blob: 80106d89d548d841d5986533f749572eb75c3a43 [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020037#include <net/arp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <net/ip.h>
39#include <net/protocol.h>
40#include <net/route.h>
41#include <net/tcp.h>
42#include <net/sock.h>
43#include <net/ip_fib.h>
Thomas Graff21c7bc2006-08-15 00:34:17 -070044#include <net/netlink.h>
Thomas Graf4e902c52006-08-17 18:14:52 -070045#include <net/nexthop.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
47#include "fib_lookup.h"
48
Stephen Hemminger832b4c52006-08-29 16:48:09 -070049static DEFINE_SPINLOCK(fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050static struct hlist_head *fib_info_hash;
51static struct hlist_head *fib_info_laddrhash;
David S. Miller123b9732011-02-01 15:34:21 -080052static unsigned int fib_info_hash_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053static unsigned int fib_info_cnt;
54
55#define DEVINDEX_HASHBITS 8
56#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
57static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
58
59#ifdef CONFIG_IP_ROUTE_MULTIPATH
60
61static DEFINE_SPINLOCK(fib_multipath_lock);
62
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000063#define for_nexthops(fi) { \
64 int nhsel; const struct fib_nh *nh; \
65 for (nhsel = 0, nh = (fi)->fib_nh; \
66 nhsel < (fi)->fib_nhs; \
67 nh++, nhsel++)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000069#define change_nexthops(fi) { \
70 int nhsel; struct fib_nh *nexthop_nh; \
71 for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
72 nhsel < (fi)->fib_nhs; \
73 nexthop_nh++, nhsel++)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75#else /* CONFIG_IP_ROUTE_MULTIPATH */
76
77/* Hope, that gcc will optimize it to get rid of dummy loop */
78
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000079#define for_nexthops(fi) { \
80 int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
81 for (nhsel = 0; nhsel < 1; nhsel++)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000083#define change_nexthops(fi) { \
84 int nhsel; \
85 struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
86 for (nhsel = 0; nhsel < 1; nhsel++)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88#endif /* CONFIG_IP_ROUTE_MULTIPATH */
89
90#define endfor_nexthops(fi) }
91
92
David S. Miller3be06862011-03-07 15:01:10 -080093const struct fib_prop fib_props[RTN_MAX + 1] = {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000094 [RTN_UNSPEC] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 .error = 0,
96 .scope = RT_SCOPE_NOWHERE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000097 },
98 [RTN_UNICAST] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 .error = 0,
100 .scope = RT_SCOPE_UNIVERSE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000101 },
102 [RTN_LOCAL] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 .error = 0,
104 .scope = RT_SCOPE_HOST,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000105 },
106 [RTN_BROADCAST] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 .error = 0,
108 .scope = RT_SCOPE_LINK,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000109 },
110 [RTN_ANYCAST] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 .error = 0,
112 .scope = RT_SCOPE_LINK,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000113 },
114 [RTN_MULTICAST] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 .error = 0,
116 .scope = RT_SCOPE_UNIVERSE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000117 },
118 [RTN_BLACKHOLE] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 .error = -EINVAL,
120 .scope = RT_SCOPE_UNIVERSE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000121 },
122 [RTN_UNREACHABLE] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 .error = -EHOSTUNREACH,
124 .scope = RT_SCOPE_UNIVERSE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000125 },
126 [RTN_PROHIBIT] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 .error = -EACCES,
128 .scope = RT_SCOPE_UNIVERSE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000129 },
130 [RTN_THROW] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 .error = -EAGAIN,
132 .scope = RT_SCOPE_UNIVERSE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000133 },
134 [RTN_NAT] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 .error = -EINVAL,
136 .scope = RT_SCOPE_NOWHERE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000137 },
138 [RTN_XRESOLVE] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 .error = -EINVAL,
140 .scope = RT_SCOPE_NOWHERE,
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000141 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142};
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144/* Release a nexthop info record */
Yan, Zheng19c1ea12011-09-04 20:24:20 +0000145static void free_fib_info_rcu(struct rcu_head *head)
146{
147 struct fib_info *fi = container_of(head, struct fib_info, rcu);
148
149 if (fi->fib_metrics != (u32 *) dst_default_metrics)
150 kfree(fi->fib_metrics);
151 kfree(fi);
152}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
154void free_fib_info(struct fib_info *fi)
155{
156 if (fi->fib_dead == 0) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000157 pr_warning("Freeing alive fib_info %p\n", fi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 return;
159 }
160 change_nexthops(fi) {
David S. Miller71fceff2010-01-15 01:16:40 -0800161 if (nexthop_nh->nh_dev)
162 dev_put(nexthop_nh->nh_dev);
163 nexthop_nh->nh_dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 } endfor_nexthops(fi);
165 fib_info_cnt--;
Denis V. Lunev57d7a602008-04-16 02:00:50 -0700166 release_net(fi->fib_net);
Yan, Zheng19c1ea12011-09-04 20:24:20 +0000167 call_rcu(&fi->rcu, free_fib_info_rcu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
170void fib_release_info(struct fib_info *fi)
171{
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700172 spin_lock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 if (fi && --fi->fib_treeref == 0) {
174 hlist_del(&fi->fib_hash);
175 if (fi->fib_prefsrc)
176 hlist_del(&fi->fib_lhash);
177 change_nexthops(fi) {
David S. Miller71fceff2010-01-15 01:16:40 -0800178 if (!nexthop_nh->nh_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 continue;
David S. Miller71fceff2010-01-15 01:16:40 -0800180 hlist_del(&nexthop_nh->nh_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 } endfor_nexthops(fi)
182 fi->fib_dead = 1;
183 fib_info_put(fi);
184 }
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700185 spin_unlock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186}
187
