaccess.h> |
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|
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#include <linux/netfilter_arp.h> |
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|
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/* |
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* Interface to generic neighbour cache. |
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*/ |
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static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd); |
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static bool arp_key_eq(const struct neighbour *n, const void *pkey); |
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static int arp_constructor(struct neighbour *neigh); |
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static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); |
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static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); |
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static void parp_redo(struct sk_buff *skb); |
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static int arp_is_multicast(const void *pkey); |
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|
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static const struct neigh_ops arp_generic_ops = { |
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.family = AF_INET, |
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.solicit = arp_solicit, |
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.error_report = arp_error_report, |
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.output = neigh_resolve_output, |
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.connected_output = neigh_connected_output, |
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}; |
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|
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static const struct neigh_ops arp_hh_ops = { |
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.family = AF_INET, |
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.solicit = arp_solicit, |
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.error_report = arp_error_report, |
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.output = neigh_resolve_output, |
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.connected_output = neigh_resolve_output, |
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}; |
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|
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static const struct neigh_ops arp_direct_ops = { |
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.family = AF_INET, |
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.output = neigh_direct_output, |
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.connected_output = neigh_direct_output, |
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}; |
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|
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struct neigh_table arp_tbl = { |
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.family = AF_INET, |
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.key_len = 4, |
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.protocol = cpu_to_be16(ETH_P_IP), |
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.hash = arp_hash, |
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.key_eq = arp_key_eq, |
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.constructor = arp_constructor, |
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.proxy_redo = parp_redo, |
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.is_multicast = arp_is_multicast, |
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.id = "arp_cache", |
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.parms = { |
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.tbl = &arp_tbl, |
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.reachable_time = 30 * HZ, |
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.data = { |
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[NEIGH_VAR_MCAST_PROBES] = 3, |
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[NEIGH_VAR_UCAST_PROBES] = 3, |
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[NEIGH_VAR_RETRANS_TIME] = 1 * HZ, |
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[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, |
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[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, |
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[NEIGH_VAR_GC_STALETIME] = 60 * HZ, |
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[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, |
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[NEIGH_VAR_PROXY_QLEN] = 64, |
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[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, |
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[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, |
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[NEIGH_VAR_LOCKTIME] = 1 * HZ, |
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}, |
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}, |
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.gc_interval = 30 * HZ, |
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.gc_thresh1 = 128, |
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.gc_thresh2 = 512, |
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.gc_thresh3 = 1024, |
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}; |
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EXPORT_SYMBOL(arp_tbl); |
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|
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int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) |
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{ |
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switch (dev->type) { |
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case ARPHRD_ETHER: |
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case ARPHRD_FDDI: |
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case ARPHRD_IEEE802: |
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ip_eth_mc_map(addr, haddr); |
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return 0; |
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case ARPHRD_INFINIBAND: |
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ip_ib_mc_map(addr, dev->broadcast, haddr); |
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return 0; |
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case ARPHRD_IPGRE: |
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ip_ipgre_mc_map(addr, dev->broadcast, haddr); |
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return 0; |
