Implement control and input streams over ENet for GFE 2.11

limelight-common/ControlStream.c

@@ -4,11 +4,17 @@
 
 #include "ByteBuffer.h"
 
-// NV control stream packet header
-typedef struct _NVCTL_PACKET_HEADER {
+#include <enet/enet.h>
+
+// NV control stream packet header for TCP
+typedef struct _NVCTL_TCP_PACKET_HEADER {
     unsigned short type;
     unsigned short payloadLength;
-} NVCTL_PACKET_HEADER, *PNVCTL_PACKET_HEADER;
+} NVCTL_TCP_PACKET_HEADER, *PNVCTL_TCP_PACKET_HEADER;
+
+typedef struct _NVCTL_ENET_PACKET_HEADER {
+    unsigned short type;
+} NVCTL_ENET_PACKET_HEADER, *PNVCTL_ENET_PACKET_HEADER;
 
 typedef struct _QUEUED_FRAME_INVALIDATION_TUPLE {
     int startFrame;
@@ -17,6 +23,10 @@ typedef struct _QUEUED_FRAME_INVALIDATION_TUPLE {
 } QUEUED_FRAME_INVALIDATION_TUPLE, *PQUEUED_FRAME_INVALIDATION_TUPLE;
 
 static SOCKET ctlSock = INVALID_SOCKET;
+static ENetHost* client;
+static ENetPeer* peer;
+static PLT_MUTEX enetMutex;
+
 static PLT_THREAD lossStatsThread;
 static PLT_THREAD invalidateRefFramesThread;
 static PLT_EVENT invalidateRefFramesEvent;
@@ -214,10 +224,10 @@ void connectionLostPackets(int lastReceivedPacket, int nextReceivedPacket) {
     lossCountSinceLastReport += (nextReceivedPacket - lastReceivedPacket) - 1;
 }
 
-// Reads an NV control stream packet
-static PNVCTL_PACKET_HEADER readNvctlPacket(void) {
-    NVCTL_PACKET_HEADER staticHeader;
-    PNVCTL_PACKET_HEADER fullPacket;
+// Reads an NV control stream packet from the TCP connection
+static PNVCTL_TCP_PACKET_HEADER readNvctlPacketTcp(void) {
+    NVCTL_TCP_PACKET_HEADER staticHeader;
+    PNVCTL_TCP_PACKET_HEADER fullPacket;
     SOCK_RET err;
 
     err = recv(ctlSock, (char*)&staticHeader, sizeof(staticHeader), 0);
@@ -225,7 +235,7 @@ static PNVCTL_PACKET_HEADER readNvctlPacket(void) {
         return NULL;
     }
 
-    fullPacket = (PNVCTL_PACKET_HEADER)malloc(staticHeader.payloadLength + sizeof(staticHeader));
+    fullPacket = (PNVCTL_TCP_PACKET_HEADER)malloc(staticHeader.payloadLength + sizeof(staticHeader));
     if (fullPacket == NULL) {
         return NULL;
     }
@@ -242,10 +252,53 @@ static PNVCTL_PACKET_HEADER readNvctlPacket(void) {
     return fullPacket;
 }
 
-static int sendMessageAndForget(short ptype, short paylen, const void* payload) {
-    PNVCTL_PACKET_HEADER packet;
+static int sendMessageEnet(short ptype, short paylen, const void* payload) {
+    PNVCTL_ENET_PACKET_HEADER packet;
+    ENetPacket* enetPacket;
+    ENetEvent event;
+
+    LC_ASSERT(ServerMajorVersion > 5);
+
+    packet = malloc(sizeof(*packet) + paylen);
+    if (packet == NULL) {
+        return 0;
+    }
+
+    packet->type = ptype;
+    memcpy(&packet[1], payload, paylen);
+
+    // Gen 5+ servers do control protocol over ENet instead of TCP
+    while (enet_host_service(client, &event, 0) > 0) {
+        if (event.type == ENET_EVENT_TYPE_RECEIVE) {
+            enet_packet_destroy(event.packet);
+        }
+        else if (event.type == ENET_EVENT_TYPE_DISCONNECT) {
+            Limelog("Control stream received disconnect event\n");
+            free(packet);
+            return 0;
+        }
+    }
+
+    enetPacket = enet_packet_create(packet, sizeof(*packet) + paylen, ENET_PACKET_FLAG_RELIABLE);
+    if (packet == NULL) {
+        free(packet);
+        return 0;
+    }
+
+    enet_peer_send(peer, 0, enetPacket);
+    enet_host_flush(client);
+
+    free(packet);
+
+    return 1;
+}
+
+static int sendMessageTcp(short ptype, short paylen, const void* payload) {
+    PNVCTL_TCP_PACKET_HEADER packet;
     SOCK_RET err;
 
+    LC_ASSERT(ServerMajorVersion < 5);
+
     packet = malloc(sizeof(*packet) + paylen);
     if (packet == NULL) {
         return 0;
@@ -255,7 +308,7 @@ static int sendMessageAndForget(short ptype, short paylen, const void* payload)
     packet->payloadLength = paylen;
     memcpy(&packet[1], payload, paylen);
 
