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1 | /* | |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * IPv4 Forwarding Information Base: semantics. | |
7 | * | |
8 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
16 | #include <asm/uaccess.h> | |
17 | #include <linux/bitops.h> | |
18 | #include <linux/types.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/jiffies.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/socket.h> | |
24 | #include <linux/sockios.h> | |
25 | #include <linux/errno.h> | |
26 | #include <linux/in.h> | |
27 | #include <linux/inet.h> | |
28 | #include <linux/inetdevice.h> | |
29 | #include <linux/netdevice.h> | |
30 | #include <linux/if_arp.h> | |
31 | #include <linux/proc_fs.h> | |
32 | #include <linux/skbuff.h> | |
33 | #include <linux/init.h> | |
34 | #include <linux/slab.h> | |
35 | ||
36 | #include <net/arp.h> | |
37 | #include <net/ip.h> | |
38 | #include <net/protocol.h> | |
39 | #include <net/route.h> | |
40 | #include <net/tcp.h> | |
41 | #include <net/sock.h> | |
42 | #include <net/ip_fib.h> | |
43 | #include <net/netlink.h> | |
44 | #include <net/nexthop.h> | |
45 | #include <net/lwtunnel.h> | |
46 | ||
47 | #include "fib_lookup.h" | |
48 | ||
49 | static DEFINE_SPINLOCK(fib_info_lock); | |
50 | static struct hlist_head *fib_info_hash; | |
51 | static struct hlist_head *fib_info_laddrhash; | |
52 | static unsigned int fib_info_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) { \ | |
64 | int nhsel; const struct fib_nh *nh; \ | |
65 | for (nhsel = 0, nh = (fi)->fib_nh; \ | |
66 | nhsel < (fi)->fib_nhs; \ | |
67 | nh++, nhsel++) | |
68 | ||
69 | #define change_nexthops(fi) { \ | |
70 | int nhsel; struct fib_nh *nexthop_nh; \ | |
71 | for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ | |
72 | nhsel < (fi)->fib_nhs; \ | |
73 | nexthop_nh++, nhsel++) | |
74 | ||
75 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ | |
76 | ||
77 | /* Hope, that gcc will optimize it to get rid of dummy loop */ | |
78 | ||
79 | #define for_nexthops(fi) { \ | |
80 | int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \ | |
81 | for (nhsel = 0; nhsel < 1; nhsel++) | |
82 | ||
83 | #define change_nexthops(fi) { \ | |
84 | int nhsel; \ | |
85 | struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ | |
86 | for (nhsel = 0; nhsel < 1; nhsel++) | |
87 | ||
88 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ | |
89 | ||
90 | #define endfor_nexthops(fi) } | |
91 | ||
92 | ||
93 | const struct fib_prop fib_props[RTN_MAX + 1] = { | |
94 | [RTN_UNSPEC] = { | |
95 | .error = 0, | |
96 | .scope = RT_SCOPE_NOWHERE, | |
97 | }, | |
98 | [RTN_UNICAST] = { | |
99 | .error = 0, | |
100 | .scope = RT_SCOPE_UNIVERSE, | |
101 | }, | |
102 | [RTN_LOCAL] = { | |
103 | .error = 0, | |
104 | .scope = RT_SCOPE_HOST, | |
105 | }, | |
106 | [RTN_BROADCAST] = { | |
107 | .error = 0, | |
108 | .scope = RT_SCOPE_LINK, | |
109 | }, | |
110 | [RTN_ANYCAST] = { | |
111 | .error = 0, | |
112 | .scope = RT_SCOPE_LINK, | |
113 | }, | |
114 | [RTN_MULTICAST] = { | |
115 | .error = 0, | |
116 | .scope = RT_SCOPE_UNIVERSE, | |
117 | }, | |
118 | [RTN_BLACKHOLE] = { | |
119 | .error = -EINVAL, | |
120 | .scope = RT_SCOPE_UNIVERSE, | |
121 | }, | |
122 | [RTN_UNREACHABLE] = { | |
123 | .error = -EHOSTUNREACH, | |
124 | .scope = RT_SCOPE_UNIVERSE, | |
125 | }, | |
126 | [RTN_PROHIBIT] = { | |
127 | .error = -EACCES, | |
128 | .scope = RT_SCOPE_UNIVERSE, | |
129 | }, | |
130 | [RTN_THROW] = { | |
131 | .error = -EAGAIN, | |
132 | .scope = RT_SCOPE_UNIVERSE, | |
133 | }, | |
134 | [RTN_NAT] = { | |
135 | .error = -EINVAL, | |
136 | .scope = RT_SCOPE_NOWHERE, | |
137 | }, | |
138 | [RTN_XRESOLVE] = { | |
139 | .error = -EINVAL, | |
140 | .scope = RT_SCOPE_NOWHERE, | |
141 | }, | |
142 | }; | |
143 | ||
144 | static void rt_fibinfo_free(struct rtable __rcu **rtp) | |
145 | { | |
146 | struct rtable *rt = rcu_dereference_protected(*rtp, 1); | |
147 | ||
148 | if (!rt) | |
149 | return; | |
150 | ||
151 | /* Not even needed : RCU_INIT_POINTER(*rtp, NULL); | |
152 | * because we waited an RCU grace period before calling | |
153 | * free_fib_info_rcu() | |
154 | */ | |
155 | ||
156 | dst_free(&rt->dst); | |
157 | } | |
158 | ||
159 | static void free_nh_exceptions(struct fib_nh *nh) | |
160 | { | |
161 | struct fnhe_hash_bucket *hash; | |
162 | int i; | |
163 | ||
164 | hash = rcu_dereference_protected(nh->nh_exceptions, 1); | |
165 | if (!hash) | |
166 | return; | |
167 | for (i = 0; i < FNHE_HASH_SIZE; i++) { | |
168 | struct fib_nh_exception *fnhe; | |
169 | ||
170 | fnhe = rcu_dereference_protected(hash[i].chain, 1); | |
171 | while (fnhe) { | |
172 | struct fib_nh_exception *next; | |
173 | ||
174 | next = rcu_dereference_protected(fnhe->fnhe_next, 1); | |
175 | ||
176 | rt_fibinfo_free(&fnhe->fnhe_rth_input); | |
177 | rt_fibinfo_free(&fnhe->fnhe_rth_output); | |
178 | ||
179 | kfree(fnhe); | |
180 | ||
181 | fnhe = next; | |
182 | } | |
183 | } | |
184 | kfree(hash); | |
185 | } | |
186 | ||
187 | static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp) | |
188 | { | |
189 | int cpu; | |
190 | ||
191 | if (!rtp) | |
192 | return; | |
193 | ||
194 | for_each_possible_cpu(cpu) { | |
195 | struct rtable *rt; | |
196 | ||
197 | rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1); | |
198 | if (rt) | |
199 | dst_free(&rt->dst); | |
200 | } | |
201 | free_percpu(rtp); | |
202 | } | |
203 | ||
204 | /* Release a nexthop info record */ | |
205 | static void free_fib_info_rcu(struct rcu_head *head) | |
206 | { | |
207 | struct fib_info *fi = container_of(head, struct fib_info, rcu); | |
208 | ||
209 | change_nexthops(fi) { | |
210 | if (nexthop_nh->nh_dev) | |
211 | dev_put(nexthop_nh->nh_dev); | |
212 | lwtstate_put(nexthop_nh->nh_lwtstate); | |
213 | free_nh_exceptions(nexthop_nh); | |
214 | rt_fibinfo_free_cpus(nexthop_nh->nh_pcpu_rth_output); | |
215 | rt_fibinfo_free(&nexthop_nh->nh_rth_input); | |
216 | } endfor_nexthops(fi); | |
217 | ||
218 | if (fi->fib_metrics != (u32 *) dst_default_metrics) | |
219 | kfree(fi->fib_metrics); | |
220 | kfree(fi); | |
221 | } | |
222 | ||
223 | void free_fib_info(struct fib_info *fi) | |
224 | { | |
225 | if (fi->fib_dead == 0) { | |
