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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 | ||
832b4c5e | 50 | static DEFINE_SPINLOCK(fib_info_lock); |
1da177e4 LT |
51 | static struct hlist_head *fib_info_hash; |
52 | static struct hlist_head *fib_info_laddrhash; | |
53 | static unsigned int fib_hash_size; | |
54 | static unsigned int fib_info_cnt; | |
55 | ||
56 | #define DEVINDEX_HASHBITS 8 | |
57 | #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) | |
58 | static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; | |
59 | ||
60 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
61 | ||
62 | static DEFINE_SPINLOCK(fib_multipath_lock); | |
63 | ||
64 | #define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \ | |
65 | for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++) | |
66 | ||
67 | #define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \ | |
68 | for (nhsel=0, nh = (struct fib_nh*)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++) | |
69 | ||
70 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ | |
71 | ||
72 | /* Hope, that gcc will optimize it to get rid of dummy loop */ | |
73 | ||
74 | #define for_nexthops(fi) { int nhsel=0; const struct fib_nh * nh = (fi)->fib_nh; \ | |
75 | for (nhsel=0; nhsel < 1; nhsel++) | |
76 | ||
77 | #define change_nexthops(fi) { int nhsel=0; struct fib_nh * nh = (struct fib_nh*)((fi)->fib_nh); \ | |
78 | for (nhsel=0; nhsel < 1; nhsel++) | |
79 | ||
80 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ | |
81 | ||
82 | #define endfor_nexthops(fi) } | |
83 | ||
84 | ||
e905a9ed | 85 | static const struct |
1da177e4 LT |
86 | { |
87 | int error; | |
88 | u8 scope; | |
a0ee18b9 | 89 | } fib_props[RTN_MAX + 1] = { |
e905a9ed | 90 | { |
1da177e4 LT |
91 | .error = 0, |
92 | .scope = RT_SCOPE_NOWHERE, | |
93 | }, /* RTN_UNSPEC */ | |
94 | { | |
95 | .error = 0, | |
96 | .scope = RT_SCOPE_UNIVERSE, | |
97 | }, /* RTN_UNICAST */ | |
98 | { | |
99 | .error = 0, | |
100 | .scope = RT_SCOPE_HOST, | |
101 | }, /* RTN_LOCAL */ | |
102 | { | |
103 | .error = 0, | |
104 | .scope = RT_SCOPE_LINK, | |
105 | }, /* RTN_BROADCAST */ | |
106 | { | |
107 | .error = 0, | |
108 | .scope = RT_SCOPE_LINK, | |
109 | }, /* RTN_ANYCAST */ | |
110 | { | |
111 | .error = 0, | |
112 | .scope = RT_SCOPE_UNIVERSE, | |
113 | }, /* RTN_MULTICAST */ | |
114 | { | |
115 | .error = -EINVAL, | |
116 | .scope = RT_SCOPE_UNIVERSE, | |
117 | }, /* RTN_BLACKHOLE */ | |
118 | { | |
119 | .error = -EHOSTUNREACH, | |
120 | .scope = RT_SCOPE_UNIVERSE, | |
121 | }, /* RTN_UNREACHABLE */ | |
122 | { | |
123 | .error = -EACCES, | |
124 | .scope = RT_SCOPE_UNIVERSE, | |
125 | }, /* RTN_PROHIBIT */ | |
126 | { | |
127 | .error = -EAGAIN, | |
128 | .scope = RT_SCOPE_UNIVERSE, | |
129 | }, /* RTN_THROW */ | |
130 | { | |
131 | .error = -EINVAL, | |
132 | .scope = RT_SCOPE_NOWHERE, | |
133 | }, /* RTN_NAT */ | |
134 | { | |
135 | .error = -EINVAL, | |
136 | .scope = RT_SCOPE_NOWHERE, | |
137 | }, /* RTN_XRESOLVE */ | |
138 | }; | |
139 | ||
140 | ||
141 | /* Release a nexthop info record */ | |
142 | ||
143 | void free_fib_info(struct fib_info *fi) | |
144 | { | |
145 | if (fi->fib_dead == 0) { | |
a6db9010 | 146 | printk(KERN_WARNING "Freeing alive fib_info %p\n", fi); |
1da177e4 LT |
147 | return; |
148 | } | |
149 | change_nexthops(fi) { | |
150 | if (nh->nh_dev) | |
151 | dev_put(nh->nh_dev); | |
152 | nh->nh_dev = NULL; | |
153 | } endfor_nexthops(fi); | |
154 | fib_info_cnt--; | |
57d7a600 | 155 | release_net(fi->fib_net); |
1da177e4 LT |
156 | kfree(fi); |
157 | } | |
158 | ||
159 | void fib_release_info(struct fib_info *fi) | |
160 | { | |
832b4c5e | 161 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
162 | if (fi && --fi->fib_treeref == 0) { |
163 | hlist_del(&fi->fib_hash); | |
164 | if (fi->fib_prefsrc) | |
165 | hlist_del(&fi->fib_lhash); | |
166 | change_nexthops(fi) { | |
167 | if (!nh->nh_dev) | |
168 | continue; | |
169 | hlist_del(&nh->nh_hash); | |
170 | } endfor_nexthops(fi) | |
171 | fi->fib_dead = 1; | |
172 | fib_info_put(fi); | |
173 | } | |
832b4c5e | 174 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
175 | } |
176 | ||
177 | static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) | |
178 | { | |
179 | const struct fib_nh *onh = ofi->fib_nh; | |
180 | ||
181 | for_nexthops(fi) { | |
182 | if (nh->nh_oif != onh->nh_oif || | |
183 | nh->nh_gw != onh->nh_gw || | |
184 | nh->nh_scope != onh->nh_scope || | |
185 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
186 | nh->nh_weight != onh->nh_weight || | |
187 | #endif | |
188 | #ifdef CONFIG_NET_CLS_ROUTE | |
189 | nh->nh_tclassid != onh->nh_tclassid || | |
190 | #endif | |
191 | ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD)) | |
192 | return -1; | |
193 | onh++; | |
194 | } endfor_nexthops(fi); | |
195 | return 0; | |
196 | } | |
197 | ||
88ebc72f DM |
198 | static inline unsigned int fib_devindex_hashfn(unsigned int val) |
199 | { | |
