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 <asm/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 <trace/events/fib.h>
51 #ifndef CONFIG_IP_MULTIPLE_TABLES
53 static int __net_init fib4_rules_init(struct net *net)
55 struct fib_table *local_table, *main_table;
57 main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
61 local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
65 hlist_add_head_rcu(&local_table->tb_hlist,
66 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
67 hlist_add_head_rcu(&main_table->tb_hlist,
68 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
72 fib_free_table(main_table);
77 struct fib_table *fib_new_table(struct net *net, u32 id)
79 struct fib_table *tb, *alias = NULL;
84 tb = fib_get_table(net, id);
88 if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
89 alias = fib_new_table(net, RT_TABLE_MAIN);
91 tb = fib_trie_table(id, alias);
97 rcu_assign_pointer(net->ipv4.fib_local, tb);
100 rcu_assign_pointer(net->ipv4.fib_main, tb);
102 case RT_TABLE_DEFAULT:
103 rcu_assign_pointer(net->ipv4.fib_default, tb);
109 h = id & (FIB_TABLE_HASHSZ - 1);
110 hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
114 /* caller must hold either rtnl or rcu read lock */
115 struct fib_table *fib_get_table(struct net *net, u32 id)
117 struct fib_table *tb;
118 struct hlist_head *head;
123 h = id & (FIB_TABLE_HASHSZ - 1);
125 head = &net->ipv4.fib_table_hash[h];
126 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
132 #endif /* CONFIG_IP_MULTIPLE_TABLES */
134 static void fib_replace_table(struct net *net, struct fib_table *old,
135 struct fib_table *new)
137 #ifdef CONFIG_IP_MULTIPLE_TABLES
138 switch (new->tb_id) {
140 rcu_assign_pointer(net->ipv4.fib_local, new);
143 rcu_assign_pointer(net->ipv4.fib_main, new);
145 case RT_TABLE_DEFAULT:
146 rcu_assign_pointer(net->ipv4.fib_default, new);
153 /* replace the old table in the hlist */
154 hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
157 int fib_unmerge(struct net *net)
159 struct fib_table *old, *new;
161 /* attempt to fetch local table if it has been allocated */
162 old = fib_get_table(net, RT_TABLE_LOCAL);
166 new = fib_trie_unmerge(old);
170 /* replace merged table with clean table */
172 fib_replace_table(net, old, new);
179 static void fib_flush(struct net *net)
184 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
185 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
186 struct hlist_node *tmp;
187 struct fib_table *tb;
189 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
190 flushed += fib_table_flush(tb, false);
197 void fib_flush_external(struct net *net)
199 struct fib_table *tb;
200 struct hlist_head *head;
203 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
204 head = &net->ipv4.fib_table_hash[h];
205 hlist_for_each_entry(tb, head, tb_hlist)
206 fib_table_flush_external(tb);
211 * Find address type as if only "dev" was present in the system. If
212 * on_dev is NULL then all interfaces are taken into consideration.
