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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 | * 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 | |
16 | #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> |
29 | #include <linux/inetdevice.h> |
30 | #include <linux/netdevice.h> |
31 | #include <linux/if_arp.h> |
32 | #include <linux/proc_fs.h> |
33 | #include <linux/skbuff.h> |
34 | #include <linux/init.h> |
35 | #include <linux/slab.h> |
36 | |
37 | #include <net/arp.h> |
38 | #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> |
44 | #include <net/netlink.h> |
45 | #include <net/nexthop.h> |
46 | |
47 | #include "fib_lookup.h" |
48 | |
49 | static DEFINE_SPINLOCK(fib_info_lock); |
50 | static struct hlist_head *fib_info_hash; |
51 | static struct hlist_head *fib_info_laddrhash; |
52 | static unsigned int fib_hash_size; |
53 | static unsigned int fib_info_cnt; |
54 | |
55 | #define DEVINDEX_HASHBITS 8 |
56 | #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) |
57 | static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; |
58 | |
59 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
60 | |
61 | static DEFINE_SPINLOCK(fib_multipath_lock); |
62 | |
63 | #define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \ |
64 | for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++) |
65 | |
66 | #define change_nexthops(fi) { int nhsel; struct fib_nh *nexthop_nh; \ |
67 | for (nhsel=0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nexthop_nh++, nhsel++) |
68 | |
69 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ |
70 | |
71 | /* Hope, that gcc will optimize it to get rid of dummy loop */ |
72 | |
73 | #define for_nexthops(fi) { int nhsel = 0; const struct fib_nh * nh = (fi)->fib_nh; \ |
74 | for (nhsel=0; nhsel < 1; nhsel++) |
75 | |
76 | #define change_nexthops(fi) { int nhsel = 0; struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
77 | for (nhsel=0; nhsel < 1; nhsel++) |
78 | |
79 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
80 | |
81 | #define endfor_nexthops(fi) } |
82 | |
83 | |
84 | static const struct |
85 | { |
86 | int error; |
87 | u8 scope; |
88 | } fib_props[RTN_MAX + 1] = { |
89 | { |
90 | .error = 0, |
91 | .scope = RT_SCOPE_NOWHERE, |
92 | }, /* RTN_UNSPEC */ |
93 | { |
94 | .error = 0, |
95 | .scope = RT_SCOPE_UNIVERSE, |
96 | }, /* RTN_UNICAST */ |
97 | { |
98 | .error = 0, |
99 | .scope = RT_SCOPE_HOST, |
100 | }, /* RTN_LOCAL */ |
101 | { |
102 | .error = 0, |
103 | .scope = RT_SCOPE_LINK, |
104 | }, /* RTN_BROADCAST */ |
105 | { |
106 | .error = 0, |
107 | .scope = RT_SCOPE_LINK, |
108 | }, /* RTN_ANYCAST */ |
109 | { |
110 | .error = 0, |
111 | .scope = RT_SCOPE_UNIVERSE, |
112 | }, /* RTN_MULTICAST */ |
113 | { |
114 | .error = -EINVAL, |
115 | .scope = RT_SCOPE_UNIVERSE, |
116 | }, /* RTN_BLACKHOLE */ |
117 | { |
118 | .error = -EHOSTUNREACH, |
119 | .scope = RT_SCOPE_UNIVERSE, |
120 | }, /* RTN_UNREACHABLE */ |
121 | { |
122 | .error = -EACCES, |
123 | .scope = RT_SCOPE_UNIVERSE, |
124 | }, /* RTN_PROHIBIT */ |
125 | { |
126 | .error = -EAGAIN, |
127 | .scope = RT_SCOPE_UNIVERSE, |
128 | }, /* RTN_THROW */ |
129 | { |
130 | .error = -EINVAL, |
131 | .scope = RT_SCOPE_NOWHERE, |
132 | }, /* RTN_NAT */ |
133 | { |
134 | .error = -EINVAL, |
135 | .scope = RT_SCOPE_NOWHERE, |
136 | }, /* RTN_XRESOLVE */ |
137 | }; |
138 | |
139 | |
140 | /* Release a nexthop info record */ |
141 | |
142 | void free_fib_info(struct fib_info *fi) |
143 | { |
144 | if (fi->fib_dead == 0) { |
145 | printk(KERN_WARNING "Freeing alive fib_info %p\n", fi); |
146 | return; |
147 | } |
148 | change_nexthops(fi) { |
149 | if (nexthop_nh->nh_dev) |
150 | dev_put(nexthop_nh->nh_dev); |
151 | nexthop_nh->nh_dev = NULL; |
152 | } endfor_nexthops(fi); |
153 | fib_info_cnt--; |
154 | release_net(fi->fib_net); |
155 | kfree(fi); |
156 | } |
157 | |
158 | void fib_release_info(struct fib_info *fi) |
159 | { |
160 | spin_lock_bh(&fib_info_lock); |
161 | if (fi && --fi->fib_treeref == 0) { |
162 | hlist_del(&fi->fib_hash); |
163 | if (fi->fib_prefsrc) |
164 | hlist_del(&fi->fib_lhash); |
165 | change_nexthops(fi) { |
166 | if (!nexthop_nh->nh_dev) |
167 | continue; |
168 | hlist_del(&nexthop_nh->nh_hash); |
169 | } endfor_nexthops(fi) |
170 | fi->fib_dead = 1; |
171 | fib_info_put(fi); |
172 | } |
173 | spin_unlock_bh(&fib_info_lock); |
174 | } |
