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https://mirrors.bfsu.edu.cn/git/linux.git
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1788 lines
42 KiB
C
1788 lines
42 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* IPv4 Forwarding Information Base: semantics.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/uaccess.h>
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#include <linux/bitops.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/jiffies.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/errno.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/inetdevice.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/proc_fs.h>
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#include <linux/skbuff.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/netlink.h>
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#include <net/arp.h>
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#include <net/ip.h>
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#include <net/protocol.h>
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#include <net/route.h>
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#include <net/tcp.h>
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#include <net/sock.h>
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#include <net/ip_fib.h>
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#include <net/netlink.h>
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#include <net/nexthop.h>
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#include <net/lwtunnel.h>
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#include <net/fib_notifier.h>
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#include "fib_lookup.h"
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static DEFINE_SPINLOCK(fib_info_lock);
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static struct hlist_head *fib_info_hash;
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static struct hlist_head *fib_info_laddrhash;
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static unsigned int fib_info_hash_size;
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static unsigned int fib_info_cnt;
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#define DEVINDEX_HASHBITS 8
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#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
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static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
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#ifdef CONFIG_IP_ROUTE_MULTIPATH
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#define for_nexthops(fi) { \
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int nhsel; const struct fib_nh *nh; \
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for (nhsel = 0, nh = (fi)->fib_nh; \
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nhsel < (fi)->fib_nhs; \
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nh++, nhsel++)
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#define change_nexthops(fi) { \
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int nhsel; struct fib_nh *nexthop_nh; \
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for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
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nhsel < (fi)->fib_nhs; \
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nexthop_nh++, nhsel++)
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#else /* CONFIG_IP_ROUTE_MULTIPATH */
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/* Hope, that gcc will optimize it to get rid of dummy loop */
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#define for_nexthops(fi) { \
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int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
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for (nhsel = 0; nhsel < 1; nhsel++)
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#define change_nexthops(fi) { \
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int nhsel; \
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struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
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for (nhsel = 0; nhsel < 1; nhsel++)
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#endif /* CONFIG_IP_ROUTE_MULTIPATH */
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#define endfor_nexthops(fi) }
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const struct fib_prop fib_props[RTN_MAX + 1] = {
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[RTN_UNSPEC] = {
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.error = 0,
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.scope = RT_SCOPE_NOWHERE,
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},
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[RTN_UNICAST] = {
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.error = 0,
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.scope = RT_SCOPE_UNIVERSE,
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},
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[RTN_LOCAL] = {
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.error = 0,
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.scope = RT_SCOPE_HOST,
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},
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[RTN_BROADCAST] = {
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.error = 0,
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.scope = RT_SCOPE_LINK,
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},
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[RTN_ANYCAST] = {
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.error = 0,
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.scope = RT_SCOPE_LINK,
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},
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[RTN_MULTICAST] = {
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.error = 0,
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.scope = RT_SCOPE_UNIVERSE,
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},
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[RTN_BLACKHOLE] = {
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.error = -EINVAL,
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.scope = RT_SCOPE_UNIVERSE,
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},
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[RTN_UNREACHABLE] = {
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.error = -EHOSTUNREACH,
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.scope = RT_SCOPE_UNIVERSE,
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},
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[RTN_PROHIBIT] = {
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.error = -EACCES,
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.scope = RT_SCOPE_UNIVERSE,
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},
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[RTN_THROW] = {
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.error = -EAGAIN,
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.scope = RT_SCOPE_UNIVERSE,
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},
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[RTN_NAT] = {
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.error = -EINVAL,
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.scope = RT_SCOPE_NOWHERE,
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},
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[RTN_XRESOLVE] = {
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.error = -EINVAL,
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.scope = RT_SCOPE_NOWHERE,
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},
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};
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static void rt_fibinfo_free(struct rtable __rcu **rtp)
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{
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struct rtable *rt = rcu_dereference_protected(*rtp, 1);
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if (!rt)
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return;
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/* Not even needed : RCU_INIT_POINTER(*rtp, NULL);
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* because we waited an RCU grace period before calling
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* free_fib_info_rcu()
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*/
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dst_dev_put(&rt->dst);
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dst_release_immediate(&rt->dst);
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}
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static void free_nh_exceptions(struct fib_nh *nh)
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{
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struct fnhe_hash_bucket *hash;
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int i;
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hash = rcu_dereference_protected(nh->nh_exceptions, 1);
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if (!hash)
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return;
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for (i = 0; i < FNHE_HASH_SIZE; i++) {
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struct fib_nh_exception *fnhe;
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fnhe = rcu_dereference_protected(hash[i].chain, 1);
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while (fnhe) {
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struct fib_nh_exception *next;
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next = rcu_dereference_protected(fnhe->fnhe_next, 1);
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rt_fibinfo_free(&fnhe->fnhe_rth_input);
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rt_fibinfo_free(&fnhe->fnhe_rth_output);
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kfree(fnhe);
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fnhe = next;
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}
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}
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kfree(hash);
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}
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static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp)
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{
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int cpu;
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if (!rtp)
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return;
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for_each_possible_cpu(cpu) {
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struct rtable *rt;
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rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1);
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if (rt) {
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dst_dev_put(&rt->dst);
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dst_release_immediate(&rt->dst);
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}
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}
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free_percpu(rtp);
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}
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/* Release a nexthop info record */
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static void free_fib_info_rcu(struct rcu_head *head)
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{
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struct fib_info *fi = container_of(head, struct fib_info, rcu);
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struct dst_metrics *m;
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change_nexthops(fi) {
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if (nexthop_nh->nh_dev)
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dev_put(nexthop_nh->nh_dev);
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lwtstate_put(nexthop_nh->nh_lwtstate);
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free_nh_exceptions(nexthop_nh);
