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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![David Ahern](/assets/img/avatar_default.png)
A bug report (https://bugzilla.kernel.org/show_bug.cgi?id=107071) noted that the follwoing ip command is failing with v4.3: $ ip route add 10.248.5.0/24 dev bond0.250 table vlan_250 src 10.248.5.154 RTNETLINK answers: Invalid argument021dd3b8a1
changed the lookup of the given preferred source address to use the table id passed in, but this assumes the local entries are in the given table which is not necessarily true for non-VRF use cases. When validating the preferred source fallback to the local table on failure. Fixes:021dd3b8a1
("net: Add routes to the table associated with the device") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1600 lines
37 KiB
C
1600 lines
37 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 <asm/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 <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 "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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u32 fib_multipath_secret __read_mostly;
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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_free(&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_free(&rt->dst);
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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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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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if (fi->fib_metrics != (u32 *) dst_default_metrics)
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kfree(fi->fib_metrics);
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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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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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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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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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}
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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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{
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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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return remaining > 0 ? 0 : nhs;
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}
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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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{
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struct net *net = cfg->fc_nlinfo.nl_net;
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int ret;
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change_nexthops(fi) {
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int attrlen;
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if (!rtnh_ok(rtnh, remaining))
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return -EINVAL;
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nexthop_nh->nh_flags =
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(cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
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nexthop_nh->nh_oif = rtnh->rtnh_ifindex;
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nexthop_nh->nh_weight = rtnh->rtnh_hops + 1;
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|
|
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 net_device *dev = NULL;
|
|
struct nlattr *nla_entype;
|
|
|
|
nla_entype = nla_find(attrs, attrlen,
|
|
RTA_ENCAP_TYPE);
|
|
if (!nla_entype)
|
|
goto err_inval;
|
|
if (cfg->fc_oif)
|
|
dev = __dev_get_by_index(net, cfg->fc_oif);
|
|
ret = lwtunnel_build_state(dev, nla_get_u16(
|
|
nla_entype),
|
|
nla, AF_INET, cfg,
|
|
&lwtstate);
|
|
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);
|
|
|
|
net_get_random_once(&fib_multipath_secret,
|
|
sizeof(fib_multipath_secret));
|
|
}
|
|
|
|
static inline void fib_add_weight(struct fib_info *fi,
|
|
const struct fib_nh *nh)
|
|
{
|
|
fi->fib_weight += nh->nh_weight;
|
|
}
|
|
|
|
#else /* CONFIG_IP_ROUTE_MULTIPATH */
|
|
|
|
#define fib_rebalance(fi) do { } while (0)
|
|
#define fib_add_weight(fi, nh) do { } while (0)
|
|
|
|
#endif /* CONFIG_IP_ROUTE_MULTIPATH */
|
|
|
|
static int fib_encap_match(struct net *net, u16 encap_type,
|
|
struct nlattr *encap,
|
|
int oif, const struct fib_nh *nh,
|
|
const struct fib_config *cfg)
|
|
{
|
|
struct lwtunnel_state *lwtstate;
|
|
struct net_device *dev = NULL;
|
|
int ret, result = 0;
|
|
|
|
if (encap_type == LWTUNNEL_ENCAP_NONE)
|
|
return 0;
|
|
|
|
if (oif)
|
|
dev = __dev_get_by_index(net, oif);
|
|
ret = lwtunnel_build_state(dev, encap_type, encap,
|
|
AF_INET, cfg, &lwtstate);
|
|
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 net *net = cfg->fc_nlinfo.nl_net;
|
|
#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(net, cfg->fc_encap_type,
|
|
cfg->fc_encap, cfg->fc_oif,
|
|
fi->fib_nh, cfg))
|
|
return 1;
|
|
}
|
|
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;
|
|
}
|
|
|
|
|
|
/*
|
|
* 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_info *fi,
|
|
struct fib_nh *nh)
|
|
{
|
|
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)
|
|
return -EINVAL;
|
|
dev = __dev_get_by_index(net, nh->nh_oif);
