[PATCH] knfsd: SUNRPC: add a "generic" function to see if the peer uses a secure port

The only reason svcsock.c looks at a sockaddr's port is to check whether the
remote peer is connecting from a privileged port.  Refactor this check to hide
processing that is specific to address format.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/sunrpc/svcsock.c

@@ -938,6 +938,22 @@ svc_tcp_data_ready(struct sock *sk, int count)
 		wake_up_interruptible(sk->sk_sleep);
 }
 
+static inline int svc_port_is_privileged(struct sockaddr *sin)
+{
+	switch (sin->sa_family) {
+	case AF_INET:
+		return ntohs(((struct sockaddr_in *)sin)->sin_port)
+			< PROT_SOCK;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	case AF_INET6:
+		return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
+			< PROT_SOCK;
+#endif
+	default:
+		return 0;
+	}
+}
+
 /*
  * Accept a TCP connection
  */
@@ -984,7 +1000,7 @@ svc_tcp_accept(struct svc_sock *svsk)
 	 * hosts here, but when we get encryption, the IP of the host won't
 	 * tell us anything.  For now just warn about unpriv connections.
 	 */
-	if (ntohs(sin.sin_port) >= 1024) {
+	if (!svc_port_is_privileged((struct sockaddr *) &sin)) {
 		dprintk(KERN_WARNING
 			"%s: connect from unprivileged port: %s\n",
 			serv->sv_name,
@@ -1334,7 +1350,6 @@ int
 svc_recv(struct svc_rqst *rqstp, long timeout)
 {
 	struct svc_sock		*svsk = NULL;
-	struct sockaddr_in	*sin = svc_addr_in(rqstp);
 	struct svc_serv		*serv = rqstp->rq_server;
 	struct svc_pool		*pool = rqstp->rq_pool;
 	int			len, i;
@@ -1431,7 +1446,7 @@ svc_recv(struct svc_rqst *rqstp, long timeout)
 	svsk->sk_lastrecv = get_seconds();
 	clear_bit(SK_OLD, &svsk->sk_flags);
 
-	rqstp->rq_secure = ntohs(sin->sin_port) < PROT_SOCK;
+	rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
 	rqstp->rq_chandle.defer = svc_defer;
 
 	if (serv->sv_stats)