175 | |
176 | static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) |
177 | { |
178 | const struct fib_nh *onh = ofi->fib_nh; |
179 | |
180 | for_nexthops(fi) { |
181 | if (nh->nh_oif != onh->nh_oif || |
182 | nh->nh_gw != onh->nh_gw || |
183 | nh->nh_scope != onh->nh_scope || |
184 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
185 | nh->nh_weight != onh->nh_weight || |
186 | #endif |
187 | #ifdef CONFIG_NET_CLS_ROUTE |
188 | nh->nh_tclassid != onh->nh_tclassid || |
189 | #endif |
190 | ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD)) |
191 | return -1; |
192 | onh++; |
193 | } endfor_nexthops(fi); |
194 | return 0; |
195 | } |
196 | |
197 | static inline unsigned int fib_devindex_hashfn(unsigned int val) |
198 | { |
199 | unsigned int mask = DEVINDEX_HASHSIZE - 1; |
200 | |
201 | return (val ^ |
202 | (val >> DEVINDEX_HASHBITS) ^ |
203 | (val >> (DEVINDEX_HASHBITS * 2))) & mask; |
204 | } |
205 | |
206 | static inline unsigned int fib_info_hashfn(const struct fib_info *fi) |
207 | { |
208 | unsigned int mask = (fib_hash_size - 1); |
209 | unsigned int val = fi->fib_nhs; |
210 | |
211 | val ^= fi->fib_protocol; |
212 | val ^= (__force u32)fi->fib_prefsrc; |
213 | val ^= fi->fib_priority; |
214 | for_nexthops(fi) { |
215 | val ^= fib_devindex_hashfn(nh->nh_oif); |
216 | } endfor_nexthops(fi) |
217 | |
218 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; |
219 | } |
220 | |
221 | static struct fib_info *fib_find_info(const struct fib_info *nfi) |
222 | { |
223 | struct hlist_head *head; |
224 | struct hlist_node *node; |
225 | struct fib_info *fi; |
226 | unsigned int hash; |
227 | |
228 | hash = fib_info_hashfn(nfi); |
229 | head = &fib_info_hash[hash]; |
230 | |
231 | hlist_for_each_entry(fi, node, head, fib_hash) { |
232 | if (!net_eq(fi->fib_net, nfi->fib_net)) |
233 | continue; |
234 | if (fi->fib_nhs != nfi->fib_nhs) |
235 | continue; |
236 | if (nfi->fib_protocol == fi->fib_protocol && |
237 | nfi->fib_prefsrc == fi->fib_prefsrc && |
238 | nfi->fib_priority == fi->fib_priority && |
239 | memcmp(nfi->fib_metrics, fi->fib_metrics, |
240 | sizeof(fi->fib_metrics)) == 0 && |
241 | ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 && |
242 | (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) |
243 | return fi; |
244 | } |
245 | |
246 | return NULL; |
247 | } |
248 | |
249 | /* Check, that the gateway is already configured. |
250 | Used only by redirect accept routine. |
251 | */ |
252 | |
253 | int ip_fib_check_default(__be32 gw, struct net_device *dev) |
254 | { |
255 | struct hlist_head *head; |
256 | struct hlist_node *node; |
257 | struct fib_nh *nh; |
258 | unsigned int hash; |
259 | |
260 | spin_lock(&fib_info_lock); |
261 | |
262 | hash = fib_devindex_hashfn(dev->ifindex); |
263 | head = &fib_info_devhash[hash]; |
264 | hlist_for_each_entry(nh, node, head, nh_hash) { |
265 | if (nh->nh_dev == dev && |
266 | nh->nh_gw == gw && |
267 | !(nh->nh_flags&RTNH_F_DEAD)) { |
268 | spin_unlock(&fib_info_lock); |
269 | return 0; |
270 | } |
271 | } |
272 | |
273 | spin_unlock(&fib_info_lock); |
274 | |
275 | return -1; |
276 | } |
277 | |
278 | static inline size_t fib_nlmsg_size(struct fib_info *fi) |
279 | { |
280 | size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) |
281 | + nla_total_size(4) /* RTA_TABLE */ |
282 | + nla_total_size(4) /* RTA_DST */ |
283 | + nla_total_size(4) /* RTA_PRIORITY */ |
284 | + nla_total_size(4); /* RTA_PREFSRC */ |
285 | |
286 | /* space for nested metrics */ |
287 | payload += nla_total_size((RTAX_MAX * nla_total_size(4))); |
288 | |
289 | if (fi->fib_nhs) { |
290 | /* Also handles the special case fib_nhs == 1 */ |
291 | |
292 | /* each nexthop is packed in an attribute */ |
293 | size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); |
294 | |
295 | /* may contain flow and gateway attribute */ |
296 | nhsize += 2 * nla_total_size(4); |
297 | |
298 | /* all nexthops are packed in a nested attribute */ |
299 | payload += nla_total_size(fi->fib_nhs * nhsize); |
300 | } |
301 | |
302 | return payload; |
303 | } |
304 | |
305 | void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
306 | int dst_len, u32 tb_id, struct nl_info *info, |
307 | unsigned int nlm_flags) |
308 | { |
309 | struct sk_buff *skb; |
310 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
311 | int err = -ENOBUFS; |
312 | |
