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![Wolfram Sang](/assets/img/avatar_default.png)
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20220818210219.8467-1-wsa+renesas@sang-engineering.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1472 lines
36 KiB
C
1472 lines
36 KiB
C
// 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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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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#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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#include <linux/uaccess.h>
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#include <linux/netfilter_arp.h>
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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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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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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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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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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_INTERVAL_PROBE_TIME_MS] = 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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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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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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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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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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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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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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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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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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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_reason(skb, SKB_DROP_REASON_NEIGH_FAILED);
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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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/* 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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skb_dst_set(skb, dst_clone(dst));
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arp_xmit(skb);
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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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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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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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if (!saddr)
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saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
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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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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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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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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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static int arp_accept(struct in_device *in_dev, __be32 sip)
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{
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struct net *net = dev_net(in_dev->dev);
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int scope = RT_SCOPE_LINK;
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|
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switch (IN_DEV_ARP_ACCEPT(in_dev)) {
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case 0: /* Don't create new entries from garp */
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return 0;
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case 1: /* Create new entries from garp */
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return 1;
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case 2: /* Create a neighbor in the arp table only if sip
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* is in the same subnet as an address configured
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* on the interface that received the garp message
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*/
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return !!inet_confirm_addr(net, in_dev, sip, 0, scope);
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default:
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return 0;
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}
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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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|
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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);
|
|
return flag;
|
|
}
|
|
|
|
/*
|
|
* Check if we can use proxy ARP for this path
|
|
*/
|
|
static inline int arp_fwd_proxy(struct in_device *in_dev,
|
|
struct net_device *dev, struct rtable *rt)
|
|
{
|
|
struct in_device *out_dev;
|
|
int imi, omi = -1;
|
|
|
|
if (rt->dst.dev == dev)
|
|
return 0;
|
|
|
|
if (!IN_DEV_PROXY_ARP(in_dev))
|
|
return 0;
|
|
imi = IN_DEV_MEDIUM_ID(in_dev);
|
|
if (imi == 0)
|
|
return 1;
|
|
if (imi == -1)
|
|
return 0;
|
|
|
|
/* place to check for proxy_arp for routes */
|
|
|
|
out_dev = __in_dev_get_rcu(rt->dst.dev);
|
|
if (out_dev)
|
|
omi = IN_DEV_MEDIUM_ID(out_dev);
|
|
|
|
return omi != imi && omi != -1;
|
|
}
|
|
|
|
/*
|
|
* Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
|
|
*
|
|
* RFC3069 supports proxy arp replies back to the same interface. This
|
|
* is done to support (ethernet) switch features, like RFC 3069, where
|
|
* the individual ports are not allowed to communicate with each
|
|
* other, BUT they are allowed to talk to the upstream router. As
|
|
* described in RFC 3069, it is possible to allow these hosts to
|
|
* communicate through the upstream router, by proxy_arp'ing.
|
|
*
|
|
* RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation"
|
|
*
|
|
* This technology is known by different names:
|
|
* In RFC 3069 it is called VLAN Aggregation.
|
|
* Cisco and Allied Telesyn call it Private VLAN.
|
|
* Hewlett-Packard call it Source-Port filtering or port-isolation.
|
|
* Ericsson call it MAC-Forced Forwarding (RFC Draft).
|
|
*
|
|
*/
|
|
static inline int arp_fwd_pvlan(struct in_device *in_dev,
|
|
struct net_device *dev, struct rtable *rt,
|
|
__be32 sip, __be32 tip)
|
|
{
|
|
/* Private VLAN is only concerned about the same ethernet segment */
|
|
if (rt->dst.dev != dev)
|
|
return 0;
|
|
|
|
/* Don't reply on self probes (often done by windowz boxes)*/
|
|
if (sip == tip)
|
|
return 0;
|
|
|
|
if (IN_DEV_PROXY_ARP_PVLAN(in_dev))
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Interface to link layer: send routine and receive handler.
|
|
*/
|
|
|
|
/*
|
|
* 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,
|
|
struct net_device *dev, __be32 src_ip,
|
|
const unsigned char *dest_hw,
|
|
const unsigned char *src_hw,
|
|
const unsigned char *target_hw)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct arphdr *arp;
|
|
unsigned char *arp_ptr;
|
|
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 || arp_accept(in_dev, sip)) {
|
|
is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
|
|
sip, tip, sha, tha);
|
|
}
|
|
|
|
if (arp_accept(in_dev, sip)) {
|
|
/* 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;
|
|
strscpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
|
|
err = 0;
|
|
}
|
|
neigh_release(neigh);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
int arp_invalidate(struct net_device *dev, __be32 ip, bool force)
|
|
{
|
|
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_VALID) && !force) {
|
|
neigh_release(neigh);
|
|
return 0;
|
|
}
|
|
|
|
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, true);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
struct in_device *in_dev;
|
|
bool evict_nocarrier;
|
|
|
|
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);
|
|
|
|
in_dev = __in_dev_get_rtnl(dev);
|
|
if (!in_dev)
|
|
evict_nocarrier = true;
|
|
else
|
|
evict_nocarrier = IN_DEV_ARP_EVICT_NOCARRIER(in_dev);
|
|
|
|
if (evict_nocarrier && !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,
|
|
};
|
|
|
|
#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,
|
|
};
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
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,
|
|
};
|
|
|
|
void __init arp_init(void)
|
|
{
|
|
neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl);
|
|
|
|
dev_add_pack(&arp_packet_type);
|
|
register_pernet_subsys(&arp_net_ops);
|
|
#ifdef CONFIG_SYSCTL
|
|
neigh_sysctl_register(NULL, &arp_tbl.parms, NULL);
|
|
#endif
|
|
register_netdevice_notifier(&arp_netdev_notifier);
|
|
}
|