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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
[deliverable/linux.git] / net / ipv4 / fib_frontend.c
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
114 /* caller must hold either rtnl or rcu read lock */
115 struct fib_table *fib_get_table(struct net *net, u32 id)
116 {
117 struct fib_table *tb;
118 struct hlist_head *head;
119 unsigned int h;
120
121 if (id == 0)
122 id = RT_TABLE_MAIN;
123 h = id & (FIB_TABLE_HASHSZ - 1);
124
125 head = &net->ipv4.fib_table_hash[h];
126 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
127 if (tb->tb_id == id)
128 return tb;
129 }
130 return NULL;
131 }
132 #endif /* CONFIG_IP_MULTIPLE_TABLES */
133
134 static void fib_replace_table(struct net *net, struct fib_table *old,
135 struct fib_table *new)
136 {
137 #ifdef CONFIG_IP_MULTIPLE_TABLES
138 switch (new->tb_id) {
139 case RT_TABLE_LOCAL:
140 rcu_assign_pointer(net->ipv4.fib_local, new);
141 break;
142 case RT_TABLE_MAIN:
143 rcu_assign_pointer(net->ipv4.fib_main, new);
144 break;
145 case RT_TABLE_DEFAULT:
146 rcu_assign_pointer(net->ipv4.fib_default, new);
147 break;
148 default:
149 break;
150 }
151
152 #endif
153 /* replace the old table in the hlist */
154 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
155 }
156
157 int fib_unmerge(struct net *net)
158 {
159 struct fib_table *old, *new;
160
161 /* attempt to fetch local table if it has been allocated */
162 old = fib_get_table(net, RT_TABLE_LOCAL);
163 if (!old)
164 return 0;
165
166 new = fib_trie_unmerge(old);
167 if (!new)
168 return -ENOMEM;
169
170 /* replace merged table with clean table */
171 if (new != old) {
172 fib_replace_table(net, old, new);
173 fib_free_table(old);
174 }
175
176 return 0;
177 }
178
179 static void fib_flush(struct net *net)
180 {
181 int flushed = 0;
182 unsigned int h;
183
184 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
185 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
186 struct hlist_node *tmp;
187 struct fib_table *tb;
188
189 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
190 flushed += fib_table_flush(tb);
191 }
192
193 if (flushed)
194 rt_cache_flush(net);
195 }
196
197 void fib_flush_external(struct net *net)
198 {
199 struct fib_table *tb;
200 struct hlist_head *head;
201 unsigned int h;
202
203 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
204 head = &net->ipv4.fib_table_hash[h];
205 hlist_for_each_entry(tb, head, tb_hlist)
206 fib_table_flush_external(tb);
207 }
208 }
209
210 /*
211 * Find address type as if only "dev" was present in the system. If
212 * on_dev is NULL then all interfaces are taken into consideration.
