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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * IPv4 Forwarding Information Base: FIB frontend.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 */
11
12#include <linux/module.h>
13#include <linux/uaccess.h>
14#include <linux/bitops.h>
15#include <linux/capability.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/string.h>
20#include <linux/socket.h>
21#include <linux/sockios.h>
22#include <linux/errno.h>
23#include <linux/in.h>
24#include <linux/inet.h>
25#include <linux/inetdevice.h>
26#include <linux/netdevice.h>
27#include <linux/if_addr.h>
28#include <linux/if_arp.h>
29#include <linux/skbuff.h>
30#include <linux/cache.h>
31#include <linux/init.h>
32#include <linux/list.h>
33#include <linux/slab.h>
34
35#include <net/inet_dscp.h>
36#include <net/ip.h>
37#include <net/protocol.h>
38#include <net/route.h>
39#include <net/tcp.h>
40#include <net/sock.h>
41#include <net/arp.h>
42#include <net/ip_fib.h>
43#include <net/nexthop.h>
44#include <net/rtnetlink.h>
45#include <net/xfrm.h>
46#include <net/l3mdev.h>
47#include <net/lwtunnel.h>
48#include <trace/events/fib.h>
49
50#ifndef CONFIG_IP_MULTIPLE_TABLES
51
52static int __net_init fib4_rules_init(struct net *net)
53{
54 struct fib_table *local_table, *main_table;
55
56 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
57 if (!main_table)
58 return -ENOMEM;
59
60 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
61 if (!local_table)
62 goto fail;
63
64 hlist_add_head_rcu(&local_table->tb_hlist,
65 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
66 hlist_add_head_rcu(&main_table->tb_hlist,
67 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
68 return 0;
69
70fail:
71 fib_free_table(main_table);
72 return -ENOMEM;
73}
74#else
75
76struct fib_table *fib_new_table(struct net *net, u32 id)
77{
78 struct fib_table *tb, *alias = NULL;
79 unsigned int h;
80
81 if (id == 0)
82 id = RT_TABLE_MAIN;
83 tb = fib_get_table(net, id);
84 if (tb)
85 return tb;
86
87 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
88 alias = fib_new_table(net, RT_TABLE_MAIN);
89
90 tb = fib_trie_table(id, alias);
91 if (!tb)
92 return NULL;
93
94 switch (id) {
95 case RT_TABLE_MAIN:
96 rcu_assign_pointer(net->ipv4.fib_main, tb);
97 break;
98 case RT_TABLE_DEFAULT:
99 rcu_assign_pointer(net->ipv4.fib_default, tb);
100 break;
101 default:
102 break;
103 }
104
105 h = id & (FIB_TABLE_HASHSZ - 1);
106 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
107 return tb;
108}
109EXPORT_SYMBOL_GPL(fib_new_table);
110
111/* caller must hold either rtnl or rcu read lock */
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 head = &net->ipv4.fib_table_hash[h];
123 hlist_for_each_entry_rcu(tb, head, tb_hlist,
124 lockdep_rtnl_is_held()) {
125 if (tb->tb_id == id)
126 return tb;
127 }
128 return NULL;
129}
130#endif /* CONFIG_IP_MULTIPLE_TABLES */
131
132static 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
152int 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
184void 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, false);
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 */
206static 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 struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
227
228 if (!dev || dev == nhc->nhc_dev)
229 ret = res.type;
230 }
231 }
232
233 rcu_read_unlock();
234 return ret;
235}
236
237unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
238{
239 return __inet_dev_addr_type(net, NULL, addr, tb_id);
240}
241EXPORT_SYMBOL(inet_addr_type_table);
242
243unsigned int inet_addr_type(struct net *net, __be32 addr)
244{
245 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
246}
247EXPORT_SYMBOL(inet_addr_type);
248
249unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
250 __be32 addr)
251{
252 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
253
254 return __inet_dev_addr_type(net, dev, addr, rt_table);
255}
256EXPORT_SYMBOL(inet_dev_addr_type);
257
258/* inet_addr_type with dev == NULL but using the table from a dev
259 * if one is associated
260 */
261unsigned int inet_addr_type_dev_table(struct net *net,
262 const struct net_device *dev,
263 __be32 addr)
264{
265 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
266
267 return __inet_dev_addr_type(net, NULL, addr, rt_table);
268}
269EXPORT_SYMBOL(inet_addr_type_dev_table);
270
271__be32 fib_compute_spec_dst(struct sk_buff *skb)
272{
273 struct net_device *dev = skb->dev;
274 struct in_device *in_dev;
275 struct fib_result res;
276 struct rtable *rt;
277 struct net *net;
278 int scope;
279
280 rt = skb_rtable(skb);
281 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
282 RTCF_LOCAL)
283 return ip_hdr(skb)->daddr;
284
285 in_dev = __in_dev_get_rcu(dev);
286
287 net = dev_net(dev);
288
289 scope = RT_SCOPE_UNIVERSE;
290 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
291 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
292 struct flowi4 fl4 = {
293 .flowi4_iif = LOOPBACK_IFINDEX,
294 .flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev),
295 .daddr = ip_hdr(skb)->saddr,
296 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(ip_hdr(skb))),
297 .flowi4_scope = scope,
298 .flowi4_mark = vmark ? skb->mark : 0,
299 };
300 if (!fib_lookup(net, &fl4, &res, 0))
301 return fib_result_prefsrc(net, &res);
302 } else {
303 scope = RT_SCOPE_LINK;
304 }
305
306 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
307}
308
309bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
310{
311 bool dev_match = false;
312#ifdef CONFIG_IP_ROUTE_MULTIPATH
313 if (unlikely(fi->nh)) {
314 dev_match = nexthop_uses_dev(fi->nh, dev);
315 } else {
316 int ret;
317
318 for (ret = 0; ret < fib_info_num_path(fi); ret++) {
319 const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
320
321 if (nhc_l3mdev_matches_dev(nhc, dev)) {
322 dev_match = true;
323 break;
324 }
325 }
326 }
327#else
328 if (fib_info_nhc(fi, 0)->nhc_dev == dev)
329 dev_match = true;
330#endif
331
332 return dev_match;
333}
334EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
335
336/* Given (packet source, input interface) and optional (dst, oif, tos):
337 * - (main) check, that source is valid i.e. not broadcast or our local
338 * address.
