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[DUMMY]: Avoid an oops when dummy_init_one() failed
[net-next-2.6.git] / net / ipv4 / fib_semantics.c
CommitLineData
1da177e4
LT		 1/*
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 *
8 * Version: $Id: fib_semantics.c,v 1.19 2002/01/12 07:54:56 davem Exp $
9 *
10 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
1da177e4
LT		 18#include <asm/uaccess.h>
19#include <asm/system.h>
20#include <linux/bitops.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/jiffies.h>
24#include <linux/mm.h>
25#include <linux/string.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/errno.h>
29#include <linux/in.h>
30#include <linux/inet.h>
14c85021 31#include <linux/inetdevice.h>
1da177e4
LT		 32#include <linux/netdevice.h>
33#include <linux/if_arp.h>
34#include <linux/proc_fs.h>
35#include <linux/skbuff.h>
36#include <linux/netlink.h>
37#include <linux/init.h>
38
14c85021 39#include <net/arp.h>
1da177e4
LT		 40#include <net/ip.h>
41#include <net/protocol.h>
42#include <net/route.h>
43#include <net/tcp.h>
44#include <net/sock.h>
45#include <net/ip_fib.h>
46#include <net/ip_mp_alg.h>
47
48#include "fib_lookup.h"
49
50#define FSprintk(a...)
51
52static DEFINE_RWLOCK(fib_info_lock);
53static struct hlist_head *fib_info_hash;
54static struct hlist_head *fib_info_laddrhash;
55static unsigned int fib_hash_size;
56static unsigned int fib_info_cnt;
57
58#define DEVINDEX_HASHBITS 8
59#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
60static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
61
62#ifdef CONFIG_IP_ROUTE_MULTIPATH
63
64static DEFINE_SPINLOCK(fib_multipath_lock);
65
66#define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \
67for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
68
69#define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \
70for (nhsel=0, nh = (struct fib_nh*)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
71
72#else /* CONFIG_IP_ROUTE_MULTIPATH */
73
74/* Hope, that gcc will optimize it to get rid of dummy loop */
75
76#define for_nexthops(fi) { int nhsel=0; const struct fib_nh * nh = (fi)->fib_nh; \
77for (nhsel=0; nhsel < 1; nhsel++)
78
79#define change_nexthops(fi) { int nhsel=0; struct fib_nh * nh = (struct fib_nh*)((fi)->fib_nh); \
80for (nhsel=0; nhsel < 1; nhsel++)
81
82#endif /* CONFIG_IP_ROUTE_MULTIPATH */
83
84#define endfor_nexthops(fi) }
85
86
9b5b5cff 87static const struct
1da177e4
LT		 88{
89 int error;
90 u8 scope;
91} fib_props[RTA_MAX + 1] = {
92 {
93 .error = 0,
94 .scope = RT_SCOPE_NOWHERE,
95 }, /* RTN_UNSPEC */
96 {
97 .error = 0,
98 .scope = RT_SCOPE_UNIVERSE,
99 }, /* RTN_UNICAST */
100 {
101 .error = 0,
102 .scope = RT_SCOPE_HOST,
103 }, /* RTN_LOCAL */
104 {
105 .error = 0,
106 .scope = RT_SCOPE_LINK,
107 }, /* RTN_BROADCAST */
108 {
109 .error = 0,
110 .scope = RT_SCOPE_LINK,
111 }, /* RTN_ANYCAST */
112 {
113 .error = 0,
114 .scope = RT_SCOPE_UNIVERSE,
115 }, /* RTN_MULTICAST */
116 {
117 .error = -EINVAL,
118 .scope = RT_SCOPE_UNIVERSE,
119 }, /* RTN_BLACKHOLE */
120 {
121 .error = -EHOSTUNREACH,
122 .scope = RT_SCOPE_UNIVERSE,
123 }, /* RTN_UNREACHABLE */
124 {
125 .error = -EACCES,
126 .scope = RT_SCOPE_UNIVERSE,
127 }, /* RTN_PROHIBIT */
128 {
129 .error = -EAGAIN,
130 .scope = RT_SCOPE_UNIVERSE,
131 }, /* RTN_THROW */
132 {
133 .error = -EINVAL,
134 .scope = RT_SCOPE_NOWHERE,
135 }, /* RTN_NAT */
136 {
137 .error = -EINVAL,
138 .scope = RT_SCOPE_NOWHERE,
139 }, /* RTN_XRESOLVE */
140};
141
142
143/* Release a nexthop info record */
144
145void free_fib_info(struct fib_info *fi)
146{
147 if (fi->fib_dead == 0) {
148 printk("Freeing alive fib_info %p\n", fi);
149 return;
150 }
151 change_nexthops(fi) {
152 if (nh->nh_dev)
153 dev_put(nh->nh_dev);
154 nh->nh_dev = NULL;
155 } endfor_nexthops(fi);
156 fib_info_cnt--;
157 kfree(fi);
158}
159
160void fib_release_info(struct fib_info *fi)
