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6e8fcbf640
Found in 2.4 by Yixin Pan <yxpan@hotmail.com>. > When I read fib_semantics.c of Linux-2.4.32, write_lock(&fib_info_lock) = > is used in fib_release_info() instead of write_lock_bh(&fib_info_lock). = > Is the following case possible: a BH interrupts fib_release_info() while = > holding the write lock, and calls ip_check_fib_default() which calls = > read_lock(&fib_info_lock), and spin forever. Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
1345 lines
32 KiB
C
1345 lines
32 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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* Version: $Id: fib_semantics.c,v 1.19 2002/01/12 07:54:56 davem Exp $
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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 <asm/system.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/netlink.h>
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#include <linux/init.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/ip_mp_alg.h>
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#include "fib_lookup.h"
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#define FSprintk(a...)
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static DEFINE_RWLOCK(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_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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static DEFINE_SPINLOCK(fib_multipath_lock);
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#define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \
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for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
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#define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \
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for (nhsel=0, nh = (struct fib_nh*)((fi)->fib_nh); nhsel < (fi)->fib_nhs; 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) { int nhsel=0; 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) { int nhsel=0; struct fib_nh * 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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static const struct
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{
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int error;
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u8 scope;
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} fib_props[RTA_MAX + 1] = {
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{
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.error = 0,
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.scope = RT_SCOPE_NOWHERE,
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}, /* RTN_UNSPEC */
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{
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.error = 0,
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.scope = RT_SCOPE_UNIVERSE,
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}, /* RTN_UNICAST */
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{
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.error = 0,
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.scope = RT_SCOPE_HOST,
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}, /* RTN_LOCAL */
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{
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.error = 0,
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.scope = RT_SCOPE_LINK,
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}, /* RTN_BROADCAST */
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{
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.error = 0,
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.scope = RT_SCOPE_LINK,
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}, /* RTN_ANYCAST */
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{
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.error = 0,
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.scope = RT_SCOPE_UNIVERSE,
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}, /* RTN_MULTICAST */
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{
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.error = -EINVAL,
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.scope = RT_SCOPE_UNIVERSE,
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}, /* RTN_BLACKHOLE */
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{
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.error = -EHOSTUNREACH,
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.scope = RT_SCOPE_UNIVERSE,
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}, /* RTN_UNREACHABLE */
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{
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.error = -EACCES,
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.scope = RT_SCOPE_UNIVERSE,
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}, /* RTN_PROHIBIT */
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{
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.error = -EAGAIN,
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.scope = RT_SCOPE_UNIVERSE,
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}, /* RTN_THROW */
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{
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.error = -EINVAL,
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.scope = RT_SCOPE_NOWHERE,
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}, /* RTN_NAT */
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{
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.error = -EINVAL,
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.scope = RT_SCOPE_NOWHERE,
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}, /* RTN_XRESOLVE */
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};
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/* Release a nexthop info record */
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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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printk("Freeing alive fib_info %p\n", fi);
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return;
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}
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change_nexthops(fi) {
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if (nh->nh_dev)
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dev_put(nh->nh_dev);
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nh->nh_dev = NULL;
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} endfor_nexthops(fi);
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fib_info_cnt--;
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kfree(fi);
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}
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void fib_release_info(struct fib_info *fi)
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{
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write_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 (!nh->nh_dev)
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continue;
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hlist_del(&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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write_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_NET_CLS_ROUTE
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nh->nh_tclassid != onh->nh_tclassid ||
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#endif
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((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
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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_info_hashfn(const struct fib_info *fi)
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{
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unsigned int mask = (fib_hash_size - 1);
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unsigned int val = fi->fib_nhs;
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val ^= fi->fib_protocol;
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val ^= fi->fib_prefsrc;
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val ^= fi->fib_priority;
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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 hlist_node *node;
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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, node, head, fib_hash) {
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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_prefsrc == fi->fib_prefsrc &&
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nfi->fib_priority == fi->fib_priority &&
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memcmp(nfi->fib_metrics, fi->fib_metrics,
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sizeof(fi->fib_metrics)) == 0 &&
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((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
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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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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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/* 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(u32 gw, struct net_device *dev)
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{
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struct hlist_head *head;
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struct hlist_node *node;
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struct fib_nh *nh;
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unsigned int hash;
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read_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, node, 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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read_unlock(&fib_info_lock);
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return 0;
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}
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}
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read_unlock(&fib_info_lock);
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return -1;
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}
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void rtmsg_fib(int event, u32 key, struct fib_alias *fa,
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int z, int tb_id,
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struct nlmsghdr *n, struct netlink_skb_parms *req)
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{
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struct sk_buff *skb;
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u32 pid = req ? req->pid : n->nlmsg_pid;
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int size = NLMSG_SPACE(sizeof(struct rtmsg)+256);
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skb = alloc_skb(size, GFP_KERNEL);
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if (!skb)
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return;
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if (fib_dump_info(skb, pid, n->nlmsg_seq, event, tb_id,
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fa->fa_type, fa->fa_scope, &key, z,
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fa->fa_tos,
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fa->fa_info, 0) < 0) {
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kfree_skb(skb);
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return;
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}
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NETLINK_CB(skb).dst_group = RTNLGRP_IPV4_ROUTE;
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if (n->nlmsg_flags&NLM_F_ECHO)
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atomic_inc(&skb->users);
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netlink_broadcast(rtnl, skb, pid, RTNLGRP_IPV4_ROUTE, GFP_KERNEL);
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if (n->nlmsg_flags&NLM_F_ECHO)
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netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
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}
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/* Return the first fib alias matching TOS with
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* priority less than or equal to PRIO.
