/* logging.c - Useful logging functions

 * Copyright (C) 1998-2001, 2003-2006, 2009-2010,

 *               2017  Free Software Foundation, Inc.

 * Copyright (C) 1998-1999, 2001-2006, 2008-2017  Werner Koch

 *

 * This file is part of Libgpg-error.

 *

 * Libgpg-error is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * Libgpg-error 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this program; if not, see <https://www.gnu.org/licenses/>.

 * SPDX-License-Identifier: LGPL-2.1+

 *

 * This file was originally a part of GnuPG.

 */

#include <config.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <stdarg.h>

#include <stddef.h>

#include <errno.h>

#include <time.h>

#include <sys/types.h>

#include <sys/stat.h>

#ifdef HAVE_W32_SYSTEM

# ifdef HAVE_WINSOCK2_H

#  include <winsock2.h>

# endif

# include <windows.h>

#else /*!HAVE_W32_SYSTEM*/

# include <sys/socket.h>

# include <sys/un.h>

# include <netinet/in.h>

# include <arpa/inet.h>

#endif /*!HAVE_W32_SYSTEM*/

#include <unistd.h>

#include <fcntl.h>

#include <assert.h>

/* #include <execinfo.h> */

#define _GPGRT_NEED_AFLOCAL 1

#include "gpgrt-int.h"

#ifdef HAVE_W32_SYSTEM

# ifndef S_IRWXG

#  define S_IRGRP S_IRUSR

#  define S_IWGRP S_IWUSR

# endif

# ifndef S_IRWXO

#  define S_IROTH S_IRUSR

#  define S_IWOTH S_IWUSR

# endif

#endif

#ifdef HAVE_W32CE_SYSTEM

# define isatty(a)  (0)

#endif

#undef WITH_IPV6

#if defined (AF_INET6) && defined(PF_INET) \

    && defined (INET6_ADDRSTRLEN) && defined(HAVE_INET_PTON)

# define WITH_IPV6 1

#endif

#ifndef EAFNOSUPPORT

# define EAFNOSUPPORT EINVAL

#endif

#ifndef INADDR_NONE  /* Slowaris is missing that.  */

#define INADDR_NONE  ((unsigned long)(-1))

#endif /*INADDR_NONE*/

#ifdef HAVE_W32_SYSTEM

#define sock_close(a)  closesocket(a)

#else

#define sock_close(a)  close(a)

#endif

static estream_t logstream;

static int log_socket = -1;

static char prefix_buffer[80];

static int with_time;

static int with_prefix;

static int with_pid;

#ifdef HAVE_W32_SYSTEM

static int no_registry;

#endif

static int (*get_pid_suffix_cb)(unsigned long *r_value);

static const char * (*socket_dir_cb)(void);

static int running_detached;

static int force_prefixes;

static int missing_lf;

static int errorcount;

/* Get the error count as maintained by the log fucntions.  With CLEAR

 * set reset the counter.  */

int

_gpgrt_get_errorcount (int clear)

{

  int n = errorcount;

  if (clear)

    errorcount = 0;

  return n;

}

/* Increment the error count as maintainer by the log functions.  */

void

_gpgrt_inc_errorcount (void)

{

   errorcount++;

}

/* The following 3 functions are used by _gpgrt_fopencookie to write logs

   to a socket.  */

struct fun_cookie_s

{

  int fd;

  int quiet;

  int want_socket;

  int is_socket;

#ifdef HAVE_W32CE_SYSTEM

  int use_writefile;

#endif

  char name[1];

};

/* Write NBYTES of BUFFER to file descriptor FD. */

static int

writen (int fd, const void *buffer, size_t nbytes, int is_socket)

{

  const char *buf = buffer;

  size_t nleft = nbytes;

  int nwritten;

#ifndef HAVE_W32_SYSTEM

  (void)is_socket; /* Not required.  */

#endif

  while (nleft > 0)

    {

#ifdef HAVE_W32_SYSTEM

      if (is_socket)

        nwritten = send (fd, buf, nleft, 0);

      else

#endif

        nwritten = write (fd, buf, nleft);

      if (nwritten < 0 && errno == EINTR)

        continue;

      if (nwritten < 0)

        return -1;

      nleft -= nwritten;

      buf = buf + nwritten;

    }

  return 0;

}

/* Returns true if STR represents a valid port number in decimal

   notation and no garbage is following.  */

static int

parse_portno (const char *str, unsigned short *r_port)

{

  unsigned int value;

  for (value=0; *str && (*str >= '0' && *str <= '9'); str++)

