Commit | Line | Data |
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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> | |
f21c7bc5 | 45 | #include <net/netlink.h> |
4e902c57 | 46 | #include <net/nexthop.h> |
1da177e4 LT |
47 | |
48 | #include "fib_lookup.h" | |
49 | ||
50 | #define FSprintk(a...) | |
51 | ||
832b4c5e | 52 | static DEFINE_SPINLOCK(fib_info_lock); |
1da177e4 LT |
53 | static struct hlist_head *fib_info_hash; |
54 | static struct hlist_head *fib_info_laddrhash; | |
55 | static unsigned int fib_hash_size; | |
56 | static unsigned int fib_info_cnt; | |
57 | ||
58 | #define DEVINDEX_HASHBITS 8 | |
59 | #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) | |
60 | static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; | |
61 | ||
62 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
63 | ||
64 | static DEFINE_SPINLOCK(fib_multipath_lock); | |
65 | ||
66 | #define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \ | |
67 | for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++) | |
68 | ||
69 | #define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \ | |
70 | for (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; \ | |
77 | for (nhsel=0; nhsel < 1; nhsel++) | |
78 | ||
79 | #define change_nexthops(fi) { int nhsel=0; struct fib_nh * nh = (struct fib_nh*)((fi)->fib_nh); \ | |
80 | for (nhsel=0; nhsel < 1; nhsel++) | |
81 | ||
82 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ | |
83 | ||
84 | #define endfor_nexthops(fi) } | |
85 | ||
86 | ||
e905a9ed | 87 | static const struct |
1da177e4 LT |
88 | { |
89 | int error; | |
90 | u8 scope; | |
a0ee18b9 | 91 | } fib_props[RTN_MAX + 1] = { |
e905a9ed | 92 | { |
1da177e4 LT |
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 | ||
145 | void 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 | ||
160 | void fib_release_info(struct fib_info *fi) | |
161 | { | |
832b4c5e | 162 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
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 | } | |
832b4c5e | 175 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
176 | } |
177 | ||
178 | static __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 | ||
199 | static 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; | |
81f7bf6c | 205 | val ^= (__force u32)fi->fib_prefsrc; |
1da177e4 LT |
206 | val ^= fi->fib_priority; |
207 | ||
208 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; | |
209 | } | |
210 | ||
211 | static 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 | ||
237 | static 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 | ||
d878e72e | 250 | int ip_fib_check_default(__be32 gw, struct net_device *dev) |
1da177e4 LT |
251 | { |
252 | struct hlist_head *head; | |
253 | struct hlist_node *node; | |
254 | struct fib_nh *nh; | |
255 | unsigned int hash; | |
256 | ||
832b4c5e | 257 | spin_lock(&fib_info_lock); |
1da177e4 LT |
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)) { | |
832b4c5e | 265 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
266 | return 0; |
267 | } | |
268 | } | |
269 | ||
832b4c5e | 270 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
271 | |
272 | return -1; | |
273 | } | |
274 | ||
339bf98f TG |
275 | static inline size_t fib_nlmsg_size(struct fib_info *fi) |
276 | { | |
277 | size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) | |
278 | + nla_total_size(4) /* RTA_TABLE */ | |
279 | + nla_total_size(4) /* RTA_DST */ | |
280 | + nla_total_size(4) /* RTA_PRIORITY */ | |
281 | + nla_total_size(4); /* RTA_PREFSRC */ | |
282 | ||
283 | /* space for nested metrics */ | |
284 | payload += nla_total_size((RTAX_MAX * nla_total_size(4))); | |
285 | ||
286 | if (fi->fib_nhs) { | |
287 | /* Also handles the special case fib_nhs == 1 */ | |
288 | ||
289 | /* each nexthop is packed in an attribute */ | |
290 | size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); | |
291 | ||
292 | /* may contain flow and gateway attribute */ | |
293 | nhsize += 2 * nla_total_size(4); | |
294 | ||
295 | /* all nexthops are packed in a nested attribute */ | |
296 | payload += nla_total_size(fi->fib_nhs * nhsize); | |
297 | } | |
298 | ||
299 | return payload; | |
300 | } | |
301 | ||
81f7bf6c | 302 | void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
