Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * INET An implementation of the TCP/IP protocol suite for the LINUX
4 : * operating system. INET is implemented using the BSD Socket
5 : * interface as the means of communication with the user level.
6 : *
7 : * IPv4 Forwarding Information Base: FIB frontend.
8 : *
9 : * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 : */
11 :
12 : #include <linux/module.h>
13 : #include <linux/uaccess.h>
14 : #include <linux/bitops.h>
15 : #include <linux/capability.h>
16 : #include <linux/types.h>
17 : #include <linux/kernel.h>
18 : #include <linux/mm.h>
19 : #include <linux/string.h>
20 : #include <linux/socket.h>
21 : #include <linux/sockios.h>
22 : #include <linux/errno.h>
23 : #include <linux/in.h>
24 : #include <linux/inet.h>
25 : #include <linux/inetdevice.h>
26 : #include <linux/netdevice.h>
27 : #include <linux/if_addr.h>
28 : #include <linux/if_arp.h>
29 : #include <linux/skbuff.h>
30 : #include <linux/cache.h>
31 : #include <linux/init.h>
32 : #include <linux/list.h>
33 : #include <linux/slab.h>
34 :
35 : #include <net/ip.h>
36 : #include <net/protocol.h>
37 : #include <net/route.h>
38 : #include <net/tcp.h>
39 : #include <net/sock.h>
40 : #include <net/arp.h>
41 : #include <net/ip_fib.h>
42 : #include <net/nexthop.h>
43 : #include <net/rtnetlink.h>
44 : #include <net/xfrm.h>
45 : #include <net/l3mdev.h>
46 : #include <net/lwtunnel.h>
47 : #include <trace/events/fib.h>
48 :
49 : #ifndef CONFIG_IP_MULTIPLE_TABLES
50 :
51 1 : static int __net_init fib4_rules_init(struct net *net)
52 : {
53 1 : struct fib_table *local_table, *main_table;
54 :
55 1 : main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
56 1 : if (!main_table)
57 : return -ENOMEM;
58 :
59 1 : local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
60 1 : if (!local_table)
61 0 : goto fail;
62 :
63 2 : hlist_add_head_rcu(&local_table->tb_hlist,
64 1 : &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
65 1 : hlist_add_head_rcu(&main_table->tb_hlist,
66 : &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
67 : return 0;
68 :
69 0 : fail:
70 0 : fib_free_table(main_table);
71 0 : return -ENOMEM;
72 : }
73 : #else
74 :
75 : struct fib_table *fib_new_table(struct net *net, u32 id)
76 : {
77 : struct fib_table *tb, *alias = NULL;
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 : if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
87 : alias = fib_new_table(net, RT_TABLE_MAIN);
88 :
89 : tb = fib_trie_table(id, alias);
90 : if (!tb)
91 : return NULL;
92 :
93 : switch (id) {
94 : case RT_TABLE_MAIN:
95 : rcu_assign_pointer(net->ipv4.fib_main, tb);
96 : break;
97 : case RT_TABLE_DEFAULT:
98 : rcu_assign_pointer(net->ipv4.fib_default, tb);
99 : break;
100 : default:
101 : break;
102 : }
103 :
104 : h = id & (FIB_TABLE_HASHSZ - 1);
105 : hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
106 : return tb;
107 : }
108 : EXPORT_SYMBOL_GPL(fib_new_table);
109 :
110 : /* caller must hold either rtnl or rcu read lock */
111 : struct fib_table *fib_get_table(struct net *net, u32 id)
112 : {
113 : struct fib_table *tb;
114 : struct hlist_head *head;
115 : unsigned int h;
116 :
117 : if (id == 0)
118 : id = RT_TABLE_MAIN;
119 : h = id & (FIB_TABLE_HASHSZ - 1);
120 :
121 : head = &net->ipv4.fib_table_hash[h];
122 : hlist_for_each_entry_rcu(tb, head, tb_hlist,
123 : lockdep_rtnl_is_held()) {
124 : if (tb->tb_id == id)
125 : return tb;
126 : }
127 : return NULL;
128 : }
129 : #endif /* CONFIG_IP_MULTIPLE_TABLES */
130 :
131 0 : static void fib_replace_table(struct net *net, struct fib_table *old,
132 : struct fib_table *new)
133 : {
134 : #ifdef CONFIG_IP_MULTIPLE_TABLES
135 : switch (new->tb_id) {
136 : case RT_TABLE_MAIN:
137 : rcu_assign_pointer(net->ipv4.fib_main, new);
138 : break;
139 : case RT_TABLE_DEFAULT:
140 : rcu_assign_pointer(net->ipv4.fib_default, new);
141 : break;
142 : default:
143 : break;
144 : }
145 :
146 : #endif
147 : /* replace the old table in the hlist */
148 0 : hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
149 : }
150 :
151 0 : int fib_unmerge(struct net *net)
152 : {
153 0 : struct fib_table *old, *new, *main_table;
154 :
155 : /* attempt to fetch local table if it has been allocated */
156 0 : old = fib_get_table(net, RT_TABLE_LOCAL);
157 0 : if (!old)
158 : return 0;
159 :
160 0 : new = fib_trie_unmerge(old);
161 0 : if (!new)
162 : return -ENOMEM;
163 :
164 : /* table is already unmerged */
165 0 : if (new == old)
166 : return 0;
167 :
168 : /* replace merged table with clean table */
169 0 : fib_replace_table(net, old, new);
170 0 : fib_free_table(old);
171 :
172 : /* attempt to fetch main table if it has been allocated */
173 0 : main_table = fib_get_table(net, RT_TABLE_MAIN);
174 0 : if (!main_table)
175 : return 0;
176 :
177 : /* flush local entries from main table */
178 0 : fib_table_flush_external(main_table);
179 :
180 0 : return 0;
181 : }
182 :
183 0 : void fib_flush(struct net *net)
184 : {
185 0 : int flushed = 0;
186 0 : unsigned int h;
187 :
188 0 : for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
189 0 : struct hlist_head *head = &net->ipv4.fib_table_hash[h];
190 0 : struct hlist_node *tmp;
191 0 : struct fib_table *tb;
192 :
193 0 : hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
194 0 : flushed += fib_table_flush(net, tb, false);
195 : }
196 :
197 0 : if (flushed)
198 0 : rt_cache_flush(net);
199 0 : }
200 :
201 : /*
202 : * Find address type as if only "dev" was present in the system. If
203 : * on_dev is NULL then all interfaces are taken into consideration.