226 | pr_warn("Freeing alive fib_info %p\n", fi); | |
227 | return; | |
228 | } | |
229 | fib_info_cnt--; | |
230 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
231 | change_nexthops(fi) { | |
232 | if (nexthop_nh->nh_tclassid) | |
233 | fi->fib_net->ipv4.fib_num_tclassid_users--; | |
234 | } endfor_nexthops(fi); | |
235 | #endif | |
236 | call_rcu(&fi->rcu, free_fib_info_rcu); | |
237 | } | |
238 | ||
239 | void fib_release_info(struct fib_info *fi) | |
240 | { | |
241 | spin_lock_bh(&fib_info_lock); | |
242 | if (fi && --fi->fib_treeref == 0) { | |
243 | hlist_del(&fi->fib_hash); | |
244 | if (fi->fib_prefsrc) | |
245 | hlist_del(&fi->fib_lhash); | |
246 | change_nexthops(fi) { | |
247 | if (!nexthop_nh->nh_dev) | |
248 | continue; | |
249 | hlist_del(&nexthop_nh->nh_hash); | |
250 | } endfor_nexthops(fi) | |
251 | fi->fib_dead = 1; | |
252 | fib_info_put(fi); | |
253 | } | |
254 | spin_unlock_bh(&fib_info_lock); | |
255 | } | |
256 | ||
257 | static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi) | |
258 | { | |
259 | const struct fib_nh *onh = ofi->fib_nh; | |
260 | ||
261 | for_nexthops(fi) { | |
262 | if (nh->nh_oif != onh->nh_oif || | |
263 | nh->nh_gw != onh->nh_gw || | |
264 | nh->nh_scope != onh->nh_scope || | |
265 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
266 | nh->nh_weight != onh->nh_weight || | |
267 | #endif | |
268 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
269 | nh->nh_tclassid != onh->nh_tclassid || | |
270 | #endif | |
271 | lwtunnel_cmp_encap(nh->nh_lwtstate, onh->nh_lwtstate) || | |
272 | ((nh->nh_flags ^ onh->nh_flags) & ~RTNH_COMPARE_MASK)) | |
273 | return -1; | |
274 | onh++; | |
275 | } endfor_nexthops(fi); | |
276 | return 0; | |
277 | } | |
278 | ||
279 | static inline unsigned int fib_devindex_hashfn(unsigned int val) | |
280 | { | |
281 | unsigned int mask = DEVINDEX_HASHSIZE - 1; | |
282 | ||
283 | return (val ^ | |
284 | (val >> DEVINDEX_HASHBITS) ^ | |
285 | (val >> (DEVINDEX_HASHBITS * 2))) & mask; | |
286 | } | |
287 | ||
288 | static inline unsigned int fib_info_hashfn(const struct fib_info *fi) | |
289 | { | |
290 | unsigned int mask = (fib_info_hash_size - 1); | |
291 | unsigned int val = fi->fib_nhs; | |
292 | ||
293 | val ^= (fi->fib_protocol << 8) | fi->fib_scope; | |
294 | val ^= (__force u32)fi->fib_prefsrc; | |
295 | val ^= fi->fib_priority; | |
296 | for_nexthops(fi) { | |
297 | val ^= fib_devindex_hashfn(nh->nh_oif); | |
298 | } endfor_nexthops(fi) | |
299 | ||
300 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; | |
301 | } | |
302 | ||
303 | static struct fib_info *fib_find_info(const struct fib_info *nfi) | |
304 | { | |
305 | struct hlist_head *head; | |
306 | struct fib_info *fi; | |
307 | unsigned int hash; | |
308 | ||
309 | hash = fib_info_hashfn(nfi); | |
310 | head = &fib_info_hash[hash]; | |
311 | ||
312 | hlist_for_each_entry(fi, head, fib_hash) { | |
313 | if (!net_eq(fi->fib_net, nfi->fib_net)) | |
314 | continue; | |
315 | if (fi->fib_nhs != nfi->fib_nhs) | |
316 | continue; | |
317 | if (nfi->fib_protocol == fi->fib_protocol && | |
318 | nfi->fib_scope == fi->fib_scope && | |
319 | nfi->fib_prefsrc == fi->fib_prefsrc && | |
320 | nfi->fib_priority == fi->fib_priority && | |
321 | nfi->fib_type == fi->fib_type && | |
322 | memcmp(nfi->fib_metrics, fi->fib_metrics, | |
323 | sizeof(u32) * RTAX_MAX) == 0 && | |
324 | !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) && | |
325 | (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0)) | |
326 | return fi; | |
327 | } | |
328 | ||
329 | return NULL; | |
330 | } | |
331 | ||
332 | /* Check, that the gateway is already configured. | |
333 | * Used only by redirect accept routine. | |
334 | */ | |
335 | int ip_fib_check_default(__be32 gw, struct net_device *dev) | |
336 | { | |
337 | struct hlist_head *head; | |
338 | struct fib_nh *nh; | |
339 | unsigned int hash; | |
340 | ||
341 | spin_lock(&fib_info_lock); | |
342 | ||
343 | hash = fib_devindex_hashfn(dev->ifindex); | |
344 | head = &fib_info_devhash[hash]; | |
345 | hlist_for_each_entry(nh, head, nh_hash) { | |
346 | if (nh->nh_dev == dev && | |
347 | nh->nh_gw == gw && | |
348 | !(nh->nh_flags & RTNH_F_DEAD)) { | |
349 | spin_unlock(&fib_info_lock); | |
350 | return 0; | |
351 | } | |
352 | } | |
353 | ||
354 | spin_unlock(&fib_info_lock); | |
355 | ||
356 | return -1; | |
357 | } | |
358 | ||
359 | static inline size_t fib_nlmsg_size(struct fib_info *fi) | |
360 | { | |
361 | size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) | |
362 | + nla_total_size(4) /* RTA_TABLE */ | |
363 | + nla_total_size(4) /* RTA_DST */ | |
364 | + nla_total_size(4) /* RTA_PRIORITY */ | |
365 | + nla_total_size(4) /* RTA_PREFSRC */ | |
366 | + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */ | |
367 | ||
368 | /* space for nested metrics */ | |
369 | payload += nla_total_size((RTAX_MAX * nla_total_size(4))); | |
370 | ||
371 | if (fi->fib_nhs) { | |
372 | size_t nh_encapsize = 0; | |
373 | /* Also handles the special case fib_nhs == 1 */ | |
374 | ||
375 | /* each nexthop is packed in an attribute */ | |
376 | size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); | |
377 | ||
378 | /* may contain flow and gateway attribute */ | |
379 | nhsize += 2 * nla_total_size(4); | |
380 | ||
381 | /* grab encap info */ | |
382 | for_nexthops(fi) { | |
383 | if (nh->nh_lwtstate) { | |
384 | /* RTA_ENCAP_TYPE */ | |
385 | nh_encapsize += lwtunnel_get_encap_size( | |
386 | nh->nh_lwtstate); | |
387 | /* RTA_ENCAP */ | |
388 | nh_encapsize += nla_total_size(2); | |
389 | } | |
390 | } endfor_nexthops(fi); | |
391 | ||
392 | /* all nexthops are packed in a nested attribute */ | |
393 | payload += nla_total_size((fi->fib_nhs * nhsize) + | |
394 | nh_encapsize); | |
395 | ||
396 | } | |
397 | ||
398 | return payload; | |
399 | } | |
400 | ||
401 | void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, | |
402 | int dst_len, u32 tb_id, const struct nl_info *info, | |
403 | unsigned int nlm_flags) | |
404 | { | |
405 | struct sk_buff *skb; | |
406 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; | |
407 | int err = -ENOBUFS; | |
408 | ||