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default: |
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if (dir) { |
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memcpy(haddr, dev->broadcast, dev->addr_len); |
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return 0; |
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} |
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} |
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return -EINVAL; |
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} |
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static u32 arp_hash(const void *pkey, |
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const struct net_device *dev, |
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__u32 *hash_rnd) |
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{ |
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return arp_hashfn(pkey, dev, hash_rnd); |
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} |
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|
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static bool arp_key_eq(const struct neighbour *neigh, const void *pkey) |
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{ |
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return neigh_key_eq32(neigh, pkey); |
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} |
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|
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static int arp_constructor(struct neighbour *neigh) |
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{ |
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__be32 addr; |
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struct net_device *dev = neigh->dev; |
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struct in_device *in_dev; |
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struct neigh_parms *parms; |
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u32 inaddr_any = INADDR_ANY; |
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|
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if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) |
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memcpy(neigh->primary_key, &inaddr_any, arp_tbl.key_len); |
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addr = *(__be32 *)neigh->primary_key; |
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rcu_read_lock(); |
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in_dev = __in_dev_get_rcu(dev); |
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if (!in_dev) { |
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rcu_read_unlock(); |
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return -EINVAL; |
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} |
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neigh->type = inet_addr_type_dev_table(dev_net(dev), dev, addr); |
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parms = in_dev->arp_parms; |
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__neigh_parms_put(neigh->parms); |
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neigh->parms = neigh_parms_clone(parms); |
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rcu_read_unlock(); |
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|
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if (!dev->header_ops) { |
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neigh->nud_state = NUD_NOARP; |
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neigh->ops = &arp_direct_ops; |
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neigh->output = neigh_direct_output; |
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} else { |
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/* Good devices (checked by reading texts, but only Ethernet is |
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tested) |
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|
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ARPHRD_ETHER: (ethernet, apfddi) |
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ARPHRD_FDDI: (fddi) |
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ARPHRD_IEEE802: (tr) |
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ARPHRD_METRICOM: (strip) |
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ARPHRD_ARCNET: |
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etc. etc. etc. |
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|
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ARPHRD_IPDDP will also work, if author repairs it. |
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I did not it, because this driver does not work even |
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in old paradigm. |
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*/ |
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|
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if (neigh->type == RTN_MULTICAST) { |
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neigh->nud_state = NUD_NOARP; |
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arp_mc_map(addr, neigh->ha, dev, 1); |
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} else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { |
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neigh->nud_state = NUD_NOARP; |
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memcpy(neigh->ha, dev->dev_addr, dev->addr_len); |
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} else if (neigh->type == RTN_BROADCAST || |
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(dev->flags & IFF_POINTOPOINT)) { |
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neigh->nud_state = NUD_NOARP; |
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memcpy(neigh->ha, dev->broadcast, dev->addr_len); |
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} |
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if (dev->header_ops->cache) |
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neigh->ops = &arp_hh_ops; |
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else |
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neigh->ops = &arp_generic_ops; |
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|
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if (neigh->nud_state & NUD_VALID) |
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neigh->output = neigh->ops->connected_output; |
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else |
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neigh->output = neigh->ops->output; |
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} |
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return 0; |
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} |
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static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) |
