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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
49#ifndef CONFIG_IP_MULTIPLE_TABLES
50
51static int __net_init fib4_rules_init(struct net *net)
52{
53 struct fib_table *local_table, *main_table;
54
55 local_table = fib_trie_table(RT_TABLE_LOCAL);
56 if (local_table == NULL)
57 return -ENOMEM;
58
59 main_table = fib_trie_table(RT_TABLE_MAIN);
60 if (main_table == NULL)
61 goto fail;
62
63 hlist_add_head_rcu(&local_table->tb_hlist,
64 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
65 hlist_add_head_rcu(&main_table->tb_hlist,
66 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
67 return 0;
68
69fail:
70 kfree(local_table);
71 return -ENOMEM;
72}
73#else
74
75struct fib_table *fib_new_table(struct net *net, u32 id)
76{
77 struct fib_table *tb;
78 unsigned int h;
79
80 if (id == 0)
81 id = RT_TABLE_MAIN;
82 tb = fib_get_table(net, id);
83 if (tb)
84 return tb;
85
86 tb = fib_trie_table(id);
87 if (!tb)
88 return NULL;
89
90 switch (id) {
91 case RT_TABLE_LOCAL:
92 net->ipv4.fib_local = tb;
93 break;
94
95 case RT_TABLE_MAIN:
96 net->ipv4.fib_main = tb;
97 break;
98
99 case RT_TABLE_DEFAULT:
100 net->ipv4.fib_default = tb;
101 break;
102
103 default:
104 break;
105 }
106
107 h = id & (FIB_TABLE_HASHSZ - 1);
108 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
109 return tb;
110}
111
112struct fib_table *fib_get_table(struct net *net, u32 id)
113{
114 struct fib_table *tb;
115 struct hlist_head *head;
116 unsigned int h;
117
118 if (id == 0)
119 id = RT_TABLE_MAIN;
120 h = id & (FIB_TABLE_HASHSZ - 1);
121
122 rcu_read_lock();
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 rcu_read_unlock();
127 return tb;
128 }
129 }
130 rcu_read_unlock();
131 return NULL;
132}
133#endif /* CONFIG_IP_MULTIPLE_TABLES */
134
135static void fib_flush(struct net *net)
136{
137 int flushed = 0;
138 struct fib_table *tb;
139 struct hlist_head *head;
140 unsigned int h;
141
142 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
143 head = &net->ipv4.fib_table_hash[h];
144 hlist_for_each_entry(tb, head, tb_hlist)
145 flushed += fib_table_flush(tb);
146 }
147
148 if (flushed)
149 rt_cache_flush(net);
150}
151
152/*
153 * Find address type as if only "dev" was present in the system. If
154 * on_dev is NULL then all interfaces are taken into consideration.
155 */
156static inline unsigned int __inet_dev_addr_type(struct net *net,
157 const struct net_device *dev,
158 __be32 addr)
159{
160 struct flowi4 fl4 = { .daddr = addr };
161 struct fib_result res;
162 unsigned int ret = RTN_BROADCAST;
163 struct fib_table *local_table;
164
165 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
166 return RTN_BROADCAST;
167 if (ipv4_is_multicast(addr))
168 return RTN_MULTICAST;
169
170 local_table = fib_get_table(net, RT_TABLE_LOCAL);
171 if (local_table) {
172 ret = RTN_UNICAST;
173 rcu_read_lock();
174 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
175 if (!dev || dev == res.fi->fib_dev)
176 ret = res.type;
177 }
178 rcu_read_unlock();
179 }
180 return ret;
181}
182
183unsigned int inet_addr_type(struct net *net, __be32 addr)
184{
185 return __inet_dev_addr_type(net, NULL, addr);
186}
187EXPORT_SYMBOL(inet_addr_type);
188
189unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
190 __be32 addr)
191{
192 return __inet_dev_addr_type(net, dev, addr);
193}
194EXPORT_SYMBOL(inet_dev_addr_type);
195
196__be32 fib_compute_spec_dst(struct sk_buff *skb)
197{
198 struct net_device *dev = skb->dev;
199 struct in_device *in_dev;
200 struct fib_result res;
201 struct rtable *rt;
202 struct flowi4 fl4;
203 struct net *net;
204 int scope;
205
206 rt = skb_rtable(skb);
207 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
208 RTCF_LOCAL)
209 return ip_hdr(skb)->daddr;
210
211 in_dev = __in_dev_get_rcu(dev);
212 BUG_ON(!in_dev);
213
214 net = dev_net(dev);
215
216 scope = RT_SCOPE_UNIVERSE;
217 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
218 fl4.flowi4_oif = 0;
219 fl4.flowi4_iif = LOOPBACK_IFINDEX;
220 fl4.daddr = ip_hdr(skb)->saddr;
221 fl4.saddr = 0;
222 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
223 fl4.flowi4_scope = scope;
224 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
225 if (!fib_lookup(net, &fl4, &res))
226 return FIB_RES_PREFSRC(net, res);
227 } else {
228 scope = RT_SCOPE_LINK;
229 }
230
231 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
232}
233
234/* Given (packet source, input interface) and optional (dst, oif, tos):
235 * - (main) check, that source is valid i.e. not broadcast or our local
236 * address.
237 * - figure out what "logical" interface this packet arrived
238 * and calculate "specific destination" address.
239 * - check, that packet arrived from expected physical interface.
240 * called with rcu_read_lock()
241 */
242static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
243 u8 tos, int oif, struct net_device *dev,
244 int rpf, struct in_device *idev, u32 *itag)
245{
246 int ret, no_addr, accept_local;
247 struct fib_result res;
248 struct flowi4 fl4;
249 struct net *net;
250 bool dev_match;
251
252 fl4.flowi4_oif = 0;
253 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
254 fl4.daddr = src;
255 fl4.saddr = dst;
256 fl4.flowi4_tos = tos;
257 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
258
259 no_addr = idev->ifa_list == NULL;
260
261 accept_local = IN_DEV_ACCEPT_LOCAL(idev);
262 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
263
264 net = dev_net(dev);
265 if (fib_lookup(net, &fl4, &res))
266 goto last_resort;
267 if (res.type != RTN_UNICAST) {
268 if (res.type != RTN_LOCAL || !accept_local)
269 goto e_inval;
270 }
271 fib_combine_itag(itag, &res);
272 dev_match = false;
273
274#ifdef CONFIG_IP_ROUTE_MULTIPATH
275 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
276 struct fib_nh *nh = &res.fi->fib_nh[ret];
277
278 if (nh->nh_dev == dev) {
279 dev_match = true;
280 break;
281 }
282 }
283#else
284 if (FIB_RES_DEV(res) == dev)
285 dev_match = true;
286#endif
287 if (dev_match) {
288 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
289 return ret;
290 }
291 if (no_addr)
292 goto last_resort;
293 if (rpf == 1)
294 goto e_rpf;
295 fl4.flowi4_oif = dev->ifindex;
296
297 ret = 0;
298 if (fib_lookup(net, &fl4, &res) == 0) {
299 if (res.type == RTN_UNICAST)
300 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
301 }
302 return ret;
303
304last_resort:
305 if (rpf)
306 goto e_rpf;
307 *itag = 0;
308 return 0;
309
310e_inval:
311 return -EINVAL;
312e_rpf:
313 return -EXDEV;
314}
315
316/* Ignore rp_filter for packets protected by IPsec. */
317int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
318 u8 tos, int oif, struct net_device *dev,
319 struct in_device *idev, u32 *itag)
320{
321 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
322
323 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
324 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
325 *itag = 0;
326 return 0;
327 }
328 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
329}
330
331static inline __be32 sk_extract_addr(struct sockaddr *addr)
332{
333 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
334}
335
336static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
337{
338 struct nlattr *nla;
339
340 nla = (struct nlattr *) ((char *) mx + len);
341 nla->nla_type = type;
342 nla->nla_len = nla_attr_size(4);
343 *(u32 *) nla_data(nla) = value;
344
345 return len + nla_total_size(4);
346}
347
348static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
349 struct fib_config *cfg)
350{
351 __be32 addr;
352 int plen;
353
354 memset(cfg, 0, sizeof(*cfg));
355 cfg->fc_nlinfo.nl_net = net;
356
357 if (rt->rt_dst.sa_family != AF_INET)
358 return -EAFNOSUPPORT;
359
360 /*
361 * Check mask for validity:
362 * a) it must be contiguous.
363 * b) destination must have all host bits clear.
364 * c) if application forgot to set correct family (AF_INET),
365 * reject request unless it is absolutely clear i.e.
366 * both family and mask are zero.