204 : */
205 16 : static inline unsigned int __inet_dev_addr_type(struct net *net,
206 : const struct net_device *dev,
207 : __be32 addr, u32 tb_id)
208 : {
209 16 : struct flowi4 fl4 = { .daddr = addr };
210 16 : struct fib_result res;
211 16 : unsigned int ret = RTN_BROADCAST;
212 16 : struct fib_table *table;
213 :
214 16 : if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
215 : return RTN_BROADCAST;
216 12 : if (ipv4_is_multicast(addr))
217 : return RTN_MULTICAST;
218 :
219 12 : rcu_read_lock();
220 :
221 12 : table = fib_get_table(net, tb_id);
222 12 : if (table) {
223 12 : ret = RTN_UNICAST;
224 12 : if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
225 12 : struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
226 :
227 12 : if (!dev || dev == nhc->nhc_dev)
228 12 : ret = res.type;
229 : }
230 : }
231 :
232 12 : rcu_read_unlock();
233 12 : return ret;
234 : }
235 :
236 12 : unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
237 : {
238 12 : return __inet_dev_addr_type(net, NULL, addr, tb_id);
239 : }
240 : EXPORT_SYMBOL(inet_addr_type_table);
241 :
242 0 : unsigned int inet_addr_type(struct net *net, __be32 addr)
243 : {
244 0 : return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
245 : }
246 : EXPORT_SYMBOL(inet_addr_type);
247 :
248 0 : unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
249 : __be32 addr)
250 : {
251 0 : u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
252 :
253 0 : return __inet_dev_addr_type(net, dev, addr, rt_table);
254 : }
255 : EXPORT_SYMBOL(inet_dev_addr_type);
256 :
257 : /* inet_addr_type with dev == NULL but using the table from a dev
258 : * if one is associated
259 : */
260 4 : unsigned int inet_addr_type_dev_table(struct net *net,
261 : const struct net_device *dev,
262 : __be32 addr)
263 : {
264 4 : u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
265 :
266 4 : return __inet_dev_addr_type(net, NULL, addr, rt_table);
267 : }
268 : EXPORT_SYMBOL(inet_addr_type_dev_table);
269 :
270 0 : __be32 fib_compute_spec_dst(struct sk_buff *skb)
271 : {
272 0 : struct net_device *dev = skb->dev;
273 0 : struct in_device *in_dev;
274 0 : struct fib_result res;
275 0 : struct rtable *rt;
276 0 : struct net *net;
277 0 : int scope;
278 :
279 0 : rt = skb_rtable(skb);
280 0 : if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
281 : RTCF_LOCAL)
282 0 : return ip_hdr(skb)->daddr;
283 :
284 0 : in_dev = __in_dev_get_rcu(dev);
285 :
286 0 : net = dev_net(dev);
287 :
288 0 : scope = RT_SCOPE_UNIVERSE;
289 0 : if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
290 0 : bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
291 0 : struct flowi4 fl4 = {
292 : .flowi4_iif = LOOPBACK_IFINDEX,
293 0 : .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
294 0 : .daddr = ip_hdr(skb)->saddr,
295 0 : .flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK,
296 : .flowi4_scope = scope,
297 0 : .flowi4_mark = vmark ? skb->mark : 0,
298 : };
299 0 : if (!fib_lookup(net, &fl4, &res, 0))
300 0 : return fib_result_prefsrc(net, &res);
301 : } else {
302 : scope = RT_SCOPE_LINK;
303 : }
304 :
305 0 : return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
306 : }
307 :
308 0 : bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
309 : {
310 0 : bool dev_match = false;
311 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
312 : if (unlikely(fi->nh)) {
313 : dev_match = nexthop_uses_dev(fi->nh, dev);
314 : } else {
315 : int ret;
316 :
317 : for (ret = 0; ret < fib_info_num_path(fi); ret++) {
318 : const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
319 :
320 : if (nhc_l3mdev_matches_dev(nhc, dev)) {
321 : dev_match = true;
322 : break;
323 : }
324 : }
325 : }
326 : #else
327 0 : if (fib_info_nhc(fi, 0)->nhc_dev == dev)
328 0 : dev_match = true;
329 : #endif
330 :
331 0 : return dev_match;
332 : }
333 : EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
334 :
335 : /* Given (packet source, input interface) and optional (dst, oif, tos):
336 : * - (main) check, that source is valid i.e. not broadcast or our local
337 : * address.
338 : * - figure out what "logical" interface this packet arrived
339 : * and calculate "specific destination" address.
340 : * - check, that packet arrived from expected physical interface.
341 : * called with rcu_read_lock()
342 : */
343 0 : static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
344 : u8 tos, int oif, struct net_device *dev,
345 : int rpf, struct in_device *idev, u32 *itag)
346 : {
347 0 : struct net *net = dev_net(dev);
348 0 : struct flow_keys flkeys;
349 0 : int ret, no_addr;
350 0 : struct fib_result res;
351 0 : struct flowi4 fl4;
352 0 : bool dev_match;
353 :
354 0 : fl4.flowi4_oif = 0;
355 0 : fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
356 0 : if (!fl4.flowi4_iif)
357 0 : fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
358 0 : fl4.daddr = src;
359 0 : fl4.saddr = dst;
360 0 : fl4.flowi4_tos = tos;
361 0 : fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
362 0 : fl4.flowi4_tun_key.tun_id = 0;
363 0 : fl4.flowi4_flags = 0;
364 0 : fl4.flowi4_uid = sock_net_uid(net, NULL);
365 0 : fl4.flowi4_multipath_hash = 0;
366 :
367 0 : no_addr = idev->ifa_list == NULL;
368 :
369 0 : fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
370 0 : if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
371 0 : fl4.flowi4_proto = 0;
372 0 : fl4.fl4_sport = 0;
373 0 : fl4.fl4_dport = 0;
374 : }
375 :
376 0 : if (fib_lookup(net, &fl4, &res, 0))
377 0 : goto last_resort;
378 0 : if (res.type != RTN_UNICAST &&
379 0 : (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
380 0 : goto e_inval;
381 0 : fib_combine_itag(itag, &res);
382 :
383 0 : dev_match = fib_info_nh_uses_dev(res.fi, dev);
384 : /* This is not common, loopback packets retain skb_dst so normally they
385 : * would not even hit this slow path.
386 : */
387 0 : dev_match = dev_match || (res.type == RTN_LOCAL &&
388 0 : dev == net->loopback_dev);
389 0 : if (dev_match) {
390 0 : ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
391 0 : return ret;
392 : }
393 0 : if (no_addr)
394 0 : goto last_resort;
395 0 : if (rpf == 1)
396 0 : goto e_rpf;
397 0 : fl4.flowi4_oif = dev->ifindex;
398 :
399 0 : ret = 0;
400 0 : if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
401 0 : if (res.type == RTN_UNICAST)
402 0 : ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
403 : }
404 : return ret;
405 :
406 0 : last_resort:
407 0 : if (rpf)
408 0 : goto e_rpf;
409 0 : *itag = 0;
410 0 : return 0;
411 :
412 0 : e_inval:
413 0 : return -EINVAL;
414 : e_rpf:
415 : return -EXDEV;
416 : }
417 :
418 : /* Ignore rp_filter for packets protected by IPsec. */
419 73 : int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
420 : u8 tos, int oif, struct net_device *dev,
421 : struct in_device *idev, u32 *itag)
422 : {
423 73 : int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
424 73 : struct net *net = dev_net(dev);
425 :
426 73 : if (!r && !fib_num_tclassid_users(net) &&
427 73 : (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
428 73 : if (IN_DEV_ACCEPT_LOCAL(idev))
429 0 : goto ok;
430 : /* with custom local routes in place, checking local addresses
431 : * only will be too optimistic, with custom rules, checking
432 : * local addresses only can be too strict, e.g. due to vrf
433 : */
434 73 : if (net->ipv4.fib_has_custom_local_routes ||
435 73 : fib4_has_custom_rules(net))
436 0 : goto full_check;
437 73 : if (inet_lookup_ifaddr_rcu(net, src))
438 : return -EINVAL;
439 :
440 73 : ok:
441 73 : *itag = 0;
442 73 : return 0;
443 : }
444 :
445 0 : full_check:
446 0 : return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
447 : }
448 :
449 0 : static inline __be32 sk_extract_addr(struct sockaddr *addr)
450 : {
451 0 : return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
452 : }
453 :
454 0 : static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
455 : {
456 0 : struct nlattr *nla;
457 :
458 0 : nla = (struct nlattr *) ((char *) mx + len);
459 0 : nla->nla_type = type;
460 0 : nla->nla_len = nla_attr_size(4);
461 0 : *(u32 *) nla_data(nla) = value;
462 :
463 0 : return len + nla_total_size(4);
464 : }
465 :
466 0 : static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
467 : struct fib_config *cfg)
468 : {
469 0 : __be32 addr;
470 0 : int plen;
471 :
472 0 : memset(cfg, 0, sizeof(*cfg));
473 0 : cfg->fc_nlinfo.nl_net = net;
474 :
475 0 : if (rt->rt_dst.sa_family != AF_INET)
476 : return -EAFNOSUPPORT;
477 :
478 : /*
479 : * Check mask for validity:
480 : * a) it must be contiguous.
