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 | * | |
1da177e4 LT |
8 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
1da177e4 LT |
16 | #include <asm/uaccess.h> |
17 | #include <asm/system.h> | |
18 | #include <linux/bitops.h> | |
19 | #include <linux/types.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/jiffies.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/socket.h> | |
25 | #include <linux/sockios.h> | |
26 | #include <linux/errno.h> | |
27 | #include <linux/in.h> | |
28 | #include <linux/inet.h> | |
14c85021 | 29 | #include <linux/inetdevice.h> |
1da177e4 LT |
30 | #include <linux/netdevice.h> |
31 | #include <linux/if_arp.h> | |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/skbuff.h> | |
1da177e4 | 34 | #include <linux/init.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
1da177e4 | 36 | |
14c85021 | 37 | #include <net/arp.h> |
1da177e4 LT |
38 | #include <net/ip.h> |
39 | #include <net/protocol.h> | |
40 | #include <net/route.h> | |
41 | #include <net/tcp.h> | |
42 | #include <net/sock.h> | |
43 | #include <net/ip_fib.h> | |
f21c7bc5 | 44 | #include <net/netlink.h> |
4e902c57 | 45 | #include <net/nexthop.h> |
1da177e4 LT |
46 | |
47 | #include "fib_lookup.h" | |
48 | ||
832b4c5e | 49 | static DEFINE_SPINLOCK(fib_info_lock); |
1da177e4 LT |
50 | static struct hlist_head *fib_info_hash; |
51 | static struct hlist_head *fib_info_laddrhash; | |
52 | static unsigned int fib_hash_size; | |
53 | static unsigned int fib_info_cnt; | |
54 | ||
55 | #define DEVINDEX_HASHBITS 8 | |
56 | #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) | |
57 | static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; | |
58 | ||
59 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
60 | ||
61 | static DEFINE_SPINLOCK(fib_multipath_lock); | |
62 | ||
63 | #define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \ | |
64 | for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++) | |
65 | ||
71fceff0 DM |
66 | #define change_nexthops(fi) { int nhsel; struct fib_nh *nexthop_nh; \ |
67 | for (nhsel=0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nexthop_nh++, nhsel++) | |
1da177e4 LT |
68 | |
69 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ | |
70 | ||
71 | /* Hope, that gcc will optimize it to get rid of dummy loop */ | |
72 | ||
d9319100 | 73 | #define for_nexthops(fi) { int nhsel = 0; const struct fib_nh * nh = (fi)->fib_nh; \ |
1da177e4 LT |
74 | for (nhsel=0; nhsel < 1; nhsel++) |
75 | ||
71fceff0 | 76 | #define change_nexthops(fi) { int nhsel = 0; struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
1da177e4 LT |
77 | for (nhsel=0; nhsel < 1; nhsel++) |
78 | ||
79 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ | |
80 | ||
81 | #define endfor_nexthops(fi) } | |
82 | ||
83 | ||
e905a9ed | 84 | static const struct |
1da177e4 LT |
85 | { |
86 | int error; | |
87 | u8 scope; | |
a0ee18b9 | 88 | } fib_props[RTN_MAX + 1] = { |
e905a9ed | 89 | { |
1da177e4 LT |
90 | .error = 0, |
91 | .scope = RT_SCOPE_NOWHERE, | |
92 | }, /* RTN_UNSPEC */ | |
93 | { | |
94 | .error = 0, | |
95 | .scope = RT_SCOPE_UNIVERSE, | |
96 | }, /* RTN_UNICAST */ | |
97 | { | |
98 | .error = 0, | |
99 | .scope = RT_SCOPE_HOST, | |
100 | }, /* RTN_LOCAL */ | |
101 | { | |
102 | .error = 0, | |
103 | .scope = RT_SCOPE_LINK, | |
104 | }, /* RTN_BROADCAST */ | |
105 | { | |
106 | .error = 0, | |
107 | .scope = RT_SCOPE_LINK, | |
108 | }, /* RTN_ANYCAST */ | |
109 | { | |
110 | .error = 0, | |
111 | .scope = RT_SCOPE_UNIVERSE, | |
112 | }, /* RTN_MULTICAST */ | |
113 | { | |
114 | .error = -EINVAL, | |
115 | .scope = RT_SCOPE_UNIVERSE, | |
116 | }, /* RTN_BLACKHOLE */ | |
117 | { | |
118 | .error = -EHOSTUNREACH, | |
119 | .scope = RT_SCOPE_UNIVERSE, | |
120 | }, /* RTN_UNREACHABLE */ | |
121 | { | |
122 | .error = -EACCES, | |
123 | .scope = RT_SCOPE_UNIVERSE, | |
124 | }, /* RTN_PROHIBIT */ | |
125 | { | |
126 | .error = -EAGAIN, | |
127 | .scope = RT_SCOPE_UNIVERSE, | |
128 | }, /* RTN_THROW */ | |
129 | { | |
130 | .error = -EINVAL, | |
131 | .scope = RT_SCOPE_NOWHERE, | |
132 | }, /* RTN_NAT */ | |
133 | { | |
134 | .error = -EINVAL, | |
135 | .scope = RT_SCOPE_NOWHERE, | |
136 | }, /* RTN_XRESOLVE */ | |
137 | }; | |
138 | ||
139 | ||
140 | /* Release a nexthop info record */ | |
141 | ||
142 | void free_fib_info(struct fib_info *fi) | |
143 | { | |
144 | if (fi->fib_dead == 0) { | |
a6db9010 | 145 | printk(KERN_WARNING "Freeing alive fib_info %p\n", fi); |
1da177e4 LT |
146 | return; |
147 | } | |
148 | change_nexthops(fi) { | |
71fceff0 DM |
149 | if (nexthop_nh->nh_dev) |
150 | dev_put(nexthop_nh->nh_dev); | |
151 | nexthop_nh->nh_dev = NULL; | |
1da177e4 LT |
152 | } endfor_nexthops(fi); |
153 | fib_info_cnt--; | |
57d7a600 | 154 | release_net(fi->fib_net); |
1da177e4 LT |
155 | kfree(fi); |
156 | } | |
157 | ||
