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/inet_dscp.h> |
36 | #include <net/ip.h> |
37 | #include <net/protocol.h> |
38 | #include <net/route.h> |
39 | #include <net/tcp.h> |
40 | #include <net/sock.h> |
41 | #include <net/arp.h> |
42 | #include <net/ip_fib.h> |
43 | #include <net/nexthop.h> |
44 | #include <net/rtnetlink.h> |
45 | #include <net/xfrm.h> |
46 | #include <net/l3mdev.h> |
47 | #include <net/lwtunnel.h> |
48 | #include <trace/events/fib.h> |
49 | |
50 | #ifndef CONFIG_IP_MULTIPLE_TABLES |
51 | |
52 | static int __net_init fib4_rules_init(struct net *net) |
53 | { |
54 | struct fib_table *local_table, *main_table; |
55 | |
56 | main_table = fib_trie_table(RT_TABLE_MAIN, NULL); |
57 | if (!main_table) |
58 | return -ENOMEM; |
59 | |
60 | local_table = fib_trie_table(RT_TABLE_LOCAL, main_table); |
61 | if (!local_table) |
62 | goto fail; |
63 | |
64 | hlist_add_head_rcu(&local_table->tb_hlist, |
65 | &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]); |
66 | hlist_add_head_rcu(&main_table->tb_hlist, |
67 | &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]); |
68 | return 0; |
69 | |
70 | fail: |
71 | fib_free_table(main_table); |
72 | return -ENOMEM; |
73 | } |
74 | #else |
75 | |
76 | struct fib_table *fib_new_table(struct net *net, u32 id) |
77 | { |
78 | struct fib_table *tb, *alias = NULL; |
79 | unsigned int h; |
80 | |
81 | if (id == 0) |
82 | id = RT_TABLE_MAIN; |
83 | tb = fib_get_table(net, id); |
84 | if (tb) |
85 | return tb; |
86 | |
87 | if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules) |
88 | alias = fib_new_table(net, id: RT_TABLE_MAIN); |
89 | |
90 | tb = fib_trie_table(id, alias); |
91 | if (!tb) |
92 | return NULL; |
93 | |
94 | switch (id) { |
95 | case RT_TABLE_MAIN: |
96 | rcu_assign_pointer(net->ipv4.fib_main, tb); |
97 | break; |
98 | case RT_TABLE_DEFAULT: |
99 | rcu_assign_pointer(net->ipv4.fib_default, tb); |
100 | break; |
101 | default: |
102 | break; |
103 | } |
104 | |
105 | h = id & (FIB_TABLE_HASHSZ - 1); |
106 | hlist_add_head_rcu(n: &tb->tb_hlist, h: &net->ipv4.fib_table_hash[h]); |
107 | return tb; |
108 | } |
109 | EXPORT_SYMBOL_GPL(fib_new_table); |
110 | |
111 | /* caller must hold either rtnl or rcu read lock */ |
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 | head = &net->ipv4.fib_table_hash[h]; |
123 | hlist_for_each_entry_rcu(tb, head, tb_hlist, |
124 | lockdep_rtnl_is_held()) { |
125 | if (tb->tb_id == id) |
126 | return tb; |
127 | } |
128 | return NULL; |
129 | } |
130 | #endif /* CONFIG_IP_MULTIPLE_TABLES */ |
131 | |
132 | static void fib_replace_table(struct net *net, struct fib_table *old, |
133 | struct fib_table *new) |
134 | { |
135 | #ifdef CONFIG_IP_MULTIPLE_TABLES |
136 | switch (new->tb_id) { |
137 | case RT_TABLE_MAIN: |
138 | rcu_assign_pointer(net->ipv4.fib_main, new); |
139 | break; |
140 | case RT_TABLE_DEFAULT: |
141 | rcu_assign_pointer(net->ipv4.fib_default, new); |
142 | break; |
143 | default: |
144 | break; |
145 | } |
146 | |
147 | #endif |
148 | /* replace the old table in the hlist */ |
149 | hlist_replace_rcu(old: &old->tb_hlist, new: &new->tb_hlist); |
150 | } |
151 | |
152 | int fib_unmerge(struct net *net) |
153 | { |
154 | struct fib_table *old, *new, *main_table; |
155 | |
156 | /* attempt to fetch local table if it has been allocated */ |
157 | old = fib_get_table(net, id: RT_TABLE_LOCAL); |
158 | if (!old) |
159 | return 0; |
160 | |
161 | new = fib_trie_unmerge(main_tb: old); |
162 | if (!new) |
163 | return -ENOMEM; |
164 | |
165 | /* table is already unmerged */ |
166 | if (new == old) |
167 | return 0; |
168 | |
169 | /* replace merged table with clean table */ |
170 | fib_replace_table(net, old, new); |
171 | fib_free_table(tb: old); |
172 | |
173 | /* attempt to fetch main table if it has been allocated */ |
174 | main_table = fib_get_table(net, id: RT_TABLE_MAIN); |
175 | if (!main_table) |
176 | return 0; |
177 | |
178 | /* flush local entries from main table */ |
179 | fib_table_flush_external(table: main_table); |
180 | |
181 | return 0; |
182 | } |
183 | |
184 | void fib_flush(struct net *net) |
185 | { |
186 | int flushed = 0; |
187 | unsigned int h; |
188 | |
189 | for (h = 0; h < FIB_TABLE_HASHSZ; h++) { |
190 | struct hlist_head *head = &net->ipv4.fib_table_hash[h]; |
191 | struct hlist_node *tmp; |
192 | struct fib_table *tb; |
193 | |
194 | hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) |
195 | flushed += fib_table_flush(net, table: tb, flush_all: false); |
196 | } |
197 | |
198 | if (flushed) |
199 | rt_cache_flush(net); |
200 | } |
201 | |
202 | /* |
203 | * Find address type as if only "dev" was present in the system. If |
204 | * on_dev is NULL then all interfaces are taken into consideration. |
205 | */ |
206 | static inline unsigned int __inet_dev_addr_type(struct net *net, |
207 | const struct net_device *dev, |
208 | __be32 addr, u32 tb_id) |
209 | { |
210 | struct flowi4 fl4 = { .daddr = addr }; |
211 | struct fib_result res; |
212 | unsigned int ret = RTN_BROADCAST; |
213 | struct fib_table *table; |
214 | |
215 | if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr)) |
216 | return RTN_BROADCAST; |
217 | if (ipv4_is_multicast(addr)) |
218 | return RTN_MULTICAST; |
219 | |
220 | rcu_read_lock(); |
221 | |
222 | table = fib_get_table(net, id: tb_id); |
223 | if (table) { |
224 | ret = RTN_UNICAST; |
225 | if (!fib_table_lookup(tb: table, flp: &fl4, res: &res, FIB_LOOKUP_NOREF)) { |
226 | struct fib_nh_common *nhc = fib_info_nhc(fi: res.fi, nhsel: 0); |
227 | |
228 | if (!dev || dev == nhc->nhc_dev) |
229 | ret = res.type; |
230 | } |
231 | } |
232 | |
233 | rcu_read_unlock(); |
234 | return ret; |
235 | } |
236 | |
237 | unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id) |
238 | { |
239 | return __inet_dev_addr_type(net, NULL, addr, tb_id); |
240 | } |
241 | EXPORT_SYMBOL(inet_addr_type_table); |
242 | |
243 | unsigned int inet_addr_type(struct net *net, __be32 addr) |
244 | { |
245 | return __inet_dev_addr_type(net, NULL, addr, tb_id: RT_TABLE_LOCAL); |
246 | } |
247 | EXPORT_SYMBOL(inet_addr_type); |
248 | |
249 | unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, |
250 | __be32 addr) |
251 | { |
252 | u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; |
253 | |
254 | return __inet_dev_addr_type(net, dev, addr, tb_id: rt_table); |
255 | } |
256 | EXPORT_SYMBOL(inet_dev_addr_type); |
257 | |
258 | /* inet_addr_type with dev == NULL but using the table from a dev |
