Uwe Zeisberger | f30c226 | 2006-10-03 23:01:26 +0200 | [diff] [blame] | 1 | /* linux/net/ipv4/arp.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * Copyright (C) 1994 by Florian La Roche |
| 4 | * |
| 5 | * This module implements the Address Resolution Protocol ARP (RFC 826), |
| 6 | * which is used to convert IP addresses (or in the future maybe other |
| 7 | * high-level addresses) into a low-level hardware address (like an Ethernet |
| 8 | * address). |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | * |
| 15 | * Fixes: |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 16 | * Alan Cox : Removed the Ethernet assumptions in |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | * Florian's code |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 18 | * Alan Cox : Fixed some small errors in the ARP |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | * logic |
| 20 | * Alan Cox : Allow >4K in /proc |
| 21 | * Alan Cox : Make ARP add its own protocol entry |
| 22 | * Ross Martin : Rewrote arp_rcv() and arp_get_info() |
| 23 | * Stephen Henson : Add AX25 support to arp_get_info() |
| 24 | * Alan Cox : Drop data when a device is downed. |
| 25 | * Alan Cox : Use init_timer(). |
| 26 | * Alan Cox : Double lock fixes. |
| 27 | * Martin Seine : Move the arphdr structure |
| 28 | * to if_arp.h for compatibility. |
| 29 | * with BSD based programs. |
| 30 | * Andrew Tridgell : Added ARP netmask code and |
| 31 | * re-arranged proxy handling. |
| 32 | * Alan Cox : Changed to use notifiers. |
| 33 | * Niibe Yutaka : Reply for this device or proxies only. |
| 34 | * Alan Cox : Don't proxy across hardware types! |
| 35 | * Jonathan Naylor : Added support for NET/ROM. |
| 36 | * Mike Shaver : RFC1122 checks. |
| 37 | * Jonathan Naylor : Only lookup the hardware address for |
| 38 | * the correct hardware type. |
| 39 | * Germano Caronni : Assorted subtle races. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 40 | * Craig Schlenter : Don't modify permanent entry |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | * during arp_rcv. |
| 42 | * Russ Nelson : Tidied up a few bits. |
| 43 | * Alexey Kuznetsov: Major changes to caching and behaviour, |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 44 | * eg intelligent arp probing and |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | * generation |
| 46 | * of host down events. |
| 47 | * Alan Cox : Missing unlock in device events. |
| 48 | * Eckes : ARP ioctl control errors. |
| 49 | * Alexey Kuznetsov: Arp free fix. |
| 50 | * Manuel Rodriguez: Gratuitous ARP. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 51 | * Jonathan Layes : Added arpd support through kerneld |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | * message queue (960314) |
| 53 | * Mike Shaver : /proc/sys/net/ipv4/arp_* support |
| 54 | * Mike McLagan : Routing by source |
| 55 | * Stuart Cheshire : Metricom and grat arp fixes |
| 56 | * *** FOR 2.1 clean this up *** |
| 57 | * Lawrence V. Stefani: (08/12/96) Added FDDI support. |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 58 | * Alan Cox : Took the AP1000 nasty FDDI hack and |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | * folded into the mainstream FDDI code. |
| 60 | * Ack spit, Linus how did you allow that |
| 61 | * one in... |
| 62 | * Jes Sorensen : Make FDDI work again in 2.1.x and |
| 63 | * clean up the APFDDI & gen. FDDI bits. |
| 64 | * Alexey Kuznetsov: new arp state machine; |
| 65 | * now it is in net/core/neighbour.c. |
| 66 | * Krzysztof Halasa: Added Frame Relay ARP support. |
| 67 | * Arnaldo C. Melo : convert /proc/net/arp to seq_file |
| 68 | * Shmulik Hen: Split arp_send to arp_create and |
| 69 | * arp_xmit so intermediate drivers like |
| 70 | * bonding can change the skb before |
| 71 | * sending (e.g. insert 8021q tag). |
| 72 | * Harald Welte : convert to make use of jenkins hash |
Jesper Dangaard Brouer | 6532414 | 2010-01-05 05:50:47 +0000 | [diff] [blame] | 73 | * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | */ |
| 75 | |
Joe Perches | 91df42b | 2012-05-15 14:11:54 +0000 | [diff] [blame] | 76 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 77 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | #include <linux/module.h> |
| 79 | #include <linux/types.h> |
| 80 | #include <linux/string.h> |
| 81 | #include <linux/kernel.h> |
Randy Dunlap | 4fc268d | 2006-01-11 12:17:47 -0800 | [diff] [blame] | 82 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | #include <linux/socket.h> |
| 84 | #include <linux/sockios.h> |
| 85 | #include <linux/errno.h> |
| 86 | #include <linux/in.h> |
| 87 | #include <linux/mm.h> |
| 88 | #include <linux/inet.h> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 89 | #include <linux/inetdevice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | #include <linux/netdevice.h> |
| 91 | #include <linux/etherdevice.h> |
| 92 | #include <linux/fddidevice.h> |
| 93 | #include <linux/if_arp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | #include <linux/skbuff.h> |
| 95 | #include <linux/proc_fs.h> |
| 96 | #include <linux/seq_file.h> |
| 97 | #include <linux/stat.h> |
| 98 | #include <linux/init.h> |
| 99 | #include <linux/net.h> |
| 100 | #include <linux/rcupdate.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 101 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | #ifdef CONFIG_SYSCTL |
| 103 | #include <linux/sysctl.h> |
| 104 | #endif |
| 105 | |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 106 | #include <net/net_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | #include <net/ip.h> |
| 108 | #include <net/icmp.h> |
| 109 | #include <net/route.h> |
| 110 | #include <net/protocol.h> |
| 111 | #include <net/tcp.h> |
| 112 | #include <net/sock.h> |
| 113 | #include <net/arp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | #include <net/ax25.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | #include <net/netrom.h> |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 116 | #include <net/dst_metadata.h> |
| 117 | #include <net/ip_tunnels.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 119 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | |
| 121 | #include <linux/netfilter_arp.h> |
| 122 | |
| 123 | /* |
| 124 | * Interface to generic neighbour cache. |
| 125 | */ |
David S. Miller | 2c2aba6 | 2011-12-28 15:06:58 -0500 | [diff] [blame] | 126 | static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd); |
Eric W. Biederman | 60395a2 | 2015-03-03 17:10:44 -0600 | [diff] [blame] | 127 | static bool arp_key_eq(const struct neighbour *n, const void *pkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | static int arp_constructor(struct neighbour *neigh); |
| 129 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); |
| 130 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); |
| 131 | static void parp_redo(struct sk_buff *skb); |
| 132 | |
Stephen Hemminger | 89d69d2 | 2009-09-01 11:13:19 +0000 | [diff] [blame] | 133 | static const struct neigh_ops arp_generic_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | .family = AF_INET, |
| 135 | .solicit = arp_solicit, |
| 136 | .error_report = arp_error_report, |
| 137 | .output = neigh_resolve_output, |
| 138 | .connected_output = neigh_connected_output, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | }; |
| 140 | |
Stephen Hemminger | 89d69d2 | 2009-09-01 11:13:19 +0000 | [diff] [blame] | 141 | static const struct neigh_ops arp_hh_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | .family = AF_INET, |
| 143 | .solicit = arp_solicit, |
| 144 | .error_report = arp_error_report, |
| 145 | .output = neigh_resolve_output, |
| 146 | .connected_output = neigh_resolve_output, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | }; |
| 148 | |
Stephen Hemminger | 89d69d2 | 2009-09-01 11:13:19 +0000 | [diff] [blame] | 149 | static const struct neigh_ops arp_direct_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | .family = AF_INET, |
David S. Miller | 8f40b16 | 2011-07-17 13:34:11 -0700 | [diff] [blame] | 151 | .output = neigh_direct_output, |
| 152 | .connected_output = neigh_direct_output, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | }; |
| 154 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | struct neigh_table arp_tbl = { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 156 | .family = AF_INET, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 157 | .key_len = 4, |
Eric W. Biederman | bdf53c5 | 2015-03-02 00:13:22 -0600 | [diff] [blame] | 158 | .protocol = cpu_to_be16(ETH_P_IP), |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 159 | .hash = arp_hash, |
Eric W. Biederman | 60395a2 | 2015-03-03 17:10:44 -0600 | [diff] [blame] | 160 | .key_eq = arp_key_eq, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 161 | .constructor = arp_constructor, |
| 162 | .proxy_redo = parp_redo, |
| 163 | .id = "arp_cache", |
| 164 | .parms = { |
| 165 | .tbl = &arp_tbl, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 166 | .reachable_time = 30 * HZ, |
Jiri Pirko | 1f9248e | 2013-12-07 19:26:53 +0100 | [diff] [blame] | 167 | .data = { |
| 168 | [NEIGH_VAR_MCAST_PROBES] = 3, |
