fib_frontend.c 24.1 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.
 *
 *		IPv4 Forwarding Information Base: FIB frontend.
 *
 * Version:	$Id: fib_frontend.c,v 1.26 2001/10/31 21:55:54 davem Exp $
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *		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>
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#include <linux/capability.h>
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#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/inet.h>
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#include <linux/inetdevice.h>
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#include <linux/netdevice.h>
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#include <linux/if_addr.h>
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#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/init.h>
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#include <linux/list.h>
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#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <net/icmp.h>
#include <net/arp.h>
#include <net/ip_fib.h>
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#include <net/rtnetlink.h>
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#ifndef CONFIG_IP_MULTIPLE_TABLES

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static int __net_init fib4_rules_init(struct net *net)
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{
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	struct fib_table *local_table, *main_table;

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	local_table = fib_hash_table(RT_TABLE_LOCAL);
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	if (local_table == NULL)
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		return -ENOMEM;

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	main_table  = fib_hash_table(RT_TABLE_MAIN);
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	if (main_table == NULL)
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		goto fail;

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	hlist_add_head_rcu(&local_table->tb_hlist,
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				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
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	hlist_add_head_rcu(&main_table->tb_hlist,
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				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
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	return 0;

fail:
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	kfree(local_table);
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	return -ENOMEM;
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}
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#else
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struct fib_table *fib_new_table(struct net *net, u32 id)
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{
	struct fib_table *tb;
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	unsigned int h;
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	if (id == 0)
		id = RT_TABLE_MAIN;
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	tb = fib_get_table(net, id);
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	if (tb)
		return tb;
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	tb = fib_hash_table(id);
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	if (!tb)
		return NULL;
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	h = id & (FIB_TABLE_HASHSZ - 1);
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	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
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	return tb;
}

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struct fib_table *fib_get_table(struct net *net, u32 id)
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{
	struct fib_table *tb;
	struct hlist_node *node;
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	struct hlist_head *head;
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	unsigned int h;
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	if (id == 0)
		id = RT_TABLE_MAIN;
	h = id & (FIB_TABLE_HASHSZ - 1);
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	rcu_read_lock();
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	head = &net->ipv4.fib_table_hash[h];
	hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
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		if (tb->tb_id == id) {
			rcu_read_unlock();
			return tb;
		}
	}
	rcu_read_unlock();
	return NULL;
}
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#endif /* CONFIG_IP_MULTIPLE_TABLES */

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void fib_select_default(struct net *net,
			const struct flowi *flp, struct fib_result *res)
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{
	struct fib_table *tb;
	int table = RT_TABLE_MAIN;
#ifdef CONFIG_IP_MULTIPLE_TABLES
	if (res->r == NULL || res->r->action != FR_ACT_TO_TBL)
		return;
	table = res->r->table;
#endif
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	tb = fib_get_table(net, table);
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	if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
		tb->tb_select_default(tb, flp, res);
}

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static void fib_flush(struct net *net)
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{
	int flushed = 0;
	struct fib_table *tb;
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	struct hlist_node *node;
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	struct hlist_head *head;
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	unsigned int h;
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	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
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		head = &net->ipv4.fib_table_hash[h];
		hlist_for_each_entry(tb, node, head, tb_hlist)
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			flushed += tb->tb_flush(tb);
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	}

	if (flushed)
		rt_cache_flush(-1);
}

/*
 *	Find the first device with a given source address.
 */

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struct net_device * ip_dev_find(struct net *net, __be32 addr)
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{
	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
	struct fib_result res;
	struct net_device *dev = NULL;
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	struct fib_table *local_table;
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#ifdef CONFIG_IP_MULTIPLE_TABLES
	res.r = NULL;
#endif

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	local_table = fib_get_table(net, RT_TABLE_LOCAL);
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	if (!local_table || local_table->tb_lookup(local_table, &fl, &res))
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		return NULL;
	if (res.type != RTN_LOCAL)
		goto out;
	dev = FIB_RES_DEV(res);

	if (dev)
		dev_hold(dev);
out:
	fib_res_put(&res);
	return dev;
}

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/*
 * Find address type as if only "dev" was present in the system. If
 * on_dev is NULL then all interfaces are taken into consideration.
 */
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static inline unsigned __inet_dev_addr_type(struct net *net,
					    const struct net_device *dev,
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					    __be32 addr)
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{
	struct flowi		fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
	struct fib_result	res;
	unsigned ret = RTN_BROADCAST;
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	struct fib_table *local_table;
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	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
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		return RTN_BROADCAST;
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	if (ipv4_is_multicast(addr))
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		return RTN_MULTICAST;