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rt_fibinfo_free_cpus(nexthop_nh->nh_pcpu_rth_output);
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rt_fibinfo_free(&nexthop_nh->nh_rth_input);
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} endfor_nexthops(fi);
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m = fi->fib_metrics;
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if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt))
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kfree(m);
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kfree(fi);
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}
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void free_fib_info(struct fib_info *fi)
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{
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if (fi->fib_dead == 0) {
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pr_warn("Freeing alive fib_info %p\n", fi);
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return;
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}
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fib_info_cnt--;
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#ifdef CONFIG_IP_ROUTE_CLASSID
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change_nexthops(fi) {
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if (nexthop_nh->nh_tclassid)
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fi->fib_net->ipv4.fib_num_tclassid_users--;
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} endfor_nexthops(fi);
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#endif
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call_rcu(&fi->rcu, free_fib_info_rcu);
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}
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EXPORT_SYMBOL_GPL(free_fib_info);
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void fib_release_info(struct fib_info *fi)
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{
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spin_lock_bh(&fib_info_lock);
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if (fi && --fi->fib_treeref == 0) {
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hlist_del(&fi->fib_hash);
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if (fi->fib_prefsrc)
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hlist_del(&fi->fib_lhash);
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change_nexthops(fi) {
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if (!nexthop_nh->nh_dev)
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continue;
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hlist_del(&nexthop_nh->nh_hash);
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} endfor_nexthops(fi)
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fi->fib_dead = 1;
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fib_info_put(fi);
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}
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spin_unlock_bh(&fib_info_lock);
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}
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static inline int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
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{
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const struct fib_nh *onh = ofi->fib_nh;
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for_nexthops(fi) {
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if (nh->nh_oif != onh->nh_oif ||
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nh->nh_gw != onh->nh_gw ||
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nh->nh_scope != onh->nh_scope ||
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#ifdef CONFIG_IP_ROUTE_MULTIPATH
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nh->nh_weight != onh->nh_weight ||
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#endif
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#ifdef CONFIG_IP_ROUTE_CLASSID
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nh->nh_tclassid != onh->nh_tclassid ||
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#endif
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lwtunnel_cmp_encap(nh->nh_lwtstate, onh->nh_lwtstate) ||
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((nh->nh_flags ^ onh->nh_flags) & ~RTNH_COMPARE_MASK))
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return -1;
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onh++;
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} endfor_nexthops(fi);
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return 0;
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}
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static inline unsigned int fib_devindex_hashfn(unsigned int val)
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{
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unsigned int mask = DEVINDEX_HASHSIZE - 1;
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return (val ^
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(val >> DEVINDEX_HASHBITS) ^
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(val >> (DEVINDEX_HASHBITS * 2))) & mask;
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}
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static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
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{
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unsigned int mask = (fib_info_hash_size - 1);
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unsigned int val = fi->fib_nhs;
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val ^= (fi->fib_protocol << 8) | fi->fib_scope;
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val ^= (__force u32)fi->fib_prefsrc;
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val ^= fi->fib_priority;
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for_nexthops(fi) {
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val ^= fib_devindex_hashfn(nh->nh_oif);
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} endfor_nexthops(fi)
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return (val ^ (val >> 7) ^ (val >> 12)) & mask;
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}
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static struct fib_info *fib_find_info(const struct fib_info *nfi)
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{
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struct hlist_head *head;
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struct fib_info *fi;
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unsigned int hash;
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hash = fib_info_hashfn(nfi);
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head = &fib_info_hash[hash];
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hlist_for_each_entry(fi, head, fib_hash) {
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if (!net_eq(fi->fib_net, nfi->fib_net))
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continue;
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if (fi->fib_nhs != nfi->fib_nhs)
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continue;
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if (nfi->fib_protocol == fi->fib_protocol &&
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nfi->fib_scope == fi->fib_scope &&
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nfi->fib_prefsrc == fi->fib_prefsrc &&
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nfi->fib_priority == fi->fib_priority &&
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nfi->fib_type == fi->fib_type &&
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memcmp(nfi->fib_metrics, fi->fib_metrics,
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sizeof(u32) * RTAX_MAX) == 0 &&
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!((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
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(nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
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return fi;
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}
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return NULL;
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}
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/* Check, that the gateway is already configured.
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* Used only by redirect accept routine.
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*/
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int ip_fib_check_default(__be32 gw, struct net_device *dev)
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{
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struct hlist_head *head;
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struct fib_nh *nh;
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unsigned int hash;
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spin_lock(&fib_info_lock);
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hash = fib_devindex_hashfn(dev->ifindex);
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head = &fib_info_devhash[hash];
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hlist_for_each_entry(nh, head, nh_hash) {
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if (nh->nh_dev == dev &&
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nh->nh_gw == gw &&
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!(nh->nh_flags & RTNH_F_DEAD)) {
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spin_unlock(&fib_info_lock);
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return 0;
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}
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}
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spin_unlock(&fib_info_lock);
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return -1;
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}
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static inline size_t fib_nlmsg_size(struct fib_info *fi)
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{
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size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
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+ nla_total_size(4) /* RTA_TABLE */
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+ nla_total_size(4) /* RTA_DST */
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+ nla_total_size(4) /* RTA_PRIORITY */
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+ nla_total_size(4) /* RTA_PREFSRC */
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+ nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
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/* space for nested metrics */
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payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
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if (fi->fib_nhs) {
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size_t nh_encapsize = 0;
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/* Also handles the special case fib_nhs == 1 */
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/* each nexthop is packed in an attribute */
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size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
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/* may contain flow and gateway attribute */
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nhsize += 2 * nla_total_size(4);
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/* grab encap info */
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for_nexthops(fi) {
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if (nh->nh_lwtstate) {
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/* RTA_ENCAP_TYPE */
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nh_encapsize += lwtunnel_get_encap_size(
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nh->nh_lwtstate);
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/* RTA_ENCAP */
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nh_encapsize += nla_total_size(2);
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}
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} endfor_nexthops(fi);
