Commit | Line | Data |
---|---|---|
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> | |
1da177e4 LT |
36 | #include <linux/init.h> |
37 | ||
14c85021 | 38 | #include <net/arp.h> |
1da177e4 LT |
39 | #include <net/ip.h> |
40 | #include <net/protocol.h> | |
41 | #include <net/route.h> | |
42 | #include <net/tcp.h> | |
43 | #include <net/sock.h> | |
44 | #include <net/ip_fib.h> | |
45 | #include <net/ip_mp_alg.h> | |
f21c7bc5 | 46 | #include <net/netlink.h> |
4e902c57 | 47 | #include <net/nexthop.h> |
1da177e4 LT |
48 | |
49 | #include "fib_lookup.h" | |
50 | ||
51 | #define FSprintk(a...) | |
52 | ||
832b4c5e | 53 | static DEFINE_SPINLOCK(fib_info_lock); |
1da177e4 LT |
54 | static struct hlist_head *fib_info_hash; |
55 | static struct hlist_head *fib_info_laddrhash; | |
56 | static unsigned int fib_hash_size; | |
57 | static unsigned int fib_info_cnt; | |
58 | ||
59 | #define DEVINDEX_HASHBITS 8 | |
60 | #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) | |
61 | static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; | |
62 | ||
63 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
64 | ||
65 | static DEFINE_SPINLOCK(fib_multipath_lock); | |
66 | ||
67 | #define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \ | |
68 | for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++) | |
69 | ||
70 | #define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \ | |
71 | for (nhsel=0, nh = (struct fib_nh*)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++) | |
72 | ||
73 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ | |
74 | ||
75 | /* Hope, that gcc will optimize it to get rid of dummy loop */ | |
76 | ||
77 | #define for_nexthops(fi) { int nhsel=0; const struct fib_nh * nh = (fi)->fib_nh; \ | |
78 | for (nhsel=0; nhsel < 1; nhsel++) | |
79 | ||
80 | #define change_nexthops(fi) { int nhsel=0; struct fib_nh * nh = (struct fib_nh*)((fi)->fib_nh); \ | |
81 | for (nhsel=0; nhsel < 1; nhsel++) | |
82 | ||
83 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ | |
84 | ||
85 | #define endfor_nexthops(fi) } | |
86 | ||
87 | ||
9b5b5cff | 88 | static const struct |
1da177e4 LT |
89 | { |
90 | int error; | |
91 | u8 scope; | |
92 | } fib_props[RTA_MAX + 1] = { | |
93 | { | |
94 | .error = 0, | |
95 | .scope = RT_SCOPE_NOWHERE, | |
96 | }, /* RTN_UNSPEC */ | |
97 | { | |
98 | .error = 0, | |
99 | .scope = RT_SCOPE_UNIVERSE, | |
100 | }, /* RTN_UNICAST */ | |
101 | { | |
102 | .error = 0, | |
103 | .scope = RT_SCOPE_HOST, | |
104 | }, /* RTN_LOCAL */ | |
105 | { | |
106 | .error = 0, | |
107 | .scope = RT_SCOPE_LINK, | |
108 | }, /* RTN_BROADCAST */ | |
109 | { | |
110 | .error = 0, | |
111 | .scope = RT_SCOPE_LINK, | |
112 | }, /* RTN_ANYCAST */ | |
113 | { | |
114 | .error = 0, | |
115 | .scope = RT_SCOPE_UNIVERSE, | |
116 | }, /* RTN_MULTICAST */ | |
117 | { | |
118 | .error = -EINVAL, | |
119 | .scope = RT_SCOPE_UNIVERSE, | |
120 | }, /* RTN_BLACKHOLE */ | |
121 | { | |
122 | .error = -EHOSTUNREACH, | |
123 | .scope = RT_SCOPE_UNIVERSE, | |
124 | }, /* RTN_UNREACHABLE */ | |
125 | { | |
126 | .error = -EACCES, | |
127 | .scope = RT_SCOPE_UNIVERSE, | |
128 | }, /* RTN_PROHIBIT */ | |
129 | { | |
130 | .error = -EAGAIN, | |
131 | .scope = RT_SCOPE_UNIVERSE, | |
132 | }, /* RTN_THROW */ | |
133 | { | |
134 | .error = -EINVAL, | |
135 | .scope = RT_SCOPE_NOWHERE, | |
136 | }, /* RTN_NAT */ | |
137 | { | |
138 | .error = -EINVAL, | |
139 | .scope = RT_SCOPE_NOWHERE, | |
140 | }, /* RTN_XRESOLVE */ | |
141 | }; | |
142 | ||
143 | ||
144 | /* Release a nexthop info record */ | |
145 | ||
146 | void free_fib_info(struct fib_info *fi) | |
147 | { | |
148 | if (fi->fib_dead == 0) { | |
149 | printk("Freeing alive fib_info %p\n", fi); | |
150 | return; | |
151 | } | |
152 | change_nexthops(fi) { | |
153 | if (nh->nh_dev) | |
154 | dev_put(nh->nh_dev); | |
155 | nh->nh_dev = NULL; | |
156 | } endfor_nexthops(fi); | |
157 | fib_info_cnt--; | |
158 | kfree(fi); | |
159 | } | |
160 | ||
161 | void fib_release_info(struct fib_info *fi) | |
162 | { | |
832b4c5e | 163 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
164 | if (fi && --fi->fib_treeref == 0) { |
165 | hlist_del(&fi->fib_hash); | |
166 | if (fi->fib_prefsrc) | |
167 | hlist_del(&fi->fib_lhash); | |
168 | change_nexthops(fi) { | |
169 | if (!nh->nh_dev) | |
170 | continue; | |
171 | hlist_del(&nh->nh_hash); | |
172 | } endfor_nexthops(fi) | |
173 | fi->fib_dead = 1; | |
174 | fib_info_put(fi); | |
175 | } | |
832b4c5e | 176 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
177 | } |
178 | ||
179 | static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) | |
180 | { | |
181 | const struct fib_nh *onh = ofi->fib_nh; | |
182 | ||
183 | for_nexthops(fi) { | |
184 | if (nh->nh_oif != onh->nh_oif || | |
185 | nh->nh_gw != onh->nh_gw || | |