481 : * b) destination must have all host bits clear.
482 : * c) if application forgot to set correct family (AF_INET),
483 : * reject request unless it is absolutely clear i.e.
484 : * both family and mask are zero.
485 : */
486 0 : plen = 32;
487 0 : addr = sk_extract_addr(&rt->rt_dst);
488 0 : if (!(rt->rt_flags & RTF_HOST)) {
489 0 : __be32 mask = sk_extract_addr(&rt->rt_genmask);
490 :
491 0 : if (rt->rt_genmask.sa_family != AF_INET) {
492 0 : if (mask || rt->rt_genmask.sa_family)
493 : return -EAFNOSUPPORT;
494 : }
495 :
496 0 : if (bad_mask(mask, addr))
497 : return -EINVAL;
498 :
499 0 : plen = inet_mask_len(mask);
500 : }
501 :
502 0 : cfg->fc_dst_len = plen;
503 0 : cfg->fc_dst = addr;
504 :
505 0 : if (cmd != SIOCDELRT) {
506 0 : cfg->fc_nlflags = NLM_F_CREATE;
507 0 : cfg->fc_protocol = RTPROT_BOOT;
508 : }
509 :
510 0 : if (rt->rt_metric)
511 0 : cfg->fc_priority = rt->rt_metric - 1;
512 :
513 0 : if (rt->rt_flags & RTF_REJECT) {
514 0 : cfg->fc_scope = RT_SCOPE_HOST;
515 0 : cfg->fc_type = RTN_UNREACHABLE;
516 0 : return 0;
517 : }
518 :
519 0 : cfg->fc_scope = RT_SCOPE_NOWHERE;
520 0 : cfg->fc_type = RTN_UNICAST;
521 :
522 0 : if (rt->rt_dev) {
523 0 : char *colon;
524 0 : struct net_device *dev;
525 0 : char devname[IFNAMSIZ];
526 :
527 0 : if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
528 0 : return -EFAULT;
529 :
530 0 : devname[IFNAMSIZ-1] = 0;
531 0 : colon = strchr(devname, ':');
532 0 : if (colon)
533 0 : *colon = 0;
534 0 : dev = __dev_get_by_name(net, devname);
535 0 : if (!dev)
536 : return -ENODEV;
537 0 : cfg->fc_oif = dev->ifindex;
538 0 : cfg->fc_table = l3mdev_fib_table(dev);
539 0 : if (colon) {
540 0 : const struct in_ifaddr *ifa;
541 0 : struct in_device *in_dev;
542 :
543 0 : in_dev = __in_dev_get_rtnl(dev);
544 0 : if (!in_dev)
545 : return -ENODEV;
546 :
547 0 : *colon = ':';
548 :
549 0 : rcu_read_lock();
550 0 : in_dev_for_each_ifa_rcu(ifa, in_dev) {
551 0 : if (strcmp(ifa->ifa_label, devname) == 0)
552 : break;
553 : }
554 0 : rcu_read_unlock();
555 :
556 0 : if (!ifa)
557 : return -ENODEV;
558 0 : cfg->fc_prefsrc = ifa->ifa_local;
559 : }
560 : }
561 :
562 0 : addr = sk_extract_addr(&rt->rt_gateway);
563 0 : if (rt->rt_gateway.sa_family == AF_INET && addr) {
564 0 : unsigned int addr_type;
565 :
566 0 : cfg->fc_gw4 = addr;
567 0 : cfg->fc_gw_family = AF_INET;
568 0 : addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
569 0 : if (rt->rt_flags & RTF_GATEWAY &&
570 : addr_type == RTN_UNICAST)
571 0 : cfg->fc_scope = RT_SCOPE_UNIVERSE;
572 : }
573 :
574 0 : if (cmd == SIOCDELRT)
575 : return 0;
576 :
577 0 : if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
578 : return -EINVAL;
579 :
580 0 : if (cfg->fc_scope == RT_SCOPE_NOWHERE)
581 0 : cfg->fc_scope = RT_SCOPE_LINK;
582 :
583 0 : if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
584 0 : struct nlattr *mx;
585 0 : int len = 0;
586 :
587 0 : mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
588 0 : if (!mx)
589 : return -ENOMEM;
590 :
591 0 : if (rt->rt_flags & RTF_MTU)
592 0 : len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
593 :
594 0 : if (rt->rt_flags & RTF_WINDOW)
595 0 : len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
596 :
597 0 : if (rt->rt_flags & RTF_IRTT)
598 0 : len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
599 :
600 0 : cfg->fc_mx = mx;
601 0 : cfg->fc_mx_len = len;
602 : }
603 :
604 : return 0;
605 : }
606 :
607 : /*
608 : * Handle IP routing ioctl calls.