339 * - figure out what "logical" interface this packet arrived
340 * and calculate "specific destination" address.
341 * - check, that packet arrived from expected physical interface.
342 * called with rcu_read_lock()
343 */
344static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
345 dscp_t dscp, int oif, struct net_device *dev,
346 int rpf, struct in_device *idev, u32 *itag)
347{
348 struct net *net = dev_net(dev);
349 enum skb_drop_reason reason;
350 struct flow_keys flkeys;
351 int ret, no_addr;
352 struct fib_result res;
353 struct flowi4 fl4;
354 bool dev_match;
355
356 fl4.flowi4_oif = 0;
357 fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev);
358 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
359 fl4.daddr = src;
360 fl4.saddr = dst;
361 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
362 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
363 fl4.flowi4_tun_key.tun_id = 0;
364 fl4.flowi4_flags = 0;
365 fl4.flowi4_uid = sock_net_uid(net, NULL);
366 fl4.flowi4_multipath_hash = 0;
367
368 no_addr = idev->ifa_list == NULL;
369
370 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
371 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
372 fl4.flowi4_proto = 0;
373 fl4.fl4_sport = 0;
374 fl4.fl4_dport = 0;
375 } else {
376 swap(fl4.fl4_sport, fl4.fl4_dport);
377 }
378
379 if (fib_lookup(net, &fl4, &res, 0))
380 goto last_resort;
381 if (res.type != RTN_UNICAST) {
382 if (res.type != RTN_LOCAL) {
383 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
384 goto e_inval;
385 } else if (!IN_DEV_ACCEPT_LOCAL(idev)) {
386 reason = SKB_DROP_REASON_IP_LOCAL_SOURCE;
387 goto e_inval;
388 }
389 }
390 fib_combine_itag(itag, &res);
391
392 dev_match = fib_info_nh_uses_dev(res.fi, dev);
393 /* This is not common, loopback packets retain skb_dst so normally they
394 * would not even hit this slow path.
395 */
396 dev_match = dev_match || (res.type == RTN_LOCAL &&
397 dev == net->loopback_dev);
398 if (dev_match) {
399 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
400 return ret;
401 }
402 if (no_addr)
403 goto last_resort;
404 if (rpf == 1)
405 goto e_rpf;
406 fl4.flowi4_oif = dev->ifindex;
407
408 ret = 0;
409 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
410 if (res.type == RTN_UNICAST)
411 ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
412 }
413 return ret;
414
415last_resort:
416 if (rpf)
417 goto e_rpf;
418 *itag = 0;
419 return 0;
420
421e_inval:
422 return -reason;
423e_rpf:
424 return -SKB_DROP_REASON_IP_RPFILTER;
425}
426
427/* Ignore rp_filter for packets protected by IPsec. */
428int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
429 dscp_t dscp, int oif, struct net_device *dev,
430 struct in_device *idev, u32 *itag)
431{
432 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
433 struct net *net = dev_net(dev);
434
435 if (!r && !fib_num_tclassid_users(net) &&
436 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
437 if (IN_DEV_ACCEPT_LOCAL(idev))
438 goto ok;
439 /* with custom local routes in place, checking local addresses
440 * only will be too optimistic, with custom rules, checking
441 * local addresses only can be too strict, e.g. due to vrf
442 */
443 if (net->ipv4.fib_has_custom_local_routes ||
444 fib4_has_custom_rules(net))
445 goto full_check;
446 /* Within the same container, it is regarded as a martian source,
447 * and the same host but different containers are not.
448 */
449 if (inet_lookup_ifaddr_rcu(net, src))
450 return -SKB_DROP_REASON_IP_LOCAL_SOURCE;
451
452ok:
453 *itag = 0;
454 return 0;
455 }
456
457full_check:
458 return __fib_validate_source(skb, src, dst, dscp, oif, dev, r, idev,
459 itag);
460}
461
462static inline __be32 sk_extract_addr(struct sockaddr *addr)
463{
464 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
465}
466
467static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
468{
469 struct nlattr *nla;
470
471 nla = (struct nlattr *) ((char *) mx + len);
472 nla->nla_type = type;
473 nla->nla_len = nla_attr_size(4);
474 *(u32 *) nla_data(nla) = value;
475
476 return len + nla_total_size(4);
477}
478
479static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
480 struct fib_config *cfg)
481{
482 __be32 addr;
483 int plen;
484
485 memset(cfg, 0, sizeof(*cfg));
486 cfg->fc_nlinfo.nl_net = net;
487
488 if (rt->rt_dst.sa_family != AF_INET)
489 return -EAFNOSUPPORT;
490
491 /*
492 * Check mask for validity:
493 * a) it must be contiguous.
494 * b) destination must have all host bits clear.
495 * c) if application forgot to set correct family (AF_INET),
496 * reject request unless it is absolutely clear i.e.
497 * both family and mask are zero.