186 | nh->nh_scope != onh->nh_scope || | |
187 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
188 | nh->nh_weight != onh->nh_weight || | |
189 | #endif | |
190 | #ifdef CONFIG_NET_CLS_ROUTE | |
191 | nh->nh_tclassid != onh->nh_tclassid || | |
192 | #endif | |
193 | ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD)) | |
194 | return -1; | |
195 | onh++; | |
196 | } endfor_nexthops(fi); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | static inline unsigned int fib_info_hashfn(const struct fib_info *fi) | |
201 | { | |
202 | unsigned int mask = (fib_hash_size - 1); | |
203 | unsigned int val = fi->fib_nhs; | |
204 | ||
205 | val ^= fi->fib_protocol; | |
206 | val ^= fi->fib_prefsrc; | |
207 | val ^= fi->fib_priority; | |
208 | ||
209 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; | |
210 | } | |
211 | ||
212 | static struct fib_info *fib_find_info(const struct fib_info *nfi) | |
213 | { | |
214 | struct hlist_head *head; | |
215 | struct hlist_node *node; | |
216 | struct fib_info *fi; | |
217 | unsigned int hash; | |
218 | ||
219 | hash = fib_info_hashfn(nfi); | |
220 | head = &fib_info_hash[hash]; | |
221 | ||
222 | hlist_for_each_entry(fi, node, head, fib_hash) { | |
223 | if (fi->fib_nhs != nfi->fib_nhs) | |
224 | continue; | |
225 | if (nfi->fib_protocol == fi->fib_protocol && | |
226 | nfi->fib_prefsrc == fi->fib_prefsrc && | |
227 | nfi->fib_priority == fi->fib_priority && | |
228 | memcmp(nfi->fib_metrics, fi->fib_metrics, | |
229 | sizeof(fi->fib_metrics)) == 0 && | |
230 | ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 && | |
231 | (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) | |
232 | return fi; | |
233 | } | |
234 | ||
235 | return NULL; | |
236 | } | |
237 | ||
238 | static inline unsigned int fib_devindex_hashfn(unsigned int val) | |
239 | { | |
240 | unsigned int mask = DEVINDEX_HASHSIZE - 1; | |
241 | ||
242 | return (val ^ | |
243 | (val >> DEVINDEX_HASHBITS) ^ | |
244 | (val >> (DEVINDEX_HASHBITS * 2))) & mask; | |
245 | } | |
246 | ||
247 | /* Check, that the gateway is already configured. | |
248 | Used only by redirect accept routine. | |
249 | */ | |
250 | ||
d878e72e | 251 | int ip_fib_check_default(__be32 gw, struct net_device *dev) |
1da177e4 LT |
252 | { |
253 | struct hlist_head *head; | |
254 | struct hlist_node *node; | |
255 | struct fib_nh *nh; | |
256 | unsigned int hash; | |
257 | ||
832b4c5e | 258 | spin_lock(&fib_info_lock); |
1da177e4 LT |
259 | |
260 | hash = fib_devindex_hashfn(dev->ifindex); | |
261 | head = &fib_info_devhash[hash]; | |
262 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
263 | if (nh->nh_dev == dev && | |
264 | nh->nh_gw == gw && | |
265 | !(nh->nh_flags&RTNH_F_DEAD)) { | |
832b4c5e | 266 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
267 | return 0; |
268 | } | |
269 | } | |
270 | ||
832b4c5e | 271 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
272 | |
273 | return -1; | |
274 | } | |
275 | ||
276 | void rtmsg_fib(int event, u32 key, struct fib_alias *fa, | |
4e902c57 | 277 | int dst_len, u32 tb_id, struct nl_info *info) |
1da177e4 LT |
278 | { |
279 | struct sk_buff *skb; | |
f21c7bc5 | 280 | int payload = sizeof(struct rtmsg) + 256; |
4e902c57 | 281 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
f21c7bc5 | 282 | int err = -ENOBUFS; |
1da177e4 | 283 | |
f21c7bc5 TG |
284 | skb = nlmsg_new(nlmsg_total_size(payload), GFP_KERNEL); |
285 | if (skb == NULL) | |
286 | goto errout; | |
1da177e4 | 287 | |
4e902c57 | 288 | err = fib_dump_info(skb, info->pid, seq, event, tb_id, |
be403ea1 | 289 | fa->fa_type, fa->fa_scope, key, dst_len, |
4e902c57 | 290 | fa->fa_tos, fa->fa_info, 0); |
f21c7bc5 | 291 | if (err < 0) { |
1da177e4 | 292 | kfree_skb(skb); |
f21c7bc5 | 293 | goto errout; |
1da177e4 | 294 | } |
f21c7bc5 | 295 | |
4e902c57 TG |
296 | err = rtnl_notify(skb, info->pid, RTNLGRP_IPV4_ROUTE, |
297 | info->nlh, GFP_KERNEL); | |
f21c7bc5 TG |
298 | errout: |
299 | if (err < 0) | |
300 | rtnl_set_sk_err(RTNLGRP_IPV4_ROUTE, err); | |
1da177e4 LT |
301 | } |
302 | ||
303 | /* Return the first fib alias matching TOS with | |
304 | * priority less than or equal to PRIO. | |
305 | */ | |
306 | struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio) | |
307 | { | |
308 | if (fah) { | |
309 | struct fib_alias *fa; | |
310 | list_for_each_entry(fa, fah, fa_list) { | |
311 | if (fa->fa_tos > tos) | |
312 | continue; | |
313 | if (fa->fa_info->fib_priority >= prio || | |
314 | fa->fa_tos < tos) | |
315 | return fa; | |
316 | } | |
317 | } | |
318 | return NULL; | |
319 | } | |
320 | ||
321 | int fib_detect_death(struct fib_info *fi, int order, | |
322 | struct fib_info **last_resort, int *last_idx, int *dflt) | |
323 | { | |
324 | struct neighbour *n; | |
325 | int state = NUD_NONE; | |
