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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/init.h>
35#include <linux/list.h>
36#include <linux/slab.h>
37
38#include <net/ip.h>
39#include <net/protocol.h>
40#include <net/route.h>
41#include <net/tcp.h>
42#include <net/sock.h>
43#include <net/arp.h>
44#include <net/ip_fib.h>
45#include <net/rtnetlink.h>
46#include <net/xfrm.h>
47
48#ifndef CONFIG_IP_MULTIPLE_TABLES
49
50static int __net_init fib4_rules_init(struct net *net)
51{
52 struct fib_table *local_table, *main_table;
53
54 local_table = fib_trie_table(RT_TABLE_LOCAL);
55 if (local_table == NULL)
56 return -ENOMEM;
57
58 main_table = fib_trie_table(RT_TABLE_MAIN);
59 if (main_table == NULL)
60 goto fail;
61
62 hlist_add_head_rcu(&local_table->tb_hlist,
63 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
64 hlist_add_head_rcu(&main_table->tb_hlist,
65 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
66 return 0;
67
68fail:
69 kfree(local_table);
70 return -ENOMEM;
71}
72#else
73
74struct fib_table *fib_new_table(struct net *net, u32 id)
75{
76 struct fib_table *tb;
77 unsigned int h;
78
79 if (id == 0)
80 id = RT_TABLE_MAIN;
81 tb = fib_get_table(net, id);
82 if (tb)
83 return tb;
84
85 tb = fib_trie_table(id);
86 if (!tb)
87 return NULL;
88 h = id & (FIB_TABLE_HASHSZ - 1);
89 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
90 return tb;
91}
92
93struct fib_table *fib_get_table(struct net *net, u32 id)
94{
95 struct fib_table *tb;
96 struct hlist_node *node;
97 struct hlist_head *head;
98 unsigned int h;
99
100 if (id == 0)
101 id = RT_TABLE_MAIN;
102 h = id & (FIB_TABLE_HASHSZ - 1);
103
104 rcu_read_lock();
105 head = &net->ipv4.fib_table_hash[h];
106 hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
107 if (tb->tb_id == id) {
108 rcu_read_unlock();
109 return tb;
110 }
111 }
112 rcu_read_unlock();
113 return NULL;
114}
115#endif /* CONFIG_IP_MULTIPLE_TABLES */
116
117static void fib_flush(struct net *net)
118{
119 int flushed = 0;
120 struct fib_table *tb;
121 struct hlist_node *node;
122 struct hlist_head *head;
123 unsigned int h;
124
125 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
126 head = &net->ipv4.fib_table_hash[h];
127 hlist_for_each_entry(tb, node, head, tb_hlist)
128 flushed += fib_table_flush(tb);
129 }
130
131 if (flushed)
132 rt_cache_flush(net, -1);
133}
134
135/*
136 * Find address type as if only "dev" was present in the system. If
137 * on_dev is NULL then all interfaces are taken into consideration.
138 */
139static inline unsigned int __inet_dev_addr_type(struct net *net,
140 const struct net_device *dev,
141 __be32 addr)
142{
143 struct flowi4 fl4 = { .daddr = addr };
144 struct fib_result res;
145 unsigned int ret = RTN_BROADCAST;
146 struct fib_table *local_table;
147
148 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
149 return RTN_BROADCAST;
150 if (ipv4_is_multicast(addr))
151 return RTN_MULTICAST;
152
153#ifdef CONFIG_IP_MULTIPLE_TABLES
154 res.r = NULL;
155#endif
156
157 local_table = fib_get_table(net, RT_TABLE_LOCAL);
158 if (local_table) {
159 ret = RTN_UNICAST;
160 rcu_read_lock();
161 if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
162 if (!dev || dev == res.fi->fib_dev)
163 ret = res.type;
164 }
165 rcu_read_unlock();
166 }
167 return ret;
168}
169
170unsigned int inet_addr_type(struct net *net, __be32 addr)
171{
172 return __inet_dev_addr_type(net, NULL, addr);
173}
174EXPORT_SYMBOL(inet_addr_type);
175
176unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
177 __be32 addr)
178{
179 return __inet_dev_addr_type(net, dev, addr);
180}
181EXPORT_SYMBOL(inet_dev_addr_type);
182
183/* Given (packet source, input interface) and optional (dst, oif, tos):
184 * - (main) check, that source is valid i.e. not broadcast or our local
185 * address.
