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Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[deliverable/linux.git] / net / ipv4 / fib_frontend.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * IPv4 Forwarding Information Base: FIB frontend.
7 *
8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16 #include <linux/module.h>
17 #include <asm/uaccess.h>
18 #include <asm/system.h>
19 #include <linux/bitops.h>
20 #include <linux/capability.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/string.h>
25 #include <linux/socket.h>
26 #include <linux/sockios.h>
27 #include <linux/errno.h>
28 #include <linux/in.h>
29 #include <linux/inet.h>
30 #include <linux/inetdevice.h>
31 #include <linux/netdevice.h>
32 #include <linux/if_addr.h>
33 #include <linux/if_arp.h>
34 #include <linux/skbuff.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
48 #ifndef CONFIG_IP_MULTIPLE_TABLES
49
50 static int __net_init fib4_rules_init(struct net *net)
51 {
52 struct fib_table *local_table, *main_table;
53
54 local_table = fib_hash_table(RT_TABLE_LOCAL);
55 if (local_table == NULL)
56 return -ENOMEM;
57
58 main_table = fib_hash_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
68 fail:
69 kfree(local_table);
70 return -ENOMEM;
71 }
72 #else
73
74 struct 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_hash_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
93 struct 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
117 void fib_select_default(struct net *net,
118 const struct flowi *flp, struct fib_result *res)
119 {
120 struct fib_table *tb;
121 int table = RT_TABLE_MAIN;
122 #ifdef CONFIG_IP_MULTIPLE_TABLES
123 if (res->r == NULL || res->r->action != FR_ACT_TO_TBL)
124 return;
125 table = res->r->table;
126 #endif
127 tb = fib_get_table(net, table);
128 if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
129 fib_table_select_default(tb, flp, res);
130 }
131
132 static void fib_flush(struct net *net)
133 {
134 int flushed = 0;
135 struct fib_table *tb;
136 struct hlist_node *node;
137 struct hlist_head *head;
138 unsigned int h;
139
140 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
141 head = &net->ipv4.fib_table_hash[h];
142 hlist_for_each_entry(tb, node, head, tb_hlist)
143 flushed += fib_table_flush(tb);
144 }
145
146 if (flushed)
147 rt_cache_flush(net, -1);
148 }
149
150 /**
151 * __ip_dev_find - find the first device with a given source address.
152 * @net: the net namespace
153 * @addr: the source address
154 * @devref: if true, take a reference on the found device
155 *
156 * If a caller uses devref=false, it should be protected by RCU, or RTNL
157 */
158 struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
159 {
160 struct flowi fl = {
161 .fl4_dst = addr,
162 };
163 struct fib_result res = { 0 };
164 struct net_device *dev = NULL;
165 struct fib_table *local_table;
166
167 #ifdef CONFIG_IP_MULTIPLE_TABLES
168 res.r = NULL;
169 #endif
170
171 rcu_read_lock();
172 local_table = fib_get_table(net, RT_TABLE_LOCAL);
173 if (!local_table ||
174 fib_table_lookup(local_table, &fl, &res, FIB_LOOKUP_NOREF)) {
175 rcu_read_unlock();
176 return NULL;
177 }
178 if (res.type != RTN_LOCAL)
179 goto out;
180 dev = FIB_RES_DEV(res);
181
182 if (dev && devref)
183 dev_hold(dev);
184 out:
185 rcu_read_unlock();
186 return dev;
187 }
188 EXPORT_SYMBOL(__ip_dev_find);
189
190 /*
191 * Find address type as if only "dev" was present in the system. If
192 * on_dev is NULL then all interfaces are taken into consideration.
