releases/4.16.17/rxrpc-fix-error-reception-on-af_inet6-sockets.patch

From foo@baz Sun Jun 17 12:07:34 CEST 2018
From: David Howells <dhowells@redhat.com>
Date: Thu, 10 May 2018 23:26:00 +0100
Subject: rxrpc: Fix error reception on AF_INET6 sockets

From: David Howells <dhowells@redhat.com>

[ Upstream commit f2aeed3a591ff29a82495eeaa92ac4780bad7487 ]

AF_RXRPC tries to turn on IP_RECVERR and IP_MTU_DISCOVER on the UDP socket
it just opened for communications with the outside world, regardless of the
type of socket.  Unfortunately, this doesn't work with an AF_INET6 socket.

Fix this by turning on IPV6_RECVERR and IPV6_MTU_DISCOVER instead if the
socket is of the AF_INET6 family.

Without this, kAFS server and address rotation doesn't work correctly
because the algorithm doesn't detect received network errors.

Fixes: 75b54cb57ca3 ("rxrpc: Add IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/rxrpc/local_object.c |   57 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 42 insertions(+), 15 deletions(-)

--- a/net/rxrpc/local_object.c
+++ b/net/rxrpc/local_object.c
@@ -133,22 +133,49 @@ static int rxrpc_open_socket(struct rxrp
 		}
 	}
 
-	/* we want to receive ICMP errors */
-	opt = 1;
-	ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
-				(char *) &opt, sizeof(opt));
-	if (ret < 0) {
-		_debug("setsockopt failed");
-		goto error;
-	}
+	switch (local->srx.transport.family) {
+	case AF_INET:
+		/* we want to receive ICMP errors */
+		opt = 1;
+		ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
+					(char *) &opt, sizeof(opt));
+		if (ret < 0) {
+			_debug("setsockopt failed");
+			goto error;
+		}
+
+		/* we want to set the don't fragment bit */
+		opt = IP_PMTUDISC_DO;
+		ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
+					(char *) &opt, sizeof(opt));
+		if (ret < 0) {
+			_debug("setsockopt failed");
+			goto error;
+		}
+		break;
+
+	case AF_INET6:
+		/* we want to receive ICMP errors */
+		opt = 1;
+		ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR,
+					(char *) &opt, sizeof(opt));
+		if (ret < 0) {
+			_debug("setsockopt failed");
+			goto error;
+		}
+
+		/* we want to set the don't fragment bit */
+		opt = IPV6_PMTUDISC_DO;
+		ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_MTU_DISCOVER,
+					(char *) &opt, sizeof(opt));
+		if (ret < 0) {
+			_debug("setsockopt failed");
+			goto error;
+		}
+		break;
 
-	/* we want to set the don't fragment bit */
-	opt = IP_PMTUDISC_DO;
-	ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
-				(char *) &opt, sizeof(opt));
-	if (ret < 0) {
-		_debug("setsockopt failed");
-		goto error;
+	default:
+		BUG();
 	}
 
 	/* set the socket up */