    {

      value = value * 10 + (*str - '0');

      if (value > 65535)

        return 0;

    }

  if (*str || !value)

    return 0;

  *r_port = value;

  return 1;

}

static gpgrt_ssize_t

fun_writer (void *cookie_arg, const void *buffer, size_t size)

{

  struct fun_cookie_s *cookie = cookie_arg;

  /* FIXME: Use only estream with a callback for socket writing.  This

     avoids the ugly mix of fd and estream code.  */

  /* Note that we always try to reconnect to the socket but print

     error messages only the first time an error occurred.  If

     RUNNING_DETACHED is set we don't fall back to stderr and even do

     not print any error messages.  This is needed because detached

     processes often close stderr and by writing to file descriptor 2

     we might send the log message to a file not intended for logging

     (e.g. a pipe or network connection). */

  if (cookie->want_socket && cookie->fd == -1)

    {

#ifdef WITH_IPV6

      struct sockaddr_in6 srvr_addr_in6;

#endif

      struct sockaddr_in srvr_addr_in;

#ifndef HAVE_W32_SYSTEM

      struct sockaddr_un srvr_addr_un;

#endif

      const char *name_for_err = "";

      size_t addrlen;

      struct sockaddr *srvr_addr = NULL;

      unsigned short port = 0;

      int af = AF_LOCAL;

      int pf = PF_LOCAL;

      const char *name = cookie->name;

      /* Not yet open or meanwhile closed due to an error. */

      cookie->is_socket = 0;

      /* Check whether this is a TCP socket or a local socket.  */

      if (!strncmp (name, "tcp://", 6) && name[6])

        {

          name += 6;

          af = AF_INET;

          pf = PF_INET;

        }

#ifndef HAVE_W32_SYSTEM

      else if (!strncmp (name, "socket://", 9))

        name += 9;

#endif

      if (af == AF_LOCAL)

        {

          addrlen = 0;

#ifndef HAVE_W32_SYSTEM

          memset (&srvr_addr, 0, sizeof srvr_addr);

          srvr_addr_un.sun_family = af;

          if (!*name && (name = socket_dir_cb ()) && *name)

            {

              if (strlen (name) + 7 < sizeof (srvr_addr_un.sun_path)-1)

                {

                  strncpy (srvr_addr_un.sun_path,

                           name, sizeof (srvr_addr_un.sun_path)-1);

                  strcat (srvr_addr_un.sun_path, "/S.log");

                  srvr_addr_un.sun_path[sizeof (srvr_addr_un.sun_path)-1] = 0;

                  srvr_addr = (struct sockaddr *)&srvr_addr_un;

                  addrlen = SUN_LEN (&srvr_addr_un);

                  name_for_err = srvr_addr_un.sun_path;

                }

            }

          else

            {

              if (*name && strlen (name) < sizeof (srvr_addr_un.sun_path)-1)

                {

                  strncpy (srvr_addr_un.sun_path,

                           name, sizeof (srvr_addr_un.sun_path)-1);

                  srvr_addr_un.sun_path[sizeof (srvr_addr_un.sun_path)-1] = 0;

                  srvr_addr = (struct sockaddr *)&srvr_addr_un;

                  addrlen = SUN_LEN (&srvr_addr_un);

                }

            }

#endif /*!HAVE_W32SYSTEM*/

        }

      else

        {

          char *addrstr, *p;

#ifdef HAVE_INET_PTON

          void *addrbuf = NULL;

#endif /*HAVE_INET_PTON*/

          addrstr = _gpgrt_malloc (strlen (name) + 1);

          if (!addrstr)

            addrlen = 0; /* This indicates an error.  */

          else if (*name == '[')

            {

              /* Check for IPv6 literal address.  */

              strcpy (addrstr, name+1);

              p = strchr (addrstr, ']');

              if (!p || p[1] != ':' || !parse_portno (p+2, &port))

                {

                  _gpg_err_set_errno (EINVAL);

                  addrlen = 0;

                }

              else

                {

                  *p = 0;

#ifdef WITH_IPV6

                  af = AF_INET6;

                  pf = PF_INET6;

                  memset (&srvr_addr_in6, 0, sizeof srvr_addr_in6);

                  srvr_addr_in6.sin6_family = af;

                  srvr_addr_in6.sin6_port = htons (port);

#ifdef HAVE_INET_PTON

                  addrbuf = &srvr_addr_in6.sin6_addr;