161{
162 write_lock(&fib_info_lock);
163 if (fi && --fi->fib_treeref == 0) {
164 hlist_del(&fi->fib_hash);
165 if (fi->fib_prefsrc)
166 hlist_del(&fi->fib_lhash);
167 change_nexthops(fi) {
168 if (!nh->nh_dev)
169 continue;
170 hlist_del(&nh->nh_hash);
171 } endfor_nexthops(fi)
172 fi->fib_dead = 1;
173 fib_info_put(fi);
174 }
175 write_unlock(&fib_info_lock);
176}
177
178static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
179{
180 const struct fib_nh *onh = ofi->fib_nh;
181
182 for_nexthops(fi) {
183 if (nh->nh_oif != onh->nh_oif ||
184 nh->nh_gw != onh->nh_gw ||
185 nh->nh_scope != onh->nh_scope ||
186#ifdef CONFIG_IP_ROUTE_MULTIPATH
187 nh->nh_weight != onh->nh_weight ||
188#endif
189#ifdef CONFIG_NET_CLS_ROUTE
190 nh->nh_tclassid != onh->nh_tclassid ||
191#endif
192 ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
193 return -1;
194 onh++;
195 } endfor_nexthops(fi);
196 return 0;
197}
198
199static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
200{
201 unsigned int mask = (fib_hash_size - 1);
202 unsigned int val = fi->fib_nhs;
203
204 val ^= fi->fib_protocol;
205 val ^= fi->fib_prefsrc;
206 val ^= fi->fib_priority;
207
208 return (val ^ (val >> 7) ^ (val >> 12)) & mask;
209}
210
211static struct fib_info *fib_find_info(const struct fib_info *nfi)
212{
213 struct hlist_head *head;
214 struct hlist_node *node;
215 struct fib_info *fi;
216 unsigned int hash;
217
218 hash = fib_info_hashfn(nfi);
219 head = &fib_info_hash[hash];
220
221 hlist_for_each_entry(fi, node, head, fib_hash) {
222 if (fi->fib_nhs != nfi->fib_nhs)
223 continue;
224 if (nfi->fib_protocol == fi->fib_protocol &&
225 nfi->fib_prefsrc == fi->fib_prefsrc &&
226 nfi->fib_priority == fi->fib_priority &&
227 memcmp(nfi->fib_metrics, fi->fib_metrics,
228 sizeof(fi->fib_metrics)) == 0 &&
229 ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
230 (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
231 return fi;
232 }
233
234 return NULL;
235}
236
237static inline unsigned int fib_devindex_hashfn(unsigned int val)
238{
239 unsigned int mask = DEVINDEX_HASHSIZE - 1;
240
241 return (val ^
242 (val >> DEVINDEX_HASHBITS) ^
243 (val >> (DEVINDEX_HASHBITS * 2))) & mask;
244}
245
246/* Check, that the gateway is already configured.
247 Used only by redirect accept routine.
248 */
249
250int ip_fib_check_default(u32 gw, struct net_device *dev)
251{
252 struct hlist_head *head;
253 struct hlist_node *node;
254 struct fib_nh *nh;
255 unsigned int hash;
256
257 read_lock(&fib_info_lock);
258
259 hash = fib_devindex_hashfn(dev->ifindex);
260 head = &fib_info_devhash[hash];
261 hlist_for_each_entry(nh, node, head, nh_hash) {
262 if (nh->nh_dev == dev &&
263 nh->nh_gw == gw &&
264 !(nh->nh_flags&RTNH_F_DEAD)) {
265 read_unlock(&fib_info_lock);
266 return 0;
267 }
268 }
269
270 read_unlock(&fib_info_lock);
271
272 return -1;
273}
274
275void rtmsg_fib(int event, u32 key, struct fib_alias *fa,
276 int z, int tb_id,
277 struct nlmsghdr *n, struct netlink_skb_parms *req)
278{
279 struct sk_buff *skb;
9ed19f33 280 u32 pid = req ? req->pid : n->nlmsg_pid;
1da177e4
LT		 281 int size = NLMSG_SPACE(sizeof(struct rtmsg)+256);
282
283 skb = alloc_skb(size, GFP_KERNEL);
284 if (!skb)
285 return;
286
287 if (fib_dump_info(skb, pid, n->nlmsg_seq, event, tb_id,
288 fa->fa_type, fa->fa_scope, &key, z,
289 fa->fa_tos,
b6544c0b 290 fa->fa_info, 0) < 0) {
1da177e4
LT		 291 kfree_skb(skb);
292 return;
293 }
ac6d439d 294 NETLINK_CB(skb).dst_group = RTNLGRP_IPV4_ROUTE;
1da177e4
LT		 295 if (n->nlmsg_flags&NLM_F_ECHO)
296 atomic_inc(&skb->users);
ac6d439d 297 netlink_broadcast(rtnl, skb, pid, RTNLGRP_IPV4_ROUTE, GFP_KERNEL);
1da177e4
LT		 298 if (n->nlmsg_flags&NLM_F_ECHO)
299 netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
300}
301
302/* Return the first fib alias matching TOS with
303 * priority less than or equal to PRIO.