326 | ||
327 | n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev); | |
328 | if (n) { | |
329 | state = n->nud_state; | |
330 | neigh_release(n); | |
331 | } | |
332 | if (state==NUD_REACHABLE) | |
333 | return 0; | |
334 | if ((state&NUD_VALID) && order != *dflt) | |
335 | return 0; | |
336 | if ((state&NUD_VALID) || | |
337 | (*last_idx<0 && order > *dflt)) { | |
338 | *last_resort = fi; | |
339 | *last_idx = order; | |
340 | } | |
341 | return 1; | |
342 | } | |
343 | ||
344 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
345 | ||
4e902c57 | 346 | static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining) |
1da177e4 LT |
347 | { |
348 | int nhs = 0; | |
1da177e4 | 349 | |
4e902c57 | 350 | while (rtnh_ok(rtnh, remaining)) { |
1da177e4 | 351 | nhs++; |
4e902c57 TG |
352 | rtnh = rtnh_next(rtnh, &remaining); |
353 | } | |
354 | ||
355 | /* leftover implies invalid nexthop configuration, discard it */ | |
356 | return remaining > 0 ? 0 : nhs; | |
1da177e4 LT |
357 | } |
358 | ||
4e902c57 TG |
359 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
360 | int remaining, struct fib_config *cfg) | |
1da177e4 | 361 | { |
1da177e4 | 362 | change_nexthops(fi) { |
4e902c57 TG |
363 | int attrlen; |
364 | ||
365 | if (!rtnh_ok(rtnh, remaining)) | |
1da177e4 | 366 | return -EINVAL; |
4e902c57 TG |
367 | |
368 | nh->nh_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; | |
369 | nh->nh_oif = rtnh->rtnh_ifindex; | |
370 | nh->nh_weight = rtnh->rtnh_hops + 1; | |
371 | ||
372 | attrlen = rtnh_attrlen(rtnh); | |
373 | if (attrlen > 0) { | |
374 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
375 | ||
376 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 377 | nh->nh_gw = nla ? nla_get_be32(nla) : 0; |
1da177e4 | 378 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 TG |
379 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
380 | nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; | |
1da177e4 LT |
381 | #endif |
382 | } | |
4e902c57 TG |
383 | |
384 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 | 385 | } endfor_nexthops(fi); |
4e902c57 | 386 | |
1da177e4 LT |
387 | return 0; |
388 | } | |
389 | ||
390 | #endif | |
391 | ||
4e902c57 | 392 | int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) |
1da177e4 LT |
393 | { |
394 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
395 | struct rtnexthop *rtnh; |
396 | int remaining; | |
1da177e4 LT |
397 | #endif |
398 | ||
4e902c57 | 399 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
1da177e4 LT |
400 | return 1; |
401 | ||
4e902c57 TG |
402 | if (cfg->fc_oif || cfg->fc_gw) { |
403 | if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && | |
404 | (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) | |
1da177e4 LT |
405 | return 0; |
406 | return 1; | |
407 | } | |
408 | ||
409 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 | 410 | if (cfg->fc_mp == NULL) |
1da177e4 | 411 | return 0; |
4e902c57 TG |
412 | |
413 | rtnh = cfg->fc_mp; | |
414 | remaining = cfg->fc_mp_len; | |
1da177e4 LT |
415 | |
416 | for_nexthops(fi) { | |
4e902c57 | 417 | int attrlen; |
1da177e4 | 418 | |
4e902c57 | 419 | if (!rtnh_ok(rtnh, remaining)) |
1da177e4 | 420 | return -EINVAL; |
4e902c57 TG |
421 | |
422 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) | |
1da177e4 | 423 | return 1; |
4e902c57 TG |
424 | |
425 | attrlen = rtnh_attrlen(rtnh); | |
426 | if (attrlen < 0) { | |
427 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
428 | ||
429 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 430 | if (nla && nla_get_be32(nla) != nh->nh_gw) |
1da177e4 LT |
431 | return 1; |
432 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 TG |
433 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
434 | if (nla && nla_get_u32(nla) != nh->nh_tclassid) | |
1da177e4 LT |
435 | return 1; |
436 | #endif | |
437 | } | |
4e902c57 TG |
438 | |
439 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 LT |
440 | } endfor_nexthops(fi); |
441 | #endif | |
442 | return 0; | |
443 | } | |
444 | ||
445 | ||
446 | /* | |
447 | Picture | |
448 | ------- | |
449 | ||
450 | Semantics of nexthop is very messy by historical reasons. | |
451 | We have to take into account, that: | |
452 | a) gateway can be actually local interface address, | |
453 | so that gatewayed route is direct. | |
454 | b) gateway must be on-link address, possibly | |
455 | described not by an ifaddr, but also by a direct route. | |
456 | c) If both gateway and interface are specified, they should not | |
457 | contradict. | |
458 | d) If we use tunnel routes, gateway could be not on-link. | |
459 | ||
460 | Attempt to reconcile all of these (alas, self-contradictory) conditions | |
461 | results in pretty ugly and hairy code with obscure logic. | |