259 | * if one is associated |
260 | */ |
261 | unsigned int inet_addr_type_dev_table(struct net *net, |
262 | const struct net_device *dev, |
263 | __be32 addr) |
264 | { |
265 | u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL; |
266 | |
267 | return __inet_dev_addr_type(net, NULL, addr, tb_id: rt_table); |
268 | } |
269 | EXPORT_SYMBOL(inet_addr_type_dev_table); |
270 | |
271 | __be32 fib_compute_spec_dst(struct sk_buff *skb) |
272 | { |
273 | struct net_device *dev = skb->dev; |
274 | struct in_device *in_dev; |
275 | struct fib_result res; |
276 | struct rtable *rt; |
277 | struct net *net; |
278 | int scope; |
279 | |
280 | rt = skb_rtable(skb); |
281 | if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) == |
282 | RTCF_LOCAL) |
283 | return ip_hdr(skb)->daddr; |
284 | |
285 | in_dev = __in_dev_get_rcu(dev); |
286 | |
287 | net = dev_net(dev); |
288 | |
289 | scope = RT_SCOPE_UNIVERSE; |
290 | if (!ipv4_is_zeronet(addr: ip_hdr(skb)->saddr)) { |
291 | bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); |
292 | struct flowi4 fl4 = { |
293 | .flowi4_iif = LOOPBACK_IFINDEX, |
294 | .flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev), |
295 | .daddr = ip_hdr(skb)->saddr, |
296 | .flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK, |
297 | .flowi4_scope = scope, |
298 | .flowi4_mark = vmark ? skb->mark : 0, |
299 | }; |
300 | if (!fib_lookup(net, flp: &fl4, res: &res, flags: 0)) |
301 | return fib_result_prefsrc(net, res: &res); |
302 | } else { |
303 | scope = RT_SCOPE_LINK; |
304 | } |
305 | |
306 | return inet_select_addr(dev, dst: ip_hdr(skb)->saddr, scope); |
307 | } |
308 | |
309 | bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev) |
310 | { |
311 | bool dev_match = false; |
312 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
313 | if (unlikely(fi->nh)) { |
314 | dev_match = nexthop_uses_dev(nh: fi->nh, dev); |
315 | } else { |
316 | int ret; |
317 | |
318 | for (ret = 0; ret < fib_info_num_path(fi); ret++) { |
319 | const struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel: ret); |
320 | |
321 | if (nhc_l3mdev_matches_dev(nhc, dev)) { |
322 | dev_match = true; |
323 | break; |
324 | } |
325 | } |
326 | } |
327 | #else |
328 | if (fib_info_nhc(fi, 0)->nhc_dev == dev) |
329 | dev_match = true; |
330 | #endif |
331 | |
332 | return dev_match; |
333 | } |
334 | EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev); |
335 | |
336 | /* Given (packet source, input interface) and optional (dst, oif, tos): |
337 | * - (main) check, that source is valid i.e. not broadcast or our local |
338 | * address. |
339 | * - figure out what "logical" interface this packet arrived |
340 | * and calculate "specific destination" address. |
341 | * - check, that packet arrived from expected physical interface. |
342 | * called with rcu_read_lock() |
343 | */ |
344 | static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, |
345 | u8 tos, int oif, struct net_device *dev, |
346 | int rpf, struct in_device *idev, u32 *itag) |
347 | { |
348 | struct net *net = dev_net(dev); |
349 | struct flow_keys flkeys; |
350 | int ret, no_addr; |
351 | struct fib_result res; |
352 | struct flowi4 fl4; |
353 | bool dev_match; |
354 | |
355 | fl4.flowi4_oif = 0; |
356 | fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(dev); |
357 | fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX; |
358 | fl4.daddr = src; |
359 | fl4.saddr = dst; |
360 | fl4.flowi4_tos = tos; |
361 | fl4.flowi4_scope = RT_SCOPE_UNIVERSE; |
362 | fl4.flowi4_tun_key.tun_id = 0; |
363 | fl4.flowi4_flags = 0; |
364 | fl4.flowi4_uid = sock_net_uid(net, NULL); |
365 | fl4.flowi4_multipath_hash = 0; |
366 | |
367 | no_addr = idev->ifa_list == NULL; |
368 | |
369 | fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0; |
370 | if (!fib4_rules_early_flow_dissect(net, skb, fl4: &fl4, flkeys: &flkeys)) { |
371 | fl4.flowi4_proto = 0; |
372 | fl4.fl4_sport = 0; |
373 | fl4.fl4_dport = 0; |
374 | } else { |
375 | swap(fl4.fl4_sport, fl4.fl4_dport); |
376 | } |
377 | |
378 | if (fib_lookup(net, flp: &fl4, res: &res, flags: 0)) |
379 | goto last_resort; |
380 | if (res.type != RTN_UNICAST && |
381 | (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev))) |
382 | goto e_inval; |
383 | fib_combine_itag(itag, res: &res); |
384 | |
385 | dev_match = fib_info_nh_uses_dev(res.fi, dev); |
386 | /* This is not common, loopback packets retain skb_dst so normally they |
387 | * would not even hit this slow path. |
388 | */ |
389 | dev_match = dev_match || (res.type == RTN_LOCAL && |
390 | dev == net->loopback_dev); |
391 | if (dev_match) { |
392 | ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; |
393 | return ret; |
394 | } |
395 | if (no_addr) |
396 | goto last_resort; |
397 | if (rpf == 1) |
398 | goto e_rpf; |
399 | fl4.flowi4_oif = dev->ifindex; |
400 | |
401 | ret = 0; |
402 | if (fib_lookup(net, flp: &fl4, res: &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { |
403 | if (res.type == RTN_UNICAST) |
404 | ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; |
405 | } |
406 | return ret; |
407 | |
408 | last_resort: |
409 | if (rpf) |
410 | goto e_rpf; |
411 | *itag = 0; |
412 | return 0; |
413 | |
414 | e_inval: |
415 | return -EINVAL; |
416 | e_rpf: |
417 | return -EXDEV; |
418 | } |
419 | |
420 | /* Ignore rp_filter for packets protected by IPsec. */ |
421 | int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, |
422 | u8 tos, int oif, struct net_device *dev, |
423 | struct in_device *idev, u32 *itag) |
424 | { |
425 | int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev); |
426 | struct net *net = dev_net(dev); |
427 | |
428 | if (!r && !fib_num_tclassid_users(net) && |
429 | (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) { |
430 | if (IN_DEV_ACCEPT_LOCAL(idev)) |
431 | goto ok; |
432 | /* with custom local routes in place, checking local addresses |
433 | * only will be too optimistic, with custom rules, checking |
434 | * local addresses only can be too strict, e.g. due to vrf |
435 | */ |
436 | if (net->ipv4.fib_has_custom_local_routes || |
437 | fib4_has_custom_rules(net)) |
438 | goto full_check; |
439 | /* Within the same container, it is regarded as a martian source, |
440 | * and the same host but different containers are not. |
441 | */ |
442 | if (inet_lookup_ifaddr_rcu(net, addr: src)) |
443 | return -EINVAL; |
444 | |
445 | ok: |
446 | *itag = 0; |
