blob: 9b096d6ff3f28eadd6a71fd234a172b8a1d15061 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * IPv4 Forwarding Information Base: semantics.
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <asm/uaccess.h>
17#include <asm/system.h>
18#include <linux/bitops.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/jiffies.h>
22#include <linux/mm.h>
23#include <linux/string.h>
24#include <linux/socket.h>
25#include <linux/sockios.h>
26#include <linux/errno.h>
27#include <linux/in.h>
28#include <linux/inet.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020029#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/netdevice.h>
31#include <linux/if_arp.h>
32#include <linux/proc_fs.h>
33#include <linux/skbuff.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/init.h>
35
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020036#include <net/arp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <net/ip.h>
38#include <net/protocol.h>
39#include <net/route.h>
40#include <net/tcp.h>
41#include <net/sock.h>
42#include <net/ip_fib.h>
Thomas Graff21c7bc2006-08-15 00:34:17 -070043#include <net/netlink.h>
Thomas Graf4e902c52006-08-17 18:14:52 -070044#include <net/nexthop.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46#include "fib_lookup.h"
47
Stephen Hemminger832b4c52006-08-29 16:48:09 -070048static DEFINE_SPINLOCK(fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049static struct hlist_head *fib_info_hash;
50static struct hlist_head *fib_info_laddrhash;
51static unsigned int fib_hash_size;
52static unsigned int fib_info_cnt;
53
54#define DEVINDEX_HASHBITS 8
55#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
56static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
57
58#ifdef CONFIG_IP_ROUTE_MULTIPATH
59
60static DEFINE_SPINLOCK(fib_multipath_lock);
61
62#define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \
63for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
64
65#define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \
Jianjun Kongd93191002008-11-03 00:23:42 -080066for (nhsel=0, nh = (struct fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68#else /* CONFIG_IP_ROUTE_MULTIPATH */
69
70/* Hope, that gcc will optimize it to get rid of dummy loop */
71
Jianjun Kongd93191002008-11-03 00:23:42 -080072#define for_nexthops(fi) { int nhsel = 0; const struct fib_nh * nh = (fi)->fib_nh; \
Linus Torvalds1da177e2005-04-16 15:20:36 -070073for (nhsel=0; nhsel < 1; nhsel++)
74
Jianjun Kongd93191002008-11-03 00:23:42 -080075#define change_nexthops(fi) { int nhsel = 0; struct fib_nh * nh = (struct fib_nh *)((fi)->fib_nh); \
Linus Torvalds1da177e2005-04-16 15:20:36 -070076for (nhsel=0; nhsel < 1; nhsel++)
77
78#endif /* CONFIG_IP_ROUTE_MULTIPATH */
79
80#define endfor_nexthops(fi) }
81
82
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090083static const struct
Linus Torvalds1da177e2005-04-16 15:20:36 -070084{
85 int error;
86 u8 scope;
Thomas Grafa0ee18b2007-03-24 20:32:54 -070087} fib_props[RTN_MAX + 1] = {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090088 {
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 .error = 0,
90 .scope = RT_SCOPE_NOWHERE,
91 }, /* RTN_UNSPEC */
92 {
93 .error = 0,
94 .scope = RT_SCOPE_UNIVERSE,
95 }, /* RTN_UNICAST */
96 {
97 .error = 0,
98 .scope = RT_SCOPE_HOST,
99 }, /* RTN_LOCAL */
100 {
101 .error = 0,
102 .scope = RT_SCOPE_LINK,
103 }, /* RTN_BROADCAST */
104 {
105 .error = 0,
106 .scope = RT_SCOPE_LINK,
107 }, /* RTN_ANYCAST */
108 {
109 .error = 0,
110 .scope = RT_SCOPE_UNIVERSE,
111 }, /* RTN_MULTICAST */
112 {
113 .error = -EINVAL,
114 .scope = RT_SCOPE_UNIVERSE,
115 }, /* RTN_BLACKHOLE */
116 {
117 .error = -EHOSTUNREACH,
118 .scope = RT_SCOPE_UNIVERSE,
119 }, /* RTN_UNREACHABLE */
120 {
121 .error = -EACCES,
122 .scope = RT_SCOPE_UNIVERSE,
123 }, /* RTN_PROHIBIT */
124 {
125 .error = -EAGAIN,
126 .scope = RT_SCOPE_UNIVERSE,
127 }, /* RTN_THROW */
128 {
129 .error = -EINVAL,
130 .scope = RT_SCOPE_NOWHERE,
131 }, /* RTN_NAT */
132 {
133 .error = -EINVAL,
134 .scope = RT_SCOPE_NOWHERE,
135 }, /* RTN_XRESOLVE */
136};
137
138
139/* Release a nexthop info record */
140
141void free_fib_info(struct fib_info *fi)
142{
143 if (fi->fib_dead == 0) {
Stephen Hemmingera6db9012008-01-12 20:58:35 -0800144 printk(KERN_WARNING "Freeing alive fib_info %p\n", fi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 return;
146 }
147 change_nexthops(fi) {
148 if (nh->nh_dev)
149 dev_put(nh->nh_dev);
150 nh->nh_dev = NULL;
151 } endfor_nexthops(fi);
152 fib_info_cnt--;
Denis V. Lunev57d7a602008-04-16 02:00:50 -0700153 release_net(fi->fib_net);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 kfree(fi);
155}
156
157void fib_release_info(struct fib_info *fi)
158{
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700159 spin_lock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 if (fi && --fi->fib_treeref == 0) {
161 hlist_del(&fi->fib_hash);
162 if (fi->fib_prefsrc)
163 hlist_del(&fi->fib_lhash);
164 change_nexthops(fi) {
165 if (!nh->nh_dev)
166 continue;
167 hlist_del(&nh->nh_hash);
168 } endfor_nexthops(fi)
169 fi->fib_dead = 1;
170 fib_info_put(fi);
171 }
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700172 spin_unlock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173}
174
175static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
176{
177 const struct fib_nh *onh = ofi->fib_nh;
178
179 for_nexthops(fi) {
180 if (nh->nh_oif != onh->nh_oif ||
181 nh->nh_gw != onh->nh_gw ||
182 nh->nh_scope != onh->nh_scope ||
183#ifdef CONFIG_IP_ROUTE_MULTIPATH
