]>
Commit | Line | Data |
---|---|---|
1 | /* linux/net/ipv4/arp.c | |
2 | * | |
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: | |
16 | * Alan Cox : Removed the Ethernet assumptions in | |
17 | * Florian's code | |
18 | * Alan Cox : Fixed some small errors in the ARP | |
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. | |
40 | * Craig Schlenter : Don't modify permanent entry | |
41 | * during arp_rcv. | |
42 | * Russ Nelson : Tidied up a few bits. | |
43 | * Alexey Kuznetsov: Major changes to caching and behaviour, | |
44 | * eg intelligent arp probing and | |
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. | |
51 | * Jonathan Layes : Added arpd support through kerneld | |
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. | |
58 | * Alan Cox : Took the AP1000 nasty FDDI hack and | |
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 | |
73 | * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. | |
74 | */ | |
75 | ||
76 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
77 | ||
78 | #include <linux/module.h> | |
79 | #include <linux/types.h> | |
80 | #include <linux/string.h> | |
81 | #include <linux/kernel.h> | |
82 | #include <linux/capability.h> | |
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> | |
89 | #include <linux/inetdevice.h> | |
90 | #include <linux/netdevice.h> | |
91 | #include <linux/etherdevice.h> | |
92 | #include <linux/fddidevice.h> | |
93 | #include <linux/if_arp.h> | |
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> | |
101 | #include <linux/slab.h> | |
102 | #ifdef CONFIG_SYSCTL | |
103 | #include <linux/sysctl.h> | |
104 | #endif | |
105 | ||
106 | #include <net/net_namespace.h> | |
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> | |
114 | #include <net/ax25.h> | |
115 | #include <net/netrom.h> | |
116 | ||
117 | #include <linux/uaccess.h> | |
118 | ||
119 | #include <linux/netfilter_arp.h> | |
120 | ||
121 | /* | |
122 | * Interface to generic neighbour cache. | |
123 | */ | |
124 | static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd); | |
125 | static bool arp_key_eq(const struct neighbour *n, const void *pkey); | |
126 | static int arp_constructor(struct neighbour *neigh); | |
127 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); | |
128 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); | |
129 | static void parp_redo(struct sk_buff *skb); | |
130 | ||
131 | static const struct neigh_ops arp_generic_ops = { | |
132 | .family = AF_INET, | |
133 | .solicit = arp_solicit, | |
134 | .error_report = arp_error_report, | |
135 | .output = neigh_resolve_output, | |
136 | .connected_output = neigh_connected_output, | |
137 | }; | |
138 | ||
139 | static const struct neigh_ops arp_hh_ops = { | |
140 | .family = AF_INET, | |
141 | .solicit = arp_solicit, | |
142 | .error_report = arp_error_report, | |
143 | .output = neigh_resolve_output, | |
144 | .connected_output = neigh_resolve_output, | |
145 | }; | |
146 | ||
147 | static const struct neigh_ops arp_direct_ops = { | |
148 | .family = AF_INET, | |
149 | .output = neigh_direct_output, | |
150 | .connected_output = neigh_direct_output, | |
151 | }; | |
152 | ||
153 | struct neigh_table arp_tbl = { | |
154 | .family = AF_INET, | |
155 | .key_len = 4, | |
156 | .protocol = cpu_to_be16(ETH_P_IP), | |
157 | .hash = arp_hash, | |
158 | .key_eq = arp_key_eq, | |
159 | .constructor = arp_constructor, | |
160 | .proxy_redo = parp_redo, | |
161 | .id = "arp_cache", | |
162 | .parms = { | |
163 | .tbl = &arp_tbl, | |
164 | .reachable_time = 30 * HZ, | |
165 | .data = { | |
166 | [NEIGH_VAR_MCAST_PROBES] = 3, | |
167 | [NEIGH_VAR_UCAST_PROBES] = 3, | |
168 | [NEIGH_VAR_RETRANS_TIME] = 1 * HZ, | |
169 | [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, | |
170 | [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, | |
171 | [NEIGH_VAR_GC_STALETIME] = 60 * HZ, | |
172 | [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024, | |
173 | [NEIGH_VAR_PROXY_QLEN] = 64, | |
174 | [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, | |
175 | [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, | |
176 | [NEIGH_VAR_LOCKTIME] = 1 * HZ, | |
177 | }, | |
178 | }, | |
179 | .gc_interval = 30 * HZ, | |
180 | .gc_thresh1 = 128, | |
181 | .gc_thresh2 = 512, | |
182 | .gc_thresh3 = 1024, | |
183 | }; | |
184 | EXPORT_SYMBOL(arp_tbl); | |
185 | ||
186 | int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) | |
187 | { | |
188 | switch (dev->type) { | |
189 | case ARPHRD_ETHER: | |
190 | case ARPHRD_FDDI: | |
191 | case ARPHRD_IEEE802: | |
192 | ip_eth_mc_map(addr, haddr); | |
193 | return 0; | |
194 | case ARPHRD_INFINIBAND: | |
195 | ip_ib_mc_map(addr, dev->broadcast, haddr); | |
196 | return 0; | |
197 | case ARPHRD_IPGRE: | |
198 | ip_ipgre_mc_map(addr, dev->broadcast, haddr); | |
199 | return 0; | |
200 | default: | |
201 | if (dir) { | |
202 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
203 | return 0; | |
204 | } | |
205 | } | |
206 | return -EINVAL; | |
207 | } | |
208 | ||
209 | ||
210 | static u32 arp_hash(const void *pkey, | |
211 | const struct net_device *dev, | |
212 | __u32 *hash_rnd) | |
213 | { | |
214 | return arp_hashfn(pkey, dev, hash_rnd); | |
215 | } | |
216 | ||
217 | static bool arp_key_eq(const struct neighbour *neigh, const void *pkey) | |