200 | unsigned int mask = DEVINDEX_HASHSIZE - 1; | |
201 | ||
202 | return (val ^ | |
203 | (val >> DEVINDEX_HASHBITS) ^ | |
204 | (val >> (DEVINDEX_HASHBITS * 2))) & mask; | |
205 | } | |
206 | ||
1da177e4 LT |
207 | static inline unsigned int fib_info_hashfn(const struct fib_info *fi) |
208 | { | |
209 | unsigned int mask = (fib_hash_size - 1); | |
210 | unsigned int val = fi->fib_nhs; | |
211 | ||
212 | val ^= fi->fib_protocol; | |
81f7bf6c | 213 | val ^= (__force u32)fi->fib_prefsrc; |
1da177e4 | 214 | val ^= fi->fib_priority; |
88ebc72f DM |
215 | for_nexthops(fi) { |
216 | val ^= fib_devindex_hashfn(nh->nh_oif); | |
217 | } endfor_nexthops(fi) | |
1da177e4 LT |
218 | |
219 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; | |
220 | } | |
221 | ||
222 | static struct fib_info *fib_find_info(const struct fib_info *nfi) | |
223 | { | |
224 | struct hlist_head *head; | |
225 | struct hlist_node *node; | |
226 | struct fib_info *fi; | |
227 | unsigned int hash; | |
228 | ||
229 | hash = fib_info_hashfn(nfi); | |
230 | head = &fib_info_hash[hash]; | |
231 | ||
232 | hlist_for_each_entry(fi, node, head, fib_hash) { | |
4814bdbd DL |
233 | if (fi->fib_net != nfi->fib_net) |
234 | continue; | |
1da177e4 LT |
235 | if (fi->fib_nhs != nfi->fib_nhs) |
236 | continue; | |
237 | if (nfi->fib_protocol == fi->fib_protocol && | |
238 | nfi->fib_prefsrc == fi->fib_prefsrc && | |
239 | nfi->fib_priority == fi->fib_priority && | |
240 | memcmp(nfi->fib_metrics, fi->fib_metrics, | |
241 | sizeof(fi->fib_metrics)) == 0 && | |
242 | ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 && | |
243 | (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) | |
244 | return fi; | |
245 | } | |
246 | ||
247 | return NULL; | |
248 | } | |
249 | ||
1da177e4 LT |
250 | /* Check, that the gateway is already configured. |
251 | Used only by redirect accept routine. | |
252 | */ | |
253 | ||
d878e72e | 254 | int ip_fib_check_default(__be32 gw, struct net_device *dev) |
1da177e4 LT |
255 | { |
256 | struct hlist_head *head; | |
257 | struct hlist_node *node; | |
258 | struct fib_nh *nh; | |
259 | unsigned int hash; | |
260 | ||
832b4c5e | 261 | spin_lock(&fib_info_lock); |
1da177e4 LT |
262 | |
263 | hash = fib_devindex_hashfn(dev->ifindex); | |
264 | head = &fib_info_devhash[hash]; | |
265 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
266 | if (nh->nh_dev == dev && | |
267 | nh->nh_gw == gw && | |
268 | !(nh->nh_flags&RTNH_F_DEAD)) { | |
832b4c5e | 269 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
270 | return 0; |
271 | } | |
272 | } | |
273 | ||
832b4c5e | 274 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
275 | |
276 | return -1; | |
277 | } | |
278 | ||
339bf98f TG |
279 | static inline size_t fib_nlmsg_size(struct fib_info *fi) |
280 | { | |
281 | size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) | |
282 | + nla_total_size(4) /* RTA_TABLE */ | |
283 | + nla_total_size(4) /* RTA_DST */ | |
284 | + nla_total_size(4) /* RTA_PRIORITY */ | |
285 | + nla_total_size(4); /* RTA_PREFSRC */ | |
286 | ||
287 | /* space for nested metrics */ | |
288 | payload += nla_total_size((RTAX_MAX * nla_total_size(4))); | |
289 | ||
290 | if (fi->fib_nhs) { | |
291 | /* Also handles the special case fib_nhs == 1 */ | |
292 | ||
293 | /* each nexthop is packed in an attribute */ | |
294 | size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); | |
295 | ||
296 | /* may contain flow and gateway attribute */ | |
297 | nhsize += 2 * nla_total_size(4); | |
298 | ||
299 | /* all nexthops are packed in a nested attribute */ | |
300 | payload += nla_total_size(fi->fib_nhs * nhsize); | |
301 | } | |
302 | ||
303 | return payload; | |
304 | } | |
305 | ||
81f7bf6c | 306 | void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
b8f55831 MK |
307 | int dst_len, u32 tb_id, struct nl_info *info, |
308 | unsigned int nlm_flags) | |
1da177e4 LT |
309 | { |
310 | struct sk_buff *skb; | |
4e902c57 | 311 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
f21c7bc5 | 312 | int err = -ENOBUFS; |
1da177e4 | 313 | |
339bf98f | 314 | skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
f21c7bc5 TG |
315 | if (skb == NULL) |
316 | goto errout; | |
1da177e4 | 317 | |
4e902c57 | 318 | err = fib_dump_info(skb, info->pid, seq, event, tb_id, |
be403ea1 | 319 | fa->fa_type, fa->fa_scope, key, dst_len, |
b8f55831 | 320 | fa->fa_tos, fa->fa_info, nlm_flags); |
26932566 PM |
321 | if (err < 0) { |
322 | /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ | |
323 | WARN_ON(err == -EMSGSIZE); | |
324 | kfree_skb(skb); | |
325 | goto errout; | |
326 | } | |
4d1169c1 | 327 | err = rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE, |
4e902c57 | 328 | info->nlh, GFP_KERNEL); |
f21c7bc5 TG |
329 | errout: |
330 | if (err < 0) | |
4d1169c1 | 331 | rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); |
1da177e4 LT |
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, | |
