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);
299 scope = RT_SCOPE_UNIVERSE;
300 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
301 struct flowi4 fl4 = {
302 .flowi4_iif = LOOPBACK_IFINDEX,
303 .daddr = ip_hdr(skb)->saddr,
304 .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
305 .flowi4_scope = scope,
306 .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
308 if (!fib_lookup(net, &fl4, &res, 0))
309 return FIB_RES_PREFSRC(net, res);
311 scope = RT_SCOPE_LINK;
314 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
317 /* Given (packet source, input interface) and optional (dst, oif, tos):
318 * - (main) check, that source is valid i.e. not broadcast or our local
320 * - figure out what "logical" interface this packet arrived
321 * and calculate "specific destination" address.
322 * - check, that packet arrived from expected physical interface.
323 * called with rcu_read_lock()
325 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
326 u8 tos, int oif, struct net_device *dev,
327 int rpf, struct in_device *idev, u32 *itag)
330 struct fib_result res;
332 struct net *net = dev_net(dev);
336 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
338 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
341 fl4.flowi4_tos = tos;
342 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
343 fl4.flowi4_tun_key.tun_id = 0;
344 fl4.flowi4_flags = 0;
345 fl4.flowi4_uid = sock_net_uid(net, NULL);
347 no_addr = idev->ifa_list == NULL;
349 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
351 trace_fib_validate_source(dev, &fl4);
353 if (fib_lookup(net, &fl4, &res, 0))
355 if (res.type != RTN_UNICAST &&
356 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
358 fib_combine_itag(itag, &res);
361 #ifdef CONFIG_IP_ROUTE_MULTIPATH
362 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
363 struct fib_nh *nh = &res.fi->fib_nh[ret];
365 if (nh->nh_dev == dev) {
368 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
374 if (FIB_RES_DEV(res) == dev)
378 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
385 fl4.flowi4_oif = dev->ifindex;
388 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
389 if (res.type == RTN_UNICAST)
390 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
406 /* Ignore rp_filter for packets protected by IPsec. */
407 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
408 u8 tos, int oif, struct net_device *dev,
409 struct in_device *idev, u32 *itag)
411 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
412 struct net *net = dev_net(dev);
414 if (!r && !fib_num_tclassid_users(net) &&
415 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
416 if (IN_DEV_ACCEPT_LOCAL(idev))
418 /* with custom local routes in place, checking local addresses
419 * only will be too optimistic, with custom rules, checking
420 * local addresses only can be too strict, e.g. due to vrf
422 if (net->ipv4.fib_has_custom_local_routes ||
423 fib4_has_custom_rules(net))
425 if (inet_lookup_ifaddr_rcu(net, src))
434 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
437 static inline __be32 sk_extract_addr(struct sockaddr *addr)
439 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
442 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
446 nla = (struct nlattr *) ((char *) mx + len);
447 nla->nla_type = type;
448 nla->nla_len = nla_attr_size(4);
449 *(u32 *) nla_data(nla) = value;
451 return len + nla_total_size(4);
454 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
455 struct fib_config *cfg)
460 memset(cfg, 0, sizeof(*cfg));
461 cfg->fc_nlinfo.nl_net = net;
463 if (rt->rt_dst.sa_family != AF_INET)
464 return -EAFNOSUPPORT;
467 * Check mask for validity:
468 * a) it must be contiguous.
469 * b) destination must have all host bits clear.
470 * c) if application forgot to set correct family (AF_INET),
471 * reject request unless it is absolutely clear i.e.
472 * both family and mask are zero.
