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[mirror_ubuntu-zesty-kernel.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 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 if (colon) {
513 struct in_ifaddr *ifa;
514 struct in_device *in_dev = __in_dev_get_rtnl(dev);
515 if (!in_dev)
516 return -ENODEV;
517 *colon = ':';
518 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
519 if (strcmp(ifa->ifa_label, devname) == 0)
520 break;
521 if (!ifa)
522 return -ENODEV;
523 cfg->fc_prefsrc = ifa->ifa_local;
524 }
525 }
526
527 addr = sk_extract_addr(&rt->rt_gateway);
528 if (rt->rt_gateway.sa_family == AF_INET && addr) {
529 unsigned int addr_type;
530
531 cfg->fc_gw = addr;
532 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
533 if (rt->rt_flags & RTF_GATEWAY &&
534 addr_type == RTN_UNICAST)
535 cfg->fc_scope = RT_SCOPE_UNIVERSE;
536 }
537
538 if (cmd == SIOCDELRT)
539 return 0;
540
541 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
542 return -EINVAL;
543
544 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
545 cfg->fc_scope = RT_SCOPE_LINK;
546
547 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
548 struct nlattr *mx;
549 int len = 0;
550
551 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
552 if (!mx)
553 return -ENOMEM;
554
555 if (rt->rt_flags & RTF_MTU)
556 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
557
558 if (rt->rt_flags & RTF_WINDOW)
559 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
560
561 if (rt->rt_flags & RTF_IRTT)
562 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
563
564 cfg->fc_mx = mx;
565 cfg->fc_mx_len = len;
566 }
567
568 return 0;
569 }
570
571 /*
572 * Handle IP routing ioctl calls.
573 * These are used to manipulate the routing tables
574 */
575 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
576 {
577 struct fib_config cfg;
578 struct rtentry rt;
579 int err;
580
581 switch (cmd) {
582 case SIOCADDRT: /* Add a route */
583 case SIOCDELRT: /* Delete a route */
584 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
585 return -EPERM;
586
587 if (copy_from_user(&rt, arg, sizeof(rt)))
588 return -EFAULT;
589
590 rtnl_lock();
591 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
592 if (err == 0) {
593 struct fib_table *tb;
594
595 if (cmd == SIOCDELRT) {
596 tb = fib_get_table(net, cfg.fc_table);
597 if (tb)
598 err = fib_table_delete(tb, &cfg);
599 else
600 err = -ESRCH;
601 } else {
602 tb = fib_new_table(net, cfg.fc_table);
603 if (tb)
604 err = fib_table_insert(tb, &cfg);
605 else
606 err = -ENOBUFS;
607 }
608
609 /* allocated by rtentry_to_fib_config() */
610 kfree(cfg.fc_mx);
611 }
612 rtnl_unlock();
613 return err;
614 }
615 return -EINVAL;
616 }
617
618 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
619 [RTA_DST] = { .type = NLA_U32 },
620 [RTA_SRC] = { .type = NLA_U32 },
621 [RTA_IIF] = { .type = NLA_U32 },
622 [RTA_OIF] = { .type = NLA_U32 },
623 [RTA_GATEWAY] = { .type = NLA_U32 },
624 [RTA_PRIORITY] = { .type = NLA_U32 },
625 [RTA_PREFSRC] = { .type = NLA_U32 },
626 [RTA_METRICS] = { .type = NLA_NESTED },
627 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
628 [RTA_FLOW] = { .type = NLA_U32 },
629 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
630 [RTA_ENCAP] = { .type = NLA_NESTED },
631 };
632
633 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
634 struct nlmsghdr *nlh, struct fib_config *cfg)
635 {
636 struct nlattr *attr;
637 int err, remaining;
638 struct rtmsg *rtm;
639
640 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
