2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * IPv4 Forwarding Information Base: FIB frontend.
8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
16 #include <linux/module.h>
17 #include <linux/uaccess.h>
18 #include <linux/bitops.h>
19 #include <linux/capability.h>
20 #include <linux/types.h>
21 #include <linux/kernel.h>
23 #include <linux/string.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/errno.h>
28 #include <linux/inet.h>
29 #include <linux/inetdevice.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_addr.h>
32 #include <linux/if_arp.h>
33 #include <linux/skbuff.h>
34 #include <linux/cache.h>
35 #include <linux/init.h>
36 #include <linux/list.h>
37 #include <linux/slab.h>
40 #include <net/protocol.h>
41 #include <net/route.h>
45 #include <net/ip_fib.h>
46 #include <net/rtnetlink.h>
48 #include <net/l3mdev.h>
49 #include <net/lwtunnel.h>
50 #include <trace/events/fib.h>
52 #ifndef CONFIG_IP_MULTIPLE_TABLES
54 static int __net_init fib4_rules_init(struct net *net)
56 struct fib_table *local_table, *main_table;
58 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
62 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
66 hlist_add_head_rcu(&local_table->tb_hlist,
67 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
68 hlist_add_head_rcu(&main_table->tb_hlist,
69 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
73 fib_free_table(main_table);
77 static bool fib4_has_custom_rules(struct net *net)
83 struct fib_table *fib_new_table(struct net *net, u32 id)
85 struct fib_table *tb, *alias = NULL;
90 tb = fib_get_table(net, id);
94 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
95 alias = fib_new_table(net, RT_TABLE_MAIN);
97 tb = fib_trie_table(id, alias);
103 rcu_assign_pointer(net->ipv4.fib_main, tb);
105 case RT_TABLE_DEFAULT:
106 rcu_assign_pointer(net->ipv4.fib_default, tb);
112 h = id & (FIB_TABLE_HASHSZ - 1);
113 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
116 EXPORT_SYMBOL_GPL(fib_new_table);
118 /* caller must hold either rtnl or rcu read lock */
119 struct fib_table *fib_get_table(struct net *net, u32 id)
121 struct fib_table *tb;
122 struct hlist_head *head;
127 h = id & (FIB_TABLE_HASHSZ - 1);
129 head = &net->ipv4.fib_table_hash[h];
130 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
137 static bool fib4_has_custom_rules(struct net *net)
139 return net->ipv4.fib_has_custom_rules;
141 #endif /* CONFIG_IP_MULTIPLE_TABLES */
143 static void fib_replace_table(struct net *net, struct fib_table *old,
144 struct fib_table *new)
146 #ifdef CONFIG_IP_MULTIPLE_TABLES
147 switch (new->tb_id) {
149 rcu_assign_pointer(net->ipv4.fib_main, new);
151 case RT_TABLE_DEFAULT:
152 rcu_assign_pointer(net->ipv4.fib_default, new);
159 /* replace the old table in the hlist */
160 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
163 int fib_unmerge(struct net *net)
165 struct fib_table *old, *new, *main_table;
167 /* attempt to fetch local table if it has been allocated */
168 old = fib_get_table(net, RT_TABLE_LOCAL);
172 new = fib_trie_unmerge(old);
176 /* table is already unmerged */
180 /* replace merged table with clean table */
181 fib_replace_table(net, old, new);
184 /* attempt to fetch main table if it has been allocated */
185 main_table = fib_get_table(net, RT_TABLE_MAIN);
189 /* flush local entries from main table */
190 fib_table_flush_external(main_table);
195 static void fib_flush(struct net *net)
200 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
201 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
202 struct hlist_node *tmp;
203 struct fib_table *tb;
205 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
206 flushed += fib_table_flush(net, tb);
214 * Find address type as if only "dev" was present in the system. If
215 * on_dev is NULL then all interfaces are taken into consideration.