#endif /*HAVE_INET_PTON*/

                  srvr_addr = (struct sockaddr *)&srvr_addr_in6;

                  addrlen = sizeof srvr_addr_in6;

#else

                  _gpg_err_set_errno (EAFNOSUPPORT);

                  addrlen = 0;

#endif

                }

            }

          else

            {

              /* Check for IPv4 literal address.  */

              strcpy (addrstr, name);

              p = strchr (addrstr, ':');

              if (!p || !parse_portno (p+1, &port))

                {

                  _gpg_err_set_errno (EINVAL);

                  addrlen = 0;

                }

              else

                {

                  *p = 0;

                  memset (&srvr_addr_in, 0, sizeof srvr_addr_in);

                  srvr_addr_in.sin_family = af;

                  srvr_addr_in.sin_port = htons (port);

#ifdef HAVE_INET_PTON

                  addrbuf = &srvr_addr_in.sin_addr;

#endif /*HAVE_INET_PTON*/

                  srvr_addr = (struct sockaddr *)&srvr_addr_in;

                  addrlen = sizeof srvr_addr_in;

                }

            }

          if (addrlen)

            {

#ifdef HAVE_INET_PTON

              if (inet_pton (af, addrstr, addrbuf) != 1)

                addrlen = 0;

#else /*!HAVE_INET_PTON*/

              /* We need to use the old function.  If we are here v6

                 support isn't enabled anyway and thus we can do fine

                 without.  Note that Windows has a compatible inet_pton

                 function named inetPton, but only since Vista.  */

              srvr_addr_in.sin_addr.s_addr = inet_addr (addrstr);

              if (srvr_addr_in.sin_addr.s_addr == INADDR_NONE)

                addrlen = 0;

#endif /*!HAVE_INET_PTON*/

            }

          _gpgrt_free (addrstr);

        }

      cookie->fd = addrlen? socket (pf, SOCK_STREAM, 0) : -1;

      if (cookie->fd == -1)

        {

          if (!cookie->quiet && !running_detached

              && isatty (_gpgrt_fileno (es_stderr)))

            _gpgrt_fprintf (es_stderr,

                            "failed to create socket for logging: %s\n",

                            strerror (errno));

        }

      else

        {

          if (connect (cookie->fd, srvr_addr, addrlen) == -1)

            {

              if (!cookie->quiet && !running_detached

                  && isatty (_gpgrt_fileno (es_stderr)))

                _gpgrt_fprintf (es_stderr, "can't connect to '%s%s': %s\n",

                                cookie->name, name_for_err, strerror(errno));

              sock_close (cookie->fd);

              cookie->fd = -1;

            }

        }

      if (cookie->fd == -1)

        {

          if (!running_detached)

            {

              /* Due to all the problems with apps not running

                 detached but being called with stderr closed or used

                 for a different purposes, it does not make sense to

                 switch to stderr.  We therefore disable it. */

              if (!cookie->quiet)

                {

                  /* fputs ("switching logging to stderr\n", stderr);*/

                  cookie->quiet = 1;

                }

              cookie->fd = -1; /*fileno (stderr);*/

            }

        }

      else /* Connection has been established. */

        {

          cookie->quiet = 0;

          cookie->is_socket = 1;

        }

    }

  log_socket = cookie->fd;

  if (cookie->fd != -1)

    {

#ifdef HAVE_W32CE_SYSTEM

      if (cookie->use_writefile)

        {

          DWORD nwritten;

          WriteFile ((HANDLE)cookie->fd, buffer, size, &nwritten, NULL);

          return (gpgrt_ssize_t)size; /* Okay.  */

        }

#endif

      if (!writen (cookie->fd, buffer, size, cookie->is_socket))

        return (gpgrt_ssize_t)size; /* Okay. */

    }

  if (!running_detached && cookie->fd != -1

      && isatty (_gpgrt_fileno (es_stderr)))

    {

      if (*cookie->name)

        _gpgrt_fprintf (es_stderr, "error writing to '%s': %s\n",

                        cookie->name, strerror(errno));

      else

        _gpgrt_fprintf (es_stderr, "error writing to file descriptor %d: %s\n",

                        cookie->fd, strerror(errno));

    }

  if (cookie->is_socket && cookie->fd != -1)

    {

      sock_close (cookie->fd);

      cookie->fd = -1;

      log_socket = -1;

    }

  return (gpgrt_ssize_t)size;

}

static int

fun_closer (void *cookie_arg)

