/*
 * SIPB service monitor: TCP connections
 *
 * Nickolai Zeldovich <kolya@MIT.EDU>
 * May 2002
 */

#include <async.h>
#include <dns.h>
#include "sipbmon.h"

struct tcpconn_t {
  bool abort;

  tcpconn_t () : abort (false) {}
};

static void
tcpconn_write_cb (int fd, cbi cb, tcpconn_t *tc)
{
  fdcb (fd, selwrite, NULL);

  if (tc->abort) {
    close (fd);
    delete tc;
    return;
  }

  sockaddr_in sin;
  socklen_t sn = sizeof (sin);
  if (!getpeername (fd, (sockaddr *) &sin, &sn)) {
    (*cb) (fd);
    delete tc;
    return;
  }

  int err = 0;
  sn = sizeof (err);
  getsockopt (fd, SOL_SOCKET, SO_ERROR, (char *) &err, &sn);
  close (fd);
  errno = err ? err : ECONNREFUSED;
  (*cb) (-1);
  delete tc;
}

static void
tcpconn_name_cb (u_int16_t port, cbi cb, tcpconn_t *tc, ptr<hostent>h, int err)
{
  if (tc->abort) {
    delete tc;
    return;
  }

  if (!h) {
    errno = ENOENT;
    (*cb) (-1);
    delete tc;
    return;
  }

  sockaddr_in sin;
  bzero (&sin, sizeof (sin));
  sin.sin_family = AF_INET;
  sin.sin_port = htons (port);
  sin.sin_addr = *(in_addr *) h->h_addr;

  int fd = inetsocket (SOCK_STREAM);
  if (fd < 0) {
    (*cb) (-1);
    delete tc;
    return;
  }

  make_async (fd);
  close_on_exec (fd);
  if (connect (fd, (sockaddr *) &sin, sizeof (sin)) < 0
      && errno != EINPROGRESS) {
    close (fd);
    (*cb) (-1);
    delete tc;
    return;
  }

  fdcb (fd, selwrite, wrap (&tcpconn_write_cb, fd, cb, tc));
}

tcpconn_t *
tcpconn (str host, u_int16_t port, cbi cb)
{
  tcpconn_t *tc = New tcpconn_t;

  dns_hostbyname (host, wrap (&tcpconn_name_cb, port, cb, tc), true);
  return tc;
}

void
tcpconn_abort (tcpconn_t *tc)
{
  tc->abort = true;
}