184 nh->nh_weight != onh->nh_weight ||
185#endif
186#ifdef CONFIG_NET_CLS_ROUTE
187 nh->nh_tclassid != onh->nh_tclassid ||
188#endif
189 ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
190 return -1;
191 onh++;
192 } endfor_nexthops(fi);
193 return 0;
194}
195
David S. Miller88ebc722008-01-12 21:49:01 -0800196static inline unsigned int fib_devindex_hashfn(unsigned int val)
197{
198 unsigned int mask = DEVINDEX_HASHSIZE - 1;
199
200 return (val ^
201 (val >> DEVINDEX_HASHBITS) ^
202 (val >> (DEVINDEX_HASHBITS * 2))) & mask;
203}
204
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
206{
207 unsigned int mask = (fib_hash_size - 1);
208 unsigned int val = fi->fib_nhs;
209
210 val ^= fi->fib_protocol;
Al Viro81f7bf62006-09-27 18:40:00 -0700211 val ^= (__force u32)fi->fib_prefsrc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 val ^= fi->fib_priority;
David S. Miller88ebc722008-01-12 21:49:01 -0800213 for_nexthops(fi) {
214 val ^= fib_devindex_hashfn(nh->nh_oif);
215 } endfor_nexthops(fi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
217 return (val ^ (val >> 7) ^ (val >> 12)) & mask;
218}
219
220static struct fib_info *fib_find_info(const struct fib_info *nfi)
221{
222 struct hlist_head *head;
223 struct hlist_node *node;
224 struct fib_info *fi;
225 unsigned int hash;
226
227 hash = fib_info_hashfn(nfi);
228 head = &fib_info_hash[hash];
229
230 hlist_for_each_entry(fi, node, head, fib_hash) {
Denis V. Lunev4814bdb2008-01-31 18:50:07 -0800231 if (fi->fib_net != nfi->fib_net)
232 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 if (fi->fib_nhs != nfi->fib_nhs)
234 continue;
235 if (nfi->fib_protocol == fi->fib_protocol &&
236 nfi->fib_prefsrc == fi->fib_prefsrc &&
237 nfi->fib_priority == fi->fib_priority &&
238 memcmp(nfi->fib_metrics, fi->fib_metrics,
239 sizeof(fi->fib_metrics)) == 0 &&
240 ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
241 (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
242 return fi;
243 }
244
245 return NULL;
246}
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248/* Check, that the gateway is already configured.
249 Used only by redirect accept routine.
250 */
251
Al Virod878e72e2006-09-26 22:18:13 -0700252int ip_fib_check_default(__be32 gw, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
254 struct hlist_head *head;
255 struct hlist_node *node;
256 struct fib_nh *nh;
257 unsigned int hash;
258
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700259 spin_lock(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
261 hash = fib_devindex_hashfn(dev->ifindex);
262 head = &fib_info_devhash[hash];
263 hlist_for_each_entry(nh, node, head, nh_hash) {
264 if (nh->nh_dev == dev &&
265 nh->nh_gw == gw &&
266 !(nh->nh_flags&RTNH_F_DEAD)) {
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700267 spin_unlock(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 return 0;
269 }
270 }
271
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700272 spin_unlock(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 return -1;
275}
276
Thomas Graf339bf982006-11-10 14:10:15 -0800277static inline size_t fib_nlmsg_size(struct fib_info *fi)
278{
279 size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
280 + nla_total_size(4) /* RTA_TABLE */
281 + nla_total_size(4) /* RTA_DST */
282 + nla_total_size(4) /* RTA_PRIORITY */
283 + nla_total_size(4); /* RTA_PREFSRC */
284
285 /* space for nested metrics */
286 payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
287
288 if (fi->fib_nhs) {
289 /* Also handles the special case fib_nhs == 1 */
290
291 /* each nexthop is packed in an attribute */
292 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
293
294 /* may contain flow and gateway attribute */
295 nhsize += 2 * nla_total_size(4);
296
297 /* all nexthops are packed in a nested attribute */
298 payload += nla_total_size(fi->fib_nhs * nhsize);
299 }
300
301 return payload;
302}
303
Al Viro81f7bf62006-09-27 18:40:00 -0700304void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
Milan Kocianb8f55832007-05-23 14:55:06 -0700305 int dst_len, u32 tb_id, struct nl_info *info,
306 unsigned int nlm_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307{
308 struct sk_buff *skb;
Thomas Graf4e902c52006-08-17 18:14:52 -0700309 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
Thomas Graff21c7bc2006-08-15 00:34:17 -0700310 int err = -ENOBUFS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
Thomas Graf339bf982006-11-10 14:10:15 -0800312 skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
Thomas Graff21c7bc2006-08-15 00:34:17 -0700313 if (skb == NULL)
314 goto errout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315
Thomas Graf4e902c52006-08-17 18:14:52 -0700316 err = fib_dump_info(skb, info->pid, seq, event, tb_id,
Thomas Grafbe403ea2006-08-17 18:15:17 -0700317 fa->fa_type, fa->fa_scope, key, dst_len,
Milan Kocianb8f55832007-05-23 14:55:06 -0700318 fa->fa_tos, fa->fa_info, nlm_flags);
Patrick McHardy26932562007-01-31 23:16:40 -0800319 if (err < 0) {
320 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
321 WARN_ON(err == -EMSGSIZE);
322 kfree_skb(skb);
323 goto errout;
324 }
Pablo Neira Ayuso1ce85fe2009-02-24 23:18:28 -0800325 rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE,
326 info->nlh, GFP_KERNEL);
327 return;
Thomas Graff21c7bc2006-08-15 00:34:17 -0700328errout:
329 if (err < 0)
Denis V. Lunev4d1169c2008-01-10 03:26:13 -0800330 rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331}
332
333/* Return the first fib alias matching TOS with
334 * priority less than or equal to PRIO.