c17860a0 | 353 | struct fib_info **last_resort, int *last_idx, int dflt) |
1da177e4 LT |
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; | |
c17860a0 | 365 | if ((state&NUD_VALID) && order != dflt) |
1da177e4 LT |
366 | return 0; |
367 | if ((state&NUD_VALID) || | |
c17860a0 | 368 | (*last_idx<0 && order > dflt)) { |
1da177e4 LT |
369 | *last_resort = fi; |
370 | *last_idx = order; | |
371 | } | |
372 | return 1; | |
373 | } | |
374 | ||
375 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
376 | ||
4e902c57 | 377 | static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining) |
1da177e4 LT |
378 | { |
379 | int nhs = 0; | |
1da177e4 | 380 | |
4e902c57 | 381 | while (rtnh_ok(rtnh, remaining)) { |
1da177e4 | 382 | nhs++; |
4e902c57 TG |
383 | rtnh = rtnh_next(rtnh, &remaining); |
384 | } | |
385 | ||
386 | /* leftover implies invalid nexthop configuration, discard it */ | |
387 | return remaining > 0 ? 0 : nhs; | |
1da177e4 LT |
388 | } |
389 | ||
4e902c57 TG |
390 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
391 | int remaining, struct fib_config *cfg) | |
1da177e4 | 392 | { |
1da177e4 | 393 | change_nexthops(fi) { |
4e902c57 TG |
394 | int attrlen; |
395 | ||
396 | if (!rtnh_ok(rtnh, remaining)) | |
1da177e4 | 397 | return -EINVAL; |
4e902c57 TG |
398 | |
399 | nh->nh_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; | |
400 | nh->nh_oif = rtnh->rtnh_ifindex; | |
401 | nh->nh_weight = rtnh->rtnh_hops + 1; | |
402 | ||
403 | attrlen = rtnh_attrlen(rtnh); | |
404 | if (attrlen > 0) { | |
405 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
406 | ||
407 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 408 | nh->nh_gw = nla ? nla_get_be32(nla) : 0; |
1da177e4 | 409 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 TG |
410 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
411 | nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; | |
1da177e4 LT |
412 | #endif |
413 | } | |
4e902c57 TG |
414 | |
415 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 | 416 | } endfor_nexthops(fi); |
4e902c57 | 417 | |
1da177e4 LT |
418 | return 0; |
419 | } | |
420 | ||
421 | #endif | |
422 | ||
4e902c57 | 423 | int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) |
1da177e4 LT |
424 | { |
425 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
426 | struct rtnexthop *rtnh; |
427 | int remaining; | |
1da177e4 LT |
428 | #endif |
429 | ||
4e902c57 | 430 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
1da177e4 LT |
431 | return 1; |
432 | ||
4e902c57 TG |
433 | if (cfg->fc_oif || cfg->fc_gw) { |
434 | if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && | |
435 | (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) | |
1da177e4 LT |
436 | return 0; |
437 | return 1; | |
438 | } | |
439 | ||
440 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 | 441 | if (cfg->fc_mp == NULL) |
1da177e4 | 442 | return 0; |
4e902c57 TG |
443 | |
444 | rtnh = cfg->fc_mp; | |
445 | remaining = cfg->fc_mp_len; | |
e905a9ed | 446 | |
1da177e4 | 447 | for_nexthops(fi) { |
4e902c57 | 448 | int attrlen; |
1da177e4 | 449 | |
4e902c57 | 450 | if (!rtnh_ok(rtnh, remaining)) |
1da177e4 | 451 | return -EINVAL; |
4e902c57 TG |
452 | |
453 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) | |
1da177e4 | 454 | return 1; |
4e902c57 TG |
455 | |
456 | attrlen = rtnh_attrlen(rtnh); | |
457 | if (attrlen < 0) { | |
458 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
459 | ||
460 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 461 | if (nla && nla_get_be32(nla) != nh->nh_gw) |
1da177e4 LT |
462 | return 1; |
463 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 TG |
464 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
465 | if (nla && nla_get_u32(nla) != nh->nh_tclassid) | |
1da177e4 LT |
466 | return 1; |
467 | #endif | |
468 | } | |
4e902c57 TG |
469 | |
470 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 LT |
471 | } endfor_nexthops(fi); |
472 | #endif | |
473 | return 0; | |
474 | } | |
475 | ||
476 | ||
477 | /* | |
478 | Picture | |
479 | ------- | |
480 | ||
481 | Semantics of nexthop is very messy by historical reasons. | |
482 | We have to take into account, that: | |
483 | a) gateway can be actually local interface address, | |
484 | so that gatewayed route is direct. | |
485 | b) gateway must be on-link address, possibly | |
486 | described not by an ifaddr, but also by a direct route. | |
487 | c) If both gateway and interface are specified, they should not | |
488 | contradict. | |
489 | d) If we use tunnel routes, gateway could be not on-link. | |
490 | ||
491 | Attempt to reconcile all of these (alas, self-contradictory) conditions | |
492 | results in pretty ugly and hairy code with obscure logic. | |
493 | ||
494 | I chose to generalized it instead, so that the size | |
495 | of code does not increase practically, but it becomes | |
496 | much more general. | |
497 | Every prefix is assigned a "scope" value: "host" is local address, | |
