SUNRPC: add side channel to use non-generic cred for rpc call.

The credential passed in rpc_message.rpc_cred is always a
generic credential except in one instance.
When gss_destroying_context() calls rpc_call_null(), it passes
a specific credential that it needs to destroy.
In this case the RPC acts *on* the credential rather than
being authorized by it.

This special case deserves explicit support and providing that will
mean that rpc_message.rpc_cred is *always* generic, allowing
some optimizations.

So add "tk_op_cred" to rpc_task and "rpc_op_cred" to the setup data.
Use this to pass the cred down from rpc_call_null(), and have
rpcauth_bindcred() notice it and bind it in place.

Credit to kernel test robot <fengguang.wu@intel.com> for finding
a bug in earlier version of this patch.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
NeilBrown 2018-12-03 11:30:30 +11:00 committed by Anna Schumaker
parent a68a72e135
commit 1de7eea929
4 changed files with 11 additions and 2 deletions

View file

@ -71,6 +71,7 @@ struct rpc_task {
struct rpc_clnt * tk_client; /* RPC client */
struct rpc_xprt * tk_xprt; /* Transport */
struct rpc_cred * tk_op_cred; /* cred being operated on */
struct rpc_rqst * tk_rqstp; /* RPC request */
@ -105,6 +106,7 @@ struct rpc_task_setup {
struct rpc_task *task;
struct rpc_clnt *rpc_client;
struct rpc_xprt *rpc_xprt;
struct rpc_cred *rpc_op_cred; /* credential being operated on */
const struct rpc_message *rpc_message;
const struct rpc_call_ops *callback_ops;
void *callback_data;