route.c 75.8 KB
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/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		ROUTE - implementation of the IP router.
 *
 * Version:	$Id: route.c,v 1.103 2002/01/12 07:44:09 davem Exp $
 *
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 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Linus Torvalds, <Linus.Torvalds@helsinki.fi>
 *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Fixes:
 *		Alan Cox	:	Verify area fixes.
 *		Alan Cox	:	cli() protects routing changes
 *		Rui Oliveira	:	ICMP routing table updates
 *		(rco@di.uminho.pt)	Routing table insertion and update
 *		Linus Torvalds	:	Rewrote bits to be sensible
 *		Alan Cox	:	Added BSD route gw semantics
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 *		Alan Cox	:	Super /proc >4K
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 *		Alan Cox	:	MTU in route table
 *		Alan Cox	: 	MSS actually. Also added the window
 *					clamper.
 *		Sam Lantinga	:	Fixed route matching in rt_del()
 *		Alan Cox	:	Routing cache support.
 *		Alan Cox	:	Removed compatibility cruft.
 *		Alan Cox	:	RTF_REJECT support.
 *		Alan Cox	:	TCP irtt support.
 *		Jonathan Naylor	:	Added Metric support.
 *	Miquel van Smoorenburg	:	BSD API fixes.
 *	Miquel van Smoorenburg	:	Metrics.
 *		Alan Cox	:	Use __u32 properly
 *		Alan Cox	:	Aligned routing errors more closely with BSD
 *					our system is still very different.
 *		Alan Cox	:	Faster /proc handling
 *	Alexey Kuznetsov	:	Massive rework to support tree based routing,
 *					routing caches and better behaviour.
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 *
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 *		Olaf Erb	:	irtt wasn't being copied right.
 *		Bjorn Ekwall	:	Kerneld route support.
 *		Alan Cox	:	Multicast fixed (I hope)
 * 		Pavel Krauz	:	Limited broadcast fixed
 *		Mike McLagan	:	Routing by source
 *	Alexey Kuznetsov	:	End of old history. Split to fib.c and
 *					route.c and rewritten from scratch.
 *		Andi Kleen	:	Load-limit warning messages.
 *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
 *	Vitaly E. Lavrov	:	Race condition in ip_route_input_slow.
 *	Tobias Ringstrom	:	Uninitialized res.type in ip_route_output_slow.
 *	Vladimir V. Ivanov	:	IP rule info (flowid) is really useful.
 *		Marc Boucher	:	routing by fwmark
 *	Robert Olsson		:	Added rt_cache statistics
 *	Arnaldo C. Melo		:	Convert proc stuff to seq_file
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 *	Eric Dumazet		:	hashed spinlocks and rt_check_expire() fixes.
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 * 	Ilia Sotnikov		:	Ignore TOS on PMTUD and Redirect
 * 	Ilia Sotnikov		:	Removed TOS from hash calculations
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 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
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#include <linux/bootmem.h>
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#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
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#include <linux/workqueue.h>
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#include <linux/skbuff.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/pkt_sched.h>
#include <linux/mroute.h>
#include <linux/netfilter_ipv4.h>
#include <linux/random.h>
#include <linux/jhash.h>
#include <linux/rcupdate.h>
#include <linux/times.h>
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#include <net/dst.h>
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#include <net/net_namespace.h>
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#include <net/protocol.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/inetpeer.h>
#include <net/sock.h>
#include <net/ip_fib.h>
#include <net/arp.h>
#include <net/tcp.h>
#include <net/icmp.h>
#include <net/xfrm.h>
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#include <net/netevent.h>
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#include <net/rtnetlink.h>
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#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif

#define RT_FL_TOS(oldflp) \
    ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))

#define IP_MAX_MTU	0xFFF0

#define RT_GC_TIMEOUT (300*HZ)

static int ip_rt_max_size;
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static int ip_rt_gc_timeout __read_mostly	= RT_GC_TIMEOUT;
static int ip_rt_gc_interval __read_mostly	= 60 * HZ;
static int ip_rt_gc_min_interval __read_mostly	= HZ / 2;
static int ip_rt_redirect_number __read_mostly	= 9;
static int ip_rt_redirect_load __read_mostly	= HZ / 50;
static int ip_rt_redirect_silence __read_mostly	= ((HZ / 50) << (9 + 1));
static int ip_rt_error_cost __read_mostly	= HZ;
static int ip_rt_error_burst __read_mostly	= 5 * HZ;
static int ip_rt_gc_elasticity __read_mostly	= 8;
static int ip_rt_mtu_expires __read_mostly	= 10 * 60 * HZ;
static int ip_rt_min_pmtu __read_mostly		= 512 + 20 + 20;
static int ip_rt_min_advmss __read_mostly	= 256;
static int ip_rt_secret_interval __read_mostly	= 10 * 60 * HZ;
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static void rt_worker_func(struct work_struct *work);
static DECLARE_DELAYED_WORK(expires_work, rt_worker_func);
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static struct timer_list rt_secret_timer;

/*
 *	Interface to generic destination cache.
 */

static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
static void		 ipv4_dst_destroy(struct dst_entry *dst);
static void		 ipv4_dst_ifdown(struct dst_entry *dst,
					 struct net_device *dev, int how);
static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
static void		 ipv4_link_failure(struct sk_buff *skb);
static void		 ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
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static int rt_garbage_collect(struct dst_ops *ops);
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static struct dst_ops ipv4_dst_ops = {
	.family =		AF_INET,
	.protocol =		__constant_htons(ETH_P_IP),
	.gc =			rt_garbage_collect,
	.check =		ipv4_dst_check,
	.destroy =		ipv4_dst_destroy,
	.ifdown =		ipv4_dst_ifdown,
	.negative_advice =	ipv4_negative_advice,
	.link_failure =		ipv4_link_failure,
	.update_pmtu =		ip_rt_update_pmtu,
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	.local_out =		ip_local_out,
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	.entry_size =		sizeof(struct rtable),
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	.entries =		ATOMIC_INIT(0),
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};

#define ECN_OR_COST(class)	TC_PRIO_##class

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const __u8 ip_tos2prio[16] = {
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	TC_PRIO_BESTEFFORT,
	ECN_OR_COST(FILLER),
	TC_PRIO_BESTEFFORT,
	ECN_OR_COST(BESTEFFORT),
	TC_PRIO_BULK,
	ECN_OR_COST(BULK),
	TC_PRIO_BULK,
	ECN_OR_COST(BULK),
	TC_PRIO_INTERACTIVE,
	ECN_OR_COST(INTERACTIVE),
	TC_PRIO_INTERACTIVE,
	ECN_OR_COST(INTERACTIVE),
	TC_PRIO_INTERACTIVE_BULK,
	ECN_OR_COST(INTERACTIVE_BULK),
	TC_PRIO_INTERACTIVE_BULK,
	ECN_OR_COST(INTERACTIVE_BULK)
};


/*
 * Route cache.
 */

/* The locking scheme is rather straight forward:
 *
 * 1) Read-Copy Update protects the buckets of the central route hash.
 * 2) Only writers remove entries, and they hold the lock
 *    as they look at rtable reference counts.
 * 3) Only readers acquire references to rtable entries,
 *    they do so with atomic increments and with the
 *    lock held.
 */

struct rt_hash_bucket {
	struct rtable	*chain;
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};
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
	defined(CONFIG_PROVE_LOCKING)
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/*
 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
 * The size of this table is a power of two and depends on the number of CPUS.
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 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
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 */
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#ifdef CONFIG_LOCKDEP
# define RT_HASH_LOCK_SZ	256
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#else
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# if NR_CPUS >= 32
#  define RT_HASH_LOCK_SZ	4096
# elif NR_CPUS >= 16
#  define RT_HASH_LOCK_SZ	2048
# elif NR_CPUS >= 8
#  define RT_HASH_LOCK_SZ	1024
# elif NR_CPUS >= 4
#  define RT_HASH_LOCK_SZ	512
# else
#  define RT_HASH_LOCK_SZ	256
# endif
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#endif

static spinlock_t	*rt_hash_locks;
# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
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static __init void rt_hash_lock_init(void)
{
	int i;

	rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
			GFP_KERNEL);
	if (!rt_hash_locks)
		panic("IP: failed to allocate rt_hash_locks\n");

	for (i = 0; i < RT_HASH_LOCK_SZ; i++)
		spin_lock_init(&rt_hash_locks[i]);
}
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#else
# define rt_hash_lock_addr(slot) NULL
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static inline void rt_hash_lock_init(void)
{
}
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#endif
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static struct rt_hash_bucket 	*rt_hash_table __read_mostly;
static unsigned			rt_hash_mask __read_mostly;
static unsigned int		rt_hash_log  __read_mostly;
static atomic_t			rt_genid __read_mostly;
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static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
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#define RT_CACHE_STAT_INC(field) \
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	(__raw_get_cpu_var(rt_cache_stat).field++)
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static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx)
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{
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	return jhash_3words((__force u32)(__be32)(daddr),
			    (__force u32)(__be32)(saddr),
			    idx, atomic_read(&rt_genid))
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		& rt_hash_mask;
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}

#ifdef CONFIG_PROC_FS
struct rt_cache_iter_state {
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	struct seq_net_private p;
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	int bucket;
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	int genid;
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};

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static struct rtable *rt_cache_get_first(struct seq_file *seq)
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{
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	struct rt_cache_iter_state *st = seq->private;
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	struct rtable *r = NULL;

	for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
		rcu_read_lock_bh();
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		r = rcu_dereference(rt_hash_table[st->bucket].chain);
		while (r) {
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			if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
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			    r->rt_genid == st->genid)
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				return r;
			r = rcu_dereference(r->u.dst.rt_next);
		}
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		rcu_read_unlock_bh();
	}
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	return r;
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}

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static struct rtable *__rt_cache_get_next(struct seq_file *seq,
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					  struct rtable *r)
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{
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	struct rt_cache_iter_state *st = seq->private;
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	r = r->u.dst.rt_next;
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	while (!r) {
		rcu_read_unlock_bh();
		if (--st->bucket < 0)
			break;
		rcu_read_lock_bh();
		r = rt_hash_table[st->bucket].chain;
	}
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	return rcu_dereference(r);
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}

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static struct rtable *rt_cache_get_next(struct seq_file *seq,
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					struct rtable *r)
{
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	struct rt_cache_iter_state *st = seq->private;
	while ((r = __rt_cache_get_next(seq, r)) != NULL) {
		if (dev_net(r->u.dst.dev) != seq_file_net(seq))
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			continue;
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		if (r->rt_genid == st->genid)
			break;
	}
	return r;
}

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static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
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{
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	struct rtable *r = rt_cache_get_first(seq);
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	if (r)
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		while (pos && (r = rt_cache_get_next(seq, r)))
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			--pos;
	return pos ? NULL : r;
}

static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
{
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	struct rt_cache_iter_state *st = seq->private;
	if (*pos)
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		return rt_cache_get_idx(seq, *pos - 1);
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	st->genid = atomic_read(&rt_genid);
	return SEQ_START_TOKEN;
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}

static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
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	struct rtable *r;
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	if (v == SEQ_START_TOKEN)
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		r = rt_cache_get_first(seq);
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	else
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		r = rt_cache_get_next(seq, v);
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	++*pos;
	return r;
}

static void rt_cache_seq_stop(struct seq_file *seq, void *v)
{
	if (v && v != SEQ_START_TOKEN)
		rcu_read_unlock_bh();
}

static int rt_cache_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_printf(seq, "%-127s\n",
			   "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
			   "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
			   "HHUptod\tSpecDst");
	else {
		struct rtable *r = v;
		char temp[256];

		sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
			      "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
			r->u.dst.dev ? r->u.dst.dev->name : "*",
			(unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
			r->rt_flags, atomic_read(&r->u.dst.__refcnt),
			r->u.dst.__use, 0, (unsigned long)r->rt_src,
			(dst_metric(&r->u.dst, RTAX_ADVMSS) ?
			     (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
			dst_metric(&r->u.dst, RTAX_WINDOW),
			(int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
			      dst_metric(&r->u.dst, RTAX_RTTVAR)),
			r->fl.fl4_tos,
			r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
			r->u.dst.hh ? (r->u.dst.hh->hh_output ==
				       dev_queue_xmit) : 0,
			r->rt_spec_dst);
		seq_printf(seq, "%-127s\n", temp);
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	}
	return 0;
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}

