s4-rpc: split the dcesrv reply code out of dcerpc_server

this allows us to remove a dependency on the dcerpc_server from code
that uses rpc forwarding

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

2 files changed, 255 insertions, 0 deletions

diff --git a/source4/rpc_server/common/forward.c b/source4/rpc_server/common/forward.c
index 113ac5f6c4..45ce6dcac9 100644
--- a/source4/rpc_server/common/forward.c
+++ b/source4/rpc_server/common/forward.c
@@ -22,6 +22,7 @@
 #include "includes.h"
 #include <tevent.h>
 #include "rpc_server/dcerpc_server.h"
+#include "librpc/gen_ndr/dcerpc.h"
 #include "rpc_server/common/common.h"
 #include "messaging/irpc.h"
 #include "auth/auth.h"
diff --git a/source4/rpc_server/common/reply.c b/source4/rpc_server/common/reply.c
new file mode 100644
index 0000000000..d883317d6e
--- /dev/null
+++ b/source4/rpc_server/common/reply.c
@@ -0,0 +1,254 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   server side dcerpc common code
+
+   Copyright (C) Andrew Tridgell 2003-2010
+   Copyright (C) Stefan (metze) Metzmacher 2004-2005
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "auth/auth.h"
+#include "auth/gensec/gensec.h"
+#include "../lib/util/dlinklist.h"
+#include "rpc_server/dcerpc_server.h"
+#include "rpc_server/dcerpc_server_proto.h"
+#include "rpc_server/common/proto.h"
+#include "librpc/rpc/dcerpc_proto.h"
+#include "system/filesys.h"
+#include "libcli/security/security.h"
+#include "param/param.h"
+#include "../lib/tsocket/tsocket.h"
+#include "../libcli/named_pipe_auth/npa_tstream.h"
+#include "smbd/service_stream.h"
+#include "../lib/tsocket/tsocket.h"
+#include "lib/socket/socket.h"
+#include "smbd/process_model.h"
+#include "lib/messaging/irpc.h"
+
+
+/*
+  move a call from an existing linked list to the specified list. This
+  prevents bugs where we forget to remove the call from a previous
+  list when moving it.
+ */
+static void dcesrv_call_set_list(struct dcesrv_call_state *call,
+				 enum dcesrv_call_list list)
+{
+	switch (call->list) {
+	case DCESRV_LIST_NONE:
+		break;
+	case DCESRV_LIST_CALL_LIST:
+		DLIST_REMOVE(call->conn->call_list, call);
+		break;
+	case DCESRV_LIST_FRAGMENTED_CALL_LIST:
+		DLIST_REMOVE(call->conn->incoming_fragmented_call_list, call);
+		break;
+	case DCESRV_LIST_PENDING_CALL_LIST:
+		DLIST_REMOVE(call->conn->pending_call_list, call);
+		break;
+	}
+	call->list = list;
+	switch (list) {
+	case DCESRV_LIST_NONE:
+		break;
+	case DCESRV_LIST_CALL_LIST:
+		DLIST_ADD_END(call->conn->call_list, call, struct dcesrv_call_state *);
+		break;
+	case DCESRV_LIST_FRAGMENTED_CALL_LIST:
+		DLIST_ADD_END(call->conn->incoming_fragmented_call_list, call, struct dcesrv_call_state *);
+		break;
+	case DCESRV_LIST_PENDING_CALL_LIST:
+		DLIST_ADD_END(call->conn->pending_call_list, call, struct dcesrv_call_state *);
+		break;
+	}
+}
+
+
+void dcesrv_init_hdr(struct ncacn_packet *pkt, bool bigendian)
+{
+	pkt->rpc_vers = 5;
+	pkt->rpc_vers_minor = 0;
+	if (bigendian) {
+		pkt->drep[0] = 0;
+	} else {
+		pkt->drep[0] = DCERPC_DREP_LE;
+	}
+	pkt->drep[1] = 0;
+	pkt->drep[2] = 0;
+	pkt->drep[3] = 0;
+}
+
+
+/*
+  return a dcerpc fault
+*/
+NTSTATUS dcesrv_fault(struct dcesrv_call_state *call, uint32_t fault_code)
+{
+	struct ncacn_packet pkt;
+	struct data_blob_list_item *rep;
+	uint8_t zeros[4];
+	NTSTATUS status;
+
+	/* setup a bind_ack */
+	dcesrv_init_hdr(&pkt, lpcfg_rpc_big_endian(call->conn->dce_ctx->lp_ctx));
+	pkt.auth_length = 0;
+	pkt.call_id = call->pkt.call_id;
+	pkt.ptype = DCERPC_PKT_FAULT;
+	pkt.pfc_flags = DCERPC_PFC_FLAG_FIRST | DCERPC_PFC_FLAG_LAST;
+	pkt.u.fault.alloc_hint = 0;
+	pkt.u.fault.context_id = 0;
+	pkt.u.fault.cancel_count = 0;
+	pkt.u.fault.status = fault_code;
+
+	ZERO_STRUCT(zeros);
+	pkt.u.fault._pad = data_blob_const(zeros, sizeof(zeros));
+
+	rep = talloc(call, struct data_blob_list_item);