-    err = send(ctlSock, (char*)packet, sizeof(*packet) + paylen, 0);
+    err = send(ctlSock, (char*) packet, sizeof(*packet) + paylen, 0);
     free(packet);
 
     if (err != sizeof(*packet) + paylen) {
@@ -265,23 +318,60 @@ static int sendMessageAndForget(short ptype, short paylen, const void* payload)
     return 1;
 }
 
-static PNVCTL_PACKET_HEADER sendMessage(short ptype, short paylen, const void* payload) {
-    if (!sendMessageAndForget(ptype, paylen, payload)) {
-        return NULL;
+static int sendMessageAndForget(short ptype, short paylen, const void* payload) {
+    int ret;
+
+    // Unlike regular sockets, ENet sockets aren't safe to invoke from multiple
+    // threads at once. We have to synchronize them with a lock.
+    if (ServerMajorVersion >= 5) {
+        PltLockMutex(&enetMutex);
+        ret = sendMessageEnet(ptype, paylen, payload);
+        PltUnlockMutex(&enetMutex);
+    }
+    else {
+        ret = sendMessageTcp(ptype, paylen, payload);
     }
 
-    return readNvctlPacket();
+    return ret;
 }
 
 static int sendMessageAndDiscardReply(short ptype, short paylen, const void* payload) {
-    PNVCTL_PACKET_HEADER reply;
+    // Discard the response
+    if (ServerMajorVersion >= 5) {
+        ENetEvent event;
 
-    reply = sendMessage(ptype, paylen, payload);
-    if (reply == NULL) {
-        return 0;
+        PltLockMutex(&enetMutex);
+
+        if (!sendMessageEnet(ptype, paylen, payload)) {
+            PltUnlockMutex(&enetMutex);
+            return 0;
+        }
+
+        if (enet_host_service(client, &event, CONTROL_STREAM_TIMEOUT_SEC * 1000) <= 0 ||
+            event.type != ENET_EVENT_TYPE_RECEIVE) {
+            PltUnlockMutex(&enetMutex);
+            return 0;
+        }
+
+        enet_packet_destroy(event.packet);
+
+        PltUnlockMutex(&enetMutex);
+    }
+    else {
+        PNVCTL_TCP_PACKET_HEADER reply;
+
+        if (!sendMessageTcp(ptype, paylen, payload)) {
+            return 0;
+        }
+
+        reply = readNvctlPacketTcp();
+        if (reply == NULL) {
+            return 0;
+        }
+
+        free(reply);
     }
 
-    free(reply);
     return 1;
 }
 
@@ -433,6 +523,10 @@ int stopControlStream(void) {
     LbqSignalQueueShutdown(&invalidReferenceFrameTuples);
     PltSetEvent(&invalidateRefFramesEvent);
     
+    if (peer != NULL) {
+        enet_peer_reset(peer);
+    }
+
     if (ctlSock != INVALID_SOCKET) {
         shutdownTcpSocket(ctlSock);
     }
@@ -445,12 +539,32 @@ int stopControlStream(void) {
 
     PltCloseThread(&lossStatsThread);
     PltCloseThread(&invalidateRefFramesThread);
+
+    peer = NULL;
+    if (client != NULL) {
+        enet_host_destroy(client);
+        client = NULL;
+    }
     
     if (ctlSock != INVALID_SOCKET) {
         closeSocket(ctlSock);
         ctlSock = INVALID_SOCKET;
     }
 
+    PltDeleteMutex(&enetMutex);
+
+    return 0;
+}
+
+// Called by the input stream to send a packet for Gen 5+ servers
+int sendInputPacketOnControlStream(unsigned char* data, int length) {
+    LC_ASSERT(ServerMajorVersion >= 5);
+
+    // Send the input data (no reply expected)
+    if (sendMessageAndForget(0x0207, length, data) == 0) {
+        return -1;
+    }
+
     return 0;
 }
 
@@ -458,13 +572,46 @@ int stopControlStream(void) {
 int startControlStream(void) {
     int err;
 
-    ctlSock = connectTcpSocket(&RemoteAddr, RemoteAddrLen,
-                               47995, CONTROL_STREAM_TIMEOUT_SEC);
-    if (ctlSock == INVALID_SOCKET) {
-        return LastSocketFail();
-    }
+    PltCreateMutex(&enetMutex);
 