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static const struct seq_operations rt_cache_seq_ops = {
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	.start  = rt_cache_seq_start,
	.next   = rt_cache_seq_next,
	.stop   = rt_cache_seq_stop,
	.show   = rt_cache_seq_show,
};

static int rt_cache_seq_open(struct inode *inode, struct file *file)
{
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	return seq_open_net(inode, file, &rt_cache_seq_ops,
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			sizeof(struct rt_cache_iter_state));
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}

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static const struct file_operations rt_cache_seq_fops = {
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	.owner	 = THIS_MODULE,
	.open	 = rt_cache_seq_open,
	.read	 = seq_read,
	.llseek	 = seq_lseek,
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	.release = seq_release_net,
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};


static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
{
	int cpu;

	if (*pos == 0)
		return SEQ_START_TOKEN;

	for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
		if (!cpu_possible(cpu))
			continue;
		*pos = cpu+1;
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		return &per_cpu(rt_cache_stat, cpu);
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	}
	return NULL;
}

static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	int cpu;

	for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
		if (!cpu_possible(cpu))
			continue;
		*pos = cpu+1;
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		return &per_cpu(rt_cache_stat, cpu);
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	}
	return NULL;
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}

static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
{

}

static int rt_cpu_seq_show(struct seq_file *seq, void *v)
{
	struct rt_cache_stat *st = v;

	if (v == SEQ_START_TOKEN) {
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		seq_printf(seq, "entries  in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src  out_hit out_slow_tot out_slow_mc  gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
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		return 0;
	}
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	seq_printf(seq,"%08x  %08x %08x %08x %08x %08x %08x %08x "
		   " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
		   atomic_read(&ipv4_dst_ops.entries),
		   st->in_hit,
		   st->in_slow_tot,
		   st->in_slow_mc,
		   st->in_no_route,
		   st->in_brd,
		   st->in_martian_dst,
		   st->in_martian_src,

		   st->out_hit,
		   st->out_slow_tot,
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		   st->out_slow_mc,
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		   st->gc_total,
		   st->gc_ignored,
		   st->gc_goal_miss,
		   st->gc_dst_overflow,
		   st->in_hlist_search,
		   st->out_hlist_search
		);
	return 0;
}

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static const struct seq_operations rt_cpu_seq_ops = {
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	.start  = rt_cpu_seq_start,
	.next   = rt_cpu_seq_next,
	.stop   = rt_cpu_seq_stop,
	.show   = rt_cpu_seq_show,
};


static int rt_cpu_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &rt_cpu_seq_ops);
}

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static const struct file_operations rt_cpu_seq_fops = {
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	.owner	 = THIS_MODULE,
	.open	 = rt_cpu_seq_open,
	.read	 = seq_read,
	.llseek	 = seq_lseek,
	.release = seq_release,
};

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#ifdef CONFIG_NET_CLS_ROUTE
static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
			   int length, int *eof, void *data)
{
	unsigned int i;

	if ((offset & 3) || (length & 3))
		return -EIO;

	if (offset >= sizeof(struct ip_rt_acct) * 256) {
		*eof = 1;
		return 0;
	}

	if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
		length = sizeof(struct ip_rt_acct) * 256 - offset;
		*eof = 1;
	}

	offset /= sizeof(u32);

	if (length > 0) {
		u32 *dst = (u32 *) buffer;

		*start = buffer;
		memset(dst, 0, length);

		for_each_possible_cpu(i) {
			unsigned int j;
			u32 *src;

			src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset;
			for (j = 0; j < length/4; j++)
				dst[j] += src[j];
		}
	}
	return length;
}
#endif
544

545
static int __net_init ip_rt_do_proc_init(struct net *net)
546 547 548 549 550 551 552 553
{
	struct proc_dir_entry *pde;

	pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
			&rt_cache_seq_fops);
	if (!pde)
		goto err1;

554 555
	pde = proc_create("rt_cache", S_IRUGO,
			  net->proc_net_stat, &rt_cpu_seq_fops);
556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575
	if (!pde)
		goto err2;

#ifdef CONFIG_NET_CLS_ROUTE
	pde = create_proc_read_entry("rt_acct", 0, net->proc_net,
			ip_rt_acct_read, NULL);
	if (!pde)
		goto err3;
#endif
	return 0;

#ifdef CONFIG_NET_CLS_ROUTE
err3:
	remove_proc_entry("rt_cache", net->proc_net_stat);
#endif
err2:
	remove_proc_entry("rt_cache", net->proc_net);
err1:
	return -ENOMEM;
}
576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593

static void __net_exit ip_rt_do_proc_exit(struct net *net)
{
	remove_proc_entry("rt_cache", net->proc_net_stat);
	remove_proc_entry("rt_cache", net->proc_net);
	remove_proc_entry("rt_acct", net->proc_net);
}

static struct pernet_operations ip_rt_proc_ops __net_initdata =  {
	.init = ip_rt_do_proc_init,
	.exit = ip_rt_do_proc_exit,
};

static int __init ip_rt_proc_init(void)
{
	return register_pernet_subsys(&ip_rt_proc_ops);
}

594
#else
595
static inline int ip_rt_proc_init(void)
596 597 598
{
	return 0;
}
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#endif /* CONFIG_PROC_FS */
600

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static inline void rt_free(struct rtable *rt)
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{
	call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
}

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static inline void rt_drop(struct rtable *rt)
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{
	ip_rt_put(rt);
	call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
}

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static inline int rt_fast_clean(struct rtable *rth)
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{
	/* Kill broadcast/multicast entries very aggresively, if they
	   collide in hash table with more useful entries */
	return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
617
		rth->fl.iif && rth->u.dst.rt_next;
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}

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static inline int rt_valuable(struct rtable *rth)
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{
	return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
		rth->u.dst.expires;
}

static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
{
	unsigned long age;
	int ret = 0;

	if (atomic_read(&rth->u.dst.__refcnt))
		goto out;

	ret = 1;
	if (rth->u.dst.expires &&
	    time_after_eq(jiffies, rth->u.dst.expires))
		goto out;

	age = jiffies - rth->u.dst.lastuse;
	ret = 0;
	if ((age <= tmo1 && !rt_fast_clean(rth)) ||
	    (age <= tmo2 && rt_valuable(rth)))
		goto out;
	ret = 1;
out:	return ret;
}

/* Bits of score are:
 * 31: very valuable
 * 30: not quite useless
 * 29..0: usage counter
 */
static inline u32 rt_score(struct rtable *rt)
{
	u32 score = jiffies - rt->u.dst.lastuse;

	score = ~score & ~(3<<30);

	if (rt_valuable(rt))
		score |= (1<<31);

	if (!rt->fl.iif ||
	    !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
		score |= (1<<30);

	return score;
}

static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
{
671 672
	return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
		(fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
673
		(fl1->mark ^ fl2->mark) |
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		(*(u16 *)&fl1->nl_u.ip4_u.tos ^
		 *(u16 *)&fl2->nl_u.ip4_u.tos) |
		(fl1->oif ^ fl2->oif) |
		(fl1->iif ^ fl2->iif)) == 0;
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}

680 681
static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
{
682
	return dev_net(rt1->u.dst.dev) == dev_net(rt2->u.dst.dev);
683 684
}

685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714
/*
 * Perform a full scan of hash table and free all entries.
 * Can be called by a softirq or a process.
 * In the later case, we want to be reschedule if necessary
 */
static void rt_do_flush(int process_context)
{
	unsigned int i;
	struct rtable *rth, *next;

	for (i = 0; i <= rt_hash_mask; i++) {
		if (process_context && need_resched())
			cond_resched();
		rth = rt_hash_table[i].chain;
		if (!rth)
			continue;

		spin_lock_bh(rt_hash_lock_addr(i));
		rth = rt_hash_table[i].chain;
		rt_hash_table[i].chain = NULL;
		spin_unlock_bh(rt_hash_lock_addr(i));

		for (; rth; rth = next) {
			next = rth->u.dst.rt_next;
			rt_free(rth);
		}
	}
}

static void rt_check_expire(void)
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{
716 717
	static unsigned int rover;
	unsigned int i = rover, goal;
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	struct rtable *rth, **rthp;
719 720 721 722 723 724
	u64 mult;

	mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
	if (ip_rt_gc_timeout > 1)
		do_div(mult, ip_rt_gc_timeout);
	goal = (unsigned int)mult;
725 726
	if (goal > rt_hash_mask)
		goal = rt_hash_mask + 1;
727
	for (; goal > 0; goal--) {
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		unsigned long tmo = ip_rt_gc_timeout;

		i = (i + 1) & rt_hash_mask;
		rthp = &rt_hash_table[i].chain;

733 734 735
		if (need_resched())
			cond_resched();

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		if (*rthp == NULL)
737
			continue;
738
		spin_lock_bh(rt_hash_lock_addr(i));
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		while ((rth = *rthp) != NULL) {
740 741 742 743 744
			if (rth->rt_genid != atomic_read(&rt_genid)) {
				*rthp = rth->u.dst.rt_next;
				rt_free(rth);
				continue;
			}
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			if (rth->u.dst.expires) {
				/* Entry is expired even if it is in use */
747
				if (time_before_eq(jiffies, rth->u.dst.expires)) {
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					tmo >>= 1;
749
					rthp = &rth->u.dst.rt_next;
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					continue;
				}
			} else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
				tmo >>= 1;
754
				rthp = &rth->u.dst.rt_next;
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				continue;
			}

			/* Cleanup aged off entries. */
759
			*rthp = rth->u.dst.rt_next;
760
			rt_free(rth);
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		}
762
		spin_unlock_bh(rt_hash_lock_addr(i));
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	}
	rover = i;
765 766 767 768
}

/*
 * rt_worker_func() is run in process context.
769
 * we call rt_check_expire() to scan part of the hash table
770 771 772
 */
static void rt_worker_func(struct work_struct *work)
{
773
	rt_check_expire();
774
	schedule_delayed_work(&expires_work, ip_rt_gc_interval);
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}

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/*
 * Pertubation of rt_genid by a small quantity [1..256]
 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
 * many times (2^24) without giving recent rt_genid.
 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
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 */
783
static void rt_cache_invalidate(void)
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{
785
	unsigned char shuffle;
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787 788
	get_random_bytes(&shuffle, sizeof(shuffle));
	atomic_add(shuffle + 1U, &rt_genid);
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}

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/*
 * delay < 0  : invalidate cache (fast : entries will be deleted later)
 * delay >= 0 : invalidate & flush cache (can be long)
 */
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void rt_cache_flush(int delay)
{
797 798 799
	rt_cache_invalidate();
	if (delay >= 0)
		rt_do_flush(!in_softirq());
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}

802
/*
803
 * We change rt_genid and let gc do the cleanup
804
 */
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static void rt_secret_rebuild(unsigned long dummy)
{
807
	rt_cache_invalidate();
808
	mod_timer(&rt_secret_timer, jiffies + ip_rt_secret_interval);
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}

/*
   Short description of GC goals.

   We want to build algorithm, which will keep routing cache
   at some equilibrium point, when number of aged off entries
   is kept approximately equal to newly generated ones.