335 */
336struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
337{
338 if (fah) {
339 struct fib_alias *fa;
340 list_for_each_entry(fa, fah, fa_list) {
341 if (fa->fa_tos > tos)
342 continue;
343 if (fa->fa_info->fib_priority >= prio ||
344 fa->fa_tos < tos)
345 return fa;
346 }
347 }
348 return NULL;
349}
350
351int fib_detect_death(struct fib_info *fi, int order,
Denis V. Lunevc17860a2007-12-08 00:22:13 -0800352 struct fib_info **last_resort, int *last_idx, int dflt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353{
354 struct neighbour *n;
355 int state = NUD_NONE;
356
357 n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev);
358 if (n) {
359 state = n->nud_state;
360 neigh_release(n);
361 }
Jianjun Kongd93191002008-11-03 00:23:42 -0800362 if (state == NUD_REACHABLE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 return 0;
Denis V. Lunevc17860a2007-12-08 00:22:13 -0800364 if ((state&NUD_VALID) && order != dflt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 return 0;
366 if ((state&NUD_VALID) ||
Denis V. Lunevc17860a2007-12-08 00:22:13 -0800367 (*last_idx<0 && order > dflt)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 *last_resort = fi;
369 *last_idx = order;
370 }
371 return 1;
372}
373
374#ifdef CONFIG_IP_ROUTE_MULTIPATH
375
Thomas Graf4e902c52006-08-17 18:14:52 -0700376static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377{
378 int nhs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
Thomas Graf4e902c52006-08-17 18:14:52 -0700380 while (rtnh_ok(rtnh, remaining)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 nhs++;
Thomas Graf4e902c52006-08-17 18:14:52 -0700382 rtnh = rtnh_next(rtnh, &remaining);
383 }
384
385 /* leftover implies invalid nexthop configuration, discard it */
386 return remaining > 0 ? 0 : nhs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387}
388
Thomas Graf4e902c52006-08-17 18:14:52 -0700389static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
390 int remaining, struct fib_config *cfg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 change_nexthops(fi) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700393 int attrlen;
394
395 if (!rtnh_ok(rtnh, remaining))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 return -EINVAL;
Thomas Graf4e902c52006-08-17 18:14:52 -0700397
398 nh->nh_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
399 nh->nh_oif = rtnh->rtnh_ifindex;
400 nh->nh_weight = rtnh->rtnh_hops + 1;
401
402 attrlen = rtnh_attrlen(rtnh);
403 if (attrlen > 0) {
404 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
405
406 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
Al Viro17fb2c62006-09-26 22:15:25 -0700407 nh->nh_gw = nla ? nla_get_be32(nla) : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408#ifdef CONFIG_NET_CLS_ROUTE
Thomas Graf4e902c52006-08-17 18:14:52 -0700409 nla = nla_find(attrs, attrlen, RTA_FLOW);
410 nh->nh_tclassid = nla ? nla_get_u32(nla) : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411#endif
412 }
Thomas Graf4e902c52006-08-17 18:14:52 -0700413
414 rtnh = rtnh_next(rtnh, &remaining);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 } endfor_nexthops(fi);
Thomas Graf4e902c52006-08-17 18:14:52 -0700416
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 return 0;
418}
419
420#endif
421
Thomas Graf4e902c52006-08-17 18:14:52 -0700422int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423{
424#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700425 struct rtnexthop *rtnh;
426 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427#endif
428
Thomas Graf4e902c52006-08-17 18:14:52 -0700429 if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 return 1;
431
Thomas Graf4e902c52006-08-17 18:14:52 -0700432 if (cfg->fc_oif || cfg->fc_gw) {
433 if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
434 (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 return 0;
436 return 1;
437 }
438
439#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700440 if (cfg->fc_mp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 return 0;
Thomas Graf4e902c52006-08-17 18:14:52 -0700442
443 rtnh = cfg->fc_mp;
444 remaining = cfg->fc_mp_len;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 for_nexthops(fi) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700447 int attrlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
Thomas Graf4e902c52006-08-17 18:14:52 -0700449 if (!rtnh_ok(rtnh, remaining))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 return -EINVAL;
Thomas Graf4e902c52006-08-17 18:14:52 -0700451
452 if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 return 1;
Thomas Graf4e902c52006-08-17 18:14:52 -0700454
455 attrlen = rtnh_attrlen(rtnh);
456 if (attrlen < 0) {
457 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
458
459 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
Al Viro17fb2c62006-09-26 22:15:25 -0700460 if (nla && nla_get_be32(nla) != nh->nh_gw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 return 1;
462#ifdef CONFIG_NET_CLS_ROUTE
Thomas Graf4e902c52006-08-17 18:14:52 -0700463 nla = nla_find(attrs, attrlen, RTA_FLOW);
464 if (nla && nla_get_u32(nla) != nh->nh_tclassid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 return 1;
466#endif
467 }
Thomas Graf4e902c52006-08-17 18:14:52 -0700468
469 rtnh = rtnh_next(rtnh, &remaining);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 } endfor_nexthops(fi);
471#endif
472 return 0;
473}
474
475
476/*
477 Picture
478 -------
479
480 Semantics of nexthop is very messy by historical reasons.
481 We have to take into account, that:
482 a) gateway can be actually local interface address,
483 so that gatewayed route is direct.