214 static inline unsigned int __inet_dev_addr_type(struct net *net,
215 const struct net_device *dev,
216 __be32 addr, u32 tb_id)
218 struct flowi4 fl4 = { .daddr = addr };
219 struct fib_result res;
220 unsigned int ret = RTN_BROADCAST;
221 struct fib_table *table;
223 if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
224 return RTN_BROADCAST;
225 if (ipv4_is_multicast(addr))
226 return RTN_MULTICAST;
230 table = fib_get_table(net, tb_id);
233 if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
234 if (!dev || dev == res.fi->fib_dev)
243 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
245 return __inet_dev_addr_type(net, NULL, addr, tb_id);
247 EXPORT_SYMBOL(inet_addr_type_table);
249 unsigned int inet_addr_type(struct net *net, __be32 addr)
251 return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
253 EXPORT_SYMBOL(inet_addr_type);
255 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
258 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
260 return __inet_dev_addr_type(net, dev, addr, rt_table);
262 EXPORT_SYMBOL(inet_dev_addr_type);
264 /* inet_addr_type with dev == NULL but using the table from a dev
265 * if one is associated
267 unsigned int inet_addr_type_dev_table(struct net *net,
268 const struct net_device *dev,
271 u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
273 return __inet_dev_addr_type(net, NULL, addr, rt_table);
275 EXPORT_SYMBOL(inet_addr_type_dev_table);
277 __be32 fib_compute_spec_dst(struct sk_buff *skb)
279 struct net_device *dev = skb->dev;
280 struct in_device *in_dev;
281 struct fib_result res;
286 rt = skb_rtable(skb);
287 if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
289 return ip_hdr(skb)->daddr;
291 in_dev = __in_dev_get_rcu(dev);
295 scope = RT_SCOPE_UNIVERSE;
296 if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
297 bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
298 struct flowi4 fl4 = {
299 .flowi4_iif = LOOPBACK_IFINDEX,
300 .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
301 .daddr = ip_hdr(skb)->saddr,
302 .flowi4_tos = ip_hdr(skb)->tos & IPTOS_RT_MASK,
303 .flowi4_scope = scope,
304 .flowi4_mark = vmark ? skb->mark : 0,
306 if (!fib_lookup(net, &fl4, &res, 0))
307 return FIB_RES_PREFSRC(net, res);
309 scope = RT_SCOPE_LINK;
312 return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
315 /* Given (packet source, input interface) and optional (dst, oif, tos):
316 * - (main) check, that source is valid i.e. not broadcast or our local
318 * - figure out what "logical" interface this packet arrived
319 * and calculate "specific destination" address.
320 * - check, that packet arrived from expected physical interface.
321 * called with rcu_read_lock()
323 static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
324 u8 tos, int oif, struct net_device *dev,
325 int rpf, struct in_device *idev, u32 *itag)
328 struct fib_result res;
334 fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
336 fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
339 fl4.flowi4_tos = tos;
340 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
341 fl4.flowi4_tun_key.tun_id = 0;
342 fl4.flowi4_flags = 0;
344 no_addr = idev->ifa_list == NULL;
346 fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
348 trace_fib_validate_source(dev, &fl4);
351 if (fib_lookup(net, &fl4, &res, 0))
353 if (res.type != RTN_UNICAST &&
354 (res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
356 if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
357 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
359 fib_combine_itag(itag, &res);
362 #ifdef CONFIG_IP_ROUTE_MULTIPATH
363 for (ret = 0; ret < res.fi->fib_nhs; ret++) {
364 struct fib_nh *nh = &res.fi->fib_nh[ret];
366 if (nh->nh_dev == dev) {
369 } else if (l3mdev_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
375 if (FIB_RES_DEV(res) == dev)
379 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
386 fl4.flowi4_oif = dev->ifindex;
389 if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
390 if (res.type == RTN_UNICAST)
391 ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
407 /* Ignore rp_filter for packets protected by IPsec. */
408 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
409 u8 tos, int oif, struct net_device *dev,
410 struct in_device *idev, u32 *itag)
412 int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
414 if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
415 IN_DEV_ACCEPT_LOCAL(idev) &&
416 (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
420 return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
423 static inline __be32 sk_extract_addr(struct sockaddr *addr)
425 return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
428 static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
432 nla = (struct nlattr *) ((char *) mx + len);
433 nla->nla_type = type;
434 nla->nla_len = nla_attr_size(4);
435 *(u32 *) nla_data(nla) = value;
437 return len + nla_total_size(4);
440 static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
441 struct fib_config *cfg)
446 memset(cfg, 0, sizeof(*cfg));
447 cfg->fc_nlinfo.nl_net = net;
449 if (rt->rt_dst.sa_family != AF_INET)
450 return -EAFNOSUPPORT;
453 * Check mask for validity:
454 * a) it must be contiguous.
455 * b) destination must have all host bits clear.
456 * c) if application forgot to set correct family (AF_INET),
457 * reject request unless it is absolutely clear i.e.
458 * both family and mask are zero.
