foo.c

void socket_watcher_init(Loop *loop, SocketWatcher *watcher, const char *endpoint,
                         void *data)
  FUNC_ATTR_NONNULL_ARG(1) FUNC_ATTR_NONNULL_ARG(2) FUNC_ATTR_NONNULL_ARG(3)
{
  xstrlcpy(watcher->addr, endpoint, sizeof(watcher->addr));

  char *addr = xstrdup(endpoint);
  char *host_end = strrchr(addr, ':');

  if (host_end && addr != host_end) {
    uv_getaddrinfo_t request;

    *host_end = '\0';
    int retval = uv_getaddrinfo(&loop->uv, &request, NULL, addr, host_end+1,
                                &(struct addrinfo){
                                  .ai_family = AF_UNSPEC,
                                  .ai_socktype = SOCK_STREAM,
                                });
    if (retval == 0) {
      struct addrinfo *ai = request.addrinfo;

      // DEBUG
      /* void *addr = (ai->ai_family == AF_INET) */
      /*   ? &((struct sockaddr_in  *)ai->ai_addr)->sin_addr */
      /*   : &((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr; */
      /* char canon[INET6_ADDRSTRLEN]; */
      /* inet_ntop(ai->ai_family, addr, canon, sizeof(canon)); */
      /* ILOG("%s: %s", (ai->ai_family == 2 ? "AF_INET" : */
      /*       ai->ai_family == 30 ? "AF_INET6" : "AF_WTF"), canon); */
      // DEBUG END

      memcpy(&watcher->uv.tcp.addr, ai->ai_addr, ai->ai_addrlen);
      uv_tcp_init(&loop->uv, &watcher->uv.tcp.handle);
      watcher->stream = (uv_stream_t *)&watcher->uv.tcp.handle;

      freeaddrinfo(request.addrinfo);
    }
  } else {
    uv_pipe_init(&loop->uv, &watcher->uv.pipe.handle, 0);
    watcher->stream = (uv_stream_t *)&watcher->uv.pipe.handle;
  }

  watcher->stream->data = watcher;
  watcher->cb = NULL;
  watcher->close_cb = NULL;
  watcher->events = NULL;

  xfree(addr);
}