313 | skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
314 | if (skb == NULL) |
315 | goto errout; |
316 | |
317 | err = fib_dump_info(skb, info->pid, seq, event, tb_id, |
318 | fa->fa_type, fa->fa_scope, key, dst_len, |
319 | fa->fa_tos, fa->fa_info, nlm_flags); |
320 | if (err < 0) { |
321 | /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ |
322 | WARN_ON(err == -EMSGSIZE); |
323 | kfree_skb(skb); |
324 | goto errout; |
325 | } |
326 | rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE, |
327 | info->nlh, GFP_KERNEL); |
328 | return; |
329 | errout: |
330 | if (err < 0) |
331 | rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); |
332 | } |
333 | |
334 | /* Return the first fib alias matching TOS with |
335 | * priority less than or equal to PRIO. |
336 | */ |
337 | struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio) |
338 | { |
339 | if (fah) { |
340 | struct fib_alias *fa; |
341 | list_for_each_entry(fa, fah, fa_list) { |
342 | if (fa->fa_tos > tos) |
343 | continue; |
344 | if (fa->fa_info->fib_priority >= prio || |
345 | fa->fa_tos < tos) |
346 | return fa; |
347 | } |
348 | } |
349 | return NULL; |
350 | } |
351 | |
352 | int fib_detect_death(struct fib_info *fi, int order, |
353 | struct fib_info **last_resort, int *last_idx, int dflt) |
354 | { |
355 | struct neighbour *n; |
356 | int state = NUD_NONE; |
357 | |
358 | n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev); |
359 | if (n) { |
360 | state = n->nud_state; |
361 | neigh_release(n); |
362 | } |
363 | if (state == NUD_REACHABLE) |
364 | return 0; |
365 | if ((state&NUD_VALID) && order != dflt) |
366 | return 0; |
367 | if ((state&NUD_VALID) || |
368 | (*last_idx<0 && order > dflt)) { |
369 | *last_resort = fi; |
370 | *last_idx = order; |
371 | } |
372 | return 1; |
373 | } |
374 | |
375 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
376 | |
377 | static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining) |
378 | { |
379 | int nhs = 0; |
380 | |
381 | while (rtnh_ok(rtnh, remaining)) { |
382 | nhs++; |
383 | rtnh = rtnh_next(rtnh, &remaining); |
384 | } |
385 | |
386 | /* leftover implies invalid nexthop configuration, discard it */ |
387 | return remaining > 0 ? 0 : nhs; |
388 | } |
389 | |
390 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
391 | int remaining, struct fib_config *cfg) |
392 | { |
393 | change_nexthops(fi) { |
394 | int attrlen; |
395 | |
396 | if (!rtnh_ok(rtnh, remaining)) |
397 | return -EINVAL; |
398 | |
399 | nexthop_nh->nh_flags = |
400 | (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; |
401 | nexthop_nh->nh_oif = rtnh->rtnh_ifindex; |
402 | nexthop_nh->nh_weight = rtnh->rtnh_hops + 1; |
403 | |
404 | attrlen = rtnh_attrlen(rtnh); |
405 | if (attrlen > 0) { |
406 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); |
407 | |
408 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
409 | nexthop_nh->nh_gw = nla ? nla_get_be32(nla) : 0; |
410 | #ifdef CONFIG_NET_CLS_ROUTE |
411 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
412 | nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; |
413 | #endif |
414 | } |
415 | |
416 | rtnh = rtnh_next(rtnh, &remaining); |
417 | } endfor_nexthops(fi); |
418 | |
419 | return 0; |
420 | } |
421 | |
422 | #endif |
423 | |
424 | int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) |
425 | { |
426 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
427 | struct rtnexthop *rtnh; |
428 | int remaining; |
429 | #endif |
430 | |
431 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
432 | return 1; |
433 | |
434 | if (cfg->fc_oif || cfg->fc_gw) { |
435 | if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && |
436 | (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) |
437 | return 0; |
438 | return 1; |
439 | } |
440 | |
441 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
442 | if (cfg->fc_mp == NULL) |
443 | return 0; |
444 | |
445 | rtnh = cfg->fc_mp; |
446 | remaining = cfg->fc_mp_len; |
447 | |
448 | for_nexthops(fi) { |
449 | int attrlen; |
450 | |
451 | if (!rtnh_ok(rtnh, remaining)) |
452 | return -EINVAL; |
453 | |
454 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) |
455 | return 1; |
456 | |
457 | attrlen = rtnh_attrlen(rtnh); |
458 | if (attrlen < 0) { |
459 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); |
460 | |
461 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); |