b8f55831 MK |
303 | int dst_len, u32 tb_id, struct nl_info *info, |
304 | unsigned int nlm_flags) | |
1da177e4 LT |
305 | { |
306 | struct sk_buff *skb; | |
4e902c57 | 307 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
f21c7bc5 | 308 | int err = -ENOBUFS; |
1da177e4 | 309 | |
339bf98f | 310 | skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
f21c7bc5 TG |
311 | if (skb == NULL) |
312 | goto errout; | |
1da177e4 | 313 | |
4e902c57 | 314 | err = fib_dump_info(skb, info->pid, seq, event, tb_id, |
be403ea1 | 315 | fa->fa_type, fa->fa_scope, key, dst_len, |
b8f55831 | 316 | fa->fa_tos, fa->fa_info, nlm_flags); |
26932566 PM |
317 | if (err < 0) { |
318 | /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ | |
319 | WARN_ON(err == -EMSGSIZE); | |
320 | kfree_skb(skb); | |
321 | goto errout; | |
322 | } | |
4e902c57 TG |
323 | err = rtnl_notify(skb, info->pid, RTNLGRP_IPV4_ROUTE, |
324 | info->nlh, GFP_KERNEL); | |
f21c7bc5 TG |
325 | errout: |
326 | if (err < 0) | |
327 | rtnl_set_sk_err(RTNLGRP_IPV4_ROUTE, err); | |
1da177e4 LT |
328 | } |
329 | ||
330 | /* Return the first fib alias matching TOS with | |
331 | * priority less than or equal to PRIO. | |
332 | */ | |
333 | struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio) | |
334 | { | |
335 | if (fah) { | |
336 | struct fib_alias *fa; | |
337 | list_for_each_entry(fa, fah, fa_list) { | |
338 | if (fa->fa_tos > tos) | |
339 | continue; | |
340 | if (fa->fa_info->fib_priority >= prio || | |
341 | fa->fa_tos < tos) | |
342 | return fa; | |
343 | } | |
344 | } | |
345 | return NULL; | |
346 | } | |
347 | ||
348 | int fib_detect_death(struct fib_info *fi, int order, | |
349 | struct fib_info **last_resort, int *last_idx, int *dflt) | |
350 | { | |
351 | struct neighbour *n; | |
352 | int state = NUD_NONE; | |
353 | ||
354 | n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev); | |
355 | if (n) { | |
356 | state = n->nud_state; | |
357 | neigh_release(n); | |
358 | } | |
359 | if (state==NUD_REACHABLE) | |
360 | return 0; | |
361 | if ((state&NUD_VALID) && order != *dflt) | |
362 | return 0; | |
363 | if ((state&NUD_VALID) || | |
364 | (*last_idx<0 && order > *dflt)) { | |
365 | *last_resort = fi; | |
366 | *last_idx = order; | |
367 | } | |
368 | return 1; | |
369 | } | |
370 | ||
371 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
372 | ||
4e902c57 | 373 | static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining) |
1da177e4 LT |
374 | { |
375 | int nhs = 0; | |
1da177e4 | 376 | |
4e902c57 | 377 | while (rtnh_ok(rtnh, remaining)) { |
1da177e4 | 378 | nhs++; |
4e902c57 TG |
379 | rtnh = rtnh_next(rtnh, &remaining); |
380 | } | |
381 | ||
382 | /* leftover implies invalid nexthop configuration, discard it */ | |
383 | return remaining > 0 ? 0 : nhs; | |
1da177e4 LT |
384 | } |
385 | ||
4e902c57 TG |
386 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
387 | int remaining, struct fib_config *cfg) | |
1da177e4 | 388 | { |
1da177e4 | 389 | change_nexthops(fi) { |
4e902c57 TG |
390 | int attrlen; |
391 | ||
392 | if (!rtnh_ok(rtnh, remaining)) | |
1da177e4 | 393 | return -EINVAL; |
4e902c57 TG |
394 | |
395 | nh->nh_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; | |
396 | nh->nh_oif = rtnh->rtnh_ifindex; | |
397 | nh->nh_weight = rtnh->rtnh_hops + 1; | |
398 | ||
399 | attrlen = rtnh_attrlen(rtnh); | |
400 | if (attrlen > 0) { | |
401 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
402 | ||
403 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 404 | nh->nh_gw = nla ? nla_get_be32(nla) : 0; |
1da177e4 | 405 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 TG |
406 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
407 | nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; | |
1da177e4 LT |
408 | #endif |
409 | } | |
4e902c57 TG |
410 | |
411 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 | 412 | } endfor_nexthops(fi); |
4e902c57 | 413 | |
1da177e4 LT |
414 | return 0; |
415 | } | |
416 | ||
417 | #endif | |
418 | ||
4e902c57 | 419 | int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) |
1da177e4 LT |
420 | { |
421 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
422 | struct rtnexthop *rtnh; |
423 | int remaining; | |
