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net: add recursion limit to GRO
[linux/fpc-iii.git] / net / ipv4 / fib_frontend.c
blob1b25daf8c7f12ada5a6ea7178d95c6c086f9098d
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: FIB frontend.
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 <linux/module.h>
17 #include <asm/uaccess.h>
18 #include <linux/bitops.h>
19 #include <linux/capability.h>
20 #include <linux/types.h>
21 #include <linux/kernel.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>
29 #include <linux/inetdevice.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_addr.h>
32 #include <linux/if_arp.h>
33 #include <linux/skbuff.h>
34 #include <linux/cache.h>
35 #include <linux/init.h>
36 #include <linux/list.h>
37 #include <linux/slab.h>
38
39 #include <net/ip.h>
40 #include <net/protocol.h>
41 #include <net/route.h>
42 #include <net/tcp.h>
43 #include <net/sock.h>
44 #include <net/arp.h>
45 #include <net/ip_fib.h>
46 #include <net/rtnetlink.h>
47 #include <net/xfrm.h>
48 #include <net/l3mdev.h>
49 #include <trace/events/fib.h>
50
51 #ifndef CONFIG_IP_MULTIPLE_TABLES
52
53 static int __net_init fib4_rules_init(struct net *net)
54 {
55 struct fib_table *local_table, *main_table;
56
57 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
58 if (!main_table)
59 return -ENOMEM;
60
61 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
62 if (!local_table)
63 goto fail;
64
65 hlist_add_head_rcu(&local_table->tb_hlist,
66 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
67 hlist_add_head_rcu(&main_table->tb_hlist,
68 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
69 return 0;
70
71 fail:
72 fib_free_table(main_table);
73 return -ENOMEM;
74 }
75 #else
76
77 struct fib_table *fib_new_table(struct net *net, u32 id)
78 {
79 struct fib_table *tb, *alias = NULL;
80 unsigned int h;
81
82 if (id == 0)
83 id = RT_TABLE_MAIN;
84 tb = fib_get_table(net, id);
85 if (tb)
86 return tb;
87
88 if (id == RT_TABLE_LOCAL)
89 alias = fib_new_table(net, RT_TABLE_MAIN);
90
91 tb = fib_trie_table(id, alias);
92 if (!tb)
93 return NULL;
94
95 switch (id) {
96 case RT_TABLE_LOCAL:
97 rcu_assign_pointer(net->ipv4.fib_local, tb);
98 break;
99 case RT_TABLE_MAIN:
100 rcu_assign_pointer(net->ipv4.fib_main, tb);
101 break;
102 case RT_TABLE_DEFAULT:
103 rcu_assign_pointer(net->ipv4.fib_default, tb);
104 break;
105 default:
106 break;
107 }
108
109 h = id & (FIB_TABLE_HASHSZ - 1);
110 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
111 return tb;
112 }
113 EXPORT_SYMBOL_GPL(fib_new_table);
114
115 /* caller must hold either rtnl or rcu read lock */
116 struct fib_table *fib_get_table(struct net *net, u32 id)
117 {
118 struct fib_table *tb;
119 struct hlist_head *head;
120 unsigned int h;
121
122 if (id == 0)
123 id = RT_TABLE_MAIN;
124 h = id & (FIB_TABLE_HASHSZ - 1);
125
126 head = &net->ipv4.fib_table_hash[h];
127 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
128 if (tb->tb_id == id)
129 return tb;
130 }
131 return NULL;
132 }
133 #endif /* CONFIG_IP_MULTIPLE_TABLES */
134
135 static void fib_replace_table(struct net *net, struct fib_table *old,
136 struct fib_table *new)
137 {
138 #ifdef CONFIG_IP_MULTIPLE_TABLES
139 switch (new->tb_id) {
140 case RT_TABLE_LOCAL:
141 rcu_assign_pointer(net->ipv4.fib_local, new);
142 break;
143 case RT_TABLE_MAIN:
144 rcu_assign_pointer(net->ipv4.fib_main, new);
145 break;
146 case RT_TABLE_DEFAULT:
147 rcu_assign_pointer(net->ipv4.fib_default, new);
148 break;
149 default:
150 break;
151 }
152
153 #endif
154 /* replace the old table in the hlist */
155 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
156 }
157
158 int fib_unmerge(struct net *net)
159 {
160 struct fib_table *old, *new;
161
162 /* attempt to fetch local table if it has been allocated */
163 old = fib_get_table(net, RT_TABLE_LOCAL);
164 if (!old)
165 return 0;
166
167 new = fib_trie_unmerge(old);
168 if (!new)
169 return -ENOMEM;
170
171 /* replace merged table with clean table */
172 if (new != old) {
173 fib_replace_table(net, old, new);
174 fib_free_table(old);
175 }
176
177 return 0;
178 }
179
180 static void fib_flush(struct net *net)
181 {
182 int flushed = 0;
183 unsigned int h;
184
185 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
186 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
187 struct hlist_node *tmp;
188 struct fib_table *tb;
189
190 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
191 flushed += fib_table_flush(tb);
192 }
193
194 if (flushed)
195 rt_cache_flush(net);
196 }
197
198 void fib_flush_external(struct net *net)
199 {
200 struct fib_table *tb;
201 struct hlist_head *head;
202 unsigned int h;
203
204 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
205 head = &net->ipv4.fib_table_hash[h];
206 hlist_for_each_entry(tb, head, tb_hlist)
207 fib_table_flush_external(tb);
208 }
209 }
210
211 /*
212 * Find address type as if only "dev" was present in the system. If
213 * on_dev is NULL then all interfaces are taken into consideration.