498 */
499 plen = 32;
500 addr = sk_extract_addr(&rt->rt_dst);
501 if (!(rt->rt_flags & RTF_HOST)) {
502 __be32 mask = sk_extract_addr(&rt->rt_genmask);
503
504 if (rt->rt_genmask.sa_family != AF_INET) {
505 if (mask || rt->rt_genmask.sa_family)
506 return -EAFNOSUPPORT;
507 }
508
509 if (bad_mask(mask, addr))
510 return -EINVAL;
511
512 plen = inet_mask_len(mask);
513 }
514
515 cfg->fc_dst_len = plen;
516 cfg->fc_dst = addr;
517
518 if (cmd != SIOCDELRT) {
519 cfg->fc_nlflags = NLM_F_CREATE;
520 cfg->fc_protocol = RTPROT_BOOT;
521 }
522
523 if (rt->rt_metric)
524 cfg->fc_priority = rt->rt_metric - 1;
525
526 if (rt->rt_flags & RTF_REJECT) {
527 cfg->fc_scope = RT_SCOPE_HOST;
528 cfg->fc_type = RTN_UNREACHABLE;
529 return 0;
530 }
531
532 cfg->fc_scope = RT_SCOPE_NOWHERE;
533 cfg->fc_type = RTN_UNICAST;
534
535 if (rt->rt_dev) {
536 char *colon;
537 struct net_device *dev;
538 char devname[IFNAMSIZ];
539
540 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
541 return -EFAULT;
542
543 devname[IFNAMSIZ-1] = 0;
544 colon = strchr(devname, ':');
545 if (colon)
546 *colon = 0;
547 dev = __dev_get_by_name(net, devname);
548 if (!dev)
549 return -ENODEV;
550 cfg->fc_oif = dev->ifindex;
551 cfg->fc_table = l3mdev_fib_table(dev);
552 if (colon) {
553 const struct in_ifaddr *ifa;
554 struct in_device *in_dev;
555
556 in_dev = __in_dev_get_rtnl(dev);
557 if (!in_dev)
558 return -ENODEV;
559
560 *colon = ':';
561
562 rcu_read_lock();
563 in_dev_for_each_ifa_rcu(ifa, in_dev) {
564 if (strcmp(ifa->ifa_label, devname) == 0)
565 break;
566 }
567 rcu_read_unlock();
568
569 if (!ifa)
570 return -ENODEV;
571 cfg->fc_prefsrc = ifa->ifa_local;
572 }
573 }
574
575 addr = sk_extract_addr(&rt->rt_gateway);
576 if (rt->rt_gateway.sa_family == AF_INET && addr) {
577 unsigned int addr_type;
578
579 cfg->fc_gw4 = addr;
580 cfg->fc_gw_family = AF_INET;
581 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
582 if (rt->rt_flags & RTF_GATEWAY &&
583 addr_type == RTN_UNICAST)
584 cfg->fc_scope = RT_SCOPE_UNIVERSE;
585 }
586
587 if (!cfg->fc_table)
588 cfg->fc_table = RT_TABLE_MAIN;
589
590 if (cmd == SIOCDELRT)
591 return 0;
592
593 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
594 return -EINVAL;
595
596 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
597 cfg->fc_scope = RT_SCOPE_LINK;
598
599 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
600 struct nlattr *mx;
601 int len = 0;
602
603 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
604 if (!mx)
605 return -ENOMEM;
606
607 if (rt->rt_flags & RTF_MTU)
608 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
609
610 if (rt->rt_flags & RTF_WINDOW)
611 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
612
613 if (rt->rt_flags & RTF_IRTT)
614 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
615
616 cfg->fc_mx = mx;
617 cfg->fc_mx_len = len;
618 }
619
620 return 0;
621}
622
623/*
624 * Handle IP routing ioctl calls.
625 * These are used to manipulate the routing tables
626 */
627int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
628{
629 struct fib_config cfg;
630 int err;
631
632 switch (cmd) {
633 case SIOCADDRT: /* Add a route */
634 case SIOCDELRT: /* Delete a route */
635 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
636 return -EPERM;
637
638 rtnl_lock();
639 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
640 if (err == 0) {
641 struct fib_table *tb;
642
643 if (cmd == SIOCDELRT) {
644 tb = fib_get_table(net, cfg.fc_table);
645 if (tb)
646 err = fib_table_delete(net, tb, &cfg,
647 NULL);
648 else
649 err = -ESRCH;
650 } else {
651 tb = fib_new_table(net, cfg.fc_table);
652 if (tb)
653 err = fib_table_insert(net, tb,
654 &cfg, NULL);
655 else
656 err = -ENOBUFS;
657 }
658
659 /* allocated by rtentry_to_fib_config() */
660 kfree(cfg.fc_mx);
661 }
662 rtnl_unlock();
663 return err;
664 }
665 return -EINVAL;
666}
667
668const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
669 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
670 [RTA_DST] = { .type = NLA_U32 },
671 [RTA_SRC] = { .type = NLA_U32 },
672 [RTA_IIF] = { .type = NLA_U32 },
673 [RTA_OIF] = { .type = NLA_U32 },
674 [RTA_GATEWAY] = { .type = NLA_U32 },
675 [RTA_PRIORITY] = { .type = NLA_U32 },
676 [RTA_PREFSRC] = { .type = NLA_U32 },
677 [RTA_METRICS] = { .type = NLA_NESTED },
678 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
679 [RTA_FLOW] = { .type = NLA_U32 },
680 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
681 [RTA_ENCAP] = { .type = NLA_NESTED },
682 [RTA_UID] = { .type = NLA_U32 },
683 [RTA_MARK] = { .type = NLA_U32 },
684 [RTA_TABLE] = { .type = NLA_U32 },
685 [RTA_IP_PROTO] = { .type = NLA_U8 },
686 [RTA_SPORT] = { .type = NLA_U16 },
687 [RTA_DPORT] = { .type = NLA_U16 },
688 [RTA_NH_ID] = { .type = NLA_U32 },
689};
690
691int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
692 struct netlink_ext_ack *extack)
693{
694 struct rtvia *via;
695 int alen;
696
697 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
698 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
699 return -EINVAL;
700 }
701
702 via = nla_data(nla);
703 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
704
705 switch (via->rtvia_family) {
706 case AF_INET:
707 if (alen != sizeof(__be32)) {
708 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
709 return -EINVAL;
710 }
711 cfg->fc_gw_family = AF_INET;
712 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
713 break;
714 case AF_INET6:
715#if IS_ENABLED(CONFIG_IPV6)
716 if (alen != sizeof(struct in6_addr)) {
717 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
718 return -EINVAL;
719 }
720 cfg->fc_gw_family = AF_INET6;
721 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
722#else
723 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
724 return -EINVAL;
725#endif
726 break;
727 default:
728 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
729 return -EINVAL;
730 }
731
732 return 0;
733}
734