461 addr = sk_extract_addr(&rt->rt_dst);
462 if (!(rt->rt_flags & RTF_HOST)) {
463 __be32 mask = sk_extract_addr(&rt->rt_genmask);
465 if (rt->rt_genmask.sa_family != AF_INET) {
466 if (mask || rt->rt_genmask.sa_family)
467 return -EAFNOSUPPORT;
470 if (bad_mask(mask, addr))
473 plen = inet_mask_len(mask);
476 cfg->fc_dst_len = plen;
479 if (cmd != SIOCDELRT) {
480 cfg->fc_nlflags = NLM_F_CREATE;
481 cfg->fc_protocol = RTPROT_BOOT;
485 cfg->fc_priority = rt->rt_metric - 1;
487 if (rt->rt_flags & RTF_REJECT) {
488 cfg->fc_scope = RT_SCOPE_HOST;
489 cfg->fc_type = RTN_UNREACHABLE;
493 cfg->fc_scope = RT_SCOPE_NOWHERE;
494 cfg->fc_type = RTN_UNICAST;
498 struct net_device *dev;
499 char devname[IFNAMSIZ];
501 if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
504 devname[IFNAMSIZ-1] = 0;
505 colon = strchr(devname, ':');
508 dev = __dev_get_by_name(net, devname);
511 cfg->fc_oif = dev->ifindex;
512 cfg->fc_table = l3mdev_fib_table(dev);
514 struct in_ifaddr *ifa;
515 struct in_device *in_dev = __in_dev_get_rtnl(dev);
519 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
520 if (strcmp(ifa->ifa_label, devname) == 0)
524 cfg->fc_prefsrc = ifa->ifa_local;
528 addr = sk_extract_addr(&rt->rt_gateway);
529 if (rt->rt_gateway.sa_family == AF_INET && addr) {
530 unsigned int addr_type;
533 addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
534 if (rt->rt_flags & RTF_GATEWAY &&
535 addr_type == RTN_UNICAST)
536 cfg->fc_scope = RT_SCOPE_UNIVERSE;
539 if (cmd == SIOCDELRT)
542 if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
545 if (cfg->fc_scope == RT_SCOPE_NOWHERE)
546 cfg->fc_scope = RT_SCOPE_LINK;
548 if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
552 mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
556 if (rt->rt_flags & RTF_MTU)
557 len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
559 if (rt->rt_flags & RTF_WINDOW)
560 len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
562 if (rt->rt_flags & RTF_IRTT)
563 len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
566 cfg->fc_mx_len = len;
573 * Handle IP routing ioctl calls.
574 * These are used to manipulate the routing tables
576 int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
578 struct fib_config cfg;
583 case SIOCADDRT: /* Add a route */
584 case SIOCDELRT: /* Delete a route */
585 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
588 if (copy_from_user(&rt, arg, sizeof(rt)))
592 err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
594 struct fib_table *tb;
596 if (cmd == SIOCDELRT) {
597 tb = fib_get_table(net, cfg.fc_table);
599 err = fib_table_delete(tb, &cfg);
603 tb = fib_new_table(net, cfg.fc_table);
605 err = fib_table_insert(tb, &cfg);
610 /* allocated by rtentry_to_fib_config() */
619 const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
620 [RTA_DST] = { .type = NLA_U32 },
621 [RTA_SRC] = { .type = NLA_U32 },
622 [RTA_IIF] = { .type = NLA_U32 },
623 [RTA_OIF] = { .type = NLA_U32 },
624 [RTA_GATEWAY] = { .type = NLA_U32 },
