socket.c

#include <arpa/inet.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/poll.h>
#include "../defines.h"
#include "packet.h"
#include "../util/dbg.h"
#include "../util/common.h"
#include "processes/feedback_receiver.h"
#include "processes/data_transmitter.h"
#include "processes/data_receiver.h"
#include "socket.h"
#include "block.h"
#include "receiver.h"
#include "clock.h"

PrrtSocket* PrrtSocket_create(const uint16_t port, const uint8_t is_sender) {
    PrrtSocket *sock_ptr = (PrrtSocket*) calloc(1, sizeof(PrrtSocket));
    check_mem(sock_ptr);

    sock_ptr->is_sender = is_sender;

    sock_ptr->sequenceNumberSource = 1;
    sock_ptr->sequenceNumberRedundancy = 1;

    sock_ptr->rttMean = 0;
    sock_ptr->rttDev = 0;

    sock_ptr->dataStore = NULL;

    check(sock_ptr->dataSocketFd = socket(AF_INET, SOCK_DGRAM, 0), "Cannot create data socket.")
    check(sock_ptr->feedbackSocketFd = socket(AF_INET, SOCK_DGRAM, 0), "Cannot create feedback socket.");

    pthread_mutexattr_t attr;
    check(pthread_mutexattr_init(&attr) == 0, "Mutex attr init failed.");
    check(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) == 0, "Setting type failed.");
    check(pthread_mutex_init(&sock_ptr->closingMutex, &attr) == 0, "Mutex init failed.");

    // Bind Data Socket
    struct sockaddr_in address;
    memset((char *) &address, 0, sizeof(address));
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = htonl(INADDR_ANY);
    address.sin_port = htons(port);

    check(bind(sock_ptr->dataSocketFd, (struct sockaddr *) &address, sizeof(address)) == EXIT_SUCCESS,
          "Cannot bind data socket.");

    if (is_sender) {
        // Bind Feedback Socket
        struct sockaddr_in address;
        memset((char *) &address, 0, sizeof(address));
        address.sin_family = AF_INET;
        address.sin_addr.s_addr = htonl(INADDR_ANY);
        check(port <= 65534, "Port %d cannot be bound to.", port);
        address.sin_port = htons((uint16_t) (port + 1));

        check(bind(sock_ptr->feedbackSocketFd, (struct sockaddr *) &address, sizeof(address)) == EXIT_SUCCESS,
              "Cannot bind feedback socket.");

        check(pthread_mutex_init(&sock_ptr->outQueueFilledMutex, NULL) == 0, "Mutex init failed.");
        check(pthread_cond_init(&sock_ptr->outQueueFilledCv, NULL) == 0, "Cond init failed.");
        sock_ptr->outQueue = List_create();

        check(pthread_create(&sock_ptr->receiveFeedbackThread, NULL, receive_feedback_loop, (void *) sock_ptr) ==
              EXIT_SUCCESS, "Cannot create receive feedback thread.");
        check(pthread_create(&sock_ptr->sendThread, NULL, send_data_loop, (void *) sock_ptr) == EXIT_SUCCESS,
              "Cannot create send thread.");

        sock_ptr->receivers = List_create();
    } else {
        sock_ptr->forwardPacketTable = calloc(1, sizeof(PrrtForwardPacketTable));
        check_mem(sock_ptr->forwardPacketTable)
        check(PrrtForwardPacketTable_create(sock_ptr->forwardPacketTable) == 0, "Creating table failed.");

        check(pthread_mutex_init(&sock_ptr->inQueueFilledMutex, NULL) == 0, "Mutex init failed.");
        check(pthread_cond_init(&sock_ptr->inQueueFilledCv, NULL) == 0, "Cond init failed.");
        sock_ptr->inQueue = List_create();

        check(pthread_create(&sock_ptr->receiveDataThread, NULL, receive_data_loop, (void *) sock_ptr) == EXIT_SUCCESS,
              "Cannot create data receiving thread.");
    }

    return sock_ptr;

    error:
        PrrtSocket_close(sock_ptr);
        return NULL;
}

int PrrtSocket_connect(PrrtSocket *sock_ptr, const char *host, const uint16_t port) {
    PrrtReceiver *recv = PrrtReceiver_create(host, port);
    List_push(sock_ptr->receivers, recv);
    return 0;
}

int PrrtSocket_send(PrrtSocket *sock_ptr, const uint8_t *data, const size_t data_len) {
    check(sock_ptr->is_sender, "Cannot send on receiver socket.")
    check(pthread_mutex_lock(&sock_ptr->outQueueFilledMutex) == 0, "Lock failed.");