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/* all nexthops are packed in a nested attribute */
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payload += nla_total_size((fi->fib_nhs * nhsize) +
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nh_encapsize);
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}
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return payload;
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}
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void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
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int dst_len, u32 tb_id, const struct nl_info *info,
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unsigned int nlm_flags)
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{
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struct sk_buff *skb;
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u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
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int err = -ENOBUFS;
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skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
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if (!skb)
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goto errout;
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err = fib_dump_info(skb, info->portid, seq, event, tb_id,
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fa->fa_type, key, dst_len,
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fa->fa_tos, fa->fa_info, nlm_flags);
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if (err < 0) {
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/* -EMSGSIZE implies BUG in fib_nlmsg_size() */
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WARN_ON(err == -EMSGSIZE);
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kfree_skb(skb);
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goto errout;
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}
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rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE,
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info->nlh, GFP_KERNEL);
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return;
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errout:
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if (err < 0)
|
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rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
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}
|
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|
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static int fib_detect_death(struct fib_info *fi, int order,
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struct fib_info **last_resort, int *last_idx,
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int dflt)
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{
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struct neighbour *n;
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int state = NUD_NONE;
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|
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n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev);
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if (n) {
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state = n->nud_state;
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neigh_release(n);
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} else {
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return 0;
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|
}
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if (state == NUD_REACHABLE)
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return 0;
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if ((state & NUD_VALID) && order != dflt)
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|
return 0;
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|
if ((state & NUD_VALID) ||
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(*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) {
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*last_resort = fi;
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*last_idx = order;
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}
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return 1;
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|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
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|
|
static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining,
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struct netlink_ext_ack *extack)
|
|
{
|
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int nhs = 0;
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while (rtnh_ok(rtnh, remaining)) {
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nhs++;
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rtnh = rtnh_next(rtnh, &remaining);
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}
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|
|
/* leftover implies invalid nexthop configuration, discard it */
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if (remaining > 0) {
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NL_SET_ERR_MSG(extack,
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"Invalid nexthop configuration - extra data after nexthops");
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nhs = 0;
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}
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|
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return nhs;
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}
|
|
|
|
static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
|
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int remaining, struct fib_config *cfg,
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struct netlink_ext_ack *extack)
|
|
{
|
|
int ret;
|
|
|
|
change_nexthops(fi) {
|
|
int attrlen;
|
|
|
|
if (!rtnh_ok(rtnh, remaining)) {
|
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NL_SET_ERR_MSG(extack,
|
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"Invalid nexthop configuration - extra data after nexthop");
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return -EINVAL;
|
|
}
|
|
|
|
if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Invalid flags for nexthop - can not contain DEAD or LINKDOWN");
|
|
return -EINVAL;
|
|
}
|
|
|
|
nexthop_nh->nh_flags =
|
|
(cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
|
|
nexthop_nh->nh_oif = rtnh->rtnh_ifindex;
|
|
nexthop_nh->nh_weight = rtnh->rtnh_hops + 1;
|
|
|
|
attrlen = rtnh_attrlen(rtnh);
|
|
if (attrlen > 0) {
|
|
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
|
|
|
|
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
|
|
nexthop_nh->nh_gw = nla ? nla_get_in_addr(nla) : 0;
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
nla = nla_find(attrs, attrlen, RTA_FLOW);
|
|
nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0;
|
|
if (nexthop_nh->nh_tclassid)
|
|
fi->fib_net->ipv4.fib_num_tclassid_users++;
|
|
#endif
|
|
nla = nla_find(attrs, attrlen, RTA_ENCAP);
|
|
if (nla) {
|
|
struct lwtunnel_state *lwtstate;
|
|
struct nlattr *nla_entype;
|
|
|
|
nla_entype = nla_find(attrs, attrlen,
|
|
RTA_ENCAP_TYPE);
|
|
if (!nla_entype) {
|
|
NL_SET_BAD_ATTR(extack, nla);
|
|
NL_SET_ERR_MSG(extack,
|
|
"Encap type is missing");
|
|
goto err_inval;
|
|
}
|
|
|
|
ret = lwtunnel_build_state(nla_get_u16(
|
|
nla_entype),
|
|
nla, AF_INET, cfg,
|
|
&lwtstate, extack);
|
|
if (ret)
|
|
goto errout;
|
|
nexthop_nh->nh_lwtstate =
|
|
lwtstate_get(lwtstate);
|
|
}
|
|
}
|
|
|
|
rtnh = rtnh_next(rtnh, &remaining);
|
|
} endfor_nexthops(fi);
|
|
|
|
return 0;
|
|
|
|
err_inval:
|
|
ret = -EINVAL;
|
|
|
|
errout:
|
|
return ret;
|
|
}
|
|
|
|
static void fib_rebalance(struct fib_info *fi)
|
|
{
|
|
int total;
|
|
int w;
|
|
struct in_device *in_dev;
|
|
|
|
if (fi->fib_nhs < 2)
|
|
return;
|
|
|
|
total = 0;
|
|
for_nexthops(fi) {
|
|
if (nh->nh_flags & RTNH_F_DEAD)
|
|
continue;
|
|
|
|
in_dev = __in_dev_get_rtnl(nh->nh_dev);
|
|
|
|
if (in_dev &&
|
|
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
|
|
nh->nh_flags & RTNH_F_LINKDOWN)
|
|
continue;
|
|
|
|
total += nh->nh_weight;
|
|
} endfor_nexthops(fi);
|
|
|
|
w = 0;
|
|
change_nexthops(fi) {
|
|
int upper_bound;
|
|
|
|
in_dev = __in_dev_get_rtnl(nexthop_nh->nh_dev);
|
|
|
|
if (nexthop_nh->nh_flags & RTNH_F_DEAD) {
|
|
upper_bound = -1;
|
|
} else if (in_dev &&
|
|
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
|
|
nexthop_nh->nh_flags & RTNH_F_LINKDOWN) {
|
|
upper_bound = -1;
|
|
} else {
|
|
w += nexthop_nh->nh_weight;
|
|
upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31,
|
|
total) - 1;
|
|
}
|
|
|
|
atomic_set(&nexthop_nh->nh_upper_bound, upper_bound);
|
|
} endfor_nexthops(fi);
|
|
}
|
|
#else /* CONFIG_IP_ROUTE_MULTIPATH */
|
|
|
|
#define fib_rebalance(fi) do { } while (0)
|
|
|
|
#endif /* CONFIG_IP_ROUTE_MULTIPATH */
|
|
|
|
static int fib_encap_match(u16 encap_type,
|
|
struct nlattr *encap,
|
|
const struct fib_nh *nh,
|
|
const struct fib_config *cfg,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
struct lwtunnel_state *lwtstate;
|
|
int ret, result = 0;
|
|
|
|
if (encap_type == LWTUNNEL_ENCAP_NONE)
|
|
return 0;
|
|
|
|
ret = lwtunnel_build_state(encap_type, encap, AF_INET,
|
|
cfg, &lwtstate, extack);
|
|
if (!ret) {
|
|
result = lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
|
|
lwtstate_free(lwtstate);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
int fib_nh_match(struct fib_config *cfg, struct fib_info *fi,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
struct rtnexthop *rtnh;
|
|
int remaining;
|
|
#endif
|
|
|
|
if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
|
|
return 1;
|
|
|
|
if (cfg->fc_oif || cfg->fc_gw) {
|
|
if (cfg->fc_encap) {
|
|
if (fib_encap_match(cfg->fc_encap_type, cfg->fc_encap,
|
|
fi->fib_nh, cfg, extack))
|
|
return 1;
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
if (cfg->fc_flow &&
|
|
cfg->fc_flow != fi->fib_nh->nh_tclassid)
|
|
return 1;
|
|
#endif
|
|
if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
|
|
(!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (!cfg->fc_mp)
|
|
return 0;
|
|
|
|
rtnh = cfg->fc_mp;
|
|
remaining = cfg->fc_mp_len;
|
|
|
|
for_nexthops(fi) {
|
|
int attrlen;
|
|
|
|
if (!rtnh_ok(rtnh, remaining))
|
|
return -EINVAL;
|
|
|
|
if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif)
|
|
return 1;
|
|
|
|
attrlen = rtnh_attrlen(rtnh);
|
|
if (attrlen > 0) {
|
|
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
|
|
|
|
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
|
|
if (nla && nla_get_in_addr(nla) != nh->nh_gw)
|
|
return 1;
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
nla = nla_find(attrs, attrlen, RTA_FLOW);
|
|
if (nla && nla_get_u32(nla) != nh->nh_tclassid)
|
|
return 1;
|
|
#endif
|
|
}
|
|
|
|
rtnh = rtnh_next(rtnh, &remaining);
|
|
} endfor_nexthops(fi);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi)
|
|
{
|
|
struct nlattr *nla;
|
|
int remaining;
|
|
|
|
if (!cfg->fc_mx)
|
|
return true;
|
|
|
|
nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
|
|
int type = nla_type(nla);
|
|
u32 fi_val, val;
|
|
|
|
if (!type)
|
|
continue;
|
|
if (type > RTAX_MAX)
|
|
return false;
|
|
|
|
if (type == RTAX_CC_ALGO) {
|
|
char tmp[TCP_CA_NAME_MAX];
|
|
bool ecn_ca = false;
|
|
|
|
nla_strlcpy(tmp, nla, sizeof(tmp));
|
|
val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca);
|
|
} else {
|
|
val = nla_get_u32(nla);
|
|
}
|
|
|
|
fi_val = fi->fib_metrics->metrics[type - 1];
|
|
if (type == RTAX_FEATURES)
|
|
fi_val &= ~DST_FEATURE_ECN_CA;
|
|
|
|
if (fi_val != val)
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/*
|
|
* Picture
|
|
* -------
|
|
*
|
|
* Semantics of nexthop is very messy by historical reasons.
|
|
* We have to take into account, that:
|
|
* a) gateway can be actually local interface address,
|
|
* so that gatewayed route is direct.
|
|
* b) gateway must be on-link address, possibly
|
|
* described not by an ifaddr, but also by a direct route.
|
|
* c) If both gateway and interface are specified, they should not
|
|
* contradict.
|
|
* d) If we use tunnel routes, gateway could be not on-link.
