/*
     This file is part of libmicrohttpd
     Copyright (C) 2016-2020 Christian Grothoff
     Copyright (C) 2016-2022 Evgeny Grin (Karlson2k)

     libmicrohttpd is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     libmicrohttpd is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with libmicrohttpd; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/

/**
 * @file test_upgrade.c
 * @brief  Testcase for libmicrohttpd upgrading a connection
 * @author Christian Grothoff
 * @author Karlson2k (Evgeny Grin)
 */

#include "mhd_options.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <stddef.h>
#ifndef WINDOWS
#include <unistd.h>
#endif
#ifdef HAVE_STDBOOL_H
#include <stdbool.h>
#endif /* HAVE_STDBOOL_H */

#include "mhd_sockets.h"
#ifdef HAVE_NETINET_IP_H
#include <netinet/ip.h>
#endif /* HAVE_NETINET_IP_H */

#include "platform.h"
#include "microhttpd.h"

#include "test_helpers.h"

#ifdef HTTPS_SUPPORT
#include <gnutls/gnutls.h>
#include "../testcurl/https/tls_test_keys.h"

#if defined(HAVE_FORK) && defined(HAVE_WAITPID)
#include <sys/types.h>
#include <sys/wait.h>
#endif /* HAVE_FORK && HAVE_WAITPID */
#endif /* HTTPS_SUPPORT */


_MHD_NORETURN static void
_externalErrorExit_func (const char *errDesc, const char *funcName, int lineNum)
{
  fflush (stdout);
  if ((NULL != errDesc) && (0 != errDesc[0]))
    fprintf (stderr, "%s", errDesc);
  else
    fprintf (stderr, "System or external library call failed");
  if ((NULL != funcName) && (0 != funcName[0]))
    fprintf (stderr, " in %s", funcName);
  if (0 < lineNum)
    fprintf (stderr, " at line %d", lineNum);

  fprintf (stderr, ".\nLast errno value: %d (%s)\n", (int) errno,
           strerror (errno));
#ifdef MHD_WINSOCK_SOCKETS
  fprintf (stderr, "WSAGetLastError() value: %d\n", (int) WSAGetLastError ());
#endif /* MHD_WINSOCK_SOCKETS */
  fflush (stderr);
  exit (99);
}


_MHD_NORETURN static void
_mhdErrorExit_func (const char *errDesc, const char *funcName, int lineNum)
{
  fflush (stdout);
  if ((NULL != errDesc) && (0 != errDesc[0]))
    fprintf (stderr, "%s", errDesc);
  else
    fprintf (stderr, "MHD unexpected error");
  if ((NULL != funcName) && (0 != funcName[0]))
    fprintf (stderr, " in %s", funcName);
  if (0 < lineNum)
    fprintf (stderr, " at line %d", lineNum);

  fprintf (stderr, ".\nLast errno value: %d (%s)\n", (int) errno,
           strerror (errno));

  fflush (stderr);
  exit (8);
}


static void
_testErrorLog_func (const char *errDesc, const char *funcName, int lineNum)
{
  fflush (stdout);
  if ((NULL != errDesc) && (0 != errDesc[0]))
    fprintf (stderr, "%s", errDesc);
  else
    fprintf (stderr, "System or external library call resulted in error");
  if ((NULL != funcName) && (0 != funcName[0]))
    fprintf (stderr, " in %s", funcName);
  if (0 < lineNum)
    fprintf (stderr, " at line %d", lineNum);

  fprintf (stderr, ".\nLast errno value: %d (%s)\n", (int) errno,
           strerror (errno));
#ifdef MHD_WINSOCK_SOCKETS
  fprintf (stderr, "WSAGetLastError() value: %d\n", (int) WSAGetLastError ());
#endif /* MHD_WINSOCK_SOCKETS */
  fflush (stderr);
}


#if defined(HAVE___FUNC__)
#define externalErrorExit(ignore) \
    _externalErrorExit_func(NULL, __func__, __LINE__)
#define externalErrorExitDesc(errDesc) \
    _externalErrorExit_func(errDesc, __func__, __LINE__)
#define mhdErrorExit(ignore) \
    _mhdErrorExit_func(NULL, __func__, __LINE__)
#define mhdErrorExitDesc(errDesc) \
    _mhdErrorExit_func(errDesc, __func__, __LINE__)
#define testErrorLog(ignore) \
    _testErrorLog_func(NULL, __func__, __LINE__)
#define testErrorLogDesc(errDesc) \
    _testErrorLog_func(errDesc, __func__, __LINE__)
#elif defined(HAVE___FUNCTION__)
#define externalErrorExit(ignore) \
    _externalErrorExit_func(NULL, __FUNCTION__, __LINE__)
#define externalErrorExitDesc(errDesc) \
    _externalErrorExit_func(errDesc, __FUNCTION__, __LINE__)
#define mhdErrorExit(ignore) \
    _mhdErrorExit_func(NULL, __FUNCTION__, __LINE__)
#define mhdErrorExitDesc(errDesc) \
    _mhdErrorExit_func(errDesc, __FUNCTION__, __LINE__)
#define testErrorLog(ignore) \
    _testErrorLog_func(NULL, __FUNCTION__, __LINE__)
#define testErrorLogDesc(errDesc) \
    _testErrorLog_func(errDesc, __FUNCTION__, __LINE__)
#else
#define externalErrorExit(ignore) _externalErrorExit_func(NULL, NULL, __LINE__)
#define externalErrorExitDesc(errDesc) \
  _externalErrorExit_func(errDesc, NULL, __LINE__)
#define mhdErrorExit(ignore) _mhdErrorExit_func(NULL, NULL, __LINE__)
#define mhdErrorExitDesc(errDesc) _mhdErrorExit_func(errDesc, NULL, __LINE__)
#define testErrorLog(ignore) _testErrorLog_func(NULL, NULL, __LINE__)
#define testErrorLogDesc(errDesc) _testErrorLog_func(errDesc, NULL, __LINE__)
#endif


static void
fflush_allstd (void)
{
  fflush (stderr);
  fflush (stdout);
}


static int verbose = 0;

static uint16_t global_port;

enum tls_tool
{
  TLS_CLI_NO_TOOL = 0,
  TLS_CLI_GNUTLS,
  TLS_CLI_OPENSSL,
  TLS_LIB_GNUTLS
};

static enum tls_tool use_tls_tool;