218 | { | |
219 | return neigh_key_eq32(neigh, pkey); | |
220 | } | |
221 | ||
222 | static int arp_constructor(struct neighbour *neigh) | |
223 | { | |
224 | __be32 addr = *(__be32 *)neigh->primary_key; | |
225 | struct net_device *dev = neigh->dev; | |
226 | struct in_device *in_dev; | |
227 | struct neigh_parms *parms; | |
228 | ||
229 | rcu_read_lock(); | |
230 | in_dev = __in_dev_get_rcu(dev); | |
231 | if (!in_dev) { | |
232 | rcu_read_unlock(); | |
233 | return -EINVAL; | |
234 | } | |
235 | ||
236 | neigh->type = inet_addr_type(dev_net(dev), addr); | |
237 | ||
238 | parms = in_dev->arp_parms; | |
239 | __neigh_parms_put(neigh->parms); | |
240 | neigh->parms = neigh_parms_clone(parms); | |
241 | rcu_read_unlock(); | |
242 | ||
243 | if (!dev->header_ops) { | |
244 | neigh->nud_state = NUD_NOARP; | |
245 | neigh->ops = &arp_direct_ops; | |
246 | neigh->output = neigh_direct_output; | |
247 | } else { | |
248 | /* Good devices (checked by reading texts, but only Ethernet is | |
249 | tested) | |
250 | ||
251 | ARPHRD_ETHER: (ethernet, apfddi) | |
252 | ARPHRD_FDDI: (fddi) | |
253 | ARPHRD_IEEE802: (tr) | |
254 | ARPHRD_METRICOM: (strip) | |
255 | ARPHRD_ARCNET: | |
256 | etc. etc. etc. | |
257 | ||
258 | ARPHRD_IPDDP will also work, if author repairs it. | |
259 | I did not it, because this driver does not work even | |
260 | in old paradigm. | |
261 | */ | |
262 | ||
263 | if (neigh->type == RTN_MULTICAST) { | |
264 | neigh->nud_state = NUD_NOARP; | |
265 | arp_mc_map(addr, neigh->ha, dev, 1); | |
266 | } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { | |
267 | neigh->nud_state = NUD_NOARP; | |
268 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); | |
269 | } else if (neigh->type == RTN_BROADCAST || | |
270 | (dev->flags & IFF_POINTOPOINT)) { | |
271 | neigh->nud_state = NUD_NOARP; | |
272 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); | |
273 | } | |
274 | ||
275 | if (dev->header_ops->cache) | |
276 | neigh->ops = &arp_hh_ops; | |
277 | else | |
278 | neigh->ops = &arp_generic_ops; | |
279 | ||
280 | if (neigh->nud_state & NUD_VALID) | |
281 | neigh->output = neigh->ops->connected_output; | |
282 | else | |
283 | neigh->output = neigh->ops->output; | |
284 | } | |
285 | return 0; | |
286 | } | |
287 | ||
288 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) | |
289 | { | |
290 | dst_link_failure(skb); | |
291 | kfree_skb(skb); | |
292 | } | |
293 | ||
294 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) | |
295 | { | |
296 | __be32 saddr = 0; | |
297 | u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL; | |
298 | struct net_device *dev = neigh->dev; | |
299 | __be32 target = *(__be32 *)neigh->primary_key; | |
300 | int probes = atomic_read(&neigh->probes); | |
301 | struct in_device *in_dev; | |
302 | ||
303 | rcu_read_lock(); | |
304 | in_dev = __in_dev_get_rcu(dev); | |
305 | if (!in_dev) { | |
306 | rcu_read_unlock(); | |
307 | return; | |
308 | } | |
309 | switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { | |
310 | default: | |
311 | case 0: /* By default announce any local IP */ | |
312 | if (skb && inet_addr_type(dev_net(dev), | |
313 | ip_hdr(skb)->saddr) == RTN_LOCAL) | |
314 | saddr = ip_hdr(skb)->saddr; | |
315 | break; | |
316 | case 1: /* Restrict announcements of saddr in same subnet */ | |
317 | if (!skb) | |
318 | break; | |
319 | saddr = ip_hdr(skb)->saddr; | |
320 | if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { | |
321 | /* saddr should be known to target */ | |
322 | if (inet_addr_onlink(in_dev, target, saddr)) | |
323 | break; | |
324 | } | |
325 | saddr = 0; | |
326 | break; | |
327 | case 2: /* Avoid secondary IPs, get a primary/preferred one */ | |
328 | break; | |
329 | } | |
330 | rcu_read_unlock(); | |
331 | ||
332 | if (!saddr) | |
333 | saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); | |
334 | ||
335 | probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); | |
336 | if (probes < 0) { | |
337 | if (!(neigh->nud_state & NUD_VALID)) | |
338 | pr_debug("trying to ucast probe in NUD_INVALID\n"); | |
339 | neigh_ha_snapshot(dst_ha, neigh, dev); | |
340 | dst_hw = dst_ha; | |
341 | } else { | |
342 | probes -= NEIGH_VAR(neigh->parms, APP_PROBES); | |
343 | if (probes < 0) { | |
344 | neigh_app_ns(neigh); | |
345 | return; | |
346 | } | |
347 | } | |
348 | ||
349 | arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, | |
350 | dst_hw, dev->dev_addr, NULL); | |
351 | } | |
352 | ||
353 | static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) | |
354 | { | |
355 | struct net *net = dev_net(in_dev->dev); | |
356 | int scope; | |
357 | ||
358 | switch (IN_DEV_ARP_IGNORE(in_dev)) { | |
359 | case 0: /* Reply, the tip is already validated */ | |
360 | return 0; | |
361 | case 1: /* Reply only if tip is configured on the incoming interface */ | |
362 | sip = 0; | |
363 | scope = RT_SCOPE_HOST; | |
364 | break; | |
365 | case 2: /* | |
366 | * Reply only if tip is configured on the incoming interface | |
367 | * and is in same subnet as sip | |
368 | */ | |
369 | scope = RT_SCOPE_HOST; | |
370 | break; | |
371 | case 3: /* Do not reply for scope host addresses */ | |
372 | sip = 0; | |
373 | scope = RT_SCOPE_LINK; | |
374 | in_dev = NULL; | |
375 | break; | |
376 | case 4: /* Reserved */ | |
377 | case 5: | |