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{ |
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dst_link_failure(skb); |
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kfree_skb(skb); |
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} |
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|
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/* Create and send an arp packet. */ |
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static void arp_send_dst(int type, int ptype, __be32 dest_ip, |
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struct net_device *dev, __be32 src_ip, |
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const unsigned char *dest_hw, |
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const unsigned char *src_hw, |
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const unsigned char *target_hw, |
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struct dst_entry *dst) |
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{ |
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struct sk_buff *skb; |
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|
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/* arp on this interface. */ |
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if (dev->flags & IFF_NOARP) |
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return; |
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skb = arp_create(type, ptype, dest_ip, dev, src_ip, |
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dest_hw, src_hw, target_hw); |
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if (!skb) |
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return; |
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|
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skb_dst_set(skb, dst_clone(dst)); |
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arp_xmit(skb); |
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} |
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|
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void arp_send(int type, int ptype, __be32 dest_ip, |
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struct net_device *dev, __be32 src_ip, |
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const unsigned char *dest_hw, const unsigned char *src_hw, |
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const unsigned char *target_hw) |
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{ |
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arp_send_dst(type, ptype, dest_ip, dev, src_ip, dest_hw, src_hw, |
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target_hw, NULL); |
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} |
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EXPORT_SYMBOL(arp_send); |
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|
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static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) |
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{ |
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__be32 saddr = 0; |
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u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL; |
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struct net_device *dev = neigh->dev; |
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__be32 target = *(__be32 *)neigh->primary_key; |
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int probes = atomic_read(&neigh->probes); |
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struct in_device *in_dev; |
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struct dst_entry *dst = NULL; |
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|
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rcu_read_lock(); |
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in_dev = __in_dev_get_rcu(dev); |
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if (!in_dev) { |
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rcu_read_unlock(); |
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return; |
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} |
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switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { |
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default: |
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case 0: /* By default announce any local IP */ |
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if (skb && inet_addr_type_dev_table(dev_net(dev), dev, |
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ip_hdr(skb)->saddr) == RTN_LOCAL) |
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saddr = ip_hdr(skb)->saddr; |
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break; |
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case 1: /* Restrict announcements of saddr in same subnet */ |
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if (!skb) |
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break; |
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saddr = ip_hdr(skb)->saddr; |
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if (inet_addr_type_dev_table(dev_net(dev), dev, |
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saddr) == RTN_LOCAL) { |
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/* saddr should be known to target */ |
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if (inet_addr_onlink(in_dev, target, saddr)) |
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break; |
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} |
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saddr = 0; |
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break; |
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case 2: /* Avoid secondary IPs, get a primary/preferred one */ |
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break; |
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} |
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rcu_read_unlock(); |
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|
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if (!saddr) |
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saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); |
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|
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probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); |
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if (probes < 0) { |
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if (!(neigh->nud_state & NUD_VALID)) |
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pr_debug("trying to ucast probe in NUD_INVALID\n"); |
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neigh_ha_snapshot(dst_ha, neigh, dev); |
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dst_hw = dst_ha; |