304 */
305struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
306{
307 if (fah) {
308 struct fib_alias *fa;
309 list_for_each_entry(fa, fah, fa_list) {
310 if (fa->fa_tos > tos)
311 continue;
312 if (fa->fa_info->fib_priority >= prio ||
313 fa->fa_tos < tos)
314 return fa;
315 }
316 }
317 return NULL;
318}
319
320int fib_detect_death(struct fib_info *fi, int order,
321 struct fib_info **last_resort, int *last_idx, int *dflt)
322{
323 struct neighbour *n;
324 int state = NUD_NONE;
325
326 n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev);
327 if (n) {
328 state = n->nud_state;
329 neigh_release(n);
330 }
331 if (state==NUD_REACHABLE)
332 return 0;
333 if ((state&NUD_VALID) && order != *dflt)
334 return 0;
335 if ((state&NUD_VALID) ||
336 (*last_idx<0 && order > *dflt)) {
337 *last_resort = fi;
338 *last_idx = order;
339 }
340 return 1;
341}
342
343#ifdef CONFIG_IP_ROUTE_MULTIPATH
344
345static u32 fib_get_attr32(struct rtattr *attr, int attrlen, int type)
346{
347 while (RTA_OK(attr,attrlen)) {
348 if (attr->rta_type == type)
349 return *(u32*)RTA_DATA(attr);
350 attr = RTA_NEXT(attr, attrlen);
351 }
352 return 0;
353}
354
355static int
356fib_count_nexthops(struct rtattr *rta)
357{
358 int nhs = 0;
359 struct rtnexthop *nhp = RTA_DATA(rta);
360 int nhlen = RTA_PAYLOAD(rta);
361
362 while (nhlen >= (int)sizeof(struct rtnexthop)) {
363 if ((nhlen -= nhp->rtnh_len) < 0)
364 return 0;
365 nhs++;
366 nhp = RTNH_NEXT(nhp);
367 };
368 return nhs;
369}
370
371static int
372fib_get_nhs(struct fib_info *fi, const struct rtattr *rta, const struct rtmsg *r)
373{
374 struct rtnexthop *nhp = RTA_DATA(rta);
375 int nhlen = RTA_PAYLOAD(rta);
376
377 change_nexthops(fi) {
378 int attrlen = nhlen - sizeof(struct rtnexthop);
379 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
380 return -EINVAL;
381 nh->nh_flags = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
382 nh->nh_oif = nhp->rtnh_ifindex;
383 nh->nh_weight = nhp->rtnh_hops + 1;
384 if (attrlen) {
385 nh->nh_gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
386#ifdef CONFIG_NET_CLS_ROUTE
387 nh->nh_tclassid = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_FLOW);
388#endif
389 }
390 nhp = RTNH_NEXT(nhp);
391 } endfor_nexthops(fi);
392 return 0;
393}
394
395#endif
396
397int fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct kern_rta *rta,
398 struct fib_info *fi)
399{
400#ifdef CONFIG_IP_ROUTE_MULTIPATH
401 struct rtnexthop *nhp;
402 int nhlen;
403#endif
404
405 if (rta->rta_priority &&
406 *rta->rta_priority != fi->fib_priority)
407 return 1;
408
409 if (rta->rta_oif || rta->rta_gw) {
410 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
411 (!rta->rta_gw || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 4) == 0))
412 return 0;
413 return 1;
414 }
415
416#ifdef CONFIG_IP_ROUTE_MULTIPATH
417 if (rta->rta_mp == NULL)
418 return 0;
419 nhp = RTA_DATA(rta->rta_mp);
420 nhlen = RTA_PAYLOAD(rta->rta_mp);
421
422 for_nexthops(fi) {
423 int attrlen = nhlen - sizeof(struct rtnexthop);
424 u32 gw;
425
426 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
427 return -EINVAL;
428 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
429 return 1;
430 if (attrlen) {
431 gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
432 if (gw && gw != nh->nh_gw)
433 return 1;
434#ifdef CONFIG_NET_CLS_ROUTE
435 gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_FLOW);
436 if (gw && gw != nh->nh_tclassid)
437 return 1;
438#endif
439 }
440 nhp = RTNH_NEXT(nhp);
441 } endfor_nexthops(fi);
442#endif
443 return 0;
444}
445
446
447/*
448 Picture
449 -------
450
451 Semantics of nexthop is very messy by historical reasons.
452 We have to take into account, that:
453 a) gateway can be actually local interface address,
454 so that gatewayed route is direct.
455 b) gateway must be on-link address, possibly
456 described not by an ifaddr, but also by a direct route.
457 c) If both gateway and interface are specified, they should not
458 contradict.
459 d) If we use tunnel routes, gateway could be not on-link.
460
461 Attempt to reconcile all of these (alas, self-contradictory) conditions
462 results in pretty ugly and hairy code with obscure logic.
463
464 I chose to generalized it instead, so that the size
465 of code does not increase practically, but it becomes
466 much more general.
467 Every prefix is assigned a "scope" value: "host" is local address,
468 "link" is direct route,
469 [ ... "site" ... "interior" ... ]
470 and "universe" is true gateway route with global meaning.
471
472 Every prefix refers to a set of "nexthop"s (gw, oif),
473 where gw must have narrower scope. This recursion stops
474 when gw has LOCAL scope or if "nexthop" is declared ONLINK,
475 which means that gw is forced to be on link.
476
477 Code is still hairy, but now it is apparently logically