498 | "link" is direct route, | |
499 | [ ... "site" ... "interior" ... ] | |
500 | and "universe" is true gateway route with global meaning. | |
501 | ||
502 | Every prefix refers to a set of "nexthop"s (gw, oif), | |
503 | where gw must have narrower scope. This recursion stops | |
504 | when gw has LOCAL scope or if "nexthop" is declared ONLINK, | |
505 | which means that gw is forced to be on link. | |
506 | ||
507 | Code is still hairy, but now it is apparently logically | |
508 | consistent and very flexible. F.e. as by-product it allows | |
509 | to co-exists in peace independent exterior and interior | |
510 | routing processes. | |
511 | ||
512 | Normally it looks as following. | |
513 | ||
514 | {universe prefix} -> (gw, oif) [scope link] | |
e905a9ed | 515 | | |
1da177e4 | 516 | |-> {link prefix} -> (gw, oif) [scope local] |
e905a9ed | 517 | | |
1da177e4 LT |
518 | |-> {local prefix} (terminal node) |
519 | */ | |
520 | ||
4e902c57 TG |
521 | static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, |
522 | struct fib_nh *nh) | |
1da177e4 LT |
523 | { |
524 | int err; | |
86167a37 | 525 | struct net *net; |
1da177e4 | 526 | |
86167a37 | 527 | net = cfg->fc_nlinfo.nl_net; |
1da177e4 LT |
528 | if (nh->nh_gw) { |
529 | struct fib_result res; | |
530 | ||
531 | #ifdef CONFIG_IP_ROUTE_PERVASIVE | |
532 | if (nh->nh_flags&RTNH_F_PERVASIVE) | |
533 | return 0; | |
534 | #endif | |
535 | if (nh->nh_flags&RTNH_F_ONLINK) { | |
536 | struct net_device *dev; | |
537 | ||
4e902c57 | 538 | if (cfg->fc_scope >= RT_SCOPE_LINK) |
1da177e4 | 539 | return -EINVAL; |
86167a37 | 540 | if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST) |
1da177e4 | 541 | return -EINVAL; |
86167a37 | 542 | if ((dev = __dev_get_by_index(net, nh->nh_oif)) == NULL) |
1da177e4 LT |
543 | return -ENODEV; |
544 | if (!(dev->flags&IFF_UP)) | |
545 | return -ENETDOWN; | |
546 | nh->nh_dev = dev; | |
547 | dev_hold(dev); | |
548 | nh->nh_scope = RT_SCOPE_LINK; | |
549 | return 0; | |
550 | } | |
551 | { | |
4e902c57 TG |
552 | struct flowi fl = { |
553 | .nl_u = { | |
554 | .ip4_u = { | |
555 | .daddr = nh->nh_gw, | |
556 | .scope = cfg->fc_scope + 1, | |
557 | }, | |
558 | }, | |
559 | .oif = nh->nh_oif, | |
560 | }; | |
1da177e4 LT |
561 | |
562 | /* It is not necessary, but requires a bit of thinking */ | |
563 | if (fl.fl4_scope < RT_SCOPE_LINK) | |
564 | fl.fl4_scope = RT_SCOPE_LINK; | |
86167a37 | 565 | if ((err = fib_lookup(net, &fl, &res)) != 0) |
1da177e4 LT |
566 | return err; |
567 | } | |
568 | err = -EINVAL; | |
569 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) | |
570 | goto out; | |
571 | nh->nh_scope = res.scope; | |
572 | nh->nh_oif = FIB_RES_OIF(res); | |
573 | if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL) | |
574 | goto out; | |
575 | dev_hold(nh->nh_dev); | |
576 | err = -ENETDOWN; | |
577 | if (!(nh->nh_dev->flags & IFF_UP)) | |
578 | goto out; | |
579 | err = 0; | |
580 | out: | |
581 | fib_res_put(&res); | |
582 | return err; | |
583 | } else { | |
584 | struct in_device *in_dev; | |
585 | ||
586 | if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK)) | |
587 | return -EINVAL; | |
588 | ||
86167a37 | 589 | in_dev = inetdev_by_index(net, nh->nh_oif); |
1da177e4 LT |
590 | if (in_dev == NULL) |
591 | return -ENODEV; | |
592 | if (!(in_dev->dev->flags&IFF_UP)) { | |
593 | in_dev_put(in_dev); | |
594 | return -ENETDOWN; | |
595 | } | |
596 | nh->nh_dev = in_dev->dev; | |
597 | dev_hold(nh->nh_dev); | |
598 | nh->nh_scope = RT_SCOPE_HOST; | |
599 | in_dev_put(in_dev); | |
600 | } | |
601 | return 0; | |
602 | } | |
603 | ||
81f7bf6c | 604 | static inline unsigned int fib_laddr_hashfn(__be32 val) |
1da177e4 LT |
605 | { |
606 | unsigned int mask = (fib_hash_size - 1); | |
607 | ||
81f7bf6c | 608 | return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask; |
1da177e4 LT |
609 | } |
610 | ||
611 | static struct hlist_head *fib_hash_alloc(int bytes) | |
612 | { | |
613 | if (bytes <= PAGE_SIZE) | |
88f83491 | 614 | return kzalloc(bytes, GFP_KERNEL); |
1da177e4 LT |
615 | else |
616 | return (struct hlist_head *) | |
88f83491 | 617 | __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(bytes)); |
1da177e4 LT |
618 | } |
619 | ||
620 | static void fib_hash_free(struct hlist_head *hash, int bytes) | |
621 | { | |
622 | if (!hash) | |
623 | return; | |
624 | ||
625 | if (bytes <= PAGE_SIZE) | |
626 | kfree(hash); | |
627 | else | |
628 | free_pages((unsigned long) hash, get_order(bytes)); | |
629 | } | |
630 | ||
631 | static void fib_hash_move(struct hlist_head *new_info_hash, | |
632 | struct hlist_head *new_laddrhash, | |
633 | unsigned int new_size) | |
634 | { | |
b7656e7f | 635 | struct hlist_head *old_info_hash, *old_laddrhash; |
1da177e4 | 636 | unsigned int old_size = fib_hash_size; |
b7656e7f | 637 | unsigned int i, bytes; |
1da177e4 | 638 | |
832b4c5e | 639 | spin_lock_bh(&fib_info_lock); |
b7656e7f DM |
640 | old_info_hash = fib_info_hash; |