#if defined(HTTPS_SUPPORT) && defined(HAVE_FORK) && defined(HAVE_WAITPID)
/**
 * Fork child that connects via GnuTLS-CLI to our @a port.  Allows us to
 * talk to our port over a socket in @a sp without having to worry
 * about TLS.
 *
 * @param location where the socket is returned
 * @return -1 on error, otherwise PID of TLS child process
 */
static pid_t
gnutlscli_connect (int *sock,
                   uint16_t port)
{
  pid_t chld;
  int sp[2];
  char destination[30];

  if (0 != socketpair (AF_UNIX,
                       SOCK_STREAM,
                       0,
                       sp))
  {
    testErrorLogDesc ("socketpair() failed");
    return (pid_t) -1;
  }
  chld = fork ();
  if (0 != chld)
  {
    *sock = sp[1];
    MHD_socket_close_chk_ (sp[0]);
    return chld;
  }
  MHD_socket_close_chk_ (sp[1]);
  (void) close (0);
  (void) close (1);
  if (-1 == dup2 (sp[0], 0))
    externalErrorExitDesc ("dup2() failed");
  if (-1 == dup2 (sp[0], 1))
    externalErrorExitDesc ("dup2() failed");
  MHD_socket_close_chk_ (sp[0]);
  if (TLS_CLI_GNUTLS == use_tls_tool)
  {
    snprintf (destination,
              sizeof(destination),
              "%u",
              (unsigned int) port);
    execlp ("gnutls-cli",
            "gnutls-cli",
            "--insecure",
            "-p",
            destination,
            "127.0.0.1",
            (char *) NULL);
  }
  else if (TLS_CLI_OPENSSL == use_tls_tool)
  {
    snprintf (destination,
              sizeof(destination),
              "127.0.0.1:%u",
              (unsigned int) port);
    execlp ("openssl",
            "openssl",
            "s_client",
            "-connect",
            destination,
            "-verify",
            "1",
            (char *) NULL);
  }
  _exit (1);
}


#endif /* HTTPS_SUPPORT && HAVE_FORK && HAVE_WAITPID */


/**
 * Wrapper structure for plain&TLS sockets
 */
struct wr_socket
{
  /**
   * Real network socket
   */
  MHD_socket fd;

  /**
   * Type of this socket
   */
  enum wr_type
  {
    wr_invalid = 0,
    wr_plain = 1,
    wr_tls = 2
  } t;
#ifdef HTTPS_SUPPORT
  /**
   * TLS credentials
   */
  gnutls_certificate_credentials_t tls_crd;

  /**
   * TLS session.
   */
  gnutls_session_t tls_s;

  /**
   * TLS handshake already succeed?
   */
  bool tls_connected;
#endif
};


/**
 * Get underlying real socket.
 * @return FD of real socket
 */
#define wr_fd(s) ((s)->fd)


/**
 * Create wr_socket with plain TCP underlying socket
 * @return created socket on success, NULL otherwise
 */
static struct wr_socket *
wr_create_plain_sckt (void)
{
  struct wr_socket *s = malloc (sizeof(struct wr_socket));
  if (NULL == s)
  {
    testErrorLogDesc ("malloc() failed");
    return NULL;
  }
  s->t = wr_plain;
  s->fd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (MHD_INVALID_SOCKET != s->fd)
    return s; /* Success */
  testErrorLogDesc ("socket() failed");
  free (s);
  return NULL;
}


/**
 * Create wr_socket with TLS TCP underlying socket
 * @return created socket on success, NULL otherwise
 */
static struct wr_socket *
wr_create_tls_sckt (void)
{
#ifdef HTTPS_SUPPORT
  struct wr_socket *s = malloc (sizeof(struct wr_socket));
  if (NULL == s)
  {
    testErrorLogDesc ("malloc() failed");
    return NULL;
  }
  s->t = wr_tls;
  s->tls_connected = 0;
  s->fd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (MHD_INVALID_SOCKET != s->fd)
  {
    if (GNUTLS_E_SUCCESS == gnutls_init (&(s->tls_s), GNUTLS_CLIENT))
    {
      if (GNUTLS_E_SUCCESS == gnutls_set_default_priority (s->tls_s))
      {
        if (GNUTLS_E_SUCCESS ==
            gnutls_certificate_allocate_credentials (&(s->tls_crd)))
        {
          if (GNUTLS_E_SUCCESS == gnutls_credentials_set (s->tls_s,
                                                          GNUTLS_CRD_CERTIFICATE,
                                                          s->tls_crd))
          {
#if (GNUTLS_VERSION_NUMBER + 0 >= 0x030109) && ! defined(_WIN64)
            gnutls_transport_set_int (s->tls_s, (int) (s->fd));
#else  /* GnuTLS before 3.1.9 or Win x64 */
            gnutls_transport_set_ptr (s->tls_s,
                                      (gnutls_transport_ptr_t) (intptr_t) (s->fd));
#endif /* GnuTLS before 3.1.9 or Win x64 */
            return s;
          }
          else
            testErrorLogDesc ("gnutls_credentials_set() failed");
          gnutls_certificate_free_credentials (s->tls_crd);
        }
        else
          testErrorLogDesc ("gnutls_certificate_allocate_credentials() failed");
      }
      else
        testErrorLogDesc ("gnutls_set_default_priority() failed");
      gnutls_deinit (s->tls_s);
    }
    else
      testErrorLogDesc ("gnutls_init() failed");
    (void) MHD_socket_close_ (s->fd);
  }
  else
    testErrorLogDesc ("socket() failed");
  free (s);
#endif /* HTTPS_SUPPORT */
  return NULL;
}


/**
 * Create wr_socket with plain TCP underlying socket
 * from already created TCP socket.
 * @param plain_sk real TCP socket
 * @return created socket on success, NULL otherwise
 */
static struct wr_socket *
wr_create_from_plain_sckt (MHD_socket plain_sk)
{
  struct wr_socket *s = malloc (sizeof(struct wr_socket));

  if (NULL == s)
  {
    testErrorLogDesc ("malloc() failed");
    return NULL;
  }
  s->t = wr_plain;
  s->fd = plain_sk;
  return s;
}