   Current expiration strength is variable "expire".
   We try to adjust it dynamically, so that if networking
   is idle expires is large enough to keep enough of warm entries,
   and when load increases it reduces to limit cache size.
 */

824
static int rt_garbage_collect(struct dst_ops *ops)
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{
	static unsigned long expire = RT_GC_TIMEOUT;
	static unsigned long last_gc;
	static int rover;
	static int equilibrium;
	struct rtable *rth, **rthp;
	unsigned long now = jiffies;
	int goal;

	/*
	 * Garbage collection is pretty expensive,
	 * do not make it too frequently.
	 */

	RT_CACHE_STAT_INC(gc_total);

	if (now - last_gc < ip_rt_gc_min_interval &&
	    atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
		RT_CACHE_STAT_INC(gc_ignored);
		goto out;
	}

	/* Calculate number of entries, which we want to expire now. */
	goal = atomic_read(&ipv4_dst_ops.entries) -
		(ip_rt_gc_elasticity << rt_hash_log);
	if (goal <= 0) {
		if (equilibrium < ipv4_dst_ops.gc_thresh)
			equilibrium = ipv4_dst_ops.gc_thresh;
		goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
		if (goal > 0) {
855
			equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
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			goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
		}
	} else {
		/* We are in dangerous area. Try to reduce cache really
		 * aggressively.
		 */
862
		goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
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		equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
	}

	if (now - last_gc >= ip_rt_gc_min_interval)
		last_gc = now;

	if (goal <= 0) {
		equilibrium += goal;
		goto work_done;
	}

	do {
		int i, k;

		for (i = rt_hash_mask, k = rover; i >= 0; i--) {
			unsigned long tmo = expire;

			k = (k + 1) & rt_hash_mask;
			rthp = &rt_hash_table[k].chain;
882
			spin_lock_bh(rt_hash_lock_addr(k));
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			while ((rth = *rthp) != NULL) {
884 885
				if (rth->rt_genid == atomic_read(&rt_genid) &&
					!rt_may_expire(rth, tmo, expire)) {
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					tmo >>= 1;
887
					rthp = &rth->u.dst.rt_next;
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					continue;
				}
890
				*rthp = rth->u.dst.rt_next;
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				rt_free(rth);
				goal--;
			}
894
			spin_unlock_bh(rt_hash_lock_addr(k));
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			if (goal <= 0)
				break;
		}
		rover = k;

		if (goal <= 0)
			goto work_done;

		/* Goal is not achieved. We stop process if:

		   - if expire reduced to zero. Otherwise, expire is halfed.
		   - if table is not full.
		   - if we are called from interrupt.
		   - jiffies check is just fallback/debug loop breaker.
		     We will not spin here for long time in any case.
		 */

		RT_CACHE_STAT_INC(gc_goal_miss);

		if (expire == 0)
			break;

		expire >>= 1;
#if RT_CACHE_DEBUG >= 2
		printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
				atomic_read(&ipv4_dst_ops.entries), goal, i);
#endif

		if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
			goto out;
	} while (!in_softirq() && time_before_eq(jiffies, now));

	if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
		goto out;
	if (net_ratelimit())
		printk(KERN_WARNING "dst cache overflow\n");
	RT_CACHE_STAT_INC(gc_dst_overflow);
	return 1;

work_done:
	expire += ip_rt_gc_min_interval;
	if (expire > ip_rt_gc_timeout ||
	    atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
		expire = ip_rt_gc_timeout;
#if RT_CACHE_DEBUG >= 2
	printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
			atomic_read(&ipv4_dst_ops.entries), goal, rover);
#endif
out:	return 0;
}

static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
{
	struct rtable	*rth, **rthp;
	unsigned long	now;
	struct rtable *cand, **candp;
	u32 		min_score;
	int		chain_length;
	int attempts = !in_softirq();

restart:
	chain_length = 0;
	min_score = ~(u32)0;
	cand = NULL;
	candp = NULL;
	now = jiffies;

	rthp = &rt_hash_table[hash].chain;

964
	spin_lock_bh(rt_hash_lock_addr(hash));
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	while ((rth = *rthp) != NULL) {
966 967 968 969 970
		if (rth->rt_genid != atomic_read(&rt_genid)) {
			*rthp = rth->u.dst.rt_next;
			rt_free(rth);
			continue;
		}
971
		if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
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			/* Put it first */
973
			*rthp = rth->u.dst.rt_next;
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			/*
			 * Since lookup is lockfree, the deletion
			 * must be visible to another weakly ordered CPU before
			 * the insertion at the start of the hash chain.
			 */
979
			rcu_assign_pointer(rth->u.dst.rt_next,
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					   rt_hash_table[hash].chain);
			/*
			 * Since lookup is lockfree, the update writes
			 * must be ordered for consistency on SMP.
			 */
			rcu_assign_pointer(rt_hash_table[hash].chain, rth);

987
			dst_use(&rth->u.dst, now);
988
			spin_unlock_bh(rt_hash_lock_addr(hash));
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			rt_drop(rt);
			*rp = rth;
			return 0;
		}

		if (!atomic_read(&rth->u.dst.__refcnt)) {
			u32 score = rt_score(rth);

			if (score <= min_score) {
				cand = rth;
				candp = rthp;
				min_score = score;
			}
		}

		chain_length++;

1007
		rthp = &rth->u.dst.rt_next;
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	}

	if (cand) {
		/* ip_rt_gc_elasticity used to be average length of chain
		 * length, when exceeded gc becomes really aggressive.
		 *
		 * The second limit is less certain. At the moment it allows
		 * only 2 entries per bucket. We will see.
		 */
		if (chain_length > ip_rt_gc_elasticity) {
1018
			*candp = cand->u.dst.rt_next;
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			rt_free(cand);
		}
	}

	/* Try to bind route to arp only if it is output
	   route or unicast forwarding path.
	 */
	if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
		int err = arp_bind_neighbour(&rt->u.dst);
		if (err) {
1029
			spin_unlock_bh(rt_hash_lock_addr(hash));
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			if (err != -ENOBUFS) {
				rt_drop(rt);
				return err;
			}

			/* Neighbour tables are full and nothing
			   can be released. Try to shrink route cache,
			   it is most likely it holds some neighbour records.
			 */
			if (attempts-- > 0) {
				int saved_elasticity = ip_rt_gc_elasticity;
				int saved_int = ip_rt_gc_min_interval;
				ip_rt_gc_elasticity	= 1;
				ip_rt_gc_min_interval	= 0;
1045
				rt_garbage_collect(&ipv4_dst_ops);
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				ip_rt_gc_min_interval	= saved_int;
				ip_rt_gc_elasticity	= saved_elasticity;
				goto restart;
			}

			if (net_ratelimit())
				printk(KERN_WARNING "Neighbour table overflow.\n");
			rt_drop(rt);
			return -ENOBUFS;
		}
	}

1058
	rt->u.dst.rt_next = rt_hash_table[hash].chain;
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#if RT_CACHE_DEBUG >= 2
1060
	if (rt->u.dst.rt_next) {
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		struct rtable *trt;
1062
		printk(KERN_DEBUG "rt_cache @%02x: " NIPQUAD_FMT, hash,
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		       NIPQUAD(rt->rt_dst));
1064
		for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1065
			printk(" . " NIPQUAD_FMT, NIPQUAD(trt->rt_dst));
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		printk("\n");
	}
#endif
	rt_hash_table[hash].chain = rt;
1070
	spin_unlock_bh(rt_hash_lock_addr(hash));
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	*rp = rt;
	return 0;
}

void rt_bind_peer(struct rtable *rt, int create)
{
	static DEFINE_SPINLOCK(rt_peer_lock);
	struct inet_peer *peer;

	peer = inet_getpeer(rt->rt_dst, create);

	spin_lock_bh(&rt_peer_lock);
	if (rt->peer == NULL) {
		rt->peer = peer;
		peer = NULL;
	}
	spin_unlock_bh(&rt_peer_lock);
	if (peer)
		inet_putpeer(peer);
}

/*
 * Peer allocation may fail only in serious out-of-memory conditions.  However
 * we still can generate some output.
 * Random ID selection looks a bit dangerous because we have no chances to
 * select ID being unique in a reasonable period of time.
 * But broken packet identifier may be better than no packet at all.
 */
static void ip_select_fb_ident(struct iphdr *iph)
{
	static DEFINE_SPINLOCK(ip_fb_id_lock);
	static u32 ip_fallback_id;
	u32 salt;

	spin_lock_bh(&ip_fb_id_lock);
1106
	salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
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	iph->id = htons(salt & 0xFFFF);
	ip_fallback_id = salt;
	spin_unlock_bh(&ip_fb_id_lock);
}

void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
{
	struct rtable *rt = (struct rtable *) dst;

	if (rt) {
		if (rt->peer == NULL)
			rt_bind_peer(rt, 1);

		/* If peer is attached to destination, it is never detached,
		   so that we need not to grab a lock to dereference it.
		 */
		if (rt->peer) {
			iph->id = htons(inet_getid(rt->peer, more));
			return;
		}
	} else
1128
		printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1129
		       __builtin_return_address(0));
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	ip_select_fb_ident(iph);
}

static void rt_del(unsigned hash, struct rtable *rt)
{
1136
	struct rtable **rthp, *aux;
L
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1138
	rthp = &rt_hash_table[hash].chain;
1139
	spin_lock_bh(rt_hash_lock_addr(hash));
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	ip_rt_put(rt);
1141 1142 1143 1144 1145
	while ((aux = *rthp) != NULL) {
		if (aux == rt || (aux->rt_genid != atomic_read(&rt_genid))) {
			*rthp = aux->u.dst.rt_next;
			rt_free(aux);
			continue;
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		}
1147 1148
		rthp = &aux->u.dst.rt_next;
	}
1149
	spin_unlock_bh(rt_hash_lock_addr(hash));
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}

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void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
		    __be32 saddr, struct net_device *dev)
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{
	int i, k;
	struct in_device *in_dev = in_dev_get(dev);
	struct rtable *rth, **rthp;
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	__be32  skeys[2] = { saddr, 0 };
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	int  ikeys[2] = { dev->ifindex, 0 };
1160
	struct netevent_redirect netevent;
1161
	struct net *net;
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	if (!in_dev)
		return;

1166
	net = dev_net(dev);
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	if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1168
	    || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw)
1169
	    || ipv4_is_zeronet(new_gw))
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		goto reject_redirect;

	if (!IN_DEV_SHARED_MEDIA(in_dev)) {
		if (!inet_addr_onlink(in_dev, new_gw, old_gw))
			goto reject_redirect;
		if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
			goto reject_redirect;
	} else {
1178
		if (inet_addr_type(net, new_gw) != RTN_UNICAST)
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			goto reject_redirect;
	}

	for (i = 0; i < 2; i++) {
		for (k = 0; k < 2; k++) {
A
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			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
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			rthp=&rt_hash_table[hash].chain;

			rcu_read_lock();
			while ((rth = rcu_dereference(*rthp)) != NULL) {
				struct rtable *rt;

				if (rth->fl.fl4_dst != daddr ||
				    rth->fl.fl4_src != skeys[i] ||
				    rth->fl.oif != ikeys[k] ||
1195
				    rth->fl.iif != 0 ||
1196
				    rth->rt_genid != atomic_read(&rt_genid) ||
1197
				    !net_eq(dev_net(rth->u.dst.dev), net)) {
1198
					rthp = &rth->u.dst.rt_next;
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					continue;
				}

				if (rth->rt_dst != daddr ||
				    rth->rt_src != saddr ||
				    rth->u.dst.error ||
				    rth->rt_gateway != old_gw ||
				    rth->u.dst.dev != dev)
					break;

				dst_hold(&rth->u.dst);
				rcu_read_unlock();

				rt = dst_alloc(&ipv4_dst_ops);
				if (rt == NULL) {
					ip_rt_put(rth);
					in_dev_put(in_dev);
					return;
				}

				/* Copy all the information. */
				*rt = *rth;
1221
				INIT_RCU_HEAD(&rt->u.dst.rcu_head);
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				rt->u.dst.__use		= 1;
				atomic_set(&rt->u.dst.__refcnt, 1);
				rt->u.dst.child		= NULL;
				if (rt->u.dst.dev)
					dev_hold(rt->u.dst.dev);
				if (rt->idev)
					in_dev_hold(rt->idev);
				rt->u.dst.obsolete	= 0;
				rt->u.dst.lastuse	= jiffies;
				rt->u.dst.path		= &rt->u.dst;
				rt->u.dst.neighbour	= NULL;
				rt->u.dst.hh		= NULL;
				rt->u.dst.xfrm		= NULL;
1235
				rt->rt_genid		= atomic_read(&rt_genid);
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				rt->rt_flags		|= RTCF_REDIRECTED;

				/* Gateway is different ... */
				rt->rt_gateway		= new_gw;

				/* Redirect received -> path was valid */
				dst_confirm(&rth->u.dst);

				if (rt->peer)
					atomic_inc(&rt->peer->refcnt);

				if (arp_bind_neighbour(&rt->u.dst) ||
				    !(rt->u.dst.neighbour->nud_state &
					    NUD_VALID)) {
					if (rt->u.dst.neighbour)
						neigh_event_send(rt->u.dst.neighbour, NULL);
					ip_rt_put(rth);
					rt_drop(rt);
					goto do_next;
				}
1256

1257 1258
				netevent.old = &rth->u.dst;
				netevent.new = &rt->u.dst;
1259 1260
				call_netevent_notifiers(NETEVENT_REDIRECT,
							&netevent);
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				rt_del(hash, rth);
				if (!rt_intern_hash(hash, rt, &rt))
					ip_rt_put(rt);
				goto do_next;
			}
			rcu_read_unlock();
		do_next:
			;
		}
	}
	in_dev_put(in_dev);
	return;

reject_redirect:
#ifdef CONFIG_IP_ROUTE_VERBOSE
	if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1278 1279 1280
		printk(KERN_INFO "Redirect from " NIPQUAD_FMT " on %s about "
			NIPQUAD_FMT " ignored.\n"
			"  Advised path = " NIPQUAD_FMT " -> " NIPQUAD_FMT "\n",
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		       NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
1282
		       NIPQUAD(saddr), NIPQUAD(daddr));
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#endif
	in_dev_put(in_dev);
}

static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
{
1289
	struct rtable *rt = (struct rtable *)dst;
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	struct dst_entry *ret = dst;

	if (rt) {
		if (dst->obsolete) {
			ip_rt_put(rt);
			ret = NULL;
		} else if ((rt->rt_flags & RTCF_REDIRECTED) ||
			   rt->u.dst.expires) {
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			unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
						rt->fl.oif);
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#if RT_CACHE_DEBUG >= 1
1301
			printk(KERN_DEBUG "ipv4_negative_advice: redirect to "
1302
					  NIPQUAD_FMT "/%02x dropped\n",
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				NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
#endif
			rt_del(hash, rt);
			ret = NULL;
		}
	}
	return ret;
}

