SUNRPC: Set IPV6ONLY flag on PF_INET6 RPC listener sockets

We are about to convert to using separate RPC listener sockets for
PF_INET and PF_INET6.  This echoes the way IPv6 is handled in user
space by TI-RPC, and eliminates the need for ULPs to worry about
mapped IPv4 AF_INET6 addresses when doing address comparisons.

Start by setting the IPV6ONLY flag on PF_INET6 RPC listener sockets.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index d00bc3307745..ac6cd65220c7 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1144,13 +1144,11 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
                 svc_tcp_init(svsk, serv);
 
         /*
-         * We start one listener per sv_serv.  We want AF_INET
-         * requests to be automatically shunted to our PF_INET6
-         * listener using a mapped IPv4 address.  Make sure
-         * no-one starts an equivalent IPv4 listener, which
-         * would steal our incoming connections.
+         * If this is a PF_INET6 listener, we want to avoid
+         * getting requests from IPv4 remotes.  Those should
+         * be shunted to a PF_INET listener via rpcbind.
          */
-        val = 0;
+        val = 1;
         if (inet->sk_family == PF_INET6)
                 kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
                                         (char *)&val, sizeof(val));