#ifdef CONFIG_IP_MULTIPLE_TABLES
	res.r = NULL;
#endif
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	local_table = fib_get_table(net, RT_TABLE_LOCAL);
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	if (local_table) {
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		ret = RTN_UNICAST;
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		if (!local_table->tb_lookup(local_table, &fl, &res)) {
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			if (!dev || dev == res.fi->fib_dev)
				ret = res.type;
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			fib_res_put(&res);
		}
	}
	return ret;
}

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unsigned int inet_addr_type(struct net *net, __be32 addr)
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{
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	return __inet_dev_addr_type(net, NULL, addr);
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}

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unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
				__be32 addr)
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{
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       return __inet_dev_addr_type(net, dev, addr);
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}

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/* Given (packet source, input interface) and optional (dst, oif, tos):
   - (main) check, that source is valid i.e. not broadcast or our local
     address.
   - figure out what "logical" interface this packet arrived
     and calculate "specific destination" address.
   - check, that packet arrived from expected physical interface.
 */

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int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
			struct net_device *dev, __be32 *spec_dst, u32 *itag)
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{
	struct in_device *in_dev;
	struct flowi fl = { .nl_u = { .ip4_u =
				      { .daddr = src,
					.saddr = dst,
					.tos = tos } },
			    .iif = oif };
	struct fib_result res;
	int no_addr, rpf;
	int ret;
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	struct net *net;
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	no_addr = rpf = 0;
	rcu_read_lock();
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	in_dev = __in_dev_get_rcu(dev);
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	if (in_dev) {
		no_addr = in_dev->ifa_list == NULL;
		rpf = IN_DEV_RPFILTER(in_dev);
	}
	rcu_read_unlock();

	if (in_dev == NULL)
		goto e_inval;

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	net = dev_net(dev);
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	if (fib_lookup(net, &fl, &res))
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		goto last_resort;
	if (res.type != RTN_UNICAST)
		goto e_inval_res;
	*spec_dst = FIB_RES_PREFSRC(res);
	fib_combine_itag(itag, &res);
#ifdef CONFIG_IP_ROUTE_MULTIPATH
	if (FIB_RES_DEV(res) == dev || res.fi->fib_nhs > 1)
#else
	if (FIB_RES_DEV(res) == dev)
#endif
	{
		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
		fib_res_put(&res);
		return ret;
	}
	fib_res_put(&res);
	if (no_addr)
		goto last_resort;
	if (rpf)
		goto e_inval;
	fl.oif = dev->ifindex;

	ret = 0;
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	if (fib_lookup(net, &fl, &res) == 0) {
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		if (res.type == RTN_UNICAST) {
			*spec_dst = FIB_RES_PREFSRC(res);
			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
		}
		fib_res_put(&res);
	}
	return ret;

last_resort:
	if (rpf)
		goto e_inval;
	*spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
	*itag = 0;
	return 0;

e_inval_res:
	fib_res_put(&res);
e_inval:
	return -EINVAL;
}

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static inline __be32 sk_extract_addr(struct sockaddr *addr)
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{
	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
}

static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
{
	struct nlattr *nla;

	nla = (struct nlattr *) ((char *) mx + len);
	nla->nla_type = type;
	nla->nla_len = nla_attr_size(4);
	*(u32 *) nla_data(nla) = value;

	return len + nla_total_size(4);
}

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static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
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				 struct fib_config *cfg)
{
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	__be32 addr;
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	int plen;

	memset(cfg, 0, sizeof(*cfg));
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	cfg->fc_nlinfo.nl_net = net;
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	if (rt->rt_dst.sa_family != AF_INET)
		return -EAFNOSUPPORT;