214 */
215 static inline unsigned int __inet_dev_addr_type(struct net *net,
216 const struct net_device *dev,
217 __be32 addr, u32 tb_id)
218 {
219 struct flowi4 fl4 = { .daddr = addr };
220 struct fib_result res;
221 unsigned int ret = RTN_BROADCAST;
222 struct fib_table *table;
223
224 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
225 return RTN_BROADCAST;
226 if (ipv4_is_multicast(addr))
227 return RTN_MULTICAST;
228
229 rcu_read_lock();
230
231 table = fib_get_table(net, tb_id);
232 if (table) {
233 ret = RTN_UNICAST;
234 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
235 if (!dev || dev == res.fi->fib_dev)
236 ret = res.type;
237 }
238 }
239
240 rcu_read_unlock();
241 return ret;
242 }
243
244 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
245 {
246 return __inet_dev_addr_type(net, NULL, addr, tb_id);
247 }
248 EXPORT_SYMBOL(inet_addr_type_table);
249
250 unsigned int inet_addr_type(struct net *net, __be32 addr)
251 {
252 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
253 }
254 EXPORT_SYMBOL(inet_addr_type);
255
256 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
257 __be32 addr)
258 {
259 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
260
261 return __inet_dev_addr_type(net, dev, addr, rt_table);
262 }
263 EXPORT_SYMBOL(inet_dev_addr_type);
264
265 /* inet_addr_type with dev == NULL but using the table from a dev
266 * if one is associated
267 */
268 unsigned int inet_addr_type_dev_table(struct net *net,
269 const struct net_device *dev,
270 __be32 addr)
271 {
272 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
273
274 return __inet_dev_addr_type(net, NULL, addr, rt_table);
275 }
276 EXPORT_SYMBOL(inet_addr_type_dev_table);
277
278 __be32 fib_compute_spec_dst(struct sk_buff *skb)
279 {
280 struct net_device *dev = skb->dev;
281 struct in_device *in_dev;
282 struct fib_result res;
283 struct rtable *rt;
284 struct net *net;
285 int scope;
286
287 rt = skb_rtable(skb);
288 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
289 RTCF_LOCAL)
290 return ip_hdr(skb)->daddr;
291
292 in_dev = __in_dev_get_rcu(dev);
293 BUG_ON(!in_dev);
294
295 net = dev_net(dev);
296
297 scope = RT_SCOPE_UNIVERSE;
298 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
299 struct flowi4 fl4 = {
300 .flowi4_iif = LOOPBACK_IFINDEX,
301 .daddr = ip_hdr(skb)->saddr,
302 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
303 .flowi4_scope = scope,
304 .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
305 };
306 if (!fib_lookup(net, &fl4, &res, 0))
307 return FIB_RES_PREFSRC(net, res);
308 } else {
309 scope = RT_SCOPE_LINK;
310 }
311
312 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
313 }
314
315 /* Given (packet source, input interface) and optional (dst, oif, tos):
316 * - (main) check, that source is valid i.e. not broadcast or our local
317 * address.
318 * - figure out what "logical" interface this packet arrived
319 * and calculate "specific destination" address.
320 * - check, that packet arrived from expected physical interface.