462 | ||
463 | I chose to generalized it instead, so that the size | |
464 | of code does not increase practically, but it becomes | |
465 | much more general. | |
466 | Every prefix is assigned a "scope" value: "host" is local address, | |
467 | "link" is direct route, | |
468 | [ ... "site" ... "interior" ... ] | |
469 | and "universe" is true gateway route with global meaning. | |
470 | ||
471 | Every prefix refers to a set of "nexthop"s (gw, oif), | |
472 | where gw must have narrower scope. This recursion stops | |
473 | when gw has LOCAL scope or if "nexthop" is declared ONLINK, | |
474 | which means that gw is forced to be on link. | |
475 | ||
476 | Code is still hairy, but now it is apparently logically | |
477 | consistent and very flexible. F.e. as by-product it allows | |
478 | to co-exists in peace independent exterior and interior | |
479 | routing processes. | |
480 | ||
481 | Normally it looks as following. | |
482 | ||
483 | {universe prefix} -> (gw, oif) [scope link] | |
484 | | | |
485 | |-> {link prefix} -> (gw, oif) [scope local] | |
486 | | | |
487 | |-> {local prefix} (terminal node) | |
488 | */ | |
489 | ||
4e902c57 TG |
490 | static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, |
491 | struct fib_nh *nh) | |
1da177e4 LT |
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 | ||
4e902c57 | 505 | if (cfg->fc_scope >= RT_SCOPE_LINK) |
1da177e4 LT |
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 | { | |
4e902c57 TG |
519 | struct flowi fl = { |
520 | .nl_u = { | |
521 | .ip4_u = { | |
522 | .daddr = nh->nh_gw, | |
523 | .scope = cfg->fc_scope + 1, | |
524 | }, | |
525 | }, | |
526 | .oif = nh->nh_oif, | |
527 | }; | |
1da177e4 LT |
528 | |
529 | /* It is not necessary, but requires a bit of thinking */ | |
530 | if (fl.fl4_scope < RT_SCOPE_LINK) | |
531 | fl.fl4_scope = RT_SCOPE_LINK; | |
532 | if ((err = fib_lookup(&fl, &res)) != 0) | |
533 | return err; | |
534 | } | |
535 | err = -EINVAL; | |
536 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) | |
537 | goto out; | |
538 | nh->nh_scope = res.scope; | |
539 | nh->nh_oif = FIB_RES_OIF(res); | |
540 | if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL) | |
541 | goto out; | |
542 | dev_hold(nh->nh_dev); | |
543 | err = -ENETDOWN; | |
544 | if (!(nh->nh_dev->flags & IFF_UP)) | |
545 | goto out; | |
546 | err = 0; | |
547 | out: | |
548 | fib_res_put(&res); | |
549 | return err; | |
550 | } else { | |
551 | struct in_device *in_dev; | |
552 | ||
553 | if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK)) | |
554 | return -EINVAL; | |
555 | ||
556 | in_dev = inetdev_by_index(nh->nh_oif); | |
557 | if (in_dev == NULL) | |
558 | return -ENODEV; | |
559 | if (!(in_dev->dev->flags&IFF_UP)) { | |
560 | in_dev_put(in_dev); | |
561 | return -ENETDOWN; | |
562 | } | |
563 | nh->nh_dev = in_dev->dev; | |
564 | dev_hold(nh->nh_dev); | |
565 | nh->nh_scope = RT_SCOPE_HOST; | |
566 | in_dev_put(in_dev); | |
567 | } | |
568 | return 0; | |
569 | } | |
570 | ||
571 | static inline unsigned int fib_laddr_hashfn(u32 val) | |
572 | { | |
573 | unsigned int mask = (fib_hash_size - 1); | |
574 | ||
575 | return (val ^ (val >> 7) ^ (val >> 14)) & mask; | |
576 | } | |
577 | ||
578 | static struct hlist_head *fib_hash_alloc(int bytes) | |
579 | { | |
580 | if (bytes <= PAGE_SIZE) | |
581 | return kmalloc(bytes, GFP_KERNEL); | |
582 | else | |
583 | return (struct hlist_head *) | |
584 | __get_free_pages(GFP_KERNEL, get_order(bytes)); | |
585 | } | |
586 | ||
587 | static void fib_hash_free(struct hlist_head *hash, int bytes) | |
588 | { | |
589 | if (!hash) | |
590 | return; | |
591 | ||
592 | if (bytes <= PAGE_SIZE) | |
593 | kfree(hash); | |
594 | else | |
595 | free_pages((unsigned long) hash, get_order(bytes)); | |
596 | } | |
597 | ||
598 | static void fib_hash_move(struct hlist_head *new_info_hash, | |
599 | struct hlist_head *new_laddrhash, | |
600 | unsigned int new_size) | |
601 | { | |
b7656e7f | 602 | struct hlist_head *old_info_hash, *old_laddrhash; |
1da177e4 | 603 | unsigned int old_size = fib_hash_size; |
b7656e7f | 604 | unsigned int i, bytes; |
1da177e4 | 605 | |
832b4c5e | 606 | spin_lock_bh(&fib_info_lock); |
b7656e7f DM |
607 | old_info_hash = fib_info_hash; |
608 | old_laddrhash = fib_info_laddrhash; | |
1da177e4 LT |
609 | fib_hash_size = new_size; |
610 | ||
611 | for (i = 0; i < old_size; i++) { | |
612 | struct hlist_head *head = &fib_info_hash[i]; | |
613 | struct hlist_node *node, *n; | |
614 | struct fib_info *fi; | |
615 | ||
616 | hlist_for_each_entry_safe(fi, node, n, head, fib_hash) { | |
617 | struct hlist_head *dest; | |
618 | unsigned int new_hash; | |
619 | ||
620 | hlist_del(&fi->fib_hash); | |
621 | ||
622 | new_hash = fib_info_hashfn(fi); | |
623 | dest = &new_info_hash[new_hash]; | |
