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 <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever
2013-03-16 15:54:43 -04:00
committed by Trond Myklebust
parent fb15b26f8b
commit 9568c5e9a6
6 changed files with 88 additions and 25 deletions

View File

@@ -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