#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

volatile int alive = 1;

void sigterm(int s) {
    printf("Sigterm received...\n");
    alive = 0;
    return;
}

void sigint(int s) {
    printf("Sigint received...\n");
    alive = 0;
    return;
}

int main(int argc, char **argv) {
    struct sigaction sig;
    struct sockaddr_in sa;
    int sfd, tmp;

    memset(&sig, 0, sizeof(sig));

    sig.sa_handler = sigterm;
    sigaction(SIGTERM, &sig, NULL);
    sig.sa_handler = sigint;
    sigaction(SIGINT, &sig, NULL);

    memset(&sa, 0, sizeof(sa));
    sa.sin_family = AF_INET;

    sfd = socket(AF_INET, SOCK_STREAM, 0);
    bind(sfd, (struct sockaddr *)&sa, sizeof(sa));
    listen(sfd, 20);

    tmp = sizeof(sa);
    getsockname(sfd, (struct sockaddr *)&sa, &tmp);
    printf("Bound to: %d\n", ntohs(sa.sin_port));

    while(alive) {
        int cfd, socklen;
        struct sockaddr_in csa;
        printf("Alive...\n");

        socklen = sizeof(csa);
        cfd = accept(sfd, (struct sockaddr *)&csa, &socklen);
        printf("Accept received: %d\n", cfd);
        if(cfd < 0) {
            printf("Error return: %d with errno %d (%s)\n", cfd, errno, strerror(errno));
        }
        write(cfd, "Goodbye.\r\n", strlen("Goodbye.\r\n"));
        shutdown(cfd, 2);
        close(cfd);
    }

    printf("Done, alive cleared.\n");
    close(sfd);
    exit(1);
}