624 | hlist_add_head(&fi->fib_hash, dest); | |
625 | } | |
626 | } | |
627 | fib_info_hash = new_info_hash; | |
628 | ||
629 | for (i = 0; i < old_size; i++) { | |
630 | struct hlist_head *lhead = &fib_info_laddrhash[i]; | |
631 | struct hlist_node *node, *n; | |
632 | struct fib_info *fi; | |
633 | ||
634 | hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) { | |
635 | struct hlist_head *ldest; | |
636 | unsigned int new_hash; | |
637 | ||
638 | hlist_del(&fi->fib_lhash); | |
639 | ||
640 | new_hash = fib_laddr_hashfn(fi->fib_prefsrc); | |
641 | ldest = &new_laddrhash[new_hash]; | |
642 | hlist_add_head(&fi->fib_lhash, ldest); | |
643 | } | |
644 | } | |
645 | fib_info_laddrhash = new_laddrhash; | |
646 | ||
832b4c5e | 647 | spin_unlock_bh(&fib_info_lock); |
b7656e7f DM |
648 | |
649 | bytes = old_size * sizeof(struct hlist_head *); | |
650 | fib_hash_free(old_info_hash, bytes); | |
651 | fib_hash_free(old_laddrhash, bytes); | |
1da177e4 LT |
652 | } |
653 | ||
4e902c57 | 654 | struct fib_info *fib_create_info(struct fib_config *cfg) |
1da177e4 LT |
655 | { |
656 | int err; | |
657 | struct fib_info *fi = NULL; | |
658 | struct fib_info *ofi; | |
1da177e4 | 659 | int nhs = 1; |
1da177e4 LT |
660 | |
661 | /* Fast check to catch the most weird cases */ | |
4e902c57 | 662 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) |
1da177e4 LT |
663 | goto err_inval; |
664 | ||
665 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
666 | if (cfg->fc_mp) { |
667 | nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); | |
1da177e4 LT |
668 | if (nhs == 0) |
669 | goto err_inval; | |
670 | } | |
671 | #endif | |
672 | #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED | |
4e902c57 TG |
673 | if (cfg->fc_mp_alg) { |
674 | if (cfg->fc_mp_alg < IP_MP_ALG_NONE || | |
675 | cfg->fc_mp_alg > IP_MP_ALG_MAX) | |
1da177e4 LT |
676 | goto err_inval; |
677 | } | |
678 | #endif | |
679 | ||
680 | err = -ENOBUFS; | |
681 | if (fib_info_cnt >= fib_hash_size) { | |
682 | unsigned int new_size = fib_hash_size << 1; | |
683 | struct hlist_head *new_info_hash; | |
684 | struct hlist_head *new_laddrhash; | |
685 | unsigned int bytes; | |
686 | ||
687 | if (!new_size) | |
688 | new_size = 1; | |
689 | bytes = new_size * sizeof(struct hlist_head *); | |
690 | new_info_hash = fib_hash_alloc(bytes); | |
691 | new_laddrhash = fib_hash_alloc(bytes); | |
692 | if (!new_info_hash || !new_laddrhash) { | |
693 | fib_hash_free(new_info_hash, bytes); | |
694 | fib_hash_free(new_laddrhash, bytes); | |
695 | } else { | |
696 | memset(new_info_hash, 0, bytes); | |
697 | memset(new_laddrhash, 0, bytes); | |
698 | ||
699 | fib_hash_move(new_info_hash, new_laddrhash, new_size); | |
700 | } | |
701 | ||
702 | if (!fib_hash_size) | |
703 | goto failure; | |
704 | } | |
705 | ||
0da974f4 | 706 | fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); |
1da177e4 LT |
707 | if (fi == NULL) |
708 | goto failure; | |
709 | fib_info_cnt++; | |
1da177e4 | 710 | |
4e902c57 TG |
711 | fi->fib_protocol = cfg->fc_protocol; |
712 | fi->fib_flags = cfg->fc_flags; | |
713 | fi->fib_priority = cfg->fc_priority; | |
714 | fi->fib_prefsrc = cfg->fc_prefsrc; | |
1da177e4 LT |
715 | |
716 | fi->fib_nhs = nhs; | |
717 | change_nexthops(fi) { | |
718 | nh->nh_parent = fi; | |
719 | } endfor_nexthops(fi) | |
720 | ||
4e902c57 TG |
721 | if (cfg->fc_mx) { |
722 | struct nlattr *nla; | |
723 | int remaining; | |
724 | ||
725 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { | |
726 | int type = nla->nla_type; | |
727 | ||
728 | if (type) { | |
729 | if (type > RTAX_MAX) | |
1da177e4 | 730 | goto err_inval; |
4e902c57 | 731 | fi->fib_metrics[type - 1] = nla_get_u32(nla); |
1da177e4 | 732 | } |
1da177e4 LT |
733 | } |
734 | } | |
1da177e4 | 735 | |
4e902c57 | 736 | if (cfg->fc_mp) { |
1da177e4 | 737 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
4e902c57 TG |
738 | err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); |
739 | if (err != 0) | |
1da177e4 | 740 | goto failure; |
4e902c57 | 741 | if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) |
1da177e4 | 742 | goto err_inval; |
4e902c57 | 743 | if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) |
1da177e4 LT |
744 | goto err_inval; |
745 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 | 746 | if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) |
1da177e4 LT |
747 | goto err_inval; |
748 | #endif | |
749 | #else | |
750 | goto err_inval; | |
751 | #endif | |
752 | } else { | |
753 | struct fib_nh *nh = fi->fib_nh; | |
4e902c57 TG |
754 | |
755 | nh->nh_oif = cfg->fc_oif; | |
756 | nh->nh_gw = cfg->fc_gw; | |
757 | nh->nh_flags = cfg->fc_flags; | |
1da177e4 | 758 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 | 759 | nh->nh_tclassid = cfg->fc_flow; |