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000188static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189{
190 const struct fib_nh *onh = ofi->fib_nh;
191
192 for_nexthops(fi) {
193 if (nh->nh_oif != onh->nh_oif ||
194 nh->nh_gw != onh->nh_gw ||
195 nh->nh_scope != onh->nh_scope ||
196#ifdef CONFIG_IP_ROUTE_MULTIPATH
197 nh->nh_weight != onh->nh_weight ||
198#endif
Patrick McHardyc7066f72011-01-14 13:36:42 +0100199#ifdef CONFIG_IP_ROUTE_CLASSID
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 nh->nh_tclassid != onh->nh_tclassid ||
201#endif
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000202 ((nh->nh_flags ^ onh->nh_flags) & ~RTNH_F_DEAD))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 return -1;
204 onh++;
205 } endfor_nexthops(fi);
206 return 0;
207}
208
David S. Miller88ebc722008-01-12 21:49:01 -0800209static inline unsigned int fib_devindex_hashfn(unsigned int val)
210{
211 unsigned int mask = DEVINDEX_HASHSIZE - 1;
212
213 return (val ^
214 (val >> DEVINDEX_HASHBITS) ^
215 (val >> (DEVINDEX_HASHBITS * 2))) & mask;
216}
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
219{
David S. Miller123b9732011-02-01 15:34:21 -0800220 unsigned int mask = (fib_info_hash_size - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 unsigned int val = fi->fib_nhs;
222
David S. Miller37e826c2011-03-24 18:06:47 -0700223 val ^= (fi->fib_protocol << 8) | fi->fib_scope;
Al Viro81f7bf62006-09-27 18:40:00 -0700224 val ^= (__force u32)fi->fib_prefsrc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 val ^= fi->fib_priority;
David S. Miller88ebc722008-01-12 21:49:01 -0800226 for_nexthops(fi) {
227 val ^= fib_devindex_hashfn(nh->nh_oif);
228 } endfor_nexthops(fi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 return (val ^ (val >> 7) ^ (val >> 12)) & mask;
231}
232
233static struct fib_info *fib_find_info(const struct fib_info *nfi)
234{
235 struct hlist_head *head;
236 struct hlist_node *node;
237 struct fib_info *fi;
238 unsigned int hash;
239
240 hash = fib_info_hashfn(nfi);
241 head = &fib_info_hash[hash];
242
243 hlist_for_each_entry(fi, node, head, fib_hash) {
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800244 if (!net_eq(fi->fib_net, nfi->fib_net))
Denis V. Lunev4814bdb2008-01-31 18:50:07 -0800245 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 if (fi->fib_nhs != nfi->fib_nhs)
247 continue;
248 if (nfi->fib_protocol == fi->fib_protocol &&
David S. Miller37e826c2011-03-24 18:06:47 -0700249 nfi->fib_scope == fi->fib_scope &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 nfi->fib_prefsrc == fi->fib_prefsrc &&
251 nfi->fib_priority == fi->fib_priority &&
252 memcmp(nfi->fib_metrics, fi->fib_metrics,
Eric Dumazetfcd13f42011-03-24 07:01:24 +0000253 sizeof(u32) * RTAX_MAX) == 0 &&
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000254 ((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_F_DEAD) == 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
256 return fi;
257 }
258
259 return NULL;
260}
261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262/* Check, that the gateway is already configured.
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000263 * Used only by redirect accept routine.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 */
Al Virod878e72e2006-09-26 22:18:13 -0700265int ip_fib_check_default(__be32 gw, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
267 struct hlist_head *head;
268 struct hlist_node *node;
269 struct fib_nh *nh;
270 unsigned int hash;
271
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700272 spin_lock(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 hash = fib_devindex_hashfn(dev->ifindex);
275 head = &fib_info_devhash[hash];
276 hlist_for_each_entry(nh, node, head, nh_hash) {
277 if (nh->nh_dev == dev &&
278 nh->nh_gw == gw &&
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000279 !(nh->nh_flags & RTNH_F_DEAD)) {
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700280 spin_unlock(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 return 0;
282 }
283 }
284
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700285 spin_unlock(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
287 return -1;
288}
289
Thomas Graf339bf982006-11-10 14:10:15 -0800290static inline size_t fib_nlmsg_size(struct fib_info *fi)
291{
292 size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
293 + nla_total_size(4) /* RTA_TABLE */
294 + nla_total_size(4) /* RTA_DST */
295 + nla_total_size(4) /* RTA_PRIORITY */
296 + nla_total_size(4); /* RTA_PREFSRC */
297
298 /* space for nested metrics */
299 payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
300
301 if (fi->fib_nhs) {
302 /* Also handles the special case fib_nhs == 1 */
303
304 /* each nexthop is packed in an attribute */
305 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
306
307 /* may contain flow and gateway attribute */
308 nhsize += 2 * nla_total_size(4);
309
310 /* all nexthops are packed in a nested attribute */
311 payload += nla_total_size(fi->fib_nhs * nhsize);
312 }
313
314 return payload;
315}
316
Al Viro81f7bf62006-09-27 18:40:00 -0700317void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
Milan Kocianb8f55832007-05-23 14:55:06 -0700318 int dst_len, u32 tb_id, struct nl_info *info,
319 unsigned int nlm_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
321 struct sk_buff *skb;
Thomas Graf4e902c52006-08-17 18:14:52 -0700322 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
Thomas Graff21c7bc2006-08-15 00:34:17 -0700323 int err = -ENOBUFS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324
Thomas Graf339bf982006-11-10 14:10:15 -0800325 skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
Thomas Graff21c7bc2006-08-15 00:34:17 -0700326 if (skb == NULL)
327 goto errout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
Thomas Graf4e902c52006-08-17 18:14:52 -0700329 err = fib_dump_info(skb, info->pid, seq, event, tb_id,
David S. Miller37e826c2011-03-24 18:06:47 -0700330 fa->fa_type, key, dst_len,
Milan Kocianb8f55832007-05-23 14:55:06 -0700331 fa->fa_tos, fa->fa_info, nlm_flags);
Patrick McHardy26932562007-01-31 23:16:40 -0800332 if (err < 0) {
333 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
334 WARN_ON(err == -EMSGSIZE);
335 kfree_skb(skb);
336 goto errout;
337 }
Pablo Neira Ayuso1ce85fe2009-02-24 23:18:28 -0800338 rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE,
339 info->nlh, GFP_KERNEL);
340 return;
Thomas Graff21c7bc2006-08-15 00:34:17 -0700341errout:
342 if (err < 0)
Denis V. Lunev4d1169c2008-01-10 03:26:13 -0800343 rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344}
345
346/* Return the first fib alias matching TOS with
347 * priority less than or equal to PRIO.