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} else { |
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probes -= NEIGH_VAR(neigh->parms, APP_PROBES); |
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if (probes < 0) { |
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neigh_app_ns(neigh); |
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return; |
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} |
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} |
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|
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if (skb && !(dev->priv_flags & IFF_XMIT_DST_RELEASE)) |
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dst = skb_dst(skb); |
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arp_send_dst(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, |
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dst_hw, dev->dev_addr, NULL, dst); |
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} |
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|
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static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) |
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{ |
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struct net *net = dev_net(in_dev->dev); |
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int scope; |
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|
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switch (IN_DEV_ARP_IGNORE(in_dev)) { |
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case 0: /* Reply, the tip is already validated */ |
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return 0; |
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case 1: /* Reply only if tip is configured on the incoming interface */ |
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sip = 0; |
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scope = RT_SCOPE_HOST; |
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break; |
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case 2: /* |
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* Reply only if tip is configured on the incoming interface |
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* and is in same subnet as sip |
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*/ |
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scope = RT_SCOPE_HOST; |
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break; |
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case 3: /* Do not reply for scope host addresses */ |
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sip = 0; |
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scope = RT_SCOPE_LINK; |
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in_dev = NULL; |
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break; |
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case 4: /* Reserved */ |
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case 5: |
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case 6: |
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case 7: |
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return 0; |
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case 8: /* Do not reply */ |
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return 1; |
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default: |
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return 0; |
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} |
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return !inet_confirm_addr(net, in_dev, sip, tip, scope); |
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} |
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|
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static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) |
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{ |
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struct rtable *rt; |
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int flag = 0; |
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/*unsigned long now; */ |
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struct net *net = dev_net(dev); |
|
|
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rt = ip_route_output(net, sip, tip, 0, l3mdev_master_ifindex_rcu(dev)); |
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if (IS_ERR(rt)) |
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return 1; |
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if (rt->dst.dev != dev) { |
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__NET_INC_STATS(net, LINUX_MIB_ARPFILTER); |
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flag = 1; |
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} |
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ip_rt_put(rt); |
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return flag; |
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} |
|
|
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/* |
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* Check if we can use proxy ARP for this path |
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*/ |
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static inline int arp_fwd_proxy(struct in_device *in_dev, |
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struct net_device *dev, struct rtable *rt) |
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{ |
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struct in_device *out_dev; |
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int imi, omi = -1; |
|
|
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if (rt->dst.dev == dev) |
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return 0; |
|
|
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if (!IN_DEV_PROXY_ARP(in_dev)) |
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return 0; |
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imi = IN_DEV_MEDIUM_ID(in_dev); |
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if (imi == 0) |
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return 1; |
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if (imi == -1) |
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return 0; |
|
|
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/* place to check for proxy_arp for routes */ |
|
|
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out_dev = __in_dev_get_rcu(rt->dst.dev); |
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if (out_dev) |
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omi = IN_DEV_MEDIUM_ID(out_dev); |
|
|
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return omi != imi && omi != -1; |
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} |
|
|
|
/* |
|
* Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) |
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* |
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* RFC3069 supports proxy arp replies back to the same interface. This |
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* is done to support (ethernet) switch features, like RFC 3069, where |
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* the individual ports are not allowed to communicate with each |
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* other, BUT they are allowed to talk to the upstream router. As |
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* described in RFC 3069, it is possible to allow these hosts to |
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* communicate through the upstream router, by proxy_arp'ing. |
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* |
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* RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" |
|
* |
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* This technology is known by different names: |
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* In RFC 3069 it is called VLAN Aggregation. |
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* Cisco and Allied Telesyn call it Private VLAN. |
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* Hewlett-Packard call it Source-Port filtering or port-isolation. |
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* Ericsson call it MAC-Forced Forwarding (RFC Draft). |
|
* |
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*/ |
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static inline int arp_fwd_pvlan(struct in_device *in_dev, |
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struct net_device *dev, struct rtable *rt, |
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__be32 sip, __be32 tip) |
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{ |
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/* Private VLAN is only concerned about the same ethernet segment */ |
|
if (rt->dst.dev != dev) |
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return 0; |
|
|
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/* Don't reply on self probes (often done by windowz boxes)*/ |
|
if (sip == tip) |
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return 0; |
|
|
|
if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) |
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return 1; |
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else |
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return 0; |
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} |
|
|
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/* |
|
* Interface to link layer: send routine and receive handler. |
|
*/ |
|
|
|
/* |
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* Create an arp packet. If dest_hw is not set, we create a broadcast |
|
* message. |
|
*/ |
|
struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, |
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struct net_device *dev, __be32 src_ip, |
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const unsigned char *dest_hw, |
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const unsigned char *src_hw, |
|
const unsigned char *target_hw) |
|
{ |
|
struct sk_buff *skb; |
|
struct arphdr *arp; |
|
unsigned char *arp_ptr; |
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int hlen = LL_RESERVED_SPACE(dev); |
|
int tlen = dev->needed_tailroom; |
|
|
|
/* |
|
* Allocate a buffer |
|
*/ |
|
|
|
skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC); |
|
if (!skb) |
|
return NULL; |
|
|
|
skb_reserve(skb, hlen); |
|
skb_reset_network_header(skb); |
|
arp = skb_put(skb, arp_hdr_len(dev)); |
|
skb->dev = dev; |
|
skb->protocol = htons(ETH_P_ARP); |
|
if (!src_hw) |
|
src_hw = dev->dev_addr; |
|
if (!dest_hw) |
|
dest_hw = dev->broadcast; |
|
|
|
/* |
|
* Fill the device header for the ARP frame |
|
*/ |
|
if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) |
|
goto out; |
|
|
|
/* |
|
* Fill out the arp protocol part. |
|
* |
|
* The arp hardware type should match the device type, except for FDDI, |
|
* which (according to RFC 1390) should always equal 1 (Ethernet). |
|
*/ |
|
/* |
|
* Exceptions everywhere. AX.25 uses the AX.25 PID value not the |
|
* DIX code for the protocol. Make these device structure fields. |
|
*/ |
|
switch (dev->type) { |
|
default: |
|
arp->ar_hrd = htons(dev->type); |
|
arp->ar_pro = htons(ETH_P_IP); |
|
break; |
|
|
|
#if IS_ENABLED(CONFIG_AX25) |
|
case ARPHRD_AX25: |
|
arp->ar_hrd = htons(ARPHRD_AX25); |
|
arp->ar_pro = htons(AX25_P_IP); |
|
break; |
|
|
|
#if IS_ENABLED(CONFIG_NETROM) |
|
case ARPHRD_NETROM: |
|
arp->ar_hrd = htons(ARPHRD_NETROM); |
|
arp->ar_pro = htons(AX25_P_IP); |
|
break; |
|
#endif |
|
#endif |
|
|
|
#if IS_ENABLED(CONFIG_FDDI) |
|
case ARPHRD_FDDI: |
|
arp->ar_hrd = htons(ARPHRD_ETHER); |
|
arp->ar_pro = htons(ETH_P_IP); |
|
break; |
|
#endif |
|
} |
|
|
|
arp->ar_hln = dev->addr_len; |
|
arp->ar_pln = 4; |
|
arp->ar_op = htons(type); |
|
|
|
arp_ptr = (unsigned char *)(arp + 1); |
|
|
|
memcpy(arp_ptr, src_hw, dev->addr_len); |
|
arp_ptr += dev->addr_len; |
|
memcpy(arp_ptr, &src_ip, 4); |
|
arp_ptr += 4; |
|
|
|
switch (dev->type) { |
|
#if IS_ENABLED(CONFIG_FIREWIRE_NET) |
|
case ARPHRD_IEEE1394: |
|
break; |
|
#endif |
|
default: |
|
if (target_hw) |
|
memcpy(arp_ptr, target_hw, dev->addr_len); |
|
else |
|
memset(arp_ptr, 0, dev->addr_len); |
|
arp_ptr += dev->addr_len; |
|
} |
|
memcpy(arp_ptr, &dest_ip, 4); |
|
|
|
return skb; |
|
|
|
out: |
|
kfree_skb(skb); |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(arp_create); |
|
|
|
static int arp_xmit_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
|
{ |
|
return dev_queue_xmit(skb); |
|
} |
|
|
|
/* |
|
* Send an arp packet. |
|
*/ |
|
void arp_xmit(struct sk_buff *skb) |
|
{ |
|
/* Send it off, maybe filter it using firewalling first. */ |
|
NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, |
|
dev_net(skb->dev), NULL, skb, NULL, skb->dev, |
|
arp_xmit_finish); |
|
} |
|
EXPORT_SYMBOL(arp_xmit); |
|
|
|
static bool arp_is_garp(struct net *net, struct net_device *dev, |
|
int *addr_type, __be16 ar_op, |
|
__be32 sip, __be32 tip, |
|
unsigned char *sha, unsigned char *tha) |
|
{ |
|
bool is_garp = tip == sip; |
|
|
|
/* Gratuitous ARP _replies_ also require target hwaddr to be |
|
* the same as source. |
|
*/ |
|
if (is_garp && ar_op == htons(ARPOP_REPLY)) |
|
is_garp = |
|
/* IPv4 over IEEE 1394 doesn't provide target |
|
* hardware address field in its ARP payload. |
|
*/ |
|
tha && |
|
!memcmp(tha, sha, dev->addr_len); |
|
|
|
if (is_garp) { |
|
*addr_type = inet_addr_type_dev_table(net, dev, sip); |
|
if (*addr_type != RTN_UNICAST) |
|
is_garp = false; |
|
} |
|
return is_garp; |