378 | case 6: | |
379 | case 7: | |
380 | return 0; | |
381 | case 8: /* Do not reply */ | |
382 | return 1; | |
383 | default: | |
384 | return 0; | |
385 | } | |
386 | return !inet_confirm_addr(net, in_dev, sip, tip, scope); | |
387 | } | |
388 | ||
389 | static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) | |
390 | { | |
391 | struct rtable *rt; | |
392 | int flag = 0; | |
393 | /*unsigned long now; */ | |
394 | struct net *net = dev_net(dev); | |
395 | ||
396 | rt = ip_route_output(net, sip, tip, 0, 0); | |
397 | if (IS_ERR(rt)) | |
398 | return 1; | |
399 | if (rt->dst.dev != dev) { | |
400 | NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); | |
401 | flag = 1; | |
402 | } | |
403 | ip_rt_put(rt); | |
404 | return flag; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Check if we can use proxy ARP for this path | |
409 | */ | |
410 | static inline int arp_fwd_proxy(struct in_device *in_dev, | |
411 | struct net_device *dev, struct rtable *rt) | |
412 | { | |
413 | struct in_device *out_dev; | |
414 | int imi, omi = -1; | |
415 | ||
416 | if (rt->dst.dev == dev) | |
417 | return 0; | |
418 | ||
419 | if (!IN_DEV_PROXY_ARP(in_dev)) | |
420 | return 0; | |
421 | imi = IN_DEV_MEDIUM_ID(in_dev); | |
422 | if (imi == 0) | |
423 | return 1; | |
424 | if (imi == -1) | |
425 | return 0; | |
426 | ||
427 | /* place to check for proxy_arp for routes */ | |
428 | ||
429 | out_dev = __in_dev_get_rcu(rt->dst.dev); | |
430 | if (out_dev) | |
431 | omi = IN_DEV_MEDIUM_ID(out_dev); | |
432 | ||
433 | return omi != imi && omi != -1; | |
434 | } | |
435 | ||
436 | /* | |
437 | * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) | |
438 | * | |
439 | * RFC3069 supports proxy arp replies back to the same interface. This | |
440 | * is done to support (ethernet) switch features, like RFC 3069, where | |
441 | * the individual ports are not allowed to communicate with each | |
442 | * other, BUT they are allowed to talk to the upstream router. As | |
443 | * described in RFC 3069, it is possible to allow these hosts to | |
444 | * communicate through the upstream router, by proxy_arp'ing. | |
445 | * | |
446 | * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" | |
447 | * | |
448 | * This technology is known by different names: | |
449 | * In RFC 3069 it is called VLAN Aggregation. | |
450 | * Cisco and Allied Telesyn call it Private VLAN. | |
451 | * Hewlett-Packard call it Source-Port filtering or port-isolation. | |
452 | * Ericsson call it MAC-Forced Forwarding (RFC Draft). | |
453 | * | |
454 | */ | |
455 | static inline int arp_fwd_pvlan(struct in_device *in_dev, | |
456 | struct net_device *dev, struct rtable *rt, | |
457 | __be32 sip, __be32 tip) | |
458 | { | |
459 | /* Private VLAN is only concerned about the same ethernet segment */ | |
460 | if (rt->dst.dev != dev) | |
461 | return 0; | |
462 | ||
463 | /* Don't reply on self probes (often done by windowz boxes)*/ | |
464 | if (sip == tip) | |
465 | return 0; | |
466 | ||
467 | if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) | |
468 | return 1; | |
469 | else | |
470 | return 0; | |
471 | } | |
472 | ||
473 | /* | |
474 | * Interface to link layer: send routine and receive handler. | |
475 | */ | |
476 | ||
477 | /* | |
478 | * Create an arp packet. If dest_hw is not set, we create a broadcast | |
479 | * message. | |
480 | */ | |
481 | struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, | |
482 | struct net_device *dev, __be32 src_ip, | |
483 | const unsigned char *dest_hw, | |
484 | const unsigned char *src_hw, | |
485 | const unsigned char *target_hw) | |
486 | { | |
487 | struct sk_buff *skb; | |
488 | struct arphdr *arp; | |
489 | unsigned char *arp_ptr; | |
490 | int hlen = LL_RESERVED_SPACE(dev); | |
491 | int tlen = dev->needed_tailroom; | |
492 | ||
493 | /* | |
494 | * Allocate a buffer | |
495 | */ | |
496 | ||
497 | skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC); | |
498 | if (!skb) | |
499 | return NULL; | |
500 | ||
501 | skb_reserve(skb, hlen); | |
502 | skb_reset_network_header(skb); | |
503 | arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); | |
504 | skb->dev = dev; | |
505 | skb->protocol = htons(ETH_P_ARP); | |
506 | if (!src_hw) | |
507 | src_hw = dev->dev_addr; | |
508 | if (!dest_hw) | |
509 | dest_hw = dev->broadcast; | |
510 | ||
511 | /* | |
512 | * Fill the device header for the ARP frame | |
513 | */ | |
514 | if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) | |
515 | goto out; | |
516 | ||
517 | /* | |
518 | * Fill out the arp protocol part. | |
519 | * | |
520 | * The arp hardware type should match the device type, except for FDDI, | |
521 | * which (according to RFC 1390) should always equal 1 (Ethernet). | |
522 | */ | |
523 | /* | |
524 | * Exceptions everywhere. AX.25 uses the AX.25 PID value not the | |
525 | * DIX code for the protocol. Make these device structure fields. | |
526 | */ | |
527 | switch (dev->type) { | |
528 | default: | |
529 | arp->ar_hrd = htons(dev->type); | |
530 | arp->ar_pro = htons(ETH_P_IP); | |
531 | break; | |
532 | ||
533 | #if IS_ENABLED(CONFIG_AX25) | |
534 | case ARPHRD_AX25: | |
535 | arp->ar_hrd = htons(ARPHRD_AX25); | |
536 | arp->ar_pro = htons(AX25_P_IP); | |
537 | break; | |
538 | ||
539 | #if IS_ENABLED(CONFIG_NETROM) | |