348 */
349struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
350{
351 if (fah) {
352 struct fib_alias *fa;
353 list_for_each_entry(fa, fah, fa_list) {
354 if (fa->fa_tos > tos)
355 continue;
356 if (fa->fa_info->fib_priority >= prio ||
357 fa->fa_tos < tos)
358 return fa;
359 }
360 }
361 return NULL;
362}
363
364int fib_detect_death(struct fib_info *fi, int order,
Denis V. Lunevc17860a2007-12-08 00:22:13 -0800365 struct fib_info **last_resort, int *last_idx, int dflt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366{
367 struct neighbour *n;
368 int state = NUD_NONE;
369
370 n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev);
371 if (n) {
372 state = n->nud_state;
373 neigh_release(n);
374 }
Jianjun Kongd9319102008-11-03 00:23:42 -0800375 if (state == NUD_REACHABLE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 return 0;
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000377 if ((state & NUD_VALID) && order != dflt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 return 0;
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000379 if ((state & NUD_VALID) ||
380 (*last_idx < 0 && order > dflt)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 *last_resort = fi;
382 *last_idx = order;
383 }
384 return 1;
385}
386
387#ifdef CONFIG_IP_ROUTE_MULTIPATH
388
Thomas Graf4e902c52006-08-17 18:14:52 -0700389static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
391 int nhs = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
Thomas Graf4e902c52006-08-17 18:14:52 -0700393 while (rtnh_ok(rtnh, remaining)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 nhs++;
Thomas Graf4e902c52006-08-17 18:14:52 -0700395 rtnh = rtnh_next(rtnh, &remaining);
396 }
397
398 /* leftover implies invalid nexthop configuration, discard it */
399 return remaining > 0 ? 0 : nhs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400}
401
Thomas Graf4e902c52006-08-17 18:14:52 -0700402static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
403 int remaining, struct fib_config *cfg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 change_nexthops(fi) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700406 int attrlen;
407
408 if (!rtnh_ok(rtnh, remaining))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 return -EINVAL;
Thomas Graf4e902c52006-08-17 18:14:52 -0700410
David S. Miller71fceff2010-01-15 01:16:40 -0800411 nexthop_nh->nh_flags =
412 (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
413 nexthop_nh->nh_oif = rtnh->rtnh_ifindex;
414 nexthop_nh->nh_weight = rtnh->rtnh_hops + 1;
Thomas Graf4e902c52006-08-17 18:14:52 -0700415
416 attrlen = rtnh_attrlen(rtnh);
417 if (attrlen > 0) {
418 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
419
420 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
David S. Miller71fceff2010-01-15 01:16:40 -0800421 nexthop_nh->nh_gw = nla ? nla_get_be32(nla) : 0;
Patrick McHardyc7066f72011-01-14 13:36:42 +0100422#ifdef CONFIG_IP_ROUTE_CLASSID
Thomas Graf4e902c52006-08-17 18:14:52 -0700423 nla = nla_find(attrs, attrlen, RTA_FLOW);
David S. Miller71fceff2010-01-15 01:16:40 -0800424 nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425#endif
426 }
Thomas Graf4e902c52006-08-17 18:14:52 -0700427
428 rtnh = rtnh_next(rtnh, &remaining);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 } endfor_nexthops(fi);
Thomas Graf4e902c52006-08-17 18:14:52 -0700430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 return 0;
432}
433
434#endif
435
Thomas Graf4e902c52006-08-17 18:14:52 -0700436int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437{
438#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700439 struct rtnexthop *rtnh;
440 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441#endif
442
Thomas Graf4e902c52006-08-17 18:14:52 -0700443 if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return 1;
445
Thomas Graf4e902c52006-08-17 18:14:52 -0700446 if (cfg->fc_oif || cfg->fc_gw) {
447 if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
448 (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 return 0;
450 return 1;
451 }
452
453#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700454 if (cfg->fc_mp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 return 0;
Thomas Graf4e902c52006-08-17 18:14:52 -0700456
457 rtnh = cfg->fc_mp;
458 remaining = cfg->fc_mp_len;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900459
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 for_nexthops(fi) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700461 int attrlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
Thomas Graf4e902c52006-08-17 18:14:52 -0700463 if (!rtnh_ok(rtnh, remaining))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 return -EINVAL;
Thomas Graf4e902c52006-08-17 18:14:52 -0700465
466 if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 return 1;
Thomas Graf4e902c52006-08-17 18:14:52 -0700468
469 attrlen = rtnh_attrlen(rtnh);
470 if (attrlen < 0) {
471 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
472
473 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
Al Viro17fb2c62006-09-26 22:15:25 -0700474 if (nla && nla_get_be32(nla) != nh->nh_gw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 return 1;
Patrick McHardyc7066f72011-01-14 13:36:42 +0100476#ifdef CONFIG_IP_ROUTE_CLASSID
Thomas Graf4e902c52006-08-17 18:14:52 -0700477 nla = nla_find(attrs, attrlen, RTA_FLOW);
478 if (nla && nla_get_u32(nla) != nh->nh_tclassid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 return 1;
480#endif
481 }
Thomas Graf4e902c52006-08-17 18:14:52 -0700482
483 rtnh = rtnh_next(rtnh, &remaining);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 } endfor_nexthops(fi);
485#endif
486 return 0;
487}
488
489
490/*
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000491 * Picture
492 * -------
493 *
494 * Semantics of nexthop is very messy by historical reasons.
495 * We have to take into account, that:
496 * a) gateway can be actually local interface address,
497 * so that gatewayed route is direct.
498 * b) gateway must be on-link address, possibly
499 * described not by an ifaddr, but also by a direct route.
500 * c) If both gateway and interface are specified, they should not
501 * contradict.
502 * d) If we use tunnel routes, gateway could be not on-link.
503 *
504 * Attempt to reconcile all of these (alas, self-contradictory) conditions
505 * results in pretty ugly and hairy code with obscure logic.
506 *
507 * I chose to generalized it instead, so that the size
508 * of code does not increase practically, but it becomes
509 * much more general.
510 * Every prefix is assigned a "scope" value: "host" is local address,
511 * "link" is direct route,
512 * [ ... "site" ... "interior" ... ]
513 * and "universe" is true gateway route with global meaning.
514 *
515 * Every prefix refers to a set of "nexthop"s (gw, oif),
516 * where gw must have narrower scope. This recursion stops
517 * when gw has LOCAL scope or if "nexthop" is declared ONLINK,
518 * which means that gw is forced to be on link.