321 * called with rcu_read_lock()
322 */
323 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
324 u8 tos, int oif, struct net_device *dev,
325 int rpf, struct in_device *idev, u32 *itag)
326 {
327 int ret, no_addr;
328 struct fib_result res;
329 struct flowi4 fl4;
330 struct net *net;
331 bool dev_match;
332
333 fl4.flowi4_oif = 0;
334 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
335 if (!fl4.flowi4_iif)
336 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
337 fl4.daddr = src;
338 fl4.saddr = dst;
339 fl4.flowi4_tos = tos;
340 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
341 fl4.flowi4_tun_key.tun_id = 0;
342 fl4.flowi4_flags = 0;
343
344 no_addr = idev->ifa_list == NULL;
345
346 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
347
348 trace_fib_validate_source(dev, &fl4);
349
350 net = dev_net(dev);
351 if (fib_lookup(net, &fl4, &res, 0))
352 goto last_resort;
353 if (res.type != RTN_UNICAST &&
354 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
355 goto e_inval;
356 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
357 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
358 goto last_resort;
359 fib_combine_itag(itag, &res);
360 dev_match = false;
361
362 #ifdef CONFIG_IP_ROUTE_MULTIPATH
363 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
364 struct fib_nh *nh = &res.fi->fib_nh[ret];
365
366 if (nh->nh_dev == dev) {
367 dev_match = true;
368 break;
369 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
370 dev_match = true;
371 break;
372 }
373 }
374 #else
375 if (FIB_RES_DEV(res) == dev)
376 dev_match = true;
377 #endif
378 if (dev_match) {
379 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
380 return ret;
381 }
382 if (no_addr)
383 goto last_resort;
384 if (rpf == 1)
385 goto e_rpf;
386 fl4.flowi4_oif = dev->ifindex;
387
388 ret = 0;
389 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
390 if (res.type == RTN_UNICAST)
391 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
392 }
393 return ret;
394
395 last_resort:
396 if (rpf)
397 goto e_rpf;
398 *itag = 0;
399 return 0;
400
401 e_inval:
402 return -EINVAL;
403 e_rpf:
404 return -EXDEV;
405 }
406
407 /* Ignore rp_filter for packets protected by IPsec. */
408 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
409 u8 tos, int oif, struct net_device *dev,
410 struct in_device *idev, u32 *itag)
411 {
412 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
413
414 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
415 IN_DEV_ACCEPT_LOCAL(idev) &&
416 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
417 *itag = 0;
418 return 0;
419 }
420 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
421 }
422
423 static inline __be32 sk_extract_addr(struct sockaddr *addr)
424 {
425 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
426 }
427
428 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
429 {
430 struct nlattr *nla;
431
432 nla = (struct nlattr *) ((char *) mx + len);
433 nla->nla_type = type;
434 nla->nla_len = nla_attr_size(4);
435 *(u32 *) nla_data(nla) = value;
436
437 return len + nla_total_size(4);
438 }
439
440 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
441 struct fib_config *cfg)
442 {
443 __be32 addr;
444 int plen;
445
446 memset(cfg, 0, sizeof(*cfg));
447 cfg->fc_nlinfo.nl_net = net;
448
449 if (rt->rt_dst.sa_family != AF_INET)
450 return -EAFNOSUPPORT;
451
452 /*
453 * Check mask for validity:
454 * a) it must be contiguous.
455 * b) destination must have all host bits clear.
456 * c) if application forgot to set correct family (AF_INET),
457 * reject request unless it is absolutely clear i.e.
458 * both family and mask are zero.
459 */
460 plen = 32;
461 addr = sk_extract_addr(&rt->rt_dst);
462 if (!(rt->rt_flags & RTF_HOST)) {
463 __be32 mask = sk_extract_addr(&rt->rt_genmask);
464
465 if (rt->rt_genmask.sa_family != AF_INET) {
466 if (mask || rt->rt_genmask.sa_family)
467 return -EAFNOSUPPORT;
468 }
469
470 if (bad_mask(mask, addr))
471 return -EINVAL;
472
473 plen = inet_mask_len(mask);
474 }
475
476 cfg->fc_dst_len = plen;
477 cfg->fc_dst = addr;
478
479 if (cmd != SIOCDELRT) {
480 cfg->fc_nlflags = NLM_F_CREATE;
481 cfg->fc_protocol = RTPROT_BOOT;
482 }
483
484 if (rt->rt_metric)
485 cfg->fc_priority = rt->rt_metric - 1;
486
487 if (rt->rt_flags & RTF_REJECT) {
488 cfg->fc_scope = RT_SCOPE_HOST;
489 cfg->fc_type = RTN_UNREACHABLE;
490 return 0;
491 }
492
493 cfg->fc_scope = RT_SCOPE_NOWHERE;
494 cfg->fc_type = RTN_UNICAST;
495
496 if (rt->rt_dev) {
497 char *colon;
498 struct net_device *dev;
499 char devname[IFNAMSIZ];
500
501 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
502 return -EFAULT;
503
504 devname[IFNAMSIZ-1] = 0;
505 colon = strchr(devname, ':');
506 if (colon)
507 *colon = 0;
508 dev = __dev_get_by_name(net, devname);
509 if (!dev)
510 return -ENODEV;
511 cfg->fc_oif = dev->ifindex;
512 cfg->fc_table = l3mdev_fib_table(dev);
513 if (colon) {
514 struct in_ifaddr *ifa;
515 struct in_device *in_dev = __in_dev_get_rtnl(dev);
516 if (!in_dev)
517 return -ENODEV;
518 *colon = ':';
519 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
520 if (strcmp(ifa->ifa_label, devname) == 0)
521 break;
522 if (!ifa)
523 return -ENODEV;
524 cfg->fc_prefsrc = ifa->ifa_local;
525 }
526 }
527
528 addr = sk_extract_addr(&rt->rt_gateway);
529 if (rt->rt_gateway.sa_family == AF_INET && addr) {
530 unsigned int addr_type;
531
532 cfg->fc_gw = addr;
533 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
534 if (rt->rt_flags & RTF_GATEWAY &&
535 addr_type == RTN_UNICAST)
536 cfg->fc_scope = RT_SCOPE_UNIVERSE;
537 }
538
539 if (cmd == SIOCDELRT)
540 return 0;
541
542 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
543 return -EINVAL;
544
545 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
546 cfg->fc_scope = RT_SCOPE_LINK;
547
548 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
549 struct nlattr *mx;
550 int len = 0;
551
552 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
553 if (!mx)
554 return -ENOMEM;
555
556 if (rt->rt_flags & RTF_MTU)
557 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
558
559 if (rt->rt_flags & RTF_WINDOW)
560 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
561
562 if (rt->rt_flags & RTF_IRTT)
563 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
564
565 cfg->fc_mx = mx;
566 cfg->fc_mx_len = len;
567 }
568
569 return 0;
570 }
571
572 /*
573 * Handle IP routing ioctl calls.
