![Sébastien Barré](/assets/img/avatar_default.png)
Commit7a9bc9b81a
("ipv4: Elide fib_validate_source() completely when possible.") introduced a short-circuit to avoid calling fib_validate_source when not needed. That change took rp_filter into account, but not accept_local. This resulted in a change of behaviour: with rp_filter and accept_local off, incoming packets with a local address in the source field should be dropped. Here is how to reproduce the change pre/post7a9bc9b81a
commit: -configure the same IPv4 address on hosts A and B. -try to send an ARP request from B to A. -The ARP request will be dropped before that commit, but accepted and answered after that commit. This adds a check for ACCEPT_LOCAL, to maintain full fib validation in case it is 0. We also leave __fib_validate_source() earlier when possible, based on the same check as fib_validate_source(), once the accept_local stuff is verified. Cc: Gregory Detal <gregory.detal@uclouvain.be> Cc: Christoph Paasch <christoph.paasch@uclouvain.be> Cc: Hannes Frederic Sowa <hannes@redhat.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Sébastien Barré <sebastien.barre@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
1182 lines
27 KiB
C
1182 lines
27 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: FIB frontend.
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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/module.h>
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#include <asm/uaccess.h>
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#include <linux/bitops.h>
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#include <linux/capability.h>
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#include <linux/types.h>
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#include <linux/kernel.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_addr.h>
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#include <linux/if_arp.h>
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#include <linux/skbuff.h>
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#include <linux/cache.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/slab.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/arp.h>
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#include <net/ip_fib.h>
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#include <net/rtnetlink.h>
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#include <net/xfrm.h>
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#ifndef CONFIG_IP_MULTIPLE_TABLES
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static int __net_init fib4_rules_init(struct net *net)
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{
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struct fib_table *local_table, *main_table;
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local_table = fib_trie_table(RT_TABLE_LOCAL);
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if (local_table == NULL)
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return -ENOMEM;
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main_table = fib_trie_table(RT_TABLE_MAIN);
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if (main_table == NULL)
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goto fail;
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hlist_add_head_rcu(&local_table->tb_hlist,
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&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
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hlist_add_head_rcu(&main_table->tb_hlist,
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&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
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return 0;
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fail:
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kfree(local_table);
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return -ENOMEM;
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}
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#else
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struct fib_table *fib_new_table(struct net *net, u32 id)
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{
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struct fib_table *tb;
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unsigned int h;
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if (id == 0)
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id = RT_TABLE_MAIN;
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tb = fib_get_table(net, id);
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if (tb)
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return tb;
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tb = fib_trie_table(id);
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if (!tb)
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return NULL;
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switch (id) {
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case RT_TABLE_LOCAL:
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net->ipv4.fib_local = tb;
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break;
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case RT_TABLE_MAIN:
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net->ipv4.fib_main = tb;
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break;
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case RT_TABLE_DEFAULT:
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net->ipv4.fib_default = tb;
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break;
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default:
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break;
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}
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h = id & (FIB_TABLE_HASHSZ - 1);
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hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
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return tb;
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}
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struct fib_table *fib_get_table(struct net *net, u32 id)
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{
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struct fib_table *tb;
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struct hlist_head *head;
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unsigned int h;
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if (id == 0)
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id = RT_TABLE_MAIN;
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h = id & (FIB_TABLE_HASHSZ - 1);
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rcu_read_lock();
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head = &net->ipv4.fib_table_hash[h];
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hlist_for_each_entry_rcu(tb, head, tb_hlist) {
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if (tb->tb_id == id) {
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rcu_read_unlock();
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return tb;
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}
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}
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rcu_read_unlock();
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return NULL;
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}
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#endif /* CONFIG_IP_MULTIPLE_TABLES */
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static void fib_flush(struct net *net)
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{
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int flushed = 0;
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struct fib_table *tb;
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struct hlist_head *head;
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unsigned int h;
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for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
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head = &net->ipv4.fib_table_hash[h];
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hlist_for_each_entry(tb, head, tb_hlist)
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flushed += fib_table_flush(tb);
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}
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if (flushed)
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rt_cache_flush(net);
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}
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/*
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* Find address type as if only "dev" was present in the system. If
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* on_dev is NULL then all interfaces are taken into consideration.