213 */
214 static inline unsigned int __inet_dev_addr_type(struct net *net,
215 const struct net_device *dev,
216 __be32 addr, u32 tb_id)
217 {
218 struct flowi4 fl4 = { .daddr = addr };
219 struct fib_result res;
220 unsigned int ret = RTN_BROADCAST;
221 struct fib_table *table;
222
223 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
224 return RTN_BROADCAST;
225 if (ipv4_is_multicast(addr))
226 return RTN_MULTICAST;
227
228 rcu_read_lock();
229
230 table = fib_get_table(net, tb_id);
231 if (table) {
232 ret = RTN_UNICAST;
233 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
234 if (!dev || dev == res.fi->fib_dev)
235 ret = res.type;
236 }
237 }
238
239 rcu_read_unlock();
240 return ret;
241 }
242
243 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
244 {
245 return __inet_dev_addr_type(net, NULL, addr, tb_id);
246 }
247 EXPORT_SYMBOL(inet_addr_type_table);
248
249 unsigned int inet_addr_type(struct net *net, __be32 addr)
250 {
251 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
252 }
253 EXPORT_SYMBOL(inet_addr_type);
254
255 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
256 __be32 addr)
257 {
258 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
259
260 return __inet_dev_addr_type(net, dev, addr, rt_table);
261 }
262 EXPORT_SYMBOL(inet_dev_addr_type);
263
264 /* inet_addr_type with dev == NULL but using the table from a dev
265 * if one is associated
266 */
267 unsigned int inet_addr_type_dev_table(struct net *net,
268 const struct net_device *dev,
269 __be32 addr)
270 {
271 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
272
273 return __inet_dev_addr_type(net, NULL, addr, rt_table);
274 }
275 EXPORT_SYMBOL(inet_addr_type_dev_table);
276
277 __be32 fib_compute_spec_dst(struct sk_buff *skb)
278 {
279 struct net_device *dev = skb->dev;
280 struct in_device *in_dev;
281 struct fib_result res;
282 struct rtable *rt;
283 struct flowi4 fl4;
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 fl4.flowi4_oif = 0;
300 fl4.flowi4_iif = LOOPBACK_IFINDEX;
301 fl4.daddr = ip_hdr(skb)->saddr;
302 fl4.saddr = 0;
303 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
304 fl4.flowi4_scope = scope;
305 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
306 fl4.flowi4_tun_key.tun_id = 0;
307 if (!fib_lookup(net, &fl4, &res, 0))
308 return FIB_RES_PREFSRC(net, res);
309 } else {
310 scope = RT_SCOPE_LINK;
311 }
312
313 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
314 }
315
316 /* Given (packet source, input interface) and optional (dst, oif, tos):
317 * - (main) check, that source is valid i.e. not broadcast or our local
318 * address.
319 * - figure out what "logical" interface this packet arrived
320 * and calculate "specific destination" address.
321 * - check, that packet arrived from expected physical interface.
322 * called with rcu_read_lock()
323 */
324 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
325 u8 tos, int oif, struct net_device *dev,
326 int rpf, struct in_device *idev, u32 *itag)
327 {
328 int ret, no_addr;
329 struct fib_result res;
330 struct flowi4 fl4;
331 struct net *net;
332 bool dev_match;
333
334 fl4.flowi4_oif = 0;
335 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
336 if (!fl4.flowi4_iif)
337 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
338 fl4.daddr = src;
339 fl4.saddr = dst;
340 fl4.flowi4_tos = tos;
341 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
342 fl4.flowi4_tun_key.tun_id = 0;
343 fl4.flowi4_flags = 0;
344
345 no_addr = idev->ifa_list == NULL;
346
347 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
348
349 trace_fib_validate_source(dev, &fl4);
350
351 net = dev_net(dev);
352 if (fib_lookup(net, &fl4, &res, 0))
353 goto last_resort;
354 if (res.type != RTN_UNICAST &&
355 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
356 goto e_inval;
357 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
358 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
359 goto last_resort;
360 fib_combine_itag(itag, &res);
361 dev_match = false;
362
363 #ifdef CONFIG_IP_ROUTE_MULTIPATH
364 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
365 struct fib_nh *nh = &res.fi->fib_nh[ret];
366
367 if (nh->nh_dev == dev) {
368 dev_match = true;
369 break;
370 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
371 dev_match = true;
372 break;
373 }
374 }
375 #else
376 if (FIB_RES_DEV(res) == dev)
377 dev_match = true;
378 #endif
379 if (dev_match) {
380 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
381 return ret;
382 }
383 if (no_addr)
384 goto last_resort;
385 if (rpf == 1)
386 goto e_rpf;
387 fl4.flowi4_oif = dev->ifindex;
388
389 ret = 0;
390 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
391 if (res.type == RTN_UNICAST)
392 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
393 }
394 return ret;
395
396 last_resort:
397 if (rpf)
398 goto e_rpf;
399 *itag = 0;
400 return 0;
401
402 e_inval:
403 return -EINVAL;
404 e_rpf:
405 return -EXDEV;
406 }
407
408 /* Ignore rp_filter for packets protected by IPsec. */
409 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
410 u8 tos, int oif, struct net_device *dev,
411 struct in_device *idev, u32 *itag)
412 {
413 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
414
415 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
416 IN_DEV_ACCEPT_LOCAL(idev) &&
417 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
418 *itag = 0;
419 return 0;
420 }
421 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
422 }
423
424 static inline __be32 sk_extract_addr(struct sockaddr *addr)
425 {
426 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
427 }
428
429 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
430 {
431 struct nlattr *nla;
432
433 nla = (struct nlattr *) ((char *) mx + len);
434 nla->nla_type = type;
435 nla->nla_len = nla_attr_size(4);
436 *(u32 *) nla_data(nla) = value;
437
438 return len + nla_total_size(4);
439 }
440
441 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
442 struct fib_config *cfg)
443 {
444 __be32 addr;
445 int plen;
446
447 memset(cfg, 0, sizeof(*cfg));
448 cfg->fc_nlinfo.nl_net = net;
449
450 if (rt->rt_dst.sa_family != AF_INET)
451 return -EAFNOSUPPORT;
452
453 /*
454 * Check mask for validity:
455 * a) it must be contiguous.