/*
 * Algorithm:
 *	1. The first ip_rt_redirect_number redirects are sent
 *	   with exponential backoff, then we stop sending them at all,
 *	   assuming that the host ignores our redirects.
 *	2. If we did not see packets requiring redirects
 *	   during ip_rt_redirect_silence, we assume that the host
 *	   forgot redirected route and start to send redirects again.
 *
 * This algorithm is much cheaper and more intelligent than dumb load limiting
 * in icmp.c.
 *
 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
 * and "frag. need" (breaks PMTU discovery) in icmp.c.
 */

void ip_rt_send_redirect(struct sk_buff *skb)
{
1330
	struct rtable *rt = skb->rtable;
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	struct in_device *in_dev = in_dev_get(rt->u.dst.dev);

	if (!in_dev)
		return;

	if (!IN_DEV_TX_REDIRECTS(in_dev))
		goto out;

	/* No redirected packets during ip_rt_redirect_silence;
	 * reset the algorithm.
	 */
	if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
		rt->u.dst.rate_tokens = 0;

	/* Too many ignored redirects; do not send anything
	 * set u.dst.rate_last to the last seen redirected packet.
	 */
	if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
		rt->u.dst.rate_last = jiffies;
		goto out;
	}

	/* Check for load limit; set rate_last to the latest sent
	 * redirect.
	 */
1356 1357
	if (rt->u.dst.rate_tokens == 0 ||
	    time_after(jiffies,
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		       (rt->u.dst.rate_last +
			(ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
		icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
		rt->u.dst.rate_last = jiffies;
		++rt->u.dst.rate_tokens;
#ifdef CONFIG_IP_ROUTE_VERBOSE
		if (IN_DEV_LOG_MARTIANS(in_dev) &&
		    rt->u.dst.rate_tokens == ip_rt_redirect_number &&
		    net_ratelimit())
1367 1368
			printk(KERN_WARNING "host " NIPQUAD_FMT "/if%d ignores "
				"redirects for " NIPQUAD_FMT " to " NIPQUAD_FMT ".\n",
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				NIPQUAD(rt->rt_src), rt->rt_iif,
				NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
#endif
	}
out:
1374
	in_dev_put(in_dev);
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}

static int ip_error(struct sk_buff *skb)
{
1379
	struct rtable *rt = skb->rtable;
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	unsigned long now;
	int code;

	switch (rt->u.dst.error) {
		case EINVAL:
		default:
			goto out;
		case EHOSTUNREACH:
			code = ICMP_HOST_UNREACH;
			break;
		case ENETUNREACH:
			code = ICMP_NET_UNREACH;
1392
			IP_INC_STATS_BH(IPSTATS_MIB_INNOROUTES);
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			break;
		case EACCES:
			code = ICMP_PKT_FILTERED;
			break;
	}

	now = jiffies;
	rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
	if (rt->u.dst.rate_tokens > ip_rt_error_burst)
		rt->u.dst.rate_tokens = ip_rt_error_burst;
	rt->u.dst.rate_last = now;
	if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
		rt->u.dst.rate_tokens -= ip_rt_error_cost;
		icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
	}

out:	kfree_skb(skb);
	return 0;
1411
}
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/*
 *	The last two values are not from the RFC but
 *	are needed for AMPRnet AX.25 paths.
 */

1418
static const unsigned short mtu_plateau[] =
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{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };

S
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static inline unsigned short guess_mtu(unsigned short old_mtu)
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{
	int i;
1424

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	for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
		if (old_mtu > mtu_plateau[i])
			return mtu_plateau[i];
	return 68;
}

1431 1432
unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
				 unsigned short new_mtu)
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{
	int i;
	unsigned short old_mtu = ntohs(iph->tot_len);
	struct rtable *rth;
1437 1438
	__be32  skeys[2] = { iph->saddr, 0, };
	__be32  daddr = iph->daddr;
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	unsigned short est_mtu = 0;

	if (ipv4_config.no_pmtu_disc)
		return 0;

	for (i = 0; i < 2; i++) {
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		unsigned hash = rt_hash(daddr, skeys[i], 0);
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		rcu_read_lock();
		for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1449
		     rth = rcu_dereference(rth->u.dst.rt_next)) {
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			if (rth->fl.fl4_dst == daddr &&
			    rth->fl.fl4_src == skeys[i] &&
			    rth->rt_dst  == daddr &&
			    rth->rt_src  == iph->saddr &&
			    rth->fl.iif == 0 &&
1455
			    !(dst_metric_locked(&rth->u.dst, RTAX_MTU)) &&
1456
			    net_eq(dev_net(rth->u.dst.dev), net) &&
1457
			    rth->rt_genid == atomic_read(&rt_genid)) {
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				unsigned short mtu = new_mtu;

				if (new_mtu < 68 || new_mtu >= old_mtu) {

					/* BSD 4.2 compatibility hack :-( */
					if (mtu == 0 &&
					    old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
					    old_mtu >= 68 + (iph->ihl << 2))
						old_mtu -= iph->ihl << 2;

					mtu = guess_mtu(old_mtu);
				}
				if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
1471
					if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
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						dst_confirm(&rth->u.dst);
						if (mtu < ip_rt_min_pmtu) {
							mtu = ip_rt_min_pmtu;
							rth->u.dst.metrics[RTAX_LOCK-1] |=
								(1 << RTAX_MTU);
						}
						rth->u.dst.metrics[RTAX_MTU-1] = mtu;
						dst_set_expires(&rth->u.dst,
							ip_rt_mtu_expires);
					}
					est_mtu = mtu;
				}
			}
		}
		rcu_read_unlock();
	}
	return est_mtu ? : new_mtu;
}

static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
{
	if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
	    !(dst_metric_locked(dst, RTAX_MTU))) {
		if (mtu < ip_rt_min_pmtu) {
			mtu = ip_rt_min_pmtu;
			dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
		}
		dst->metrics[RTAX_MTU-1] = mtu;
		dst_set_expires(dst, ip_rt_mtu_expires);
1501
		call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
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	}
}

static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
{
	return NULL;
}

static void ipv4_dst_destroy(struct dst_entry *dst)
{
	struct rtable *rt = (struct rtable *) dst;
	struct inet_peer *peer = rt->peer;
	struct in_device *idev = rt->idev;

	if (peer) {
		rt->peer = NULL;
		inet_putpeer(peer);
	}

	if (idev) {
		rt->idev = NULL;
		in_dev_put(idev);
	}
}

static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
			    int how)
{
	struct rtable *rt = (struct rtable *) dst;
	struct in_device *idev = rt->idev;
1532
	if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1533
		struct in_device *loopback_idev =
1534
			in_dev_get(dev_net(dev)->loopback_dev);
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		if (loopback_idev) {
			rt->idev = loopback_idev;
			in_dev_put(idev);
		}
	}
}

static void ipv4_link_failure(struct sk_buff *skb)
{
	struct rtable *rt;

	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);

1548
	rt = skb->rtable;
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1549 1550 1551 1552 1553 1554
	if (rt)
		dst_set_expires(&rt->u.dst, 0);
}

static int ip_rt_bug(struct sk_buff *skb)
{
1555
	printk(KERN_DEBUG "ip_rt_bug: " NIPQUAD_FMT " -> " NIPQUAD_FMT ", %s\n",
1556
		NIPQUAD(ip_hdr(skb)->saddr), NIPQUAD(ip_hdr(skb)->daddr),
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		skb->dev ? skb->dev->name : "?");
	kfree_skb(skb);
	return 0;
}

/*
   We do not cache source address of outgoing interface,
   because it is used only by IP RR, TS and SRR options,
   so that it out of fast path.

   BTW remember: "addr" is allowed to be not aligned
   in IP options!
 */

void ip_rt_get_source(u8 *addr, struct rtable *rt)
{
A
Al Viro 已提交
1573
	__be32 src;
L
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1574 1575 1576 1577
	struct fib_result res;

	if (rt->fl.iif == 0)
		src = rt->rt_src;
1578
	else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) {
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		src = FIB_RES_PREFSRC(res);
		fib_res_put(&res);
	} else
		src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
					RT_SCOPE_UNIVERSE);
	memcpy(addr, &src, 4);
}

#ifdef CONFIG_NET_CLS_ROUTE
static void set_class_tag(struct rtable *rt, u32 tag)
{
	if (!(rt->u.dst.tclassid & 0xFFFF))
		rt->u.dst.tclassid |= tag & 0xFFFF;
	if (!(rt->u.dst.tclassid & 0xFFFF0000))
		rt->u.dst.tclassid |= tag & 0xFFFF0000;
}
#endif

static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
{
	struct fib_info *fi = res->fi;

	if (fi) {
		if (FIB_RES_GW(*res) &&
		    FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
			rt->rt_gateway = FIB_RES_GW(*res);
		memcpy(rt->u.dst.metrics, fi->fib_metrics,
		       sizeof(rt->u.dst.metrics));
		if (fi->fib_mtu == 0) {
			rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
			if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
			    rt->rt_gateway != rt->rt_dst &&
			    rt->u.dst.dev->mtu > 576)
				rt->u.dst.metrics[RTAX_MTU-1] = 576;
		}
#ifdef CONFIG_NET_CLS_ROUTE
		rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
#endif
	} else
		rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;

	if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
		rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
	if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
		rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
	if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
		rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
				       ip_rt_min_advmss);
	if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
		rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;

#ifdef CONFIG_NET_CLS_ROUTE
#ifdef CONFIG_IP_MULTIPLE_TABLES
	set_class_tag(rt, fib_rules_tclass(res));
#endif
	set_class_tag(rt, itag);
#endif
1636
	rt->rt_type = res->type;
L
Linus Torvalds 已提交
1637 1638
}

A
Al Viro 已提交
1639
static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
L
Linus Torvalds 已提交
1640 1641 1642 1643
				u8 tos, struct net_device *dev, int our)
{
	unsigned hash;
	struct rtable *rth;
A
Al Viro 已提交
1644
	__be32 spec_dst;
L
Linus Torvalds 已提交
1645 1646 1647 1648 1649 1650 1651 1652
	struct in_device *in_dev = in_dev_get(dev);
	u32 itag = 0;

	/* Primary sanity checks. */

	if (in_dev == NULL)
		return -EINVAL;

1653
	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1654
	    ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
L
Linus Torvalds 已提交
1655 1656
		goto e_inval;

1657 1658
	if (ipv4_is_zeronet(saddr)) {
		if (!ipv4_is_local_multicast(daddr))
L
Linus Torvalds 已提交
1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672
			goto e_inval;
		spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
	} else if (fib_validate_source(saddr, 0, tos, 0,
					dev, &spec_dst, &itag) < 0)
		goto e_inval;

	rth = dst_alloc(&ipv4_dst_ops);
	if (!rth)
		goto e_nobufs;

	rth->u.dst.output= ip_rt_bug;

	atomic_set(&rth->u.dst.__refcnt, 1);
	rth->u.dst.flags= DST_HOST;
1673
	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
L
Linus Torvalds 已提交
1674 1675 1676 1677
		rth->u.dst.flags |= DST_NOPOLICY;
	rth->fl.fl4_dst	= daddr;
	rth->rt_dst	= daddr;
	rth->fl.fl4_tos	= tos;
1678
	rth->fl.mark    = skb->mark;
L
Linus Torvalds 已提交
1679 1680 1681 1682 1683 1684 1685
	rth->fl.fl4_src	= saddr;
	rth->rt_src	= saddr;
#ifdef CONFIG_NET_CLS_ROUTE
	rth->u.dst.tclassid = itag;
#endif
	rth->rt_iif	=
	rth->fl.iif	= dev->ifindex;
1686
	rth->u.dst.dev	= init_net.loopback_dev;
L
Linus Torvalds 已提交
1687 1688 1689 1690 1691
	dev_hold(rth->u.dst.dev);
	rth->idev	= in_dev_get(rth->u.dst.dev);
	rth->fl.oif	= 0;
	rth->rt_gateway	= daddr;
	rth->rt_spec_dst= spec_dst;
1692
	rth->rt_genid	= atomic_read(&rt_genid);
L
Linus Torvalds 已提交
1693
	rth->rt_flags	= RTCF_MULTICAST;
1694
	rth->rt_type	= RTN_MULTICAST;
L
Linus Torvalds 已提交
1695 1696 1697 1698 1699 1700
	if (our) {
		rth->u.dst.input= ip_local_deliver;
		rth->rt_flags |= RTCF_LOCAL;
	}