447 | return 0; |
448 | } |
449 | |
450 | full_check: |
451 | return __fib_validate_source(skb, src, dst, tos, oif, dev, rpf: r, idev, itag); |
452 | } |
453 | |
454 | static inline __be32 (struct sockaddr *addr) |
455 | { |
456 | return ((struct sockaddr_in *) addr)->sin_addr.s_addr; |
457 | } |
458 | |
459 | static int put_rtax(struct nlattr *mx, int len, int type, u32 value) |
460 | { |
461 | struct nlattr *nla; |
462 | |
463 | nla = (struct nlattr *) ((char *) mx + len); |
464 | nla->nla_type = type; |
465 | nla->nla_len = nla_attr_size(payload: 4); |
466 | *(u32 *) nla_data(nla) = value; |
467 | |
468 | return len + nla_total_size(payload: 4); |
469 | } |
470 | |
471 | static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, |
472 | struct fib_config *cfg) |
473 | { |
474 | __be32 addr; |
475 | int plen; |
476 | |
477 | memset(cfg, 0, sizeof(*cfg)); |
478 | cfg->fc_nlinfo.nl_net = net; |
479 | |
480 | if (rt->rt_dst.sa_family != AF_INET) |
481 | return -EAFNOSUPPORT; |
482 | |
483 | /* |
484 | * Check mask for validity: |
485 | * a) it must be contiguous. |
486 | * b) destination must have all host bits clear. |
487 | * c) if application forgot to set correct family (AF_INET), |
488 | * reject request unless it is absolutely clear i.e. |
489 | * both family and mask are zero. |
490 | */ |
491 | plen = 32; |
492 | addr = sk_extract_addr(addr: &rt->rt_dst); |
493 | if (!(rt->rt_flags & RTF_HOST)) { |
494 | __be32 mask = sk_extract_addr(addr: &rt->rt_genmask); |
495 | |
496 | if (rt->rt_genmask.sa_family != AF_INET) { |
497 | if (mask || rt->rt_genmask.sa_family) |
498 | return -EAFNOSUPPORT; |
499 | } |
500 | |
501 | if (bad_mask(mask, addr)) |
502 | return -EINVAL; |
503 | |
504 | plen = inet_mask_len(mask); |
505 | } |
506 | |
507 | cfg->fc_dst_len = plen; |
508 | cfg->fc_dst = addr; |
509 | |
510 | if (cmd != SIOCDELRT) { |
511 | cfg->fc_nlflags = NLM_F_CREATE; |
512 | cfg->fc_protocol = RTPROT_BOOT; |
513 | } |
514 | |
515 | if (rt->rt_metric) |
516 | cfg->fc_priority = rt->rt_metric - 1; |
517 | |
518 | if (rt->rt_flags & RTF_REJECT) { |
519 | cfg->fc_scope = RT_SCOPE_HOST; |
520 | cfg->fc_type = RTN_UNREACHABLE; |
521 | return 0; |
522 | } |
523 | |
524 | cfg->fc_scope = RT_SCOPE_NOWHERE; |
525 | cfg->fc_type = RTN_UNICAST; |
526 | |
527 | if (rt->rt_dev) { |
528 | char *colon; |
529 | struct net_device *dev; |
530 | char devname[IFNAMSIZ]; |
531 | |
532 | if (copy_from_user(to: devname, from: rt->rt_dev, IFNAMSIZ-1)) |
533 | return -EFAULT; |
534 | |
535 | devname[IFNAMSIZ-1] = 0; |
536 | colon = strchr(devname, ':'); |
537 | if (colon) |
538 | *colon = 0; |
539 | dev = __dev_get_by_name(net, name: devname); |
540 | if (!dev) |
541 | return -ENODEV; |
542 | cfg->fc_oif = dev->ifindex; |
543 | cfg->fc_table = l3mdev_fib_table(dev); |
544 | if (colon) { |
545 | const struct in_ifaddr *ifa; |
546 | struct in_device *in_dev; |
547 | |
548 | in_dev = __in_dev_get_rtnl(dev); |
549 | if (!in_dev) |
550 | return -ENODEV; |
551 | |
552 | *colon = ':'; |
553 | |
554 | rcu_read_lock(); |
555 | in_dev_for_each_ifa_rcu(ifa, in_dev) { |
556 | if (strcmp(ifa->ifa_label, devname) == 0) |
557 | break; |
558 | } |
559 | rcu_read_unlock(); |
560 | |
561 | if (!ifa) |
562 | return -ENODEV; |
563 | cfg->fc_prefsrc = ifa->ifa_local; |
564 | } |
565 | } |
566 | |
567 | addr = sk_extract_addr(addr: &rt->rt_gateway); |
568 | if (rt->rt_gateway.sa_family == AF_INET && addr) { |
569 | unsigned int addr_type; |
570 | |
571 | cfg->fc_gw4 = addr; |
572 | cfg->fc_gw_family = AF_INET; |
573 | addr_type = inet_addr_type_table(net, addr, cfg->fc_table); |
574 | if (rt->rt_flags & RTF_GATEWAY && |
575 | addr_type == RTN_UNICAST) |
576 | cfg->fc_scope = RT_SCOPE_UNIVERSE; |
577 | } |
578 | |
579 | if (!cfg->fc_table) |
580 | cfg->fc_table = RT_TABLE_MAIN; |
581 | |
582 | if (cmd == SIOCDELRT) |
583 | return 0; |
584 | |
585 | if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family) |
586 | return -EINVAL; |
587 | |
588 | if (cfg->fc_scope == RT_SCOPE_NOWHERE) |
589 | cfg->fc_scope = RT_SCOPE_LINK; |
590 | |
591 | if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) { |
592 | struct nlattr *mx; |
593 | int len = 0; |
594 | |
595 | mx = kcalloc(n: 3, size: nla_total_size(payload: 4), GFP_KERNEL); |
596 | if (!mx) |
597 | return -ENOMEM; |
598 | |
599 | if (rt->rt_flags & RTF_MTU) |
600 | len = put_rtax(mx, len, RTAX_ADVMSS, value: rt->rt_mtu - 40); |
601 | |
602 | if (rt->rt_flags & RTF_WINDOW) |
603 | len = put_rtax(mx, len, RTAX_WINDOW, value: rt->rt_window); |
604 | |
605 | if (rt->rt_flags & RTF_IRTT) |
606 | len = put_rtax(mx, len, RTAX_RTT, value: rt->rt_irtt << 3); |
607 | |
608 | cfg->fc_mx = mx; |
609 | cfg->fc_mx_len = len; |
610 | } |
611 | |
612 | return 0; |
613 | } |
614 | |
615 | /* |
616 | * Handle IP routing ioctl calls. |
617 | * These are used to manipulate the routing tables |
618 | */ |
619 | int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt) |
620 | { |
621 | struct fib_config cfg; |
622 | int err; |
623 | |
624 | switch (cmd) { |
625 | case SIOCADDRT: /* Add a route */ |
626 | case SIOCDELRT: /* Delete a route */ |
627 | if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN)) |
628 | return -EPERM; |
629 | |
630 | rtnl_lock(); |
631 | err = rtentry_to_fib_config(net, cmd, rt, cfg: &cfg); |
632 | if (err == 0) { |
633 | struct fib_table *tb; |
634 | |
635 | if (cmd == SIOCDELRT) { |
636 | tb = fib_get_table(net, id: cfg.fc_table); |
637 | if (tb) |
638 | err = fib_table_delete(net, tb, &cfg, |
639 | NULL); |
640 | else |
641 | err = -ESRCH; |
642 | } else { |
643 | tb = fib_new_table(net, cfg.fc_table); |
644 | if (tb) |
645 | err = fib_table_insert(net, tb, |
646 | &cfg, NULL); |
647 | else |
648 | err = -ENOBUFS; |
649 | } |
650 | |
651 | /* allocated by rtentry_to_fib_config() */ |
652 | kfree(objp: cfg.fc_mx); |
653 | } |
654 | rtnl_unlock(); |
655 | return err; |
656 | } |
657 | return -EINVAL; |
658 | } |
659 | |
660 | const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = { |
661 | [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, |
662 | [RTA_DST] = { .type = NLA_U32 }, |
663 | [RTA_SRC] = { .type = NLA_U32 }, |
664 | [RTA_IIF] = { .type = NLA_U32 }, |
665 | [RTA_OIF] = { .type = NLA_U32 }, |
666 | [RTA_GATEWAY] = { .type = NLA_U32 }, |
667 | [RTA_PRIORITY] = { .type = NLA_U32 }, |
668 | [RTA_PREFSRC] = { .type = NLA_U32 }, |
669 | [RTA_METRICS] = { .type = NLA_NESTED }, |