|
} |
|
|
|
/* |
|
* Process an arp request. |
|
*/ |
|
|
|
static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) |
|
{ |
|
struct net_device *dev = skb->dev; |
|
struct in_device *in_dev = __in_dev_get_rcu(dev); |
|
struct arphdr *arp; |
|
unsigned char *arp_ptr; |
|
struct rtable *rt; |
|
unsigned char *sha; |
|
unsigned char *tha = NULL; |
|
__be32 sip, tip; |
|
u16 dev_type = dev->type; |
|
int addr_type; |
|
struct neighbour *n; |
|
struct dst_entry *reply_dst = NULL; |
|
bool is_garp = false; |
|
|
|
/* arp_rcv below verifies the ARP header and verifies the device |
|
* is ARP'able. |
|
*/ |
|
|
|
if (!in_dev) |
|
goto out_free_skb; |
|
|
|
arp = arp_hdr(skb); |
|
|
|
switch (dev_type) { |
|
default: |
|
if (arp->ar_pro != htons(ETH_P_IP) || |
|
htons(dev_type) != arp->ar_hrd) |
|
goto out_free_skb; |
|
break; |
|
case ARPHRD_ETHER: |
|
case ARPHRD_FDDI: |
|
case ARPHRD_IEEE802: |
|
/* |
|
* ETHERNET, and Fibre Channel (which are IEEE 802 |
|
* devices, according to RFC 2625) devices will accept ARP |
|
* hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). |
|
* This is the case also of FDDI, where the RFC 1390 says that |
|
* FDDI devices should accept ARP hardware of (1) Ethernet, |
|
* however, to be more robust, we'll accept both 1 (Ethernet) |
|
* or 6 (IEEE 802.2) |
|
*/ |
|
if ((arp->ar_hrd != htons(ARPHRD_ETHER) && |
|
arp->ar_hrd != htons(ARPHRD_IEEE802)) || |
|
arp->ar_pro != htons(ETH_P_IP)) |
|
goto out_free_skb; |
|
break; |
|
case ARPHRD_AX25: |
|
if (arp->ar_pro != htons(AX25_P_IP) || |
|
arp->ar_hrd != htons(ARPHRD_AX25)) |
|
goto out_free_skb; |
|
break; |
|
case ARPHRD_NETROM: |
|
if (arp->ar_pro != htons(AX25_P_IP) || |
|
arp->ar_hrd != htons(ARPHRD_NETROM)) |
|
goto out_free_skb; |
|
break; |
|
} |
|
|
|
/* Understand only these message types */ |
|
|
|
if (arp->ar_op != htons(ARPOP_REPLY) && |
|
arp->ar_op != htons(ARPOP_REQUEST)) |
|
goto out_free_skb; |
|
|
|
/* |
|
* Extract fields |
|
*/ |
|
arp_ptr = (unsigned char *)(arp + 1); |
|
sha = arp_ptr; |
|
arp_ptr += dev->addr_len; |
|
memcpy(&sip, arp_ptr, 4); |
|
arp_ptr += 4; |
|
switch (dev_type) { |
|
#if IS_ENABLED(CONFIG_FIREWIRE_NET) |
|
case ARPHRD_IEEE1394: |
|
break; |
|
#endif |
|
default: |
|
tha = arp_ptr; |
|
arp_ptr += dev->addr_len; |
|
} |
|
memcpy(&tip, arp_ptr, 4); |
|
/* |
|
* Check for bad requests for 127.x.x.x and requests for multicast |
|
* addresses. If this is one such, delete it. |
|
*/ |
|
if (ipv4_is_multicast(tip) || |
|
(!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) |
|
goto out_free_skb; |
|
|
|
/* |
|
* For some 802.11 wireless deployments (and possibly other networks), |
|
* there will be an ARP proxy and gratuitous ARP frames are attacks |
|
* and thus should not be accepted. |
|
*/ |
|
if (sip == tip && IN_DEV_ORCONF(in_dev, DROP_GRATUITOUS_ARP)) |
|
goto out_free_skb; |
|
|
|
/* |
|
* Special case: We must set Frame Relay source Q.922 address |
|
*/ |
|
if (dev_type == ARPHRD_DLCI) |
|
sha = dev->broadcast; |
|
|
|
/* |
|
* Process entry. The idea here is we want to send a reply if it is a |
|
* request for us or if it is a request for someone else that we hold |
|
* a proxy for. We want to add an entry to our cache if it is a reply |
|
* to us or if it is a request for our address. |
|
* (The assumption for this last is that if someone is requesting our |
|
* address, they are probably intending to talk to us, so it saves time |
|
* if we cache their address. Their address is also probably not in |
|
* our cache, since ours is not in their cache.) |
|
* |
|
* Putting this another way, we only care about replies if they are to |
|
* us, in which case we add them to the cache. For requests, we care |
|
* about those for us and those for our proxies. We reply to both, |
|
* and in the case of requests for us we add the requester to the arp |
|
* cache. |
|
*/ |
|
|
|
if (arp->ar_op == htons(ARPOP_REQUEST) && skb_metadata_dst(skb)) |
|
reply_dst = (struct dst_entry *) |
|
iptunnel_metadata_reply(skb_metadata_dst(skb), |
|
GFP_ATOMIC); |
|
|
|
/* Special case: IPv4 duplicate address detection packet (RFC2131) */ |
|
if (sip == 0) { |
|
if (arp->ar_op == htons(ARPOP_REQUEST) && |
|
inet_addr_type_dev_table(net, dev, tip) == RTN_LOCAL && |
|
!arp_ignore(in_dev, sip, tip)) |
|
arp_send_dst(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, |
|
sha, dev->dev_addr, sha, reply_dst); |
|
goto out_consume_skb; |
|
} |
|
|
|
if (arp->ar_op == htons(ARPOP_REQUEST) && |
|
ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { |
|
|
|
rt = skb_rtable(skb); |
|
addr_type = rt->rt_type; |
|
|
|
if (addr_type == RTN_LOCAL) { |
|
int dont_send; |
|
|
|
dont_send = arp_ignore(in_dev, sip, tip); |
|
if (!dont_send && IN_DEV_ARPFILTER(in_dev)) |
|
dont_send = arp_filter(sip, tip, dev); |
|
if (!dont_send) { |
|
n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
|
if (n) { |
|
arp_send_dst(ARPOP_REPLY, ETH_P_ARP, |
|
sip, dev, tip, sha, |
|
dev->dev_addr, sha, |
|
reply_dst); |
|
neigh_release(n); |
|
} |
|
} |
|
goto out_consume_skb; |
|
} else if (IN_DEV_FORWARD(in_dev)) { |
|
if (addr_type == RTN_UNICAST && |
|
(arp_fwd_proxy(in_dev, dev, rt) || |
|
arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || |
|
(rt->dst.dev != dev && |
|
pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) { |
|
n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
|
if (n) |
|
neigh_release(n); |
|
|
|
if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || |
|
skb->pkt_type == PACKET_HOST || |
|
NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) { |
|
arp_send_dst(ARPOP_REPLY, ETH_P_ARP, |
|
sip, dev, tip, sha, |
|
dev->dev_addr, sha, |
|
reply_dst); |
|
} else { |
|
pneigh_enqueue(&arp_tbl, |
|
in_dev->arp_parms, skb); |
|
goto out_free_dst; |
|
} |
|
goto out_consume_skb; |
|
} |
|
} |
|
} |
|
|
|
/* Update our ARP tables */ |
|
|
|
n = __neigh_lookup(&arp_tbl, &sip, dev, 0); |
|
|
|
addr_type = -1; |
|
if (n || IN_DEV_ARP_ACCEPT(in_dev)) { |
|
is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op, |
|
sip, tip, sha, tha); |
|
} |
|
|
|
if (IN_DEV_ARP_ACCEPT(in_dev)) { |
|
/* Unsolicited ARP is not accepted by default. |
|
It is possible, that this option should be enabled for some |
|
devices (strip is candidate) |
|
*/ |
|
if (!n && |
|
(is_garp || |
|
(arp->ar_op == htons(ARPOP_REPLY) && |
|
(addr_type == RTN_UNICAST || |
|
(addr_type < 0 && |
|
/* postpone calculation to as late as possible */ |
|
inet_addr_type_dev_table(net, dev, sip) == |
|
RTN_UNICAST))))) |
|
n = __neigh_lookup(&arp_tbl, &sip, dev, 1); |
|
} |
|
|
|
if (n) { |
|
int state = NUD_REACHABLE; |
|
int override; |
|
|
|
/* If several different ARP replies follows back-to-back, |
|
use the FIRST one. It is possible, if several proxy |
|
agents are active. Taking the first reply prevents |
|
arp trashing and chooses the fastest router. |
|
*/ |
|