519 *
520 * Code is still hairy, but now it is apparently logically
521 * consistent and very flexible. F.e. as by-product it allows
522 * to co-exists in peace independent exterior and interior
523 * routing processes.
524 *
525 * Normally it looks as following.
526 *
527 * {universe prefix} -> (gw, oif) [scope link]
528 * |
529 * |-> {link prefix} -> (gw, oif) [scope local]
530 * |
531 * |-> {local prefix} (terminal node)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 */
Thomas Graf4e902c52006-08-17 18:14:52 -0700533static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
534 struct fib_nh *nh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535{
536 int err;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800537 struct net *net;
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000538 struct net_device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Denis V. Lunev86167a32008-01-21 17:34:00 -0800540 net = cfg->fc_nlinfo.nl_net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 if (nh->nh_gw) {
542 struct fib_result res;
543
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000544 if (nh->nh_flags & RTNH_F_ONLINK) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
Thomas Graf4e902c52006-08-17 18:14:52 -0700546 if (cfg->fc_scope >= RT_SCOPE_LINK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 return -EINVAL;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800548 if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 return -EINVAL;
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000550 dev = __dev_get_by_index(net, nh->nh_oif);
551 if (!dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 return -ENODEV;
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000553 if (!(dev->flags & IFF_UP))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 return -ENETDOWN;
555 nh->nh_dev = dev;
556 dev_hold(dev);
557 nh->nh_scope = RT_SCOPE_LINK;
558 return 0;
559 }
Eric Dumazetebc0ffa2010-10-05 10:41:36 +0000560 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 {
David S. Miller9ade2282011-03-12 02:02:42 -0500562 struct flowi4 fl4 = {
563 .daddr = nh->nh_gw,
564 .flowi4_scope = cfg->fc_scope + 1,
565 .flowi4_oif = nh->nh_oif,
Thomas Graf4e902c52006-08-17 18:14:52 -0700566 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 /* It is not necessary, but requires a bit of thinking */
David S. Miller9ade2282011-03-12 02:02:42 -0500569 if (fl4.flowi4_scope < RT_SCOPE_LINK)
570 fl4.flowi4_scope = RT_SCOPE_LINK;
571 err = fib_lookup(net, &fl4, &res);
Eric Dumazetebc0ffa2010-10-05 10:41:36 +0000572 if (err) {
573 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 return err;
Eric Dumazetebc0ffa2010-10-05 10:41:36 +0000575 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 }
577 err = -EINVAL;
578 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
579 goto out;
580 nh->nh_scope = res.scope;
581 nh->nh_oif = FIB_RES_OIF(res);
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000582 nh->nh_dev = dev = FIB_RES_DEV(res);
583 if (!dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 goto out;
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000585 dev_hold(dev);
Eric Dumazet8723e1b2010-10-19 00:39:26 +0000586 err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 } else {
588 struct in_device *in_dev;
589
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000590 if (nh->nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 return -EINVAL;
592
Eric Dumazet8723e1b2010-10-19 00:39:26 +0000593 rcu_read_lock();
594 err = -ENODEV;
Denis V. Lunev86167a32008-01-21 17:34:00 -0800595 in_dev = inetdev_by_index(net, nh->nh_oif);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 if (in_dev == NULL)
Eric Dumazet8723e1b2010-10-19 00:39:26 +0000597 goto out;
598 err = -ENETDOWN;
599 if (!(in_dev->dev->flags & IFF_UP))
600 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 nh->nh_dev = in_dev->dev;
602 dev_hold(nh->nh_dev);
603 nh->nh_scope = RT_SCOPE_HOST;
Eric Dumazet8723e1b2010-10-19 00:39:26 +0000604 err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 }
Eric Dumazet8723e1b2010-10-19 00:39:26 +0000606out:
607 rcu_read_unlock();
608 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609}
610
Al Viro81f7bf62006-09-27 18:40:00 -0700611static inline unsigned int fib_laddr_hashfn(__be32 val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612{
David S. Miller123b9732011-02-01 15:34:21 -0800613 unsigned int mask = (fib_info_hash_size - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000615 return ((__force u32)val ^
616 ((__force u32)val >> 7) ^
617 ((__force u32)val >> 14)) & mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618}
619
David S. Miller123b9732011-02-01 15:34:21 -0800620static struct hlist_head *fib_info_hash_alloc(int bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621{
622 if (bytes <= PAGE_SIZE)
Joonwoo Park88f83492007-11-26 23:29:32 +0800623 return kzalloc(bytes, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 else
625 return (struct hlist_head *)
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000626 __get_free_pages(GFP_KERNEL | __GFP_ZERO,
627 get_order(bytes));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628}
629
David S. Miller123b9732011-02-01 15:34:21 -0800630static void fib_info_hash_free(struct hlist_head *hash, int bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631{
632 if (!hash)
633 return;
634
635 if (bytes <= PAGE_SIZE)
636 kfree(hash);
637 else
638 free_pages((unsigned long) hash, get_order(bytes));
639}
640
David S. Miller123b9732011-02-01 15:34:21 -0800641static void fib_info_hash_move(struct hlist_head *new_info_hash,
642 struct hlist_head *new_laddrhash,
643 unsigned int new_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644{
David S. Millerb7656e72005-08-05 04:12:48 -0700645 struct hlist_head *old_info_hash, *old_laddrhash;
David S. Miller123b9732011-02-01 15:34:21 -0800646 unsigned int old_size = fib_info_hash_size;
David S. Millerb7656e72005-08-05 04:12:48 -0700647 unsigned int i, bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700649 spin_lock_bh(&fib_info_lock);
David S. Millerb7656e72005-08-05 04:12:48 -0700650 old_info_hash = fib_info_hash;
651 old_laddrhash = fib_info_laddrhash;
