path: root/net/core/rtnetlink.c

/*
 * 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.
 *
 *		Routing netlink socket interface: protocol independent part.
 *
 * 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.
 *
 *	Fixes:
 *	Vitaly E. Lavrov		RTA_OK arithmetics was wrong.
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/security.h>
#include <linux/mutex.h>
#include <linux/if_addr.h>

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/string.h>

#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/arp.h>
#include <net/route.h>
#include <net/udp.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <net/fib_rules.h>
#include <net/netlink.h>
#ifdef CONFIG_NET_WIRELESS_RTNETLINK
#include <linux/wireless.h>
#include <net/iw_handler.h>
#endif	/* CONFIG_NET_WIRELESS_RTNETLINK */

static DEFINE_MUTEX(rtnl_mutex);
static struct sock *rtnl;

void rtnl_lock(void)
{
	mutex_lock(&rtnl_mutex);
}

void __rtnl_unlock(void)
{
	mutex_unlock(&rtnl_mutex);
}

void rtnl_unlock(void)
{
	mutex_unlock(&rtnl_mutex);
	if (rtnl && rtnl->sk_receive_queue.qlen)
		rtnl->sk_data_ready(rtnl, 0);
	netdev_run_todo();
}

int rtnl_trylock(void)
{
	return mutex_trylock(&rtnl_mutex);
}

int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
{
	memset(tb, 0, sizeof(struct rtattr*)*maxattr);

	while (RTA_OK(rta, len)) {
		unsigned flavor = rta->rta_type;
		if (flavor && flavor <= maxattr)
			tb[flavor-1] = rta;
		rta = RTA_NEXT(rta, len);
	}
	return 0;
}

struct rtnetlink_link * rtnetlink_links[NPROTO];

static const int rtm_min[RTM_NR_FAMILIES] =
{
	[RTM_FAM(RTM_NEWLINK)]      = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
	[RTM_FAM(RTM_NEWADDR)]      = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
	[RTM_FAM(RTM_NEWROUTE)]     = NLMSG_LENGTH(sizeof(struct rtmsg)),
	[RTM_FAM(RTM_NEWRULE)]      = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
	[RTM_FAM(RTM_NEWQDISC)]     = NLMSG_LENGTH(sizeof(struct tcmsg)),
	[RTM_FAM(RTM_NEWTCLASS)]    = NLMSG_LENGTH(sizeof(struct tcmsg)),
	[RTM_FAM(RTM_NEWTFILTER)]   = NLMSG_LENGTH(sizeof(struct tcmsg)),
	[RTM_FAM(RTM_NEWACTION)]    = NLMSG_LENGTH(sizeof(struct tcamsg)),
	[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
	[RTM_FAM(RTM_GETANYCAST)]   = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
};

static const int rta_max[RTM_NR_FAMILIES] =
{
	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
	[RTM_FAM(RTM_NEWRULE)]      = FRA_MAX,
	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
};

void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
{
	struct rtattr *rta;
	int size = RTA_LENGTH(attrlen);

	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
	rta->rta_type = attrtype;
	rta->rta_len = size;
	memcpy(RTA_DATA(rta), data, attrlen);
	memset(RTA_DATA(rta) + attrlen, 0, RTA_ALIGN(size) - size);
}

size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
{
	size_t ret = RTA_PAYLOAD(rta);
	char *src = RTA_DATA(rta);

	if (ret > 0 && src[ret - 1] == '\0')
		ret--;
	if (size > 0) {
		size_t len = (ret >= size) ? size - 1 : ret;
		memset(dest, 0, size);
		memcpy(dest, src, len);
	}
	return ret;
}

int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
{
	int err = 0;

	NETLINK_CB(skb).dst_group = group;
	if (echo)