186 * - figure out what "logical" interface this packet arrived
187 * and calculate "specific destination" address.
188 * - check, that packet arrived from expected physical interface.
189 * called with rcu_read_lock()
190 */
191int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos,
192 int oif, struct net_device *dev, __be32 *spec_dst,
193 u32 *itag)
194{
195 struct in_device *in_dev;
196 struct flowi4 fl4;
197 struct fib_result res;
198 int no_addr, rpf, accept_local;
199 bool dev_match;
200 int ret;
201 struct net *net;
202
203 fl4.flowi4_oif = 0;
204 fl4.flowi4_iif = oif;
205 fl4.daddr = src;
206 fl4.saddr = dst;
207 fl4.flowi4_tos = tos;
208 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
209
210 no_addr = rpf = accept_local = 0;
211 in_dev = __in_dev_get_rcu(dev);
212 if (in_dev) {
213 no_addr = in_dev->ifa_list == NULL;
214
215 /* Ignore rp_filter for packets protected by IPsec. */
216 rpf = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(in_dev);
217
218 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
219 fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
220 }
221
222 if (in_dev == NULL)
223 goto e_inval;
224
225 net = dev_net(dev);
226 if (fib_lookup(net, &fl4, &res))
227 goto last_resort;
228 if (res.type != RTN_UNICAST) {
229 if (res.type != RTN_LOCAL || !accept_local)
230 goto e_inval;
231 }
232 *spec_dst = FIB_RES_PREFSRC(net, res);
233 fib_combine_itag(itag, &res);
234 dev_match = false;
235
236#ifdef CONFIG_IP_ROUTE_MULTIPATH
237 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
238 struct fib_nh *nh = &res.fi->fib_nh[ret];
239
240 if (nh->nh_dev == dev) {
241 dev_match = true;
242 break;
243 }
244 }
245#else
246 if (FIB_RES_DEV(res) == dev)
247 dev_match = true;
248#endif
249 if (dev_match) {
250 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
251 return ret;
252 }
253 if (no_addr)
254 goto last_resort;
255 if (rpf == 1)
256 goto e_rpf;
257 fl4.flowi4_oif = dev->ifindex;
258
259 ret = 0;
260 if (fib_lookup(net, &fl4, &res) == 0) {
261 if (res.type == RTN_UNICAST) {
262 *spec_dst = FIB_RES_PREFSRC(net, res);
263 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
264 }
265 }
266 return ret;
267
268last_resort:
269 if (rpf)
270 goto e_rpf;
271 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
272 *itag = 0;
273 return 0;
274
275e_inval:
276 return -EINVAL;
277e_rpf:
278 return -EXDEV;
279}
280
281static inline __be32 sk_extract_addr(struct sockaddr *addr)
282{
283 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
284}
285
286static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
287{
288 struct nlattr *nla;
289
290 nla = (struct nlattr *) ((char *) mx + len);
291 nla->nla_type = type;
292 nla->nla_len = nla_attr_size(4);
293 *(u32 *) nla_data(nla) = value;
294
295 return len + nla_total_size(4);
296}
297
298static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
299 struct fib_config *cfg)
300{
301 __be32 addr;
302 int plen;
303
304 memset(cfg, 0, sizeof(*cfg));
305 cfg->fc_nlinfo.nl_net = net;
306
307 if (rt->rt_dst.sa_family != AF_INET)
308 return -EAFNOSUPPORT;
309
310 /*
311 * Check mask for validity:
312 * a) it must be contiguous.
313 * b) destination must have all host bits clear.
314 * c) if application forgot to set correct family (AF_INET),
315 * reject request unless it is absolutely clear i.e.
316 * both family and mask are zero.
