SUNRPC: use sockaddr + size when creating remote transport endpoints

Prepare for more generic transport endpoint handling needed by transports
that might use different forms of addressing, such as IPv6.

Introduce a single function call to replace the two-call
xprt_create_proto/rpc_create_client API.  Define a new rpc_create_args
structure that allows callers to pass in remote endpoint addresses of
varying length.

Test-plan:
Compile kernel with CONFIG_NFS enabled.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 136 insertions, 0 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index ff1e90fd81ab..dbb93bdf6cc9 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -192,6 +192,67 @@ out_no_xprt:
         return ERR_PTR(err);
 }
 
+/*
+ * rpc_create - create an RPC client and transport with one call
+ * @args: rpc_clnt create argument structure
+ *
+ * Creates and initializes an RPC transport and an RPC client.
+ *
+ * It can ping the server in order to determine if it is up, and to see if
+ * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
+ * this behavior so asynchronous tasks can also use rpc_create.
+ */
+struct rpc_clnt *rpc_create(struct rpc_create_args *args)
+{
+        struct rpc_xprt *xprt;
+        struct rpc_clnt *clnt;
+
+        xprt = xprt_create_transport(args->protocol, args->address,
+                                        args->addrsize, args->timeout);
+        if (IS_ERR(xprt))
+                return (struct rpc_clnt *)xprt;
+
+        /*
+         * By default, kernel RPC client connects from a reserved port.
+         * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
+         * but it is always enabled for rpciod, which handles the connect
+         * operation.
+         */
+        xprt->resvport = 1;
+        if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
+                xprt->resvport = 0;
+
+        dprintk("RPC:       creating %s client for %s (xprt %p)\n",
+                args->program->name, args->servername, xprt);
+
+        clnt = rpc_new_client(xprt, args->servername, args->program,
+                                args->version, args->authflavor);
+        if (IS_ERR(clnt))
+                return clnt;
+
+        if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
+                int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
+                if (err != 0) {
+                        rpc_shutdown_client(clnt);
+                        return ERR_PTR(err);
+                }
+        }
+
+        clnt->cl_softrtry = 1;
+        if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
+                clnt->cl_softrtry = 0;
+
+        if (args->flags & RPC_CLNT_CREATE_INTR)
+                clnt->cl_intr = 1;
+        if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
+                clnt->cl_autobind = 1;
+        if (args->flags & RPC_CLNT_CREATE_ONESHOT)
+                clnt->cl_oneshot = 1;
+
+        return clnt;
+}
+EXPORT_SYMBOL(rpc_create);
+
 /**
  * Create an RPC client
  * @xprt - pointer to xprt struct
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 4987517cc74b..17f56cfe2412 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -887,6 +887,81 @@ void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long i
         to->to_exponential = 0;
 }
 
+/**
+ * xprt_create_transport - create an RPC transport
+ * @proto: requested transport protocol
+ * @ap: remote peer address
+ * @size: length of address
+ * @to: timeout parameters
+ *
+ */
+struct rpc_xprt *xprt_create_transport(int proto, struct sockaddr *ap, size_t size, struct rpc_timeout *to)
+{
+        int result;
+        struct rpc_xprt *xprt;
+        struct rpc_rqst *req;
+
+        if ((xprt = kzalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL) {
+                dprintk("RPC:      xprt_create_transport: no memory\n");
+                return ERR_PTR(-ENOMEM);
+        }
+        if (size <= sizeof(xprt->addr)) {
+                memcpy(&xprt->addr, ap, size);
+                xprt->addrlen = size;
+        } else {
+                kfree(xprt);
+                dprintk("RPC:      xprt_create_transport: address too large\n");
+                return ERR_PTR(-EBADF);
+        }
+
+        switch (proto) {
+        case IPPROTO_UDP:
+                result = xs_setup_udp(xprt, to);
+                break;
+        case IPPROTO_TCP:
+                result = xs_setup_tcp(xprt, to);
+                break;
+        default:
+                printk(KERN_ERR "RPC: unrecognized transport protocol: %d\n",
+                                proto);
+                return ERR_PTR(-EIO);
+        }
+        if (result) {
+                kfree(xprt);
+                dprintk("RPC:      xprt_create_transport: failed, %d\n", result);
+                return ERR_PTR(result);
+        }
+
+        spin_lock_init(&xprt->transport_lock);
+        spin_lock_init(&xprt->reserve_lock);
+
+        INIT_LIST_HEAD(&xprt->free);
+        INIT_LIST_HEAD(&xprt->recv);
+        INIT_WORK(&xprt->task_cleanup, xprt_autoclose, xprt);
+        init_timer(&xprt->timer);
+        xprt->timer.function = xprt_init_autodisconnect;
+        xprt->timer.data = (unsigned long) xprt;
+        xprt->last_used = jiffies;
+        xprt->cwnd = RPC_INITCWND;
+
+        rpc_init_wait_queue(&xprt->binding, "xprt_binding");
+        rpc_init_wait_queue(&xprt->pending, "xprt_pending");
+        rpc_init_wait_queue(&xprt->sending, "xprt_sending");
+        rpc_init_wait_queue(&xprt->resend, "xprt_resend");
+        rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
+
+        /* initialize free list */
+        for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--)
+                list_add(&req->rq_list, &xprt->free);
+
+        xprt_init_xid(xprt);
+
+        dprintk("RPC:      created transport %p with %u slots\n", xprt,
+                        xprt->max_reqs);
+
+        return xprt;
+}
+
 static struct rpc_xprt *xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to)
 {
         int result;