367 */
368 plen = 32;
369 addr = sk_extract_addr(&rt->rt_dst);
370 if (!(rt->rt_flags & RTF_HOST)) {
371 __be32 mask = sk_extract_addr(&rt->rt_genmask);
372
373 if (rt->rt_genmask.sa_family != AF_INET) {
374 if (mask || rt->rt_genmask.sa_family)
375 return -EAFNOSUPPORT;
376 }
377
378 if (bad_mask(mask, addr))
379 return -EINVAL;
380
381 plen = inet_mask_len(mask);
382 }
383
384 cfg->fc_dst_len = plen;
385 cfg->fc_dst = addr;
386
387 if (cmd != SIOCDELRT) {
388 cfg->fc_nlflags = NLM_F_CREATE;
389 cfg->fc_protocol = RTPROT_BOOT;
390 }
391
392 if (rt->rt_metric)
393 cfg->fc_priority = rt->rt_metric - 1;
394
395 if (rt->rt_flags & RTF_REJECT) {
396 cfg->fc_scope = RT_SCOPE_HOST;
397 cfg->fc_type = RTN_UNREACHABLE;
398 return 0;
399 }
400
401 cfg->fc_scope = RT_SCOPE_NOWHERE;
402 cfg->fc_type = RTN_UNICAST;
403
404 if (rt->rt_dev) {
405 char *colon;
406 struct net_device *dev;
407 char devname[IFNAMSIZ];
408
409 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
410 return -EFAULT;
411
412 devname[IFNAMSIZ-1] = 0;
413 colon = strchr(devname, ':');
414 if (colon)
415 *colon = 0;
416 dev = __dev_get_by_name(net, devname);
417 if (!dev)
418 return -ENODEV;
419 cfg->fc_oif = dev->ifindex;
420 if (colon) {
421 struct in_ifaddr *ifa;
422 struct in_device *in_dev = __in_dev_get_rtnl(dev);
423 if (!in_dev)
424 return -ENODEV;
425 *colon = ':';
426 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
427 if (strcmp(ifa->ifa_label, devname) == 0)
428 break;
429 if (ifa == NULL)
430 return -ENODEV;
431 cfg->fc_prefsrc = ifa->ifa_local;
432 }
433 }
434
435 addr = sk_extract_addr(&rt->rt_gateway);
436 if (rt->rt_gateway.sa_family == AF_INET && addr) {
437 cfg->fc_gw = addr;
438 if (rt->rt_flags & RTF_GATEWAY &&
439 inet_addr_type(net, addr) == RTN_UNICAST)
440 cfg->fc_scope = RT_SCOPE_UNIVERSE;
441 }
442
443 if (cmd == SIOCDELRT)
444 return 0;
445
446 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
447 return -EINVAL;
448
449 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
450 cfg->fc_scope = RT_SCOPE_LINK;
451
452 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
453 struct nlattr *mx;
454 int len = 0;
455
456 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
457 if (mx == NULL)
458 return -ENOMEM;
459
460 if (rt->rt_flags & RTF_MTU)
461 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
462
463 if (rt->rt_flags & RTF_WINDOW)
464 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
465
466 if (rt->rt_flags & RTF_IRTT)
467 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
468
469 cfg->fc_mx = mx;
470 cfg->fc_mx_len = len;
471 }
472
473 return 0;
474}
475
476/*
477 * Handle IP routing ioctl calls.
478 * These are used to manipulate the routing tables
479 */
480int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
481{
482 struct fib_config cfg;
483 struct rtentry rt;
484 int err;
485
486 switch (cmd) {
487 case SIOCADDRT: /* Add a route */
488 case SIOCDELRT: /* Delete a route */
489 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
490 return -EPERM;
491
492 if (copy_from_user(&rt, arg, sizeof(rt)))
493 return -EFAULT;
494
495 rtnl_lock();
496 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
497 if (err == 0) {
498 struct fib_table *tb;
499
500 if (cmd == SIOCDELRT) {
501 tb = fib_get_table(net, cfg.fc_table);
502 if (tb)
503 err = fib_table_delete(tb, &cfg);
504 else
505 err = -ESRCH;
506 } else {
507 tb = fib_new_table(net, cfg.fc_table);
508 if (tb)
509 err = fib_table_insert(tb, &cfg);
510 else
511 err = -ENOBUFS;
512 }
513
514 /* allocated by rtentry_to_fib_config() */
515 kfree(cfg.fc_mx);
516 }
517 rtnl_unlock();
518 return err;
519 }
520 return -EINVAL;
521}
522
523const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
524 [RTA_DST] = { .type = NLA_U32 },
525 [RTA_SRC] = { .type = NLA_U32 },
526 [RTA_IIF] = { .type = NLA_U32 },
527 [RTA_OIF] = { .type = NLA_U32 },
528 [RTA_GATEWAY] = { .type = NLA_U32 },
529 [RTA_PRIORITY] = { .type = NLA_U32 },
530 [RTA_PREFSRC] = { .type = NLA_U32 },
531 [RTA_METRICS] = { .type = NLA_NESTED },
532 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
533 [RTA_FLOW] = { .type = NLA_U32 },
534};
535
536static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
537 struct nlmsghdr *nlh, struct fib_config *cfg)
538{
539 struct nlattr *attr;
540 int err, remaining;
541 struct rtmsg *rtm;
542
543 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
544 if (err < 0)
545 goto errout;
546
547 memset(cfg, 0, sizeof(*cfg));
548
549 rtm = nlmsg_data(nlh);
550 cfg->fc_dst_len = rtm->rtm_dst_len;
551 cfg->fc_tos = rtm->rtm_tos;
552 cfg->fc_table = rtm->rtm_table;
553 cfg->fc_protocol = rtm->rtm_protocol;
554 cfg->fc_scope = rtm->rtm_scope;
555 cfg->fc_type = rtm->rtm_type;
556 cfg->fc_flags = rtm->rtm_flags;
557 cfg->fc_nlflags = nlh->nlmsg_flags;
558
559 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
560 cfg->fc_nlinfo.nlh = nlh;
561 cfg->fc_nlinfo.nl_net = net;
562
563 if (cfg->fc_type > RTN_MAX) {
564 err = -EINVAL;
565 goto errout;
566 }
567
568 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
569 switch (nla_type(attr)) {
570 case RTA_DST:
571 cfg->fc_dst = nla_get_be32(attr);
572 break;
573 case RTA_OIF:
574 cfg->fc_oif = nla_get_u32(attr);
575 break;
576 case RTA_GATEWAY:
577 cfg->fc_gw = nla_get_be32(attr);
578 break;
579 case RTA_PRIORITY:
580 cfg->fc_priority = nla_get_u32(attr);
581 break;
582 case RTA_PREFSRC:
583 cfg->fc_prefsrc = nla_get_be32(attr);
584 break;
585 case RTA_METRICS:
586 cfg->fc_mx = nla_data(attr);
587 cfg->fc_mx_len = nla_len(attr);
588 break;
589 case RTA_MULTIPATH:
590 cfg->fc_mp = nla_data(attr);
591 cfg->fc_mp_len = nla_len(attr);
592 break;
593 case RTA_FLOW:
594 cfg->fc_flow = nla_get_u32(attr);
595 break;
596 case RTA_TABLE:
597 cfg->fc_table = nla_get_u32(attr);
598 break;
599 }
600 }
601
602 return 0;
603errout:
604 return err;
605}
606
607static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
608{
609 struct net *net = sock_net(skb->sk);
610 struct fib_config cfg;
611 struct fib_table *tb;
612 int err;
613
614 err = rtm_to_fib_config(net, skb, nlh, &cfg);
615 if (err < 0)
616 goto errout;
617
618 tb = fib_get_table(net, cfg.fc_table);
619 if (tb == NULL) {
620 err = -ESRCH;
621 goto errout;
622 }
623
624 err = fib_table_delete(tb, &cfg);
625errout:
626 return err;
627}
628
629static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
630{
631 struct net *net = sock_net(skb->sk);
632 struct fib_config cfg;
633 struct fib_table *tb;
634 int err;
635
636 err = rtm_to_fib_config(net, skb, nlh, &cfg);
637 if (err < 0)
638 goto errout;
639
640 tb = fib_new_table(net, cfg.fc_table);
641 if (tb == NULL) {
642 err = -ENOBUFS;
643 goto errout;
644 }
645
646 err = fib_table_insert(tb, &cfg);
647errout:
648 return err;
649}
650
651static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
652{
653 struct net *net = sock_net(skb->sk);
654 unsigned int h, s_h;
655 unsigned int e = 0, s_e;
656 struct fib_table *tb;
657 struct hlist_head *head;
658 int dumped = 0;
659
660 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
661 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
662 return skb->len;
663
664 s_h = cb->args[0];
665 s_e = cb->args[1];
666
667 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
668 e = 0;
669 head = &net->ipv4.fib_table_hash[h];
670 hlist_for_each_entry(tb, head, tb_hlist) {
671 if (e < s_e)
672 goto next;
673 if (dumped)
674 memset(&cb->args[2], 0, sizeof(cb->args) -
675 2 * sizeof(cb->args[0]));
676 if (fib_table_dump(tb, skb, cb) < 0)
677 goto out;
678 dumped = 1;
679next:
680 e++;
681 }
682 }
683out:
684 cb->args[1] = e;
685 cb->args[0] = h;
686
687 return skb->len;
688}
689
690/* Prepare and feed intra-kernel routing request.
