SUNRPC: Use struct xdr_stream when constructing RPC Call header

Modernize and harden the code path that constructs each RPC Call
message.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 40 insertions, 21 deletions

diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index fc8a59134640..1d5b7ed9c6f7 100644
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -99,37 +99,55 @@ unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
  * Marshal credentials.
  * Maybe we should keep a cached credential for performance reasons.
  */
-static __be32 *
-unx_marshal(struct rpc_task *task, __be32 *p)
+static int
+unx_marshal(struct rpc_task *task, struct xdr_stream *xdr)
 {
         struct rpc_clnt *clnt = task->tk_client;
         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
-        __be32          *base, *hold;
+        __be32          *p, *cred_len, *gidarr_len;
         int             i;
         struct group_info *gi = cred->cr_cred->group_info;
 
-        *p++ = htonl(RPC_AUTH_UNIX);
-        base = p++;
-        *p++ = htonl(jiffies/HZ);
-
-        /*
-         * Copy the UTS nodename captured when the client was created.
-         */
-        p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
-
-        *p++ = htonl((u32) from_kuid(&init_user_ns, cred->cr_cred->fsuid));
-        *p++ = htonl((u32) from_kgid(&init_user_ns, cred->cr_cred->fsgid));
-        hold = p++;
+        /* Credential */
+
+        p = xdr_reserve_space(xdr, 3 * sizeof(*p));
+        if (!p)
+                goto marshal_failed;
+        *p++ = rpc_auth_unix;
+        cred_len = p++;
+        *p++ = xdr_zero;        /* stamp */
+        if (xdr_stream_encode_opaque(xdr, clnt->cl_nodename,
+                                     clnt->cl_nodelen) < 0)
+                goto marshal_failed;
+        p = xdr_reserve_space(xdr, 3 * sizeof(*p));
+        if (!p)
+                goto marshal_failed;
+        *p++ = cpu_to_be32(from_kuid(&init_user_ns, cred->cr_cred->fsuid));
+        *p++ = cpu_to_be32(from_kgid(&init_user_ns, cred->cr_cred->fsgid));
+
+        gidarr_len = p++;
         if (gi)
                 for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++)
-                        *p++ = htonl((u32) from_kgid(&init_user_ns, gi->gid[i]));
-        *hold = htonl(p - hold - 1);            /* gid array length */
-        *base = htonl((p - base - 1) << 2);     /* cred length */
+                        *p++ = cpu_to_be32(from_kgid(&init_user_ns,
+                                                     gi->gid[i]));
+        *gidarr_len = cpu_to_be32(p - gidarr_len - 1);
+        *cred_len = cpu_to_be32((p - cred_len - 1) << 2);
+        p = xdr_reserve_space(xdr, (p - gidarr_len - 1) << 2);
+        if (!p)
+                goto marshal_failed;
+
+        /* Verifier */
+
+        p = xdr_reserve_space(xdr, 2 * sizeof(*p));
+        if (!p)
+                goto marshal_failed;
+        *p++ = rpc_auth_null;
+        *p   = xdr_zero;
 
-        *p++ = htonl(RPC_AUTH_NULL);
-        *p++ = htonl(0);
+        return 0;
 
-        return p;
+marshal_failed:
+        return -EMSGSIZE;
 }
 
 /*
@@ -202,6 +220,7 @@ const struct rpc_credops unix_credops = {
         .crdestroy      = unx_destroy_cred,
         .crmatch        = unx_match,
         .crmarshal      = unx_marshal,
+        .crwrap_req     = rpcauth_wrap_req_encode,
         .crrefresh      = unx_refresh,
         .crvalidate     = unx_validate,
 };