735static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
736 struct nlmsghdr *nlh, struct fib_config *cfg,
737 struct netlink_ext_ack *extack)
738{
739 bool has_gw = false, has_via = false;
740 struct nlattr *attr;
741 int err, remaining;
742 struct rtmsg *rtm;
743
744 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
745 rtm_ipv4_policy, extack);
746 if (err < 0)
747 goto errout;
748
749 memset(cfg, 0, sizeof(*cfg));
750
751 rtm = nlmsg_data(nlh);
752
753 if (!inet_validate_dscp(rtm->rtm_tos)) {
754 NL_SET_ERR_MSG(extack,
755 "Invalid dsfield (tos): ECN bits must be 0");
756 err = -EINVAL;
757 goto errout;
758 }
759 cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos);
760
761 cfg->fc_dst_len = rtm->rtm_dst_len;
762 cfg->fc_table = rtm->rtm_table;
763 cfg->fc_protocol = rtm->rtm_protocol;
764 cfg->fc_scope = rtm->rtm_scope;
765 cfg->fc_type = rtm->rtm_type;
766 cfg->fc_flags = rtm->rtm_flags;
767 cfg->fc_nlflags = nlh->nlmsg_flags;
768
769 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
770 cfg->fc_nlinfo.nlh = nlh;
771 cfg->fc_nlinfo.nl_net = net;
772
773 if (cfg->fc_type > RTN_MAX) {
774 NL_SET_ERR_MSG(extack, "Invalid route type");
775 err = -EINVAL;
776 goto errout;
777 }
778
779 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
780 switch (nla_type(attr)) {
781 case RTA_DST:
782 cfg->fc_dst = nla_get_be32(attr);
783 break;
784 case RTA_OIF:
785 cfg->fc_oif = nla_get_u32(attr);
786 break;
787 case RTA_GATEWAY:
788 has_gw = true;
789 cfg->fc_gw4 = nla_get_be32(attr);
790 if (cfg->fc_gw4)
791 cfg->fc_gw_family = AF_INET;
792 break;
793 case RTA_VIA:
794 has_via = true;
795 err = fib_gw_from_via(cfg, attr, extack);
796 if (err)
797 goto errout;
798 break;
799 case RTA_PRIORITY:
800 cfg->fc_priority = nla_get_u32(attr);
801 break;
802 case RTA_PREFSRC:
803 cfg->fc_prefsrc = nla_get_be32(attr);
804 break;
805 case RTA_METRICS:
806 cfg->fc_mx = nla_data(attr);
807 cfg->fc_mx_len = nla_len(attr);
808 break;
809 case RTA_MULTIPATH:
810 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
811 nla_len(attr),
812 extack);
813 if (err < 0)
814 goto errout;
815 cfg->fc_mp = nla_data(attr);
816 cfg->fc_mp_len = nla_len(attr);
817 break;
818 case RTA_FLOW:
819 cfg->fc_flow = nla_get_u32(attr);
820 break;
821 case RTA_TABLE:
822 cfg->fc_table = nla_get_u32(attr);
823 break;
824 case RTA_ENCAP:
825 cfg->fc_encap = attr;
826 break;
827 case RTA_ENCAP_TYPE:
828 cfg->fc_encap_type = nla_get_u16(attr);
829 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
830 extack);
831 if (err < 0)
832 goto errout;
833 break;
834 case RTA_NH_ID:
835 cfg->fc_nh_id = nla_get_u32(attr);
836 break;
837 }
838 }
839
840 if (cfg->fc_nh_id) {
841 if (cfg->fc_oif || cfg->fc_gw_family ||
842 cfg->fc_encap || cfg->fc_mp) {
843 NL_SET_ERR_MSG(extack,
844 "Nexthop specification and nexthop id are mutually exclusive");
845 return -EINVAL;
846 }
847 }
848
849 if (has_gw && has_via) {
850 NL_SET_ERR_MSG(extack,
851 "Nexthop configuration can not contain both GATEWAY and VIA");
852 return -EINVAL;
853 }
854
855 if (!cfg->fc_table)
856 cfg->fc_table = RT_TABLE_MAIN;
857
858 return 0;
859errout:
860 return err;
861}
862
863static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
864 struct netlink_ext_ack *extack)
865{
866 struct net *net = sock_net(skb->sk);
867 struct fib_config cfg;
868 struct fib_table *tb;
869 int err;
870
871 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
872 if (err < 0)
873 goto errout;
874
875 if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
876 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
877 err = -EINVAL;
878 goto errout;
879 }
880
881 tb = fib_get_table(net, cfg.fc_table);
882 if (!tb) {
883 NL_SET_ERR_MSG(extack, "FIB table does not exist");
884 err = -ESRCH;
885 goto errout;
886 }
887
888 err = fib_table_delete(net, tb, &cfg, extack);
889errout:
890 return err;
891}
892
893static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
894 struct netlink_ext_ack *extack)
895{
896 struct net *net = sock_net(skb->sk);
897 struct fib_config cfg;
898 struct fib_table *tb;
899 int err;
900
901 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
902 if (err < 0)
903 goto errout;
904
905 tb = fib_new_table(net, cfg.fc_table);
906 if (!tb) {
907 err = -ENOBUFS;
908 goto errout;
909 }
910
911 err = fib_table_insert(net, tb, &cfg, extack);
912 if (!err && cfg.fc_type == RTN_LOCAL)
913 net->ipv4.fib_has_custom_local_routes = true;
914errout:
915 return err;
916}
917
918int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
919 struct fib_dump_filter *filter,
920 struct netlink_callback *cb)
921{
922 struct netlink_ext_ack *extack = cb->extack;
923 struct nlattr *tb[RTA_MAX + 1];
924 struct rtmsg *rtm;
925 int err, i;
926
927 if (filter->rtnl_held)
928 ASSERT_RTNL();
929
930 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
931 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
932 return -EINVAL;
933 }
934
935 rtm = nlmsg_data(nlh);
936 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
937 rtm->rtm_scope) {
938 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
939 return -EINVAL;
940 }
941
942 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
943 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
944 return -EINVAL;
945 }
946 if (rtm->rtm_flags & RTM_F_CLONED)
947 filter->dump_routes = false;
948 else
949 filter->dump_exceptions = false;
950
951 filter->flags = rtm->rtm_flags;
952 filter->protocol = rtm->rtm_protocol;
953 filter->rt_type = rtm->rtm_type;
954 filter->table_id = rtm->rtm_table;
955
956 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
957 rtm_ipv4_policy, extack);
958 if (err < 0)
959 return err;
960
961 for (i = 0; i <= RTA_MAX; ++i) {
962 int ifindex;
963
964 if (!tb[i])
965 continue;
966
967 switch (i) {
968 case RTA_TABLE:
969 filter->table_id = nla_get_u32(tb[i]);
970 break;
971 case RTA_OIF:
972 ifindex = nla_get_u32(tb[i]);
973 if (filter->rtnl_held)
974 filter->dev = __dev_get_by_index(net, ifindex);
