SUNRPC: Introduce a specific rpcb_create for contacting localhost

Add rpcb_create_local() for use by rpcb_register() and upcoming IPv6
registration functions.

Ensure any errors encountered by rpcb_create_local() are properly
reported.

We can also use a statically allocated constant loopback socket address
instead of one allocated on the stack and initialized every time the
function is called.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 31 insertions, 11 deletions

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 0021fad464e0..35c1ded1fc47 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -116,6 +116,29 @@ static void rpcb_map_release(void *data)
         kfree(map);
 }
 
+static const struct sockaddr_in rpcb_inaddr_loopback = {
+        .sin_family             = AF_INET,
+        .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
+        .sin_port               = htons(RPCBIND_PORT),
+};
+
+static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
+                                          size_t addrlen, u32 version)
+{
+        struct rpc_create_args args = {
+                .protocol       = XPRT_TRANSPORT_UDP,
+                .address        = addr,
+                .addrsize       = addrlen,
+                .servername     = "localhost",
+                .program        = &rpcb_program,
+                .version        = version,
+                .authflavor     = RPC_AUTH_UNIX,
+                .flags          = RPC_CLNT_CREATE_NOPING,
+        };
+
+        return rpc_create(&args);
+}
+
 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
                                     size_t salen, int proto, u32 version,
                                     int privileged)
@@ -161,10 +184,6 @@ static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
  */
 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
 {
-        struct sockaddr_in sin = {
-                .sin_family             = AF_INET,
-                .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
-        };
         struct rpcbind_args map = {
                 .r_prog         = prog,
                 .r_vers         = vers,
@@ -184,14 +203,15 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
                         "rpcbind\n", (port ? "" : "un"),
                         prog, vers, prot, port);
 
-        rpcb_clnt = rpcb_create("localhost", (struct sockaddr *) &sin,
-                                sizeof(sin), XPRT_TRANSPORT_UDP, RPCBVERS_2, 1);
-        if (IS_ERR(rpcb_clnt))
-                return PTR_ERR(rpcb_clnt);
+        rpcb_clnt = rpcb_create_local((struct sockaddr *)&rpcb_inaddr_loopback,
+                                        sizeof(rpcb_inaddr_loopback),
+                                        RPCBVERS_2);
+        if (!IS_ERR(rpcb_clnt)) {
+                error = rpc_call_sync(rpcb_clnt, &msg, 0);
+                rpc_shutdown_client(rpcb_clnt);
+        } else
+                error = PTR_ERR(rpcb_clnt);
 
-        error = rpc_call_sync(rpcb_clnt, &msg, 0);
-
-        rpc_shutdown_client(rpcb_clnt);
         if (error < 0)
                 printk(KERN_WARNING "RPC: failed to contact local rpcbind "
                                 "server (errno %d).\n", -error);