641 | old_laddrhash = fib_info_laddrhash; | |
1da177e4 LT |
642 | fib_hash_size = new_size; |
643 | ||
644 | for (i = 0; i < old_size; i++) { | |
645 | struct hlist_head *head = &fib_info_hash[i]; | |
646 | struct hlist_node *node, *n; | |
647 | struct fib_info *fi; | |
648 | ||
649 | hlist_for_each_entry_safe(fi, node, n, head, fib_hash) { | |
650 | struct hlist_head *dest; | |
651 | unsigned int new_hash; | |
652 | ||
653 | hlist_del(&fi->fib_hash); | |
654 | ||
655 | new_hash = fib_info_hashfn(fi); | |
656 | dest = &new_info_hash[new_hash]; | |
657 | hlist_add_head(&fi->fib_hash, dest); | |
658 | } | |
659 | } | |
660 | fib_info_hash = new_info_hash; | |
661 | ||
662 | for (i = 0; i < old_size; i++) { | |
663 | struct hlist_head *lhead = &fib_info_laddrhash[i]; | |
664 | struct hlist_node *node, *n; | |
665 | struct fib_info *fi; | |
666 | ||
667 | hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) { | |
668 | struct hlist_head *ldest; | |
669 | unsigned int new_hash; | |
670 | ||
671 | hlist_del(&fi->fib_lhash); | |
672 | ||
673 | new_hash = fib_laddr_hashfn(fi->fib_prefsrc); | |
674 | ldest = &new_laddrhash[new_hash]; | |
675 | hlist_add_head(&fi->fib_lhash, ldest); | |
676 | } | |
677 | } | |
678 | fib_info_laddrhash = new_laddrhash; | |
679 | ||
832b4c5e | 680 | spin_unlock_bh(&fib_info_lock); |
b7656e7f DM |
681 | |
682 | bytes = old_size * sizeof(struct hlist_head *); | |
683 | fib_hash_free(old_info_hash, bytes); | |
684 | fib_hash_free(old_laddrhash, bytes); | |
1da177e4 LT |
685 | } |
686 | ||
4e902c57 | 687 | struct fib_info *fib_create_info(struct fib_config *cfg) |
1da177e4 LT |
688 | { |
689 | int err; | |
690 | struct fib_info *fi = NULL; | |
691 | struct fib_info *ofi; | |
1da177e4 | 692 | int nhs = 1; |
7462bd74 | 693 | struct net *net = cfg->fc_nlinfo.nl_net; |
1da177e4 LT |
694 | |
695 | /* Fast check to catch the most weird cases */ | |
4e902c57 | 696 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) |
1da177e4 LT |
697 | goto err_inval; |
698 | ||
699 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
700 | if (cfg->fc_mp) { |
701 | nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); | |
1da177e4 LT |
702 | if (nhs == 0) |
703 | goto err_inval; | |
704 | } | |
705 | #endif | |
1da177e4 LT |
706 | |
707 | err = -ENOBUFS; | |
708 | if (fib_info_cnt >= fib_hash_size) { | |
709 | unsigned int new_size = fib_hash_size << 1; | |
710 | struct hlist_head *new_info_hash; | |
711 | struct hlist_head *new_laddrhash; | |
712 | unsigned int bytes; | |
713 | ||
714 | if (!new_size) | |
715 | new_size = 1; | |
716 | bytes = new_size * sizeof(struct hlist_head *); | |
717 | new_info_hash = fib_hash_alloc(bytes); | |
718 | new_laddrhash = fib_hash_alloc(bytes); | |
719 | if (!new_info_hash || !new_laddrhash) { | |
720 | fib_hash_free(new_info_hash, bytes); | |
721 | fib_hash_free(new_laddrhash, bytes); | |
88f83491 | 722 | } else |
1da177e4 | 723 | fib_hash_move(new_info_hash, new_laddrhash, new_size); |
1da177e4 LT |
724 | |
725 | if (!fib_hash_size) | |
726 | goto failure; | |
727 | } | |
728 | ||
0da974f4 | 729 | fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); |
1da177e4 LT |
730 | if (fi == NULL) |
731 | goto failure; | |
732 | fib_info_cnt++; | |
1da177e4 | 733 | |
57d7a600 | 734 | fi->fib_net = hold_net(net); |
4e902c57 TG |
735 | fi->fib_protocol = cfg->fc_protocol; |
736 | fi->fib_flags = cfg->fc_flags; | |
737 | fi->fib_priority = cfg->fc_priority; | |
738 | fi->fib_prefsrc = cfg->fc_prefsrc; | |
1da177e4 LT |
739 | |
740 | fi->fib_nhs = nhs; | |
741 | change_nexthops(fi) { | |
742 | nh->nh_parent = fi; | |
743 | } endfor_nexthops(fi) | |
744 | ||
4e902c57 TG |
745 | if (cfg->fc_mx) { |
746 | struct nlattr *nla; | |
747 | int remaining; | |
748 | ||
749 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { | |
8f4c1f9b | 750 | int type = nla_type(nla); |
4e902c57 TG |
751 | |
752 | if (type) { | |
753 | if (type > RTAX_MAX) | |
1da177e4 | 754 | goto err_inval; |
4e902c57 | 755 | fi->fib_metrics[type - 1] = nla_get_u32(nla); |
1da177e4 | 756 | } |
1da177e4 LT |
757 | } |
758 | } | |
1da177e4 | 759 | |
4e902c57 | 760 | if (cfg->fc_mp) { |
1da177e4 | 761 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
4e902c57 TG |
762 | err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); |
763 | if (err != 0) | |
1da177e4 | 764 | goto failure; |
4e902c57 | 765 | if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) |
1da177e4 | 766 | goto err_inval; |
4e902c57 | 767 | if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) |
1da177e4 LT |
768 | goto err_inval; |
769 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 | 770 | if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) |
1da177e4 LT |
771 | goto err_inval; |
772 | #endif | |
773 | #else | |
774 | goto err_inval; | |
775 | #endif | |
776 | } else { | |
777 | struct fib_nh *nh = fi->fib_nh; | |
4e902c57 TG |
778 | |
779 | nh->nh_oif = cfg->fc_oif; | |
