[PATCH net] net: diag: support v4mapped sockets in inet_diag_find_one_icsk()

From: Eric Dumazet <edumazet@google.com>

Lorenzo reported that we could not properly find v4mapped sockets
in inet_diag_find_one_icsk(). This patch fixes the issue.

Reported-by: Lorenzo Colitti <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/inet_diag.c |   21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 8bb8e7ad8548..6029157a19ed 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c

@@ -361,13 +361,20 @@ struct sock *inet_diag_find_one_icsk(struct net *net,
 				 req->id.idiag_dport, req->id.idiag_src[0],
 				 req->id.idiag_sport, req->id.idiag_if);
 #if IS_ENABLED(CONFIG_IPV6)
-	else if (req->sdiag_family == AF_INET6)
-		sk = inet6_lookup(net, hashinfo,
-				  (struct in6_addr *)req->id.idiag_dst,
-				  req->id.idiag_dport,
-				  (struct in6_addr *)req->id.idiag_src,
-				  req->id.idiag_sport,
-				  req->id.idiag_if);
+	else if (req->sdiag_family == AF_INET6) {
+		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
+		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
+			sk = inet_lookup(net, hashinfo, req->id.idiag_dst[3],
+					 req->id.idiag_dport, req->id.idiag_src[3],
+					 req->id.idiag_sport, req->id.idiag_if);
+		else
+			sk = inet6_lookup(net, hashinfo,
+					  (struct in6_addr *)req->id.idiag_dst,
+					  req->id.idiag_dport,
+					  (struct in6_addr *)req->id.idiag_src,
+					  req->id.idiag_sport,
+					  req->id.idiag_if);
+	}
 #endif
 	else
 		return ERR_PTR(-EINVAL);

On Wed, Jan 20, 2016 at 4:25 PM, Eric Dumazet [off-list ref] wrote:

Lorenzo reported that we could not properly find v4mapped sockets
in inet_diag_find_one_icsk(). This patch fixes the issue.

Reported-by: Lorenzo Colitti <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>

This fixes the problem for me. I tested that SOCK_DESTROY (which uses
inet_diag_find_one_icsk) can successfully find/close the following
AF_INET6 sockets:

- Listen sockets bound to either :: or ::ffff:0.0.0.0
- Accepted IPv4 connections on sockets bound to either :: or ::ffff:0.0.0.0
- Active IPv4 connections

Acked-by: Lorenzo Colitti <redacted>

From: Eric Dumazet <redacted>
Date: Wed, 20 Jan 2016 16:25:01 -0800

From: Eric Dumazet <edumazet@google.com>

Lorenzo reported that we could not properly find v4mapped sockets
in inet_diag_find_one_icsk(). This patch fixes the issue.

Reported-by: Lorenzo Colitti <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.