574 * These are used to manipulate the routing tables
575 */
576 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
577 {
578 struct fib_config cfg;
579 struct rtentry rt;
580 int err;
581
582 switch (cmd) {
583 case SIOCADDRT: /* Add a route */
584 case SIOCDELRT: /* Delete a route */
585 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
586 return -EPERM;
587
588 if (copy_from_user(&rt, arg, sizeof(rt)))
589 return -EFAULT;
590
591 rtnl_lock();
592 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
593 if (err == 0) {
594 struct fib_table *tb;
595
596 if (cmd == SIOCDELRT) {
597 tb = fib_get_table(net, cfg.fc_table);
598 if (tb)
599 err = fib_table_delete(tb, &cfg);
600 else
601 err = -ESRCH;
602 } else {
603 tb = fib_new_table(net, cfg.fc_table);
604 if (tb)
605 err = fib_table_insert(tb, &cfg);
606 else
607 err = -ENOBUFS;
608 }
609
610 /* allocated by rtentry_to_fib_config() */
611 kfree(cfg.fc_mx);
612 }
613 rtnl_unlock();
614 return err;
615 }
616 return -EINVAL;
617 }
618
619 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
620 [RTA_DST] = { .type = NLA_U32 },
621 [RTA_SRC] = { .type = NLA_U32 },
622 [RTA_IIF] = { .type = NLA_U32 },
623 [RTA_OIF] = { .type = NLA_U32 },
624 [RTA_GATEWAY] = { .type = NLA_U32 },
625 [RTA_PRIORITY] = { .type = NLA_U32 },
626 [RTA_PREFSRC] = { .type = NLA_U32 },
627 [RTA_METRICS] = { .type = NLA_NESTED },
628 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
629 [RTA_FLOW] = { .type = NLA_U32 },
630 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
631 [RTA_ENCAP] = { .type = NLA_NESTED },
632 };
633
634 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
635 struct nlmsghdr *nlh, struct fib_config *cfg)
636 {
637 struct nlattr *attr;
638 int err, remaining;
639 struct rtmsg *rtm;
640
641 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
642 if (err < 0)
643 goto errout;
644
645 memset(cfg, 0, sizeof(*cfg));
646
647 rtm = nlmsg_data(nlh);
648 cfg->fc_dst_len = rtm->rtm_dst_len;
649 cfg->fc_tos = rtm->rtm_tos;
650 cfg->fc_table = rtm->rtm_table;
651 cfg->fc_protocol = rtm->rtm_protocol;
652 cfg->fc_scope = rtm->rtm_scope;
653 cfg->fc_type = rtm->rtm_type;
654 cfg->fc_flags = rtm->rtm_flags;
655 cfg->fc_nlflags = nlh->nlmsg_flags;
656
657 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
658 cfg->fc_nlinfo.nlh = nlh;
659 cfg->fc_nlinfo.nl_net = net;
660
661 if (cfg->fc_type > RTN_MAX) {
662 err = -EINVAL;
663 goto errout;
664 }
665
666 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
667 switch (nla_type(attr)) {
668 case RTA_DST:
669 cfg->fc_dst = nla_get_be32(attr);
670 break;
671 case RTA_OIF:
672 cfg->fc_oif = nla_get_u32(attr);
673 break;
674 case RTA_GATEWAY:
675 cfg->fc_gw = nla_get_be32(attr);
676 break;
677 case RTA_PRIORITY:
678 cfg->fc_priority = nla_get_u32(attr);
679 break;
680 case RTA_PREFSRC:
681 cfg->fc_prefsrc = nla_get_be32(attr);
682 break;
683 case RTA_METRICS:
684 cfg->fc_mx = nla_data(attr);
685 cfg->fc_mx_len = nla_len(attr);
686 break;
687 case RTA_MULTIPATH:
688 cfg->fc_mp = nla_data(attr);
689 cfg->fc_mp_len = nla_len(attr);
690 break;
691 case RTA_FLOW:
692 cfg->fc_flow = nla_get_u32(attr);
693 break;
694 case RTA_TABLE:
695 cfg->fc_table = nla_get_u32(attr);
696 break;
697 case RTA_ENCAP:
698 cfg->fc_encap = attr;
699 break;
700 case RTA_ENCAP_TYPE:
701 cfg->fc_encap_type = nla_get_u16(attr);
702 break;
703 }
704 }
705
706 return 0;
707 errout:
708 return err;
709 }
710
711 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
712 {
713 struct net *net = sock_net(skb->sk);
714 struct fib_config cfg;
715 struct fib_table *tb;
716 int err;
717
718 err = rtm_to_fib_config(net, skb, nlh, &cfg);
719 if (err < 0)
720 goto errout;
721
722 tb = fib_get_table(net, cfg.fc_table);
723 if (!tb) {
724 err = -ESRCH;
725 goto errout;
726 }
727
728 err = fib_table_delete(tb, &cfg);
729 errout:
730 return err;
731 }
732
733 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