	/*
	 * Check mask for validity:
	 * a) it must be contiguous.
	 * b) destination must have all host bits clear.
	 * c) if application forgot to set correct family (AF_INET),
	 *    reject request unless it is absolutely clear i.e.
	 *    both family and mask are zero.
	 */
	plen = 32;
	addr = sk_extract_addr(&rt->rt_dst);
	if (!(rt->rt_flags & RTF_HOST)) {
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		__be32 mask = sk_extract_addr(&rt->rt_genmask);
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		if (rt->rt_genmask.sa_family != AF_INET) {
			if (mask || rt->rt_genmask.sa_family)
				return -EAFNOSUPPORT;
		}

		if (bad_mask(mask, addr))
			return -EINVAL;

		plen = inet_mask_len(mask);
	}

	cfg->fc_dst_len = plen;
	cfg->fc_dst = addr;

	if (cmd != SIOCDELRT) {
		cfg->fc_nlflags = NLM_F_CREATE;
		cfg->fc_protocol = RTPROT_BOOT;
	}

	if (rt->rt_metric)
		cfg->fc_priority = rt->rt_metric - 1;

	if (rt->rt_flags & RTF_REJECT) {
		cfg->fc_scope = RT_SCOPE_HOST;
		cfg->fc_type = RTN_UNREACHABLE;
		return 0;
	}

	cfg->fc_scope = RT_SCOPE_NOWHERE;
	cfg->fc_type = RTN_UNICAST;

	if (rt->rt_dev) {
		char *colon;
		struct net_device *dev;
		char devname[IFNAMSIZ];

		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
			return -EFAULT;

		devname[IFNAMSIZ-1] = 0;
		colon = strchr(devname, ':');
		if (colon)
			*colon = 0;
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		dev = __dev_get_by_name(net, devname);
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		if (!dev)
			return -ENODEV;
		cfg->fc_oif = dev->ifindex;
		if (colon) {
			struct in_ifaddr *ifa;
			struct in_device *in_dev = __in_dev_get_rtnl(dev);
			if (!in_dev)
				return -ENODEV;
			*colon = ':';
			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
				if (strcmp(ifa->ifa_label, devname) == 0)
					break;
			if (ifa == NULL)
				return -ENODEV;
			cfg->fc_prefsrc = ifa->ifa_local;
		}
	}

	addr = sk_extract_addr(&rt->rt_gateway);
	if (rt->rt_gateway.sa_family == AF_INET && addr) {
		cfg->fc_gw = addr;
		if (rt->rt_flags & RTF_GATEWAY &&
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		    inet_addr_type(net, addr) == RTN_UNICAST)
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			cfg->fc_scope = RT_SCOPE_UNIVERSE;
	}

	if (cmd == SIOCDELRT)
		return 0;

	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
		return -EINVAL;

	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
		cfg->fc_scope = RT_SCOPE_LINK;

	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
		struct nlattr *mx;
		int len = 0;

		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
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		if (mx == NULL)
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			return -ENOMEM;

		if (rt->rt_flags & RTF_MTU)
			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);

		if (rt->rt_flags & RTF_WINDOW)
			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);

		if (rt->rt_flags & RTF_IRTT)
			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);

		cfg->fc_mx = mx;
		cfg->fc_mx_len = len;
	}

	return 0;
}

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/*
 *	Handle IP routing ioctl calls. These are used to manipulate the routing tables
 */
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int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
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{
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	struct fib_config cfg;
	struct rtentry rt;
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	int err;

	switch (cmd) {
	case SIOCADDRT:		/* Add a route */
	case SIOCDELRT:		/* Delete a route */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
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		if (copy_from_user(&rt, arg, sizeof(rt)))
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			return -EFAULT;
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		rtnl_lock();
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		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
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		if (err == 0) {
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			struct fib_table *tb;

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			if (cmd == SIOCDELRT) {
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				tb = fib_get_table(net, cfg.fc_table);
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				if (tb)
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					err = tb->tb_delete(tb, &cfg);
				else
					err = -ESRCH;
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			} else {
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				tb = fib_new_table(net, cfg.fc_table);
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				if (tb)
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					err = tb->tb_insert(tb, &cfg);
				else
					err = -ENOBUFS;
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			}
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			/* allocated by rtentry_to_fib_config() */
			kfree(cfg.fc_mx);
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		}
		rtnl_unlock();
		return err;
	}
	return -EINVAL;
}

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const struct nla_policy rtm_ipv4_policy[RTA_MAX+1] = {
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	[RTA_DST]		= { .type = NLA_U32 },
	[RTA_SRC]		= { .type = NLA_U32 },
	[RTA_IIF]		= { .type = NLA_U32 },
	[RTA_OIF]		= { .type = NLA_U32 },
	[RTA_GATEWAY]		= { .type = NLA_U32 },
	[RTA_PRIORITY]		= { .type = NLA_U32 },
	[RTA_PREFSRC]		= { .type = NLA_U32 },
	[RTA_METRICS]		= { .type = NLA_NESTED },
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	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
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	[RTA_PROTOINFO]		= { .type = NLA_U32 },
	[RTA_FLOW]		= { .type = NLA_U32 },
};