| 169 | [NEIGH_VAR_UCAST_PROBES] = 3, |
| 170 | [NEIGH_VAR_RETRANS_TIME] = 1 * HZ, |
| 171 | [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, |
| 172 | [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, |
| 173 | [NEIGH_VAR_GC_STALETIME] = 60 * HZ, |
| 174 | [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024, |
| 175 | [NEIGH_VAR_PROXY_QLEN] = 64, |
| 176 | [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, |
| 177 | [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, |
| 178 | [NEIGH_VAR_LOCKTIME] = 1 * HZ, |
| 179 | }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | }, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 181 | .gc_interval = 30 * HZ, |
| 182 | .gc_thresh1 = 128, |
| 183 | .gc_thresh2 = 512, |
| 184 | .gc_thresh3 = 1024, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | }; |
Eric Dumazet | 4bc2f18 | 2010-07-09 21:22:10 +0000 | [diff] [blame] | 186 | EXPORT_SYMBOL(arp_tbl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
Al Viro | 714e85b | 2006-11-14 20:51:49 -0800 | [diff] [blame] | 188 | int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | { |
| 190 | switch (dev->type) { |
| 191 | case ARPHRD_ETHER: |
| 192 | case ARPHRD_FDDI: |
| 193 | case ARPHRD_IEEE802: |
| 194 | ip_eth_mc_map(addr, haddr); |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 195 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | case ARPHRD_INFINIBAND: |
Rolf Manderscheid | a9e527e | 2007-12-10 13:38:41 -0700 | [diff] [blame] | 197 | ip_ib_mc_map(addr, dev->broadcast, haddr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | return 0; |
Timo Teräs | 93ca3bb | 2011-03-28 22:40:53 +0000 | [diff] [blame] | 199 | case ARPHRD_IPGRE: |
| 200 | ip_ipgre_mc_map(addr, dev->broadcast, haddr); |
| 201 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | default: |
| 203 | if (dir) { |
| 204 | memcpy(haddr, dev->broadcast, dev->addr_len); |
| 205 | return 0; |
| 206 | } |
| 207 | } |
| 208 | return -EINVAL; |
| 209 | } |
| 210 | |
| 211 | |
Eric Dumazet | d6bf781 | 2010-10-04 06:15:44 +0000 | [diff] [blame] | 212 | static u32 arp_hash(const void *pkey, |
| 213 | const struct net_device *dev, |
David S. Miller | 2c2aba6 | 2011-12-28 15:06:58 -0500 | [diff] [blame] | 214 | __u32 *hash_rnd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | { |
Eric W. Biederman | 60395a2 | 2015-03-03 17:10:44 -0600 | [diff] [blame] | 216 | return arp_hashfn(pkey, dev, hash_rnd); |
| 217 | } |
| 218 | |
| 219 | static bool arp_key_eq(const struct neighbour *neigh, const void *pkey) |
| 220 | { |
| 221 | return neigh_key_eq32(neigh, pkey); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | } |
| 223 | |
| 224 | static int arp_constructor(struct neighbour *neigh) |
| 225 | { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 226 | __be32 addr = *(__be32 *)neigh->primary_key; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | struct net_device *dev = neigh->dev; |
| 228 | struct in_device *in_dev; |
| 229 | struct neigh_parms *parms; |
| 230 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | rcu_read_lock(); |
Herbert Xu | e5ed639 | 2005-10-03 14:35:55 -0700 | [diff] [blame] | 232 | in_dev = __in_dev_get_rcu(dev); |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 233 | if (!in_dev) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | rcu_read_unlock(); |
| 235 | return -EINVAL; |
| 236 | } |
| 237 | |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 238 | neigh->type = inet_addr_type_dev_table(dev_net(dev), dev, addr); |
Denis V. Lunev | a79878f | 2008-01-14 22:56:01 -0800 | [diff] [blame] | 239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | parms = in_dev->arp_parms; |
| 241 | __neigh_parms_put(neigh->parms); |
| 242 | neigh->parms = neigh_parms_clone(parms); |
| 243 | rcu_read_unlock(); |
| 244 | |
Stephen Hemminger | 3b04ddd | 2007-10-09 01:40:57 -0700 | [diff] [blame] | 245 | if (!dev->header_ops) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | neigh->nud_state = NUD_NOARP; |
| 247 | neigh->ops = &arp_direct_ops; |
David S. Miller | 8f40b16 | 2011-07-17 13:34:11 -0700 | [diff] [blame] | 248 | neigh->output = neigh_direct_output; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | } else { |
| 250 | /* Good devices (checked by reading texts, but only Ethernet is |
| 251 | tested) |
| 252 | |
| 253 | ARPHRD_ETHER: (ethernet, apfddi) |
| 254 | ARPHRD_FDDI: (fddi) |
| 255 | ARPHRD_IEEE802: (tr) |
| 256 | ARPHRD_METRICOM: (strip) |
| 257 | ARPHRD_ARCNET: |
| 258 | etc. etc. etc. |
| 259 | |
| 260 | ARPHRD_IPDDP will also work, if author repairs it. |
| 261 | I did not it, because this driver does not work even |
| 262 | in old paradigm. |
| 263 | */ |
| 264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | if (neigh->type == RTN_MULTICAST) { |
| 266 | neigh->nud_state = NUD_NOARP; |
| 267 | arp_mc_map(addr, neigh->ha, dev, 1); |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 268 | } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | neigh->nud_state = NUD_NOARP; |
| 270 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 271 | } else if (neigh->type == RTN_BROADCAST || |
| 272 | (dev->flags & IFF_POINTOPOINT)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | neigh->nud_state = NUD_NOARP; |
| 274 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); |
| 275 | } |
Stephen Hemminger | 3b04ddd | 2007-10-09 01:40:57 -0700 | [diff] [blame] | 276 | |
| 277 | if (dev->header_ops->cache) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | neigh->ops = &arp_hh_ops; |
| 279 | else |
| 280 | neigh->ops = &arp_generic_ops; |
Stephen Hemminger | 3b04ddd | 2007-10-09 01:40:57 -0700 | [diff] [blame] | 281 | |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 282 | if (neigh->nud_state & NUD_VALID) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | neigh->output = neigh->ops->connected_output; |
| 284 | else |
| 285 | neigh->output = neigh->ops->output; |
| 286 | } |
| 287 | return 0; |
| 288 | } |
| 289 | |
| 290 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) |
| 291 | { |
| 292 | dst_link_failure(skb); |
| 293 | kfree_skb(skb); |
| 294 | } |
| 295 | |
Thomas Graf | 0accfc2 | 2015-07-21 10:43:57 +0200 | [diff] [blame] | 296 | /* Create and send an arp packet. */ |
| 297 | static void arp_send_dst(int type, int ptype, __be32 dest_ip, |
| 298 | struct net_device *dev, __be32 src_ip, |
| 299 | const unsigned char *dest_hw, |
| 300 | const unsigned char *src_hw, |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 301 | const unsigned char *target_hw, |
| 302 | struct dst_entry *dst) |
Thomas Graf | 0accfc2 | 2015-07-21 10:43:57 +0200 | [diff] [blame] | 303 | { |
| 304 | struct sk_buff *skb; |
| 305 | |
| 306 | /* arp on this interface. */ |
| 307 | if (dev->flags & IFF_NOARP) |
| 308 | return; |
| 309 | |
| 310 | skb = arp_create(type, ptype, dest_ip, dev, src_ip, |
| 311 | dest_hw, src_hw, target_hw); |
| 312 | if (!skb) |
| 313 | return; |
| 314 | |
Jiri Benc | 181a422 | 2015-10-01 16:25:43 +0200 | [diff] [blame] | 315 | skb_dst_set(skb, dst_clone(dst)); |
Thomas Graf | 0accfc2 | 2015-07-21 10:43:57 +0200 | [diff] [blame] | 316 | arp_xmit(skb); |
| 317 | } |
| 318 | |
| 319 | void arp_send(int type, int ptype, __be32 dest_ip, |
| 320 | struct net_device *dev, __be32 src_ip, |
| 321 | const unsigned char *dest_hw, const unsigned char *src_hw, |
| 322 | const unsigned char *target_hw) |
| 323 | { |
| 324 | arp_send_dst(type, ptype, dest_ip, dev, src_ip, dest_hw, src_hw, |
| 325 | target_hw, NULL); |
| 326 | } |
| 327 | EXPORT_SYMBOL(arp_send); |
| 328 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) |
| 330 | { |
Al Viro | a61ced5 | 2006-09-26 21:27:54 -0700 | [diff] [blame] | 331 | __be32 saddr = 0; |
Cong Wang | cf0be880 | 2012-12-23 15:23:16 +0000 | [diff] [blame] | 332 | u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | struct net_device *dev = neigh->dev; |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 334 | __be32 target = *(__be32 *)neigh->primary_key; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | int probes = atomic_read(&neigh->probes); |
Eric Dumazet | 4b4194c | 2010-06-22 07:43:15 +0000 | [diff] [blame] | 336 | struct in_device *in_dev; |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 337 | struct dst_entry *dst = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | |
Eric Dumazet | 4b4194c | 2010-06-22 07:43:15 +0000 | [diff] [blame] | 339 | rcu_read_lock(); |
| 340 | in_dev = __in_dev_get_rcu(dev); |
| 341 | if (!in_dev) { |
| 342 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | return; |
Eric Dumazet | 4b4194c | 2010-06-22 07:43:15 +0000 | [diff] [blame] | 344 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { |
| 346 | default: |
| 347 | case 0: /* By default announce any local IP */ |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 348 | if (skb && inet_addr_type_dev_table(dev_net(dev), dev, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 349 | ip_hdr(skb)->saddr) == RTN_LOCAL) |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 350 | saddr = ip_hdr(skb)->saddr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | break; |