478 consistent and very flexible. F.e. as by-product it allows
479 to co-exists in peace independent exterior and interior
480 routing processes.
481
482 Normally it looks as following.
483
484 {universe prefix} -> (gw, oif) [scope link]
485 |
486 |-> {link prefix} -> (gw, oif) [scope local]
487 |
488 |-> {local prefix} (terminal node)
489 */
490
491static int fib_check_nh(const struct rtmsg *r, struct fib_info *fi, struct fib_nh *nh)
492{
493 int err;
494
495 if (nh->nh_gw) {
496 struct fib_result res;
497
498#ifdef CONFIG_IP_ROUTE_PERVASIVE
499 if (nh->nh_flags&RTNH_F_PERVASIVE)
500 return 0;
501#endif
502 if (nh->nh_flags&RTNH_F_ONLINK) {
503 struct net_device *dev;
504
505 if (r->rtm_scope >= RT_SCOPE_LINK)
506 return -EINVAL;
507 if (inet_addr_type(nh->nh_gw) != RTN_UNICAST)
508 return -EINVAL;
509 if ((dev = __dev_get_by_index(nh->nh_oif)) == NULL)
510 return -ENODEV;
511 if (!(dev->flags&IFF_UP))
512 return -ENETDOWN;
513 nh->nh_dev = dev;
514 dev_hold(dev);
515 nh->nh_scope = RT_SCOPE_LINK;
516 return 0;
517 }
518 {
519 struct flowi fl = { .nl_u = { .ip4_u =
520 { .daddr = nh->nh_gw,
521 .scope = r->rtm_scope + 1 } },
522 .oif = nh->nh_oif };
523
524 /* It is not necessary, but requires a bit of thinking */
525 if (fl.fl4_scope < RT_SCOPE_LINK)
526 fl.fl4_scope = RT_SCOPE_LINK;
527 if ((err = fib_lookup(&fl, &res)) != 0)
528 return err;
529 }
530 err = -EINVAL;
531 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
532 goto out;
533 nh->nh_scope = res.scope;
534 nh->nh_oif = FIB_RES_OIF(res);
535 if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
536 goto out;
537 dev_hold(nh->nh_dev);
538 err = -ENETDOWN;
539 if (!(nh->nh_dev->flags & IFF_UP))
540 goto out;
541 err = 0;
542out:
543 fib_res_put(&res);
544 return err;
545 } else {
546 struct in_device *in_dev;
547
548 if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
549 return -EINVAL;
550
551 in_dev = inetdev_by_index(nh->nh_oif);
552 if (in_dev == NULL)
553 return -ENODEV;
554 if (!(in_dev->dev->flags&IFF_UP)) {
555 in_dev_put(in_dev);
556 return -ENETDOWN;
557 }
558 nh->nh_dev = in_dev->dev;
559 dev_hold(nh->nh_dev);
560 nh->nh_scope = RT_SCOPE_HOST;
561 in_dev_put(in_dev);
562 }
563 return 0;
564}
565
566static inline unsigned int fib_laddr_hashfn(u32 val)
567{
568 unsigned int mask = (fib_hash_size - 1);
569
570 return (val ^ (val >> 7) ^ (val >> 14)) & mask;
571}
572
573static struct hlist_head *fib_hash_alloc(int bytes)
574{
575 if (bytes <= PAGE_SIZE)
576 return kmalloc(bytes, GFP_KERNEL);
577 else
578 return (struct hlist_head *)
579 __get_free_pages(GFP_KERNEL, get_order(bytes));
580}
581
582static void fib_hash_free(struct hlist_head *hash, int bytes)
583{
584 if (!hash)
585 return;
586
587 if (bytes <= PAGE_SIZE)
588 kfree(hash);
589 else
590 free_pages((unsigned long) hash, get_order(bytes));
591}
592
593static void fib_hash_move(struct hlist_head *new_info_hash,
594 struct hlist_head *new_laddrhash,
595 unsigned int new_size)
596{
b7656e7f 597 struct hlist_head *old_info_hash, *old_laddrhash;
1da177e4 598 unsigned int old_size = fib_hash_size;
b7656e7f 599 unsigned int i, bytes;
1da177e4
LT		 600
601 write_lock(&fib_info_lock);
b7656e7f
DM		 602 old_info_hash = fib_info_hash;
603 old_laddrhash = fib_info_laddrhash;
1da177e4
LT		 604 fib_hash_size = new_size;
605
606 for (i = 0; i < old_size; i++) {
607 struct hlist_head *head = &fib_info_hash[i];
608 struct hlist_node *node, *n;
609 struct fib_info *fi;
610
611 hlist_for_each_entry_safe(fi, node, n, head, fib_hash) {
612 struct hlist_head *dest;
613 unsigned int new_hash;
614
615 hlist_del(&fi->fib_hash);
616
617 new_hash = fib_info_hashfn(fi);
618 dest = &new_info_hash[new_hash];
619 hlist_add_head(&fi->fib_hash, dest);
620 }
621 }
622 fib_info_hash = new_info_hash;
623
624 for (i = 0; i < old_size; i++) {
625 struct hlist_head *lhead = &fib_info_laddrhash[i];
626 struct hlist_node *node, *n;
627 struct fib_info *fi;
628
629 hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) {
630 struct hlist_head *ldest;
631 unsigned int new_hash;
632
633 hlist_del(&fi->fib_lhash);
634
635 new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
636 ldest = &new_laddrhash[new_hash];
637 hlist_add_head(&fi->fib_lhash, ldest);
638 }
639 }
640 fib_info_laddrhash = new_laddrhash;
641
642 write_unlock(&fib_info_lock);
b7656e7f
DM		 643
644 bytes = old_size * sizeof(struct hlist_head *);
645 fib_hash_free(old_info_hash, bytes);
646 fib_hash_free(old_laddrhash, bytes);
1da177e4
LT		 647}
648
649struct fib_info *
650fib_create_info(const struct rtmsg *r, struct kern_rta *rta,
651 const struct nlmsghdr *nlh, int *errp)
652{
653 int err;
654 struct fib_info *fi = NULL;
655 struct fib_info *ofi;
656#ifdef CONFIG_IP_ROUTE_MULTIPATH
657 int nhs = 1;
658#else
659 const int nhs = 1;
660#endif
661#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
662 u32 mp_alg = IP_MP_ALG_NONE;