625 [RTA_PRIORITY] = { .type = NLA_U32 },
626 [RTA_PREFSRC] = { .type = NLA_U32 },
627 [RTA_METRICS] = { .type = NLA_NESTED },
628 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
629 [RTA_FLOW] = { .type = NLA_U32 },
630 [RTA_ENCAP_TYPE] = { .type = NLA_U16 },
631 [RTA_ENCAP] = { .type = NLA_NESTED },
634 static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
635 struct nlmsghdr *nlh, struct fib_config *cfg)
641 err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
645 memset(cfg, 0, sizeof(*cfg));
647 rtm = nlmsg_data(nlh);
648 cfg->fc_dst_len = rtm->rtm_dst_len;
649 cfg->fc_tos = rtm->rtm_tos;
650 cfg->fc_table = rtm->rtm_table;
651 cfg->fc_protocol = rtm->rtm_protocol;
652 cfg->fc_scope = rtm->rtm_scope;
653 cfg->fc_type = rtm->rtm_type;
654 cfg->fc_flags = rtm->rtm_flags;
655 cfg->fc_nlflags = nlh->nlmsg_flags;
657 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
658 cfg->fc_nlinfo.nlh = nlh;
659 cfg->fc_nlinfo.nl_net = net;
661 if (cfg->fc_type > RTN_MAX) {
666 nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
667 switch (nla_type(attr)) {
669 cfg->fc_dst = nla_get_be32(attr);
672 cfg->fc_oif = nla_get_u32(attr);
675 cfg->fc_gw = nla_get_be32(attr);
678 cfg->fc_priority = nla_get_u32(attr);
681 cfg->fc_prefsrc = nla_get_be32(attr);
684 cfg->fc_mx = nla_data(attr);
685 cfg->fc_mx_len = nla_len(attr);
688 cfg->fc_mp = nla_data(attr);
689 cfg->fc_mp_len = nla_len(attr);
692 cfg->fc_flow = nla_get_u32(attr);
695 cfg->fc_table = nla_get_u32(attr);
698 cfg->fc_encap = attr;
701 cfg->fc_encap_type = nla_get_u16(attr);
711 static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
713 struct net *net = sock_net(skb->sk);
714 struct fib_config cfg;
715 struct fib_table *tb;
718 err = rtm_to_fib_config(net, skb, nlh, &cfg);
722 tb = fib_get_table(net, cfg.fc_table);
728 err = fib_table_delete(tb, &cfg);
733 static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
735 struct net *net = sock_net(skb->sk);
736 struct fib_config cfg;
737 struct fib_table *tb;
740 err = rtm_to_fib_config(net, skb, nlh, &cfg);
744 tb = fib_new_table(net, cfg.fc_table);
750 err = fib_table_insert(tb, &cfg);
755 static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
757 struct net *net = sock_net(skb->sk);
759 unsigned int e = 0, s_e;
760 struct fib_table *tb;
761 struct hlist_head *head;
764 if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
765 ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
773 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
775 head = &net->ipv4.fib_table_hash[h];
776 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
780 memset(&cb->args[2], 0, sizeof(cb->args) -
781 2 * sizeof(cb->args[0]));
782 err = fib_table_dump(tb, skb, cb);
784 if (likely(skb->len))
805 /* Prepare and feed intra-kernel routing request.
806 * Really, it should be netlink message, but :-( netlink
807 * can be not configured, so that we feed it directly
808 * to fib engine. It is legal, because all events occur
809 * only when netlink is already locked.