609 : * These are used to manipulate the routing tables
610 : */
611 0 : int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
612 : {
613 0 : struct fib_config cfg;
614 0 : int err;
615 :
616 0 : switch (cmd) {
617 0 : case SIOCADDRT: /* Add a route */
618 : case SIOCDELRT: /* Delete a route */
619 0 : if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
620 : return -EPERM;
621 :
622 0 : rtnl_lock();
623 0 : err = rtentry_to_fib_config(net, cmd, rt, &cfg);
624 0 : if (err == 0) {
625 0 : struct fib_table *tb;
626 :
627 0 : if (cmd == SIOCDELRT) {
628 0 : tb = fib_get_table(net, cfg.fc_table);
629 0 : if (tb)
630 0 : err = fib_table_delete(net, tb, &cfg,
631 : NULL);
632 : else
633 : err = -ESRCH;
634 : } else {
635 0 : tb = fib_new_table(net, cfg.fc_table);
636 0 : if (tb)
637 0 : err = fib_table_insert(net, tb,
638 : &cfg, NULL);
639 : else
640 : err = -ENOBUFS;
641 : }
642 :
643 : /* allocated by rtentry_to_fib_config() */
644 0 : kfree(cfg.fc_mx);
645 : }
646 0 : rtnl_unlock();
647 0 : return err;
648 : }
649 : return -EINVAL;
650 : }
651 :
652 : const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
653 : [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
654 : [RTA_DST] = { .type = NLA_U32 },
655 : [RTA_SRC] = { .type = NLA_U32 },
656 : [RTA_IIF] = { .type = NLA_U32 },
657 : [RTA_OIF] = { .type = NLA_U32 },
658 : [RTA_GATEWAY] = { .type = NLA_U32 },
659 : [RTA_PRIORITY] = { .type = NLA_U32 },
660 : [RTA_PREFSRC] = { .type = NLA_U32 },
661 : [RTA_METRICS] = { .type = NLA_NESTED },
662 : [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
663 : [RTA_FLOW] = { .type = NLA_U32 },
664 : [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
665 : [RTA_ENCAP] = { .type = NLA_NESTED },
666 : [RTA_UID] = { .type = NLA_U32 },
667 : [RTA_MARK] = { .type = NLA_U32 },
668 : [RTA_TABLE] = { .type = NLA_U32 },
669 : [RTA_IP_PROTO] = { .type = NLA_U8 },
670 : [RTA_SPORT] = { .type = NLA_U16 },
671 : [RTA_DPORT] = { .type = NLA_U16 },
672 : [RTA_NH_ID] = { .type = NLA_U32 },
673 : };
674 :
675 0 : int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
676 : struct netlink_ext_ack *extack)
677 : {
678 0 : struct rtvia *via;
679 0 : int alen;
680 :
681 0 : if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
682 0 : NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
683 0 : return -EINVAL;
684 : }
685 :
686 0 : via = nla_data(nla);
687 0 : alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
688 :
689 0 : switch (via->rtvia_family) {
690 0 : case AF_INET:
691 0 : if (alen != sizeof(__be32)) {
692 0 : NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
693 0 : return -EINVAL;
694 : }
695 0 : cfg->fc_gw_family = AF_INET;
696 0 : cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
697 0 : break;
698 0 : case AF_INET6:
699 : #if IS_ENABLED(CONFIG_IPV6)
700 : if (alen != sizeof(struct in6_addr)) {
701 : NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
702 : return -EINVAL;
703 : }
704 : cfg->fc_gw_family = AF_INET6;
705 : cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
706 : #else
707 0 : NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
708 : return -EINVAL;
709 : #endif
710 0 : break;
711 0 : default:
712 0 : NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
713 : return -EINVAL;
714 : }
715 :
716 0 : return 0;
717 : }
718 :
719 2 : static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
720 : struct nlmsghdr *nlh, struct fib_config *cfg,
721 : struct netlink_ext_ack *extack)
722 : {
723 2 : bool has_gw = false, has_via = false;
724 2 : struct nlattr *attr;
725 2 : int err, remaining;
726 2 : struct rtmsg *rtm;
727 :
728 2 : err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
729 : rtm_ipv4_policy, extack);
730 2 : if (err < 0)
731 0 : goto errout;
732 :
733 2 : memset(cfg, 0, sizeof(*cfg));
734 :
735 2 : rtm = nlmsg_data(nlh);
736 2 : cfg->fc_dst_len = rtm->rtm_dst_len;
737 2 : cfg->fc_tos = rtm->rtm_tos;
738 2 : cfg->fc_table = rtm->rtm_table;
739 2 : cfg->fc_protocol = rtm->rtm_protocol;
740 2 : cfg->fc_scope = rtm->rtm_scope;
741 2 : cfg->fc_type = rtm->rtm_type;
742 2 : cfg->fc_flags = rtm->rtm_flags;
743 2 : cfg->fc_nlflags = nlh->nlmsg_flags;
744 :
745 2 : cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
746 2 : cfg->fc_nlinfo.nlh = nlh;
747 2 : cfg->fc_nlinfo.nl_net = net;
748 :
749 2 : if (cfg->fc_type > RTN_MAX) {
750 0 : NL_SET_ERR_MSG(extack, "Invalid route type");
751 0 : err = -EINVAL;
752 0 : goto errout;
753 : }
754 :
755 8 : nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
756 6 : switch (nla_type(attr)) {
757 : case RTA_DST:
758 2 : cfg->fc_dst = nla_get_be32(attr);
759 2 : break;
760 : case RTA_OIF:
761 2 : cfg->fc_oif = nla_get_u32(attr);
762 2 : break;
763 1 : case RTA_GATEWAY:
764 1 : has_gw = true;
765 1 : cfg->fc_gw4 = nla_get_be32(attr);
766 1 : if (cfg->fc_gw4)
767 1 : cfg->fc_gw_family = AF_INET;
768 : break;
769 0 : case RTA_VIA:
770 0 : has_via = true;
771 0 : err = fib_gw_from_via(cfg, attr, extack);
772 0 : if (err)
773 0 : goto errout;
774 : break;
775 : case RTA_PRIORITY:
776 1 : cfg->fc_priority = nla_get_u32(attr);
777 1 : break;
778 : case RTA_PREFSRC:
779 0 : cfg->fc_prefsrc = nla_get_be32(attr);
780 0 : break;
781 : case RTA_METRICS:
782 0 : cfg->fc_mx = nla_data(attr);
783 0 : cfg->fc_mx_len = nla_len(attr);
784 0 : break;
785 : case RTA_MULTIPATH:
786 0 : err = lwtunnel_valid_encap_type_attr(nla_data(attr),
787 : nla_len(attr),
788 : extack);
789 0 : if (err < 0)
790 : goto errout;
791 0 : cfg->fc_mp = nla_data(attr);
792 0 : cfg->fc_mp_len = nla_len(attr);
793 0 : break;
794 : case RTA_FLOW:
795 0 : cfg->fc_flow = nla_get_u32(attr);
796 0 : break;
797 : case RTA_TABLE:
798 0 : cfg->fc_table = nla_get_u32(attr);
799 0 : break;
800 0 : case RTA_ENCAP:
801 0 : cfg->fc_encap = attr;
802 0 : break;
803 : case RTA_ENCAP_TYPE:
804 0 : cfg->fc_encap_type = nla_get_u16(attr);
805 0 : err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
806 : extack);
807 0 : if (err < 0)
808 0 : goto errout;
809 : break;
810 : case RTA_NH_ID:
811 0 : cfg->fc_nh_id = nla_get_u32(attr);
812 0 : break;
813 : }
814 6 : }
815 :
816 2 : if (cfg->fc_nh_id) {
817 0 : if (cfg->fc_oif || cfg->fc_gw_family ||
818 0 : cfg->fc_encap || cfg->fc_mp) {
819 0 : NL_SET_ERR_MSG(extack,
820 : "Nexthop specification and nexthop id are mutually exclusive");
821 0 : return -EINVAL;
