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