    PrrtPacket *packet = PrrtPacket_create_data_packet(5, data, (uint32_t) data_len, 0);

    List_push(sock_ptr->outQueue, packet);
    check(pthread_cond_signal(&sock_ptr->outQueueFilledCv) == 0, "Signal failed.");
    check(pthread_mutex_unlock(&sock_ptr->outQueueFilledMutex) == 0, "Unlock failed");

    return 0;
    error:
        PERROR("There was a failure while sending from socket.%s", "");
        return -1;
}

int32_t PrrtSocket_recv(PrrtSocket *sock_ptr, void *buf_ptr) {
    check(sock_ptr->is_sender == false, "Cannot receive on sender socket.")
    while (1) {
        check(pthread_mutex_lock(&sock_ptr->inQueueFilledMutex) == 0, "Lock failed.");
        while (List_count(sock_ptr->inQueue) == 0) {
            check(pthread_mutex_lock(&sock_ptr->closingMutex) == 0, "Lock failed.");
            if (sock_ptr->closing) {
                check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");
                check(pthread_mutex_unlock(&sock_ptr->inQueueFilledMutex) == 0, "Unlock failed.");
                return -1;
            }
            check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");
            check(pthread_cond_wait(&sock_ptr->inQueueFilledCv, &sock_ptr->inQueueFilledMutex) == 0, "Wait failed.");
        }
        PrrtPacket *packet = List_shift(sock_ptr->inQueue);

        uint32_t len = (uint32_t) (packet->payload_len - PRRT_PACKET_DATA_HEADER_SIZE);
        PrrtPacket_copy_payload_to_buffer(buf_ptr, packet, PRRT_PACKET_DATA_HEADER_SIZE);
        PrrtPacket_destroy(packet);

        check(pthread_mutex_unlock(&sock_ptr->inQueueFilledMutex) == 0, "Unlock failed.");
        return len;
    }
    error:
        PERROR("There was a failure while receiving from socket.%s", "");
        return -1;
}

int PrrtSocket_interrupt(PrrtSocket *sock_ptr) {
    check(pthread_mutex_lock(&sock_ptr->closingMutex) == 0, "Lock failed.");
    sock_ptr->closing = true;
    check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");

    void **res = NULL;
    if (sock_ptr->sendThread != 0) {
        check(pthread_mutex_lock(&sock_ptr->outQueueFilledMutex) == 0, "Lock failed.");
        check(pthread_cond_broadcast(&sock_ptr->outQueueFilledCv) == 0, "Broadcast failed.");
        check(pthread_mutex_unlock(&sock_ptr->outQueueFilledMutex) == 0, "Unlock failed.");

        check(pthread_join(sock_ptr->sendThread, res) == 0, "Join failed.");
        sock_ptr->sendThread = 0;
    }

    if (sock_ptr->receiveDataThread != 0) {
        check(pthread_mutex_lock(&sock_ptr->inQueueFilledMutex) == 0, "Lock failed.");
        check(pthread_cond_broadcast(&sock_ptr->inQueueFilledCv) == 0, "Broadcast failed");
        check(pthread_mutex_unlock(&sock_ptr->inQueueFilledMutex) == 0, "Unlock failed");

        check(pthread_cancel(sock_ptr->receiveDataThread) == 0, "Cancel failed.");
        check(pthread_join(sock_ptr->receiveDataThread, res) == 0, "Join failed.");

        sock_ptr->receiveDataThread = 0;
    }

    if (sock_ptr->receiveFeedbackThread != 0) {
        check(pthread_cancel(sock_ptr->receiveFeedbackThread) == 0, "Cancel failed.");
        check(pthread_join(sock_ptr->receiveFeedbackThread, res) == 0, "Join failed.");

        sock_ptr->receiveFeedbackThread = 0;
    }
    return EXIT_SUCCESS;

    error:
        PERROR("Interruping socket failed.%s","");
        return EXIT_FAILURE;
}

int PrrtSocket_close(PrrtSocket *sock_ptr) {
    debug("Closing socket.");
    check(pthread_mutex_lock(&sock_ptr->closingMutex) == 0, "Lock failed.");
    if (!sock_ptr->closing) {
        check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");
        check(PrrtSocket_interrupt(sock_ptr) == EXIT_SUCCESS, "Interrupt failed.");
    } else {
        check(pthread_mutex_unlock(&sock_ptr->closingMutex) == 0, "Unlock failed.");
    }

    if (sock_ptr->dataStore != NULL) {
        List *dataList = List_create();
        BPTree_get_range(sock_ptr->dataStore, dataList, 0, SEQNO_SPACE - 1);
        while (List_count(dataList) > 0) {
            PrrtPacket *packet = List_shift(dataList);
            PrrtPacket_destroy(packet);
        }