641 if (err < 0)
642 goto errout;
643
644 memset(cfg, 0, sizeof(*cfg));
645
646 rtm = nlmsg_data(nlh);
647 cfg->fc_dst_len = rtm->rtm_dst_len;
648 cfg->fc_tos = rtm->rtm_tos;
649 cfg->fc_table = rtm->rtm_table;
650 cfg->fc_protocol = rtm->rtm_protocol;
651 cfg->fc_scope = rtm->rtm_scope;
652 cfg->fc_type = rtm->rtm_type;
653 cfg->fc_flags = rtm->rtm_flags;
654 cfg->fc_nlflags = nlh->nlmsg_flags;
655
656 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
657 cfg->fc_nlinfo.nlh = nlh;
658 cfg->fc_nlinfo.nl_net = net;
659
660 if (cfg->fc_type > RTN_MAX) {
661 err = -EINVAL;
662 goto errout;
663 }
664
665 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
666 switch (nla_type(attr)) {
667 case RTA_DST:
668 cfg->fc_dst = nla_get_be32(attr);
669 break;
670 case RTA_OIF:
671 cfg->fc_oif = nla_get_u32(attr);
672 break;
673 case RTA_GATEWAY:
674 cfg->fc_gw = nla_get_be32(attr);
675 break;
676 case RTA_PRIORITY:
677 cfg->fc_priority = nla_get_u32(attr);
678 break;
679 case RTA_PREFSRC:
680 cfg->fc_prefsrc = nla_get_be32(attr);
681 break;
682 case RTA_METRICS:
683 cfg->fc_mx = nla_data(attr);
684 cfg->fc_mx_len = nla_len(attr);
685 break;
686 case RTA_MULTIPATH:
687 cfg->fc_mp = nla_data(attr);
688 cfg->fc_mp_len = nla_len(attr);
689 break;
690 case RTA_FLOW:
691 cfg->fc_flow = nla_get_u32(attr);
692 break;
693 case RTA_TABLE:
694 cfg->fc_table = nla_get_u32(attr);
695 break;
696 case RTA_ENCAP:
697 cfg->fc_encap = attr;
698 break;
699 case RTA_ENCAP_TYPE:
700 cfg->fc_encap_type = nla_get_u16(attr);
701 break;
702 }
703 }
704
705 return 0;
706 errout:
707 return err;
708 }
709
710 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
711 {
712 struct net *net = sock_net(skb->sk);
713 struct fib_config cfg;
714 struct fib_table *tb;
715 int err;
716
717 err = rtm_to_fib_config(net, skb, nlh, &cfg);
718 if (err < 0)
719 goto errout;
720
721 tb = fib_get_table(net, cfg.fc_table);
722 if (!tb) {
723 err = -ESRCH;
724 goto errout;
725 }
726
727 err = fib_table_delete(tb, &cfg);
728 errout:
729 return err;
730 }
731
732 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
733 {
734 struct net *net = sock_net(skb->sk);
735 struct fib_config cfg;
736 struct fib_table *tb;
737 int err;
738
739 err = rtm_to_fib_config(net, skb, nlh, &cfg);
740 if (err < 0)
741 goto errout;
742
743 tb = fib_new_table(net, cfg.fc_table);
744 if (!tb) {
745 err = -ENOBUFS;
746 goto errout;
747 }
748
749 err = fib_table_insert(tb, &cfg);
750 errout:
751 return err;
752 }
753
754 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
755 {
756 struct net *net = sock_net(skb->sk);
757 unsigned int h, s_h;
758 unsigned int e = 0, s_e;
759 struct fib_table *tb;
760 struct hlist_head *head;
761 int dumped = 0;
762
763 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
764 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
765 return skb->len;
766
767 s_h = cb->args[0];
768 s_e = cb->args[1];
769
770 rcu_read_lock();
771
772 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
773 e = 0;
774 head = &net->ipv4.fib_table_hash[h];
775 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
776 if (e < s_e)
777 goto next;
778 if (dumped)
779 memset(&cb->args[2], 0, sizeof(cb->args) -
780 2 * sizeof(cb->args[0]));
781 if (fib_table_dump(tb, skb, cb) < 0)
782 goto out;
783 dumped = 1;
784 next:
785 e++;
786 }
787 }
788 out:
789 rcu_read_unlock();
790
791 cb->args[1] = e;
792 cb->args[0] = h;
793
794 return skb->len;
795 }
796
797 /* Prepare and feed intra-kernel routing request.
