InputStream.c

#include "Limelight-internal.h"
#include "PlatformSockets.h"
#include "PlatformThreads.h"
#include "LinkedBlockingQueue.h"
#include "Input.h"

#include <openssl/evp.h>
#include <openssl/aes.h>

static SOCKET inputSock = INVALID_SOCKET;
static int initialized;

static LINKED_BLOCKING_QUEUE packetQueue;
static PLT_THREAD inputSendThread;

static char* _aesKeyData;
static char* _aesIv;

#define MAX_INPUT_PACKET_SIZE 128
#define INPUT_STREAM_TIMEOUT_SEC 10

// Contains input stream packets
typedef struct _PACKET_HOLDER {
    int packetLength;
    union {
        NV_KEYBOARD_PACKET keyboard;
        NV_MOUSE_MOVE_PACKET mouseMove;
        NV_MOUSE_BUTTON_PACKET mouseButton;
        NV_CONTROLLER_PACKET controller;
        NV_MULTI_CONTROLLER_PACKET multiController;
        NV_SCROLL_PACKET scroll;
    } packet;
    LINKED_BLOCKING_QUEUE_ENTRY entry;
} PACKET_HOLDER, *PPACKET_HOLDER;

// Initializes the input stream
int initializeInputStream(char* aesKeyData, int aesKeyDataLength,
    char* aesIv, int aesIvLength) {
    
    if (aesKeyDataLength != 16) {
        Limelog("Invalid key size.");
        return -1;
    }
    
    _aesKeyData = (char*)malloc(aesKeyDataLength);
    _aesIv = (char*)malloc(aesIvLength);
    
    memcpy(_aesKeyData, aesKeyData, aesKeyDataLength);
    memcpy(_aesIv, aesIv, aesIvLength);
    
    LbqInitializeLinkedBlockingQueue(&packetQueue, 30);

    initialized = 1;
    return 0;
}

int encryptData(const unsigned char* packet, size_t packetLen, char *encryptedBuffer, size_t *encryptedSize)
{
    EVP_CIPHER_CTX *ctx;
    int ret = -1;
    int len;
    int tagOffset = 0;
    char aad[] = {};
    
    printf("Initialize context\n");
    if (!(ctx = EVP_CIPHER_CTX_new()))
        return -1;
    
    printf("Init alg\n");
    if (ServerMajorVersion < 7)
        ret = EVP_EncryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, NULL, NULL);
    else
        ret = EVP_EncryptInit_ex(ctx, EVP_aes_128_gcm(), NULL, NULL, NULL);
    
    if (ret != 1)
        goto clean;
    
    if (ServerMajorVersion >= 7) {
        printf("Set iv len\n");
        if ((ret = EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, 16, NULL)) != 1)
            goto clean;
        
        tagOffset = 16;
    }
    
    printf("Set iv and key\n");
    if ((ret = EVP_EncryptInit_ex(ctx, NULL, NULL, _aesKeyData, _aesIv)) != 1)
        goto clean;
    
    printf("Set aad\n");
    if (ServerMajorVersion >= 7 && (ret = EVP_EncryptUpdate(ctx, NULL, &len, aad, 0)) != 1)
        goto clean;
    
    printf("Encrypt\n");
    if ((ret = EVP_EncryptUpdate(ctx, encryptedBuffer + tagOffset, &len, packet, packetLen)) != 1)
        goto clean;
    
    *encryptedSize = len;
    printf("Len1 %d\n", *encryptedSize);
    
    printf("Final Encrypt\n");
    if ((ret = EVP_EncryptFinal_ex(ctx, encryptedBuffer + tagOffset + len, &len)) != 1)
        goto clean;
    
    *encryptedSize += len;
    
    if (ServerMajorVersion >= 7) {
        printf("Set tag\n");
        if ((ret = EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_GET_TAG, 16, encryptedBuffer)) != 1)
            goto clean;
        