1da177e4 LT |
424 | #endif |
425 | ||
4e902c57 | 426 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
1da177e4 LT |
427 | return 1; |
428 | ||
4e902c57 TG |
429 | if (cfg->fc_oif || cfg->fc_gw) { |
430 | if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && | |
431 | (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) | |
1da177e4 LT |
432 | return 0; |
433 | return 1; | |
434 | } | |
435 | ||
436 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 | 437 | if (cfg->fc_mp == NULL) |
1da177e4 | 438 | return 0; |
4e902c57 TG |
439 | |
440 | rtnh = cfg->fc_mp; | |
441 | remaining = cfg->fc_mp_len; | |
e905a9ed | 442 | |
1da177e4 | 443 | for_nexthops(fi) { |
4e902c57 | 444 | int attrlen; |
1da177e4 | 445 | |
4e902c57 | 446 | if (!rtnh_ok(rtnh, remaining)) |
1da177e4 | 447 | return -EINVAL; |
4e902c57 TG |
448 | |
449 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) | |
1da177e4 | 450 | return 1; |
4e902c57 TG |
451 | |
452 | attrlen = rtnh_attrlen(rtnh); | |
453 | if (attrlen < 0) { | |
454 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
455 | ||
456 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 457 | if (nla && nla_get_be32(nla) != nh->nh_gw) |
1da177e4 LT |
458 | return 1; |
459 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 TG |
460 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
461 | if (nla && nla_get_u32(nla) != nh->nh_tclassid) | |
1da177e4 LT |
462 | return 1; |
463 | #endif | |
464 | } | |
4e902c57 TG |
465 | |
466 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 LT |
467 | } endfor_nexthops(fi); |
468 | #endif | |
469 | return 0; | |
470 | } | |
471 | ||
472 | ||
473 | /* | |
474 | Picture | |
475 | ------- | |
476 | ||
477 | Semantics of nexthop is very messy by historical reasons. | |
478 | We have to take into account, that: | |
479 | a) gateway can be actually local interface address, | |
480 | so that gatewayed route is direct. | |
481 | b) gateway must be on-link address, possibly | |
482 | described not by an ifaddr, but also by a direct route. | |
483 | c) If both gateway and interface are specified, they should not | |
484 | contradict. | |
485 | d) If we use tunnel routes, gateway could be not on-link. | |
486 | ||
487 | Attempt to reconcile all of these (alas, self-contradictory) conditions | |
488 | results in pretty ugly and hairy code with obscure logic. | |
489 | ||
490 | I chose to generalized it instead, so that the size | |
491 | of code does not increase practically, but it becomes | |
492 | much more general. | |
493 | Every prefix is assigned a "scope" value: "host" is local address, | |
494 | "link" is direct route, | |
495 | [ ... "site" ... "interior" ... ] | |
496 | and "universe" is true gateway route with global meaning. | |
497 | ||
498 | Every prefix refers to a set of "nexthop"s (gw, oif), | |
499 | where gw must have narrower scope. This recursion stops | |
500 | when gw has LOCAL scope or if "nexthop" is declared ONLINK, | |
501 | which means that gw is forced to be on link. | |
502 | ||
503 | Code is still hairy, but now it is apparently logically | |
504 | consistent and very flexible. F.e. as by-product it allows | |
505 | to co-exists in peace independent exterior and interior | |
506 | routing processes. | |
507 | ||
508 | Normally it looks as following. | |
509 | ||
510 | {universe prefix} -> (gw, oif) [scope link] | |
e905a9ed | 511 | | |
1da177e4 | 512 | |-> {link prefix} -> (gw, oif) [scope local] |
e905a9ed | 513 | | |
1da177e4 LT |
514 | |-> {local prefix} (terminal node) |
515 | */ | |
516 | ||
4e902c57 TG |
517 | static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, |
518 | struct fib_nh *nh) | |
1da177e4 LT |
519 | { |
520 | int err; | |
521 | ||
522 | if (nh->nh_gw) { | |
523 | struct fib_result res; | |
524 | ||
525 | #ifdef CONFIG_IP_ROUTE_PERVASIVE | |
526 | if (nh->nh_flags&RTNH_F_PERVASIVE) | |
527 | return 0; | |
528 | #endif | |
529 | if (nh->nh_flags&RTNH_F_ONLINK) { | |
530 | struct net_device *dev; | |
531 | ||
4e902c57 | 532 | if (cfg->fc_scope >= RT_SCOPE_LINK) |
1da177e4 LT |
533 | return -EINVAL; |
534 | if (inet_addr_type(nh->nh_gw) != RTN_UNICAST) | |
535 | return -EINVAL; | |
536 | if ((dev = __dev_get_by_index(nh->nh_oif)) == NULL) | |