822 : }
823 : }
824 :
825 2 : if (has_gw && has_via) {
826 0 : NL_SET_ERR_MSG(extack,
827 : "Nexthop configuration can not contain both GATEWAY and VIA");
828 0 : return -EINVAL;
829 : }
830 :
831 : return 0;
832 : errout:
833 : return err;
834 : }
835 :
836 0 : static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
837 : struct netlink_ext_ack *extack)
838 : {
839 0 : struct net *net = sock_net(skb->sk);
840 0 : struct fib_config cfg;
841 0 : struct fib_table *tb;
842 0 : int err;
843 :
844 0 : err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
845 0 : if (err < 0)
846 0 : goto errout;
847 :
848 0 : if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
849 0 : NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
850 0 : err = -EINVAL;
851 0 : goto errout;
852 : }
853 :
854 0 : tb = fib_get_table(net, cfg.fc_table);
855 0 : if (!tb) {
856 0 : NL_SET_ERR_MSG(extack, "FIB table does not exist");
857 0 : err = -ESRCH;
858 0 : goto errout;
859 : }
860 :
861 0 : err = fib_table_delete(net, tb, &cfg, extack);
862 0 : errout:
863 0 : return err;
864 : }
865 :
866 2 : static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
867 : struct netlink_ext_ack *extack)
868 : {
869 2 : struct net *net = sock_net(skb->sk);
870 2 : struct fib_config cfg;
871 2 : struct fib_table *tb;
872 2 : int err;
873 :
874 2 : err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
875 2 : if (err < 0)
876 0 : goto errout;
877 :
878 2 : tb = fib_new_table(net, cfg.fc_table);
879 2 : if (!tb) {
880 0 : err = -ENOBUFS;
881 0 : goto errout;
882 : }
883 :
884 2 : err = fib_table_insert(net, tb, &cfg, extack);
885 2 : if (!err && cfg.fc_type == RTN_LOCAL)
886 0 : net->ipv4.fib_has_custom_local_routes = true;
887 2 : errout:
888 2 : return err;
889 : }
890 :
891 0 : int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
892 : struct fib_dump_filter *filter,
893 : struct netlink_callback *cb)
894 : {
895 0 : struct netlink_ext_ack *extack = cb->extack;
896 0 : struct nlattr *tb[RTA_MAX + 1];
897 0 : struct rtmsg *rtm;
898 0 : int err, i;
899 :
900 0 : ASSERT_RTNL();
901 :
902 0 : if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
903 0 : NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
904 0 : return -EINVAL;
905 : }
906 :
907 0 : rtm = nlmsg_data(nlh);
908 0 : if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
909 0 : rtm->rtm_scope) {
910 0 : NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
911 0 : return -EINVAL;
912 : }
913 :
914 0 : if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
915 0 : NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
916 0 : return -EINVAL;
917 : }
918 0 : if (rtm->rtm_flags & RTM_F_CLONED)
919 0 : filter->dump_routes = false;
920 : else
921 0 : filter->dump_exceptions = false;
922 :
923 0 : filter->flags = rtm->rtm_flags;
924 0 : filter->protocol = rtm->rtm_protocol;
925 0 : filter->rt_type = rtm->rtm_type;
926 0 : filter->table_id = rtm->rtm_table;
927 :
928 0 : err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
929 : rtm_ipv4_policy, extack);
930 0 : if (err < 0)
931 : return err;
932 :
933 0 : for (i = 0; i <= RTA_MAX; ++i) {
934 0 : int ifindex;
935 :
936 0 : if (!tb[i])
937 0 : continue;
938 :
939 0 : switch (i) {
940 0 : case RTA_TABLE:
941 0 : filter->table_id = nla_get_u32(tb[i]);
942 0 : break;
943 0 : case RTA_OIF:
944 0 : ifindex = nla_get_u32(tb[i]);
945 0 : filter->dev = __dev_get_by_index(net, ifindex);
946 0 : if (!filter->dev)
947 : return -ENODEV;
948 : break;
949 0 : default:
950 0 : NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
951 : return -EINVAL;
952 : }
953 : }
954 :
955 0 : if (filter->flags || filter->protocol || filter->rt_type ||
956 0 : filter->table_id || filter->dev) {
957 0 : filter->filter_set = 1;
958 0 : cb->answer_flags = NLM_F_DUMP_FILTERED;
959 : }
960 :
961 : return 0;
962 : }
963 : EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
964 :
965 2 : static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
966 : {
967 2 : struct fib_dump_filter filter = { .dump_routes = true,
968 : .dump_exceptions = true };
969 2 : const struct nlmsghdr *nlh = cb->nlh;
970 2 : struct net *net = sock_net(skb->sk);
971 2 : unsigned int h, s_h;
972 2 : unsigned int e = 0, s_e;
973 2 : struct fib_table *tb;
974 2 : struct hlist_head *head;
975 2 : int dumped = 0, err;
976 :
977 2 : if (cb->strict_check) {
978 0 : err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
979 0 : if (err < 0)
980 : return err;
981 2 : } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
982 2 : struct rtmsg *rtm = nlmsg_data(nlh);
983 :
984 2 : filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
985 : }
986 :
987 : /* ipv4 does not use prefix flag */
988 2 : if (filter.flags & RTM_F_PREFIX)
989 0 : return skb->len;
990 :
991 2 : if (filter.table_id) {
992 0 : tb = fib_get_table(net, filter.table_id);
993 0 : if (!tb) {
994 0 : if (rtnl_msg_family(cb->nlh) != PF_INET)
995 0 : return skb->len;
996 :
997 0 : NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
998 0 : return -ENOENT;
999 : }
1000 :
1001 0 : rcu_read_lock();
1002 0 : err = fib_table_dump(tb, skb, cb, &filter);
1003 0 : rcu_read_unlock();
1004 0 : return skb->len ? : err;
1005 : }
1006 :
1007 2 : s_h = cb->args[0];
1008 2 : s_e = cb->args[1];
1009 :
1010 2 : rcu_read_lock();
1011 :
1012 4 : for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
1013 2 : e = 0;
1014 2 : head = &net->ipv4.fib_table_hash[h];
1015 6 : hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1016 2 : if (e < s_e)
1017 0 : goto next;
1018 2 : if (dumped)
1019 1 : memset(&cb->args[2], 0, sizeof(cb->args) -
1020 : 2 * sizeof(cb->args[0]));
1021 2 : err = fib_table_dump(tb, skb, cb, &filter);
1022 2 : if (err < 0) {
1023 0 : if (likely(skb->len))
1024 0 : goto out;
1025 :
1026 0 : goto out_err;
1027 : }
1028 : dumped = 1;
1029 2 : next:
1030 2 : e++;
1031 : }
1032 : }
1033 2 : out:
1034 2 : err = skb->len;
1035 2 : out_err:
1036 2 : rcu_read_unlock();
1037 :
1038 2 : cb->args[1] = e;
1039 2 : cb->args[0] = h;
1040 :
1041 2 : return err;
1042 : }
1043 :
1044 : /* Prepare and feed intra-kernel routing request.
1045 : * Really, it should be netlink message, but :-( netlink
1046 : * can be not configured, so that we feed it directly
1047 : * to fib engine. It is legal, because all events occur
1048 : * only when netlink is already locked.