David S. Miller123b9732011-02-01 15:34:21 -0800652 fib_info_hash_size = new_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
654 for (i = 0; i < old_size; i++) {
655 struct hlist_head *head = &fib_info_hash[i];
656 struct hlist_node *node, *n;
657 struct fib_info *fi;
658
659 hlist_for_each_entry_safe(fi, node, n, head, fib_hash) {
660 struct hlist_head *dest;
661 unsigned int new_hash;
662
663 hlist_del(&fi->fib_hash);
664
665 new_hash = fib_info_hashfn(fi);
666 dest = &new_info_hash[new_hash];
667 hlist_add_head(&fi->fib_hash, dest);
668 }
669 }
670 fib_info_hash = new_info_hash;
671
672 for (i = 0; i < old_size; i++) {
673 struct hlist_head *lhead = &fib_info_laddrhash[i];
674 struct hlist_node *node, *n;
675 struct fib_info *fi;
676
677 hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) {
678 struct hlist_head *ldest;
679 unsigned int new_hash;
680
681 hlist_del(&fi->fib_lhash);
682
683 new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
684 ldest = &new_laddrhash[new_hash];
685 hlist_add_head(&fi->fib_lhash, ldest);
686 }
687 }
688 fib_info_laddrhash = new_laddrhash;
689
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700690 spin_unlock_bh(&fib_info_lock);
David S. Millerb7656e72005-08-05 04:12:48 -0700691
692 bytes = old_size * sizeof(struct hlist_head *);
David S. Miller123b9732011-02-01 15:34:21 -0800693 fib_info_hash_free(old_info_hash, bytes);
694 fib_info_hash_free(old_laddrhash, bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695}
696
David S. Miller436c3b62011-03-24 17:42:21 -0700697__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
698{
699 nh->nh_saddr = inet_select_addr(nh->nh_dev,
700 nh->nh_gw,
David S. Miller37e826c2011-03-24 18:06:47 -0700701 nh->nh_parent->fib_scope);
David S. Miller436c3b62011-03-24 17:42:21 -0700702 nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid);
703
704 return nh->nh_saddr;
705}
706
Thomas Graf4e902c52006-08-17 18:14:52 -0700707struct fib_info *fib_create_info(struct fib_config *cfg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708{
709 int err;
710 struct fib_info *fi = NULL;
711 struct fib_info *ofi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 int nhs = 1;
Denis V. Lunev7462bd742008-01-31 18:49:32 -0800713 struct net *net = cfg->fc_nlinfo.nl_net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714
David S. Miller4c8237c2011-03-07 14:27:38 -0800715 if (cfg->fc_type > RTN_MAX)
716 goto err_inval;
717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 /* Fast check to catch the most weird cases */
Thomas Graf4e902c52006-08-17 18:14:52 -0700719 if (fib_props[cfg->fc_type].scope > cfg->fc_scope)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 goto err_inval;
721
722#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700723 if (cfg->fc_mp) {
724 nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 if (nhs == 0)
726 goto err_inval;
727 }
728#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
730 err = -ENOBUFS;
David S. Miller123b9732011-02-01 15:34:21 -0800731 if (fib_info_cnt >= fib_info_hash_size) {
732 unsigned int new_size = fib_info_hash_size << 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 struct hlist_head *new_info_hash;
734 struct hlist_head *new_laddrhash;
735 unsigned int bytes;
736
737 if (!new_size)
738 new_size = 1;
739 bytes = new_size * sizeof(struct hlist_head *);
David S. Miller123b9732011-02-01 15:34:21 -0800740 new_info_hash = fib_info_hash_alloc(bytes);
741 new_laddrhash = fib_info_hash_alloc(bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 if (!new_info_hash || !new_laddrhash) {
David S. Miller123b9732011-02-01 15:34:21 -0800743 fib_info_hash_free(new_info_hash, bytes);
744 fib_info_hash_free(new_laddrhash, bytes);
Joonwoo Park88f83492007-11-26 23:29:32 +0800745 } else
David S. Miller123b9732011-02-01 15:34:21 -0800746 fib_info_hash_move(new_info_hash, new_laddrhash, new_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
David S. Miller123b9732011-02-01 15:34:21 -0800748 if (!fib_info_hash_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 goto failure;
750 }
751
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700752 fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 if (fi == NULL)
754 goto failure;
David S. Miller725d1e12011-01-28 14:05:05 -0800755 if (cfg->fc_mx) {
756 fi->fib_metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
757 if (!fi->fib_metrics)
758 goto failure;
759 } else
760 fi->fib_metrics = (u32 *) dst_default_metrics;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 fib_info_cnt++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762
Denis V. Lunev57d7a602008-04-16 02:00:50 -0700763 fi->fib_net = hold_net(net);
Thomas Graf4e902c52006-08-17 18:14:52 -0700764 fi->fib_protocol = cfg->fc_protocol;
David S. Miller37e826c2011-03-24 18:06:47 -0700765 fi->fib_scope = cfg->fc_scope;
Thomas Graf4e902c52006-08-17 18:14:52 -0700766 fi->fib_flags = cfg->fc_flags;
767 fi->fib_priority = cfg->fc_priority;
768 fi->fib_prefsrc = cfg->fc_prefsrc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769
770 fi->fib_nhs = nhs;
771 change_nexthops(fi) {
David S. Miller71fceff2010-01-15 01:16:40 -0800772 nexthop_nh->nh_parent = fi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 } endfor_nexthops(fi)
774
Thomas Graf4e902c52006-08-17 18:14:52 -0700775 if (cfg->fc_mx) {
776 struct nlattr *nla;
777 int remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
Thomas Graf4e902c52006-08-17 18:14:52 -0700779 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
Thomas Graf8f4c1f92007-09-12 14:44:36 +0200780 int type = nla_type(nla);
Thomas Graf4e902c52006-08-17 18:14:52 -0700781
782 if (type) {
783 if (type > RTAX_MAX)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 goto err_inval;
Thomas Graf4e902c52006-08-17 18:14:52 -0700785 fi->fib_metrics[type - 1] = nla_get_u32(nla);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 }
788 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789
Thomas Graf4e902c52006-08-17 18:14:52 -0700790 if (cfg->fc_mp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791#ifdef CONFIG_IP_ROUTE_MULTIPATH
Thomas Graf4e902c52006-08-17 18:14:52 -0700792 err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg);