537 | return -ENODEV; | |
538 | if (!(dev->flags&IFF_UP)) | |
539 | return -ENETDOWN; | |
540 | nh->nh_dev = dev; | |
541 | dev_hold(dev); | |
542 | nh->nh_scope = RT_SCOPE_LINK; | |
543 | return 0; | |
544 | } | |
545 | { | |
4e902c57 TG |
546 | struct flowi fl = { |
547 | .nl_u = { | |
548 | .ip4_u = { | |
549 | .daddr = nh->nh_gw, | |
550 | .scope = cfg->fc_scope + 1, | |
551 | }, | |
552 | }, | |
553 | .oif = nh->nh_oif, | |
554 | }; | |
1da177e4 LT |
555 | |
556 | /* It is not necessary, but requires a bit of thinking */ | |
557 | if (fl.fl4_scope < RT_SCOPE_LINK) | |
558 | fl.fl4_scope = RT_SCOPE_LINK; | |
559 | if ((err = fib_lookup(&fl, &res)) != 0) | |
560 | return err; | |
561 | } | |
562 | err = -EINVAL; | |
563 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) | |
564 | goto out; | |
565 | nh->nh_scope = res.scope; | |
566 | nh->nh_oif = FIB_RES_OIF(res); | |
567 | if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL) | |
568 | goto out; | |
569 | dev_hold(nh->nh_dev); | |
570 | err = -ENETDOWN; | |
571 | if (!(nh->nh_dev->flags & IFF_UP)) | |
572 | goto out; | |
573 | err = 0; | |
574 | out: | |
575 | fib_res_put(&res); | |
576 | return err; | |
577 | } else { | |
578 | struct in_device *in_dev; | |
579 | ||
580 | if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK)) | |
581 | return -EINVAL; | |
582 | ||
583 | in_dev = inetdev_by_index(nh->nh_oif); | |
584 | if (in_dev == NULL) | |
585 | return -ENODEV; | |
586 | if (!(in_dev->dev->flags&IFF_UP)) { | |
587 | in_dev_put(in_dev); | |
588 | return -ENETDOWN; | |
589 | } | |
590 | nh->nh_dev = in_dev->dev; | |
591 | dev_hold(nh->nh_dev); | |
592 | nh->nh_scope = RT_SCOPE_HOST; | |
593 | in_dev_put(in_dev); | |
594 | } | |
595 | return 0; | |
596 | } | |
597 | ||
81f7bf6c | 598 | static inline unsigned int fib_laddr_hashfn(__be32 val) |
1da177e4 LT |
599 | { |
600 | unsigned int mask = (fib_hash_size - 1); | |
601 | ||
81f7bf6c | 602 | return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask; |
1da177e4 LT |
603 | } |
604 | ||
605 | static struct hlist_head *fib_hash_alloc(int bytes) | |
606 | { | |
607 | if (bytes <= PAGE_SIZE) | |
608 | return kmalloc(bytes, GFP_KERNEL); | |
609 | else | |
610 | return (struct hlist_head *) | |
611 | __get_free_pages(GFP_KERNEL, get_order(bytes)); | |
612 | } | |
613 | ||
614 | static void fib_hash_free(struct hlist_head *hash, int bytes) | |
615 | { | |
616 | if (!hash) | |
617 | return; | |
618 | ||
619 | if (bytes <= PAGE_SIZE) | |
620 | kfree(hash); | |
621 | else | |
622 | free_pages((unsigned long) hash, get_order(bytes)); | |
623 | } | |
624 | ||
625 | static void fib_hash_move(struct hlist_head *new_info_hash, | |
626 | struct hlist_head *new_laddrhash, | |
627 | unsigned int new_size) | |
628 | { | |
b7656e7f | 629 | struct hlist_head *old_info_hash, *old_laddrhash; |
1da177e4 | 630 | unsigned int old_size = fib_hash_size; |
b7656e7f | 631 | unsigned int i, bytes; |
1da177e4 | 632 | |
832b4c5e | 633 | spin_lock_bh(&fib_info_lock); |
b7656e7f DM |
634 | old_info_hash = fib_info_hash; |
635 | old_laddrhash = fib_info_laddrhash; | |
1da177e4 LT |
636 | fib_hash_size = new_size; |
637 | ||
638 | for (i = 0; i < old_size; i++) { | |
639 | struct hlist_head *head = &fib_info_hash[i]; | |
640 | struct hlist_node *node, *n; | |
641 | struct fib_info *fi; | |
642 | ||
643 | hlist_for_each_entry_safe(fi, node, n, head, fib_hash) { | |
644 | struct hlist_head *dest; | |
645 | unsigned int new_hash; | |
646 | ||
647 | hlist_del(&fi->fib_hash); | |
648 | ||
649 | new_hash = fib_info_hashfn(fi); | |
650 | dest = &new_info_hash[new_hash]; | |
651 | hlist_add_head(&fi->fib_hash, dest); | |
652 | } | |
653 | } | |
654 | fib_info_hash = new_info_hash; | |
655 | ||
656 | for (i = 0; i < old_size; i++) { | |
657 | struct hlist_head *lhead = &fib_info_laddrhash[i]; | |
658 | struct hlist_node *node, *n; | |
659 | struct fib_info *fi; | |
660 | ||
661 | hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) { | |
662 | struct hlist_head *ldest; | |
663 | unsigned int new_hash; | |
664 | ||
665 | hlist_del(&fi->fib_lhash); | |
666 | ||
667 | new_hash = fib_laddr_hashfn(fi->fib_prefsrc); | |
668 | ldest = &new_laddrhash[new_hash]; | |
669 | hlist_add_head(&fi->fib_lhash, ldest); | |