        *encryptedSize += tagOffset;
    }
    
    printf("Len %d\n", *encryptedSize);
    
clean:
    EVP_CIPHER_CTX_free(ctx);
    return ret;
}

// Destroys and cleans up the input stream
void destroyInputStream(void) {
    PLINKED_BLOCKING_QUEUE_ENTRY entry, nextEntry;

    entry = LbqDestroyLinkedBlockingQueue(&packetQueue);

    while (entry != NULL) {
        nextEntry = entry->flink;

        // The entry is stored in the data buffer
        free(entry->data);

        entry = nextEntry;
    }

    initialized = 0;
}

// Checks if values are compatible with controller batching
static int checkDirs(short currentVal, short newVal, int* dir) {
    if (currentVal == newVal) {
        return 1;
    }

    // We want to send a new packet if we've now zeroed an axis
    if (newVal == 0) {
        return 0;
    }

    if (*dir == 0) {
        if (newVal < currentVal) {
            *dir = -1;
        }
        else {
            *dir = 1;
        }
    }
    else if (*dir == -1) {
        return newVal < currentVal;
    }
    else if (newVal < currentVal) {
        return 0;
    }

    return 1;
}

#define OAES_DATA_OFFSET 32

// Input thread proc
static void inputSendThreadProc(void* context) {
    SOCK_RET err;
    PPACKET_HOLDER holder;
    char encryptedBuffer[MAX_INPUT_PACKET_SIZE];
    size_t encryptedSize;

    while (!PltIsThreadInterrupted(&inputSendThread)) {
        int encryptedLengthPrefix;

        err = LbqWaitForQueueElement(&packetQueue, (void**)&holder);
        if (err != LBQ_SUCCESS) {
            return;
        }

        // If it's a multi-controller packet we can do batching
        if (holder->packet.multiController.header.packetType == htonl(PACKET_TYPE_MULTI_CONTROLLER)) {
            PPACKET_HOLDER controllerBatchHolder;
            PNV_MULTI_CONTROLLER_PACKET origPkt;
            int dirs[6];

            memset(dirs, 0, sizeof(dirs));

            origPkt = &holder->packet.multiController;
            for (;;) {
                PNV_MULTI_CONTROLLER_PACKET newPkt;

                // Peek at the next packet
                if (LbqPeekQueueElement(&packetQueue, (void**)&controllerBatchHolder) != LBQ_SUCCESS) {
                    break;
                }

                // If it's not a controller packet, we're done
                if (controllerBatchHolder->packet.multiController.header.packetType != htonl(PACKET_TYPE_MULTI_CONTROLLER)) {
                    break;
                }

                // Check if it's able to be batched
                newPkt = &controllerBatchHolder->packet.multiController;
                if (newPkt->buttonFlags != origPkt->buttonFlags ||
                    newPkt->controllerNumber != origPkt->controllerNumber ||
                    !checkDirs(origPkt->leftTrigger, newPkt->leftTrigger, &dirs[0]) ||
                    !checkDirs(origPkt->rightTrigger, newPkt->rightTrigger, &dirs[1]) ||
                    !checkDirs(origPkt->leftStickX, newPkt->leftStickX, &dirs[2]) ||
                    !checkDirs(origPkt->leftStickY, newPkt->leftStickY, &dirs[3]) ||
                    !checkDirs(origPkt->rightStickX, newPkt->rightStickX, &dirs[4]) ||
                    !checkDirs(origPkt->rightStickY, newPkt->rightStickY, &dirs[5])) {
                    // Batching not allowed
                    break;
                }

                // Remove the batchable controller packet
                if (LbqPollQueueElement(&packetQueue, (void**)&controllerBatchHolder) != LBQ_SUCCESS) {
                    break;
                }

                // Update the original packet
                origPkt->leftTrigger = newPkt->leftTrigger;
                origPkt->rightTrigger = newPkt->rightTrigger;
                origPkt->leftStickX = newPkt->leftStickX;
                origPkt->leftStickY = newPkt->leftStickY;
                origPkt->rightStickX = newPkt->rightStickX;
                origPkt->rightStickY = newPkt->rightStickY;