217 static inline unsigned int __inet_dev_addr_type(struct net *net,
218 const struct net_device *dev,
219 __be32 addr, u32 tb_id)
221 struct flowi4 fl4 = { .daddr = addr };
222 struct fib_result res;
223 unsigned int ret = RTN_BROADCAST;
224 struct fib_table *table;
226 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
227 return RTN_BROADCAST;
228 if (ipv4_is_multicast(addr))
229 return RTN_MULTICAST;
233 table = fib_get_table(net, tb_id);
236 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
237 if (!dev || dev == res.fi->fib_dev)
246 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
248 return __inet_dev_addr_type(net, NULL, addr, tb_id);
250 EXPORT_SYMBOL(inet_addr_type_table);
252 unsigned int inet_addr_type(struct net *net, __be32 addr)
254 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
256 EXPORT_SYMBOL(inet_addr_type);
258 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
261 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
263 return __inet_dev_addr_type(net, dev, addr, rt_table);
265 EXPORT_SYMBOL(inet_dev_addr_type);
267 /* inet_addr_type with dev == NULL but using the table from a dev
268 * if one is associated
270 unsigned int inet_addr_type_dev_table(struct net *net,
271 const struct net_device *dev,
274 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
276 return __inet_dev_addr_type(net, NULL, addr, rt_table);
278 EXPORT_SYMBOL(inet_addr_type_dev_table);
280 __be32 fib_compute_spec_dst(struct sk_buff *skb)
282 struct net_device *dev = skb->dev;
283 struct in_device *in_dev;
284 struct fib_result res;
289 rt = skb_rtable(skb);
290 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
292 return ip_hdr(skb)->daddr;
294 in_dev = __in_dev_get_rcu(dev);
298 scope = RT_SCOPE_UNIVERSE;
299 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
300 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
301 struct flowi4 fl4 = {
302 .flowi4_iif = LOOPBACK_IFINDEX,
303 .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
304 .daddr = ip_hdr(skb)->saddr,
305 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
306 .flowi4_scope = scope,
307 .flowi4_mark = vmark ? skb->mark : 0,
309 if (!fib_lookup(net, &fl4, &res, 0))
310 return FIB_RES_PREFSRC(net, res);
312 scope = RT_SCOPE_LINK;
315 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
318 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
320 bool dev_match = false;
321 #ifdef CONFIG_IP_ROUTE_MULTIPATH
324 for (ret = 0; ret < fi->fib_nhs; ret++) {
325 struct fib_nh *nh = &fi->fib_nh[ret];
327 if (nh->nh_dev == dev) {
330 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
336 if (fi->fib_nh[0].nh_dev == dev)
342 EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
344 /* Given (packet source, input interface) and optional (dst, oif, tos):
345 * - (main) check, that source is valid i.e. not broadcast or our local
347 * - figure out what "logical" interface this packet arrived
348 * and calculate "specific destination" address.
349 * - check, that packet arrived from expected physical interface.
