path: root/net/ipv4/devinet.c

/*
 *	NET3	IP device support routines.
 *
 *	Version: $Id: devinet.c,v 1.44 2001/10/31 21:55:54 davem Exp $
 *
 *		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.
 *
 *	Derived from the IP parts of dev.c 1.0.19
 * 		Authors:	Ross Biro
 *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *				Mark Evans, <evansmp@uhura.aston.ac.uk>
 *
 *	Additional Authors:
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *	Changes:
 *		Alexey Kuznetsov:	pa_* fields are replaced with ifaddr
 *					lists.
 *		Cyrus Durgin:		updated for kmod
 *		Matthias Andree:	in devinet_ioctl, compare label and
 *					address (4.4BSD alias style support),
 *					fall back to comparing just the label
 *					if no match found.
 */


#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_addr.h>
#include <linux/if_ether.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/notifier.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
#include <linux/kmod.h>

#include <net/arp.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/ip_fib.h>
#include <net/rtnetlink.h>

struct ipv4_devconf ipv4_devconf = {
	.data = {
		[NET_IPV4_CONF_ACCEPT_REDIRECTS - 1] = 1,
		[NET_IPV4_CONF_SEND_REDIRECTS - 1] = 1,
		[NET_IPV4_CONF_SECURE_REDIRECTS - 1] = 1,
		[NET_IPV4_CONF_SHARED_MEDIA - 1] = 1,
	},
};

static struct ipv4_devconf ipv4_devconf_dflt = {
	.data = {
		[NET_IPV4_CONF_ACCEPT_REDIRECTS - 1] = 1,
		[NET_IPV4_CONF_SEND_REDIRECTS - 1] = 1,
		[NET_IPV4_CONF_SECURE_REDIRECTS - 1] = 1,
		[NET_IPV4_CONF_SHARED_MEDIA - 1] = 1,
		[NET_IPV4_CONF_ACCEPT_SOURCE_ROUTE - 1] = 1,
	},
};

#define IPV4_DEVCONF_DFLT(attr) IPV4_DEVCONF(ipv4_devconf_dflt, attr)

static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
	[IFA_LOCAL]     	= { .type = NLA_U32 },
	[IFA_ADDRESS]   	= { .type = NLA_U32 },
	[IFA_BROADCAST] 	= { .type = NLA_U32 },
	[IFA_ANYCAST]   	= { .type = NLA_U32 },
	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
};

static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);

static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
			 int destroy);
#ifdef CONFIG_SYSCTL
static void devinet_sysctl_register(struct in_device *in_dev,
				    struct ipv4_devconf *p);
static void devinet_sysctl_unregister(struct ipv4_devconf *p);
#endif

/* Locks all the inet devices. */

static struct in_ifaddr *inet_alloc_ifa(void)
{
	struct in_ifaddr *ifa = kzalloc(sizeof(*ifa), GFP_KERNEL);

	if (ifa) {
		INIT_RCU_HEAD(&ifa->rcu_head);
	}

	return ifa;
}

static void inet_rcu_free_ifa(struct rcu_head *head)
{
	struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head);
	if (ifa->ifa_dev)
		in_dev_put(ifa->ifa_dev);
	kfree(ifa);
}

static inline void inet_free_ifa(struct in_ifaddr *ifa)
{
	call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
}

void in_dev_finish_destroy(struct in_device *idev)
{
	struct net_device *dev = idev->dev;

	BUG_TRAP(!idev->ifa_list);
	BUG_TRAP(!idev->mc_list);
#ifdef NET_REFCNT_DEBUG
	printk(KERN_DEBUG "in_dev_finish_destroy: %p=%s\n",
	       idev, dev ? dev->name : "NIL");
#endif
	dev_put(dev);
	if (!idev->dead)
		printk("Freeing alive in_device %p\n", idev);
	else {
		kfree(idev);
	}
}

static struct in_device *inetdev_init(struct net_device *dev)
{
	struct in_device *in_dev;

	ASSERT_RTNL();

	in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL);
	if (!in_dev)
		goto out;
	INIT_RCU_HEAD(&in_dev->rcu_head);
	memcpy(&in_dev->cnf, &ipv4_devconf_dflt, sizeof(in_dev->cnf));
	in_dev->cnf.sysctl = NULL;
	in_dev->dev = dev;
	if ((in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl)) == NULL)
		goto out_kfree;
	/* Reference in_dev->dev */
	dev_hold(dev);
#ifdef CONFIG_SYSCTL
	neigh_sysctl_register(dev, in_dev->arp_parms, NET_IPV4,
			      NET_IPV4_NEIGH, "ipv4", NULL, NULL);
#endif

	/* Account for reference dev->ip_ptr (below) */
	in_dev_hold(in_dev);

#ifdef CONFIG_SYSCTL
	devinet_sysctl_register(in_dev, &in_dev->cnf);
#endif
	ip_mc_init_dev(in_dev);
	if (dev->flags & IFF_UP)
		ip_mc_up(in_dev);

	/* we can receive as soon as ip_ptr is set -- do this last */
	rcu_assign_pointer(dev->ip_ptr, in_dev);
out:
	return in_dev;
out_kfree:
	kfree(in_dev);
	in_dev = NULL;
	goto out;
}

static void in_dev_rcu_put(struct rcu_head *head)
{
	struct in_device *idev = container_of(head, struct in_device, rcu_head);
	in_dev_put(idev);
}

static void inetdev_destroy(struct in_device *in_dev)
{
	struct in_ifaddr *ifa;
	struct net_device *dev;

	ASSERT_RTNL();

	dev = in_dev->dev;

	in_dev->dead = 1;

	ip_mc_destroy_dev(in_dev);

	while ((ifa = in_dev->ifa_list) != NULL) {
		inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
		in