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static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
			    struct nlmsghdr *nlh, struct fib_config *cfg)
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{
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	struct nlattr *attr;
	int err, remaining;
	struct rtmsg *rtm;

	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
	if (err < 0)
		goto errout;

	memset(cfg, 0, sizeof(*cfg));

	rtm = nlmsg_data(nlh);
	cfg->fc_dst_len = rtm->rtm_dst_len;
	cfg->fc_tos = rtm->rtm_tos;
	cfg->fc_table = rtm->rtm_table;
	cfg->fc_protocol = rtm->rtm_protocol;
	cfg->fc_scope = rtm->rtm_scope;
	cfg->fc_type = rtm->rtm_type;
	cfg->fc_flags = rtm->rtm_flags;
	cfg->fc_nlflags = nlh->nlmsg_flags;

	cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
	cfg->fc_nlinfo.nlh = nlh;
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	cfg->fc_nlinfo.nl_net = net;
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	if (cfg->fc_type > RTN_MAX) {
		err = -EINVAL;
		goto errout;
	}

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	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
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		switch (nla_type(attr)) {
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		case RTA_DST:
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			cfg->fc_dst = nla_get_be32(attr);
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			break;
		case RTA_OIF:
			cfg->fc_oif = nla_get_u32(attr);
			break;
		case RTA_GATEWAY:
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			cfg->fc_gw = nla_get_be32(attr);
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			break;
		case RTA_PRIORITY:
			cfg->fc_priority = nla_get_u32(attr);
			break;
		case RTA_PREFSRC:
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			cfg->fc_prefsrc = nla_get_be32(attr);
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			break;
		case RTA_METRICS:
			cfg->fc_mx = nla_data(attr);
			cfg->fc_mx_len = nla_len(attr);
			break;
		case RTA_MULTIPATH:
			cfg->fc_mp = nla_data(attr);
			cfg->fc_mp_len = nla_len(attr);
			break;
		case RTA_FLOW:
			cfg->fc_flow = nla_get_u32(attr);
			break;
		case RTA_TABLE:
			cfg->fc_table = nla_get_u32(attr);
			break;
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		}
	}
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	return 0;
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errout:
	return err;
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}

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static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
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{
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	struct net *net = skb->sk->sk_net;
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	struct fib_config cfg;
	struct fib_table *tb;
	int err;
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591
	err = rtm_to_fib_config(net, skb, nlh, &cfg);
592 593
	if (err < 0)
		goto errout;
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594

595
	tb = fib_get_table(net, cfg.fc_table);
596 597 598 599 600 601 602 603
	if (tb == NULL) {
		err = -ESRCH;
		goto errout;
	}

	err = tb->tb_delete(tb, &cfg);
errout:
	return err;
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}

606
static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
L
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607
{
608
	struct net *net = skb->sk->sk_net;
609 610 611
	struct fib_config cfg;
	struct fib_table *tb;
	int err;
L
Linus Torvalds 已提交
612

613
	err = rtm_to_fib_config(net, skb, nlh, &cfg);
614 615
	if (err < 0)
		goto errout;
L
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616

617
	tb = fib_new_table(net, cfg.fc_table);
618 619 620 621 622 623 624 625
	if (tb == NULL) {
		err = -ENOBUFS;
		goto errout;
	}

	err = tb->tb_insert(tb, &cfg);
errout:
	return err;
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}

628
static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
L
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629
{
630
	struct net *net = skb->sk->sk_net;
631 632
	unsigned int h, s_h;
	unsigned int e = 0, s_e;
L
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633
	struct fib_table *tb;
634
	struct hlist_node *node;
635
	struct hlist_head *head;
636
	int dumped = 0;
L
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638 639
	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
L
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		return ip_rt_dump(skb, cb);

642 643 644 645 646
	s_h = cb->args[0];
	s_e = cb->args[1];