691 * Really, it should be netlink message, but :-( netlink
692 * can be not configured, so that we feed it directly
693 * to fib engine. It is legal, because all events occur
694 * only when netlink is already locked.
695 */
696static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
697{
698 struct net *net = dev_net(ifa->ifa_dev->dev);
699 struct fib_table *tb;
700 struct fib_config cfg = {
701 .fc_protocol = RTPROT_KERNEL,
702 .fc_type = type,
703 .fc_dst = dst,
704 .fc_dst_len = dst_len,
705 .fc_prefsrc = ifa->ifa_local,
706 .fc_oif = ifa->ifa_dev->dev->ifindex,
707 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
708 .fc_nlinfo = {
709 .nl_net = net,
710 },
711 };
712
713 if (type == RTN_UNICAST)
714 tb = fib_new_table(net, RT_TABLE_MAIN);
715 else
716 tb = fib_new_table(net, RT_TABLE_LOCAL);
717
718 if (tb == NULL)
719 return;
720
721 cfg.fc_table = tb->tb_id;
722
723 if (type != RTN_LOCAL)
724 cfg.fc_scope = RT_SCOPE_LINK;
725 else
726 cfg.fc_scope = RT_SCOPE_HOST;
727
728 if (cmd == RTM_NEWROUTE)
729 fib_table_insert(tb, &cfg);
730 else
731 fib_table_delete(tb, &cfg);
732}
733
734void fib_add_ifaddr(struct in_ifaddr *ifa)
735{
736 struct in_device *in_dev = ifa->ifa_dev;
737 struct net_device *dev = in_dev->dev;
738 struct in_ifaddr *prim = ifa;
739 __be32 mask = ifa->ifa_mask;
740 __be32 addr = ifa->ifa_local;
741 __be32 prefix = ifa->ifa_address & mask;
742
743 if (ifa->ifa_flags & IFA_F_SECONDARY) {
744 prim = inet_ifa_byprefix(in_dev, prefix, mask);
745 if (prim == NULL) {
746 pr_warn("%s: bug: prim == NULL\n", __func__);
747 return;
748 }
749 }
750
751 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
752
753 if (!(dev->flags & IFF_UP))
754 return;
755
756 /* Add broadcast address, if it is explicitly assigned. */
757 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
758 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
759
760 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
761 (prefix != addr || ifa->ifa_prefixlen < 32)) {
762 fib_magic(RTM_NEWROUTE,
763 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
764 prefix, ifa->ifa_prefixlen, prim);
765
766 /* Add network specific broadcasts, when it takes a sense */
767 if (ifa->ifa_prefixlen < 31) {
768 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
769 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
770 32, prim);
771 }
772 }
773}
774
775/* Delete primary or secondary address.
776 * Optionally, on secondary address promotion consider the addresses
777 * from subnet iprim as deleted, even if they are in device list.
778 * In this case the secondary ifa can be in device list.
779 */
780void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
781{
782 struct in_device *in_dev = ifa->ifa_dev;
783 struct net_device *dev = in_dev->dev;
784 struct in_ifaddr *ifa1;
785 struct in_ifaddr *prim = ifa, *prim1 = NULL;
786 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
787 __be32 any = ifa->ifa_address & ifa->ifa_mask;
788#define LOCAL_OK 1
789#define BRD_OK 2
790#define BRD0_OK 4
791#define BRD1_OK 8
792 unsigned int ok = 0;
793 int subnet = 0; /* Primary network */
794 int gone = 1; /* Address is missing */
795 int same_prefsrc = 0; /* Another primary with same IP */
796
797 if (ifa->ifa_flags & IFA_F_SECONDARY) {
798 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
799 if (prim == NULL) {
800 pr_warn("%s: bug: prim == NULL\n", __func__);
801 return;
802 }
803 if (iprim && iprim != prim) {
804 pr_warn("%s: bug: iprim != prim\n", __func__);
805 return;
806 }
807 } else if (!ipv4_is_zeronet(any) &&
808 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
809 fib_magic(RTM_DELROUTE,
810 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
811 any, ifa->ifa_prefixlen, prim);
812 subnet = 1;
813 }
814
815 /* Deletion is more complicated than add.
816 * We should take care of not to delete too much :-)
817 *
818 * Scan address list to be sure that addresses are really gone.
819 */
820
821 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
822 if (ifa1 == ifa) {
823 /* promotion, keep the IP */
824 gone = 0;
825 continue;
826 }
827 /* Ignore IFAs from our subnet */
828 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
829 inet_ifa_match(ifa1->ifa_address, iprim))
830 continue;
831
832 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
833 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
834 /* Another address from our subnet? */
835 if (ifa1->ifa_mask == prim->ifa_mask &&
836 inet_ifa_match(ifa1->ifa_address, prim))
837 prim1 = prim;
838 else {
839 /* We reached the secondaries, so
840 * same_prefsrc should be determined.
841 */
842 if (!same_prefsrc)
843 continue;
844 /* Search new prim1 if ifa1 is not
845 * using the current prim1
846 */
847 if (!prim1 ||
848 ifa1->ifa_mask != prim1->ifa_mask ||
849 !inet_ifa_match(ifa1->ifa_address, prim1))
850 prim1 = inet_ifa_byprefix(in_dev,
851 ifa1->ifa_address,
852 ifa1->ifa_mask);
853 if (!prim1)
854 continue;
855 if (prim1->ifa_local != prim->ifa_local)
856 continue;
857 }
858 } else {
859 if (prim->ifa_local != ifa1->ifa_local)
860 continue;
861 prim1 = ifa1;
862 if (prim != prim1)
863 same_prefsrc = 1;
864 }
865 if (ifa->ifa_local == ifa1->ifa_local)
866 ok |= LOCAL_OK;
867 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
868 ok |= BRD_OK;
869 if (brd == ifa1->ifa_broadcast)
870 ok |= BRD1_OK;
871 if (any == ifa1->ifa_broadcast)
872 ok |= BRD0_OK;
873 /* primary has network specific broadcasts */
874 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
875 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
876 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
877
878 if (!ipv4_is_zeronet(any1)) {
879 if (ifa->ifa_broadcast == brd1 ||
880 ifa->ifa_broadcast == any1)
881 ok |= BRD_OK;
882 if (brd == brd1 || brd == any1)
883 ok |= BRD1_OK;
884 if (any == brd1 || any == any1)
885 ok |= BRD0_OK;
886 }
887 }
888 }
889
890 if (!(ok & BRD_OK))
891 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
892 if (subnet && ifa->ifa_prefixlen < 31) {
893 if (!(ok & BRD1_OK))
894 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
895 if (!(ok & BRD0_OK))
896 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
897 }
898 if (!(ok & LOCAL_OK)) {
899 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
900
901 /* Check, that this local address finally disappeared. */
902 if (gone &&
903 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
904 /* And the last, but not the least thing.
905 * We must flush stray FIB entries.
906 *
907 * First of all, we scan fib_info list searching
908 * for stray nexthop entries, then ignite fib_flush.
909 */
910 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
911 fib_flush(dev_net(dev));
912 }
913 }
914#undef LOCAL_OK
915#undef BRD_OK
916#undef BRD0_OK
917#undef BRD1_OK
918}
919
920static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
921{
922
923 struct fib_result res;
924 struct flowi4 fl4 = {
925 .flowi4_mark = frn->fl_mark,
926 .daddr = frn->fl_addr,
927 .flowi4_tos = frn->fl_tos,
928 .flowi4_scope = frn->fl_scope,
929 };
930
931 frn->err = -ENOENT;
932 if (tb) {
933 local_bh_disable();
934
935 frn->tb_id = tb->tb_id;
936 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
937
938 if (!frn->err) {
939 frn->prefixlen = res.prefixlen;
940 frn->nh_sel = res.nh_sel;
941 frn->type = res.type;
942 frn->scope = res.scope;
943 }
944 local_bh_enable();
945 }
946}
947
948static void nl_fib_input(struct sk_buff *skb)
949{
950 struct net *net;
951 struct fib_result_nl *frn;
952 struct nlmsghdr *nlh;
953 struct fib_table *tb;
954 u32 portid;
955
956 net = sock_net(skb->sk);
957 nlh = nlmsg_hdr(skb);
958 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
959 nlmsg_len(nlh) < sizeof(*frn))
960 return;
961
962 skb = netlink_skb_clone(skb, GFP_KERNEL);
963 if (skb == NULL)
964 return;
965 nlh = nlmsg_hdr(skb);
966
967 frn = (struct fib_result_nl *) nlmsg_data(nlh);
968 tb = fib_get_table(net, frn->tb_id_in);
969
970 nl_fib_lookup(frn, tb);
971
972 portid = NETLINK_CB(skb).portid; /* netlink portid */
973 NETLINK_CB(skb).portid = 0; /* from kernel */
974 NETLINK_CB(skb).dst_group = 0; /* unicast */
975 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
976}
977
978static int __net_init nl_fib_lookup_init(struct net *net)
979{
980 struct sock *sk;
981 struct netlink_kernel_cfg cfg = {
982 .input = nl_fib_input,
983 };
984
985 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
986 if (sk == NULL)
987 return -EAFNOSUPPORT;
988 net->ipv4.fibnl = sk;
989 return 0;
990}
991
992static void nl_fib_lookup_exit(struct net *net)
993{
994 netlink_kernel_release(net->ipv4.fibnl);
995 net->ipv4.fibnl = NULL;
996}
997
998static void fib_disable_ip(struct net_device *dev, int force)
999{
1000 if (fib_sync_down_dev(dev, force))
1001 fib_flush(dev_net(dev));
1002 rt_cache_flush(dev_net(dev));
1003 arp_ifdown(dev);
1004}
1005
1006static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1007{
1008 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1009 struct net_device *dev = ifa->ifa_dev->dev;
1010 struct net *net = dev_net(dev);
1011
1012 switch (event) {
1013 case NETDEV_UP:
1014 fib_add_ifaddr(ifa);
1015#ifdef CONFIG_IP_ROUTE_MULTIPATH
1016 fib_sync_up(dev);
1017#endif
1018 atomic_inc(&net->ipv4.dev_addr_genid);
1019 rt_cache_flush(dev_net(dev));
1020 break;
1021 case NETDEV_DOWN:
1022 fib_del_ifaddr(ifa, NULL);
1023 atomic_inc(&net->ipv4.dev_addr_genid);
1024 if (ifa->ifa_dev->ifa_list == NULL) {
1025 /* Last address was deleted from this interface.
