Commit 82efee14 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv4: introduce __ip_dev_find() 



ip_dev_find(net, addr) finds a device given an IPv4 source address and
takes a reference on it.

Introduce __ip_dev_find(), taking a third argument, to optionally take
the device reference. Callers not asking the reference to be taken
should be in an rcu_read_lock() protected section.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 828bac87

include/linux/inetdevice.h

+6 −1
Original line number Diff line number Diff line
@@ -159,7 +159,12 @@ struct in_ifaddr { 
extern int register_inetaddr_notifier(struct notifier_block *nb);

extern int unregister_inetaddr_notifier(struct notifier_block *nb);



extern struct net_device *ip_dev_find(struct net *net, __be32 addr);

extern struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref);

static inline struct net_device *ip_dev_find(struct net *net, __be32 addr)

{

	return __ip_dev_find(net, addr, true);

}



extern int		inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b);

extern int		devinet_ioctl(struct net *net, unsigned int cmd, void __user *);

extern void		devinet_init(void);

net/ipv4/fib_frontend.c

+19 −13
Original line number Diff line number Diff line
@@ -147,34 +147,40 @@ static void fib_flush(struct net *net) 
		rt_cache_flush(net, -1);

}



/*

 *	Find the first device with a given source address.

/**

 * __ip_dev_find - find the first device with a given source address.

 * @net: the net namespace

 * @addr: the source address

 * @devref: if true, take a reference on the found device

 *

 * If a caller uses devref=false, it should be protected by RCU

 */



struct net_device * ip_dev_find(struct net *net, __be32 addr)

struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)

{

	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } },

			    .flags = FLOWI_FLAG_MATCH_ANY_IIF };

	struct fib_result res;

	struct flowi fl = {

		.nl_u = {

			.ip4_u = {

				.daddr = addr

			}

		},

		.flags = FLOWI_FLAG_MATCH_ANY_IIF

	};

	struct fib_result res = { 0 };

	struct net_device *dev = NULL;



#ifdef CONFIG_IP_MULTIPLE_TABLES

	res.r = NULL;

#endif



	if (fib_lookup(net, &fl, &res))

		return NULL;

	if (res.type != RTN_LOCAL)

		goto out;

	dev = FIB_RES_DEV(res);



	if (dev)

	if (dev && devref)

		dev_hold(dev);

out:

	fib_res_put(&res);

	return dev;

}

EXPORT_SYMBOL(ip_dev_find);

EXPORT_SYMBOL(__ip_dev_find);



/*

 * Find address type as if only "dev" was present in the system. If

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