793 if (err != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 goto failure;
Thomas Graf4e902c52006-08-17 18:14:52 -0700795 if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 goto err_inval;
Thomas Graf4e902c52006-08-17 18:14:52 -0700797 if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 goto err_inval;
Patrick McHardyc7066f72011-01-14 13:36:42 +0100799#ifdef CONFIG_IP_ROUTE_CLASSID
Thomas Graf4e902c52006-08-17 18:14:52 -0700800 if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 goto err_inval;
802#endif
803#else
804 goto err_inval;
805#endif
806 } else {
807 struct fib_nh *nh = fi->fib_nh;
Thomas Graf4e902c52006-08-17 18:14:52 -0700808
809 nh->nh_oif = cfg->fc_oif;
810 nh->nh_gw = cfg->fc_gw;
811 nh->nh_flags = cfg->fc_flags;
Patrick McHardyc7066f72011-01-14 13:36:42 +0100812#ifdef CONFIG_IP_ROUTE_CLASSID
Thomas Graf4e902c52006-08-17 18:14:52 -0700813 nh->nh_tclassid = cfg->fc_flow;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815#ifdef CONFIG_IP_ROUTE_MULTIPATH
816 nh->nh_weight = 1;
817#endif
818 }
819
Thomas Graf4e902c52006-08-17 18:14:52 -0700820 if (fib_props[cfg->fc_type].error) {
821 if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 goto err_inval;
823 goto link_it;
David S. Miller4c8237c2011-03-07 14:27:38 -0800824 } else {
825 switch (cfg->fc_type) {
826 case RTN_UNICAST:
827 case RTN_LOCAL:
828 case RTN_BROADCAST:
829 case RTN_ANYCAST:
830 case RTN_MULTICAST:
831 break;
832 default:
833 goto err_inval;
834 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 }
836
Thomas Graf4e902c52006-08-17 18:14:52 -0700837 if (cfg->fc_scope > RT_SCOPE_HOST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 goto err_inval;
839
Thomas Graf4e902c52006-08-17 18:14:52 -0700840 if (cfg->fc_scope == RT_SCOPE_HOST) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 struct fib_nh *nh = fi->fib_nh;
842
843 /* Local address is added. */
844 if (nhs != 1 || nh->nh_gw)
845 goto err_inval;
846 nh->nh_scope = RT_SCOPE_NOWHERE;
Denis V. Lunev7462bd742008-01-31 18:49:32 -0800847 nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 err = -ENODEV;
849 if (nh->nh_dev == NULL)
850 goto failure;
851 } else {
852 change_nexthops(fi) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000853 err = fib_check_nh(cfg, fi, nexthop_nh);
854 if (err != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 goto failure;
856 } endfor_nexthops(fi)
857 }
858
859 if (fi->fib_prefsrc) {
Thomas Graf4e902c52006-08-17 18:14:52 -0700860 if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
861 fi->fib_prefsrc != cfg->fc_dst)
Denis V. Lunev7462bd742008-01-31 18:49:32 -0800862 if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 goto err_inval;
864 }
865
David S. Miller1fc050a2011-03-07 20:54:48 -0800866 change_nexthops(fi) {
David S. Miller436c3b62011-03-24 17:42:21 -0700867 fib_info_update_nh_saddr(net, nexthop_nh);
David S. Miller1fc050a2011-03-07 20:54:48 -0800868 } endfor_nexthops(fi)
869
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870link_it:
Eric Dumazet6a31d2a2010-10-04 20:00:18 +0000871 ofi = fib_find_info(fi);
872 if (ofi) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 fi->fib_dead = 1;
874 free_fib_info(fi);
875 ofi->fib_treeref++;
876 return ofi;
877 }
878
879 fi->fib_treeref++;
880 atomic_inc(&fi->fib_clntref);
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700881 spin_lock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 hlist_add_head(&fi->fib_hash,
883 &fib_info_hash[fib_info_hashfn(fi)]);
884 if (fi->fib_prefsrc) {
885 struct hlist_head *head;
886
887 head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
888 hlist_add_head(&fi->fib_lhash, head);
889 }
890 change_nexthops(fi) {
891 struct hlist_head *head;
892 unsigned int hash;
893
David S. Miller71fceff2010-01-15 01:16:40 -0800894 if (!nexthop_nh->nh_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 continue;
David S. Miller71fceff2010-01-15 01:16:40 -0800896 hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 head = &fib_info_devhash[hash];
David S. Miller71fceff2010-01-15 01:16:40 -0800898 hlist_add_head(&nexthop_nh->nh_hash, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 } endfor_nexthops(fi)
Stephen Hemminger832b4c52006-08-29 16:48:09 -0700900 spin_unlock_bh(&fib_info_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 return fi;
902
903err_inval:
904 err = -EINVAL;
905
906failure:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900907 if (fi) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 fi->fib_dead = 1;
909 free_fib_info(fi);
910 }
Thomas Graf4e902c52006-08-17 18:14:52 -0700911
912 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913}
914
Thomas Grafbe403ea2006-08-17 18:15:17 -0700915int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
David S. Miller37e826c2011-03-24 18:06:47 -0700916 u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos,
Thomas Grafbe403ea2006-08-17 18:15:17 -0700917 struct fib_info *fi, unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918{
Thomas Grafbe403ea2006-08-17 18:15:17 -0700919 struct nlmsghdr *nlh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 struct rtmsg *rtm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921
Thomas Grafbe403ea2006-08-17 18:15:17 -0700922 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
923 if (nlh == NULL)
Patrick McHardy26932562007-01-31 23:16:40 -0800924 return -EMSGSIZE;
Thomas Grafbe403ea2006-08-17 18:15:17 -0700925
926 rtm = nlmsg_data(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 rtm->rtm_family = AF_INET;
928 rtm->rtm_dst_len = dst_len;
929 rtm->rtm_src_len = 0;
930 rtm->rtm_tos = tos;
Krzysztof Piotr Oledzki709772e2008-06-10 15:44:49 -0700931 if (tb_id < 256)
932 rtm->rtm_table = tb_id;
933 else
934 rtm->rtm_table = RT_TABLE_COMPAT;
Thomas Grafbe403ea2006-08-17 18:15:17 -0700935 NLA_PUT_U32(skb, RTA_TABLE, tb_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 rtm->rtm_type = type;
937 rtm->rtm_flags = fi->fib_flags;
David S. Miller37e826c2011-03-24 18:06:47 -0700938 rtm->rtm_scope = fi->fib_scope;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 rtm->rtm_protocol = fi->fib_protocol;
Thomas Grafbe403ea2006-08-17 18:15:17 -0700940
941 if (rtm->rtm_dst_len)