456 * b) destination must have all host bits clear.
457 * c) if application forgot to set correct family (AF_INET),
458 * reject request unless it is absolutely clear i.e.
459 * both family and mask are zero.
460 */
461 plen = 32;
462 addr = sk_extract_addr(&rt->rt_dst);
463 if (!(rt->rt_flags & RTF_HOST)) {
464 __be32 mask = sk_extract_addr(&rt->rt_genmask);
465
466 if (rt->rt_genmask.sa_family != AF_INET) {
467 if (mask || rt->rt_genmask.sa_family)
468 return -EAFNOSUPPORT;
469 }
470
471 if (bad_mask(mask, addr))
472 return -EINVAL;
473
474 plen = inet_mask_len(mask);
475 }
476
477 cfg->fc_dst_len = plen;
478 cfg->fc_dst = addr;
479
480 if (cmd != SIOCDELRT) {
481 cfg->fc_nlflags = NLM_F_CREATE;
482 cfg->fc_protocol = RTPROT_BOOT;
483 }
484
485 if (rt->rt_metric)
486 cfg->fc_priority = rt->rt_metric - 1;
487
488 if (rt->rt_flags & RTF_REJECT) {
489 cfg->fc_scope = RT_SCOPE_HOST;
490 cfg->fc_type = RTN_UNREACHABLE;
491 return 0;
492 }
493
494 cfg->fc_scope = RT_SCOPE_NOWHERE;
495 cfg->fc_type = RTN_UNICAST;
496
497 if (rt->rt_dev) {
498 char *colon;
499 struct net_device *dev;
500 char devname[IFNAMSIZ];
501
502 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
503 return -EFAULT;
504
505 devname[IFNAMSIZ-1] = 0;
506 colon = strchr(devname, ':');
507 if (colon)
508 *colon = 0;
509 dev = __dev_get_by_name(net, devname);
510 if (!dev)
511 return -ENODEV;
512 cfg->fc_oif = dev->ifindex;
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 pr_warn("%s: bug: prim == NULL\n", __func__);
910 return;
911 }
912 if (iprim && iprim != prim) {
913 pr_warn("%s: bug: iprim != prim\n", __func__);
914 return;
915 }
916 } else if (!ipv4_is_zeronet(any) &&
917 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
918 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
919 fib_magic(RTM_DELROUTE,
920 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
921 any, ifa->ifa_prefixlen, prim);
922 subnet = 1;
923 }
924
925 if (in_dev->dead)
926 goto no_promotions;
927
928 /* Deletion is more complicated than add.
929 * We should take care of not to delete too much :-)
930 *
931 * Scan address list to be sure that addresses are really gone.