975 else
976 filter->dev = dev_get_by_index_rcu(net, ifindex);
977 if (!filter->dev)
978 return -ENODEV;
979 break;
980 default:
981 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
982 return -EINVAL;
983 }
984 }
985
986 if (filter->flags || filter->protocol || filter->rt_type ||
987 filter->table_id || filter->dev) {
988 filter->filter_set = 1;
989 cb->answer_flags = NLM_F_DUMP_FILTERED;
990 }
991
992 return 0;
993}
994EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
995
996static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
997{
998 struct fib_dump_filter filter = {
999 .dump_routes = true,
1000 .dump_exceptions = true,
1001 .rtnl_held = false,
1002 };
1003 const struct nlmsghdr *nlh = cb->nlh;
1004 struct net *net = sock_net(skb->sk);
1005 unsigned int h, s_h;
1006 unsigned int e = 0, s_e;
1007 struct fib_table *tb;
1008 struct hlist_head *head;
1009 int dumped = 0, err = 0;
1010
1011 rcu_read_lock();
1012 if (cb->strict_check) {
1013 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
1014 if (err < 0)
1015 goto unlock;
1016 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
1017 struct rtmsg *rtm = nlmsg_data(nlh);
1018
1019 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
1020 }
1021
1022 /* ipv4 does not use prefix flag */
1023 if (filter.flags & RTM_F_PREFIX)
1024 goto unlock;
1025
1026 if (filter.table_id) {
1027 tb = fib_get_table(net, filter.table_id);
1028 if (!tb) {
1029 if (rtnl_msg_family(cb->nlh) != PF_INET)
1030 goto unlock;
1031
1032 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
1033 err = -ENOENT;
1034 goto unlock;
1035 }
1036 err = fib_table_dump(tb, skb, cb, &filter);
1037 goto unlock;
1038 }
1039
1040 s_h = cb->args[0];
1041 s_e = cb->args[1];
1042
1043 err = 0;
1044 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1045 e = 0;
1046 head = &net->ipv4.fib_table_hash[h];
1047 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1048 if (e < s_e)
1049 goto next;
1050 if (dumped)
1051 memset(&cb->args[2], 0, sizeof(cb->args) -
1052 2 * sizeof(cb->args[0]));
1053 err = fib_table_dump(tb, skb, cb, &filter);
1054 if (err < 0)
1055 goto out;
1056 dumped = 1;
1057next:
1058 e++;
1059 }
1060 }
1061out:
1062
1063 cb->args[1] = e;
1064 cb->args[0] = h;
1065
1066unlock:
1067 rcu_read_unlock();
1068 return err;
1069}
1070
1071/* Prepare and feed intra-kernel routing request.
1072 * Really, it should be netlink message, but :-( netlink
1073 * can be not configured, so that we feed it directly
1074 * to fib engine. It is legal, because all events occur
1075 * only when netlink is already locked.
1076 */
1077static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1078 struct in_ifaddr *ifa, u32 rt_priority)
1079{
1080 struct net *net = dev_net(ifa->ifa_dev->dev);
1081 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1082 struct fib_table *tb;
1083 struct fib_config cfg = {
1084 .fc_protocol = RTPROT_KERNEL,
1085 .fc_type = type,
1086 .fc_dst = dst,
1087 .fc_dst_len = dst_len,
1088 .fc_priority = rt_priority,
1089 .fc_prefsrc = ifa->ifa_local,
1090 .fc_oif = ifa->ifa_dev->dev->ifindex,
1091 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1092 .fc_nlinfo = {
1093 .nl_net = net,
1094 },
1095 };
1096
1097 if (!tb_id)
1098 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1099
1100 tb = fib_new_table(net, tb_id);
1101 if (!tb)
1102 return;
1103
1104 cfg.fc_table = tb->tb_id;
1105
1106 if (type != RTN_LOCAL)
1107 cfg.fc_scope = RT_SCOPE_LINK;
1108 else
1109 cfg.fc_scope = RT_SCOPE_HOST;
1110
1111 if (cmd == RTM_NEWROUTE)
1112 fib_table_insert(net, tb, &cfg, NULL);
1113 else
1114 fib_table_delete(net, tb, &cfg, NULL);
1115}
1116
1117void fib_add_ifaddr(struct in_ifaddr *ifa)
1118{
1119 struct in_device *in_dev = ifa->ifa_dev;
1120 struct net_device *dev = in_dev->dev;
1121 struct in_ifaddr *prim = ifa;
1122 __be32 mask = ifa->ifa_mask;
1123 __be32 addr = ifa->ifa_local;
1124 __be32 prefix = ifa->ifa_address & mask;
1125
1126 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1127 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1128 if (!prim) {
1129 pr_warn("%s: bug: prim == NULL\n", __func__);
1130 return;
1131 }
1132 }
1133
1134 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1135
1136 if (!(dev->flags & IFF_UP))
1137 return;
1138
1139 /* Add broadcast address, if it is explicitly assigned. */
1140 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) {
1141 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1142 prim, 0);
1143 arp_invalidate(dev, ifa->ifa_broadcast, false);
1144 }
1145
1146 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1147 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1148 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1149 fib_magic(RTM_NEWROUTE,
1150 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1151 prefix, ifa->ifa_prefixlen, prim,
1152 ifa->ifa_rt_priority);
1153
1154 /* Add the network broadcast address, when it makes sense */
1155 if (ifa->ifa_prefixlen < 31) {
1156 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1157 32, prim, 0);
1158 arp_invalidate(dev, prefix | ~mask, false);
1159 }
1160 }
1161}
1162
1163void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1164{
1165 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1166 struct in_device *in_dev = ifa->ifa_dev;
1167 struct net_device *dev = in_dev->dev;
1168
1169 if (!(dev->flags & IFF_UP) ||
1170 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1171 ipv4_is_zeronet(prefix) ||
1172 (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1173 return;
1174
1175 /* add the new */
1176 fib_magic(RTM_NEWROUTE,
1177 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1178 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1179
1180 /* delete the old */
1181 fib_magic(RTM_DELROUTE,
1182 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1183 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1184}
1185
1186/* Delete primary or secondary address.
