SUNRPC: Fix RPCAUTH_LOOKUP_ROOTCREDS

The current RPCAUTH_LOOKUP_ROOTCREDS flag only works for AUTH_SYS
authentication, and then only as a special case in the code. This patch
removes the auth_sys special casing, and replaces it with generic code.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/auth.h

@@ -89,7 +89,6 @@ struct rpc_auth {
 
 /* Flags for rpcauth_lookupcred() */
 #define RPCAUTH_LOOKUP_NEW		0x01	/* Accept an uninitialised cred */
-#define RPCAUTH_LOOKUP_ROOTCREDS	0x02	/* This really ought to go! */
 
 /*
  * Client authentication ops
@@ -136,7 +135,8 @@ void			rpcauth_release(struct rpc_auth *);
 struct rpc_cred *	rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int);
 void			rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
 struct rpc_cred *	rpcauth_lookupcred(struct rpc_auth *, int);
-struct rpc_cred *	rpcauth_bindcred(struct rpc_task *);
+void			rpcauth_bindcred(struct rpc_task *);
+void			rpcauth_bind_root_cred(struct rpc_task *);
 void			rpcauth_holdcred(struct rpc_task *);
 void			put_rpccred(struct rpc_cred *);
 void			rpcauth_unbindcred(struct rpc_task *);

net/sunrpc/auth.c

@@ -285,9 +285,6 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 
 	nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
 
-	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
-		nr = acred->uid & RPC_CREDCACHE_MASK;
-
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
 		if (!entry->cr_ops->crmatch(acred, entry, flags))
@@ -378,30 +375,38 @@ rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
 }
 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
 
-struct rpc_cred *
-rpcauth_bindcred(struct rpc_task *task)
+void
+rpcauth_bind_root_cred(struct rpc_task *task)
 {
 	struct rpc_auth *auth = task->tk_client->cl_auth;
 	struct auth_cred acred = {
-		.uid = current->fsuid,
-		.gid = current->fsgid,
-		.group_info = current->group_info,
+		.uid = 0,
+		.gid = 0,
 	};
 	struct rpc_cred *ret;
-	int flags = 0;
 
 	dprintk("RPC: %5u looking up %s cred\n",
 		task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
-	get_group_info(acred.group_info);
-	if (task->tk_flags & RPC_TASK_ROOTCREDS)
-		flags |= RPCAUTH_LOOKUP_ROOTCREDS;
-	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
+	ret = auth->au_ops->lookup_cred(auth, &acred, 0);
+	if (!IS_ERR(ret))
+		task->tk_msg.rpc_cred = ret;
+	else
+		task->tk_status = PTR_ERR(ret);
+}
+
+void
+rpcauth_bindcred(struct rpc_task *task)
+{
+	struct rpc_auth *auth = task->tk_client->cl_auth;
+	struct rpc_cred *ret;
+
+	dprintk("RPC: %5u looking up %s cred\n",
+		task->tk_pid, auth->au_ops->au_name);
+	ret = rpcauth_lookupcred(auth, 0);
 	if (!IS_ERR(ret))
 		task->tk_msg.rpc_cred = ret;
 	else
 		task->tk_status = PTR_ERR(ret);
-	put_group_info(acred.group_info);
-	return ret;
 }
 
 void

net/sunrpc/auth_unix.c

@@ -60,7 +60,8 @@ static struct rpc_cred *
 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 {
 	struct unx_cred	*cred;
-	int		i;
+	unsigned int groups = 0;
+	unsigned int i;
 
 	dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
 			acred->uid, acred->gid);
@@ -70,21 +71,17 @@ unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 
 	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
 	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
-	if (flags & RPCAUTH_LOOKUP_ROOTCREDS) {
-		cred->uc_uid = 0;
-		cred->uc_gid = 0;
-		cred->uc_gids[0] = NOGROUP;
-	} else {
-		int groups = acred->group_info->ngroups;
-		if (groups > NFS_NGROUPS)
-			groups = NFS_NGROUPS;
-
-		cred->uc_gid = acred->gid;
-		for (i = 0; i < groups; i++)
-			cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
-		if (i < NFS_NGROUPS)
-		  cred->uc_gids[i] = NOGROUP;
-	}
+
+	if (acred->group_info != NULL)
+		groups = acred->group_info->ngroups;
+	if (groups > NFS_NGROUPS)
+		groups = NFS_NGROUPS;
+
+	cred->uc_gid = acred->gid;
+	for (i = 0; i < groups; i++)
+		cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
+	if (i < NFS_NGROUPS)
+		cred->uc_gids[i] = NOGROUP;
 
 	return &cred->uc_base;
 }
@@ -118,26 +115,21 @@ static int
 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
 {
 	struct unx_cred	*cred = container_of(rcred, struct unx_cred, uc_base);
-	int		i;
+	unsigned int groups = 0;
+	unsigned int i;
 
-	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) {
-		int groups;
 
-		if (cred->uc_uid != acred->uid
-		 || cred->uc_gid != acred->gid)
-			return 0;
+	if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid)
+		return 0;
 
+	if (acred->group_info != NULL)
 		groups = acred->group_info->ngroups;
-		if (groups > NFS_NGROUPS)
-			groups = NFS_NGROUPS;
-		for (i = 0; i < groups ; i++)
-			if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
-				return 0;
-		return 1;
-	}
-	return (cred->uc_uid == 0
-	     && cred->uc_gid == 0
-	     && cred->uc_gids[0] == (gid_t) NOGROUP);
+	if (groups > NFS_NGROUPS)
+		groups = NFS_NGROUPS;
+	for (i = 0; i < groups ; i++)
+		if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
+			return 0;
+	return 1;
 }
 
 /*

net/sunrpc/sched.c

@@ -821,8 +821,10 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta
 		/* Bind the user cred */
 		if (task->tk_msg.rpc_cred != NULL)
 			rpcauth_holdcred(task);
-		else
+		else if (!(task_setup_data->flags & RPC_TASK_ROOTCREDS))
 			rpcauth_bindcred(task);
+		else
+			rpcauth_bind_root_cred(task);
 		if (task->tk_action == NULL)
 			rpc_call_start(task);
 	}