409 | skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); | |
410 | if (!skb) | |
411 | goto errout; | |
412 | ||
413 | err = fib_dump_info(skb, info->portid, seq, event, tb_id, | |
414 | fa->fa_type, key, dst_len, | |
415 | fa->fa_tos, fa->fa_info, nlm_flags); | |
416 | if (err < 0) { | |
417 | /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ | |
418 | WARN_ON(err == -EMSGSIZE); | |
419 | kfree_skb(skb); | |
420 | goto errout; | |
421 | } | |
422 | rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE, | |
423 | info->nlh, GFP_KERNEL); | |
424 | return; | |
425 | errout: | |
426 | if (err < 0) | |
427 | rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err); | |
428 | } | |
429 | ||
430 | static int fib_detect_death(struct fib_info *fi, int order, | |
431 | struct fib_info **last_resort, int *last_idx, | |
432 | int dflt) | |
433 | { | |
434 | struct neighbour *n; | |
435 | int state = NUD_NONE; | |
436 | ||
437 | n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev); | |
438 | if (n) { | |
439 | state = n->nud_state; | |
440 | neigh_release(n); | |
441 | } else { | |
442 | return 0; | |
443 | } | |
444 | if (state == NUD_REACHABLE) | |
445 | return 0; | |
446 | if ((state & NUD_VALID) && order != dflt) | |
447 | return 0; | |
448 | if ((state & NUD_VALID) || | |
449 | (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) { | |
450 | *last_resort = fi; | |
451 | *last_idx = order; | |
452 | } | |
453 | return 1; | |
454 | } | |
455 | ||
456 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
457 | ||
458 | static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining) | |
459 | { | |
460 | int nhs = 0; | |
461 | ||
462 | while (rtnh_ok(rtnh, remaining)) { | |
463 | nhs++; | |
464 | rtnh = rtnh_next(rtnh, &remaining); | |
465 | } | |
466 | ||
467 | /* leftover implies invalid nexthop configuration, discard it */ | |
468 | return remaining > 0 ? 0 : nhs; | |
469 | } | |
470 | ||
471 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, | |
472 | int remaining, struct fib_config *cfg) | |
473 | { | |
474 | struct net *net = cfg->fc_nlinfo.nl_net; | |
475 | int ret; | |
476 | ||
477 | change_nexthops(fi) { | |
478 | int attrlen; | |
479 | ||
480 | if (!rtnh_ok(rtnh, remaining)) | |
481 | return -EINVAL; | |
482 | ||
483 | nexthop_nh->nh_flags = | |
484 | (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; | |
485 | nexthop_nh->nh_oif = rtnh->rtnh_ifindex; | |
486 | nexthop_nh->nh_weight = rtnh->rtnh_hops + 1; | |
487 | ||
488 | attrlen = rtnh_attrlen(rtnh); | |
489 | if (attrlen > 0) { | |
490 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
491 | ||
492 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
493 | nexthop_nh->nh_gw = nla ? nla_get_in_addr(nla) : 0; | |
494 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
495 | nla = nla_find(attrs, attrlen, RTA_FLOW); | |
496 | nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; | |
497 | if (nexthop_nh->nh_tclassid) | |
498 | fi->fib_net->ipv4.fib_num_tclassid_users++; | |
499 | #endif | |
500 | nla = nla_find(attrs, attrlen, RTA_ENCAP); | |
501 | if (nla) { | |
502 | struct lwtunnel_state *lwtstate; | |
503 | struct net_device *dev = NULL; | |
504 | struct nlattr *nla_entype; | |
505 | ||
506 | nla_entype = nla_find(attrs, attrlen, | |
507 | RTA_ENCAP_TYPE); | |
508 | if (!nla_entype) | |
509 | goto err_inval; | |
510 | if (cfg->fc_oif) | |
511 | dev = __dev_get_by_index(net, cfg->fc_oif); | |
512 | ret = lwtunnel_build_state(dev, nla_get_u16( | |
513 | nla_entype), | |
514 | nla, AF_INET, cfg, | |
515 | &lwtstate); | |
516 | if (ret) | |
517 | goto errout; | |
518 | nexthop_nh->nh_lwtstate = | |
519 | lwtstate_get(lwtstate); | |
520 | } | |
521 | } | |
522 | ||
523 | rtnh = rtnh_next(rtnh, &remaining); | |
524 | } endfor_nexthops(fi); | |
525 | ||
526 | return 0; | |
527 | ||
528 | err_inval: | |
529 | ret = -EINVAL; | |
530 | ||
531 | errout: | |
532 | return ret; | |
533 | } | |
534 | ||
535 | #endif | |
536 | ||
537 | static int fib_encap_match(struct net *net, u16 encap_type, | |
538 | struct nlattr *encap, | |
539 | int oif, const struct fib_nh *nh, | |
540 | const struct fib_config *cfg) | |
541 | { | |
542 | struct lwtunnel_state *lwtstate; | |
543 | struct net_device *dev = NULL; | |
544 | int ret, result = 0; | |
545 | ||
546 | if (encap_type == LWTUNNEL_ENCAP_NONE) | |
547 | return 0; | |
548 | ||
549 | if (oif) | |
550 | dev = __dev_get_by_index(net, oif); | |
551 | ret = lwtunnel_build_state(dev, encap_type, encap, | |
552 | AF_INET, cfg, &lwtstate); | |
553 | if (!ret) { | |
554 | result = lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate); | |
555 | lwtstate_free(lwtstate); | |
556 | } | |
557 | ||
558 | return result; | |
559 | } | |
560 | ||
561 | int fib_nh_match(struct fib_config *cfg, struct fib_info *fi) | |
562 | { | |
563 | struct net *net = cfg->fc_nlinfo.nl_net; | |
564 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
565 | struct rtnexthop *rtnh; | |
566 | int remaining; | |
567 | #endif | |
568 | ||
569 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) | |
570 | return 1; | |
571 | ||
572 | if (cfg->fc_oif || cfg->fc_gw) { | |
573 | if (cfg->fc_encap) { | |
574 | if (fib_encap_match(net, cfg->fc_encap_type, | |
575 | cfg->fc_encap, cfg->fc_oif, | |
576 | fi->fib_nh, cfg)) | |
577 | return 1; | |
578 | } | |
579 | if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) && | |
580 | (!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw)) | |
581 | return 0; | |
582 | return 1; | |
583 | } | |
584 | ||
585 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
586 | if (!cfg->fc_mp) | |
587 | return 0; | |
588 | ||
589 | rtnh = cfg->fc_mp; | |
590 | remaining = cfg->fc_mp_len; | |
591 | ||
592 | for_nexthops(fi) { | |
593 | int attrlen; | |
594 | ||
595 | if (!rtnh_ok(rtnh, remaining)) | |
596 | return -EINVAL; | |
597 | ||
598 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif) | |
599 | return 1; | |
600 | ||
601 | attrlen = rtnh_attrlen(rtnh); | |
602 | if (attrlen > 0) { | |
603 | struct nlattr *nla, *attrs = rtnh_attrs(rtnh); | |
604 | ||
605 | nla = nla_find(attrs, attrlen, RTA_GATEWAY); | |
606 | if (nla && nla_get_in_addr(nla) != nh->nh_gw) | |
607 | return 1; | |