350 * called with rcu_read_lock()
352 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
353 u8 tos, int oif, struct net_device *dev,
354 int rpf, struct in_device *idev, u32 *itag)
356 struct net *net = dev_net(dev);
357 struct flow_keys flkeys;
359 struct fib_result res;
364 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
366 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
369 fl4.flowi4_tos = tos;
370 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
371 fl4.flowi4_tun_key.tun_id = 0;
372 fl4.flowi4_flags = 0;
373 fl4.flowi4_uid = sock_net_uid(net, NULL);
375 no_addr = idev->ifa_list == NULL;
377 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
378 if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
379 fl4.flowi4_proto = 0;
384 if (fib_lookup(net, &fl4, &res, 0))
386 if (res.type != RTN_UNICAST &&
387 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
389 fib_combine_itag(itag, &res);
391 dev_match = fib_info_nh_uses_dev(res.fi, dev);
393 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
400 fl4.flowi4_oif = dev->ifindex;
403 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
404 if (res.type == RTN_UNICAST)
405 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
421 /* Ignore rp_filter for packets protected by IPsec. */
422 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
423 u8 tos, int oif, struct net_device *dev,
424 struct in_device *idev, u32 *itag)
426 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
427 struct net *net = dev_net(dev);
429 if (!r && !fib_num_tclassid_users(net) &&
430 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
431 if (IN_DEV_ACCEPT_LOCAL(idev))
433 /* with custom local routes in place, checking local addresses
434 * only will be too optimistic, with custom rules, checking
435 * local addresses only can be too strict, e.g. due to vrf
437 if (net->ipv4.fib_has_custom_local_routes ||
438 fib4_has_custom_rules(net))
440 if (inet_lookup_ifaddr_rcu(net, src))
449 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
452 static inline __be32 sk_extract_addr(struct sockaddr *addr)
454 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
457 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
461 nla = (struct nlattr *) ((char *) mx + len);
462 nla->nla_type = type;
463 nla->nla_len = nla_attr_size(4);
464 *(u32 *) nla_data(nla) = value;
466 return len + nla_total_size(4);
469 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
470 struct fib_config *cfg)
475 memset(cfg, 0, sizeof(*cfg));
476 cfg->fc_nlinfo.nl_net = net;
478 if (rt->rt_dst.sa_family != AF_INET)
479 return -EAFNOSUPPORT;
482 * Check mask for validity:
483 * a) it must be contiguous.
484 * b) destination must have all host bits clear.
485 * c) if application forgot to set correct family (AF_INET),
486 * reject request unless it is absolutely clear i.e.
487 * both family and mask are zero.
490 addr = sk_extract_addr(&rt->rt_dst);
491 if (!(rt->rt_flags & RTF_HOST)) {
492 __be32 mask = sk_extract_addr(&rt->rt_genmask);
494 if (rt->rt_genmask.sa_family != AF_INET) {
495 if (mask || rt->rt_genmask.sa_family)
496 return -EAFNOSUPPORT;
499 if (bad_mask(mask, addr))
502 plen = inet_mask_len(mask);
505 cfg->fc_dst_len = plen;
508 if (cmd != SIOCDELRT) {
509 cfg->fc_nlflags = NLM_F_CREATE;
510 cfg->fc_protocol = RTPROT_BOOT;
514 cfg->fc_priority = rt->rt_metric - 1;
516 if (rt->rt_flags & RTF_REJECT) {
517 cfg->fc_scope = RT_SCOPE_HOST;
518 cfg->fc_type = RTN_UNREACHABLE;
522 cfg->fc_scope = RT_SCOPE_NOWHERE;
523 cfg->fc_type = RTN_UNICAST;
527 struct net_device *dev;
528 char devname[IFNAMSIZ];
530 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
533 devname[IFNAMSIZ-1] = 0;
534 colon = strchr(devname, ':');
537 dev = __dev_get_by_name(net, devname);
540 cfg->fc_oif = dev->ifindex;
541 cfg->fc_table = l3mdev_fib_table(dev);
543 struct in_ifaddr *ifa;
544 struct in_device *in_dev = __in_dev_get_rtnl(dev);
548 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
549 if (strcmp(ifa->ifa_label, devname) == 0)
553 cfg->fc_prefsrc = ifa->ifa_local;
557 addr = sk_extract_addr(&rt->rt_gateway);
558 if (rt->rt_gateway.sa_family == AF_INET && addr) {
559 unsigned int addr_type;
562 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
563 if (rt->rt_flags & RTF_GATEWAY &&
564 addr_type == RTN_UNICAST)
565 cfg->fc_scope = RT_SCOPE_UNIVERSE;
568 if (cmd == SIOCDELRT)
571 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
574 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
575 cfg->fc_scope = RT_SCOPE_LINK;
577 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
581 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
585 if (rt->rt_flags & RTF_MTU)
586 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
588 if (rt->rt_flags & RTF_WINDOW)
589 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
591 if (rt->rt_flags & RTF_IRTT)
592 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
595 cfg->fc_mx_len = len;
602 * Handle IP routing ioctl calls.
