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, false);
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_result_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->fib_nh_dev == dev) {
330 } else if (l3mdev_master_ifindex_rcu(nh->fib_nh_dev) == dev->ifindex) {
336 if (fi->fib_nh[0].fib_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_NHC(res)->nhc_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_NHC(res)->nhc_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 cfg->fc_gw_family = AF_INET;
563 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
564 if (rt->rt_flags & RTF_GATEWAY &&
565 addr_type == RTN_UNICAST)
566 cfg->fc_scope = RT_SCOPE_UNIVERSE;
569 if (cmd == SIOCDELRT)
572 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
575 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
576 cfg->fc_scope = RT_SCOPE_LINK;
578 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
582 mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
586 if (rt->rt_flags & RTF_MTU)
587 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
589 if (rt->rt_flags & RTF_WINDOW)
590 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
592 if (rt->rt_flags & RTF_IRTT)
593 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
596 cfg->fc_mx_len = len;
603 * Handle IP routing ioctl calls.
604 * These are used to manipulate the routing tables
606 int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
608 struct fib_config cfg;
612 case SIOCADDRT: /* Add a route */
613 case SIOCDELRT: /* Delete a route */
614 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
618 err = rtentry_to_fib_config(net, cmd, rt, &cfg);
620 struct fib_table *tb;
622 if (cmd == SIOCDELRT) {
623 tb = fib_get_table(net, cfg.fc_table);
625 err = fib_table_delete(net, tb, &cfg,
630 tb = fib_new_table(net, cfg.fc_table);
632 err = fib_table_insert(net, tb,
638 /* allocated by rtentry_to_fib_config() */
647 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
648 [RTA_DST] = { .type = NLA_U32 },
649 [RTA_SRC] = { .type = NLA_U32 },
650 [RTA_IIF] = { .type = NLA_U32 },
651 [RTA_OIF] = { .type = NLA_U32 },
652 [RTA_GATEWAY] = { .type = NLA_U32 },
653 [RTA_PRIORITY] = { .type = NLA_U32 },
654 [RTA_PREFSRC] = { .type = NLA_U32 },
655 [RTA_METRICS] = { .type = NLA_NESTED },
656 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
657 [RTA_FLOW] = { .type = NLA_U32 },
658 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
659 [RTA_ENCAP] = { .type = NLA_NESTED },
660 [RTA_UID] = { .type = NLA_U32 },
661 [RTA_MARK] = { .type = NLA_U32 },
662 [RTA_TABLE] = { .type = NLA_U32 },
663 [RTA_IP_PROTO] = { .type = NLA_U8 },
664 [RTA_SPORT] = { .type = NLA_U16 },
665 [RTA_DPORT] = { .type = NLA_U16 },
668 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
669 struct netlink_ext_ack *extack)
674 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
675 NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
680 alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
682 switch (via->rtvia_family) {
684 if (alen != sizeof(__be32)) {
685 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
688 cfg->fc_gw_family = AF_INET;
689 cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
693 if (alen != sizeof(struct in6_addr)) {
694 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
697 cfg->fc_gw_family = AF_INET6;
698 cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
700 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
705 NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
712 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
713 struct nlmsghdr *nlh, struct fib_config *cfg,
714 struct netlink_ext_ack *extack)
716 bool has_gw = false, has_via = false;
721 err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
722 rtm_ipv4_policy, extack);
726 memset(cfg, 0, sizeof(*cfg));
728 rtm = nlmsg_data(nlh);
729 cfg->fc_dst_len = rtm->rtm_dst_len;
730 cfg->fc_tos = rtm->rtm_tos;
731 cfg->fc_table = rtm->rtm_table;
732 cfg->fc_protocol = rtm->rtm_protocol;
733 cfg->fc_scope = rtm->rtm_scope;
734 cfg->fc_type = rtm->rtm_type;
735 cfg->fc_flags = rtm->rtm_flags;
736 cfg->fc_nlflags = nlh->nlmsg_flags;
738 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
739 cfg->fc_nlinfo.nlh = nlh;
740 cfg->fc_nlinfo.nl_net = net;
742 if (cfg->fc_type > RTN_MAX) {
743 NL_SET_ERR_MSG(extack, "Invalid route type");
748 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
749 switch (nla_type(attr)) {