1026 * Disable IP.
1027 */
1028 fib_disable_ip(dev, 1);
1029 } else {
1030 rt_cache_flush(dev_net(dev));
1031 }
1032 break;
1033 }
1034 return NOTIFY_DONE;
1035}
1036
1037static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1038{
1039 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1040 struct in_device *in_dev;
1041 struct net *net = dev_net(dev);
1042
1043 if (event == NETDEV_UNREGISTER) {
1044 fib_disable_ip(dev, 2);
1045 rt_flush_dev(dev);
1046 return NOTIFY_DONE;
1047 }
1048
1049 in_dev = __in_dev_get_rtnl(dev);
1050 if (!in_dev)
1051 return NOTIFY_DONE;
1052
1053 switch (event) {
1054 case NETDEV_UP:
1055 for_ifa(in_dev) {
1056 fib_add_ifaddr(ifa);
1057 } endfor_ifa(in_dev);
1058#ifdef CONFIG_IP_ROUTE_MULTIPATH
1059 fib_sync_up(dev);
1060#endif
1061 atomic_inc(&net->ipv4.dev_addr_genid);
1062 rt_cache_flush(net);
1063 break;
1064 case NETDEV_DOWN:
1065 fib_disable_ip(dev, 0);
1066 break;
1067 case NETDEV_CHANGEMTU:
1068 case NETDEV_CHANGE:
1069 rt_cache_flush(net);
1070 break;
1071 }
1072 return NOTIFY_DONE;
1073}
1074
1075static struct notifier_block fib_inetaddr_notifier = {
1076 .notifier_call = fib_inetaddr_event,
1077};
1078
1079static struct notifier_block fib_netdev_notifier = {
1080 .notifier_call = fib_netdev_event,
1081};
1082
1083static int __net_init ip_fib_net_init(struct net *net)
1084{
1085 int err;
1086 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1087
1088 /* Avoid false sharing : Use at least a full cache line */
1089 size = max_t(size_t, size, L1_CACHE_BYTES);
1090
1091 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1092 if (net->ipv4.fib_table_hash == NULL)
1093 return -ENOMEM;
1094
1095 err = fib4_rules_init(net);
1096 if (err < 0)
1097 goto fail;
1098 return 0;
1099
1100fail:
1101 kfree(net->ipv4.fib_table_hash);
1102 return err;
1103}
1104
1105static void ip_fib_net_exit(struct net *net)
1106{
1107 unsigned int i;
1108
1109#ifdef CONFIG_IP_MULTIPLE_TABLES
1110 fib4_rules_exit(net);
1111#endif
1112
1113 rtnl_lock();
1114 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1115 struct fib_table *tb;
1116 struct hlist_head *head;
1117 struct hlist_node *tmp;
1118
1119 head = &net->ipv4.fib_table_hash[i];
1120 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1121 hlist_del(&tb->tb_hlist);
1122 fib_table_flush(tb);
1123 fib_free_table(tb);
1124 }
1125 }
1126 rtnl_unlock();
1127 kfree(net->ipv4.fib_table_hash);
1128}
1129
1130static int __net_init fib_net_init(struct net *net)
1131{
1132 int error;
1133
1134#ifdef CONFIG_IP_ROUTE_CLASSID
1135 net->ipv4.fib_num_tclassid_users = 0;
1136#endif
1137 error = ip_fib_net_init(net);
1138 if (error < 0)
1139 goto out;
1140 error = nl_fib_lookup_init(net);
1141 if (error < 0)
1142 goto out_nlfl;
1143 error = fib_proc_init(net);
1144 if (error < 0)
1145 goto out_proc;
1146out:
1147 return error;
1148
1149out_proc:
1150 nl_fib_lookup_exit(net);
1151out_nlfl:
1152 ip_fib_net_exit(net);
1153 goto out;
1154}
1155
1156static void __net_exit fib_net_exit(struct net *net)
1157{
1158 fib_proc_exit(net);
1159 nl_fib_lookup_exit(net);
1160 ip_fib_net_exit(net);
1161}
1162
1163static struct pernet_operations fib_net_ops = {
1164 .init = fib_net_init,
1165 .exit = fib_net_exit,
1166};
1167
1168void __init ip_fib_init(void)
1169{
1170 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1171 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1172 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1173
1174 register_pernet_subsys(&fib_net_ops);
1175 register_netdevice_notifier(&fib_netdev_notifier);
1176 register_inetaddr_notifier(&fib_inetaddr_notifier);
1177
1178 fib_trie_init();
1179}
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 <net/lwtunnel.h>
50#include <trace/events/fib.h>
51
52#ifndef CONFIG_IP_MULTIPLE_TABLES
53
54static int __net_init fib4_rules_init(struct net *net)
55{
56 struct fib_table *local_table, *main_table;
57
58 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
59 if (!main_table)
60 return -ENOMEM;
61
62 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
63 if (!local_table)
64 goto fail;
65
66 hlist_add_head_rcu(&local_table->tb_hlist,
67 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
68 hlist_add_head_rcu(&main_table->tb_hlist,
69 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
70 return 0;
71
72fail:
73 fib_free_table(main_table);
74 return -ENOMEM;
75}
76
77static bool fib4_has_custom_rules(struct net *net)
78{
79 return false;
80}
81#else
82
83struct fib_table *fib_new_table(struct net *net, u32 id)
84{
85 struct fib_table *tb, *alias = NULL;
86 unsigned int h;
87
88 if (id == 0)
89 id = RT_TABLE_MAIN;
90 tb = fib_get_table(net, id);
91 if (tb)
92 return tb;
93
94 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
95 alias = fib_new_table(net, RT_TABLE_MAIN);
96
97 tb = fib_trie_table(id, alias);
98 if (!tb)
99 return NULL;
100
101 switch (id) {
102 case RT_TABLE_MAIN:
103 rcu_assign_pointer(net->ipv4.fib_main, tb);
104 break;
105 case RT_TABLE_DEFAULT:
106 rcu_assign_pointer(net->ipv4.fib_default, tb);
107 break;
108 default:
109 break;
110 }
111
112 h = id & (FIB_TABLE_HASHSZ - 1);
113 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
114 return tb;
115}
116EXPORT_SYMBOL_GPL(fib_new_table);
117
118/* caller must hold either rtnl or rcu read lock */
119struct fib_table *fib_get_table(struct net *net, u32 id)
120{
121 struct fib_table *tb;
122 struct hlist_head *head;
123 unsigned int h;
124
125 if (id == 0)
126 id = RT_TABLE_MAIN;
127 h = id & (FIB_TABLE_HASHSZ - 1);
128
129 head = &net->ipv4.fib_table_hash[h];
130 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
131 if (tb->tb_id == id)
132 return tb;
133 }
134 return NULL;
135}
136
137static bool fib4_has_custom_rules(struct net *net)
138{
139 return net->ipv4.fib_has_custom_rules;
140}
141#endif /* CONFIG_IP_MULTIPLE_TABLES */
142
143static void fib_replace_table(struct net *net, struct fib_table *old,
144 struct fib_table *new)
145{
146#ifdef CONFIG_IP_MULTIPLE_TABLES
147 switch (new->tb_id) {
148 case RT_TABLE_MAIN:
149 rcu_assign_pointer(net->ipv4.fib_main, new);
150 break;
151 case RT_TABLE_DEFAULT:
152 rcu_assign_pointer(net->ipv4.fib_default, new);
153 break;
154 default:
155 break;
156 }
157
158#endif
159 /* replace the old table in the hlist */
160 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
161}
162
163int fib_unmerge(struct net *net)
164{
165 struct fib_table *old, *new, *main_table;
166
167 /* attempt to fetch local table if it has been allocated */
168 old = fib_get_table(net, RT_TABLE_LOCAL);
169 if (!old)
170 return 0;
171
172 new = fib_trie_unmerge(old);
173 if (!new)
174 return -ENOMEM;
175
176 /* table is already unmerged */
177 if (new == old)
178 return 0;
179
180 /* replace merged table with clean table */
181 fib_replace_table(net, old, new);
182 fib_free_table(old);
183
184 /* attempt to fetch main table if it has been allocated */
185 main_table = fib_get_table(net, RT_TABLE_MAIN);
186 if (!main_table)
187 return 0;
188
189 /* flush local entries from main table */
190 fib_table_flush_external(main_table);
191
192 return 0;
193}
194
195static void fib_flush(struct net *net)
196{
197 int flushed = 0;
198 unsigned int h;
199
200 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
201 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
202 struct hlist_node *tmp;
203 struct fib_table *tb;
204
205 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
206 flushed += fib_table_flush(net, tb);
207 }
208
209 if (flushed)
210 rt_cache_flush(net);
211}
212
213/*
214 * Find address type as if only "dev" was present in the system. If
215 * on_dev is NULL then all interfaces are taken into consideration.