462 | if (nla && nla_get_be32(nla) != nh->nh_gw) |
463 | return 1; |
464 | #ifdef CONFIG_NET_CLS_ROUTE |
465 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
466 | if (nla && nla_get_u32(nla) != nh->nh_tclassid) |
467 | return 1; |
468 | #endif |
469 | } |
470 | |
471 | rtnh = rtnh_next(rtnh, &remaining); |
472 | } endfor_nexthops(fi); |
473 | #endif |
474 | return 0; |
475 | } |
476 | |
477 | |
478 | /* |
479 | Picture |
480 | ------- |
481 | |
482 | Semantics of nexthop is very messy by historical reasons. |
483 | We have to take into account, that: |
484 | a) gateway can be actually local interface address, |
485 | so that gatewayed route is direct. |
486 | b) gateway must be on-link address, possibly |
487 | described not by an ifaddr, but also by a direct route. |
488 | c) If both gateway and interface are specified, they should not |
489 | contradict. |
490 | d) If we use tunnel routes, gateway could be not on-link. |
491 | |
492 | Attempt to reconcile all of these (alas, self-contradictory) conditions |
493 | results in pretty ugly and hairy code with obscure logic. |
494 | |
495 | I chose to generalized it instead, so that the size |
496 | of code does not increase practically, but it becomes |
497 | much more general. |
498 | Every prefix is assigned a "scope" value: "host" is local address, |
499 | "link" is direct route, |
500 | [ ... "site" ... "interior" ... ] |
501 | and "universe" is true gateway route with global meaning. |
502 | |
503 | Every prefix refers to a set of "nexthop"s (gw, oif), |
504 | where gw must have narrower scope. This recursion stops |
505 | when gw has LOCAL scope or if "nexthop" is declared ONLINK, |
506 | which means that gw is forced to be on link. |
507 | |
508 | Code is still hairy, but now it is apparently logically |
509 | consistent and very flexible. F.e. as by-product it allows |
510 | to co-exists in peace independent exterior and interior |
511 | routing processes. |
512 | |
513 | Normally it looks as following. |
514 | |
515 | {universe prefix} -> (gw, oif) [scope link] |
516 | | |
517 | |-> {link prefix} -> (gw, oif) [scope local] |
518 | | |
519 | |-> {local prefix} (terminal node) |
520 | */ |
521 | |
522 | static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, |
523 | struct fib_nh *nh) |
524 | { |
525 | int err; |
526 | struct net *net; |
527 | |
528 | net = cfg->fc_nlinfo.nl_net; |
529 | if (nh->nh_gw) { |
530 | struct fib_result res; |
531 | |
532 | if (nh->nh_flags&RTNH_F_ONLINK) { |
533 | struct net_device *dev; |
534 | |
535 | if (cfg->fc_scope >= RT_SCOPE_LINK) |
536 | return -EINVAL; |
537 | if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST) |
538 | return -EINVAL; |
539 | if ((dev = __dev_get_by_index(net, nh->nh_oif)) == NULL) |
540 | return -ENODEV; |
541 | if (!(dev->flags&IFF_UP)) |
542 | return -ENETDOWN; |
543 | nh->nh_dev = dev; |
544 | dev_hold(dev); |
545 | nh->nh_scope = RT_SCOPE_LINK; |
546 | return 0; |
547 | } |
548 | { |
549 | struct flowi fl = { |
550 | .nl_u = { |
551 | .ip4_u = { |
552 | .daddr = nh->nh_gw, |
553 | .scope = cfg->fc_scope + 1, |
554 | }, |
555 | }, |
556 | .oif = nh->nh_oif, |
557 | }; |
558 | |
559 | /* It is not necessary, but requires a bit of thinking */ |
560 | if (fl.fl4_scope < RT_SCOPE_LINK) |
561 | fl.fl4_scope = RT_SCOPE_LINK; |
562 | if ((err = fib_lookup(net, &fl, &res)) != 0) |
563 | return err; |
564 | } |
565 | err = -EINVAL; |
566 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) |
567 | goto out; |
568 | nh->nh_scope = res.scope; |
569 | nh->nh_oif = FIB_RES_OIF(res); |
570 | if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL) |
571 | goto out; |
572 | dev_hold(nh->nh_dev); |
573 | err = -ENETDOWN; |
574 | if (!(nh->nh_dev->flags & IFF_UP)) |
575 | goto out; |
576 | err = 0; |
577 | out: |
578 | fib_res_put(&res); |
579 | return err; |
580 | } else { |
581 | struct in_device *in_dev; |
582 | |
583 | if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK)) |
584 | return -EINVAL; |
585 | |
586 | in_dev = inetdev_by_index(net, nh->nh_oif); |
587 | if (in_dev == NULL) |
588 | return -ENODEV; |
589 | if (!(in_dev->dev->flags&IFF_UP)) { |
590 | in_dev_put(in_dev); |
591 | return -ENETDOWN; |
592 | } |
593 | nh->nh_dev = in_dev->dev; |
594 | dev_hold(nh->nh_dev); |
595 | nh->nh_scope = RT_SCOPE_HOST; |
596 | in_dev_put(in_dev); |
597 | } |
598 | return 0; |