751 cfg->fc_dst = nla_get_be32(attr);
754 cfg->fc_oif = nla_get_u32(attr);
758 cfg->fc_gw4 = nla_get_be32(attr);
760 cfg->fc_gw_family = AF_INET;
764 err = fib_gw_from_via(cfg, attr, extack);
769 cfg->fc_priority = nla_get_u32(attr);
772 cfg->fc_prefsrc = nla_get_be32(attr);
775 cfg->fc_mx = nla_data(attr);
776 cfg->fc_mx_len = nla_len(attr);
779 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
784 cfg->fc_mp = nla_data(attr);
785 cfg->fc_mp_len = nla_len(attr);
788 cfg->fc_flow = nla_get_u32(attr);
791 cfg->fc_table = nla_get_u32(attr);
794 cfg->fc_encap = attr;
797 cfg->fc_encap_type = nla_get_u16(attr);
798 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
806 if (has_gw && has_via) {
807 NL_SET_ERR_MSG(extack,
808 "Nexthop configuration can not contain both GATEWAY and VIA");
817 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
818 struct netlink_ext_ack *extack)
820 struct net *net = sock_net(skb->sk);
821 struct fib_config cfg;
822 struct fib_table *tb;
825 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
829 tb = fib_get_table(net, cfg.fc_table);
831 NL_SET_ERR_MSG(extack, "FIB table does not exist");
836 err = fib_table_delete(net, tb, &cfg, extack);
841 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
842 struct netlink_ext_ack *extack)
844 struct net *net = sock_net(skb->sk);
845 struct fib_config cfg;
846 struct fib_table *tb;
849 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
853 tb = fib_new_table(net, cfg.fc_table);
859 err = fib_table_insert(net, tb, &cfg, extack);
860 if (!err && cfg.fc_type == RTN_LOCAL)
861 net->ipv4.fib_has_custom_local_routes = true;
866 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
867 struct fib_dump_filter *filter,
868 struct netlink_callback *cb)
870 struct netlink_ext_ack *extack = cb->extack;
871 struct nlattr *tb[RTA_MAX + 1];
877 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
878 NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
882 rtm = nlmsg_data(nlh);
883 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
885 NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
888 if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
889 NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
893 filter->dump_all_families = (rtm->rtm_family == AF_UNSPEC);
894 filter->flags = rtm->rtm_flags;
895 filter->protocol = rtm->rtm_protocol;
896 filter->rt_type = rtm->rtm_type;
897 filter->table_id = rtm->rtm_table;
899 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
900 rtm_ipv4_policy, extack);
904 for (i = 0; i <= RTA_MAX; ++i) {
912 filter->table_id = nla_get_u32(tb[i]);
915 ifindex = nla_get_u32(tb[i]);
916 filter->dev = __dev_get_by_index(net, ifindex);
921 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
926 if (filter->flags || filter->protocol || filter->rt_type ||
927 filter->table_id || filter->dev) {
928 filter->filter_set = 1;
929 cb->answer_flags = NLM_F_DUMP_FILTERED;
934 EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
936 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
938 const struct nlmsghdr *nlh = cb->nlh;
939 struct net *net = sock_net(skb->sk);
940 struct fib_dump_filter filter = {};
942 unsigned int e = 0, s_e;
943 struct fib_table *tb;
944 struct hlist_head *head;
947 if (cb->strict_check) {
948 err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
951 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
952 struct rtmsg *rtm = nlmsg_data(nlh);
954 filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
957 /* fib entries are never clones and ipv4 does not use prefix flag */
958 if (filter.flags & (RTM_F_PREFIX | RTM_F_CLONED))
961 if (filter.table_id) {
962 tb = fib_get_table(net, filter.table_id);
964 if (filter.dump_all_families)
967 NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
971 err = fib_table_dump(tb, skb, cb, &filter);
972 return skb->len ? : err;
980 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
982 head = &net->ipv4.fib_table_hash[h];
983 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
987 memset(&cb->args[2], 0, sizeof(cb->args) -
988 2 * sizeof(cb->args[0]));
989 err = fib_table_dump(tb, skb, cb, &filter);
991 if (likely(skb->len))
1012 /* Prepare and feed intra-kernel routing request.
1013 * Really, it should be netlink message, but :-( netlink
1014 * can be not configured, so that we feed it directly
1015 * to fib engine. It is legal, because all events occur
1016 * only when netlink is already locked.