811 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
813 struct net *net = dev_net(ifa->ifa_dev->dev);
814 u32 tb_id = l3mdev_fib_table(ifa->ifa_dev->dev);
815 struct fib_table *tb;
816 struct fib_config cfg = {
817 .fc_protocol = RTPROT_KERNEL,
820 .fc_dst_len = dst_len,
821 .fc_prefsrc = ifa->ifa_local,
822 .fc_oif = ifa->ifa_dev->dev->ifindex,
823 .fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
830 tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
832 tb = fib_new_table(net, tb_id);
836 cfg.fc_table = tb->tb_id;
838 if (type != RTN_LOCAL)
839 cfg.fc_scope = RT_SCOPE_LINK;
841 cfg.fc_scope = RT_SCOPE_HOST;
843 if (cmd == RTM_NEWROUTE)
844 fib_table_insert(tb, &cfg);
846 fib_table_delete(tb, &cfg);
849 void fib_add_ifaddr(struct in_ifaddr *ifa)
851 struct in_device *in_dev = ifa->ifa_dev;
852 struct net_device *dev = in_dev->dev;
853 struct in_ifaddr *prim = ifa;
854 __be32 mask = ifa->ifa_mask;
855 __be32 addr = ifa->ifa_local;
856 __be32 prefix = ifa->ifa_address & mask;
858 if (ifa->ifa_flags & IFA_F_SECONDARY) {
859 prim = inet_ifa_byprefix(in_dev, prefix, mask);
861 pr_warn("%s: bug: prim == NULL\n", __func__);
866 fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
868 if (!(dev->flags & IFF_UP))
871 /* Add broadcast address, if it is explicitly assigned. */
872 if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
873 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
875 if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
876 (prefix != addr || ifa->ifa_prefixlen < 32)) {
877 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
878 fib_magic(RTM_NEWROUTE,
879 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
880 prefix, ifa->ifa_prefixlen, prim);
882 /* Add network specific broadcasts, when it takes a sense */
883 if (ifa->ifa_prefixlen < 31) {
884 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
885 fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
891 /* Delete primary or secondary address.
892 * Optionally, on secondary address promotion consider the addresses
893 * from subnet iprim as deleted, even if they are in device list.
894 * In this case the secondary ifa can be in device list.
896 void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
898 struct in_device *in_dev = ifa->ifa_dev;
899 struct net_device *dev = in_dev->dev;
900 struct in_ifaddr *ifa1;
901 struct in_ifaddr *prim = ifa, *prim1 = NULL;
902 __be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
903 __be32 any = ifa->ifa_address & ifa->ifa_mask;
909 int subnet = 0; /* Primary network */
910 int gone = 1; /* Address is missing */
911 int same_prefsrc = 0; /* Another primary with same IP */
913 if (ifa->ifa_flags & IFA_F_SECONDARY) {
914 prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
916 /* if the device has been deleted, we don't perform
920 pr_warn("%s: bug: prim == NULL\n", __func__);
923 if (iprim && iprim != prim) {
924 pr_warn("%s: bug: iprim != prim\n", __func__);
927 } else if (!ipv4_is_zeronet(any) &&
928 (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
929 if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE))
930 fib_magic(RTM_DELROUTE,
931 dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
932 any, ifa->ifa_prefixlen, prim);
939 /* Deletion is more complicated than add.
940 * We should take care of not to delete too much :-)
942 * Scan address list to be sure that addresses are really gone.
945 for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
947 /* promotion, keep the IP */
951 /* Ignore IFAs from our subnet */
952 if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
953 inet_ifa_match(ifa1->ifa_address, iprim))
956 /* Ignore ifa1 if it uses different primary IP (prefsrc) */
957 if (ifa1->ifa_flags & IFA_F_SECONDARY) {
958 /* Another address from our subnet? */
959 if (ifa1->ifa_mask == prim->ifa_mask &&
960 inet_ifa_match(ifa1->ifa_address, prim))
963 /* We reached the secondaries, so
964 * same_prefsrc should be determined.
968 /* Search new prim1 if ifa1 is not
969 * using the current prim1
972 ifa1->ifa_mask != prim1->ifa_mask ||
973 !inet_ifa_match(ifa1->ifa_address, prim1))
974 prim1 = inet_ifa_byprefix(in_dev,
979 if (prim1->ifa_local != prim->ifa_local)
983 if (prim->ifa_local != ifa1->ifa_local)
989 if (ifa->ifa_local == ifa1->ifa_local)
991 if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
993 if (brd == ifa1->ifa_broadcast)
995 if (any == ifa1->ifa_broadcast)
997 /* primary has network specific broadcasts */
998 if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
999 __be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
1000 __be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
1002 if (!ipv4_is_zeronet(any1)) {
1003 if (ifa->ifa_broadcast == brd1 ||
1004 ifa->ifa_broadcast == any1)
1006 if (brd == brd1 || brd == any1)
1008 if (any == brd1 || any == any1)
1016 fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
1017 if (subnet && ifa->ifa_prefixlen < 31) {
1018 if (!(ok & BRD1_OK))
1019 fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
1020 if (!(ok & BRD0_OK))
1021 fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
1023 if (!(ok & LOCAL_OK)) {
1024 unsigned int addr_type;
1026 fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
1028 /* Check, that this local address finally disappeared. */
1029 addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
1031 if (gone && addr_type != RTN_LOCAL) {
1032 /* And the last, but not the least thing.