/**
 * Connect socket to specified address.
 * @param s socket to use
 * @param addr address to connect
 * @param length of structure pointed by @a addr
 * @return zero on success, -1 otherwise.
 */
static int
wr_connect (struct wr_socket *s,
            const struct sockaddr *addr,
            unsigned int length)
{
  if (0 != connect (s->fd, addr, (socklen_t) length))
  {
    testErrorLogDesc ("connect() failed");
    return -1;
  }
  if (wr_plain == s->t)
    return 0;
#ifdef HTTPS_SUPPORT
  if (wr_tls == s->t)
  {
    /* Do not try handshake here as
     * it require processing on MHD side and
     * when testing with "external" polling,
     * test will call MHD processing only
     * after return from wr_connect(). */
    s->tls_connected = 0;
    return 0;
  }
#endif /* HTTPS_SUPPORT */
  testErrorLogDesc ("HTTPS socket connect called, but code does not support" \
                    " HTTPS sockets");
  return -1;
}


#ifdef HTTPS_SUPPORT
/* Only to be called from wr_send() and wr_recv() ! */
static bool
wr_handshake (struct wr_socket *s)
{
  int res = gnutls_handshake (s->tls_s);
  if (GNUTLS_E_SUCCESS == res)
    s->tls_connected = true;
  else if (GNUTLS_E_AGAIN == res)
    MHD_socket_set_error_ (MHD_SCKT_EAGAIN_);
  else
  {
    testErrorLogDesc ("gnutls_handshake() failed with hard error");
    MHD_socket_set_error_ (MHD_SCKT_ECONNABORTED_); /* hard error */
  }
  return s->tls_connected;
}


#endif /* HTTPS_SUPPORT */


/**
 * Send data to remote by socket.
 * @param s the socket to use
 * @param buf the buffer with data to send
 * @param len the length of data in @a buf
 * @return number of bytes were sent if succeed,
 *         -1 if failed. Use #MHD_socket_get_error_()
 *         to get socket error.
 */
static ssize_t
wr_send (struct wr_socket *s,
         const void *buf,
         size_t len)
{
  if (wr_plain == s->t)
    return MHD_send_ (s->fd, buf, len);
#ifdef HTTPS_SUPPORT
  if (wr_tls == s->t)
  {
    ssize_t ret;
    if (! s->tls_connected && ! wr_handshake (s))
      return -1;

    ret = gnutls_record_send (s->tls_s, buf, len);
    if (ret > 0)
      return ret;
    if (GNUTLS_E_AGAIN == ret)
      MHD_socket_set_error_ (MHD_SCKT_EAGAIN_);
    else
    {
      testErrorLogDesc ("gnutls_record_send() failed with hard error");
      MHD_socket_set_error_ (MHD_SCKT_ECONNABORTED_);   /* hard error */
      return -1;
    }
  }
#endif /* HTTPS_SUPPORT */
  testErrorLogDesc ("HTTPS socket send called, but code does not support" \
                    " HTTPS sockets");
  return -1;
}


/**
 * Receive data from remote by socket.
 * @param s the socket to use
 * @param buf the buffer to store received data
 * @param len the length of @a buf
 * @return number of bytes were received if succeed,
 *         -1 if failed. Use #MHD_socket_get_error_()
 *         to get socket error.
 */
static ssize_t
wr_recv (struct wr_socket *s,
         void *buf,
         size_t len)
{
  if (wr_plain == s->t)
    return MHD_recv_ (s->fd, buf, len);
#ifdef HTTPS_SUPPORT
  if (wr_tls == s->t)
  {
    ssize_t ret;
    if (! s->tls_connected && ! wr_handshake (s))
      return -1;

    ret = gnutls_record_recv (s->tls_s, buf, len);
    if (ret > 0)
      return ret;
    if (GNUTLS_E_AGAIN == ret)
      MHD_socket_set_error_ (MHD_SCKT_EAGAIN_);
    else
    {
      testErrorLogDesc ("gnutls_record_recv() failed with hard error");
      MHD_socket_set_error_ (MHD_SCKT_ECONNABORTED_);   /* hard error */
      return -1;
    }
  }
#endif /* HTTPS_SUPPORT */
  return -1;
}


/**
 * Close socket and release allocated resourced
 * @param s the socket to close
 * @return zero on succeed, -1 otherwise
 */
static int
wr_close (struct wr_socket *s)
{
  int ret = (MHD_socket_close_ (s->fd)) ? 0 : -1;
#ifdef HTTPS_SUPPORT
  if (wr_tls == s->t)
  {
    gnutls_deinit (s->tls_s);
    gnutls_certificate_free_credentials (s->tls_crd);
  }
#endif /* HTTPS_SUPPORT */
  free (s);
  return ret;
}


/**
 * Thread we use to run the interaction with the upgraded socket.
 */
static pthread_t pt;

/**
 * Will be set to the upgraded socket.
 */
static struct wr_socket *volatile usock;

/**
 * Thread we use to run the interaction with the upgraded socket.
 */
static pthread_t pt_client;

/**
 * Flag set to 1 once the test is finished.
 */
static volatile bool done;


static const char *
term_reason_str (enum MHD_RequestTerminationCode term_code)
{
  switch ((int) term_code)
  {
  case MHD_REQUEST_TERMINATED_COMPLETED_OK:
    return "COMPLETED_OK";
  case MHD_REQUEST_TERMINATED_WITH_ERROR:
    return "TERMINATED_WITH_ERROR";
  case MHD_REQUEST_TERMINATED_TIMEOUT_REACHED:
    return "TIMEOUT_REACHED";
  case MHD_REQUEST_TERMINATED_DAEMON_SHUTDOWN:
    return "DAEMON_SHUTDOWN";
  case MHD_REQUEST_TERMINATED_READ_ERROR:
    return "READ_ERROR";
  case MHD_REQUEST_TERMINATED_CLIENT_ABORT:
    return "CLIENT_ABORT";
  case -1:
    return "(not called)";
  default:
    return "(unknown code)";
  }
  return "(problem)"; /* unreachable */
}