{

  struct fun_cookie_s *cookie = cookie_arg;

  if (cookie->fd != -1 && cookie->fd != 2)

    sock_close (cookie->fd);

  _gpgrt_free (cookie);

  log_socket = -1;

  return 0;

}

/* Common function to either set the logging to a file or a file

   descriptor. */

static void

set_file_fd (const char *name, int fd)

{

  estream_t fp;

  int want_socket;

#ifdef HAVE_W32CE_SYSTEM

  int use_writefile = 0;

#endif

  struct fun_cookie_s *cookie;

  /* Close an open log stream.  */

  if (logstream)

    {

      if (logstream != es_stderr)

        _gpgrt_fclose (logstream);

      logstream = NULL;

    }

  /* Figure out what kind of logging we want.  */

  if (name && !strcmp (name, "-"))

    {

      name = NULL;

      fd = _gpgrt_fileno (es_stderr);

    }

  want_socket = 0;

  if (name && !strncmp (name, "tcp://", 6) && name[6])

    want_socket = 1;

#ifndef HAVE_W32_SYSTEM

  else if (name && !strncmp (name, "socket://", 9))

    want_socket = 2;

#endif /*HAVE_W32_SYSTEM*/

#ifdef HAVE_W32CE_SYSTEM

  else if (name && !strcmp (name, "GPG2:"))

    {

      HANDLE hd;

      ActivateDevice (L"Drivers\\"GNUPG_NAME"_Log", 0);

      /* Ignore a filename and write the debug output to the GPG2:

         device.  */

      hd = CreateFile (L"GPG2:", GENERIC_WRITE,

                       FILE_SHARE_READ | FILE_SHARE_WRITE,

                       NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

      fd = (hd == INVALID_HANDLE_VALUE)? -1 : (int)hd;

      name = NULL;

      force_prefixes = 1;

      use_writefile = 1;

    }

#endif /*HAVE_W32CE_SYSTEM*/

  /* Setup a new stream.  */

  cookie = _gpgrt_malloc (sizeof *cookie + (name? strlen (name):0));

  if (!cookie)

    return; /* oops */

  strcpy (cookie->name, name? name:"");

  cookie->quiet = 0;

  cookie->is_socket = 0;

  cookie->want_socket = want_socket;

#ifdef HAVE_W32CE_SYSTEM

  cookie->use_writefile = use_writefile;

#endif

  if (!name)

    cookie->fd = fd;

  else if (want_socket)

    cookie->fd = -1;

  else

    {

      do

        cookie->fd = open (name, O_WRONLY|O_APPEND|O_CREAT,

                           (S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR|S_IWGRP|S_IWOTH));

      while (cookie->fd == -1 && errno == EINTR);

    }

  log_socket = cookie->fd;

  {

    es_cookie_io_functions_t io = { NULL };

    io.func_write = fun_writer;

    io.func_close = fun_closer;

    fp = _gpgrt_fopencookie (cookie, "w", io);

  }

  /* On error default to a stderr based estream.  */

  if (!fp)

    fp = es_stderr;

  _gpgrt_setvbuf (fp, NULL, _IOLBF, 0);

  logstream = fp;

  /* We always need to print the prefix and the pid for socket mode,

     so that the server reading the socket can do something

     meaningful. */

  force_prefixes = want_socket;

  missing_lf = 0;

}

/* Set the file to write log to.  The special names NULL and "-" may

 * be used to select stderr and names formatted like

 * "socket:///home/foo/mylogs" may be used to write the logging to the

 * socket "/home/foo/mylogs".  If the connection to the socket fails

 * or a write error is detected, the function writes to stderr and

 * tries the next time again to connect the socket.  Calling this

 * function with (NULL, NULL, -1) sets the default sink.

 * Warning: This function is not thread-safe.

 */

void

_gpgrt_log_set_sink (const char *name, estream_t stream, int fd)

{

  if (name && !stream && fd == -1)

    set_file_fd (name, -1);

  else if (!name && !stream && fd != -1)

    {

      if (!_gpgrt_fd_valid_p (fd))

        _gpgrt_log_fatal ("gpgrt_log_set_sink: fd is invalid: %s\n",

                     strerror (errno));

      set_file_fd (NULL, fd);

    }

  else if (!name && stream && fd == -1)

    {

      _gpgrt_log_fatal ("gpgrt_log_set_sink: stream arg not yet supported\n");

    }

  else /* default */

    set_file_fd ("-", -1);

}

/* Set a function to retrieve the directory name of a socket if

 * only "socket://" has been given to log_set_file.