|
|
if (!dev)
|
|
return -ENODEV;
|
|
if (!(dev->flags & IFF_UP))
|
|
return -ENETDOWN;
|
|
addr_type = inet_addr_type_dev_table(net, dev, nh->nh_gw);
|
|
if (addr_type != RTN_UNICAST)
|
|
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) {
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
}
|
|
err = -EINVAL;
|
|
if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
|
|
goto out;
|
|
nh->nh_scope = res.scope;
|
|
nh->nh_oif = FIB_RES_OIF(res);
|
|
nh->nh_dev = dev = FIB_RES_DEV(res);
|
|
if (!dev)
|
|
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))
|
|
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))
|
|
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(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_FEATURES && (val & ~RTAX_FEATURE_MASK))
|
|
return -EINVAL;
|
|
fi->fib_metrics[type - 1] = val;
|
|
}
|
|
|
|
if (ecn_ca)
|
|
fi->fib_metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct fib_info *fib_create_info(struct fib_config *cfg)
|
|
{
|
|
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)
|
|
goto err_inval;
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (cfg->fc_mp) {
|
|
nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len);
|
|
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;
|
|
fib_info_cnt++;
|
|
if (cfg->fc_mx) {
|
|
fi->fib_metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
|
|
if (!fi->fib_metrics)
|
|
goto failure;
|
|
} else
|
|
fi->fib_metrics = (u32 *) dst_default_metrics;
|
|
|
|
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_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);
|
|
if (err != 0)
|
|
goto failure;
|
|
if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif)
|
|
goto err_inval;
|
|
if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw)
|
|
goto err_inval;
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow)
|
|
goto err_inval;
|
|
#endif
|
|
#else
|
|
goto err_inval;
|
|
#endif
|
|
} else {
|
|
struct fib_nh *nh = fi->fib_nh;
|
|
|
|
if (cfg->fc_encap) {
|
|
struct lwtunnel_state *lwtstate;
|
|
struct net_device *dev = NULL;
|
|
|
|
if (cfg->fc_encap_type == LWTUNNEL_ENCAP_NONE)
|
|
goto err_inval;
|
|
if (cfg->fc_oif)
|
|
dev = __dev_get_by_index(net, cfg->fc_oif);
|
|
err = lwtunnel_build_state(dev, cfg->fc_encap_type,
|
|
cfg->fc_encap, AF_INET, cfg,
|
|
&lwtstate);
|
|
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)
|
|
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:
|
|
goto err_inval;
|
|
}
|
|
}
|
|
|
|
if (cfg->fc_scope > RT_SCOPE_HOST)
|
|
goto err_inval;
|
|
|
|
if (cfg->fc_scope == RT_SCOPE_HOST) {
|
|
struct fib_nh *nh = fi->fib_nh;
|
|
|
|
/* Local address is added. */
|
|
if (nhs != 1 || nh->nh_gw)
|
|
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, fi, nexthop_nh);
|
|
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))
|
|
goto err_inval;
|
|
|
|
change_nexthops(fi) {
|
|
fib_info_update_nh_saddr(net, nexthop_nh);
|
|
fib_add_weight(fi, 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++;
|
|
atomic_inc(&fi->fib_clntref);
|
|
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) < 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) {
|
|
struct in_device *in_dev;
|
|
|
|
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) {
|
|
in_dev = __in_dev_get_rtnl(fi->fib_nh->nh_dev);
|
|
if (in_dev &&
|
|
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
|
|
rtm->rtm_flags |= RTNH_F_DEAD;
|
|
}
|
|
#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);
|
|
}
|
|
#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) {
|
|
struct in_device *in_dev;
|
|
|
|
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) {
|
|
in_dev = __in_dev_get_rtnl(nh->nh_dev);
|
|
if (in_dev &&
|
|
IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
|
|
rtnh->rtnh_flags |= RTNH_F_DEAD;
|
|
}
|
|
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);
|
|
/* 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 *net, __be32 local)
|
|
{
|
|
int ret = 0;
|
|
unsigned int hash = fib_laddr_hashfn(local);
|
|
struct hlist_head *head = &fib_info_laddrhash[hash];
|
|
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))
|
|
continue;
|
|
if (fi->fib_prefsrc == local) {
|
|
fi->fib_flags |= RTNH_F_DEAD;
|
|
ret++;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
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. */
|
|
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;
|
|
} endfor_nexthops(fi)
|
|
|
|
if (alive > 0) {
|
|
fi->fib_flags &= ~nh_flags;
|
|
ret++;
|
|
}
|
|
|
|
fib_rebalance(fi);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
|
|
void fib_select_multipath(struct fib_result *res, int hash)
|
|
{
|
|
struct fib_info *fi = res->fi;
|
|
|
|
for_nexthops(fi) {
|
|
if (hash > atomic_read(&nh->nh_upper_bound))
|
|
continue;
|
|
|
|
res->nh_sel = nhsel;
|
|
return;
|
|
} endfor_nexthops(fi);
|
|
|
|
/* Race condition: route has just become dead. */
|
|
res->nh_sel = 0;
|
|
}
|
|
#endif
|
|
|
|
void fib_select_path(struct net *net, struct fib_result *res,
|
|
struct flowi4 *fl4, int mp_hash)
|
|
{
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (res->fi->fib_nhs > 1 && fl4->flowi4_oif == 0) {
|
|
if (mp_hash < 0)
|
|
mp_hash = get_hash_from_flowi4(fl4) >> 1;
|
|
|
|
fib_select_multipath(res, mp_hash);
|
|
}
|
|
else
|
|
#endif
|
|
if (!res->prefixlen &&
|
|
res->table->tb_num_default > 1 &&
|
|
res->type == RTN_UNICAST && !fl4->flowi4_oif)
|
|
fib_select_default(fl4, res);
|
|
|
|
if (!fl4->saddr)
|
|
fl4->saddr = FIB_RES_PREFSRC(net, *res);
|
|
}
|
|
EXPORT_SYMBOL_GPL(fib_select_path);
|