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*/
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struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
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{
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if (fah) {
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struct fib_alias *fa;
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list_for_each_entry(fa, fah, fa_list) {
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if (fa->fa_tos > tos)
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continue;
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if (fa->fa_info->fib_priority >= prio ||
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fa->fa_tos < tos)
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return fa;
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}
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}
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return NULL;
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}
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int fib_detect_death(struct fib_info *fi, int order,
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struct fib_info **last_resort, int *last_idx, 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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}
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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)) {
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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 u32 fib_get_attr32(struct rtattr *attr, int attrlen, int type)
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{
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while (RTA_OK(attr,attrlen)) {
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if (attr->rta_type == type)
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return *(u32*)RTA_DATA(attr);
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attr = RTA_NEXT(attr, attrlen);
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}
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return 0;
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}
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static int
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fib_count_nexthops(struct rtattr *rta)
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{
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int nhs = 0;
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struct rtnexthop *nhp = RTA_DATA(rta);
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int nhlen = RTA_PAYLOAD(rta);
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while (nhlen >= (int)sizeof(struct rtnexthop)) {
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if ((nhlen -= nhp->rtnh_len) < 0)
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return 0;
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nhs++;
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nhp = RTNH_NEXT(nhp);
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};
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return nhs;
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}
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static int
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fib_get_nhs(struct fib_info *fi, const struct rtattr *rta, const struct rtmsg *r)
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{
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struct rtnexthop *nhp = RTA_DATA(rta);
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int nhlen = RTA_PAYLOAD(rta);
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change_nexthops(fi) {
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int attrlen = nhlen - sizeof(struct rtnexthop);
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if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
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return -EINVAL;
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nh->nh_flags = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
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nh->nh_oif = nhp->rtnh_ifindex;
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nh->nh_weight = nhp->rtnh_hops + 1;
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if (attrlen) {
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nh->nh_gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
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#ifdef CONFIG_NET_CLS_ROUTE
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nh->nh_tclassid = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_FLOW);
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#endif
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}
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nhp = RTNH_NEXT(nhp);
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} endfor_nexthops(fi);
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return 0;
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}
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#endif
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int fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct kern_rta *rta,
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struct fib_info *fi)
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{
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#ifdef CONFIG_IP_ROUTE_MULTIPATH
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struct rtnexthop *nhp;
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int nhlen;
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#endif
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if (rta->rta_priority &&
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*rta->rta_priority != fi->fib_priority)
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return 1;
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if (rta->rta_oif || rta->rta_gw) {
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if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
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(!rta->rta_gw || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 4) == 0))
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return 0;
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return 1;
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}
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#ifdef CONFIG_IP_ROUTE_MULTIPATH
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if (rta->rta_mp == NULL)
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return 0;
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nhp = RTA_DATA(rta->rta_mp);
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nhlen = RTA_PAYLOAD(rta->rta_mp);
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for_nexthops(fi) {
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int attrlen = nhlen - sizeof(struct rtnexthop);
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u32 gw;
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if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
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return -EINVAL;
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if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
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return 1;
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if (attrlen) {
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gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
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if (gw && gw != nh->nh_gw)
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return 1;
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#ifdef CONFIG_NET_CLS_ROUTE
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gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_FLOW);
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if (gw && gw != nh->nh_tclassid)
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return 1;
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#endif
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}
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nhp = RTNH_NEXT(nhp);
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} endfor_nexthops(fi);
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#endif
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return 0;
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}
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/*
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Picture
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-------
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Semantics of nexthop is very messy by historical reasons.
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We have to take into account, that:
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a) gateway can be actually local interface address,
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so that gatewayed route is direct.
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b) gateway must be on-link address, possibly
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described not by an ifaddr, but also by a direct route.
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c) If both gateway and interface are specified, they should not
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contradict.
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d) If we use tunnel routes, gateway could be not on-link.
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Attempt to reconcile all of these (alas, self-contradictory) conditions
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results in pretty ugly and hairy code with obscure logic.
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I chose to generalized it instead, so that the size
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of code does not increase practically, but it becomes
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much more general.
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Every prefix is assigned a "scope" value: "host" is local address,
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"link" is direct route,
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[ ... "site" ... "interior" ... ]
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and "universe" is true gateway route with global meaning.
