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Merge branches 'ib-mfd-gpio-i2c-3.19', 'ib-mfd-iio-3.19' and 'ib-mfd-regulator-v3...
[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 <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;
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 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
262
263 net = dev_net(dev);
264 if (fib_lookup(net, &fl4, &res))
265 goto last_resort;
266 if (res.type != RTN_UNICAST &&
267 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
268 goto e_inval;
269 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
270 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
271 goto last_resort;
272 fib_combine_itag(itag, &res);
273 dev_match = false;
274
275 #ifdef CONFIG_IP_ROUTE_MULTIPATH
276 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
277 struct fib_nh *nh = &res.fi->fib_nh[ret];
278
279 if (nh->nh_dev == dev) {
280 dev_match = true;
281 break;
282 }
283 }
284 #else
285 if (FIB_RES_DEV(res) == dev)
286 dev_match = true;
287 #endif
288 if (dev_match) {
289 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
290 return ret;
291 }
292 if (no_addr)
293 goto last_resort;
294 if (rpf == 1)
295 goto e_rpf;
296 fl4.flowi4_oif = dev->ifindex;
297
298 ret = 0;
299 if (fib_lookup(net, &fl4, &res) == 0) {
300 if (res.type == RTN_UNICAST)
301 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
302 }
303 return ret;
304
305 last_resort:
306 if (rpf)
307 goto e_rpf;
308 *itag = 0;
309 return 0;
310
311 e_inval:
312 return -EINVAL;
313 e_rpf:
314 return -EXDEV;
315 }
316
317 /* Ignore rp_filter for packets protected by IPsec. */
318 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
319 u8 tos, int oif, struct net_device *dev,
320 struct in_device *idev, u32 *itag)
321 {
322 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
323
324 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
325 IN_DEV_ACCEPT_LOCAL(idev) &&
326 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
327 *itag = 0;
328 return 0;
329 }
330 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
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 (!ns_capable(net->user_ns, 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.portid = NETLINK_CB(skb).portid;
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)
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)
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_head *head;
660 int dumped = 0;
661
662 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
663 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
664 return skb->len;
665
666 s_h = cb->args[0];
667 s_e = cb->args[1];
668
669 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
670 e = 0;
671 head = &net->ipv4.fib_table_hash[h];
672 hlist_for_each_entry(tb, head, tb_hlist) {
673 if (e < s_e)
674 goto next;
675 if (dumped)
676 memset(&cb->args[2], 0, sizeof(cb->args) -
677 2 * sizeof(cb->args[0]));
678 if (fib_table_dump(tb, skb, cb) < 0)
679 goto out;
680 dumped = 1;
681 next:
682 e++;
683 }
684 }
685 out:
686 cb->args[1] = e;
687 cb->args[0] = h;
688
689 return skb->len;
690 }
691
692 /* Prepare and feed intra-kernel routing request.
693 * Really, it should be netlink message, but :-( netlink
694 * can be not configured, so that we feed it directly
695 * to fib engine. It is legal, because all events occur
696 * only when netlink is already locked.
697 */
698 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
699 {
700 struct net *net = dev_net(ifa->ifa_dev->dev);
701 struct fib_table *tb;
702 struct fib_config cfg = {
703 .fc_protocol = RTPROT_KERNEL,
704 .fc_type = type,
705 .fc_dst = dst,
706 .fc_dst_len = dst_len,
707 .fc_prefsrc = ifa->ifa_local,
708 .fc_oif = ifa->ifa_dev->dev->ifindex,
709 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
710 .fc_nlinfo = {
711 .nl_net = net,
712 },
713 };
714
715 if (type == RTN_UNICAST)
716 tb = fib_new_table(net, RT_TABLE_MAIN);
717 else
718 tb = fib_new_table(net, RT_TABLE_LOCAL);
719
720 if (tb == NULL)
721 return;
722
723 cfg.fc_table = tb->tb_id;
724
725 if (type != RTN_LOCAL)
726 cfg.fc_scope = RT_SCOPE_LINK;
727 else
728 cfg.fc_scope = RT_SCOPE_HOST;
729
730 if (cmd == RTM_NEWROUTE)
731 fib_table_insert(tb, &cfg);
732 else
733 fib_table_delete(tb, &cfg);
734 }
735
736 void fib_add_ifaddr(struct in_ifaddr *ifa)
737 {
738 struct in_device *in_dev = ifa->ifa_dev;
739 struct net_device *dev = in_dev->dev;
740 struct in_ifaddr *prim = ifa;
741 __be32 mask = ifa->ifa_mask;
742 __be32 addr = ifa->ifa_local;
743 __be32 prefix = ifa->ifa_address & mask;
744
745 if (ifa->ifa_flags & IFA_F_SECONDARY) {
746 prim = inet_ifa_byprefix(in_dev, prefix, mask);
747 if (prim == NULL) {
748 pr_warn("%s: bug: prim == NULL\n", __func__);
749 return;
750 }
751 }
752
753 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
754
755 if (!(dev->flags & IFF_UP))
756 return;
757
758 /* Add broadcast address, if it is explicitly assigned. */
759 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
760 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
761
762 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
763 (prefix != addr || ifa->ifa_prefixlen < 32)) {
764 fib_magic(RTM_NEWROUTE,
765 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
766 prefix, ifa->ifa_prefixlen, prim);
767
768 /* Add network specific broadcasts, when it takes a sense */
769 if (ifa->ifa_prefixlen < 31) {
770 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
771 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
772 32, prim);
773 }
774 }
775 }
776
777 /* Delete primary or secondary address.