1018 static void fib_magic(int cmd, int type, __be32 dst, int dst_len,
1019 struct in_ifaddr *ifa, u32 rt_priority)
1021 struct net *net = dev_net(ifa->ifa_dev->dev);
1022 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
1023 struct fib_table *tb;
1024 struct fib_config cfg = {
1025 .fc_protocol = RTPROT_KERNEL,
1028 .fc_dst_len = dst_len,
1029 .fc_priority = rt_priority,
1030 .fc_prefsrc = ifa->ifa_local,
1031 .fc_oif = ifa->ifa_dev->dev->ifindex,
1032 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
1039 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
1041 tb = fib_new_table(net, tb_id);
1045 cfg.fc_table = tb->tb_id;
1047 if (type != RTN_LOCAL)
1048 cfg.fc_scope = RT_SCOPE_LINK;
1050 cfg.fc_scope = RT_SCOPE_HOST;
1052 if (cmd == RTM_NEWROUTE)
1053 fib_table_insert(net, tb, &cfg, NULL);
1055 fib_table_delete(net, tb, &cfg, NULL);
1058 void fib_add_ifaddr(struct in_ifaddr *ifa)
1060 struct in_device *in_dev = ifa->ifa_dev;
1061 struct net_device *dev = in_dev->dev;
1062 struct in_ifaddr *prim = ifa;
1063 __be32 mask = ifa->ifa_mask;
1064 __be32 addr = ifa->ifa_local;
1065 __be32 prefix = ifa->ifa_address & mask;
1067 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1068 prim = inet_ifa_byprefix(in_dev, prefix, mask);
1070 pr_warn("%s: bug: prim == NULL\n", __func__);
1075 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim, 0);
1077 if (!(dev->flags & IFF_UP))
1080 /* Add broadcast address, if it is explicitly assigned. */
1081 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
1082 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1085 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
1086 (prefix != addr || ifa->ifa_prefixlen < 32)) {
1087 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1088 fib_magic(RTM_NEWROUTE,
1089 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1090 prefix, ifa->ifa_prefixlen, prim,
1091 ifa->ifa_rt_priority);
1093 /* Add network specific broadcasts, when it takes a sense */
1094 if (ifa->ifa_prefixlen < 31) {
1095 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32,
1097 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
1103 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric)
1105 __be32 prefix = ifa->ifa_address & ifa->ifa_mask;
1106 struct in_device *in_dev = ifa->ifa_dev;
1107 struct net_device *dev = in_dev->dev;
1109 if (!(dev->flags & IFF_UP) ||
1110 ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
1111 ipv4_is_zeronet(prefix) ||
1112 prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)
1116 fib_magic(RTM_NEWROUTE,
1117 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1118 prefix, ifa->ifa_prefixlen, ifa, new_metric);
1120 /* delete the old */
1121 fib_magic(RTM_DELROUTE,
1122 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1123 prefix, ifa->ifa_prefixlen, ifa, ifa->ifa_rt_priority);
1126 /* Delete primary or secondary address.
1127 * Optionally, on secondary address promotion consider the addresses
1128 * from subnet iprim as deleted, even if they are in device list.
1129 * In this case the secondary ifa can be in device list.
1131 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
1133 struct in_device *in_dev = ifa->ifa_dev;
1134 struct net_device *dev = in_dev->dev;
1135 struct in_ifaddr *ifa1;
1136 struct in_ifaddr *prim = ifa, *prim1 = NULL;
1137 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
1138 __be32 any = ifa->ifa_address & ifa->ifa_mask;
1143 unsigned int ok = 0;
1144 int subnet = 0; /* Primary network */
1145 int gone = 1; /* Address is missing */
1146 int same_prefsrc = 0; /* Another primary with same IP */
1148 if (ifa->ifa_flags & IFA_F_SECONDARY) {
1149 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
1151 /* if the device has been deleted, we don't perform
1155 pr_warn("%s: bug: prim == NULL\n", __func__);
1158 if (iprim && iprim != prim) {
1159 pr_warn("%s: bug: iprim != prim\n", __func__);
1162 } else if (!ipv4_is_zeronet(any) &&
1163 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
1164 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
1165 fib_magic(RTM_DELROUTE,
1166 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
1167 any, ifa->ifa_prefixlen, prim, 0);
1174 /* Deletion is more complicated than add.
1175 * We should take care of not to delete too much :-)
1177 * Scan address list to be sure that addresses are really gone.