608 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
609 | nla = nla_find(attrs, attrlen, RTA_FLOW); | |
610 | if (nla && nla_get_u32(nla) != nh->nh_tclassid) | |
611 | return 1; | |
612 | #endif | |
613 | } | |
614 | ||
615 | rtnh = rtnh_next(rtnh, &remaining); | |
616 | } endfor_nexthops(fi); | |
617 | #endif | |
618 | return 0; | |
619 | } | |
620 | ||
621 | ||
622 | /* | |
623 | * Picture | |
624 | * ------- | |
625 | * | |
626 | * Semantics of nexthop is very messy by historical reasons. | |
627 | * We have to take into account, that: | |
628 | * a) gateway can be actually local interface address, | |
629 | * so that gatewayed route is direct. | |
630 | * b) gateway must be on-link address, possibly | |
631 | * described not by an ifaddr, but also by a direct route. | |
632 | * c) If both gateway and interface are specified, they should not | |
633 | * contradict. | |
634 | * d) If we use tunnel routes, gateway could be not on-link. | |
635 | * | |
636 | * Attempt to reconcile all of these (alas, self-contradictory) conditions | |
637 | * results in pretty ugly and hairy code with obscure logic. | |
638 | * | |
639 | * I chose to generalized it instead, so that the size | |
640 | * of code does not increase practically, but it becomes | |
641 | * much more general. | |
642 | * Every prefix is assigned a "scope" value: "host" is local address, | |
643 | * "link" is direct route, | |
644 | * [ ... "site" ... "interior" ... ] | |
645 | * and "universe" is true gateway route with global meaning. | |
646 | * | |
647 | * Every prefix refers to a set of "nexthop"s (gw, oif), | |
648 | * where gw must have narrower scope. This recursion stops | |
649 | * when gw has LOCAL scope or if "nexthop" is declared ONLINK, | |
650 | * which means that gw is forced to be on link. | |
651 | * | |
652 | * Code is still hairy, but now it is apparently logically | |
653 | * consistent and very flexible. F.e. as by-product it allows | |
654 | * to co-exists in peace independent exterior and interior | |
655 | * routing processes. | |
656 | * | |
657 | * Normally it looks as following. | |
658 | * | |
659 | * {universe prefix} -> (gw, oif) [scope link] | |
660 | * | | |
661 | * |-> {link prefix} -> (gw, oif) [scope local] | |
662 | * | | |
663 | * |-> {local prefix} (terminal node) | |
664 | */ | |
665 | static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi, | |
666 | struct fib_nh *nh) | |
667 | { | |
668 | int err = 0; | |
669 | struct net *net; | |
670 | struct net_device *dev; | |
671 | ||
672 | net = cfg->fc_nlinfo.nl_net; | |
673 | if (nh->nh_gw) { | |
674 | struct fib_result res; | |
675 | ||
676 | if (nh->nh_flags & RTNH_F_ONLINK) { | |
677 | unsigned int addr_type; | |
678 | ||
679 | if (cfg->fc_scope >= RT_SCOPE_LINK) | |
680 | return -EINVAL; | |
681 | dev = __dev_get_by_index(net, nh->nh_oif); | |
682 | if (!dev) | |
683 | return -ENODEV; | |
684 | if (!(dev->flags & IFF_UP)) | |
685 | return -ENETDOWN; | |
686 | addr_type = inet_addr_type_dev_table(net, dev, nh->nh_gw); | |
687 | if (addr_type != RTN_UNICAST) | |
688 | return -EINVAL; | |
689 | if (!netif_carrier_ok(dev)) | |
690 | nh->nh_flags |= RTNH_F_LINKDOWN; | |
691 | nh->nh_dev = dev; | |
692 | dev_hold(dev); | |
693 | nh->nh_scope = RT_SCOPE_LINK; | |
694 | return 0; | |
695 | } | |
696 | rcu_read_lock(); | |
697 | { | |
698 | struct fib_table *tbl = NULL; | |
699 | struct flowi4 fl4 = { | |
700 | .daddr = nh->nh_gw, | |
701 | .flowi4_scope = cfg->fc_scope + 1, | |
702 | .flowi4_oif = nh->nh_oif, | |
703 | .flowi4_iif = LOOPBACK_IFINDEX, | |
704 | }; | |
705 | ||
706 | /* It is not necessary, but requires a bit of thinking */ | |
707 | if (fl4.flowi4_scope < RT_SCOPE_LINK) | |
708 | fl4.flowi4_scope = RT_SCOPE_LINK; | |
709 | ||
710 | if (cfg->fc_table) | |
711 | tbl = fib_get_table(net, cfg->fc_table); | |
712 | ||
713 | if (tbl) | |
714 | err = fib_table_lookup(tbl, &fl4, &res, | |
715 | FIB_LOOKUP_IGNORE_LINKSTATE | | |
716 | FIB_LOOKUP_NOREF); | |
717 | ||
718 | /* on error or if no table given do full lookup. This | |
719 | * is needed for example when nexthops are in the local | |
720 | * table rather than the given table | |
721 | */ | |
722 | if (!tbl || err) { | |
723 | err = fib_lookup(net, &fl4, &res, | |
724 | FIB_LOOKUP_IGNORE_LINKSTATE); | |
725 | } | |
726 | ||
727 | if (err) { | |
728 | rcu_read_unlock(); | |
729 | return err; | |
730 | } | |
731 | } | |
732 | err = -EINVAL; | |
733 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) | |
734 | goto out; | |
735 | nh->nh_scope = res.scope; | |
736 | nh->nh_oif = FIB_RES_OIF(res); | |
737 | nh->nh_dev = dev = FIB_RES_DEV(res); | |
738 | if (!dev) | |
739 | goto out; | |
740 | dev_hold(dev); | |
741 | if (!netif_carrier_ok(dev)) | |
742 | nh->nh_flags |= RTNH_F_LINKDOWN; | |
743 | err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN; | |
744 | } else { | |
745 | struct in_device *in_dev; | |
746 | ||
747 | if (nh->nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) | |
748 | return -EINVAL; | |
749 | ||
750 | rcu_read_lock(); | |
751 | err = -ENODEV; | |
752 | in_dev = inetdev_by_index(net, nh->nh_oif); | |
753 | if (!in_dev) | |
754 | goto out; | |
755 | err = -ENETDOWN; | |
756 | if (!(in_dev->dev->flags & IFF_UP)) | |
757 | goto out; | |
758 | nh->nh_dev = in_dev->dev; | |
759 | dev_hold(nh->nh_dev); | |
760 | nh->nh_scope = RT_SCOPE_HOST; | |
761 | if (!netif_carrier_ok(nh->nh_dev)) | |
762 | nh->nh_flags |= RTNH_F_LINKDOWN; | |
763 | err = 0; | |
764 | } | |
765 | out: | |
766 | rcu_read_unlock(); | |
767 | return err; | |
768 | } | |
769 | ||
770 | static inline unsigned int fib_laddr_hashfn(__be32 val) | |
771 | { | |
772 | unsigned int mask = (fib_info_hash_size - 1); | |
773 | ||
774 | return ((__force u32)val ^ | |
775 | ((__force u32)val >> 7) ^ | |
776 | ((__force u32)val >> 14)) & mask; | |
777 | } | |
778 | ||
779 | static struct hlist_head *fib_info_hash_alloc(int bytes) | |
780 | { | |
781 | if (bytes <= PAGE_SIZE) | |
782 | return kzalloc(bytes, GFP_KERNEL); | |
783 | else | |
784 | return (struct hlist_head *) | |
785 | __get_free_pages(GFP_KERNEL | __GFP_ZERO, | |
786 | get_order(bytes)); | |
787 | } | |
788 | ||