475 addr = sk_extract_addr(&rt->rt_dst);
476 if (!(rt->rt_flags & RTF_HOST)) {
477 __be32 mask = sk_extract_addr(&rt->rt_genmask);
479 if (rt->rt_genmask.sa_family != AF_INET) {
480 if (mask || rt->rt_genmask.sa_family)
481 return -EAFNOSUPPORT;
484 if (bad_mask(mask, addr))
487 plen = inet_mask_len(mask);
490 cfg->fc_dst_len = plen;
493 if (cmd != SIOCDELRT) {
494 cfg->fc_nlflags = NLM_F_CREATE;
495 cfg->fc_protocol = RTPROT_BOOT;
499 cfg->fc_priority = rt->rt_metric - 1;
501 if (rt->rt_flags & RTF_REJECT) {
502 cfg->fc_scope = RT_SCOPE_HOST;
503 cfg->fc_type = RTN_UNREACHABLE;
507 cfg->fc_scope = RT_SCOPE_NOWHERE;
508 cfg->fc_type = RTN_UNICAST;
512 struct net_device *dev;
513 char devname[IFNAMSIZ];
515 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
518 devname[IFNAMSIZ-1] = 0;
519 colon = strchr(devname, ':');
522 dev = __dev_get_by_name(net, devname);
525 cfg->fc_oif = dev->ifindex;
526 cfg->fc_table = l3mdev_fib_table(dev);
528 struct in_ifaddr *ifa;
529 struct in_device *in_dev = __in_dev_get_rtnl(dev);
533 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
534 if (strcmp(ifa->ifa_label, devname) == 0)
538 cfg->fc_prefsrc = ifa->ifa_local;
542 addr = sk_extract_addr(&rt->rt_gateway);
543 if (rt->rt_gateway.sa_family == AF_INET && addr) {
544 unsigned int addr_type;
547 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
548 if (rt->rt_flags & RTF_GATEWAY &&
549 addr_type == RTN_UNICAST)
550 cfg->fc_scope = RT_SCOPE_UNIVERSE;
553 if (cmd == SIOCDELRT)
556 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
559 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
560 cfg->fc_scope = RT_SCOPE_LINK;
562 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
566 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
570 if (rt->rt_flags & RTF_MTU)
571 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
573 if (rt->rt_flags & RTF_WINDOW)
574 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
576 if (rt->rt_flags & RTF_IRTT)
577 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
580 cfg->fc_mx_len = len;
587 * Handle IP routing ioctl calls.
588 * These are used to manipulate the routing tables
590 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
592 struct fib_config cfg;
597 case SIOCADDRT: /* Add a route */
598 case SIOCDELRT: /* Delete a route */
599 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
602 if (copy_from_user(&rt, arg, sizeof(rt)))
606 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
608 struct fib_table *tb;
610 if (cmd == SIOCDELRT) {
611 tb = fib_get_table(net, cfg.fc_table);
613 err = fib_table_delete(net, tb, &cfg,
618 tb = fib_new_table(net, cfg.fc_table);
620 err = fib_table_insert(net, tb,
626 /* allocated by rtentry_to_fib_config() */
635 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
636 [RTA_DST] = { .type = NLA_U32 },
637 [RTA_SRC] = { .type = NLA_U32 },
638 [RTA_IIF] = { .type = NLA_U32 },
639 [RTA_OIF] = { .type = NLA_U32 },
640 [RTA_GATEWAY] = { .type = NLA_U32 },
641 [RTA_PRIORITY] = { .type = NLA_U32 },
642 [RTA_PREFSRC] = { .type = NLA_U32 },
643 [RTA_METRICS] = { .type = NLA_NESTED },
644 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
645 [RTA_FLOW] = { .type = NLA_U32 },
646 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
647 [RTA_ENCAP] = { .type = NLA_NESTED },
648 [RTA_UID] = { .type = NLA_U32 },
649 [RTA_MARK] = { .type = NLA_U32 },
652 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
653 struct nlmsghdr *nlh, struct fib_config *cfg,
654 struct netlink_ext_ack *extack)
660 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy,
665 memset(cfg, 0, sizeof(*cfg));
667 rtm = nlmsg_data(nlh);
668 cfg->fc_dst_len = rtm->rtm_dst_len;
669 cfg->fc_tos = rtm->rtm_tos;
670 cfg->fc_table = rtm->rtm_table;
671 cfg->fc_protocol = rtm->rtm_protocol;
672 cfg->fc_scope = rtm->rtm_scope;
673 cfg->fc_type = rtm->rtm_type;
674 cfg->fc_flags = rtm->rtm_flags;
675 cfg->fc_nlflags = nlh->nlmsg_flags;
677 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
678 cfg->fc_nlinfo.nlh = nlh;
679 cfg->fc_nlinfo.nl_net = net;
681 if (cfg->fc_type > RTN_MAX) {
682 NL_SET_ERR_MSG(extack, "Invalid route type");
687 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
688 switch (nla_type(attr)) {
690 cfg->fc_dst = nla_get_be32(attr);
693 cfg->fc_oif = nla_get_u32(attr);
696 cfg->fc_gw = nla_get_be32(attr);
699 cfg->fc_priority = nla_get_u32(attr);
702 cfg->fc_prefsrc = nla_get_be32(attr);
705 cfg->fc_mx = nla_data(attr);
706 cfg->fc_mx_len = nla_len(attr);
709 err = lwtunnel_valid_encap_type_attr(nla_data(attr),
714 cfg->fc_mp = nla_data(attr);
715 cfg->fc_mp_len = nla_len(attr);
718 cfg->fc_flow = nla_get_u32(attr);
721 cfg->fc_table = nla_get_u32(attr);
724 cfg->fc_encap = attr;
727 cfg->fc_encap_type = nla_get_u16(attr);
728 err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
741 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
742 struct netlink_ext_ack *extack)