+	if (!rep) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	status = ncacn_push_auth(&rep->blob, call, &pkt, NULL);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	dcerpc_set_frag_length(&rep->blob, rep->blob.length);
+
+	DLIST_ADD_END(call->replies, rep, struct data_blob_list_item *);
+	dcesrv_call_set_list(call, DCESRV_LIST_CALL_LIST);
+
+	if (call->conn->call_list && call->conn->call_list->replies) {
+		if (call->conn->transport.report_output_data) {
+			call->conn->transport.report_output_data(call->conn);
+		}
+	}
+
+	return NT_STATUS_OK;
+}
+
+
+
+_PUBLIC_ NTSTATUS dcesrv_reply(struct dcesrv_call_state *call)
+{
+	struct ndr_push *push;
+	NTSTATUS status;
+	DATA_BLOB stub;
+	uint32_t total_length, chunk_size;
+	struct dcesrv_connection_context *context = call->context;
+	size_t sig_size = 0;
+
+	/* call the reply function */
+	status = context->iface->reply(call, call, call->r);
+	if (!NT_STATUS_IS_OK(status)) {
+		return dcesrv_fault(call, call->fault_code);
+	}
+
+	/* form the reply NDR */
+	push = ndr_push_init_ctx(call);
+	NT_STATUS_HAVE_NO_MEMORY(push);
+
+	/* carry over the pointer count to the reply in case we are
+	   using full pointer. See NDR specification for full
+	   pointers */
+	push->ptr_count = call->ndr_pull->ptr_count;
+
+	if (lpcfg_rpc_big_endian(call->conn->dce_ctx->lp_ctx)) {
+		push->flags |= LIBNDR_FLAG_BIGENDIAN;
+	}
+
+	status = context->iface->ndr_push(call, call, push, call->r);
+	if (!NT_STATUS_IS_OK(status)) {
+		return dcesrv_fault(call, call->fault_code);
+	}
+
+	stub = ndr_push_blob(push);
+
+	total_length = stub.length;
+
+	/* we can write a full max_recv_frag size, minus the dcerpc
+	   request header size */
+	chunk_size = call->conn->cli_max_recv_frag;
+	chunk_size -= DCERPC_REQUEST_LENGTH;
+	if (call->conn->auth_state.auth_info &&
+	    call->conn->auth_state.gensec_security) {
+		sig_size = gensec_sig_size(call->conn->auth_state.gensec_security,
+					   call->conn->cli_max_recv_frag);
+		if (sig_size) {
+			chunk_size -= DCERPC_AUTH_TRAILER_LENGTH;
+			chunk_size -= sig_size;
+		}
+	}
+	chunk_size -= (chunk_size % 16);
+
+	do {
+		uint32_t length;
+		struct data_blob_list_item *rep;
+		struct ncacn_packet pkt;
+
+		rep = talloc(call, struct data_blob_list_item);
+		NT_STATUS_HAVE_NO_MEMORY(rep);
+
+		length = MIN(chunk_size, stub.length);
+
+		/* form the dcerpc response packet */
+		dcesrv_init_hdr(&pkt, lpcfg_rpc_big_endian(call->conn->dce_ctx->lp_ctx));
+		pkt.auth_length = 0;
+		pkt.call_id = call->pkt.call_id;
+		pkt.ptype = DCERPC_PKT_RESPONSE;
+		pkt.pfc_flags = 0;
+		if (stub.length == total_length) {
+			pkt.pfc_flags |= DCERPC_PFC_FLAG_FIRST;
+		}
+		if (length == stub.length) {
+			pkt.pfc_flags |= DCERPC_PFC_FLAG_LAST;
+		}
+		pkt.u.response.alloc_hint = stub.length;
+		pkt.u.response.context_id = call->pkt.u.request.context_id;
+		pkt.u.response.cancel_count = 0;
+		pkt.u.response.stub_and_verifier.data = stub.data;
+		pkt.u.response.stub_and_verifier.length = length;
+
+		if (!dcesrv_auth_response(call, &rep->blob, sig_size, &pkt)) {
+			return dcesrv_fault(call, DCERPC_FAULT_OTHER);
+		}
+
+		dcerpc_set_frag_length(&rep->blob, rep->blob.length);
+
+		DLIST_ADD_END(call->replies, rep, struct data_blob_list_item *);
+
+		stub.data += length;
+		stub.length -= length;
+	} while (stub.length != 0);
+
+	/* move the call from the pending to the finished calls list */
+	dcesrv_call_set_list(call, DCESRV_LIST_CALL_LIST);
+
+	if (call->conn->call_list && call->conn->call_list->replies) {
+		if (call->conn->transport.report_output_data) {
+			call->conn->transport.report_output_data(call->conn);
+		}
+	}
+
+	return NT_STATUS_OK;
+}
+
+NTSTATUS dcesrv_generic_session_key(struct dcesrv_connection *c,
+				    DATA_BLOB *session_key)
+{
+	return dcerpc_generic_session_key(NULL, session_key);
+}