603 * These are used to manipulate the routing tables
605 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
607 struct fib_config cfg;
611 case SIOCADDRT: /* Add a route */
612 case SIOCDELRT: /* Delete a route */
613 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
617 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
619 struct fib_table *tb;
621 if (cmd == SIOCDELRT) {
622 tb = fib_get_table(net, cfg.fc_table);
624 err = fib_table_delete(net, tb, &cfg,
629 tb = fib_new_table(net, cfg.fc_table);
631 err = fib_table_insert(net, tb,
637 /* allocated by rtentry_to_fib_config() */
646 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
647 [RTA_DST] = { .type = NLA_U32 },
648 [RTA_SRC] = { .type = NLA_U32 },
649 [RTA_IIF] = { .type = NLA_U32 },
650 [RTA_OIF] = { .type = NLA_U32 },
651 [RTA_GATEWAY] = { .type = NLA_U32 },
652 [RTA_PRIORITY] = { .type = NLA_U32 },
653 [RTA_PREFSRC] = { .type = NLA_U32 },
654 [RTA_METRICS] = { .type = NLA_NESTED },
655 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
656 [RTA_FLOW] = { .type = NLA_U32 },
657 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
658 [RTA_ENCAP] = { .type = NLA_NESTED },
659 [RTA_UID] = { .type = NLA_U32 },
660 [RTA_MARK] = { .type = NLA_U32 },
661 [RTA_TABLE] = { .type = NLA_U32 },
662 [RTA_IP_PROTO] = { .type = NLA_U8 },
663 [RTA_SPORT] = { .type = NLA_U16 },
664 [RTA_DPORT] = { .type = NLA_U16 },
667 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
668 struct nlmsghdr *nlh, struct fib_config *cfg,
669 struct netlink_ext_ack *extack)
675 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
680 memset(cfg, 0, sizeof(*cfg));
682 rtm = nlmsg_data(nlh);
683 cfg->fc_dst_len = rtm->rtm_dst_len;
684 cfg->fc_tos = rtm->rtm_tos;
685 cfg->fc_table = rtm->rtm_table;
686 cfg->fc_protocol = rtm->rtm_protocol;
687 cfg->fc_scope = rtm->rtm_scope;
688 cfg->fc_type = rtm->rtm_type;
689 cfg->fc_flags = rtm->rtm_flags;
690 cfg->fc_nlflags = nlh->nlmsg_flags;
692 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
693 cfg->fc_nlinfo.nlh = nlh;
694 cfg->fc_nlinfo.nl_net = net;
696 if (cfg->fc_type > RTN_MAX) {
697 NL_SET_ERR_MSG(extack, "Invalid route type");
702 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
703 switch (nla_type(attr)) {
705 cfg->fc_dst = nla_get_be32(attr);
708 cfg->fc_oif = nla_get_u32(attr);
711 cfg->fc_gw = nla_get_be32(attr);
714 cfg->fc_priority = nla_get_u32(attr);
717 cfg->fc_prefsrc = nla_get_be32(attr);
720 cfg->fc_mx = nla_data(attr);
721 cfg->fc_mx_len = nla_len(attr);
724 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
729 cfg->fc_mp = nla_data(attr);
730 cfg->fc_mp_len = nla_len(attr);
733 cfg->fc_flow = nla_get_u32(attr);
736 cfg->fc_table = nla_get_u32(attr);
739 cfg->fc_encap = attr;
742 cfg->fc_encap_type = nla_get_u16(attr);
743 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
756 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
757 struct netlink_ext_ack *extack)
759 struct net *net = sock_net(skb->sk);
760 struct fib_config cfg;
761 struct fib_table *tb;
764 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
768 tb = fib_get_table(net, cfg.fc_table);
770 NL_SET_ERR_MSG(extack, "FIB table does not exist");
775 err = fib_table_delete(net, tb, &cfg, extack);