|
|
*
|
|
* Attempt to reconcile all of these (alas, self-contradictory) conditions
|
|
* results in pretty ugly and hairy code with obscure logic.
|
|
*
|
|
* I chose to generalized it instead, so that the size
|
|
* of code does not increase practically, but it becomes
|
|
* much more general.
|
|
* Every prefix is assigned a "scope" value: "host" is local address,
|
|
* "link" is direct route,
|
|
* [ ... "site" ... "interior" ... ]
|
|
* and "universe" is true gateway route with global meaning.
|
|
*
|
|
* Every prefix refers to a set of "nexthop"s (gw, oif),
|
|
* where gw must have narrower scope. This recursion stops
|
|
* when gw has LOCAL scope or if "nexthop" is declared ONLINK,
|
|
* which means that gw is forced to be on link.
|
|
*
|
|
* Code is still hairy, but now it is apparently logically
|
|
* consistent and very flexible. F.e. as by-product it allows
|
|
* to co-exists in peace independent exterior and interior
|
|
* routing processes.
|
|
*
|
|
* Normally it looks as following.
|
|
*
|
|
* {universe prefix} -> (gw, oif) [scope link]
|
|
* |
|
|
* |-> {link prefix} -> (gw, oif) [scope local]
|
|
* |
|
|
* |-> {local prefix} (terminal node)
|
|
*/
|
|
static int fib_check_nh(struct fib_config *cfg, struct fib_nh *nh,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
int err = 0;
|
|
struct net *net;
|
|
struct net_device *dev;
|
|
|
|
net = cfg->fc_nlinfo.nl_net;
|
|
if (nh->nh_gw) {
|
|
struct fib_result res;
|
|
|
|
if (nh->nh_flags & RTNH_F_ONLINK) {
|
|
unsigned int addr_type;
|
|
|
|
if (cfg->fc_scope >= RT_SCOPE_LINK) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop has invalid scope");
|
|
return -EINVAL;
|
|
}
|
|
dev = __dev_get_by_index(net, nh->nh_oif);
|
|
if (!dev)
|
|
return -ENODEV;
|
|
if (!(dev->flags & IFF_UP)) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop device is not up");
|
|
return -ENETDOWN;
|
|
}
|
|
addr_type = inet_addr_type_dev_table(net, dev, nh->nh_gw);
|
|
if (addr_type != RTN_UNICAST) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop has invalid gateway");
|
|
return -EINVAL;
|
|
}
|
|
if (!netif_carrier_ok(dev))
|
|
nh->nh_flags |= RTNH_F_LINKDOWN;
|
|
nh->nh_dev = dev;
|
|
dev_hold(dev);
|
|
nh->nh_scope = RT_SCOPE_LINK;
|
|
return 0;
|
|
}
|
|
rcu_read_lock();
|
|
{
|
|
struct fib_table *tbl = NULL;
|
|
struct flowi4 fl4 = {
|
|
.daddr = nh->nh_gw,
|
|
.flowi4_scope = cfg->fc_scope + 1,
|
|
.flowi4_oif = nh->nh_oif,
|
|
.flowi4_iif = LOOPBACK_IFINDEX,
|
|
};
|
|
|
|
/* It is not necessary, but requires a bit of thinking */
|
|
if (fl4.flowi4_scope < RT_SCOPE_LINK)
|
|
fl4.flowi4_scope = RT_SCOPE_LINK;
|
|
|
|
if (cfg->fc_table)
|
|
tbl = fib_get_table(net, cfg->fc_table);
|
|
|
|
if (tbl)
|
|
err = fib_table_lookup(tbl, &fl4, &res,
|
|
FIB_LOOKUP_IGNORE_LINKSTATE |
|
|
FIB_LOOKUP_NOREF);
|
|
|
|
/* on error or if no table given do full lookup. This
|
|
* is needed for example when nexthops are in the local
|
|
* table rather than the given table
|
|
*/
|
|
if (!tbl || err) {
|
|
err = fib_lookup(net, &fl4, &res,
|
|
FIB_LOOKUP_IGNORE_LINKSTATE);
|
|
}
|
|
|
|
if (err) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop has invalid gateway");
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
}
|
|
err = -EINVAL;
|
|
if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) {
|
|
NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
|
|
goto out;
|
|
}
|
|
nh->nh_scope = res.scope;
|
|
nh->nh_oif = FIB_RES_OIF(res);
|
|
nh->nh_dev = dev = FIB_RES_DEV(res);
|
|
if (!dev) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"No egress device for nexthop gateway");
|
|
goto out;
|
|
}
|
|
dev_hold(dev);
|
|
if (!netif_carrier_ok(dev))
|
|
nh->nh_flags |= RTNH_F_LINKDOWN;
|
|
err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
|
|
} else {
|
|
struct in_device *in_dev;
|
|
|
|
if (nh->nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Invalid flags for nexthop - PERVASIVE and ONLINK can not be set");
|
|
return -EINVAL;
|
|
}
|
|
rcu_read_lock();
|
|
err = -ENODEV;
|
|
in_dev = inetdev_by_index(net, nh->nh_oif);
|
|
if (!in_dev)
|
|
goto out;
|
|
err = -ENETDOWN;
|
|
if (!(in_dev->dev->flags & IFF_UP)) {
|
|
NL_SET_ERR_MSG(extack, "Device for nexthop is not up");
|
|
goto out;
|
|
}
|
|
nh->nh_dev = in_dev->dev;
|
|
dev_hold(nh->nh_dev);
|
|
nh->nh_scope = RT_SCOPE_HOST;
|
|
if (!netif_carrier_ok(nh->nh_dev))
|
|
nh->nh_flags |= RTNH_F_LINKDOWN;
|
|
err = 0;
|
|
}
|
|
out:
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
|
|
static inline unsigned int fib_laddr_hashfn(__be32 val)
|
|
{
|
|
unsigned int mask = (fib_info_hash_size - 1);
|
|
|
|
return ((__force u32)val ^
|
|
((__force u32)val >> 7) ^
|
|
((__force u32)val >> 14)) & mask;
|
|
}
|
|
|
|
static struct hlist_head *fib_info_hash_alloc(int bytes)
|
|
{
|
|
if (bytes <= PAGE_SIZE)
|
|
return kzalloc(bytes, GFP_KERNEL);
|
|
else
|
|
return (struct hlist_head *)
|
|
__get_free_pages(GFP_KERNEL | __GFP_ZERO,
|
|
get_order(bytes));
|
|
}
|
|
|
|
static void fib_info_hash_free(struct hlist_head *hash, int bytes)
|
|
{
|
|
if (!hash)
|
|
return;
|
|
|
|
if (bytes <= PAGE_SIZE)
|
|
kfree(hash);
|
|
else
|
|
free_pages((unsigned long) hash, get_order(bytes));
|
|
}
|
|
|
|
static void fib_info_hash_move(struct hlist_head *new_info_hash,
|
|
struct hlist_head *new_laddrhash,
|
|
unsigned int new_size)
|
|
{
|
|
struct hlist_head *old_info_hash, *old_laddrhash;
|
|
unsigned int old_size = fib_info_hash_size;
|
|