932 */
933
934 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
935 if (ifa1 == ifa) {
936 /* promotion, keep the IP */
937 gone = 0;
938 continue;
939 }
940 /* Ignore IFAs from our subnet */
941 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
942 inet_ifa_match(ifa1->ifa_address, iprim))
943 continue;
944
945 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
946 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
947 /* Another address from our subnet? */
948 if (ifa1->ifa_mask == prim->ifa_mask &&
949 inet_ifa_match(ifa1->ifa_address, prim))
950 prim1 = prim;
951 else {
952 /* We reached the secondaries, so
953 * same_prefsrc should be determined.
954 */
955 if (!same_prefsrc)
956 continue;
957 /* Search new prim1 if ifa1 is not
958 * using the current prim1
959 */
960 if (!prim1 ||
961 ifa1->ifa_mask != prim1->ifa_mask ||
962 !inet_ifa_match(ifa1->ifa_address, prim1))
963 prim1 = inet_ifa_byprefix(in_dev,
964 ifa1->ifa_address,
965 ifa1->ifa_mask);
966 if (!prim1)
967 continue;
968 if (prim1->ifa_local != prim->ifa_local)
969 continue;
970 }
971 } else {
972 if (prim->ifa_local != ifa1->ifa_local)
973 continue;
974 prim1 = ifa1;
975 if (prim != prim1)
976 same_prefsrc = 1;
977 }
978 if (ifa->ifa_local == ifa1->ifa_local)
979 ok |= LOCAL_OK;
980 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
981 ok |= BRD_OK;
982 if (brd == ifa1->ifa_broadcast)
983 ok |= BRD1_OK;
984 if (any == ifa1->ifa_broadcast)
985 ok |= BRD0_OK;
986 /* primary has network specific broadcasts */
987 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
988 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
989 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
990
991 if (!ipv4_is_zeronet(any1)) {
992 if (ifa->ifa_broadcast == brd1 ||
993 ifa->ifa_broadcast == any1)
994 ok |= BRD_OK;
995 if (brd == brd1 || brd == any1)
996 ok |= BRD1_OK;
997 if (any == brd1 || any == any1)
998 ok |= BRD0_OK;
999 }
1000 }
1001 }
1002
1003 no_promotions:
1004 if (!(ok & BRD_OK))
1005 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1006 if (subnet && ifa->ifa_prefixlen < 31) {
1007 if (!(ok & BRD1_OK))
1008 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1009 if (!(ok & BRD0_OK))
1010 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1011 }
1012 if (!(ok & LOCAL_OK)) {
1013 unsigned int addr_type;
1014
1015 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1016
1017 /* Check, that this local address finally disappeared. */
1018 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1019 ifa->ifa_local);
1020 if (gone && addr_type != RTN_LOCAL) {
1021 /* And the last, but not the least thing.
1022 * We must flush stray FIB entries.
1023 *
1024 * First of all, we scan fib_info list searching
1025 * for stray nexthop entries, then ignite fib_flush.