#ifdef CONFIG_IP_MROUTE
1701
	if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
L
Linus Torvalds 已提交
1702 1703 1704 1705 1706
		rth->u.dst.input = ip_mr_input;
#endif
	RT_CACHE_STAT_INC(in_slow_mc);

	in_dev_put(in_dev);
A
Al Viro 已提交
1707
	hash = rt_hash(daddr, saddr, dev->ifindex);
1708
	return rt_intern_hash(hash, rth, &skb->rtable);
L
Linus Torvalds 已提交
1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722

e_nobufs:
	in_dev_put(in_dev);
	return -ENOBUFS;

e_inval:
	in_dev_put(in_dev);
	return -EINVAL;
}


static void ip_handle_martian_source(struct net_device *dev,
				     struct in_device *in_dev,
				     struct sk_buff *skb,
A
Al Viro 已提交
1723 1724
				     __be32 daddr,
				     __be32 saddr)
L
Linus Torvalds 已提交
1725 1726 1727 1728 1729 1730 1731 1732
{
	RT_CACHE_STAT_INC(in_martian_src);
#ifdef CONFIG_IP_ROUTE_VERBOSE
	if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
		/*
		 *	RFC1812 recommendation, if source is martian,
		 *	the only hint is MAC header.
		 */
1733 1734
		printk(KERN_WARNING "martian source " NIPQUAD_FMT " from "
			NIPQUAD_FMT", on dev %s\n",
L
Linus Torvalds 已提交
1735
			NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1736
		if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
L
Linus Torvalds 已提交
1737
			int i;
1738
			const unsigned char *p = skb_mac_header(skb);
L
Linus Torvalds 已提交
1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
			printk(KERN_WARNING "ll header: ");
			for (i = 0; i < dev->hard_header_len; i++, p++) {
				printk("%02x", *p);
				if (i < (dev->hard_header_len - 1))
					printk(":");
			}
			printk("\n");
		}
	}
#endif
}

S
Stephen Hemminger 已提交
1751 1752 1753 1754 1755
static int __mkroute_input(struct sk_buff *skb,
			   struct fib_result *res,
			   struct in_device *in_dev,
			   __be32 daddr, __be32 saddr, u32 tos,
			   struct rtable **result)
L
Linus Torvalds 已提交
1756 1757 1758 1759 1760 1761
{

	struct rtable *rth;
	int err;
	struct in_device *out_dev;
	unsigned flags = 0;
1762 1763
	__be32 spec_dst;
	u32 itag;
L
Linus Torvalds 已提交
1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774

	/* get a working reference to the output device */
	out_dev = in_dev_get(FIB_RES_DEV(*res));
	if (out_dev == NULL) {
		if (net_ratelimit())
			printk(KERN_CRIT "Bug in ip_route_input" \
			       "_slow(). Please, report\n");
		return -EINVAL;
	}


1775
	err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
L
Linus Torvalds 已提交
1776 1777
				  in_dev->dev, &spec_dst, &itag);
	if (err < 0) {
1778
		ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
L
Linus Torvalds 已提交
1779
					 saddr);
1780

L
Linus Torvalds 已提交
1781 1782 1783 1784 1785 1786 1787
		err = -EINVAL;
		goto cleanup;
	}

	if (err)
		flags |= RTCF_DIRECTSRC;

1788
	if (out_dev == in_dev && err && !(flags & RTCF_MASQ) &&
L
Linus Torvalds 已提交
1789 1790 1791 1792 1793 1794 1795 1796
	    (IN_DEV_SHARED_MEDIA(out_dev) ||
	     inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
		flags |= RTCF_DOREDIRECT;

	if (skb->protocol != htons(ETH_P_IP)) {
		/* Not IP (i.e. ARP). Do not create route, if it is
		 * invalid for proxy arp. DNAT routes are always valid.
		 */
1797
		if (out_dev == in_dev) {
L
Linus Torvalds 已提交
1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809
			err = -EINVAL;
			goto cleanup;
		}
	}


	rth = dst_alloc(&ipv4_dst_ops);
	if (!rth) {
		err = -ENOBUFS;
		goto cleanup;
	}

1810
	atomic_set(&rth->u.dst.__refcnt, 1);
L
Linus Torvalds 已提交
1811
	rth->u.dst.flags= DST_HOST;
1812
	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
L
Linus Torvalds 已提交
1813
		rth->u.dst.flags |= DST_NOPOLICY;
1814
	if (IN_DEV_CONF_GET(out_dev, NOXFRM))
L
Linus Torvalds 已提交
1815 1816 1817 1818
		rth->u.dst.flags |= DST_NOXFRM;
	rth->fl.fl4_dst	= daddr;
	rth->rt_dst	= daddr;
	rth->fl.fl4_tos	= tos;
1819
	rth->fl.mark    = skb->mark;
L
Linus Torvalds 已提交
1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832
	rth->fl.fl4_src	= saddr;
	rth->rt_src	= saddr;
	rth->rt_gateway	= daddr;
	rth->rt_iif 	=
		rth->fl.iif	= in_dev->dev->ifindex;
	rth->u.dst.dev	= (out_dev)->dev;
	dev_hold(rth->u.dst.dev);
	rth->idev	= in_dev_get(rth->u.dst.dev);
	rth->fl.oif 	= 0;
	rth->rt_spec_dst= spec_dst;

	rth->u.dst.input = ip_forward;
	rth->u.dst.output = ip_output;
1833
	rth->rt_genid = atomic_read(&rt_genid);
L
Linus Torvalds 已提交
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844

	rt_set_nexthop(rth, res, itag);

	rth->rt_flags = flags;

	*result = rth;
	err = 0;
 cleanup:
	/* release the working reference to the output device */
	in_dev_put(out_dev);
	return err;
1845
}
L
Linus Torvalds 已提交
1846

S
Stephen Hemminger 已提交
1847 1848 1849 1850 1851
static int ip_mkroute_input(struct sk_buff *skb,
			    struct fib_result *res,
			    const struct flowi *fl,
			    struct in_device *in_dev,
			    __be32 daddr, __be32 saddr, u32 tos)
L
Linus Torvalds 已提交
1852
{
C
Chuck Short 已提交
1853
	struct rtable* rth = NULL;
L
Linus Torvalds 已提交
1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867
	int err;
	unsigned hash;

#ifdef CONFIG_IP_ROUTE_MULTIPATH
	if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
		fib_select_multipath(fl, res);
#endif

	/* create a routing cache entry */
	err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
	if (err)
		return err;

	/* put it into the cache */
A
Al Viro 已提交
1868
	hash = rt_hash(daddr, saddr, fl->iif);
1869
	return rt_intern_hash(hash, rth, &skb->rtable);
L
Linus Torvalds 已提交
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881
}

/*
 *	NOTE. We drop all the packets that has local source
 *	addresses, because every properly looped back packet
 *	must have correct destination already attached by output routine.
 *
 *	Such approach solves two big problems:
 *	1. Not simplex devices are handled properly.
 *	2. IP spoofing attempts are filtered with 100% of guarantee.
 */

A
Al Viro 已提交
1882
static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
L
Linus Torvalds 已提交
1883 1884 1885 1886 1887 1888 1889 1890 1891 1892
			       u8 tos, struct net_device *dev)
{
	struct fib_result res;
	struct in_device *in_dev = in_dev_get(dev);
	struct flowi fl = { .nl_u = { .ip4_u =
				      { .daddr = daddr,
					.saddr = saddr,
					.tos = tos,
					.scope = RT_SCOPE_UNIVERSE,
				      } },
1893
			    .mark = skb->mark,
L
Linus Torvalds 已提交
1894 1895 1896 1897 1898
			    .iif = dev->ifindex };
	unsigned	flags = 0;
	u32		itag = 0;
	struct rtable * rth;
	unsigned	hash;
A
Al Viro 已提交
1899
	__be32		spec_dst;
L
Linus Torvalds 已提交
1900 1901
	int		err = -EINVAL;
	int		free_res = 0;
1902
	struct net    * net = dev_net(dev);
L
Linus Torvalds 已提交
1903 1904 1905 1906 1907 1908 1909 1910 1911 1912

	/* IP on this device is disabled. */

	if (!in_dev)
		goto out;

	/* Check for the most weird martians, which can be not detected
	   by fib_lookup.
	 */

1913
	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1914
	    ipv4_is_loopback(saddr))
L
Linus Torvalds 已提交
1915 1916
		goto martian_source;

1917
	if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
L
Linus Torvalds 已提交
1918 1919 1920 1921 1922
		goto brd_input;

	/* Accept zero addresses only to limited broadcast;
	 * I even do not know to fix it or not. Waiting for complains :-)
	 */
1923
	if (ipv4_is_zeronet(saddr))
L
Linus Torvalds 已提交
1924 1925
		goto martian_source;

1926
	if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
1927
	    ipv4_is_loopback(daddr))
L
Linus Torvalds 已提交
1928 1929 1930 1931 1932
		goto martian_destination;

	/*
	 *	Now we are ready to route packet.
	 */
1933
	if ((err = fib_lookup(net, &fl, &res)) != 0) {
L
Linus Torvalds 已提交
1934
		if (!IN_DEV_FORWARD(in_dev))
1935
			goto e_hostunreach;
L
Linus Torvalds 已提交
1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947
		goto no_route;
	}
	free_res = 1;

	RT_CACHE_STAT_INC(in_slow_tot);

	if (res.type == RTN_BROADCAST)
		goto brd_input;

	if (res.type == RTN_LOCAL) {
		int result;
		result = fib_validate_source(saddr, daddr, tos,
1948
					     net->loopback_dev->ifindex,
L
Linus Torvalds 已提交
1949 1950 1951 1952 1953 1954 1955 1956 1957 1958
					     dev, &spec_dst, &itag);
		if (result < 0)
			goto martian_source;
		if (result)
			flags |= RTCF_DIRECTSRC;
		spec_dst = daddr;
		goto local_input;
	}

	if (!IN_DEV_FORWARD(in_dev))
1959
		goto e_hostunreach;
L
Linus Torvalds 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
	if (res.type != RTN_UNICAST)
		goto martian_destination;

	err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
done:
	in_dev_put(in_dev);
	if (free_res)
		fib_res_put(&res);
out:	return err;

brd_input:
	if (skb->protocol != htons(ETH_P_IP))
		goto e_inval;

1974
	if (ipv4_is_zeronet(saddr))
L
Linus Torvalds 已提交
1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993
		spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
	else {
		err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
					  &itag);
		if (err < 0)
			goto martian_source;
		if (err)
			flags |= RTCF_DIRECTSRC;
	}
	flags |= RTCF_BROADCAST;
	res.type = RTN_BROADCAST;
	RT_CACHE_STAT_INC(in_brd);

local_input:
	rth = dst_alloc(&ipv4_dst_ops);
	if (!rth)
		goto e_nobufs;

	rth->u.dst.output= ip_rt_bug;
1994
	rth->rt_genid = atomic_read(&rt_genid);
L
Linus Torvalds 已提交
1995 1996 1997

	atomic_set(&rth->u.dst.__refcnt, 1);
	rth->u.dst.flags= DST_HOST;
1998
	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
L
Linus Torvalds 已提交
1999 2000 2001 2002
		rth->u.dst.flags |= DST_NOPOLICY;
	rth->fl.fl4_dst	= daddr;
	rth->rt_dst	= daddr;
	rth->fl.fl4_tos	= tos;
2003
	rth->fl.mark    = skb->mark;
L
Linus Torvalds 已提交
2004 2005 2006 2007 2008 2009 2010
	rth->fl.fl4_src	= saddr;
	rth->rt_src	= saddr;
#ifdef CONFIG_NET_CLS_ROUTE
	rth->u.dst.tclassid = itag;
#endif
	rth->rt_iif	=
	rth->fl.iif	= dev->ifindex;
2011
	rth->u.dst.dev	= net->loopback_dev;
L
Linus Torvalds 已提交
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
	dev_hold(rth->u.dst.dev);
	rth->idev	= in_dev_get(rth->u.dst.dev);
	rth->rt_gateway	= daddr;
	rth->rt_spec_dst= spec_dst;
	rth->u.dst.input= ip_local_deliver;
	rth->rt_flags 	= flags|RTCF_LOCAL;
	if (res.type == RTN_UNREACHABLE) {
		rth->u.dst.input= ip_error;
		rth->u.dst.error= -err;
		rth->rt_flags 	&= ~RTCF_LOCAL;
	}
	rth->rt_type	= res.type;
A
Al Viro 已提交
2024
	hash = rt_hash(daddr, saddr, fl.iif);
2025
	err = rt_intern_hash(hash, rth, &skb->rtable);
L
Linus Torvalds 已提交
2026 2027 2028 2029 2030 2031
	goto done;

no_route:
	RT_CACHE_STAT_INC(in_no_route);
	spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
	res.type = RTN_UNREACHABLE;
2032 2033
	if (err == -ESRCH)
		err = -ENETUNREACH;
L
Linus Torvalds 已提交
2034 2035 2036 2037 2038 2039 2040 2041 2042
	goto local_input;