216 */
217static inline unsigned int __inet_dev_addr_type(struct net *net,
218 const struct net_device *dev,
219 __be32 addr, u32 tb_id)
220{
221 struct flowi4 fl4 = { .daddr = addr };
222 struct fib_result res;
223 unsigned int ret = RTN_BROADCAST;
224 struct fib_table *table;
225
226 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
227 return RTN_BROADCAST;
228 if (ipv4_is_multicast(addr))
229 return RTN_MULTICAST;
230
231 rcu_read_lock();
232
233 table = fib_get_table(net, tb_id);
234 if (table) {
235 ret = RTN_UNICAST;
236 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
237 if (!dev || dev == res.fi->fib_dev)
238 ret = res.type;
239 }
240 }
241
242 rcu_read_unlock();
243 return ret;
244}
245
246unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
247{
248 return __inet_dev_addr_type(net, NULL, addr, tb_id);
249}
250EXPORT_SYMBOL(inet_addr_type_table);
251
252unsigned int inet_addr_type(struct net *net, __be32 addr)
253{
254 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
255}
256EXPORT_SYMBOL(inet_addr_type);
257
258unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
259 __be32 addr)
260{
261 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
262
263 return __inet_dev_addr_type(net, dev, addr, rt_table);
264}
265EXPORT_SYMBOL(inet_dev_addr_type);
266
267/* inet_addr_type with dev == NULL but using the table from a dev
268 * if one is associated
269 */
270unsigned int inet_addr_type_dev_table(struct net *net,
271 const struct net_device *dev,
272 __be32 addr)
273{
274 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
275
276 return __inet_dev_addr_type(net, NULL, addr, rt_table);
277}
278EXPORT_SYMBOL(inet_addr_type_dev_table);
279
280__be32 fib_compute_spec_dst(struct sk_buff *skb)
281{
282 struct net_device *dev = skb->dev;
283 struct in_device *in_dev;
284 struct fib_result res;
285 struct rtable *rt;
286 struct net *net;
287 int scope;
288
289 rt = skb_rtable(skb);
290 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
291 RTCF_LOCAL)
292 return ip_hdr(skb)->daddr;
293
294 in_dev = __in_dev_get_rcu(dev);
295 BUG_ON(!in_dev);
296
297 net = dev_net(dev);
298
299 scope = RT_SCOPE_UNIVERSE;
300 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
301 struct flowi4 fl4 = {
302 .flowi4_iif = LOOPBACK_IFINDEX,
303 .daddr = ip_hdr(skb)->saddr,
304 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
305 .flowi4_scope = scope,
306 .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
307 };
308 if (!fib_lookup(net, &fl4, &res, 0))
309 return FIB_RES_PREFSRC(net, res);
310 } else {
311 scope = RT_SCOPE_LINK;
312 }
313
314 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
315}
316
317/* Given (packet source, input interface) and optional (dst, oif, tos):
318 * - (main) check, that source is valid i.e. not broadcast or our local
319 * address.
320 * - figure out what "logical" interface this packet arrived
321 * and calculate "specific destination" address.
322 * - check, that packet arrived from expected physical interface.
323 * called with rcu_read_lock()
324 */
325static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
326 u8 tos, int oif, struct net_device *dev,
327 int rpf, struct in_device *idev, u32 *itag)
328{
329 struct net *net = dev_net(dev);
330 struct flow_keys flkeys;
331 int ret, no_addr;
332 struct fib_result res;
333 struct flowi4 fl4;
334 bool dev_match;
335
336 fl4.flowi4_oif = 0;
337 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
338 if (!fl4.flowi4_iif)
339 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
340 fl4.daddr = src;
341 fl4.saddr = dst;
342 fl4.flowi4_tos = tos;
343 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
344 fl4.flowi4_tun_key.tun_id = 0;
345 fl4.flowi4_flags = 0;
346 fl4.flowi4_uid = sock_net_uid(net, NULL);
347
348 no_addr = idev->ifa_list == NULL;
349
350 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
351 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
352 fl4.flowi4_proto = 0;
353 fl4.fl4_sport = 0;
354 fl4.fl4_dport = 0;
355 }
356
357 trace_fib_validate_source(dev, &fl4);
358
359 if (fib_lookup(net, &fl4, &res, 0))
360 goto last_resort;
361 if (res.type != RTN_UNICAST &&
362 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
363 goto e_inval;
364 fib_combine_itag(itag, &res);
365 dev_match = false;
366
367#ifdef CONFIG_IP_ROUTE_MULTIPATH
368 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
369 struct fib_nh *nh = &res.fi->fib_nh[ret];
370
371 if (nh->nh_dev == dev) {
372 dev_match = true;
373 break;
374 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
375 dev_match = true;
376 break;
377 }
378 }
379#else
380 if (FIB_RES_DEV(res) == dev)
381 dev_match = true;
382#endif
383 if (dev_match) {
384 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
385 return ret;
386 }
387 if (no_addr)
388 goto last_resort;
389 if (rpf == 1)
390 goto e_rpf;
391 fl4.flowi4_oif = dev->ifindex;
392
393 ret = 0;
394 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
395 if (res.type == RTN_UNICAST)
396 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
397 }
398 return ret;
399
400last_resort:
401 if (rpf)
402 goto e_rpf;
403 *itag = 0;
404 return 0;
405
406e_inval:
407 return -EINVAL;
408e_rpf:
409 return -EXDEV;
410}
411
412/* Ignore rp_filter for packets protected by IPsec. */
413int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
414 u8 tos, int oif, struct net_device *dev,
415 struct in_device *idev, u32 *itag)
416{
417 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
418 struct net *net = dev_net(dev);
419
420 if (!r && !fib_num_tclassid_users(net) &&
421 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
422 if (IN_DEV_ACCEPT_LOCAL(idev))
423 goto ok;
424 /* with custom local routes in place, checking local addresses
425 * only will be too optimistic, with custom rules, checking
426 * local addresses only can be too strict, e.g. due to vrf
427 */
428 if (net->ipv4.fib_has_custom_local_routes ||
429 fib4_has_custom_rules(net))
430 goto full_check;
431 if (inet_lookup_ifaddr_rcu(net, src))
432 return -EINVAL;
433
434ok:
435 *itag = 0;
436 return 0;
437 }
438
439full_check:
440 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
441}
442
443static inline __be32 sk_extract_addr(struct sockaddr *addr)
444{
445 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
446}
447
448static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
449{
450 struct nlattr *nla;
451
452 nla = (struct nlattr *) ((char *) mx + len);
453 nla->nla_type = type;
454 nla->nla_len = nla_attr_size(4);
455 *(u32 *) nla_data(nla) = value;
456
457 return len + nla_total_size(4);
458}
459
460static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
461 struct fib_config *cfg)
462{
463 __be32 addr;
464 int plen;
465
466 memset(cfg, 0, sizeof(*cfg));
467 cfg->fc_nlinfo.nl_net = net;
468
469 if (rt->rt_dst.sa_family != AF_INET)
470 return -EAFNOSUPPORT;
471
472 /*
473 * Check mask for validity:
474 * a) it must be contiguous.
475 * b) destination must have all host bits clear.
476 * c) if application forgot to set correct family (AF_INET),
477 * reject request unless it is absolutely clear i.e.
478 * both family and mask are zero.
