From 73bfd370c878d3feb3c3111cc17af066dc1f455b Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 23 Dec 2013 14:35:55 +0100 Subject: [PATCH] netlink: only do not deliver to tap when both sides are kernel sks We should also deliver packets to nlmon devices when we are in netlink_unicast_kernel(), and only one of the {src,dst} sockets is user sk and the other one kernel sk. That's e.g. the case in netlink diag, netlink route, etc. Still, forbid to deliver messages from kernel to kernel sks. Signed-off-by: Daniel Borkmann Signed-off-by: Jakub Zawadzki Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index bca50b95c182..56e09d8a55fd 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -239,6 +239,13 @@ static void netlink_deliver_tap(struct sk_buff *skb) rcu_read_unlock(); } +static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, + struct sk_buff *skb) +{ + if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) + netlink_deliver_tap(skb); +} + static void netlink_overrun(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); @@ -1697,14 +1704,10 @@ static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, ret = -ECONNREFUSED; if (nlk->netlink_rcv != NULL) { - /* We could do a netlink_deliver_tap(skb) here as well - * but since this is intended for the kernel only, we - * should rather let it stay under the hood. - */ - ret = skb->len; netlink_skb_set_owner_r(skb, sk); NETLINK_CB(skb).sk = ssk; + netlink_deliver_tap_kernel(sk, ssk, skb); nlk->netlink_rcv(skb); consume_skb(skb); } else { -- 2.20.1