From 99f3a9c0e6be54f4db7380d3087c545550be73c5 Mon Sep 17 00:00:00 2001
From: Armin Novak <armin.novak@thincast.com>
Date: Wed, 25 Oct 2023 16:53:22 +0200
Subject: [PATCH] [core,gateway] add rts_recv_ping_pdu

---
 libfreerdp/core/gateway/rpc_client.c |  8 +++-----
 libfreerdp/core/gateway/rts.c        | 30 ++++++++++++++++++++++++++++
 libfreerdp/core/gateway/rts.h        |  2 ++
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/libfreerdp/core/gateway/rpc_client.c b/libfreerdp/core/gateway/rpc_client.c
index 42ef9bf53..e04e69b48 100644
--- a/libfreerdp/core/gateway/rpc_client.c
+++ b/libfreerdp/core/gateway/rpc_client.c
@@ -195,15 +195,13 @@ static int rpc_client_recv_pdu_int(rdpRpc* rpc, RPC_PDU* pdu)
 	WLog_VRB(TAG, "client state %s, vc state %s", rpc_client_state_str(rpc->State),
 	         rpc_vc_state_str(rpc->VirtualConnection->State));
 
-	if (!rts_extract_pdu_signature(&found, pdu->s, NULL))
-		return FALSE;
+	const BOOL rc = rts_match_pdu_signature_ex(&RTS_PDU_PING_SIGNATURE, pdu->s, NULL, &found);
 	rts_print_pdu_signature(rpc->log, WLOG_TRACE, &found);
+	if (rc)
+		return rts_recv_ping_pdu(rpc, pdu->s);
 
 	if (rpc->VirtualConnection->State < VIRTUAL_CONNECTION_STATE_OPENED)
 	{
-		if (rts_match_pdu_signature_ex(&RTS_PDU_PING_SIGNATURE, pdu->s, NULL, &found))
-			return 1;
-
 		switch (rpc->VirtualConnection->State)
 		{
 			case VIRTUAL_CONNECTION_STATE_INITIAL:
diff --git a/libfreerdp/core/gateway/rts.c b/libfreerdp/core/gateway/rts.c
index 04e19ec95..fefac17e2 100644
--- a/libfreerdp/core/gateway/rts.c
+++ b/libfreerdp/core/gateway/rts.c
@@ -1862,6 +1862,36 @@ static int rts_recv_flow_control_ack_with_destination_pdu(rdpRpc* rpc, wStream*
 	return 1;
 }
 
+BOOL rts_recv_ping_pdu(rdpRpc* rpc, wStream* s)
+{
+	BOOL rc = FALSE;
+	rpcconn_hdr_t header = { 0 };
+
+	WINPR_ASSERT(rpc);
+	WINPR_ASSERT(rpc->auth);
+	WINPR_ASSERT(s);
+
+	if (!rts_read_pdu_header(s, &header))
+		goto fail;
+
+	rc = TRUE;
+	if (header.common.ptype != PTYPE_RTS)
+	{
+		WLog_Print(rpc->log, WLOG_ERROR, "received invalid ping PDU, type is 0x%" PRIx32,
+		           header.common.ptype);
+		rc = FALSE;
+	}
+	if (header.rts.Flags != RTS_FLAG_PING)
+	{
+		WLog_Print(rpc->log, WLOG_ERROR, "received unexpected ping PDU::Flags 0x%" PRIx32,
+		           header.rts.Flags);
+		rc = FALSE;
+	}
+fail:
+	rts_free_pdu_header(&header, FALSE);
+	return rc;
+}
+
 static int rts_send_ping_pdu(rdpRpc* rpc)
 {
 	BOOL status = FALSE;
diff --git a/libfreerdp/core/gateway/rts.h b/libfreerdp/core/gateway/rts.h
index 77c44affd..a76efb566 100644
--- a/libfreerdp/core/gateway/rts.h
+++ b/libfreerdp/core/gateway/rts.h
@@ -104,4 +104,6 @@ FREERDP_LOCAL BOOL rts_send_flow_control_ack_pdu(rdpRpc* rpc);
 FREERDP_LOCAL BOOL rts_recv_out_of_sequence_pdu(rdpRpc* rpc, wStream* buffer,
                                                 const rpcconn_hdr_t* header);
 
+FREERDP_LOCAL BOOL rts_recv_ping_pdu(rdpRpc* rpc, wStream* s);
+
 #endif /* FREERDP_LIB_CORE_GATEWAY_RTS_H */