670 | [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, |
671 | [RTA_FLOW] = { .type = NLA_U32 }, |
672 | [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, |
673 | [RTA_ENCAP] = { .type = NLA_NESTED }, |
674 | [RTA_UID] = { .type = NLA_U32 }, |
675 | [RTA_MARK] = { .type = NLA_U32 }, |
676 | [RTA_TABLE] = { .type = NLA_U32 }, |
677 | [RTA_IP_PROTO] = { .type = NLA_U8 }, |
678 | [RTA_SPORT] = { .type = NLA_U16 }, |
679 | [RTA_DPORT] = { .type = NLA_U16 }, |
680 | [RTA_NH_ID] = { .type = NLA_U32 }, |
681 | }; |
682 | |
683 | int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, |
684 | struct netlink_ext_ack *extack) |
685 | { |
686 | struct rtvia *via; |
687 | int alen; |
688 | |
689 | if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { |
690 | NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA" ); |
691 | return -EINVAL; |
692 | } |
693 | |
694 | via = nla_data(nla); |
695 | alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr); |
696 | |
697 | switch (via->rtvia_family) { |
698 | case AF_INET: |
699 | if (alen != sizeof(__be32)) { |
700 | NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA" ); |
701 | return -EINVAL; |
702 | } |
703 | cfg->fc_gw_family = AF_INET; |
704 | cfg->fc_gw4 = *((__be32 *)via->rtvia_addr); |
705 | break; |
706 | case AF_INET6: |
707 | #if IS_ENABLED(CONFIG_IPV6) |
708 | if (alen != sizeof(struct in6_addr)) { |
709 | NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA" ); |
710 | return -EINVAL; |
711 | } |
712 | cfg->fc_gw_family = AF_INET6; |
713 | cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr); |
714 | #else |
715 | NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel" ); |
716 | return -EINVAL; |
717 | #endif |
718 | break; |
719 | default: |
720 | NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA" ); |
721 | return -EINVAL; |
722 | } |
723 | |
724 | return 0; |
725 | } |
726 | |
727 | static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, |
728 | struct nlmsghdr *nlh, struct fib_config *cfg, |
729 | struct netlink_ext_ack *extack) |
730 | { |
731 | bool has_gw = false, has_via = false; |
732 | struct nlattr *attr; |
733 | int err, remaining; |
734 | struct rtmsg *rtm; |
735 | |
736 | err = nlmsg_validate_deprecated(nlh, hdrlen: sizeof(*rtm), RTA_MAX, |
737 | policy: rtm_ipv4_policy, extack); |
738 | if (err < 0) |
739 | goto errout; |
740 | |
741 | memset(cfg, 0, sizeof(*cfg)); |
742 | |
743 | rtm = nlmsg_data(nlh); |
744 | |
745 | if (!inet_validate_dscp(val: rtm->rtm_tos)) { |
746 | NL_SET_ERR_MSG(extack, |
747 | "Invalid dsfield (tos): ECN bits must be 0" ); |
748 | err = -EINVAL; |
749 | goto errout; |
750 | } |
751 | cfg->fc_dscp = inet_dsfield_to_dscp(dsfield: rtm->rtm_tos); |
752 | |
753 | cfg->fc_dst_len = rtm->rtm_dst_len; |
754 | cfg->fc_table = rtm->rtm_table; |
755 | cfg->fc_protocol = rtm->rtm_protocol; |
756 | cfg->fc_scope = rtm->rtm_scope; |
757 | cfg->fc_type = rtm->rtm_type; |
758 | cfg->fc_flags = rtm->rtm_flags; |
759 | cfg->fc_nlflags = nlh->nlmsg_flags; |
760 | |
761 | cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; |
762 | cfg->fc_nlinfo.nlh = nlh; |
763 | cfg->fc_nlinfo.nl_net = net; |
764 | |
765 | if (cfg->fc_type > RTN_MAX) { |
766 | NL_SET_ERR_MSG(extack, "Invalid route type" ); |
767 | err = -EINVAL; |
768 | goto errout; |
769 | } |
770 | |
771 | nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) { |
772 | switch (nla_type(nla: attr)) { |
773 | case RTA_DST: |
774 | cfg->fc_dst = nla_get_be32(nla: attr); |
775 | break; |
776 | case RTA_OIF: |
777 | cfg->fc_oif = nla_get_u32(nla: attr); |
778 | break; |
779 | case RTA_GATEWAY: |
780 | has_gw = true; |
781 | cfg->fc_gw4 = nla_get_be32(nla: attr); |
782 | if (cfg->fc_gw4) |
783 | cfg->fc_gw_family = AF_INET; |
784 | break; |
785 | case RTA_VIA: |
786 | has_via = true; |
787 | err = fib_gw_from_via(cfg, nla: attr, extack); |
788 | if (err) |
789 | goto errout; |
790 | break; |
791 | case RTA_PRIORITY: |
792 | cfg->fc_priority = nla_get_u32(nla: attr); |
793 | break; |
794 | case RTA_PREFSRC: |
795 | cfg->fc_prefsrc = nla_get_be32(nla: attr); |
796 | break; |
797 | case RTA_METRICS: |
798 | cfg->fc_mx = nla_data(nla: attr); |
799 | cfg->fc_mx_len = nla_len(nla: attr); |
800 | break; |
801 | case RTA_MULTIPATH: |
802 | err = lwtunnel_valid_encap_type_attr(attr: nla_data(nla: attr), |
803 | len: nla_len(nla: attr), |
804 | extack); |
805 | if (err < 0) |
806 | goto errout; |
807 | cfg->fc_mp = nla_data(nla: attr); |
808 | cfg->fc_mp_len = nla_len(nla: attr); |
809 | break; |
810 | case RTA_FLOW: |
811 | cfg->fc_flow = nla_get_u32(nla: attr); |
812 | break; |
813 | case RTA_TABLE: |
814 | cfg->fc_table = nla_get_u32(nla: attr); |
815 | break; |
816 | case RTA_ENCAP: |
817 | cfg->fc_encap = attr; |
818 | break; |
819 | case RTA_ENCAP_TYPE: |
820 | cfg->fc_encap_type = nla_get_u16(nla: attr); |
821 | err = lwtunnel_valid_encap_type(encap_type: cfg->fc_encap_type, |
822 | extack); |
823 | if (err < 0) |
824 | goto errout; |
825 | break; |
826 | case RTA_NH_ID: |
827 | cfg->fc_nh_id = nla_get_u32(nla: attr); |
828 | break; |
829 | } |
830 | } |
831 | |
832 | if (cfg->fc_nh_id) { |
833 | if (cfg->fc_oif || cfg->fc_gw_family || |
834 | cfg->fc_encap || cfg->fc_mp) { |
835 | NL_SET_ERR_MSG(extack, |
836 | "Nexthop specification and nexthop id are mutually exclusive" ); |
837 | return -EINVAL; |
838 | } |
839 | } |
840 | |
841 | if (has_gw && has_via) { |
842 | NL_SET_ERR_MSG(extack, |
843 | "Nexthop configuration can not contain both GATEWAY and VIA" ); |
844 | return -EINVAL; |
845 | } |
846 | |
847 | if (!cfg->fc_table) |
848 | cfg->fc_table = RT_TABLE_MAIN; |
849 | |
850 | return 0; |
851 | errout: |
852 | return err; |
853 | } |
854 | |
855 | static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, |
856 | struct netlink_ext_ack *extack) |
857 | { |
858 | struct net *net = sock_net(sk: skb->sk); |
859 | struct fib_config cfg; |
860 | struct fib_table *tb; |
861 | int err; |
862 | |
863 | err = rtm_to_fib_config(net, skb, nlh, cfg: &cfg, extack); |
864 | if (err < 0) |
865 | goto errout; |
866 | |
867 | if (cfg.fc_nh_id && !nexthop_find_by_id(net, id: cfg.fc_nh_id)) { |
868 | NL_SET_ERR_MSG(extack, "Nexthop id does not exist" ); |
869 | err = -EINVAL; |
870 | goto errout; |
871 | } |
872 | |
873 | tb = fib_get_table(net, id: cfg.fc_table); |
874 | if (!tb) { |
875 | NL_SET_ERR_MSG(extack, "FIB table does not exist" ); |
876 | err = -ESRCH; |
