sock.c:sock_create

sock.c

int sock_create(const char* const port, int backlog) {
  typedef struct addrinfo addrinfo;

  addrinfo hints = {0};
  {
    hints.ai_family = AF_INET; // IPv4.
    hints.ai_socktype = SOCK_STREAM; // TCP.
    hints.ai_flags = AI_PASSIVE; // Server.
  }

  addrinfo* head;
  {
    const int result = getaddrinfo(NULL, port, &hints, &head);
    if (result) {
      fprintf(stderr, "getaddrinfo. err[%s]\n", gai_strerror(result));
      exit(1);
    }
  }

  int sfd = 0;
  for (addrinfo* p = head; p != NULL; p = p->ai_next) {
    sfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
    if (sfd == -1) {
      continue;
    }

    int val = 1;
    if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) == -1) {
      error("setsockopt");
    }

    if (bind(sfd, p->ai_addr, p->ai_addrlen) == -1) {
      close(sfd);
      continue;
    }
    break;
  }
  freeaddrinfo(head);

  if (!sfd) {
    error("socket, bind");
  }

  if (listen(sfd, backlog) == -1) {
    error("listen");
  }
  return sfd;
}