| 352 | case 1: /* Restrict announcements of saddr in same subnet */ |
| 353 | if (!skb) |
| 354 | break; |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 355 | saddr = ip_hdr(skb)->saddr; |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 356 | if (inet_addr_type_dev_table(dev_net(dev), dev, |
| 357 | saddr) == RTN_LOCAL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | /* saddr should be known to target */ |
| 359 | if (inet_addr_onlink(in_dev, target, saddr)) |
| 360 | break; |
| 361 | } |
| 362 | saddr = 0; |
| 363 | break; |
| 364 | case 2: /* Avoid secondary IPs, get a primary/preferred one */ |
| 365 | break; |
| 366 | } |
Eric Dumazet | 4b4194c | 2010-06-22 07:43:15 +0000 | [diff] [blame] | 367 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | if (!saddr) |
| 370 | saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); |
| 371 | |
Jiri Pirko | 1f9248e | 2013-12-07 19:26:53 +0100 | [diff] [blame] | 372 | probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 373 | if (probes < 0) { |
| 374 | if (!(neigh->nud_state & NUD_VALID)) |
Joe Perches | 91df42b | 2012-05-15 14:11:54 +0000 | [diff] [blame] | 375 | pr_debug("trying to ucast probe in NUD_INVALID\n"); |
Eric Dumazet | 9650388 | 2012-12-21 07:32:10 +0000 | [diff] [blame] | 376 | neigh_ha_snapshot(dst_ha, neigh, dev); |
Cong Wang | cf0be880 | 2012-12-23 15:23:16 +0000 | [diff] [blame] | 377 | dst_hw = dst_ha; |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 378 | } else { |
Jiri Pirko | 1f9248e | 2013-12-07 19:26:53 +0100 | [diff] [blame] | 379 | probes -= NEIGH_VAR(neigh->parms, APP_PROBES); |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 380 | if (probes < 0) { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 381 | neigh_app_ns(neigh); |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 382 | return; |
| 383 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | } |
| 385 | |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 386 | if (skb && !(dev->priv_flags & IFF_XMIT_DST_RELEASE)) |
Jiri Benc | 181a422 | 2015-10-01 16:25:43 +0200 | [diff] [blame] | 387 | dst = skb_dst(skb); |
Thomas Graf | 0accfc2 | 2015-07-21 10:43:57 +0200 | [diff] [blame] | 388 | arp_send_dst(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 389 | dst_hw, dev->dev_addr, NULL, dst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | } |
| 391 | |
Denis V. Lunev | 9bd85e3 | 2008-01-14 23:05:55 -0800 | [diff] [blame] | 392 | static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | { |
Nicolas Dichtel | b601fa19 | 2013-12-10 15:02:40 +0100 | [diff] [blame] | 394 | struct net *net = dev_net(in_dev->dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | int scope; |
| 396 | |
| 397 | switch (IN_DEV_ARP_IGNORE(in_dev)) { |
| 398 | case 0: /* Reply, the tip is already validated */ |
| 399 | return 0; |
| 400 | case 1: /* Reply only if tip is configured on the incoming interface */ |
| 401 | sip = 0; |
| 402 | scope = RT_SCOPE_HOST; |
| 403 | break; |
| 404 | case 2: /* |
| 405 | * Reply only if tip is configured on the incoming interface |
| 406 | * and is in same subnet as sip |
| 407 | */ |
| 408 | scope = RT_SCOPE_HOST; |
| 409 | break; |
| 410 | case 3: /* Do not reply for scope host addresses */ |
| 411 | sip = 0; |
| 412 | scope = RT_SCOPE_LINK; |
Nicolas Dichtel | b601fa19 | 2013-12-10 15:02:40 +0100 | [diff] [blame] | 413 | in_dev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | break; |
| 415 | case 4: /* Reserved */ |
| 416 | case 5: |
| 417 | case 6: |
| 418 | case 7: |
| 419 | return 0; |
| 420 | case 8: /* Do not reply */ |
| 421 | return 1; |
| 422 | default: |
| 423 | return 0; |
| 424 | } |
Nicolas Dichtel | b601fa19 | 2013-12-10 15:02:40 +0100 | [diff] [blame] | 425 | return !inet_confirm_addr(net, in_dev, sip, tip, scope); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | } |
| 427 | |
Al Viro | ed9bad0 | 2006-09-27 18:36:36 -0700 | [diff] [blame] | 428 | static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | struct rtable *rt; |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 431 | int flag = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | /*unsigned long now; */ |
Pavel Emelyanov | ca12a1a | 2008-07-16 20:28:42 -0700 | [diff] [blame] | 433 | struct net *net = dev_net(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | |
David S. Miller | 78fbfd8 | 2011-03-12 00:00:52 -0500 | [diff] [blame] | 435 | rt = ip_route_output(net, sip, tip, 0, 0); |
David S. Miller | b23dd4f | 2011-03-02 14:31:35 -0800 | [diff] [blame] | 436 | if (IS_ERR(rt)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | return 1; |
Changli Gao | d8d1f30 | 2010-06-10 23:31:35 -0700 | [diff] [blame] | 438 | if (rt->dst.dev != dev) { |
Pavel Emelyanov | de0744a | 2008-07-16 20:31:16 -0700 | [diff] [blame] | 439 | NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | flag = 1; |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 441 | } |
| 442 | ip_rt_put(rt); |
| 443 | return flag; |
| 444 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | /* |
| 447 | * Check if we can use proxy ARP for this path |
| 448 | */ |
Jesper Dangaard Brouer | 6532414 | 2010-01-05 05:50:47 +0000 | [diff] [blame] | 449 | static inline int arp_fwd_proxy(struct in_device *in_dev, |
| 450 | struct net_device *dev, struct rtable *rt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | { |
| 452 | struct in_device *out_dev; |
| 453 | int imi, omi = -1; |
| 454 | |
Changli Gao | d8d1f30 | 2010-06-10 23:31:35 -0700 | [diff] [blame] | 455 | if (rt->dst.dev == dev) |
Jesper Dangaard Brouer | 6532414 | 2010-01-05 05:50:47 +0000 | [diff] [blame] | 456 | return 0; |
| 457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | if (!IN_DEV_PROXY_ARP(in_dev)) |
| 459 | return 0; |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 460 | imi = IN_DEV_MEDIUM_ID(in_dev); |
| 461 | if (imi == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | return 1; |
| 463 | if (imi == -1) |
| 464 | return 0; |
| 465 | |
| 466 | /* place to check for proxy_arp for routes */ |
| 467 | |
Changli Gao | d8d1f30 | 2010-06-10 23:31:35 -0700 | [diff] [blame] | 468 | out_dev = __in_dev_get_rcu(rt->dst.dev); |
Eric Dumazet | faa9dcf | 2010-06-03 04:09:10 +0000 | [diff] [blame] | 469 | if (out_dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | omi = IN_DEV_MEDIUM_ID(out_dev); |
Eric Dumazet | faa9dcf | 2010-06-03 04:09:10 +0000 | [diff] [blame] | 471 | |
Eric Dumazet | a02cec2 | 2010-09-22 20:43:57 +0000 | [diff] [blame] | 472 | return omi != imi && omi != -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | } |
| 474 | |
| 475 | /* |
Jesper Dangaard Brouer | 6532414 | 2010-01-05 05:50:47 +0000 | [diff] [blame] | 476 | * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) |
| 477 | * |
| 478 | * RFC3069 supports proxy arp replies back to the same interface. This |
| 479 | * is done to support (ethernet) switch features, like RFC 3069, where |
| 480 | * the individual ports are not allowed to communicate with each |
| 481 | * other, BUT they are allowed to talk to the upstream router. As |
| 482 | * described in RFC 3069, it is possible to allow these hosts to |
| 483 | * communicate through the upstream router, by proxy_arp'ing. |
| 484 | * |
| 485 | * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" |
| 486 | * |
| 487 | * This technology is known by different names: |
| 488 | * In RFC 3069 it is called VLAN Aggregation. |
| 489 | * Cisco and Allied Telesyn call it Private VLAN. |
| 490 | * Hewlett-Packard call it Source-Port filtering or port-isolation. |
| 491 | * Ericsson call it MAC-Forced Forwarding (RFC Draft). |
| 492 | * |
| 493 | */ |
| 494 | static inline int arp_fwd_pvlan(struct in_device *in_dev, |
| 495 | struct net_device *dev, struct rtable *rt, |
| 496 | __be32 sip, __be32 tip) |
| 497 | { |
| 498 | /* Private VLAN is only concerned about the same ethernet segment */ |
Changli Gao | d8d1f30 | 2010-06-10 23:31:35 -0700 | [diff] [blame] | 499 | if (rt->dst.dev != dev) |
Jesper Dangaard Brouer | 6532414 | 2010-01-05 05:50:47 +0000 | [diff] [blame] | 500 | return 0; |
| 501 | |
| 502 | /* Don't reply on self probes (often done by windowz boxes)*/ |
| 503 | if (sip == tip) |
| 504 | return 0; |
| 505 | |
| 506 | if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) |
| 507 | return 1; |
| 508 | else |
| 509 | return 0; |
| 510 | } |
| 511 | |
| 512 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | * Interface to link layer: send routine and receive handler. |
| 514 | */ |
| 515 | |
| 516 | /* |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 517 | * Create an arp packet. If dest_hw is not set, we create a broadcast |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | * message. |
| 519 | */ |
Al Viro | ed9bad0 | 2006-09-27 18:36:36 -0700 | [diff] [blame] | 520 | struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, |
| 521 | struct net_device *dev, __be32 src_ip, |
Jan Engelhardt | abfdf1c | 2008-01-31 03:59:24 -0800 | [diff] [blame] | 522 | const unsigned char *dest_hw, |
| 523 | const unsigned char *src_hw, |
| 524 | const unsigned char *target_hw) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | { |
| 526 | struct sk_buff *skb; |
| 527 | struct arphdr *arp; |
| 528 | unsigned char *arp_ptr; |
Herbert Xu | 6608824 | 2011-11-18 02:20:04 +0000 | [diff] [blame] | 529 | int hlen = LL_RESERVED_SPACE(dev); |
| 530 | int tlen = dev->needed_tailroom; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | |
| 532 | /* |
| 533 | * Allocate a buffer |
| 534 | */ |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 535 | |
Herbert Xu | 6608824 | 2011-11-18 02:20:04 +0000 | [diff] [blame] | 536 | skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC); |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 537 | if (!skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | return NULL; |
| 539 | |
Herbert Xu | 6608824 | 2011-11-18 02:20:04 +0000 | [diff] [blame] | 540 | skb_reserve(skb, hlen); |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 541 | skb_reset_network_header(skb); |
Pavel Emelyanov | 988b705 | 2008-03-03 12:20:57 -0800 | [diff] [blame] | 542 | arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | skb->dev = dev; |
| 544 | skb->protocol = htons(ETH_P_ARP); |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 545 | if (!src_hw) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | src_hw = dev->dev_addr; |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 547 | if (!dest_hw) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | dest_hw = dev->broadcast; |
| 549 | |
| 550 | /* |
| 551 | * Fill the device header for the ARP frame |
| 552 | */ |
Stephen Hemminger | 0c4e858 | 2007-10-09 01:36:32 -0700 | [diff] [blame] | 553 | if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | goto out; |
| 555 | |
| 556 | /* |
| 557 | * Fill out the arp protocol part. |
| 558 | * |
| 559 | * The arp hardware type should match the device type, except for FDDI, |
| 560 | * which (according to RFC 1390) should always equal 1 (Ethernet). |
| 561 | */ |
| 562 | /* |
| 563 | * Exceptions everywhere. AX.25 uses the AX.25 PID value not the |
| 564 | * DIX code for the protocol. Make these device structure fields. |
| 565 | */ |
| 566 | switch (dev->type) { |
| 567 | default: |
| 568 | arp->ar_hrd = htons(dev->type); |
| 569 | arp->ar_pro = htons(ETH_P_IP); |
| 570 | break; |
| 571 | |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 572 | #if IS_ENABLED(CONFIG_AX25) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | case ARPHRD_AX25: |
| 574 | arp->ar_hrd = htons(ARPHRD_AX25); |
| 575 | arp->ar_pro = htons(AX25_P_IP); |
| 576 | break; |
| 577 | |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 578 | #if IS_ENABLED(CONFIG_NETROM) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | case ARPHRD_NETROM: |
| 580 | arp->ar_hrd = htons(ARPHRD_NETROM); |
| 581 | arp->ar_pro = htons(AX25_P_IP); |
| 582 | break; |
| 583 | #endif |
| 584 | #endif |
| 585 | |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 586 | #if IS_ENABLED(CONFIG_FDDI) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | case ARPHRD_FDDI: |
| 588 | arp->ar_hrd = htons(ARPHRD_ETHER); |
| 589 | arp->ar_pro = htons(ETH_P_IP); |
| 590 | break; |
| 591 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | } |
| 593 | |
| 594 | arp->ar_hln = dev->addr_len; |
| 595 | arp->ar_pln = 4; |
| 596 | arp->ar_op = htons(type); |
| 597 | |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 598 | arp_ptr = (unsigned char *)(arp + 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | |
| 600 | memcpy(arp_ptr, src_hw, dev->addr_len); |
Jianjun Kong | f4cca7f | 2008-11-03 02:48:14 -0800 | [diff] [blame] | 601 | arp_ptr += dev->addr_len; |
| 602 | memcpy(arp_ptr, &src_ip, 4); |
| 603 | arp_ptr += 4; |
YOSHIFUJI Hideaki / 吉藤英明 | 6752c8d | 2013-03-25 08:26:16 +0000 | [diff] [blame] | 604 | |
| 605 | switch (dev->type) { |
| 606 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) |
| 607 | case ARPHRD_IEEE1394: |
| 608 | break; |
| 609 | #endif |
| 610 | default: |
Ian Morris | 00db412 | 2015-04-03 09:17:27 +0100 | [diff] [blame] | 611 | if (target_hw) |
YOSHIFUJI Hideaki / 吉藤英明 | 6752c8d | 2013-03-25 08:26:16 +0000 | [diff] [blame] | 612 | memcpy(arp_ptr, target_hw, dev->addr_len); |
| 613 | else |
| 614 | memset(arp_ptr, 0, dev->addr_len); |
| 615 | arp_ptr += dev->addr_len; |
| 616 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | memcpy(arp_ptr, &dest_ip, 4); |
| 618 | |
| 619 | return skb; |
| 620 | |
| 621 | out: |
| 622 | kfree_skb(skb); |
| 623 | return NULL; |
| 624 | } |
Eric Dumazet | 4bc2f18 | 2010-07-09 21:22:10 +0000 | [diff] [blame] | 625 | EXPORT_SYMBOL(arp_create); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | |
Eric W. Biederman | 0c4b51f | 2015-09-15 20:04:18 -0500 | [diff] [blame] | 627 | static int arp_xmit_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
Eric W. Biederman | f9e4306 | 2015-09-15 20:04:05 -0500 | [diff] [blame] | 628 | { |
| 629 | return dev_queue_xmit(skb); |
| 630 | } |
| 631 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | /* |
| 633 | * Send an arp packet. |
| 634 | */ |
| 635 | void arp_xmit(struct sk_buff *skb) |
| 636 | { |
| 637 | /* Send it off, maybe filter it using firewalling first. */ |
Eric W. Biederman | 29a26a5 | 2015-09-15 20:04:16 -0500 | [diff] [blame] | 638 | NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, |
| 639 | dev_net(skb->dev), NULL, skb, NULL, skb->dev, |
| 640 | arp_xmit_finish); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | } |
Eric Dumazet | 4bc2f18 | 2010-07-09 21:22:10 +0000 | [diff] [blame] | 642 | EXPORT_SYMBOL(arp_xmit); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | |
| 644 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | * Process an arp request. |
| 646 | */ |
| 647 | |
Eric W. Biederman | 0c4b51f | 2015-09-15 20:04:18 -0500 | [diff] [blame] | 648 | static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 649 | { |
| 650 | struct net_device *dev = skb->dev; |
Eric Dumazet | faa9dcf | 2010-06-03 04:09:10 +0000 | [diff] [blame] | 651 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | struct arphdr *arp; |
| 653 | unsigned char *arp_ptr; |
| 654 | struct rtable *rt; |
Mark Ryden | e0260fe | 2007-12-19 23:38:11 -0800 | [diff] [blame] | 655 | unsigned char *sha; |
Al Viro | 9e12bb2 | 2006-09-26 21:25:20 -0700 | [diff] [blame] | 656 | __be32 sip, tip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | u16 dev_type = dev->type; |
| 658 | int addr_type; |
| 659 | struct neighbour *n; |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 660 | struct dst_entry *reply_dst = NULL; |
Salam Noureddine | 56022a8 | 2013-12-24 14:17:02 -0800 | [diff] [blame] | 661 | bool is_garp = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | |
| 663 | /* arp_rcv below verifies the ARP header and verifies the device |
| 664 | * is ARP'able. |
| 665 | */ |
| 666 | |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 667 | if (!in_dev) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 668 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | |
Arnaldo Carvalho de Melo | d0a92be | 2007-03-12 20:56:31 -0300 | [diff] [blame] | 670 | arp = arp_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | |
| 672 | switch (dev_type) { |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 673 | default: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | if (arp->ar_pro != htons(ETH_P_IP) || |
| 675 | htons(dev_type) != arp->ar_hrd) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 676 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | case ARPHRD_ETHER: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | case ARPHRD_FDDI: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | case ARPHRD_IEEE802: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | /* |
Paul Gortmaker | 211ed86 | 2012-05-10 17:14:35 -0400 | [diff] [blame] | 682 | * ETHERNET, and Fibre Channel (which are IEEE 802 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | * devices, according to RFC 2625) devices will accept ARP |
| 684 | * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). |
| 685 | * This is the case also of FDDI, where the RFC 1390 says that |
| 686 | * FDDI devices should accept ARP hardware of (1) Ethernet, |
| 687 | * however, to be more robust, we'll accept both 1 (Ethernet) |
| 688 | * or 6 (IEEE 802.2) |
| 689 | */ |
| 690 | if ((arp->ar_hrd != htons(ARPHRD_ETHER) && |
| 691 | arp->ar_hrd != htons(ARPHRD_IEEE802)) || |
| 692 | arp->ar_pro != htons(ETH_P_IP)) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 693 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | case ARPHRD_AX25: |
| 696 | if (arp->ar_pro != htons(AX25_P_IP) || |
| 697 | arp->ar_hrd != htons(ARPHRD_AX25)) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 698 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 699 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | case ARPHRD_NETROM: |
| 701 | if (arp->ar_pro != htons(AX25_P_IP) || |
| 702 | arp->ar_hrd != htons(ARPHRD_NETROM)) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 703 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | } |
| 706 | |
| 707 | /* Understand only these message types */ |
| 708 | |
| 709 | if (arp->ar_op != htons(ARPOP_REPLY) && |