193 */
194 static inline unsigned __inet_dev_addr_type(struct net *net,
195 const struct net_device *dev,
196 __be32 addr)
197 {
198 struct flowi fl = { .fl4_dst = addr };
199 struct fib_result res;
200 unsigned ret = RTN_BROADCAST;
201 struct fib_table *local_table;
202
203 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
204 return RTN_BROADCAST;
205 if (ipv4_is_multicast(addr))
206 return RTN_MULTICAST;
207
208 #ifdef CONFIG_IP_MULTIPLE_TABLES
209 res.r = NULL;
210 #endif
211
212 local_table = fib_get_table(net, RT_TABLE_LOCAL);
213 if (local_table) {
214 ret = RTN_UNICAST;
215 rcu_read_lock();
216 if (!fib_table_lookup(local_table, &fl, &res, FIB_LOOKUP_NOREF)) {
217 if (!dev || dev == res.fi->fib_dev)
218 ret = res.type;
219 }
220 rcu_read_unlock();
221 }
222 return ret;
223 }
224
225 unsigned int inet_addr_type(struct net *net, __be32 addr)
226 {
227 return __inet_dev_addr_type(net, NULL, addr);
228 }
229 EXPORT_SYMBOL(inet_addr_type);
230
231 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
232 __be32 addr)
233 {
234 return __inet_dev_addr_type(net, dev, addr);
235 }
236 EXPORT_SYMBOL(inet_dev_addr_type);
237
238 /* Given (packet source, input interface) and optional (dst, oif, tos):
239 * - (main) check, that source is valid i.e. not broadcast or our local
240 * address.
241 * - figure out what "logical" interface this packet arrived
242 * and calculate "specific destination" address.
243 * - check, that packet arrived from expected physical interface.
244 * called with rcu_read_lock()
245 */
246 int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
247 struct net_device *dev, __be32 *spec_dst,
248 u32 *itag, u32 mark)
249 {
250 struct in_device *in_dev;
251 struct flowi fl = {
252 .fl4_dst = src,
253 .fl4_src = dst,
254 .fl4_tos = tos,
255 .mark = mark,
256 .iif = oif
257 };
258 struct fib_result res;
259 int no_addr, rpf, accept_local;
260 bool dev_match;
261 int ret;
262 struct net *net;
263
264 no_addr = rpf = accept_local = 0;
265 in_dev = __in_dev_get_rcu(dev);
266 if (in_dev) {
267 no_addr = in_dev->ifa_list == NULL;
268 rpf = IN_DEV_RPFILTER(in_dev);
269 accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
270 if (mark && !IN_DEV_SRC_VMARK(in_dev))
271 fl.mark = 0;
272 }
273
274 if (in_dev == NULL)
275 goto e_inval;
276
277 net = dev_net(dev);
278 if (fib_lookup(net, &fl, &res))
279 goto last_resort;
280 if (res.type != RTN_UNICAST) {
281 if (res.type != RTN_LOCAL || !accept_local)
282 goto e_inval;
283 }
284 *spec_dst = FIB_RES_PREFSRC(res);
285 fib_combine_itag(itag, &res);
286 dev_match = false;
287
288 #ifdef CONFIG_IP_ROUTE_MULTIPATH
289 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
290 struct fib_nh *nh = &res.fi->fib_nh[ret];
291
292 if (nh->nh_dev == dev) {
293 dev_match = true;
294 break;
295 }
296 }
297 #else
298 if (FIB_RES_DEV(res) == dev)
299 dev_match = true;
300 #endif
301 if (dev_match) {
302 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
303 return ret;
304 }
305 if (no_addr)
306 goto last_resort;
307 if (rpf == 1)
308 goto e_rpf;
309 fl.oif = dev->ifindex;
310
311 ret = 0;
312 if (fib_lookup(net, &fl, &res) == 0) {
313 if (res.type == RTN_UNICAST) {
314 *spec_dst = FIB_RES_PREFSRC(res);
315 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
316 }
317 }
318 return ret;
319
320 last_resort:
321 if (rpf)
322 goto e_rpf;
323 *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
324 *itag = 0;
325 return 0;
326
327 e_inval:
328 return -EINVAL;
329 e_rpf:
330 return -EXDEV;
331 }
332
333 static inline __be32 sk_extract_addr(struct sockaddr *addr)
334 {
335 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
336 }
337
338 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
339 {
340 struct nlattr *nla;
341
342 nla = (struct nlattr *) ((char *) mx + len);
343 nla->nla_type = type;
344 nla->nla_len = nla_attr_size(4);
345 *(u32 *) nla_data(nla) = value;
346
347 return len + nla_total_size(4);
348 }
349
350 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
351 struct fib_config *cfg)
352 {
353 __be32 addr;
354 int plen;
355
356 memset(cfg, 0, sizeof(*cfg));
357 cfg->fc_nlinfo.nl_net = net;
358
359 if (rt->rt_dst.sa_family != AF_INET)
360 return -EAFNOSUPPORT;
361
362 /*
363 * Check mask for validity:
364 * a) it must be contiguous.