744 struct net *net = sock_net(skb->sk);
745 struct fib_config cfg;
746 struct fib_table *tb;
749 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
753 tb = fib_get_table(net, cfg.fc_table);
755 NL_SET_ERR_MSG(extack, "FIB table does not exist");
760 err = fib_table_delete(net, tb, &cfg, extack);
765 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
766 struct netlink_ext_ack *extack)
768 struct net *net = sock_net(skb->sk);
769 struct fib_config cfg;
770 struct fib_table *tb;
773 err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
777 tb = fib_new_table(net, cfg.fc_table);
783 err = fib_table_insert(net, tb, &cfg, extack);
784 if (!err && cfg.fc_type == RTN_LOCAL)
785 net->ipv4.fib_has_custom_local_routes = true;
790 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
792 struct net *net = sock_net(skb->sk);
794 unsigned int e = 0, s_e;
795 struct fib_table *tb;
796 struct hlist_head *head;
799 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
800 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
808 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
810 head = &net->ipv4.fib_table_hash[h];
811 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
815 memset(&cb->args[2], 0, sizeof(cb->args) -
816 2 * sizeof(cb->args[0]));
817 err = fib_table_dump(tb, skb, cb);
819 if (likely(skb->len))
840 /* Prepare and feed intra-kernel routing request.
841 * Really, it should be netlink message, but :-( netlink
842 * can be not configured, so that we feed it directly
843 * to fib engine. It is legal, because all events occur
844 * only when netlink is already locked.
846 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
848 struct net *net = dev_net(ifa->ifa_dev->dev);
849 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
850 struct fib_table *tb;
851 struct fib_config cfg = {
852 .fc_protocol = RTPROT_KERNEL,
855 .fc_dst_len = dst_len,
856 .fc_prefsrc = ifa->ifa_local,
857 .fc_oif = ifa->ifa_dev->dev->ifindex,
858 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
865 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
867 tb = fib_new_table(net, tb_id);
871 cfg.fc_table = tb->tb_id;
873 if (type != RTN_LOCAL)
874 cfg.fc_scope = RT_SCOPE_LINK;
876 cfg.fc_scope = RT_SCOPE_HOST;
878 if (cmd == RTM_NEWROUTE)
879 fib_table_insert(net, tb, &cfg, NULL);
881 fib_table_delete(net, tb, &cfg, NULL);
884 void fib_add_ifaddr(struct in_ifaddr *ifa)
886 struct in_device *in_dev = ifa->ifa_dev;
887 struct net_device *dev = in_dev->dev;
888 struct in_ifaddr *prim = ifa;
889 __be32 mask = ifa->ifa_mask;
890 __be32 addr = ifa->ifa_local;
891 __be32 prefix = ifa->ifa_address & mask;
893 if (ifa->ifa_flags & IFA_F_SECONDARY) {
894 prim = inet_ifa_byprefix(in_dev, prefix, mask);
896 pr_warn("%s: bug: prim == NULL\n", __func__);
901 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
903 if (!(dev->flags & IFF_UP))
906 /* Add broadcast address, if it is explicitly assigned. */
907 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
908 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
910 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
911 (prefix != addr || ifa->ifa_prefixlen < 32)) {
912 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
913 fib_magic(RTM_NEWROUTE,
914 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
915 prefix, ifa->ifa_prefixlen, prim);
917 /* Add network specific broadcasts, when it takes a sense */
918 if (ifa->ifa_prefixlen < 31) {
919 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
920 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
926 /* Delete primary or secondary address.
927 * Optionally, on secondary address promotion consider the addresses
928 * from subnet iprim as deleted, even if they are in device list.
929 * In this case the secondary ifa can be in device list.
931 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
933 struct in_device *in_dev = ifa->ifa_dev;
934 struct net_device *dev = in_dev->dev;
935 struct in_ifaddr *ifa1;
936 struct in_ifaddr *prim = ifa, *prim1 = NULL;
937 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
938 __be32 any = ifa->ifa_address & ifa->ifa_mask;
944 int subnet = 0; /* Primary network */
945 int gone = 1; /* Address is missing */
946 int same_prefsrc = 0; /* Another primary with same IP */
948 if (ifa->ifa_flags & IFA_F_SECONDARY) {
949 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
951 /* if the device has been deleted, we don't perform
955 pr_warn("%s: bug: prim == NULL\n", __func__);
958 if (iprim && iprim != prim) {
959 pr_warn("%s: bug: iprim != prim\n", __func__);
962 } else if (!ipv4_is_zeronet(any) &&
963 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
964 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
965 fib_magic(RTM_DELROUTE,
966 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
967 any, ifa->ifa_prefixlen, prim);
974 /* Deletion is more complicated than add.