734 {
735 struct net *net = sock_net(skb->sk);
736 struct fib_config cfg;
737 struct fib_table *tb;
738 int err;
739
740 err = rtm_to_fib_config(net, skb, nlh, &cfg);
741 if (err < 0)
742 goto errout;
743
744 tb = fib_new_table(net, cfg.fc_table);
745 if (!tb) {
746 err = -ENOBUFS;
747 goto errout;
748 }
749
750 err = fib_table_insert(tb, &cfg);
751 errout:
752 return err;
753 }
754
755 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
756 {
757 struct net *net = sock_net(skb->sk);
758 unsigned int h, s_h;
759 unsigned int e = 0, s_e;
760 struct fib_table *tb;
761 struct hlist_head *head;
762 int dumped = 0;
763
764 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
765 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
766 return skb->len;
767
768 s_h = cb->args[0];
769 s_e = cb->args[1];
770
771 rcu_read_lock();
772
773 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
774 e = 0;
775 head = &net->ipv4.fib_table_hash[h];
776 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
777 if (e < s_e)
778 goto next;
779 if (dumped)
780 memset(&cb->args[2], 0, sizeof(cb->args) -
781 2 * sizeof(cb->args[0]));
782 if (fib_table_dump(tb, skb, cb) < 0)
783 goto out;
784 dumped = 1;
785 next:
786 e++;
787 }
788 }
789 out:
790 rcu_read_unlock();
791
792 cb->args[1] = e;
793 cb->args[0] = h;
794
795 return skb->len;
796 }
797
798 /* Prepare and feed intra-kernel routing request.
799 * Really, it should be netlink message, but :-( netlink
800 * can be not configured, so that we feed it directly
801 * to fib engine. It is legal, because all events occur
802 * only when netlink is already locked.
803 */
804 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
805 {
806 struct net *net = dev_net(ifa->ifa_dev->dev);
807 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
808 struct fib_table *tb;
809 struct fib_config cfg = {
810 .fc_protocol = RTPROT_KERNEL,
811 .fc_type = type,
812 .fc_dst = dst,
813 .fc_dst_len = dst_len,
814 .fc_prefsrc = ifa->ifa_local,
815 .fc_oif = ifa->ifa_dev->dev->ifindex,
816 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
817 .fc_nlinfo = {
818 .nl_net = net,
819 },
820 };
821
822 if (!tb_id)
823 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
824
825 tb = fib_new_table(net, tb_id);
826 if (!tb)
827 return;
828
829 cfg.fc_table = tb->tb_id;
830
831 if (type != RTN_LOCAL)
832 cfg.fc_scope = RT_SCOPE_LINK;
833 else
834 cfg.fc_scope = RT_SCOPE_HOST;
835
836 if (cmd == RTM_NEWROUTE)
837 fib_table_insert(tb, &cfg);
838 else
839 fib_table_delete(tb, &cfg);
840 }
841
842 void fib_add_ifaddr(struct in_ifaddr *ifa)
843 {
844 struct in_device *in_dev = ifa->ifa_dev;
845 struct net_device *dev = in_dev->dev;
846 struct in_ifaddr *prim = ifa;
847 __be32 mask = ifa->ifa_mask;
848 __be32 addr = ifa->ifa_local;
849 __be32 prefix = ifa->ifa_address & mask;
850
851 if (ifa->ifa_flags & IFA_F_SECONDARY) {
852 prim = inet_ifa_byprefix(in_dev, prefix, mask);
853 if (!prim) {
854 pr_warn("%s: bug: prim == NULL\n", __func__);
855 return;
856 }
857 }
858
859 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
860
861 if (!(dev->flags & IFF_UP))
862 return;
863
864 /* Add broadcast address, if it is explicitly assigned. */
865 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
866 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
867
868 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
869 (prefix != addr || ifa->ifa_prefixlen < 32)) {
870 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
871 fib_magic(RTM_NEWROUTE,
872 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
873 prefix, ifa->ifa_prefixlen, prim);
874
875 /* Add network specific broadcasts, when it takes a sense */
876 if (ifa->ifa_prefixlen < 31) {
877 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
878 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
879 32, prim);
880 }
881 }
882 }
883
884 /* Delete primary or secondary address.