1180 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
1182 /* promotion, keep the IP */
1186 /* Ignore IFAs from our subnet */
1187 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
1188 inet_ifa_match(ifa1->ifa_address, iprim))
1191 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
1192 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
1193 /* Another address from our subnet? */
1194 if (ifa1->ifa_mask == prim->ifa_mask &&
1195 inet_ifa_match(ifa1->ifa_address, prim))
1198 /* We reached the secondaries, so
1199 * same_prefsrc should be determined.
1203 /* Search new prim1 if ifa1 is not
1204 * using the current prim1
1207 ifa1->ifa_mask != prim1->ifa_mask ||
1208 !inet_ifa_match(ifa1->ifa_address, prim1))
1209 prim1 = inet_ifa_byprefix(in_dev,
1214 if (prim1->ifa_local != prim->ifa_local)
1218 if (prim->ifa_local != ifa1->ifa_local)
1224 if (ifa->ifa_local == ifa1->ifa_local)
1226 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1228 if (brd == ifa1->ifa_broadcast)
1230 if (any == ifa1->ifa_broadcast)
1232 /* primary has network specific broadcasts */
1233 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1234 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1235 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1237 if (!ipv4_is_zeronet(any1)) {
1238 if (ifa->ifa_broadcast == brd1 ||
1239 ifa->ifa_broadcast == any1)
1241 if (brd == brd1 || brd == any1)
1243 if (any == brd1 || any == any1)
1251 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32,
1253 if (subnet && ifa->ifa_prefixlen < 31) {
1254 if (!(ok & BRD1_OK))
1255 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32,
1257 if (!(ok & BRD0_OK))
1258 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32,
1261 if (!(ok & LOCAL_OK)) {
1262 unsigned int addr_type;
1264 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim, 0);
1266 /* Check, that this local address finally disappeared. */
1267 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1269 if (gone && addr_type != RTN_LOCAL) {
1270 /* And the last, but not the least thing.
1271 * We must flush stray FIB entries.
1273 * First of all, we scan fib_info list searching
1274 * for stray nexthop entries, then ignite fib_flush.
1276 if (fib_sync_down_addr(dev, ifa->ifa_local))
1277 fib_flush(dev_net(dev));
1286 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1289 struct fib_result res;
1290 struct flowi4 fl4 = {
1291 .flowi4_mark = frn->fl_mark,
1292 .daddr = frn->fl_addr,
1293 .flowi4_tos = frn->fl_tos,
1294 .flowi4_scope = frn->fl_scope,
1296 struct fib_table *tb;
1300 tb = fib_get_table(net, frn->tb_id_in);
1306 frn->tb_id = tb->tb_id;
1307 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1310 frn->prefixlen = res.prefixlen;
1311 frn->nh_sel = res.nh_sel;
1312 frn->type = res.type;
1313 frn->scope = res.scope;
1321 static void nl_fib_input(struct sk_buff *skb)
1324 struct fib_result_nl *frn;
1325 struct nlmsghdr *nlh;
1328 net = sock_net(skb->sk);
1329 nlh = nlmsg_hdr(skb);
1330 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1331 skb->len < nlh->nlmsg_len ||
1332 nlmsg_len(nlh) < sizeof(*frn))
1335 skb = netlink_skb_clone(skb, GFP_KERNEL);
1338 nlh = nlmsg_hdr(skb);
1340 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1341 nl_fib_lookup(net, frn);
1343 portid = NETLINK_CB(skb).portid; /* netlink portid */
1344 NETLINK_CB(skb).portid = 0; /* from kernel */
1345 NETLINK_CB(skb).dst_group = 0; /* unicast */
1346 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1349 static int __net_init nl_fib_lookup_init(struct net *net)
1352 struct netlink_kernel_cfg cfg = {
1353 .input = nl_fib_input,
1356 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1358 return -EAFNOSUPPORT;
1359 net->ipv4.fibnl = sk;
1363 static void nl_fib_lookup_exit(struct net *net)
1365 netlink_kernel_release(net->ipv4.fibnl);
1366 net->ipv4.fibnl = NULL;
1369 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1372 if (fib_sync_down_dev(dev, event, force))
1373 fib_flush(dev_net(dev));
1375 rt_cache_flush(dev_net(dev));
1379 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1381 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1382 struct net_device *dev = ifa->ifa_dev->dev;
1383 struct net *net = dev_net(dev);
1387 fib_add_ifaddr(ifa);
1388 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1389 fib_sync_up(dev, RTNH_F_DEAD);
1391 atomic_inc(&net->ipv4.dev_addr_genid);
1392 rt_cache_flush(dev_net(dev));
1395 fib_del_ifaddr(ifa, NULL);
1396 atomic_inc(&net->ipv4.dev_addr_genid);
1397 if (!ifa->ifa_dev->ifa_list) {
1398 /* Last address was deleted from this interface.
