nfsd: support callbacks with gss flavors

This patch adds server-side support for callbacks other than AUTH_SYS.
Signed-off-by: Olga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfsd/nfs4callback.c

@@ -358,6 +358,7 @@ static struct rpc_program cb_program = {
 		.nrvers		= ARRAY_SIZE(nfs_cb_version),
 		.version	= nfs_cb_version,
 		.stats		= &cb_stats,
+		.pipe_dir_name  = "/nfsd4_cb",
 };
 
 /* Reference counting, callback cleanup, etc., all look racy as heck.
@@ -382,7 +383,7 @@ static int do_probe_callback(void *data)
 		.program	= &cb_program,
 		.prognumber	= cb->cb_prog,
 		.version	= nfs_cb_version[1]->number,
-		.authflavor	= RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
+		.authflavor	= clp->cl_flavor,
 		.flags		= (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
 		.client_name    = clp->cl_principal,
 	};

fs/nfsd/nfs4state.c

@@ -786,6 +786,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	}
 	copy_verf(new, &clverifier);
 	new->cl_addr = sin->sin_addr.s_addr;
+	new->cl_flavor = rqstp->rq_flavor;
 	princ = svc_gss_principal(rqstp);
 	if (princ) {
 		new->cl_principal = kstrdup(princ, GFP_KERNEL);

include/linux/nfsd/state.h

@@ -124,6 +124,7 @@ struct nfs4_client {
 	nfs4_verifier		cl_verifier; 	/* generated by client */
 	time_t                  cl_time;        /* time of last lease renewal */
 	__be32			cl_addr; 	/* client ipaddress */
+	u32			cl_flavor;	/* setclientid pseudoflavor */
 	char			*cl_principal;	/* setclientid principal name */
 	struct svc_cred		cl_cred; 	/* setclientid principal */
 	clientid_t		cl_clientid;	/* generated by server */

net/sunrpc/rpc_pipe.c

@@ -407,6 +407,7 @@ enum {
 	RPCAUTH_nfs,
 	RPCAUTH_portmap,
 	RPCAUTH_statd,
+	RPCAUTH_nfsd4_cb,
 	RPCAUTH_RootEOF
 };
 
@@ -440,6 +441,10 @@ static struct rpc_filelist files[] = {
 		.name = "statd",
 		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
 	},
+	[RPCAUTH_nfsd4_cb] = {
+		.name = "nfsd4_cb",
+		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
+	},
 };
 
 enum {