        List_destroy(dataList);

        sock_ptr->dataStore = BPTree_destroy(sock_ptr->dataStore);
    }

    if (sock_ptr->blockStore != NULL) {
        List *blockList = List_create();
        BPTree_get_range(sock_ptr->blockStore, blockList, 0, SEQNO_SPACE - 1);
        while (List_count(blockList) > 0) {
            PrrtBlock *block = List_shift(blockList);
            PrrtBlock_destroy(block);
        }

        List_destroy(blockList);

        sock_ptr->blockStore = BPTree_destroy(sock_ptr->blockStore);
    }

    if (sock_ptr->receivers != NULL) {
        while (List_count(sock_ptr->receivers) > 0) {
            PrrtReceiver *recv = List_shift(sock_ptr->receivers);
            PrrtReceiver_destroy(recv);
        }
        List_destroy(sock_ptr->receivers);
        sock_ptr->receivers = NULL;
    }

    if (sock_ptr->outQueue != NULL) {
        check(pthread_mutex_destroy(&sock_ptr->outQueueFilledMutex) == 0, "Mutex destroy failed.");
        check(pthread_cond_destroy(&sock_ptr->outQueueFilledCv) == 0, "Cond destroy failed.");
        List_destroy(sock_ptr->outQueue);
        sock_ptr->outQueue = NULL;
    }

    if (sock_ptr->inQueue != NULL) {
        check(pthread_mutex_destroy(&sock_ptr->inQueueFilledMutex) == 0, "Mutex destroy failed.");
        check(pthread_cond_destroy(&sock_ptr->inQueueFilledCv) == 0, "Cond destroy failed.");
        List_destroy(sock_ptr->inQueue);
        sock_ptr->inQueue = NULL;
    }

    if (sock_ptr->forwardPacketTable != NULL) {
        check(PrrtForwardPacketTable_destroy(sock_ptr->forwardPacketTable), "Destroy failed.");
        sock_ptr->forwardPacketTable = NULL;
    }

    check(pthread_mutex_destroy(&sock_ptr->closingMutex) == 0, "Mutex destroy failed.");

    close(sock_ptr->dataSocketFd);
    close(sock_ptr->feedbackSocketFd);
    debug("Socket closed.");
    return 0;

    error:
        PERROR("Closing socket failed.%s", "");
        return -1;
}

PrrtPacket *PrrtSocket_recv_feedback(PrrtSocket *sock_ptr, const size_t length)
{
    char bufin[MAX_PAYLOAD_LENGTH];
    ssize_t n;
    struct sockaddr_in remote;
    socklen_t addrlen = sizeof(remote);

    struct pollfd fds;
    int timeout_msecs = 1000;
    fds.fd = sock_ptr->feedbackSocketFd;
    fds.events = POLLIN;

    n = poll(&fds, 1, timeout_msecs);
    check(n >= 0, "Select failed.")
    if (n == 0) {
        return NULL;
    }
    uint32_t receive_time = PrrtClock_get_current_time();

    n = recvfrom(sock_ptr->feedbackSocketFd, bufin, length, 0, (struct sockaddr *) &remote, &addrlen);
    check(n >= 0, "Receiving feedback failed.");

    PrrtPacket *packet_ptr = calloc(1, sizeof(PrrtPacket));
    check_mem(packet_ptr);
    PrrtPacket_decode(bufin, (uint16_t) n, packet_ptr);

    PrrtPacketFeedbackPayload* feedbackPayload = packet_ptr->payload;
    int32_t delta = (receive_time - feedbackPayload->forward_trip_timestamp) - sock_ptr->rttMean;
    // TODO: ensure that there are no arithemtic problems via rounding etc.
    sock_ptr->rttMean = (uint32_t) (sock_ptr->rttMean + RRT_ALPHA * delta);
    sock_ptr->rttDev = (uint32_t) (sock_ptr->rttDev + RRT_ALPHA * (labs(delta) - sock_ptr->rttDev));

    return packet_ptr;

    error:
    return NULL;
}