netfilter: nfnetlink: add RCU in nfnetlink_rcv_msg()

Goal of this patch is to permit nfnetlink providers not mandate
nfnl_mutex being held while nfnetlink_rcv_msg() calls them.

If struct nfnl_callback contains a non NULL call_rcu(), then
nfnetlink_rcv_msg() will use it instead of call() field, holding
rcu_read_lock instead of nfnl_mutex

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Florian Westphal <fw@strlen.de>
CC: Eric Leblond <eric@regit.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Eric Dumazet
2011-07-18 16:08:07 +02:00
committed by Patrick McHardy
parent 131ad62d8f
commit 6b75e3e8d6
2 changed files with 33 additions and 10 deletions

View File

@ -60,6 +60,9 @@ struct nfnl_callback {
int (*call)(struct sock *nl, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const cda[]);
int (*call_rcu)(struct sock *nl, struct sk_buff *skb,
const struct nlmsghdr *nlh,
const struct nlattr * const cda[]);
const struct nla_policy *policy; /* netlink attribute policy */
const u_int16_t attr_count; /* number of nlattr's */
};