877 | goto errout; |
878 | } |
879 | |
880 | err = fib_table_delete(net, tb, &cfg, extack); |
881 | errout: |
882 | return err; |
883 | } |
884 | |
885 | static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, |
886 | struct netlink_ext_ack *extack) |
887 | { |
888 | struct net *net = sock_net(sk: skb->sk); |
889 | struct fib_config cfg; |
890 | struct fib_table *tb; |
891 | int err; |
892 | |
893 | err = rtm_to_fib_config(net, skb, nlh, cfg: &cfg, extack); |
894 | if (err < 0) |
895 | goto errout; |
896 | |
897 | tb = fib_new_table(net, cfg.fc_table); |
898 | if (!tb) { |
899 | err = -ENOBUFS; |
900 | goto errout; |
901 | } |
902 | |
903 | err = fib_table_insert(net, tb, &cfg, extack); |
904 | if (!err && cfg.fc_type == RTN_LOCAL) |
905 | net->ipv4.fib_has_custom_local_routes = true; |
906 | errout: |
907 | return err; |
908 | } |
909 | |
910 | int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, |
911 | struct fib_dump_filter *filter, |
912 | struct netlink_callback *cb) |
913 | { |
914 | struct netlink_ext_ack *extack = cb->extack; |
915 | struct nlattr *tb[RTA_MAX + 1]; |
916 | struct rtmsg *rtm; |
917 | int err, i; |
918 | |
919 | ASSERT_RTNL(); |
920 | |
921 | if (nlh->nlmsg_len < nlmsg_msg_size(payload: sizeof(*rtm))) { |
922 | NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request" ); |
923 | return -EINVAL; |
924 | } |
925 | |
926 | rtm = nlmsg_data(nlh); |
927 | if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos || |
928 | rtm->rtm_scope) { |
929 | NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request" ); |
930 | return -EINVAL; |
931 | } |
932 | |
933 | if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) { |
934 | NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request" ); |
935 | return -EINVAL; |
936 | } |
937 | if (rtm->rtm_flags & RTM_F_CLONED) |
938 | filter->dump_routes = false; |
939 | else |
940 | filter->dump_exceptions = false; |
941 | |
942 | filter->flags = rtm->rtm_flags; |
943 | filter->protocol = rtm->rtm_protocol; |
944 | filter->rt_type = rtm->rtm_type; |
945 | filter->table_id = rtm->rtm_table; |
946 | |
947 | err = nlmsg_parse_deprecated_strict(nlh, hdrlen: sizeof(*rtm), tb, RTA_MAX, |
948 | policy: rtm_ipv4_policy, extack); |
949 | if (err < 0) |
950 | return err; |
951 | |
952 | for (i = 0; i <= RTA_MAX; ++i) { |
953 | int ifindex; |
954 | |
955 | if (!tb[i]) |
956 | continue; |
957 | |
958 | switch (i) { |
959 | case RTA_TABLE: |
960 | filter->table_id = nla_get_u32(nla: tb[i]); |
961 | break; |
962 | case RTA_OIF: |
963 | ifindex = nla_get_u32(nla: tb[i]); |
964 | filter->dev = __dev_get_by_index(net, ifindex); |
965 | if (!filter->dev) |
966 | return -ENODEV; |
967 | break; |
968 | default: |
969 | NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request" ); |
970 | return -EINVAL; |
971 | } |
972 | } |
973 | |
974 | if (filter->flags || filter->protocol || filter->rt_type || |
975 | filter->table_id || filter->dev) { |
976 | filter->filter_set = 1; |
977 | cb->answer_flags = NLM_F_DUMP_FILTERED; |
978 | } |
979 | |
980 | return 0; |
981 | } |
982 | EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req); |
983 | |
984 | static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) |
985 | { |
986 | struct fib_dump_filter filter = { .dump_routes = true, |
987 | .dump_exceptions = true }; |
988 | const struct nlmsghdr *nlh = cb->nlh; |
989 | struct net *net = sock_net(sk: skb->sk); |
990 | unsigned int h, s_h; |
991 | unsigned int e = 0, s_e; |
992 | struct fib_table *tb; |
993 | struct hlist_head *head; |
994 | int dumped = 0, err; |
995 | |
996 | if (cb->strict_check) { |
997 | err = ip_valid_fib_dump_req(net, nlh, &filter, cb); |
998 | if (err < 0) |
999 | return err; |
1000 | } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { |
1001 | struct rtmsg *rtm = nlmsg_data(nlh); |
1002 | |
1003 | filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED); |
1004 | } |
1005 | |
1006 | /* ipv4 does not use prefix flag */ |
1007 | if (filter.flags & RTM_F_PREFIX) |
1008 | return skb->len; |
1009 | |
1010 | if (filter.table_id) { |
1011 | tb = fib_get_table(net, id: filter.table_id); |
1012 | if (!tb) { |
1013 | if (rtnl_msg_family(nlh: cb->nlh) != PF_INET) |
1014 | return skb->len; |
1015 | |
1016 | NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist" ); |
1017 | return -ENOENT; |
1018 | } |
1019 | |
1020 | rcu_read_lock(); |
1021 | err = fib_table_dump(table: tb, skb, cb, filter: &filter); |
1022 | rcu_read_unlock(); |
1023 | return skb->len ? : err; |
1024 | } |
1025 | |
1026 | s_h = cb->args[0]; |
1027 | s_e = cb->args[1]; |
1028 | |
1029 | rcu_read_lock(); |
1030 | |
1031 | for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { |
1032 | e = 0; |
1033 | head = &net->ipv4.fib_table_hash[h]; |
1034 | hlist_for_each_entry_rcu(tb, head, tb_hlist) { |
1035 | if (e < s_e) |
1036 | goto next; |
1037 | if (dumped) |
1038 | memset(&cb->args[2], 0, sizeof(cb->args) - |
1039 | 2 * sizeof(cb->args[0])); |
1040 | err = fib_table_dump(table: tb, skb, cb, filter: &filter); |
1041 | if (err < 0) { |
1042 | if (likely(skb->len)) |
1043 | goto out; |
1044 | |
1045 | goto out_err; |
1046 | } |
1047 | dumped = 1; |
1048 | next: |
1049 | e++; |
1050 | } |
1051 | } |
1052 | out: |
1053 | err = skb->len; |
1054 | out_err: |
1055 | rcu_read_unlock(); |
1056 | |
1057 | cb->args[1] = e; |
1058 | cb->args[0] = h; |
1059 | |
1060 | return err; |
1061 | } |
1062 | |
1063 | /* Prepare and feed intra-kernel routing request. |
1064 | * Really, it should be netlink message, but :-( netlink |
1065 | * can be not configured, so that we feed it directly |
1066 | * to fib engine. It is legal, because all events occur |
1067 | * only when netlink is already locked. |
1068 | */ |
1069 | static void fib_magic(int cmd, int type, __be32 dst, int dst_len, |
1070 | struct in_ifaddr *ifa, u32 rt_priority) |
1071 | { |
1072 | struct net *net = dev_net(dev: ifa->ifa_dev->dev); |
1073 | u32 tb_id = l3mdev_fib_table(dev: ifa->ifa_dev->dev); |
1074 | struct fib_table *tb; |
1075 | struct fib_config cfg = { |
1076 | .fc_protocol = RTPROT_KERNEL, |
1077 | .fc_type = type, |
1078 | .fc_dst = dst, |
1079 | .fc_dst_len = dst_len, |
1080 | .fc_priority = rt_priority, |
1081 | .fc_prefsrc = ifa->ifa_local, |
1082 | .fc_oif = ifa->ifa_dev->dev->ifindex, |
1083 | .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND, |
1084 | .fc_nlinfo = { |
1085 | .nl_net = net, |
1086 | }, |