540 | case ARPHRD_NETROM: | |
541 | arp->ar_hrd = htons(ARPHRD_NETROM); | |
542 | arp->ar_pro = htons(AX25_P_IP); | |
543 | break; | |
544 | #endif | |
545 | #endif | |
546 | ||
547 | #if IS_ENABLED(CONFIG_FDDI) | |
548 | case ARPHRD_FDDI: | |
549 | arp->ar_hrd = htons(ARPHRD_ETHER); | |
550 | arp->ar_pro = htons(ETH_P_IP); | |
551 | break; | |
552 | #endif | |
553 | } | |
554 | ||
555 | arp->ar_hln = dev->addr_len; | |
556 | arp->ar_pln = 4; | |
557 | arp->ar_op = htons(type); | |
558 | ||
559 | arp_ptr = (unsigned char *)(arp + 1); | |
560 | ||
561 | memcpy(arp_ptr, src_hw, dev->addr_len); | |
562 | arp_ptr += dev->addr_len; | |
563 | memcpy(arp_ptr, &src_ip, 4); | |
564 | arp_ptr += 4; | |
565 | ||
566 | switch (dev->type) { | |
567 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) | |
568 | case ARPHRD_IEEE1394: | |
569 | break; | |
570 | #endif | |
571 | default: | |
572 | if (target_hw) | |
573 | memcpy(arp_ptr, target_hw, dev->addr_len); | |
574 | else | |
575 | memset(arp_ptr, 0, dev->addr_len); | |
576 | arp_ptr += dev->addr_len; | |
577 | } | |
578 | memcpy(arp_ptr, &dest_ip, 4); | |
579 | ||
580 | return skb; | |
581 | ||
582 | out: | |
583 | kfree_skb(skb); | |
584 | return NULL; | |
585 | } | |
586 | EXPORT_SYMBOL(arp_create); | |
587 | ||
588 | /* | |
589 | * Send an arp packet. | |
590 | */ | |
591 | void arp_xmit(struct sk_buff *skb) | |
592 | { | |
593 | /* Send it off, maybe filter it using firewalling first. */ | |
594 | NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, NULL, skb, | |
595 | NULL, skb->dev, dev_queue_xmit_sk); | |
596 | } | |
597 | EXPORT_SYMBOL(arp_xmit); | |
598 | ||
599 | /* | |
600 | * Create and send an arp packet. | |
601 | */ | |
602 | void arp_send(int type, int ptype, __be32 dest_ip, | |
603 | struct net_device *dev, __be32 src_ip, | |
604 | const unsigned char *dest_hw, const unsigned char *src_hw, | |
605 | const unsigned char *target_hw) | |
606 | { | |
607 | struct sk_buff *skb; | |
608 | ||
609 | /* | |
610 | * No arp on this interface. | |
611 | */ | |
612 | ||
613 | if (dev->flags&IFF_NOARP) | |
614 | return; | |
615 | ||
616 | skb = arp_create(type, ptype, dest_ip, dev, src_ip, | |
617 | dest_hw, src_hw, target_hw); | |
618 | if (!skb) | |
619 | return; | |
620 | ||
621 | arp_xmit(skb); | |
622 | } | |
623 | EXPORT_SYMBOL(arp_send); | |
624 | ||
625 | /* | |
626 | * Process an arp request. | |
627 | */ | |
628 | ||
629 | static int arp_process(struct sock *sk, struct sk_buff *skb) | |
630 | { | |
631 | struct net_device *dev = skb->dev; | |
632 | struct in_device *in_dev = __in_dev_get_rcu(dev); | |
633 | struct arphdr *arp; | |
634 | unsigned char *arp_ptr; | |
635 | struct rtable *rt; | |
636 | unsigned char *sha; | |
637 | __be32 sip, tip; | |
638 | u16 dev_type = dev->type; | |
639 | int addr_type; | |
640 | struct neighbour *n; | |
641 | struct net *net = dev_net(dev); | |
642 | bool is_garp = false; | |
643 | ||
644 | /* arp_rcv below verifies the ARP header and verifies the device | |
645 | * is ARP'able. | |
646 | */ | |
647 | ||
648 | if (!in_dev) | |
649 | goto out; | |
650 | ||
651 | arp = arp_hdr(skb); | |
652 | ||
653 | switch (dev_type) { | |
654 | default: | |
655 | if (arp->ar_pro != htons(ETH_P_IP) || | |
656 | htons(dev_type) != arp->ar_hrd) | |
657 | goto out; | |
658 | break; | |
659 | case ARPHRD_ETHER: | |
660 | case ARPHRD_FDDI: | |
661 | case ARPHRD_IEEE802: | |
662 | /* | |
663 | * ETHERNET, and Fibre Channel (which are IEEE 802 | |
664 | * devices, according to RFC 2625) devices will accept ARP | |
665 | * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). | |
666 | * This is the case also of FDDI, where the RFC 1390 says that | |
667 | * FDDI devices should accept ARP hardware of (1) Ethernet, | |
668 | * however, to be more robust, we'll accept both 1 (Ethernet) | |
669 | * or 6 (IEEE 802.2) | |
670 | */ | |
671 | if ((arp->ar_hrd != htons(ARPHRD_ETHER) && | |
672 | arp->ar_hrd != htons(ARPHRD_IEEE802)) || | |
673 | arp->ar_pro != htons(ETH_P_IP)) | |
674 | goto out; | |
675 | break; | |
676 | case ARPHRD_AX25: | |
677 | if (arp->ar_pro != htons(AX25_P_IP) || | |
678 | arp->ar_hrd != htons(ARPHRD_AX25)) | |
679 | goto out; | |
680 | break; | |
681 | case ARPHRD_NETROM: | |
682 | if (arp->ar_pro != htons(AX25_P_IP) || | |
683 | arp->ar_hrd != htons(ARPHRD_NETROM)) | |
684 | goto out; | |
685 | break; | |
686 | } | |
687 | ||
688 | /* Understand only these message types */ | |
689 | ||
690 | if (arp->ar_op != htons(ARPOP_REPLY) && | |
691 | arp->ar_op != htons(ARPOP_REQUEST)) | |
692 | goto out; | |
693 | ||
694 | /* | |
695 | * Extract fields | |
696 | */ | |
697 | arp_ptr = (unsigned char *)(arp + 1); | |
698 | sha = arp_ptr; | |
699 | arp_ptr += dev->addr_len; | |
700 | memcpy(&sip, arp_ptr, 4); | |
701 | arp_ptr += 4; | |
702 | switch (dev_type) { | |
703 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) | |
704 | case ARPHRD_IEEE1394: | |
705 | break; | |
706 | #endif | |
707 | default: | |
708 | arp_ptr += dev->addr_len; | |
709 | } | |
710 | memcpy(&tip, arp_ptr, 4); | |
711 | /* | |
712 | * Check for bad requests for 127.x.x.x and requests for multicast | |
713 | * addresses. If this is one such, delete it. | |
714 | */ | |
715 | if (ipv4_is_multicast(tip) || | |
716 | (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) | |
