SUNRPC: create an IPv6-savvy mechanism for binding to a reserved port

Clone xs_bindresvport into two functions, one that can handle IPv4
addresses, and one that can handle IPv6 addresses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index cd7c18b24527..8295ae28391a 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1261,6 +1261,39 @@ static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
         return err;
 }
 
+static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
+{
+        struct sockaddr_in6 myaddr = {
+                .sin6_family = AF_INET6,
+        };
+        struct sockaddr_in6 *sa;
+        int err;
+        unsigned short port = transport->port;
+
+        if (!transport->xprt.resvport)
+                port = 0;
+        sa = (struct sockaddr_in6 *)&transport->addr;
+        myaddr.sin6_addr = sa->sin6_addr;
+        do {
+                myaddr.sin6_port = htons(port);
+                err = kernel_bind(sock, (struct sockaddr *) &myaddr,
+                                                sizeof(myaddr));
+                if (!transport->xprt.resvport)
+                        break;
+                if (err == 0) {
+                        transport->port = port;
+                        break;
+                }
+                if (port <= xprt_min_resvport)
+                        port = xprt_max_resvport;
+                else
+                        port--;
+        } while (err == -EADDRINUSE && port != transport->port);
+        dprintk("RPC:       xs_bind6 "NIP6_FMT":%u: %s (%d)\n",
+                NIP6(myaddr.sin6_addr), port, err ? "failed" : "ok", err);
+        return err;
+}
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key xs_key[2];
 static struct lock_class_key xs_slock_key[2];