	/*
	 *	Do not cache martian addresses: they should be logged (RFC1812)
	 */
martian_destination:
	RT_CACHE_STAT_INC(in_martian_dst);
#ifdef CONFIG_IP_ROUTE_VERBOSE
	if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2043 2044
		printk(KERN_WARNING "martian destination " NIPQUAD_FMT " from "
			NIPQUAD_FMT ", dev %s\n",
L
Linus Torvalds 已提交
2045 2046
			NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
#endif
2047 2048

e_hostunreach:
2049 2050
	err = -EHOSTUNREACH;
	goto done;
2051

L
Linus Torvalds 已提交
2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064
e_inval:
	err = -EINVAL;
	goto done;

e_nobufs:
	err = -ENOBUFS;
	goto done;

martian_source:
	ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
	goto e_inval;
}

A
Al Viro 已提交
2065
int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
L
Linus Torvalds 已提交
2066 2067 2068 2069 2070
		   u8 tos, struct net_device *dev)
{
	struct rtable * rth;
	unsigned	hash;
	int iif = dev->ifindex;
2071
	struct net *net;
L
Linus Torvalds 已提交
2072

2073
	net = dev_net(dev);
L
Linus Torvalds 已提交
2074
	tos &= IPTOS_RT_MASK;
A
Al Viro 已提交
2075
	hash = rt_hash(daddr, saddr, iif);
L
Linus Torvalds 已提交
2076 2077 2078

	rcu_read_lock();
	for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2079
	     rth = rcu_dereference(rth->u.dst.rt_next)) {
2080 2081 2082 2083 2084
		if (((rth->fl.fl4_dst ^ daddr) |
		     (rth->fl.fl4_src ^ saddr) |
		     (rth->fl.iif ^ iif) |
		     rth->fl.oif |
		     (rth->fl.fl4_tos ^ tos)) == 0 &&
2085
		    rth->fl.mark == skb->mark &&
2086
		    net_eq(dev_net(rth->u.dst.dev), net) &&
2087
		    rth->rt_genid == atomic_read(&rt_genid)) {
2088
			dst_use(&rth->u.dst, jiffies);
L
Linus Torvalds 已提交
2089 2090
			RT_CACHE_STAT_INC(in_hit);
			rcu_read_unlock();
2091
			skb->rtable = rth;
L
Linus Torvalds 已提交
2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108
			return 0;
		}
		RT_CACHE_STAT_INC(in_hlist_search);
	}
	rcu_read_unlock();

	/* Multicast recognition logic is moved from route cache to here.
	   The problem was that too many Ethernet cards have broken/missing
	   hardware multicast filters :-( As result the host on multicasting
	   network acquires a lot of useless route cache entries, sort of
	   SDR messages from all the world. Now we try to get rid of them.
	   Really, provided software IP multicast filter is organized
	   reasonably (at least, hashed), it does not result in a slowdown
	   comparing with route cache reject entries.
	   Note, that multicast routers are not affected, because
	   route cache entry is created eventually.
	 */
2109
	if (ipv4_is_multicast(daddr)) {
L
Linus Torvalds 已提交
2110 2111 2112
		struct in_device *in_dev;

		rcu_read_lock();
2113
		if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
L
Linus Torvalds 已提交
2114
			int our = ip_check_mc(in_dev, daddr, saddr,
2115
				ip_hdr(skb)->protocol);
L
Linus Torvalds 已提交
2116 2117
			if (our
#ifdef CONFIG_IP_MROUTE
2118 2119
			    || (!ipv4_is_local_multicast(daddr) &&
				IN_DEV_MFORWARD(in_dev))
L
Linus Torvalds 已提交
2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132
#endif
			    ) {
				rcu_read_unlock();
				return ip_route_input_mc(skb, daddr, saddr,
							 tos, dev, our);
			}
		}
		rcu_read_unlock();
		return -EINVAL;
	}
	return ip_route_input_slow(skb, daddr, saddr, tos, dev);
}

S
Stephen Hemminger 已提交
2133 2134 2135 2136 2137 2138
static int __mkroute_output(struct rtable **result,
			    struct fib_result *res,
			    const struct flowi *fl,
			    const struct flowi *oldflp,
			    struct net_device *dev_out,
			    unsigned flags)
L
Linus Torvalds 已提交
2139 2140 2141 2142 2143 2144
{
	struct rtable *rth;
	struct in_device *in_dev;
	u32 tos = RT_FL_TOS(oldflp);
	int err = 0;

2145
	if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
L
Linus Torvalds 已提交
2146 2147
		return -EINVAL;

2148
	if (fl->fl4_dst == htonl(0xFFFFFFFF))
L
Linus Torvalds 已提交
2149
		res->type = RTN_BROADCAST;
2150
	else if (ipv4_is_multicast(fl->fl4_dst))
L
Linus Torvalds 已提交
2151
		res->type = RTN_MULTICAST;
2152
	else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
L
Linus Torvalds 已提交
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170
		return -EINVAL;

	if (dev_out->flags & IFF_LOOPBACK)
		flags |= RTCF_LOCAL;

	/* get work reference to inet device */
	in_dev = in_dev_get(dev_out);
	if (!in_dev)
		return -EINVAL;

	if (res->type == RTN_BROADCAST) {
		flags |= RTCF_BROADCAST | RTCF_LOCAL;
		if (res->fi) {
			fib_info_put(res->fi);
			res->fi = NULL;
		}
	} else if (res->type == RTN_MULTICAST) {
		flags |= RTCF_MULTICAST|RTCF_LOCAL;
2171
		if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
L
Linus Torvalds 已提交
2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188
				 oldflp->proto))
			flags &= ~RTCF_LOCAL;
		/* If multicast route do not exist use
		   default one, but do not gateway in this case.
		   Yes, it is hack.
		 */
		if (res->fi && res->prefixlen < 4) {
			fib_info_put(res->fi);
			res->fi = NULL;
		}
	}


	rth = dst_alloc(&ipv4_dst_ops);
	if (!rth) {
		err = -ENOBUFS;
		goto cleanup;
2189
	}
L
Linus Torvalds 已提交
2190

2191
	atomic_set(&rth->u.dst.__refcnt, 1);
L
Linus Torvalds 已提交
2192
	rth->u.dst.flags= DST_HOST;
2193
	if (IN_DEV_CONF_GET(in_dev, NOXFRM))
L
Linus Torvalds 已提交
2194
		rth->u.dst.flags |= DST_NOXFRM;
2195
	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
L
Linus Torvalds 已提交
2196 2197 2198 2199 2200 2201
		rth->u.dst.flags |= DST_NOPOLICY;

	rth->fl.fl4_dst	= oldflp->fl4_dst;
	rth->fl.fl4_tos	= tos;
	rth->fl.fl4_src	= oldflp->fl4_src;
	rth->fl.oif	= oldflp->oif;
2202
	rth->fl.mark    = oldflp->mark;
L
Linus Torvalds 已提交
2203 2204 2205
	rth->rt_dst	= fl->fl4_dst;
	rth->rt_src	= fl->fl4_src;
	rth->rt_iif	= oldflp->oif ? : dev_out->ifindex;
2206
	/* get references to the devices that are to be hold by the routing
L
Linus Torvalds 已提交
2207 2208 2209 2210 2211 2212 2213 2214
	   cache entry */
	rth->u.dst.dev	= dev_out;
	dev_hold(dev_out);
	rth->idev	= in_dev_get(dev_out);
	rth->rt_gateway = fl->fl4_dst;
	rth->rt_spec_dst= fl->fl4_src;

	rth->u.dst.output=ip_output;
2215
	rth->rt_genid = atomic_read(&rt_genid);
L
Linus Torvalds 已提交
2216 2217 2218 2219 2220 2221 2222 2223 2224

	RT_CACHE_STAT_INC(out_slow_tot);

	if (flags & RTCF_LOCAL) {
		rth->u.dst.input = ip_local_deliver;
		rth->rt_spec_dst = fl->fl4_dst;
	}
	if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
		rth->rt_spec_dst = fl->fl4_src;
2225
		if (flags & RTCF_LOCAL &&
L
Linus Torvalds 已提交
2226 2227 2228 2229 2230 2231 2232
		    !(dev_out->flags & IFF_LOOPBACK)) {
			rth->u.dst.output = ip_mc_output;
			RT_CACHE_STAT_INC(out_slow_mc);
		}
#ifdef CONFIG_IP_MROUTE
		if (res->type == RTN_MULTICAST) {
			if (IN_DEV_MFORWARD(in_dev) &&
2233
			    !ipv4_is_local_multicast(oldflp->fl4_dst)) {
L
Linus Torvalds 已提交
2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252
				rth->u.dst.input = ip_mr_input;
				rth->u.dst.output = ip_mc_output;
			}
		}
#endif
	}

	rt_set_nexthop(rth, res, 0);

	rth->rt_flags = flags;

	*result = rth;
 cleanup:
	/* release work reference to inet device */
	in_dev_put(in_dev);

	return err;
}

S
Stephen Hemminger 已提交
2253 2254 2255 2256 2257 2258
static int ip_mkroute_output(struct rtable **rp,
			     struct fib_result *res,
			     const struct flowi *fl,
			     const struct flowi *oldflp,
			     struct net_device *dev_out,
			     unsigned flags)
L
Linus Torvalds 已提交
2259
{
C
Chuck Short 已提交
2260
	struct rtable *rth = NULL;
L
Linus Torvalds 已提交
2261 2262 2263
	int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
	unsigned hash;
	if (err == 0) {
A
Al Viro 已提交
2264
		hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif);
L
Linus Torvalds 已提交
2265 2266
		err = rt_intern_hash(hash, rth, rp);
	}
2267

L
Linus Torvalds 已提交
2268 2269 2270 2271 2272 2273 2274
	return err;
}

/*
 * Major route resolver routine.
 */

2275 2276
static int ip_route_output_slow(struct net *net, struct rtable **rp,
				const struct flowi *oldflp)
L
Linus Torvalds 已提交
2277 2278 2279 2280 2281 2282 2283 2284 2285 2286
{
	u32 tos	= RT_FL_TOS(oldflp);
	struct flowi fl = { .nl_u = { .ip4_u =
				      { .daddr = oldflp->fl4_dst,
					.saddr = oldflp->fl4_src,
					.tos = tos & IPTOS_RT_MASK,
					.scope = ((tos & RTO_ONLINK) ?
						  RT_SCOPE_LINK :
						  RT_SCOPE_UNIVERSE),
				      } },
2287
			    .mark = oldflp->mark,
2288
			    .iif = net->loopback_dev->ifindex,
L
Linus Torvalds 已提交
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303
			    .oif = oldflp->oif };
	struct fib_result res;
	unsigned flags = 0;
	struct net_device *dev_out = NULL;
	int free_res = 0;
	int err;


	res.fi		= NULL;
#ifdef CONFIG_IP_MULTIPLE_TABLES
	res.r		= NULL;
#endif

	if (oldflp->fl4_src) {
		err = -EINVAL;
2304
		if (ipv4_is_multicast(oldflp->fl4_src) ||
2305
		    ipv4_is_lbcast(oldflp->fl4_src) ||
2306
		    ipv4_is_zeronet(oldflp->fl4_src))
L
Linus Torvalds 已提交
2307 2308 2309
			goto out;

		/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2310
		dev_out = ip_dev_find(net, oldflp->fl4_src);
2311
		if (dev_out == NULL)
L
Linus Torvalds 已提交
2312 2313 2314 2315
			goto out;

