From 7399e5dc6272c066002fbefba91d7b2ac592569c Mon Sep 17 00:00:00 2001
From: Lauri Kasanen <cand@gmx.com>
Date: Fri, 14 Oct 2022 11:34:52 +0300
Subject: [PATCH] Add frame number to udp packets

---
 common/network/Udp.cxx       | 17 ++++++++++-------
 common/network/Udp.h         |  5 +++++
 common/rfb/EncodeManager.cxx |  3 +++
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/common/network/Udp.cxx b/common/network/Udp.cxx
index e59d0f1..9fd4dfa 100644
--- a/common/network/Udp.cxx
+++ b/common/network/Udp.cxx
@@ -40,7 +40,7 @@ using namespace network;
 static rfb::LogWriter vlog("WebUdp");
 static WuHost *host = NULL;
 
-rfb::IntParameter udpSize("udpSize", "UDP packet data size", 1300, 500, 1400);
+rfb::IntParameter udpSize("udpSize", "UDP packet data size", 1296, 500, 1400);
 
 extern settings_t settings;
 
@@ -95,10 +95,11 @@ void *udpserver(void *nport) {
 }
 
 // Send one packet, split into N UDP-sized pieces
-static uint8_t udpsend(WuClient *client, const uint8_t *data, unsigned len, uint32_t *id) {
+static uint8_t udpsend(WuClient *client, const uint8_t *data, unsigned len, uint32_t *id,
+			const uint32_t *frame) {
 	const uint32_t DATA_MAX = udpSize;
 
-	uint8_t buf[1400 + sizeof(uint32_t) * 4];
+	uint8_t buf[1400 + sizeof(uint32_t) * 5];
 	const uint32_t pieces = (len / DATA_MAX) + ((len % DATA_MAX) ? 1 : 0);
 
 	uint32_t i;
@@ -111,12 +112,13 @@ static uint8_t udpsend(WuClient *client, const uint8_t *data, unsigned len, uint
 		memcpy(&buf[4], &i, sizeof(uint32_t));
 		memcpy(&buf[8], &pieces, sizeof(uint32_t));
 		memcpy(&buf[12], &hash, sizeof(uint32_t));
+		memcpy(&buf[16], frame, sizeof(uint32_t));
 
-		memcpy(&buf[16], data, curlen);
+		memcpy(&buf[20], data, curlen);
 		data += curlen;
 		len -= curlen;
 
-		if (WuHostSendBinary(host, client, buf, curlen + sizeof(uint32_t) * 4) < 0)
+		if (WuHostSendBinary(host, client, buf, curlen + sizeof(uint32_t) * 5) < 0)
 			return 1;
 	}
 
@@ -125,7 +127,8 @@ static uint8_t udpsend(WuClient *client, const uint8_t *data, unsigned len, uint
 	return 0;
 }
 
-UdpStream::UdpStream(): OutStream(), client(NULL), total_len(0), id(0), failed(false) {
+UdpStream::UdpStream(): OutStream(), client(NULL), total_len(0), id(0), failed(false),
+	                frame(0) {
 	ptr = data;
 	end = data + UDPSTREAM_BUFSIZE;
 
@@ -137,7 +140,7 @@ void UdpStream::flush() {
 	total_len += len;
 
 	if (client) {
-		if (udpsend(client, data, len, &id)) {
+		if (udpsend(client, data, len, &id, &frame)) {
 			vlog.error("Error sending udp, client gone?");
 			failed = true;
 		}
diff --git a/common/network/Udp.h b/common/network/Udp.h
index 0bdeb22..38c9f46 100644
--- a/common/network/Udp.h
+++ b/common/network/Udp.h
@@ -40,6 +40,10 @@ namespace network {
 				client = cli;
 			}
 
+			void setFrameNumber(const unsigned in) {
+				frame = in;
+			}
+
 			bool isFailed() const;
 			void clearFailed();
 		private:
@@ -48,6 +52,7 @@ namespace network {
 			size_t total_len;
 			uint32_t id;
 			bool failed;
+			uint32_t frame;
 	};
 }
 
diff --git a/common/rfb/EncodeManager.cxx b/common/rfb/EncodeManager.cxx
index cc6f571..0c45fdc 100644
--- a/common/rfb/EncodeManager.cxx
+++ b/common/rfb/EncodeManager.cxx
@@ -675,6 +675,9 @@ Encoder *EncodeManager::startRect(const Rect& rect, int type, const bool trackQu
 
   beforeLength = conn->getOutStream(conn->cp.supportsUdp)->length();
 
+  if (conn->cp.supportsUdp)
+    ((network::UdpStream *) conn->getOutStream(conn->cp.supportsUdp))->setFrameNumber(updates);
+
   stats[klass][activeType].rects++;
   stats[klass][activeType].pixels += rect.area();
   equiv = 12 + rect.area() * (conn->cp.pf().bpp/8);