| 710 | arp->ar_op != htons(ARPOP_REQUEST)) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 711 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | |
| 713 | /* |
| 714 | * Extract fields |
| 715 | */ |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 716 | arp_ptr = (unsigned char *)(arp + 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | sha = arp_ptr; |
| 718 | arp_ptr += dev->addr_len; |
| 719 | memcpy(&sip, arp_ptr, 4); |
| 720 | arp_ptr += 4; |
YOSHIFUJI Hideaki / 吉藤英明 | 6752c8d | 2013-03-25 08:26:16 +0000 | [diff] [blame] | 721 | switch (dev_type) { |
| 722 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) |
| 723 | case ARPHRD_IEEE1394: |
| 724 | break; |
| 725 | #endif |
| 726 | default: |
| 727 | arp_ptr += dev->addr_len; |
| 728 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | memcpy(&tip, arp_ptr, 4); |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 730 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | * Check for bad requests for 127.x.x.x and requests for multicast |
| 732 | * addresses. If this is one such, delete it. |
| 733 | */ |
Thomas Graf | d0daebc3 | 2012-06-12 00:44:01 +0000 | [diff] [blame] | 734 | if (ipv4_is_multicast(tip) || |
| 735 | (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 736 | goto out_free_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | |
Johannes Berg | 97daf33 | 2016-02-04 13:31:18 +0100 | [diff] [blame] | 738 | /* |
| 739 | * For some 802.11 wireless deployments (and possibly other networks), |
| 740 | * there will be an ARP proxy and gratuitous ARP frames are attacks |
| 741 | * and thus should not be accepted. |
| 742 | */ |
| 743 | if (sip == tip && IN_DEV_ORCONF(in_dev, DROP_GRATUITOUS_ARP)) |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 744 | goto out_free_skb; |
Johannes Berg | 97daf33 | 2016-02-04 13:31:18 +0100 | [diff] [blame] | 745 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | /* |
| 747 | * Special case: We must set Frame Relay source Q.922 address |
| 748 | */ |
| 749 | if (dev_type == ARPHRD_DLCI) |
| 750 | sha = dev->broadcast; |
| 751 | |
| 752 | /* |
| 753 | * Process entry. The idea here is we want to send a reply if it is a |
| 754 | * request for us or if it is a request for someone else that we hold |
| 755 | * a proxy for. We want to add an entry to our cache if it is a reply |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 756 | * to us or if it is a request for our address. |
| 757 | * (The assumption for this last is that if someone is requesting our |
| 758 | * address, they are probably intending to talk to us, so it saves time |
| 759 | * if we cache their address. Their address is also probably not in |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | * our cache, since ours is not in their cache.) |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 761 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | * Putting this another way, we only care about replies if they are to |
| 763 | * us, in which case we add them to the cache. For requests, we care |
| 764 | * about those for us and those for our proxies. We reply to both, |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 765 | * and in the case of requests for us we add the requester to the arp |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | * cache. |
| 767 | */ |
| 768 | |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 769 | if (arp->ar_op == htons(ARPOP_REQUEST) && skb_metadata_dst(skb)) |
| 770 | reply_dst = (struct dst_entry *) |
| 771 | iptunnel_metadata_reply(skb_metadata_dst(skb), |
| 772 | GFP_ATOMIC); |
| 773 | |
Eric W. Biederman | f8a68e7 | 2009-06-30 16:27:17 +0000 | [diff] [blame] | 774 | /* Special case: IPv4 duplicate address detection packet (RFC2131) */ |
| 775 | if (sip == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | if (arp->ar_op == htons(ARPOP_REQUEST) && |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 777 | inet_addr_type_dev_table(net, dev, tip) == RTN_LOCAL && |
Denis V. Lunev | 9bd85e3 | 2008-01-14 23:05:55 -0800 | [diff] [blame] | 778 | !arp_ignore(in_dev, sip, tip)) |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 779 | arp_send_dst(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, |
| 780 | sha, dev->dev_addr, sha, reply_dst); |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 781 | goto out_consume_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | } |
| 783 | |
| 784 | if (arp->ar_op == htons(ARPOP_REQUEST) && |
David S. Miller | c6cffba | 2012-07-26 11:14:38 +0000 | [diff] [blame] | 785 | ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | |
Eric Dumazet | 511c3f9 | 2009-06-02 05:14:27 +0000 | [diff] [blame] | 787 | rt = skb_rtable(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | addr_type = rt->rt_type; |
| 789 | |
| 790 | if (addr_type == RTN_LOCAL) { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 791 | int dont_send; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 793 | dont_send = arp_ignore(in_dev, sip, tip); |
Ben Greear | 8164f1b | 2008-11-16 19:19:38 -0800 | [diff] [blame] | 794 | if (!dont_send && IN_DEV_ARPFILTER(in_dev)) |
Changli Gao | ae9c416 | 2010-12-01 20:07:31 +0000 | [diff] [blame] | 795 | dont_send = arp_filter(sip, tip, dev); |
Ben Greear | 8164f1b | 2008-11-16 19:19:38 -0800 | [diff] [blame] | 796 | if (!dont_send) { |
| 797 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
| 798 | if (n) { |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 799 | arp_send_dst(ARPOP_REPLY, ETH_P_ARP, |
| 800 | sip, dev, tip, sha, |
| 801 | dev->dev_addr, sha, |
| 802 | reply_dst); |
Ben Greear | 8164f1b | 2008-11-16 19:19:38 -0800 | [diff] [blame] | 803 | neigh_release(n); |
| 804 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | } |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 806 | goto out_consume_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | } else if (IN_DEV_FORWARD(in_dev)) { |
Jesper Dangaard Brouer | 6532414 | 2010-01-05 05:50:47 +0000 | [diff] [blame] | 808 | if (addr_type == RTN_UNICAST && |
| 809 | (arp_fwd_proxy(in_dev, dev, rt) || |
| 810 | arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || |
Thomas Graf | 70620c4 | 2012-02-10 04:07:11 +0000 | [diff] [blame] | 811 | (rt->dst.dev != dev && |
| 812 | pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
| 814 | if (n) |
| 815 | neigh_release(n); |
| 816 | |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 817 | if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | skb->pkt_type == PACKET_HOST || |
Jiri Pirko | 1f9248e | 2013-12-07 19:26:53 +0100 | [diff] [blame] | 819 | NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) { |
Jiri Benc | 63d008a | 2015-09-22 18:12:11 +0200 | [diff] [blame] | 820 | arp_send_dst(ARPOP_REPLY, ETH_P_ARP, |
| 821 | sip, dev, tip, sha, |
| 822 | dev->dev_addr, sha, |
| 823 | reply_dst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | } else { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 825 | pneigh_enqueue(&arp_tbl, |
| 826 | in_dev->arp_parms, skb); |
Jiri Benc | 181a422 | 2015-10-01 16:25:43 +0200 | [diff] [blame] | 827 | goto out_free_dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 828 | } |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 829 | goto out_consume_skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | } |
| 831 | } |
| 832 | } |
| 833 | |
| 834 | /* Update our ARP tables */ |
| 835 | |
| 836 | n = __neigh_lookup(&arp_tbl, &sip, dev, 0); |
| 837 | |
Neil Horman | 124d37e | 2012-03-15 05:25:58 +0000 | [diff] [blame] | 838 | if (IN_DEV_ARP_ACCEPT(in_dev)) { |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 839 | unsigned int addr_type = inet_addr_type_dev_table(net, dev, sip); |
| 840 | |
Neil Horman | abd596a | 2006-03-20 22:39:47 -0800 | [diff] [blame] | 841 | /* Unsolicited ARP is not accepted by default. |
| 842 | It is possible, that this option should be enabled for some |
| 843 | devices (strip is candidate) |
| 844 | */ |
Salam Noureddine | 56022a8 | 2013-12-24 14:17:02 -0800 | [diff] [blame] | 845 | is_garp = arp->ar_op == htons(ARPOP_REQUEST) && tip == sip && |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 846 | addr_type == RTN_UNICAST; |
Salam Noureddine | 56022a8 | 2013-12-24 14:17:02 -0800 | [diff] [blame] | 847 | |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 848 | if (!n && |
Salam Noureddine | 56022a8 | 2013-12-24 14:17:02 -0800 | [diff] [blame] | 849 | ((arp->ar_op == htons(ARPOP_REPLY) && |
David Ahern | 30bbaa1 | 2015-08-13 14:59:05 -0600 | [diff] [blame] | 850 | addr_type == RTN_UNICAST) || is_garp)) |
Jean Delvare | 1b1ac75 | 2007-07-14 20:51:44 -0700 | [diff] [blame] | 851 | n = __neigh_lookup(&arp_tbl, &sip, dev, 1); |
Neil Horman | abd596a | 2006-03-20 22:39:47 -0800 | [diff] [blame] | 852 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | |
| 854 | if (n) { |
| 855 | int state = NUD_REACHABLE; |
| 856 | int override; |
| 857 | |
| 858 | /* If several different ARP replies follows back-to-back, |
| 859 | use the FIRST one. It is possible, if several proxy |
| 860 | agents are active. Taking the first reply prevents |
| 861 | arp trashing and chooses the fastest router. |