317 */
318 plen = 32;
319 addr = sk_extract_addr(&rt->rt_dst);
320 if (!(rt->rt_flags & RTF_HOST)) {
321 __be32 mask = sk_extract_addr(&rt->rt_genmask);
322
323 if (rt->rt_genmask.sa_family != AF_INET) {
324 if (mask || rt->rt_genmask.sa_family)
325 return -EAFNOSUPPORT;
326 }
327
328 if (bad_mask(mask, addr))
329 return -EINVAL;
330
331 plen = inet_mask_len(mask);
332 }
333
334 cfg->fc_dst_len = plen;
335 cfg->fc_dst = addr;
336
337 if (cmd != SIOCDELRT) {
338 cfg->fc_nlflags = NLM_F_CREATE;
339 cfg->fc_protocol = RTPROT_BOOT;
340 }
341
342 if (rt->rt_metric)
343 cfg->fc_priority = rt->rt_metric - 1;
344
345 if (rt->rt_flags & RTF_REJECT) {
346 cfg->fc_scope = RT_SCOPE_HOST;
347 cfg->fc_type = RTN_UNREACHABLE;
348 return 0;
349 }
350
351 cfg->fc_scope = RT_SCOPE_NOWHERE;
352 cfg->fc_type = RTN_UNICAST;
353
354 if (rt->rt_dev) {
355 char *colon;
356 struct net_device *dev;
357 char devname[IFNAMSIZ];
358
359 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
360 return -EFAULT;
361
362 devname[IFNAMSIZ-1] = 0;
363 colon = strchr(devname, ':');
364 if (colon)
365 *colon = 0;
366 dev = __dev_get_by_name(net, devname);
367 if (!dev)
368 return -ENODEV;
369 cfg->fc_oif = dev->ifindex;
370 if (colon) {
371 struct in_ifaddr *ifa;
372 struct in_device *in_dev = __in_dev_get_rtnl(dev);
373 if (!in_dev)
374 return -ENODEV;
375 *colon = ':';
376 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
377 if (strcmp(ifa->ifa_label, devname) == 0)
378 break;
379 if (ifa == NULL)
380 return -ENODEV;
381 cfg->fc_prefsrc = ifa->ifa_local;
382 }
383 }
384
385 addr = sk_extract_addr(&rt->rt_gateway);
386 if (rt->rt_gateway.sa_family == AF_INET && addr) {
387 cfg->fc_gw = addr;
388 if (rt->rt_flags & RTF_GATEWAY &&
389 inet_addr_type(net, addr) == RTN_UNICAST)
390 cfg->fc_scope = RT_SCOPE_UNIVERSE;
391 }
392
393 if (cmd == SIOCDELRT)
394 return 0;
395
396 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
397 return -EINVAL;
398
399 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
400 cfg->fc_scope = RT_SCOPE_LINK;
401
402 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
403 struct nlattr *mx;
404 int len = 0;
405
406 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
407 if (mx == NULL)
408 return -ENOMEM;
409
410 if (rt->rt_flags & RTF_MTU)
411 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
412
413 if (rt->rt_flags & RTF_WINDOW)
414 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
415
416 if (rt->rt_flags & RTF_IRTT)
417 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
418
419 cfg->fc_mx = mx;
420 cfg->fc_mx_len = len;
421 }
422
423 return 0;
424}
425
426/*
427 * Handle IP routing ioctl calls.