789 | static void fib_info_hash_free(struct hlist_head *hash, int bytes) | |
790 | { | |
791 | if (!hash) | |
792 | return; | |
793 | ||
794 | if (bytes <= PAGE_SIZE) | |
795 | kfree(hash); | |
796 | else | |
797 | free_pages((unsigned long) hash, get_order(bytes)); | |
798 | } | |
799 | ||
800 | static void fib_info_hash_move(struct hlist_head *new_info_hash, | |
801 | struct hlist_head *new_laddrhash, | |
802 | unsigned int new_size) | |
803 | { | |
804 | struct hlist_head *old_info_hash, *old_laddrhash; | |
805 | unsigned int old_size = fib_info_hash_size; | |
806 | unsigned int i, bytes; | |
807 | ||
808 | spin_lock_bh(&fib_info_lock); | |
809 | old_info_hash = fib_info_hash; | |
810 | old_laddrhash = fib_info_laddrhash; | |
811 | fib_info_hash_size = new_size; | |
812 | ||
813 | for (i = 0; i < old_size; i++) { | |
814 | struct hlist_head *head = &fib_info_hash[i]; | |
815 | struct hlist_node *n; | |
816 | struct fib_info *fi; | |
817 | ||
818 | hlist_for_each_entry_safe(fi, n, head, fib_hash) { | |
819 | struct hlist_head *dest; | |
820 | unsigned int new_hash; | |
821 | ||
822 | new_hash = fib_info_hashfn(fi); | |
823 | dest = &new_info_hash[new_hash]; | |
824 | hlist_add_head(&fi->fib_hash, dest); | |
825 | } | |
826 | } | |
827 | fib_info_hash = new_info_hash; | |
828 | ||
829 | for (i = 0; i < old_size; i++) { | |
830 | struct hlist_head *lhead = &fib_info_laddrhash[i]; | |
831 | struct hlist_node *n; | |
832 | struct fib_info *fi; | |
833 | ||
834 | hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) { | |
835 | struct hlist_head *ldest; | |
836 | unsigned int new_hash; | |
837 | ||
838 | new_hash = fib_laddr_hashfn(fi->fib_prefsrc); | |
839 | ldest = &new_laddrhash[new_hash]; | |
840 | hlist_add_head(&fi->fib_lhash, ldest); | |
841 | } | |
842 | } | |
843 | fib_info_laddrhash = new_laddrhash; | |
844 | ||
845 | spin_unlock_bh(&fib_info_lock); | |
846 | ||
847 | bytes = old_size * sizeof(struct hlist_head *); | |
848 | fib_info_hash_free(old_info_hash, bytes); | |
849 | fib_info_hash_free(old_laddrhash, bytes); | |
850 | } | |
851 | ||
852 | __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh) | |
853 | { | |
854 | nh->nh_saddr = inet_select_addr(nh->nh_dev, | |
855 | nh->nh_gw, | |
856 | nh->nh_parent->fib_scope); | |
857 | nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid); | |
858 | ||
859 | return nh->nh_saddr; | |
860 | } | |
861 | ||
862 | static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc) | |
863 | { | |
864 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || | |
865 | fib_prefsrc != cfg->fc_dst) { | |
866 | u32 tb_id = cfg->fc_table; | |
867 | ||
868 | if (tb_id == RT_TABLE_MAIN) | |
869 | tb_id = RT_TABLE_LOCAL; | |
870 | ||
871 | if (inet_addr_type_table(cfg->fc_nlinfo.nl_net, | |
872 | fib_prefsrc, tb_id) != RTN_LOCAL) { | |
873 | return false; | |
874 | } | |
875 | } | |
876 | return true; | |
877 | } | |
878 | ||
879 | static int | |
880 | fib_convert_metrics(struct fib_info *fi, const struct fib_config *cfg) | |
881 | { | |
882 | bool ecn_ca = false; | |
883 | struct nlattr *nla; | |
884 | int remaining; | |
885 | ||
886 | if (!cfg->fc_mx) | |
887 | return 0; | |
888 | ||
889 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { | |
890 | int type = nla_type(nla); | |
891 | u32 val; | |
892 | ||
893 | if (!type) | |
894 | continue; | |
895 | if (type > RTAX_MAX) | |
896 | return -EINVAL; | |
897 | ||
898 | if (type == RTAX_CC_ALGO) { | |
899 | char tmp[TCP_CA_NAME_MAX]; | |
900 | ||
901 | nla_strlcpy(tmp, nla, sizeof(tmp)); | |
902 | val = tcp_ca_get_key_by_name(tmp, &ecn_ca); | |
903 | if (val == TCP_CA_UNSPEC) | |
904 | return -EINVAL; | |
905 | } else { | |
906 | val = nla_get_u32(nla); | |
907 | } | |
908 | if (type == RTAX_ADVMSS && val > 65535 - 40) | |
909 | val = 65535 - 40; | |
910 | if (type == RTAX_MTU && val > 65535 - 15) | |
911 | val = 65535 - 15; | |
912 | if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) | |
913 | return -EINVAL; | |
914 | fi->fib_metrics[type - 1] = val; | |
915 | } | |
916 | ||
917 | if (ecn_ca) | |
918 | fi->fib_metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA; | |
919 | ||
920 | return 0; | |
921 | } | |
922 | ||
923 | struct fib_info *fib_create_info(struct fib_config *cfg) | |
924 | { | |
925 | int err; | |
926 | struct fib_info *fi = NULL; | |
927 | struct fib_info *ofi; | |
928 | int nhs = 1; | |
929 | struct net *net = cfg->fc_nlinfo.nl_net; | |
930 | ||
931 | if (cfg->fc_type > RTN_MAX) | |
932 | goto err_inval; | |
933 | ||
934 | /* Fast check to catch the most weird cases */ | |
935 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) | |
936 | goto err_inval; | |
937 | ||
938 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
939 | if (cfg->fc_mp) { | |
940 | nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len); | |
941 | if (nhs == 0) | |
942 | goto err_inval; | |
943 | } | |
944 | #endif | |
945 | ||
946 | err = -ENOBUFS; | |
947 | if (fib_info_cnt >= fib_info_hash_size) { | |
948 | unsigned int new_size = fib_info_hash_size << 1; | |
949 | struct hlist_head *new_info_hash; | |
950 | struct hlist_head *new_laddrhash; | |
951 | unsigned int bytes; | |
952 | ||
953 | if (!new_size) | |
954 | new_size = 16; | |
955 | bytes = new_size * sizeof(struct hlist_head *); | |
956 | new_info_hash = fib_info_hash_alloc(bytes); | |
957 | new_laddrhash = fib_info_hash_alloc(bytes); | |
958 | if (!new_info_hash || !new_laddrhash) { | |
959 | fib_info_hash_free(new_info_hash, bytes); | |
960 | fib_info_hash_free(new_laddrhash, bytes); | |
961 | } else | |
962 | fib_info_hash_move(new_info_hash, new_laddrhash, new_size); | |
963 | ||
964 | if (!fib_info_hash_size) | |
965 | goto failure; | |
966 | } | |
967 | ||
968 | fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL); | |
969 | if (!fi) | |
970 | goto failure; | |
971 | fib_info_cnt++; | |
972 | if (cfg->fc_mx) { | |
973 | fi->fib_metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL); | |
974 | if (!fi->fib_metrics) | |
975 | goto failure; | |
976 | } else | |
977 | fi->fib_metrics = (u32 *) dst_default_metrics; | |
978 | ||
979 | fi->fib_net = net; | |
980 | fi->fib_protocol = cfg->fc_protocol; | |
981 | fi->fib_scope = cfg->fc_scope; | |