780 | nh->nh_gw = cfg->fc_gw; | |
781 | nh->nh_flags = cfg->fc_flags; | |
1da177e4 | 782 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 | 783 | nh->nh_tclassid = cfg->fc_flow; |
1da177e4 | 784 | #endif |
1da177e4 LT |
785 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
786 | nh->nh_weight = 1; | |
787 | #endif | |
788 | } | |
789 | ||
4e902c57 TG |
790 | if (fib_props[cfg->fc_type].error) { |
791 | if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) | |
1da177e4 LT |
792 | goto err_inval; |
793 | goto link_it; | |
794 | } | |
795 | ||
4e902c57 | 796 | if (cfg->fc_scope > RT_SCOPE_HOST) |
1da177e4 LT |
797 | goto err_inval; |
798 | ||
4e902c57 | 799 | if (cfg->fc_scope == RT_SCOPE_HOST) { |
1da177e4 LT |
800 | struct fib_nh *nh = fi->fib_nh; |
801 | ||
802 | /* Local address is added. */ | |
803 | if (nhs != 1 || nh->nh_gw) | |
804 | goto err_inval; | |
805 | nh->nh_scope = RT_SCOPE_NOWHERE; | |
7462bd74 | 806 | nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif); |
1da177e4 LT |
807 | err = -ENODEV; |
808 | if (nh->nh_dev == NULL) | |
809 | goto failure; | |
810 | } else { | |
811 | change_nexthops(fi) { | |
4e902c57 | 812 | if ((err = fib_check_nh(cfg, fi, nh)) != 0) |
1da177e4 LT |
813 | goto failure; |
814 | } endfor_nexthops(fi) | |
815 | } | |
816 | ||
817 | if (fi->fib_prefsrc) { | |
4e902c57 TG |
818 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
819 | fi->fib_prefsrc != cfg->fc_dst) | |
7462bd74 | 820 | if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL) |
1da177e4 LT |
821 | goto err_inval; |
822 | } | |
823 | ||
824 | link_it: | |
825 | if ((ofi = fib_find_info(fi)) != NULL) { | |
826 | fi->fib_dead = 1; | |
827 | free_fib_info(fi); | |
828 | ofi->fib_treeref++; | |
829 | return ofi; | |
830 | } | |
831 | ||
832 | fi->fib_treeref++; | |
833 | atomic_inc(&fi->fib_clntref); | |
832b4c5e | 834 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
835 | hlist_add_head(&fi->fib_hash, |
836 | &fib_info_hash[fib_info_hashfn(fi)]); | |
837 | if (fi->fib_prefsrc) { | |
838 | struct hlist_head *head; | |
839 | ||
840 | head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; | |
841 | hlist_add_head(&fi->fib_lhash, head); | |
842 | } | |
843 | change_nexthops(fi) { | |
844 | struct hlist_head *head; | |
845 | unsigned int hash; | |
846 | ||
847 | if (!nh->nh_dev) | |
848 | continue; | |
849 | hash = fib_devindex_hashfn(nh->nh_dev->ifindex); | |
850 | head = &fib_info_devhash[hash]; | |
851 | hlist_add_head(&nh->nh_hash, head); | |
852 | } endfor_nexthops(fi) | |
832b4c5e | 853 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
854 | return fi; |
855 | ||
856 | err_inval: | |
857 | err = -EINVAL; | |
858 | ||
859 | failure: | |
e905a9ed | 860 | if (fi) { |
1da177e4 LT |
861 | fi->fib_dead = 1; |
862 | free_fib_info(fi); | |
863 | } | |
4e902c57 TG |
864 | |
865 | return ERR_PTR(err); | |
1da177e4 LT |
866 | } |
867 | ||
e5b43760 | 868 | /* Note! fib_semantic_match intentionally uses RCU list functions. */ |
1da177e4 | 869 | int fib_semantic_match(struct list_head *head, const struct flowi *flp, |
1ef1b8c8 | 870 | struct fib_result *res, __be32 zone, __be32 mask, |
1da177e4 LT |
871 | int prefixlen) |
872 | { | |
873 | struct fib_alias *fa; | |
874 | int nh_sel = 0; | |
875 | ||
e5b43760 | 876 | list_for_each_entry_rcu(fa, head, fa_list) { |
1da177e4 LT |
877 | int err; |
878 | ||
879 | if (fa->fa_tos && | |
880 | fa->fa_tos != flp->fl4_tos) | |
881 | continue; | |
882 | ||
883 | if (fa->fa_scope < flp->fl4_scope) | |
884 | continue; | |
885 | ||
886 | fa->fa_state |= FA_S_ACCESSED; | |
887 | ||
888 | err = fib_props[fa->fa_type].error; | |
889 | if (err == 0) { | |
890 | struct fib_info *fi = fa->fa_info; | |
891 | ||
892 | if (fi->fib_flags & RTNH_F_DEAD) | |
893 | continue; | |
894 | ||
895 | switch (fa->fa_type) { | |
896 | case RTN_UNICAST: | |
897 | case RTN_LOCAL: | |
898 | case RTN_BROADCAST: | |
899 | case RTN_ANYCAST: | |
900 | case RTN_MULTICAST: | |
901 | for_nexthops(fi) { | |
902 | if (nh->nh_flags&RTNH_F_DEAD) | |
903 | continue; | |
904 | if (!flp->oif || flp->oif == nh->nh_oif) | |
905 | break; | |
906 | } | |
907 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
908 | if (nhsel < fi->fib_nhs) { | |
909 | nh_sel = nhsel; | |
910 | goto out_fill_res; | |
911 | } | |
912 | #else | |
913 | if (nhsel < 1) { | |
914 | goto out_fill_res; | |
915 | } | |
916 | #endif | |
917 | endfor_nexthops(fi); | |
918 | continue; | |
919 | ||
920 | default: | |
a6db9010 SH |
921 | printk(KERN_WARNING "fib_semantic_match bad type %#x\n", |
922 | fa->fa_type); | |
1da177e4 | 923 | return -EINVAL; |
3ff50b79 | 924 | } |
1da177e4 LT |
925 | } |
926 | return err; | |
927 | } | |
928 | return 1; | |
929 | ||
930 | out_fill_res: | |
931 | res->prefixlen = prefixlen; | |
932 | res->nh_sel = nh_sel; | |
933 | res->type = fa->fa_type; | |
934 | res->scope = fa->fa_scope; | |
935 | res->fi = fa->fa_info; | |
1da177e4 LT |
936 | atomic_inc(&res->fi->fib_clntref); |