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*/
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static inline unsigned int __inet_dev_addr_type(struct net *net,
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const struct net_device *dev,
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__be32 addr)
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{
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struct flowi4 fl4 = { .daddr = addr };
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struct fib_result res;
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unsigned int ret = RTN_BROADCAST;
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struct fib_table *local_table;
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if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
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return RTN_BROADCAST;
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if (ipv4_is_multicast(addr))
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return RTN_MULTICAST;
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local_table = fib_get_table(net, RT_TABLE_LOCAL);
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if (local_table) {
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ret = RTN_UNICAST;
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rcu_read_lock();
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if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
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if (!dev || dev == res.fi->fib_dev)
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ret = res.type;
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}
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rcu_read_unlock();
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}
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return ret;
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}
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unsigned int inet_addr_type(struct net *net, __be32 addr)
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{
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return __inet_dev_addr_type(net, NULL, addr);
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}
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EXPORT_SYMBOL(inet_addr_type);
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unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
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__be32 addr)
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{
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return __inet_dev_addr_type(net, dev, addr);
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}
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EXPORT_SYMBOL(inet_dev_addr_type);
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__be32 fib_compute_spec_dst(struct sk_buff *skb)
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{
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struct net_device *dev = skb->dev;
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struct in_device *in_dev;
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struct fib_result res;
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struct rtable *rt;
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struct flowi4 fl4;
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struct net *net;
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int scope;
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rt = skb_rtable(skb);
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if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
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RTCF_LOCAL)
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return ip_hdr(skb)->daddr;
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in_dev = __in_dev_get_rcu(dev);
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BUG_ON(!in_dev);
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net = dev_net(dev);
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scope = RT_SCOPE_UNIVERSE;
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if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
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fl4.flowi4_oif = 0;
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fl4.flowi4_iif = LOOPBACK_IFINDEX;
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fl4.daddr = ip_hdr(skb)->saddr;
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fl4.saddr = 0;
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fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
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fl4.flowi4_scope = scope;
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fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0;
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if (!fib_lookup(net, &fl4, &res))
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return FIB_RES_PREFSRC(net, res);
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} else {
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scope = RT_SCOPE_LINK;
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}
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return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
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}
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/* Given (packet source, input interface) and optional (dst, oif, tos):
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* - (main) check, that source is valid i.e. not broadcast or our local
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* address.
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* - figure out what "logical" interface this packet arrived
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* and calculate "specific destination" address.
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* - check, that packet arrived from expected physical interface.
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* called with rcu_read_lock()
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*/
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static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
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u8 tos, int oif, struct net_device *dev,
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int rpf, struct in_device *idev, u32 *itag)
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{
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int ret, no_addr;
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struct fib_result res;
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struct flowi4 fl4;
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struct net *net;
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bool dev_match;
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fl4.flowi4_oif = 0;
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fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
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fl4.daddr = src;
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fl4.saddr = dst;
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fl4.flowi4_tos = tos;
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fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
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no_addr = idev->ifa_list == NULL;
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fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
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net = dev_net(dev);
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if (fib_lookup(net, &fl4, &res))
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goto last_resort;
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if (res.type != RTN_UNICAST &&
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(res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
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goto e_inval;
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if (!rpf && !fib_num_tclassid_users(dev_net(dev)) &&
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(dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev)))
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goto last_resort;
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fib_combine_itag(itag, &res);
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dev_match = false;
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#ifdef CONFIG_IP_ROUTE_MULTIPATH
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for (ret = 0; ret < res.fi->fib_nhs; ret++) {
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struct fib_nh *nh = &res.fi->fib_nh[ret];
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if (nh->nh_dev == dev) {
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dev_match = true;
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break;
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}
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}
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#else
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if (FIB_RES_DEV(res) == dev)
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dev_match = true;
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#endif
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if (dev_match) {
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ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
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return ret;
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}
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if (no_addr)
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goto last_resort;
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if (rpf == 1)
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goto e_rpf;
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fl4.flowi4_oif = dev->ifindex;
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ret = 0;
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if (fib_lookup(net, &fl4, &res) == 0) {
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if (res.type == RTN_UNICAST)
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ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
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}
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return ret;
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last_resort:
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if (rpf)
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goto e_rpf;
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*itag = 0;
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return 0;
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e_inval:
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return -EINVAL;
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e_rpf:
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return -EXDEV;
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}
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/* Ignore rp_filter for packets protected by IPsec. */
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int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
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u8 tos, int oif, struct net_device *dev,
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struct in_device *idev, u32 *itag)
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{
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int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
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if (!r && !fib_num_tclassid_users(dev_net(dev)) &&
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IN_DEV_ACCEPT_LOCAL(idev) &&
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(dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
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*itag = 0;
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return 0;
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}
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return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
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}
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static inline __be32 sk_extract_addr(struct sockaddr *addr)
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{
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return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
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}
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static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
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{
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struct nlattr *nla;
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nla = (struct nlattr *) ((char *) mx + len);
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nla->nla_type = type;
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nla->nla_len = nla_attr_size(4);
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*(u32 *) nla_data(nla) = value;
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return len + nla_total_size(4);
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}
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static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
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struct fib_config *cfg)
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{
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__be32 addr;
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int plen;
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memset(cfg, 0, sizeof(*cfg));
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cfg->fc_nlinfo.nl_net = net;
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if (rt->rt_dst.sa_family != AF_INET)
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return -EAFNOSUPPORT;
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/*
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* Check mask for validity:
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* a) it must be contiguous.