798 * Really, it should be netlink message, but :-( netlink
799 * can be not configured, so that we feed it directly
800 * to fib engine. It is legal, because all events occur
801 * only when netlink is already locked.
802 */
803 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
804 {
805 struct net *net = dev_net(ifa->ifa_dev->dev);
806 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
807 struct fib_table *tb;
808 struct fib_config cfg = {
809 .fc_protocol = RTPROT_KERNEL,
810 .fc_type = type,
811 .fc_dst = dst,
812 .fc_dst_len = dst_len,
813 .fc_prefsrc = ifa->ifa_local,
814 .fc_oif = ifa->ifa_dev->dev->ifindex,
815 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
816 .fc_nlinfo = {
817 .nl_net = net,
818 },
819 };
820
821 if (!tb_id)
822 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
823
824 tb = fib_new_table(net, tb_id);
825 if (!tb)
826 return;
827
828 cfg.fc_table = tb->tb_id;
829
830 if (type != RTN_LOCAL)
831 cfg.fc_scope = RT_SCOPE_LINK;
832 else
833 cfg.fc_scope = RT_SCOPE_HOST;
834
835 if (cmd == RTM_NEWROUTE)
836 fib_table_insert(tb, &cfg);
837 else
838 fib_table_delete(tb, &cfg);
839 }
840
841 void fib_add_ifaddr(struct in_ifaddr *ifa)
842 {
843 struct in_device *in_dev = ifa->ifa_dev;
844 struct net_device *dev = in_dev->dev;
845 struct in_ifaddr *prim = ifa;
846 __be32 mask = ifa->ifa_mask;
847 __be32 addr = ifa->ifa_local;
848 __be32 prefix = ifa->ifa_address & mask;
849
850 if (ifa->ifa_flags & IFA_F_SECONDARY) {
851 prim = inet_ifa_byprefix(in_dev, prefix, mask);
852 if (!prim) {
853 pr_warn("%s: bug: prim == NULL\n", __func__);
854 return;
855 }
856 }
857
858 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
859
860 if (!(dev->flags & IFF_UP))
861 return;
862
863 /* Add broadcast address, if it is explicitly assigned. */
864 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
865 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
866
867 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
868 (prefix != addr || ifa->ifa_prefixlen < 32)) {
869 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
870 fib_magic(RTM_NEWROUTE,
871 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
872 prefix, ifa->ifa_prefixlen, prim);
873
874 /* Add network specific broadcasts, when it takes a sense */
875 if (ifa->ifa_prefixlen < 31) {
876 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
877 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
878 32, prim);
879 }
880 }
881 }
882
883 /* Delete primary or secondary address.
884 * Optionally, on secondary address promotion consider the addresses
885 * from subnet iprim as deleted, even if they are in device list.
886 * In this case the secondary ifa can be in device list.
887 */
888 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
889 {
890 struct in_device *in_dev = ifa->ifa_dev;
891 struct net_device *dev = in_dev->dev;
892 struct in_ifaddr *ifa1;
893 struct in_ifaddr *prim = ifa, *prim1 = NULL;
894 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
895 __be32 any = ifa->ifa_address & ifa->ifa_mask;
896 #define LOCAL_OK 1
897 #define BRD_OK 2
898 #define BRD0_OK 4
899 #define BRD1_OK 8
900 unsigned int ok = 0;
901 int subnet = 0; /* Primary network */
902 int gone = 1; /* Address is missing */
903 int same_prefsrc = 0; /* Another primary with same IP */
904
905 if (ifa->ifa_flags & IFA_F_SECONDARY) {
906 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
907 if (!prim) {
908 /* if the device has been deleted, we don't perform
909 * address promotion
910 */
911 if (!in_dev->dead)
912 pr_warn("%s: bug: prim == NULL\n", __func__);
913 return;
914 }
915 if (iprim && iprim != prim) {
916 pr_warn("%s: bug: iprim != prim\n", __func__);
917 return;
918 }
919 } else if (!ipv4_is_zeronet(any) &&
920 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
921 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
922 fib_magic(RTM_DELROUTE,
923 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
924 any, ifa->ifa_prefixlen, prim);
925 subnet = 1;
926 }
927
928 if (in_dev->dead)
929 goto no_promotions;
930
931 /* Deletion is more complicated than add.