885 * Optionally, on secondary address promotion consider the addresses
886 * from subnet iprim as deleted, even if they are in device list.
887 * In this case the secondary ifa can be in device list.
888 */
889 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
890 {
891 struct in_device *in_dev = ifa->ifa_dev;
892 struct net_device *dev = in_dev->dev;
893 struct in_ifaddr *ifa1;
894 struct in_ifaddr *prim = ifa, *prim1 = NULL;
895 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
896 __be32 any = ifa->ifa_address & ifa->ifa_mask;
897 #define LOCAL_OK 1
898 #define BRD_OK 2
899 #define BRD0_OK 4
900 #define BRD1_OK 8
901 unsigned int ok = 0;
902 int subnet = 0; /* Primary network */
903 int gone = 1; /* Address is missing */
904 int same_prefsrc = 0; /* Another primary with same IP */
905
906 if (ifa->ifa_flags & IFA_F_SECONDARY) {
907 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
908 if (!prim) {
909 /* if the device has been deleted, we don't perform
910 * address promotion
911 */
912 if (!in_dev->dead)
913 pr_warn("%s: bug: prim == NULL\n", __func__);
914 return;
915 }
916 if (iprim && iprim != prim) {
917 pr_warn("%s: bug: iprim != prim\n", __func__);
918 return;
919 }
920 } else if (!ipv4_is_zeronet(any) &&
921 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
922 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
923 fib_magic(RTM_DELROUTE,
924 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
925 any, ifa->ifa_prefixlen, prim);
926 subnet = 1;
927 }
928
929 if (in_dev->dead)
930 goto no_promotions;
931
932 /* Deletion is more complicated than add.
933 * We should take care of not to delete too much :-)
934 *
935 * Scan address list to be sure that addresses are really gone.
936 */
937
938 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
939 if (ifa1 == ifa) {
940 /* promotion, keep the IP */
941 gone = 0;
942 continue;
943 }
944 /* Ignore IFAs from our subnet */
945 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
946 inet_ifa_match(ifa1->ifa_address, iprim))
947 continue;
948
949 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
950 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
951 /* Another address from our subnet? */
952 if (ifa1->ifa_mask == prim->ifa_mask &&
953 inet_ifa_match(ifa1->ifa_address, prim))
954 prim1 = prim;
955 else {
956 /* We reached the secondaries, so
957 * same_prefsrc should be determined.
958 */
959 if (!same_prefsrc)
960 continue;
961 /* Search new prim1 if ifa1 is not
962 * using the current prim1
963 */
964 if (!prim1 ||
965 ifa1->ifa_mask != prim1->ifa_mask ||
966 !inet_ifa_match(ifa1->ifa_address, prim1))
967 prim1 = inet_ifa_byprefix(in_dev,
968 ifa1->ifa_address,
969 ifa1->ifa_mask);
970 if (!prim1)
971 continue;
972 if (prim1->ifa_local != prim->ifa_local)
973 continue;
974 }
975 } else {
976 if (prim->ifa_local != ifa1->ifa_local)
977 continue;
978 prim1 = ifa1;
979 if (prim != prim1)
980 same_prefsrc = 1;
981 }
982 if (ifa->ifa_local == ifa1->ifa_local)
983 ok |= LOCAL_OK;
984 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
985 ok |= BRD_OK;
986 if (brd == ifa1->ifa_broadcast)
987 ok |= BRD1_OK;
988 if (any == ifa1->ifa_broadcast)
989 ok |= BRD0_OK;
990 /* primary has network specific broadcasts */
991 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
992 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
993 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
994
995 if (!ipv4_is_zeronet(any1)) {
996 if (ifa->ifa_broadcast == brd1 ||
997 ifa->ifa_broadcast == any1)
998 ok |= BRD_OK;
999 if (brd == brd1 || brd == any1)
1000 ok |= BRD1_OK;
1001 if (any == brd1 || any == any1)
1002 ok |= BRD0_OK;
1003 }
1004 }
1005 }
1006
1007 no_promotions:
1008 if (!(ok & BRD_OK))
1009 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1010 if (subnet && ifa->ifa_prefixlen < 31) {
1011 if (!(ok & BRD1_OK))
1012 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1013 if (!(ok & BRD0_OK))
1014 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1015 }
1016 if (!(ok & LOCAL_OK)) {
1017 unsigned int addr_type;
1018
1019 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1020
1021 /* Check, that this local address finally disappeared. */
1022 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1023 ifa->ifa_local);
1024 if (gone && addr_type != RTN_LOCAL) {
1025 /* And the last, but not the least thing.