1da177e4 | 760 | #endif |
1da177e4 LT |
761 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
762 | nh->nh_weight = 1; | |
763 | #endif | |
764 | } | |
765 | ||
766 | #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED | |
4e902c57 | 767 | fi->fib_mp_alg = cfg->fc_mp_alg; |
1da177e4 LT |
768 | #endif |
769 | ||
4e902c57 TG |
770 | if (fib_props[cfg->fc_type].error) { |
771 | if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) | |
1da177e4 LT |
772 | goto err_inval; |
773 | goto link_it; | |
774 | } | |
775 | ||
4e902c57 | 776 | if (cfg->fc_scope > RT_SCOPE_HOST) |
1da177e4 LT |
777 | goto err_inval; |
778 | ||
4e902c57 | 779 | if (cfg->fc_scope == RT_SCOPE_HOST) { |
1da177e4 LT |
780 | struct fib_nh *nh = fi->fib_nh; |
781 | ||
782 | /* Local address is added. */ | |
783 | if (nhs != 1 || nh->nh_gw) | |
784 | goto err_inval; | |
785 | nh->nh_scope = RT_SCOPE_NOWHERE; | |
786 | nh->nh_dev = dev_get_by_index(fi->fib_nh->nh_oif); | |
787 | err = -ENODEV; | |
788 | if (nh->nh_dev == NULL) | |
789 | goto failure; | |
790 | } else { | |
791 | change_nexthops(fi) { | |
4e902c57 | 792 | if ((err = fib_check_nh(cfg, fi, nh)) != 0) |
1da177e4 LT |
793 | goto failure; |
794 | } endfor_nexthops(fi) | |
795 | } | |
796 | ||
797 | if (fi->fib_prefsrc) { | |
4e902c57 TG |
798 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
799 | fi->fib_prefsrc != cfg->fc_dst) | |
1da177e4 LT |
800 | if (inet_addr_type(fi->fib_prefsrc) != RTN_LOCAL) |
801 | goto err_inval; | |
802 | } | |
803 | ||
804 | link_it: | |
805 | if ((ofi = fib_find_info(fi)) != NULL) { | |
806 | fi->fib_dead = 1; | |
807 | free_fib_info(fi); | |
808 | ofi->fib_treeref++; | |
809 | return ofi; | |
810 | } | |
811 | ||
812 | fi->fib_treeref++; | |
813 | atomic_inc(&fi->fib_clntref); | |
832b4c5e | 814 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
815 | hlist_add_head(&fi->fib_hash, |
816 | &fib_info_hash[fib_info_hashfn(fi)]); | |
817 | if (fi->fib_prefsrc) { | |
818 | struct hlist_head *head; | |
819 | ||
820 | head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; | |
821 | hlist_add_head(&fi->fib_lhash, head); | |
822 | } | |
823 | change_nexthops(fi) { | |
824 | struct hlist_head *head; | |
825 | unsigned int hash; | |
826 | ||
827 | if (!nh->nh_dev) | |
828 | continue; | |
829 | hash = fib_devindex_hashfn(nh->nh_dev->ifindex); | |
830 | head = &fib_info_devhash[hash]; | |
831 | hlist_add_head(&nh->nh_hash, head); | |
832 | } endfor_nexthops(fi) | |
832b4c5e | 833 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
834 | return fi; |
835 | ||
836 | err_inval: | |
837 | err = -EINVAL; | |
838 | ||
839 | failure: | |
1da177e4 LT |
840 | if (fi) { |
841 | fi->fib_dead = 1; | |
842 | free_fib_info(fi); | |
843 | } | |
4e902c57 TG |
844 | |
845 | return ERR_PTR(err); | |
1da177e4 LT |
846 | } |
847 | ||
e5b43760 | 848 | /* Note! fib_semantic_match intentionally uses RCU list functions. */ |
1da177e4 | 849 | int fib_semantic_match(struct list_head *head, const struct flowi *flp, |
1ef1b8c8 | 850 | struct fib_result *res, __be32 zone, __be32 mask, |
1da177e4 LT |
851 | int prefixlen) |
852 | { | |
853 | struct fib_alias *fa; | |
854 | int nh_sel = 0; | |
855 | ||
e5b43760 | 856 | list_for_each_entry_rcu(fa, head, fa_list) { |
1da177e4 LT |
857 | int err; |
858 | ||
859 | if (fa->fa_tos && | |
860 | fa->fa_tos != flp->fl4_tos) | |
861 | continue; | |
862 | ||
863 | if (fa->fa_scope < flp->fl4_scope) | |
864 | continue; | |
865 | ||
866 | fa->fa_state |= FA_S_ACCESSED; | |
867 | ||
868 | err = fib_props[fa->fa_type].error; | |
869 | if (err == 0) { | |
870 | struct fib_info *fi = fa->fa_info; | |
871 | ||
872 | if (fi->fib_flags & RTNH_F_DEAD) | |
873 | continue; | |
874 | ||
875 | switch (fa->fa_type) { | |
876 | case RTN_UNICAST: | |
877 | case RTN_LOCAL: | |
878 | case RTN_BROADCAST: | |
879 | case RTN_ANYCAST: | |
880 | case RTN_MULTICAST: | |
881 | for_nexthops(fi) { | |
882 | if (nh->nh_flags&RTNH_F_DEAD) | |
883 | continue; | |
884 | if (!flp->oif || flp->oif == nh->nh_oif) | |
885 | break; | |
886 | } | |
887 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
888 | if (nhsel < fi->fib_nhs) { | |
889 | nh_sel = nhsel; | |
890 | goto out_fill_res; | |
891 | } | |
892 | #else | |
893 | if (nhsel < 1) { | |
894 | goto out_fill_res; | |
895 | } | |
896 | #endif | |
897 | endfor_nexthops(fi); | |
898 | continue; | |
899 | ||
900 | default: | |
901 | printk(KERN_DEBUG "impossible 102\n"); | |
902 | return -EINVAL; | |
903 | }; | |
904 | } | |
905 | return err; | |
906 | } | |
907 | return 1; | |
908 | ||
909 | out_fill_res: | |
910 | res->prefixlen = prefixlen; | |
911 | res->nh_sel = nh_sel; | |
912 | res->type = fa->fa_type; | |
913 | res->scope = fa->fa_scope; | |
914 | res->fi = fa->fa_info; | |