932 * We should take care of not to delete too much :-)
933 *
934 * Scan address list to be sure that addresses are really gone.
935 */
936
937 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
938 if (ifa1 == ifa) {
939 /* promotion, keep the IP */
940 gone = 0;
941 continue;
942 }
943 /* Ignore IFAs from our subnet */
944 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
945 inet_ifa_match(ifa1->ifa_address, iprim))
946 continue;
947
948 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
949 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
950 /* Another address from our subnet? */
951 if (ifa1->ifa_mask == prim->ifa_mask &&
952 inet_ifa_match(ifa1->ifa_address, prim))
953 prim1 = prim;
954 else {
955 /* We reached the secondaries, so
956 * same_prefsrc should be determined.
957 */
958 if (!same_prefsrc)
959 continue;
960 /* Search new prim1 if ifa1 is not
961 * using the current prim1
962 */
963 if (!prim1 ||
964 ifa1->ifa_mask != prim1->ifa_mask ||
965 !inet_ifa_match(ifa1->ifa_address, prim1))
966 prim1 = inet_ifa_byprefix(in_dev,
967 ifa1->ifa_address,
968 ifa1->ifa_mask);
969 if (!prim1)
970 continue;
971 if (prim1->ifa_local != prim->ifa_local)
972 continue;
973 }
974 } else {
975 if (prim->ifa_local != ifa1->ifa_local)
976 continue;
977 prim1 = ifa1;
978 if (prim != prim1)
979 same_prefsrc = 1;
980 }
981 if (ifa->ifa_local == ifa1->ifa_local)
982 ok |= LOCAL_OK;
983 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
984 ok |= BRD_OK;
985 if (brd == ifa1->ifa_broadcast)
986 ok |= BRD1_OK;
987 if (any == ifa1->ifa_broadcast)
988 ok |= BRD0_OK;
989 /* primary has network specific broadcasts */
990 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
991 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
992 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
993
994 if (!ipv4_is_zeronet(any1)) {
995 if (ifa->ifa_broadcast == brd1 ||
996 ifa->ifa_broadcast == any1)
997 ok |= BRD_OK;
998 if (brd == brd1 || brd == any1)
999 ok |= BRD1_OK;
1000 if (any == brd1 || any == any1)
1001 ok |= BRD0_OK;
1002 }
1003 }
1004 }
1005
1006 no_promotions:
1007 if (!(ok & BRD_OK))
1008 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1009 if (subnet && ifa->ifa_prefixlen < 31) {
1010 if (!(ok & BRD1_OK))
1011 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1012 if (!(ok & BRD0_OK))
1013 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1014 }
1015 if (!(ok & LOCAL_OK)) {
1016 unsigned int addr_type;
1017
1018 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1019
1020 /* Check, that this local address finally disappeared. */
1021 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1022 ifa->ifa_local);
1023 if (gone && addr_type != RTN_LOCAL) {
1024 /* And the last, but not the least thing.
1025 * We must flush stray FIB entries.
1026 *
1027 * First of all, we scan fib_info list searching
1028 * for stray nexthop entries, then ignite fib_flush.