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* b) destination must have all host bits clear.
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* c) if application forgot to set correct family (AF_INET),
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* reject request unless it is absolutely clear i.e.
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* both family and mask are zero.
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*/
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plen = 32;
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addr = sk_extract_addr(&rt->rt_dst);
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if (!(rt->rt_flags & RTF_HOST)) {
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__be32 mask = sk_extract_addr(&rt->rt_genmask);
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if (rt->rt_genmask.sa_family != AF_INET) {
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if (mask || rt->rt_genmask.sa_family)
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return -EAFNOSUPPORT;
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}
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if (bad_mask(mask, addr))
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return -EINVAL;
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plen = inet_mask_len(mask);
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}
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cfg->fc_dst_len = plen;
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cfg->fc_dst = addr;
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if (cmd != SIOCDELRT) {
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cfg->fc_nlflags = NLM_F_CREATE;
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cfg->fc_protocol = RTPROT_BOOT;
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}
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if (rt->rt_metric)
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cfg->fc_priority = rt->rt_metric - 1;
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if (rt->rt_flags & RTF_REJECT) {
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cfg->fc_scope = RT_SCOPE_HOST;
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cfg->fc_type = RTN_UNREACHABLE;
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return 0;
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}
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cfg->fc_scope = RT_SCOPE_NOWHERE;
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cfg->fc_type = RTN_UNICAST;
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if (rt->rt_dev) {
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char *colon;
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struct net_device *dev;
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char devname[IFNAMSIZ];
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if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
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return -EFAULT;
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devname[IFNAMSIZ-1] = 0;
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colon = strchr(devname, ':');
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if (colon)
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*colon = 0;
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dev = __dev_get_by_name(net, devname);
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if (!dev)
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return -ENODEV;
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cfg->fc_oif = dev->ifindex;
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if (colon) {
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struct in_ifaddr *ifa;
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struct in_device *in_dev = __in_dev_get_rtnl(dev);
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if (!in_dev)
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return -ENODEV;
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*colon = ':';
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for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
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if (strcmp(ifa->ifa_label, devname) == 0)
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break;
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if (ifa == NULL)
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return -ENODEV;
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cfg->fc_prefsrc = ifa->ifa_local;
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}
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}
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|
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addr = sk_extract_addr(&rt->rt_gateway);
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if (rt->rt_gateway.sa_family == AF_INET && addr) {
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cfg->fc_gw = addr;
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if (rt->rt_flags & RTF_GATEWAY &&
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inet_addr_type(net, addr) == RTN_UNICAST)
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cfg->fc_scope = RT_SCOPE_UNIVERSE;
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}
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|
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if (cmd == SIOCDELRT)
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return 0;
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|
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if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
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return -EINVAL;
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|
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if (cfg->fc_scope == RT_SCOPE_NOWHERE)
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cfg->fc_scope = RT_SCOPE_LINK;
|
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|
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if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
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struct nlattr *mx;
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int len = 0;
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|
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mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
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if (mx == NULL)
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return -ENOMEM;
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|
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if (rt->rt_flags & RTF_MTU)
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len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
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|
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if (rt->rt_flags & RTF_WINDOW)
|
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len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
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|
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if (rt->rt_flags & RTF_IRTT)
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len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
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|
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cfg->fc_mx = mx;
|
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cfg->fc_mx_len = len;
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}
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|
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return 0;
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}
|
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|
|
/*
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* Handle IP routing ioctl calls.
