s3-dcerpc: Delay parsing rpc header in client code

Signed-off-by: Günther Deschner <gd@samba.org>

diff --git a/source3/rpc_client/cli_pipe.c b/source3/rpc_client/cli_pipe.c
index 91eb767667b4f0bbb443c6744a99b6702e4c2b81..a4b4e7991637ee5fc97c6616f713e03150c83a77 100644 (file)
--- a/source3/rpc_client/cli_pipe.c
+++ b/source3/rpc_client/cli_pipe.c
@@ -671,7 +671,7 @@ static NTSTATUS parse_rpc_header(struct rpc_pipe_client *cli,
 struct get_complete_frag_state {
        struct event_context *ev;
        struct rpc_pipe_client *cli;
-       struct ncacn_packet_header *prhdr;
+       uint16_t frag_len;
        prs_struct *pdu;
 };
 
@@ -681,11 +681,11 @@ static void get_complete_frag_got_rest(struct tevent_req *subreq);
 static struct tevent_req *get_complete_frag_send(TALLOC_CTX *mem_ctx,
                                                 struct event_context *ev,
                                                 struct rpc_pipe_client *cli,
-                                                struct ncacn_packet_header *prhdr,
                                                 prs_struct *pdu)
 {
        struct tevent_req *req, *subreq;
        struct get_complete_frag_state *state;
+       DATA_BLOB blob;
        uint32_t pdu_len;
        NTSTATUS status;
 
@@ -696,7 +696,7 @@ static struct tevent_req *get_complete_frag_send(TALLOC_CTX *mem_ctx,
        }
        state->ev = ev;
        state->cli = cli;
-       state->prhdr = prhdr;
+       state->frag_len = RPC_HEADER_LEN;
        state->pdu = pdu;
 
        pdu_len = prs_data_size(pdu);
@@ -719,23 +719,21 @@ static struct tevent_req *get_complete_frag_send(TALLOC_CTX *mem_ctx,
                return req;
        }
 
-       status = parse_rpc_header(cli, prhdr, pdu);
-       if (!NT_STATUS_IS_OK(status)) {
-               goto post_status;
-       }
+       blob = data_blob_const(prs_data_p(state->pdu), pdu_len);
+       state->frag_len = dcerpc_get_frag_length(&blob);
 
        /*
         * Ensure we have frag_len bytes of data.
         */
-       if (pdu_len < prhdr->frag_length) {
-               if (!rpc_grow_buffer(pdu, prhdr->frag_length)) {
+       if (pdu_len < state->frag_len) {
+               if (!rpc_grow_buffer(pdu, state->frag_len)) {
                        status = NT_STATUS_NO_MEMORY;
                        goto post_status;
                }
                subreq = rpc_read_send(state, state->ev,
                                       state->cli->transport,
                                       (uint8_t *)(prs_data_p(pdu) + pdu_len),
-                                      prhdr->frag_length - pdu_len);
+                                      state->frag_len - pdu_len);
                if (subreq == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto post_status;
@@ -762,6 +760,7 @@ static void get_complete_frag_got_header(struct tevent_req *subreq)
        struct get_complete_frag_state *state = tevent_req_data(
                req, struct get_complete_frag_state);
        NTSTATUS status;
+       DATA_BLOB pdu;
 
        status = rpc_read_recv(subreq);
        TALLOC_FREE(subreq);
@@ -770,13 +769,11 @@ static void get_complete_frag_got_header(struct tevent_req *subreq)
                return;
        }
 
-       status = parse_rpc_header(state->cli, state->prhdr, state->pdu);
-       if (!NT_STATUS_IS_OK(status)) {
-               tevent_req_nterror(req, status);
-               return;
-       }
+       pdu = data_blob_const(prs_data_p(state->pdu),
+                             prs_data_size(state->pdu));
+       state->frag_len = dcerpc_get_frag_length(&pdu);
 
-       if (!rpc_grow_buffer(state->pdu, state->prhdr->frag_length)) {
+       if (!rpc_grow_buffer(state->pdu, state->frag_len)) {
                tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
                return;
        }
@@ -789,7 +786,7 @@ static void get_complete_frag_got_header(struct tevent_req *subreq)
        subreq = rpc_read_send(
                state, state->ev, state->cli->transport,
                (uint8_t *)(prs_data_p(state->pdu) + RPC_HEADER_LEN),
-               state->prhdr->frag_length - RPC_HEADER_LEN);
+               state->frag_len - RPC_HEADER_LEN);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
@@ -1187,6 +1184,11 @@ static NTSTATUS cli_pipe_validate_current_pdu(struct rpc_pipe_client *cli,
        NTSTATUS ret = NT_STATUS_OK;
        uint32 current_pdu_len = prs_data_size(current_pdu);
 
+       ret = parse_rpc_header(cli, prhdr, current_pdu);
+       if (!NT_STATUS_IS_OK(ret)) {
+               return ret;
+       }
+
        if (current_pdu_len != prhdr->frag_length) {
                DEBUG(5,("cli_pipe_validate_current_pdu: incorrect pdu length %u, expected %u\n",
                        (unsigned int)current_pdu_len, (unsigned int)prhdr->frag_length));
@@ -1672,7 +1674,7 @@ static void rpc_api_pipe_trans_done(struct tevent_req *subreq)
 
        /* Ensure we have enough data for a pdu. */
        subreq = get_complete_frag_send(state, state->ev, state->cli,
-                                       &state->rhdr, &state->incoming_frag);
+                                       &state->incoming_frag);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }
@@ -1763,7 +1765,7 @@ static void rpc_api_pipe_got_pdu(struct tevent_req *subreq)
        }
 
        subreq = get_complete_frag_send(state, state->ev, state->cli,
-                                       &state->rhdr, &state->incoming_frag);
+                                       &state->incoming_frag);
        if (tevent_req_nomem(subreq, req)) {
                return;
        }