717 | goto out; | |
718 | ||
719 | /* | |
720 | * Special case: We must set Frame Relay source Q.922 address | |
721 | */ | |
722 | if (dev_type == ARPHRD_DLCI) | |
723 | sha = dev->broadcast; | |
724 | ||
725 | /* | |
726 | * Process entry. The idea here is we want to send a reply if it is a | |
727 | * request for us or if it is a request for someone else that we hold | |
728 | * a proxy for. We want to add an entry to our cache if it is a reply | |
729 | * to us or if it is a request for our address. | |
730 | * (The assumption for this last is that if someone is requesting our | |
731 | * address, they are probably intending to talk to us, so it saves time | |
732 | * if we cache their address. Their address is also probably not in | |
733 | * our cache, since ours is not in their cache.) | |
734 | * | |
735 | * Putting this another way, we only care about replies if they are to | |
736 | * us, in which case we add them to the cache. For requests, we care | |
737 | * about those for us and those for our proxies. We reply to both, | |
738 | * and in the case of requests for us we add the requester to the arp | |
739 | * cache. | |
740 | */ | |
741 | ||
742 | /* Special case: IPv4 duplicate address detection packet (RFC2131) */ | |
743 | if (sip == 0) { | |
744 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
745 | inet_addr_type(net, tip) == RTN_LOCAL && | |
746 | !arp_ignore(in_dev, sip, tip)) | |
747 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, | |
748 | dev->dev_addr, sha); | |
749 | goto out; | |
750 | } | |
751 | ||
752 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
753 | ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { | |
754 | ||
755 | rt = skb_rtable(skb); | |
756 | addr_type = rt->rt_type; | |
757 | ||
758 | if (addr_type == RTN_LOCAL) { | |
759 | int dont_send; | |
760 | ||
761 | dont_send = arp_ignore(in_dev, sip, tip); | |
762 | if (!dont_send && IN_DEV_ARPFILTER(in_dev)) | |
763 | dont_send = arp_filter(sip, tip, dev); | |
764 | if (!dont_send) { | |
765 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); | |
766 | if (n) { | |
767 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, | |
768 | dev, tip, sha, dev->dev_addr, | |
769 | sha); | |
770 | neigh_release(n); | |
771 | } | |
772 | } | |
773 | goto out; | |
774 | } else if (IN_DEV_FORWARD(in_dev)) { | |
775 | if (addr_type == RTN_UNICAST && | |
776 | (arp_fwd_proxy(in_dev, dev, rt) || | |
777 | arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || | |
778 | (rt->dst.dev != dev && | |
779 | pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) { | |
780 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); | |
781 | if (n) | |
782 | neigh_release(n); | |
783 | ||
784 | if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || | |
785 | skb->pkt_type == PACKET_HOST || | |
786 | NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) { | |
787 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, | |
788 | dev, tip, sha, dev->dev_addr, | |
789 | sha); | |
790 | } else { | |
791 | pneigh_enqueue(&arp_tbl, | |
792 | in_dev->arp_parms, skb); | |
793 | return 0; | |
794 | } | |
795 | goto out; | |
796 | } | |
797 | } | |
798 | } | |
799 | ||
800 | /* Update our ARP tables */ | |
801 | ||
802 | n = __neigh_lookup(&arp_tbl, &sip, dev, 0); | |
803 | ||
804 | if (IN_DEV_ARP_ACCEPT(in_dev)) { | |
805 | /* Unsolicited ARP is not accepted by default. | |
806 | It is possible, that this option should be enabled for some | |
807 | devices (strip is candidate) | |
808 | */ | |
809 | is_garp = arp->ar_op == htons(ARPOP_REQUEST) && tip == sip && | |
810 | inet_addr_type(net, sip) == RTN_UNICAST; | |
811 | ||
812 | if (!n && | |
813 | ((arp->ar_op == htons(ARPOP_REPLY) && | |
814 | inet_addr_type(net, sip) == RTN_UNICAST) || is_garp)) | |
815 | n = __neigh_lookup(&arp_tbl, &sip, dev, 1); | |
816 | } | |
817 | ||
818 | if (n) { | |
819 | int state = NUD_REACHABLE; | |
820 | int override; | |
821 | ||
822 | /* If several different ARP replies follows back-to-back, | |
823 | use the FIRST one. It is possible, if several proxy | |
824 | agents are active. Taking the first reply prevents | |
825 | arp trashing and chooses the fastest router. | |
826 | */ | |
827 | override = time_after(jiffies, | |
828 | n->updated + | |
829 | NEIGH_VAR(n->parms, LOCKTIME)) || | |
830 | is_garp; | |
831 | ||
832 | /* Broadcast replies and request packets | |
833 | do not assert neighbour reachability. | |
834 | */ | |
835 | if (arp->ar_op != htons(ARPOP_REPLY) || | |
836 | skb->pkt_type != PACKET_HOST) | |
837 | state = NUD_STALE; | |
838 | neigh_update(n, sha, state, | |
839 | override ? NEIGH_UPDATE_F_OVERRIDE : 0); | |
840 | neigh_release(n); | |
841 | } | |
842 | ||
843 | out: | |
844 | consume_skb(skb); | |
845 | return 0; | |
846 | } | |
847 | ||
848 | static void parp_redo(struct sk_buff *skb) | |
849 | { | |
850 | arp_process(NULL, skb); | |
851 | } | |
852 | ||
853 | ||
854 | /* | |
855 | * Receive an arp request from the device layer. | |
856 | */ | |
857 | ||
858 | static int arp_rcv(struct sk_buff *skb, struct net_device *dev, | |
859 | struct packet_type *pt, struct net_device *orig_dev) | |
860 | { | |
861 | const struct arphdr *arp; | |
862 | ||
863 | /* do not tweak dropwatch on an ARP we will ignore */ | |