663#endif
664
665 /* Fast check to catch the most weird cases */
666 if (fib_props[r->rtm_type].scope > r->rtm_scope)
667 goto err_inval;
668
669#ifdef CONFIG_IP_ROUTE_MULTIPATH
670 if (rta->rta_mp) {
671 nhs = fib_count_nexthops(rta->rta_mp);
672 if (nhs == 0)
673 goto err_inval;
674 }
675#endif
676#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
677 if (rta->rta_mp_alg) {
678 mp_alg = *rta->rta_mp_alg;
679
680 if (mp_alg < IP_MP_ALG_NONE ||
681 mp_alg > IP_MP_ALG_MAX)
682 goto err_inval;
683 }
684#endif
685
686 err = -ENOBUFS;
687 if (fib_info_cnt >= fib_hash_size) {
688 unsigned int new_size = fib_hash_size << 1;
689 struct hlist_head *new_info_hash;
690 struct hlist_head *new_laddrhash;
691 unsigned int bytes;
692
693 if (!new_size)
694 new_size = 1;
695 bytes = new_size * sizeof(struct hlist_head *);
696 new_info_hash = fib_hash_alloc(bytes);
697 new_laddrhash = fib_hash_alloc(bytes);
698 if (!new_info_hash || !new_laddrhash) {
699 fib_hash_free(new_info_hash, bytes);
700 fib_hash_free(new_laddrhash, bytes);
701 } else {
702 memset(new_info_hash, 0, bytes);
703 memset(new_laddrhash, 0, bytes);
704
705 fib_hash_move(new_info_hash, new_laddrhash, new_size);
706 }
707
708 if (!fib_hash_size)
709 goto failure;
710 }
711
0da974f4 712 fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
1da177e4
LT		 713 if (fi == NULL)
714 goto failure;
715 fib_info_cnt++;
1da177e4
LT		 716
717 fi->fib_protocol = r->rtm_protocol;
718
719 fi->fib_nhs = nhs;
720 change_nexthops(fi) {
721 nh->nh_parent = fi;
722 } endfor_nexthops(fi)
723
724 fi->fib_flags = r->rtm_flags;
725 if (rta->rta_priority)
726 fi->fib_priority = *rta->rta_priority;
727 if (rta->rta_mx) {
728 int attrlen = RTA_PAYLOAD(rta->rta_mx);
729 struct rtattr *attr = RTA_DATA(rta->rta_mx);
730
731 while (RTA_OK(attr, attrlen)) {
732 unsigned flavor = attr->rta_type;
733 if (flavor) {
734 if (flavor > RTAX_MAX)
735 goto err_inval;
736 fi->fib_metrics[flavor-1] = *(unsigned*)RTA_DATA(attr);
737 }
738 attr = RTA_NEXT(attr, attrlen);
739 }
740 }
741 if (rta->rta_prefsrc)
742 memcpy(&fi->fib_prefsrc, rta->rta_prefsrc, 4);
743
744 if (rta->rta_mp) {
745#ifdef CONFIG_IP_ROUTE_MULTIPATH
746 if ((err = fib_get_nhs(fi, rta->rta_mp, r)) != 0)
747 goto failure;
748 if (rta->rta_oif && fi->fib_nh->nh_oif != *rta->rta_oif)
749 goto err_inval;
750 if (rta->rta_gw && memcmp(&fi->fib_nh->nh_gw, rta->rta_gw, 4))
751 goto err_inval;
752#ifdef CONFIG_NET_CLS_ROUTE
753 if (rta->rta_flow && memcmp(&fi->fib_nh->nh_tclassid, rta->rta_flow, 4))
754 goto err_inval;
755#endif
756#else
757 goto err_inval;
758#endif
759 } else {
760 struct fib_nh *nh = fi->fib_nh;
761 if (rta->rta_oif)
762 nh->nh_oif = *rta->rta_oif;
763 if (rta->rta_gw)
764 memcpy(&nh->nh_gw, rta->rta_gw, 4);
765#ifdef CONFIG_NET_CLS_ROUTE
766 if (rta->rta_flow)
767 memcpy(&nh->nh_tclassid, rta->rta_flow, 4);
768#endif
769 nh->nh_flags = r->rtm_flags;
770#ifdef CONFIG_IP_ROUTE_MULTIPATH
771 nh->nh_weight = 1;
772#endif
773 }
774
775#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
776 fi->fib_mp_alg = mp_alg;
777#endif
778
779 if (fib_props[r->rtm_type].error) {
780 if (rta->rta_gw || rta->rta_oif || rta->rta_mp)
781 goto err_inval;
782 goto link_it;
783 }
784
785 if (r->rtm_scope > RT_SCOPE_HOST)
786 goto err_inval;
787
788 if (r->rtm_scope == RT_SCOPE_HOST) {
789 struct fib_nh *nh = fi->fib_nh;
790
791 /* Local address is added. */
792 if (nhs != 1 || nh->nh_gw)
793 goto err_inval;
794 nh->nh_scope = RT_SCOPE_NOWHERE;
795 nh->nh_dev = dev_get_by_index(fi->fib_nh->nh_oif);
796 err = -ENODEV;
797 if (nh->nh_dev == NULL)
798 goto failure;
799 } else {
800 change_nexthops(fi) {
801 if ((err = fib_check_nh(r, fi, nh)) != 0)
802 goto failure;
803 } endfor_nexthops(fi)
804 }
805
806 if (fi->fib_prefsrc) {
807 if (r->rtm_type != RTN_LOCAL || rta->rta_dst == NULL ||
808 memcmp(&fi->fib_prefsrc, rta->rta_dst, 4))
809 if (inet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
810 goto err_inval;
811 }
812
813link_it:
814 if ((ofi = fib_find_info(fi)) != NULL) {
815 fi->fib_dead = 1;
816 free_fib_info(fi);
817 ofi->fib_treeref++;
818 return ofi;
819 }
820
821 fi->fib_treeref++;
822 atomic_inc(&fi->fib_clntref);
823 write_lock(&fib_info_lock);
824 hlist_add_head(&fi->fib_hash,
825 &fib_info_hash[fib_info_hashfn(fi)]);
826 if (fi->fib_prefsrc) {
827 struct hlist_head *head;
828
829 head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
830 hlist_add_head(&fi->fib_lhash, head);
831 }
832 change_nexthops(fi) {
833 struct hlist_head *head;
834 unsigned int hash;
835
836 if (!nh->nh_dev)
837 continue;
838 hash = fib_devindex_hashfn(nh->nh_dev->ifindex);
839 head = &fib_info_devhash[hash];
840 hlist_add_head(&nh->nh_hash, head);
841 } endfor_nexthops(fi)
842 write_unlock(&fib_info_lock);
843 return fi;
844
845err_inval:
846 err = -EINVAL;
847
848failure:
849 *errp = err;
850 if (fi) {