158 | void fib_release_info(struct fib_info *fi) | |
159 | { | |
832b4c5e | 160 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
161 | if (fi && --fi->fib_treeref == 0) { |
162 | hlist_del(&fi->fib_hash); | |
163 | if (fi->fib_prefsrc) | |
164 | hlist_del(&fi->fib_lhash); | |
165 | change_nexthops(fi) { | |
71fceff0 | 166 | if (!nexthop_nh->nh_dev) |
1da177e4 | 167 | continue; |
71fceff0 | 168 | hlist_del(&nexthop_nh->nh_hash); |
1da177e4 LT |
169 | } endfor_nexthops(fi) |
170 | fi->fib_dead = 1; | |
171 | fib_info_put(fi); | |
172 | } | |
832b4c5e | 173 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
174 | } |
175 | ||
176 | static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) | |
177 | { | |
178 | const struct fib_nh *onh = ofi->fib_nh; | |
179 | ||
180 | for_nexthops(fi) { | |
181 | if (nh->nh_oif != onh->nh_oif || | |
182 | nh->nh_gw != onh->nh_gw || | |
183 | nh->nh_scope != onh->nh_scope || | |
184 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
185 | nh->nh_weight != onh->nh_weight || | |
186 | #endif | |
187 | #ifdef CONFIG_NET_CLS_ROUTE | |
188 | nh->nh_tclassid != onh->nh_tclassid || | |
189 | #endif | |
190 | ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD)) | |
191 | return -1; | |
192 | onh++; | |
193 | } endfor_nexthops(fi); | |
194 | return 0; | |
195 | } | |
196 | ||
88ebc72f DM |
197 | static inline unsigned int fib_devindex_hashfn(unsigned int val) |
198 | { | |
199 | unsigned int mask = DEVINDEX_HASHSIZE - 1; | |
200 | ||
201 | return (val ^ | |
202 | (val >> DEVINDEX_HASHBITS) ^ | |
203 | (val >> (DEVINDEX_HASHBITS * 2))) & mask; | |
204 | } | |
205 | ||
1da177e4 LT |
206 | static inline unsigned int fib_info_hashfn(const struct fib_info *fi) |
207 | { | |
208 | unsigned int mask = (fib_hash_size - 1); | |
209 | unsigned int val = fi->fib_nhs; | |
210 | ||
211 | val ^= fi->fib_protocol; | |
81f7bf6c | 212 | val ^= (__force u32)fi->fib_prefsrc; |
1da177e4 | 213 | val ^= fi->fib_priority; |
88ebc72f DM |
214 | for_nexthops(fi) { |
215 | val ^= fib_devindex_hashfn(nh->nh_oif); | |
216 | } endfor_nexthops(fi) | |
1da177e4 LT |
217 | |
218 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; | |
219 | } | |
220 | ||
221 | static struct fib_info *fib_find_info(const struct fib_info *nfi) | |
222 | { | |
223 | struct hlist_head *head; | |
224 | struct hlist_node *node; | |
225 | struct fib_info *fi; | |
226 | unsigned int hash; | |
227 | ||
228 | hash = fib_info_hashfn(nfi); | |
229 | head = &fib_info_hash[hash]; | |
230 | ||
231 | hlist_for_each_entry(fi, node, head, fib_hash) { | |
09ad9bc7 | 232 | if (!net_eq(fi->fib_net, nfi->fib_net)) |
4814bdbd | 233 | continue; |
1da177e4 LT |
234 | if (fi->fib_nhs != nfi->fib_nhs) |
235 | continue; | |
236 | if (nfi->fib_protocol == fi->fib_protocol && | |
237 | nfi->fib_prefsrc == fi->fib_prefsrc && | |
238 | nfi->fib_priority == fi->fib_priority && | |
239 | memcmp(nfi->fib_metrics, fi->fib_metrics, | |
240 | sizeof(fi->fib_metrics)) == 0 && | |
241 | ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 && | |
242 | (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) | |
243 | return fi; | |
244 | } | |
245 | ||
246 | return NULL; | |
247 | } | |
248 | ||
1da177e4 LT |
249 | /* Check, that the gateway is already configured. |
250 | Used only by redirect accept routine. | |
251 | */ | |
252 | ||
d878e72e | 253 | int ip_fib_check_default(__be32 gw, struct net_device *dev) |
1da177e4 LT |
254 | { |
255 | struct hlist_head *head; | |
256 | struct hlist_node *node; | |
257 | struct fib_nh *nh; | |
258 | unsigned int hash; | |
259 | ||
832b4c5e | 260 | spin_lock(&fib_info_lock); |
1da177e4 LT |
261 | |
262 | hash = fib_devindex_hashfn(dev->ifindex); | |
263 | head = &fib_info_devhash[hash]; | |
264 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
265 | if (nh->nh_dev == dev && | |
266 | nh->nh_gw == gw && | |
267 | !(nh->nh_flags&RTNH_F_DEAD)) { | |
832b4c5e | 268 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
269 | return 0; |
270 | } | |
271 | } | |
272 | ||
832b4c5e | 273 | spin_unlock(&fib_info_lock); |
1da177e4 LT |
274 | |
275 | return -1; | |
276 | } | |
277 | ||
339bf98f TG |
278 | static inline size_t fib_nlmsg_size(struct fib_info *fi) |
279 | { | |
280 | size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) | |
281 | + nla_total_size(4) /* RTA_TABLE */ | |
282 | + nla_total_size(4) /* RTA_DST */ | |
283 | + nla_total_size(4) /* RTA_PRIORITY */ | |
284 | + nla_total_size(4); /* RTA_PREFSRC */ | |
285 | ||
286 | /* space for nested metrics */ | |
287 | payload += nla_total_size((RTAX_MAX * nla_total_size(4))); | |
288 | ||
289 | if (fi->fib_nhs) { | |
290 | /* Also handles the special case fib_nhs == 1 */ | |
291 | ||
292 | /* each nexthop is packed in an attribute */ | |
293 | size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); | |
294 | ||