 * Warning: This function is not thread-safe.  */

void

_gpgrt_log_set_socket_dir_cb (const char *(*fnc)(void))

{

  socket_dir_cb = fnc;

}

/* Warning: This function is not thread-safe.  */

void

_gpgrt_log_set_pid_suffix_cb (int (*cb)(unsigned long *r_value))

{

  get_pid_suffix_cb = cb;

}

/* Warning: Changing TEXT is not thread-safe.  Changing only flags

 * might be thread-safe.  */

void

_gpgrt_log_set_prefix (const char *text, unsigned int flags)

{

  if (text)

    {

      strncpy (prefix_buffer, text, sizeof (prefix_buffer)-1);

      prefix_buffer[sizeof (prefix_buffer)-1] = 0;

    }

  with_prefix = (flags & GPGRT_LOG_WITH_PREFIX);

  with_time = (flags & GPGRT_LOG_WITH_TIME);

  with_pid  = (flags & GPGRT_LOG_WITH_PID);

  running_detached = (flags & GPGRT_LOG_RUN_DETACHED);

#ifdef HAVE_W32_SYSTEM

  no_registry = (flags & GPGRT_LOG_NO_REGISTRY);

#endif

}

const char *

_gpgrt_log_get_prefix (unsigned int *flags)

{

  if (flags)

    {

      *flags = 0;

      if (with_prefix)

        *flags |= GPGRT_LOG_WITH_PREFIX;

      if (with_time)

        *flags |= GPGRT_LOG_WITH_TIME;

      if (with_pid)

        *flags |= GPGRT_LOG_WITH_PID;

      if (running_detached)

        *flags |= GPGRT_LOG_RUN_DETACHED;

#ifdef HAVE_W32_SYSTEM

      if (no_registry)

        *flags |= GPGRT_LOG_NO_REGISTRY;

#endif

    }

  return prefix_buffer;

}

/* This function returns true if the file descriptor FD is in use for

 * logging.  This is preferable over a test using log_get_fd in that

 * it allows the logging code to use more then one file descriptor.  */

int

_gpgrt_log_test_fd (int fd)

{

  if (logstream)

    {

      int tmp = _gpgrt_fileno (logstream);

      if ( tmp != -1 && tmp == fd)

        return 1;

    }

  if (log_socket != -1 && log_socket == fd)

    return 1;

  return 0;

}

int

_gpgrt_log_get_fd ()

{

  return logstream? _gpgrt_fileno (logstream) : -1;

}

estream_t

_gpgrt_log_get_stream ()

{

  if (!logstream)

    {

      /* Make sure a log stream has been set.  */

      _gpgrt_log_set_sink (NULL, NULL, -1);

      assert (logstream);

    }

  return logstream;

}

/* Note: LOGSTREAM is expected to be locked.  */

static int

print_prefix (int level, int leading_backspace)

{

  int rc;

  int length = 0;

  if (level != GPGRT_LOGLVL_CONT)

    { /* Note this does not work for multiple line logging as we would

       * need to print to a buffer first */

      if (with_time && !force_prefixes)

        {

          struct tm *tp;

          time_t atime = time (NULL);

          tp = localtime (&atime);

          rc = _gpgrt_fprintf_unlocked (logstream,

                                        "%04d-%02d-%02d %02d:%02d:%02d ",

                               1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday,

                               tp->tm_hour, tp->tm_min, tp->tm_sec );

          if (rc > 0)

            length += rc;

        }

      if (with_prefix || force_prefixes)

        {

          _gpgrt_fputs_unlocked (prefix_buffer, logstream);

          length += strlen (prefix_buffer);

        }

      if (with_pid || force_prefixes)

        {

          unsigned long pidsuf;

          int pidfmt;

          if (get_pid_suffix_cb && (pidfmt=get_pid_suffix_cb (&pidsuf)))

            rc = _gpgrt_fprintf_unlocked (logstream,

                                          pidfmt == 1? "[%u.%lu]":"[%u.%lx]",

                                          (unsigned int)getpid (), pidsuf);

          else

            rc = _gpgrt_fprintf_unlocked (logstream, "[%u]",

                                          (unsigned int)getpid ());

          if (rc > 0)

            length += rc;

        }

      if ((!with_time && (with_prefix || with_pid)) || force_prefixes)

        {

          _gpgrt_putc_unlocked (':', logstream);

          length++;

        }

      /* A leading backspace suppresses the extra space so that we can

         correctly output, programname, filename and linenumber. */

      if (!leading_backspace

          && (with_time || with_prefix || with_pid || force_prefixes))