975 * We should take care of not to delete too much :-)
977 * Scan address list to be sure that addresses are really gone.
980 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
982 /* promotion, keep the IP */
986 /* Ignore IFAs from our subnet */
987 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
988 inet_ifa_match(ifa1->ifa_address, iprim))
991 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
992 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
993 /* Another address from our subnet? */
994 if (ifa1->ifa_mask == prim->ifa_mask &&
995 inet_ifa_match(ifa1->ifa_address, prim))
998 /* We reached the secondaries, so
999 * same_prefsrc should be determined.
1003 /* Search new prim1 if ifa1 is not
1004 * using the current prim1
1007 ifa1->ifa_mask != prim1->ifa_mask ||
1008 !inet_ifa_match(ifa1->ifa_address, prim1))
1009 prim1 = inet_ifa_byprefix(in_dev,
1014 if (prim1->ifa_local != prim->ifa_local)
1018 if (prim->ifa_local != ifa1->ifa_local)
1024 if (ifa->ifa_local == ifa1->ifa_local)
1026 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
1028 if (brd == ifa1->ifa_broadcast)
1030 if (any == ifa1->ifa_broadcast)
1032 /* primary has network specific broadcasts */
1033 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
1034 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1035 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1037 if (!ipv4_is_zeronet(any1)) {
1038 if (ifa->ifa_broadcast == brd1 ||
1039 ifa->ifa_broadcast == any1)
1041 if (brd == brd1 || brd == any1)
1043 if (any == brd1 || any == any1)
1051 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1052 if (subnet && ifa->ifa_prefixlen < 31) {
1053 if (!(ok & BRD1_OK))
1054 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1055 if (!(ok & BRD0_OK))
1056 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1058 if (!(ok & LOCAL_OK)) {
1059 unsigned int addr_type;
1061 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1063 /* Check, that this local address finally disappeared. */
1064 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1066 if (gone && addr_type != RTN_LOCAL) {
1067 /* And the last, but not the least thing.
1068 * We must flush stray FIB entries.
1070 * First of all, we scan fib_info list searching
1071 * for stray nexthop entries, then ignite fib_flush.
1073 if (fib_sync_down_addr(dev, ifa->ifa_local))
1074 fib_flush(dev_net(dev));
1083 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1086 struct fib_result res;
1087 struct flowi4 fl4 = {
1088 .flowi4_mark = frn->fl_mark,
1089 .daddr = frn->fl_addr,
1090 .flowi4_tos = frn->fl_tos,
1091 .flowi4_scope = frn->fl_scope,
1093 struct fib_table *tb;
1097 tb = fib_get_table(net, frn->tb_id_in);
1103 frn->tb_id = tb->tb_id;
1104 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1107 frn->prefixlen = res.prefixlen;
1108 frn->nh_sel = res.nh_sel;
1109 frn->type = res.type;
1110 frn->scope = res.scope;
1118 static void nl_fib_input(struct sk_buff *skb)
1121 struct fib_result_nl *frn;
1122 struct nlmsghdr *nlh;
1125 net = sock_net(skb->sk);
1126 nlh = nlmsg_hdr(skb);
1127 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1128 skb->len < nlh->nlmsg_len ||
1129 nlmsg_len(nlh) < sizeof(*frn))
1132 skb = netlink_skb_clone(skb, GFP_KERNEL);
1135 nlh = nlmsg_hdr(skb);
1137 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1138 nl_fib_lookup(net, frn);
1140 portid = NETLINK_CB(skb).portid; /* netlink portid */
1141 NETLINK_CB(skb).portid = 0; /* from kernel */
1142 NETLINK_CB(skb).dst_group = 0; /* unicast */
1143 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1146 static int __net_init nl_fib_lookup_init(struct net *net)
1149 struct netlink_kernel_cfg cfg = {
1150 .input = nl_fib_input,
1153 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1155 return -EAFNOSUPPORT;
1156 net->ipv4.fibnl = sk;
1160 static void nl_fib_lookup_exit(struct net *net)
1162 netlink_kernel_release(net->ipv4.fibnl);
1163 net->ipv4.fibnl = NULL;
1166 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1169 if (fib_sync_down_dev(dev, event, force))
1170 fib_flush(dev_net(dev));
1172 rt_cache_flush(dev_net(dev));
1176 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1178 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1179 struct net_device *dev = ifa->ifa_dev->dev;
1180 struct net *net = dev_net(dev);
1184 fib_add_ifaddr(ifa);
1185 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1186 fib_sync_up(dev, RTNH_F_DEAD);
1188 atomic_inc(&net->ipv4.dev_addr_genid);
1189 rt_cache_flush(dev_net(dev));
1192 fib_del_ifaddr(ifa, NULL);
1193 atomic_inc(&net->ipv4.dev_addr_genid);
1194 if (!ifa->ifa_dev->ifa_list) {
1195 /* Last address was deleted from this interface.