365 * b) destination must have all host bits clear.
366 * c) if application forgot to set correct family (AF_INET),
367 * reject request unless it is absolutely clear i.e.
368 * both family and mask are zero.
369 */
370 plen = 32;
371 addr = sk_extract_addr(&rt->rt_dst);
372 if (!(rt->rt_flags & RTF_HOST)) {
373 __be32 mask = sk_extract_addr(&rt->rt_genmask);
374
375 if (rt->rt_genmask.sa_family != AF_INET) {
376 if (mask || rt->rt_genmask.sa_family)
377 return -EAFNOSUPPORT;
378 }
379
380 if (bad_mask(mask, addr))
381 return -EINVAL;
382
383 plen = inet_mask_len(mask);
384 }
385
386 cfg->fc_dst_len = plen;
387 cfg->fc_dst = addr;
388
389 if (cmd != SIOCDELRT) {
390 cfg->fc_nlflags = NLM_F_CREATE;
391 cfg->fc_protocol = RTPROT_BOOT;
392 }
393
394 if (rt->rt_metric)
395 cfg->fc_priority = rt->rt_metric - 1;
396
397 if (rt->rt_flags & RTF_REJECT) {
398 cfg->fc_scope = RT_SCOPE_HOST;
399 cfg->fc_type = RTN_UNREACHABLE;
400 return 0;
401 }
402
403 cfg->fc_scope = RT_SCOPE_NOWHERE;
404 cfg->fc_type = RTN_UNICAST;
405
406 if (rt->rt_dev) {
407 char *colon;
408 struct net_device *dev;
409 char devname[IFNAMSIZ];
410
411 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
412 return -EFAULT;
413
414 devname[IFNAMSIZ-1] = 0;
415 colon = strchr(devname, ':');
416 if (colon)
417 *colon = 0;
418 dev = __dev_get_by_name(net, devname);
419 if (!dev)
420 return -ENODEV;
421 cfg->fc_oif = dev->ifindex;
422 if (colon) {
423 struct in_ifaddr *ifa;
424 struct in_device *in_dev = __in_dev_get_rtnl(dev);
425 if (!in_dev)
426 return -ENODEV;
427 *colon = ':';
428 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
429 if (strcmp(ifa->ifa_label, devname) == 0)
430 break;
431 if (ifa == NULL)
432 return -ENODEV;
433 cfg->fc_prefsrc = ifa->ifa_local;
434 }
435 }
436
437 addr = sk_extract_addr(&rt->rt_gateway);
438 if (rt->rt_gateway.sa_family == AF_INET && addr) {
439 cfg->fc_gw = addr;
440 if (rt->rt_flags & RTF_GATEWAY &&
441 inet_addr_type(net, addr) == RTN_UNICAST)
442 cfg->fc_scope = RT_SCOPE_UNIVERSE;
443 }
444
445 if (cmd == SIOCDELRT)
446 return 0;
447
448 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
449 return -EINVAL;
450
451 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
452 cfg->fc_scope = RT_SCOPE_LINK;
453
454 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
455 struct nlattr *mx;
456 int len = 0;
457
458 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
459 if (mx == NULL)
460 return -ENOMEM;
461
462 if (rt->rt_flags & RTF_MTU)
463 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
464
465 if (rt->rt_flags & RTF_WINDOW)
466 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
467
468 if (rt->rt_flags & RTF_IRTT)
469 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
470
471 cfg->fc_mx = mx;
472 cfg->fc_mx_len = len;
473 }
474
475 return 0;
476 }
477
478 /*
479 * Handle IP routing ioctl calls.