unsigned int i, bytes;
|
|
|
|
spin_lock_bh(&fib_info_lock);
|
|
old_info_hash = fib_info_hash;
|
|
old_laddrhash = fib_info_laddrhash;
|
|
fib_info_hash_size = new_size;
|
|
|
|
for (i = 0; i < old_size; i++) {
|
|
struct hlist_head *head = &fib_info_hash[i];
|
|
struct hlist_node *n;
|
|
struct fib_info *fi;
|
|
|
|
hlist_for_each_entry_safe(fi, n, head, fib_hash) {
|
|
struct hlist_head *dest;
|
|
unsigned int new_hash;
|
|
|
|
new_hash = fib_info_hashfn(fi);
|
|
dest = &new_info_hash[new_hash];
|
|
hlist_add_head(&fi->fib_hash, dest);
|
|
}
|
|
}
|
|
fib_info_hash = new_info_hash;
|
|
|
|
for (i = 0; i < old_size; i++) {
|
|
struct hlist_head *lhead = &fib_info_laddrhash[i];
|
|
struct hlist_node *n;
|
|
struct fib_info *fi;
|
|
|
|
hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) {
|
|
struct hlist_head *ldest;
|
|
unsigned int new_hash;
|
|
|
|
new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
|
|
ldest = &new_laddrhash[new_hash];
|
|
hlist_add_head(&fi->fib_lhash, ldest);
|
|
}
|
|
}
|
|
fib_info_laddrhash = new_laddrhash;
|
|
|
|
spin_unlock_bh(&fib_info_lock);
|
|
|
|
bytes = old_size * sizeof(struct hlist_head *);
|
|
fib_info_hash_free(old_info_hash, bytes);
|
|
fib_info_hash_free(old_laddrhash, bytes);
|
|
}
|
|
|
|
__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
|
|
{
|
|
nh->nh_saddr = inet_select_addr(nh->nh_dev,
|
|
nh->nh_gw,
|
|
nh->nh_parent->fib_scope);
|
|
nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid);
|
|
|
|
return nh->nh_saddr;
|
|
}
|
|
|
|
static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
|
|
{
|
|
if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
|
|
fib_prefsrc != cfg->fc_dst) {
|
|
u32 tb_id = cfg->fc_table;
|
|
int rc;
|
|
|
|
if (tb_id == RT_TABLE_MAIN)
|
|
tb_id = RT_TABLE_LOCAL;
|
|
|
|
rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
|
|
fib_prefsrc, tb_id);
|
|
|
|
if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) {
|
|
rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
|
|
fib_prefsrc, RT_TABLE_LOCAL);
|
|
}
|
|
|
|
if (rc != RTN_LOCAL)
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static int
|
|
fib_convert_metrics(struct fib_info *fi, const struct fib_config *cfg)
|
|
{
|
|
bool ecn_ca = false;
|
|
struct nlattr *nla;
|
|
int remaining;
|
|
|
|
if (!cfg->fc_mx)
|
|
return 0;
|
|
|
|
nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
|
|
int type = nla_type(nla);
|
|
u32 val;
|
|
|
|
if (!type)
|
|
continue;
|
|
if (type > RTAX_MAX)
|
|
return -EINVAL;
|
|
|
|
if (type == RTAX_CC_ALGO) {
|
|
char tmp[TCP_CA_NAME_MAX];
|
|
|
|
nla_strlcpy(tmp, nla, sizeof(tmp));
|
|
val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca);
|
|
if (val == TCP_CA_UNSPEC)
|
|
return -EINVAL;
|
|
} else {
|
|
val = nla_get_u32(nla);
|
|
}
|
|
if (type == RTAX_ADVMSS && val > 65535 - 40)
|
|
val = 65535 - 40;
|
|
if (type == RTAX_MTU && val > 65535 - 15)
|
|
val = 65535 - 15;
|
|
if (type == RTAX_HOPLIMIT && val > 255)
|
|
val = 255;
|
|
if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK))
|
|
return -EINVAL;
|
|
fi->fib_metrics->metrics[type - 1] = val;
|
|
}
|
|
|
|
if (ecn_ca)
|
|
fi->fib_metrics->metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct fib_info *fib_create_info(struct fib_config *cfg,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
int err;
|
|
struct fib_info *fi = NULL;
|
|
struct fib_info *ofi;
|
|
int nhs = 1;
|
|
struct net *net = cfg->fc_nlinfo.nl_net;
|
|
|
|
if (cfg->fc_type > RTN_MAX)
|
|
goto err_inval;
|
|
|
|
/* Fast check to catch the most weird cases */
|
|
if (fib_props[cfg->fc_type].scope > cfg->fc_scope) {
|
|
NL_SET_ERR_MSG(extack, "Invalid scope");
|
|
goto err_inval;
|
|
}
|
|
|
|
if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Invalid rtm_flags - can not contain DEAD or LINKDOWN");
|
|
goto err_inval;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (cfg->fc_mp) {
|
|
nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack);
|
|
if (nhs == 0)
|
|
goto err_inval;
|
|
}
|
|
#endif
|
|
|
|
err = -ENOBUFS;
|
|
if (fib_info_cnt >= fib_info_hash_size) {
|
|
unsigned int new_size = fib_info_hash_size << 1;
|
|
struct hlist_head *new_info_hash;
|
|
struct hlist_head *new_laddrhash;
|
|
unsigned int bytes;
|
|
|
|
if (!new_size)
|
|
new_size = 16;
|
|
bytes = new_size * sizeof(struct hlist_head *);
|
|
new_info_hash = fib_info_hash_alloc(bytes);
|
|
new_laddrhash = fib_info_hash_alloc(bytes);
|
|
if (!new_info_hash || !new_laddrhash) {
|
|
fib_info_hash_free(new_info_hash, bytes);
|
|
fib_info_hash_free(new_laddrhash, bytes);
|
|
} else
|
|
fib_info_hash_move(new_info_hash, new_laddrhash, new_size);
|
|
|
|
if (!fib_info_hash_size)
|
|
goto failure;
|
|
}
|
|
|
|
fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
|
|
if (!fi)
|
|
goto failure;
|
|
if (cfg->fc_mx) {
|
|
fi->fib_metrics = kzalloc(sizeof(*fi->fib_metrics), GFP_KERNEL);
|
|
if (unlikely(!fi->fib_metrics)) {
|
|
kfree(fi);
|
|
return ERR_PTR(err);
|
|
}
|
|
refcount_set(&fi->fib_metrics->refcnt, 1);
|
|
} else {
|
|
fi->fib_metrics = (struct dst_metrics *)&dst_default_metrics;
|
|
}
|
|
fib_info_cnt++;
|
|
fi->fib_net = net;
|
|
fi->fib_protocol = cfg->fc_protocol;
|
|
fi->fib_scope = cfg->fc_scope;
|
|
fi->fib_flags = cfg->fc_flags;
|
|
fi->fib_priority = cfg->fc_priority;
|
|
fi->fib_prefsrc = cfg->fc_prefsrc;
|
|
fi->fib_type = cfg->fc_type;
|
|
fi->fib_tb_id = cfg->fc_table;
|
|
|
|
fi->fib_nhs = nhs;
|
|
change_nexthops(fi) {
|
|