1049 : */
1050 10 : static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1051 : struct in_ifaddr *ifa, u32 rt_priority)
1052 : {
1053 10 : struct net *net = dev_net(ifa->ifa_dev->dev);
1054 10 : u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1055 10 : struct fib_table *tb;
1056 10 : struct fib_config cfg = {
1057 : .fc_protocol = RTPROT_KERNEL,
1058 : .fc_type = type,
1059 : .fc_dst = dst,
1060 : .fc_dst_len = dst_len,
1061 : .fc_priority = rt_priority,
1062 10 : .fc_prefsrc = ifa->ifa_local,
1063 10 : .fc_oif = ifa->ifa_dev->dev->ifindex,
1064 : .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1065 : .fc_nlinfo = {
1066 : .nl_net = net,
1067 : },
1068 : };
1069 :
1070 10 : if (!tb_id)
1071 10 : tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1072 :
1073 10 : tb = fib_new_table(net, tb_id);
1074 10 : if (!tb)
1075 0 : return;
1076 :
1077 10 : cfg.fc_table = tb->tb_id;
1078 :
1079 10 : if (type != RTN_LOCAL)
1080 6 : cfg.fc_scope = RT_SCOPE_LINK;
1081 : else
1082 4 : cfg.fc_scope = RT_SCOPE_HOST;
1083 :
1084 10 : if (cmd == RTM_NEWROUTE)
1085 10 : fib_table_insert(net, tb, &cfg, NULL);
1086 : else
1087 0 : fib_table_delete(net, tb, &cfg, NULL);
1088 : }
1089 :
1090 3 : void fib_add_ifaddr(struct in_ifaddr *ifa)
1091 : {
1092 3 : struct in_device *in_dev = ifa->ifa_dev;
1093 3 : struct net_device *dev = in_dev->dev;
1094 3 : struct in_ifaddr *prim = ifa;
1095 3 : __be32 mask = ifa->ifa_mask;
1096 3 : __be32 addr = ifa->ifa_local;
1097 3 : __be32 prefix = ifa->ifa_address & mask;
1098 :
1099 3 : if (ifa->ifa_flags & IFA_F_SECONDARY) {
1100 0 : prim = inet_ifa_byprefix(in_dev, prefix, mask);
1101 0 : if (!prim) {
1102 0 : pr_warn("%s: bug: prim == NULL\n", __func__);
1103 0 : return;
1104 : }
1105 : }
1106 :
1107 3 : fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1108 :
1109 3 : if (!(dev->flags & IFF_UP))
1110 : return;
1111 :
1112 : /* Add broadcast address, if it is explicitly assigned. */
1113 2 : if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1114 1 : fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1115 : prim, 0);
1116 :
1117 2 : if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1118 0 : (prefix != addr || ifa->ifa_prefixlen < 32)) {
1119 2 : if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1120 2 : fib_magic(RTM_NEWROUTE,
1121 2 : dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1122 2 : prefix, ifa->ifa_prefixlen, prim,
1123 : ifa->ifa_rt_priority);
1124 :
1125 : /* Add network specific broadcasts, when it takes a sense */
1126 2 : if (ifa->ifa_prefixlen < 31) {
1127 2 : fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1128 : prim, 0);
1129 2 : fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1130 : 32, prim, 0);
1131 : }
1132 : }
1133 : }
1134 :
1135 0 : void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1136 : {
1137 0 : __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1138 0 : struct in_device *in_dev = ifa->ifa_dev;
1139 0 : struct net_device *dev = in_dev->dev;
1140 :
1141 0 : if (!(dev->flags & IFF_UP) ||
1142 0 : ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1143 0 : ipv4_is_zeronet(prefix) ||
1144 0 : (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32))
1145 : return;
1146 :
1147 : /* add the new */
1148 0 : fib_magic(RTM_NEWROUTE,
1149 0 : dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1150 0 : prefix, ifa->ifa_prefixlen, ifa, new_metric);
1151 :
1152 : /* delete the old */
1153 0 : fib_magic(RTM_DELROUTE,
1154 0 : dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1155 0 : prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1156 : }
1157 :
1158 : /* Delete primary or secondary address.
1159 : * Optionally, on secondary address promotion consider the addresses
1160 : * from subnet iprim as deleted, even if they are in device list.
1161 : * In this case the secondary ifa can be in device list.
1162 : */
1163 0 : void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1164 : {
1165 0 : struct in_device *in_dev = ifa->ifa_dev;
1166 0 : struct net_device *dev = in_dev->dev;
1167 0 : struct in_ifaddr *ifa1;
1168 0 : struct in_ifaddr *prim = ifa, *prim1 = NULL;
1169 0 : __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1170 0 : __be32 any = ifa->ifa_address & ifa->ifa_mask;
1171 : #define LOCAL_OK 1
1172 : #define BRD_OK 2
1173 : #define BRD0_OK 4
1174 : #define BRD1_OK 8
1175 0 : unsigned int ok = 0;
1176 0 : int subnet = 0; /* Primary network */
1177 0 : int gone = 1; /* Address is missing */
1178 0 : int same_prefsrc = 0; /* Another primary with same IP */
1179 :
1180 0 : if (ifa->ifa_flags & IFA_F_SECONDARY) {
1181 0 : prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1182 0 : if (!prim) {
1183 : /* if the device has been deleted, we don't perform
1184 : * address promotion
1185 : */
1186 0 : if (!in_dev->dead)
1187 0 : pr_warn("%s: bug: prim == NULL\n", __func__);
1188 0 : return;
1189 : }
1190 0 : if (iprim && iprim != prim) {
1191 0 : pr_warn("%s: bug: iprim != prim\n", __func__);
1192 0 : return;
1193 : }
1194 0 : } else if (!ipv4_is_zeronet(any) &&
1195 0 : (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1196 0 : if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1197 0 : fib_magic(RTM_DELROUTE,
1198 0 : dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1199 0 : any, ifa->ifa_prefixlen, prim, 0);
1200 : subnet = 1;
1201 : }
1202 :
1203 0 : if (in_dev->dead)
1204 0 : goto no_promotions;
1205 :
1206 : /* Deletion is more complicated than add.
1207 : * We should take care of not to delete too much :-)
1208 : *
1209 : * Scan address list to be sure that addresses are really gone.
1210 : */
1211 0 : rcu_read_lock();
1212 0 : in_dev_for_each_ifa_rcu(ifa1, in_dev) {
1213 0 : if (ifa1 == ifa) {
1214 : /* promotion, keep the IP */
1215 0 : gone = 0;
1216 0 : continue;
1217 : }
1218 : /* Ignore IFAs from our subnet */
1219 0 : if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1220 0 : inet_ifa_match(ifa1->ifa_address, iprim))
1221 0 : continue;
1222 :
1223 : /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1224 0 : if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1225 : /* Another address from our subnet? */
1226 0 : if (ifa1->ifa_mask == prim->ifa_mask &&
1227 0 : inet_ifa_match(ifa1->ifa_address, prim))
1228 : prim1 = prim;
1229 : else {
1230 : /* We reached the secondaries, so
1231 : * same_prefsrc should be determined.