/**
 * Callback used by MHD to notify the application about completed
 * requests.  Frees memory.
 *
 * @param cls client-defined closure
 * @param connection connection handle
 * @param req_cls value as set by the last call to
 *        the #MHD_AccessHandlerCallback
 * @param toe reason for request termination
 */
static void
notify_completed_cb (void *cls,
                     struct MHD_Connection *connection,
                     void **req_cls,
                     enum MHD_RequestTerminationCode toe)
{
  (void) cls;
  (void) connection;  /* Unused. Silent compiler warning. */
  if (verbose)
    printf ("notify_completed_cb() has been called with '%s' code.\n",
            term_reason_str (toe));
  if ( (toe != MHD_REQUEST_TERMINATED_COMPLETED_OK) &&
       (toe != MHD_REQUEST_TERMINATED_CLIENT_ABORT) &&
       (toe != MHD_REQUEST_TERMINATED_DAEMON_SHUTDOWN) )
    mhdErrorExitDesc ("notify_completed_cb() called with wrong code");
  if (NULL == req_cls)
    mhdErrorExitDesc ("'req_cls' parameter is NULL");
  if (NULL == *req_cls)
    mhdErrorExitDesc ("'*req_cls' pointer is NULL");
  if (! pthread_equal (**((pthread_t **) req_cls),
                       pthread_self ()))
    mhdErrorExitDesc ("notify_completed_cb() is called in wrong thread");
  free (*req_cls);
  *req_cls = NULL;
}


/**
 * Logging callback.
 *
 * @param cls logging closure (NULL)
 * @param uri access URI
 * @param connection connection handle
 * @return #TEST_PTR
 */
static void *
log_cb (void *cls,
        const char *uri,
        struct MHD_Connection *connection)
{
  pthread_t *ppth;

  (void) cls;
  (void) connection;  /* Unused. Silent compiler warning. */
  if (NULL == uri)
    mhdErrorExitDesc ("The 'uri' parameter is NULL");
  if (0 != strcmp (uri, "/"))
  {
    fprintf (stderr, "Wrong 'uri' value: '%s'. ", uri);
    mhdErrorExit ();
  }
  ppth = malloc (sizeof (pthread_t));
  if (NULL == ppth)
    externalErrorExitDesc ("malloc() failed");
  *ppth = pthread_self ();
  return (void *) ppth;
}


/**
 * Function to check that MHD properly notifies about starting
 * and stopping.
 *
 * @param cls client-defined closure
 * @param connection connection handle
 * @param socket_context socket-specific pointer where the
 *                       client can associate some state specific
 *                       to the TCP connection; note that this is
 *                       different from the "req_cls" which is per
 *                       HTTP request.  The client can initialize
 *                       during #MHD_CONNECTION_NOTIFY_STARTED and
 *                       cleanup during #MHD_CONNECTION_NOTIFY_CLOSED
 *                       and access in the meantime using
 *                       #MHD_CONNECTION_INFO_SOCKET_CONTEXT.
 * @param toe reason for connection notification
 * @see #MHD_OPTION_NOTIFY_CONNECTION
 * @ingroup request
 */
static void
notify_connection_cb (void *cls,
                      struct MHD_Connection *connection,
                      void **socket_context,
                      enum MHD_ConnectionNotificationCode toe)
{
  static int started = MHD_NO;

  (void) cls;
  (void) connection;  /* Unused. Silent compiler warning. */
  switch (toe)
  {
  case MHD_CONNECTION_NOTIFY_STARTED:
    if (MHD_NO != started)
      mhdErrorExitDesc ("The connection has been already started");
    started = MHD_YES;
    *socket_context = &started;
    break;
  case MHD_CONNECTION_NOTIFY_CLOSED:
    if (MHD_YES != started)
      mhdErrorExitDesc ("The connection has not been started before");
    if (&started != *socket_context)
      mhdErrorExitDesc ("Wrong '*socket_context' value");
    *socket_context = NULL;
    started = MHD_NO;
    break;
  }
}


/**
 * Change socket to blocking.
 *
 * @param fd the socket to manipulate
 */
static void
make_blocking (MHD_socket fd)
{
#if defined(MHD_POSIX_SOCKETS)
  int flags;

  flags = fcntl (fd, F_GETFL);
  if (-1 == flags)
    externalErrorExitDesc ("fcntl() failed");
  if ((flags & ~O_NONBLOCK) != flags)
    if (-1 == fcntl (fd, F_SETFL, flags & ~O_NONBLOCK))
      externalErrorExitDesc ("fcntl() failed");
#elif defined(MHD_WINSOCK_SOCKETS)
  unsigned long flags = 0;

  if (0 != ioctlsocket (fd, (int) FIONBIO, &flags))
    externalErrorExitDesc ("ioctlsocket() failed");
#endif /* MHD_WINSOCK_SOCKETS */

}


static void
send_all (struct wr_socket *sock,
          const char *text)
{
  size_t len = strlen (text);
  ssize_t ret;
  size_t off;

  make_blocking (wr_fd (sock));
  for (off = 0; off < len; off += (size_t) ret)
  {
    ret = wr_send (sock,
                   &text[off],
                   len - off);
    if (0 > ret)
    {
      if (MHD_SCKT_ERR_IS_EAGAIN_ (MHD_socket_get_error_ ()) ||
          MHD_SCKT_ERR_IS_EINTR_ (MHD_socket_get_error_ ()))
      {
        ret = 0;
        continue;
      }
      externalErrorExitDesc ("send() failed");
    }
  }
}