Al Viro17fb2c62006-09-26 22:15:25 -0700942 NLA_PUT_BE32(skb, RTA_DST, dst);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700943
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 if (fi->fib_priority)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700945 NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority);
946
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700948 goto nla_put_failure;
949
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 if (fi->fib_prefsrc)
Al Viro17fb2c62006-09-26 22:15:25 -0700951 NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 if (fi->fib_nhs == 1) {
954 if (fi->fib_nh->nh_gw)
Al Viro17fb2c62006-09-26 22:15:25 -0700955 NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700956
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 if (fi->fib_nh->nh_oif)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700958 NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif);
Patrick McHardyc7066f72011-01-14 13:36:42 +0100959#ifdef CONFIG_IP_ROUTE_CLASSID
Patrick McHardy8265abc2006-07-21 15:09:55 -0700960 if (fi->fib_nh[0].nh_tclassid)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700961 NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid);
Patrick McHardy8265abc2006-07-21 15:09:55 -0700962#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 }
964#ifdef CONFIG_IP_ROUTE_MULTIPATH
965 if (fi->fib_nhs > 1) {
Thomas Grafbe403ea2006-08-17 18:15:17 -0700966 struct rtnexthop *rtnh;
967 struct nlattr *mp;
968
969 mp = nla_nest_start(skb, RTA_MULTIPATH);
970 if (mp == NULL)
971 goto nla_put_failure;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972
973 for_nexthops(fi) {
Thomas Grafbe403ea2006-08-17 18:15:17 -0700974 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
975 if (rtnh == NULL)
976 goto nla_put_failure;
977
978 rtnh->rtnh_flags = nh->nh_flags & 0xFF;
979 rtnh->rtnh_hops = nh->nh_weight - 1;
980 rtnh->rtnh_ifindex = nh->nh_oif;
981
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 if (nh->nh_gw)
Al Viro17fb2c62006-09-26 22:15:25 -0700983 NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw);
Patrick McHardyc7066f72011-01-14 13:36:42 +0100984#ifdef CONFIG_IP_ROUTE_CLASSID
Patrick McHardy8265abc2006-07-21 15:09:55 -0700985 if (nh->nh_tclassid)
Thomas Grafbe403ea2006-08-17 18:15:17 -0700986 NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid);
Patrick McHardy8265abc2006-07-21 15:09:55 -0700987#endif
Thomas Grafbe403ea2006-08-17 18:15:17 -0700988 /* length of rtnetlink header + attributes */
989 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 } endfor_nexthops(fi);
Thomas Grafbe403ea2006-08-17 18:15:17 -0700991
992 nla_nest_end(skb, mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 }
994#endif
Thomas Grafbe403ea2006-08-17 18:15:17 -0700995 return nlmsg_end(skb, nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996
Thomas Grafbe403ea2006-08-17 18:15:17 -0700997nla_put_failure:
Patrick McHardy26932562007-01-31 23:16:40 -0800998 nlmsg_cancel(skb, nlh);
999 return -EMSGSIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000}
1001
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002/*
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001003 * Update FIB if:
1004 * - local address disappeared -> we must delete all the entries
1005 * referring to it.
1006 * - device went down -> we must shutdown all nexthops going via it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 */
Denis V. Lunev4814bdb2008-01-31 18:50:07 -08001008int fib_sync_down_addr(struct net *net, __be32 local)
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001009{
1010 int ret = 0;
1011 unsigned int hash = fib_laddr_hashfn(local);
1012 struct hlist_head *head = &fib_info_laddrhash[hash];
1013 struct hlist_node *node;
1014 struct fib_info *fi;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001016 if (fib_info_laddrhash == NULL || local == 0)
1017 return 0;
1018
1019 hlist_for_each_entry(fi, node, head, fib_lhash) {
Octavian Purdila09ad9bc2009-11-25 15:14:13 -08001020 if (!net_eq(fi->fib_net, net))
Denis V. Lunev4814bdb2008-01-31 18:50:07 -08001021 continue;
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001022 if (fi->fib_prefsrc == local) {
1023 fi->fib_flags |= RTNH_F_DEAD;
1024 ret++;
1025 }
1026 }
1027 return ret;
1028}
1029
1030int fib_sync_down_dev(struct net_device *dev, int force)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031{
1032 int ret = 0;
1033 int scope = RT_SCOPE_NOWHERE;
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001034 struct fib_info *prev_fi = NULL;
1035 unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1036 struct hlist_head *head = &fib_info_devhash[hash];
1037 struct hlist_node *node;
1038 struct fib_nh *nh;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001039
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 if (force)
1041 scope = -1;
1042
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001043 hlist_for_each_entry(nh, node, head, nh_hash) {
1044 struct fib_info *fi = nh->nh_parent;
1045 int dead;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001047 BUG_ON(!fi->fib_nhs);
1048 if (nh->nh_dev != dev || fi == prev_fi)
1049 continue;
1050 prev_fi = fi;
1051 dead = 0;
1052 change_nexthops(fi) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001053 if (nexthop_nh->nh_flags & RTNH_F_DEAD)
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001054 dead++;
David S. Miller71fceff2010-01-15 01:16:40 -08001055 else if (nexthop_nh->nh_dev == dev &&
1056 nexthop_nh->nh_scope != scope) {
1057 nexthop_nh->nh_flags |= RTNH_F_DEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058#ifdef CONFIG_IP_ROUTE_MULTIPATH
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001059 spin_lock_bh(&fib_multipath_lock);
David S. Miller71fceff2010-01-15 01:16:40 -08001060 fi->fib_power -= nexthop_nh->nh_power;
1061 nexthop_nh->nh_power = 0;
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001062 spin_unlock_bh(&fib_multipath_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063#endif
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001064 dead++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065 }
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001066#ifdef CONFIG_IP_ROUTE_MULTIPATH