778 * Optionally, on secondary address promotion consider the addresses
779 * from subnet iprim as deleted, even if they are in device list.
780 * In this case the secondary ifa can be in device list.
781 */
782 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
783 {
784 struct in_device *in_dev = ifa->ifa_dev;
785 struct net_device *dev = in_dev->dev;
786 struct in_ifaddr *ifa1;
787 struct in_ifaddr *prim = ifa, *prim1 = NULL;
788 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
789 __be32 any = ifa->ifa_address & ifa->ifa_mask;
790 #define LOCAL_OK 1
791 #define BRD_OK 2
792 #define BRD0_OK 4
793 #define BRD1_OK 8
794 unsigned int ok = 0;
795 int subnet = 0; /* Primary network */
796 int gone = 1; /* Address is missing */
797 int same_prefsrc = 0; /* Another primary with same IP */
798
799 if (ifa->ifa_flags & IFA_F_SECONDARY) {
800 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
801 if (prim == NULL) {
802 pr_warn("%s: bug: prim == NULL\n", __func__);
803 return;
804 }
805 if (iprim && iprim != prim) {
806 pr_warn("%s: bug: iprim != prim\n", __func__);
807 return;
808 }
809 } else if (!ipv4_is_zeronet(any) &&
810 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
811 fib_magic(RTM_DELROUTE,
812 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
813 any, ifa->ifa_prefixlen, prim);
814 subnet = 1;
815 }
816
817 /* Deletion is more complicated than add.
818 * We should take care of not to delete too much :-)
819 *
820 * Scan address list to be sure that addresses are really gone.
821 */
822
823 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
824 if (ifa1 == ifa) {
825 /* promotion, keep the IP */
826 gone = 0;
827 continue;
828 }
829 /* Ignore IFAs from our subnet */
830 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
831 inet_ifa_match(ifa1->ifa_address, iprim))
832 continue;
833
834 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
835 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
836 /* Another address from our subnet? */
837 if (ifa1->ifa_mask == prim->ifa_mask &&
838 inet_ifa_match(ifa1->ifa_address, prim))
839 prim1 = prim;
840 else {
841 /* We reached the secondaries, so
842 * same_prefsrc should be determined.
843 */
844 if (!same_prefsrc)
845 continue;
846 /* Search new prim1 if ifa1 is not
847 * using the current prim1
848 */
849 if (!prim1 ||
850 ifa1->ifa_mask != prim1->ifa_mask ||
851 !inet_ifa_match(ifa1->ifa_address, prim1))
852 prim1 = inet_ifa_byprefix(in_dev,
853 ifa1->ifa_address,
854 ifa1->ifa_mask);
855 if (!prim1)
856 continue;
857 if (prim1->ifa_local != prim->ifa_local)
858 continue;
859 }
860 } else {
861 if (prim->ifa_local != ifa1->ifa_local)
862 continue;
863 prim1 = ifa1;
864 if (prim != prim1)
865 same_prefsrc = 1;
866 }
867 if (ifa->ifa_local == ifa1->ifa_local)
868 ok |= LOCAL_OK;
869 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
870 ok |= BRD_OK;
871 if (brd == ifa1->ifa_broadcast)
872 ok |= BRD1_OK;
873 if (any == ifa1->ifa_broadcast)
874 ok |= BRD0_OK;
875 /* primary has network specific broadcasts */
876 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
877 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
878 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
879
880 if (!ipv4_is_zeronet(any1)) {
881 if (ifa->ifa_broadcast == brd1 ||
882 ifa->ifa_broadcast == any1)
883 ok |= BRD_OK;
884 if (brd == brd1 || brd == any1)
885 ok |= BRD1_OK;
886 if (any == brd1 || any == any1)
887 ok |= BRD0_OK;
888 }
889 }
890 }
891
892 if (!(ok & BRD_OK))
893 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
894 if (subnet && ifa->ifa_prefixlen < 31) {
895 if (!(ok & BRD1_OK))
896 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
897 if (!(ok & BRD0_OK))
898 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
899 }
900 if (!(ok & LOCAL_OK)) {
901 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
902
903 /* Check, that this local address finally disappeared. */
904 if (gone &&
905 inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
906 /* And the last, but not the least thing.