295 | /* may contain flow and gateway attribute */ | |
296 | nhsize += 2 * nla_total_size(4); | |
297 | ||
298 | /* all nexthops are packed in a nested attribute */ | |
299 | payload += nla_total_size(fi->fib_nhs * nhsize); | |
300 | } | |
301 | ||
302 | return payload; | |
303 | } | |
304 | ||
81f7bf6c | 305 | void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
b8f55831 MK |
306 | int dst_len, u32 tb_id, struct nl_info *info, |
307 | unsigned int nlm_flags) | |
1da177e4 LT |
308 | { |
309 | struct sk_buff *skb; | |
4e902c57 | 310 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
f21c7bc5 | 311 | int err = -ENOBUFS; |
1da177e4 | 312 | |
339bf98f | 313 | skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); |
f21c7bc5 TG |
314 | if (skb == NULL) |
315 | goto errout; | |
1da177e4 | 316 | |
4e902c57 | 317 | err = fib_dump_info(skb, info->pid, seq, event, tb_id, |
be403ea1 | 318 | fa->fa_type, fa->fa_scope, key, dst_len, |
b8f55831 | 319 | fa->fa_tos, fa->fa_info, nlm_flags); |
26932566 PM |
320 | if (err < 0) { |
321 | /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ | |
322 | WARN_ON(err == -EMSGSIZE); | |
323 | kfree_skb(skb); | |
324 | goto errout; | |
325 | } | |
1ce85fe4 PNA |
326 | rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE, |
327 | info->nlh, GFP_KERNEL); | |
328 | return; | |
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 | } | |
d9319100 | 363 | if (state == NUD_REACHABLE) |
1da177e4 | 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 | 398 | |
71fceff0 DM |
399 | nexthop_nh->nh_flags = |
400 | (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; | |
401 | nexthop_nh->nh_oif = rtnh->rtnh_ifindex; | |
402 | nexthop_nh->nh_weight = rtnh->rtnh_hops + 1; | |
4e902c57 TG |
403 | |
404 | attrlen = rtnh_attrlen(rtnh); | |
405 | if (attrlen > 0) { | |
406 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
407 | ||
408 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
71fceff0 | 409 | nexthop_nh->nh_gw = nla ? nla_get_be32(nla) : 0; |
1da177e4 | 410 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 | 411 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
71fceff0 | 412 | nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; |
1da177e4 LT |
413 | #endif |
414 | } | |
4e902c57 TG |
415 | |
416 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 | 417 | } endfor_nexthops(fi); |
4e902c57 | 418 | |
1da177e4 LT |
419 | return 0; |
420 | } | |
421 | ||
422 | #endif | |
423 | ||
4e902c57 | 424 | int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) |
1da177e4 LT |
425 | { |
426 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
427 | struct rtnexthop *rtnh; |
428 | int remaining; | |
1da177e4 LT |
429 | #endif |
430 | ||
4e902c57 | 431 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
1da177e4 LT |
432 | return 1; |
433 | ||
4e902c57 TG |
434 | if (cfg->fc_oif || cfg->fc_gw) { |
435 | if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && | |
436 | (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) | |
1da177e4 LT |
437 | return 0; |
438 | return 1; | |
439 | } | |
440 | ||
441 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 | 442 | if (cfg->fc_mp == NULL) |
1da177e4 | 443 | return 0; |
4e902c57 TG |
444 | |
445 | rtnh = cfg->fc_mp; | |
446 | remaining = cfg->fc_mp_len; | |
e905a9ed | 447 | |
1da177e4 | 448 | for_nexthops(fi) { |
4e902c57 | 449 | int attrlen; |
1da177e4 | 450 | |
4e902c57 | 451 | if (!rtnh_ok(rtnh, remaining)) |
1da177e4 | 452 | return -EINVAL; |
4e902c57 TG |
453 | |
454 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) | |
1da177e4 | 455 | return 1; |
4e902c57 TG |
456 | |
457 | attrlen = rtnh_attrlen(rtnh); | |
458 | if (attrlen < 0) { | |
459 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
460 | ||
461 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
17fb2c64 | 462 | if (nla && nla_get_be32(nla) != nh->nh_gw) |
1da177e4 LT |
463 | return 1; |
464 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 TG |
465 | nla = nla_find(attrs, attrlen, RTA_FLOW); |
466 | if (nla && nla_get_u32(nla) != nh->nh_tclassid) | |
1da177e4 LT |
467 | return 1; |
468 | #endif | |
469 | } | |
4e902c57 TG |
470 | |
471 | rtnh = rtnh_next(rtnh, &remaining); | |
1da177e4 LT |
472 | } endfor_nexthops(fi); |
473 | #endif | |
474 | return 0; | |
475 | } | |
476 | ||
477 | ||
478 | /* | |
479 | Picture | |
480 | ------- | |
481 | ||
482 | Semantics of nexthop is very messy by historical reasons. | |
483 | We have to take into account, that: | |
484 | a) gateway can be actually local interface address, | |
485 | so that gatewayed route is direct. | |
486 | b) gateway must be on-link address, possibly | |
487 | described not by an ifaddr, but also by a direct route. | |
488 | c) If both gateway and interface are specified, they should not | |
489 | contradict. | |