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Every prefix refers to a set of "nexthop"s (gw, oif),
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where gw must have narrower scope. This recursion stops
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when gw has LOCAL scope or if "nexthop" is declared ONLINK,
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which means that gw is forced to be on link.
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|
Code is still hairy, but now it is apparently logically
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consistent and very flexible. F.e. as by-product it allows
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to co-exists in peace independent exterior and interior
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routing processes.
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|
Normally it looks as following.
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{universe prefix} -> (gw, oif) [scope link]
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|
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|
|-> {link prefix} -> (gw, oif) [scope local]
|
|
|
|
|
|-> {local prefix} (terminal node)
|
|
*/
|
|
|
|
static int fib_check_nh(const struct rtmsg *r, struct fib_info *fi, struct fib_nh *nh)
|
|
{
|
|
int err;
|
|
|
|
if (nh->nh_gw) {
|
|
struct fib_result res;
|
|
|
|
#ifdef CONFIG_IP_ROUTE_PERVASIVE
|
|
if (nh->nh_flags&RTNH_F_PERVASIVE)
|
|
return 0;
|
|
#endif
|
|
if (nh->nh_flags&RTNH_F_ONLINK) {
|
|
struct net_device *dev;
|
|
|
|
if (r->rtm_scope >= RT_SCOPE_LINK)
|
|
return -EINVAL;
|
|
if (inet_addr_type(nh->nh_gw) != RTN_UNICAST)
|
|
return -EINVAL;
|
|
if ((dev = __dev_get_by_index(nh->nh_oif)) == NULL)
|
|
return -ENODEV;
|
|
if (!(dev->flags&IFF_UP))
|
|
return -ENETDOWN;
|
|
nh->nh_dev = dev;
|
|
dev_hold(dev);
|
|
nh->nh_scope = RT_SCOPE_LINK;
|
|
return 0;
|
|
}
|
|
{
|
|
struct flowi fl = { .nl_u = { .ip4_u =
|
|
{ .daddr = nh->nh_gw,
|
|
.scope = r->rtm_scope + 1 } },
|
|
.oif = nh->nh_oif };
|
|
|
|
/* It is not necessary, but requires a bit of thinking */
|
|
if (fl.fl4_scope < RT_SCOPE_LINK)
|
|
fl.fl4_scope = RT_SCOPE_LINK;
|
|
if ((err = fib_lookup(&fl, &res)) != 0)
|
|
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);
|
|
if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
|
|
goto out;
|
|
dev_hold(nh->nh_dev);
|
|
err = -ENETDOWN;
|
|
if (!(nh->nh_dev->flags & IFF_UP))
|
|
goto out;
|
|
err = 0;
|
|
out:
|
|
fib_res_put(&res);
|
|
return err;
|
|
} else {
|
|
struct in_device *in_dev;
|
|
|
|
if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
|
|
return -EINVAL;
|
|
|
|
in_dev = inetdev_by_index(nh->nh_oif);
|
|
if (in_dev == NULL)
|
|
return -ENODEV;
|
|
if (!(in_dev->dev->flags&IFF_UP)) {
|
|
in_dev_put(in_dev);
|
|
return -ENETDOWN;
|
|
}
|
|
nh->nh_dev = in_dev->dev;
|
|
dev_hold(nh->nh_dev);
|
|
nh->nh_scope = RT_SCOPE_HOST;
|
|
in_dev_put(in_dev);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned int fib_laddr_hashfn(u32 val)
|
|
{
|
|
unsigned int mask = (fib_hash_size - 1);
|
|
|
|
return (val ^ (val >> 7) ^ (val >> 14)) & mask;
|
|
}
|
|
|
|
static struct hlist_head *fib_hash_alloc(int bytes)
|
|
{
|
|
if (bytes <= PAGE_SIZE)
|
|
return kmalloc(bytes, GFP_KERNEL);
|
|
else
|
|
return (struct hlist_head *)
|
|
__get_free_pages(GFP_KERNEL, get_order(bytes));
|
|
}
|
|
|
|
static void fib_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_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_hash_size;
|
|
unsigned int i, bytes;