/**
 * Read character-by-character until we
 * get 'CRLNCRLN'.
 */
static void
recv_hdr (struct wr_socket *sock)
{
  unsigned int i;
  char next;
  char c;
  ssize_t ret;

  make_blocking (wr_fd (sock));
  next = '\r';
  i = 0;
  while (i < 4)
  {
    ret = wr_recv (sock,
                   &c,
                   1);
    if (0 > ret)
    {
      if (MHD_SCKT_ERR_IS_EAGAIN_ (MHD_socket_get_error_ ()))
        continue;
      if (MHD_SCKT_ERR_IS_EINTR_ (MHD_socket_get_error_ ()))
        continue;
      externalErrorExitDesc ("recv() failed");
    }
    if (0 == ret)
      mhdErrorExitDesc ("The server unexpectedly closed connection");
    if (c == next)
    {
      i++;
      if (next == '\r')
        next = '\n';
      else
        next = '\r';
      continue;
    }
    if (c == '\r')
    {
      i = 1;
      next = '\n';
      continue;
    }
    i = 0;
    next = '\r';
  }
}


static void
recv_all (struct wr_socket *sock,
          const char *text)
{
  size_t len = strlen (text);
  char buf[len];
  ssize_t ret;
  size_t off;

  make_blocking (wr_fd (sock));
  for (off = 0; off < len; off += (size_t) ret)
  {
    ret = wr_recv (sock,
                   &buf[off],
                   len - off);
    if (0 > ret)
    {
      if (MHD_SCKT_ERR_IS_EAGAIN_ (MHD_socket_get_error_ ()) ||
          MHD_SCKT_ERR_IS_EINTR_ (MHD_socket_get_error_ ()))
      {
        ret = 0;
        continue;
      }
      externalErrorExitDesc ("recv() failed");
    }
    if (0 == ret)
      mhdErrorExitDesc ("The server unexpectedly closed connection");
  }
  if (0 != strncmp (text, buf, len))
  {
    fprintf (stderr, "Wrong received text. Expected: '%s' ."
             "Got: '%.*s'. ", text, (int) len, buf);
    mhdErrorExit ();
  }
}


/**
 * Main function for the thread that runs the interaction with
 * the upgraded socket.
 *
 * @param cls the handle for the upgrade
 */
static void *
run_usock (void *cls)
{
  struct MHD_UpgradeResponseHandle *urh = cls;

  send_all (usock,
            "Hello");
  recv_all (usock,
            "World");
  send_all (usock,
            "Finished");
  MHD_upgrade_action (urh,
                      MHD_UPGRADE_ACTION_CLOSE);
  free (usock);
  usock = NULL;
  return NULL;
}


/**
 * Main function for the thread that runs the client-side of the
 * interaction with the upgraded socket.
 *
 * @param cls the client socket
 */
static void *
run_usock_client (void *cls)
{
  struct wr_socket *sock = cls;

  send_all (sock,
            "GET / HTTP/1.1\r\nHost: localhost\r\nConnection: Upgrade\r\n\r\n");
  recv_hdr (sock);
  recv_all (sock,
            "Hello");
  send_all (sock,
            "World");
  recv_all (sock,
            "Finished");
  wr_close (sock);
  done = true;
  return NULL;
}


/**
 * Function called after a protocol "upgrade" response was sent
 * successfully and the socket should now be controlled by some
 * protocol other than HTTP.
 *
 * Any data already received on the socket will be made available in
 * @e extra_in.  This can happen if the application sent extra data
 * before MHD send the upgrade response.  The application should
 * treat data from @a extra_in as if it had read it from the socket.
 *
 * Note that the application must not close() @a sock directly,
 * but instead use #MHD_upgrade_action() for special operations
 * on @a sock.
 *
 * Except when in 'thread-per-connection' mode, implementations
 * of this function should never block (as it will still be called
 * from within the main event loop).
 *
 * @param cls closure, whatever was given to #MHD_create_response_for_upgrade().
 * @param connection original HTTP connection handle,
 *                   giving the function a last chance
 *                   to inspect the original HTTP request
 * @param req_cls last value left in `req_cls` of the `MHD_AccessHandlerCallback`
 * @param extra_in if we happened to have read bytes after the
 *                 HTTP header already (because the client sent
 *                 more than the HTTP header of the request before
 *                 we sent the upgrade response),
 *                 these are the extra bytes already read from @a sock
 *                 by MHD.  The application should treat these as if
 *                 it had read them from @a sock.
 * @param extra_in_size number of bytes in @a extra_in
 * @param sock socket to use for bi-directional communication
 *        with the client.  For HTTPS, this may not be a socket
 *        that is directly connected to the client and thus certain
 *        operations (TCP-specific setsockopt(), getsockopt(), etc.)
 *        may not work as expected (as the socket could be from a
 *        socketpair() or a TCP-loopback).  The application is expected
 *        to perform read()/recv() and write()/send() calls on the socket.
 *        The application may also call shutdown(), but must not call
 *        close() directly.
 * @param urh argument for #MHD_upgrade_action()s on this @a connection.
 *        Applications must eventually use this callback to (indirectly)
 *        perform the close() action on the @a sock.
 */
static void
upgrade_cb (void *cls,
            struct MHD_Connection *connection,
            void *req_cls,
            const char *extra_in,
            size_t extra_in_size,
            MHD_socket sock,
            struct MHD_UpgradeResponseHandle *urh)
{
  (void) cls;
  (void) connection;
  (void) req_cls;
  (void) extra_in; /* Unused. Silent compiler warning. */

  usock = wr_create_from_plain_sckt (sock);
  if (0 != extra_in_size)
    mhdErrorExitDesc ("'extra_in_size' is not zero");
  if (0 != pthread_create (&pt,
                           NULL,
                           &run_usock,
                           urh))
    externalErrorExitDesc ("pthread_create() failed");
}


/**
 * A client has requested the given url using the given method
 * (#MHD_HTTP_METHOD_GET, #MHD_HTTP_METHOD_PUT,
 * #MHD_HTTP_METHOD_DELETE, #MHD_HTTP_METHOD_POST, etc).  The callback
 * must call MHD callbacks to provide content to give back to the
 * client and return an HTTP status code (i.e. #MHD_HTTP_OK,
 * #MHD_HTTP_NOT_FOUND, etc.).
 *
 * @param cls argument given together with the function
 *        pointer when the handler was registered with MHD
 * @param url the requested url
 * @param method the HTTP method used (#MHD_HTTP_METHOD_GET,
 *        #MHD_HTTP_METHOD_PUT, etc.)
 * @param version the HTTP version string (i.e.
 *        #MHD_HTTP_VERSION_1_1)
 * @param upload_data the data being uploaded (excluding HEADERS,
 *        for a POST that fits into memory and that is encoded
 *        with a supported encoding, the POST data will NOT be
 *        given in upload_data and is instead available as
 *        part of #MHD_get_connection_values; very large POST
 *        data *will* be made available incrementally in
 *        @a upload_data)
 * @param upload_data_size set initially to the size of the
 *        @a upload_data provided; the method must update this
 *        value to the number of bytes NOT processed;
 * @param req_cls pointer that the callback can set to some
 *        address and that will be preserved by MHD for future
 *        calls for this request; since the access handler may
 *        be called many times (i.e., for a PUT/POST operation
 *        with plenty of upload data) this allows the application
 *        to easily associate some request-specific state.
 *        If necessary, this state can be cleaned up in the
 *        global #MHD_RequestCompletedCallback (which
 *        can be set with the #MHD_OPTION_NOTIFY_COMPLETED).
 *        Initially, `*req_cls` will be NULL.
 * @return #MHD_YES if the connection was handled successfully,
 *         #MHD_NO if the socket must be closed due to a serious
 *         error while handling the request
 */
static enum MHD_Result
ahc_upgrade (void *cls,
             struct MHD_Connection *connection,
             const char *url,
             const char *method,
             const char *version,
             const char *upload_data,
             size_t *upload_data_size,
             void **req_cls)
{
  struct MHD_Response *resp;
  (void) cls;
  (void) url;
  (void) method;                        /* Unused. Silent compiler warning. */
  (void) version;
  (void) upload_data;
  (void) upload_data_size;  /* Unused. Silent compiler warning. */