490 | d) If we use tunnel routes, gateway could be not on-link. | |
491 | ||
492 | Attempt to reconcile all of these (alas, self-contradictory) conditions | |
493 | results in pretty ugly and hairy code with obscure logic. | |
494 | ||
495 | I chose to generalized it instead, so that the size | |
496 | of code does not increase practically, but it becomes | |
497 | much more general. | |
498 | Every prefix is assigned a "scope" value: "host" is local address, | |
499 | "link" is direct route, | |
500 | [ ... "site" ... "interior" ... ] | |
501 | and "universe" is true gateway route with global meaning. | |
502 | ||
503 | Every prefix refers to a set of "nexthop"s (gw, oif), | |
504 | where gw must have narrower scope. This recursion stops | |
505 | when gw has LOCAL scope or if "nexthop" is declared ONLINK, | |
506 | which means that gw is forced to be on link. | |
507 | ||
508 | Code is still hairy, but now it is apparently logically | |
509 | consistent and very flexible. F.e. as by-product it allows | |
510 | to co-exists in peace independent exterior and interior | |
511 | routing processes. | |
512 | ||
513 | Normally it looks as following. | |
514 | ||
515 | {universe prefix} -> (gw, oif) [scope link] | |
e905a9ed | 516 | | |
1da177e4 | 517 | |-> {link prefix} -> (gw, oif) [scope local] |
e905a9ed | 518 | | |
1da177e4 LT |
519 | |-> {local prefix} (terminal node) |
520 | */ | |
521 | ||
4e902c57 TG |
522 | static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, |
523 | struct fib_nh *nh) | |
1da177e4 LT |
524 | { |
525 | int err; | |
86167a37 | 526 | struct net *net; |
1da177e4 | 527 | |
86167a37 | 528 | net = cfg->fc_nlinfo.nl_net; |
1da177e4 LT |
529 | if (nh->nh_gw) { |
530 | struct fib_result res; | |
531 | ||
1da177e4 LT |
532 | if (nh->nh_flags&RTNH_F_ONLINK) { |
533 | struct net_device *dev; | |
534 | ||
4e902c57 | 535 | if (cfg->fc_scope >= RT_SCOPE_LINK) |
1da177e4 | 536 | return -EINVAL; |
86167a37 | 537 | if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST) |
1da177e4 | 538 | return -EINVAL; |
86167a37 | 539 | if ((dev = __dev_get_by_index(net, nh->nh_oif)) == NULL) |
1da177e4 LT |
540 | return -ENODEV; |
541 | if (!(dev->flags&IFF_UP)) | |
542 | return -ENETDOWN; | |
543 | nh->nh_dev = dev; | |
544 | dev_hold(dev); | |
545 | nh->nh_scope = RT_SCOPE_LINK; | |
546 | return 0; | |
547 | } | |
548 | { | |
4e902c57 TG |
549 | struct flowi fl = { |
550 | .nl_u = { | |
551 | .ip4_u = { | |
552 | .daddr = nh->nh_gw, | |
553 | .scope = cfg->fc_scope + 1, | |
554 | }, | |
555 | }, | |
556 | .oif = nh->nh_oif, | |
557 | }; | |
1da177e4 LT |
558 | |
559 | /* It is not necessary, but requires a bit of thinking */ | |
560 | if (fl.fl4_scope < RT_SCOPE_LINK) | |
561 | fl.fl4_scope = RT_SCOPE_LINK; | |
86167a37 | 562 | if ((err = fib_lookup(net, &fl, &res)) != 0) |
1da177e4 LT |
563 | return err; |
564 | } | |
565 | err = -EINVAL; | |
566 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) | |
567 | goto out; | |
568 | nh->nh_scope = res.scope; | |
569 | nh->nh_oif = FIB_RES_OIF(res); | |
570 | if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL) | |
571 | goto out; | |
572 | dev_hold(nh->nh_dev); | |
573 | err = -ENETDOWN; | |
574 | if (!(nh->nh_dev->flags & IFF_UP)) | |
575 | goto out; | |
576 | err = 0; | |
577 | out: | |
578 | fib_res_put(&res); | |
579 | return err; | |
580 | } else { | |
581 | struct in_device *in_dev; | |
582 | ||
583 | if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK)) | |
584 | return -EINVAL; | |
585 | ||
86167a37 | 586 | in_dev = inetdev_by_index(net, nh->nh_oif); |
1da177e4 LT |
587 | if (in_dev == NULL) |
588 | return -ENODEV; | |
589 | if (!(in_dev->dev->flags&IFF_UP)) { | |
590 | in_dev_put(in_dev); | |
591 | return -ENETDOWN; | |
592 | } | |
593 | nh->nh_dev = in_dev->dev; | |
594 | dev_hold(nh->nh_dev); | |
595 | nh->nh_scope = RT_SCOPE_HOST; | |
596 | in_dev_put(in_dev); | |
597 | } | |
598 | return 0; | |
599 | } | |
600 | ||
81f7bf6c | 601 | static inline unsigned int fib_laddr_hashfn(__be32 val) |
1da177e4 LT |
602 | { |
603 | unsigned int mask = (fib_hash_size - 1); | |
604 | ||
81f7bf6c | 605 | return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask; |
1da177e4 LT |
606 | } |
607 | ||
608 | static struct hlist_head *fib_hash_alloc(int bytes) | |
609 | { | |
610 | if (bytes <= PAGE_SIZE) | |
88f83491 | 611 | return kzalloc(bytes, GFP_KERNEL); |
1da177e4 LT |
612 | else |
613 | return (struct hlist_head *) | |
88f83491 | 614 | __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(bytes)); |
1da177e4 LT |
615 | } |
616 | ||
617 | static void fib_hash_free(struct hlist_head *hash, int bytes) | |
618 | { | |
619 | if (!hash) | |
620 | return; | |
621 | ||
622 | if (bytes <= PAGE_SIZE) | |
623 | kfree(hash); | |
624 | else | |
625 | free_pages((unsigned long) hash, get_order(bytes)); | |
626 | } | |