        {

          _gpgrt_putc_unlocked (' ', logstream);

          length++;

        }

    }

  switch (level)

    {

    case GPGRT_LOGLVL_BEGIN: break;

    case GPGRT_LOGLVL_CONT: break;

    case GPGRT_LOGLVL_INFO: break;

    case GPGRT_LOGLVL_WARN: break;

    case GPGRT_LOGLVL_ERROR: break;

    case GPGRT_LOGLVL_FATAL:

      _gpgrt_fputs_unlocked ("Fatal: ", logstream);

      length += 7;

      break;

    case GPGRT_LOGLVL_BUG:

      _gpgrt_fputs_unlocked ("Ohhhh jeeee: ", logstream);

      length += 13;

      break;

    case GPGRT_LOGLVL_DEBUG:

      _gpgrt_fputs_unlocked ("DBG: ", logstream);

      length += 5;

      break;

    default:

      rc = _gpgrt_fprintf_unlocked (logstream,

                                    "[Unknown log level %d]: ", level);

      if (rc > 0)

        length += rc;

      break;

    }

  return length;

}

/* Internal worker function.  Exported so that we can use it in

 * visibility.c.  Returs the number of characters printed or 0 if the

 * line ends in a LF. */

int

_gpgrt_logv_internal (int level, int ignore_arg_ptr, const char *extrastring,

                      const char *prefmt, const char *fmt, va_list arg_ptr)

{

  int leading_backspace = (fmt && *fmt == '\b');

  int length;

  int rc;

  if (!logstream)

    {

#ifdef HAVE_W32_SYSTEM

      char *tmp;

      tmp = (no_registry

             ? NULL

             : _gpgrt_w32_reg_query_string (NULL, "Software\\\\GNU\\\\GnuPG",

                                            "DefaultLogFile"));

      _gpgrt_log_set_sink (tmp && *tmp? tmp : NULL, NULL, -1);

      _gpgrt_free (tmp);

#else

      /* Make sure a log stream has been set.  */

      _gpgrt_log_set_sink (NULL, NULL, -1);

#endif

      assert (logstream);

    }

  _gpgrt_flockfile (logstream);

  if (missing_lf && level != GPGRT_LOGLVL_CONT)

    _gpgrt_putc_unlocked ('\n', logstream );

  missing_lf = 0;

  length = print_prefix (level, leading_backspace);

  if (leading_backspace)

    fmt++;

  if (fmt)

    {

      if (prefmt)

        {

          _gpgrt_fputs_unlocked (prefmt, logstream);

          length += strlen (prefmt);

        }

      if (ignore_arg_ptr)

        { /* This is used by log_string and comes with the extra

           * feature that after a LF the next line is indent at the

           * length of the prefix.  Note that we do not yet include

           * the length of the timestamp and pid in the indent

           * computation.  */

          const char *p, *pend;

          for (p = fmt; (pend = strchr (p, '\n')); p = pend+1)

            {

              rc = _gpgrt_fprintf_unlocked (logstream, "%*s%.*s",

                                 (int)((p != fmt

                                        && (with_prefix || force_prefixes))

                                       ?strlen (prefix_buffer)+2:0), "",

                                 (int)(pend - p)+1, p);

              if (rc > 0)

                length += rc;

            }

          _gpgrt_fputs_unlocked (p, logstream);

          length += strlen (p);

        }

      else

        {

          rc = _gpgrt_vfprintf_unlocked (logstream, fmt, arg_ptr);

          if (rc > 0)

            length += rc;

        }

      if (*fmt && fmt[strlen(fmt)-1] != '\n')

        missing_lf = 1;

    }

  /* If we have an EXTRASTRING print it now while we still hold the

   * lock on the logstream.  */

  if (extrastring)

    {

      int c;

      if (missing_lf)

        {

          _gpgrt_putc_unlocked ('\n', logstream);

          missing_lf = 0;

          length = 0;

        }

      length += print_prefix (level, leading_backspace);

      _gpgrt_fputs_unlocked (">> ", logstream);

      length += 3;

      missing_lf = 1;

      while ((c = *extrastring++))

        {

          missing_lf = 1;

          if (c == '\\')

            {

              _gpgrt_fputs_unlocked ("\\\\", logstream);

              length += 2;

            }

          else if (c == '\r')

            {

              _gpgrt_fputs_unlocked ("\\r", logstream);

              length += 2;

            }

          else if (c == '\n')