780 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
781 struct netlink_ext_ack *extack)
783 struct net *net = sock_net(skb->sk);
784 struct fib_config cfg;
785 struct fib_table *tb;
788 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
792 tb = fib_new_table(net, cfg.fc_table);
798 err = fib_table_insert(net, tb, &cfg, extack);
799 if (!err && cfg.fc_type == RTN_LOCAL)
800 net->ipv4.fib_has_custom_local_routes = true;
805 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
806 struct fib_dump_filter *filter,
807 struct netlink_callback *cb)
809 struct netlink_ext_ack *extack = cb->extack;
810 struct nlattr *tb[RTA_MAX + 1];
816 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
817 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
821 rtm = nlmsg_data(nlh);
822 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
824 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
827 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
828 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
832 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC);
833 filter->flags = rtm->rtm_flags;
834 filter->protocol = rtm->rtm_protocol;
835 filter->rt_type = rtm->rtm_type;
836 filter->table_id = rtm->rtm_table;
838 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
839 rtm_ipv4_policy, extack);
843 for (i = 0; i <= RTA_MAX; ++i) {
851 filter->table_id = nla_get_u32(tb[i]);
854 ifindex = nla_get_u32(tb[i]);
855 filter->dev = __dev_get_by_index(net, ifindex);
860 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
865 if (filter->flags || filter->protocol || filter->rt_type ||
866 filter->table_id || filter->dev) {
867 filter->filter_set = 1;
868 cb->answer_flags = NLM_F_DUMP_FILTERED;
873 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
875 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
877 const struct nlmsghdr *nlh = cb->nlh;
878 struct net *net = sock_net(skb->sk);
879 struct fib_dump_filter filter = {};
881 unsigned int e = 0, s_e;
882 struct fib_table *tb;
883 struct hlist_head *head;
886 if (cb->strict_check) {
887 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
890 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
891 struct rtmsg *rtm = nlmsg_data(nlh);
893 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
896 /* fib entries are never clones and ipv4 does not use prefix flag */
897 if (filter.flags & (RTM_F_PREFIX | RTM_F_CLONED))
900 if (filter.table_id) {
901 tb = fib_get_table(net, filter.table_id);
903 if (filter.dump_all_families)
906 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
910 err = fib_table_dump(tb, skb, cb, &filter);
911 return skb->len ? : err;
919 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
921 head = &net->ipv4.fib_table_hash[h];
922 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
926 memset(&cb->args[2], 0, sizeof(cb->args) -
927 2 * sizeof(cb->args[0]));
928 err = fib_table_dump(tb, skb, cb, &filter);
930 if (likely(skb->len))
951 /* Prepare and feed intra-kernel routing request.
952 * Really, it should be netlink message, but :-( netlink
953 * can be not configured, so that we feed it directly
954 * to fib engine. It is legal, because all events occur
955 * only when netlink is already locked.