480 * These are used to manipulate the routing tables
481 */
482 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
483 {
484 struct fib_config cfg;
485 struct rtentry rt;
486 int err;
487
488 switch (cmd) {
489 case SIOCADDRT: /* Add a route */
490 case SIOCDELRT: /* Delete a route */
491 if (!capable(CAP_NET_ADMIN))
492 return -EPERM;
493
494 if (copy_from_user(&rt, arg, sizeof(rt)))
495 return -EFAULT;
496
497 rtnl_lock();
498 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
499 if (err == 0) {
500 struct fib_table *tb;
501
502 if (cmd == SIOCDELRT) {
503 tb = fib_get_table(net, cfg.fc_table);
504 if (tb)
505 err = fib_table_delete(tb, &cfg);
506 else
507 err = -ESRCH;
508 } else {
509 tb = fib_new_table(net, cfg.fc_table);
510 if (tb)
511 err = fib_table_insert(tb, &cfg);
512 else
513 err = -ENOBUFS;
514 }
515
516 /* allocated by rtentry_to_fib_config() */
517 kfree(cfg.fc_mx);
518 }
519 rtnl_unlock();
520 return err;
521 }
522 return -EINVAL;
523 }
524
525 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
526 [RTA_DST] = { .type = NLA_U32 },
527 [RTA_SRC] = { .type = NLA_U32 },
528 [RTA_IIF] = { .type = NLA_U32 },
529 [RTA_OIF] = { .type = NLA_U32 },
530 [RTA_GATEWAY] = { .type = NLA_U32 },
531 [RTA_PRIORITY] = { .type = NLA_U32 },
532 [RTA_PREFSRC] = { .type = NLA_U32 },
533 [RTA_METRICS] = { .type = NLA_NESTED },
534 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
535 [RTA_FLOW] = { .type = NLA_U32 },
536 };
537
538 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
539 struct nlmsghdr *nlh, struct fib_config *cfg)
540 {
541 struct nlattr *attr;
542 int err, remaining;
543 struct rtmsg *rtm;
544
545 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
546 if (err < 0)
547 goto errout;
548
549 memset(cfg, 0, sizeof(*cfg));
550
551 rtm = nlmsg_data(nlh);
552 cfg->fc_dst_len = rtm->rtm_dst_len;
553 cfg->fc_tos = rtm->rtm_tos;
554 cfg->fc_table = rtm->rtm_table;
555 cfg->fc_protocol = rtm->rtm_protocol;
556 cfg->fc_scope = rtm->rtm_scope;
557 cfg->fc_type = rtm->rtm_type;
558 cfg->fc_flags = rtm->rtm_flags;
559 cfg->fc_nlflags = nlh->nlmsg_flags;
560
561 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
562 cfg->fc_nlinfo.nlh = nlh;
563 cfg->fc_nlinfo.nl_net = net;
564
565 if (cfg->fc_type > RTN_MAX) {
566 err = -EINVAL;
567 goto errout;
568 }
569
570 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
571 switch (nla_type(attr)) {
572 case RTA_DST:
573 cfg->fc_dst = nla_get_be32(attr);
574 break;
575 case RTA_OIF:
576 cfg->fc_oif = nla_get_u32(attr);
577 break;
578 case RTA_GATEWAY:
579 cfg->fc_gw = nla_get_be32(attr);
580 break;
581 case RTA_PRIORITY:
582 cfg->fc_priority = nla_get_u32(attr);
583 break;
584 case RTA_PREFSRC:
585 cfg->fc_prefsrc = nla_get_be32(attr);
586 break;
587 case RTA_METRICS:
588 cfg->fc_mx = nla_data(attr);
589 cfg->fc_mx_len = nla_len(attr);
590 break;
591 case RTA_MULTIPATH:
592 cfg->fc_mp = nla_data(attr);
593 cfg->fc_mp_len = nla_len(attr);
594 break;
595 case RTA_FLOW:
596 cfg->fc_flow = nla_get_u32(attr);
597 break;
598 case RTA_TABLE:
599 cfg->fc_table = nla_get_u32(attr);
600 break;
601 }
602 }
603
604 return 0;
605 errout:
606 return err;
607 }
608
609 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
610 {
611 struct net *net = sock_net(skb->sk);
612 struct fib_config cfg;
613 struct fib_table *tb;
614 int err;
615
616 err = rtm_to_fib_config(net, skb, nlh, &cfg);
617 if (err < 0)
618 goto errout;
619
620 tb = fib_get_table(net, cfg.fc_table);
621 if (tb == NULL) {
622 err = -ESRCH;
623 goto errout;
624 }
625
626 err = fib_table_delete(tb, &cfg);
627 errout:
628 return err;
629 }
630
631 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
632 {
633 struct net *net = sock_net(skb->sk);
634 struct fib_config cfg;
635 struct fib_table *tb;
636 int err;
637
638 err = rtm_to_fib_config(net, skb, nlh, &cfg);
639 if (err < 0)
640 goto errout;
641
642 tb = fib_new_table(net, cfg.fc_table);
643 if (tb == NULL) {
644 err = -ENOBUFS;
645 goto errout;
646 }
647
648 err = fib_table_insert(tb, &cfg);
649 errout:
650 return err;
651 }
652
653 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
654 {
655 struct net *net = sock_net(skb->sk);
656 unsigned int h, s_h;
657 unsigned int e = 0, s_e;
658 struct fib_table *tb;
659 struct hlist_node *node;
660 struct hlist_head *head;
661 int dumped = 0;
662
663 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
664 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
665 return ip_rt_dump(skb, cb);
666
667 s_h = cb->args[0];
668 s_e = cb->args[1];
669
670 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
671 e = 0;
672 head = &net->ipv4.fib_table_hash[h];
673 hlist_for_each_entry(tb, node, head, tb_hlist) {
674 if (e < s_e)
675 goto next;
676 if (dumped)
677 memset(&cb->args[2], 0, sizeof(cb->args) -
678 2 * sizeof(cb->args[0]));
679 if (fib_table_dump(tb, skb, cb) < 0)
680 goto out;
681 dumped = 1;
682 next:
683 e++;
684 }
685 }
686 out:
687 cb->args[1] = e;
688 cb->args[0] = h;
689
690 return skb->len;
691 }
692
693 /* Prepare and feed intra-kernel routing request.
694 * Really, it should be netlink message, but :-( netlink
695 * can be not configured, so that we feed it directly
696 * to fib engine. It is legal, because all events occur
697 * only when netlink is already locked.