982 | fi->fib_flags = cfg->fc_flags; | |
983 | fi->fib_priority = cfg->fc_priority; | |
984 | fi->fib_prefsrc = cfg->fc_prefsrc; | |
985 | fi->fib_type = cfg->fc_type; | |
986 | ||
987 | fi->fib_nhs = nhs; | |
988 | change_nexthops(fi) { | |
989 | nexthop_nh->nh_parent = fi; | |
990 | nexthop_nh->nh_pcpu_rth_output = alloc_percpu(struct rtable __rcu *); | |
991 | if (!nexthop_nh->nh_pcpu_rth_output) | |
992 | goto failure; | |
993 | } endfor_nexthops(fi) | |
994 | ||
995 | err = fib_convert_metrics(fi, cfg); | |
996 | if (err) | |
997 | goto failure; | |
998 | ||
999 | if (cfg->fc_mp) { | |
1000 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1001 | err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg); | |
1002 | if (err != 0) | |
1003 | goto failure; | |
1004 | if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) | |
1005 | goto err_inval; | |
1006 | if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) | |
1007 | goto err_inval; | |
1008 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
1009 | if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) | |
1010 | goto err_inval; | |
1011 | #endif | |
1012 | #else | |
1013 | goto err_inval; | |
1014 | #endif | |
1015 | } else { | |
1016 | struct fib_nh *nh = fi->fib_nh; | |
1017 | ||
1018 | if (cfg->fc_encap) { | |
1019 | struct lwtunnel_state *lwtstate; | |
1020 | struct net_device *dev = NULL; | |
1021 | ||
1022 | if (cfg->fc_encap_type == LWTUNNEL_ENCAP_NONE) | |
1023 | goto err_inval; | |
1024 | if (cfg->fc_oif) | |
1025 | dev = __dev_get_by_index(net, cfg->fc_oif); | |
1026 | err = lwtunnel_build_state(dev, cfg->fc_encap_type, | |
1027 | cfg->fc_encap, AF_INET, cfg, | |
1028 | &lwtstate); | |
1029 | if (err) | |
1030 | goto failure; | |
1031 | ||
1032 | nh->nh_lwtstate = lwtstate_get(lwtstate); | |
1033 | } | |
1034 | nh->nh_oif = cfg->fc_oif; | |
1035 | nh->nh_gw = cfg->fc_gw; | |
1036 | nh->nh_flags = cfg->fc_flags; | |
1037 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
1038 | nh->nh_tclassid = cfg->fc_flow; | |
1039 | if (nh->nh_tclassid) | |
1040 | fi->fib_net->ipv4.fib_num_tclassid_users++; | |
1041 | #endif | |
1042 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1043 | nh->nh_weight = 1; | |
1044 | #endif | |
1045 | } | |
1046 | ||
1047 | if (fib_props[cfg->fc_type].error) { | |
1048 | if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) | |
1049 | goto err_inval; | |
1050 | goto link_it; | |
1051 | } else { | |
1052 | switch (cfg->fc_type) { | |
1053 | case RTN_UNICAST: | |
1054 | case RTN_LOCAL: | |
1055 | case RTN_BROADCAST: | |
1056 | case RTN_ANYCAST: | |
1057 | case RTN_MULTICAST: | |
1058 | break; | |
1059 | default: | |
1060 | goto err_inval; | |
1061 | } | |
1062 | } | |
1063 | ||
1064 | if (cfg->fc_scope > RT_SCOPE_HOST) | |
1065 | goto err_inval; | |
1066 | ||
1067 | if (cfg->fc_scope == RT_SCOPE_HOST) { | |
1068 | struct fib_nh *nh = fi->fib_nh; | |
1069 | ||
1070 | /* Local address is added. */ | |
1071 | if (nhs != 1 || nh->nh_gw) | |
1072 | goto err_inval; | |
1073 | nh->nh_scope = RT_SCOPE_NOWHERE; | |
1074 | nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif); | |
1075 | err = -ENODEV; | |
1076 | if (!nh->nh_dev) | |
1077 | goto failure; | |
1078 | } else { | |
1079 | int linkdown = 0; | |
1080 | ||
1081 | change_nexthops(fi) { | |
1082 | err = fib_check_nh(cfg, fi, nexthop_nh); | |
1083 | if (err != 0) | |
1084 | goto failure; | |
1085 | if (nexthop_nh->nh_flags & RTNH_F_LINKDOWN) | |
1086 | linkdown++; | |
1087 | } endfor_nexthops(fi) | |
1088 | if (linkdown == fi->fib_nhs) | |
1089 | fi->fib_flags |= RTNH_F_LINKDOWN; | |
1090 | } | |
1091 | ||
1092 | if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) | |
1093 | goto err_inval; | |
1094 | ||
1095 | change_nexthops(fi) { | |
1096 | fib_info_update_nh_saddr(net, nexthop_nh); | |
1097 | } endfor_nexthops(fi) | |
1098 | ||
1099 | link_it: | |
1100 | ofi = fib_find_info(fi); | |
1101 | if (ofi) { | |
1102 | fi->fib_dead = 1; | |
1103 | free_fib_info(fi); | |
1104 | ofi->fib_treeref++; | |
1105 | return ofi; | |
1106 | } | |
1107 | ||
1108 | fi->fib_treeref++; | |
1109 | atomic_inc(&fi->fib_clntref); | |
1110 | spin_lock_bh(&fib_info_lock); | |
1111 | hlist_add_head(&fi->fib_hash, | |
1112 | &fib_info_hash[fib_info_hashfn(fi)]); | |
1113 | if (fi->fib_prefsrc) { | |
1114 | struct hlist_head *head; | |
1115 | ||
1116 | head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)]; | |
1117 | hlist_add_head(&fi->fib_lhash, head); | |
1118 | } | |
1119 | change_nexthops(fi) { | |
1120 | struct hlist_head *head; | |
1121 | unsigned int hash; | |
1122 | ||
1123 | if (!nexthop_nh->nh_dev) | |
1124 | continue; | |
1125 | hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex); | |
1126 | head = &fib_info_devhash[hash]; | |
1127 | hlist_add_head(&nexthop_nh->nh_hash, head); | |
1128 | } endfor_nexthops(fi) | |
1129 | spin_unlock_bh(&fib_info_lock); | |
1130 | return fi; | |
1131 | ||
1132 | err_inval: | |
1133 | err = -EINVAL; | |
1134 | ||
1135 | failure: | |
1136 | if (fi) { | |
1137 | fi->fib_dead = 1; | |
1138 | free_fib_info(fi); | |
1139 | } | |
1140 | ||
1141 | return ERR_PTR(err); | |
1142 | } | |
1143 | ||
1144 | int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, | |
1145 | u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos, | |
1146 | struct fib_info *fi, unsigned int flags) | |
1147 | { | |
1148 | struct nlmsghdr *nlh; | |
1149 | struct rtmsg *rtm; | |
1150 | ||
1151 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); | |
1152 | if (!nlh) | |
1153 | return -EMSGSIZE; | |
1154 | ||
1155 | rtm = nlmsg_data(nlh); | |
1156 | rtm->rtm_family = AF_INET; | |
1157 | rtm->rtm_dst_len = dst_len; | |
1158 | rtm->rtm_src_len = 0; | |
1159 | rtm->rtm_tos = tos; | |
1160 | if (tb_id < 256) | |
1161 | rtm->rtm_table = tb_id; | |
1162 | else | |
1163 | rtm->rtm_table = RT_TABLE_COMPAT; | |
1164 | if (nla_put_u32(skb, RTA_TABLE, tb_id)) | |
1165 | goto nla_put_failure; | |
1166 | rtm->rtm_type = type; | |
1167 | rtm->rtm_flags = fi->fib_flags; | |
1168 | rtm->rtm_scope = fi->fib_scope; | |
1169 | rtm->rtm_protocol = fi->fib_protocol; | |
1170 | ||
1171 | if (rtm->rtm_dst_len && | |