1026 */
1027 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
1028 fib_flush(dev_net(dev));
1029 }
1030 }
1031 #undef LOCAL_OK
1032 #undef BRD_OK
1033 #undef BRD0_OK
1034 #undef BRD1_OK
1035 }
1036
1037 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1038 {
1039
1040 struct fib_result res;
1041 struct flowi4 fl4 = {
1042 .flowi4_mark = frn->fl_mark,
1043 .daddr = frn->fl_addr,
1044 .flowi4_tos = frn->fl_tos,
1045 .flowi4_scope = frn->fl_scope,
1046 };
1047 struct fib_table *tb;
1048
1049 rcu_read_lock();
1050
1051 tb = fib_get_table(net, frn->tb_id_in);
1052
1053 frn->err = -ENOENT;
1054 if (tb) {
1055 local_bh_disable();
1056
1057 frn->tb_id = tb->tb_id;
1058 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1059
1060 if (!frn->err) {
1061 frn->prefixlen = res.prefixlen;
1062 frn->nh_sel = res.nh_sel;
1063 frn->type = res.type;
1064 frn->scope = res.scope;
1065 }
1066 local_bh_enable();
1067 }
1068
1069 rcu_read_unlock();
1070 }
1071
1072 static void nl_fib_input(struct sk_buff *skb)
1073 {
1074 struct net *net;
1075 struct fib_result_nl *frn;
1076 struct nlmsghdr *nlh;
1077 u32 portid;
1078
1079 net = sock_net(skb->sk);
1080 nlh = nlmsg_hdr(skb);
1081 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1082 nlmsg_len(nlh) < sizeof(*frn))
1083 return;
1084
1085 skb = netlink_skb_clone(skb, GFP_KERNEL);
1086 if (!skb)
1087 return;
1088 nlh = nlmsg_hdr(skb);
1089
1090 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1091 nl_fib_lookup(net, frn);
1092
1093 portid = NETLINK_CB(skb).portid; /* netlink portid */
1094 NETLINK_CB(skb).portid = 0; /* from kernel */
1095 NETLINK_CB(skb).dst_group = 0; /* unicast */
1096 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1097 }
1098
1099 static int __net_init nl_fib_lookup_init(struct net *net)
1100 {
1101 struct sock *sk;
1102 struct netlink_kernel_cfg cfg = {
1103 .input = nl_fib_input,
1104 };
1105
1106 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1107 if (!sk)
1108 return -EAFNOSUPPORT;
1109 net->ipv4.fibnl = sk;
1110 return 0;
1111 }
1112
1113 static void nl_fib_lookup_exit(struct net *net)
1114 {
1115 netlink_kernel_release(net->ipv4.fibnl);
1116 net->ipv4.fibnl = NULL;
1117 }
1118
1119 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1120 bool force)
1121 {
1122 if (fib_sync_down_dev(dev, event, force))
1123 fib_flush(dev_net(dev));
1124 rt_cache_flush(dev_net(dev));
1125 arp_ifdown(dev);
1126 }
1127
1128 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1129 {
1130 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1131 struct net_device *dev = ifa->ifa_dev->dev;
1132 struct net *net = dev_net(dev);
1133
1134 switch (event) {
1135 case NETDEV_UP:
1136 fib_add_ifaddr(ifa);
1137 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1138 fib_sync_up(dev, RTNH_F_DEAD);
1139 #endif
1140 atomic_inc(&net->ipv4.dev_addr_genid);
1141 rt_cache_flush(dev_net(dev));
1142 break;
1143 case NETDEV_DOWN:
1144 fib_del_ifaddr(ifa, NULL);
1145 atomic_inc(&net->ipv4.dev_addr_genid);
1146 if (!ifa->ifa_dev->ifa_list) {
1147 /* Last address was deleted from this interface.
1148 * Disable IP.
1149 */
1150 fib_disable_ip(dev, event, true);
1151 } else {
1152 rt_cache_flush(dev_net(dev));
1153 }
1154 break;
1155 }
1156 return NOTIFY_DONE;
1157 }
1158
1159 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1160 {
1161 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1162 struct netdev_notifier_changeupper_info *info;
1163 struct in_device *in_dev;
1164 struct net *net = dev_net(dev);
1165 unsigned int flags;
1166
1167 if (event == NETDEV_UNREGISTER) {
1168 fib_disable_ip(dev, event, true);
1169 rt_flush_dev(dev);
1170 return NOTIFY_DONE;
1171 }
1172
1173 in_dev = __in_dev_get_rtnl(dev);
1174 if (!in_dev)
1175 return NOTIFY_DONE;
1176
1177 switch (event) {
1178 case NETDEV_UP:
1179 for_ifa(in_dev) {