627 | ||
628 | static void fib_hash_move(struct hlist_head *new_info_hash, | |
629 | struct hlist_head *new_laddrhash, | |
630 | unsigned int new_size) | |
631 | { | |
b7656e7f | 632 | struct hlist_head *old_info_hash, *old_laddrhash; |
1da177e4 | 633 | unsigned int old_size = fib_hash_size; |
b7656e7f | 634 | unsigned int i, bytes; |
1da177e4 | 635 | |
832b4c5e | 636 | spin_lock_bh(&fib_info_lock); |
b7656e7f DM |
637 | old_info_hash = fib_info_hash; |
638 | old_laddrhash = fib_info_laddrhash; | |
1da177e4 LT |
639 | fib_hash_size = new_size; |
640 | ||
641 | for (i = 0; i < old_size; i++) { | |
642 | struct hlist_head *head = &fib_info_hash[i]; | |
643 | struct hlist_node *node, *n; | |
644 | struct fib_info *fi; | |
645 | ||
646 | hlist_for_each_entry_safe(fi, node, n, head, fib_hash) { | |
647 | struct hlist_head *dest; | |
648 | unsigned int new_hash; | |
649 | ||
650 | hlist_del(&fi->fib_hash); | |
651 | ||
652 | new_hash = fib_info_hashfn(fi); | |
653 | dest = &new_info_hash[new_hash]; | |
654 | hlist_add_head(&fi->fib_hash, dest); | |
655 | } | |
656 | } | |
657 | fib_info_hash = new_info_hash; | |
658 | ||
659 | for (i = 0; i < old_size; i++) { | |
660 | struct hlist_head *lhead = &fib_info_laddrhash[i]; | |
661 | struct hlist_node *node, *n; | |
662 | struct fib_info *fi; | |
663 | ||
664 | hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) { | |
665 | struct hlist_head *ldest; | |
666 | unsigned int new_hash; | |
667 | ||
668 | hlist_del(&fi->fib_lhash); | |
669 | ||
670 | new_hash = fib_laddr_hashfn(fi->fib_prefsrc); | |
671 | ldest = &new_laddrhash[new_hash]; | |
672 | hlist_add_head(&fi->fib_lhash, ldest); | |
673 | } | |
674 | } | |
675 | fib_info_laddrhash = new_laddrhash; | |
676 | ||
832b4c5e | 677 | spin_unlock_bh(&fib_info_lock); |
b7656e7f DM |
678 | |
679 | bytes = old_size * sizeof(struct hlist_head *); | |
680 | fib_hash_free(old_info_hash, bytes); | |
681 | fib_hash_free(old_laddrhash, bytes); | |
1da177e4 LT |
682 | } |
683 | ||
4e902c57 | 684 | struct fib_info *fib_create_info(struct fib_config *cfg) |
1da177e4 LT |
685 | { |
686 | int err; | |
687 | struct fib_info *fi = NULL; | |
688 | struct fib_info *ofi; | |
1da177e4 | 689 | int nhs = 1; |
7462bd74 | 690 | struct net *net = cfg->fc_nlinfo.nl_net; |
1da177e4 LT |
691 | |
692 | /* Fast check to catch the most weird cases */ | |
4e902c57 | 693 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) |
1da177e4 LT |
694 | goto err_inval; |
695 | ||
696 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
4e902c57 TG |
697 | if (cfg->fc_mp) { |
698 | nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); | |
1da177e4 LT |
699 | if (nhs == 0) |
700 | goto err_inval; | |
701 | } | |
702 | #endif | |
1da177e4 LT |
703 | |
704 | err = -ENOBUFS; | |
705 | if (fib_info_cnt >= fib_hash_size) { | |
706 | unsigned int new_size = fib_hash_size << 1; | |
707 | struct hlist_head *new_info_hash; | |
708 | struct hlist_head *new_laddrhash; | |
709 | unsigned int bytes; | |
710 | ||
711 | if (!new_size) | |
712 | new_size = 1; | |
713 | bytes = new_size * sizeof(struct hlist_head *); | |
714 | new_info_hash = fib_hash_alloc(bytes); | |
715 | new_laddrhash = fib_hash_alloc(bytes); | |
716 | if (!new_info_hash || !new_laddrhash) { | |
717 | fib_hash_free(new_info_hash, bytes); | |
718 | fib_hash_free(new_laddrhash, bytes); | |
88f83491 | 719 | } else |
1da177e4 | 720 | fib_hash_move(new_info_hash, new_laddrhash, new_size); |
1da177e4 LT |
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 | |
57d7a600 | 731 | fi->fib_net = hold_net(net); |
4e902c57 TG |
732 | fi->fib_protocol = cfg->fc_protocol; |
733 | fi->fib_flags = cfg->fc_flags; | |
734 | fi->fib_priority = cfg->fc_priority; | |
735 | fi->fib_prefsrc = cfg->fc_prefsrc; | |
1da177e4 LT |
736 | |
737 | fi->fib_nhs = nhs; | |
738 | change_nexthops(fi) { | |
71fceff0 | 739 | nexthop_nh->nh_parent = fi; |
1da177e4 LT |
740 | } endfor_nexthops(fi) |
741 | ||
4e902c57 TG |
742 | if (cfg->fc_mx) { |
743 | struct nlattr *nla; | |
744 | int remaining; | |
745 | ||
746 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { | |
8f4c1f9b | 747 | int type = nla_type(nla); |
4e902c57 TG |
748 | |
749 | if (type) { | |
750 | if (type > RTAX_MAX) | |
1da177e4 | 751 | goto err_inval; |
4e902c57 | 752 | fi->fib_metrics[type - 1] = nla_get_u32(nla); |
1da177e4 | 753 | } |
1da177e4 LT |
754 | } |
755 | } | |
1da177e4 | 756 | |
4e902c57 | 757 | if (cfg->fc_mp) { |
1da177e4 | 758 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
4e902c57 TG |
759 | err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); |
760 | if (err != 0) | |
1da177e4 | 761 | goto failure; |
4e902c57 | 762 | if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) |
1da177e4 | 763 | goto err_inval; |
4e902c57 | 764 | if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) |
1da177e4 LT |