864 | if (dev->flags & IFF_NOARP || | |
865 | skb->pkt_type == PACKET_OTHERHOST || | |
866 | skb->pkt_type == PACKET_LOOPBACK) | |
867 | goto consumeskb; | |
868 | ||
869 | skb = skb_share_check(skb, GFP_ATOMIC); | |
870 | if (!skb) | |
871 | goto out_of_mem; | |
872 | ||
873 | /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ | |
874 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) | |
875 | goto freeskb; | |
876 | ||
877 | arp = arp_hdr(skb); | |
878 | if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) | |
879 | goto freeskb; | |
880 | ||
881 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); | |
882 | ||
883 | return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, NULL, skb, | |
884 | dev, NULL, arp_process); | |
885 | ||
886 | consumeskb: | |
887 | consume_skb(skb); | |
888 | return 0; | |
889 | freeskb: | |
890 | kfree_skb(skb); | |
891 | out_of_mem: | |
892 | return 0; | |
893 | } | |
894 | ||
895 | /* | |
896 | * User level interface (ioctl) | |
897 | */ | |
898 | ||
899 | /* | |
900 | * Set (create) an ARP cache entry. | |
901 | */ | |
902 | ||
903 | static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) | |
904 | { | |
905 | if (!dev) { | |
906 | IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; | |
907 | return 0; | |
908 | } | |
909 | if (__in_dev_get_rtnl(dev)) { | |
910 | IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); | |
911 | return 0; | |
912 | } | |
913 | return -ENXIO; | |
914 | } | |
915 | ||
916 | static int arp_req_set_public(struct net *net, struct arpreq *r, | |
917 | struct net_device *dev) | |
918 | { | |
919 | __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
920 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
921 | ||
922 | if (mask && mask != htonl(0xFFFFFFFF)) | |
923 | return -EINVAL; | |
924 | if (!dev && (r->arp_flags & ATF_COM)) { | |
925 | dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, | |
926 | r->arp_ha.sa_data); | |
927 | if (!dev) | |
928 | return -ENODEV; | |
929 | } | |
930 | if (mask) { | |
931 | if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1)) | |
932 | return -ENOBUFS; | |
933 | return 0; | |
934 | } | |
935 | ||
936 | return arp_req_set_proxy(net, dev, 1); | |
937 | } | |
938 | ||
939 | static int arp_req_set(struct net *net, struct arpreq *r, | |
940 | struct net_device *dev) | |
941 | { | |
942 | __be32 ip; | |
943 | struct neighbour *neigh; | |
944 | int err; | |
945 | ||
946 | if (r->arp_flags & ATF_PUBL) | |
947 | return arp_req_set_public(net, r, dev); | |
948 | ||
949 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
950 | if (r->arp_flags & ATF_PERM) | |
951 | r->arp_flags |= ATF_COM; | |
952 | if (!dev) { | |
953 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); | |
954 | ||
955 | if (IS_ERR(rt)) | |
956 | return PTR_ERR(rt); | |
957 | dev = rt->dst.dev; | |
958 | ip_rt_put(rt); | |
959 | if (!dev) | |
960 | return -EINVAL; | |
961 | } | |
962 | switch (dev->type) { | |
963 | #if IS_ENABLED(CONFIG_FDDI) | |
964 | case ARPHRD_FDDI: | |
965 | /* | |
966 | * According to RFC 1390, FDDI devices should accept ARP | |
967 | * hardware types of 1 (Ethernet). However, to be more | |
968 | * robust, we'll accept hardware types of either 1 (Ethernet) | |
969 | * or 6 (IEEE 802.2). | |
970 | */ | |
971 | if (r->arp_ha.sa_family != ARPHRD_FDDI && | |
972 | r->arp_ha.sa_family != ARPHRD_ETHER && | |
973 | r->arp_ha.sa_family != ARPHRD_IEEE802) | |
974 | return -EINVAL; | |
975 | break; | |
976 | #endif | |
977 | default: | |
978 | if (r->arp_ha.sa_family != dev->type) | |
979 | return -EINVAL; | |
980 | break; | |
981 | } | |
982 | ||
983 | neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); | |
984 | err = PTR_ERR(neigh); | |
985 | if (!IS_ERR(neigh)) { | |
986 | unsigned int state = NUD_STALE; | |
987 | if (r->arp_flags & ATF_PERM) | |
988 | state = NUD_PERMANENT; | |
989 | err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? | |
990 | r->arp_ha.sa_data : NULL, state, | |
991 | NEIGH_UPDATE_F_OVERRIDE | | |
992 | NEIGH_UPDATE_F_ADMIN); | |
993 | neigh_release(neigh); | |
994 | } | |
995 | return err; | |
996 | } | |
997 | ||
998 | static unsigned int arp_state_to_flags(struct neighbour *neigh) | |
999 | { | |
1000 | if (neigh->nud_state&NUD_PERMANENT) | |
1001 | return ATF_PERM | ATF_COM; | |
1002 | else if (neigh->nud_state&NUD_VALID) | |
1003 | return ATF_COM; | |
1004 | else | |
1005 | return 0; | |
1006 | } | |
1007 | ||
1008 | /* | |
1009 | * Get an ARP cache entry. | |
1010 | */ | |
1011 | ||
1012 | static int arp_req_get(struct arpreq *r, struct net_device *dev) | |
1013 | { | |
1014 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; | |
1015 | struct neighbour *neigh; | |
1016 | int err = -ENXIO; | |
1017 | ||
1018 | neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1019 | if (neigh) { | |
1020 | read_lock_bh(&neigh->lock); | |
1021 | memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); | |
1022 | r->arp_flags = arp_state_to_flags(neigh); | |
1023 | read_unlock_bh(&neigh->lock); | |
1024 | r->arp_ha.sa_family = dev->type; | |
1025 | strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); | |
1026 | neigh_release(neigh); | |
1027 | err = 0; | |
1028 | } | |
1029 | return err; | |
1030 | } | |
1031 | ||
