From 9568c5e9a61de49f67f524404a27a1014a8d7f1e Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Sat, 16 Mar 2013 15:54:43 -0400 Subject: SUNRPC: Introduce rpcauth_get_pseudoflavor() A SECINFO reply may contain flavors whose kernel module is not yet loaded by the client's kernel. A new RPC client API, called rpcauth_get_pseudoflavor(), is introduced to do proper checking for support of a security flavor. When this API is invoked, the RPC client now tries to load the module for each flavor first before performing the "is this supported?" check. This means if a module is available on the client, but has not been loaded yet, it will be loaded and registered automatically when the SECINFO reply is processed. The new API can take a full GSS tuple (OID, QoP, and service). Previously only the OID and service were considered. nfs_find_best_sec() is updated to verify all flavors requested in a SECINFO reply, including AUTH_NULL and AUTH_UNIX. Previously these two flavors were simply assumed to be supported without consulting the RPC client. Note that the replaced version of nfs_find_best_sec() can return RPC_AUTH_MAXFLAVOR if the server returns a recognized OID but an unsupported "service" value. nfs_find_best_sec() now returns RPC_AUTH_UNIX in this case. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- net/sunrpc/auth.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'net/sunrpc/auth.c') diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index f5294047df77..9b81be8d9946 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -123,6 +123,41 @@ rpcauth_unregister(const struct rpc_authops *ops) } EXPORT_SYMBOL_GPL(rpcauth_unregister); +/** + * rpcauth_get_pseudoflavor - check if security flavor is supported + * @flavor: a security flavor + * @info: a GSS mech OID, quality of protection, and service value + * + * Verifies that an appropriate kernel module is available or already loaded. + * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is + * not supported locally. + */ +rpc_authflavor_t +rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info) +{ + const struct rpc_authops *ops; + rpc_authflavor_t pseudoflavor; + + ops = auth_flavors[flavor]; + if (ops == NULL) + request_module("rpc-auth-%u", flavor); + spin_lock(&rpc_authflavor_lock); + ops = auth_flavors[flavor]; + if (ops == NULL || !try_module_get(ops->owner)) { + spin_unlock(&rpc_authflavor_lock); + return RPC_AUTH_MAXFLAVOR; + } + spin_unlock(&rpc_authflavor_lock); + + pseudoflavor = flavor; + if (ops->info2flavor != NULL) + pseudoflavor = ops->info2flavor(info); + + module_put(ops->owner); + return pseudoflavor; +} +EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor); + /** * rpcauth_list_flavors - discover registered flavors and pseudoflavors * @array: array to fill in -- cgit v1.2.3