1087 | }; |
1088 | |
1089 | if (!tb_id) |
1090 | tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL; |
1091 | |
1092 | tb = fib_new_table(net, tb_id); |
1093 | if (!tb) |
1094 | return; |
1095 | |
1096 | cfg.fc_table = tb->tb_id; |
1097 | |
1098 | if (type != RTN_LOCAL) |
1099 | cfg.fc_scope = RT_SCOPE_LINK; |
1100 | else |
1101 | cfg.fc_scope = RT_SCOPE_HOST; |
1102 | |
1103 | if (cmd == RTM_NEWROUTE) |
1104 | fib_table_insert(net, tb, &cfg, NULL); |
1105 | else |
1106 | fib_table_delete(net, tb, &cfg, NULL); |
1107 | } |
1108 | |
1109 | void fib_add_ifaddr(struct in_ifaddr *ifa) |
1110 | { |
1111 | struct in_device *in_dev = ifa->ifa_dev; |
1112 | struct net_device *dev = in_dev->dev; |
1113 | struct in_ifaddr *prim = ifa; |
1114 | __be32 mask = ifa->ifa_mask; |
1115 | __be32 addr = ifa->ifa_local; |
1116 | __be32 prefix = ifa->ifa_address & mask; |
1117 | |
1118 | if (ifa->ifa_flags & IFA_F_SECONDARY) { |
1119 | prim = inet_ifa_byprefix(in_dev, prefix, mask); |
1120 | if (!prim) { |
1121 | pr_warn("%s: bug: prim == NULL\n" , __func__); |
1122 | return; |
1123 | } |
1124 | } |
1125 | |
1126 | fib_magic(RTM_NEWROUTE, type: RTN_LOCAL, dst: addr, dst_len: 32, ifa: prim, rt_priority: 0); |
1127 | |
1128 | if (!(dev->flags & IFF_UP)) |
1129 | return; |
1130 | |
1131 | /* Add broadcast address, if it is explicitly assigned. */ |
1132 | if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF)) { |
1133 | fib_magic(RTM_NEWROUTE, type: RTN_BROADCAST, dst: ifa->ifa_broadcast, dst_len: 32, |
1134 | ifa: prim, rt_priority: 0); |
1135 | arp_invalidate(dev, ip: ifa->ifa_broadcast, force: false); |
1136 | } |
1137 | |
1138 | if (!ipv4_is_zeronet(addr: prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && |
1139 | (prefix != addr || ifa->ifa_prefixlen < 32)) { |
1140 | if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) |
1141 | fib_magic(RTM_NEWROUTE, |
1142 | type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, |
1143 | dst: prefix, dst_len: ifa->ifa_prefixlen, ifa: prim, |
1144 | rt_priority: ifa->ifa_rt_priority); |
1145 | |
1146 | /* Add the network broadcast address, when it makes sense */ |
1147 | if (ifa->ifa_prefixlen < 31) { |
1148 | fib_magic(RTM_NEWROUTE, type: RTN_BROADCAST, dst: prefix | ~mask, |
1149 | dst_len: 32, ifa: prim, rt_priority: 0); |
1150 | arp_invalidate(dev, ip: prefix | ~mask, force: false); |
1151 | } |
1152 | } |
1153 | } |
1154 | |
1155 | void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric) |
1156 | { |
1157 | __be32 prefix = ifa->ifa_address & ifa->ifa_mask; |
1158 | struct in_device *in_dev = ifa->ifa_dev; |
1159 | struct net_device *dev = in_dev->dev; |
1160 | |
1161 | if (!(dev->flags & IFF_UP) || |
1162 | ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) || |
1163 | ipv4_is_zeronet(addr: prefix) || |
1164 | (prefix == ifa->ifa_local && ifa->ifa_prefixlen == 32)) |
1165 | return; |
1166 | |
1167 | /* add the new */ |
1168 | fib_magic(RTM_NEWROUTE, |
1169 | type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, |
1170 | dst: prefix, dst_len: ifa->ifa_prefixlen, ifa, rt_priority: new_metric); |
1171 | |
1172 | /* delete the old */ |
1173 | fib_magic(RTM_DELROUTE, |
1174 | type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, |
1175 | dst: prefix, dst_len: ifa->ifa_prefixlen, ifa, rt_priority: ifa->ifa_rt_priority); |
1176 | } |
1177 | |
1178 | /* Delete primary or secondary address. |
1179 | * Optionally, on secondary address promotion consider the addresses |
1180 | * from subnet iprim as deleted, even if they are in device list. |
1181 | * In this case the secondary ifa can be in device list. |
1182 | */ |
1183 | void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) |
1184 | { |
1185 | struct in_device *in_dev = ifa->ifa_dev; |
1186 | struct net_device *dev = in_dev->dev; |
1187 | struct in_ifaddr *ifa1; |
1188 | struct in_ifaddr *prim = ifa, *prim1 = NULL; |
1189 | __be32 brd = ifa->ifa_address | ~ifa->ifa_mask; |
1190 | __be32 any = ifa->ifa_address & ifa->ifa_mask; |
1191 | #define LOCAL_OK 1 |
1192 | #define BRD_OK 2 |
1193 | #define BRD0_OK 4 |
1194 | #define BRD1_OK 8 |
1195 | unsigned int ok = 0; |
1196 | int subnet = 0; /* Primary network */ |
1197 | int gone = 1; /* Address is missing */ |
1198 | int same_prefsrc = 0; /* Another primary with same IP */ |
1199 | |
1200 | if (ifa->ifa_flags & IFA_F_SECONDARY) { |
1201 | prim = inet_ifa_byprefix(in_dev, prefix: any, mask: ifa->ifa_mask); |
1202 | if (!prim) { |
1203 | /* if the device has been deleted, we don't perform |
1204 | * address promotion |
1205 | */ |
1206 | if (!in_dev->dead) |
1207 | pr_warn("%s: bug: prim == NULL\n" , __func__); |
1208 | return; |
1209 | } |
1210 | if (iprim && iprim != prim) { |
1211 | pr_warn("%s: bug: iprim != prim\n" , __func__); |
1212 | return; |
1213 | } |
1214 | } else if (!ipv4_is_zeronet(addr: any) && |
1215 | (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { |
1216 | if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) |
1217 | fib_magic(RTM_DELROUTE, |
1218 | type: dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, |
1219 | dst: any, dst_len: ifa->ifa_prefixlen, ifa: prim, rt_priority: 0); |
1220 | subnet = 1; |
1221 | } |
1222 | |
1223 | if (in_dev->dead) |
1224 | goto no_promotions; |
1225 | |
1226 | /* Deletion is more complicated than add. |
1227 | * We should take care of not to delete too much :-) |
1228 | * |
1229 | * Scan address list to be sure that addresses are really gone. |
1230 | */ |
1231 | rcu_read_lock(); |
1232 | in_dev_for_each_ifa_rcu(ifa1, in_dev) { |
1233 | if (ifa1 == ifa) { |
1234 | /* promotion, keep the IP */ |
1235 | gone = 0; |
1236 | continue; |
1237 | } |
1238 | /* Ignore IFAs from our subnet */ |
1239 | if (iprim && ifa1->ifa_mask == iprim->ifa_mask && |
1240 | inet_ifa_match(addr: ifa1->ifa_address, ifa: iprim)) |
1241 | continue; |
1242 | |
1243 | /* Ignore ifa1 if it uses different primary IP (prefsrc) */ |
1244 | if (ifa1->ifa_flags & IFA_F_SECONDARY) { |
1245 | /* Another address from our subnet? */ |
1246 | if (ifa1->ifa_mask == prim->ifa_mask && |
1247 | inet_ifa_match(addr: ifa1->ifa_address, ifa: prim)) |
1248 | prim1 = prim; |
1249 | else { |
1250 | /* We reached the secondaries, so |
1251 | * same_prefsrc should be determined. |
1252 | */ |
1253 | if (!same_prefsrc) |
1254 | continue; |
1255 | /* Search new prim1 if ifa1 is not |
1256 | * using the current prim1 |
1257 | */ |
1258 | if (!prim1 || |