1232 : */
1233 0 : if (!same_prefsrc)
1234 0 : continue;
1235 : /* Search new prim1 if ifa1 is not
1236 : * using the current prim1
1237 : */
1238 0 : if (!prim1 ||
1239 0 : ifa1->ifa_mask != prim1->ifa_mask ||
1240 0 : !inet_ifa_match(ifa1->ifa_address, prim1))
1241 0 : prim1 = inet_ifa_byprefix(in_dev,
1242 : ifa1->ifa_address,
1243 : ifa1->ifa_mask);
1244 0 : if (!prim1)
1245 0 : continue;
1246 0 : if (prim1->ifa_local != prim->ifa_local)
1247 0 : continue;
1248 : }
1249 : } else {
1250 0 : if (prim->ifa_local != ifa1->ifa_local)
1251 0 : continue;
1252 0 : prim1 = ifa1;
1253 0 : if (prim != prim1)
1254 0 : same_prefsrc = 1;
1255 : }
1256 0 : if (ifa->ifa_local == ifa1->ifa_local)
1257 0 : ok |= LOCAL_OK;
1258 0 : if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1259 0 : ok |= BRD_OK;
1260 0 : if (brd == ifa1->ifa_broadcast)
1261 0 : ok |= BRD1_OK;
1262 0 : if (any == ifa1->ifa_broadcast)
1263 0 : ok |= BRD0_OK;
1264 : /* primary has network specific broadcasts */
1265 0 : if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1266 0 : __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1267 0 : __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1268 :
1269 0 : if (!ipv4_is_zeronet(any1)) {
1270 0 : if (ifa->ifa_broadcast == brd1 ||
1271 : ifa->ifa_broadcast == any1)
1272 0 : ok |= BRD_OK;
1273 0 : if (brd == brd1 || brd == any1)
1274 0 : ok |= BRD1_OK;
1275 0 : if (any == brd1 || any == any1)
1276 0 : ok |= BRD0_OK;
1277 : }
1278 : }
1279 : }
1280 0 : rcu_read_unlock();
1281 :
1282 0 : no_promotions:
1283 0 : if (!(ok & BRD_OK))
1284 0 : fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1285 : prim, 0);
1286 0 : if (subnet && ifa->ifa_prefixlen < 31) {
1287 0 : if (!(ok & BRD1_OK))
1288 0 : fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1289 : prim, 0);
1290 0 : if (!(ok & BRD0_OK))
1291 0 : fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1292 : prim, 0);
1293 : }
1294 0 : if (!(ok & LOCAL_OK)) {
1295 0 : unsigned int addr_type;
1296 :
1297 0 : fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1298 :
1299 : /* Check, that this local address finally disappeared. */
1300 0 : addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1301 : ifa->ifa_local);
1302 0 : if (gone && addr_type != RTN_LOCAL) {
1303 : /* And the last, but not the least thing.
1304 : * We must flush stray FIB entries.
1305 : *
1306 : * First of all, we scan fib_info list searching
1307 : * for stray nexthop entries, then ignite fib_flush.
1308 : */
1309 0 : if (fib_sync_down_addr(dev, ifa->ifa_local))
1310 0 : fib_flush(dev_net(dev));
1311 : }
1312 : }
1313 : #undef LOCAL_OK
1314 : #undef BRD_OK
1315 : #undef BRD0_OK
1316 : #undef BRD1_OK
1317 : }
1318 :
1319 0 : static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1320 : {
1321 :
1322 0 : struct fib_result res;
1323 0 : struct flowi4 fl4 = {
1324 0 : .flowi4_mark = frn->fl_mark,
1325 0 : .daddr = frn->fl_addr,
1326 0 : .flowi4_tos = frn->fl_tos,
1327 0 : .flowi4_scope = frn->fl_scope,
1328 : };
1329 0 : struct fib_table *tb;
1330 :
1331 0 : rcu_read_lock();
1332 :
1333 0 : tb = fib_get_table(net, frn->tb_id_in);
1334 :
1335 0 : frn->err = -ENOENT;
1336 0 : if (tb) {
1337 0 : local_bh_disable();
1338 :
1339 0 : frn->tb_id = tb->tb_id;
1340 0 : frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1341 :
1342 0 : if (!frn->err) {
1343 0 : frn->prefixlen = res.prefixlen;
1344 0 : frn->nh_sel = res.nh_sel;
1345 0 : frn->type = res.type;
1346 0 : frn->scope = res.scope;
1347 : }
1348 0 : local_bh_enable();
1349 : }
1350 :
1351 0 : rcu_read_unlock();
1352 0 : }
1353 :
1354 0 : static void nl_fib_input(struct sk_buff *skb)
1355 : {
1356 0 : struct net *net;
1357 0 : struct fib_result_nl *frn;
1358 0 : struct nlmsghdr *nlh;
1359 0 : u32 portid;
1360 :
1361 0 : net = sock_net(skb->sk);
1362 0 : nlh = nlmsg_hdr(skb);
1363 0 : if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1364 0 : skb->len < nlh->nlmsg_len ||
1365 0 : nlmsg_len(nlh) < sizeof(*frn))
1366 : return;
1367 :
1368 0 : skb = netlink_skb_clone(skb, GFP_KERNEL);
1369 0 : if (!skb)
1370 : return;
1371 0 : nlh = nlmsg_hdr(skb);
1372 :
1373 0 : frn = (struct fib_result_nl *) nlmsg_data(nlh);
1374 0 : nl_fib_lookup(net, frn);
1375 :
1376 0 : portid = NETLINK_CB(skb).portid; /* netlink portid */
1377 0 : NETLINK_CB(skb).portid = 0; /* from kernel */
1378 0 : NETLINK_CB(skb).dst_group = 0; /* unicast */
1379 0 : netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1380 : }
1381 :
1382 1 : static int __net_init nl_fib_lookup_init(struct net *net)
1383 : {
1384 1 : struct sock *sk;
1385 1 : struct netlink_kernel_cfg cfg = {
1386 : .input = nl_fib_input,
1387 : };
1388 :
1389 1 : sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1390 1 : if (!sk)
1391 : return -EAFNOSUPPORT;
1392 1 : net->ipv4.fibnl = sk;
1393 1 : return 0;
1394 : }
1395 :
1396 0 : static void nl_fib_lookup_exit(struct net *net)
1397 : {
1398 0 : netlink_kernel_release(net->ipv4.fibnl);
1399 0 : net->ipv4.fibnl = NULL;
1400 0 : }
1401 :
1402 0 : static void fib_disable_ip(struct net_device *dev, unsigned long event,
1403 : bool force)
1404 : {
1405 0 : if (fib_sync_down_dev(dev, event, force))
1406 0 : fib_flush(dev_net(dev));
1407 : else
1408 0 : rt_cache_flush(dev_net(dev));
1409 0 : arp_ifdown(dev);
1410 0 : }
1411 :
1412 2 : static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1413 : {
1414 2 : struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1415 2 : struct net_device *dev = ifa->ifa_dev->dev;
1416 2 : struct net *net = dev_net(dev);
1417 :
1418 2 : switch (event) {
1419 2 : case NETDEV_UP:
1420 2 : fib_add_ifaddr(ifa);
1421 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
1422 : fib_sync_up(dev, RTNH_F_DEAD);
1423 : #endif
1424 2 : atomic_inc(&net->ipv4.dev_addr_genid);
1425 2 : rt_cache_flush(dev_net(dev));
1426 2 : break;
1427 0 : case NETDEV_DOWN:
1428 0 : fib_del_ifaddr(ifa, NULL);
1429 0 : atomic_inc(&net->ipv4.dev_addr_genid);
1430 0 : if (!ifa->ifa_dev->ifa_list) {
1431 : /* Last address was deleted from this interface.