765 | goto err_inval; |
766 | #ifdef CONFIG_NET_CLS_ROUTE | |
4e902c57 | 767 | if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) |
1da177e4 LT |
768 | goto err_inval; |
769 | #endif | |
770 | #else | |
771 | goto err_inval; | |
772 | #endif | |
773 | } else { | |
774 | struct fib_nh *nh = fi->fib_nh; | |
4e902c57 TG |
775 | |
776 | nh->nh_oif = cfg->fc_oif; | |
777 | nh->nh_gw = cfg->fc_gw; | |
778 | nh->nh_flags = cfg->fc_flags; | |
1da177e4 | 779 | #ifdef CONFIG_NET_CLS_ROUTE |
4e902c57 | 780 | nh->nh_tclassid = cfg->fc_flow; |
1da177e4 | 781 | #endif |
1da177e4 LT |
782 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
783 | nh->nh_weight = 1; | |
784 | #endif | |
785 | } | |
786 | ||
4e902c57 TG |
787 | if (fib_props[cfg->fc_type].error) { |
788 | if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) | |
1da177e4 LT |
789 | goto err_inval; |
790 | goto link_it; | |
791 | } | |
792 | ||
4e902c57 | 793 | if (cfg->fc_scope > RT_SCOPE_HOST) |
1da177e4 LT |
794 | goto err_inval; |
795 | ||
4e902c57 | 796 | if (cfg->fc_scope == RT_SCOPE_HOST) { |
1da177e4 LT |
797 | struct fib_nh *nh = fi->fib_nh; |
798 | ||
799 | /* Local address is added. */ | |
800 | if (nhs != 1 || nh->nh_gw) | |
801 | goto err_inval; | |
802 | nh->nh_scope = RT_SCOPE_NOWHERE; | |
7462bd74 | 803 | nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif); |
1da177e4 LT |
804 | err = -ENODEV; |
805 | if (nh->nh_dev == NULL) | |
806 | goto failure; | |
807 | } else { | |
808 | change_nexthops(fi) { | |
71fceff0 | 809 | if ((err = fib_check_nh(cfg, fi, nexthop_nh)) != 0) |
1da177e4 LT |
810 | goto failure; |
811 | } endfor_nexthops(fi) | |
812 | } | |
813 | ||
814 | if (fi->fib_prefsrc) { | |
4e902c57 TG |
815 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
816 | fi->fib_prefsrc != cfg->fc_dst) | |
7462bd74 | 817 | if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL) |
1da177e4 LT |
818 | goto err_inval; |
819 | } | |
820 | ||
821 | link_it: | |
822 | if ((ofi = fib_find_info(fi)) != NULL) { | |
823 | fi->fib_dead = 1; | |
824 | free_fib_info(fi); | |
825 | ofi->fib_treeref++; | |
826 | return ofi; | |
827 | } | |
828 | ||
829 | fi->fib_treeref++; | |
830 | atomic_inc(&fi->fib_clntref); | |
832b4c5e | 831 | spin_lock_bh(&fib_info_lock); |
1da177e4 LT |
832 | hlist_add_head(&fi->fib_hash, |
833 | &fib_info_hash[fib_info_hashfn(fi)]); | |
834 | if (fi->fib_prefsrc) { | |
835 | struct hlist_head *head; | |
836 | ||
837 | head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; | |
838 | hlist_add_head(&fi->fib_lhash, head); | |
839 | } | |
840 | change_nexthops(fi) { | |
841 | struct hlist_head *head; | |
842 | unsigned int hash; | |
843 | ||
71fceff0 | 844 | if (!nexthop_nh->nh_dev) |
1da177e4 | 845 | continue; |
71fceff0 | 846 | hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex); |
1da177e4 | 847 | head = &fib_info_devhash[hash]; |
71fceff0 | 848 | hlist_add_head(&nexthop_nh->nh_hash, head); |
1da177e4 | 849 | } endfor_nexthops(fi) |
832b4c5e | 850 | spin_unlock_bh(&fib_info_lock); |
1da177e4 LT |
851 | return fi; |
852 | ||
853 | err_inval: | |
854 | err = -EINVAL; | |
855 | ||
856 | failure: | |
e905a9ed | 857 | if (fi) { |
1da177e4 LT |
858 | fi->fib_dead = 1; |
859 | free_fib_info(fi); | |
860 | } | |
4e902c57 TG |
861 | |
862 | return ERR_PTR(err); | |
1da177e4 LT |
863 | } |
864 | ||
e5b43760 | 865 | /* Note! fib_semantic_match intentionally uses RCU list functions. */ |
1da177e4 | 866 | int fib_semantic_match(struct list_head *head, const struct flowi *flp, |
e204a345 | 867 | struct fib_result *res, int prefixlen) |
1da177e4 LT |
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: | |
a6db9010 SH |
917 | printk(KERN_WARNING "fib_semantic_match bad type %#x\n", |
918 | fa->fa_type); | |
1da177e4 | 919 | return -EINVAL; |
3ff50b79 | 920 | } |
1da177e4 LT |
921 | } |
922 | return err; | |
923 | } | |
924 | return 1; | |
925 | ||
926 | out_fill_res: | |
927 | res->prefixlen = prefixlen; | |
928 | res->nh_sel = nh_sel; | |
929 | res->type = fa->fa_type; | |
930 | res->scope = fa->fa_scope; | |
931 | res->fi = fa->fa_info; | |
1da177e4 LT |
932 | atomic_inc(&res->fi->fib_clntref); |
933 | return 0; | |
934 | } | |
935 | ||
936 | /* Find appropriate source address to this destination */ | |
937 | ||
b83738ae | 938 | __be32 __fib_res_prefsrc(struct fib_result *res) |
1da177e4 LT |
939 | { |
940 | return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope); | |
941 | } | |
942 | ||
be403ea1 | 943 | int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, |
81f7bf6c | 944 | u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos, |
be403ea1 | 945 | struct fib_info *fi, unsigned int flags) |
1da177e4 | 946 | { |
be403ea1 | 947 | struct nlmsghdr *nlh; |
1da177e4 | 948 | struct rtmsg *rtm; |
1da177e4 | 949 | |
be403ea1 TG |