937 | return 0; | |
938 | } | |
939 | ||
940 | /* Find appropriate source address to this destination */ | |
941 | ||
b83738ae | 942 | __be32 __fib_res_prefsrc(struct fib_result *res) |
1da177e4 LT |
943 | { |
944 | return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope); | |
945 | } | |
946 | ||
be403ea1 | 947 | int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
81f7bf6c | 948 | u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos, |
be403ea1 | 949 | struct fib_info *fi, unsigned int flags) |
1da177e4 | 950 | { |
be403ea1 | 951 | struct nlmsghdr *nlh; |
1da177e4 | 952 | struct rtmsg *rtm; |
1da177e4 | 953 | |
be403ea1 TG |
954 | nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags); |
955 | if (nlh == NULL) | |
26932566 | 956 | return -EMSGSIZE; |
be403ea1 TG |
957 | |
958 | rtm = nlmsg_data(nlh); | |
1da177e4 LT |
959 | rtm->rtm_family = AF_INET; |
960 | rtm->rtm_dst_len = dst_len; | |
961 | rtm->rtm_src_len = 0; | |
962 | rtm->rtm_tos = tos; | |
963 | rtm->rtm_table = tb_id; | |
be403ea1 | 964 | NLA_PUT_U32(skb, RTA_TABLE, tb_id); |
1da177e4 LT |
965 | rtm->rtm_type = type; |
966 | rtm->rtm_flags = fi->fib_flags; | |
967 | rtm->rtm_scope = scope; | |
1da177e4 | 968 | rtm->rtm_protocol = fi->fib_protocol; |
be403ea1 TG |
969 | |
970 | if (rtm->rtm_dst_len) | |
17fb2c64 | 971 | NLA_PUT_BE32(skb, RTA_DST, dst); |
be403ea1 | 972 | |
1da177e4 | 973 | if (fi->fib_priority) |
be403ea1 TG |
974 | NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority); |
975 | ||
1da177e4 | 976 | if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) |
be403ea1 TG |
977 | goto nla_put_failure; |
978 | ||
1da177e4 | 979 | if (fi->fib_prefsrc) |
17fb2c64 | 980 | NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc); |
be403ea1 | 981 | |
1da177e4 LT |
982 | if (fi->fib_nhs == 1) { |
983 | if (fi->fib_nh->nh_gw) | |
17fb2c64 | 984 | NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw); |
be403ea1 | 985 | |
1da177e4 | 986 | if (fi->fib_nh->nh_oif) |
be403ea1 | 987 | NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif); |
8265abc0 PM |
988 | #ifdef CONFIG_NET_CLS_ROUTE |
989 | if (fi->fib_nh[0].nh_tclassid) | |
be403ea1 | 990 | NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid); |
8265abc0 | 991 | #endif |
1da177e4 LT |
992 | } |
993 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
994 | if (fi->fib_nhs > 1) { | |
be403ea1 TG |
995 | struct rtnexthop *rtnh; |
996 | struct nlattr *mp; | |
997 | ||
998 | mp = nla_nest_start(skb, RTA_MULTIPATH); | |
999 | if (mp == NULL) | |
1000 | goto nla_put_failure; | |
1da177e4 LT |
1001 | |
1002 | for_nexthops(fi) { | |
be403ea1 TG |
1003 | rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
1004 | if (rtnh == NULL) | |
1005 | goto nla_put_failure; | |
1006 | ||
1007 | rtnh->rtnh_flags = nh->nh_flags & 0xFF; | |
1008 | rtnh->rtnh_hops = nh->nh_weight - 1; | |
1009 | rtnh->rtnh_ifindex = nh->nh_oif; | |
1010 | ||
1da177e4 | 1011 | if (nh->nh_gw) |
17fb2c64 | 1012 | NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw); |
8265abc0 PM |
1013 | #ifdef CONFIG_NET_CLS_ROUTE |
1014 | if (nh->nh_tclassid) | |
be403ea1 | 1015 | NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid); |
8265abc0 | 1016 | #endif |
be403ea1 TG |
1017 | /* length of rtnetlink header + attributes */ |
1018 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; | |
1da177e4 | 1019 | } endfor_nexthops(fi); |
be403ea1 TG |
1020 | |
1021 | nla_nest_end(skb, mp); | |
1da177e4 LT |
1022 | } |
1023 | #endif | |
be403ea1 | 1024 | return nlmsg_end(skb, nlh); |
1da177e4 | 1025 | |
be403ea1 | 1026 | nla_put_failure: |
26932566 PM |
1027 | nlmsg_cancel(skb, nlh); |
1028 | return -EMSGSIZE; | |
1da177e4 LT |
1029 | } |
1030 | ||
1da177e4 LT |
1031 | /* |
1032 | Update FIB if: | |
1033 | - local address disappeared -> we must delete all the entries | |
1034 | referring to it. | |
1035 | - device went down -> we must shutdown all nexthops going via it. | |
1036 | */ | |
4814bdbd | 1037 | int fib_sync_down_addr(struct net *net, __be32 local) |
1da177e4 LT |
1038 | { |
1039 | int ret = 0; | |
85326fa5 DL |
1040 | unsigned int hash = fib_laddr_hashfn(local); |
1041 | struct hlist_head *head = &fib_info_laddrhash[hash]; | |
1042 | struct hlist_node *node; | |
1043 | struct fib_info *fi; | |
1da177e4 | 1044 | |
85326fa5 DL |
1045 | if (fib_info_laddrhash == NULL || local == 0) |
1046 | return 0; | |
1da177e4 | 1047 | |
85326fa5 | 1048 | hlist_for_each_entry(fi, node, head, fib_lhash) { |
4814bdbd DL |
1049 | if (fi->fib_net != net) |
1050 | continue; | |
85326fa5 DL |
1051 | if (fi->fib_prefsrc == local) { |
1052 | fi->fib_flags |= RTNH_F_DEAD; | |
1053 | ret++; | |
1da177e4 LT |
1054 | } |
1055 | } | |
85326fa5 DL |
1056 | return ret; |
1057 | } | |
1058 | ||
1059 | int fib_sync_down_dev(struct net_device *dev, int force) | |
1060 | { | |
1061 | int ret = 0; | |
1062 | int scope = RT_SCOPE_NOWHERE; | |
1063 | struct fib_info *prev_fi = NULL; | |