1401 fib_disable_ip(dev, event, true);
1403 rt_cache_flush(dev_net(dev));
1410 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1412 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1413 struct netdev_notifier_changeupper_info *upper_info = ptr;
1414 struct netdev_notifier_info_ext *info_ext = ptr;
1415 struct in_device *in_dev;
1416 struct net *net = dev_net(dev);
1419 if (event == NETDEV_UNREGISTER) {
1420 fib_disable_ip(dev, event, true);
1425 in_dev = __in_dev_get_rtnl(dev);
1432 fib_add_ifaddr(ifa);
1433 } endfor_ifa(in_dev);
1434 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1435 fib_sync_up(dev, RTNH_F_DEAD);
1437 atomic_inc(&net->ipv4.dev_addr_genid);
1438 rt_cache_flush(net);
1441 fib_disable_ip(dev, event, false);
1444 flags = dev_get_flags(dev);
1445 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1446 fib_sync_up(dev, RTNH_F_LINKDOWN);
1448 fib_sync_down_dev(dev, event, false);
1449 rt_cache_flush(net);
1451 case NETDEV_CHANGEMTU:
1452 fib_sync_mtu(dev, info_ext->ext.mtu);
1453 rt_cache_flush(net);
1455 case NETDEV_CHANGEUPPER:
1457 /* flush all routes if dev is linked to or unlinked from
1458 * an L3 master device (e.g., VRF)
1460 if (upper_info->upper_dev &&
1461 netif_is_l3_master(upper_info->upper_dev))
1462 fib_disable_ip(dev, NETDEV_DOWN, true);
1468 static struct notifier_block fib_inetaddr_notifier = {
1469 .notifier_call = fib_inetaddr_event,
1472 static struct notifier_block fib_netdev_notifier = {
1473 .notifier_call = fib_netdev_event,
1476 static int __net_init ip_fib_net_init(struct net *net)
1479 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1481 err = fib4_notifier_init(net);
1485 /* Avoid false sharing : Use at least a full cache line */
1486 size = max_t(size_t, size, L1_CACHE_BYTES);
1488 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1489 if (!net->ipv4.fib_table_hash) {
1491 goto err_table_hash_alloc;
1494 err = fib4_rules_init(net);
1496 goto err_rules_init;
1500 kfree(net->ipv4.fib_table_hash);
1501 err_table_hash_alloc:
1502 fib4_notifier_exit(net);
1506 static void ip_fib_net_exit(struct net *net)
1511 #ifdef CONFIG_IP_MULTIPLE_TABLES
1512 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1513 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1515 /* Destroy the tables in reverse order to guarantee that the
1516 * local table, ID 255, is destroyed before the main table, ID
1517 * 254. This is necessary as the local table may contain
1518 * references to data contained in the main table.
1520 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1521 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1522 struct hlist_node *tmp;
1523 struct fib_table *tb;
1525 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1526 hlist_del(&tb->tb_hlist);
1527 fib_table_flush(net, tb, true);
1532 #ifdef CONFIG_IP_MULTIPLE_TABLES
1533 fib4_rules_exit(net);
1536 kfree(net->ipv4.fib_table_hash);
1537 fib4_notifier_exit(net);
1540 static int __net_init fib_net_init(struct net *net)
1544 #ifdef CONFIG_IP_ROUTE_CLASSID
1545 net->ipv4.fib_num_tclassid_users = 0;
1547 error = ip_fib_net_init(net);
1550 error = nl_fib_lookup_init(net);
1553 error = fib_proc_init(net);
1560 nl_fib_lookup_exit(net);
1562 ip_fib_net_exit(net);
1566 static void __net_exit fib_net_exit(struct net *net)
1569 nl_fib_lookup_exit(net);
1570 ip_fib_net_exit(net);
1573 static struct pernet_operations fib_net_ops = {
1574 .init = fib_net_init,
1575 .exit = fib_net_exit,
1578 void __init ip_fib_init(void)
1582 register_pernet_subsys(&fib_net_ops);
1584 register_netdevice_notifier(&fib_netdev_notifier);
1585 register_inetaddr_notifier(&fib_inetaddr_notifier);
1587 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1588 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1589 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);