|
|
|
|
write_lock_bh(&fib_info_lock);
|
|
old_info_hash = fib_info_hash;
|
|
old_laddrhash = fib_info_laddrhash;
|
|
fib_hash_size = new_size;
|
|
|
|
for (i = 0; i < old_size; i++) {
|
|
struct hlist_head *head = &fib_info_hash[i];
|
|
struct hlist_node *node, *n;
|
|
struct fib_info *fi;
|
|
|
|
hlist_for_each_entry_safe(fi, node, n, head, fib_hash) {
|
|
struct hlist_head *dest;
|
|
unsigned int new_hash;
|
|
|
|
hlist_del(&fi->fib_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 *node, *n;
|
|
struct fib_info *fi;
|
|
|
|
hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) {
|
|
struct hlist_head *ldest;
|
|
unsigned int new_hash;
|
|
|
|
hlist_del(&fi->fib_lhash);
|
|
|
|
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;
|
|
|
|
write_unlock_bh(&fib_info_lock);
|
|
|
|
bytes = old_size * sizeof(struct hlist_head *);
|
|
fib_hash_free(old_info_hash, bytes);
|
|
fib_hash_free(old_laddrhash, bytes);
|
|
}
|
|
|
|
struct fib_info *
|
|
fib_create_info(const struct rtmsg *r, struct kern_rta *rta,
|
|
const struct nlmsghdr *nlh, int *errp)
|
|
{
|
|
int err;
|
|
struct fib_info *fi = NULL;
|
|
struct fib_info *ofi;
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
int nhs = 1;
|
|
#else
|
|
const int nhs = 1;
|
|
#endif
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
|
|
u32 mp_alg = IP_MP_ALG_NONE;
|
|
#endif
|
|
|
|
/* Fast check to catch the most weird cases */
|
|
if (fib_props[r->rtm_type].scope > r->rtm_scope)
|
|
goto err_inval;
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (rta->rta_mp) {
|
|
nhs = fib_count_nexthops(rta->rta_mp);
|
|
if (nhs == 0)
|
|
goto err_inval;
|
|
}
|
|
#endif
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
|
|
if (rta->rta_mp_alg) {
|
|
mp_alg = *rta->rta_mp_alg;
|
|
|
|
if (mp_alg < IP_MP_ALG_NONE ||
|
|
mp_alg > IP_MP_ALG_MAX)
|
|
goto err_inval;
|
|
}
|
|
#endif
|
|
|
|
err = -ENOBUFS;
|
|
if (fib_info_cnt >= fib_hash_size) {
|
|
unsigned int new_size = fib_hash_size << 1;
|
|
struct hlist_head *new_info_hash;
|
|
struct hlist_head *new_laddrhash;
|
|
unsigned int bytes;
|
|
|
|
if (!new_size)
|
|
new_size = 1;
|
|
bytes = new_size * sizeof(struct hlist_head *);
|
|
new_info_hash = fib_hash_alloc(bytes);
|
|
new_laddrhash = fib_hash_alloc(bytes);
|
|
if (!new_info_hash || !new_laddrhash) {
|
|
fib_hash_free(new_info_hash, bytes);
|
|
fib_hash_free(new_laddrhash, bytes);
|
|
} else {
|
|
memset(new_info_hash, 0, bytes);
|
|
memset(new_laddrhash, 0, bytes);
|
|
|
|
fib_hash_move(new_info_hash, new_laddrhash, new_size);
|
|
}
|
|
|
|
if (!fib_hash_size)
|
|
goto failure;
|
|
}
|
|
|
|
fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
|
|
if (fi == NULL)
|
|
goto failure;
|
|
fib_info_cnt++;
|
|
|
|
fi->fib_protocol = r->rtm_protocol;
|
|
|
|
fi->fib_nhs = nhs;
|
|
change_nexthops(fi) {
|
|
nh->nh_parent = fi;
|
|
} endfor_nexthops(fi)
|
|
|
|
fi->fib_flags = r->rtm_flags;
|
|
if (rta->rta_priority)
|
|
fi->fib_priority = *rta->rta_priority;
|
|
if (rta->rta_mx) {
|
|
int attrlen = RTA_PAYLOAD(rta->rta_mx);
|
|
struct rtattr *attr = RTA_DATA(rta->rta_mx);
|
|
|
|
while (RTA_OK(attr, attrlen)) {
|
|
unsigned flavor = attr->rta_type;
|
|
if (flavor) {
|
|
if (flavor > RTAX_MAX)
|
|
goto err_inval;
|
|
fi->fib_metrics[flavor-1] = *(unsigned*)RTA_DATA(attr);
|
|
}
|
|
attr = RTA_NEXT(attr, attrlen);
|
|
}
|
|
}
|
|
if (rta->rta_prefsrc)
|
|
memcpy(&fi->fib_prefsrc, rta->rta_prefsrc, 4);
|
|
|
|
if (rta->rta_mp) {
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if ((err = fib_get_nhs(fi, rta->rta_mp, r)) != 0)