|
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* These are used to manipulate the routing tables
|
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*/
|
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int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
|
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{
|
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struct fib_config cfg;
|
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struct rtentry rt;
|
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int err;
|
|
|
|
switch (cmd) {
|
|
case SIOCADDRT: /* Add a route */
|
|
case SIOCDELRT: /* Delete a route */
|
|
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (copy_from_user(&rt, arg, sizeof(rt)))
|
|
return -EFAULT;
|
|
|
|
rtnl_lock();
|
|
err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
|
|
if (err == 0) {
|
|
struct fib_table *tb;
|
|
|
|
if (cmd == SIOCDELRT) {
|
|
tb = fib_get_table(net, cfg.fc_table);
|
|
if (tb)
|
|
err = fib_table_delete(tb, &cfg);
|
|
else
|
|
err = -ESRCH;
|
|
} else {
|
|
tb = fib_new_table(net, cfg.fc_table);
|
|
if (tb)
|
|
err = fib_table_insert(tb, &cfg);
|
|
else
|
|
err = -ENOBUFS;
|
|
}
|
|
|
|
/* allocated by rtentry_to_fib_config() */
|
|
kfree(cfg.fc_mx);
|
|
}
|
|
rtnl_unlock();
|
|
return err;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
|
|
[RTA_DST] = { .type = NLA_U32 },
|
|
[RTA_SRC] = { .type = NLA_U32 },
|
|
[RTA_IIF] = { .type = NLA_U32 },
|
|
[RTA_OIF] = { .type = NLA_U32 },
|
|
[RTA_GATEWAY] = { .type = NLA_U32 },
|
|
[RTA_PRIORITY] = { .type = NLA_U32 },
|
|
[RTA_PREFSRC] = { .type = NLA_U32 },
|
|
[RTA_METRICS] = { .type = NLA_NESTED },
|
|
[RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
|
|
[RTA_FLOW] = { .type = NLA_U32 },
|
|
};
|
|
|
|
static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
|
|
struct nlmsghdr *nlh, struct fib_config *cfg)
|
|
{
|
|
struct nlattr *attr;
|
|
int err, remaining;
|
|
struct rtmsg *rtm;
|
|
|
|
err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
|
|
if (err < 0)
|
|
goto errout;
|
|
|
|
memset(cfg, 0, sizeof(*cfg));
|
|
|
|
rtm = nlmsg_data(nlh);
|
|
cfg->fc_dst_len = rtm->rtm_dst_len;
|
|
cfg->fc_tos = rtm->rtm_tos;
|
|
cfg->fc_table = rtm->rtm_table;
|
|
cfg->fc_protocol = rtm->rtm_protocol;
|
|
cfg->fc_scope = rtm->rtm_scope;
|
|
cfg->fc_type = rtm->rtm_type;
|
|
cfg->fc_flags = rtm->rtm_flags;
|
|
cfg->fc_nlflags = nlh->nlmsg_flags;
|
|
|
|
cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
|
|
cfg->fc_nlinfo.nlh = nlh;
|
|
cfg->fc_nlinfo.nl_net = net;
|
|
|
|
if (cfg->fc_type > RTN_MAX) {
|
|
err = -EINVAL;
|
|
goto errout;
|
|
}
|
|
|
|
nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
|
|
switch (nla_type(attr)) {
|
|
case RTA_DST:
|
|
cfg->fc_dst = nla_get_be32(attr);
|
|
break;
|
|
case RTA_OIF:
|
|
cfg->fc_oif = nla_get_u32(attr);
|
|
break;
|
|
case RTA_GATEWAY:
|
|
cfg->fc_gw = nla_get_be32(attr);
|
|
break;
|
|
case RTA_PRIORITY:
|
|
cfg->fc_priority = nla_get_u32(attr);
|
|
break;
|
|
case RTA_PREFSRC:
|
|
cfg->fc_prefsrc = nla_get_be32(attr);
|
|
break;
|
|
case RTA_METRICS:
|
|
cfg->fc_mx = nla_data(attr);
|
|
cfg->fc_mx_len = nla_len(attr);
|
|
break;
|
|
case RTA_MULTIPATH:
|
|
cfg->fc_mp = nla_data(attr);
|
|
cfg->fc_mp_len = nla_len(attr);
|
|
break;
|
|
case RTA_FLOW:
|
|
cfg->fc_flow = nla_get_u32(attr);
|
|
break;
|
|
case RTA_TABLE:
|
|
cfg->fc_table = nla_get_u32(attr);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
errout:
|
|
return err;
|
|
}
|
|
|
|
static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
struct fib_config cfg;
|
|
struct fib_table *tb;
|
|
int err;
|
|
|
|
err = rtm_to_fib_config(net, skb, nlh, &cfg);
|
|
if (err < 0)
|
|
goto errout;
|
|
|
|
tb = fib_get_table(net, cfg.fc_table);
|
|
if (tb == NULL) {
|
|
err = -ESRCH;
|
|
goto errout;
|
|
}
|
|
|
|
err = fib_table_delete(tb, &cfg);
|
|
errout:
|
|
return err;
|
|
}
|
|
|
|
static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
struct fib_config cfg;
|
|
struct fib_table *tb;
|
|
int err;
|
|
|
|
err = rtm_to_fib_config(net, skb, nlh, &cfg);
|
|
if (err < 0)
|
|
goto errout;
|
|
|
|
tb = fib_new_table(net, cfg.fc_table);
|
|
if (tb == NULL) {
|
|
err = -ENOBUFS;
|
|
goto errout;
|
|
}
|
|
|
|
err = fib_table_insert(tb, &cfg);
|
|
errout:
|
|
return err;
|
|
}
|
|
|
|
static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
unsigned int h, s_h;
|
|
unsigned int e = 0, s_e;
|
|
struct fib_table *tb;
|
|
struct hlist_head *head;
|
|
int dumped = 0;
|
|
|
|
if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
|
|
((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
|
|
return skb->len;
|
|
|
|
s_h = cb->args[0];
|
|
s_e = cb->args[1];
|
|
|
|
for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
|
|
e = 0;
|
|
head = &net->ipv4.fib_table_hash[h];
|
|
hlist_for_each_entry(tb, head, tb_hlist) {
|
|
if (e < s_e)
|
|
goto next;
|
|
if (dumped)
|
|
memset(&cb->args[2], 0, sizeof(cb->args) -
|
|
2 * sizeof(cb->args[0]));
|
|
if (fib_table_dump(tb, skb, cb) < 0)
|
|
goto out;
|
|
dumped = 1;
|
|
next:
|
|
e++;
|
|
}
|
|
}
|
|
out:
|
|
cb->args[1] = e;
|
|
cb->args[0] = h;
|
|
|
|
return skb->len;
|
|
}
|
|
|
|
/* Prepare and feed intra-kernel routing request.