-    enableNoDelay(ctlSock);
+    if (ServerMajorVersion >= 5) {
+        ENetAddress address;
+        ENetEvent event;
+
+        // Create a client that can use 1 outgoing connection and 1 channel
+        client = enet_host_create(NULL, 1, 1, 0, 0);
+        if (client == NULL) {
+            return -1;
+        }
+
+        enet_address_set_host(&address, RemoteAddrString);
+        address.port = 47999;
+
+        // Connect to the host
+        peer = enet_host_connect(client, &address, 1, 0);
+        if (peer == NULL) {
+            return -1;
+        }
+
+        // Wait for the connect to complete
+        if (enet_host_service(client, &event, CONTROL_STREAM_TIMEOUT_SEC * 1000) <= 0 ||
+            event.type != ENET_EVENT_TYPE_CONNECT) {
+            Limelog("RTSP: Failed to connect to UDP port 47999\n");
+            return -1;
+        }
+
+        // Ensure the connect verify ACK is sent immediately
+        enet_host_flush(client);
+    }
+    else {
+        ctlSock = connectTcpSocket(&RemoteAddr, RemoteAddrLen,
+            47995, CONTROL_STREAM_TIMEOUT_SEC);
+        if (ctlSock == INVALID_SOCKET) {
+            return LastSocketFail();
+        }
+
+        enableNoDelay(ctlSock);
+    }
 
     // Send START A
     if (!sendMessageAndDiscardReply(packetTypes[IDX_START_A],

limelight-common/InputStream.c

@@ -258,13 +258,24 @@ static void inputSendThreadProc(void* context) {
         memcpy(&encryptedBuffer[OAES_DATA_OFFSET - sizeof(encryptedLengthPrefix)],
             &encryptedLengthPrefix, sizeof(encryptedLengthPrefix));
 
-        // Send the encrypted payload
-        err = send(inputSock, (const char*)&encryptedBuffer[OAES_DATA_OFFSET - sizeof(encryptedLengthPrefix)],
-            (int)(encryptedSize + sizeof(encryptedLengthPrefix)), 0);
-        if (err <= 0) {
-            Limelog("Input: send() failed: %d\n", (int)LastSocketError());
-            ListenerCallbacks.connectionTerminated(LastSocketError());
-            return;
+        if (ServerMajorVersion < 5) {
+            // Send the encrypted payload
+            err = send(inputSock, (const char*) &encryptedBuffer[OAES_DATA_OFFSET - sizeof(encryptedLengthPrefix)],
+                (int) (encryptedSize + sizeof(encryptedLengthPrefix)), 0);
+            if (err <= 0) {
+                Limelog("Input: send() failed: %d\n", (int) LastSocketError());
+                ListenerCallbacks.connectionTerminated(LastSocketError());
+                return;
+            }
+        }
+        else {
+            err = sendInputPacketOnControlStream(&encryptedBuffer[OAES_DATA_OFFSET - sizeof(encryptedLengthPrefix)],
+                (int) (encryptedSize + sizeof(encryptedLengthPrefix)));
+            if (err < 0) {
+                Limelog("Input: sendInputPacketOnControlStream() failed: %d\n", err);
+                ListenerCallbacks.connectionTerminated(LastSocketError());
+                return;
+            }
         }
     }
 }
@@ -273,13 +284,16 @@ static void inputSendThreadProc(void* context) {
 int startInputStream(void) {
     int err;
 
-    inputSock = connectTcpSocket(&RemoteAddr, RemoteAddrLen,
-                                 35043, INPUT_STREAM_TIMEOUT_SEC);
-    if (inputSock == INVALID_SOCKET) {
-        return LastSocketFail();
-    }
+    // After Gen 5, we send input on the control stream
+    if (ServerMajorVersion < 5) {
+        inputSock = connectTcpSocket(&RemoteAddr, RemoteAddrLen,
+            35043, INPUT_STREAM_TIMEOUT_SEC);
+        if (inputSock == INVALID_SOCKET) {
+            return LastSocketFail();
+        }
 
-    enableNoDelay(inputSock);
+        enableNoDelay(inputSock);
+    }
 
     err = PltCreateThread(inputSendThreadProc, NULL, &inputSendThread);
     if (err != 0) {

limelight-common/Limelight-internal.h

@@ -34,6 +34,7 @@ void connectionDetectedFrameLoss(int startFrame, int endFrame);
 void connectionReceivedCompleteFrame(int frameIndex);
 void connectionSawFrame(int frameIndex);
 void connectionLostPackets(int lastReceivedPacket, int nextReceivedPacket);
+int sendInputPacketOnControlStream(unsigned char* data, int length);
 
 int performRtspHandshake(void);
 void terminateRtspHandshake(void);

limelight-common/SdpGenerator.c

@@ -148,9 +148,9 @@ static int addGen4Options(PSDP_OPTION* head, char* addrStr) {
 static int addGen5Options(PSDP_OPTION* head) {
     int err = 0;
 
-    // We want to use the legacy TCP connections for control and input rather than the new UDP stuff
-    err |= addAttributeString(head, "x-nv-general.useReliableUdp", "0");
-    err |= addAttributeString(head, "x-nv-ri.useControlChannel", "0");
+    // We want to use the new ENet connections for control and input
+    err |= addAttributeString(head, "x-nv-general.useReliableUdp", "1");
+    err |= addAttributeString(head, "x-nv-ri.useControlChannel", "1");
     
     // Disable dynamic resolution switching
     err |= addAttributeString(head, "x-nv-vqos[0].drc.enable", "0");