  if (NULL == req_cls)
    mhdErrorExitDesc ("'req_cls' is NULL");
  if (NULL == *req_cls)
    mhdErrorExitDesc ("'*req_cls' value is NULL");
  if (! pthread_equal (**((pthread_t **) req_cls), pthread_self ()))
    mhdErrorExitDesc ("ahc_upgrade() is called in wrong thread");
  resp = MHD_create_response_for_upgrade (&upgrade_cb,
                                          NULL);
  if (NULL == resp)
    mhdErrorExitDesc ("MHD_create_response_for_upgrade() failed");
  if (MHD_YES != MHD_add_response_header (resp,
                                          MHD_HTTP_HEADER_UPGRADE,
                                          "Hello World Protocol"))
    mhdErrorExitDesc ("MHD_add_response_header() failed");
  if (MHD_YES != MHD_queue_response (connection,
                                     MHD_HTTP_SWITCHING_PROTOCOLS,
                                     resp))
    mhdErrorExitDesc ("MHD_queue_response() failed");
  MHD_destroy_response (resp);
  return MHD_YES;
}


/**
 * Run the MHD external event loop using select.
 *
 * @param daemon daemon to run it for
 */
static void
run_mhd_select_loop (struct MHD_Daemon *daemon)
{
  fd_set rs;
  fd_set ws;
  fd_set es;
  MHD_socket max_fd;
  uint64_t to64;
  struct timeval tv;

  while (! done)
  {
    FD_ZERO (&rs);
    FD_ZERO (&ws);
    FD_ZERO (&es);
    max_fd = MHD_INVALID_SOCKET;
    to64 = 1000;

    if (MHD_YES !=
        MHD_get_fdset (daemon,
                       &rs,
                       &ws,
                       &es,
                       &max_fd))
      mhdErrorExitDesc ("MHD_get_fdset() failed");
    (void) MHD_get_timeout64 (daemon,
                              &to64);
    if (1000 < to64)
      to64 = 1000;
#if ! defined(_WIN32) || defined(__CYGWIN__)
    tv.tv_sec = (time_t) (to64 / 1000);
#else  /* Native W32 */
    tv.tv_sec = (long) (to64 / 1000);
#endif /* Native W32 */
    tv.tv_usec = (long) (1000 * (to64 % 1000));
    if (0 > MHD_SYS_select_ (max_fd + 1,
                             &rs,
                             &ws,
                             &es,
                             &tv))
    {
#ifdef MHD_POSIX_SOCKETS
      if (EINTR != errno)
        externalErrorExitDesc ("Unexpected select() error");
#else
      if ((WSAEINVAL != WSAGetLastError ()) ||
          (0 != rs.fd_count) || (0 != ws.fd_count) || (0 != es.fd_count) )
        externalErrorExitDesc ("Unexpected select() error");
      Sleep ((DWORD) (tv.tv_sec * 1000 + tv.tv_usec / 1000));
#endif
    }
    MHD_run_from_select (daemon,
                         &rs,
                         &ws,
                         &es);
  }
}


#ifdef HAVE_POLL

/**
 * Run the MHD external event loop using select.
 *
 * @param daemon daemon to run it for
 */
_MHD_NORETURN static void
run_mhd_poll_loop (struct MHD_Daemon *daemon)
{
  (void) daemon; /* Unused. Silent compiler warning. */
  externalErrorExitDesc ("Not implementable with MHD API");
}


#endif /* HAVE_POLL */


#ifdef EPOLL_SUPPORT
/**
 * Run the MHD external event loop using select.
 *
 * @param daemon daemon to run it for
 */
static void
run_mhd_epoll_loop (struct MHD_Daemon *daemon)
{
  const union MHD_DaemonInfo *di;
  MHD_socket ep;
  fd_set rs;
  uint64_t to64;
  struct timeval tv;
  int ret;

  di = MHD_get_daemon_info (daemon,
                            MHD_DAEMON_INFO_EPOLL_FD);
  if (NULL == di)
    mhdErrorExitDesc ("MHD_get_daemon_info() failed");
  ep = di->listen_fd;
  while (! done)
  {
    FD_ZERO (&rs);
    to64 = 1000;

    FD_SET (ep, &rs);
    (void) MHD_get_timeout64 (daemon,
                              &to64);
    if (1000 < to64)
      to64 = 1000;
#if ! defined(_WIN32) || defined(__CYGWIN__)
    tv.tv_sec = (time_t) (to64 / 1000);
#else  /* Native W32 */
    tv.tv_sec = (long) (to64 / 1000);
#endif /* Native W32 */
    tv.tv_usec = (int) (1000 * (to64 % 1000));
    ret = select (ep + 1,
                  &rs,
                  NULL,
                  NULL,
                  &tv);
    if (0 > ret)
    {
#ifdef MHD_POSIX_SOCKETS
      if (EINTR != errno)
        externalErrorExitDesc ("Unexpected select() error");
#else
      if ((WSAEINVAL != WSAGetLastError ()) ||
          (0 != rs.fd_count) || (0 != ws.fd_count) || (0 != es.fd_count) )
        externalErrorExitDesc ("Unexpected select() error");
      Sleep (tv.tv_sec * 1000 + tv.tv_usec / 1000);
#endif
    }
    MHD_run (daemon);
  }
}