|
|
* Really, it should be netlink message, but :-( netlink
|
|
* can be not configured, so that we feed it directly
|
|
* to fib engine. It is legal, because all events occur
|
|
* only when netlink is already locked.
|
|
*/
|
|
static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
|
|
{
|
|
struct net *net = dev_net(ifa->ifa_dev->dev);
|
|
struct fib_table *tb;
|
|
struct fib_config cfg = {
|
|
.fc_protocol = RTPROT_KERNEL,
|
|
.fc_type = type,
|
|
.fc_dst = dst,
|
|
.fc_dst_len = dst_len,
|
|
.fc_prefsrc = ifa->ifa_local,
|
|
.fc_oif = ifa->ifa_dev->dev->ifindex,
|
|
.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
|
|
.fc_nlinfo = {
|
|
.nl_net = net,
|
|
},
|
|
};
|
|
|
|
if (type == RTN_UNICAST)
|
|
tb = fib_new_table(net, RT_TABLE_MAIN);
|
|
else
|
|
tb = fib_new_table(net, RT_TABLE_LOCAL);
|
|
|
|
if (tb == NULL)
|
|
return;
|
|
|
|
cfg.fc_table = tb->tb_id;
|
|
|
|
if (type != RTN_LOCAL)
|
|
cfg.fc_scope = RT_SCOPE_LINK;
|
|
else
|
|
cfg.fc_scope = RT_SCOPE_HOST;
|
|
|
|
if (cmd == RTM_NEWROUTE)
|
|
fib_table_insert(tb, &cfg);
|
|
else
|
|
fib_table_delete(tb, &cfg);
|
|
}
|
|
|
|
void fib_add_ifaddr(struct in_ifaddr *ifa)
|
|
{
|
|
struct in_device *in_dev = ifa->ifa_dev;
|
|
struct net_device *dev = in_dev->dev;
|
|
struct in_ifaddr *prim = ifa;
|
|
__be32 mask = ifa->ifa_mask;
|
|
__be32 addr = ifa->ifa_local;
|
|
__be32 prefix = ifa->ifa_address & mask;
|
|
|
|
if (ifa->ifa_flags & IFA_F_SECONDARY) {
|
|
prim = inet_ifa_byprefix(in_dev, prefix, mask);
|
|
if (prim == NULL) {
|
|
pr_warn("%s: bug: prim == NULL\n", __func__);
|
|
return;
|
|
}
|
|
}
|
|
|
|
fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
|
|
|
|
if (!(dev->flags & IFF_UP))
|
|
return;
|
|
|
|
/* Add broadcast address, if it is explicitly assigned. */
|
|
if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
|
|
fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
|
|
|
|
if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
|
|
(prefix != addr || ifa->ifa_prefixlen < 32)) {
|
|
fib_magic(RTM_NEWROUTE,
|
|
dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
|
|
prefix, ifa->ifa_prefixlen, prim);
|
|
|
|
/* Add network specific broadcasts, when it takes a sense */
|
|
if (ifa->ifa_prefixlen < 31) {
|
|
fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
|
|
fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix | ~mask,
|
|
32, prim);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Delete primary or secondary address.
|
|
* Optionally, on secondary address promotion consider the addresses
|
|
* from subnet iprim as deleted, even if they are in device list.
|
|
* In this case the secondary ifa can be in device list.