|
|
goto failure;
|
|
if (rta->rta_oif && fi->fib_nh->nh_oif != *rta->rta_oif)
|
|
goto err_inval;
|
|
if (rta->rta_gw && memcmp(&fi->fib_nh->nh_gw, rta->rta_gw, 4))
|
|
goto err_inval;
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (rta->rta_flow && memcmp(&fi->fib_nh->nh_tclassid, rta->rta_flow, 4))
|
|
goto err_inval;
|
|
#endif
|
|
#else
|
|
goto err_inval;
|
|
#endif
|
|
} else {
|
|
struct fib_nh *nh = fi->fib_nh;
|
|
if (rta->rta_oif)
|
|
nh->nh_oif = *rta->rta_oif;
|
|
if (rta->rta_gw)
|
|
memcpy(&nh->nh_gw, rta->rta_gw, 4);
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (rta->rta_flow)
|
|
memcpy(&nh->nh_tclassid, rta->rta_flow, 4);
|
|
#endif
|
|
nh->nh_flags = r->rtm_flags;
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
nh->nh_weight = 1;
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
|
|
fi->fib_mp_alg = mp_alg;
|
|
#endif
|
|
|
|
if (fib_props[r->rtm_type].error) {
|
|
if (rta->rta_gw || rta->rta_oif || rta->rta_mp)
|
|
goto err_inval;
|
|
goto link_it;
|
|
}
|
|
|
|
if (r->rtm_scope > RT_SCOPE_HOST)
|
|
goto err_inval;
|
|
|
|
if (r->rtm_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(fi->fib_nh->nh_oif);
|
|
err = -ENODEV;
|
|
if (nh->nh_dev == NULL)
|
|
goto failure;
|
|
} else {
|
|
change_nexthops(fi) {
|
|
if ((err = fib_check_nh(r, fi, nh)) != 0)
|
|
goto failure;
|
|
} endfor_nexthops(fi)
|
|
}
|
|
|
|
if (fi->fib_prefsrc) {
|
|
if (r->rtm_type != RTN_LOCAL || rta->rta_dst == NULL ||
|
|
memcmp(&fi->fib_prefsrc, rta->rta_dst, 4))
|
|
if (inet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
|
|
goto err_inval;
|
|
}
|
|
|
|
link_it:
|
|
if ((ofi = fib_find_info(fi)) != NULL) {
|
|
fi->fib_dead = 1;
|
|
free_fib_info(fi);
|
|
ofi->fib_treeref++;
|
|
return ofi;
|
|
}
|
|
|
|
fi->fib_treeref++;
|
|
atomic_inc(&fi->fib_clntref);
|
|
write_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 (!nh->nh_dev)
|
|
continue;
|
|
hash = fib_devindex_hashfn(nh->nh_dev->ifindex);
|
|
head = &fib_info_devhash[hash];
|
|
hlist_add_head(&nh->nh_hash, head);
|
|
} endfor_nexthops(fi)
|
|
write_unlock_bh(&fib_info_lock);
|
|
return fi;
|
|
|
|
err_inval:
|
|
err = -EINVAL;
|
|
|
|
failure:
|
|
*errp = err;
|
|
if (fi) {
|
|
fi->fib_dead = 1;
|
|
free_fib_info(fi);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Note! fib_semantic_match intentionally uses RCU list functions. */
|
|
int fib_semantic_match(struct list_head *head, const struct flowi *flp,
|
|
struct fib_result *res, __u32 zone, __u32 mask,
|
|
int prefixlen)
|
|
{
|
|
struct fib_alias *fa;
|
|
int nh_sel = 0;
|
|
|
|
list_for_each_entry_rcu(fa, head, fa_list) {
|
|
int err;
|
|
|
|
if (fa->fa_tos &&
|
|
fa->fa_tos != flp->fl4_tos)
|
|
continue;
|
|
|
|
if (fa->fa_scope < flp->fl4_scope)
|
|
continue;
|
|
|
|
fa->fa_state |= FA_S_ACCESSED;
|
|
|
|
err = fib_props[fa->fa_type].error;
|
|
if (err == 0) {
|
|
struct fib_info *fi = fa->fa_info;
|
|
|
|
if (fi->fib_flags & RTNH_F_DEAD)
|
|
continue;
|
|
|
|
switch (fa->fa_type) {
|
|
case RTN_UNICAST:
|
|
case RTN_LOCAL:
|
|
case RTN_BROADCAST:
|
|
case RTN_ANYCAST:
|
|
case RTN_MULTICAST:
|
|
for_nexthops(fi) {
|
|
if (nh->nh_flags&RTNH_F_DEAD)
|
|
continue;
|
|
if (!flp->oif || flp->oif == nh->nh_oif)
|
|
break;
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (nhsel < fi->fib_nhs) {
|
|
nh_sel = nhsel;
|
|
goto out_fill_res;
|
|
}
|
|
#else
|
|
if (nhsel < 1) {
|
|
goto out_fill_res;
|
|
}
|
|
#endif
|
|
endfor_nexthops(fi);
|
|
continue;
|
|
|
|
default:
|
|
printk(KERN_DEBUG "impossible 102\n");
|
|
return -EINVAL;
|
|
};
|