	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
		e = 0;
647 648
		head = &net->ipv4.fib_table_hash[h];
		hlist_for_each_entry(tb, node, head, tb_hlist) {
649 650 651 652
			if (e < s_e)
				goto next;
			if (dumped)
				memset(&cb->args[2], 0, sizeof(cb->args) -
653
						 2 * sizeof(cb->args[0]));
654 655 656 657 658 659
			if (tb->tb_dump(tb, skb, cb) < 0)
				goto out;
			dumped = 1;
next:
			e++;
		}
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	}
661 662 663
out:
	cb->args[1] = e;
	cb->args[0] = h;
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	return skb->len;
}

/* Prepare and feed intra-kernel routing request.
   Really, it should be netlink message, but :-( netlink
   can be not configured, so that we feed it directly
   to fib engine. It is legal, because all events occur
   only when netlink is already locked.
 */

A
Al Viro 已提交
675
static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
L
Linus Torvalds 已提交
676
{
677
	struct net *net = dev_net(ifa->ifa_dev->dev);
678 679 680 681 682 683 684 685 686
	struct fib_table *tb;
	struct fib_config cfg = {
		.fc_protocol = RTPROT_KERNEL,
		.fc_type = type,
		.fc_dst = dst,
		.fc_dst_len = dst_len,
		.fc_prefsrc = ifa->ifa_local,
		.fc_oif = ifa->ifa_dev->dev->ifindex,
		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
687
		.fc_nlinfo = {
688
			.nl_net = net,
689
		},
690
	};
L
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691 692

	if (type == RTN_UNICAST)
693
		tb = fib_new_table(net, RT_TABLE_MAIN);
L
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694
	else
695
		tb = fib_new_table(net, RT_TABLE_LOCAL);
L
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696 697 698 699

	if (tb == NULL)
		return;

700
	cfg.fc_table = tb->tb_id;
L
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702 703 704 705
	if (type != RTN_LOCAL)
		cfg.fc_scope = RT_SCOPE_LINK;
	else
		cfg.fc_scope = RT_SCOPE_HOST;
L
Linus Torvalds 已提交
706 707

	if (cmd == RTM_NEWROUTE)
708
		tb->tb_insert(tb, &cfg);
L
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709
	else
710
		tb->tb_delete(tb, &cfg);
L
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}

713
void fib_add_ifaddr(struct in_ifaddr *ifa)
L
Linus Torvalds 已提交
714 715 716 717
{
	struct in_device *in_dev = ifa->ifa_dev;
	struct net_device *dev = in_dev->dev;
	struct in_ifaddr *prim = ifa;
A
Al Viro 已提交
718 719 720
	__be32 mask = ifa->ifa_mask;
	__be32 addr = ifa->ifa_local;
	__be32 prefix = ifa->ifa_address&mask;
L
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721 722 723 724

	if (ifa->ifa_flags&IFA_F_SECONDARY) {
		prim = inet_ifa_byprefix(in_dev, prefix, mask);
		if (prim == NULL) {
725
			printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n");
L
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			return;
		}
	}

	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);

	if (!(dev->flags&IFF_UP))
		return;

	/* Add broadcast address, if it is explicitly assigned. */
A
Al Viro 已提交
736
	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
L
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		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);

739
	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) &&
L
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	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
		fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL :
			  RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim);

		/* Add network specific broadcasts, when it takes a sense */
		if (ifa->ifa_prefixlen < 31) {
			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim);
		}
	}
}

static void fib_del_ifaddr(struct in_ifaddr *ifa)
{
	struct in_device *in_dev = ifa->ifa_dev;
	struct net_device *dev = in_dev->dev;
	struct in_ifaddr *ifa1;
	struct in_ifaddr *prim = ifa;
A
Al Viro 已提交
758 759
	__be32 brd = ifa->ifa_address|~ifa->ifa_mask;
	__be32 any = ifa->ifa_address&ifa->ifa_mask;
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#define LOCAL_OK	1
#define BRD_OK		2
#define BRD0_OK		4
#define BRD1_OK		8
	unsigned ok = 0;

	if (!(ifa->ifa_flags&IFA_F_SECONDARY))
		fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL :
			  RTN_UNICAST, any, ifa->ifa_prefixlen, prim);
	else {
		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
		if (prim == NULL) {
772
			printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
L
Linus Torvalds 已提交
773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803
			return;
		}
	}

	/* Deletion is more complicated than add.
	   We should take care of not to delete too much :-)