428 * These are used to manipulate the routing tables
429 */
430int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
431{
432 struct fib_config cfg;
433 struct rtentry rt;
434 int err;
435
436 switch (cmd) {
437 case SIOCADDRT: /* Add a route */
438 case SIOCDELRT: /* Delete a route */
439 if (!capable(CAP_NET_ADMIN))
440 return -EPERM;
441
442 if (copy_from_user(&rt, arg, sizeof(rt)))
443 return -EFAULT;
444
445 rtnl_lock();
446 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
447 if (err == 0) {
448 struct fib_table *tb;
449
450 if (cmd == SIOCDELRT) {
451 tb = fib_get_table(net, cfg.fc_table);
452 if (tb)
453 err = fib_table_delete(tb, &cfg);
454 else
455 err = -ESRCH;
456 } else {
457 tb = fib_new_table(net, cfg.fc_table);
458 if (tb)
459 err = fib_table_insert(tb, &cfg);
460 else
461 err = -ENOBUFS;
462 }
463
464 /* allocated by rtentry_to_fib_config() */
465 kfree(cfg.fc_mx);
466 }
467 rtnl_unlock();
468 return err;
469 }
470 return -EINVAL;
471}
472
473const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
474 [RTA_DST] = { .type = NLA_U32 },
475 [RTA_SRC] = { .type = NLA_U32 },
476 [RTA_IIF] = { .type = NLA_U32 },
477 [RTA_OIF] = { .type = NLA_U32 },
478 [RTA_GATEWAY] = { .type = NLA_U32 },
479 [RTA_PRIORITY] = { .type = NLA_U32 },
480 [RTA_PREFSRC] = { .type = NLA_U32 },
481 [RTA_METRICS] = { .type = NLA_NESTED },
482 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
483 [RTA_FLOW] = { .type = NLA_U32 },
484};
485
486static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
487 struct nlmsghdr *nlh, struct fib_config *cfg)
488{
489 struct nlattr *attr;
490 int err, remaining;
491 struct rtmsg *rtm;
492
493 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
494 if (err < 0)
495 goto errout;
496
497 memset(cfg, 0, sizeof(*cfg));
498
499 rtm = nlmsg_data(nlh);
500 cfg->fc_dst_len = rtm->rtm_dst_len;
501 cfg->fc_tos = rtm->rtm_tos;
502 cfg->fc_table = rtm->rtm_table;
503 cfg->fc_protocol = rtm->rtm_protocol;
504 cfg->fc_scope = rtm->rtm_scope;
505 cfg->fc_type = rtm->rtm_type;
506 cfg->fc_flags = rtm->rtm_flags;
507 cfg->fc_nlflags = nlh->nlmsg_flags;
508
509 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
510 cfg->fc_nlinfo.nlh = nlh;
511 cfg->fc_nlinfo.nl_net = net;
512
513 if (cfg->fc_type > RTN_MAX) {
514 err = -EINVAL;
515 goto errout;
516 }
517
518 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
519 switch (nla_type(attr)) {
520 case RTA_DST:
521 cfg->fc_dst = nla_get_be32(attr);
522 break;
523 case RTA_OIF:
524 cfg->fc_oif = nla_get_u32(attr);
525 break;
526 case RTA_GATEWAY:
527 cfg->fc_gw = nla_get_be32(attr);
528 break;
529 case RTA_PRIORITY:
530 cfg->fc_priority = nla_get_u32(attr);
531 break;
532 case RTA_PREFSRC:
533 cfg->fc_prefsrc = nla_get_be32(attr);
534 break;
535 case RTA_METRICS:
536 cfg->fc_mx = nla_data(attr);
537 cfg->fc_mx_len = nla_len(attr);
538 break;
539 case RTA_MULTIPATH:
540 cfg->fc_mp = nla_data(attr);
541 cfg->fc_mp_len = nla_len(attr);
542 break;
543 case RTA_FLOW:
544 cfg->fc_flow = nla_get_u32(attr);
545 break;
546 case RTA_TABLE:
547 cfg->fc_table = nla_get_u32(attr);
548 break;
549 }
550 }
551
552 return 0;
553errout:
554 return err;
555}
556
557static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
558{
559 struct net *net = sock_net(skb->sk);
560 struct fib_config cfg;
561 struct fib_table *tb;
562 int err;
563
564 err = rtm_to_fib_config(net, skb, nlh, &cfg);
565 if (err < 0)
566 goto errout;
567
568 tb = fib_get_table(net, cfg.fc_table);
569 if (tb == NULL) {
570 err = -ESRCH;
571 goto errout;
572 }
573
574 err = fib_table_delete(tb, &cfg);
575errout:
576 return err;
577}
578
579static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
580{
581 struct net *net = sock_net(skb->sk);
582 struct fib_config cfg;
583 struct fib_table *tb;
584 int err;
585
586 err = rtm_to_fib_config(net, skb, nlh, &cfg);
587 if (err < 0)
588 goto errout;
589
590 tb = fib_new_table(net, cfg.fc_table);
591 if (tb == NULL) {
592 err = -ENOBUFS;
593 goto errout;
594 }
595
596 err = fib_table_insert(tb, &cfg);
597errout:
598 return err;
599}
600
601static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
602{
603 struct net *net = sock_net(skb->sk);
604 unsigned int h, s_h;
605 unsigned int e = 0, s_e;
606 struct fib_table *tb;
607 struct hlist_node *node;
608 struct hlist_head *head;
609 int dumped = 0;
610
611 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
612 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
613 return ip_rt_dump(skb, cb);
614
615 s_h = cb->args[0];
616 s_e = cb->args[1];
617
618 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
619 e = 0;
620 head = &net->ipv4.fib_table_hash[h];
621 hlist_for_each_entry(tb, node, head, tb_hlist) {
622 if (e < s_e)
623 goto next;
624 if (dumped)
625 memset(&cb->args[2], 0, sizeof(cb->args) -
626 2 * sizeof(cb->args[0]));
627 if (fib_table_dump(tb, skb, cb) < 0)
628 goto out;
629 dumped = 1;
630next:
631 e++;
632 }
633 }
634out:
635 cb->args[1] = e;
636 cb->args[0] = h;
637
638 return skb->len;
639}
640
641/* Prepare and feed intra-kernel routing request.