484 b) gateway must be on-link address, possibly
485 described not by an ifaddr, but also by a direct route.
486 c) If both gateway and interface are specified, they should not
487 contradict.
488 d) If we use tunnel routes, gateway could be not on-link.
489
490 Attempt to reconcile all of these (alas, self-contradictory) conditions
491 results in pretty ugly and hairy code with obscure logic.
492
493 I chose to generalized it instead, so that the size
494 of code does not increase practically, but it becomes
495 much more general.
496 Every prefix is assigned a "scope" value: "host" is local address,
497 "link" is direct route,
498 [ ... "site" ... "interior" ... ]
499 and "universe" is true gateway route with global meaning.
500
501 Every prefix refers to a set of "nexthop"s (gw, oif),
502 where gw must have narrower scope. This recursion stops
503 when gw has LOCAL scope or if "nexthop" is declared ONLINK,
504 which means that gw is forced to be on link.
505
506 Code is still hairy, but now it is apparently logically
507 consistent and very flexible. F.e. as by-product it allows
508 to co-exists in peace independent exterior and interior
509 routing processes.
510
511 Normally it looks as following.
512
513 {universe prefix} -> (gw, oif) [scope link]
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900514 |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 |-> {link prefix} -> (gw, oif) [scope local]
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900516 |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 |-> {local prefix} (terminal node)
518 */
519
Thomas Graf4e902c52006-08-17 18:14:52 -0700520static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
521 struct fib_nh *nh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522{
523 int err;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800524 struct net *net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525
Denis V. Lunev86167a32008-01-21 17:34:00 -0800526 net = cfg->fc_nlinfo.nl_net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 if (nh->nh_gw) {
528 struct fib_result res;
529
530#ifdef CONFIG_IP_ROUTE_PERVASIVE
531 if (nh->nh_flags&RTNH_F_PERVASIVE)
532 return 0;
533#endif
534 if (nh->nh_flags&RTNH_F_ONLINK) {
535 struct net_device *dev;
536
Thomas Graf4e902c52006-08-17 18:14:52 -0700537 if (cfg->fc_scope >= RT_SCOPE_LINK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 return -EINVAL;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800539 if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 return -EINVAL;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800541 if ((dev = __dev_get_by_index(net, nh->nh_oif)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 return -ENODEV;
543 if (!(dev->flags&IFF_UP))
544 return -ENETDOWN;
545 nh->nh_dev = dev;
546 dev_hold(dev);
547 nh->nh_scope = RT_SCOPE_LINK;
548 return 0;
549 }
550 {
Thomas Graf4e902c52006-08-17 18:14:52 -0700551 struct flowi fl = {
552 .nl_u = {
553 .ip4_u = {
554 .daddr = nh->nh_gw,
555 .scope = cfg->fc_scope + 1,
556 },
557 },
558 .oif = nh->nh_oif,
559 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560
561 /* It is not necessary, but requires a bit of thinking */
562 if (fl.fl4_scope < RT_SCOPE_LINK)
563 fl.fl4_scope = RT_SCOPE_LINK;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800564 if ((err = fib_lookup(net, &fl, &res)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 return err;
566 }
567 err = -EINVAL;
568 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
569 goto out;
570 nh->nh_scope = res.scope;
571 nh->nh_oif = FIB_RES_OIF(res);
572 if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
573 goto out;
574 dev_hold(nh->nh_dev);
575 err = -ENETDOWN;
576 if (!(nh->nh_dev->flags & IFF_UP))
577 goto out;
578 err = 0;
579out:
580 fib_res_put(&res);
581 return err;
582 } else {
583 struct in_device *in_dev;
584
585 if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
586 return -EINVAL;
587
Denis V. Lunev86167a32008-01-21 17:34:00 -0800588 in_dev = inetdev_by_index(net, nh->nh_oif);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 if (in_dev == NULL)
590 return -ENODEV;
591 if (!(in_dev->dev->flags&IFF_UP)) {
592 in_dev_put(in_dev);
593 return -ENETDOWN;
594 }
595 nh->nh_dev = in_dev->dev;
596 dev_hold(nh->nh_dev);
597 nh->nh_scope = RT_SCOPE_HOST;
598 in_dev_put(in_dev);
599 }
600 return 0;
601}
602
Al Viro81f7bf62006-09-27 18:40:00 -0700603static inline unsigned int fib_laddr_hashfn(__be32 val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604{
605 unsigned int mask = (fib_hash_size - 1);
606
Al Viro81f7bf62006-09-27 18:40:00 -0700607 return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608}
609
610static struct hlist_head *fib_hash_alloc(int bytes)
611{
612 if (bytes <= PAGE_SIZE)
Joonwoo Park88f83492007-11-26 23:29:32 +0800613 return kzalloc(bytes, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 else
615 return (struct hlist_head *)
Joonwoo Park88f83492007-11-26 23:29:32 +0800616 __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(bytes));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617}
618
619static void fib_hash_free(struct hlist_head *hash, int bytes)
620{
621 if (!hash)
622 return;
623
624 if (bytes <= PAGE_SIZE)
625 kfree(hash);
626 else
627 free_pages((unsigned long) hash, get_order(bytes));