479 */
480 plen = 32;
481 addr = sk_extract_addr(&rt->rt_dst);
482 if (!(rt->rt_flags & RTF_HOST)) {
483 __be32 mask = sk_extract_addr(&rt->rt_genmask);
484
485 if (rt->rt_genmask.sa_family != AF_INET) {
486 if (mask || rt->rt_genmask.sa_family)
487 return -EAFNOSUPPORT;
488 }
489
490 if (bad_mask(mask, addr))
491 return -EINVAL;
492
493 plen = inet_mask_len(mask);
494 }
495
496 cfg->fc_dst_len = plen;
497 cfg->fc_dst = addr;
498
499 if (cmd != SIOCDELRT) {
500 cfg->fc_nlflags = NLM_F_CREATE;
501 cfg->fc_protocol = RTPROT_BOOT;
502 }
503
504 if (rt->rt_metric)
505 cfg->fc_priority = rt->rt_metric - 1;
506
507 if (rt->rt_flags & RTF_REJECT) {
508 cfg->fc_scope = RT_SCOPE_HOST;
509 cfg->fc_type = RTN_UNREACHABLE;
510 return 0;
511 }
512
513 cfg->fc_scope = RT_SCOPE_NOWHERE;
514 cfg->fc_type = RTN_UNICAST;
515
516 if (rt->rt_dev) {
517 char *colon;
518 struct net_device *dev;
519 char devname[IFNAMSIZ];
520
521 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
522 return -EFAULT;
523
524 devname[IFNAMSIZ-1] = 0;
525 colon = strchr(devname, ':');
526 if (colon)
527 *colon = 0;
528 dev = __dev_get_by_name(net, devname);
529 if (!dev)
530 return -ENODEV;
531 cfg->fc_oif = dev->ifindex;
532 cfg->fc_table = l3mdev_fib_table(dev);
533 if (colon) {
534 struct in_ifaddr *ifa;
535 struct in_device *in_dev = __in_dev_get_rtnl(dev);
536 if (!in_dev)
537 return -ENODEV;
538 *colon = ':';
539 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
540 if (strcmp(ifa->ifa_label, devname) == 0)
541 break;
542 if (!ifa)
543 return -ENODEV;
544 cfg->fc_prefsrc = ifa->ifa_local;
545 }
546 }
547
548 addr = sk_extract_addr(&rt->rt_gateway);
549 if (rt->rt_gateway.sa_family == AF_INET && addr) {
550 unsigned int addr_type;
551
552 cfg->fc_gw = addr;
553 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
554 if (rt->rt_flags & RTF_GATEWAY &&
555 addr_type == RTN_UNICAST)
556 cfg->fc_scope = RT_SCOPE_UNIVERSE;
557 }
558
559 if (cmd == SIOCDELRT)
560 return 0;
561
562 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
563 return -EINVAL;
564
565 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
566 cfg->fc_scope = RT_SCOPE_LINK;
567
568 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
569 struct nlattr *mx;
570 int len = 0;
571
572 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
573 if (!mx)
574 return -ENOMEM;
575
576 if (rt->rt_flags & RTF_MTU)
577 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
578
579 if (rt->rt_flags & RTF_WINDOW)
580 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
581
582 if (rt->rt_flags & RTF_IRTT)
583 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
584
585 cfg->fc_mx = mx;
586 cfg->fc_mx_len = len;
587 }
588
589 return 0;
590}
591
592/*
593 * Handle IP routing ioctl calls.
594 * These are used to manipulate the routing tables
595 */
596int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
597{
598 struct fib_config cfg;
599 int err;
600
601 switch (cmd) {
602 case SIOCADDRT: /* Add a route */
603 case SIOCDELRT: /* Delete a route */
604 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
605 return -EPERM;
606
607 rtnl_lock();
608 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
609 if (err == 0) {
610 struct fib_table *tb;
611
612 if (cmd == SIOCDELRT) {
613 tb = fib_get_table(net, cfg.fc_table);
614 if (tb)
615 err = fib_table_delete(net, tb, &cfg,
616 NULL);
617 else
618 err = -ESRCH;
619 } else {
620 tb = fib_new_table(net, cfg.fc_table);
621 if (tb)
622 err = fib_table_insert(net, tb,
623 &cfg, NULL);
624 else
625 err = -ENOBUFS;
626 }
627
628 /* allocated by rtentry_to_fib_config() */
629 kfree(cfg.fc_mx);
630 }
631 rtnl_unlock();
632 return err;
633 }
634 return -EINVAL;
635}
636
637const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
638 [RTA_DST] = { .type = NLA_U32 },
639 [RTA_SRC] = { .type = NLA_U32 },
640 [RTA_IIF] = { .type = NLA_U32 },
641 [RTA_OIF] = { .type = NLA_U32 },
642 [RTA_GATEWAY] = { .type = NLA_U32 },
643 [RTA_PRIORITY] = { .type = NLA_U32 },
644 [RTA_PREFSRC] = { .type = NLA_U32 },
645 [RTA_METRICS] = { .type = NLA_NESTED },
646 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
647 [RTA_FLOW] = { .type = NLA_U32 },
648 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
649 [RTA_ENCAP] = { .type = NLA_NESTED },
650 [RTA_UID] = { .type = NLA_U32 },
651 [RTA_MARK] = { .type = NLA_U32 },
652 [RTA_TABLE] = { .type = NLA_U32 },
653};
654
655static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
656 struct nlmsghdr *nlh, struct fib_config *cfg,
657 struct netlink_ext_ack *extack)
658{
659 struct nlattr *attr;
660 int err, remaining;
661 struct rtmsg *rtm;
662
663 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
664 extack);
665 if (err < 0)
666 goto errout;
667
668 memset(cfg, 0, sizeof(*cfg));
669
670 rtm = nlmsg_data(nlh);
671 cfg->fc_dst_len = rtm->rtm_dst_len;
672 cfg->fc_tos = rtm->rtm_tos;
673 cfg->fc_table = rtm->rtm_table;
674 cfg->fc_protocol = rtm->rtm_protocol;
675 cfg->fc_scope = rtm->rtm_scope;
676 cfg->fc_type = rtm->rtm_type;
677 cfg->fc_flags = rtm->rtm_flags;
678 cfg->fc_nlflags = nlh->nlmsg_flags;
679
680 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
681 cfg->fc_nlinfo.nlh = nlh;
682 cfg->fc_nlinfo.nl_net = net;
683
684 if (cfg->fc_type > RTN_MAX) {
685 NL_SET_ERR_MSG(extack, "Invalid route type");
686 err = -EINVAL;
687 goto errout;
688 }
689
690 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
691 switch (nla_type(attr)) {
692 case RTA_DST:
693 cfg->fc_dst = nla_get_be32(attr);
694 break;
695 case RTA_OIF:
696 cfg->fc_oif = nla_get_u32(attr);
697 break;
698 case RTA_GATEWAY:
699 cfg->fc_gw = nla_get_be32(attr);
700 break;
701 case RTA_PRIORITY:
702 cfg->fc_priority = nla_get_u32(attr);
703 break;
704 case RTA_PREFSRC:
705 cfg->fc_prefsrc = nla_get_be32(attr);
706 break;
707 case RTA_METRICS:
708 cfg->fc_mx = nla_data(attr);
709 cfg->fc_mx_len = nla_len(attr);
710 break;
711 case RTA_MULTIPATH:
712 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
713 nla_len(attr),
714 extack);
715 if (err < 0)
716 goto errout;
717 cfg->fc_mp = nla_data(attr);
718 cfg->fc_mp_len = nla_len(attr);
719 break;
720 case RTA_FLOW:
721 cfg->fc_flow = nla_get_u32(attr);
722 break;
723 case RTA_TABLE:
724 cfg->fc_table = nla_get_u32(attr);
725 break;
726 case RTA_ENCAP:
727 cfg->fc_encap = attr;
728 break;
729 case RTA_ENCAP_TYPE:
730 cfg->fc_encap_type = nla_get_u16(attr);
731 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
732 extack);
733 if (err < 0)
734 goto errout;
735 break;
736 }
737 }
738
739 return 0;
740errout:
741 return err;
742}
743
744static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
745 struct netlink_ext_ack *extack)
746{
747 struct net *net = sock_net(skb->sk);
748 struct fib_config cfg;
749 struct fib_table *tb;
750 int err;
751
752 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
753 if (err < 0)
754 goto errout;
755
756 tb = fib_get_table(net, cfg.fc_table);
757 if (!tb) {
758 NL_SET_ERR_MSG(extack, "FIB table does not exist");
759 err = -ESRCH;
760 goto errout;
761 }
762
763 err = fib_table_delete(net, tb, &cfg, extack);
764errout:
765 return err;
766}
767
768static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
769 struct netlink_ext_ack *extack)
770{
771 struct net *net = sock_net(skb->sk);
772 struct fib_config cfg;
773 struct fib_table *tb;
774 int err;
775
776 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
777 if (err < 0)
778 goto errout;
779
780 tb = fib_new_table(net, cfg.fc_table);
781 if (!tb) {
782 err = -ENOBUFS;
783 goto errout;
784 }
785
786 err = fib_table_insert(net, tb, &cfg, extack);
787 if (!err && cfg.fc_type == RTN_LOCAL)
788 net->ipv4.fib_has_custom_local_routes = true;
789errout:
790 return err;
791}
792
793static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
794{
795 struct net *net = sock_net(skb->sk);
796 unsigned int h, s_h;
797 unsigned int e = 0, s_e;
798 struct fib_table *tb;
799 struct hlist_head *head;
800 int dumped = 0, err;
801
802 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
803 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
804 return skb->len;
805
806 s_h = cb->args[0];
807 s_e = cb->args[1];
808
809 rcu_read_lock();
810
811 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
812 e = 0;
813 head = &net->ipv4.fib_table_hash[h];
814 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
815 if (e < s_e)
816 goto next;
817 if (dumped)
818 memset(&cb->args[2], 0, sizeof(cb->args) -
819 2 * sizeof(cb->args[0]));
820 err = fib_table_dump(tb, skb, cb);
821 if (err < 0) {
822 if (likely(skb->len))
823 goto out;
824
825 goto out_err;
826 }
827 dumped = 1;
828next:
829 e++;
830 }
831 }
832out:
833 err = skb->len;
834out_err:
835 rcu_read_unlock();
836
837 cb->args[1] = e;
838 cb->args[0] = h;
839
840 return err;
841}
842
843/* Prepare and feed intra-kernel routing request.