                // Free the batched packet holder
                free(controllerBatchHolder);
            }
        }
        // If it's a mouse move packet, we can also do batching
        else if (holder->packet.mouseMove.header.packetType == htonl(PACKET_TYPE_MOUSE_MOVE)) {
            PPACKET_HOLDER mouseBatchHolder;
            int totalDeltaX = (short)htons(holder->packet.mouseMove.deltaX);
            int totalDeltaY = (short)htons(holder->packet.mouseMove.deltaY);

            for (;;) {
                int partialDeltaX;
                int partialDeltaY;

                // Peek at the next packet
                if (LbqPeekQueueElement(&packetQueue, (void**)&mouseBatchHolder) != LBQ_SUCCESS) {
                    break;
                }

                // If it's not a mouse move packet, we're done
                if (mouseBatchHolder->packet.mouseMove.header.packetType != htonl(PACKET_TYPE_MOUSE_MOVE)) {
                    break;
                }

                partialDeltaX = (short)htons(mouseBatchHolder->packet.mouseMove.deltaX);
                partialDeltaY = (short)htons(mouseBatchHolder->packet.mouseMove.deltaY);

                // Check for overflow
                if (partialDeltaX + totalDeltaX > INT16_MAX ||
                    partialDeltaX + totalDeltaX < INT16_MIN ||
                    partialDeltaY + totalDeltaY > INT16_MAX ||
                    partialDeltaY + totalDeltaY < INT16_MIN) {
                    // Total delta would overflow our 16-bit short
                    break;
                }

                // Remove the batchable mouse move packet
                if (LbqPollQueueElement(&packetQueue, (void**)&mouseBatchHolder) != LBQ_SUCCESS) {
                    break;
                }

                totalDeltaX += partialDeltaX;
                totalDeltaY += partialDeltaY;

                // Free the batched packet holder
                free(mouseBatchHolder);
            }

            // Update the original packet
            holder->packet.mouseMove.deltaX = htons((short)totalDeltaX);
            holder->packet.mouseMove.deltaY = htons((short)totalDeltaY);
        }
        
        encryptedSize = sizeof(encryptedBuffer);
        err = encryptData((const unsigned char*)&holder->packet, holder->packetLength,
            ((unsigned char*)encryptedBuffer) + 4, &encryptedSize);
        
        free(holder);
        
        if (err != 1) {
            Limelog("Input: Encryption failed: %d\n", (int)err);
            ListenerCallbacks.connectionTerminated(err);
            return;
        }
        
        // Overwrite the last 4 bytes before the encrypted data with the length so
        // we can send the message all at once. GFE can choke if it gets the header
        // before the rest of the message.
        encryptedLengthPrefix = htonl((unsigned long)encryptedSize);
        memcpy(&encryptedBuffer, &encryptedLengthPrefix, sizeof(encryptedLengthPrefix));
        
        if (ServerMajorVersion == 7 && encryptedSize - sizeof(encryptedLengthPrefix) >= 32) {
            printf("Update IV\n");
            memcpy(_aesIv, encryptedBuffer + sizeof(encryptedLengthPrefix) - 16, 16);
        }
        
        if (ServerMajorVersion < 5) {
            // Send the encrypted payload
            err = send(inputSock, (const char*) &encryptedBuffer,
                (int) (encryptedSize + sizeof(encryptedLengthPrefix)), 0);
            if (err <= 0) {
                Limelog("Input: send() failed: %d\n", (int) LastSocketError());
                ListenerCallbacks.connectionTerminated(LastSocketError());
                return;
            }
        }
        else {
            err = (SOCK_RET)sendInputPacketOnControlStream((unsigned char*) &encryptedBuffer,
                (int) (encryptedSize + sizeof(encryptedLengthPrefix)));
            if (err < 0) {
                Limelog("Input: sendInputPacketOnControlStream() failed: %d\n", (int) err);
                ListenerCallbacks.connectionTerminated(LastSocketError());
                return;
            }
        }
    }
}

// Begin the input stream
int startInputStream(void) {
    int err;