#endif /* EPOLL_SUPPORT */

/**
 * Run the MHD external event loop using select.
 *
 * @param daemon daemon to run it for
 */
static void
run_mhd_loop (struct MHD_Daemon *daemon,
              unsigned int flags)
{
  if (0 == (flags & (MHD_USE_POLL | MHD_USE_EPOLL)))
    run_mhd_select_loop (daemon);
#ifdef HAVE_POLL
  else if (0 != (flags & MHD_USE_POLL))
    run_mhd_poll_loop (daemon);
#endif /* HAVE_POLL */
#ifdef EPOLL_SUPPORT
  else if (0 != (flags & MHD_USE_EPOLL))
    run_mhd_epoll_loop (daemon);
#endif
  else
    externalErrorExitDesc ("Wrong 'flags' value");
}


static bool test_tls;

/**
 * Test upgrading a connection.
 *
 * @param flags which event loop style should be tested
 * @param pool size of the thread pool, 0 to disable
 */
static unsigned int
test_upgrade (unsigned int flags,
              unsigned int pool)
{
  struct MHD_Daemon *d = NULL;
  struct wr_socket *sock;
  struct sockaddr_in sa;
  enum MHD_FLAG used_flags;
  const union MHD_DaemonInfo *dinfo;
#if defined(HTTPS_SUPPORT) && defined(HAVE_FORK) && defined(HAVE_WAITPID)
  pid_t pid = -1;
#endif /* HTTPS_SUPPORT && HAVE_FORK && HAVE_WAITPID */

  done = false;

  if (! test_tls)
    d = MHD_start_daemon (flags | MHD_USE_ERROR_LOG | MHD_ALLOW_UPGRADE,
                          global_port,
                          NULL, NULL,
                          &ahc_upgrade, NULL,
                          MHD_OPTION_URI_LOG_CALLBACK, &log_cb, NULL,
                          MHD_OPTION_NOTIFY_COMPLETED, &notify_completed_cb,
                          NULL,
                          MHD_OPTION_NOTIFY_CONNECTION, &notify_connection_cb,
                          NULL,
                          MHD_OPTION_THREAD_POOL_SIZE, pool,
                          MHD_OPTION_END);
#ifdef HTTPS_SUPPORT
  else
    d = MHD_start_daemon (flags | MHD_USE_ERROR_LOG | MHD_ALLOW_UPGRADE
                          | MHD_USE_TLS,
                          global_port,
                          NULL, NULL,
                          &ahc_upgrade, NULL,
                          MHD_OPTION_URI_LOG_CALLBACK, &log_cb, NULL,
                          MHD_OPTION_NOTIFY_COMPLETED, &notify_completed_cb,
                          NULL,
                          MHD_OPTION_NOTIFY_CONNECTION, &notify_connection_cb,
                          NULL,
                          MHD_OPTION_HTTPS_MEM_KEY, srv_signed_key_pem,
                          MHD_OPTION_HTTPS_MEM_CERT, srv_signed_cert_pem,
                          MHD_OPTION_THREAD_POOL_SIZE, pool,
                          MHD_OPTION_END);
#endif /* HTTPS_SUPPORT */
  if (NULL == d)
    mhdErrorExitDesc ("MHD_start_daemon() failed");
  dinfo = MHD_get_daemon_info (d,
                               MHD_DAEMON_INFO_FLAGS);
  if (NULL == dinfo)
    mhdErrorExitDesc ("MHD_get_daemon_info() failed");
  used_flags = dinfo->flags;
  dinfo = MHD_get_daemon_info (d,
                               MHD_DAEMON_INFO_BIND_PORT);
  if ( (NULL == dinfo) ||
       (0 == dinfo->port) )
    mhdErrorExitDesc ("MHD_get_daemon_info() failed");
  global_port = dinfo->port; /* Re-use the same port for the next checks */
  if (! test_tls || (TLS_LIB_GNUTLS == use_tls_tool))
  {
    sock = test_tls ? wr_create_tls_sckt () : wr_create_plain_sckt ();
    if (NULL == sock)
      externalErrorExitDesc ("Create socket failed");
    sa.sin_family = AF_INET;
    sa.sin_port = htons (dinfo->port);
    sa.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
    if (0 != wr_connect (sock,
                         (struct sockaddr *) &sa,
                         sizeof (sa)))
      externalErrorExitDesc ("Connect socket failed");
  }
  else
  {
#if defined(HTTPS_SUPPORT) && defined(HAVE_FORK) && defined(HAVE_WAITPID)
    MHD_socket tls_fork_sock;
    uint16_t port;

    port = dinfo->port;
    if (-1 == (pid = gnutlscli_connect (&tls_fork_sock,
                                        port)))
      externalErrorExitDesc ("gnutlscli_connect() failed");

    sock =  wr_create_from_plain_sckt (tls_fork_sock);
    if (NULL == sock)
      externalErrorExitDesc ("wr_create_from_plain_sckt() failed");
#else  /* !HTTPS_SUPPORT || !HAVE_FORK || !HAVE_WAITPID */
    externalErrorExitDesc ("Unsupported 'use_tls_tool' value");
#endif /* !HTTPS_SUPPORT || !HAVE_FORK || !HAVE_WAITPID */
  }

  if (0 != pthread_create (&pt_client,
                           NULL,
                           &run_usock_client,
                           sock))
    externalErrorExitDesc ("pthread_create() failed");
  if (0 == (flags & MHD_USE_INTERNAL_POLLING_THREAD) )
    run_mhd_loop (d, used_flags);
  if (0 != pthread_join (pt_client,
                         NULL))
    externalErrorExitDesc ("pthread_join() failed");
  if (0 != pthread_join (pt,
                         NULL))
    externalErrorExitDesc ("pthread_join() failed");
#if defined(HTTPS_SUPPORT) && defined(HAVE_FORK) && defined(HAVE_WAITPID)
  if (test_tls && (TLS_LIB_GNUTLS != use_tls_tool))
  {
    if ((pid_t) -1 == waitpid (pid, NULL, 0))
      externalErrorExitDesc ("waitpid() failed");
  }
#endif /* HTTPS_SUPPORT && HAVE_FORK && HAVE_WAITPID */
  MHD_stop_daemon (d);
  return 0;
}