907 * We must flush stray FIB entries.
908 *
909 * First of all, we scan fib_info list searching
910 * for stray nexthop entries, then ignite fib_flush.
911 */
912 if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
913 fib_flush(dev_net(dev));
914 }
915 }
916 #undef LOCAL_OK
917 #undef BRD_OK
918 #undef BRD0_OK
919 #undef BRD1_OK
920 }
921
922 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
923 {
924
925 struct fib_result res;
926 struct flowi4 fl4 = {
927 .flowi4_mark = frn->fl_mark,
928 .daddr = frn->fl_addr,
929 .flowi4_tos = frn->fl_tos,
930 .flowi4_scope = frn->fl_scope,
931 };
932
933 frn->err = -ENOENT;
934 if (tb) {
935 local_bh_disable();
936
937 frn->tb_id = tb->tb_id;
938 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
939
940 if (!frn->err) {
941 frn->prefixlen = res.prefixlen;
942 frn->nh_sel = res.nh_sel;
943 frn->type = res.type;
944 frn->scope = res.scope;
945 }
946 local_bh_enable();
947 }
948 }
949
950 static void nl_fib_input(struct sk_buff *skb)
951 {
952 struct net *net;
953 struct fib_result_nl *frn;
954 struct nlmsghdr *nlh;
955 struct fib_table *tb;
956 u32 portid;
957
958 net = sock_net(skb->sk);
959 nlh = nlmsg_hdr(skb);
960 if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
961 nlmsg_len(nlh) < sizeof(*frn))
962 return;
963
964 skb = netlink_skb_clone(skb, GFP_KERNEL);
965 if (skb == NULL)
966 return;
967 nlh = nlmsg_hdr(skb);
968
969 frn = (struct fib_result_nl *) nlmsg_data(nlh);
970 tb = fib_get_table(net, frn->tb_id_in);
971
972 nl_fib_lookup(frn, tb);
973
974 portid = NETLINK_CB(skb).portid; /* netlink portid */
975 NETLINK_CB(skb).portid = 0; /* from kernel */
976 NETLINK_CB(skb).dst_group = 0; /* unicast */
977 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
978 }
979
980 static int __net_init nl_fib_lookup_init(struct net *net)
981 {
982 struct sock *sk;
983 struct netlink_kernel_cfg cfg = {
984 .input = nl_fib_input,
985 };
986
987 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
988 if (sk == NULL)
989 return -EAFNOSUPPORT;
990 net->ipv4.fibnl = sk;
991 return 0;
992 }
993
994 static void nl_fib_lookup_exit(struct net *net)
995 {
996 netlink_kernel_release(net->ipv4.fibnl);
997 net->ipv4.fibnl = NULL;
998 }
999
1000 static void fib_disable_ip(struct net_device *dev, int force)
1001 {
1002 if (fib_sync_down_dev(dev, force))
1003 fib_flush(dev_net(dev));
1004 rt_cache_flush(dev_net(dev));
1005 arp_ifdown(dev);
1006 }
1007
1008 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1009 {
1010 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1011 struct net_device *dev = ifa->ifa_dev->dev;
1012 struct net *net = dev_net(dev);
1013
1014 switch (event) {
1015 case NETDEV_UP:
1016 fib_add_ifaddr(ifa);
1017 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1018 fib_sync_up(dev);
1019 #endif
1020 atomic_inc(&net->ipv4.dev_addr_genid);
1021 rt_cache_flush(dev_net(dev));
1022 break;
1023 case NETDEV_DOWN:
1024 fib_del_ifaddr(ifa, NULL);
1025 atomic_inc(&net->ipv4.dev_addr_genid);
1026 if (ifa->ifa_dev->ifa_list == NULL) {
1027 /* Last address was deleted from this interface.
1028 * Disable IP.