		/* I removed check for oif == dev_out->oif here.
		   It was wrong for two reasons:
2316 2317
		   1. ip_dev_find(net, saddr) can return wrong iface, if saddr
		      is assigned to multiple interfaces.
L
Linus Torvalds 已提交
2318 2319 2320 2321
		   2. Moreover, we are allowed to send packets with saddr
		      of another iface. --ANK
		 */

2322
		if (oldflp->oif == 0
2323 2324
		    && (ipv4_is_multicast(oldflp->fl4_dst) ||
			oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
L
Linus Torvalds 已提交
2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
			/* Special hack: user can direct multicasts
			   and limited broadcast via necessary interface
			   without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
			   This hack is not just for fun, it allows
			   vic,vat and friends to work.
			   They bind socket to loopback, set ttl to zero
			   and expect that it will work.
			   From the viewpoint of routing cache they are broken,
			   because we are not allowed to build multicast path
			   with loopback source addr (look, routing cache
			   cannot know, that ttl is zero, so that packet
			   will not leave this host and route is valid).
			   Luckily, this hack is good workaround.
			 */

			fl.oif = dev_out->ifindex;
			goto make_route;
		}
		if (dev_out)
			dev_put(dev_out);
		dev_out = NULL;
	}


	if (oldflp->oif) {
2350
		dev_out = dev_get_by_index(net, oldflp->oif);
L
Linus Torvalds 已提交
2351 2352 2353
		err = -ENODEV;
		if (dev_out == NULL)
			goto out;
2354 2355 2356

		/* RACE: Check return value of inet_select_addr instead. */
		if (__in_dev_get_rtnl(dev_out) == NULL) {
L
Linus Torvalds 已提交
2357 2358 2359 2360
			dev_put(dev_out);
			goto out;	/* Wrong error code */
		}

2361 2362
		if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
		    oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
L
Linus Torvalds 已提交
2363 2364 2365 2366 2367 2368
			if (!fl.fl4_src)
				fl.fl4_src = inet_select_addr(dev_out, 0,
							      RT_SCOPE_LINK);
			goto make_route;
		}
		if (!fl.fl4_src) {
2369
			if (ipv4_is_multicast(oldflp->fl4_dst))
L
Linus Torvalds 已提交
2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383
				fl.fl4_src = inet_select_addr(dev_out, 0,
							      fl.fl4_scope);
			else if (!oldflp->fl4_dst)
				fl.fl4_src = inet_select_addr(dev_out, 0,
							      RT_SCOPE_HOST);
		}
	}

	if (!fl.fl4_dst) {
		fl.fl4_dst = fl.fl4_src;
		if (!fl.fl4_dst)
			fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
		if (dev_out)
			dev_put(dev_out);
2384
		dev_out = net->loopback_dev;
L
Linus Torvalds 已提交
2385
		dev_hold(dev_out);
2386
		fl.oif = net->loopback_dev->ifindex;
L
Linus Torvalds 已提交
2387 2388 2389 2390 2391
		res.type = RTN_LOCAL;
		flags |= RTCF_LOCAL;
		goto make_route;
	}

2392
	if (fib_lookup(net, &fl, &res)) {
L
Linus Torvalds 已提交
2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430
		res.fi = NULL;
		if (oldflp->oif) {
			/* Apparently, routing tables are wrong. Assume,
			   that the destination is on link.

			   WHY? DW.
			   Because we are allowed to send to iface
			   even if it has NO routes and NO assigned
			   addresses. When oif is specified, routing
			   tables are looked up with only one purpose:
			   to catch if destination is gatewayed, rather than
			   direct. Moreover, if MSG_DONTROUTE is set,
			   we send packet, ignoring both routing tables
			   and ifaddr state. --ANK


			   We could make it even if oif is unknown,
			   likely IPv6, but we do not.
			 */

			if (fl.fl4_src == 0)
				fl.fl4_src = inet_select_addr(dev_out, 0,
							      RT_SCOPE_LINK);
			res.type = RTN_UNICAST;
			goto make_route;
		}
		if (dev_out)
			dev_put(dev_out);
		err = -ENETUNREACH;
		goto out;
	}
	free_res = 1;

	if (res.type == RTN_LOCAL) {
		if (!fl.fl4_src)
			fl.fl4_src = fl.fl4_dst;
		if (dev_out)
			dev_put(dev_out);
2431
		dev_out = net->loopback_dev;
L
Linus Torvalds 已提交
2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446
		dev_hold(dev_out);
		fl.oif = dev_out->ifindex;
		if (res.fi)
			fib_info_put(res.fi);
		res.fi = NULL;
		flags |= RTCF_LOCAL;
		goto make_route;
	}

#ifdef CONFIG_IP_ROUTE_MULTIPATH
	if (res.fi->fib_nhs > 1 && fl.oif == 0)
		fib_select_multipath(&fl, &res);
	else
#endif
	if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2447
		fib_select_default(net, &fl, &res);
L
Linus Torvalds 已提交
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469

	if (!fl.fl4_src)
		fl.fl4_src = FIB_RES_PREFSRC(res);

	if (dev_out)
		dev_put(dev_out);
	dev_out = FIB_RES_DEV(res);
	dev_hold(dev_out);
	fl.oif = dev_out->ifindex;


make_route:
	err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);


	if (free_res)
		fib_res_put(&res);
	if (dev_out)
		dev_put(dev_out);
out:	return err;
}

2470 2471
int __ip_route_output_key(struct net *net, struct rtable **rp,
			  const struct flowi *flp)
L
Linus Torvalds 已提交
2472 2473 2474 2475
{
	unsigned hash;
	struct rtable *rth;

A
Al Viro 已提交
2476
	hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif);
L
Linus Torvalds 已提交
2477 2478 2479

	rcu_read_lock_bh();
	for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2480
		rth = rcu_dereference(rth->u.dst.rt_next)) {
L
Linus Torvalds 已提交
2481 2482 2483 2484
		if (rth->fl.fl4_dst == flp->fl4_dst &&
		    rth->fl.fl4_src == flp->fl4_src &&
		    rth->fl.iif == 0 &&
		    rth->fl.oif == flp->oif &&
2485
		    rth->fl.mark == flp->mark &&
L
Linus Torvalds 已提交
2486
		    !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2487
			    (IPTOS_RT_MASK | RTO_ONLINK)) &&
2488
		    net_eq(dev_net(rth->u.dst.dev), net) &&
2489
		    rth->rt_genid == atomic_read(&rt_genid)) {
2490
			dst_use(&rth->u.dst, jiffies);
L
Linus Torvalds 已提交
2491 2492 2493 2494 2495 2496 2497 2498 2499
			RT_CACHE_STAT_INC(out_hit);
			rcu_read_unlock_bh();
			*rp = rth;
			return 0;
		}
		RT_CACHE_STAT_INC(out_hlist_search);
	}
	rcu_read_unlock_bh();

2500
	return ip_route_output_slow(net, rp, flp);
L
Linus Torvalds 已提交
2501 2502
}

2503 2504
EXPORT_SYMBOL_GPL(__ip_route_output_key);

2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
{
}

static struct dst_ops ipv4_dst_blackhole_ops = {
	.family			=	AF_INET,
	.protocol		=	__constant_htons(ETH_P_IP),
	.destroy		=	ipv4_dst_destroy,
	.check			=	ipv4_dst_check,
	.update_pmtu		=	ipv4_rt_blackhole_update_pmtu,
	.entry_size		=	sizeof(struct rtable),
2516
	.entries		=	ATOMIC_INIT(0),
2517 2518 2519
};


2520
static int ipv4_dst_blackhole(struct rtable **rp, struct flowi *flp)
2521 2522 2523 2524 2525 2526 2527 2528 2529 2530
{
	struct rtable *ort = *rp;
	struct rtable *rt = (struct rtable *)
		dst_alloc(&ipv4_dst_blackhole_ops);

	if (rt) {
		struct dst_entry *new = &rt->u.dst;

		atomic_set(&new->__refcnt, 1);
		new->__use = 1;
2531 2532
		new->input = dst_discard;
		new->output = dst_discard;
2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543
		memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));

		new->dev = ort->u.dst.dev;
		if (new->dev)
			dev_hold(new->dev);

		rt->fl = ort->fl;

		rt->idev = ort->idev;
		if (rt->idev)
			in_dev_hold(rt->idev);
2544
		rt->rt_genid = atomic_read(&rt_genid);
2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563
		rt->rt_flags = ort->rt_flags;
		rt->rt_type = ort->rt_type;
		rt->rt_dst = ort->rt_dst;
		rt->rt_src = ort->rt_src;
		rt->rt_iif = ort->rt_iif;
		rt->rt_gateway = ort->rt_gateway;
		rt->rt_spec_dst = ort->rt_spec_dst;
		rt->peer = ort->peer;
		if (rt->peer)
			atomic_inc(&rt->peer->refcnt);

		dst_free(new);
	}

	dst_release(&(*rp)->u.dst);
	*rp = rt;
	return (rt ? 0 : -ENOMEM);
}

2564 2565
int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
			 struct sock *sk, int flags)
L
Linus Torvalds 已提交
2566 2567 2568
{
	int err;

2569
	if ((err = __ip_route_output_key(net, rp, flp)) != 0)
L
Linus Torvalds 已提交
2570 2571 2572 2573 2574 2575 2576
		return err;

	if (flp->proto) {
		if (!flp->fl4_src)
			flp->fl4_src = (*rp)->rt_src;
		if (!flp->fl4_dst)
			flp->fl4_dst = (*rp)->rt_dst;
2577 2578
		err = __xfrm_lookup((struct dst_entry **)rp, flp, sk,
				    flags ? XFRM_LOOKUP_WAIT : 0);
2579
		if (err == -EREMOTE)
2580
			err = ipv4_dst_blackhole(rp, flp);
2581 2582

		return err;
L
Linus Torvalds 已提交
2583 2584 2585 2586 2587
	}

	return 0;
}

2588 2589
EXPORT_SYMBOL_GPL(ip_route_output_flow);

2590
int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
L
Linus Torvalds 已提交
2591
{
2592
	return ip_route_output_flow(net, rp, flp, NULL, 0);
L
Linus Torvalds 已提交
2593 2594 2595
}

static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
2596
			int nowait, unsigned int flags)
L
Linus Torvalds 已提交
2597
{
2598
	struct rtable *rt = skb->rtable;
L
Linus Torvalds 已提交
2599
	struct rtmsg *r;
2600
	struct nlmsghdr *nlh;
2601 2602
	long expires;
	u32 id = 0, ts = 0, tsage = 0, error;
2603 2604 2605

	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
	if (nlh == NULL)
2606
		return -EMSGSIZE;
2607 2608

	r = nlmsg_data(nlh);
L
Linus Torvalds 已提交
2609 2610 2611 2612 2613
	r->rtm_family	 = AF_INET;
	r->rtm_dst_len	= 32;
	r->rtm_src_len	= 0;
	r->rtm_tos	= rt->fl.fl4_tos;
	r->rtm_table	= RT_TABLE_MAIN;
2614
	NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
L
Linus Torvalds 已提交
2615 2616 2617 2618 2619 2620
	r->rtm_type	= rt->rt_type;
	r->rtm_scope	= RT_SCOPE_UNIVERSE;
	r->rtm_protocol = RTPROT_UNSPEC;
	r->rtm_flags	= (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
	if (rt->rt_flags & RTCF_NOTIFY)
		r->rtm_flags |= RTM_F_NOTIFY;
2621

2622
	NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2623

L
Linus Torvalds 已提交
2624 2625
	if (rt->fl.fl4_src) {
		r->rtm_src_len = 32;
2626
		NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
L
Linus Torvalds 已提交
2627 2628
	}
	if (rt->u.dst.dev)
2629
		NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
L
Linus Torvalds 已提交
2630 2631
#ifdef CONFIG_NET_CLS_ROUTE
	if (rt->u.dst.tclassid)
2632
		NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
L
Linus Torvalds 已提交
2633 2634
#endif
	if (rt->fl.iif)
2635
		NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
L
Linus Torvalds 已提交
2636
	else if (rt->rt_src != rt->fl.fl4_src)
2637
		NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2638

L
Linus Torvalds 已提交
2639
	if (rt->rt_dst != rt->rt_gateway)
2640
		NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2641

L
Linus Torvalds 已提交
2642
	if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2643 2644
		goto nla_put_failure;