1187 * Optionally, on secondary address promotion consider the addresses
1188 * from subnet iprim as deleted, even if they are in device list.
1189 * In this case the secondary ifa can be in device list.
1190 */
1191void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1192{
1193 struct in_device *in_dev = ifa->ifa_dev;
1194 struct net_device *dev = in_dev->dev;
1195 struct in_ifaddr *ifa1;
1196 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1197 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1198 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1199#define LOCAL_OK 1
1200#define BRD_OK 2
1201#define BRD0_OK 4
1202#define BRD1_OK 8
1203 unsigned int ok = 0;
1204 int subnet = 0; /* Primary network */
1205 int gone = 1; /* Address is missing */
1206 int same_prefsrc = 0; /* Another primary with same IP */
1207
1208 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1209 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1210 if (!prim) {
1211 /* if the device has been deleted, we don't perform
1212 * address promotion
1213 */
1214 if (!in_dev->dead)
1215 pr_warn("%s: bug: prim == NULL\n", __func__);
1216 return;
1217 }
1218 if (iprim && iprim != prim) {
1219 pr_warn("%s: bug: iprim != prim\n", __func__);
1220 return;
1221 }
1222 } else if (!ipv4_is_zeronet(any) &&
1223 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1224 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1225 fib_magic(RTM_DELROUTE,
1226 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1227 any, ifa->ifa_prefixlen, prim, 0);
1228 subnet = 1;
1229 }
1230
1231 if (in_dev->dead)
1232 goto no_promotions;
1233
1234 /* Deletion is more complicated than add.
1235 * We should take care of not to delete too much :-)
1236 *
1237 * Scan address list to be sure that addresses are really gone.
1238 */
1239 rcu_read_lock();
1240 in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1241 if (ifa1 == ifa) {
1242 /* promotion, keep the IP */
1243 gone = 0;
1244 continue;
1245 }
1246 /* Ignore IFAs from our subnet */
1247 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1248 inet_ifa_match(ifa1->ifa_address, iprim))
1249 continue;
1250
1251 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1252 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1253 /* Another address from our subnet? */
1254 if (ifa1->ifa_mask == prim->ifa_mask &&
1255 inet_ifa_match(ifa1->ifa_address, prim))
1256 prim1 = prim;
1257 else {
1258 /* We reached the secondaries, so
1259 * same_prefsrc should be determined.
1260 */
1261 if (!same_prefsrc)
1262 continue;
1263 /* Search new prim1 if ifa1 is not
1264 * using the current prim1
1265 */
1266 if (!prim1 ||
1267 ifa1->ifa_mask != prim1->ifa_mask ||
1268 !inet_ifa_match(ifa1->ifa_address, prim1))
1269 prim1 = inet_ifa_byprefix(in_dev,
1270 ifa1->ifa_address,
1271 ifa1->ifa_mask);
1272 if (!prim1)
1273 continue;
1274 if (prim1->ifa_local != prim->ifa_local)
1275 continue;
1276 }
1277 } else {
1278 if (prim->ifa_local != ifa1->ifa_local)
1279 continue;
1280 prim1 = ifa1;
1281 if (prim != prim1)
1282 same_prefsrc = 1;
1283 }
1284 if (ifa->ifa_local == ifa1->ifa_local)
1285 ok |= LOCAL_OK;
1286 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1287 ok |= BRD_OK;
1288 if (brd == ifa1->ifa_broadcast)
1289 ok |= BRD1_OK;
1290 if (any == ifa1->ifa_broadcast)
1291 ok |= BRD0_OK;
1292 /* primary has network specific broadcasts */
1293 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1294 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1295 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1296
1297 if (!ipv4_is_zeronet(any1)) {
1298 if (ifa->ifa_broadcast == brd1 ||
1299 ifa->ifa_broadcast == any1)
1300 ok |= BRD_OK;
1301 if (brd == brd1 || brd == any1)
1302 ok |= BRD1_OK;
1303 if (any == brd1 || any == any1)
1304 ok |= BRD0_OK;
1305 }
1306 }
1307 }
1308 rcu_read_unlock();
1309
1310no_promotions:
1311 if (!(ok & BRD_OK))
1312 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1313 prim, 0);
1314 if (subnet && ifa->ifa_prefixlen < 31) {
1315 if (!(ok & BRD1_OK))
1316 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1317 prim, 0);
1318 if (!(ok & BRD0_OK))
1319 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1320 prim, 0);
1321 }
1322 if (!(ok & LOCAL_OK)) {
1323 unsigned int addr_type;
1324
1325 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1326
1327 /* Check, that this local address finally disappeared. */
1328 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1329 ifa->ifa_local);
1330 if (gone && addr_type != RTN_LOCAL) {
1331 /* And the last, but not the least thing.