|
}
|
|
return err;
|
|
}
|
|
return 1;
|
|
|
|
out_fill_res:
|
|
res->prefixlen = prefixlen;
|
|
res->nh_sel = nh_sel;
|
|
res->type = fa->fa_type;
|
|
res->scope = fa->fa_scope;
|
|
res->fi = fa->fa_info;
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
|
|
res->netmask = mask;
|
|
res->network = zone &
|
|
(0xFFFFFFFF >> (32 - prefixlen));
|
|
#endif
|
|
atomic_inc(&res->fi->fib_clntref);
|
|
return 0;
|
|
}
|
|
|
|
/* Find appropriate source address to this destination */
|
|
|
|
u32 __fib_res_prefsrc(struct fib_result *res)
|
|
{
|
|
return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope);
|
|
}
|
|
|
|
int
|
|
fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
|
|
u8 tb_id, u8 type, u8 scope, void *dst, int dst_len, u8 tos,
|
|
struct fib_info *fi, unsigned int flags)
|
|
{
|
|
struct rtmsg *rtm;
|
|
struct nlmsghdr *nlh;
|
|
unsigned char *b = skb->tail;
|
|
|
|
nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
|
|
rtm = NLMSG_DATA(nlh);
|
|
rtm->rtm_family = AF_INET;
|
|
rtm->rtm_dst_len = dst_len;
|
|
rtm->rtm_src_len = 0;
|
|
rtm->rtm_tos = tos;
|
|
rtm->rtm_table = tb_id;
|
|
rtm->rtm_type = type;
|
|
rtm->rtm_flags = fi->fib_flags;
|
|
rtm->rtm_scope = scope;
|
|
if (rtm->rtm_dst_len)
|
|
RTA_PUT(skb, RTA_DST, 4, dst);
|
|
rtm->rtm_protocol = fi->fib_protocol;
|
|
if (fi->fib_priority)
|
|
RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
|
|
if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
|
|
goto rtattr_failure;
|
|
if (fi->fib_prefsrc)
|
|
RTA_PUT(skb, RTA_PREFSRC, 4, &fi->fib_prefsrc);
|
|
if (fi->fib_nhs == 1) {
|
|
if (fi->fib_nh->nh_gw)
|
|
RTA_PUT(skb, RTA_GATEWAY, 4, &fi->fib_nh->nh_gw);
|
|
if (fi->fib_nh->nh_oif)
|
|
RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (fi->fib_nh[0].nh_tclassid)
|
|
RTA_PUT(skb, RTA_FLOW, 4, &fi->fib_nh[0].nh_tclassid);
|
|
#endif
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (fi->fib_nhs > 1) {
|
|
struct rtnexthop *nhp;
|
|
struct rtattr *mp_head;
|
|
if (skb_tailroom(skb) <= RTA_SPACE(0))
|
|
goto rtattr_failure;
|
|
mp_head = (struct rtattr*)skb_put(skb, RTA_SPACE(0));
|
|
|
|
for_nexthops(fi) {
|
|
if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
|
|
goto rtattr_failure;
|
|
nhp = (struct rtnexthop*)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
|
|
nhp->rtnh_flags = nh->nh_flags & 0xFF;
|
|
nhp->rtnh_hops = nh->nh_weight-1;
|
|
nhp->rtnh_ifindex = nh->nh_oif;
|
|
if (nh->nh_gw)
|
|
RTA_PUT(skb, RTA_GATEWAY, 4, &nh->nh_gw);
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (nh->nh_tclassid)
|
|
RTA_PUT(skb, RTA_FLOW, 4, &nh->nh_tclassid);
|
|
#endif
|
|
nhp->rtnh_len = skb->tail - (unsigned char*)nhp;
|
|
} endfor_nexthops(fi);
|
|
mp_head->rta_type = RTA_MULTIPATH;
|
|
mp_head->rta_len = skb->tail - (u8*)mp_head;
|
|
}
|
|
#endif
|
|
nlh->nlmsg_len = skb->tail - b;
|
|
return skb->len;
|
|
|
|
nlmsg_failure:
|
|
rtattr_failure:
|
|
skb_trim(skb, b - skb->data);
|
|
return -1;
|
|
}
|
|
|
|
#ifndef CONFIG_IP_NOSIOCRT
|
|
|
|
int
|
|
fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
|
|
struct kern_rta *rta, struct rtentry *r)
|
|
{
|
|
int plen;
|
|
u32 *ptr;
|
|
|
|
memset(rtm, 0, sizeof(*rtm));
|
|
memset(rta, 0, sizeof(*rta));
|
|
|
|
if (r->rt_dst.sa_family != AF_INET)
|
|
return -EAFNOSUPPORT;
|
|
|
|
/* Check mask for validity:
|
|
a) it must be contiguous.
|
|
b) destination must have all host bits clear.
|
|
c) if application forgot to set correct family (AF_INET),
|
|
reject request unless it is absolutely clear i.e.
|
|
both family and mask are zero.