|
|
*/
|
|
void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
|
|
{
|
|
struct in_device *in_dev = ifa->ifa_dev;
|
|
struct net_device *dev = in_dev->dev;
|
|
struct in_ifaddr *ifa1;
|
|
struct in_ifaddr *prim = ifa, *prim1 = NULL;
|
|
__be32 brd = ifa->ifa_address | ~ifa->ifa_mask;
|
|
__be32 any = ifa->ifa_address & ifa->ifa_mask;
|
|
#define LOCAL_OK 1
|
|
#define BRD_OK 2
|
|
#define BRD0_OK 4
|
|
#define BRD1_OK 8
|
|
unsigned int ok = 0;
|
|
int subnet = 0; /* Primary network */
|
|
int gone = 1; /* Address is missing */
|
|
int same_prefsrc = 0; /* Another primary with same IP */
|
|
|
|
if (ifa->ifa_flags & IFA_F_SECONDARY) {
|
|
prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
|
|
if (prim == NULL) {
|
|
pr_warn("%s: bug: prim == NULL\n", __func__);
|
|
return;
|
|
}
|
|
if (iprim && iprim != prim) {
|
|
pr_warn("%s: bug: iprim != prim\n", __func__);
|
|
return;
|
|
}
|
|
} else if (!ipv4_is_zeronet(any) &&
|
|
(any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) {
|
|
fib_magic(RTM_DELROUTE,
|
|
dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST,
|
|
any, ifa->ifa_prefixlen, prim);
|
|
subnet = 1;
|
|
}
|
|
|
|
/* Deletion is more complicated than add.
|
|
* We should take care of not to delete too much :-)
|
|
*
|
|
* Scan address list to be sure that addresses are really gone.
|
|
*/
|
|
|
|
for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
|
|
if (ifa1 == ifa) {
|
|
/* promotion, keep the IP */
|
|
gone = 0;
|
|
continue;
|
|
}
|
|
/* Ignore IFAs from our subnet */
|
|
if (iprim && ifa1->ifa_mask == iprim->ifa_mask &&
|
|
inet_ifa_match(ifa1->ifa_address, iprim))
|
|
continue;
|
|
|
|
/* Ignore ifa1 if it uses different primary IP (prefsrc) */
|
|
if (ifa1->ifa_flags & IFA_F_SECONDARY) {
|
|
/* Another address from our subnet? */
|
|
if (ifa1->ifa_mask == prim->ifa_mask &&
|
|
inet_ifa_match(ifa1->ifa_address, prim))
|
|
prim1 = prim;
|
|
else {
|
|
/* We reached the secondaries, so
|
|
* same_prefsrc should be determined.
|
|
*/
|
|
if (!same_prefsrc)
|
|
continue;
|
|
/* Search new prim1 if ifa1 is not
|
|
* using the current prim1
|
|
*/
|
|
if (!prim1 ||
|
|
ifa1->ifa_mask != prim1->ifa_mask ||
|
|
!inet_ifa_match(ifa1->ifa_address, prim1))
|
|
prim1 = inet_ifa_byprefix(in_dev,
|
|
ifa1->ifa_address,
|
|
ifa1->ifa_mask);
|
|
if (!prim1)
|
|
continue;
|
|
if (prim1->ifa_local != prim->ifa_local)
|
|
continue;
|
|
}
|
|
} else {
|
|
if (prim->ifa_local != ifa1->ifa_local)
|
|
continue;
|
|
prim1 = ifa1;
|
|
if (prim != prim1)
|
|
same_prefsrc = 1;
|
|
}
|
|
if (ifa->ifa_local == ifa1->ifa_local)
|
|
ok |= LOCAL_OK;
|
|
if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
|
|
ok |= BRD_OK;
|
|
if (brd == ifa1->ifa_broadcast)
|
|
ok |= BRD1_OK;
|
|
if (any == ifa1->ifa_broadcast)
|
|
ok |= BRD0_OK;
|
|
/* primary has network specific broadcasts */
|
|
if (prim1 == ifa1 && ifa1->ifa_prefixlen < 31) {
|
|
__be32 brd1 = ifa1->ifa_address | ~ifa1->ifa_mask;
|
|
__be32 any1 = ifa1->ifa_address & ifa1->ifa_mask;
|
|
|
|
if (!ipv4_is_zeronet(any1)) {
|
|
if (ifa->ifa_broadcast == brd1 ||
|
|
ifa->ifa_broadcast == any1)
|
|
ok |= BRD_OK;
|
|
if (brd == brd1 || brd == any1)
|
|
ok |= BRD1_OK;
|
|
if (any == brd1 || any == any1)
|
|
ok |= BRD0_OK;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!(ok & BRD_OK))
|
|
fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
|
|
if (subnet && ifa->ifa_prefixlen < 31) {
|
|
if (!(ok & BRD1_OK))
|
|
fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
|
|
if (!(ok & BRD0_OK))
|
|
fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
|
|
}
|
|
if (!(ok & LOCAL_OK)) {
|
|
fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
|
|
|
|
/* Check, that this local address finally disappeared. */
|
|
if (gone &&
|
|
inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
|
|
/* And the last, but not the least thing.