1332 * We must flush stray FIB entries.
1333 *
1334 * First of all, we scan fib_info list searching
1335 * for stray nexthop entries, then ignite fib_flush.
1336 */
1337 if (fib_sync_down_addr(dev, ifa->ifa_local))
1338 fib_flush(dev_net(dev));
1339 }
1340 }
1341#undef LOCAL_OK
1342#undef BRD_OK
1343#undef BRD0_OK
1344#undef BRD1_OK
1345}
1346
1347static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1348{
1349
1350 struct fib_result res;
1351 struct flowi4 fl4 = {
1352 .flowi4_mark = frn->fl_mark,
1353 .daddr = frn->fl_addr,
1354 .flowi4_tos = frn->fl_tos & INET_DSCP_MASK,
1355 .flowi4_scope = frn->fl_scope,
1356 };
1357 struct fib_table *tb;
1358
1359 rcu_read_lock();
1360
1361 tb = fib_get_table(net, frn->tb_id_in);
1362
1363 frn->err = -ENOENT;
1364 if (tb) {
1365 local_bh_disable();
1366
1367 frn->tb_id = tb->tb_id;
1368 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1369
1370 if (!frn->err) {
1371 frn->prefixlen = res.prefixlen;
1372 frn->nh_sel = res.nh_sel;
1373 frn->type = res.type;
1374 frn->scope = res.scope;
1375 }
1376 local_bh_enable();
1377 }
1378
1379 rcu_read_unlock();
1380}
1381
1382static void nl_fib_input(struct sk_buff *skb)
1383{
1384 struct net *net;
1385 struct fib_result_nl *frn;
1386 struct nlmsghdr *nlh;
1387 u32 portid;
1388
1389 net = sock_net(skb->sk);
1390 nlh = nlmsg_hdr(skb);
1391 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1392 skb->len < nlh->nlmsg_len ||
1393 nlmsg_len(nlh) < sizeof(*frn))
1394 return;
1395
1396 skb = netlink_skb_clone(skb, GFP_KERNEL);
1397 if (!skb)
1398 return;
1399 nlh = nlmsg_hdr(skb);
1400
1401 frn = nlmsg_data(nlh);
1402 nl_fib_lookup(net, frn);
1403
1404 portid = NETLINK_CB(skb).portid; /* netlink portid */
1405 NETLINK_CB(skb).portid = 0; /* from kernel */
1406 NETLINK_CB(skb).dst_group = 0; /* unicast */
1407 nlmsg_unicast(net->ipv4.fibnl, skb, portid);
1408}
1409
1410static int __net_init nl_fib_lookup_init(struct net *net)
1411{
1412 struct sock *sk;
1413 struct netlink_kernel_cfg cfg = {
1414 .input = nl_fib_input,
1415 };
1416
1417 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1418 if (!sk)
1419 return -EAFNOSUPPORT;
1420 net->ipv4.fibnl = sk;
1421 return 0;
1422}
1423
1424static void nl_fib_lookup_exit(struct net *net)
1425{
1426 netlink_kernel_release(net->ipv4.fibnl);
1427 net->ipv4.fibnl = NULL;
1428}
1429
1430static void fib_disable_ip(struct net_device *dev, unsigned long event,
1431 bool force)
1432{
1433 if (fib_sync_down_dev(dev, event, force))
1434 fib_flush(dev_net(dev));
1435 else
1436 rt_cache_flush(dev_net(dev));
1437 arp_ifdown(dev);
1438}
1439
1440static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1441{
1442 struct in_ifaddr *ifa = ptr;
1443 struct net_device *dev = ifa->ifa_dev->dev;
1444 struct net *net = dev_net(dev);
1445
1446 switch (event) {
1447 case NETDEV_UP:
1448 fib_add_ifaddr(ifa);
1449#ifdef CONFIG_IP_ROUTE_MULTIPATH
1450 fib_sync_up(dev, RTNH_F_DEAD);
1451#endif
1452 atomic_inc(&net->ipv4.dev_addr_genid);
1453 rt_cache_flush(dev_net(dev));
1454 break;
1455 case NETDEV_DOWN:
1456 fib_del_ifaddr(ifa, NULL);
1457 atomic_inc(&net->ipv4.dev_addr_genid);
1458 if (!ifa->ifa_dev->ifa_list) {
1459 /* Last address was deleted from this interface.
1460 * Disable IP.