642 * Really, it should be netlink message, but :-( netlink
643 * can be not configured, so that we feed it directly
644 * to fib engine. It is legal, because all events occur
645 * only when netlink is already locked.
646 */
647static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
648{
649 struct net *net = dev_net(ifa->ifa_dev->dev);
650 struct fib_table *tb;
651 struct fib_config cfg = {
652 .fc_protocol = RTPROT_KERNEL,
653 .fc_type = type,
654 .fc_dst = dst,
655 .fc_dst_len = dst_len,
656 .fc_prefsrc = ifa->ifa_local,
657 .fc_oif = ifa->ifa_dev->dev->ifindex,
658 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
659 .fc_nlinfo = {
660 .nl_net = net,
661 },
662 };
663
664 if (type == RTN_UNICAST)
665 tb = fib_new_table(net, RT_TABLE_MAIN);
666 else
667 tb = fib_new_table(net, RT_TABLE_LOCAL);
668
669 if (tb == NULL)
670 return;
671
672 cfg.fc_table = tb->tb_id;
673
674 if (type != RTN_LOCAL)
675 cfg.fc_scope = RT_SCOPE_LINK;
676 else
677 cfg.fc_scope = RT_SCOPE_HOST;
678
679 if (cmd == RTM_NEWROUTE)
680 fib_table_insert(tb, &cfg);
681 else
682 fib_table_delete(tb, &cfg);
683}
684
685void fib_add_ifaddr(struct in_ifaddr *ifa)
686{
687 struct in_device *in_dev = ifa->ifa_dev;
688 struct net_device *dev = in_dev->dev;
689 struct in_ifaddr *prim = ifa;
690 __be32 mask = ifa->ifa_mask;
691 __be32 addr = ifa->ifa_local;
692 __be32 prefix = ifa->ifa_address & mask;
693
694 if (ifa->ifa_flags & IFA_F_SECONDARY) {
695 prim = inet_ifa_byprefix(in_dev, prefix, mask);
696 if (prim == NULL) {
697 pr_warn("%s: bug: prim == NULL\n", __func__);
698 return;
699 }
700 }
701
702 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
703
704 if (!(dev->flags & IFF_UP))
705 return;
706
707 /* Add broadcast address, if it is explicitly assigned. */
708 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
709 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
710
711 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
712 (prefix != addr || ifa->ifa_prefixlen < 32)) {
713 fib_magic(RTM_NEWROUTE,
714 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
715 prefix, ifa->ifa_prefixlen, prim);
716
717 /* Add network specific broadcasts, when it takes a sense */
718 if (ifa->ifa_prefixlen < 31) {
719 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
720 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
721 32, prim);
722 }
723 }
724}
725
726/* Delete primary or secondary address.
727 * Optionally, on secondary address promotion consider the addresses
728 * from subnet iprim as deleted, even if they are in device list.
729 * In this case the secondary ifa can be in device list.