599 | } |
600 | |
601 | static inline unsigned int fib_laddr_hashfn(__be32 val) |
602 | { |
603 | unsigned int mask = (fib_hash_size - 1); |
604 | |
605 | return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask; |
606 | } |
607 | |
608 | static struct hlist_head *fib_hash_alloc(int bytes) |
609 | { |
610 | if (bytes <= PAGE_SIZE) |
611 | return kzalloc(bytes, GFP_KERNEL); |
612 | else |
613 | return (struct hlist_head *) |
614 | __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(bytes)); |
615 | } |
616 | |
617 | static void fib_hash_free(struct hlist_head *hash, int bytes) |
618 | { |
619 | if (!hash) |
620 | return; |
621 | |
622 | if (bytes <= PAGE_SIZE) |
623 | kfree(hash); |
624 | else |
625 | free_pages((unsigned long) hash, get_order(bytes)); |
626 | } |
627 | |
628 | static void fib_hash_move(struct hlist_head *new_info_hash, |
629 | struct hlist_head *new_laddrhash, |
630 | unsigned int new_size) |
631 | { |
632 | struct hlist_head *old_info_hash, *old_laddrhash; |
633 | unsigned int old_size = fib_hash_size; |
634 | unsigned int i, bytes; |
635 | |
636 | spin_lock_bh(&fib_info_lock); |
637 | old_info_hash = fib_info_hash; |
638 | old_laddrhash = fib_info_laddrhash; |
639 | fib_hash_size = new_size; |
640 | |
641 | for (i = 0; i < old_size; i++) { |
642 | struct hlist_head *head = &fib_info_hash[i]; |
643 | struct hlist_node *node, *n; |
644 | struct fib_info *fi; |
645 | |
646 | hlist_for_each_entry_safe(fi, node, n, head, fib_hash) { |
647 | struct hlist_head *dest; |
648 | unsigned int new_hash; |
649 | |
650 | hlist_del(&fi->fib_hash); |
651 | |
652 | new_hash = fib_info_hashfn(fi); |
653 | dest = &new_info_hash[new_hash]; |
654 | hlist_add_head(&fi->fib_hash, dest); |
655 | } |
656 | } |
657 | fib_info_hash = new_info_hash; |
658 | |
659 | for (i = 0; i < old_size; i++) { |
660 | struct hlist_head *lhead = &fib_info_laddrhash[i]; |
661 | struct hlist_node *node, *n; |
662 | struct fib_info *fi; |
663 | |
664 | hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) { |
665 | struct hlist_head *ldest; |
666 | unsigned int new_hash; |
667 | |
668 | hlist_del(&fi->fib_lhash); |
669 | |
670 | new_hash = fib_laddr_hashfn(fi->fib_prefsrc); |
671 | ldest = &new_laddrhash[new_hash]; |
672 | hlist_add_head(&fi->fib_lhash, ldest); |
673 | } |
674 | } |
675 | fib_info_laddrhash = new_laddrhash; |
676 | |
677 | spin_unlock_bh(&fib_info_lock); |
678 | |
679 | bytes = old_size * sizeof(struct hlist_head *); |
680 | fib_hash_free(old_info_hash, bytes); |
681 | fib_hash_free(old_laddrhash, bytes); |
682 | } |
683 | |
684 | struct fib_info *fib_create_info(struct fib_config *cfg) |
685 | { |
686 | int err; |
687 | struct fib_info *fi = NULL; |
688 | struct fib_info *ofi; |
689 | int nhs = 1; |
690 | struct net *net = cfg->fc_nlinfo.nl_net; |
691 | |
692 | /* Fast check to catch the most weird cases */ |
693 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) |
694 | goto err_inval; |
695 | |
696 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
697 | if (cfg->fc_mp) { |
698 | nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); |
699 | if (nhs == 0) |
700 | goto err_inval; |
701 | } |
702 | #endif |
703 | |
704 | err = -ENOBUFS; |
705 | if (fib_info_cnt >= fib_hash_size) { |
706 | unsigned int new_size = fib_hash_size << 1; |
707 | struct hlist_head *new_info_hash; |
708 | struct hlist_head *new_laddrhash; |
709 | unsigned int bytes; |
710 | |
711 | if (!new_size) |
712 | new_size = 1; |
713 | bytes = new_size * sizeof(struct hlist_head *); |
714 | new_info_hash = fib_hash_alloc(bytes); |
715 | new_laddrhash = fib_hash_alloc(bytes); |
716 | if (!new_info_hash || !new_laddrhash) { |
717 | fib_hash_free(new_info_hash, bytes); |
718 | fib_hash_free(new_laddrhash, bytes); |
719 | } else |
720 | fib_hash_move(new_info_hash, new_laddrhash, new_size); |
721 | |
722 | if (!fib_hash_size) |
723 | goto failure; |
724 | } |
725 | |
726 | fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); |
727 | if (fi == NULL) |
728 | goto failure; |
729 | fib_info_cnt++; |
730 | |
731 | fi->fib_net = hold_net(net); |
732 | fi->fib_protocol = cfg->fc_protocol; |
733 | fi->fib_flags = cfg->fc_flags; |
734 | fi->fib_priority = cfg->fc_priority; |
735 | fi->fib_prefsrc = cfg->fc_prefsrc; |
736 | |
737 | fi->fib_nhs = nhs; |
738 | change_nexthops(fi) { |
739 | nexthop_nh->nh_parent = fi; |