670 | } | |
671 | } | |
672 | fib_info_laddrhash = new_laddrhash; | |
673 | ||
832b4c5e | 674 | spin_unlock_bh(&fib_info_lock); |
b7656e7f DM |
675 | |
676 | bytes = old_size * sizeof(struct hlist_head *); | |
677 | fib_hash_free(old_info_hash, bytes); | |
678 | fib_hash_free(old_laddrhash, bytes); | |
1da177e4 LT |
679 | } |
680 | ||
4e902c57 | 681 | struct fib_info *fib_create_info(struct fib_config *cfg) |
1da177e4 LT |
682 | { |
683 | int err; | |
684 | struct fib_info *fi = NULL; | |
685 | struct fib_info *ofi; | |
1da177e4 | 686 | int nhs = 1; |
1da177e4 LT |
687 | |
688 | /* Fast check to catch the most weird cases */ | |
4e902c57 | 689 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) |
1da177e4 LT |
690 | goto err_inval; |
691 | ||
692 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
693 | if (cfg->fc_mp) { |
694 | nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); | |
1da177e4 LT |
695 | if (nhs == 0) |
696 | goto err_inval; | |
697 | } | |
698 | #endif | |
1da177e4 LT |
699 | |
700 | err = -ENOBUFS; | |
701 | if (fib_info_cnt >= fib_hash_size) { | |
702 | unsigned int new_size = fib_hash_size << 1; | |
703 | struct hlist_head *new_info_hash; | |
704 | struct hlist_head *new_laddrhash; | |
705 | unsigned int bytes; | |
706 | ||
707 | if (!new_size) | |
708 | new_size = 1; | |
709 | bytes = new_size * sizeof(struct hlist_head *); | |
710 | new_info_hash = fib_hash_alloc(bytes); | |
711 | new_laddrhash = fib_hash_alloc(bytes); | |
712 | if (!new_info_hash || !new_laddrhash) { | |
713 | fib_hash_free(new_info_hash, bytes); | |
714 | fib_hash_free(new_laddrhash, bytes); | |
715 | } else { | |
716 | memset(new_info_hash, 0, bytes); | |
717 | memset(new_laddrhash, 0, bytes); | |
718 | ||
719 | fib_hash_move(new_info_hash, new_laddrhash, new_size); | |
720 | } | |
721 | ||
722 | if (!fib_hash_size) | |
723 | goto failure; | |
724 | } | |
725 | ||
0da974f4 | 726 | fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); |
1da177e4 LT |
727 | if (fi == NULL) |
728 | goto failure; | |
729 | fib_info_cnt++; | |
1da177e4 | 730 | |
4e902c57 TG |
731 | fi->fib_protocol = cfg->fc_protocol; |
732 | fi->fib_flags = cfg->fc_flags; | |
733 | fi->fib_priority = cfg->fc_priority; | |
734 | fi->fib_prefsrc = cfg->fc_prefsrc; | |
1da177e4 LT |
735 | |
736 | fi->fib_nhs = nhs; | |
737 | change_nexthops(fi) { | |
738 | nh->nh_parent = fi; | |
739 | } endfor_nexthops(fi) | |
740 | ||
4e902c57 TG |
741 | if (cfg->fc_mx) { |
742 | struct nlattr *nla; | |
743 | int remaining; | |
744 | ||
745 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { | |
746 | int type = nla->nla_type; | |
747 | ||
748 | if (type) { | |
749 | if (type > RTAX_MAX) | |
1da177e4 | 750 | goto err_inval; |
4e902c57 | 751 | fi->fib_metrics[type - 1] = nla_get_u32(nla); |
1da177e4 | 752 | } |
1da177e4 LT |
753 | } |
754 | } | |
1da177e4 | 755 | |
4e902c57 | 756 | if (cfg->fc_mp) { |
1da177e4 | 757 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
4e902c57 TG |
758 | err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); |
759 | if (err != 0) | |
1da177e4 | 760 | goto failure; |
4e902c57 | 761 | if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) |
1da177e4 | 762 | goto err_inval; |
4e902c57 | 763 | if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) |
1da177e4 LT |
764 | goto err_inval; |
765 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 | 766 | if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) |
1da177e4 LT |
767 | goto err_inval; |
768 | #endif | |
769 | #else | |
770 | goto err_inval; | |
771 | #endif | |
772 | } else { | |
773 | struct fib_nh *nh = fi->fib_nh; | |
4e902c57 TG |
774 | |
775 | nh->nh_oif = cfg->fc_oif; | |
776 | nh->nh_gw = cfg->fc_gw; | |
777 | nh->nh_flags = cfg->fc_flags; | |
1da177e4 | 778 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 | 779 | nh->nh_tclassid = cfg->fc_flow; |
1da177e4 | 780 | #endif |
1da177e4 LT |
781 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
782 | nh->nh_weight = 1; | |
783 | #endif | |
784 | } | |
785 | ||
4e902c57 TG |
786 | if (fib_props[cfg->fc_type].error) { |
787 | if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) | |
1da177e4 LT |
788 | goto err_inval; |
789 | goto link_it; | |