	   Scan address list to be sure that addresses are really gone.
	 */

	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
		if (ifa->ifa_local == ifa1->ifa_local)
			ok |= LOCAL_OK;
		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
			ok |= BRD_OK;
		if (brd == ifa1->ifa_broadcast)
			ok |= BRD1_OK;
		if (any == ifa1->ifa_broadcast)
			ok |= BRD0_OK;
	}

	if (!(ok&BRD_OK))
		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
	if (!(ok&BRD1_OK))
		fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
	if (!(ok&BRD0_OK))
		fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
	if (!(ok&LOCAL_OK)) {
		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);

		/* Check, that this local address finally disappeared. */
804
		if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
L
Linus Torvalds 已提交
805 806 807 808 809 810
			/* And the last, but not the least thing.
			   We must flush stray FIB entries.

			   First of all, we scan fib_info list searching
			   for stray nexthop entries, then ignite fib_flush.
			*/
811 812
			if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
				fib_flush(dev_net(dev));
L
Linus Torvalds 已提交
813 814 815 816 817 818 819 820
		}
	}
#undef LOCAL_OK
#undef BRD_OK
#undef BRD0_OK
#undef BRD1_OK
}

821 822
static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb )
{
823

824
	struct fib_result       res;
825
	struct flowi            fl = { .mark = frn->fl_mark,
826
				       .nl_u = { .ip4_u = { .daddr = frn->fl_addr,
827 828
							    .tos = frn->fl_tos,
							    .scope = frn->fl_scope } } };
829

830 831 832 833
#ifdef CONFIG_IP_MULTIPLE_TABLES
	res.r = NULL;
#endif

834
	frn->err = -ENOENT;
835 836 837 838 839 840 841 842 843 844 845
	if (tb) {
		local_bh_disable();

		frn->tb_id = tb->tb_id;
		frn->err = tb->tb_lookup(tb, &fl, &res);

		if (!frn->err) {
			frn->prefixlen = res.prefixlen;
			frn->nh_sel = res.nh_sel;
			frn->type = res.type;
			frn->scope = res.scope;
846
			fib_res_put(&res);
847 848 849 850 851
		}
		local_bh_enable();
	}
}

852
static void nl_fib_input(struct sk_buff *skb)
853
{
854
	struct net *net;
855
	struct fib_result_nl *frn;
856
	struct nlmsghdr *nlh;
857
	struct fib_table *tb;
858
	u32 pid;
859

860
	net = skb->sk->sk_net;
861
	nlh = nlmsg_hdr(skb);
862
	if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
863
	    nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
864
		return;
865 866 867 868 869

	skb = skb_clone(skb, GFP_KERNEL);
	if (skb == NULL)
		return;
	nlh = nlmsg_hdr(skb);
870

871
	frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
872
	tb = fib_get_table(net, frn->tb_id_in);
873 874

	nl_fib_lookup(frn, tb);
875

876
	pid = NETLINK_CB(skb).pid;       /* pid of sending process */
877
	NETLINK_CB(skb).pid = 0;         /* from kernel */
878
	NETLINK_CB(skb).dst_group = 0;  /* unicast */
879
	netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
880
}
881

882
static int nl_fib_lookup_init(struct net *net)
883
{
884 885 886 887
	struct sock *sk;
	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
				   nl_fib_input, NULL, THIS_MODULE);
	if (sk == NULL)
888
		return -EAFNOSUPPORT;
889
	net->ipv4.fibnl = sk;
890 891 892 893 894
	return 0;
}

static void nl_fib_lookup_exit(struct net *net)
{
895
	netlink_kernel_release(net->ipv4.fibnl);
896
	net->ipv4.fibnl = NULL;
897 898
}

L
Linus Torvalds 已提交
899 900
static void fib_disable_ip(struct net_device *dev, int force)
{
D
Denis V. Lunev 已提交
901
	if (fib_sync_down_dev(dev, force))
902
		fib_flush(dev_net(dev));
L
Linus Torvalds 已提交
903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
	rt_cache_flush(0);
	arp_ifdown(dev);
}

static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct in_ifaddr *ifa = (struct in_ifaddr*)ptr;