1432 : * Disable IP.
1433 : */
1434 0 : fib_disable_ip(dev, event, true);
1435 : } else {
1436 0 : rt_cache_flush(dev_net(dev));
1437 : }
1438 : break;
1439 : }
1440 2 : return NOTIFY_DONE;
1441 : }
1442 :
1443 7 : static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1444 : {
1445 7 : struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1446 7 : struct netdev_notifier_changeupper_info *upper_info = ptr;
1447 7 : struct netdev_notifier_info_ext *info_ext = ptr;
1448 7 : struct in_device *in_dev;
1449 7 : struct net *net = dev_net(dev);
1450 7 : struct in_ifaddr *ifa;
1451 7 : unsigned int flags;
1452 :
1453 7 : if (event == NETDEV_UNREGISTER) {
1454 0 : fib_disable_ip(dev, event, true);
1455 0 : rt_flush_dev(dev);
1456 0 : return NOTIFY_DONE;
1457 : }
1458 :
1459 7 : in_dev = __in_dev_get_rtnl(dev);
1460 7 : if (!in_dev)
1461 : return NOTIFY_DONE;
1462 :
1463 6 : switch (event) {
1464 2 : case NETDEV_UP:
1465 3 : in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1466 1 : fib_add_ifaddr(ifa);
1467 : }
1468 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
1469 : fib_sync_up(dev, RTNH_F_DEAD);
1470 : #endif
1471 2 : atomic_inc(&net->ipv4.dev_addr_genid);
1472 2 : rt_cache_flush(net);
1473 2 : break;
1474 0 : case NETDEV_DOWN:
1475 0 : fib_disable_ip(dev, event, false);
1476 0 : break;
1477 0 : case NETDEV_CHANGE:
1478 0 : flags = dev_get_flags(dev);
1479 0 : if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1480 0 : fib_sync_up(dev, RTNH_F_LINKDOWN);
1481 : else
1482 0 : fib_sync_down_dev(dev, event, false);
1483 0 : rt_cache_flush(net);
1484 0 : break;
1485 0 : case NETDEV_CHANGEMTU:
1486 0 : fib_sync_mtu(dev, info_ext->ext.mtu);
1487 0 : rt_cache_flush(net);
1488 0 : break;
1489 0 : case NETDEV_CHANGEUPPER:
1490 0 : upper_info = ptr;
1491 : /* flush all routes if dev is linked to or unlinked from
1492 : * an L3 master device (e.g., VRF)
1493 : */
1494 0 : if (upper_info->upper_dev &&
1495 0 : netif_is_l3_master(upper_info->upper_dev))
1496 0 : fib_disable_ip(dev, NETDEV_DOWN, true);
1497 : break;
1498 : }
1499 : return NOTIFY_DONE;
1500 : }
1501 :
1502 : static struct notifier_block fib_inetaddr_notifier = {
1503 : .notifier_call = fib_inetaddr_event,
1504 : };
1505 :
1506 : static struct notifier_block fib_netdev_notifier = {
1507 : .notifier_call = fib_netdev_event,
1508 : };
1509 :
1510 1 : static int __net_init ip_fib_net_init(struct net *net)
1511 : {
1512 1 : int err;
1513 1 : size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1514 :
1515 1 : err = fib4_notifier_init(net);
1516 1 : if (err)
1517 : return err;
1518 :
1519 : /* Avoid false sharing : Use at least a full cache line */
1520 1 : size = max_t(size_t, size, L1_CACHE_BYTES);
1521 :
1522 1 : net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1523 1 : if (!net->ipv4.fib_table_hash) {
1524 0 : err = -ENOMEM;
1525 0 : goto err_table_hash_alloc;
1526 : }
1527 :
1528 1 : err = fib4_rules_init(net);
1529 1 : if (err < 0)
1530 0 : goto err_rules_init;
1531 : return 0;
1532 :
1533 0 : err_rules_init:
1534 0 : kfree(net->ipv4.fib_table_hash);
1535 0 : err_table_hash_alloc:
1536 0 : fib4_notifier_exit(net);
1537 0 : return err;
1538 : }
1539 :
1540 0 : static void ip_fib_net_exit(struct net *net)
1541 : {
1542 0 : int i;
1543 :
1544 0 : rtnl_lock();
1545 : #ifdef CONFIG_IP_MULTIPLE_TABLES
1546 : RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1547 : RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1548 : #endif
1549 : /* Destroy the tables in reverse order to guarantee that the
1550 : * local table, ID 255, is destroyed before the main table, ID
1551 : * 254. This is necessary as the local table may contain
1552 : * references to data contained in the main table.
1553 : */
1554 0 : for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1555 0 : struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1556 0 : struct hlist_node *tmp;
1557 0 : struct fib_table *tb;
1558 :
1559 0 : hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1560 0 : hlist_del(&tb->tb_hlist);
1561 0 : fib_table_flush(net, tb, true);
1562 0 : fib_free_table(tb);
1563 : }
1564 : }
1565 :
1566 : #ifdef CONFIG_IP_MULTIPLE_TABLES
1567 : fib4_rules_exit(net);
1568 : #endif
1569 0 : rtnl_unlock();
1570 0 : kfree(net->ipv4.fib_table_hash);
1571 0 : fib4_notifier_exit(net);
1572 0 : }
1573 :
1574 1 : static int __net_init fib_net_init(struct net *net)
1575 : {
1576 1 : int error;
1577 :
1578 : #ifdef CONFIG_IP_ROUTE_CLASSID
1579 : net->ipv4.fib_num_tclassid_users = 0;
1580 : #endif
1581 1 : error = ip_fib_net_init(net);
1582 1 : if (error < 0)
1583 0 : goto out;
1584 1 : error = nl_fib_lookup_init(net);
1585 1 : if (error < 0)
1586 0 : goto out_nlfl;
1587 1 : error = fib_proc_init(net);
1588 1 : if (error < 0)
1589 0 : goto out_proc;
1590 1 : out:
1591 1 : return error;
1592 :
1593 0 : out_proc:
1594 0 : nl_fib_lookup_exit(net);
1595 0 : out_nlfl:
1596 0 : ip_fib_net_exit(net);
1597 0 : goto out;
1598 : }
1599 :
1600 0 : static void __net_exit fib_net_exit(struct net *net)
1601 : {
1602 0 : fib_proc_exit(net);
1603 0 : nl_fib_lookup_exit(net);
1604 0 : ip_fib_net_exit(net);
1605 0 : }
1606 :
1607 : static struct pernet_operations fib_net_ops = {
1608 : .init = fib_net_init,
1609 : .exit = fib_net_exit,
1610 : };
1611 :
1612 1 : void __init ip_fib_init(void)
1613 : {
1614 1 : fib_trie_init();
1615 :
1616 1 : register_pernet_subsys(&fib_net_ops);
1617 :
1618 1 : register_netdevice_notifier(&fib_netdev_notifier);
1619 1 : register_inetaddr_notifier(&fib_inetaddr_notifier);
1620 :
1621 1 : rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1622 1 : rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1623 1 : rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);
1624 1 : }
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