rpc/auth: Avoid NULL dereference in rpcsvc_auth_request_init()

Code section is bogus!
------------------------------------------
370:       if (!auth->authops->request_init)
371:              ret = auth->authops->request_init (req, auth->authprivate);
------------------------------------------

Seems to have been never been used historically since
logically above code has never been true to actually execute
"authops->request_init() --> auth_glusterfs_{v2,}_request_init()"

On top of that under "rpcsvc_request_init()"
verf.flavour and verf.datalen are initialized from what is
provided through 'callmsg'.
------------------------------------------
        req->verf.flavour = rpc_call_verf_flavour (callmsg);
        req->verf.datalen = rpc_call_verf_len (callmsg);

        /* AUTH */
        rpcsvc_auth_request_init (req);
        return req;
------------------------------------------

So the code in 'auth_glusterfs_{v2,}_request_init()'
performing this operation will over-write the original
flavour and datalen.

------------------------------------------
      if (!req)
                return -1;
        memset (req->verf.authdata, 0, GF_MAX_AUTH_BYTES);
        req->verf.datalen = 0;
        req->verf.flavour = AUTH_NULL;
------------------------------------------

Refactoring the whole code into a more understandable version
and also avoiding a potential NULL dereference

Change-Id: I1a430fcb4d26de8de219bd0cb3c46c141649d47d
BUG: 1049735
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/6591
Reviewed-by: Santosh Pradhan <spradhan@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 1 insertions, 7 deletions

diff --git a/rpc/rpc-lib/src/rpcsvc.c b/rpc/rpc-lib/src/rpcsvc.c
index d19a3ca0c..69db8b70b 100644
--- a/rpc/rpc-lib/src/rpcsvc.c
+++ b/rpc/rpc-lib/src/rpcsvc.c
@@ -367,13 +367,7 @@ rpcsvc_request_init (rpcsvc_t *svc, rpc_transport_t *trans,
          * been copied into the required sections of the req structure,
          * we just need to fill in the meta-data about it now.
          */
-        req->cred.flavour = rpc_call_cred_flavour (callmsg);
-        req->cred.datalen = rpc_call_cred_len (callmsg);
-        req->verf.flavour = rpc_call_verf_flavour (callmsg);
-        req->verf.datalen = rpc_call_verf_len (callmsg);
-
-        /* AUTH */
-        rpcsvc_auth_request_init (req);
+        rpcsvc_auth_request_init (req, callmsg);
         return req;
 }