| 862 | */ |
Salam Noureddine | 56022a8 | 2013-12-24 14:17:02 -0800 | [diff] [blame] | 863 | override = time_after(jiffies, |
| 864 | n->updated + |
| 865 | NEIGH_VAR(n->parms, LOCKTIME)) || |
| 866 | is_garp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | |
| 868 | /* Broadcast replies and request packets |
| 869 | do not assert neighbour reachability. |
| 870 | */ |
| 871 | if (arp->ar_op != htons(ARPOP_REPLY) || |
| 872 | skb->pkt_type != PACKET_HOST) |
| 873 | state = NUD_STALE; |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 874 | neigh_update(n, sha, state, |
| 875 | override ? NEIGH_UPDATE_F_OVERRIDE : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | neigh_release(n); |
| 877 | } |
| 878 | |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 879 | out_consume_skb: |
Neil Horman | ead2ceb | 2009-03-11 09:49:55 +0000 | [diff] [blame] | 880 | consume_skb(skb); |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 881 | |
Jiri Benc | 181a422 | 2015-10-01 16:25:43 +0200 | [diff] [blame] | 882 | out_free_dst: |
| 883 | dst_release(reply_dst); |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 884 | return NET_RX_SUCCESS; |
| 885 | |
| 886 | out_free_skb: |
| 887 | kfree_skb(skb); |
| 888 | return NET_RX_DROP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 889 | } |
| 890 | |
Herbert Xu | 444fc8f | 2005-10-03 14:18:10 -0700 | [diff] [blame] | 891 | static void parp_redo(struct sk_buff *skb) |
| 892 | { |
Eric W. Biederman | 0c4b51f | 2015-09-15 20:04:18 -0500 | [diff] [blame] | 893 | arp_process(dev_net(skb->dev), NULL, skb); |
Herbert Xu | 444fc8f | 2005-10-03 14:18:10 -0700 | [diff] [blame] | 894 | } |
| 895 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 896 | |
| 897 | /* |
| 898 | * Receive an arp request from the device layer. |
| 899 | */ |
| 900 | |
Adrian Bunk | 6c97e72 | 2006-04-12 13:57:59 -0700 | [diff] [blame] | 901 | static int arp_rcv(struct sk_buff *skb, struct net_device *dev, |
| 902 | struct packet_type *pt, struct net_device *orig_dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | { |
Eric Dumazet | 044453b | 2013-02-08 18:48:21 +0000 | [diff] [blame] | 904 | const struct arphdr *arp; |
| 905 | |
Rick Jones | 825bae5 | 2014-09-25 10:55:28 -0700 | [diff] [blame] | 906 | /* do not tweak dropwatch on an ARP we will ignore */ |
Eric Dumazet | 044453b | 2013-02-08 18:48:21 +0000 | [diff] [blame] | 907 | if (dev->flags & IFF_NOARP || |
| 908 | skb->pkt_type == PACKET_OTHERHOST || |
| 909 | skb->pkt_type == PACKET_LOOPBACK) |
Rick Jones | 825bae5 | 2014-09-25 10:55:28 -0700 | [diff] [blame] | 910 | goto consumeskb; |
Eric Dumazet | 044453b | 2013-02-08 18:48:21 +0000 | [diff] [blame] | 911 | |
| 912 | skb = skb_share_check(skb, GFP_ATOMIC); |
| 913 | if (!skb) |
| 914 | goto out_of_mem; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | |
| 916 | /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ |
Pavel Emelyanov | 988b705 | 2008-03-03 12:20:57 -0800 | [diff] [blame] | 917 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 918 | goto freeskb; |
| 919 | |
Arnaldo Carvalho de Melo | d0a92be | 2007-03-12 20:56:31 -0300 | [diff] [blame] | 920 | arp = arp_hdr(skb); |
Eric Dumazet | 044453b | 2013-02-08 18:48:21 +0000 | [diff] [blame] | 921 | if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 922 | goto freeskb; |
| 923 | |
Patrick McHardy | a61bbcf | 2005-08-14 17:24:31 -0700 | [diff] [blame] | 924 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
| 925 | |
Eric W. Biederman | 29a26a5 | 2015-09-15 20:04:16 -0500 | [diff] [blame] | 926 | return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, |
| 927 | dev_net(dev), NULL, skb, dev, NULL, |
| 928 | arp_process); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | |
Rick Jones | 825bae5 | 2014-09-25 10:55:28 -0700 | [diff] [blame] | 930 | consumeskb: |
| 931 | consume_skb(skb); |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 932 | return NET_RX_SUCCESS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | freeskb: |
| 934 | kfree_skb(skb); |
| 935 | out_of_mem: |
Zhang Shengju | 8dfd329 | 2016-03-04 14:07:54 +0000 | [diff] [blame] | 936 | return NET_RX_DROP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 937 | } |
| 938 | |
| 939 | /* |
| 940 | * User level interface (ioctl) |
| 941 | */ |
| 942 | |
| 943 | /* |
| 944 | * Set (create) an ARP cache entry. |
| 945 | */ |
| 946 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 947 | static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) |
Pavel Emelyanov | f8b33fd | 2007-12-05 21:20:50 -0800 | [diff] [blame] | 948 | { |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 949 | if (!dev) { |
Pavel Emelyanov | 586f121 | 2007-12-16 13:32:48 -0800 | [diff] [blame] | 950 | IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; |
Pavel Emelyanov | f8b33fd | 2007-12-05 21:20:50 -0800 | [diff] [blame] | 951 | return 0; |
| 952 | } |
Eric Dumazet | c506653 | 2011-01-24 13:16:16 -0800 | [diff] [blame] | 953 | if (__in_dev_get_rtnl(dev)) { |
| 954 | IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); |
Pavel Emelyanov | f8b33fd | 2007-12-05 21:20:50 -0800 | [diff] [blame] | 955 | return 0; |
| 956 | } |
| 957 | return -ENXIO; |
| 958 | } |
| 959 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 960 | static int arp_req_set_public(struct net *net, struct arpreq *r, |
| 961 | struct net_device *dev) |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 962 | { |
| 963 | __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
| 964 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; |
| 965 | |
| 966 | if (mask && mask != htonl(0xFFFFFFFF)) |
| 967 | return -EINVAL; |
| 968 | if (!dev && (r->arp_flags & ATF_COM)) { |
Eric Dumazet | 941666c | 2010-12-05 01:23:53 +0000 | [diff] [blame] | 969 | dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 970 | r->arp_ha.sa_data); |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 971 | if (!dev) |
| 972 | return -ENODEV; |
| 973 | } |
| 974 | if (mask) { |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 975 | if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1)) |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 976 | return -ENOBUFS; |
| 977 | return 0; |
| 978 | } |
Pavel Emelyanov | f8b33fd | 2007-12-05 21:20:50 -0800 | [diff] [blame] | 979 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 980 | return arp_req_set_proxy(net, dev, 1); |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 981 | } |
| 982 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 983 | static int arp_req_set(struct net *net, struct arpreq *r, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 984 | struct net_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 985 | { |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 986 | __be32 ip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | struct neighbour *neigh; |
| 988 | int err; |
| 989 | |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 990 | if (r->arp_flags & ATF_PUBL) |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 991 | return arp_req_set_public(net, r, dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | |
Pavel Emelyanov | 43dc170 | 2007-12-05 21:19:44 -0800 | [diff] [blame] | 993 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | if (r->arp_flags & ATF_PERM) |
| 995 | r->arp_flags |= ATF_COM; |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 996 | if (!dev) { |
David S. Miller | 78fbfd8 | 2011-03-12 00:00:52 -0500 | [diff] [blame] | 997 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
David S. Miller | b23dd4f | 2011-03-02 14:31:35 -0800 | [diff] [blame] | 998 | |
| 999 | if (IS_ERR(rt)) |
| 1000 | return PTR_ERR(rt); |
Changli Gao | d8d1f30 | 2010-06-10 23:31:35 -0700 | [diff] [blame] | 1001 | dev = rt->dst.dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | ip_rt_put(rt); |
| 1003 | if (!dev) |
| 1004 | return -EINVAL; |
| 1005 | } |
| 1006 | switch (dev->type) { |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 1007 | #if IS_ENABLED(CONFIG_FDDI) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | case ARPHRD_FDDI: |
| 1009 | /* |
| 1010 | * According to RFC 1390, FDDI devices should accept ARP |
| 1011 | * hardware types of 1 (Ethernet). However, to be more |
| 1012 | * robust, we'll accept hardware types of either 1 (Ethernet) |
| 1013 | * or 6 (IEEE 802.2). |
| 1014 | */ |
| 1015 | if (r->arp_ha.sa_family != ARPHRD_FDDI && |
| 1016 | r->arp_ha.sa_family != ARPHRD_ETHER && |
| 1017 | r->arp_ha.sa_family != ARPHRD_IEEE802) |
| 1018 | return -EINVAL; |
| 1019 | break; |
| 1020 | #endif |
| 1021 | default: |
| 1022 | if (r->arp_ha.sa_family != dev->type) |
| 1023 | return -EINVAL; |
| 1024 | break; |
| 1025 | } |
| 1026 | |
| 1027 | neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); |
| 1028 | err = PTR_ERR(neigh); |
| 1029 | if (!IS_ERR(neigh)) { |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 1030 | unsigned int state = NUD_STALE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1031 | if (r->arp_flags & ATF_PERM) |
