diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-09-30 03:31:56 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-09-30 21:16:05 -0700 |
| commit | 82efee1499a27c06f5afb11b07db384fdb3f7004 (patch) | |
| tree | c329e037ddf4e13cd824c131eab3bd3a2e67a0fc | |
| parent | 828bac87bb074f3366621724fdfbe314f98ccc7e (diff) | |
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: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/inetdevice.h | 7 | ||||
| -rw-r--r-- | net/ipv4/fib_frontend.c | 32 |
2 files changed, 25 insertions, 14 deletions
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h index 1ec09bb4a3a..ccd5b07d678 100644 --- a/include/linux/inetdevice.h +++ b/include/linux/inetdevice.h @@ -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); diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 981f3c59b33..4a69a957872 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -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 |