730 */
731void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
732{
733 struct in_device *in_dev = ifa->ifa_dev;
734 struct net_device *dev = in_dev->dev;
735 struct in_ifaddr *ifa1;
736 struct in_ifaddr *prim = ifa, *prim1 = NULL;
737 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
738 __be32 any = ifa->ifa_address & ifa->ifa_mask;
739#define LOCAL_OK 1
740#define BRD_OK 2
741#define BRD0_OK 4
742#define BRD1_OK 8
743 unsigned int ok = 0;
744 int subnet = 0; /* Primary network */
745 int gone = 1; /* Address is missing */
746 int same_prefsrc = 0; /* Another primary with same IP */
747
748 if (ifa->ifa_flags & IFA_F_SECONDARY) {
749 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
750 if (prim == NULL) {
751 pr_warn("%s: bug: prim == NULL\n", __func__);
752 return;
753 }
754 if (iprim && iprim != prim) {
755 pr_warn("%s: bug: iprim != prim\n", __func__);
756 return;
757 }
758 } else if (!ipv4_is_zeronet(any) &&
759 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
760 fib_magic(RTM_DELROUTE,
761 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
762 any, ifa->ifa_prefixlen, prim);
763 subnet = 1;
764 }
765
766 /* Deletion is more complicated than add.
767 * We should take care of not to delete too much :-)
768 *
769 * Scan address list to be sure that addresses are really gone.
770 */
771
772 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
773 if (ifa1 == ifa) {
774 /* promotion, keep the IP */
775 gone = 0;
776 continue;
777 }
778 /* Ignore IFAs from our subnet */
779 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
780 inet_ifa_match(ifa1->ifa_address, iprim))
781 continue;
782
783 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
784 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
785 /* Another address from our subnet? */
786 if (ifa1->ifa_mask == prim->ifa_mask &&
787 inet_ifa_match(ifa1->ifa_address, prim))
788 prim1 = prim;
789 else {
790 /* We reached the secondaries, so
791 * same_prefsrc should be determined.
792 */
793 if (!same_prefsrc)
794 continue;
795 /* Search new prim1 if ifa1 is not
796 * using the current prim1
797 */
798 if (!prim1 ||
799 ifa1->ifa_mask != prim1->ifa_mask ||
800 !inet_ifa_match(ifa1->ifa_address, prim1))
801 prim1 = inet_ifa_byprefix(in_dev,
802 ifa1->ifa_address,
803 ifa1->ifa_mask);
804 if (!prim1)
805 continue;
806 if (prim1->ifa_local != prim->ifa_local)
807 continue;
808 }
809 } else {
810 if (prim->ifa_local != ifa1->ifa_local)
811 continue;
812 prim1 = ifa1;
813 if (prim != prim1)
814 same_prefsrc = 1;
815 }
816 if (ifa->ifa_local == ifa1->ifa_local)
817 ok |= LOCAL_OK;
818 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
819 ok |= BRD_OK;
820 if (brd == ifa1->ifa_broadcast)
821 ok |= BRD1_OK;
822 if (any == ifa1->ifa_broadcast)
823 ok |= BRD0_OK;
824 /* primary has network specific broadcasts */
825 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
826 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
827 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
828
829 if (!ipv4_is_zeronet(any1)) {
830 if (ifa->ifa_broadcast == brd1 ||
831 ifa->ifa_broadcast == any1)
832 ok |= BRD_OK;
833 if (brd == brd1 || brd == any1)
834 ok |= BRD1_OK;
835 if (any == brd1 || any == any1)
836 ok |= BRD0_OK;
837 }
838 }
839 }
840
841 if (!(ok & BRD_OK))
842 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
843 if (subnet && ifa->ifa_prefixlen < 31) {
844 if (!(ok & BRD1_OK))
845 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
846 if (!(ok & BRD0_OK))
847 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
848 }
849 if (!(ok & LOCAL_OK)) {
850 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
851
852 /* Check, that this local address finally disappeared. */
853 if (gone &&
854 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
855 /* And the last, but not the least thing.
856 * We must flush stray FIB entries.
857 *
858 * First of all, we scan fib_info list searching
859 * for stray nexthop entries, then ignite fib_flush.
