From cacb6ba0f36ab14a507f4ee7697e8332899015d2 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Sat, 3 Nov 2012 09:30:34 +0000 Subject: [PATCH] net: inet_diag -- Return error code if protocol handler is missed We've observed that in case if UDP diag module is not supported in kernel the netlink returns NLMSG_DONE without notifying a caller that handler is missed. This patch makes __inet_diag_dump to return error code instead. So as example it become possible to detect such situation and handle it gracefully on userspace level. Signed-off-by: Cyrill Gorcunov CC: David Miller CC: Eric Dumazet CC: Pavel Emelyanov Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller --- net/ipv4/inet_diag.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 535584c00f91..0c34bfabc11f 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -892,13 +892,16 @@ static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, struct inet_diag_req_v2 *r, struct nlattr *bc) { const struct inet_diag_handler *handler; + int err = 0; handler = inet_diag_lock_handler(r->sdiag_protocol); if (!IS_ERR(handler)) handler->dump(skb, cb, r, bc); + else + err = PTR_ERR(handler); inet_diag_unlock_handler(handler); - return skb->len; + return err ? : skb->len; } static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) -- 2.20.1