2645 2646
	error = rt->u.dst.error;
	expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
L
Linus Torvalds 已提交
2647
	if (rt->peer) {
2648
		id = rt->peer->ip_id_count;
L
Linus Torvalds 已提交
2649
		if (rt->peer->tcp_ts_stamp) {
2650
			ts = rt->peer->tcp_ts;
2651
			tsage = get_seconds() - rt->peer->tcp_ts_stamp;
L
Linus Torvalds 已提交
2652 2653
		}
	}
2654

L
Linus Torvalds 已提交
2655 2656
	if (rt->fl.iif) {
#ifdef CONFIG_IP_MROUTE
2657
		__be32 dst = rt->rt_dst;
L
Linus Torvalds 已提交
2658

2659
		if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2660
		    IPV4_DEVCONF_ALL(&init_net, MC_FORWARDING)) {
L
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2661 2662 2663 2664 2665
			int err = ipmr_get_route(skb, r, nowait);
			if (err <= 0) {
				if (!nowait) {
					if (err == 0)
						return 0;
2666
					goto nla_put_failure;
L
Linus Torvalds 已提交
2667 2668
				} else {
					if (err == -EMSGSIZE)
2669
						goto nla_put_failure;
2670
					error = err;
L
Linus Torvalds 已提交
2671 2672 2673 2674
				}
			}
		} else
#endif
2675
			NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
L
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2676 2677
	}

2678 2679 2680
	if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
			       expires, error) < 0)
		goto nla_put_failure;
2681 2682

	return nlmsg_end(skb, nlh);
L
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2683

2684
nla_put_failure:
2685 2686
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
L
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2687 2688
}

2689
static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
L
Linus Torvalds 已提交
2690
{
2691
	struct net *net = sock_net(in_skb->sk);
2692 2693
	struct rtmsg *rtm;
	struct nlattr *tb[RTA_MAX+1];
L
Linus Torvalds 已提交
2694
	struct rtable *rt = NULL;
A
Al Viro 已提交
2695 2696 2697
	__be32 dst = 0;
	__be32 src = 0;
	u32 iif;
2698
	int err;
L
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2699 2700
	struct sk_buff *skb;

2701 2702 2703 2704 2705 2706
	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
	if (err < 0)
		goto errout;

	rtm = nlmsg_data(nlh);

L
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2707
	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2708 2709 2710 2711
	if (skb == NULL) {
		err = -ENOBUFS;
		goto errout;
	}
L
Linus Torvalds 已提交
2712 2713 2714 2715

	/* Reserve room for dummy headers, this skb can pass
	   through good chunk of routing engine.
	 */
2716
	skb_reset_mac_header(skb);
2717
	skb_reset_network_header(skb);
2718 2719

	/* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2720
	ip_hdr(skb)->protocol = IPPROTO_ICMP;
L
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2721 2722
	skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));

2723 2724
	src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
	dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2725
	iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
L
Linus Torvalds 已提交
2726 2727

	if (iif) {
2728 2729
		struct net_device *dev;

2730
		dev = __dev_get_by_index(net, iif);
2731 2732 2733 2734 2735
		if (dev == NULL) {
			err = -ENODEV;
			goto errout_free;
		}

L
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2736 2737 2738 2739 2740
		skb->protocol	= htons(ETH_P_IP);
		skb->dev	= dev;
		local_bh_disable();
		err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
		local_bh_enable();
2741

2742
		rt = skb->rtable;
2743
		if (err == 0 && rt->u.dst.error)
L
Linus Torvalds 已提交
2744 2745
			err = -rt->u.dst.error;
	} else {
2746 2747 2748 2749 2750 2751 2752 2753 2754 2755
		struct flowi fl = {
			.nl_u = {
				.ip4_u = {
					.daddr = dst,
					.saddr = src,
					.tos = rtm->rtm_tos,
				},
			},
			.oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
		};
2756
		err = ip_route_output_key(net, &rt, &fl);
L
Linus Torvalds 已提交
2757
	}
2758

L
Linus Torvalds 已提交
2759
	if (err)
2760
		goto errout_free;
L
Linus Torvalds 已提交
2761

2762
	skb->rtable = rt;
L
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2763 2764 2765 2766
	if (rtm->rtm_flags & RTM_F_NOTIFY)
		rt->rt_flags |= RTCF_NOTIFY;

	err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2767
			   RTM_NEWROUTE, 0, 0);
2768 2769
	if (err <= 0)
		goto errout_free;
L
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2770

2771
	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2772
errout:
2773
	return err;
L
Linus Torvalds 已提交
2774

2775
errout_free:
L
Linus Torvalds 已提交
2776
	kfree_skb(skb);
2777
	goto errout;
L
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2778 2779 2780 2781 2782 2783 2784
}

int ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb)
{
	struct rtable *rt;
	int h, s_h;
	int idx, s_idx;
2785 2786
	struct net *net;

2787
	net = sock_net(skb->sk);
L
Linus Torvalds 已提交
2788 2789

	s_h = cb->args[0];
2790 2791
	if (s_h < 0)
		s_h = 0;
L
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2792
	s_idx = idx = cb->args[1];
2793
	for (h = s_h; h <= rt_hash_mask; h++) {
L
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2794 2795
		rcu_read_lock_bh();
		for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2796
		     rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
2797
			if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
L
Linus Torvalds 已提交
2798
				continue;
2799 2800
			if (rt->rt_genid != atomic_read(&rt_genid))
				continue;
L
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2801 2802
			skb->dst = dst_clone(&rt->u.dst);
			if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
2803
					 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2804
					 1, NLM_F_MULTI) <= 0) {
L
Linus Torvalds 已提交
2805 2806 2807 2808 2809 2810 2811
				dst_release(xchg(&skb->dst, NULL));
				rcu_read_unlock_bh();
				goto done;
			}
			dst_release(xchg(&skb->dst, NULL));
		}
		rcu_read_unlock_bh();
2812
		s_idx = 0;
L
Linus Torvalds 已提交
2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836
	}

done:
	cb->args[0] = h;
	cb->args[1] = idx;
	return skb->len;
}

void ip_rt_multicast_event(struct in_device *in_dev)
{
	rt_cache_flush(0);
}

#ifdef CONFIG_SYSCTL
static int flush_delay;

static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
					struct file *filp, void __user *buffer,
					size_t *lenp, loff_t *ppos)
{
	if (write) {
		proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
		rt_cache_flush(flush_delay);
		return 0;
2837
	}
L
Linus Torvalds 已提交
2838 2839 2840 2841 2842 2843 2844 2845 2846 2847

	return -EINVAL;
}

static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
						int __user *name,
						int nlen,
						void __user *oldval,
						size_t __user *oldlenp,
						void __user *newval,
2848
						size_t newlen)
L
Linus Torvalds 已提交
2849 2850 2851 2852 2853
{
	int delay;
	if (newlen != sizeof(int))
		return -EINVAL;
	if (get_user(delay, (int __user *)newval))
2854 2855
		return -EFAULT;
	rt_cache_flush(delay);
L
Linus Torvalds 已提交
2856 2857 2858 2859
	return 0;
}

ctl_table ipv4_route_table[] = {
2860
	{
L
Linus Torvalds 已提交
2861 2862 2863 2864
		.ctl_name 	= NET_IPV4_ROUTE_FLUSH,
		.procname	= "flush",
		.data		= &flush_delay,
		.maxlen		= sizeof(int),
2865
		.mode		= 0200,
L
Linus Torvalds 已提交
2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886
		.proc_handler	= &ipv4_sysctl_rtcache_flush,
		.strategy	= &ipv4_sysctl_rtcache_flush_strategy,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_GC_THRESH,
		.procname	= "gc_thresh",
		.data		= &ipv4_dst_ops.gc_thresh,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_MAX_SIZE,
		.procname	= "max_size",
		.data		= &ip_rt_max_size,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		/*  Deprecated. Use gc_min_interval_ms */
2887

L
Linus Torvalds 已提交
2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009
		.ctl_name	= NET_IPV4_ROUTE_GC_MIN_INTERVAL,
		.procname	= "gc_min_interval",
		.data		= &ip_rt_gc_min_interval,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
		.procname	= "gc_min_interval_ms",
		.data		= &ip_rt_gc_min_interval,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_ms_jiffies,
		.strategy	= &sysctl_ms_jiffies,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_GC_TIMEOUT,
		.procname	= "gc_timeout",
		.data		= &ip_rt_gc_timeout,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_GC_INTERVAL,
		.procname	= "gc_interval",
		.data		= &ip_rt_gc_interval,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_REDIRECT_LOAD,
		.procname	= "redirect_load",
		.data		= &ip_rt_redirect_load,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_REDIRECT_NUMBER,
		.procname	= "redirect_number",
		.data		= &ip_rt_redirect_number,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_REDIRECT_SILENCE,
		.procname	= "redirect_silence",
		.data		= &ip_rt_redirect_silence,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_ERROR_COST,
		.procname	= "error_cost",
		.data		= &ip_rt_error_cost,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_ERROR_BURST,
		.procname	= "error_burst",
		.data		= &ip_rt_error_burst,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_GC_ELASTICITY,
		.procname	= "gc_elasticity",
		.data		= &ip_rt_gc_elasticity,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_MTU_EXPIRES,
		.procname	= "mtu_expires",
		.data		= &ip_rt_mtu_expires,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_MIN_PMTU,
		.procname	= "min_pmtu",
		.data		= &ip_rt_min_pmtu,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_MIN_ADVMSS,
		.procname	= "min_adv_mss",
		.data		= &ip_rt_min_advmss,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{
		.ctl_name	= NET_IPV4_ROUTE_SECRET_INTERVAL,
		.procname	= "secret_interval",
		.data		= &ip_rt_secret_interval,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
		.strategy	= &sysctl_jiffies,
	},
	{ .ctl_name = 0 }
};
#endif

#ifdef CONFIG_NET_CLS_ROUTE
3010
struct ip_rt_acct *ip_rt_acct __read_mostly;
L
Linus Torvalds 已提交
3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024
#endif /* CONFIG_NET_CLS_ROUTE */

static __initdata unsigned long rhash_entries;
static int __init set_rhash_entries(char *str)
{
	if (!str)
		return 0;
	rhash_entries = simple_strtoul(str, &str, 0);
	return 1;
}
__setup("rhash_entries=", set_rhash_entries);

int __init ip_rt_init(void)
{
3025
	int rc = 0;
L
Linus Torvalds 已提交
3026

3027 3028
	atomic_set(&rt_genid, (int) ((num_physpages ^ (num_physpages>>8)) ^
			     (jiffies ^ (jiffies >> 7))));
L
Linus Torvalds 已提交
3029 3030

#ifdef CONFIG_NET_CLS_ROUTE
3031
	ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct));
L
Linus Torvalds 已提交
3032 3033 3034 3035
	if (!ip_rt_acct)
		panic("IP: failed to allocate ip_rt_acct\n");
#endif

A
Alexey Dobriyan 已提交
3036 3037
	ipv4_dst_ops.kmem_cachep =
		kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3038
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3039

3040 3041
	ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;

3042 3043 3044 3045 3046
	rt_hash_table = (struct rt_hash_bucket *)
		alloc_large_system_hash("IP route cache",
					sizeof(struct rt_hash_bucket),
					rhash_entries,
					(num_physpages >= 128 * 1024) ?
3047
					15 : 17,
3048
					0,
3049 3050 3051
					&rt_hash_log,
					&rt_hash_mask,
					0);
3052 3053
	memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
	rt_hash_lock_init();
L
Linus Torvalds 已提交
3054 3055 3056 3057 3058 3059 3060

	ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
	ip_rt_max_size = (rt_hash_mask + 1) * 16;

	devinet_init();
	ip_fib_init();

3061 3062 3063
	rt_secret_timer.function = rt_secret_rebuild;
	rt_secret_timer.data = 0;
	init_timer_deferrable(&rt_secret_timer);
L
Linus Torvalds 已提交
3064 3065 3066 3067

	/* All the timers, started at system startup tend
	   to synchronize. Perturb it a bit.
	 */
3068 3069
	schedule_delayed_work(&expires_work,
		net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
L
Linus Torvalds 已提交
3070 3071 3072 3073 3074

	rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
		ip_rt_secret_interval;
	add_timer(&rt_secret_timer);

3075
	if (ip_rt_proc_init())
3076
		printk(KERN_ERR "Unable to create route proc files\n");
L
Linus Torvalds 已提交
3077 3078 3079 3080
#ifdef CONFIG_XFRM
	xfrm_init();
	xfrm4_init();
#endif
3081 3082
	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);

L
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3083 3084 3085 3086 3087 3088
	return rc;
}

EXPORT_SYMBOL(__ip_select_ident);
EXPORT_SYMBOL(ip_route_input);
EXPORT_SYMBOL(ip_route_output_key);