860 */
861 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
862 fib_flush(dev_net(dev));
863 }
864 }
865#undef LOCAL_OK
866#undef BRD_OK
867#undef BRD0_OK
868#undef BRD1_OK
869}
870
871static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
872{
873
874 struct fib_result res;
875 struct flowi4 fl4 = {
876 .flowi4_mark = frn->fl_mark,
877 .daddr = frn->fl_addr,
878 .flowi4_tos = frn->fl_tos,
879 .flowi4_scope = frn->fl_scope,
880 };
881
882#ifdef CONFIG_IP_MULTIPLE_TABLES
883 res.r = NULL;
884#endif
885
886 frn->err = -ENOENT;
887 if (tb) {
888 local_bh_disable();
889
890 frn->tb_id = tb->tb_id;
891 rcu_read_lock();
892 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
893
894 if (!frn->err) {
895 frn->prefixlen = res.prefixlen;
896 frn->nh_sel = res.nh_sel;
897 frn->type = res.type;
898 frn->scope = res.scope;
899 }
900 rcu_read_unlock();
901 local_bh_enable();
902 }
903}
904
905static void nl_fib_input(struct sk_buff *skb)
906{
907 struct net *net;
908 struct fib_result_nl *frn;
909 struct nlmsghdr *nlh;
910 struct fib_table *tb;
911 u32 pid;
912
913 net = sock_net(skb->sk);
914 nlh = nlmsg_hdr(skb);
915 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
916 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
917 return;
918
919 skb = skb_clone(skb, GFP_KERNEL);
920 if (skb == NULL)
921 return;
922 nlh = nlmsg_hdr(skb);
923
924 frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
925 tb = fib_get_table(net, frn->tb_id_in);
926
927 nl_fib_lookup(frn, tb);
928
929 pid = NETLINK_CB(skb).pid; /* pid of sending process */
930 NETLINK_CB(skb).pid = 0; /* from kernel */
931 NETLINK_CB(skb).dst_group = 0; /* unicast */
932 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
933}
934
935static int __net_init nl_fib_lookup_init(struct net *net)
936{
937 struct sock *sk;
938 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
939 nl_fib_input, NULL, THIS_MODULE);
940 if (sk == NULL)
941 return -EAFNOSUPPORT;
942 net->ipv4.fibnl = sk;
943 return 0;
944}
945
946static void nl_fib_lookup_exit(struct net *net)
947{
948 netlink_kernel_release(net->ipv4.fibnl);
949 net->ipv4.fibnl = NULL;
950}
951
952static void fib_disable_ip(struct net_device *dev, int force, int delay)
953{
954 if (fib_sync_down_dev(dev, force))
955 fib_flush(dev_net(dev));
956 rt_cache_flush(dev_net(dev), delay);
957 arp_ifdown(dev);
958}
959
960static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
961{
962 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
963 struct net_device *dev = ifa->ifa_dev->dev;
964 struct net *net = dev_net(dev);
965
966 switch (event) {
967 case NETDEV_UP:
968 fib_add_ifaddr(ifa);
969#ifdef CONFIG_IP_ROUTE_MULTIPATH
970 fib_sync_up(dev);
971#endif
972 atomic_inc(&net->ipv4.dev_addr_genid);
973 rt_cache_flush(dev_net(dev), -1);
974 break;
975 case NETDEV_DOWN:
976 fib_del_ifaddr(ifa, NULL);
977 atomic_inc(&net->ipv4.dev_addr_genid);
978 if (ifa->ifa_dev->ifa_list == NULL) {
979 /* Last address was deleted from this interface.
980 * Disable IP.