1032 | static int arp_invalidate(struct net_device *dev, __be32 ip) | |
1033 | { | |
1034 | struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1035 | int err = -ENXIO; | |
1036 | ||
1037 | if (neigh) { | |
1038 | if (neigh->nud_state & ~NUD_NOARP) | |
1039 | err = neigh_update(neigh, NULL, NUD_FAILED, | |
1040 | NEIGH_UPDATE_F_OVERRIDE| | |
1041 | NEIGH_UPDATE_F_ADMIN); | |
1042 | neigh_release(neigh); | |
1043 | } | |
1044 | ||
1045 | return err; | |
1046 | } | |
1047 | ||
1048 | static int arp_req_delete_public(struct net *net, struct arpreq *r, | |
1049 | struct net_device *dev) | |
1050 | { | |
1051 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; | |
1052 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1053 | ||
1054 | if (mask == htonl(0xFFFFFFFF)) | |
1055 | return pneigh_delete(&arp_tbl, net, &ip, dev); | |
1056 | ||
1057 | if (mask) | |
1058 | return -EINVAL; | |
1059 | ||
1060 | return arp_req_set_proxy(net, dev, 0); | |
1061 | } | |
1062 | ||
1063 | static int arp_req_delete(struct net *net, struct arpreq *r, | |
1064 | struct net_device *dev) | |
1065 | { | |
1066 | __be32 ip; | |
1067 | ||
1068 | if (r->arp_flags & ATF_PUBL) | |
1069 | return arp_req_delete_public(net, r, dev); | |
1070 | ||
1071 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
1072 | if (!dev) { | |
1073 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); | |
1074 | if (IS_ERR(rt)) | |
1075 | return PTR_ERR(rt); | |
1076 | dev = rt->dst.dev; | |
1077 | ip_rt_put(rt); | |
1078 | if (!dev) | |
1079 | return -EINVAL; | |
1080 | } | |
1081 | return arp_invalidate(dev, ip); | |
1082 | } | |
1083 | ||
1084 | /* | |
1085 | * Handle an ARP layer I/O control request. | |
1086 | */ | |
1087 | ||
1088 | int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) | |
1089 | { | |
1090 | int err; | |
1091 | struct arpreq r; | |
1092 | struct net_device *dev = NULL; | |
1093 | ||
1094 | switch (cmd) { | |
1095 | case SIOCDARP: | |
1096 | case SIOCSARP: | |
1097 | if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) | |
1098 | return -EPERM; | |
1099 | case SIOCGARP: | |
1100 | err = copy_from_user(&r, arg, sizeof(struct arpreq)); | |
1101 | if (err) | |
1102 | return -EFAULT; | |
1103 | break; | |
1104 | default: | |
1105 | return -EINVAL; | |
1106 | } | |
1107 | ||
1108 | if (r.arp_pa.sa_family != AF_INET) | |
1109 | return -EPFNOSUPPORT; | |
1110 | ||
1111 | if (!(r.arp_flags & ATF_PUBL) && | |
1112 | (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) | |
1113 | return -EINVAL; | |
1114 | if (!(r.arp_flags & ATF_NETMASK)) | |
1115 | ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = | |
1116 | htonl(0xFFFFFFFFUL); | |
1117 | rtnl_lock(); | |
1118 | if (r.arp_dev[0]) { | |
1119 | err = -ENODEV; | |
1120 | dev = __dev_get_by_name(net, r.arp_dev); | |
1121 | if (!dev) | |
1122 | goto out; | |
1123 | ||
1124 | /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ | |
1125 | if (!r.arp_ha.sa_family) | |
1126 | r.arp_ha.sa_family = dev->type; | |
1127 | err = -EINVAL; | |
1128 | if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) | |
1129 | goto out; | |
1130 | } else if (cmd == SIOCGARP) { | |
1131 | err = -ENODEV; | |
1132 | goto out; | |
1133 | } | |
1134 | ||
1135 | switch (cmd) { | |
1136 | case SIOCDARP: | |
1137 | err = arp_req_delete(net, &r, dev); | |
1138 | break; | |
1139 | case SIOCSARP: | |
1140 | err = arp_req_set(net, &r, dev); | |
1141 | break; | |
1142 | case SIOCGARP: | |
1143 | err = arp_req_get(&r, dev); | |
1144 | break; | |
1145 | } | |
1146 | out: | |
1147 | rtnl_unlock(); | |
1148 | if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) | |
1149 | err = -EFAULT; | |
1150 | return err; | |
1151 | } | |
1152 | ||
1153 | static int arp_netdev_event(struct notifier_block *this, unsigned long event, | |
1154 | void *ptr) | |
1155 | { | |
1156 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); | |
1157 | struct netdev_notifier_change_info *change_info; | |
1158 | ||
1159 | switch (event) { | |
1160 | case NETDEV_CHANGEADDR: | |
1161 | neigh_changeaddr(&arp_tbl, dev); | |
1162 | rt_cache_flush(dev_net(dev)); | |
1163 | break; | |
1164 | case NETDEV_CHANGE: | |
1165 | change_info = ptr; | |
1166 | if (change_info->flags_changed & IFF_NOARP) | |
1167 | neigh_changeaddr(&arp_tbl, dev); | |
1168 | break; | |
1169 | default: | |
1170 | break; | |
1171 | } | |
1172 | ||
1173 | return NOTIFY_DONE; | |
1174 | } | |
1175 | ||
1176 | static struct notifier_block arp_netdev_notifier = { | |
1177 | .notifier_call = arp_netdev_event, | |
1178 | }; | |
1179 | ||
1180 | /* Note, that it is not on notifier chain. | |
1181 | It is necessary, that this routine was called after route cache will be | |
1182 | flushed. | |
1183 | */ | |
1184 | void arp_ifdown(struct net_device *dev) | |
1185 | { | |
1186 | neigh_ifdown(&arp_tbl, dev); | |
1187 | } | |
1188 | ||
1189 | ||
1190 | /* | |
1191 | * Called once on startup. | |
1192 | */ | |
1193 | ||
1194 | static struct packet_type arp_packet_type __read_mostly = { | |
1195 | .type = cpu_to_be16(ETH_P_ARP), | |
1196 | .func = arp_rcv, | |
1197 | }; | |
1198 | ||
1199 | static int arp_proc_init(void); | |
1200 | ||
1201 | void __init arp_init(void) | |
1202 | { | |
1203 | neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl); | |
1204 | ||
1205 | dev_add_pack(&arp_packet_type); | |