957 static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
958 struct in_ifaddr *ifa, u32 rt_priority)
960 struct net *net = dev_net(ifa->ifa_dev->dev);
961 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
962 struct fib_table *tb;
963 struct fib_config cfg = {
964 .fc_protocol = RTPROT_KERNEL,
967 .fc_dst_len = dst_len,
968 .fc_priority = rt_priority,
969 .fc_prefsrc = ifa->ifa_local,
970 .fc_oif = ifa->ifa_dev->dev->ifindex,
971 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
978 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
980 tb = fib_new_table(net, tb_id);
984 cfg.fc_table = tb->tb_id;
986 if (type != RTN_LOCAL)
987 cfg.fc_scope = RT_SCOPE_LINK;
989 cfg.fc_scope = RT_SCOPE_HOST;
991 if (cmd == RTM_NEWROUTE)
992 fib_table_insert(net, tb, &cfg, NULL);
994 fib_table_delete(net, tb, &cfg, NULL);
997 void fib_add_ifaddr(struct in_ifaddr *ifa)
999 struct in_device *in_dev = ifa->ifa_dev;
1000 struct net_device *dev = in_dev->dev;
1001 struct in_ifaddr *prim = ifa;
1002 __be32 mask = ifa->ifa_mask;
1003 __be32 addr = ifa->ifa_local;
1004 __be32 prefix = ifa->ifa_address & mask;
1006 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1007 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1009 pr_warn("%s: bug: prim == NULL\n", __func__);
1014 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1016 if (!(dev->flags & IFF_UP))
1019 /* Add broadcast address, if it is explicitly assigned. */
1020 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1021 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1024 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1025 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1026 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1027 fib_magic(RTM_NEWROUTE,
1028 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1029 prefix, ifa->ifa_prefixlen, prim,
1030 ifa->ifa_rt_priority);
1032 /* Add network specific broadcasts, when it takes a sense */
1033 if (ifa->ifa_prefixlen < 31) {
1034 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1036 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1042 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1044 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1045 struct in_device *in_dev = ifa->ifa_dev;
1046 struct net_device *dev = in_dev->dev;
1048 if (!(dev->flags & IFF_UP) ||
1049 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1050 ipv4_is_zeronet(prefix) ||
1051 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
1055 fib_magic(RTM_NEWROUTE,
1056 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1057 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1059 /* delete the old */
1060 fib_magic(RTM_DELROUTE,
1061 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1062 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1065 /* Delete primary or secondary address.
1066 * Optionally, on secondary address promotion consider the addresses
1067 * from subnet iprim as deleted, even if they are in device list.
1068 * In this case the secondary ifa can be in device list.
1070 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1072 struct in_device *in_dev = ifa->ifa_dev;
1073 struct net_device *dev = in_dev->dev;
1074 struct in_ifaddr *ifa1;
1075 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1076 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1077 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1082 unsigned int ok = 0;
1083 int subnet = 0; /* Primary network */
1084 int gone = 1; /* Address is missing */
1085 int same_prefsrc = 0; /* Another primary with same IP */
1087 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1088 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1090 /* if the device has been deleted, we don't perform
1094 pr_warn("%s: bug: prim == NULL\n", __func__);
1097 if (iprim && iprim != prim) {
1098 pr_warn("%s: bug: iprim != prim\n", __func__);
1101 } else if (!ipv4_is_zeronet(any) &&
1102 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1103 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1104 fib_magic(RTM_DELROUTE,
1105 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1106 any, ifa->ifa_prefixlen, prim, 0);
1113 /* Deletion is more complicated than add.
1114 * We should take care of not to delete too much :-)
1116 * Scan address list to be sure that addresses are really gone.
1119 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
1121 /* promotion, keep the IP */
1125 /* Ignore IFAs from our subnet */
1126 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1127 inet_ifa_match(ifa1->ifa_address, iprim))
1130 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1131 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1132 /* Another address from our subnet? */
1133 if (ifa1->ifa_mask == prim->ifa_mask &&
1134 inet_ifa_match(ifa1->ifa_address, prim))
1137 /* We reached the secondaries, so
1138 * same_prefsrc should be determined.