981 */
982 fib_disable_ip(dev, 1, 0);
983 } else {
984 rt_cache_flush(dev_net(dev), -1);
985 }
986 break;
987 }
988 return NOTIFY_DONE;
989}
990
991static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
992{
993 struct net_device *dev = ptr;
994 struct in_device *in_dev = __in_dev_get_rtnl(dev);
995 struct net *net = dev_net(dev);
996
997 if (event == NETDEV_UNREGISTER) {
998 fib_disable_ip(dev, 2, -1);
999 return NOTIFY_DONE;
1000 }
1001
1002 if (!in_dev)
1003 return NOTIFY_DONE;
1004
1005 switch (event) {
1006 case NETDEV_UP:
1007 for_ifa(in_dev) {
1008 fib_add_ifaddr(ifa);
1009 } endfor_ifa(in_dev);
1010#ifdef CONFIG_IP_ROUTE_MULTIPATH
1011 fib_sync_up(dev);
1012#endif
1013 atomic_inc(&net->ipv4.dev_addr_genid);
1014 rt_cache_flush(dev_net(dev), -1);
1015 break;
1016 case NETDEV_DOWN:
1017 fib_disable_ip(dev, 0, 0);
1018 break;
1019 case NETDEV_CHANGEMTU:
1020 case NETDEV_CHANGE:
1021 rt_cache_flush(dev_net(dev), 0);
1022 break;
1023 case NETDEV_UNREGISTER_BATCH:
1024 /* The batch unregister is only called on the first
1025 * device in the list of devices being unregistered.
1026 * Therefore we should not pass dev_net(dev) in here.
1027 */
1028 rt_cache_flush_batch(NULL);
1029 break;
1030 }
1031 return NOTIFY_DONE;
1032}
1033
1034static struct notifier_block fib_inetaddr_notifier = {
1035 .notifier_call = fib_inetaddr_event,
1036};
1037
1038static struct notifier_block fib_netdev_notifier = {
1039 .notifier_call = fib_netdev_event,
1040};
1041
1042static int __net_init ip_fib_net_init(struct net *net)
1043{
1044 int err;
1045 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1046
1047 /* Avoid false sharing : Use at least a full cache line */
1048 size = max_t(size_t, size, L1_CACHE_BYTES);
1049
1050 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1051 if (net->ipv4.fib_table_hash == NULL)
1052 return -ENOMEM;
1053
1054 err = fib4_rules_init(net);
1055 if (err < 0)
1056 goto fail;
1057 return 0;
1058
1059fail:
1060 kfree(net->ipv4.fib_table_hash);
1061 return err;
1062}
1063
1064static void ip_fib_net_exit(struct net *net)
1065{
1066 unsigned int i;
1067
1068#ifdef CONFIG_IP_MULTIPLE_TABLES
1069 fib4_rules_exit(net);
1070#endif
1071
1072 rtnl_lock();
1073 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1074 struct fib_table *tb;
1075 struct hlist_head *head;
1076 struct hlist_node *node, *tmp;
1077
1078 head = &net->ipv4.fib_table_hash[i];
1079 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1080 hlist_del(node);
1081 fib_table_flush(tb);
1082 fib_free_table(tb);
1083 }
1084 }
1085 rtnl_unlock();
1086 kfree(net->ipv4.fib_table_hash);
1087}
1088
1089static int __net_init fib_net_init(struct net *net)
1090{
1091 int error;
1092
1093 error = ip_fib_net_init(net);
1094 if (error < 0)
1095 goto out;
1096 error = nl_fib_lookup_init(net);
1097 if (error < 0)
1098 goto out_nlfl;
1099 error = fib_proc_init(net);
1100 if (error < 0)
1101 goto out_proc;
1102out:
1103 return error;
1104
1105out_proc:
1106 nl_fib_lookup_exit(net);
1107out_nlfl:
1108 ip_fib_net_exit(net);
1109 goto out;
1110}
1111
1112static void __net_exit fib_net_exit(struct net *net)
1113{
1114 fib_proc_exit(net);
1115 nl_fib_lookup_exit(net);
1116 ip_fib_net_exit(net);
1117}
1118
1119static struct pernet_operations fib_net_ops = {
1120 .init = fib_net_init,
1121 .exit = fib_net_exit,
1122};
1123
1124void __init ip_fib_init(void)
1125{
1126 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1127 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1128 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1129
1130 register_pernet_subsys(&fib_net_ops);
1131 register_netdevice_notifier(&fib_netdev_notifier);
1132 register_inetaddr_notifier(&fib_inetaddr_notifier);
1133
1134 fib_trie_init();
1135}