	switch (event) {
	case NETDEV_UP:
		fib_add_ifaddr(ifa);
#ifdef CONFIG_IP_ROUTE_MULTIPATH
		fib_sync_up(ifa->ifa_dev->dev);
#endif
		rt_cache_flush(-1);
		break;
	case NETDEV_DOWN:
		fib_del_ifaddr(ifa);
921
		if (ifa->ifa_dev->ifa_list == NULL) {
L
Linus Torvalds 已提交
922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
			/* Last address was deleted from this interface.
			   Disable IP.
			 */
			fib_disable_ip(ifa->ifa_dev->dev, 1);
		} else {
			rt_cache_flush(-1);
		}
		break;
	}
	return NOTIFY_DONE;
}

static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;
937
	struct in_device *in_dev = __in_dev_get_rtnl(dev);
L
Linus Torvalds 已提交
938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975

	if (event == NETDEV_UNREGISTER) {
		fib_disable_ip(dev, 2);
		return NOTIFY_DONE;
	}

	if (!in_dev)
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_UP:
		for_ifa(in_dev) {
			fib_add_ifaddr(ifa);
		} endfor_ifa(in_dev);
#ifdef CONFIG_IP_ROUTE_MULTIPATH
		fib_sync_up(dev);
#endif
		rt_cache_flush(-1);
		break;
	case NETDEV_DOWN:
		fib_disable_ip(dev, 0);
		break;
	case NETDEV_CHANGEMTU:
	case NETDEV_CHANGE:
		rt_cache_flush(0);
		break;
	}
	return NOTIFY_DONE;
}

static struct notifier_block fib_inetaddr_notifier = {
	.notifier_call =fib_inetaddr_event,
};

static struct notifier_block fib_netdev_notifier = {
	.notifier_call =fib_netdev_event,
};

976
static int __net_init ip_fib_net_init(struct net *net)
L
Linus Torvalds 已提交
977
{
978
	int err;
979 980
	unsigned int i;

981 982 983 984 985
	net->ipv4.fib_table_hash = kzalloc(
			sizeof(struct hlist_head)*FIB_TABLE_HASHSZ, GFP_KERNEL);
	if (net->ipv4.fib_table_hash == NULL)
		return -ENOMEM;

986
	for (i = 0; i < FIB_TABLE_HASHSZ; i++)
987
		INIT_HLIST_HEAD(&net->ipv4.fib_table_hash[i]);
988

989 990 991 992 993 994 995 996
	err = fib4_rules_init(net);
	if (err < 0)
		goto fail;
	return 0;

fail:
	kfree(net->ipv4.fib_table_hash);
	return err;
997
}
L
Linus Torvalds 已提交
998

999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010
static void __net_exit ip_fib_net_exit(struct net *net)
{
	unsigned int i;

#ifdef CONFIG_IP_MULTIPLE_TABLES
	fib4_rules_exit(net);
#endif

	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
		struct fib_table *tb;
		struct hlist_head *head;
		struct hlist_node *node, *tmp;
1011

1012
		head = &net->ipv4.fib_table_hash[i];
1013 1014 1015 1016 1017 1018
		hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
			hlist_del(node);
			tb->tb_flush(tb);
			kfree(tb);
		}
	}
1019
	kfree(net->ipv4.fib_table_hash);
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058
}

static int __net_init fib_net_init(struct net *net)
{
	int error;

	error = ip_fib_net_init(net);
	if (error < 0)
		goto out;
	error = nl_fib_lookup_init(net);
	if (error < 0)
		goto out_nlfl;
	error = fib_proc_init(net);
	if (error < 0)
		goto out_proc;
out:
	return error;

out_proc:
	nl_fib_lookup_exit(net);
out_nlfl:
	ip_fib_net_exit(net);
	goto out;
}

static void __net_exit fib_net_exit(struct net *net)
{
	fib_proc_exit(net);
	nl_fib_lookup_exit(net);
	ip_fib_net_exit(net);
}

static struct pernet_operations fib_net_ops = {
	.init = fib_net_init,
	.exit = fib_net_exit,
};

void __init ip_fib_init(void)
{
1059 1060 1061
	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL);
	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL);
	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib);
1062 1063 1064 1065

	register_pernet_subsys(&fib_net_ops);
	register_netdevice_notifier(&fib_netdev_notifier);
	register_inetaddr_notifier(&fib_inetaddr_notifier);
1066 1067

	fib_hash_init();
L
Linus Torvalds 已提交
1068 1069 1070
}

EXPORT_SYMBOL(inet_addr_type);
1071
EXPORT_SYMBOL(inet_dev_addr_type);
S
Sean Hefty 已提交
1072
EXPORT_SYMBOL(ip_dev_find);