740 | } endfor_nexthops(fi) |
741 | |
742 | if (cfg->fc_mx) { |
743 | struct nlattr *nla; |
744 | int remaining; |
745 | |
746 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { |
747 | int type = nla_type(nla); |
748 | |
749 | if (type) { |
750 | if (type > RTAX_MAX) |
751 | goto err_inval; |
752 | fi->fib_metrics[type - 1] = nla_get_u32(nla); |
753 | } |
754 | } |
755 | } |
756 | |
757 | if (cfg->fc_mp) { |
758 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
759 | err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); |
760 | if (err != 0) |
761 | goto failure; |
762 | if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) |
763 | goto err_inval; |
764 | if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) |
765 | goto err_inval; |
766 | #ifdef CONFIG_NET_CLS_ROUTE |
767 | if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) |
768 | goto err_inval; |
769 | #endif |
770 | #else |
771 | goto err_inval; |
772 | #endif |
773 | } else { |
774 | struct fib_nh *nh = fi->fib_nh; |
775 | |
776 | nh->nh_oif = cfg->fc_oif; |
777 | nh->nh_gw = cfg->fc_gw; |
778 | nh->nh_flags = cfg->fc_flags; |
779 | #ifdef CONFIG_NET_CLS_ROUTE |
780 | nh->nh_tclassid = cfg->fc_flow; |
781 | #endif |
782 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
783 | nh->nh_weight = 1; |
784 | #endif |
785 | } |
786 | |
787 | if (fib_props[cfg->fc_type].error) { |
788 | if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) |
789 | goto err_inval; |
790 | goto link_it; |
791 | } |
792 | |
793 | if (cfg->fc_scope > RT_SCOPE_HOST) |
794 | goto err_inval; |
795 | |
796 | if (cfg->fc_scope == RT_SCOPE_HOST) { |
797 | struct fib_nh *nh = fi->fib_nh; |
798 | |
799 | /* Local address is added. */ |
800 | if (nhs != 1 || nh->nh_gw) |
801 | goto err_inval; |
802 | nh->nh_scope = RT_SCOPE_NOWHERE; |
803 | nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif); |
804 | err = -ENODEV; |
805 | if (nh->nh_dev == NULL) |
806 | goto failure; |
807 | } else { |
808 | change_nexthops(fi) { |
809 | if ((err = fib_check_nh(cfg, fi, nexthop_nh)) != 0) |
810 | goto failure; |
811 | } endfor_nexthops(fi) |
812 | } |
813 | |
814 | if (fi->fib_prefsrc) { |
815 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
816 | fi->fib_prefsrc != cfg->fc_dst) |
817 | if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL) |
818 | goto err_inval; |
819 | } |
820 | |
821 | link_it: |
822 | if ((ofi = fib_find_info(fi)) != NULL) { |
823 | fi->fib_dead = 1; |
824 | free_fib_info(fi); |
825 | ofi->fib_treeref++; |
826 | return ofi; |
827 | } |
828 | |
829 | fi->fib_treeref++; |
830 | atomic_inc(&fi->fib_clntref); |
831 | spin_lock_bh(&fib_info_lock); |
832 | hlist_add_head(&fi->fib_hash, |
833 | &fib_info_hash[fib_info_hashfn(fi)]); |
834 | if (fi->fib_prefsrc) { |
835 | struct hlist_head *head; |
836 | |
837 | head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; |
838 | hlist_add_head(&fi->fib_lhash, head); |
839 | } |
840 | change_nexthops(fi) { |
841 | struct hlist_head *head; |
842 | unsigned int hash; |
843 | |
844 | if (!nexthop_nh->nh_dev) |
845 | continue; |
846 | hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex); |
847 | head = &fib_info_devhash[hash]; |
848 | hlist_add_head(&nexthop_nh->nh_hash, head); |
849 | } endfor_nexthops(fi) |
850 | spin_unlock_bh(&fib_info_lock); |
851 | return fi; |
852 | |
853 | err_inval: |
854 | err = -EINVAL; |
855 | |
856 | failure: |
857 | if (fi) { |
858 | fi->fib_dead = 1; |
859 | free_fib_info(fi); |
860 | } |
861 | |
862 | return ERR_PTR(err); |
863 | } |
864 | |
865 | /* Note! fib_semantic_match intentionally uses RCU list functions. */ |
866 | int fib_semantic_match(struct list_head *head, const struct flowi *flp, |
867 | struct fib_result *res, int prefixlen) |
868 | { |
869 | struct fib_alias *fa; |
870 | int nh_sel = 0; |
871 | |
872 | list_for_each_entry_rcu(fa, head, fa_list) { |
873 | int err; |
874 | |
875 | if (fa->fa_tos && |
876 | fa->fa_tos != flp->fl4_tos) |
877 | continue; |
878 | |
879 | if (fa->fa_scope < flp->fl4_scope) |
880 | continue; |
881 | |
882 | fa->fa_state |= FA_S_ACCESSED; |
883 | |
884 | err = fib_props[fa->fa_type].error; |
885 | if (err == 0) { |
886 | struct fib_info *fi = fa->fa_info; |
887 | |
888 | if (fi->fib_flags & RTNH_F_DEAD) |
889 | continue; |
890 | |
891 | switch (fa->fa_type) { |
892 | case RTN_UNICAST: |
893 | case RTN_LOCAL: |