nexthop_nh->nh_parent = fi;
|
|
nexthop_nh->nh_pcpu_rth_output = alloc_percpu(struct rtable __rcu *);
|
|
if (!nexthop_nh->nh_pcpu_rth_output)
|
|
goto failure;
|
|
} endfor_nexthops(fi)
|
|
|
|
err = fib_convert_metrics(fi, cfg);
|
|
if (err)
|
|
goto failure;
|
|
|
|
if (cfg->fc_mp) {
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, extack);
|
|
if (err != 0)
|
|
goto failure;
|
|
if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop device index does not match RTA_OIF");
|
|
goto err_inval;
|
|
}
|
|
if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop gateway does not match RTA_GATEWAY");
|
|
goto err_inval;
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Nexthop class id does not match RTA_FLOW");
|
|
goto err_inval;
|
|
}
|
|
#endif
|
|
#else
|
|
NL_SET_ERR_MSG(extack,
|
|
"Multipath support not enabled in kernel");
|
|
goto err_inval;
|
|
#endif
|
|
} else {
|
|
struct fib_nh *nh = fi->fib_nh;
|
|
|
|
if (cfg->fc_encap) {
|
|
struct lwtunnel_state *lwtstate;
|
|
|
|
if (cfg->fc_encap_type == LWTUNNEL_ENCAP_NONE) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"LWT encap type not specified");
|
|
goto err_inval;
|
|
}
|
|
err = lwtunnel_build_state(cfg->fc_encap_type,
|
|
cfg->fc_encap, AF_INET, cfg,
|
|
&lwtstate, extack);
|
|
if (err)
|
|
goto failure;
|
|
|
|
nh->nh_lwtstate = lwtstate_get(lwtstate);
|
|
}
|
|
nh->nh_oif = cfg->fc_oif;
|
|
nh->nh_gw = cfg->fc_gw;
|
|
nh->nh_flags = cfg->fc_flags;
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
nh->nh_tclassid = cfg->fc_flow;
|
|
if (nh->nh_tclassid)
|
|
fi->fib_net->ipv4.fib_num_tclassid_users++;
|
|
#endif
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
nh->nh_weight = 1;
|
|
#endif
|
|
}
|
|
|
|
if (fib_props[cfg->fc_type].error) {
|
|
if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Gateway, device and multipath can not be specified for this route type");
|
|
goto err_inval;
|
|
}
|
|
goto link_it;
|
|
} else {
|
|
switch (cfg->fc_type) {
|
|
case RTN_UNICAST:
|
|
case RTN_LOCAL:
|
|
case RTN_BROADCAST:
|
|
case RTN_ANYCAST:
|
|
case RTN_MULTICAST:
|
|
break;
|
|
default:
|
|
NL_SET_ERR_MSG(extack, "Invalid route type");
|
|
goto err_inval;
|
|
}
|
|
}
|
|
|
|
if (cfg->fc_scope > RT_SCOPE_HOST) {
|
|
NL_SET_ERR_MSG(extack, "Invalid scope");
|
|
goto err_inval;
|
|
}
|
|
|
|
if (cfg->fc_scope == RT_SCOPE_HOST) {
|
|
struct fib_nh *nh = fi->fib_nh;
|
|
|
|
/* Local address is added. */
|
|
if (nhs != 1) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Route with host scope can not have multiple nexthops");
|
|
goto err_inval;
|
|
}
|
|
if (nh->nh_gw) {
|
|
NL_SET_ERR_MSG(extack,
|
|
"Route with host scope can not have a gateway");
|
|
goto err_inval;
|
|
}
|
|
nh->nh_scope = RT_SCOPE_NOWHERE;
|
|
nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif);
|
|
err = -ENODEV;
|
|
if (!nh->nh_dev)
|
|
goto failure;
|
|
} else {
|
|
int linkdown = 0;
|
|
|
|
change_nexthops(fi) {
|
|
err = fib_check_nh(cfg, nexthop_nh, extack);
|
|
if (err != 0)
|
|
goto failure;
|
|
if (nexthop_nh->nh_flags & RTNH_F_LINKDOWN)
|
|
linkdown++;
|
|
} endfor_nexthops(fi)
|
|
if (linkdown == fi->fib_nhs)
|
|
fi->fib_flags |= RTNH_F_LINKDOWN;
|
|
}
|
|
|
|
if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) {
|
|
NL_SET_ERR_MSG(extack, "Invalid prefsrc address");
|
|
goto err_inval;
|
|
}
|
|
|
|
change_nexthops(fi) {
|
|
fib_info_update_nh_saddr(net, nexthop_nh);
|
|
} endfor_nexthops(fi)
|
|
|
|
fib_rebalance(fi);
|
|
|
|
link_it:
|
|
ofi = fib_find_info(fi);
|
|
if (ofi) {
|
|
fi->fib_dead = 1;
|
|
free_fib_info(fi);
|
|
ofi->fib_treeref++;
|
|
return ofi;
|
|
}
|
|
|
|
fi->fib_treeref++;
|
|
refcount_set(&fi->fib_clntref, 1);
|
|
spin_lock_bh(&fib_info_lock);
|
|
hlist_add_head(&fi->fib_hash,
|
|
&fib_info_hash[fib_info_hashfn(fi)]);
|
|
if (fi->fib_prefsrc) {
|
|
struct hlist_head *head;
|
|
|
|
head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
|
|
hlist_add_head(&fi->fib_lhash, head);
|
|
}
|
|
change_nexthops(fi) {
|
|
struct hlist_head *head;
|
|
unsigned int hash;
|
|
|
|
if (!nexthop_nh->nh_dev)
|
|
continue;
|
|
hash = fib_devindex_hashfn(nexthop_nh->nh_dev->ifindex);
|
|
head = &fib_info_devhash[hash];
|
|
hlist_add_head(&nexthop_nh->nh_hash, head);
|
|
} endfor_nexthops(fi)
|
|
spin_unlock_bh(&fib_info_lock);
|
|
return fi;
|
|
|
|
err_inval:
|
|
err = -EINVAL;
|
|
|
|
failure:
|
|
if (fi) {
|
|
fi->fib_dead = 1;
|
|
free_fib_info(fi);
|
|
}
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
|
|
u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos,
|
|
struct fib_info *fi, unsigned int flags)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
struct rtmsg *rtm;
|
|
|
|
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
|
|
if (!nlh)
|
|
return -EMSGSIZE;
|
|
|
|
rtm = nlmsg_data(nlh);
|
|
rtm->rtm_family = AF_INET;
|
|
rtm->rtm_dst_len = dst_len;
|
|
rtm->rtm_src_len = 0;
|
|
rtm->rtm_tos = tos;
|
|
if (tb_id < 256)
|
|
rtm->rtm_table = tb_id;
|
|
else
|
|
rtm->rtm_table = RT_TABLE_COMPAT;
|
|
if (nla_put_u32(skb, RTA_TABLE, tb_id))
|
|
goto nla_put_failure;
|
|
rtm->rtm_type = type;
|
|
rtm->rtm_flags = fi->fib_flags;
|
|
rtm->rtm_scope = fi->fib_scope;
|
|
rtm->rtm_protocol = fi->fib_protocol;
|
|
|
|
if (rtm->rtm_dst_len &&
|
|
nla_put_in_addr(skb, RTA_DST, dst))
|
|
goto nla_put_failure;
|
|
if (fi->fib_priority &&
|
|
nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority))
|
|
goto nla_put_failure;
|
|
if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0)
