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 <>
Signed-off-by: default avatarDavid S. Miller <>
parent 828bac87
......@@ -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);
......@@ -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 } },
struct fib_result res;
struct flowi fl = {
.nl_u = {
.ip4_u = {
.daddr = addr
struct fib_result res = { 0 };
struct net_device *dev = NULL;
res.r = NULL;
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)
return dev;
* Find address type as if only "dev" was present in the system. If
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