698 */
699 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
700 {
701 struct net *net = dev_net(ifa->ifa_dev->dev);
702 struct fib_table *tb;
703 struct fib_config cfg = {
704 .fc_protocol = RTPROT_KERNEL,
705 .fc_type = type,
706 .fc_dst = dst,
707 .fc_dst_len = dst_len,
708 .fc_prefsrc = ifa->ifa_local,
709 .fc_oif = ifa->ifa_dev->dev->ifindex,
710 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
711 .fc_nlinfo = {
712 .nl_net = net,
713 },
714 };
715
716 if (type == RTN_UNICAST)
717 tb = fib_new_table(net, RT_TABLE_MAIN);
718 else
719 tb = fib_new_table(net, RT_TABLE_LOCAL);
720
721 if (tb == NULL)
722 return;
723
724 cfg.fc_table = tb->tb_id;
725
726 if (type != RTN_LOCAL)
727 cfg.fc_scope = RT_SCOPE_LINK;
728 else
729 cfg.fc_scope = RT_SCOPE_HOST;
730
731 if (cmd == RTM_NEWROUTE)
732 fib_table_insert(tb, &cfg);
733 else
734 fib_table_delete(tb, &cfg);
735 }
736
737 void fib_add_ifaddr(struct in_ifaddr *ifa)
738 {
739 struct in_device *in_dev = ifa->ifa_dev;
740 struct net_device *dev = in_dev->dev;
741 struct in_ifaddr *prim = ifa;
742 __be32 mask = ifa->ifa_mask;
743 __be32 addr = ifa->ifa_local;
744 __be32 prefix = ifa->ifa_address & mask;
745
746 if (ifa->ifa_flags & IFA_F_SECONDARY) {
747 prim = inet_ifa_byprefix(in_dev, prefix, mask);
748 if (prim == NULL) {
749 printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n");
750 return;
751 }
752 }
753
754 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
755
756 if (!(dev->flags & IFF_UP))
757 return;
758
759 /* Add broadcast address, if it is explicitly assigned. */
760 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
761 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
762
763 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
764 (prefix != addr || ifa->ifa_prefixlen < 32)) {
765 fib_magic(RTM_NEWROUTE,
766 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
767 prefix, ifa->ifa_prefixlen, prim);
768
769 /* Add network specific broadcasts, when it takes a sense */
770 if (ifa->ifa_prefixlen < 31) {
771 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
772 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
773 32, prim);
774 }
775 }
776 }
777
778 static void fib_del_ifaddr(struct in_ifaddr *ifa)
779 {
780 struct in_device *in_dev = ifa->ifa_dev;
781 struct net_device *dev = in_dev->dev;
782 struct in_ifaddr *ifa1;
783 struct in_ifaddr *prim = ifa;
784 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
785 __be32 any = ifa->ifa_address & ifa->ifa_mask;
786 #define LOCAL_OK 1
787 #define BRD_OK 2
788 #define BRD0_OK 4
789 #define BRD1_OK 8
790 unsigned ok = 0;
791
792 if (!(ifa->ifa_flags & IFA_F_SECONDARY))
793 fib_magic(RTM_DELROUTE,
794 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
795 any, ifa->ifa_prefixlen, prim);
796 else {
797 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
798 if (prim == NULL) {
799 printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
800 return;
801 }
802 }
803
804 /* Deletion is more complicated than add.
805 * We should take care of not to delete too much :-)
806 *
807 * Scan address list to be sure that addresses are really gone.
808 */
809
810 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
811 if (ifa->ifa_local == ifa1->ifa_local)
812 ok |= LOCAL_OK;
813 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
814 ok |= BRD_OK;
815 if (brd == ifa1->ifa_broadcast)
816 ok |= BRD1_OK;
817 if (any == ifa1->ifa_broadcast)
818 ok |= BRD0_OK;
819 }
820
821 if (!(ok & BRD_OK))
822 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
823 if (!(ok & BRD1_OK))
824 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
825 if (!(ok & BRD0_OK))
826 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
827 if (!(ok & LOCAL_OK)) {
828 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
829
830 /* Check, that this local address finally disappeared. */
831 if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
832 /* And the last, but not the least thing.
833 * We must flush stray FIB entries.
834 *
835 * First of all, we scan fib_info list searching
836 * for stray nexthop entries, then ignite fib_flush.