1026 * We must flush stray FIB entries.
1027 *
1028 * First of all, we scan fib_info list searching
1029 * for stray nexthop entries, then ignite fib_flush.
1030 */
1031 if (fib_sync_down_addr(dev, ifa->ifa_local))
1032 fib_flush(dev_net(dev));
1033 }
1034 }
1035 #undef LOCAL_OK
1036 #undef BRD_OK
1037 #undef BRD0_OK
1038 #undef BRD1_OK
1039 }
1040
1041 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1042 {
1043
1044 struct fib_result res;
1045 struct flowi4 fl4 = {
1046 .flowi4_mark = frn->fl_mark,
1047 .daddr = frn->fl_addr,
1048 .flowi4_tos = frn->fl_tos,
1049 .flowi4_scope = frn->fl_scope,
1050 };
1051 struct fib_table *tb;
1052
1053 rcu_read_lock();
1054
1055 tb = fib_get_table(net, frn->tb_id_in);
1056
1057 frn->err = -ENOENT;
1058 if (tb) {
1059 local_bh_disable();
1060
1061 frn->tb_id = tb->tb_id;
1062 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1063
1064 if (!frn->err) {
1065 frn->prefixlen = res.prefixlen;
1066 frn->nh_sel = res.nh_sel;
1067 frn->type = res.type;
1068 frn->scope = res.scope;
1069 }
1070 local_bh_enable();
1071 }
1072
1073 rcu_read_unlock();
1074 }
1075
1076 static void nl_fib_input(struct sk_buff *skb)
1077 {
1078 struct net *net;
1079 struct fib_result_nl *frn;
1080 struct nlmsghdr *nlh;
1081 u32 portid;
1082
1083 net = sock_net(skb->sk);
1084 nlh = nlmsg_hdr(skb);
1085 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1086 nlmsg_len(nlh) < sizeof(*frn))
1087 return;
1088
1089 skb = netlink_skb_clone(skb, GFP_KERNEL);
1090 if (!skb)
1091 return;
1092 nlh = nlmsg_hdr(skb);
1093
1094 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1095 nl_fib_lookup(net, frn);
1096
1097 portid = NETLINK_CB(skb).portid; /* netlink portid */
1098 NETLINK_CB(skb).portid = 0; /* from kernel */
1099 NETLINK_CB(skb).dst_group = 0; /* unicast */
1100 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1101 }
1102
1103 static int __net_init nl_fib_lookup_init(struct net *net)
1104 {
1105 struct sock *sk;
1106 struct netlink_kernel_cfg cfg = {
1107 .input = nl_fib_input,
1108 };
1109
1110 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1111 if (!sk)
1112 return -EAFNOSUPPORT;
1113 net->ipv4.fibnl = sk;
1114 return 0;
1115 }
1116
1117 static void nl_fib_lookup_exit(struct net *net)
1118 {
1119 netlink_kernel_release(net->ipv4.fibnl);
1120 net->ipv4.fibnl = NULL;
1121 }
1122
1123 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1124 bool force)
1125 {
1126 if (fib_sync_down_dev(dev, event, force))
1127 fib_flush(dev_net(dev));
1128 rt_cache_flush(dev_net(dev));
1129 arp_ifdown(dev);
1130 }
1131
1132 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1133 {
1134 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1135 struct net_device *dev = ifa->ifa_dev->dev;
1136 struct net *net = dev_net(dev);
1137
1138 switch (event) {
1139 case NETDEV_UP:
1140 fib_add_ifaddr(ifa);
1141 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1142 fib_sync_up(dev, RTNH_F_DEAD);
1143 #endif
1144 atomic_inc(&net->ipv4.dev_addr_genid);
1145 rt_cache_flush(dev_net(dev));
1146 break;
1147 case NETDEV_DOWN:
1148 fib_del_ifaddr(ifa, NULL);
1149 atomic_inc(&net->ipv4.dev_addr_genid);
1150 if (!ifa->ifa_dev->ifa_list) {
1151 /* Last address was deleted from this interface.
1152 * Disable IP.