628}
629
630static void fib_hash_move(struct hlist_head *new_info_hash,
631 struct hlist_head *new_laddrhash,
632 unsigned int new_size)
633{
David S. Millerb7656e72005-08-05 04:12:48 -0700634 struct hlist_head *old_info_hash, *old_laddrhash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 unsigned int old_size = fib_hash_size;
David S. Millerb7656e72005-08-05 04:12:48 -0700636 unsigned int i, bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700638 spin_lock_bh(&fib_info_lock);
David S. Millerb7656e72005-08-05 04:12:48 -0700639 old_info_hash = fib_info_hash;
640 old_laddrhash = fib_info_laddrhash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 fib_hash_size = new_size;
642
643 for (i = 0; i < old_size; i++) {
644 struct hlist_head *head = &fib_info_hash[i];
645 struct hlist_node *node, *n;
646 struct fib_info *fi;
647
648 hlist_for_each_entry_safe(fi, node, n, head, fib_hash) {
649 struct hlist_head *dest;
650 unsigned int new_hash;
651
652 hlist_del(&fi->fib_hash);
653
654 new_hash = fib_info_hashfn(fi);
655 dest = &new_info_hash[new_hash];
656 hlist_add_head(&fi->fib_hash, dest);
657 }
658 }
659 fib_info_hash = new_info_hash;
660
661 for (i = 0; i < old_size; i++) {
662 struct hlist_head *lhead = &fib_info_laddrhash[i];
663 struct hlist_node *node, *n;
664 struct fib_info *fi;
665
666 hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) {
667 struct hlist_head *ldest;
668 unsigned int new_hash;
669
670 hlist_del(&fi->fib_lhash);
671
672 new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
673 ldest = &new_laddrhash[new_hash];
674 hlist_add_head(&fi->fib_lhash, ldest);
675 }
676 }
677 fib_info_laddrhash = new_laddrhash;
678
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700679 spin_unlock_bh(&fib_info_lock);
David S. Millerb7656e72005-08-05 04:12:48 -0700680
681 bytes = old_size * sizeof(struct hlist_head *);
682 fib_hash_free(old_info_hash, bytes);
683 fib_hash_free(old_laddrhash, bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684}
685
Thomas Graf4e902c52006-08-17 18:14:52 -0700686struct fib_info *fib_create_info(struct fib_config *cfg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687{
688 int err;
689 struct fib_info *fi = NULL;
690 struct fib_info *ofi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 int nhs = 1;
Denis V. Lunev7462bd742008-01-31 18:49:32 -0800692 struct net *net = cfg->fc_nlinfo.nl_net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
694 /* Fast check to catch the most weird cases */
Thomas Graf4e902c52006-08-17 18:14:52 -0700695 if (fib_props[cfg->fc_type].scope > cfg->fc_scope)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 goto err_inval;
697
698#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700699 if (cfg->fc_mp) {
700 nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 if (nhs == 0)
702 goto err_inval;
703 }
704#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
706 err = -ENOBUFS;
707 if (fib_info_cnt >= fib_hash_size) {
708 unsigned int new_size = fib_hash_size << 1;
709 struct hlist_head *new_info_hash;
710 struct hlist_head *new_laddrhash;
711 unsigned int bytes;
712
713 if (!new_size)
714 new_size = 1;
715 bytes = new_size * sizeof(struct hlist_head *);
716 new_info_hash = fib_hash_alloc(bytes);
717 new_laddrhash = fib_hash_alloc(bytes);
718 if (!new_info_hash || !new_laddrhash) {
719 fib_hash_free(new_info_hash, bytes);
720 fib_hash_free(new_laddrhash, bytes);
Joonwoo Park88f83492007-11-26 23:29:32 +0800721 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 fib_hash_move(new_info_hash, new_laddrhash, new_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723
724 if (!fib_hash_size)
725 goto failure;
726 }
727
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700728 fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 if (fi == NULL)
730 goto failure;
731 fib_info_cnt++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732
Denis V. Lunev57d7a602008-04-16 02:00:50 -0700733 fi->fib_net = hold_net(net);
Thomas Graf4e902c52006-08-17 18:14:52 -0700734 fi->fib_protocol = cfg->fc_protocol;
735 fi->fib_flags = cfg->fc_flags;
736 fi->fib_priority = cfg->fc_priority;
737 fi->fib_prefsrc = cfg->fc_prefsrc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739 fi->fib_nhs = nhs;
740 change_nexthops(fi) {
741 nh->nh_parent = fi;
742 } endfor_nexthops(fi)
743
Thomas Graf4e902c52006-08-17 18:14:52 -0700744 if (cfg->fc_mx) {
745 struct nlattr *nla;
746 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
Thomas Graf4e902c52006-08-17 18:14:52 -0700748 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
Thomas Graf8f4c1f92007-09-12 14:44:36 +0200749 int type = nla_type(nla);
Thomas Graf4e902c52006-08-17 18:14:52 -0700750
751 if (type) {
752 if (type > RTAX_MAX)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 goto err_inval;
Thomas Graf4e902c52006-08-17 18:14:52 -0700754 fi->fib_metrics[type - 1] = nla_get_u32(nla);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 }
757 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758
Thomas Graf4e902c52006-08-17 18:14:52 -0700759 if (cfg->fc_mp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700761 err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg);
762 if (err != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 goto failure;