|
|
*/
|
|
plen = 32;
|
|
ptr = &((struct sockaddr_in*)&r->rt_dst)->sin_addr.s_addr;
|
|
if (!(r->rt_flags&RTF_HOST)) {
|
|
u32 mask = ((struct sockaddr_in*)&r->rt_genmask)->sin_addr.s_addr;
|
|
if (r->rt_genmask.sa_family != AF_INET) {
|
|
if (mask || r->rt_genmask.sa_family)
|
|
return -EAFNOSUPPORT;
|
|
}
|
|
if (bad_mask(mask, *ptr))
|
|
return -EINVAL;
|
|
plen = inet_mask_len(mask);
|
|
}
|
|
|
|
nl->nlmsg_flags = NLM_F_REQUEST;
|
|
nl->nlmsg_pid = 0;
|
|
nl->nlmsg_seq = 0;
|
|
nl->nlmsg_len = NLMSG_LENGTH(sizeof(*rtm));
|
|
if (cmd == SIOCDELRT) {
|
|
nl->nlmsg_type = RTM_DELROUTE;
|
|
nl->nlmsg_flags = 0;
|
|
} else {
|
|
nl->nlmsg_type = RTM_NEWROUTE;
|
|
nl->nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE;
|
|
rtm->rtm_protocol = RTPROT_BOOT;
|
|
}
|
|
|
|
rtm->rtm_dst_len = plen;
|
|
rta->rta_dst = ptr;
|
|
|
|
if (r->rt_metric) {
|
|
*(u32*)&r->rt_pad3 = r->rt_metric - 1;
|
|
rta->rta_priority = (u32*)&r->rt_pad3;
|
|
}
|
|
if (r->rt_flags&RTF_REJECT) {
|
|
rtm->rtm_scope = RT_SCOPE_HOST;
|
|
rtm->rtm_type = RTN_UNREACHABLE;
|
|
return 0;
|
|
}
|
|
rtm->rtm_scope = RT_SCOPE_NOWHERE;
|
|
rtm->rtm_type = RTN_UNICAST;
|
|
|
|
if (r->rt_dev) {
|
|
char *colon;
|
|
struct net_device *dev;
|
|
char devname[IFNAMSIZ];
|
|
|
|
if (copy_from_user(devname, r->rt_dev, IFNAMSIZ-1))
|
|
return -EFAULT;
|
|
devname[IFNAMSIZ-1] = 0;
|
|
colon = strchr(devname, ':');
|
|
if (colon)
|
|
*colon = 0;
|
|
dev = __dev_get_by_name(devname);
|
|
if (!dev)
|
|
return -ENODEV;
|
|
rta->rta_oif = &dev->ifindex;
|
|
if (colon) {
|
|
struct in_ifaddr *ifa;
|
|
struct in_device *in_dev = __in_dev_get_rtnl(dev);
|
|
if (!in_dev)
|
|
return -ENODEV;
|
|
*colon = ':';
|
|
for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
|
|
if (strcmp(ifa->ifa_label, devname) == 0)
|
|
break;
|
|
if (ifa == NULL)
|
|
return -ENODEV;
|
|
rta->rta_prefsrc = &ifa->ifa_local;
|
|
}
|
|
}
|
|
|
|
ptr = &((struct sockaddr_in*)&r->rt_gateway)->sin_addr.s_addr;
|
|
if (r->rt_gateway.sa_family == AF_INET && *ptr) {
|
|
rta->rta_gw = ptr;
|
|
if (r->rt_flags&RTF_GATEWAY && inet_addr_type(*ptr) == RTN_UNICAST)
|
|
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
|
|
}
|
|
|
|
if (cmd == SIOCDELRT)
|
|
return 0;
|
|
|
|
if (r->rt_flags&RTF_GATEWAY && rta->rta_gw == NULL)
|
|
return -EINVAL;
|
|
|
|
if (rtm->rtm_scope == RT_SCOPE_NOWHERE)
|
|
rtm->rtm_scope = RT_SCOPE_LINK;
|
|
|
|
if (r->rt_flags&(RTF_MTU|RTF_WINDOW|RTF_IRTT)) {
|
|
struct rtattr *rec;
|
|
struct rtattr *mx = kmalloc(RTA_LENGTH(3*RTA_LENGTH(4)), GFP_KERNEL);
|
|
if (mx == NULL)
|
|
return -ENOMEM;
|
|
rta->rta_mx = mx;
|
|
mx->rta_type = RTA_METRICS;
|
|
mx->rta_len = RTA_LENGTH(0);
|
|
if (r->rt_flags&RTF_MTU) {
|
|
rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
|
|
rec->rta_type = RTAX_ADVMSS;
|
|
rec->rta_len = RTA_LENGTH(4);
|
|
mx->rta_len += RTA_LENGTH(4);
|
|
*(u32*)RTA_DATA(rec) = r->rt_mtu - 40;
|
|
}
|
|
if (r->rt_flags&RTF_WINDOW) {
|
|
rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
|
|
rec->rta_type = RTAX_WINDOW;
|
|
rec->rta_len = RTA_LENGTH(4);
|
|
mx->rta_len += RTA_LENGTH(4);
|
|
*(u32*)RTA_DATA(rec) = r->rt_window;
|
|
}
|
|
if (r->rt_flags&RTF_IRTT) {
|
|
rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
|
|
rec->rta_type = RTAX_RTT;
|
|
rec->rta_len = RTA_LENGTH(4);
|
|
mx->rta_len += RTA_LENGTH(4);
|
|
*(u32*)RTA_DATA(rec) = r->rt_irtt<<3;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
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(u32 local, struct net_device *dev, int force)
|
|
{
|
|
int ret = 0;
|
|
int scope = RT_SCOPE_NOWHERE;
|
|
|
|
if (force)
|
|
scope = -1;
|
|
|
|