override = time_after(jiffies, |
|
n->updated + |
|
NEIGH_VAR(n->parms, LOCKTIME)) || |
|
is_garp; |
|
|
|
/* Broadcast replies and request packets |
|
do not assert neighbour reachability. |
|
*/ |
|
if (arp->ar_op != htons(ARPOP_REPLY) || |
|
skb->pkt_type != PACKET_HOST) |
|
state = NUD_STALE; |
|
neigh_update(n, sha, state, |
|
override ? NEIGH_UPDATE_F_OVERRIDE : 0, 0); |
|
neigh_release(n); |
|
} |
|
|
|
out_consume_skb: |
|
consume_skb(skb); |
|
|
|
out_free_dst: |
|
dst_release(reply_dst); |
|
return NET_RX_SUCCESS; |
|
|
|
out_free_skb: |
|
kfree_skb(skb); |
|
return NET_RX_DROP; |
|
} |
|
|
|
static void parp_redo(struct sk_buff *skb) |
|
{ |
|
arp_process(dev_net(skb->dev), NULL, skb); |
|
} |
|
|
|
static int arp_is_multicast(const void *pkey) |
|
{ |
|
return ipv4_is_multicast(*((__be32 *)pkey)); |
|
} |
|
|
|
/* |
|
* Receive an arp request from the device layer. |
|
*/ |
|
|
|
static int arp_rcv(struct sk_buff *skb, struct net_device *dev, |
|
struct packet_type *pt, struct net_device *orig_dev) |
|
{ |
|
const struct arphdr *arp; |
|
|
|
/* do not tweak dropwatch on an ARP we will ignore */ |
|
if (dev->flags & IFF_NOARP || |
|
skb->pkt_type == PACKET_OTHERHOST || |
|
skb->pkt_type == PACKET_LOOPBACK) |
|
goto consumeskb; |
|
|
|
skb = skb_share_check(skb, GFP_ATOMIC); |
|
if (!skb) |
|
goto out_of_mem; |
|
|
|
/* ARP header, plus 2 device addresses, plus 2 IP addresses. */ |
|
if (!pskb_may_pull(skb, arp_hdr_len(dev))) |
|
goto freeskb; |
|
|
|
arp = arp_hdr(skb); |
|
if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) |
|
goto freeskb; |
|
|
|
memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
|
|
|
return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, |
|
dev_net(dev), NULL, skb, dev, NULL, |
|
arp_process); |
|
|
|
consumeskb: |
|
consume_skb(skb); |
|
return NET_RX_SUCCESS; |
|
freeskb: |
|
kfree_skb(skb); |
|
out_of_mem: |
|
return NET_RX_DROP; |
|
} |
|
|
|
/* |
|
* User level interface (ioctl) |
|
*/ |
|
|
|
/* |
|
* Set (create) an ARP cache entry. |
|
*/ |
|
|
|
static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) |
|
{ |
|
if (!dev) { |
|
IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; |
|
return 0; |
|
} |
|
if (__in_dev_get_rtnl(dev)) { |
|
IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); |
|
return 0; |
|
} |
|
return -ENXIO; |
|
} |
|
|
|
static int arp_req_set_public(struct net *net, struct arpreq *r, |
|
struct net_device *dev) |
|
{ |
|
__be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
|
__be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; |
|
|
|
if (mask && mask != htonl(0xFFFFFFFF)) |
|
return -EINVAL; |
|
if (!dev && (r->arp_flags & ATF_COM)) { |
|
dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, |
|
r->arp_ha.sa_data); |
|
if (!dev) |
|
return -ENODEV; |
|
} |
|
if (mask) { |
|
if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1)) |
|
return -ENOBUFS; |
|
return 0; |
|
} |
|
|
|
return arp_req_set_proxy(net, dev, 1); |
|
} |
|
|
|
static int arp_req_set(struct net *net, struct arpreq *r, |
|
struct net_device *dev) |
|
{ |
|
__be32 ip; |
|
struct neighbour *neigh; |
|
int err; |
|
|
|
if (r->arp_flags & ATF_PUBL) |
|
return arp_req_set_public(net, r, dev); |
|
|
|
ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
|
if (r->arp_flags & ATF_PERM) |
|
r->arp_flags |= ATF_COM; |
|
if (!dev) { |
|
struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
|
|
|
if (IS_ERR(rt)) |
|
return PTR_ERR(rt); |
|
dev = rt->dst.dev; |
|
ip_rt_put(rt); |
|
if (!dev) |
|
return -EINVAL; |
|
} |
|
switch (dev->type) { |
|
#if IS_ENABLED(CONFIG_FDDI) |
|
case ARPHRD_FDDI: |
|
/* |
|
* According to RFC 1390, FDDI devices should accept ARP |
|
* hardware types of 1 (Ethernet). However, to be more |
|
* robust, we'll accept hardware types of either 1 (Ethernet) |
|
* or 6 (IEEE 802.2). |
|
*/ |
|
if (r->arp_ha.sa_family != ARPHRD_FDDI && |
|
r->arp_ha.sa_family != ARPHRD_ETHER && |
|
r->arp_ha.sa_family != ARPHRD_IEEE802) |
|
return -EINVAL; |
|
break; |
|
#endif |
|
default: |
|
if (r->arp_ha.sa_family != dev->type) |
|
return -EINVAL; |
|
break; |
|
} |
|
|
|
neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); |
|
err = PTR_ERR(neigh); |
|
if (!IS_ERR(neigh)) { |
|
unsigned int state = NUD_STALE; |
|
if (r->arp_flags & ATF_PERM) |
|
state = NUD_PERMANENT; |
|
err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? |
|
r->arp_ha.sa_data : NULL, state, |
|
NEIGH_UPDATE_F_OVERRIDE | |
|
NEIGH_UPDATE_F_ADMIN, 0); |
|
neigh_release(neigh); |
|
} |
|
return err; |
|
} |
|
|
|
static unsigned int arp_state_to_flags(struct neighbour *neigh) |
|
{ |
|
if (neigh->nud_state&NUD_PERMANENT) |
|
return ATF_PERM | ATF_COM; |
|
else if (neigh->nud_state&NUD_VALID) |
|
return ATF_COM; |
|
else |
|
return 0; |
|
} |
|
|
|
/* |
|
* Get an ARP cache entry. |
|
*/ |
|
|
|
static int arp_req_get(struct arpreq *r, struct net_device *dev) |
|
{ |
|
__be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
|
struct neighbour *neigh; |
|
int err = -ENXIO; |
|
|
|
neigh = neigh_lookup(&arp_tbl, &ip, dev); |
|
if (neigh) { |
|
if (!(neigh->nud_state & NUD_NOARP)) { |
|
read_lock_bh(&neigh->lock); |
|
memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); |
|
r->arp_flags = arp_state_to_flags(neigh); |
|
read_unlock_bh(&neigh->lock); |
|
r->arp_ha.sa_family = dev->type; |
|
strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); |
|
err = 0; |
|
} |
|
neigh_release(neigh); |
|
} |
|
return err; |
|
} |
|
|
|
static int arp_invalidate(struct net_device *dev, __be32 ip) |
|
{ |
|
struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); |
|
int err = -ENXIO; |
|
struct neigh_table *tbl = &arp_tbl; |
|
|
|
if (neigh) { |
|
if (neigh->nud_state & ~NUD_NOARP) |
|
err = neigh_update(neigh, NULL, NUD_FAILED, |
|
NEIGH_UPDATE_F_OVERRIDE| |
|
NEIGH_UPDATE_F_ADMIN, 0); |
|
write_lock_bh(&tbl->lock); |
|
neigh_release(neigh); |
|
neigh_remove_one(neigh, tbl); |
|
write_unlock_bh(&tbl->lock); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int arp_req_delete_public(struct net *net, struct arpreq *r, |
|
struct net_device *dev) |
|
{ |
|
__be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
|
__be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; |
|
|
|
if (mask == htonl(0xFFFFFFFF)) |
|
return pneigh_delete(&arp_tbl, net, &ip, dev); |
|
|
|
if (mask) |
|
return -EINVAL; |
|
|
|
return arp_req_set_proxy(net, dev, 0); |
|
} |
|
|
|
static int arp_req_delete(struct net *net, struct arpreq *r, |
|
struct net_device *dev) |
|
{ |
|
__be32 ip; |
|
|
|
if (r->arp_flags & ATF_PUBL) |
|
return arp_req_delete_public(net, r, dev); |
|
|
|
ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
|
if (!dev) { |
|
struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
|
if (IS_ERR(rt)) |
|
return PTR_ERR(rt); |
|
dev = rt->dst.dev; |
|
ip_rt_put(rt); |
|
if (!dev) |
|
return -EINVAL; |
|