1142 /* Search new prim1 if ifa1 is not
1143 * using the current prim1
1146 ifa1->ifa_mask != prim1->ifa_mask ||
1147 !inet_ifa_match(ifa1->ifa_address, prim1))
1148 prim1 = inet_ifa_byprefix(in_dev,
1153 if (prim1->ifa_local != prim->ifa_local)
1157 if (prim->ifa_local != ifa1->ifa_local)
1163 if (ifa->ifa_local == ifa1->ifa_local)
1165 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1167 if (brd == ifa1->ifa_broadcast)
1169 if (any == ifa1->ifa_broadcast)
1171 /* primary has network specific broadcasts */
1172 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1173 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1174 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1176 if (!ipv4_is_zeronet(any1)) {
1177 if (ifa->ifa_broadcast == brd1 ||
1178 ifa->ifa_broadcast == any1)
1180 if (brd == brd1 || brd == any1)
1182 if (any == brd1 || any == any1)
1190 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1192 if (subnet && ifa->ifa_prefixlen < 31) {
1193 if (!(ok & BRD1_OK))
1194 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1196 if (!(ok & BRD0_OK))
1197 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1200 if (!(ok & LOCAL_OK)) {
1201 unsigned int addr_type;
1203 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1205 /* Check, that this local address finally disappeared. */
1206 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1208 if (gone && addr_type != RTN_LOCAL) {
1209 /* And the last, but not the least thing.
1210 * We must flush stray FIB entries.
1212 * First of all, we scan fib_info list searching
1213 * for stray nexthop entries, then ignite fib_flush.
1215 if (fib_sync_down_addr(dev, ifa->ifa_local))
1216 fib_flush(dev_net(dev));
1225 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1228 struct fib_result res;
1229 struct flowi4 fl4 = {
1230 .flowi4_mark = frn->fl_mark,
1231 .daddr = frn->fl_addr,
1232 .flowi4_tos = frn->fl_tos,
1233 .flowi4_scope = frn->fl_scope,
1235 struct fib_table *tb;
1239 tb = fib_get_table(net, frn->tb_id_in);
1245 frn->tb_id = tb->tb_id;
1246 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1249 frn->prefixlen = res.prefixlen;
1250 frn->nh_sel = res.nh_sel;
1251 frn->type = res.type;
1252 frn->scope = res.scope;
1260 static void nl_fib_input(struct sk_buff *skb)
1263 struct fib_result_nl *frn;
1264 struct nlmsghdr *nlh;
1267 net = sock_net(skb->sk);
1268 nlh = nlmsg_hdr(skb);
1269 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1270 skb->len < nlh->nlmsg_len ||
1271 nlmsg_len(nlh) < sizeof(*frn))
1274 skb = netlink_skb_clone(skb, GFP_KERNEL);
1277 nlh = nlmsg_hdr(skb);
1279 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1280 nl_fib_lookup(net, frn);
1282 portid = NETLINK_CB(skb).portid; /* netlink portid */
1283 NETLINK_CB(skb).portid = 0; /* from kernel */
1284 NETLINK_CB(skb).dst_group = 0; /* unicast */
1285 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1288 static int __net_init nl_fib_lookup_init(struct net *net)
1291 struct netlink_kernel_cfg cfg = {
1292 .input = nl_fib_input,
1295 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1297 return -EAFNOSUPPORT;
1298 net->ipv4.fibnl = sk;
1302 static void nl_fib_lookup_exit(struct net *net)
1304 netlink_kernel_release(net->ipv4.fibnl);
1305 net->ipv4.fibnl = NULL;
1308 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1311 if (fib_sync_down_dev(dev, event, force))
1312 fib_flush(dev_net(dev));
1314 rt_cache_flush(dev_net(dev));
1318 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1320 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1321 struct net_device *dev = ifa->ifa_dev->dev;
1322 struct net *net = dev_net(dev);
1326 fib_add_ifaddr(ifa);
1327 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1328 fib_sync_up(dev, RTNH_F_DEAD);
1330 atomic_inc(&net->ipv4.dev_addr_genid);
1331 rt_cache_flush(dev_net(dev));
1334 fib_del_ifaddr(ifa, NULL);
1335 atomic_inc(&net->ipv4.dev_addr_genid);
1336 if (!ifa->ifa_dev->ifa_list) {
1337 /* Last address was deleted from this interface.