950 | nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags); |
951 | if (nlh == NULL) | |
26932566 | 952 | return -EMSGSIZE; |
be403ea1 TG |
953 | |
954 | rtm = nlmsg_data(nlh); | |
1da177e4 LT |
955 | rtm->rtm_family = AF_INET; |
956 | rtm->rtm_dst_len = dst_len; | |
957 | rtm->rtm_src_len = 0; | |
958 | rtm->rtm_tos = tos; | |
709772e6 KPO |
959 | if (tb_id < 256) |
960 | rtm->rtm_table = tb_id; | |
961 | else | |
962 | rtm->rtm_table = RT_TABLE_COMPAT; | |
be403ea1 | 963 | NLA_PUT_U32(skb, RTA_TABLE, tb_id); |
1da177e4 LT |
964 | rtm->rtm_type = type; |
965 | rtm->rtm_flags = fi->fib_flags; | |
966 | rtm->rtm_scope = scope; | |
1da177e4 | 967 | rtm->rtm_protocol = fi->fib_protocol; |
be403ea1 TG |
968 | |
969 | if (rtm->rtm_dst_len) | |
17fb2c64 | 970 | NLA_PUT_BE32(skb, RTA_DST, dst); |
be403ea1 | 971 | |
1da177e4 | 972 | if (fi->fib_priority) |
be403ea1 TG |
973 | NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority); |
974 | ||
1da177e4 | 975 | if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) |
be403ea1 TG |
976 | goto nla_put_failure; |
977 | ||
1da177e4 | 978 | if (fi->fib_prefsrc) |
17fb2c64 | 979 | NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc); |
be403ea1 | 980 | |
1da177e4 LT |
981 | if (fi->fib_nhs == 1) { |
982 | if (fi->fib_nh->nh_gw) | |
17fb2c64 | 983 | NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw); |
be403ea1 | 984 | |
1da177e4 | 985 | if (fi->fib_nh->nh_oif) |
be403ea1 | 986 | NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif); |
8265abc0 PM |
987 | #ifdef CONFIG_NET_CLS_ROUTE |
988 | if (fi->fib_nh[0].nh_tclassid) | |
be403ea1 | 989 | NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid); |
8265abc0 | 990 | #endif |
1da177e4 LT |
991 | } |
992 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
993 | if (fi->fib_nhs > 1) { | |
be403ea1 TG |
994 | struct rtnexthop *rtnh; |
995 | struct nlattr *mp; | |
996 | ||
997 | mp = nla_nest_start(skb, RTA_MULTIPATH); | |
998 | if (mp == NULL) | |
999 | goto nla_put_failure; | |
1da177e4 LT |
1000 | |
1001 | for_nexthops(fi) { | |
be403ea1 TG |
1002 | rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); |
1003 | if (rtnh == NULL) | |
1004 | goto nla_put_failure; | |
1005 | ||
1006 | rtnh->rtnh_flags = nh->nh_flags & 0xFF; | |
1007 | rtnh->rtnh_hops = nh->nh_weight - 1; | |
1008 | rtnh->rtnh_ifindex = nh->nh_oif; | |
1009 | ||
1da177e4 | 1010 | if (nh->nh_gw) |
17fb2c64 | 1011 | NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw); |
8265abc0 PM |
1012 | #ifdef CONFIG_NET_CLS_ROUTE |
1013 | if (nh->nh_tclassid) | |
be403ea1 | 1014 | NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid); |
8265abc0 | 1015 | #endif |
be403ea1 TG |
1016 | /* length of rtnetlink header + attributes */ |
1017 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; | |
1da177e4 | 1018 | } endfor_nexthops(fi); |
be403ea1 TG |
1019 | |
1020 | nla_nest_end(skb, mp); | |
1da177e4 LT |
1021 | } |
1022 | #endif | |
be403ea1 | 1023 | return nlmsg_end(skb, nlh); |
1da177e4 | 1024 | |
be403ea1 | 1025 | nla_put_failure: |
26932566 PM |
1026 | nlmsg_cancel(skb, nlh); |
1027 | return -EMSGSIZE; | |
1da177e4 LT |
1028 | } |
1029 | ||
1da177e4 LT |
1030 | /* |
1031 | Update FIB if: | |
1032 | - local address disappeared -> we must delete all the entries | |
1033 | referring to it. | |
1034 | - device went down -> we must shutdown all nexthops going via it. | |
1035 | */ | |
4814bdbd | 1036 | int fib_sync_down_addr(struct net *net, __be32 local) |
1da177e4 LT |
1037 | { |
1038 | int ret = 0; | |
85326fa5 DL |
1039 | unsigned int hash = fib_laddr_hashfn(local); |
1040 | struct hlist_head *head = &fib_info_laddrhash[hash]; | |
1041 | struct hlist_node *node; | |
1042 | struct fib_info *fi; | |
1da177e4 | 1043 | |
85326fa5 DL |
1044 | if (fib_info_laddrhash == NULL || local == 0) |
1045 | return 0; | |
1da177e4 | 1046 | |
85326fa5 | 1047 | hlist_for_each_entry(fi, node, head, fib_lhash) { |
09ad9bc7 | 1048 | if (!net_eq(fi->fib_net, net)) |
4814bdbd | 1049 | continue; |
85326fa5 DL |
1050 | if (fi->fib_prefsrc == local) { |
1051 | fi->fib_flags |= RTNH_F_DEAD; | |
1052 | ret++; | |
1da177e4 LT |
1053 | } |
1054 | } | |
85326fa5 DL |
1055 | return ret; |
1056 | } | |
1057 | ||
1058 | int fib_sync_down_dev(struct net_device *dev, int force) | |
1059 | { | |
1060 | int ret = 0; | |
1061 | int scope = RT_SCOPE_NOWHERE; | |
1062 | struct fib_info *prev_fi = NULL; | |
1063 | unsigned int hash = fib_devindex_hashfn(dev->ifindex); | |
1064 | struct hlist_head *head = &fib_info_devhash[hash]; | |
1065 | struct hlist_node *node; | |
1066 | struct fib_nh *nh; | |
1da177e4 | 1067 | |
85326fa5 DL |
1068 | if (force) |
1069 | scope = -1; | |
1da177e4 | 1070 | |
85326fa5 DL |
1071 | hlist_for_each_entry(nh, node, head, nh_hash) { |
1072 | struct fib_info *fi = nh->nh_parent; | |
1073 | int dead; | |
1da177e4 | 1074 | |
