From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Sat, 7 May 2022 13:53:59 -0400
Subject: [PATCH] SUNRPC: Ensure that the gssproxy client can start in a
 connected state
Git-commit: fd13359f54ee854f00134abc6be32da94ec53dbf
Patch-mainline: v5.18
References: git-fixes

Ensure that the gssproxy client connects to the server from the gssproxy
daemon process context so that the AF_LOCAL socket connection is done
using the correct path and namespaces.

Fixes: 1d658336b05f ("SUNRPC: Add RPC based upcall mechanism for RPCGSS auth")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 include/linux/sunrpc/clnt.h          |    1 
 net/sunrpc/auth_gss/gss_rpc_upcall.c |    1 
 net/sunrpc/clnt.c                    |   51 +++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)

--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -142,6 +142,7 @@ struct rpc_add_xprt_test {
 #define RPC_CLNT_CREATE_INFINITE_SLOTS	(1UL << 7)
 #define RPC_CLNT_CREATE_NO_IDLE_TIMEOUT	(1UL << 8)
 #define RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT	(1UL << 9)
+#define RPC_CLNT_CREATE_CONNECTED	(1UL << 12)
 
 struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -111,6 +111,7 @@ static int gssp_rpc_create(struct net *n
 		 * done without the correct namespace:
 		 */
 		.flags		= RPC_CLNT_CREATE_NOPING |
+				  RPC_CLNT_CREATE_CONNECTED |
 				  RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
 	};
 	struct rpc_clnt *clnt;
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -78,6 +78,7 @@ static void	call_connect_status(struct r
 
 static __be32	*rpc_encode_header(struct rpc_task *task);
 static __be32	*rpc_verify_header(struct rpc_task *task);
+static int	rpc_ping_noreply(struct rpc_clnt *clnt);
 static int	rpc_ping(struct rpc_clnt *clnt);
 
 static void rpc_register_client(struct rpc_clnt *clnt)
@@ -481,6 +482,12 @@ static struct rpc_clnt *rpc_create_xprt(
 			rpc_shutdown_client(clnt);
 			return ERR_PTR(err);
 		}
+	} else if (args->flags & RPC_CLNT_CREATE_CONNECTED) {
+		int err = rpc_ping_noreply(clnt);
+		if (err != 0) {
+			rpc_shutdown_client(clnt);
+			return ERR_PTR(err);
+		}
 	}
 
 	clnt->cl_softrtry = 1;
@@ -2542,6 +2549,10 @@ static void rpcproc_encode_null(void *rq
 {
 }
 
+static struct rpc_procinfo rpcproc_null_noreply = {
+	.p_encode = rpcproc_encode_null,
+};
+
 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
 {
 	return 0;
@@ -2591,6 +2602,46 @@ struct rpc_task *rpc_call_null(struct rp
 }
 EXPORT_SYMBOL_GPL(rpc_call_null);
 
+static void
+rpc_null_call_prepare(struct rpc_task *task, void *data)
+{
+	task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
+	rpc_call_start(task);
+}
+
+static const struct rpc_call_ops rpc_null_ops = {
+	.rpc_call_prepare = rpc_null_call_prepare,
+	.rpc_call_done = rpc_default_callback,
+};
+
+static int rpc_ping_noreply(struct rpc_clnt *clnt)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &rpcproc_null_noreply,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clnt,
+		.rpc_message = &msg,
+		.callback_ops = &rpc_null_ops,
+		.flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
+	};
+	struct rpc_task	*task;
+	struct rpc_cred *cred;
+	int status;
+
+	cred = authnull_ops.lookup_cred(NULL, NULL, 0);
+
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task)) {
+		put_rpccred(cred);
+		return PTR_ERR(task);
+	}
+	put_rpccred(cred);
+	status = task->tk_status;
+	rpc_put_task(task);
+	return status;
+}
+
 struct rpc_cb_add_xprt_calldata {
 	struct rpc_xprt_switch *xps;
 	struct rpc_xprt *xprt;