|
|
goto nla_put_failure;
|
|
|
|
if (fi->fib_prefsrc &&
|
|
nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
|
|
goto nla_put_failure;
|
|
if (fi->fib_nhs == 1) {
|
|
if (fi->fib_nh->nh_gw &&
|
|
nla_put_in_addr(skb, RTA_GATEWAY, fi->fib_nh->nh_gw))
|
|
goto nla_put_failure;
|
|
if (fi->fib_nh->nh_oif &&
|
|
nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif))
|
|
goto nla_put_failure;
|
|
if (fi->fib_nh->nh_flags & RTNH_F_LINKDOWN) {
|
|
struct in_device *in_dev;
|
|
|
|
rcu_read_lock();
|
|
in_dev = __in_dev_get_rcu(fi->fib_nh->nh_dev);
|
|
if (in_dev &&
|
|
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
|
|
rtm->rtm_flags |= RTNH_F_DEAD;
|
|
rcu_read_unlock();
|
|
}
|
|
if (fi->fib_nh->nh_flags & RTNH_F_OFFLOAD)
|
|
rtm->rtm_flags |= RTNH_F_OFFLOAD;
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
if (fi->fib_nh[0].nh_tclassid &&
|
|
nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid))
|
|
goto nla_put_failure;
|
|
#endif
|
|
if (fi->fib_nh->nh_lwtstate &&
|
|
lwtunnel_fill_encap(skb, fi->fib_nh->nh_lwtstate) < 0)
|
|
goto nla_put_failure;
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (fi->fib_nhs > 1) {
|
|
struct rtnexthop *rtnh;
|
|
struct nlattr *mp;
|
|
|
|
mp = nla_nest_start(skb, RTA_MULTIPATH);
|
|
if (!mp)
|
|
goto nla_put_failure;
|
|
|
|
for_nexthops(fi) {
|
|
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
|
|
if (!rtnh)
|
|
goto nla_put_failure;
|
|
|
|
rtnh->rtnh_flags = nh->nh_flags & 0xFF;
|
|
if (nh->nh_flags & RTNH_F_LINKDOWN) {
|
|
struct in_device *in_dev;
|
|
|
|
rcu_read_lock();
|
|
in_dev = __in_dev_get_rcu(nh->nh_dev);
|
|
if (in_dev &&
|
|
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
|
|
rtnh->rtnh_flags |= RTNH_F_DEAD;
|
|
rcu_read_unlock();
|
|
}
|
|
rtnh->rtnh_hops = nh->nh_weight - 1;
|
|
rtnh->rtnh_ifindex = nh->nh_oif;
|
|
|
|
if (nh->nh_gw &&
|
|
nla_put_in_addr(skb, RTA_GATEWAY, nh->nh_gw))
|
|
goto nla_put_failure;
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
if (nh->nh_tclassid &&
|
|
nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
|
|
goto nla_put_failure;
|
|
#endif
|
|
if (nh->nh_lwtstate &&
|
|
lwtunnel_fill_encap(skb, nh->nh_lwtstate) < 0)
|
|
goto nla_put_failure;
|
|
|
|
/* length of rtnetlink header + attributes */
|
|
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
|
|
} endfor_nexthops(fi);
|
|
|
|
nla_nest_end(skb, mp);
|
|
}
|
|
#endif
|
|
nlmsg_end(skb, nlh);
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
nlmsg_cancel(skb, nlh);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
/*
|
|
* Update FIB if:
|
|
* - local address disappeared -> we must delete all the entries
|
|
* referring to it.
|
|
* - device went down -> we must shutdown all nexthops going via it.
|
|
*/
|
|
int fib_sync_down_addr(struct net_device *dev, __be32 local)
|
|
{
|
|
int ret = 0;
|
|
unsigned int hash = fib_laddr_hashfn(local);
|
|
struct hlist_head *head = &fib_info_laddrhash[hash];
|
|
struct net *net = dev_net(dev);
|
|
int tb_id = l3mdev_fib_table(dev);
|
|
struct fib_info *fi;
|
|
|
|
if (!fib_info_laddrhash || local == 0)
|
|
return 0;
|
|
|
|
hlist_for_each_entry(fi, head, fib_lhash) {
|
|
if (!net_eq(fi->fib_net, net) ||
|
|
fi->fib_tb_id != tb_id)
|
|
continue;
|
|
if (fi->fib_prefsrc == local) {
|
|
fi->fib_flags |= RTNH_F_DEAD;
|
|
ret++;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int call_fib_nh_notifiers(struct fib_nh *fib_nh,
|
|
enum fib_event_type event_type)
|
|
{
|
|
struct in_device *in_dev = __in_dev_get_rtnl(fib_nh->nh_dev);
|
|
struct fib_nh_notifier_info info = {
|
|
.fib_nh = fib_nh,
|
|
};
|
|
|
|
switch (event_type) {
|
|
case FIB_EVENT_NH_ADD:
|
|
if (fib_nh->nh_flags & RTNH_F_DEAD)
|
|
break;
|
|
if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
|
|
fib_nh->nh_flags & RTNH_F_LINKDOWN)
|
|
break;
|
|
return call_fib4_notifiers(dev_net(fib_nh->nh_dev), event_type,
|
|
&info.info);
|
|
case FIB_EVENT_NH_DEL:
|
|
if ((in_dev && IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
|
|
fib_nh->nh_flags & RTNH_F_LINKDOWN) ||
|
|
(fib_nh->nh_flags & RTNH_F_DEAD))
|
|
return call_fib4_notifiers(dev_net(fib_nh->nh_dev),
|
|
event_type, &info.info);
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/* Event force Flags Description
|
|
* NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
|
|
* NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
|
|
* NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed
|
|
* NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed
|
|
*/
|
|
int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
|
|
{
|
|
int ret = 0;
|
|
int scope = RT_SCOPE_NOWHERE;
|
|
struct fib_info *prev_fi = NULL;
|
|
unsigned int hash = fib_devindex_hashfn(dev->ifindex);
|
|
struct hlist_head *head = &fib_info_devhash[hash];
|
|
struct fib_nh *nh;
|
|
|
|
if (force)
|
|
scope = -1;
|
|
|
|
hlist_for_each_entry(nh, head, nh_hash) {
|
|
struct fib_info *fi = nh->nh_parent;
|
|
int dead;
|
|
|
|
BUG_ON(!fi->fib_nhs);
|
|
if (nh->nh_dev != dev || fi == prev_fi)
|
|
continue;
|
|
prev_fi = fi;
|
|
dead = 0;
|
|
change_nexthops(fi) {
|
|
if (nexthop_nh->nh_flags & RTNH_F_DEAD)
|
|
dead++;
|
|
else if (nexthop_nh->nh_dev == dev &&
|
|
nexthop_nh->nh_scope != scope) {
|
|
switch (event) {
|
|
case NETDEV_DOWN:
|
|
case NETDEV_UNREGISTER:
|
|
nexthop_nh->nh_flags |= RTNH_F_DEAD;
|
|
/* fall through */
|
|
case NETDEV_CHANGE:
|
|
nexthop_nh->nh_flags |= RTNH_F_LINKDOWN;
|