894 | case RTN_BROADCAST: |
895 | case RTN_ANYCAST: |
896 | case RTN_MULTICAST: |
897 | for_nexthops(fi) { |
898 | if (nh->nh_flags&RTNH_F_DEAD) |
899 | continue; |
900 | if (!flp->oif || flp->oif == nh->nh_oif) |
901 | break; |
902 | } |
903 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
904 | if (nhsel < fi->fib_nhs) { |
905 | nh_sel = nhsel; |
906 | goto out_fill_res; |
907 | } |
908 | #else |
909 | if (nhsel < 1) { |
910 | goto out_fill_res; |
911 | } |
912 | #endif |
913 | endfor_nexthops(fi); |
914 | continue; |
915 | |
916 | default: |
917 | printk(KERN_WARNING "fib_semantic_match bad type %#x\n", |
918 | fa->fa_type); |
919 | return -EINVAL; |
920 | } |
921 | } |
922 | return err; |
923 | } |
924 | return 1; |
925 | |
926 | out_fill_res: |
927 | res->prefixlen = prefixlen; |
928 | res->nh_sel = nh_sel; |
929 | res->type = fa->fa_type; |
930 | res->scope = fa->fa_scope; |
931 | res->fi = fa->fa_info; |
932 | atomic_inc(&res->fi->fib_clntref); |
933 | return 0; |
934 | } |
935 | |
936 | /* Find appropriate source address to this destination */ |
937 | |
938 | __be32 __fib_res_prefsrc(struct fib_result *res) |
939 | { |
940 | return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope); |
941 | } |
942 | |
943 | int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
944 | u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos, |
945 | struct fib_info *fi, unsigned int flags) |
946 | { |
947 | struct nlmsghdr *nlh; |
948 | struct rtmsg *rtm; |
949 | |
950 | nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags); |
951 | if (nlh == NULL) |
952 | return -EMSGSIZE; |
953 | |
954 | rtm = nlmsg_data(nlh); |
955 | rtm->rtm_family = AF_INET; |
956 | rtm->rtm_dst_len = dst_len; |
957 | rtm->rtm_src_len = 0; |
958 | rtm->rtm_tos = tos; |
959 | if (tb_id < 256) |
960 | rtm->rtm_table = tb_id; |
961 | else |
962 | rtm->rtm_table = RT_TABLE_COMPAT; |
963 | NLA_PUT_U32(skb, RTA_TABLE, tb_id); |
964 | rtm->rtm_type = type; |
965 | rtm->rtm_flags = fi->fib_flags; |
966 | rtm->rtm_scope = scope; |
967 | rtm->rtm_protocol = fi->fib_protocol; |
968 | |
969 | if (rtm->rtm_dst_len) |
970 | NLA_PUT_BE32(skb, RTA_DST, dst); |
971 | |
972 | if (fi->fib_priority) |
973 | NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority); |
974 | |
975 | if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) |
976 | goto nla_put_failure; |
977 | |
978 | if (fi->fib_prefsrc) |
979 | NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc); |
980 | |
981 | if (fi->fib_nhs == 1) { |
982 | if (fi->fib_nh->nh_gw) |
983 | NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw); |
984 | |
985 | if (fi->fib_nh->nh_oif) |
986 | NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif); |
987 | #ifdef CONFIG_NET_CLS_ROUTE |
988 | if (fi->fib_nh[0].nh_tclassid) |
989 | NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid); |
990 | #endif |
991 | } |
992 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
993 | if (fi->fib_nhs > 1) { |
994 | struct rtnexthop *rtnh; |
995 | struct nlattr *mp; |
996 | |
997 | mp = nla_nest_start(skb, RTA_MULTIPATH); |
998 | if (mp == NULL) |
999 | goto nla_put_failure; |
1000 | |
1001 | for_nexthops(fi) { |
1002 | rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
1003 | if (rtnh == NULL) |
1004 | goto nla_put_failure; |
1005 | |
1006 | rtnh->rtnh_flags = nh->nh_flags & 0xFF; |
1007 | rtnh->rtnh_hops = nh->nh_weight - 1; |
1008 | rtnh->rtnh_ifindex = nh->nh_oif; |
1009 | |
1010 | if (nh->nh_gw) |
1011 | NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw); |
1012 | #ifdef CONFIG_NET_CLS_ROUTE |
1013 | if (nh->nh_tclassid) |
1014 | NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid); |
1015 | #endif |
1016 | /* length of rtnetlink header + attributes */ |
1017 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; |
1018 | } endfor_nexthops(fi); |
1019 | |
1020 | nla_nest_end(skb, mp); |
1021 | } |
1022 | #endif |
1023 | return nlmsg_end(skb, nlh); |
1024 | |
1025 | nla_put_failure: |
1026 | nlmsg_cancel(skb, nlh); |
1027 | return -EMSGSIZE; |
1028 | } |
1029 | |
1030 | /* |
1031 | Update FIB if: |
1032 | - local address disappeared -> we must delete all the entries |
1033 | referring to it. |
1034 | - device went down -> we must shutdown all nexthops going via it. |
1035 | */ |
1036 | int fib_sync_down_addr(struct net *net, __be32 local) |
1037 | { |
1038 | int ret = 0; |