    // 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);
    }

    err = PltCreateThread(inputSendThreadProc, NULL, &inputSendThread);
    if (err != 0) {
        return err;
    }

    return err;
}

// Stops the input stream
int stopInputStream(void) {
    // Signal the input send thread
    LbqSignalQueueShutdown(&packetQueue);
    PltInterruptThread(&inputSendThread);

    if (inputSock != INVALID_SOCKET) {
        shutdownTcpSocket(inputSock);
    }

    PltJoinThread(&inputSendThread);
    PltCloseThread(&inputSendThread);
    
    if (inputSock != INVALID_SOCKET) {
        closeSocket(inputSock);
        inputSock = INVALID_SOCKET;
    }

    return 0;
}

// Send a mouse move event to the streaming machine
int LiSendMouseMoveEvent(short deltaX, short deltaY) {
    PPACKET_HOLDER holder;
    int err;

    if (!initialized) {
        return -2;
    }

    holder = malloc(sizeof(*holder));
    if (holder == NULL) {
        return -1;
    }

    holder->packetLength = sizeof(NV_MOUSE_MOVE_PACKET);
    holder->packet.mouseMove.header.packetType = htonl(PACKET_TYPE_MOUSE_MOVE);
    holder->packet.mouseMove.magic = MOUSE_MOVE_MAGIC;
    // On Gen 5 servers, the header code is incremented by one
    if (ServerMajorVersion >= 5) {
        holder->packet.mouseMove.magic++;
    }
    holder->packet.mouseMove.deltaX = htons(deltaX);
    holder->packet.mouseMove.deltaY = htons(deltaY);

    err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
    if (err != LBQ_SUCCESS) {
        free(holder);
    }

    return err;
}

// Send a mouse button event to the streaming machine
int LiSendMouseButtonEvent(char action, int button) {
    PPACKET_HOLDER holder;
    int err;

    if (!initialized) {
        return -2;
    }

    holder = malloc(sizeof(*holder));
    if (holder == NULL) {
        return -1;
    }

    holder->packetLength = sizeof(NV_MOUSE_BUTTON_PACKET);
    holder->packet.mouseButton.header.packetType = htonl(PACKET_TYPE_MOUSE_BUTTON);
    holder->packet.mouseButton.action = action;
    if (ServerMajorVersion >= 5) {
        holder->packet.mouseButton.action++;
    }
    holder->packet.mouseButton.button = htonl(button);

    err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
    if (err != LBQ_SUCCESS) {
        free(holder);
    }

    return err;
}

// Send a key press event to the streaming machine
int LiSendKeyboardEvent(short keyCode, char keyAction, char modifiers) {
    PPACKET_HOLDER holder;
    int err;

    if (!initialized) {
        return -2;
    }

    holder = malloc(sizeof(*holder));
    if (holder == NULL) {
        return -1;
    }

    holder->packetLength = sizeof(NV_KEYBOARD_PACKET);
    holder->packet.keyboard.header.packetType = htonl(PACKET_TYPE_KEYBOARD);
    holder->packet.keyboard.keyAction = keyAction;
    holder->packet.keyboard.zero1 = 0;
    holder->packet.keyboard.keyCode = keyCode;
    holder->packet.keyboard.modifiers = modifiers;
    holder->packet.keyboard.zero2 = 0;

    err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
    if (err != LBQ_SUCCESS) {
        free(holder);
    }

    return err;
}

static int sendControllerEventInternal(short controllerNumber, short buttonFlags, unsigned char leftTrigger, unsigned char rightTrigger,
    short leftStickX, short leftStickY, short rightStickX, short rightStickY)
{
    PPACKET_HOLDER holder;
    int err;

    if (!initialized) {
        return -2;
    }

    holder = malloc(sizeof(*holder));
    if (holder == NULL) {
        return -1;
    }