1259 | ifa1->ifa_mask != prim1->ifa_mask || |
1260 | !inet_ifa_match(addr: ifa1->ifa_address, ifa: prim1)) |
1261 | prim1 = inet_ifa_byprefix(in_dev, |
1262 | prefix: ifa1->ifa_address, |
1263 | mask: ifa1->ifa_mask); |
1264 | if (!prim1) |
1265 | continue; |
1266 | if (prim1->ifa_local != prim->ifa_local) |
1267 | continue; |
1268 | } |
1269 | } else { |
1270 | if (prim->ifa_local != ifa1->ifa_local) |
1271 | continue; |
1272 | prim1 = ifa1; |
1273 | if (prim != prim1) |
1274 | same_prefsrc = 1; |
1275 | } |
1276 | if (ifa->ifa_local == ifa1->ifa_local) |
1277 | ok |= LOCAL_OK; |
1278 | if (ifa->ifa_broadcast == ifa1->ifa_broadcast) |
1279 | ok |= BRD_OK; |
1280 | if (brd == ifa1->ifa_broadcast) |
1281 | ok |= BRD1_OK; |
1282 | if (any == ifa1->ifa_broadcast) |
1283 | ok |= BRD0_OK; |
1284 | /* primary has network specific broadcasts */ |
1285 | if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) { |
1286 | __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask; |
1287 | __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask; |
1288 | |
1289 | if (!ipv4_is_zeronet(addr: any1)) { |
1290 | if (ifa->ifa_broadcast == brd1 || |
1291 | ifa->ifa_broadcast == any1) |
1292 | ok |= BRD_OK; |
1293 | if (brd == brd1 || brd == any1) |
1294 | ok |= BRD1_OK; |
1295 | if (any == brd1 || any == any1) |
1296 | ok |= BRD0_OK; |
1297 | } |
1298 | } |
1299 | } |
1300 | rcu_read_unlock(); |
1301 | |
1302 | no_promotions: |
1303 | if (!(ok & BRD_OK)) |
1304 | fib_magic(RTM_DELROUTE, type: RTN_BROADCAST, dst: ifa->ifa_broadcast, dst_len: 32, |
1305 | ifa: prim, rt_priority: 0); |
1306 | if (subnet && ifa->ifa_prefixlen < 31) { |
1307 | if (!(ok & BRD1_OK)) |
1308 | fib_magic(RTM_DELROUTE, type: RTN_BROADCAST, dst: brd, dst_len: 32, |
1309 | ifa: prim, rt_priority: 0); |
1310 | if (!(ok & BRD0_OK)) |
1311 | fib_magic(RTM_DELROUTE, type: RTN_BROADCAST, dst: any, dst_len: 32, |
1312 | ifa: prim, rt_priority: 0); |
1313 | } |
1314 | if (!(ok & LOCAL_OK)) { |
1315 | unsigned int addr_type; |
1316 | |
1317 | fib_magic(RTM_DELROUTE, type: RTN_LOCAL, dst: ifa->ifa_local, dst_len: 32, ifa: prim, rt_priority: 0); |
1318 | |
1319 | /* Check, that this local address finally disappeared. */ |
1320 | addr_type = inet_addr_type_dev_table(dev_net(dev), dev, |
1321 | ifa->ifa_local); |
1322 | if (gone && addr_type != RTN_LOCAL) { |
1323 | /* And the last, but not the least thing. |
1324 | * We must flush stray FIB entries. |
1325 | * |
1326 | * First of all, we scan fib_info list searching |
1327 | * for stray nexthop entries, then ignite fib_flush. |
1328 | */ |
1329 | if (fib_sync_down_addr(dev, local: ifa->ifa_local)) |
1330 | fib_flush(net: dev_net(dev)); |
1331 | } |
1332 | } |
1333 | #undef LOCAL_OK |
1334 | #undef BRD_OK |
1335 | #undef BRD0_OK |
1336 | #undef BRD1_OK |
1337 | } |
1338 | |
1339 | static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn) |
1340 | { |
1341 | |
1342 | struct fib_result res; |
1343 | struct flowi4 fl4 = { |
1344 | .flowi4_mark = frn->fl_mark, |
1345 | .daddr = frn->fl_addr, |
1346 | .flowi4_tos = frn->fl_tos, |
1347 | .flowi4_scope = frn->fl_scope, |
1348 | }; |
1349 | struct fib_table *tb; |
1350 | |
1351 | rcu_read_lock(); |
1352 | |
1353 | tb = fib_get_table(net, id: frn->tb_id_in); |
1354 | |
1355 | frn->err = -ENOENT; |
1356 | if (tb) { |
1357 | local_bh_disable(); |
1358 | |
1359 | frn->tb_id = tb->tb_id; |
1360 | frn->err = fib_table_lookup(tb, flp: &fl4, res: &res, FIB_LOOKUP_NOREF); |
1361 | |
1362 | if (!frn->err) { |
1363 | frn->prefixlen = res.prefixlen; |
1364 | frn->nh_sel = res.nh_sel; |
1365 | frn->type = res.type; |
1366 | frn->scope = res.scope; |
1367 | } |
1368 | local_bh_enable(); |
1369 | } |
1370 | |
1371 | rcu_read_unlock(); |
1372 | } |
1373 | |
1374 | static void nl_fib_input(struct sk_buff *skb) |
1375 | { |
1376 | struct net *net; |
1377 | struct fib_result_nl *frn; |
1378 | struct nlmsghdr *nlh; |
1379 | u32 portid; |
1380 | |
1381 | net = sock_net(sk: skb->sk); |
1382 | nlh = nlmsg_hdr(skb); |
1383 | if (skb->len < nlmsg_total_size(payload: sizeof(*frn)) || |
1384 | skb->len < nlh->nlmsg_len || |
1385 | nlmsg_len(nlh) < sizeof(*frn)) |
1386 | return; |
1387 | |
1388 | skb = netlink_skb_clone(skb, GFP_KERNEL); |
1389 | if (!skb) |
1390 | return; |
1391 | nlh = nlmsg_hdr(skb); |
1392 | |
1393 | frn = nlmsg_data(nlh); |
1394 | nl_fib_lookup(net, frn); |
1395 | |
1396 | portid = NETLINK_CB(skb).portid; /* netlink portid */ |
1397 | NETLINK_CB(skb).portid = 0; /* from kernel */ |
1398 | NETLINK_CB(skb).dst_group = 0; /* unicast */ |
1399 | nlmsg_unicast(sk: net->ipv4.fibnl, skb, portid); |
1400 | } |
1401 | |
1402 | static int __net_init nl_fib_lookup_init(struct net *net) |
1403 | { |
1404 | struct sock *sk; |
1405 | struct netlink_kernel_cfg cfg = { |
1406 | .input = nl_fib_input, |
1407 | }; |
1408 | |
1409 | sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, cfg: &cfg); |
1410 | if (!sk) |
1411 | return -EAFNOSUPPORT; |
1412 | net->ipv4.fibnl = sk; |
1413 | return 0; |
1414 | } |
1415 | |
1416 | static void nl_fib_lookup_exit(struct net *net) |
1417 | { |
1418 | netlink_kernel_release(sk: net->ipv4.fibnl); |
1419 | net->ipv4.fibnl = NULL; |
1420 | } |
1421 | |
1422 | static void fib_disable_ip(struct net_device *dev, unsigned long event, |
1423 | bool force) |
1424 | { |
1425 | if (fib_sync_down_dev(dev, event, force)) |
1426 | fib_flush(net: dev_net(dev)); |
1427 | else |
1428 | rt_cache_flush(net: dev_net(dev)); |
1429 | arp_ifdown(dev); |
1430 | } |
1431 | |
1432 | static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr) |
1433 | { |
1434 | struct in_ifaddr *ifa = ptr; |
1435 | struct net_device *dev = ifa->ifa_dev->dev; |
1436 | struct net *net = dev_net(dev); |
1437 | |
1438 | switch (event) { |
1439 | case NETDEV_UP: |
1440 | fib_add_ifaddr(ifa); |
1441 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1442 | fib_sync_up(dev, RTNH_F_DEAD); |
1443 | #endif |
1444 | atomic_inc(v: &net->ipv4.dev_addr_genid); |
1445 | rt_cache_flush(net: dev_net(dev)); |
1446 | break; |
1447 | case NETDEV_DOWN: |
1448 | fib_del_ifaddr(ifa, NULL); |
1449 | atomic_inc(v: &net->ipv4.dev_addr_genid); |
1450 | if (!ifa->ifa_dev->ifa_list) { |
1451 | /* Last address was deleted from this interface. |
1452 | * Disable IP. |
1453 | */ |
1454 | fib_disable_ip(dev, event, force: true); |
1455 | } else { |
1456 | rt_cache_flush(net: dev_net(dev)); |
1457 | } |
1458 | break; |
1459 | } |