915 | #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED | |
916 | res->netmask = mask; | |
917 | res->network = zone & | |
918 | (0xFFFFFFFF >> (32 - prefixlen)); | |
919 | #endif | |
920 | atomic_inc(&res->fi->fib_clntref); | |
921 | return 0; | |
922 | } | |
923 | ||
924 | /* Find appropriate source address to this destination */ | |
925 | ||
b83738ae | 926 | __be32 __fib_res_prefsrc(struct fib_result *res) |
1da177e4 LT |
927 | { |
928 | return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope); | |
929 | } | |
930 | ||
be403ea1 TG |
931 | int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
932 | u32 tb_id, u8 type, u8 scope, u32 dst, int dst_len, u8 tos, | |
933 | struct fib_info *fi, unsigned int flags) | |
1da177e4 | 934 | { |
be403ea1 | 935 | struct nlmsghdr *nlh; |
1da177e4 | 936 | struct rtmsg *rtm; |
1da177e4 | 937 | |
be403ea1 TG |
938 | nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags); |
939 | if (nlh == NULL) | |
940 | return -ENOBUFS; | |
941 | ||
942 | rtm = nlmsg_data(nlh); | |
1da177e4 LT |
943 | rtm->rtm_family = AF_INET; |
944 | rtm->rtm_dst_len = dst_len; | |
945 | rtm->rtm_src_len = 0; | |
946 | rtm->rtm_tos = tos; | |
947 | rtm->rtm_table = tb_id; | |
be403ea1 | 948 | NLA_PUT_U32(skb, RTA_TABLE, tb_id); |
1da177e4 LT |
949 | rtm->rtm_type = type; |
950 | rtm->rtm_flags = fi->fib_flags; | |
951 | rtm->rtm_scope = scope; | |
1da177e4 | 952 | rtm->rtm_protocol = fi->fib_protocol; |
be403ea1 TG |
953 | |
954 | if (rtm->rtm_dst_len) | |
17fb2c64 | 955 | NLA_PUT_BE32(skb, RTA_DST, dst); |
be403ea1 | 956 | |
1da177e4 | 957 | if (fi->fib_priority) |
be403ea1 TG |
958 | NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority); |
959 | ||
1da177e4 | 960 | if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) |
be403ea1 TG |
961 | goto nla_put_failure; |
962 | ||
1da177e4 | 963 | if (fi->fib_prefsrc) |
17fb2c64 | 964 | NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc); |
be403ea1 | 965 | |
1da177e4 LT |
966 | if (fi->fib_nhs == 1) { |
967 | if (fi->fib_nh->nh_gw) | |
17fb2c64 | 968 | NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw); |
be403ea1 | 969 | |
1da177e4 | 970 | if (fi->fib_nh->nh_oif) |
be403ea1 | 971 | NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif); |
8265abc0 PM |
972 | #ifdef CONFIG_NET_CLS_ROUTE |
973 | if (fi->fib_nh[0].nh_tclassid) | |
be403ea1 | 974 | NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid); |
8265abc0 | 975 | #endif |
1da177e4 LT |
976 | } |
977 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
978 | if (fi->fib_nhs > 1) { | |
be403ea1 TG |
979 | struct rtnexthop *rtnh; |
980 | struct nlattr *mp; | |
981 | ||
982 | mp = nla_nest_start(skb, RTA_MULTIPATH); | |
983 | if (mp == NULL) | |
984 | goto nla_put_failure; | |
1da177e4 LT |
985 | |
986 | for_nexthops(fi) { | |
be403ea1 TG |
987 | rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
988 | if (rtnh == NULL) | |
989 | goto nla_put_failure; | |
990 | ||
991 | rtnh->rtnh_flags = nh->nh_flags & 0xFF; | |
992 | rtnh->rtnh_hops = nh->nh_weight - 1; | |
993 | rtnh->rtnh_ifindex = nh->nh_oif; | |
994 | ||
1da177e4 | 995 | if (nh->nh_gw) |
17fb2c64 | 996 | NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw); |
8265abc0 PM |
997 | #ifdef CONFIG_NET_CLS_ROUTE |
998 | if (nh->nh_tclassid) | |
be403ea1 | 999 | NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid); |
8265abc0 | 1000 | #endif |
be403ea1 TG |
1001 | /* length of rtnetlink header + attributes */ |
1002 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; | |
1da177e4 | 1003 | } endfor_nexthops(fi); |
be403ea1 TG |
1004 | |
1005 | nla_nest_end(skb, mp); | |
1da177e4 LT |
1006 | } |
1007 | #endif | |
be403ea1 | 1008 | return nlmsg_end(skb, nlh); |
1da177e4 | 1009 | |
be403ea1 TG |
1010 | nla_put_failure: |
1011 | return nlmsg_cancel(skb, nlh); | |
1da177e4 LT |
1012 | } |
1013 | ||
1da177e4 LT |
1014 | /* |
1015 | Update FIB if: | |
1016 | - local address disappeared -> we must delete all the entries | |
1017 | referring to it. | |
1018 | - device went down -> we must shutdown all nexthops going via it. | |
1019 | */ | |
1020 | ||
1021 | int fib_sync_down(u32 local, struct net_device *dev, int force) | |
1022 | { | |
1023 | int ret = 0; | |
1024 | int scope = RT_SCOPE_NOWHERE; | |
1025 | ||
1026 | if (force) | |
1027 | scope = -1; | |
1028 | ||
1029 | if (local && fib_info_laddrhash) { | |
1030 | unsigned int hash = fib_laddr_hashfn(local); | |
1031 | struct hlist_head *head = &fib_info_laddrhash[hash]; | |
1032 | struct hlist_node *node; | |
1033 | struct fib_info *fi; | |
1034 | ||
1035 | hlist_for_each_entry(fi, node, head, fib_lhash) { | |
1036 | if (fi->fib_prefsrc == local) { | |
1037 | fi->fib_flags |= RTNH_F_DEAD; | |
1038 | ret++; | |
1039 | } | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | if (dev) { | |