1172 | nla_put_in_addr(skb, RTA_DST, dst)) | |
1173 | goto nla_put_failure; | |
1174 | if (fi->fib_priority && | |
1175 | nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority)) | |
1176 | goto nla_put_failure; | |
1177 | if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0) | |
1178 | goto nla_put_failure; | |
1179 | ||
1180 | if (fi->fib_prefsrc && | |
1181 | nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc)) | |
1182 | goto nla_put_failure; | |
1183 | if (fi->fib_nhs == 1) { | |
1184 | struct in_device *in_dev; | |
1185 | ||
1186 | if (fi->fib_nh->nh_gw && | |
1187 | nla_put_in_addr(skb, RTA_GATEWAY, fi->fib_nh->nh_gw)) | |
1188 | goto nla_put_failure; | |
1189 | if (fi->fib_nh->nh_oif && | |
1190 | nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif)) | |
1191 | goto nla_put_failure; | |
1192 | if (fi->fib_nh->nh_flags & RTNH_F_LINKDOWN) { | |
1193 | in_dev = __in_dev_get_rtnl(fi->fib_nh->nh_dev); | |
1194 | if (in_dev && | |
1195 | IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) | |
1196 | rtm->rtm_flags |= RTNH_F_DEAD; | |
1197 | } | |
1198 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
1199 | if (fi->fib_nh[0].nh_tclassid && | |
1200 | nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid)) | |
1201 | goto nla_put_failure; | |
1202 | #endif | |
1203 | if (fi->fib_nh->nh_lwtstate) | |
1204 | lwtunnel_fill_encap(skb, fi->fib_nh->nh_lwtstate); | |
1205 | } | |
1206 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1207 | if (fi->fib_nhs > 1) { | |
1208 | struct rtnexthop *rtnh; | |
1209 | struct nlattr *mp; | |
1210 | ||
1211 | mp = nla_nest_start(skb, RTA_MULTIPATH); | |
1212 | if (!mp) | |
1213 | goto nla_put_failure; | |
1214 | ||
1215 | for_nexthops(fi) { | |
1216 | struct in_device *in_dev; | |
1217 | ||
1218 | rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); | |
1219 | if (!rtnh) | |
1220 | goto nla_put_failure; | |
1221 | ||
1222 | rtnh->rtnh_flags = nh->nh_flags & 0xFF; | |
1223 | if (nh->nh_flags & RTNH_F_LINKDOWN) { | |
1224 | in_dev = __in_dev_get_rtnl(nh->nh_dev); | |
1225 | if (in_dev && | |
1226 | IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) | |
1227 | rtnh->rtnh_flags |= RTNH_F_DEAD; | |
1228 | } | |
1229 | rtnh->rtnh_hops = nh->nh_weight - 1; | |
1230 | rtnh->rtnh_ifindex = nh->nh_oif; | |
1231 | ||
1232 | if (nh->nh_gw && | |
1233 | nla_put_in_addr(skb, RTA_GATEWAY, nh->nh_gw)) | |
1234 | goto nla_put_failure; | |
1235 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
1236 | if (nh->nh_tclassid && | |
1237 | nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) | |
1238 | goto nla_put_failure; | |
1239 | #endif | |
1240 | if (nh->nh_lwtstate) | |
1241 | lwtunnel_fill_encap(skb, nh->nh_lwtstate); | |
1242 | /* length of rtnetlink header + attributes */ | |
1243 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh; | |
1244 | } endfor_nexthops(fi); | |
1245 | ||
1246 | nla_nest_end(skb, mp); | |
1247 | } | |
1248 | #endif | |
1249 | nlmsg_end(skb, nlh); | |
1250 | return 0; | |
1251 | ||
1252 | nla_put_failure: | |
1253 | nlmsg_cancel(skb, nlh); | |
1254 | return -EMSGSIZE; | |
1255 | } | |
1256 | ||
1257 | /* | |
1258 | * Update FIB if: | |
1259 | * - local address disappeared -> we must delete all the entries | |
1260 | * referring to it. | |
1261 | * - device went down -> we must shutdown all nexthops going via it. | |
1262 | */ | |
1263 | int fib_sync_down_addr(struct net *net, __be32 local) | |
1264 | { | |
1265 | int ret = 0; | |
1266 | unsigned int hash = fib_laddr_hashfn(local); | |
1267 | struct hlist_head *head = &fib_info_laddrhash[hash]; | |
1268 | struct fib_info *fi; | |
1269 | ||
1270 | if (!fib_info_laddrhash || local == 0) | |
1271 | return 0; | |
1272 | ||
1273 | hlist_for_each_entry(fi, head, fib_lhash) { | |
1274 | if (!net_eq(fi->fib_net, net)) | |
1275 | continue; | |
1276 | if (fi->fib_prefsrc == local) { | |
1277 | fi->fib_flags |= RTNH_F_DEAD; | |
1278 | ret++; | |
1279 | } | |
1280 | } | |
1281 | return ret; | |
1282 | } | |
1283 | ||
1284 | int fib_sync_down_dev(struct net_device *dev, unsigned long event) | |
1285 | { | |
1286 | int ret = 0; | |
1287 | int scope = RT_SCOPE_NOWHERE; | |
1288 | struct fib_info *prev_fi = NULL; | |
1289 | unsigned int hash = fib_devindex_hashfn(dev->ifindex); | |
1290 | struct hlist_head *head = &fib_info_devhash[hash]; | |
1291 | struct fib_nh *nh; | |
1292 | ||
1293 | if (event == NETDEV_UNREGISTER || | |
1294 | event == NETDEV_DOWN) | |
1295 | scope = -1; | |
1296 | ||
1297 | hlist_for_each_entry(nh, head, nh_hash) { | |
1298 | struct fib_info *fi = nh->nh_parent; | |
1299 | int dead; | |
1300 | ||
1301 | BUG_ON(!fi->fib_nhs); | |
1302 | if (nh->nh_dev != dev || fi == prev_fi) | |
1303 | continue; | |
1304 | prev_fi = fi; | |
1305 | dead = 0; | |
1306 | change_nexthops(fi) { | |
1307 | if (nexthop_nh->nh_flags & RTNH_F_DEAD) | |
1308 | dead++; | |
1309 | else if (nexthop_nh->nh_dev == dev && | |
1310 | nexthop_nh->nh_scope != scope) { | |
1311 | switch (event) { | |
1312 | case NETDEV_DOWN: | |
1313 | case NETDEV_UNREGISTER: | |
1314 | nexthop_nh->nh_flags |= RTNH_F_DEAD; | |
1315 | /* fall through */ | |
1316 | case NETDEV_CHANGE: | |
1317 | nexthop_nh->nh_flags |= RTNH_F_LINKDOWN; | |
1318 | break; | |
1319 | } | |
1320 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1321 | spin_lock_bh(&fib_multipath_lock); | |
1322 | fi->fib_power -= nexthop_nh->nh_power; | |
1323 | nexthop_nh->nh_power = 0; | |
1324 | spin_unlock_bh(&fib_multipath_lock); | |
1325 | #endif | |
1326 | dead++; | |
1327 | } | |
1328 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1329 | if (event == NETDEV_UNREGISTER && | |
1330 | nexthop_nh->nh_dev == dev) { | |
1331 | dead = fi->fib_nhs; | |
1332 | break; | |
1333 | } | |
1334 | #endif | |
1335 | } endfor_nexthops(fi) | |
1336 | if (dead == fi->fib_nhs) { | |
1337 | switch (event) { | |
1338 | case NETDEV_DOWN: | |
1339 | case NETDEV_UNREGISTER: | |
1340 | fi->fib_flags |= RTNH_F_DEAD; | |
1341 | /* fall through */ | |
1342 | case NETDEV_CHANGE: | |
1343 | fi->fib_flags |= RTNH_F_LINKDOWN; | |
1344 | break; | |
1345 | } | |
1346 | ret++; | |
1347 | } | |
1348 | } | |
1349 | ||
1350 | return ret; | |
1351 | } | |