1064 | unsigned int hash = fib_devindex_hashfn(dev->ifindex); | |
1065 | struct hlist_head *head = &fib_info_devhash[hash]; | |
1066 | struct hlist_node *node; | |
1067 | struct fib_nh *nh; | |
1da177e4 | 1068 | |
85326fa5 DL |
1069 | if (force) |
1070 | scope = -1; | |
1da177e4 | 1071 | |
85326fa5 DL |
1072 | hlist_for_each_entry(nh, node, head, nh_hash) { |
1073 | struct fib_info *fi = nh->nh_parent; | |
1074 | int dead; | |
1da177e4 | 1075 | |
85326fa5 DL |
1076 | BUG_ON(!fi->fib_nhs); |
1077 | if (nh->nh_dev != dev || fi == prev_fi) | |
1078 | continue; | |
1079 | prev_fi = fi; | |
1080 | dead = 0; | |
1081 | change_nexthops(fi) { | |
1082 | if (nh->nh_flags&RTNH_F_DEAD) | |
1083 | dead++; | |
1084 | else if (nh->nh_dev == dev && | |
1085 | nh->nh_scope != scope) { | |
1086 | nh->nh_flags |= RTNH_F_DEAD; | |
1da177e4 | 1087 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
85326fa5 DL |
1088 | spin_lock_bh(&fib_multipath_lock); |
1089 | fi->fib_power -= nh->nh_power; | |
1090 | nh->nh_power = 0; | |
1091 | spin_unlock_bh(&fib_multipath_lock); | |
1da177e4 | 1092 | #endif |
85326fa5 DL |
1093 | dead++; |
1094 | } | |
1da177e4 | 1095 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
85326fa5 DL |
1096 | if (force > 1 && nh->nh_dev == dev) { |
1097 | dead = fi->fib_nhs; | |
1098 | break; | |
1da177e4 | 1099 | } |
85326fa5 DL |
1100 | #endif |
1101 | } endfor_nexthops(fi) | |
1102 | if (dead == fi->fib_nhs) { | |
1103 | fi->fib_flags |= RTNH_F_DEAD; | |
1104 | ret++; | |
1da177e4 LT |
1105 | } |
1106 | } | |
1107 | ||
1108 | return ret; | |
1109 | } | |
1110 | ||
1111 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1112 | ||
1113 | /* | |
1114 | Dead device goes up. We wake up dead nexthops. | |
1115 | It takes sense only on multipath routes. | |
1116 | */ | |
1117 | ||
1118 | int fib_sync_up(struct net_device *dev) | |
1119 | { | |
1120 | struct fib_info *prev_fi; | |
1121 | unsigned int hash; | |
1122 | struct hlist_head *head; | |
1123 | struct hlist_node *node; | |
1124 | struct fib_nh *nh; | |
1125 | int ret; | |
1126 | ||
1127 | if (!(dev->flags&IFF_UP)) | |
1128 | return 0; | |
1129 | ||
1130 | prev_fi = NULL; | |
1131 | hash = fib_devindex_hashfn(dev->ifindex); | |
1132 | head = &fib_info_devhash[hash]; | |
1133 | ret = 0; | |
1134 | ||
1135 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
1136 | struct fib_info *fi = nh->nh_parent; | |
1137 | int alive; | |
1138 | ||
1139 | BUG_ON(!fi->fib_nhs); | |
1140 | if (nh->nh_dev != dev || fi == prev_fi) | |
1141 | continue; | |
1142 | ||
1143 | prev_fi = fi; | |
1144 | alive = 0; | |
1145 | change_nexthops(fi) { | |
1146 | if (!(nh->nh_flags&RTNH_F_DEAD)) { | |
1147 | alive++; | |
1148 | continue; | |
1149 | } | |
1150 | if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP)) | |
1151 | continue; | |
e5ed6399 | 1152 | if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev)) |
1da177e4 LT |
1153 | continue; |
1154 | alive++; | |
1155 | spin_lock_bh(&fib_multipath_lock); | |
1156 | nh->nh_power = 0; | |
1157 | nh->nh_flags &= ~RTNH_F_DEAD; | |
1158 | spin_unlock_bh(&fib_multipath_lock); | |
1159 | } endfor_nexthops(fi) | |
1160 | ||
1161 | if (alive > 0) { | |
1162 | fi->fib_flags &= ~RTNH_F_DEAD; | |
1163 | ret++; | |
1164 | } | |
1165 | } | |
1166 | ||
1167 | return ret; | |
1168 | } | |
1169 | ||
1170 | /* | |
1171 | The algorithm is suboptimal, but it provides really | |
1172 | fair weighted route distribution. | |
1173 | */ | |
1174 | ||
1175 | void fib_select_multipath(const struct flowi *flp, struct fib_result *res) | |
1176 | { | |
1177 | struct fib_info *fi = res->fi; | |
1178 | int w; | |
1179 | ||
1180 | spin_lock_bh(&fib_multipath_lock); | |
1181 | if (fi->fib_power <= 0) { | |
1182 | int power = 0; | |
1183 | change_nexthops(fi) { | |
1184 | if (!(nh->nh_flags&RTNH_F_DEAD)) { | |
1185 | power += nh->nh_weight; | |
1186 | nh->nh_power = nh->nh_weight; | |
1187 | } | |
1188 | } endfor_nexthops(fi); | |
1189 | fi->fib_power = power; | |
1190 | if (power <= 0) { | |
1191 | spin_unlock_bh(&fib_multipath_lock); | |
1192 | /* Race condition: route has just become dead. */ | |
1193 | res->nh_sel = 0; | |
1194 | return; | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | ||
1199 | /* w should be random number [0..fi->fib_power-1], | |
1200 | it is pretty bad approximation. | |
1201 | */ | |
1202 | ||
1203 | w = jiffies % fi->fib_power; | |
1204 | ||
1205 | change_nexthops(fi) { | |
1206 | if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) { | |
1207 | if ((w -= nh->nh_power) <= 0) { | |
1208 | nh->nh_power--; | |
1209 | fi->fib_power--; | |
1210 | res->nh_sel = nhsel; | |
1211 | spin_unlock_bh(&fib_multipath_lock); | |
1212 | return; | |
1213 | } | |
1214 | } | |
1215 | } endfor_nexthops(fi); | |
1216 | ||
1217 | /* Race condition: route has just become dead. */ | |
1218 | res->nh_sel = 0; | |
1219 | spin_unlock_bh(&fib_multipath_lock); | |
1220 | } | |
1221 | #endif |