790 | } | |
791 | ||
4e902c57 | 792 | if (cfg->fc_scope > RT_SCOPE_HOST) |
1da177e4 LT |
793 | goto err_inval; |
794 | ||
4e902c57 | 795 | if (cfg->fc_scope == RT_SCOPE_HOST) { |
1da177e4 LT |
796 | struct fib_nh *nh = fi->fib_nh; |
797 | ||
798 | /* Local address is added. */ | |
799 | if (nhs != 1 || nh->nh_gw) | |
800 | goto err_inval; | |
801 | nh->nh_scope = RT_SCOPE_NOWHERE; | |
802 | nh->nh_dev = dev_get_by_index(fi->fib_nh->nh_oif); | |
803 | err = -ENODEV; | |
804 | if (nh->nh_dev == NULL) | |
805 | goto failure; | |
806 | } else { | |
807 | change_nexthops(fi) { | |
4e902c57 | 808 | if ((err = fib_check_nh(cfg, fi, nh)) != 0) |
1da177e4 LT |
809 | goto failure; |
810 | } endfor_nexthops(fi) | |
811 | } | |
812 | ||
813 | if (fi->fib_prefsrc) { | |
4e902c57 TG |
814 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
815 | fi->fib_prefsrc != cfg->fc_dst) | |
1da177e4 LT |
816 | if (inet_addr_type(fi->fib_prefsrc) != RTN_LOCAL) |
817 | goto err_inval; | |
818 | } | |
819 | ||
820 | link_it: | |
821 | if ((ofi = fib_find_info(fi)) != NULL) { | |
822 | fi->fib_dead = 1; | |
823 | free_fib_info(fi); | |
824 | ofi->fib_treeref++; | |
825 | return ofi; | |
826 | } | |
827 | ||
828 | fi->fib_treeref++; | |
829 | atomic_inc(&fi->fib_clntref); | |
832b4c5e | 830 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
831 | hlist_add_head(&fi->fib_hash, |
832 | &fib_info_hash[fib_info_hashfn(fi)]); | |
833 | if (fi->fib_prefsrc) { | |
834 | struct hlist_head *head; | |
835 | ||
836 | head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; | |
837 | hlist_add_head(&fi->fib_lhash, head); | |
838 | } | |
839 | change_nexthops(fi) { | |
840 | struct hlist_head *head; | |
841 | unsigned int hash; | |
842 | ||
843 | if (!nh->nh_dev) | |
844 | continue; | |
845 | hash = fib_devindex_hashfn(nh->nh_dev->ifindex); | |
846 | head = &fib_info_devhash[hash]; | |
847 | hlist_add_head(&nh->nh_hash, head); | |
848 | } endfor_nexthops(fi) | |
832b4c5e | 849 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
850 | return fi; |
851 | ||
852 | err_inval: | |
853 | err = -EINVAL; | |
854 | ||
855 | failure: | |
e905a9ed | 856 | if (fi) { |
1da177e4 LT |
857 | fi->fib_dead = 1; |
858 | free_fib_info(fi); | |
859 | } | |
4e902c57 TG |
860 | |
861 | return ERR_PTR(err); | |
1da177e4 LT |
862 | } |
863 | ||
e5b43760 | 864 | /* Note! fib_semantic_match intentionally uses RCU list functions. */ |
1da177e4 | 865 | int fib_semantic_match(struct list_head *head, const struct flowi *flp, |
1ef1b8c8 | 866 | struct fib_result *res, __be32 zone, __be32 mask, |
1da177e4 LT |
867 | int prefixlen) |
868 | { | |
869 | struct fib_alias *fa; | |
870 | int nh_sel = 0; | |
871 | ||
e5b43760 | 872 | list_for_each_entry_rcu(fa, head, fa_list) { |
1da177e4 LT |
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_DEBUG "impossible 102\n"); | |
918 | return -EINVAL; | |
3ff50b79 | 919 | } |
1da177e4 LT |
920 | } |
921 | return err; | |
922 | } | |
923 | return 1; | |
924 | ||
925 | out_fill_res: | |
926 | res->prefixlen = prefixlen; | |
927 | res->nh_sel = nh_sel; | |
928 | res->type = fa->fa_type; | |
929 | res->scope = fa->fa_scope; | |
930 | res->fi = fa->fa_info; | |
1da177e4 LT |
931 | atomic_inc(&res->fi->fib_clntref); |
932 | return 0; | |
933 | } | |
934 | ||
935 | /* Find appropriate source address to this destination */ | |
936 | ||
b83738ae | 937 | __be32 __fib_res_prefsrc(struct fib_result *res) |
1da177e4 LT |
938 | { |
939 | return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope); | |
940 | } | |
941 | ||
be403ea1 | 942 | int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
81f7bf6c | 943 | u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos, |
be403ea1 | 944 | struct fib_info *fi, unsigned int flags) |
1da177e4 | 945 | { |
be403ea1 | 946 | struct nlmsghdr *nlh; |
1da177e4 | 947 | struct rtmsg *rtm; |
1da177e4 | 948 | |
be403ea1 TG |
949 | nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags); |
950 | if (nlh == NULL) | |
26932566 | 951 | return -EMSGSIZE; |
be403ea1 TG |
952 | |
953 | rtm = nlmsg_data(nlh); | |
1da177e4 LT |
954 | rtm->rtm_family = AF_INET; |
955 | rtm->rtm_dst_len = dst_len; | |
956 | rtm->rtm_src_len = 0; | |
957 | rtm->rtm_tos = tos; | |