1033 * We must flush stray FIB entries.
1035 * First of all, we scan fib_info list searching
1036 * for stray nexthop entries, then ignite fib_flush.
1038 if (fib_sync_down_addr(dev, ifa->ifa_local))
1039 fib_flush(dev_net(dev));
1048 static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
1051 struct fib_result res;
1052 struct flowi4 fl4 = {
1053 .flowi4_mark = frn->fl_mark,
1054 .daddr = frn->fl_addr,
1055 .flowi4_tos = frn->fl_tos,
1056 .flowi4_scope = frn->fl_scope,
1058 struct fib_table *tb;
1062 tb = fib_get_table(net, frn->tb_id_in);
1068 frn->tb_id = tb->tb_id;
1069 frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
1072 frn->prefixlen = res.prefixlen;
1073 frn->nh_sel = res.nh_sel;
1074 frn->type = res.type;
1075 frn->scope = res.scope;
1083 static void nl_fib_input(struct sk_buff *skb)
1086 struct fib_result_nl *frn;
1087 struct nlmsghdr *nlh;
1090 net = sock_net(skb->sk);
1091 nlh = nlmsg_hdr(skb);
1092 if (skb->len < nlmsg_total_size(sizeof(*frn)) ||
1093 skb->len < nlh->nlmsg_len ||
1094 nlmsg_len(nlh) < sizeof(*frn))
1097 skb = netlink_skb_clone(skb, GFP_KERNEL);
1100 nlh = nlmsg_hdr(skb);
1102 frn = (struct fib_result_nl *) nlmsg_data(nlh);
1103 nl_fib_lookup(net, frn);
1105 portid = NETLINK_CB(skb).portid; /* netlink portid */
1106 NETLINK_CB(skb).portid = 0; /* from kernel */
1107 NETLINK_CB(skb).dst_group = 0; /* unicast */
1108 netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
1111 static int __net_init nl_fib_lookup_init(struct net *net)
1114 struct netlink_kernel_cfg cfg = {
1115 .input = nl_fib_input,
1118 sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
1120 return -EAFNOSUPPORT;
1121 net->ipv4.fibnl = sk;
1125 static void nl_fib_lookup_exit(struct net *net)
1127 netlink_kernel_release(net->ipv4.fibnl);
1128 net->ipv4.fibnl = NULL;
1131 static void fib_disable_ip(struct net_device *dev, unsigned long event,
1134 if (fib_sync_down_dev(dev, event, force))
1135 fib_flush(dev_net(dev));
1136 rt_cache_flush(dev_net(dev));
1140 static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
1142 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
1143 struct net_device *dev = ifa->ifa_dev->dev;
1144 struct net *net = dev_net(dev);
1148 fib_add_ifaddr(ifa);
1149 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1150 fib_sync_up(dev, RTNH_F_DEAD);
1152 atomic_inc(&net->ipv4.dev_addr_genid);
1153 rt_cache_flush(dev_net(dev));
1156 fib_del_ifaddr(ifa, NULL);
1157 atomic_inc(&net->ipv4.dev_addr_genid);
1158 if (!ifa->ifa_dev->ifa_list) {
1159 /* Last address was deleted from this interface.