851 fi->fib_dead = 1;
852 free_fib_info(fi);
853 }
854 return NULL;
855}
856
e5b43760 857/* Note! fib_semantic_match intentionally uses RCU list functions. */
1da177e4
LT		 858int fib_semantic_match(struct list_head *head, const struct flowi *flp,
859 struct fib_result *res, __u32 zone, __u32 mask,
860 int prefixlen)
861{
862 struct fib_alias *fa;
863 int nh_sel = 0;
864
e5b43760 865 list_for_each_entry_rcu(fa, head, fa_list) {
1da177e4
LT		 866 int err;
867
868 if (fa->fa_tos &&
869 fa->fa_tos != flp->fl4_tos)
870 continue;
871
872 if (fa->fa_scope < flp->fl4_scope)
873 continue;
874
875 fa->fa_state |= FA_S_ACCESSED;
876
877 err = fib_props[fa->fa_type].error;
878 if (err == 0) {
879 struct fib_info *fi = fa->fa_info;
880
881 if (fi->fib_flags & RTNH_F_DEAD)
882 continue;
883
884 switch (fa->fa_type) {
885 case RTN_UNICAST:
886 case RTN_LOCAL:
887 case RTN_BROADCAST:
888 case RTN_ANYCAST:
889 case RTN_MULTICAST:
890 for_nexthops(fi) {
891 if (nh->nh_flags&RTNH_F_DEAD)
892 continue;
893 if (!flp->oif || flp->oif == nh->nh_oif)
894 break;
895 }
896#ifdef CONFIG_IP_ROUTE_MULTIPATH
897 if (nhsel < fi->fib_nhs) {
898 nh_sel = nhsel;
899 goto out_fill_res;
900 }
901#else
902 if (nhsel < 1) {
903 goto out_fill_res;
904 }
905#endif
906 endfor_nexthops(fi);
907 continue;
908
909 default:
910 printk(KERN_DEBUG "impossible 102\n");
911 return -EINVAL;
912 };
913 }
914 return err;
915 }
916 return 1;
917
918out_fill_res:
919 res->prefixlen = prefixlen;
920 res->nh_sel = nh_sel;
921 res->type = fa->fa_type;
922 res->scope = fa->fa_scope;
923 res->fi = fa->fa_info;
924#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
925 res->netmask = mask;
926 res->network = zone &
927 (0xFFFFFFFF >> (32 - prefixlen));
928#endif
929 atomic_inc(&res->fi->fib_clntref);
930 return 0;
931}
932
933/* Find appropriate source address to this destination */
934
935u32 __fib_res_prefsrc(struct fib_result *res)
936{
937 return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope);
938}
939
940int
941fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
942 u8 tb_id, u8 type, u8 scope, void *dst, int dst_len, u8 tos,
b6544c0b 943 struct fib_info *fi, unsigned int flags)
1da177e4
LT		 944{
945 struct rtmsg *rtm;
946 struct nlmsghdr *nlh;
947 unsigned char *b = skb->tail;
948
b6544c0b 949 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
1da177e4
LT		 950 rtm = NLMSG_DATA(nlh);
951 rtm->rtm_family = AF_INET;
952 rtm->rtm_dst_len = dst_len;
953 rtm->rtm_src_len = 0;
954 rtm->rtm_tos = tos;
955 rtm->rtm_table = tb_id;
956 rtm->rtm_type = type;
957 rtm->rtm_flags = fi->fib_flags;
958 rtm->rtm_scope = scope;
959 if (rtm->rtm_dst_len)
960 RTA_PUT(skb, RTA_DST, 4, dst);
961 rtm->rtm_protocol = fi->fib_protocol;
962 if (fi->fib_priority)
963 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
964#ifdef CONFIG_NET_CLS_ROUTE
965 if (fi->fib_nh[0].nh_tclassid)
966 RTA_PUT(skb, RTA_FLOW, 4, &fi->fib_nh[0].nh_tclassid);
967#endif
968 if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
969 goto rtattr_failure;
970 if (fi->fib_prefsrc)
971 RTA_PUT(skb, RTA_PREFSRC, 4, &fi->fib_prefsrc);
972 if (fi->fib_nhs == 1) {
973 if (fi->fib_nh->nh_gw)
974 RTA_PUT(skb, RTA_GATEWAY, 4, &fi->fib_nh->nh_gw);
975 if (fi->fib_nh->nh_oif)
976 RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
977 }
978#ifdef CONFIG_IP_ROUTE_MULTIPATH
979 if (fi->fib_nhs > 1) {
980 struct rtnexthop *nhp;
981 struct rtattr *mp_head;
982 if (skb_tailroom(skb) <= RTA_SPACE(0))
983 goto rtattr_failure;
984 mp_head = (struct rtattr*)skb_put(skb, RTA_SPACE(0));
985
986 for_nexthops(fi) {
987 if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
988 goto rtattr_failure;
989 nhp = (struct rtnexthop*)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
990 nhp->rtnh_flags = nh->nh_flags & 0xFF;
991 nhp->rtnh_hops = nh->nh_weight-1;
992 nhp->rtnh_ifindex = nh->nh_oif;
993 if (nh->nh_gw)
994 RTA_PUT(skb, RTA_GATEWAY, 4, &nh->nh_gw);
995 nhp->rtnh_len = skb->tail - (unsigned char*)nhp;
996 } endfor_nexthops(fi);
997 mp_head->rta_type = RTA_MULTIPATH;
998 mp_head->rta_len = skb->tail - (u8*)mp_head;
999 }
1000#endif
1001 nlh->nlmsg_len = skb->tail - b;
1002 return skb->len;
1003
1004nlmsg_failure:
1005rtattr_failure:
1006 skb_trim(skb, b - skb->data);
1007 return -1;
1008}
1009
1010#ifndef CONFIG_IP_NOSIOCRT
1011
1012int
1013fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
1014 struct kern_rta *rta, struct rtentry *r)
1015{
1016 int plen;
1017 u32 *ptr;
1018
1019 memset(rtm, 0, sizeof(*rtm));
1020 memset(rta, 0, sizeof(*rta));
1021
1022 if (r->rt_dst.sa_family != AF_INET)
1023 return -EAFNOSUPPORT;
1024
1025 /* Check mask for validity:
1026 a) it must be contiguous.
1027 b) destination must have all host bits clear.
1028 c) if application forgot to set correct family (AF_INET),
1029 reject request unless it is absolutely clear i.e.