837 */
838 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
839 fib_flush(dev_net(dev));
840 }
841 }
842 #undef LOCAL_OK
843 #undef BRD_OK
844 #undef BRD0_OK
845 #undef BRD1_OK
846 }
847
848 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
849 {
850
851 struct fib_result res;
852 struct flowi fl = {
853 .mark = frn->fl_mark,
854 .fl4_dst = frn->fl_addr,
855 .fl4_tos = frn->fl_tos,
856 .fl4_scope = frn->fl_scope,
857 };
858
859 #ifdef CONFIG_IP_MULTIPLE_TABLES
860 res.r = NULL;
861 #endif
862
863 frn->err = -ENOENT;
864 if (tb) {
865 local_bh_disable();
866
867 frn->tb_id = tb->tb_id;
868 rcu_read_lock();
869 frn->err = fib_table_lookup(tb, &fl, &res, FIB_LOOKUP_NOREF);
870
871 if (!frn->err) {
872 frn->prefixlen = res.prefixlen;
873 frn->nh_sel = res.nh_sel;
874 frn->type = res.type;
875 frn->scope = res.scope;
876 }
877 rcu_read_unlock();
878 local_bh_enable();
879 }
880 }
881
882 static void nl_fib_input(struct sk_buff *skb)
883 {
884 struct net *net;
885 struct fib_result_nl *frn;
886 struct nlmsghdr *nlh;
887 struct fib_table *tb;
888 u32 pid;
889
890 net = sock_net(skb->sk);
891 nlh = nlmsg_hdr(skb);
892 if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
893 nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
894 return;
895
896 skb = skb_clone(skb, GFP_KERNEL);
897 if (skb == NULL)
898 return;
899 nlh = nlmsg_hdr(skb);
900
901 frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
902 tb = fib_get_table(net, frn->tb_id_in);
903
904 nl_fib_lookup(frn, tb);
905
906 pid = NETLINK_CB(skb).pid; /* pid of sending process */
907 NETLINK_CB(skb).pid = 0; /* from kernel */
908 NETLINK_CB(skb).dst_group = 0; /* unicast */
909 netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
910 }
911
912 static int __net_init nl_fib_lookup_init(struct net *net)
913 {
914 struct sock *sk;
915 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
916 nl_fib_input, NULL, THIS_MODULE);
917 if (sk == NULL)
918 return -EAFNOSUPPORT;
919 net->ipv4.fibnl = sk;
920 return 0;
921 }
922
923 static void nl_fib_lookup_exit(struct net *net)
924 {
925 netlink_kernel_release(net->ipv4.fibnl);
926 net->ipv4.fibnl = NULL;
927 }
928
929 static void fib_disable_ip(struct net_device *dev, int force, int delay)
930 {
931 if (fib_sync_down_dev(dev, force))
932 fib_flush(dev_net(dev));
933 rt_cache_flush(dev_net(dev), delay);
934 arp_ifdown(dev);
935 }
936
937 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
938 {
939 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
940 struct net_device *dev = ifa->ifa_dev->dev;
941
942 switch (event) {
943 case NETDEV_UP:
944 fib_add_ifaddr(ifa);
945 #ifdef CONFIG_IP_ROUTE_MULTIPATH
946 fib_sync_up(dev);
947 #endif
948 rt_cache_flush(dev_net(dev), -1);
949 break;
950 case NETDEV_DOWN:
951 fib_del_ifaddr(ifa);
952 if (ifa->ifa_dev->ifa_list == NULL) {
953 /* Last address was deleted from this interface.
954 * Disable IP.