1162 fib_disable_ip(dev, event, true);
1164 rt_cache_flush(dev_net(dev));
1171 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1173 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1174 struct netdev_notifier_changeupper_info *upper_info = ptr;
1175 struct netdev_notifier_info_ext *info_ext = ptr;
1176 struct in_device *in_dev;
1177 struct net *net = dev_net(dev);
1180 if (event == NETDEV_UNREGISTER) {
1181 fib_disable_ip(dev, event, true);
1186 in_dev = __in_dev_get_rtnl(dev);
1193 fib_add_ifaddr(ifa);
1194 } endfor_ifa(in_dev);
1195 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1196 fib_sync_up(dev, RTNH_F_DEAD);
1198 atomic_inc(&net->ipv4.dev_addr_genid);
1199 rt_cache_flush(net);
1202 fib_disable_ip(dev, event, false);
1205 flags = dev_get_flags(dev);
1206 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1207 fib_sync_up(dev, RTNH_F_LINKDOWN);
1209 fib_sync_down_dev(dev, event, false);
1210 rt_cache_flush(net);
1212 case NETDEV_CHANGEMTU:
1213 fib_sync_mtu(dev, info_ext->ext.mtu);
1214 rt_cache_flush(net);
1216 case NETDEV_CHANGEUPPER:
1218 /* flush all routes if dev is linked to or unlinked from
1219 * an L3 master device (e.g., VRF)
1221 if (upper_info->upper_dev &&
1222 netif_is_l3_master(upper_info->upper_dev))
1223 fib_disable_ip(dev, NETDEV_DOWN, true);
1229 static struct notifier_block fib_inetaddr_notifier = {
1230 .notifier_call = fib_inetaddr_event,
1233 static struct notifier_block fib_netdev_notifier = {
1234 .notifier_call = fib_netdev_event,
1237 static int __net_init ip_fib_net_init(struct net *net)
1240 size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
1242 /* Avoid false sharing : Use at least a full cache line */
1243 size = max_t(size_t, size, L1_CACHE_BYTES);
1245 net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
1246 if (!net->ipv4.fib_table_hash)
1249 err = fib4_rules_init(net);
1255 kfree(net->ipv4.fib_table_hash);
1259 static void ip_fib_net_exit(struct net *net)
1264 #ifdef CONFIG_IP_MULTIPLE_TABLES
1265 RCU_INIT_POINTER(net->ipv4.fib_local, NULL);
1266 RCU_INIT_POINTER(net->ipv4.fib_main, NULL);
1267 RCU_INIT_POINTER(net->ipv4.fib_default, NULL);
1269 /* Destroy the tables in reverse order to guarantee that the
1270 * local table, ID 255, is destroyed before the main table, ID
1271 * 254. This is necessary as the local table may contain
1272 * references to data contained in the main table.
1274 for (i = FIB_TABLE_HASHSZ - 1; i >= 0; i--) {
1275 struct hlist_head *head = &net->ipv4.fib_table_hash[i];
1276 struct hlist_node *tmp;
1277 struct fib_table *tb;
1279 hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
1280 hlist_del(&tb->tb_hlist);
1281 fib_table_flush(tb, true);
1286 #ifdef CONFIG_IP_MULTIPLE_TABLES
1287 fib4_rules_exit(net);
1290 kfree(net->ipv4.fib_table_hash);
1293 static int __net_init fib_net_init(struct net *net)
1297 #ifdef CONFIG_IP_ROUTE_CLASSID
1298 net->ipv4.fib_num_tclassid_users = 0;
1300 error = ip_fib_net_init(net);
1303 error = nl_fib_lookup_init(net);
1306 error = fib_proc_init(net);
1313 nl_fib_lookup_exit(net);
1315 ip_fib_net_exit(net);
1319 static void __net_exit fib_net_exit(struct net *net)
1322 nl_fib_lookup_exit(net);
1323 ip_fib_net_exit(net);
1326 static struct pernet_operations fib_net_ops = {
1327 .init = fib_net_init,
1328 .exit = fib_net_exit,
1331 void __init ip_fib_init(void)
1335 register_pernet_subsys(&fib_net_ops);
1337 register_netdevice_notifier(&fib_netdev_notifier);
1338 register_inetaddr_notifier(&fib_inetaddr_notifier);
1340 rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
1341 rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
1342 rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);