[cahandler] Skip CLIENT_INFO on reconnects for legacy softcams (#3700)

CLIENT_INFO was sent on every new connection to .listen.camd.socket,
causing repeated "error in capmt length field read 4" in legacy softcam
logs and risking disconnect loops with softcams that cannot parse
Protocol-3 data.

Track handshake state at eDVBCAHandler level:
- First connection: send CLIENT_INFO to probe for Protocol-3
- If SERVER_INFO received: mark Protocol-3 established, always send
  CLIENT_INFO on reconnects
- If no SERVER_INFO: legacy client detected, skip CLIENT_INFO on
  subsequent connections

Author: WXbet

lib/dvb/cahandler.cpp

@@ -210,6 +210,7 @@ bool ePMTClient::processServerInfoPacket()
 			eDebug("[ePMTClient] ServerInfo: Protocol %u, Info: %s", serverProtocolVersion, receivedData + fixDataLength);
 
 			m_serverInfoReceived = true;
+			if (parent) parent->m_protocol3_established = true;
 			if (m_capmt_buffer_len > 0)
 			{
 				writeCAPMTObject(m_capmt_buffer, m_capmt_buffer_len);
@@ -345,6 +346,8 @@ eDVBCAHandler::eDVBCAHandler()
  : eServerSocket(PMT_SERVER_SOCKET, eApp), serviceLeft(eTimer::create(eApp))
 {
 	serviceIdCounter = 1;
+	m_protocol3_established = false;
+	m_handshake_attempted = false;
 	if (instance == NULL)
 	{
 		instance = this;
@@ -378,14 +381,23 @@ void eDVBCAHandler::newConnection(int socket)
 	ePMTClient *client = new ePMTClient(this, client_fd);
 	clients.push_back(client);
 
-	/* First distribute current CAPMTs in legacy format (works for all clients),
-	 * then send CLIENT_INFO to initiate Protocol-3 handshake.
-	 * - Protocol-3 softcams: receive legacy CAPMTs, then CLIENT_INFO,
-	 *   respond with SERVER_INFO -> Protocol 3 for all subsequent CAPMTs.
-	 * - Legacy softcams: receive legacy CAPMTs (works!), then CLIENT_INFO
-	 *   causes disconnect, but CAPMTs were already delivered. */
+	/* Always distribute current CAPMTs first (legacy format, works for all clients) */
 	distributeCAPMT();
-	client->sendClientInfo();
+
+	/* Send CLIENT_INFO only when appropriate:
+	 * - Protocol-3 already established (OSCam reconnect): always send
+	 * - First connection ever: send to probe for Protocol-3 support
+	 * - Legacy client detected (no SERVER_INFO after first attempt): skip
+	 *   to avoid unnecessary errors in legacy softcam logs */
+	if (m_protocol3_established)
+	{
+		client->sendClientInfo();
+	}
+	else if (!m_handshake_attempted)
+	{
+		client->sendClientInfo();
+		m_handshake_attempted = true;
+	}
 }
 
 void eDVBCAHandler::connectionLost(ePMTClient *client)

lib/dvb/cahandler.h

@@ -176,6 +176,8 @@ DECLARE_REF(eDVBCAHandler);
 	std::map<eServiceReferenceDVB, ePtr<eTable<ProgramMapSection> > > pmtCache;
 	std::map<uint32_t, uint16_t> m_service_caid;  // serviceId -> CAID (from softcam ECM_INFO)
 	uint32_t serviceIdCounter;
+	bool m_protocol3_established;  // SERVER_INFO received from at least one client
+	bool m_handshake_attempted;    // CLIENT_INFO sent at least once
 
 	void newConnection(int socket);
 	void processPMTForService(eDVBCAService *service, eTable<ProgramMapSection> *ptr);