1180 fib_add_ifaddr(ifa);
1181 } endfor_ifa(in_dev);
1182 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1183 fib_sync_up(dev, RTNH_F_DEAD);
1184 #endif
1185 atomic_inc(&net->ipv4.dev_addr_genid);
1186 rt_cache_flush(net);
1187 break;
1188 case NETDEV_DOWN:
1189 fib_disable_ip(dev, event, false);
1190 break;
1191 case NETDEV_CHANGE:
1192 flags = dev_get_flags(dev);
1193 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1194 fib_sync_up(dev, RTNH_F_LINKDOWN);
1195 else
1196 fib_sync_down_dev(dev, event, false);
1197 /* fall through */
1198 case NETDEV_CHANGEMTU:
1199 rt_cache_flush(net);
1200 break;
1201 case NETDEV_CHANGEUPPER:
1202 info = ptr;
1203 /* flush all routes if dev is linked to or unlinked from
1204 * an L3 master device (e.g., VRF)
1205 */
1206 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1207 fib_disable_ip(dev, NETDEV_DOWN, true);
1208 break;
1209 }
1210 return NOTIFY_DONE;
1211 }
1212
1213 static struct notifier_block fib_inetaddr_notifier = {
1214 .notifier_call = fib_inetaddr_event,
1215 };
1216
1217 static struct notifier_block fib_netdev_notifier = {
1218 .notifier_call = fib_netdev_event,
1219 };
1220
1221 static int __net_init ip_fib_net_init(struct net *net)
1222 {
1223 int err;
1224 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1225
1226 /* Avoid false sharing : Use at least a full cache line */
1227 size = max_t(size_t, size, L1_CACHE_BYTES);
1228
1229 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1230 if (!net->ipv4.fib_table_hash)
1231 return -ENOMEM;
1232
1233 err = fib4_rules_init(net);
1234 if (err < 0)
1235 goto fail;
1236 return 0;
1237
1238 fail:
1239 kfree(net->ipv4.fib_table_hash);
1240 return err;
1241 }
1242
1243 static void ip_fib_net_exit(struct net *net)
1244 {
1245 unsigned int i;
1246
1247 rtnl_lock();
1248 #ifdef CONFIG_IP_MULTIPLE_TABLES
1249 RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1250 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1251 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1252 #endif
1253 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1254 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1255 struct hlist_node *tmp;
1256 struct fib_table *tb;
1257
1258 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1259 hlist_del(&tb->tb_hlist);
1260 fib_table_flush(tb);
1261 fib_free_table(tb);
1262 }
1263 }
1264
1265 #ifdef CONFIG_IP_MULTIPLE_TABLES
1266 fib4_rules_exit(net);
1267 #endif
1268 rtnl_unlock();
1269 kfree(net->ipv4.fib_table_hash);
1270 }
1271
1272 static int __net_init fib_net_init(struct net *net)
1273 {
1274 int error;
1275
1276 #ifdef CONFIG_IP_ROUTE_CLASSID
1277 net->ipv4.fib_num_tclassid_users = 0;
1278 #endif
1279 error = ip_fib_net_init(net);
1280 if (error < 0)
1281 goto out;
1282 error = nl_fib_lookup_init(net);
1283 if (error < 0)
1284 goto out_nlfl;
1285 error = fib_proc_init(net);
1286 if (error < 0)
1287 goto out_proc;
1288 out:
1289 return error;
1290
1291 out_proc:
1292 nl_fib_lookup_exit(net);
1293 out_nlfl:
1294 ip_fib_net_exit(net);
1295 goto out;
1296 }
1297
1298 static void __net_exit fib_net_exit(struct net *net)
1299 {
1300 fib_proc_exit(net);
1301 nl_fib_lookup_exit(net);
1302 ip_fib_net_exit(net);
1303 }
1304
1305 static struct pernet_operations fib_net_ops = {
1306 .init = fib_net_init,
1307 .exit = fib_net_exit,
1308 };
1309
1310 void __init ip_fib_init(void)
1311 {
1312 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1313 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1314 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1315
1316 register_pernet_subsys(&fib_net_ops);
1317 register_netdevice_notifier(&fib_netdev_notifier);
1318 register_inetaddr_notifier(&fib_inetaddr_notifier);
1319
1320 fib_trie_init();
1321 }
Linux kernel - Deliverables
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