int
main (int argc,
      char *const *argv)
{
  unsigned int error_count = 0;
  unsigned int res;

  use_tls_tool = TLS_CLI_NO_TOOL;
  test_tls = has_in_name (argv[0], "_tls");

  verbose = ! (has_param (argc, argv, "-q") ||
               has_param (argc, argv, "--quiet") ||
               has_param (argc, argv, "-s") ||
               has_param (argc, argv, "--silent"));

  if (test_tls)
  {
    use_tls_tool = TLS_LIB_GNUTLS;   /* Should be always available as MHD uses it. */
#ifdef HTTPS_SUPPORT
    if (has_param (argc, argv, "--use-gnutls-cli"))
      use_tls_tool = TLS_CLI_GNUTLS;
    else if (has_param (argc, argv, "--use-openssl"))
      use_tls_tool = TLS_CLI_OPENSSL;
    else if (has_param (argc, argv, "--use-gnutls-lib"))
      use_tls_tool = TLS_LIB_GNUTLS;
#if defined(HAVE_FORK) && defined(HAVE_WAITPID)
    else if (0 == system ("gnutls-cli --version 1> /dev/null 2> /dev/null"))
      use_tls_tool = TLS_CLI_GNUTLS;
    else if (0 == system ("openssl version 1> /dev/null 2> /dev/null"))
      use_tls_tool = TLS_CLI_OPENSSL;
#endif /* HAVE_FORK && HAVE_WAITPID */
    if (verbose)
    {
      switch (use_tls_tool)
      {
      case TLS_CLI_GNUTLS:
        printf ("GnuTLS-CLI will be used for testing.\n");
        break;
      case TLS_CLI_OPENSSL:
        printf ("Command line version of OpenSSL will be used for testing.\n");
        break;
      case TLS_LIB_GNUTLS:
        printf ("GnuTLS library will be used for testing.\n");
        break;
      case TLS_CLI_NO_TOOL:
      default:
        externalErrorExitDesc ("Wrong 'use_tls_tool' value");
      }
    }
    if ( (TLS_LIB_GNUTLS == use_tls_tool) &&
         (GNUTLS_E_SUCCESS != gnutls_global_init ()) )
      externalErrorExitDesc ("gnutls_global_init() failed");

#else  /* ! HTTPS_SUPPORT */
    fprintf (stderr, "HTTPS support was disabled by configure.\n");
    return 77;
#endif /* ! HTTPS_SUPPORT */
  }

  global_port = MHD_is_feature_supported (MHD_FEATURE_AUTODETECT_BIND_PORT) ?
                0 : (test_tls ? 1091 : 1090);

  /* run tests */
  if (verbose)
    printf ("Starting HTTP \"Upgrade\" tests with %s connections.\n",
            test_tls ? "TLS" : "plain");
  /* try external select */
  res = test_upgrade (0,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with external select, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with external select.\n");

  /* Try external auto */
  res = test_upgrade (MHD_USE_AUTO,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with external 'auto', return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with external 'auto'.\n");

#ifdef EPOLL_SUPPORT
  res = test_upgrade (MHD_USE_EPOLL,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with external select with EPOLL, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with external select with EPOLL.\n");
#endif

  /* Test thread-per-connection */
  res = test_upgrade (MHD_USE_INTERNAL_POLLING_THREAD
                      | MHD_USE_THREAD_PER_CONNECTION,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with thread per connection, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with thread per connection.\n");

  res = test_upgrade (MHD_USE_AUTO | MHD_USE_INTERNAL_POLLING_THREAD
                      | MHD_USE_THREAD_PER_CONNECTION,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with thread per connection and 'auto', return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with thread per connection and 'auto'.\n");
#ifdef HAVE_POLL
  res = test_upgrade (MHD_USE_INTERNAL_POLLING_THREAD
                      | MHD_USE_THREAD_PER_CONNECTION | MHD_USE_POLL,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with thread per connection and poll, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with thread per connection and poll.\n");
#endif /* HAVE_POLL */

  /* Test different event loops, with and without thread pool */
  res = test_upgrade (MHD_USE_INTERNAL_POLLING_THREAD,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal select, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal select.\n");
  res = test_upgrade (MHD_USE_INTERNAL_POLLING_THREAD,
                      2);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal select with thread pool, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal select with thread pool.\n");
  res = test_upgrade (MHD_USE_AUTO | MHD_USE_INTERNAL_POLLING_THREAD,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal 'auto' return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal 'auto'.\n");
  res = test_upgrade (MHD_USE_AUTO | MHD_USE_INTERNAL_POLLING_THREAD,
                      2);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal 'auto' with thread pool, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal 'auto' with thread pool.\n");
#ifdef HAVE_POLL
  res = test_upgrade (MHD_USE_POLL_INTERNAL_THREAD,
                      0);
  fflush_allstd ();
  error_count += res;
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal poll, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal poll.\n");
  res = test_upgrade (MHD_USE_POLL_INTERNAL_THREAD,
                      2);
  fflush_allstd ();
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal poll with thread pool, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal poll with thread pool.\n");
#endif
#ifdef EPOLL_SUPPORT
  res = test_upgrade (MHD_USE_EPOLL_INTERNAL_THREAD,
                      0);
  fflush_allstd ();
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal epoll, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal epoll.\n");
  res = test_upgrade (MHD_USE_EPOLL_INTERNAL_THREAD,
                      2);
  fflush_allstd ();
  if (res)
    fprintf (stderr,
             "FAILED: Upgrade with internal epoll, return code %u.\n",
             res);
  else if (verbose)
    printf ("PASSED: Upgrade with internal epoll.\n");
#endif
  /* report result */
  if (0 != error_count)
    fprintf (stderr,
             "Error (code: %u)\n",
             error_count);
#ifdef HTTPS_SUPPORT
  if (test_tls && (TLS_LIB_GNUTLS == use_tls_tool))
    gnutls_global_deinit ();
#endif /* HTTPS_SUPPORT */
  return error_count != 0;       /* 0 == pass */
}