1206 | arp_proc_init(); | |
1207 | #ifdef CONFIG_SYSCTL | |
1208 | neigh_sysctl_register(NULL, &arp_tbl.parms, NULL); | |
1209 | #endif | |
1210 | register_netdevice_notifier(&arp_netdev_notifier); | |
1211 | } | |
1212 | ||
1213 | #ifdef CONFIG_PROC_FS | |
1214 | #if IS_ENABLED(CONFIG_AX25) | |
1215 | ||
1216 | /* ------------------------------------------------------------------------ */ | |
1217 | /* | |
1218 | * ax25 -> ASCII conversion | |
1219 | */ | |
1220 | static char *ax2asc2(ax25_address *a, char *buf) | |
1221 | { | |
1222 | char c, *s; | |
1223 | int n; | |
1224 | ||
1225 | for (n = 0, s = buf; n < 6; n++) { | |
1226 | c = (a->ax25_call[n] >> 1) & 0x7F; | |
1227 | ||
1228 | if (c != ' ') | |
1229 | *s++ = c; | |
1230 | } | |
1231 | ||
1232 | *s++ = '-'; | |
1233 | n = (a->ax25_call[6] >> 1) & 0x0F; | |
1234 | if (n > 9) { | |
1235 | *s++ = '1'; | |
1236 | n -= 10; | |
1237 | } | |
1238 | ||
1239 | *s++ = n + '0'; | |
1240 | *s++ = '\0'; | |
1241 | ||
1242 | if (*buf == '\0' || *buf == '-') | |
1243 | return "*"; | |
1244 | ||
1245 | return buf; | |
1246 | } | |
1247 | #endif /* CONFIG_AX25 */ | |
1248 | ||
1249 | #define HBUFFERLEN 30 | |
1250 | ||
1251 | static void arp_format_neigh_entry(struct seq_file *seq, | |
1252 | struct neighbour *n) | |
1253 | { | |
1254 | char hbuffer[HBUFFERLEN]; | |
1255 | int k, j; | |
1256 | char tbuf[16]; | |
1257 | struct net_device *dev = n->dev; | |
1258 | int hatype = dev->type; | |
1259 | ||
1260 | read_lock(&n->lock); | |
1261 | /* Convert hardware address to XX:XX:XX:XX ... form. */ | |
1262 | #if IS_ENABLED(CONFIG_AX25) | |
1263 | if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) | |
1264 | ax2asc2((ax25_address *)n->ha, hbuffer); | |
1265 | else { | |
1266 | #endif | |
1267 | for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { | |
1268 | hbuffer[k++] = hex_asc_hi(n->ha[j]); | |
1269 | hbuffer[k++] = hex_asc_lo(n->ha[j]); | |
1270 | hbuffer[k++] = ':'; | |
1271 | } | |
1272 | if (k != 0) | |
1273 | --k; | |
1274 | hbuffer[k] = 0; | |
1275 | #if IS_ENABLED(CONFIG_AX25) | |
1276 | } | |
1277 | #endif | |
1278 | sprintf(tbuf, "%pI4", n->primary_key); | |
1279 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", | |
1280 | tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); | |
1281 | read_unlock(&n->lock); | |
1282 | } | |
1283 | ||
1284 | static void arp_format_pneigh_entry(struct seq_file *seq, | |
1285 | struct pneigh_entry *n) | |
1286 | { | |
1287 | struct net_device *dev = n->dev; | |
1288 | int hatype = dev ? dev->type : 0; | |
1289 | char tbuf[16]; | |
1290 | ||
1291 | sprintf(tbuf, "%pI4", n->key); | |
1292 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", | |
1293 | tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", | |
1294 | dev ? dev->name : "*"); | |
1295 | } | |
1296 | ||
1297 | static int arp_seq_show(struct seq_file *seq, void *v) | |
1298 | { | |
1299 | if (v == SEQ_START_TOKEN) { | |
1300 | seq_puts(seq, "IP address HW type Flags " | |
1301 | "HW address Mask Device\n"); | |
1302 | } else { | |
1303 | struct neigh_seq_state *state = seq->private; | |
1304 | ||
1305 | if (state->flags & NEIGH_SEQ_IS_PNEIGH) | |
1306 | arp_format_pneigh_entry(seq, v); | |
1307 | else | |
1308 | arp_format_neigh_entry(seq, v); | |
1309 | } | |
1310 | ||
1311 | return 0; | |
1312 | } | |
1313 | ||
1314 | static void *arp_seq_start(struct seq_file *seq, loff_t *pos) | |
1315 | { | |
1316 | /* Don't want to confuse "arp -a" w/ magic entries, | |
1317 | * so we tell the generic iterator to skip NUD_NOARP. | |
1318 | */ | |
1319 | return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); | |
1320 | } | |
1321 | ||
1322 | /* ------------------------------------------------------------------------ */ | |
1323 | ||
1324 | static const struct seq_operations arp_seq_ops = { | |
1325 | .start = arp_seq_start, | |
1326 | .next = neigh_seq_next, | |
1327 | .stop = neigh_seq_stop, | |
1328 | .show = arp_seq_show, | |
1329 | }; | |
1330 | ||
1331 | static int arp_seq_open(struct inode *inode, struct file *file) | |
1332 | { | |
1333 | return seq_open_net(inode, file, &arp_seq_ops, | |
1334 | sizeof(struct neigh_seq_state)); | |
1335 | } | |
1336 | ||
1337 | static const struct file_operations arp_seq_fops = { | |
1338 | .owner = THIS_MODULE, | |
1339 | .open = arp_seq_open, | |
1340 | .read = seq_read, | |
1341 | .llseek = seq_lseek, | |
1342 | .release = seq_release_net, | |
1343 | }; | |
1344 | ||
1345 | ||
1346 | static int __net_init arp_net_init(struct net *net) | |
1347 | { | |
1348 | if (!proc_create("arp", S_IRUGO, net->proc_net, &arp_seq_fops)) | |
1349 | return -ENOMEM; | |
1350 | return 0; | |
1351 | } | |
1352 | ||
1353 | static void __net_exit arp_net_exit(struct net *net) | |
1354 | { | |
1355 | remove_proc_entry("arp", net->proc_net); | |
1356 | } | |
1357 | ||
1358 | static struct pernet_operations arp_net_ops = { | |
1359 | .init = arp_net_init, | |
1360 | .exit = arp_net_exit, | |
1361 | }; | |
1362 | ||
1363 | static int __init arp_proc_init(void) | |
1364 | { | |
1365 | return register_pernet_subsys(&arp_net_ops); | |
1366 | } | |
1367 | ||
1368 | #else /* CONFIG_PROC_FS */ | |
1369 | ||
1370 | static int __init arp_proc_init(void) | |
1371 | { | |
1372 | return 0; | |
1373 | } | |
1374 | ||
1375 | #endif /* CONFIG_PROC_FS */ |