958 | rtm->rtm_table = tb_id; | |
be403ea1 | 959 | NLA_PUT_U32(skb, RTA_TABLE, tb_id); |
1da177e4 LT |
960 | rtm->rtm_type = type; |
961 | rtm->rtm_flags = fi->fib_flags; | |
962 | rtm->rtm_scope = scope; | |
1da177e4 | 963 | rtm->rtm_protocol = fi->fib_protocol; |
be403ea1 TG |
964 | |
965 | if (rtm->rtm_dst_len) | |
17fb2c64 | 966 | NLA_PUT_BE32(skb, RTA_DST, dst); |
be403ea1 | 967 | |
1da177e4 | 968 | if (fi->fib_priority) |
be403ea1 TG |
969 | NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority); |
970 | ||
1da177e4 | 971 | if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) |
be403ea1 TG |
972 | goto nla_put_failure; |
973 | ||
1da177e4 | 974 | if (fi->fib_prefsrc) |
17fb2c64 | 975 | NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc); |
be403ea1 | 976 | |
1da177e4 LT |
977 | if (fi->fib_nhs == 1) { |
978 | if (fi->fib_nh->nh_gw) | |
17fb2c64 | 979 | NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw); |
be403ea1 | 980 | |
1da177e4 | 981 | if (fi->fib_nh->nh_oif) |
be403ea1 | 982 | NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif); |
8265abc0 PM |
983 | #ifdef CONFIG_NET_CLS_ROUTE |
984 | if (fi->fib_nh[0].nh_tclassid) | |
be403ea1 | 985 | NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid); |
8265abc0 | 986 | #endif |
1da177e4 LT |
987 | } |
988 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
989 | if (fi->fib_nhs > 1) { | |
be403ea1 TG |
990 | struct rtnexthop *rtnh; |
991 | struct nlattr *mp; | |
992 | ||
993 | mp = nla_nest_start(skb, RTA_MULTIPATH); | |
994 | if (mp == NULL) | |
995 | goto nla_put_failure; | |
1da177e4 LT |
996 | |
997 | for_nexthops(fi) { | |
be403ea1 TG |
998 | rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
999 | if (rtnh == NULL) | |
1000 | goto nla_put_failure; | |
1001 | ||
1002 | rtnh->rtnh_flags = nh->nh_flags & 0xFF; | |
1003 | rtnh->rtnh_hops = nh->nh_weight - 1; | |
1004 | rtnh->rtnh_ifindex = nh->nh_oif; | |
1005 | ||
1da177e4 | 1006 | if (nh->nh_gw) |
17fb2c64 | 1007 | NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw); |
8265abc0 PM |
1008 | #ifdef CONFIG_NET_CLS_ROUTE |
1009 | if (nh->nh_tclassid) | |
be403ea1 | 1010 | NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid); |
8265abc0 | 1011 | #endif |
be403ea1 TG |
1012 | /* length of rtnetlink header + attributes */ |
1013 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; | |
1da177e4 | 1014 | } endfor_nexthops(fi); |
be403ea1 TG |
1015 | |
1016 | nla_nest_end(skb, mp); | |
1da177e4 LT |
1017 | } |
1018 | #endif | |
be403ea1 | 1019 | return nlmsg_end(skb, nlh); |
1da177e4 | 1020 | |
be403ea1 | 1021 | nla_put_failure: |
26932566 PM |
1022 | nlmsg_cancel(skb, nlh); |
1023 | return -EMSGSIZE; | |
1da177e4 LT |
1024 | } |
1025 | ||
1da177e4 LT |
1026 | /* |
1027 | Update FIB if: | |
1028 | - local address disappeared -> we must delete all the entries | |
1029 | referring to it. | |
1030 | - device went down -> we must shutdown all nexthops going via it. | |
1031 | */ | |
1032 | ||
81f7bf6c | 1033 | int fib_sync_down(__be32 local, struct net_device *dev, int force) |
1da177e4 LT |
1034 | { |
1035 | int ret = 0; | |
1036 | int scope = RT_SCOPE_NOWHERE; | |
e905a9ed | 1037 | |
1da177e4 LT |
1038 | if (force) |
1039 | scope = -1; | |
1040 | ||
1041 | if (local && fib_info_laddrhash) { | |
1042 | unsigned int hash = fib_laddr_hashfn(local); | |
1043 | struct hlist_head *head = &fib_info_laddrhash[hash]; | |
1044 | struct hlist_node *node; | |
1045 | struct fib_info *fi; | |
1046 | ||
1047 | hlist_for_each_entry(fi, node, head, fib_lhash) { | |
1048 | if (fi->fib_prefsrc == local) { | |
1049 | fi->fib_flags |= RTNH_F_DEAD; | |
1050 | ret++; | |
1051 | } | |
1052 | } | |
1053 | } | |
1054 | ||
1055 | if (dev) { | |
1056 | struct fib_info *prev_fi = NULL; | |
1057 | unsigned int hash = fib_devindex_hashfn(dev->ifindex); | |
1058 | struct hlist_head *head = &fib_info_devhash[hash]; | |
1059 | struct hlist_node *node; | |
1060 | struct fib_nh *nh; | |
1061 | ||
1062 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
1063 | struct fib_info *fi = nh->nh_parent; | |
1064 | int dead; | |
1065 | ||
1066 | BUG_ON(!fi->fib_nhs); | |
1067 | if (nh->nh_dev != dev || fi == prev_fi) | |
1068 | continue; | |
1069 | prev_fi = fi; | |
1070 | dead = 0; | |