if (local && fib_info_laddrhash) {
|
|
unsigned int hash = fib_laddr_hashfn(local);
|
|
struct hlist_head *head = &fib_info_laddrhash[hash];
|
|
struct hlist_node *node;
|
|
struct fib_info *fi;
|
|
|
|
hlist_for_each_entry(fi, node, head, fib_lhash) {
|
|
if (fi->fib_prefsrc == local) {
|
|
fi->fib_flags |= RTNH_F_DEAD;
|
|
ret++;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (dev) {
|
|
struct fib_info *prev_fi = NULL;
|
|
unsigned int hash = fib_devindex_hashfn(dev->ifindex);
|
|
struct hlist_head *head = &fib_info_devhash[hash];
|
|
struct hlist_node *node;
|
|
struct fib_nh *nh;
|
|
|
|
hlist_for_each_entry(nh, node, 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 (nh->nh_flags&RTNH_F_DEAD)
|
|
dead++;
|
|
else if (nh->nh_dev == dev &&
|
|
nh->nh_scope != scope) {
|
|
nh->nh_flags |= RTNH_F_DEAD;
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
spin_lock_bh(&fib_multipath_lock);
|
|
fi->fib_power -= nh->nh_power;
|
|
nh->nh_power = 0;
|
|
spin_unlock_bh(&fib_multipath_lock);
|
|
#endif
|
|
dead++;
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (force > 1 && nh->nh_dev == dev) {
|
|
dead = fi->fib_nhs;
|
|
break;
|
|
}
|
|
#endif
|
|
} endfor_nexthops(fi)
|
|
if (dead == fi->fib_nhs) {
|
|
fi->fib_flags |= RTNH_F_DEAD;
|
|
ret++;
|
|
}
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
|
|
/*
|
|
Dead device goes up. We wake up dead nexthops.
|
|
It takes sense only on multipath routes.
|
|
*/
|
|
|
|
int fib_sync_up(struct net_device *dev)
|
|
{
|
|
struct fib_info *prev_fi;
|
|
unsigned int hash;
|
|
struct hlist_head *head;
|
|
struct hlist_node *node;
|
|
struct fib_nh *nh;
|
|
int ret;
|
|
|
|
if (!(dev->flags&IFF_UP))
|
|
return 0;
|
|
|
|
prev_fi = NULL;
|
|
hash = fib_devindex_hashfn(dev->ifindex);
|
|
head = &fib_info_devhash[hash];
|
|
ret = 0;
|
|
|
|
hlist_for_each_entry(nh, node, 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 (!(nh->nh_flags&RTNH_F_DEAD)) {
|
|
alive++;
|
|
continue;
|
|
}
|
|
if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
|
|
continue;
|
|
if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev))
|
|
continue;
|
|
alive++;
|
|
spin_lock_bh(&fib_multipath_lock);
|
|
nh->nh_power = 0;
|
|
nh->nh_flags &= ~RTNH_F_DEAD;
|
|
spin_unlock_bh(&fib_multipath_lock);
|
|
} endfor_nexthops(fi)
|
|
|
|
if (alive > 0) {
|
|
fi->fib_flags &= ~RTNH_F_DEAD;
|
|
ret++;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
The algorithm is suboptimal, but it provides really
|
|
fair weighted route distribution.
|
|
*/
|
|
|
|
void fib_select_multipath(const struct flowi *flp, struct fib_result *res)
|
|
{
|
|
struct fib_info *fi = res->fi;
|
|
int w;
|
|
|
|
spin_lock_bh(&fib_multipath_lock);
|
|
if (fi->fib_power <= 0) {
|
|
int power = 0;
|
|
change_nexthops(fi) {
|
|
if (!(nh->nh_flags&RTNH_F_DEAD)) {
|
|
power += nh->nh_weight;
|
|
nh->nh_power = nh->nh_weight;
|
|
}
|
|
} endfor_nexthops(fi);
|
|
fi->fib_power = power;
|
|
if (power <= 0) {
|
|
spin_unlock_bh(&fib_multipath_lock);
|
|
/* Race condition: route has just become dead. */
|
|
res->nh_sel = 0;
|
|
return;
|
|
}
|
|
}
|
|
|
|
|
|
/* w should be random number [0..fi->fib_power-1],
|
|
it is pretty bad approximation.
|
|
*/
|
|
|
|
w = jiffies % fi->fib_power;
|
|
|
|
change_nexthops(fi) {
|
|
if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
|
|
if ((w -= nh->nh_power) <= 0) {
|
|
nh->nh_power--;
|
|
fi->fib_power--;
|
|
res->nh_sel = nhsel;
|
|
spin_unlock_bh(&fib_multipath_lock);
|
|
return;
|
|
}
|
|
}
|
|
} endfor_nexthops(fi);
|
|
|
|
/* Race condition: route has just become dead. */
|
|
res->nh_sel = 0;
|
|
spin_unlock_bh(&fib_multipath_lock);
|
|
}
|
|
#endif
|