} |
|
return arp_invalidate(dev, ip); |
|
} |
|
|
|
/* |
|
* Handle an ARP layer I/O control request. |
|
*/ |
|
|
|
int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) |
|
{ |
|
int err; |
|
struct arpreq r; |
|
struct net_device *dev = NULL; |
|
|
|
switch (cmd) { |
|
case SIOCDARP: |
|
case SIOCSARP: |
|
if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
|
return -EPERM; |
|
fallthrough; |
|
case SIOCGARP: |
|
err = copy_from_user(&r, arg, sizeof(struct arpreq)); |
|
if (err) |
|
return -EFAULT; |
|
break; |
|
default: |
|
return -EINVAL; |
|
} |
|
|
|
if (r.arp_pa.sa_family != AF_INET) |
|
return -EPFNOSUPPORT; |
|
|
|
if (!(r.arp_flags & ATF_PUBL) && |
|
(r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) |
|
return -EINVAL; |
|
if (!(r.arp_flags & ATF_NETMASK)) |
|
((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = |
|
htonl(0xFFFFFFFFUL); |
|
rtnl_lock(); |
|
if (r.arp_dev[0]) { |
|
err = -ENODEV; |
|
dev = __dev_get_by_name(net, r.arp_dev); |
|
if (!dev) |
|
goto out; |
|
|
|
/* Mmmm... It is wrong... ARPHRD_NETROM==0 */ |
|
if (!r.arp_ha.sa_family) |
|
r.arp_ha.sa_family = dev->type; |
|
err = -EINVAL; |
|
if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) |
|
goto out; |
|
} else if (cmd == SIOCGARP) { |
|
err = -ENODEV; |
|
goto out; |
|
} |
|
|
|
switch (cmd) { |
|
case SIOCDARP: |
|
err = arp_req_delete(net, &r, dev); |
|
break; |
|
case SIOCSARP: |
|
err = arp_req_set(net, &r, dev); |
|
break; |
|
case SIOCGARP: |
|
err = arp_req_get(&r, dev); |
|
break; |
|
} |
|
out: |
|
rtnl_unlock(); |
|
if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
|
|
static int arp_netdev_event(struct notifier_block *this, unsigned long event, |
|
void *ptr) |
|
{ |
|
struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
|
struct netdev_notifier_change_info *change_info; |
|
|
|
switch (event) { |
|
case NETDEV_CHANGEADDR: |
|
neigh_changeaddr(&arp_tbl, dev); |
|
rt_cache_flush(dev_net(dev)); |
|
break; |
|
case NETDEV_CHANGE: |
|
change_info = ptr; |
|
if (change_info->flags_changed & IFF_NOARP) |
|
neigh_changeaddr(&arp_tbl, dev); |
|
if (!netif_carrier_ok(dev)) |
|
neigh_carrier_down(&arp_tbl, dev); |
|
break; |
|
default: |
|
break; |
|
} |
|
|
|
return NOTIFY_DONE; |
|
} |
|
|
|
static struct notifier_block arp_netdev_notifier = { |
|
.notifier_call = arp_netdev_event, |
|
}; |
|
|
|
/* Note, that it is not on notifier chain. |
|
It is necessary, that this routine was called after route cache will be |
|
flushed. |
|
*/ |
|
void arp_ifdown(struct net_device *dev) |
|
{ |
|
neigh_ifdown(&arp_tbl, dev); |
|
} |
|
|
|
|
|
/* |
|
* Called once on startup. |
|
*/ |
|
|
|
static struct packet_type arp_packet_type __read_mostly = { |
|
.type = cpu_to_be16(ETH_P_ARP), |
|
.func = arp_rcv, |
|
}; |
|
|
|
static int arp_proc_init(void); |
|
|
|
void __init arp_init(void) |
|
{ |
|
neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl); |
|
|
|
dev_add_pack(&arp_packet_type); |
|
arp_proc_init(); |
|
#ifdef CONFIG_SYSCTL |
|
neigh_sysctl_register(NULL, &arp_tbl.parms, NULL); |
|
#endif |
|
register_netdevice_notifier(&arp_netdev_notifier); |
|
} |
|
|
|
#ifdef CONFIG_PROC_FS |
|
#if IS_ENABLED(CONFIG_AX25) |
|
|
|
/* ------------------------------------------------------------------------ */ |
|
/* |
|
* ax25 -> ASCII conversion |
|
*/ |
|
static void ax2asc2(ax25_address *a, char *buf) |
|
{ |
|
char c, *s; |
|
int n; |
|
|
|
for (n = 0, s = buf; n < 6; n++) { |
|
c = (a->ax25_call[n] >> 1) & 0x7F; |
|
|
|
if (c != ' ') |
|
*s++ = c; |
|
} |
|
|
|
*s++ = '-'; |
|
n = (a->ax25_call[6] >> 1) & 0x0F; |
|
if (n > 9) { |
|
*s++ = '1'; |
|
n -= 10; |
|
} |
|
|
|
*s++ = n + '0'; |
|
*s++ = '\0'; |
|
|
|
if (*buf == '\0' || *buf == '-') { |
|
buf[0] = '*'; |
|
buf[1] = '\0'; |
|
} |
|
} |
|
#endif /* CONFIG_AX25 */ |
|
|
|
#define HBUFFERLEN 30 |
|
|
|
static void arp_format_neigh_entry(struct seq_file *seq, |
|
struct neighbour *n) |
|
{ |
|
char hbuffer[HBUFFERLEN]; |
|
int k, j; |
|
char tbuf[16]; |
|
struct net_device *dev = n->dev; |
|
int hatype = dev->type; |
|
|
|
read_lock(&n->lock); |
|
/* Convert hardware address to XX:XX:XX:XX ... form. */ |
|
#if IS_ENABLED(CONFIG_AX25) |
|
if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) |
|
ax2asc2((ax25_address *)n->ha, hbuffer); |
|
else { |
|
#endif |
|
for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { |
|
hbuffer[k++] = hex_asc_hi(n->ha[j]); |
|
hbuffer[k++] = hex_asc_lo(n->ha[j]); |
|
hbuffer[k++] = ':'; |
|
} |
|
if (k != 0) |
|
--k; |
|
hbuffer[k] = 0; |
|
#if IS_ENABLED(CONFIG_AX25) |
|
} |
|
#endif |
|
sprintf(tbuf, "%pI4", n->primary_key); |
|
seq_printf(seq, "%-16s 0x%-10x0x%-10x%-17s * %s\n", |
|
tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); |
|
read_unlock(&n->lock); |
|
} |
|
|
|
static void arp_format_pneigh_entry(struct seq_file *seq, |
|
struct pneigh_entry *n) |
|
{ |
|
struct net_device *dev = n->dev; |
|
int hatype = dev ? dev->type : 0; |
|
char tbuf[16]; |
|
|
|
sprintf(tbuf, "%pI4", n->key); |
|
seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
|
tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", |
|
dev ? dev->name : "*"); |
|
} |
|
|
|
static int arp_seq_show(struct seq_file *seq, void *v) |
|
{ |
|
if (v == SEQ_START_TOKEN) { |
|
seq_puts(seq, "IP address HW type Flags " |
|
"HW address Mask Device\n"); |
|
} else { |
|
struct neigh_seq_state *state = seq->private; |
|
|
|
if (state->flags & NEIGH_SEQ_IS_PNEIGH) |
|
arp_format_pneigh_entry(seq, v); |
|
else |
|
arp_format_neigh_entry(seq, v); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void *arp_seq_start(struct seq_file *seq, loff_t *pos) |
|
{ |
|
/* Don't want to confuse "arp -a" w/ magic entries, |
|
* so we tell the generic iterator to skip NUD_NOARP. |
|
*/ |
|
return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); |
|
} |
|
|
|
/* ------------------------------------------------------------------------ */ |
|
|
|
static const struct seq_operations arp_seq_ops = { |
|
.start = arp_seq_start, |
|
.next = neigh_seq_next, |
|
.stop = neigh_seq_stop, |
|
.show = arp_seq_show, |
|
}; |
|
|
|
/* ------------------------------------------------------------------------ */ |
|
|
|
static int __net_init arp_net_init(struct net *net) |
|
{ |
|
if (!proc_create_net("arp", 0444, net->proc_net, &arp_seq_ops, |
|
sizeof(struct neigh_seq_state))) |
|
return -ENOMEM; |
|
return 0; |
|
} |
|
|
|
static void __net_exit arp_net_exit(struct net *net) |
|
{ |
|
remove_proc_entry("arp", net->proc_net); |
|
} |
|
|
|
static struct pernet_operations arp_net_ops = { |
|
.init = arp_net_init, |
|
.exit = arp_net_exit, |
|
}; |
|
|
|
static int __init arp_proc_init(void) |
|
{ |
|
return register_pernet_subsys(&arp_net_ops); |
|
} |
|
|
|
#else /* CONFIG_PROC_FS */ |
|
|
|
static int __init arp_proc_init(void) |
|
{ |
|
return 0; |
|
} |
|
|
|
#endif /* CONFIG_PROC_FS */
|
|
|