SUNRPC client: add interface for binding to a local address

In addition to binding to a local privileged port the NFS client should
allow binding to a specific local address. This is used by the server
for callbacks. The patch adds the necessary interface.

Signed-off-by: Frank van Maarseveen <frankvm@frankvm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index c1b3797..c0d9d14 100644 (file)
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -98,6 +98,7 @@ struct rpc_create_args {
        int                     protocol;
        struct sockaddr         *address;
        size_t                  addrsize;
+       struct sockaddr         *saddress;
        struct rpc_timeout      *timeout;
        char                    *servername;
        struct rpc_program      *program;

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index ea828b0..d11cedd 100644 (file)
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -198,6 +198,7 @@ struct rpc_xprt {
 
 struct rpc_xprtsock_create {
        int                     proto;          /* IPPROTO_UDP or IPPROTO_TCP */
+       struct sockaddr *       srcaddr;        /* optional local address */
        struct sockaddr *       dstaddr;        /* remote peer address */
        size_t                  addrlen;
        struct rpc_timeout *    timeout;        /* optional timeout parameters */

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 25bbf2d..5d3fe7b 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -236,6 +236,7 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
        struct rpc_clnt *clnt;
        struct rpc_xprtsock_create xprtargs = {
                .proto = args->protocol,
+               .srcaddr = args->saddress,
                .dstaddr = args->address,
                .addrlen = args->addrsize,
                .timeout = args->timeout

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 6b7cea5..4ae7eed 100644 (file)
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -235,6 +235,7 @@ struct sock_xprt {
         * Connection of transports
         */
        struct delayed_work     connect_worker;
+       struct sockaddr_storage addr;
        unsigned short          port;
 
        /*
@@ -1145,31 +1146,36 @@ static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
        sap->sin_port = htons(port);
 }
 
-static int xs_bindresvport(struct sock_xprt *transport, struct socket *sock)
+static int xs_bind(struct sock_xprt *transport, struct socket *sock)
 {
        struct sockaddr_in myaddr = {
                .sin_family = AF_INET,
        };
+       struct sockaddr_in *sa;
        int err;
        unsigned short port = transport->port;
 
+       if (!transport->xprt.resvport)
+               port = 0;
+       sa = (struct sockaddr_in *)&transport->addr;
+       myaddr.sin_addr = sa->sin_addr;
        do {
                myaddr.sin_port = htons(port);
                err = kernel_bind(sock, (struct sockaddr *) &myaddr,
                                                sizeof(myaddr));
+               if (!transport->xprt.resvport)
+                       break;
                if (err == 0) {
                        transport->port = port;
-                       dprintk("RPC:       xs_bindresvport bound to port %u\n",
-                                       port);
-                       return 0;
+                       break;
                }
                if (port <= xprt_min_resvport)
                        port = xprt_max_resvport;
                else
                        port--;
        } while (err == -EADDRINUSE && port != transport->port);
-
-       dprintk("RPC:       can't bind to reserved port (%d).\n", -err);
+       dprintk("RPC:       xs_bind "NIPQUAD_FMT":%u: %s (%d)\n",
+               NIPQUAD(myaddr.sin_addr), port, err ? "failed" : "ok", err);
        return err;
 }
 
@@ -1228,7 +1234,7 @@ static void xs_udp_connect_worker(struct work_struct *work)
        }
        xs_reclassify_socket(sock);
 
-       if (xprt->resvport && xs_bindresvport(transport, sock) < 0) {
+       if (xs_bind(transport, sock)) {
                sock_release(sock);
                goto out;
        }
@@ -1315,7 +1321,7 @@ static void xs_tcp_connect_worker(struct work_struct *work)
                }
                xs_reclassify_socket(sock);
 
-               if (xprt->resvport && xs_bindresvport(transport, sock) < 0) {
+               if (xs_bind(transport, sock)) {
                        sock_release(sock);
                        goto out;
                }
@@ -1531,6 +1537,8 @@ static struct rpc_xprt *xs_setup_xprt(struct rpc_xprtsock_create *args, unsigned
 
        memcpy(&xprt->addr, args->dstaddr, args->addrlen);
        xprt->addrlen = args->addrlen;
+       if (args->srcaddr)
+               memcpy(&new->addr, args->srcaddr, args->addrlen);
        new->port = xs_get_random_port();
 
        return xprt;