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