|
break;
|
|
}
|
|
call_fib_nh_notifiers(nexthop_nh,
|
|
FIB_EVENT_NH_DEL);
|
|
dead++;
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (event == NETDEV_UNREGISTER &&
|
|
nexthop_nh->nh_dev == dev) {
|
|
dead = fi->fib_nhs;
|
|
break;
|
|
}
|
|
#endif
|
|
} endfor_nexthops(fi)
|
|
if (dead == fi->fib_nhs) {
|
|
switch (event) {
|
|
case NETDEV_DOWN:
|
|
case NETDEV_UNREGISTER:
|
|
fi->fib_flags |= RTNH_F_DEAD;
|
|
/* fall through */
|
|
case NETDEV_CHANGE:
|
|
fi->fib_flags |= RTNH_F_LINKDOWN;
|
|
break;
|
|
}
|
|
ret++;
|
|
}
|
|
|
|
fib_rebalance(fi);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Must be invoked inside of an RCU protected region. */
|
|
static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
|
|
{
|
|
struct fib_info *fi = NULL, *last_resort = NULL;
|
|
struct hlist_head *fa_head = res->fa_head;
|
|
struct fib_table *tb = res->table;
|
|
u8 slen = 32 - res->prefixlen;
|
|
int order = -1, last_idx = -1;
|
|
struct fib_alias *fa, *fa1 = NULL;
|
|
u32 last_prio = res->fi->fib_priority;
|
|
u8 last_tos = 0;
|
|
|
|
hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
|
|
struct fib_info *next_fi = fa->fa_info;
|
|
|
|
if (fa->fa_slen != slen)
|
|
continue;
|
|
if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
|
|
continue;
|
|
if (fa->tb_id != tb->tb_id)
|
|
continue;
|
|
if (next_fi->fib_priority > last_prio &&
|
|
fa->fa_tos == last_tos) {
|
|
if (last_tos)
|
|
continue;
|
|
break;
|
|
}
|
|
if (next_fi->fib_flags & RTNH_F_DEAD)
|
|
continue;
|
|
last_tos = fa->fa_tos;
|
|
last_prio = next_fi->fib_priority;
|
|
|
|
if (next_fi->fib_scope != res->scope ||
|
|
fa->fa_type != RTN_UNICAST)
|
|
continue;
|
|
if (!next_fi->fib_nh[0].nh_gw ||
|
|
next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
|
|
continue;
|
|
|
|
fib_alias_accessed(fa);
|
|
|
|
if (!fi) {
|
|
if (next_fi != res->fi)
|
|
break;
|
|
fa1 = fa;
|
|
} else if (!fib_detect_death(fi, order, &last_resort,
|
|
&last_idx, fa1->fa_default)) {
|
|
fib_result_assign(res, fi);
|
|
fa1->fa_default = order;
|
|
goto out;
|
|
}
|
|
fi = next_fi;
|
|
order++;
|
|
}
|
|
|
|
if (order <= 0 || !fi) {
|
|
if (fa1)
|
|
fa1->fa_default = -1;
|
|
goto out;
|
|
}
|
|
|
|
if (!fib_detect_death(fi, order, &last_resort, &last_idx,
|
|
fa1->fa_default)) {
|
|
fib_result_assign(res, fi);
|
|
fa1->fa_default = order;
|
|
goto out;
|
|
}
|
|
|
|
if (last_idx >= 0)
|
|
fib_result_assign(res, last_resort);
|
|
fa1->fa_default = last_idx;
|
|
out:
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Dead device goes up. We wake up dead nexthops.
|
|
* It takes sense only on multipath routes.
|
|
*/
|
|
int fib_sync_up(struct net_device *dev, unsigned int nh_flags)
|
|
{
|
|
struct fib_info *prev_fi;
|
|
unsigned int hash;
|
|
struct hlist_head *head;
|
|
struct fib_nh *nh;
|
|
int ret;
|
|
|
|
if (!(dev->flags & IFF_UP))
|
|
return 0;
|
|
|
|
if (nh_flags & RTNH_F_DEAD) {
|
|
unsigned int flags = dev_get_flags(dev);
|
|
|
|
if (flags & (IFF_RUNNING | IFF_LOWER_UP))
|
|
nh_flags |= RTNH_F_LINKDOWN;
|
|
}
|
|
|
|
prev_fi = NULL;
|
|
hash = fib_devindex_hashfn(dev->ifindex);
|
|
head = &fib_info_devhash[hash];
|
|
ret = 0;
|
|
|
|
hlist_for_each_entry(nh, head, nh_hash) {
|
|
struct fib_info *fi = nh->nh_parent;
|
|
int alive;
|
|
|
|
BUG_ON(!fi->fib_nhs);
|
|
if (nh->nh_dev != dev || fi == prev_fi)
|
|
continue;
|
|
|
|
prev_fi = fi;
|
|
alive = 0;
|
|
change_nexthops(fi) {
|
|
if (!(nexthop_nh->nh_flags & nh_flags)) {
|
|
alive++;
|
|
continue;
|
|
}
|
|
if (!nexthop_nh->nh_dev ||
|
|
!(nexthop_nh->nh_dev->flags & IFF_UP))
|
|
continue;
|
|
if (nexthop_nh->nh_dev != dev ||
|
|
!__in_dev_get_rtnl(dev))
|
|
continue;
|
|
alive++;
|
|
nexthop_nh->nh_flags &= ~nh_flags;
|
|
call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD);
|
|
} endfor_nexthops(fi)
|
|
|
|
if (alive > 0) {
|
|
fi->fib_flags &= ~nh_flags;
|
|
ret++;
|
|
}
|
|
|
|
fib_rebalance(fi);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
static bool fib_good_nh(const struct fib_nh *nh)
|
|
{
|
|
int state = NUD_REACHABLE;
|
|
|
|
if (nh->nh_scope == RT_SCOPE_LINK) {
|
|
struct neighbour *n;
|
|
|
|
rcu_read_lock_bh();
|
|
|
|
n = __ipv4_neigh_lookup_noref(nh->nh_dev,
|
|
(__force u32)nh->nh_gw);
|
|
if (n)
|
|
state = n->nud_state;
|
|
|
|
rcu_read_unlock_bh();
|
|
}
|
|
|
|
return !!(state & NUD_VALID);
|
|
}
|
|
|
|
void fib_select_multipath(struct fib_result *res, int hash)
|
|
{
|
|
struct fib_info *fi = res->fi;
|
|
struct net *net = fi->fib_net;
|
|
bool first = false;
|
|
|
|
for_nexthops(fi) {
|
|
if (hash > atomic_read(&nh->nh_upper_bound))
|
|
continue;
|
|
|
|
if (!net->ipv4.sysctl_fib_multipath_use_neigh ||
|
|
fib_good_nh(nh)) {
|
|
res->nh_sel = nhsel;
|
|
return;
|
|
}
|
|
if (!first) {
|
|
res->nh_sel = nhsel;
|
|
first = true;
|
|
}
|
|
} endfor_nexthops(fi);
|
|
}
|
|
#endif
|
|
|
|
void fib_select_path(struct net *net, struct fib_result *res,
|
|
struct flowi4 *fl4, const struct sk_buff *skb)
|
|
{
|
|
if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF))
|
|
goto check_saddr;
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (res->fi->fib_nhs > 1) {
|
|
int h = fib_multipath_hash(res->fi, fl4, skb);
|
|
|
|
fib_select_multipath(res, h);
|
|
}
|
|
else
|
|
#endif
|
|
if (!res->prefixlen &&
|
|
res->table->tb_num_default > 1 &&
|
|
res->type == RTN_UNICAST)
|
|
fib_select_default(fl4, res);
|
|
|
|
check_saddr:
|
|
if (!fl4->saddr)
|
|
fl4->saddr = FIB_RES_PREFSRC(net, *res);
|
|
}
|