diff mbox

netlink: use NETLINK_CB(in_skb).sk instead of looking it up

Message ID 20171016145749.31793-1-johannes@sipsolutions.net (mailing list archive)
State Not Applicable
Delegated to: Johannes Berg
Headers show

Commit Message

Johannes Berg Oct. 16, 2017, 2:57 p.m. UTC 
From: Johannes Berg <johannes.berg@intel.com>

When netlink_ack() reports an allocation error to the sending
socket, there's no need to look up the sending socket since
it's available in the SKB's CB. Use that instead of going to
the trouble of looking it up.

Note that the pointer is only available since Eric Biederman's
commit 3fbc290540a1 ("netlink: Make the sending netlink socket availabe in NETLINK_CB")
which is far newer than the original lookup code (Oct 2003)
(though the field was called 'ssk' in that commit and only got
renamed to 'sk' later, I'd actually argue 'ssk' was better - or
perhaps it should've been 'source_sk' - since there are so many
different 'sk's involved.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/netlink/af_netlink.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

Comments

David Miller Oct. 18, 2017, 11:21 a.m. UTC | #1 
From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 16 Oct 2017 16:57:49 +0200

> From: Johannes Berg <johannes.berg@intel.com>
> 
> When netlink_ack() reports an allocation error to the sending
> socket, there's no need to look up the sending socket since
> it's available in the SKB's CB. Use that instead of going to
> the trouble of looking it up.
> 
> Note that the pointer is only available since Eric Biederman's
> commit 3fbc290540a1 ("netlink: Make the sending netlink socket availabe in NETLINK_CB")
> which is far newer than the original lookup code (Oct 2003)
> (though the field was called 'ssk' in that commit and only got
> renamed to 'sk' later, I'd actually argue 'ssk' was better - or
> perhaps it should've been 'source_sk' - since there are so many
> different 'sk's involved.)
> 
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Applied to net-next.
diff mbox

Patch

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index f34750691c5c..336d9c6dcad9 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2336,16 +2336,8 @@  void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
 
 	skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
 	if (!skb) {
-		struct sock *sk;
-
-		sk = netlink_lookup(sock_net(in_skb->sk),
-				    in_skb->sk->sk_protocol,
-				    NETLINK_CB(in_skb).portid);
-		if (sk) {
-			sk->sk_err = ENOBUFS;
-			sk->sk_error_report(sk);
-			sock_put(sk);
-		}
+		NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
+		NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk);
 		return;
 	}