1030 both family and mask are zero.
1031 */
1032 plen = 32;
1033 ptr = &((struct sockaddr_in*)&r->rt_dst)->sin_addr.s_addr;
1034 if (!(r->rt_flags&RTF_HOST)) {
1035 u32 mask = ((struct sockaddr_in*)&r->rt_genmask)->sin_addr.s_addr;
1036 if (r->rt_genmask.sa_family != AF_INET) {
1037 if (mask || r->rt_genmask.sa_family)
1038 return -EAFNOSUPPORT;
1039 }
1040 if (bad_mask(mask, *ptr))
1041 return -EINVAL;
1042 plen = inet_mask_len(mask);
1043 }
1044
1045 nl->nlmsg_flags = NLM_F_REQUEST;
28633514 1046 nl->nlmsg_pid = 0;
1da177e4
LT		 1047 nl->nlmsg_seq = 0;
1048 nl->nlmsg_len = NLMSG_LENGTH(sizeof(*rtm));
1049 if (cmd == SIOCDELRT) {
1050 nl->nlmsg_type = RTM_DELROUTE;
1051 nl->nlmsg_flags = 0;
1052 } else {
1053 nl->nlmsg_type = RTM_NEWROUTE;
1054 nl->nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE;
1055 rtm->rtm_protocol = RTPROT_BOOT;
1056 }
1057
1058 rtm->rtm_dst_len = plen;
1059 rta->rta_dst = ptr;
1060
1061 if (r->rt_metric) {
1062 *(u32*)&r->rt_pad3 = r->rt_metric - 1;
1063 rta->rta_priority = (u32*)&r->rt_pad3;
1064 }
1065 if (r->rt_flags&RTF_REJECT) {
1066 rtm->rtm_scope = RT_SCOPE_HOST;
1067 rtm->rtm_type = RTN_UNREACHABLE;
1068 return 0;
1069 }
1070 rtm->rtm_scope = RT_SCOPE_NOWHERE;
1071 rtm->rtm_type = RTN_UNICAST;
1072
1073 if (r->rt_dev) {
1074 char *colon;
1075 struct net_device *dev;
1076 char devname[IFNAMSIZ];
1077
1078 if (copy_from_user(devname, r->rt_dev, IFNAMSIZ-1))
1079 return -EFAULT;
1080 devname[IFNAMSIZ-1] = 0;
1081 colon = strchr(devname, ':');
1082 if (colon)
1083 *colon = 0;
1084 dev = __dev_get_by_name(devname);
1085 if (!dev)
1086 return -ENODEV;
1087 rta->rta_oif = &dev->ifindex;
1088 if (colon) {
1089 struct in_ifaddr *ifa;
e5ed6399 1090 struct in_device *in_dev = __in_dev_get_rtnl(dev);
1da177e4
LT		 1091 if (!in_dev)
1092 return -ENODEV;
1093 *colon = ':';
1094 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
1095 if (strcmp(ifa->ifa_label, devname) == 0)
1096 break;
1097 if (ifa == NULL)
1098 return -ENODEV;
1099 rta->rta_prefsrc = &ifa->ifa_local;
1100 }
1101 }
1102
1103 ptr = &((struct sockaddr_in*)&r->rt_gateway)->sin_addr.s_addr;
1104 if (r->rt_gateway.sa_family == AF_INET && *ptr) {
1105 rta->rta_gw = ptr;
1106 if (r->rt_flags&RTF_GATEWAY && inet_addr_type(*ptr) == RTN_UNICAST)
1107 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1108 }
1109
1110 if (cmd == SIOCDELRT)
1111 return 0;
1112
1113 if (r->rt_flags&RTF_GATEWAY && rta->rta_gw == NULL)
1114 return -EINVAL;
1115
1116 if (rtm->rtm_scope == RT_SCOPE_NOWHERE)
1117 rtm->rtm_scope = RT_SCOPE_LINK;
1118
1119 if (r->rt_flags&(RTF_MTU|RTF_WINDOW|RTF_IRTT)) {
1120 struct rtattr *rec;
1121 struct rtattr *mx = kmalloc(RTA_LENGTH(3*RTA_LENGTH(4)), GFP_KERNEL);
1122 if (mx == NULL)
1123 return -ENOMEM;
1124 rta->rta_mx = mx;
1125 mx->rta_type = RTA_METRICS;
1126 mx->rta_len = RTA_LENGTH(0);
1127 if (r->rt_flags&RTF_MTU) {
1128 rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
1129 rec->rta_type = RTAX_ADVMSS;
1130 rec->rta_len = RTA_LENGTH(4);
1131 mx->rta_len += RTA_LENGTH(4);
1132 *(u32*)RTA_DATA(rec) = r->rt_mtu - 40;
1133 }
1134 if (r->rt_flags&RTF_WINDOW) {
1135 rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
1136 rec->rta_type = RTAX_WINDOW;
1137 rec->rta_len = RTA_LENGTH(4);
1138 mx->rta_len += RTA_LENGTH(4);
1139 *(u32*)RTA_DATA(rec) = r->rt_window;
1140 }
1141 if (r->rt_flags&RTF_IRTT) {
1142 rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
1143 rec->rta_type = RTAX_RTT;
1144 rec->rta_len = RTA_LENGTH(4);
1145 mx->rta_len += RTA_LENGTH(4);
1146 *(u32*)RTA_DATA(rec) = r->rt_irtt<<3;
1147 }
1148 }
1149 return 0;
1150}
1151
1152#endif
1153
1154/*
1155 Update FIB if:
1156 - local address disappeared -> we must delete all the entries
1157 referring to it.
1158 - device went down -> we must shutdown all nexthops going via it.