1352 | ||
1353 | /* Must be invoked inside of an RCU protected region. */ | |
1354 | void fib_select_default(const struct flowi4 *flp, struct fib_result *res) | |
1355 | { | |
1356 | struct fib_info *fi = NULL, *last_resort = NULL; | |
1357 | struct hlist_head *fa_head = res->fa_head; | |
1358 | struct fib_table *tb = res->table; | |
1359 | u8 slen = 32 - res->prefixlen; | |
1360 | int order = -1, last_idx = -1; | |
1361 | struct fib_alias *fa, *fa1 = NULL; | |
1362 | u32 last_prio = res->fi->fib_priority; | |
1363 | u8 last_tos = 0; | |
1364 | ||
1365 | hlist_for_each_entry_rcu(fa, fa_head, fa_list) { | |
1366 | struct fib_info *next_fi = fa->fa_info; | |
1367 | ||
1368 | if (fa->fa_slen != slen) | |
1369 | continue; | |
1370 | if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) | |
1371 | continue; | |
1372 | if (fa->tb_id != tb->tb_id) | |
1373 | continue; | |
1374 | if (next_fi->fib_priority > last_prio && | |
1375 | fa->fa_tos == last_tos) { | |
1376 | if (last_tos) | |
1377 | continue; | |
1378 | break; | |
1379 | } | |
1380 | if (next_fi->fib_flags & RTNH_F_DEAD) | |
1381 | continue; | |
1382 | last_tos = fa->fa_tos; | |
1383 | last_prio = next_fi->fib_priority; | |
1384 | ||
1385 | if (next_fi->fib_scope != res->scope || | |
1386 | fa->fa_type != RTN_UNICAST) | |
1387 | continue; | |
1388 | if (!next_fi->fib_nh[0].nh_gw || | |
1389 | next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK) | |
1390 | continue; | |
1391 | ||
1392 | fib_alias_accessed(fa); | |
1393 | ||
1394 | if (!fi) { | |
1395 | if (next_fi != res->fi) | |
1396 | break; | |
1397 | fa1 = fa; | |
1398 | } else if (!fib_detect_death(fi, order, &last_resort, | |
1399 | &last_idx, fa1->fa_default)) { | |
1400 | fib_result_assign(res, fi); | |
1401 | fa1->fa_default = order; | |
1402 | goto out; | |
1403 | } | |
1404 | fi = next_fi; | |
1405 | order++; | |
1406 | } | |
1407 | ||
1408 | if (order <= 0 || !fi) { | |
1409 | if (fa1) | |
1410 | fa1->fa_default = -1; | |
1411 | goto out; | |
1412 | } | |
1413 | ||
1414 | if (!fib_detect_death(fi, order, &last_resort, &last_idx, | |
1415 | fa1->fa_default)) { | |
1416 | fib_result_assign(res, fi); | |
1417 | fa1->fa_default = order; | |
1418 | goto out; | |
1419 | } | |
1420 | ||
1421 | if (last_idx >= 0) | |
1422 | fib_result_assign(res, last_resort); | |
1423 | fa1->fa_default = last_idx; | |
1424 | out: | |
1425 | return; | |
1426 | } | |
1427 | ||
1428 | /* | |
1429 | * Dead device goes up. We wake up dead nexthops. | |
1430 | * It takes sense only on multipath routes. | |
1431 | */ | |
1432 | int fib_sync_up(struct net_device *dev, unsigned int nh_flags) | |
1433 | { | |
1434 | struct fib_info *prev_fi; | |
1435 | unsigned int hash; | |
1436 | struct hlist_head *head; | |
1437 | struct fib_nh *nh; | |
1438 | int ret; | |
1439 | ||
1440 | if (!(dev->flags & IFF_UP)) | |
1441 | return 0; | |
1442 | ||
1443 | prev_fi = NULL; | |
1444 | hash = fib_devindex_hashfn(dev->ifindex); | |
1445 | head = &fib_info_devhash[hash]; | |
1446 | ret = 0; | |
1447 | ||
1448 | hlist_for_each_entry(nh, head, nh_hash) { | |
1449 | struct fib_info *fi = nh->nh_parent; | |
1450 | int alive; | |
1451 | ||
1452 | BUG_ON(!fi->fib_nhs); | |
1453 | if (nh->nh_dev != dev || fi == prev_fi) | |
1454 | continue; | |
1455 | ||
1456 | prev_fi = fi; | |
1457 | alive = 0; | |
1458 | change_nexthops(fi) { | |
1459 | if (!(nexthop_nh->nh_flags & nh_flags)) { | |
1460 | alive++; | |
1461 | continue; | |
1462 | } | |
1463 | if (!nexthop_nh->nh_dev || | |
1464 | !(nexthop_nh->nh_dev->flags & IFF_UP)) | |
1465 | continue; | |
1466 | if (nexthop_nh->nh_dev != dev || | |
1467 | !__in_dev_get_rtnl(dev)) | |
1468 | continue; | |
1469 | alive++; | |
1470 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1471 | spin_lock_bh(&fib_multipath_lock); | |
1472 | nexthop_nh->nh_power = 0; | |
1473 | nexthop_nh->nh_flags &= ~nh_flags; | |
1474 | spin_unlock_bh(&fib_multipath_lock); | |
1475 | #else | |
1476 | nexthop_nh->nh_flags &= ~nh_flags; | |
1477 | #endif | |
1478 | } endfor_nexthops(fi) | |
1479 | ||
1480 | if (alive > 0) { | |
1481 | fi->fib_flags &= ~nh_flags; | |
1482 | ret++; | |
1483 | } | |
1484 | } | |
1485 | ||
1486 | return ret; | |
1487 | } | |
1488 | ||
1489 | #ifdef CONFIG_IP_ROUTE_MULTIPATH | |
1490 | ||
1491 | /* | |
1492 | * The algorithm is suboptimal, but it provides really | |
1493 | * fair weighted route distribution. | |
1494 | */ | |
1495 | void fib_select_multipath(struct fib_result *res) | |
1496 | { | |
1497 | struct fib_info *fi = res->fi; | |
1498 | struct in_device *in_dev; | |
1499 | int w; | |
1500 | ||
1501 | spin_lock_bh(&fib_multipath_lock); | |
1502 | if (fi->fib_power <= 0) { | |
1503 | int power = 0; | |
1504 | change_nexthops(fi) { | |
1505 | in_dev = __in_dev_get_rcu(nexthop_nh->nh_dev); | |
1506 | if (nexthop_nh->nh_flags & RTNH_F_DEAD) | |
1507 | continue; | |
1508 | if (in_dev && | |
1509 | IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && | |
1510 | nexthop_nh->nh_flags & RTNH_F_LINKDOWN) | |
1511 | continue; | |
1512 | power += nexthop_nh->nh_weight; | |
1513 | nexthop_nh->nh_power = nexthop_nh->nh_weight; | |
1514 | } endfor_nexthops(fi); | |
1515 | fi->fib_power = power; | |
1516 | if (power <= 0) { | |
1517 | spin_unlock_bh(&fib_multipath_lock); | |
1518 | /* Race condition: route has just become dead. */ | |
1519 | res->nh_sel = 0; | |
1520 | return; | |
1521 | } | |
1522 | } | |
1523 | ||
1524 | ||
1525 | /* w should be random number [0..fi->fib_power-1], | |
1526 | * it is pretty bad approximation. | |
1527 | */ | |
1528 | ||
1529 | w = jiffies % fi->fib_power; | |
1530 | ||
1531 | change_nexthops(fi) { | |
1532 | if (!(nexthop_nh->nh_flags & RTNH_F_DEAD) && | |
1533 | nexthop_nh->nh_power) { | |
1534 | w -= nexthop_nh->nh_power; | |
1535 | if (w <= 0) { | |
1536 | nexthop_nh->nh_power--; | |
1537 | fi->fib_power--; | |
1538 | res->nh_sel = nhsel; | |
1539 | spin_unlock_bh(&fib_multipath_lock); | |
1540 | return; | |
1541 | } | |
1542 | } | |
1543 | } endfor_nexthops(fi); | |
1544 | ||
1545 | /* Race condition: route has just become dead. */ | |
1546 | res->nh_sel = 0; | |
1547 | spin_unlock_bh(&fib_multipath_lock); | |
1548 | } | |
1549 | #endif |