David S. Miller71fceff2010-01-15 01:16:40 -08001067 if (force > 1 && nexthop_nh->nh_dev == dev) {
Denis V. Lunev85326fa2008-01-31 18:48:47 -08001068 dead = fi->fib_nhs;
1069 break;
1070 }
1071#endif
1072 } endfor_nexthops(fi)
1073 if (dead == fi->fib_nhs) {
1074 fi->fib_flags |= RTNH_F_DEAD;
1075 ret++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 }
1077 }
1078
1079 return ret;
1080}
1081
David S. Miller0c838ff2011-01-31 16:16:50 -08001082/* Must be invoked inside of an RCU protected region. */
1083void fib_select_default(struct fib_result *res)
1084{
1085 struct fib_info *fi = NULL, *last_resort = NULL;
1086 struct list_head *fa_head = res->fa_head;
1087 struct fib_table *tb = res->table;
1088 int order = -1, last_idx = -1;
1089 struct fib_alias *fa;
1090
1091 list_for_each_entry_rcu(fa, fa_head, fa_list) {
1092 struct fib_info *next_fi = fa->fa_info;
1093
David S. Miller37e826c2011-03-24 18:06:47 -07001094 if (next_fi->fib_scope != res->scope ||
David S. Miller0c838ff2011-01-31 16:16:50 -08001095 fa->fa_type != RTN_UNICAST)
1096 continue;
1097
1098 if (next_fi->fib_priority > res->fi->fib_priority)
1099 break;
1100 if (!next_fi->fib_nh[0].nh_gw ||
1101 next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
1102 continue;
1103
1104 fib_alias_accessed(fa);
1105
1106 if (fi == NULL) {
1107 if (next_fi != res->fi)
1108 break;
1109 } else if (!fib_detect_death(fi, order, &last_resort,
1110 &last_idx, tb->tb_default)) {
1111 fib_result_assign(res, fi);
1112 tb->tb_default = order;
1113 goto out;
1114 }
1115 fi = next_fi;
1116 order++;
1117 }
1118
1119 if (order <= 0 || fi == NULL) {
1120 tb->tb_default = -1;
1121 goto out;
1122 }
1123
1124 if (!fib_detect_death(fi, order, &last_resort, &last_idx,
1125 tb->tb_default)) {
1126 fib_result_assign(res, fi);
1127 tb->tb_default = order;
1128 goto out;
1129 }
1130
1131 if (last_idx >= 0)
1132 fib_result_assign(res, last_resort);
1133 tb->tb_default = last_idx;
1134out:
Eric Dumazet31d40932011-02-14 11:23:04 -08001135 return;
David S. Miller0c838ff2011-01-31 16:16:50 -08001136}
1137
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138#ifdef CONFIG_IP_ROUTE_MULTIPATH
1139
1140/*
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001141 * Dead device goes up. We wake up dead nexthops.
1142 * It takes sense only on multipath routes.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144int fib_sync_up(struct net_device *dev)
1145{
1146 struct fib_info *prev_fi;
1147 unsigned int hash;
1148 struct hlist_head *head;
1149 struct hlist_node *node;
1150 struct fib_nh *nh;
1151 int ret;
1152
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001153 if (!(dev->flags & IFF_UP))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 return 0;
1155
1156 prev_fi = NULL;
1157 hash = fib_devindex_hashfn(dev->ifindex);
1158 head = &fib_info_devhash[hash];
1159 ret = 0;
1160
1161 hlist_for_each_entry(nh, node, head, nh_hash) {
1162 struct fib_info *fi = nh->nh_parent;
1163 int alive;
1164
1165 BUG_ON(!fi->fib_nhs);
1166 if (nh->nh_dev != dev || fi == prev_fi)
1167 continue;
1168
1169 prev_fi = fi;
1170 alive = 0;
1171 change_nexthops(fi) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001172 if (!(nexthop_nh->nh_flags & RTNH_F_DEAD)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 alive++;
1174 continue;
1175 }
David S. Miller71fceff2010-01-15 01:16:40 -08001176 if (nexthop_nh->nh_dev == NULL ||
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001177 !(nexthop_nh->nh_dev->flags & IFF_UP))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 continue;
David S. Miller71fceff2010-01-15 01:16:40 -08001179 if (nexthop_nh->nh_dev != dev ||
1180 !__in_dev_get_rtnl(dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181 continue;
1182 alive++;
1183 spin_lock_bh(&fib_multipath_lock);
David S. Miller71fceff2010-01-15 01:16:40 -08001184 nexthop_nh->nh_power = 0;
1185 nexthop_nh->nh_flags &= ~RTNH_F_DEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 spin_unlock_bh(&fib_multipath_lock);
1187 } endfor_nexthops(fi)
1188
1189 if (alive > 0) {
1190 fi->fib_flags &= ~RTNH_F_DEAD;
1191 ret++;
1192 }
1193 }
1194
1195 return ret;
1196}
1197
1198/*
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001199 * The algorithm is suboptimal, but it provides really
1200 * fair weighted route distribution.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201 */
David S. Miller1b7fe5932011-03-10 17:01:16 -08001202void fib_select_multipath(struct fib_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203{
1204 struct fib_info *fi = res->fi;
1205 int w;
1206
1207 spin_lock_bh(&fib_multipath_lock);
1208 if (fi->fib_power <= 0) {
1209 int power = 0;
1210 change_nexthops(fi) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001211 if (!(nexthop_nh->nh_flags & RTNH_F_DEAD)) {
David S. Miller71fceff2010-01-15 01:16:40 -08001212 power += nexthop_nh->nh_weight;
1213 nexthop_nh->nh_power = nexthop_nh->nh_weight;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 }
1215 } endfor_nexthops(fi);
1216 fi->fib_power = power;
1217 if (power <= 0) {
1218 spin_unlock_bh(&fib_multipath_lock);
1219 /* Race condition: route has just become dead. */
1220 res->nh_sel = 0;
1221 return;
1222 }
1223 }
1224
1225
1226 /* w should be random number [0..fi->fib_power-1],
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001227 * it is pretty bad approximation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 */
1229
1230 w = jiffies % fi->fib_power;
1231
1232 change_nexthops(fi) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001233 if (!(nexthop_nh->nh_flags & RTNH_F_DEAD) &&
David S. Miller71fceff2010-01-15 01:16:40 -08001234 nexthop_nh->nh_power) {
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00001235 w -= nexthop_nh->nh_power;
1236 if (w <= 0) {
David S. Miller71fceff2010-01-15 01:16:40 -08001237 nexthop_nh->nh_power--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 fi->fib_power--;
1239 res->nh_sel = nhsel;
1240 spin_unlock_bh(&fib_multipath_lock);
1241 return;
1242 }
1243 }
1244 } endfor_nexthops(fi);
1245
1246 /* Race condition: route has just become dead. */
1247 res->nh_sel = 0;
1248 spin_unlock_bh(&fib_multipath_lock);
1249}
1250#endif