From: NeilBrown <neilb@suse.de>
Date: Tue, 15 Jun 2021 11:08:05 +1000
Subject: [PATCH] SUNRPC: prevent port reuse on transports which don't request
it.
Patch-mainline: Submitted, jun 2021 - linux-nfs@vger.kernel.org
References: bnc#1186264
If an RPC client is created without RPC_CLNT_CREATE_REUSEPORT, it should
not reuse the source port when a TCP connection is re-established.
This is currently implemented by preventing the source port being
recorded after a successful connection (the call to xs_set_srcport()).
However the source port is also recorded after a successful bind in xs_bind().
This may not be needed at all and certainly is not wanted when
RPC_CLNT_CREATE_REUSEPORT wasn't requested.
So avoid that assignment when xprt.reuseport is not set.
With this change, NFSv4.1 and later mounts use a different port number on
each connection. This is helpful with some firewalls which don't cope
well with port reuse.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.com>
---
net/sunrpc/xprtsock.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1879,7 +1879,8 @@ static int xs_bind(struct sock_xprt *tra
err = kernel_bind(sock, (struct sockaddr *)&myaddr,
transport->xprt.addrlen);
if (err == 0) {
- transport->srcport = port;
+ if (transport->xprt.reuseport)
+ transport->srcport = port;
break;
}
last = port;