1029 */
1030 fib_disable_ip(dev, 1);
1031 } else {
1032 rt_cache_flush(dev_net(dev));
1033 }
1034 break;
1035 }
1036 return NOTIFY_DONE;
1037 }
1038
1039 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1040 {
1041 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1042 struct in_device *in_dev;
1043 struct net *net = dev_net(dev);
1044
1045 if (event == NETDEV_UNREGISTER) {
1046 fib_disable_ip(dev, 2);
1047 rt_flush_dev(dev);
1048 return NOTIFY_DONE;
1049 }
1050
1051 in_dev = __in_dev_get_rtnl(dev);
1052 if (!in_dev)
1053 return NOTIFY_DONE;
1054
1055 switch (event) {
1056 case NETDEV_UP:
1057 for_ifa(in_dev) {
1058 fib_add_ifaddr(ifa);
1059 } endfor_ifa(in_dev);
1060 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1061 fib_sync_up(dev);
1062 #endif
1063 atomic_inc(&net->ipv4.dev_addr_genid);
1064 rt_cache_flush(net);
1065 break;
1066 case NETDEV_DOWN:
1067 fib_disable_ip(dev, 0);
1068 break;
1069 case NETDEV_CHANGEMTU:
1070 case NETDEV_CHANGE:
1071 rt_cache_flush(net);
1072 break;
1073 }
1074 return NOTIFY_DONE;
1075 }
1076
1077 static struct notifier_block fib_inetaddr_notifier = {
1078 .notifier_call = fib_inetaddr_event,
1079 };
1080
1081 static struct notifier_block fib_netdev_notifier = {
1082 .notifier_call = fib_netdev_event,
1083 };
1084
1085 static int __net_init ip_fib_net_init(struct net *net)
1086 {
1087 int err;
1088 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1089
1090 /* Avoid false sharing : Use at least a full cache line */
1091 size = max_t(size_t, size, L1_CACHE_BYTES);
1092
1093 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1094 if (net->ipv4.fib_table_hash == NULL)
1095 return -ENOMEM;
1096
1097 err = fib4_rules_init(net);
1098 if (err < 0)
1099 goto fail;
1100 return 0;
1101
1102 fail:
1103 kfree(net->ipv4.fib_table_hash);
1104 return err;
1105 }
1106
1107 static void ip_fib_net_exit(struct net *net)
1108 {
1109 unsigned int i;
1110
1111 #ifdef CONFIG_IP_MULTIPLE_TABLES
1112 fib4_rules_exit(net);
1113 #endif
1114
1115 rtnl_lock();
1116 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1117 struct fib_table *tb;
1118 struct hlist_head *head;
1119 struct hlist_node *tmp;
1120
1121 head = &net->ipv4.fib_table_hash[i];
1122 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1123 hlist_del(&tb->tb_hlist);
1124 fib_table_flush(tb);
1125 fib_free_table(tb);
1126 }
1127 }
1128 rtnl_unlock();
1129 kfree(net->ipv4.fib_table_hash);
1130 }
1131
1132 static int __net_init fib_net_init(struct net *net)
1133 {
1134 int error;
1135
1136 #ifdef CONFIG_IP_ROUTE_CLASSID
1137 net->ipv4.fib_num_tclassid_users = 0;
1138 #endif
1139 error = ip_fib_net_init(net);
1140 if (error < 0)
1141 goto out;
1142 error = nl_fib_lookup_init(net);
1143 if (error < 0)
1144 goto out_nlfl;
1145 error = fib_proc_init(net);
1146 if (error < 0)
1147 goto out_proc;
1148 out:
1149 return error;
1150
1151 out_proc:
1152 nl_fib_lookup_exit(net);
1153 out_nlfl:
1154 ip_fib_net_exit(net);
1155 goto out;
1156 }
1157
1158 static void __net_exit fib_net_exit(struct net *net)
1159 {
1160 fib_proc_exit(net);
1161 nl_fib_lookup_exit(net);
1162 ip_fib_net_exit(net);
1163 }
1164
1165 static struct pernet_operations fib_net_ops = {
1166 .init = fib_net_init,
1167 .exit = fib_net_exit,
1168 };
1169
1170 void __init ip_fib_init(void)
1171 {
1172 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1173 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1174 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
1175
1176 register_pernet_subsys(&fib_net_ops);
1177 register_netdevice_notifier(&fib_netdev_notifier);
1178 register_inetaddr_notifier(&fib_inetaddr_notifier);
1179
1180 fib_trie_init();
1181 }
Linux kernel - Deliverables
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