1044 | struct fib_info *prev_fi = NULL; | |
1045 | unsigned int hash = fib_devindex_hashfn(dev->ifindex); | |
1046 | struct hlist_head *head = &fib_info_devhash[hash]; | |
1047 | struct hlist_node *node; | |
1048 | struct fib_nh *nh; | |
1049 | ||
1050 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
1051 | struct fib_info *fi = nh->nh_parent; | |
1052 | int dead; | |
1053 | ||
1054 | BUG_ON(!fi->fib_nhs); | |
1055 | if (nh->nh_dev != dev || fi == prev_fi) | |
1056 | continue; | |
1057 | prev_fi = fi; | |
1058 | dead = 0; | |
1059 | change_nexthops(fi) { | |
1060 | if (nh->nh_flags&RTNH_F_DEAD) | |
1061 | dead++; | |
1062 | else if (nh->nh_dev == dev && | |
1063 | nh->nh_scope != scope) { | |
1064 | nh->nh_flags |= RTNH_F_DEAD; | |
1065 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1066 | spin_lock_bh(&fib_multipath_lock); | |
1067 | fi->fib_power -= nh->nh_power; | |
1068 | nh->nh_power = 0; | |
1069 | spin_unlock_bh(&fib_multipath_lock); | |
1070 | #endif | |
1071 | dead++; | |
1072 | } | |
1073 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1074 | if (force > 1 && nh->nh_dev == dev) { | |
1075 | dead = fi->fib_nhs; | |
1076 | break; | |
1077 | } | |
1078 | #endif | |
1079 | } endfor_nexthops(fi) | |
1080 | if (dead == fi->fib_nhs) { | |
1081 | fi->fib_flags |= RTNH_F_DEAD; | |
1082 | ret++; | |
1083 | } | |
1084 | } | |
1085 | } | |
1086 | ||
1087 | return ret; | |
1088 | } | |
1089 | ||
1090 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1091 | ||
1092 | /* | |
1093 | Dead device goes up. We wake up dead nexthops. | |
1094 | It takes sense only on multipath routes. | |
1095 | */ | |
1096 | ||
1097 | int fib_sync_up(struct net_device *dev) | |
1098 | { | |
1099 | struct fib_info *prev_fi; | |
1100 | unsigned int hash; | |
1101 | struct hlist_head *head; | |
1102 | struct hlist_node *node; | |
1103 | struct fib_nh *nh; | |
1104 | int ret; | |
1105 | ||
1106 | if (!(dev->flags&IFF_UP)) | |
1107 | return 0; | |
1108 | ||
1109 | prev_fi = NULL; | |
1110 | hash = fib_devindex_hashfn(dev->ifindex); | |
1111 | head = &fib_info_devhash[hash]; | |
1112 | ret = 0; | |
1113 | ||
1114 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
1115 | struct fib_info *fi = nh->nh_parent; | |
1116 | int alive; | |
1117 | ||
1118 | BUG_ON(!fi->fib_nhs); | |
1119 | if (nh->nh_dev != dev || fi == prev_fi) | |
1120 | continue; | |
1121 | ||
1122 | prev_fi = fi; | |
1123 | alive = 0; | |
1124 | change_nexthops(fi) { | |
1125 | if (!(nh->nh_flags&RTNH_F_DEAD)) { | |
1126 | alive++; | |
1127 | continue; | |
1128 | } | |
1129 | if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP)) | |
1130 | continue; | |
e5ed6399 | 1131 | if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev)) |
1da177e4 LT |
1132 | continue; |
1133 | alive++; | |
1134 | spin_lock_bh(&fib_multipath_lock); | |
1135 | nh->nh_power = 0; | |
1136 | nh->nh_flags &= ~RTNH_F_DEAD; | |
1137 | spin_unlock_bh(&fib_multipath_lock); | |
1138 | } endfor_nexthops(fi) | |
1139 | ||
1140 | if (alive > 0) { | |
1141 | fi->fib_flags &= ~RTNH_F_DEAD; | |
1142 | ret++; | |
1143 | } | |
1144 | } | |
1145 | ||
1146 | return ret; | |
1147 | } | |
1148 | ||
1149 | /* | |
1150 | The algorithm is suboptimal, but it provides really | |
1151 | fair weighted route distribution. | |
1152 | */ | |
1153 | ||
1154 | void fib_select_multipath(const struct flowi *flp, struct fib_result *res) | |
1155 | { | |
1156 | struct fib_info *fi = res->fi; | |
1157 | int w; | |
1158 | ||
1159 | spin_lock_bh(&fib_multipath_lock); | |
1160 | if (fi->fib_power <= 0) { | |
1161 | int power = 0; | |
1162 | change_nexthops(fi) { | |
1163 | if (!(nh->nh_flags&RTNH_F_DEAD)) { | |
1164 | power += nh->nh_weight; | |
1165 | nh->nh_power = nh->nh_weight; | |
1166 | } | |
1167 | } endfor_nexthops(fi); | |
1168 | fi->fib_power = power; | |
1169 | if (power <= 0) { | |
1170 | spin_unlock_bh(&fib_multipath_lock); | |
1171 | /* Race condition: route has just become dead. */ | |
1172 | res->nh_sel = 0; | |
1173 | return; | |
1174 | } | |
1175 | } | |
1176 | ||
1177 | ||
1178 | /* w should be random number [0..fi->fib_power-1], | |
1179 | it is pretty bad approximation. | |
1180 | */ | |
1181 | ||
1182 | w = jiffies % fi->fib_power; | |
1183 | ||
1184 | change_nexthops(fi) { | |
1185 | if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) { | |
1186 | if ((w -= nh->nh_power) <= 0) { | |
1187 | nh->nh_power--; | |
1188 | fi->fib_power--; | |
1189 | res->nh_sel = nhsel; | |
1190 | spin_unlock_bh(&fib_multipath_lock); | |
1191 | return; | |
1192 | } | |
1193 | } | |
1194 | } endfor_nexthops(fi); | |
1195 | ||
1196 | /* Race condition: route has just become dead. */ | |
1197 | res->nh_sel = 0; | |
1198 | spin_unlock_bh(&fib_multipath_lock); | |
1199 | } | |
1200 | #endif |