844 * Really, it should be netlink message, but :-( netlink
845 * can be not configured, so that we feed it directly
846 * to fib engine. It is legal, because all events occur
847 * only when netlink is already locked.
848 */
849static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
850{
851 struct net *net = dev_net(ifa->ifa_dev->dev);
852 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
853 struct fib_table *tb;
854 struct fib_config cfg = {
855 .fc_protocol = RTPROT_KERNEL,
856 .fc_type = type,
857 .fc_dst = dst,
858 .fc_dst_len = dst_len,
859 .fc_prefsrc = ifa->ifa_local,
860 .fc_oif = ifa->ifa_dev->dev->ifindex,
861 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
862 .fc_nlinfo = {
863 .nl_net = net,
864 },
865 };
866
867 if (!tb_id)
868 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
869
870 tb = fib_new_table(net, tb_id);
871 if (!tb)
872 return;
873
874 cfg.fc_table = tb->tb_id;
875
876 if (type != RTN_LOCAL)
877 cfg.fc_scope = RT_SCOPE_LINK;
878 else
879 cfg.fc_scope = RT_SCOPE_HOST;
880
881 if (cmd == RTM_NEWROUTE)
882 fib_table_insert(net, tb, &cfg, NULL);
883 else
884 fib_table_delete(net, tb, &cfg, NULL);
885}
886
887void fib_add_ifaddr(struct in_ifaddr *ifa)
888{
889 struct in_device *in_dev = ifa->ifa_dev;
890 struct net_device *dev = in_dev->dev;
891 struct in_ifaddr *prim = ifa;
892 __be32 mask = ifa->ifa_mask;
893 __be32 addr = ifa->ifa_local;
894 __be32 prefix = ifa->ifa_address & mask;
895
896 if (ifa->ifa_flags & IFA_F_SECONDARY) {
897 prim = inet_ifa_byprefix(in_dev, prefix, mask);
898 if (!prim) {
899 pr_warn("%s: bug: prim == NULL\n", __func__);
900 return;
901 }
902 }
903
904 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
905
906 if (!(dev->flags & IFF_UP))
907 return;
908
909 /* Add broadcast address, if it is explicitly assigned. */
910 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
911 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
912
913 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
914 (prefix != addr || ifa->ifa_prefixlen < 32)) {
915 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
916 fib_magic(RTM_NEWROUTE,
917 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
918 prefix, ifa->ifa_prefixlen, prim);
919
920 /* Add network specific broadcasts, when it takes a sense */
921 if (ifa->ifa_prefixlen < 31) {
922 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
923 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
924 32, prim);
925 }
926 }
927}
928
929/* Delete primary or secondary address.
930 * Optionally, on secondary address promotion consider the addresses
931 * from subnet iprim as deleted, even if they are in device list.
932 * In this case the secondary ifa can be in device list.
933 */
934void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
935{
936 struct in_device *in_dev = ifa->ifa_dev;
937 struct net_device *dev = in_dev->dev;
938 struct in_ifaddr *ifa1;
939 struct in_ifaddr *prim = ifa, *prim1 = NULL;
940 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
941 __be32 any = ifa->ifa_address & ifa->ifa_mask;
942#define LOCAL_OK 1
943#define BRD_OK 2
944#define BRD0_OK 4
945#define BRD1_OK 8
946 unsigned int ok = 0;
947 int subnet = 0; /* Primary network */
948 int gone = 1; /* Address is missing */
949 int same_prefsrc = 0; /* Another primary with same IP */
950
951 if (ifa->ifa_flags & IFA_F_SECONDARY) {
952 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
953 if (!prim) {
954 /* if the device has been deleted, we don't perform
955 * address promotion
956 */
957 if (!in_dev->dead)
958 pr_warn("%s: bug: prim == NULL\n", __func__);
959 return;
960 }
961 if (iprim && iprim != prim) {
962 pr_warn("%s: bug: iprim != prim\n", __func__);
963 return;
964 }
965 } else if (!ipv4_is_zeronet(any) &&
966 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
967 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
968 fib_magic(RTM_DELROUTE,
969 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
970 any, ifa->ifa_prefixlen, prim);
971 subnet = 1;
972 }
973
974 if (in_dev->dead)
975 goto no_promotions;
976
977 /* Deletion is more complicated than add.
978 * We should take care of not to delete too much :-)
979 *
980 * Scan address list to be sure that addresses are really gone.
981 */
982
983 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
984 if (ifa1 == ifa) {
985 /* promotion, keep the IP */
986 gone = 0;
987 continue;
988 }
989 /* Ignore IFAs from our subnet */
990 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
991 inet_ifa_match(ifa1->ifa_address, iprim))
992 continue;
993
994 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
995 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
996 /* Another address from our subnet? */
997 if (ifa1->ifa_mask == prim->ifa_mask &&
998 inet_ifa_match(ifa1->ifa_address, prim))
999 prim1 = prim;
1000 else {
1001 /* We reached the secondaries, so
1002 * same_prefsrc should be determined.
1003 */
1004 if (!same_prefsrc)
1005 continue;
1006 /* Search new prim1 if ifa1 is not
1007 * using the current prim1
1008 */
1009 if (!prim1 ||
1010 ifa1->ifa_mask != prim1->ifa_mask ||
1011 !inet_ifa_match(ifa1->ifa_address, prim1))
1012 prim1 = inet_ifa_byprefix(in_dev,
1013 ifa1->ifa_address,
1014 ifa1->ifa_mask);
1015 if (!prim1)
1016 continue;
1017 if (prim1->ifa_local != prim->ifa_local)
1018 continue;
1019 }
1020 } else {
1021 if (prim->ifa_local != ifa1->ifa_local)
1022 continue;
1023 prim1 = ifa1;
1024 if (prim != prim1)
1025 same_prefsrc = 1;
1026 }
1027 if (ifa->ifa_local == ifa1->ifa_local)
1028 ok |= LOCAL_OK;
1029 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1030 ok |= BRD_OK;
1031 if (brd == ifa1->ifa_broadcast)
1032 ok |= BRD1_OK;
1033 if (any == ifa1->ifa_broadcast)
1034 ok |= BRD0_OK;
1035 /* primary has network specific broadcasts */
1036 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1037 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1038 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1039
1040 if (!ipv4_is_zeronet(any1)) {
1041 if (ifa->ifa_broadcast == brd1 ||
1042 ifa->ifa_broadcast == any1)
1043 ok |= BRD_OK;
1044 if (brd == brd1 || brd == any1)
1045 ok |= BRD1_OK;
1046 if (any == brd1 || any == any1)
1047 ok |= BRD0_OK;
1048 }
1049 }
1050 }
1051
1052no_promotions:
1053 if (!(ok & BRD_OK))
1054 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1055 if (subnet && ifa->ifa_prefixlen < 31) {
1056 if (!(ok & BRD1_OK))
1057 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1058 if (!(ok & BRD0_OK))
1059 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1060 }
1061 if (!(ok & LOCAL_OK)) {
1062 unsigned int addr_type;
1063
1064 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1065
1066 /* Check, that this local address finally disappeared. */
1067 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1068 ifa->ifa_local);
1069 if (gone && addr_type != RTN_LOCAL) {
1070 /* And the last, but not the least thing.
1071 * We must flush stray FIB entries.
1072 *
1073 * First of all, we scan fib_info list searching
1074 * for stray nexthop entries, then ignite fib_flush.
