1 files changed, 77 insertions, 16 deletions

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 28f50da60ceb..116db74dd942 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -20,6 +20,7 @@
 #include <linux/in6.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <linux/mutex.h>
 #include <net/ipv6.h>
 
 #include <linux/sunrpc/clnt.h>
@@ -110,6 +111,9 @@ static void			rpcb_getport_done(struct rpc_task *, void *);
 static void                     rpcb_map_release(void *data);
 static struct rpc_program       rpcb_program;
 
+static struct rpc_clnt *        rpcb_local_clnt;
+static struct rpc_clnt *        rpcb_local_clnt4;
+
 struct rpcbind_args {
         struct rpc_xprt *       r_xprt;
 
@@ -163,7 +167,13 @@ static const struct sockaddr_in rpcb_inaddr_loopback = {
         .sin_port               = htons(RPCBIND_PORT),
 };
 
-static struct rpc_clnt *rpcb_create_local(u32 version)
+static DEFINE_MUTEX(rpcb_create_local_mutex);
+
+/*
+ * Returns zero on success, otherwise a negative errno value
+ * is returned.
+ */
+static int rpcb_create_local(void)
 {
         struct rpc_create_args args = {
                 .protocol       = XPRT_TRANSPORT_UDP,
@@ -171,12 +181,46 @@ static struct rpc_clnt *rpcb_create_local(u32 version)
                 .addrsize       = sizeof(rpcb_inaddr_loopback),
                 .servername     = "localhost",
                 .program        = &rpcb_program,
-                .version        = version,
+                .version        = RPCBVERS_2,
                 .authflavor     = RPC_AUTH_UNIX,
                 .flags          = RPC_CLNT_CREATE_NOPING,
         };
+        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 "
+                                "client (errno %ld).\n", PTR_ERR(clnt));
+                result = -PTR_ERR(clnt);
+                goto out;
+        }
 
-        return rpc_create(&args);
+        /*
+         * This results in an RPC ping.  On systems running portmapper,
+         * the v4 ping will fail.  Proceed anyway, but disallow rpcb
+         * v4 upcalls.
+         */
+        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
+        if (IS_ERR(clnt4)) {
+                dprintk("RPC:       failed to create local rpcbind v4 "
+                                "cleint (errno %ld).\n", PTR_ERR(clnt4));
+                clnt4 = NULL;
+        }
+
+        rpcb_local_clnt = clnt;
+        rpcb_local_clnt4 = clnt4;
+
+out:
+        mutex_unlock(&rpcb_create_local_mutex);
+        return result;
 }
 
 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
@@ -208,20 +252,13 @@ static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
         return rpc_create(&args);
 }
 
-static int rpcb_register_call(const u32 version, struct rpc_message *msg)
+static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 {
-        struct rpc_clnt *rpcb_clnt;
         int result, error = 0;
 
         msg->rpc_resp = &result;
 
-        rpcb_clnt = rpcb_create_local(version);
-        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(clnt, msg, 0);
         if (error < 0) {
                 dprintk("RPC:       failed to contact local rpcbind "
                                 "server (errno %d).\n", -error);
@@ -276,6 +313,11 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
         struct rpc_message msg = {
                 .rpc_argp       = &map,
         };
+        int error;
+
+        error = rpcb_create_local();
+        if (error)
+                return error;
 
         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
                         "rpcbind\n", (port ? "" : "un"),
@@ -285,7 +327,7 @@ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
         if (port)
                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 
-        return rpcb_register_call(RPCBVERS_2, &msg);
+        return rpcb_register_call(rpcb_local_clnt, &msg);
 }
 
 /*
@@ -310,7 +352,7 @@ static int rpcb_register_inet4(const struct sockaddr *sap,
         if (port)
                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 
-        result = rpcb_register_call(RPCBVERS_4, msg);
+        result = rpcb_register_call(rpcb_local_clnt4, msg);
         kfree(map->r_addr);
         return result;
 }
@@ -337,7 +379,7 @@ static int rpcb_register_inet6(const struct sockaddr *sap,
         if (port)
                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 
-        result = rpcb_register_call(RPCBVERS_4, msg);
+        result = rpcb_register_call(rpcb_local_clnt4, msg);
         kfree(map->r_addr);
         return result;
 }
@@ -353,7 +395,7 @@ static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
         map->r_addr = "";
         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 
-        return rpcb_register_call(RPCBVERS_4, msg);
+        return rpcb_register_call(rpcb_local_clnt4, msg);
 }
 
 /**
@@ -411,6 +453,13 @@ int rpcb_v4_register(const u32 program, const u32 version,
         struct rpc_message msg = {
                 .rpc_argp       = &map,
         };
+        int error;
+
+        error = rpcb_create_local();
+        if (error)
+                return error;
+        if (rpcb_local_clnt4 == NULL)
+                return -EPROTONOSUPPORT;
 
         if (address == NULL)
                 return rpcb_unregister_all_protofamilies(&msg);
@@ -1024,3 +1073,15 @@ static struct rpc_program rpcb_program = {
         .version        = rpcb_version,
         .stats          = &rpcb_stats,
 };
+
+/**
+ * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
+ *
+ */
+void cleanup_rpcb_clnt(void)
+{
+        if (rpcb_local_clnt4)
+                rpc_shutdown_client(rpcb_local_clnt4);
+        if (rpcb_local_clnt)
+                rpc_shutdown_client(rpcb_local_clnt);
+}