85326fa5 DL |
1075 | BUG_ON(!fi->fib_nhs); |
1076 | if (nh->nh_dev != dev || fi == prev_fi) | |
1077 | continue; | |
1078 | prev_fi = fi; | |
1079 | dead = 0; | |
1080 | change_nexthops(fi) { | |
71fceff0 | 1081 | if (nexthop_nh->nh_flags&RTNH_F_DEAD) |
85326fa5 | 1082 | dead++; |
71fceff0 DM |
1083 | else if (nexthop_nh->nh_dev == dev && |
1084 | nexthop_nh->nh_scope != scope) { | |
1085 | nexthop_nh->nh_flags |= RTNH_F_DEAD; | |
1da177e4 | 1086 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
85326fa5 | 1087 | spin_lock_bh(&fib_multipath_lock); |
71fceff0 DM |
1088 | fi->fib_power -= nexthop_nh->nh_power; |
1089 | nexthop_nh->nh_power = 0; | |
85326fa5 | 1090 | spin_unlock_bh(&fib_multipath_lock); |
1da177e4 | 1091 | #endif |
85326fa5 DL |
1092 | dead++; |
1093 | } | |
1da177e4 | 1094 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
71fceff0 | 1095 | if (force > 1 && nexthop_nh->nh_dev == dev) { |
85326fa5 DL |
1096 | dead = fi->fib_nhs; |
1097 | break; | |
1da177e4 | 1098 | } |
85326fa5 DL |
1099 | #endif |
1100 | } endfor_nexthops(fi) | |
1101 | if (dead == fi->fib_nhs) { | |
1102 | fi->fib_flags |= RTNH_F_DEAD; | |
1103 | ret++; | |
1da177e4 LT |
1104 | } |
1105 | } | |
1106 | ||
1107 | return ret; | |
1108 | } | |
1109 | ||
1110 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1111 | ||
1112 | /* | |
1113 | Dead device goes up. We wake up dead nexthops. | |
1114 | It takes sense only on multipath routes. | |
1115 | */ | |
1116 | ||
1117 | int fib_sync_up(struct net_device *dev) | |
1118 | { | |
1119 | struct fib_info *prev_fi; | |
1120 | unsigned int hash; | |
1121 | struct hlist_head *head; | |
1122 | struct hlist_node *node; | |
1123 | struct fib_nh *nh; | |
1124 | int ret; | |
1125 | ||
1126 | if (!(dev->flags&IFF_UP)) | |
1127 | return 0; | |
1128 | ||
1129 | prev_fi = NULL; | |
1130 | hash = fib_devindex_hashfn(dev->ifindex); | |
1131 | head = &fib_info_devhash[hash]; | |
1132 | ret = 0; | |
1133 | ||
1134 | hlist_for_each_entry(nh, node, head, nh_hash) { | |
1135 | struct fib_info *fi = nh->nh_parent; | |
1136 | int alive; | |
1137 | ||
1138 | BUG_ON(!fi->fib_nhs); | |
1139 | if (nh->nh_dev != dev || fi == prev_fi) | |
1140 | continue; | |
1141 | ||
1142 | prev_fi = fi; | |
1143 | alive = 0; | |
1144 | change_nexthops(fi) { | |
71fceff0 | 1145 | if (!(nexthop_nh->nh_flags&RTNH_F_DEAD)) { |
1da177e4 LT |
1146 | alive++; |
1147 | continue; | |
1148 | } | |
71fceff0 DM |
1149 | if (nexthop_nh->nh_dev == NULL || |
1150 | !(nexthop_nh->nh_dev->flags&IFF_UP)) | |
1da177e4 | 1151 | continue; |
71fceff0 DM |
1152 | if (nexthop_nh->nh_dev != dev || |
1153 | !__in_dev_get_rtnl(dev)) | |
1da177e4 LT |
1154 | continue; |
1155 | alive++; | |
1156 | spin_lock_bh(&fib_multipath_lock); | |
71fceff0 DM |
1157 | nexthop_nh->nh_power = 0; |
1158 | nexthop_nh->nh_flags &= ~RTNH_F_DEAD; | |
1da177e4 LT |
1159 | spin_unlock_bh(&fib_multipath_lock); |
1160 | } endfor_nexthops(fi) | |
1161 | ||
1162 | if (alive > 0) { | |
1163 | fi->fib_flags &= ~RTNH_F_DEAD; | |
1164 | ret++; | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | return ret; | |
1169 | } | |
1170 | ||
1171 | /* | |
1172 | The algorithm is suboptimal, but it provides really | |
1173 | fair weighted route distribution. | |
1174 | */ | |
1175 | ||
1176 | void fib_select_multipath(const struct flowi *flp, struct fib_result *res) | |
1177 | { | |
1178 | struct fib_info *fi = res->fi; | |
1179 | int w; | |
1180 | ||
1181 | spin_lock_bh(&fib_multipath_lock); | |
1182 | if (fi->fib_power <= 0) { | |
1183 | int power = 0; | |
1184 | change_nexthops(fi) { | |
71fceff0 DM |
1185 | if (!(nexthop_nh->nh_flags&RTNH_F_DEAD)) { |
1186 | power += nexthop_nh->nh_weight; | |
1187 | nexthop_nh->nh_power = nexthop_nh->nh_weight; | |
1da177e4 LT |
1188 | } |
1189 | } endfor_nexthops(fi); | |
1190 | fi->fib_power = power; | |
1191 | if (power <= 0) { | |
1192 | spin_unlock_bh(&fib_multipath_lock); | |
1193 | /* Race condition: route has just become dead. */ | |
1194 | res->nh_sel = 0; | |
1195 | return; | |
1196 | } | |
1197 | } | |
1198 | ||
1199 | ||
1200 | /* w should be random number [0..fi->fib_power-1], | |
1201 | it is pretty bad approximation. | |
1202 | */ | |
1203 | ||
1204 | w = jiffies % fi->fib_power; | |
1205 | ||
1206 | change_nexthops(fi) { | |
71fceff0 DM |
1207 | if (!(nexthop_nh->nh_flags&RTNH_F_DEAD) && |
1208 | nexthop_nh->nh_power) { | |
1209 | if ((w -= nexthop_nh->nh_power) <= 0) { | |
1210 | nexthop_nh->nh_power--; | |
1da177e4 LT |
1211 | fi->fib_power--; |
1212 | res->nh_sel = nhsel; | |
1213 | spin_unlock_bh(&fib_multipath_lock); | |
1214 | return; | |
1215 | } | |
1216 | } | |
1217 | } endfor_nexthops(fi); | |
1218 | ||
1219 | /* Race condition: route has just become dead. */ | |
1220 | res->nh_sel = 0; | |
1221 | spin_unlock_bh(&fib_multipath_lock); | |
1222 | } | |
1223 | #endif |