| 1032 | state = NUD_PERMANENT; |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1033 | err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1034 | r->arp_ha.sa_data : NULL, state, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1035 | NEIGH_UPDATE_F_OVERRIDE | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1036 | NEIGH_UPDATE_F_ADMIN); |
| 1037 | neigh_release(neigh); |
| 1038 | } |
| 1039 | return err; |
| 1040 | } |
| 1041 | |
Eric Dumazet | 95c9617 | 2012-04-15 05:58:06 +0000 | [diff] [blame] | 1042 | static unsigned int arp_state_to_flags(struct neighbour *neigh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1043 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | if (neigh->nud_state&NUD_PERMANENT) |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1045 | return ATF_PERM | ATF_COM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1046 | else if (neigh->nud_state&NUD_VALID) |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1047 | return ATF_COM; |
| 1048 | else |
| 1049 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | } |
| 1051 | |
| 1052 | /* |
| 1053 | * Get an ARP cache entry. |
| 1054 | */ |
| 1055 | |
| 1056 | static int arp_req_get(struct arpreq *r, struct net_device *dev) |
| 1057 | { |
Al Viro | ed9bad0 | 2006-09-27 18:36:36 -0700 | [diff] [blame] | 1058 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | struct neighbour *neigh; |
| 1060 | int err = -ENXIO; |
| 1061 | |
| 1062 | neigh = neigh_lookup(&arp_tbl, &ip, dev); |
| 1063 | if (neigh) { |
Eric Dumazet | 11c91ef | 2015-07-27 11:33:50 +0200 | [diff] [blame] | 1064 | if (!(neigh->nud_state & NUD_NOARP)) { |
| 1065 | read_lock_bh(&neigh->lock); |
| 1066 | memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); |
| 1067 | r->arp_flags = arp_state_to_flags(neigh); |
| 1068 | read_unlock_bh(&neigh->lock); |
| 1069 | r->arp_ha.sa_family = dev->type; |
| 1070 | strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); |
| 1071 | err = 0; |
| 1072 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | neigh_release(neigh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | } |
| 1075 | return err; |
| 1076 | } |
| 1077 | |
Stephen Hemminger | 7195cf7 | 2013-12-28 11:07:18 -0800 | [diff] [blame] | 1078 | static int arp_invalidate(struct net_device *dev, __be32 ip) |
Maxim Levitsky | 545ecdc | 2011-01-08 13:57:12 +0000 | [diff] [blame] | 1079 | { |
| 1080 | struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); |
| 1081 | int err = -ENXIO; |
| 1082 | |
| 1083 | if (neigh) { |
| 1084 | if (neigh->nud_state & ~NUD_NOARP) |
| 1085 | err = neigh_update(neigh, NULL, NUD_FAILED, |
| 1086 | NEIGH_UPDATE_F_OVERRIDE| |
| 1087 | NEIGH_UPDATE_F_ADMIN); |
| 1088 | neigh_release(neigh); |
| 1089 | } |
| 1090 | |
| 1091 | return err; |
| 1092 | } |
Maxim Levitsky | 545ecdc | 2011-01-08 13:57:12 +0000 | [diff] [blame] | 1093 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1094 | static int arp_req_delete_public(struct net *net, struct arpreq *r, |
| 1095 | struct net_device *dev) |
Pavel Emelyanov | 46479b4 | 2007-12-05 21:20:18 -0800 | [diff] [blame] | 1096 | { |
| 1097 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
| 1098 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; |
| 1099 | |
| 1100 | if (mask == htonl(0xFFFFFFFF)) |
Denis V. Lunev | 2db82b5 | 2008-01-14 22:58:55 -0800 | [diff] [blame] | 1101 | return pneigh_delete(&arp_tbl, net, &ip, dev); |
Pavel Emelyanov | 46479b4 | 2007-12-05 21:20:18 -0800 | [diff] [blame] | 1102 | |
Pavel Emelyanov | f8b33fd | 2007-12-05 21:20:50 -0800 | [diff] [blame] | 1103 | if (mask) |
| 1104 | return -EINVAL; |
| 1105 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1106 | return arp_req_set_proxy(net, dev, 0); |
Pavel Emelyanov | 46479b4 | 2007-12-05 21:20:18 -0800 | [diff] [blame] | 1107 | } |
| 1108 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1109 | static int arp_req_delete(struct net *net, struct arpreq *r, |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1110 | struct net_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | { |
Pavel Emelyanov | 46479b4 | 2007-12-05 21:20:18 -0800 | [diff] [blame] | 1112 | __be32 ip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | |
Pavel Emelyanov | 46479b4 | 2007-12-05 21:20:18 -0800 | [diff] [blame] | 1114 | if (r->arp_flags & ATF_PUBL) |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1115 | return arp_req_delete_public(net, r, dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1116 | |
Pavel Emelyanov | 46479b4 | 2007-12-05 21:20:18 -0800 | [diff] [blame] | 1117 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 1118 | if (!dev) { |
David S. Miller | 78fbfd8 | 2011-03-12 00:00:52 -0500 | [diff] [blame] | 1119 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
David S. Miller | b23dd4f | 2011-03-02 14:31:35 -0800 | [diff] [blame] | 1120 | if (IS_ERR(rt)) |
| 1121 | return PTR_ERR(rt); |
Changli Gao | d8d1f30 | 2010-06-10 23:31:35 -0700 | [diff] [blame] | 1122 | dev = rt->dst.dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | ip_rt_put(rt); |
| 1124 | if (!dev) |
| 1125 | return -EINVAL; |
| 1126 | } |
Maxim Levitsky | 545ecdc | 2011-01-08 13:57:12 +0000 | [diff] [blame] | 1127 | return arp_invalidate(dev, ip); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | } |
| 1129 | |
| 1130 | /* |
| 1131 | * Handle an ARP layer I/O control request. |
| 1132 | */ |
| 1133 | |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1134 | int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | { |
| 1136 | int err; |
| 1137 | struct arpreq r; |
| 1138 | struct net_device *dev = NULL; |
| 1139 | |
| 1140 | switch (cmd) { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1141 | case SIOCDARP: |
| 1142 | case SIOCSARP: |
Eric W. Biederman | 52e804c | 2012-11-16 03:03:05 +0000 | [diff] [blame] | 1143 | if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1144 | return -EPERM; |
| 1145 | case SIOCGARP: |
| 1146 | err = copy_from_user(&r, arg, sizeof(struct arpreq)); |
| 1147 | if (err) |
| 1148 | return -EFAULT; |
| 1149 | break; |
| 1150 | default: |
| 1151 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | } |
| 1153 | |
| 1154 | if (r.arp_pa.sa_family != AF_INET) |
| 1155 | return -EPFNOSUPPORT; |
| 1156 | |
| 1157 | if (!(r.arp_flags & ATF_PUBL) && |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1158 | (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1159 | return -EINVAL; |
| 1160 | if (!(r.arp_flags & ATF_NETMASK)) |
| 1161 | ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = |
| 1162 | htonl(0xFFFFFFFFUL); |
Eric Dumazet | c506653 | 2011-01-24 13:16:16 -0800 | [diff] [blame] | 1163 | rtnl_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1164 | if (r.arp_dev[0]) { |
| 1165 | err = -ENODEV; |
Eric Dumazet | c506653 | 2011-01-24 13:16:16 -0800 | [diff] [blame] | 1166 | dev = __dev_get_by_name(net, r.arp_dev); |
Ian Morris | 51456b2 | 2015-04-03 09:17:26 +0100 | [diff] [blame] | 1167 | if (!dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1168 | goto out; |
| 1169 | |
| 1170 | /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ |
| 1171 | if (!r.arp_ha.sa_family) |
| 1172 | r.arp_ha.sa_family = dev->type; |
| 1173 | err = -EINVAL; |
| 1174 | if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) |
| 1175 | goto out; |
| 1176 | } else if (cmd == SIOCGARP) { |
| 1177 | err = -ENODEV; |
| 1178 | goto out; |
| 1179 | } |
| 1180 | |
Stephen Hemminger | 132adf5 | 2007-03-08 20:44:43 -0800 | [diff] [blame] | 1181 | switch (cmd) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | case SIOCDARP: |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1183 | err = arp_req_delete(net, &r, dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | break; |
| 1185 | case SIOCSARP: |
Pavel Emelyanov | 32e569b | 2007-12-16 13:30:39 -0800 | [diff] [blame] | 1186 | err = arp_req_set(net, &r, dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1187 | break; |
| 1188 | case SIOCGARP: |
| 1189 | err = arp_req_get(&r, dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | break; |
| 1191 | } |
| 1192 | out: |
Eric Dumazet | c506653 | 2011-01-24 13:16:16 -0800 | [diff] [blame] | 1193 | rtnl_unlock(); |
Eric Dumazet | 941666c | 2010-12-05 01:23:53 +0000 | [diff] [blame] | 1194 | if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) |
| 1195 | err = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | return err; |
| 1197 | } |
| 1198 | |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1199 | static int arp_netdev_event(struct notifier_block *this, unsigned long event, |
| 1200 | void *ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | { |
Jiri Pirko | 351638e | 2013-05-28 01:30:21 +0000 | [diff] [blame] | 1202 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
Timo Teräs | 6c8b4e3 | 2013-05-28 01:30:23 +0000 | [diff] [blame] | 1203 | struct netdev_notifier_change_info *change_info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1204 | |
| 1205 | switch (event) { |
| 1206 | case NETDEV_CHANGEADDR: |
| 1207 | neigh_changeaddr(&arp_tbl, dev); |
Nicolas Dichtel | bafa6d9 | 2012-09-07 00:45:29 +0000 | [diff] [blame] | 1208 | rt_cache_flush(dev_net(dev)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | break; |