1460 | return NOTIFY_DONE; |
1461 | } |
1462 | |
1463 | static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) |
1464 | { |
1465 | struct net_device *dev = netdev_notifier_info_to_dev(info: ptr); |
1466 | struct netdev_notifier_changeupper_info *upper_info = ptr; |
1467 | struct netdev_notifier_info_ext *info_ext = ptr; |
1468 | struct in_device *in_dev; |
1469 | struct net *net = dev_net(dev); |
1470 | struct in_ifaddr *ifa; |
1471 | unsigned int flags; |
1472 | |
1473 | if (event == NETDEV_UNREGISTER) { |
1474 | fib_disable_ip(dev, event, force: true); |
1475 | rt_flush_dev(dev); |
1476 | return NOTIFY_DONE; |
1477 | } |
1478 | |
1479 | in_dev = __in_dev_get_rtnl(dev); |
1480 | if (!in_dev) |
1481 | return NOTIFY_DONE; |
1482 | |
1483 | switch (event) { |
1484 | case NETDEV_UP: |
1485 | in_dev_for_each_ifa_rtnl(ifa, in_dev) { |
1486 | fib_add_ifaddr(ifa); |
1487 | } |
1488 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1489 | fib_sync_up(dev, RTNH_F_DEAD); |
1490 | #endif |
1491 | atomic_inc(v: &net->ipv4.dev_addr_genid); |
1492 | rt_cache_flush(net); |
1493 | break; |
1494 | case NETDEV_DOWN: |
1495 | fib_disable_ip(dev, event, force: false); |
1496 | break; |
1497 | case NETDEV_CHANGE: |
1498 | flags = dev_get_flags(dev); |
1499 | if (flags & (IFF_RUNNING | IFF_LOWER_UP)) |
1500 | fib_sync_up(dev, RTNH_F_LINKDOWN); |
1501 | else |
1502 | fib_sync_down_dev(dev, event, force: false); |
1503 | rt_cache_flush(net); |
1504 | break; |
1505 | case NETDEV_CHANGEMTU: |
1506 | fib_sync_mtu(dev, orig_mtu: info_ext->ext.mtu); |
1507 | rt_cache_flush(net); |
1508 | break; |
1509 | case NETDEV_CHANGEUPPER: |
1510 | upper_info = ptr; |
1511 | /* flush all routes if dev is linked to or unlinked from |
1512 | * an L3 master device (e.g., VRF) |
1513 | */ |
1514 | if (upper_info->upper_dev && |
1515 | netif_is_l3_master(dev: upper_info->upper_dev)) |
1516 | fib_disable_ip(dev, event: NETDEV_DOWN, force: true); |
1517 | break; |
1518 | } |
1519 | return NOTIFY_DONE; |
1520 | } |
1521 | |
1522 | static struct notifier_block fib_inetaddr_notifier = { |
1523 | .notifier_call = fib_inetaddr_event, |
1524 | }; |
1525 | |
1526 | static struct notifier_block fib_netdev_notifier = { |
1527 | .notifier_call = fib_netdev_event, |
1528 | }; |
1529 | |
1530 | static int __net_init ip_fib_net_init(struct net *net) |
1531 | { |
1532 | int err; |
1533 | size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ; |
1534 | |
1535 | err = fib4_notifier_init(net); |
1536 | if (err) |
1537 | return err; |
1538 | |
1539 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1540 | /* Default to 3-tuple */ |
1541 | net->ipv4.sysctl_fib_multipath_hash_fields = |
1542 | FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; |
1543 | #endif |
1544 | |
1545 | /* Avoid false sharing : Use at least a full cache line */ |
1546 | size = max_t(size_t, size, L1_CACHE_BYTES); |
1547 | |
1548 | net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL); |
1549 | if (!net->ipv4.fib_table_hash) { |
1550 | err = -ENOMEM; |
1551 | goto err_table_hash_alloc; |
1552 | } |
1553 | |
1554 | err = fib4_rules_init(net); |
1555 | if (err < 0) |
1556 | goto err_rules_init; |
1557 | return 0; |
1558 | |
1559 | err_rules_init: |
1560 | kfree(objp: net->ipv4.fib_table_hash); |
1561 | err_table_hash_alloc: |
1562 | fib4_notifier_exit(net); |
1563 | return err; |
1564 | } |
1565 | |
1566 | static void ip_fib_net_exit(struct net *net) |
1567 | { |
1568 | int i; |
1569 | |
1570 | ASSERT_RTNL(); |
1571 | #ifdef CONFIG_IP_MULTIPLE_TABLES |
1572 | RCU_INIT_POINTER(net->ipv4.fib_main, NULL); |
1573 | RCU_INIT_POINTER(net->ipv4.fib_default, NULL); |
1574 | #endif |
1575 | /* Destroy the tables in reverse order to guarantee that the |
1576 | * local table, ID 255, is destroyed before the main table, ID |
1577 | * 254. This is necessary as the local table may contain |
1578 | * references to data contained in the main table. |
1579 | */ |
1580 | for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) { |
1581 | struct hlist_head *head = &net->ipv4.fib_table_hash[i]; |
1582 | struct hlist_node *tmp; |
1583 | struct fib_table *tb; |
1584 | |
1585 | hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) { |
1586 | hlist_del(n: &tb->tb_hlist); |
1587 | fib_table_flush(net, table: tb, flush_all: true); |
1588 | fib_free_table(tb); |
1589 | } |
1590 | } |
1591 | |
1592 | #ifdef CONFIG_IP_MULTIPLE_TABLES |
1593 | fib4_rules_exit(net); |
1594 | #endif |
1595 | |
1596 | kfree(objp: net->ipv4.fib_table_hash); |
1597 | fib4_notifier_exit(net); |
1598 | } |
1599 | |
1600 | static int __net_init fib_net_init(struct net *net) |
1601 | { |
1602 | int error; |
1603 | |
1604 | #ifdef CONFIG_IP_ROUTE_CLASSID |
1605 | atomic_set(v: &net->ipv4.fib_num_tclassid_users, i: 0); |
1606 | #endif |
1607 | error = ip_fib_net_init(net); |
1608 | if (error < 0) |
1609 | goto out; |
1610 | error = nl_fib_lookup_init(net); |
1611 | if (error < 0) |
1612 | goto out_nlfl; |
1613 | error = fib_proc_init(net); |
1614 | if (error < 0) |
1615 | goto out_proc; |
1616 | out: |
1617 | return error; |
1618 | |
1619 | out_proc: |
1620 | nl_fib_lookup_exit(net); |
1621 | out_nlfl: |
1622 | rtnl_lock(); |
1623 | ip_fib_net_exit(net); |
1624 | rtnl_unlock(); |
1625 | goto out; |
1626 | } |
1627 | |
1628 | static void __net_exit fib_net_exit(struct net *net) |
1629 | { |
1630 | fib_proc_exit(net); |
1631 | nl_fib_lookup_exit(net); |
1632 | } |
1633 | |
1634 | static void __net_exit fib_net_exit_batch(struct list_head *net_list) |
1635 | { |
1636 | struct net *net; |
1637 | |
1638 | rtnl_lock(); |
1639 | list_for_each_entry(net, net_list, exit_list) |
1640 | ip_fib_net_exit(net); |
1641 | |
1642 | rtnl_unlock(); |
1643 | } |
1644 | |
1645 | static struct pernet_operations fib_net_ops = { |
1646 | .init = fib_net_init, |
1647 | .exit = fib_net_exit, |
1648 | .exit_batch = fib_net_exit_batch, |
1649 | }; |
1650 | |
1651 | void __init ip_fib_init(void) |
1652 | { |
1653 | fib_trie_init(); |
1654 | |
1655 | register_pernet_subsys(&fib_net_ops); |
1656 | |
1657 | register_netdevice_notifier(nb: &fib_netdev_notifier); |
1658 | register_inetaddr_notifier(nb: &fib_inetaddr_notifier); |
1659 | |
1660 | rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, flags: 0); |
1661 | rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, flags: 0); |
1662 | rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, flags: 0); |
1663 | } |
1664 | |