1039 | unsigned int hash = fib_laddr_hashfn(local); |
1040 | struct hlist_head *head = &fib_info_laddrhash[hash]; |
1041 | struct hlist_node *node; |
1042 | struct fib_info *fi; |
1043 | |
1044 | if (fib_info_laddrhash == NULL || local == 0) |
1045 | return 0; |
1046 | |
1047 | hlist_for_each_entry(fi, node, head, fib_lhash) { |
1048 | if (!net_eq(fi->fib_net, net)) |
1049 | continue; |
1050 | if (fi->fib_prefsrc == local) { |
1051 | fi->fib_flags |= RTNH_F_DEAD; |
1052 | ret++; |
1053 | } |
1054 | } |
1055 | return ret; |
1056 | } |
1057 | |
1058 | int fib_sync_down_dev(struct net_device *dev, int force) |
1059 | { |
1060 | int ret = 0; |
1061 | int scope = RT_SCOPE_NOWHERE; |
1062 | struct fib_info *prev_fi = NULL; |
1063 | unsigned int hash = fib_devindex_hashfn(dev->ifindex); |
1064 | struct hlist_head *head = &fib_info_devhash[hash]; |
1065 | struct hlist_node *node; |
1066 | struct fib_nh *nh; |
1067 | |
1068 | if (force) |
1069 | scope = -1; |
1070 | |
1071 | hlist_for_each_entry(nh, node, head, nh_hash) { |
1072 | struct fib_info *fi = nh->nh_parent; |
1073 | int dead; |
1074 | |
1075 | BUG_ON(!fi->fib_nhs); |
1076 | if (nh->nh_dev != dev || fi == prev_fi) |
1077 | continue; |
1078 | prev_fi = fi; |
1079 | dead = 0; |
1080 | change_nexthops(fi) { |
1081 | if (nexthop_nh->nh_flags&RTNH_F_DEAD) |
1082 | dead++; |
1083 | else if (nexthop_nh->nh_dev == dev && |
1084 | nexthop_nh->nh_scope != scope) { |
1085 | nexthop_nh->nh_flags |= RTNH_F_DEAD; |
1086 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1087 | spin_lock_bh(&fib_multipath_lock); |
1088 | fi->fib_power -= nexthop_nh->nh_power; |
1089 | nexthop_nh->nh_power = 0; |
1090 | spin_unlock_bh(&fib_multipath_lock); |
1091 | #endif |
1092 | dead++; |
1093 | } |
1094 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1095 | if (force > 1 && nexthop_nh->nh_dev == dev) { |
1096 | dead = fi->fib_nhs; |
1097 | break; |
1098 | } |
1099 | #endif |
1100 | } endfor_nexthops(fi) |
1101 | if (dead == fi->fib_nhs) { |
1102 | fi->fib_flags |= RTNH_F_DEAD; |
1103 | ret++; |
1104 | } |
1105 | } |
1106 | |
1107 | return ret; |
1108 | } |
1109 | |
1110 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1111 | |
1112 | /* |
1113 | Dead device goes up. We wake up dead nexthops. |
1114 | It takes sense only on multipath routes. |
1115 | */ |
1116 | |
1117 | int fib_sync_up(struct net_device *dev) |
1118 | { |
1119 | struct fib_info *prev_fi; |
1120 | unsigned int hash; |
1121 | struct hlist_head *head; |
1122 | struct hlist_node *node; |
1123 | struct fib_nh *nh; |
1124 | int ret; |
1125 | |
1126 | if (!(dev->flags&IFF_UP)) |
1127 | return 0; |
1128 | |
1129 | prev_fi = NULL; |
1130 | hash = fib_devindex_hashfn(dev->ifindex); |
1131 | head = &fib_info_devhash[hash]; |
1132 | ret = 0; |
1133 | |
1134 | hlist_for_each_entry(nh, node, head, nh_hash) { |
1135 | struct fib_info *fi = nh->nh_parent; |
1136 | int alive; |
1137 | |
1138 | BUG_ON(!fi->fib_nhs); |
1139 | if (nh->nh_dev != dev || fi == prev_fi) |
1140 | continue; |
1141 | |
1142 | prev_fi = fi; |
1143 | alive = 0; |
1144 | change_nexthops(fi) { |
1145 | if (!(nexthop_nh->nh_flags&RTNH_F_DEAD)) { |
1146 | alive++; |
1147 | continue; |
1148 | } |
1149 | if (nexthop_nh->nh_dev == NULL || |
1150 | !(nexthop_nh->nh_dev->flags&IFF_UP)) |
1151 | continue; |
1152 | if (nexthop_nh->nh_dev != dev || |
1153 | !__in_dev_get_rtnl(dev)) |
1154 | continue; |
1155 | alive++; |
1156 | spin_lock_bh(&fib_multipath_lock); |
1157 | nexthop_nh->nh_power = 0; |
1158 | nexthop_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 | |
1176 | void 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 (!(nexthop_nh->nh_flags&RTNH_F_DEAD)) { |
1186 | power += nexthop_nh->nh_weight; |
1187 | nexthop_nh->nh_power = nexthop_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 (!(nexthop_nh->nh_flags&RTNH_F_DEAD) && |
1208 | nexthop_nh->nh_power) { |
1209 | if ((w -= nexthop_nh->nh_power) <= 0) { |
1210 | nexthop_nh->nh_power--; |
1211 | fi->fib_power--; |
1212 | res->nh_sel = nhsel; |
1213 | spin_unlock_bh(&fib_multipath_lock); |
1214 | return; |
1215 | } |
1216 | } |
1217 | } endfor_nexthops(fi); |
1218 | |
1219 | /* Race condition: route has just become dead. */ |
1220 | res->nh_sel = 0; |
1221 | spin_unlock_bh(&fib_multipath_lock); |
1222 | } |
1223 | #endif |
1224 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9