1075 */
1076 if (fib_sync_down_addr(dev, ifa->ifa_local))
1077 fib_flush(dev_net(dev));
1078 }
1079 }
1080#undef LOCAL_OK
1081#undef BRD_OK
1082#undef BRD0_OK
1083#undef BRD1_OK
1084}
1085
1086static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1087{
1088
1089 struct fib_result res;
1090 struct flowi4 fl4 = {
1091 .flowi4_mark = frn->fl_mark,
1092 .daddr = frn->fl_addr,
1093 .flowi4_tos = frn->fl_tos,
1094 .flowi4_scope = frn->fl_scope,
1095 };
1096 struct fib_table *tb;
1097
1098 rcu_read_lock();
1099
1100 tb = fib_get_table(net, frn->tb_id_in);
1101
1102 frn->err = -ENOENT;
1103 if (tb) {
1104 local_bh_disable();
1105
1106 frn->tb_id = tb->tb_id;
1107 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1108
1109 if (!frn->err) {
1110 frn->prefixlen = res.prefixlen;
1111 frn->nh_sel = res.nh_sel;
1112 frn->type = res.type;
1113 frn->scope = res.scope;
1114 }
1115 local_bh_enable();
1116 }
1117
1118 rcu_read_unlock();
1119}
1120
1121static void nl_fib_input(struct sk_buff *skb)
1122{
1123 struct net *net;
1124 struct fib_result_nl *frn;
1125 struct nlmsghdr *nlh;
1126 u32 portid;
1127
1128 net = sock_net(skb->sk);
1129 nlh = nlmsg_hdr(skb);
1130 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1131 skb->len < nlh->nlmsg_len ||
1132 nlmsg_len(nlh) < sizeof(*frn))
1133 return;
1134
1135 skb = netlink_skb_clone(skb, GFP_KERNEL);
1136 if (!skb)
1137 return;
1138 nlh = nlmsg_hdr(skb);
1139
1140 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1141 nl_fib_lookup(net, frn);
1142
1143 portid = NETLINK_CB(skb).portid; /* netlink portid */
1144 NETLINK_CB(skb).portid = 0; /* from kernel */
1145 NETLINK_CB(skb).dst_group = 0; /* unicast */
1146 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1147}
1148
1149static int __net_init nl_fib_lookup_init(struct net *net)
1150{
1151 struct sock *sk;
1152 struct netlink_kernel_cfg cfg = {
1153 .input = nl_fib_input,
1154 };
1155
1156 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1157 if (!sk)
1158 return -EAFNOSUPPORT;
1159 net->ipv4.fibnl = sk;
1160 return 0;
1161}
1162
1163static void nl_fib_lookup_exit(struct net *net)
1164{
1165 netlink_kernel_release(net->ipv4.fibnl);
1166 net->ipv4.fibnl = NULL;
1167}
1168
1169static void fib_disable_ip(struct net_device *dev, unsigned long event,
1170 bool force)
1171{
1172 if (fib_sync_down_dev(dev, event, force))
1173 fib_flush(dev_net(dev));
1174 else
1175 rt_cache_flush(dev_net(dev));
1176 arp_ifdown(dev);
1177}
1178
1179static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1180{
1181 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1182 struct net_device *dev = ifa->ifa_dev->dev;
1183 struct net *net = dev_net(dev);
1184
1185 switch (event) {
1186 case NETDEV_UP:
1187 fib_add_ifaddr(ifa);
1188#ifdef CONFIG_IP_ROUTE_MULTIPATH
1189 fib_sync_up(dev, RTNH_F_DEAD);
1190#endif
1191 atomic_inc(&net->ipv4.dev_addr_genid);
1192 rt_cache_flush(dev_net(dev));
1193 break;
1194 case NETDEV_DOWN:
1195 fib_del_ifaddr(ifa, NULL);
1196 atomic_inc(&net->ipv4.dev_addr_genid);
1197 if (!ifa->ifa_dev->ifa_list) {
1198 /* Last address was deleted from this interface.
1199 * Disable IP.
1200 */
1201 fib_disable_ip(dev, event, true);
1202 } else {
1203 rt_cache_flush(dev_net(dev));
1204 }
1205 break;
1206 }
1207 return NOTIFY_DONE;
1208}
1209
1210static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1211{
1212 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1213 struct netdev_notifier_changeupper_info *info;
1214 struct in_device *in_dev;
1215 struct net *net = dev_net(dev);
1216 unsigned int flags;
1217
1218 if (event == NETDEV_UNREGISTER) {
1219 fib_disable_ip(dev, event, true);
1220 rt_flush_dev(dev);
1221 return NOTIFY_DONE;
1222 }
1223
1224 in_dev = __in_dev_get_rtnl(dev);
1225 if (!in_dev)
1226 return NOTIFY_DONE;
1227
1228 switch (event) {
1229 case NETDEV_UP:
1230 for_ifa(in_dev) {
1231 fib_add_ifaddr(ifa);
1232 } endfor_ifa(in_dev);
1233#ifdef CONFIG_IP_ROUTE_MULTIPATH
1234 fib_sync_up(dev, RTNH_F_DEAD);
1235#endif
1236 atomic_inc(&net->ipv4.dev_addr_genid);
1237 rt_cache_flush(net);
1238 break;
1239 case NETDEV_DOWN:
1240 fib_disable_ip(dev, event, false);
1241 break;
1242 case NETDEV_CHANGE:
1243 flags = dev_get_flags(dev);
1244 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1245 fib_sync_up(dev, RTNH_F_LINKDOWN);
1246 else
1247 fib_sync_down_dev(dev, event, false);
1248 /* fall through */
1249 case NETDEV_CHANGEMTU:
1250 rt_cache_flush(net);
1251 break;
1252 case NETDEV_CHANGEUPPER:
1253 info = ptr;
1254 /* flush all routes if dev is linked to or unlinked from
1255 * an L3 master device (e.g., VRF)
1256 */
1257 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1258 fib_disable_ip(dev, NETDEV_DOWN, true);
1259 break;
1260 }
1261 return NOTIFY_DONE;
1262}
1263
1264static struct notifier_block fib_inetaddr_notifier = {
1265 .notifier_call = fib_inetaddr_event,
1266};
1267
1268static struct notifier_block fib_netdev_notifier = {
1269 .notifier_call = fib_netdev_event,
1270};
1271
1272static int __net_init ip_fib_net_init(struct net *net)
1273{
1274 int err;
1275 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1276
1277 err = fib4_notifier_init(net);
1278 if (err)
1279 return err;
1280
1281 /* Avoid false sharing : Use at least a full cache line */
1282 size = max_t(size_t, size, L1_CACHE_BYTES);
1283
1284 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1285 if (!net->ipv4.fib_table_hash) {
1286 err = -ENOMEM;
1287 goto err_table_hash_alloc;
1288 }
1289
1290 err = fib4_rules_init(net);
1291 if (err < 0)
1292 goto err_rules_init;
1293 return 0;
1294
1295err_rules_init:
1296 kfree(net->ipv4.fib_table_hash);
1297err_table_hash_alloc:
1298 fib4_notifier_exit(net);
1299 return err;
1300}
1301
1302static void ip_fib_net_exit(struct net *net)
1303{
1304 int i;
1305
1306 rtnl_lock();
1307#ifdef CONFIG_IP_MULTIPLE_TABLES
1308 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1309 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1310#endif
1311 /* Destroy the tables in reverse order to guarantee that the
1312 * local table, ID 255, is destroyed before the main table, ID
1313 * 254. This is necessary as the local table may contain
1314 * references to data contained in the main table.
1315 */
1316 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1317 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1318 struct hlist_node *tmp;
1319 struct fib_table *tb;
1320
1321 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1322 hlist_del(&tb->tb_hlist);
1323 fib_table_flush(net, tb);
1324 fib_free_table(tb);
1325 }
1326 }
1327
1328#ifdef CONFIG_IP_MULTIPLE_TABLES
1329 fib4_rules_exit(net);
1330#endif
1331 rtnl_unlock();
1332 kfree(net->ipv4.fib_table_hash);
1333 fib4_notifier_exit(net);
1334}
1335
1336static int __net_init fib_net_init(struct net *net)
1337{
1338 int error;
1339
1340#ifdef CONFIG_IP_ROUTE_CLASSID
1341 net->ipv4.fib_num_tclassid_users = 0;
1342#endif
1343 error = ip_fib_net_init(net);
1344 if (error < 0)
1345 goto out;
1346 error = nl_fib_lookup_init(net);
1347 if (error < 0)
1348 goto out_nlfl;
1349 error = fib_proc_init(net);
1350 if (error < 0)
1351 goto out_proc;
1352out:
1353 return error;
1354
1355out_proc:
1356 nl_fib_lookup_exit(net);
1357out_nlfl:
1358 ip_fib_net_exit(net);
1359 goto out;
1360}
1361
1362static void __net_exit fib_net_exit(struct net *net)
1363{
1364 fib_proc_exit(net);
1365 nl_fib_lookup_exit(net);
1366 ip_fib_net_exit(net);
1367}
1368
1369static struct pernet_operations fib_net_ops = {
1370 .init = fib_net_init,
1371 .exit = fib_net_exit,
1372};
1373
1374void __init ip_fib_init(void)
1375{
1376 fib_trie_init();
1377
1378 register_pernet_subsys(&fib_net_ops);
1379
1380 register_netdevice_notifier(&fib_netdev_notifier);
1381 register_inetaddr_notifier(&fib_inetaddr_notifier);
1382
1383 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1384 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1385 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1386}