1153 */
1154 fib_disable_ip(dev, event, true);
1155 } else {
1156 rt_cache_flush(dev_net(dev));
1157 }
1158 break;
1159 }
1160 return NOTIFY_DONE;
1161 }
1162
1163 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1164 {
1165 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1166 struct netdev_notifier_changeupper_info *info;
1167 struct in_device *in_dev;
1168 struct net *net = dev_net(dev);
1169 unsigned int flags;
1170
1171 if (event == NETDEV_UNREGISTER) {
1172 fib_disable_ip(dev, event, true);
1173 rt_flush_dev(dev);
1174 return NOTIFY_DONE;
1175 }
1176
1177 in_dev = __in_dev_get_rtnl(dev);
1178 if (!in_dev)
1179 return NOTIFY_DONE;
1180
1181 switch (event) {
1182 case NETDEV_UP:
1183 for_ifa(in_dev) {
1184 fib_add_ifaddr(ifa);
1185 } endfor_ifa(in_dev);
1186 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1187 fib_sync_up(dev, RTNH_F_DEAD);
1188 #endif
1189 atomic_inc(&net->ipv4.dev_addr_genid);
1190 rt_cache_flush(net);
1191 break;
1192 case NETDEV_DOWN:
1193 fib_disable_ip(dev, event, false);
1194 break;
1195 case NETDEV_CHANGE:
1196 flags = dev_get_flags(dev);
1197 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1198 fib_sync_up(dev, RTNH_F_LINKDOWN);
1199 else
1200 fib_sync_down_dev(dev, event, false);
1201 /* fall through */
1202 case NETDEV_CHANGEMTU:
1203 rt_cache_flush(net);
1204 break;
1205 case NETDEV_CHANGEUPPER:
1206 info = ptr;
1207 /* flush all routes if dev is linked to or unlinked from
1208 * an L3 master device (e.g., VRF)
1209 */
1210 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1211 fib_disable_ip(dev, NETDEV_DOWN, true);
1212 break;
1213 }
1214 return NOTIFY_DONE;
1215 }
1216
1217 static struct notifier_block fib_inetaddr_notifier = {
1218 .notifier_call = fib_inetaddr_event,
1219 };
1220
1221 static struct notifier_block fib_netdev_notifier = {
1222 .notifier_call = fib_netdev_event,
1223 };
1224
1225 static int __net_init ip_fib_net_init(struct net *net)
1226 {
1227 int err;
1228 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1229
1230 /* Avoid false sharing : Use at least a full cache line */
1231 size = max_t(size_t, size, L1_CACHE_BYTES);
1232
1233 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1234 if (!net->ipv4.fib_table_hash)
1235 return -ENOMEM;
1236
1237 err = fib4_rules_init(net);
1238 if (err < 0)
1239 goto fail;
1240 return 0;
1241
1242 fail:
1243 kfree(net->ipv4.fib_table_hash);
1244 return err;
1245 }
1246
1247 static void ip_fib_net_exit(struct net *net)
1248 {
1249 unsigned int i;
1250
1251 rtnl_lock();
1252 #ifdef CONFIG_IP_MULTIPLE_TABLES
1253 RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1254 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1255 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1256 #endif
1257 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1258 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1259 struct hlist_node *tmp;
1260 struct fib_table *tb;
1261
1262 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1263 hlist_del(&tb->tb_hlist);
1264 fib_table_flush(tb);
1265 fib_free_table(tb);
1266 }
1267 }
1268
1269 #ifdef CONFIG_IP_MULTIPLE_TABLES
1270 fib4_rules_exit(net);
1271 #endif
1272 rtnl_unlock();
1273 kfree(net->ipv4.fib_table_hash);
1274 }
1275
1276 static int __net_init fib_net_init(struct net *net)
1277 {
1278 int error;
1279
1280 #ifdef CONFIG_IP_ROUTE_CLASSID
1281 net->ipv4.fib_num_tclassid_users = 0;
1282 #endif
1283 error = ip_fib_net_init(net);
1284 if (error < 0)
1285 goto out;
1286 error = nl_fib_lookup_init(net);
1287 if (error < 0)
1288 goto out_nlfl;
1289 error = fib_proc_init(net);
1290 if (error < 0)
1291 goto out_proc;
1292 out:
1293 return error;
1294
1295 out_proc:
1296 nl_fib_lookup_exit(net);
1297 out_nlfl:
1298 ip_fib_net_exit(net);
1299 goto out;
1300 }
1301
1302 static void __net_exit fib_net_exit(struct net *net)
1303 {
1304 fib_proc_exit(net);
1305 nl_fib_lookup_exit(net);
1306 ip_fib_net_exit(net);
1307 }
1308
1309 static struct pernet_operations fib_net_ops = {
1310 .init = fib_net_init,
1311 .exit = fib_net_exit,
1312 };
1313
1314 void __init ip_fib_init(void)
1315 {
1316 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1317 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1318 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1319
1320 register_pernet_subsys(&fib_net_ops);
1321 register_netdevice_notifier(&fib_netdev_notifier);
1322 register_inetaddr_notifier(&fib_inetaddr_notifier);
1323
1324 fib_trie_init();
1325 }
Linux with added FPC-III support