1461 */
1462 fib_disable_ip(dev, event, true);
1463 } else {
1464 rt_cache_flush(dev_net(dev));
1465 }
1466 break;
1467 }
1468 return NOTIFY_DONE;
1469}
1470
1471static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1472{
1473 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1474 struct netdev_notifier_changeupper_info *upper_info = ptr;
1475 struct netdev_notifier_info_ext *info_ext = ptr;
1476 struct in_device *in_dev;
1477 struct net *net = dev_net(dev);
1478 struct in_ifaddr *ifa;
1479 unsigned int flags;
1480
1481 if (event == NETDEV_UNREGISTER) {
1482 fib_disable_ip(dev, event, true);
1483 rt_flush_dev(dev);
1484 return NOTIFY_DONE;
1485 }
1486
1487 in_dev = __in_dev_get_rtnl(dev);
1488 if (!in_dev)
1489 return NOTIFY_DONE;
1490
1491 switch (event) {
1492 case NETDEV_UP:
1493 in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1494 fib_add_ifaddr(ifa);
1495 }
1496#ifdef CONFIG_IP_ROUTE_MULTIPATH
1497 fib_sync_up(dev, RTNH_F_DEAD);
1498#endif
1499 atomic_inc(&net->ipv4.dev_addr_genid);
1500 rt_cache_flush(net);
1501 break;
1502 case NETDEV_DOWN:
1503 fib_disable_ip(dev, event, false);
1504 break;
1505 case NETDEV_CHANGE:
1506 flags = dev_get_flags(dev);
1507 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1508 fib_sync_up(dev, RTNH_F_LINKDOWN);
1509 else
1510 fib_sync_down_dev(dev, event, false);
1511 rt_cache_flush(net);
1512 break;
1513 case NETDEV_CHANGEMTU:
1514 fib_sync_mtu(dev, info_ext->ext.mtu);
1515 rt_cache_flush(net);
1516 break;
1517 case NETDEV_CHANGEUPPER:
1518 upper_info = ptr;
1519 /* flush all routes if dev is linked to or unlinked from
1520 * an L3 master device (e.g., VRF)
1521 */
1522 if (upper_info->upper_dev &&
1523 netif_is_l3_master(upper_info->upper_dev))
1524 fib_disable_ip(dev, NETDEV_DOWN, true);
1525 break;
1526 }
1527 return NOTIFY_DONE;
1528}
1529
1530static struct notifier_block fib_inetaddr_notifier = {
1531 .notifier_call = fib_inetaddr_event,
1532};
1533
1534static struct notifier_block fib_netdev_notifier = {
1535 .notifier_call = fib_netdev_event,
1536};
1537
1538static int __net_init ip_fib_net_init(struct net *net)
1539{
1540 int err;
1541 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1542
1543 err = fib4_notifier_init(net);
1544 if (err)
1545 return err;
1546
1547#ifdef CONFIG_IP_ROUTE_MULTIPATH
1548 /* Default to 3-tuple */
1549 net->ipv4.sysctl_fib_multipath_hash_fields =
1550 FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK;
1551#endif
1552
1553 /* Avoid false sharing : Use at least a full cache line */
1554 size = max_t(size_t, size, L1_CACHE_BYTES);
1555
1556 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1557 if (!net->ipv4.fib_table_hash) {
1558 err = -ENOMEM;
1559 goto err_table_hash_alloc;
1560 }
1561
1562 err = fib4_rules_init(net);
1563 if (err < 0)
1564 goto err_rules_init;
1565 return 0;
1566
1567err_rules_init:
1568 kfree(net->ipv4.fib_table_hash);
1569err_table_hash_alloc:
1570 fib4_notifier_exit(net);
1571 return err;
1572}
1573
1574static void ip_fib_net_exit(struct net *net)
1575{
1576 int i;
1577
1578 ASSERT_RTNL();
1579#ifdef CONFIG_IP_MULTIPLE_TABLES
1580 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1581 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1582#endif
1583 /* Destroy the tables in reverse order to guarantee that the
1584 * local table, ID 255, is destroyed before the main table, ID
1585 * 254. This is necessary as the local table may contain
1586 * references to data contained in the main table.
1587 */
1588 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1589 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1590 struct hlist_node *tmp;
1591 struct fib_table *tb;
1592
1593 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1594 hlist_del(&tb->tb_hlist);
1595 fib_table_flush(net, tb, true);
1596 fib_free_table(tb);
1597 }
1598 }
1599
1600#ifdef CONFIG_IP_MULTIPLE_TABLES
1601 fib4_rules_exit(net);
1602#endif
1603
1604 kfree(net->ipv4.fib_table_hash);
1605 fib4_notifier_exit(net);
1606}
1607
1608static int __net_init fib_net_init(struct net *net)
1609{
1610 int error;
1611
1612#ifdef CONFIG_IP_ROUTE_CLASSID
1613 atomic_set(&net->ipv4.fib_num_tclassid_users, 0);
1614#endif
1615 error = ip_fib_net_init(net);
1616 if (error < 0)
1617 goto out;
1618 error = nl_fib_lookup_init(net);
1619 if (error < 0)
1620 goto out_nlfl;
1621 error = fib_proc_init(net);
1622 if (error < 0)
1623 goto out_proc;
1624out:
1625 return error;
1626
1627out_proc:
1628 nl_fib_lookup_exit(net);
1629out_nlfl:
1630 rtnl_lock();
1631 ip_fib_net_exit(net);
1632 rtnl_unlock();
1633 goto out;
1634}
1635
1636static void __net_exit fib_net_exit(struct net *net)
1637{
1638 fib_proc_exit(net);
1639 nl_fib_lookup_exit(net);
1640}
1641
1642static void __net_exit fib_net_exit_batch(struct list_head *net_list)
1643{
1644 struct net *net;
1645
1646 rtnl_lock();
1647 list_for_each_entry(net, net_list, exit_list)
1648 ip_fib_net_exit(net);
1649
1650 rtnl_unlock();
1651}
1652
1653static struct pernet_operations fib_net_ops = {
1654 .init = fib_net_init,
1655 .exit = fib_net_exit,
1656 .exit_batch = fib_net_exit_batch,
1657};
1658
1659static const struct rtnl_msg_handler fib_rtnl_msg_handlers[] __initconst = {
1660 {.protocol = PF_INET, .msgtype = RTM_NEWROUTE,
1661 .doit = inet_rtm_newroute},
1662 {.protocol = PF_INET, .msgtype = RTM_DELROUTE,
1663 .doit = inet_rtm_delroute},
1664 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, .dumpit = inet_dump_fib,
1665 .flags = RTNL_FLAG_DUMP_UNLOCKED | RTNL_FLAG_DUMP_SPLIT_NLM_DONE},
1666};
1667
1668void __init ip_fib_init(void)
1669{
1670 fib_trie_init();
1671
1672 register_pernet_subsys(&fib_net_ops);
1673
1674 register_netdevice_notifier(&fib_netdev_notifier);
1675 register_inetaddr_notifier(&fib_inetaddr_notifier);
1676
1677 rtnl_register_many(fib_rtnl_msg_handlers);
1678}