955 */
956 fib_disable_ip(dev, 1, 0);
957 } else {
958 rt_cache_flush(dev_net(dev), -1);
959 }
960 break;
961 }
962 return NOTIFY_DONE;
963 }
964
965 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
966 {
967 struct net_device *dev = ptr;
968 struct in_device *in_dev = __in_dev_get_rtnl(dev);
969
970 if (event == NETDEV_UNREGISTER) {
971 fib_disable_ip(dev, 2, -1);
972 return NOTIFY_DONE;
973 }
974
975 if (!in_dev)
976 return NOTIFY_DONE;
977
978 switch (event) {
979 case NETDEV_UP:
980 for_ifa(in_dev) {
981 fib_add_ifaddr(ifa);
982 } endfor_ifa(in_dev);
983 #ifdef CONFIG_IP_ROUTE_MULTIPATH
984 fib_sync_up(dev);
985 #endif
986 rt_cache_flush(dev_net(dev), -1);
987 break;
988 case NETDEV_DOWN:
989 fib_disable_ip(dev, 0, 0);
990 break;
991 case NETDEV_CHANGEMTU:
992 case NETDEV_CHANGE:
993 rt_cache_flush(dev_net(dev), 0);
994 break;
995 case NETDEV_UNREGISTER_BATCH:
996 /* The batch unregister is only called on the first
997 * device in the list of devices being unregistered.
998 * Therefore we should not pass dev_net(dev) in here.
999 */
1000 rt_cache_flush_batch(NULL);
1001 break;
1002 }
1003 return NOTIFY_DONE;
1004 }
1005
1006 static struct notifier_block fib_inetaddr_notifier = {
1007 .notifier_call = fib_inetaddr_event,
1008 };
1009
1010 static struct notifier_block fib_netdev_notifier = {
1011 .notifier_call = fib_netdev_event,
1012 };
1013
1014 static int __net_init ip_fib_net_init(struct net *net)
1015 {
1016 int err;
1017 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1018
1019 /* Avoid false sharing : Use at least a full cache line */
1020 size = max_t(size_t, size, L1_CACHE_BYTES);
1021
1022 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1023 if (net->ipv4.fib_table_hash == NULL)
1024 return -ENOMEM;
1025
1026 err = fib4_rules_init(net);
1027 if (err < 0)
1028 goto fail;
1029 return 0;
1030
1031 fail:
1032 kfree(net->ipv4.fib_table_hash);
1033 return err;
1034 }
1035
1036 static void ip_fib_net_exit(struct net *net)
1037 {
1038 unsigned int i;
1039
1040 #ifdef CONFIG_IP_MULTIPLE_TABLES
1041 fib4_rules_exit(net);
1042 #endif
1043
1044 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1045 struct fib_table *tb;
1046 struct hlist_head *head;
1047 struct hlist_node *node, *tmp;
1048
1049 head = &net->ipv4.fib_table_hash[i];
1050 hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
1051 hlist_del(node);
1052 fib_table_flush(tb);
1053 fib_free_table(tb);
1054 }
1055 }
1056 kfree(net->ipv4.fib_table_hash);
1057 }
1058
1059 static int __net_init fib_net_init(struct net *net)
1060 {
1061 int error;
1062
1063 error = ip_fib_net_init(net);
1064 if (error < 0)
1065 goto out;
1066 error = nl_fib_lookup_init(net);
1067 if (error < 0)
1068 goto out_nlfl;
1069 error = fib_proc_init(net);
1070 if (error < 0)
1071 goto out_proc;
1072 out:
1073 return error;
1074
1075 out_proc:
1076 nl_fib_lookup_exit(net);
1077 out_nlfl:
1078 ip_fib_net_exit(net);
1079 goto out;
1080 }
1081
1082 static void __net_exit fib_net_exit(struct net *net)
1083 {
1084 fib_proc_exit(net);
1085 nl_fib_lookup_exit(net);
1086 ip_fib_net_exit(net);
1087 }
1088
1089 static struct pernet_operations fib_net_ops = {
1090 .init = fib_net_init,
1091 .exit = fib_net_exit,
1092 };
1093
1094 void __init ip_fib_init(void)
1095 {
1096 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL);
1097 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL);
1098 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib);
1099
1100 register_pernet_subsys(&fib_net_ops);
1101 register_netdevice_notifier(&fib_netdev_notifier);
1102 register_inetaddr_notifier(&fib_inetaddr_notifier);
1103
1104 fib_hash_init();
1105 }
Linux kernel - Deliverables
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