Thomas Graf4e902c52006-08-17 18:14:52 -0700764 if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 goto err_inval;
Thomas Graf4e902c52006-08-17 18:14:52 -0700766 if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 goto err_inval;
768#ifdef CONFIG_NET_CLS_ROUTE
Thomas Graf4e902c52006-08-17 18:14:52 -0700769 if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 goto err_inval;
771#endif
772#else
773 goto err_inval;
774#endif
775 } else {
776 struct fib_nh *nh = fi->fib_nh;
Thomas Graf4e902c52006-08-17 18:14:52 -0700777
778 nh->nh_oif = cfg->fc_oif;
779 nh->nh_gw = cfg->fc_gw;
780 nh->nh_flags = cfg->fc_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781#ifdef CONFIG_NET_CLS_ROUTE
Thomas Graf4e902c52006-08-17 18:14:52 -0700782 nh->nh_tclassid = cfg->fc_flow;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784#ifdef CONFIG_IP_ROUTE_MULTIPATH
785 nh->nh_weight = 1;
786#endif
787 }
788
Thomas Graf4e902c52006-08-17 18:14:52 -0700789 if (fib_props[cfg->fc_type].error) {
790 if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 goto err_inval;
792 goto link_it;
793 }
794
Thomas Graf4e902c52006-08-17 18:14:52 -0700795 if (cfg->fc_scope > RT_SCOPE_HOST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 goto err_inval;
797
Thomas Graf4e902c52006-08-17 18:14:52 -0700798 if (cfg->fc_scope == RT_SCOPE_HOST) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 struct fib_nh *nh = fi->fib_nh;
800
801 /* Local address is added. */
802 if (nhs != 1 || nh->nh_gw)
803 goto err_inval;
804 nh->nh_scope = RT_SCOPE_NOWHERE;
Denis V. Lunev7462bd742008-01-31 18:49:32 -0800805 nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 err = -ENODEV;
807 if (nh->nh_dev == NULL)
808 goto failure;
809 } else {
810 change_nexthops(fi) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700811 if ((err = fib_check_nh(cfg, fi, nh)) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 goto failure;
813 } endfor_nexthops(fi)
814 }
815
816 if (fi->fib_prefsrc) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700817 if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
818 fi->fib_prefsrc != cfg->fc_dst)
Denis V. Lunev7462bd742008-01-31 18:49:32 -0800819 if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 goto err_inval;
821 }
822
823link_it:
824 if ((ofi = fib_find_info(fi)) != NULL) {
825 fi->fib_dead = 1;
826 free_fib_info(fi);
827 ofi->fib_treeref++;
828 return ofi;
829 }
830
831 fi->fib_treeref++;
832 atomic_inc(&fi->fib_clntref);
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700833 spin_lock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 hlist_add_head(&fi->fib_hash,
835 &fib_info_hash[fib_info_hashfn(fi)]);
836 if (fi->fib_prefsrc) {
837 struct hlist_head *head;
838
839 head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
840 hlist_add_head(&fi->fib_lhash, head);
841 }
842 change_nexthops(fi) {
843 struct hlist_head *head;
844 unsigned int hash;
845
846 if (!nh->nh_dev)
847 continue;
848 hash = fib_devindex_hashfn(nh->nh_dev->ifindex);
849 head = &fib_info_devhash[hash];
850 hlist_add_head(&nh->nh_hash, head);
851 } endfor_nexthops(fi)
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700852 spin_unlock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 return fi;
854
855err_inval:
856 err = -EINVAL;
857
858failure:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900859 if (fi) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 fi->fib_dead = 1;
861 free_fib_info(fi);
862 }
Thomas Graf4e902c52006-08-17 18:14:52 -0700863
864 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865}
866
Robert Olssone5b43762005-08-25 13:01:03 -0700867/* Note! fib_semantic_match intentionally uses RCU list functions. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868int fib_semantic_match(struct list_head *head, const struct flowi *flp,
Rami Rosene204a342009-05-18 01:19:12 +0000869 struct fib_result *res, int prefixlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870{
871 struct fib_alias *fa;
872 int nh_sel = 0;
873
Robert Olssone5b43762005-08-25 13:01:03 -0700874 list_for_each_entry_rcu(fa, head, fa_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 int err;
876
877 if (fa->fa_tos &&
878 fa->fa_tos != flp->fl4_tos)
879 continue;
880
881 if (fa->fa_scope < flp->fl4_scope)
882 continue;
883
884 fa->fa_state |= FA_S_ACCESSED;
885
886 err = fib_props[fa->fa_type].error;
887 if (err == 0) {
888 struct fib_info *fi = fa->fa_info;
889
890 if (fi->fib_flags & RTNH_F_DEAD)
891 continue;
892
893 switch (fa->fa_type) {
894 case RTN_UNICAST:
895 case RTN_LOCAL:
896 case RTN_BROADCAST:
897 case RTN_ANYCAST:
898 case RTN_MULTICAST:
899 for_nexthops(fi) {
900 if (nh->nh_flags&RTNH_F_DEAD)
901 continue;
902 if (!flp->oif || flp->oif == nh->nh_oif)
903 break;
904 }
905#ifdef CONFIG_IP_ROUTE_MULTIPATH
906 if (nhsel < fi->fib_nhs) {
907 nh_sel = nhsel;
908 goto out_fill_res;
909 }
910#else
911 if (nhsel < 1) {
912 goto out_fill_res;
913 }
914#endif
915 endfor_nexthops(fi);
916 continue;
917
918 default:
Stephen Hemmingera6db9012008-01-12 20:58:35 -0800919 printk(KERN_WARNING "fib_semantic_match bad type %#x\n",
920 fa->fa_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 return -EINVAL;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700922 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 }
924 return err;
925 }
926 return 1;
927
928out_fill_res:
929 res->prefixlen = prefixlen;
930 res->nh_sel = nh_sel;
931 res->type = fa->fa_type;
932 res->scope = fa->fa_scope;
933 res->fi = fa->fa_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 atomic_inc(&res->fi->fib_clntref);
935 return 0;
936}
937
938/* Find appropriate source address to this destination */
939
Al Virob83738a2006-09-26 22:14:15 -0700940__be32 __fib_res_prefsrc(struct fib_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941{
942 return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope);
943}
944
Thomas Grafbe403ea2006-08-17 18:15:17 -0700945int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
Al Viro81f7bf62006-09-27 18:40:00 -0700946 u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos,
Thomas Grafbe403ea2006-08-17 18:15:17 -0700947 struct fib_info *fi, unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948{
Thomas Grafbe403ea2006-08-17 18:15:17 -0700949 struct nlmsghdr *nlh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 struct rtmsg *rtm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
Thomas Grafbe403ea2006-08-17 18:15:17 -0700952 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
953 if (nlh == NULL)
Patrick McHardy26932562007-01-31 23:16:40 -0800954 return -EMSGSIZE;
Thomas Grafbe403ea2006-08-17 18:15:17 -0700955
956 rtm = nlmsg_data(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 rtm->rtm_family = AF_INET;
958 rtm->rtm_dst_len = dst_len;
959 rtm->rtm_src_len = 0;
960 rtm->rtm_tos = tos;
Krzysztof Piotr Oledzki709772e2008-06-10 15:44:49 -0700961 if (tb_id < 256)
962 rtm->rtm_table = tb_id;
963 else
964 rtm->rtm_table = RT_TABLE_COMPAT;
Thomas Grafbe403ea2006-08-17 18:15:17 -0700965 NLA_PUT_U32(skb, RTA_TABLE, tb_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 rtm->rtm_type = type;
967 rtm->rtm_flags = fi->fib_flags;
968 rtm->rtm_scope = scope;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 rtm->rtm_protocol = fi->fib_protocol;
Thomas Grafbe403ea2006-08-17 18:15:17 -0700970
971 if (rtm->rtm_dst_len)
Al Viro17fb2c62006-09-26 22:15:25 -0700972 NLA_PUT_BE32(skb, RTA_DST, dst);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700973
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 if (fi->fib_priority)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700975 NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority);
976
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700978 goto nla_put_failure;
979
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 if (fi->fib_prefsrc)
Al Viro17fb2c62006-09-26 22:15:25 -0700981 NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700982
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 if (fi->fib_nhs == 1) {
984 if (fi->fib_nh->nh_gw)
Al Viro17fb2c62006-09-26 22:15:25 -0700985 NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700986
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 if (fi->fib_nh->nh_oif)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700988 NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif);
Patrick McHardy8265abc2006-07-21 15:09:55 -0700989#ifdef CONFIG_NET_CLS_ROUTE
990 if (fi->fib_nh[0].nh_tclassid)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700991 NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid);
Patrick McHardy8265abc2006-07-21 15:09:55 -0700992#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 }
994#ifdef CONFIG_IP_ROUTE_MULTIPATH
995 if (fi->fib_nhs > 1) {
Thomas Grafbe403ea2006-08-17 18:15:17 -0700996 struct rtnexthop *rtnh;
997 struct nlattr *mp;
998
999 mp = nla_nest_start(skb, RTA_MULTIPATH);
1000 if (mp == NULL)
1001 goto nla_put_failure;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002
1003 for_nexthops(fi) {
Thomas Grafbe403ea2006-08-17 18:15:17 -07001004 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1005 if (rtnh == NULL)
1006 goto nla_put_failure;
1007
1008 rtnh->rtnh_flags = nh->nh_flags & 0xFF;
1009 rtnh->rtnh_hops = nh->nh_weight - 1;
1010 rtnh->rtnh_ifindex = nh->nh_oif;
1011
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 if (nh->nh_gw)
Al Viro17fb2c62006-09-26 22:15:25 -07001013 NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw);
Patrick McHardy8265abc2006-07-21 15:09:55 -07001014#ifdef CONFIG_NET_CLS_ROUTE
1015 if (nh->nh_tclassid)
Thomas Grafbe403ea2006-08-17 18:15:17 -07001016 NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid);
Patrick McHardy8265abc2006-07-21 15:09:55 -07001017#endif
Thomas Grafbe403ea2006-08-17 18:15:17 -07001018 /* length of rtnetlink header + attributes */
1019 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 } endfor_nexthops(fi);
Thomas Grafbe403ea2006-08-17 18:15:17 -07001021
1022 nla_nest_end(skb, mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 }
1024#endif
Thomas Grafbe403ea2006-08-17 18:15:17 -07001025 return nlmsg_end(skb, nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026
Thomas Grafbe403ea2006-08-17 18:15:17 -07001027nla_put_failure:
Patrick McHardy26932562007-01-31 23:16:40 -08001028 nlmsg_cancel(skb, nlh);
1029 return -EMSGSIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030}
1031
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032/*
1033 Update FIB if:
1034 - local address disappeared -> we must delete all the entries
1035 referring to it.
1036 - device went down -> we must shutdown all nexthops going via it.