    if (ServerMajorVersion == 3) {
        // Generation 3 servers don't support multiple controllers so we send
        // the legacy packet
        holder->packetLength = sizeof(NV_CONTROLLER_PACKET);
        holder->packet.controller.header.packetType = htonl(PACKET_TYPE_CONTROLLER);
        holder->packet.controller.headerA = C_HEADER_A;
        holder->packet.controller.headerB = C_HEADER_B;
        holder->packet.controller.buttonFlags = buttonFlags;
        holder->packet.controller.leftTrigger = leftTrigger;
        holder->packet.controller.rightTrigger = rightTrigger;
        holder->packet.controller.leftStickX = leftStickX;
        holder->packet.controller.leftStickY = leftStickY;
        holder->packet.controller.rightStickX = rightStickX;
        holder->packet.controller.rightStickY = rightStickY;
        holder->packet.controller.tailA = C_TAIL_A;
        holder->packet.controller.tailB = C_TAIL_B;
    }
    else {
        // Generation 4+ servers support passing the controller number
        holder->packetLength = sizeof(NV_MULTI_CONTROLLER_PACKET);
        holder->packet.multiController.header.packetType = htonl(PACKET_TYPE_MULTI_CONTROLLER);
        holder->packet.multiController.headerA = MC_HEADER_A;
        // On Gen 5 servers, the header code is decremented by one
        if (ServerMajorVersion >= 5) {
            holder->packet.multiController.headerA--;
        }
        holder->packet.multiController.headerB = MC_HEADER_B;
        holder->packet.multiController.controllerNumber = controllerNumber;
        holder->packet.multiController.midA = MC_ACTIVE_CONTROLLER_FLAGS;
        holder->packet.multiController.midB = MC_MID_B;
        holder->packet.multiController.buttonFlags = buttonFlags;
        holder->packet.multiController.leftTrigger = leftTrigger;
        holder->packet.multiController.rightTrigger = rightTrigger;
        holder->packet.multiController.leftStickX = leftStickX;
        holder->packet.multiController.leftStickY = leftStickY;
        holder->packet.multiController.rightStickX = rightStickX;
        holder->packet.multiController.rightStickY = rightStickY;
        holder->packet.multiController.tailA = MC_TAIL_A;
        holder->packet.multiController.tailB = MC_TAIL_B;
    }

    err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
    if (err != LBQ_SUCCESS) {
        free(holder);
    }

    return err;
}

// Send a controller event to the streaming machine
int LiSendControllerEvent(short buttonFlags, unsigned char leftTrigger, unsigned char rightTrigger,
    short leftStickX, short leftStickY, short rightStickX, short rightStickY)
{
    return sendControllerEventInternal(0, buttonFlags, leftTrigger, rightTrigger,
        leftStickX, leftStickY, rightStickX, rightStickY);
}

// Send a controller event to the streaming machine
int LiSendMultiControllerEvent(short controllerNumber, short buttonFlags, unsigned char leftTrigger, unsigned char rightTrigger,
    short leftStickX, short leftStickY, short rightStickX, short rightStickY)
{
    return sendControllerEventInternal(controllerNumber, buttonFlags, leftTrigger, rightTrigger,
        leftStickX, leftStickY, rightStickX, rightStickY);
}

// Send a scroll event to the streaming machine
int LiSendScrollEvent(signed char scrollClicks) {
    PPACKET_HOLDER holder;
    int err;

    if (!initialized) {
        return -2;
    }

    holder = malloc(sizeof(*holder));
    if (holder == NULL) {
        return -1;
    }

    holder->packetLength = sizeof(NV_SCROLL_PACKET);
    holder->packet.scroll.header.packetType = htonl(PACKET_TYPE_SCROLL);
    holder->packet.scroll.magicA = MAGIC_A;
    // On Gen 5 servers, the header code is incremented by one
    if (ServerMajorVersion >= 5) {
        holder->packet.scroll.magicA++;
    }
    holder->packet.scroll.zero1 = 0;
    holder->packet.scroll.zero2 = 0;
    holder->packet.scroll.scrollAmt1 = htons(scrollClicks * 120);
    holder->packet.scroll.scrollAmt2 = holder->packet.scroll.scrollAmt1;
    holder->packet.scroll.zero3 = 0;

    err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
    if (err != LBQ_SUCCESS) {
        free(holder);
    }

    return err;
}