1029 */
1030 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
1031 fib_flush(dev_net(dev));
1032 }
1033 }
1034 #undef LOCAL_OK
1035 #undef BRD_OK
1036 #undef BRD0_OK
1037 #undef BRD1_OK
1038 }
1039
1040 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1041 {
1042
1043 struct fib_result res;
1044 struct flowi4 fl4 = {
1045 .flowi4_mark = frn->fl_mark,
1046 .daddr = frn->fl_addr,
1047 .flowi4_tos = frn->fl_tos,
1048 .flowi4_scope = frn->fl_scope,
1049 };
1050 struct fib_table *tb;
1051
1052 rcu_read_lock();
1053
1054 tb = fib_get_table(net, frn->tb_id_in);
1055
1056 frn->err = -ENOENT;
1057 if (tb) {
1058 local_bh_disable();
1059
1060 frn->tb_id = tb->tb_id;
1061 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1062
1063 if (!frn->err) {
1064 frn->prefixlen = res.prefixlen;
1065 frn->nh_sel = res.nh_sel;
1066 frn->type = res.type;
1067 frn->scope = res.scope;
1068 }
1069 local_bh_enable();
1070 }
1071
1072 rcu_read_unlock();
1073 }
1074
1075 static void nl_fib_input(struct sk_buff *skb)
1076 {
1077 struct net *net;
1078 struct fib_result_nl *frn;
1079 struct nlmsghdr *nlh;
1080 u32 portid;
1081
1082 net = sock_net(skb->sk);
1083 nlh = nlmsg_hdr(skb);
1084 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
1085 nlmsg_len(nlh) < sizeof(*frn))
1086 return;
1087
1088 skb = netlink_skb_clone(skb, GFP_KERNEL);
1089 if (!skb)
1090 return;
1091 nlh = nlmsg_hdr(skb);
1092
1093 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1094 nl_fib_lookup(net, frn);
1095
1096 portid = NETLINK_CB(skb).portid; /* netlink portid */
1097 NETLINK_CB(skb).portid = 0; /* from kernel */
1098 NETLINK_CB(skb).dst_group = 0; /* unicast */
1099 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1100 }
1101
1102 static int __net_init nl_fib_lookup_init(struct net *net)
1103 {
1104 struct sock *sk;
1105 struct netlink_kernel_cfg cfg = {
1106 .input = nl_fib_input,
1107 };
1108
1109 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1110 if (!sk)
1111 return -EAFNOSUPPORT;
1112 net->ipv4.fibnl = sk;
1113 return 0;
1114 }
1115
1116 static void nl_fib_lookup_exit(struct net *net)
1117 {
1118 netlink_kernel_release(net->ipv4.fibnl);
1119 net->ipv4.fibnl = NULL;
1120 }
1121
1122 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1123 bool force)
1124 {
1125 if (fib_sync_down_dev(dev, event, force))
1126 fib_flush(dev_net(dev));
1127 rt_cache_flush(dev_net(dev));
1128 arp_ifdown(dev);
1129 }
1130
1131 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1132 {
1133 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1134 struct net_device *dev = ifa->ifa_dev->dev;
1135 struct net *net = dev_net(dev);
1136
1137 switch (event) {
1138 case NETDEV_UP:
1139 fib_add_ifaddr(ifa);
1140 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1141 fib_sync_up(dev, RTNH_F_DEAD);
1142 #endif
1143 atomic_inc(&net->ipv4.dev_addr_genid);
1144 rt_cache_flush(dev_net(dev));
1145 break;
1146 case NETDEV_DOWN:
1147 fib_del_ifaddr(ifa, NULL);
1148 atomic_inc(&net->ipv4.dev_addr_genid);
1149 if (!ifa->ifa_dev->ifa_list) {
1150 /* Last address was deleted from this interface.
1151 * Disable IP.