1198 fib_disable_ip(dev, event, true);
1200 rt_cache_flush(dev_net(dev));
1207 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1209 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1210 struct netdev_notifier_changeupper_info *info;
1211 struct in_device *in_dev;
1212 struct net *net = dev_net(dev);
1215 if (event == NETDEV_UNREGISTER) {
1216 fib_disable_ip(dev, event, true);
1221 in_dev = __in_dev_get_rtnl(dev);
1228 fib_add_ifaddr(ifa);
1229 } endfor_ifa(in_dev);
1230 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1231 fib_sync_up(dev, RTNH_F_DEAD);
1233 atomic_inc(&net->ipv4.dev_addr_genid);
1234 rt_cache_flush(net);
1237 fib_disable_ip(dev, event, false);
1240 flags = dev_get_flags(dev);
1241 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1242 fib_sync_up(dev, RTNH_F_LINKDOWN);
1244 fib_sync_down_dev(dev, event, false);
1246 case NETDEV_CHANGEMTU:
1247 rt_cache_flush(net);
1249 case NETDEV_CHANGEUPPER:
1251 /* flush all routes if dev is linked to or unlinked from
1252 * an L3 master device (e.g., VRF)
1254 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
1255 fib_disable_ip(dev, NETDEV_DOWN, true);
1261 static struct notifier_block fib_inetaddr_notifier = {
1262 .notifier_call = fib_inetaddr_event,
1265 static struct notifier_block fib_netdev_notifier = {
1266 .notifier_call = fib_netdev_event,
1269 static int __net_init ip_fib_net_init(struct net *net)
1272 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1274 err = fib4_notifier_init(net);
1278 /* Avoid false sharing : Use at least a full cache line */
1279 size = max_t(size_t, size, L1_CACHE_BYTES);
1281 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1282 if (!net->ipv4.fib_table_hash) {
1284 goto err_table_hash_alloc;
1287 err = fib4_rules_init(net);
1289 goto err_rules_init;
1293 kfree(net->ipv4.fib_table_hash);
1294 err_table_hash_alloc:
1295 fib4_notifier_exit(net);
1299 static void ip_fib_net_exit(struct net *net)
1304 #ifdef CONFIG_IP_MULTIPLE_TABLES
1305 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1306 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1308 for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
1309 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1310 struct hlist_node *tmp;
1311 struct fib_table *tb;
1313 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1314 hlist_del(&tb->tb_hlist);
1315 fib_table_flush(net, tb);
1320 #ifdef CONFIG_IP_MULTIPLE_TABLES
1321 fib4_rules_exit(net);
1324 kfree(net->ipv4.fib_table_hash);
1325 fib4_notifier_exit(net);
1328 static int __net_init fib_net_init(struct net *net)
1332 #ifdef CONFIG_IP_ROUTE_CLASSID
1333 net->ipv4.fib_num_tclassid_users = 0;
1335 error = ip_fib_net_init(net);
1338 error = nl_fib_lookup_init(net);
1341 error = fib_proc_init(net);
1348 nl_fib_lookup_exit(net);
1350 ip_fib_net_exit(net);
1354 static void __net_exit fib_net_exit(struct net *net)
1357 nl_fib_lookup_exit(net);
1358 ip_fib_net_exit(net);
1361 static struct pernet_operations fib_net_ops = {
1362 .init = fib_net_init,
1363 .exit = fib_net_exit,
1366 void __init ip_fib_init(void)
1370 register_pernet_subsys(&fib_net_ops);
1372 register_netdevice_notifier(&fib_netdev_notifier);
1373 register_inetaddr_notifier(&fib_inetaddr_notifier);
1375 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, 0);
1376 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, 0);
1377 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, 0);