|
|
* We must flush stray FIB entries.
|
|
*
|
|
* First of all, we scan fib_info list searching
|
|
* for stray nexthop entries, then ignite fib_flush.
|
|
*/
|
|
if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
|
|
fib_flush(dev_net(dev));
|
|
}
|
|
}
|
|
#undef LOCAL_OK
|
|
#undef BRD_OK
|
|
#undef BRD0_OK
|
|
#undef BRD1_OK
|
|
}
|
|
|
|
static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
|
|
{
|
|
|
|
struct fib_result res;
|
|
struct flowi4 fl4 = {
|
|
.flowi4_mark = frn->fl_mark,
|
|
.daddr = frn->fl_addr,
|
|
.flowi4_tos = frn->fl_tos,
|
|
.flowi4_scope = frn->fl_scope,
|
|
};
|
|
|
|
frn->err = -ENOENT;
|
|
if (tb) {
|
|
local_bh_disable();
|
|
|
|
frn->tb_id = tb->tb_id;
|
|
frn->err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
|
|
|
|
if (!frn->err) {
|
|
frn->prefixlen = res.prefixlen;
|
|
frn->nh_sel = res.nh_sel;
|
|
frn->type = res.type;
|
|
frn->scope = res.scope;
|
|
}
|
|
local_bh_enable();
|
|
}
|
|
}
|
|
|
|
static void nl_fib_input(struct sk_buff *skb)
|
|
{
|
|
struct net *net;
|
|
struct fib_result_nl *frn;
|
|
struct nlmsghdr *nlh;
|
|
struct fib_table *tb;
|
|
u32 portid;
|
|
|
|
net = sock_net(skb->sk);
|
|
nlh = nlmsg_hdr(skb);
|
|
if (skb->len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len ||
|
|
nlmsg_len(nlh) < sizeof(*frn))
|
|
return;
|
|
|
|
skb = netlink_skb_clone(skb, GFP_KERNEL);
|
|
if (skb == NULL)
|
|
return;
|
|
nlh = nlmsg_hdr(skb);
|
|
|
|
frn = (struct fib_result_nl *) nlmsg_data(nlh);
|
|
tb = fib_get_table(net, frn->tb_id_in);
|
|
|
|
nl_fib_lookup(frn, tb);
|
|
|
|
portid = NETLINK_CB(skb).portid; /* netlink portid */
|
|
NETLINK_CB(skb).portid = 0; /* from kernel */
|
|
NETLINK_CB(skb).dst_group = 0; /* unicast */
|
|
netlink_unicast(net->ipv4.fibnl, skb, portid, MSG_DONTWAIT);
|
|
}
|
|
|
|
static int __net_init nl_fib_lookup_init(struct net *net)
|
|
{
|
|
struct sock *sk;
|
|
struct netlink_kernel_cfg cfg = {
|
|
.input = nl_fib_input,
|
|
};
|
|
|
|
sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, &cfg);
|
|
if (sk == NULL)
|
|
return -EAFNOSUPPORT;
|
|
net->ipv4.fibnl = sk;
|
|
return 0;
|
|
}
|
|
|
|
static void nl_fib_lookup_exit(struct net *net)
|
|
{
|
|
netlink_kernel_release(net->ipv4.fibnl);
|
|
net->ipv4.fibnl = NULL;
|
|
}
|
|
|
|
static void fib_disable_ip(struct net_device *dev, int force)
|
|
{
|
|
if (fib_sync_down_dev(dev, force))
|
|
fib_flush(dev_net(dev));
|
|
rt_cache_flush(dev_net(dev));
|
|
arp_ifdown(dev);
|
|
}
|
|
|
|
static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
|
|
{
|
|
struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
|
|
struct net_device *dev = ifa->ifa_dev->dev;
|
|
struct net *net = dev_net(dev);
|
|
|
|
switch (event) {
|
|
case NETDEV_UP:
|
|
fib_add_ifaddr(ifa);
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
fib_sync_up(dev);
|
|
#endif
|
|
atomic_inc(&net->ipv4.dev_addr_genid);
|
|
rt_cache_flush(dev_net(dev));
|
|
break;
|
|
case NETDEV_DOWN:
|
|
fib_del_ifaddr(ifa, NULL);
|
|
atomic_inc(&net->ipv4.dev_addr_genid);
|
|
if (ifa->ifa_dev->ifa_list == NULL) {
|
|
/* Last address was deleted from this interface.
|
|
* Disable IP.