1159 */
1160
1161int fib_sync_down(u32 local, struct net_device *dev, int force)
1162{
1163 int ret = 0;
1164 int scope = RT_SCOPE_NOWHERE;
1165
1166 if (force)
1167 scope = -1;
1168
1169 if (local && fib_info_laddrhash) {
1170 unsigned int hash = fib_laddr_hashfn(local);
1171 struct hlist_head *head = &fib_info_laddrhash[hash];
1172 struct hlist_node *node;
1173 struct fib_info *fi;
1174
1175 hlist_for_each_entry(fi, node, head, fib_lhash) {
1176 if (fi->fib_prefsrc == local) {
1177 fi->fib_flags |= RTNH_F_DEAD;
1178 ret++;
1179 }
1180 }
1181 }
1182
1183 if (dev) {
1184 struct fib_info *prev_fi = NULL;
1185 unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1186 struct hlist_head *head = &fib_info_devhash[hash];
1187 struct hlist_node *node;
1188 struct fib_nh *nh;
1189
1190 hlist_for_each_entry(nh, node, head, nh_hash) {
1191 struct fib_info *fi = nh->nh_parent;
1192 int dead;
1193
1194 BUG_ON(!fi->fib_nhs);
1195 if (nh->nh_dev != dev || fi == prev_fi)
1196 continue;
1197 prev_fi = fi;
1198 dead = 0;
1199 change_nexthops(fi) {
1200 if (nh->nh_flags&RTNH_F_DEAD)
1201 dead++;
1202 else if (nh->nh_dev == dev &&
1203 nh->nh_scope != scope) {
1204 nh->nh_flags |= RTNH_F_DEAD;
1205#ifdef CONFIG_IP_ROUTE_MULTIPATH
1206 spin_lock_bh(&fib_multipath_lock);
1207 fi->fib_power -= nh->nh_power;
1208 nh->nh_power = 0;
1209 spin_unlock_bh(&fib_multipath_lock);
1210#endif
1211 dead++;
1212 }
1213#ifdef CONFIG_IP_ROUTE_MULTIPATH
1214 if (force > 1 && nh->nh_dev == dev) {
1215 dead = fi->fib_nhs;
1216 break;
1217 }
1218#endif
1219 } endfor_nexthops(fi)
1220 if (dead == fi->fib_nhs) {
1221 fi->fib_flags |= RTNH_F_DEAD;
1222 ret++;
1223 }
1224 }
1225 }
1226
1227 return ret;
1228}
1229
1230#ifdef CONFIG_IP_ROUTE_MULTIPATH
1231
1232/*
1233 Dead device goes up. We wake up dead nexthops.
1234 It takes sense only on multipath routes.
1235 */
1236
1237int fib_sync_up(struct net_device *dev)
1238{
1239 struct fib_info *prev_fi;
1240 unsigned int hash;
1241 struct hlist_head *head;
1242 struct hlist_node *node;
1243 struct fib_nh *nh;
1244 int ret;
1245
1246 if (!(dev->flags&IFF_UP))
1247 return 0;
1248
1249 prev_fi = NULL;
1250 hash = fib_devindex_hashfn(dev->ifindex);
1251 head = &fib_info_devhash[hash];
1252 ret = 0;
1253
1254 hlist_for_each_entry(nh, node, head, nh_hash) {
1255 struct fib_info *fi = nh->nh_parent;
1256 int alive;
1257
1258 BUG_ON(!fi->fib_nhs);
1259 if (nh->nh_dev != dev || fi == prev_fi)
1260 continue;
1261
1262 prev_fi = fi;
1263 alive = 0;
1264 change_nexthops(fi) {
1265 if (!(nh->nh_flags&RTNH_F_DEAD)) {
1266 alive++;
1267 continue;
1268 }
1269 if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
1270 continue;
e5ed6399 1271 if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev))
1da177e4
LT		 1272 continue;
1273 alive++;
1274 spin_lock_bh(&fib_multipath_lock);
1275 nh->nh_power = 0;
1276 nh->nh_flags &= ~RTNH_F_DEAD;
1277 spin_unlock_bh(&fib_multipath_lock);
1278 } endfor_nexthops(fi)
1279
1280 if (alive > 0) {
1281 fi->fib_flags &= ~RTNH_F_DEAD;
1282 ret++;
1283 }
1284 }
1285
1286 return ret;
1287}
1288
1289/*
1290 The algorithm is suboptimal, but it provides really
1291 fair weighted route distribution.
1292 */
1293
1294void fib_select_multipath(const struct flowi *flp, struct fib_result *res)
1295{
1296 struct fib_info *fi = res->fi;
1297 int w;
1298
1299 spin_lock_bh(&fib_multipath_lock);
1300 if (fi->fib_power <= 0) {
1301 int power = 0;
1302 change_nexthops(fi) {
1303 if (!(nh->nh_flags&RTNH_F_DEAD)) {
1304 power += nh->nh_weight;
1305 nh->nh_power = nh->nh_weight;
1306 }
1307 } endfor_nexthops(fi);
1308 fi->fib_power = power;
1309 if (power <= 0) {
1310 spin_unlock_bh(&fib_multipath_lock);
1311 /* Race condition: route has just become dead. */
1312 res->nh_sel = 0;
1313 return;
1314 }
1315 }
1316
1317
1318 /* w should be random number [0..fi->fib_power-1],
1319 it is pretty bad approximation.
1320 */
1321
1322 w = jiffies % fi->fib_power;
1323
1324 change_nexthops(fi) {
1325 if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
1326 if ((w -= nh->nh_power) <= 0) {
1327 nh->nh_power--;
1328 fi->fib_power--;
1329 res->nh_sel = nhsel;
1330 spin_unlock_bh(&fib_multipath_lock);
1331 return;
1332 }
1333 }
1334 } endfor_nexthops(fi);
1335
1336 /* Race condition: route has just become dead. */
1337 res->nh_sel = 0;
1338 spin_unlock_bh(&fib_multipath_lock);
1339}
1340#endif
Clone of davem's net-next-2.6 tree