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fix a kmap leak in virtio_console
[linux/fpc-iii.git] / net / ipv4 / fib_frontend.c
blobc7539e22868b37d59018730aca786176df5408ee
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
51 static 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
69 fail:
70 kfree(local_table);
71 return -ENOMEM;
72 }
73 #else
74
75 struct 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
112 struct 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
135 static 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 */
156 static 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
183 unsigned int inet_addr_type(struct net *net, __be32 addr)
184 {
185 return __inet_dev_addr_type(net, NULL, addr);
186 }
187 EXPORT_SYMBOL(inet_addr_type);
188
189 unsigned 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 }
194 EXPORT_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 */
242 static 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;
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
304 last_resort:
305 if (rpf)
306 goto e_rpf;
307 *itag = 0;
308 return 0;
309
310 e_inval:
311 return -EINVAL;
312 e_rpf:
313 return -EXDEV;
314 }
315
316 /* Ignore rp_filter for packets protected by IPsec. */
317 int 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
331 static inline __be32 sk_extract_addr(struct sockaddr *addr)
332 {
333 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
334 }
335
336 static 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
348 static 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 */
480 int 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
523 const 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
536 static 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;
603 errout:
604 return err;
605 }
606
607 static 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);
625 errout:
626 return err;
627 }
628
629 static 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);
647 errout:
648 return err;
649 }
650
651 static 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 ip_rt_dump(skb, cb);
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;
679 next:
680 e++;
681 }
682 }
683 out:
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 */
696 static 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
734 void 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 */
780 void 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
920 static 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
948 static 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
978 static 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
992 static void nl_fib_lookup_exit(struct net *net)
993 {
994 netlink_kernel_release(net->ipv4.fibnl);
995 net->ipv4.fibnl = NULL;
996 }
997
998 static 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
1006 static 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
1037 static 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
1075 static struct notifier_block fib_inetaddr_notifier = {
1076 .notifier_call = fib_inetaddr_event,
1077 };
1078
1079 static struct notifier_block fib_netdev_notifier = {
1080 .notifier_call = fib_netdev_event,
1081 };
1082
1083 static 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
1100 fail:
1101 kfree(net->ipv4.fib_table_hash);
1102 return err;
1103 }
1104
1105 static 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
1130 static 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;
1146 out:
1147 return error;
1148
1149 out_proc:
1150 nl_fib_lookup_exit(net);
1151 out_nlfl:
1152 ip_fib_net_exit(net);
1153 goto out;
1154 }
1155
1156 static 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
1163 static struct pernet_operations fib_net_ops = {
1164 .init = fib_net_init,
1165 .exit = fib_net_exit,
1166 };
1167
1168 void __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 }
Linux with added FPC-III support