1340 fib_disable_ip(dev, event, true);
1342 rt_cache_flush(dev_net(dev));
1349 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1351 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1352 struct netdev_notifier_changeupper_info *upper_info = ptr;
1353 struct netdev_notifier_info_ext *info_ext = ptr;
1354 struct in_device *in_dev;
1355 struct net *net = dev_net(dev);
1358 if (event == NETDEV_UNREGISTER) {
1359 fib_disable_ip(dev, event, true);
1364 in_dev = __in_dev_get_rtnl(dev);
1371 fib_add_ifaddr(ifa);
1372 } endfor_ifa(in_dev);
1373 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1374 fib_sync_up(dev, RTNH_F_DEAD);
1376 atomic_inc(&net->ipv4.dev_addr_genid);
1377 rt_cache_flush(net);
1380 fib_disable_ip(dev, event, false);
1383 flags = dev_get_flags(dev);
1384 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1385 fib_sync_up(dev, RTNH_F_LINKDOWN);
1387 fib_sync_down_dev(dev, event, false);
1388 rt_cache_flush(net);
1390 case NETDEV_CHANGEMTU:
1391 fib_sync_mtu(dev, info_ext->ext.mtu);
1392 rt_cache_flush(net);
1394 case NETDEV_CHANGEUPPER:
1396 /* flush all routes if dev is linked to or unlinked from
1397 * an L3 master device (e.g., VRF)
1399 if (upper_info->upper_dev &&
1400 netif_is_l3_master(upper_info->upper_dev))
1401 fib_disable_ip(dev, NETDEV_DOWN, true);
1407 static struct notifier_block fib_inetaddr_notifier = {
1408 .notifier_call = fib_inetaddr_event,
1411 static struct notifier_block fib_netdev_notifier = {
1412 .notifier_call = fib_netdev_event,
1415 static int __net_init ip_fib_net_init(struct net *net)
1418 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1420 err = fib4_notifier_init(net);
1424 /* Avoid false sharing : Use at least a full cache line */
1425 size = max_t(size_t, size, L1_CACHE_BYTES);
1427 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1428 if (!net->ipv4.fib_table_hash) {
1430 goto err_table_hash_alloc;
1433 err = fib4_rules_init(net);
1435 goto err_rules_init;
1439 kfree(net->ipv4.fib_table_hash);
1440 err_table_hash_alloc:
1441 fib4_notifier_exit(net);
1445 static void ip_fib_net_exit(struct net *net)
1450 #ifdef CONFIG_IP_MULTIPLE_TABLES
1451 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1452 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1454 /* Destroy the tables in reverse order to guarantee that the
1455 * local table, ID 255, is destroyed before the main table, ID
1456 * 254. This is necessary as the local table may contain
1457 * references to data contained in the main table.
1459 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1460 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1461 struct hlist_node *tmp;
1462 struct fib_table *tb;
1464 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1465 hlist_del(&tb->tb_hlist);
1466 fib_table_flush(net, tb);
1471 #ifdef CONFIG_IP_MULTIPLE_TABLES
1472 fib4_rules_exit(net);
1475 kfree(net->ipv4.fib_table_hash);
1476 fib4_notifier_exit(net);
1479 static int __net_init fib_net_init(struct net *net)
1483 #ifdef CONFIG_IP_ROUTE_CLASSID
1484 net->ipv4.fib_num_tclassid_users = 0;
1486 error = ip_fib_net_init(net);
1489 error = nl_fib_lookup_init(net);
1492 error = fib_proc_init(net);
1499 nl_fib_lookup_exit(net);
1501 ip_fib_net_exit(net);
1505 static void __net_exit fib_net_exit(struct net *net)
1508 nl_fib_lookup_exit(net);
1509 ip_fib_net_exit(net);
1512 static struct pernet_operations fib_net_ops = {
1513 .init = fib_net_init,
1514 .exit = fib_net_exit,
1517 void __init ip_fib_init(void)
1521 register_pernet_subsys(&fib_net_ops);
1523 register_netdevice_notifier(&fib_netdev_notifier);
1524 register_inetaddr_notifier(&fib_inetaddr_notifier);
1526 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1527 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1528 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);