libfreerdp-core: implement simple RPC PDU send queue according to the MS-TSGU ADM

libfreerdp/core/CMakeLists.txt

@@ -118,7 +118,7 @@ set_complex_link_libraries(VARIABLE ${MODULE_PREFIX}_LIBS
 set_complex_link_libraries(VARIABLE ${MODULE_PREFIX}_LIBS
 	MONOLITHIC ${MONOLITHIC_BUILD}
 	MODULE winpr
-	MODULES winpr-registry winpr-utils winpr-dsparse winpr-sspi winpr-crt)
+	MODULES winpr-registry winpr-utils winpr-interlocked winpr-dsparse winpr-sspi winpr-crt)
 
 if(MONOLITHIC_BUILD)
 	set(FREERDP_LIBS ${FREERDP_LIBS} ${${MODULE_PREFIX}_LIBS} PARENT_SCOPE)

libfreerdp/core/rpc.c

@@ -698,6 +698,42 @@ BOOL rpc_get_stub_data_info(rdpRpc* rpc, BYTE* buffer, UINT32* offset, UINT32* l
 	return TRUE;
 }
 
+int rpc_send_enqueue_pdu(rdpRpc* rpc, BYTE* buffer, UINT32 length)
+{
+	RPC_PDU_ENTRY* PduEntry;
+
+	PduEntry = (RPC_PDU_ENTRY*) _aligned_malloc(sizeof(RPC_PDU_ENTRY), MEMORY_ALLOCATION_ALIGNMENT);
+	PduEntry->Buffer = buffer;
+	PduEntry->Length = length;
+
+	InterlockedPushEntrySList(rpc->SendQueue, &(PduEntry->ItemEntry));
+
+	return 0;
+}
+
+int rpc_send_dequeue_pdu(rdpRpc* rpc)
+{
+	int status;
+	RPC_PDU_ENTRY* PduEntry;
+
+	PduEntry = (RPC_PDU_ENTRY*) InterlockedPopEntrySList(rpc->SendQueue);
+
+	status = rpc_in_write(rpc, PduEntry->Buffer, PduEntry->Length);
+
+	/*
+	 * This protocol specifies that only RPC PDUs are subject to the flow control abstract
+	 * data model. RTS PDUs and the HTTP request and response headers are not subject to flow control.
+	 * Implementations of this protocol MUST NOT include them when computing any of the variables
+	 * specified by this abstract data model.
+	 */
+	rpc->VirtualConnection->DefaultInChannel->BytesSent += status;
+	rpc->VirtualConnection->DefaultInChannel->SenderAvailableWindow -= status;
+
+	_aligned_free(PduEntry);
+
+	return status;
+}
+
 int rpc_out_read(rdpRpc* rpc, BYTE* data, int length)
 {
 	int status;
@@ -722,19 +758,6 @@ int rpc_in_write(rdpRpc* rpc, BYTE* data, int length)
 
 	status = tls_write_all(rpc->TlsIn, data, length);
 
-	if (status > 0)
-	{
-		/*
-		 * This protocol specifies that only RPC PDUs are subject to the flow control abstract
-		 * data model. RTS PDUs and the HTTP request and response headers are not subject to flow control.
-		 * Implementations of this protocol MUST NOT include them when computing any of the variables
-		 * specified by this abstract data model.
-		 */
-
-		rpc->VirtualConnection->DefaultInChannel->BytesSent += status;
-		rpc->VirtualConnection->DefaultInChannel->SenderAvailableWindow -= status;
-	}
-
 	return status;
 }
 
@@ -951,16 +974,14 @@ int rpc_tsg_write(rdpRpc* rpc, BYTE* data, int length, UINT16 opnum)
 	CopyMemory(&buffer[offset], Buffers[1].pvBuffer, Buffers[1].cbBuffer);
 	offset += Buffers[1].cbBuffer;
 
-	status = rpc_in_write(rpc, buffer, request_pdu->frag_length);
-
-	if (status < 0)
-	{
-		printf("rpc_tsg_write(): Error! rpc_tsg_write returned negative value.\n");
-		return -1;
-	}
+	rpc_send_enqueue_pdu(rpc, buffer, request_pdu->frag_length);
+	status = rpc_send_dequeue_pdu(rpc);
 
 	free(buffer);
 
+	if (status < 0)
+		return -1;
+
 	return length;
 }
 
@@ -1160,6 +1181,9 @@ rdpRpc* rpc_new(rdpTransport* transport)
 		rpc->max_xmit_frag = 0x0FF8;
 		rpc->max_recv_frag = 0x0FF8;
 
+		rpc->SendQueue = (PSLIST_HEADER) _aligned_malloc(sizeof(SLIST_HEADER), MEMORY_ALLOCATION_ALIGNMENT);
+		InitializeSListHead(rpc->SendQueue);
+
 		rpc->ReceiveWindow = 0x00010000;
 
 		rpc->ChannelLifetime = 0x40000000;
@@ -1182,8 +1206,16 @@ void rpc_free(rdpRpc* rpc)
 {
 	if (rpc != NULL)
 	{
+		RPC_PDU_ENTRY* PduEntry;
+
 		ntlm_http_free(rpc->NtlmHttpIn);
 		ntlm_http_free(rpc->NtlmHttpOut);
+
+		while ((PduEntry = (RPC_PDU_ENTRY*) InterlockedPopEntrySList(rpc->SendQueue)) != NULL)
+			_aligned_free(PduEntry);
+
+		_aligned_free(rpc->SendQueue);
+
 		rpc_client_virtual_connection_free(rpc->VirtualConnection);
 		rpc_virtual_connection_cookie_table_free(rpc->VirtualConnectionCookieTable);
 		free(rpc);

libfreerdp/core/rpc.h

@@ -53,7 +53,10 @@ typedef struct
 #include "transport.h"
 
 #include <time.h>
+
 #include <winpr/sspi.h>
+#include <winpr/interlocked.h>
+
 #include <freerdp/types.h>
 #include <freerdp/settings.h>
 #include <freerdp/crypto/tls.h>
@@ -651,6 +654,13 @@ struct rpc_virtual_connection_cookie_table
 };
 typedef struct rpc_virtual_connection_cookie_table RpcVirtualConnectionCookieTable;
 
+typedef struct _RPC_PDU_ENTRY
+{
+	SLIST_ENTRY ItemEntry;
+	BYTE* Buffer;
+	UINT32 Length;
+} RPC_PDU_ENTRY, *PRPC_PDU_ENTRY;
+
 struct rdp_rpc
 {
 	rdpTls* TlsIn;
@@ -678,6 +688,8 @@ struct rdp_rpc
 	UINT16 max_xmit_frag;
 	UINT16 max_recv_frag;
 
+	PSLIST_HEADER SendQueue;
+
 	UINT32 ReceiveWindow;
 
 	UINT32 ChannelLifetime;

libfreerdp/core/transport.c

@@ -376,10 +376,17 @@ void transport_get_fds(rdpTransport* transport, void** rfds, int* rcount)
 {
 #ifdef _WIN32
 	rfds[*rcount] = transport->tcp->wsa_event;
+	(*rcount)++;
 #else
 	rfds[*rcount] = (void*)(long)(transport->TcpIn->sockfd);
-#endif
 	(*rcount)++;
+
+	if (transport->SplitInputOutput)
+	{
+		rfds[*rcount] = (void*)(long)(transport->TcpOut->sockfd);
+		(*rcount)++;
+	}
+#endif
 	wait_obj_get_fds(transport->recv_event, rfds, rcount);
 }