Timo Teräs | 6c8b4e3 | 2013-05-28 01:30:23 +0000 | [diff] [blame] | 1210 | case NETDEV_CHANGE: |
| 1211 | change_info = ptr; |
| 1212 | if (change_info->flags_changed & IFF_NOARP) |
| 1213 | neigh_changeaddr(&arp_tbl, dev); |
| 1214 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | default: |
| 1216 | break; |
| 1217 | } |
| 1218 | |
| 1219 | return NOTIFY_DONE; |
| 1220 | } |
| 1221 | |
| 1222 | static struct notifier_block arp_netdev_notifier = { |
| 1223 | .notifier_call = arp_netdev_event, |
| 1224 | }; |
| 1225 | |
| 1226 | /* Note, that it is not on notifier chain. |
| 1227 | It is necessary, that this routine was called after route cache will be |
| 1228 | flushed. |
| 1229 | */ |
| 1230 | void arp_ifdown(struct net_device *dev) |
| 1231 | { |
| 1232 | neigh_ifdown(&arp_tbl, dev); |
| 1233 | } |
| 1234 | |
| 1235 | |
| 1236 | /* |
| 1237 | * Called once on startup. |
| 1238 | */ |
| 1239 | |
Stephen Hemminger | 7546dd9 | 2009-03-09 08:18:29 +0000 | [diff] [blame] | 1240 | static struct packet_type arp_packet_type __read_mostly = { |
Harvey Harrison | 09640e6 | 2009-02-01 00:45:17 -0800 | [diff] [blame] | 1241 | .type = cpu_to_be16(ETH_P_ARP), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | .func = arp_rcv, |
| 1243 | }; |
| 1244 | |
| 1245 | static int arp_proc_init(void); |
| 1246 | |
| 1247 | void __init arp_init(void) |
| 1248 | { |
WANG Cong | d7480fd | 2014-11-10 15:59:36 -0800 | [diff] [blame] | 1249 | neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1250 | |
| 1251 | dev_add_pack(&arp_packet_type); |
| 1252 | arp_proc_init(); |
| 1253 | #ifdef CONFIG_SYSCTL |
Jiri Pirko | 73af614 | 2013-12-07 19:26:55 +0100 | [diff] [blame] | 1254 | neigh_sysctl_register(NULL, &arp_tbl.parms, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | #endif |
| 1256 | register_netdevice_notifier(&arp_netdev_notifier); |
| 1257 | } |
| 1258 | |
| 1259 | #ifdef CONFIG_PROC_FS |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 1260 | #if IS_ENABLED(CONFIG_AX25) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | |
| 1262 | /* ------------------------------------------------------------------------ */ |
| 1263 | /* |
| 1264 | * ax25 -> ASCII conversion |
| 1265 | */ |
| 1266 | static char *ax2asc2(ax25_address *a, char *buf) |
| 1267 | { |
| 1268 | char c, *s; |
| 1269 | int n; |
| 1270 | |
| 1271 | for (n = 0, s = buf; n < 6; n++) { |
| 1272 | c = (a->ax25_call[n] >> 1) & 0x7F; |
| 1273 | |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1274 | if (c != ' ') |
| 1275 | *s++ = c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | } |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1277 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | *s++ = '-'; |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1279 | n = (a->ax25_call[6] >> 1) & 0x0F; |
| 1280 | if (n > 9) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1281 | *s++ = '1'; |
| 1282 | n -= 10; |
| 1283 | } |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1284 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1285 | *s++ = n + '0'; |
| 1286 | *s++ = '\0'; |
| 1287 | |
| 1288 | if (*buf == '\0' || *buf == '-') |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1289 | return "*"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1290 | |
| 1291 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1292 | } |
| 1293 | #endif /* CONFIG_AX25 */ |
| 1294 | |
| 1295 | #define HBUFFERLEN 30 |
| 1296 | |
| 1297 | static void arp_format_neigh_entry(struct seq_file *seq, |
| 1298 | struct neighbour *n) |
| 1299 | { |
| 1300 | char hbuffer[HBUFFERLEN]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | int k, j; |
| 1302 | char tbuf[16]; |
| 1303 | struct net_device *dev = n->dev; |
| 1304 | int hatype = dev->type; |
| 1305 | |
| 1306 | read_lock(&n->lock); |
| 1307 | /* Convert hardware address to XX:XX:XX:XX ... form. */ |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 1308 | #if IS_ENABLED(CONFIG_AX25) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) |
| 1310 | ax2asc2((ax25_address *)n->ha, hbuffer); |
| 1311 | else { |
| 1312 | #endif |
| 1313 | for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { |
Denis Cheng | 51f82a2 | 2008-05-21 17:34:32 -0700 | [diff] [blame] | 1314 | hbuffer[k++] = hex_asc_hi(n->ha[j]); |
| 1315 | hbuffer[k++] = hex_asc_lo(n->ha[j]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | hbuffer[k++] = ':'; |
| 1317 | } |
roel kluin | a3e8ee6 | 2009-07-29 23:46:59 +0000 | [diff] [blame] | 1318 | if (k != 0) |
| 1319 | --k; |
| 1320 | hbuffer[k] = 0; |
Igor Maravic | 40e4783 | 2011-12-05 02:25:57 +0000 | [diff] [blame] | 1321 | #if IS_ENABLED(CONFIG_AX25) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | } |
| 1323 | #endif |
Harvey Harrison | 673d57e | 2008-10-31 00:53:57 -0700 | [diff] [blame] | 1324 | sprintf(tbuf, "%pI4", n->primary_key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
| 1326 | tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); |
| 1327 | read_unlock(&n->lock); |
| 1328 | } |
| 1329 | |
| 1330 | static void arp_format_pneigh_entry(struct seq_file *seq, |
| 1331 | struct pneigh_entry *n) |
| 1332 | { |
| 1333 | struct net_device *dev = n->dev; |
| 1334 | int hatype = dev ? dev->type : 0; |
| 1335 | char tbuf[16]; |
| 1336 | |
Harvey Harrison | 673d57e | 2008-10-31 00:53:57 -0700 | [diff] [blame] | 1337 | sprintf(tbuf, "%pI4", n->key); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1338 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
| 1339 | tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", |
| 1340 | dev ? dev->name : "*"); |
| 1341 | } |
| 1342 | |
| 1343 | static int arp_seq_show(struct seq_file *seq, void *v) |
| 1344 | { |
| 1345 | if (v == SEQ_START_TOKEN) { |
| 1346 | seq_puts(seq, "IP address HW type Flags " |
| 1347 | "HW address Mask Device\n"); |
| 1348 | } else { |
| 1349 | struct neigh_seq_state *state = seq->private; |
| 1350 | |
| 1351 | if (state->flags & NEIGH_SEQ_IS_PNEIGH) |
| 1352 | arp_format_pneigh_entry(seq, v); |
| 1353 | else |
| 1354 | arp_format_neigh_entry(seq, v); |
| 1355 | } |
| 1356 | |
| 1357 | return 0; |
| 1358 | } |
| 1359 | |
| 1360 | static void *arp_seq_start(struct seq_file *seq, loff_t *pos) |
| 1361 | { |
| 1362 | /* Don't want to confuse "arp -a" w/ magic entries, |
| 1363 | * so we tell the generic iterator to skip NUD_NOARP. |
| 1364 | */ |
| 1365 | return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); |
| 1366 | } |
| 1367 | |
| 1368 | /* ------------------------------------------------------------------------ */ |
| 1369 | |
Stephen Hemminger | f690808 | 2007-03-12 14:34:29 -0700 | [diff] [blame] | 1370 | static const struct seq_operations arp_seq_ops = { |
Changli Gao | deffd77 | 2010-09-02 03:56:51 +0000 | [diff] [blame] | 1371 | .start = arp_seq_start, |
| 1372 | .next = neigh_seq_next, |
| 1373 | .stop = neigh_seq_stop, |
| 1374 | .show = arp_seq_show, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1375 | }; |
| 1376 | |
| 1377 | static int arp_seq_open(struct inode *inode, struct file *file) |
| 1378 | { |
Eric W. Biederman | 426b530 | 2008-01-24 00:13:18 -0800 | [diff] [blame] | 1379 | return seq_open_net(inode, file, &arp_seq_ops, |
| 1380 | sizeof(struct neigh_seq_state)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | } |
| 1382 | |
Arjan van de Ven | 9a32144 | 2007-02-12 00:55:35 -0800 | [diff] [blame] | 1383 | static const struct file_operations arp_seq_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1384 | .owner = THIS_MODULE, |
| 1385 | .open = arp_seq_open, |
| 1386 | .read = seq_read, |
| 1387 | .llseek = seq_lseek, |
Eric W. Biederman | 426b530 | 2008-01-24 00:13:18 -0800 | [diff] [blame] | 1388 | .release = seq_release_net, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1389 | }; |
| 1390 | |
Denis V. Lunev | ffc31d3 | 2008-03-24 15:28:43 -0700 | [diff] [blame] | 1391 | |
| 1392 | static int __net_init arp_net_init(struct net *net) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1393 | { |
Gao feng | d4beaa6 | 2013-02-18 01:34:54 +0000 | [diff] [blame] | 1394 | if (!proc_create("arp", S_IRUGO, net->proc_net, &arp_seq_fops)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | return -ENOMEM; |
| 1396 | return 0; |
| 1397 | } |
| 1398 | |
Denis V. Lunev | ffc31d3 | 2008-03-24 15:28:43 -0700 | [diff] [blame] | 1399 | static void __net_exit arp_net_exit(struct net *net) |
| 1400 | { |
Gao feng | ece31ff | 2013-02-18 01:34:56 +0000 | [diff] [blame] | 1401 | remove_proc_entry("arp", net->proc_net); |
Denis V. Lunev | ffc31d3 | 2008-03-24 15:28:43 -0700 | [diff] [blame] | 1402 | } |
| 1403 | |
| 1404 | static struct pernet_operations arp_net_ops = { |
| 1405 | .init = arp_net_init, |
| 1406 | .exit = arp_net_exit, |
| 1407 | }; |
| 1408 | |
| 1409 | static int __init arp_proc_init(void) |
| 1410 | { |
| 1411 | return register_pernet_subsys(&arp_net_ops); |
| 1412 | } |
| 1413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1414 | #else /* CONFIG_PROC_FS */ |
| 1415 | |
| 1416 | static int __init arp_proc_init(void) |
| 1417 | { |
| 1418 | return 0; |
| 1419 | } |
| 1420 | |
| 1421 | #endif /* CONFIG_PROC_FS */ |