|
|
*/
|
|
fib_disable_ip(dev, 1);
|
|
} else {
|
|
rt_cache_flush(dev_net(dev));
|
|
}
|
|
break;
|
|
}
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
|
|
{
|
|
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
|
|
struct in_device *in_dev;
|
|
struct net *net = dev_net(dev);
|
|
|
|
if (event == NETDEV_UNREGISTER) {
|
|
fib_disable_ip(dev, 2);
|
|
rt_flush_dev(dev);
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
in_dev = __in_dev_get_rtnl(dev);
|
|
if (!in_dev)
|
|
return NOTIFY_DONE;
|
|
|
|
switch (event) {
|
|
case NETDEV_UP:
|
|
for_ifa(in_dev) {
|
|
fib_add_ifaddr(ifa);
|
|
} endfor_ifa(in_dev);
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
fib_sync_up(dev);
|
|
#endif
|
|
atomic_inc(&net->ipv4.dev_addr_genid);
|
|
rt_cache_flush(net);
|
|
break;
|
|
case NETDEV_DOWN:
|
|
fib_disable_ip(dev, 0);
|
|
break;
|
|
case NETDEV_CHANGEMTU:
|
|
case NETDEV_CHANGE:
|
|
rt_cache_flush(net);
|
|
break;
|
|
}
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block fib_inetaddr_notifier = {
|
|
.notifier_call = fib_inetaddr_event,
|
|
};
|
|
|
|
static struct notifier_block fib_netdev_notifier = {
|
|
.notifier_call = fib_netdev_event,
|
|
};
|
|
|
|
static int __net_init ip_fib_net_init(struct net *net)
|
|
{
|
|
int err;
|
|
size_t size = sizeof(struct hlist_head) * FIB_TABLE_HASHSZ;
|
|
|
|
/* Avoid false sharing : Use at least a full cache line */
|
|
size = max_t(size_t, size, L1_CACHE_BYTES);
|
|
|
|
net->ipv4.fib_table_hash = kzalloc(size, GFP_KERNEL);
|
|
if (net->ipv4.fib_table_hash == NULL)
|
|
return -ENOMEM;
|
|
|
|
err = fib4_rules_init(net);
|
|
if (err < 0)
|
|
goto fail;
|
|
return 0;
|
|
|
|
fail:
|
|
kfree(net->ipv4.fib_table_hash);
|
|
return err;
|
|
}
|
|
|
|
static void ip_fib_net_exit(struct net *net)
|
|
{
|
|
unsigned int i;
|
|
|
|
#ifdef CONFIG_IP_MULTIPLE_TABLES
|
|
fib4_rules_exit(net);
|
|
#endif
|
|
|
|
rtnl_lock();
|
|
for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
|
|
struct fib_table *tb;
|
|
struct hlist_head *head;
|
|
struct hlist_node *tmp;
|
|
|
|
head = &net->ipv4.fib_table_hash[i];
|
|
hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
|
|
hlist_del(&tb->tb_hlist);
|
|
fib_table_flush(tb);
|
|
fib_free_table(tb);
|
|
}
|
|
}
|
|
rtnl_unlock();
|
|
kfree(net->ipv4.fib_table_hash);
|
|
}
|
|
|
|
static int __net_init fib_net_init(struct net *net)
|
|
{
|
|
int error;
|
|
|
|
#ifdef CONFIG_IP_ROUTE_CLASSID
|
|
net->ipv4.fib_num_tclassid_users = 0;
|
|
#endif
|
|
error = ip_fib_net_init(net);
|
|
if (error < 0)
|
|
goto out;
|
|
error = nl_fib_lookup_init(net);
|
|
if (error < 0)
|
|
goto out_nlfl;
|
|
error = fib_proc_init(net);
|
|
if (error < 0)
|
|
goto out_proc;
|
|
out:
|
|
return error;
|
|
|
|
out_proc:
|
|
nl_fib_lookup_exit(net);
|
|
out_nlfl:
|
|
ip_fib_net_exit(net);
|
|
goto out;
|
|
}
|
|
|
|
static void __net_exit fib_net_exit(struct net *net)
|
|
{
|
|
fib_proc_exit(net);
|
|
nl_fib_lookup_exit(net);
|
|
ip_fib_net_exit(net);
|
|
}
|
|
|
|
static struct pernet_operations fib_net_ops = {
|
|
.init = fib_net_init,
|
|
.exit = fib_net_exit,
|
|
};
|
|
|
|
void __init ip_fib_init(void)
|
|
{
|
|
rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
|
|
rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
|
|
rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
|
|
|
|
register_pernet_subsys(&fib_net_ops);
|
|
register_netdevice_notifier(&fib_netdev_notifier);
|
|
register_inetaddr_notifier(&fib_inetaddr_notifier);
|
|
|
|
fib_trie_init();
|
|
}
|