1071 | change_nexthops(fi) { | |
1072 | if (nh->nh_flags&RTNH_F_DEAD) | |
1073 | dead++; | |
1074 | else if (nh->nh_dev == dev && | |
1075 | nh->nh_scope != scope) { | |
1076 | nh->nh_flags |= RTNH_F_DEAD; | |
1077 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1078 | spin_lock_bh(&fib_multipath_lock); | |
1079 | fi->fib_power -= nh->nh_power; | |
1080 | nh->nh_power = 0; | |
1081 | spin_unlock_bh(&fib_multipath_lock); | |
1082 | #endif | |
1083 | dead++; | |
1084 | } | |
1085 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1086 | if (force > 1 && nh->nh_dev == dev) { | |
1087 | dead = fi->fib_nhs; | |
1088 | break; | |
1089 | } | |
1090 | #endif | |
1091 | } endfor_nexthops(fi) | |
1092 | if (dead == fi->fib_nhs) { | |
1093 | fi->fib_flags |= RTNH_F_DEAD; | |
1094 | ret++; | |
1095 | } | |
1096 | } | |
1097 | } | |
1098 | ||
1099 | return ret; | |
1100 | } | |
1101 | ||
1102 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1103 | ||
1104 | /* | |
1105 | Dead device goes up. We wake up dead nexthops. | |
1106 | It takes sense only on multipath routes. | |
1107 | */ | |
1108 | ||
1109 | int fib_sync_up(struct net_device *dev) | |
1110 | { | |
1111 | struct fib_info *prev_fi; | |
1112 | unsigned int hash; | |
1113 | struct hlist_head *head; | |
1114 | struct hlist_node *node; | |
1115 | struct fib_nh *nh; | |
1116 | int ret; | |
1117 | ||
1118 | if (!(dev->flags&IFF_UP)) | |
1119 | return 0; | |
1120 | ||
1121 | prev_fi = NULL; | |
1122 | hash = fib_devindex_hashfn(dev->ifindex); | |
1123 | head = &fib_info_devhash[hash]; | |
1124 | ret = 0; | |
1125 | ||
1126 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
1127 | struct fib_info *fi = nh->nh_parent; | |
1128 | int alive; | |
1129 | ||
1130 | BUG_ON(!fi->fib_nhs); | |
1131 | if (nh->nh_dev != dev || fi == prev_fi) | |
1132 | continue; | |
1133 | ||
1134 | prev_fi = fi; | |
1135 | alive = 0; | |
1136 | change_nexthops(fi) { | |
1137 | if (!(nh->nh_flags&RTNH_F_DEAD)) { | |
1138 | alive++; | |
1139 | continue; | |
1140 | } | |
1141 | if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP)) | |
1142 | continue; | |
e5ed6399 | 1143 | if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev)) |
1da177e4 LT |
1144 | continue; |
1145 | alive++; | |
1146 | spin_lock_bh(&fib_multipath_lock); | |
1147 | nh->nh_power = 0; | |
1148 | nh->nh_flags &= ~RTNH_F_DEAD; | |
1149 | spin_unlock_bh(&fib_multipath_lock); | |
1150 | } endfor_nexthops(fi) | |
1151 | ||
1152 | if (alive > 0) { | |
1153 | fi->fib_flags &= ~RTNH_F_DEAD; | |
1154 | ret++; | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | return ret; | |
1159 | } | |
1160 | ||
1161 | /* | |
1162 | The algorithm is suboptimal, but it provides really | |
1163 | fair weighted route distribution. | |
1164 | */ | |
1165 | ||
1166 | void fib_select_multipath(const struct flowi *flp, struct fib_result *res) | |
1167 | { | |
1168 | struct fib_info *fi = res->fi; | |
1169 | int w; | |
1170 | ||
1171 | spin_lock_bh(&fib_multipath_lock); | |
1172 | if (fi->fib_power <= 0) { | |
1173 | int power = 0; | |
1174 | change_nexthops(fi) { | |
1175 | if (!(nh->nh_flags&RTNH_F_DEAD)) { | |
1176 | power += nh->nh_weight; | |
1177 | nh->nh_power = nh->nh_weight; | |
1178 | } | |
1179 | } endfor_nexthops(fi); | |
1180 | fi->fib_power = power; | |
1181 | if (power <= 0) { | |
1182 | spin_unlock_bh(&fib_multipath_lock); | |
1183 | /* Race condition: route has just become dead. */ | |
1184 | res->nh_sel = 0; | |
1185 | return; | |
1186 | } | |
1187 | } | |
1188 | ||
1189 | ||
1190 | /* w should be random number [0..fi->fib_power-1], | |
1191 | it is pretty bad approximation. | |
1192 | */ | |
1193 | ||
1194 | w = jiffies % fi->fib_power; | |
1195 | ||
1196 | change_nexthops(fi) { | |
1197 | if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) { | |
1198 | if ((w -= nh->nh_power) <= 0) { | |
1199 | nh->nh_power--; | |
1200 | fi->fib_power--; | |
1201 | res->nh_sel = nhsel; | |
1202 | spin_unlock_bh(&fib_multipath_lock); | |
1203 | return; | |
1204 | } | |
1205 | } | |
1206 | } endfor_nexthops(fi); | |
1207 | ||
1208 | /* Race condition: route has just become dead. */ | |
1209 | res->nh_sel = 0; | |
1210 | spin_unlock_bh(&fib_multipath_lock); | |
1211 | } | |
1212 | #endif |