1 files changed, 83 insertions, 14 deletions

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index c652e4cc9fe9..9a80a922c527 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -16,6 +16,7 @@
 
 #include <linux/types.h>
 #include <linux/socket.h>
+#include <linux/un.h>
 #include <linux/in.h>
 #include <linux/in6.h>
 #include <linux/kernel.h>
@@ -32,6 +33,8 @@
 # define RPCDBG_FACILITY        RPCDBG_BIND
 #endif
 
+#define RPCBIND_SOCK_PATHNAME   "/var/run/rpcbind.sock"
+
 #define RPCBIND_PROGRAM         (100000u)
 #define RPCBIND_PORT            (111u)
 
@@ -158,20 +161,69 @@ 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),
-};
+/*
+ * Returns zero on success, otherwise a negative errno value
+ * is returned.
+ */
+static int rpcb_create_local_unix(void)
+{
+        static const struct sockaddr_un rpcb_localaddr_rpcbind = {
+                .sun_family             = AF_LOCAL,
+                .sun_path               = RPCBIND_SOCK_PATHNAME,
+        };
+        struct rpc_create_args args = {
+                .net            = &init_net,
+                .protocol       = XPRT_TRANSPORT_LOCAL,
+                .address        = (struct sockaddr *)&rpcb_localaddr_rpcbind,
+                .addrsize       = sizeof(rpcb_localaddr_rpcbind),
+                .servername     = "localhost",
+                .program        = &rpcb_program,
+                .version        = RPCBVERS_2,
+                .authflavor     = RPC_AUTH_NULL,
+        };
+        struct rpc_clnt *clnt, *clnt4;
+        int result = 0;
+
+        /*
+         * Because we requested an RPC PING at transport creation time,
+         * this works only if the user space portmapper is rpcbind, and
+         * it's listening on AF_LOCAL on the named socket.
+         */
+        clnt = rpc_create(&args);
+        if (IS_ERR(clnt)) {
+                dprintk("RPC:       failed to create AF_LOCAL rpcbind "
+                                "client (errno %ld).\n", PTR_ERR(clnt));
+                result = -PTR_ERR(clnt);
+                goto out;
+        }
+
+        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
+        if (IS_ERR(clnt4)) {
+                dprintk("RPC:       failed to bind second program to "
+                                "rpcbind v4 client (errno %ld).\n",
+                                PTR_ERR(clnt4));
+                clnt4 = NULL;
+        }
+
+        /* Protected by rpcb_create_local_mutex */
+        rpcb_local_clnt = clnt;
+        rpcb_local_clnt4 = clnt4;
 
-static DEFINE_MUTEX(rpcb_create_local_mutex);
+out:
+        return result;
+}
 
 /*
  * Returns zero on success, otherwise a negative errno value
  * is returned.
  */
-static int rpcb_create_local(void)
+static int rpcb_create_local_net(void)
 {
+        static const struct sockaddr_in rpcb_inaddr_loopback = {
+                .sin_family             = AF_INET,
+                .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
+                .sin_port               = htons(RPCBIND_PORT),
+        };
         struct rpc_create_args args = {
                 .net            = &init_net,
                 .protocol       = XPRT_TRANSPORT_TCP,
@@ -186,13 +238,6 @@ static int rpcb_create_local(void)
         struct rpc_clnt *clnt, *clnt4;
         int result = 0;
 
-        if (rpcb_local_clnt)
-                return result;
-
-        mutex_lock(&rpcb_create_local_mutex);
-        if (rpcb_local_clnt)
-                goto out;
-
         clnt = rpc_create(&args);
         if (IS_ERR(clnt)) {
                 dprintk("RPC:       failed to create local rpcbind "
@@ -214,10 +259,34 @@ static int rpcb_create_local(void)
                 clnt4 = NULL;
         }
 
+        /* Protected by rpcb_create_local_mutex */
         rpcb_local_clnt = clnt;
         rpcb_local_clnt4 = clnt4;
 
 out:
+        return result;
+}
+
+/*
+ * Returns zero on success, otherwise a negative errno value
+ * is returned.
+ */
+static int rpcb_create_local(void)
+{
+        static DEFINE_MUTEX(rpcb_create_local_mutex);
+        int result = 0;
+
+        if (rpcb_local_clnt)
+                return result;
+
+        mutex_lock(&rpcb_create_local_mutex);
+        if (rpcb_local_clnt)
+                goto out;
+
+        if (rpcb_create_local_unix() != 0)
+                result = rpcb_create_local_net();
+
+out:
         mutex_unlock(&rpcb_create_local_mutex);
         return result;
 }