1037 */
Denis V. Lunev4814bdb2008-01-31 18:50:07 -08001038int fib_sync_down_addr(struct net *net, __be32 local)
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001039{
1040 int ret = 0;
1041 unsigned int hash = fib_laddr_hashfn(local);
1042 struct hlist_head *head = &fib_info_laddrhash[hash];
1043 struct hlist_node *node;
1044 struct fib_info *fi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001046 if (fib_info_laddrhash == NULL || local == 0)
1047 return 0;
1048
1049 hlist_for_each_entry(fi, node, head, fib_lhash) {
Denis V. Lunev4814bdb2008-01-31 18:50:07 -08001050 if (fi->fib_net != net)
1051 continue;
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001052 if (fi->fib_prefsrc == local) {
1053 fi->fib_flags |= RTNH_F_DEAD;
1054 ret++;
1055 }
1056 }
1057 return ret;
1058}
1059
1060int fib_sync_down_dev(struct net_device *dev, int force)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061{
1062 int ret = 0;
1063 int scope = RT_SCOPE_NOWHERE;
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001064 struct fib_info *prev_fi = NULL;
1065 unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1066 struct hlist_head *head = &fib_info_devhash[hash];
1067 struct hlist_node *node;
1068 struct fib_nh *nh;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001069
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070 if (force)
1071 scope = -1;
1072
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001073 hlist_for_each_entry(nh, node, head, nh_hash) {
1074 struct fib_info *fi = nh->nh_parent;
1075 int dead;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001077 BUG_ON(!fi->fib_nhs);
1078 if (nh->nh_dev != dev || fi == prev_fi)
1079 continue;
1080 prev_fi = fi;
1081 dead = 0;
1082 change_nexthops(fi) {
1083 if (nh->nh_flags&RTNH_F_DEAD)
1084 dead++;
1085 else if (nh->nh_dev == dev &&
1086 nh->nh_scope != scope) {
1087 nh->nh_flags |= RTNH_F_DEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088#ifdef CONFIG_IP_ROUTE_MULTIPATH
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001089 spin_lock_bh(&fib_multipath_lock);
1090 fi->fib_power -= nh->nh_power;
1091 nh->nh_power = 0;
1092 spin_unlock_bh(&fib_multipath_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093#endif
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001094 dead++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 }
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001096#ifdef CONFIG_IP_ROUTE_MULTIPATH
1097 if (force > 1 && nh->nh_dev == dev) {
1098 dead = fi->fib_nhs;
1099 break;
1100 }
1101#endif
1102 } endfor_nexthops(fi)
1103 if (dead == fi->fib_nhs) {
1104 fi->fib_flags |= RTNH_F_DEAD;
1105 ret++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 }
1107 }
1108
1109 return ret;
1110}
1111
1112#ifdef CONFIG_IP_ROUTE_MULTIPATH
1113
1114/*
1115 Dead device goes up. We wake up dead nexthops.
1116 It takes sense only on multipath routes.
1117 */
1118
1119int fib_sync_up(struct net_device *dev)
1120{
1121 struct fib_info *prev_fi;
1122 unsigned int hash;
1123 struct hlist_head *head;
1124 struct hlist_node *node;
1125 struct fib_nh *nh;
1126 int ret;
1127
1128 if (!(dev->flags&IFF_UP))
1129 return 0;
1130
1131 prev_fi = NULL;
1132 hash = fib_devindex_hashfn(dev->ifindex);
1133 head = &fib_info_devhash[hash];
1134 ret = 0;
1135
1136 hlist_for_each_entry(nh, node, head, nh_hash) {
1137 struct fib_info *fi = nh->nh_parent;
1138 int alive;
1139
1140 BUG_ON(!fi->fib_nhs);
1141 if (nh->nh_dev != dev || fi == prev_fi)
1142 continue;
1143
1144 prev_fi = fi;
1145 alive = 0;
1146 change_nexthops(fi) {
1147 if (!(nh->nh_flags&RTNH_F_DEAD)) {
1148 alive++;
1149 continue;
1150 }
1151 if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
1152 continue;
Herbert Xue5ed6392005-10-03 14:35:55 -07001153 if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 continue;
1155 alive++;
1156 spin_lock_bh(&fib_multipath_lock);
1157 nh->nh_power = 0;
1158 nh->nh_flags &= ~RTNH_F_DEAD;
1159 spin_unlock_bh(&fib_multipath_lock);
1160 } endfor_nexthops(fi)
1161
1162 if (alive > 0) {
1163 fi->fib_flags &= ~RTNH_F_DEAD;
1164 ret++;
1165 }
1166 }
1167
1168 return ret;
1169}
1170
1171/*
1172 The algorithm is suboptimal, but it provides really
1173 fair weighted route distribution.
1174 */
1175
1176void fib_select_multipath(const struct flowi *flp, struct fib_result *res)
1177{
1178 struct fib_info *fi = res->fi;
1179 int w;
1180
1181 spin_lock_bh(&fib_multipath_lock);
1182 if (fi->fib_power <= 0) {
1183 int power = 0;
1184 change_nexthops(fi) {
1185 if (!(nh->nh_flags&RTNH_F_DEAD)) {
1186 power += nh->nh_weight;
1187 nh->nh_power = nh->nh_weight;
1188 }
1189 } endfor_nexthops(fi);
1190 fi->fib_power = power;
1191 if (power <= 0) {
1192 spin_unlock_bh(&fib_multipath_lock);
1193 /* Race condition: route has just become dead. */
1194 res->nh_sel = 0;
1195 return;
1196 }
1197 }
1198
1199
1200 /* w should be random number [0..fi->fib_power-1],
1201 it is pretty bad approximation.
1202 */
1203
1204 w = jiffies % fi->fib_power;
1205
1206 change_nexthops(fi) {
1207 if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
1208 if ((w -= nh->nh_power) <= 0) {
1209 nh->nh_power--;
1210 fi->fib_power--;
1211 res->nh_sel = nhsel;
1212 spin_unlock_bh(&fib_multipath_lock);
1213 return;
1214 }
1215 }
1216 } endfor_nexthops(fi);
1217
1218 /* Race condition: route has just become dead. */
1219 res->nh_sel = 0;
1220 spin_unlock_bh(&fib_multipath_lock);
1221}
1222#endif