1152 */
1153 fib_disable_ip(dev, event, true);
1154 } else {
1155 rt_cache_flush(dev_net(dev));
1156 }
1157 break;
1158 }
1159 return NOTIFY_DONE;
1160 }
1161
1162 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1163 {
1164 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1165 struct netdev_notifier_changeupper_info *info;
1166 struct in_device *in_dev;
1167 struct net *net = dev_net(dev);
1168 unsigned int flags;
1169
1170 if (event == NETDEV_UNREGISTER) {
1171 fib_disable_ip(dev, event, true);
1172 rt_flush_dev(dev);
1173 return NOTIFY_DONE;
1174 }
1175
1176 in_dev = __in_dev_get_rtnl(dev);
1177 if (!in_dev)
1178 return NOTIFY_DONE;
1179
1180 switch (event) {
1181 case NETDEV_UP:
1182 for_ifa(in_dev) {
1183 fib_add_ifaddr(ifa);
1184 } endfor_ifa(in_dev);
1185 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1186 fib_sync_up(dev, RTNH_F_DEAD);
1187 #endif
1188 atomic_inc(&net->ipv4.dev_addr_genid);
1189 rt_cache_flush(net);
1190 break;
1191 case NETDEV_DOWN:
1192 fib_disable_ip(dev, event, false);
1193 break;
1194 case NETDEV_CHANGE:
1195 flags = dev_get_flags(dev);
1196 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1197 fib_sync_up(dev, RTNH_F_LINKDOWN);
1198 else
1199 fib_sync_down_dev(dev, event, false);
1200 /* fall through */
1201 case NETDEV_CHANGEMTU:
1202 rt_cache_flush(net);
1203 break;
1204 case NETDEV_CHANGEUPPER:
1205 info = ptr;
1206 /* flush all routes if dev is linked to or unlinked from
1207 * an L3 master device (e.g., VRF)
1208 */
1209 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1210 fib_disable_ip(dev, NETDEV_DOWN, true);
1211 break;
1212 }
1213 return NOTIFY_DONE;
1214 }
1215
1216 static struct notifier_block fib_inetaddr_notifier = {
1217 .notifier_call = fib_inetaddr_event,
1218 };
1219
1220 static struct notifier_block fib_netdev_notifier = {
1221 .notifier_call = fib_netdev_event,
1222 };
1223
1224 static int __net_init ip_fib_net_init(struct net *net)
1225 {
1226 int err;
1227 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1228
1229 /* Avoid false sharing : Use at least a full cache line */
1230 size = max_t(size_t, size, L1_CACHE_BYTES);
1231
1232 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1233 if (!net->ipv4.fib_table_hash)
1234 return -ENOMEM;
1235
1236 err = fib4_rules_init(net);
1237 if (err < 0)
1238 goto fail;
1239 return 0;
1240
1241 fail:
1242 kfree(net->ipv4.fib_table_hash);
1243 return err;
1244 }
1245
1246 static void ip_fib_net_exit(struct net *net)
1247 {
1248 unsigned int i;
1249
1250 rtnl_lock();
1251 #ifdef CONFIG_IP_MULTIPLE_TABLES
1252 RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1253 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1254 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1255 #endif
1256 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1257 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1258 struct hlist_node *tmp;
1259 struct fib_table *tb;
1260
1261 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1262 hlist_del(&tb->tb_hlist);
1263 fib_table_flush(tb);
1264 fib_free_table(tb);
1265 }
1266 }
1267
1268 #ifdef CONFIG_IP_MULTIPLE_TABLES
1269 fib4_rules_exit(net);
1270 #endif
1271 rtnl_unlock();
1272 kfree(net->ipv4.fib_table_hash);
1273 }
1274
1275 static int __net_init fib_net_init(struct net *net)
1276 {
1277 int error;
1278
1279 #ifdef CONFIG_IP_ROUTE_CLASSID
1280 net->ipv4.fib_num_tclassid_users = 0;
1281 #endif
1282 error = ip_fib_net_init(net);
1283 if (error < 0)
1284 goto out;
1285 error = nl_fib_lookup_init(net);
1286 if (error < 0)
1287 goto out_nlfl;
1288 error = fib_proc_init(net);
1289 if (error < 0)
1290 goto out_proc;
1291 out:
1292 return error;
1293
1294 out_proc:
1295 nl_fib_lookup_exit(net);
1296 out_nlfl:
1297 ip_fib_net_exit(net);
1298 goto out;
1299 }
1300
1301 static void __net_exit fib_net_exit(struct net *net)
1302 {
1303 fib_proc_exit(net);
1304 nl_fib_lookup_exit(net);
1305 ip_fib_net_exit(net);
1306 }
1307
1308 static struct pernet_operations fib_net_ops = {
1309 .init = fib_net_init,
1310 .exit = fib_net_exit,
1311 };
1312
1313 void __init ip_fib_init(void)
1314 {
1315 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1316 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1317 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1318
1319 register_pernet_subsys(&fib_net_ops);
1320 register_netdevice_notifier(&fib_netdev_notifier);
1321 register_inetaddr_notifier(&fib_inetaddr_notifier);
1322
1323 fib_trie_init();
1324 }
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