gnupg/common/ttyio.c

/* ttyio.c -  tty i/O functions
 * Copyright (C) 1998,1999,2000,2001,2002,2003,2004,2006,2007,
 *               2009, 2010 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of either
 *
 *   - the GNU Lesser General Public License as published by the Free
 *     Software Foundation; either version 3 of the License, or (at
 *     your option) any later version.
 *
 * or
 *
 *   - the GNU General Public License as published by the Free
 *     Software Foundation; either version 2 of the License, or (at
 *     your option) any later version.
 *
 * or both in parallel, as here.
 *
 * This file 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 this program; if not, see <https://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>

#if defined(HAVE_W32_SYSTEM) && !defined(HAVE_W32CE_SYSTEM)
# define USE_W32_CONSOLE 1
#endif

#ifdef HAVE_TCGETATTR
#include <termios.h>
#else
#ifdef HAVE_TERMIO_H
/* simulate termios with termio */
#include <termio.h>
#define termios termio
#define tcsetattr ioctl
#define TCSAFLUSH TCSETAF
#define tcgetattr(A,B) ioctl(A,TCGETA,B)
#define HAVE_TCGETATTR
#endif
#endif
#ifdef USE_W32_CONSOLE
# ifdef HAVE_WINSOCK2_H
#  include <winsock2.h>
# endif
# include <windows.h>
# ifdef HAVE_TCGETATTR
#  error mingw32 and termios
# endif
#endif
#include <errno.h>
#include <ctype.h>

#include "util.h"
#include "ttyio.h"
#include "common-defs.h"

#define CONTROL_D ('D' - 'A' + 1)


#ifdef USE_W32_CONSOLE
static struct {
    HANDLE in, out;
} con;
#define DEF_INPMODE  (ENABLE_LINE_INPUT|ENABLE_ECHO_INPUT    \
					|ENABLE_PROCESSED_INPUT )
#define HID_INPMODE  (ENABLE_LINE_INPUT|ENABLE_PROCESSED_INPUT )
#define DEF_OUTMODE  (ENABLE_WRAP_AT_EOL_OUTPUT|ENABLE_PROCESSED_OUTPUT)

#else /* yeah, we have a real OS */
static FILE *ttyfp = NULL;
#endif

static int initialized;
static int last_prompt_len;
static int batchmode;
static int no_terminal;

#ifdef HAVE_TCGETATTR
    static struct termios termsave;
    static int restore_termios;
#endif

/* Hooks set by gpgrlhelp.c if required. */
static void (*my_rl_set_completer) (rl_completion_func_t *);
static void (*my_rl_inhibit_completion) (int);
static void (*my_rl_cleanup_after_signal) (void);
static void (*my_rl_init_stream) (FILE *);
static char *(*my_rl_readline) (const char*);
static void (*my_rl_add_history) (const char*);
static int (*my_rl_rw_history)(const char *, int, int);

/* This is a wrapper around ttyname so that we can use it even when
   the standard streams are redirected.  It figures the name out the
   first time and returns it in a statically allocated buffer. */
const char *
tty_get_ttyname (void)
{
  static char *name;

  /* On a GNU system ctermid() always return /dev/tty, so this does
     not make much sense - however if it is ever changed we do the
     Right Thing now. */
#ifdef HAVE_CTERMID
  static int got_name;

  if (!got_name)
    {
      const char *s;
      /* Note that despite our checks for these macros the function is
         not necessarily thread save.  We mainly do this for
         portability reasons, in case L_ctermid is not defined. */
# if defined(_POSIX_THREAD_SAFE_FUNCTIONS) || defined(_POSIX_TRHEADS)
      char buffer[L_ctermid];
      s = ctermid (buffer);
# else
      s = ctermid (NULL);
# endif
      if (s)
        name = strdup (s);
      got_name = 1;
    }
#endif /*HAVE_CTERMID*/
  /* Assume the standard tty on memory error or when there is no
     ctermid. */
  return name? name : "/dev/tty";
}



#ifdef HAVE_TCGETATTR
static void
cleanup(void)
{
    if( restore_termios ) {
	restore_termios = 0; /* do it prios in case it is interrupted again */
	if( tcsetattr(fileno(ttyfp), TCSAFLUSH, &termsave) )
	    log_error("tcsetattr() failed: %s\n", strerror(errno) );
    }
}
#endif

static void
init_ttyfp(void)
{
    if( initialized )
	return;

#if defined(USE_W32_CONSOLE)
    {
	SECURITY_ATTRIBUTES sa;

	memset(&sa, 0, sizeof(sa));
	sa.nLength = sizeof(sa);
	sa.bInheritHandle = TRUE;
	con.out = CreateFileA( "CONOUT$", GENERIC_READ|GENERIC_WRITE,
			       FILE_SHARE_READ|FILE_SHARE_WRITE,
			       &sa, OPEN_EXISTING, 0, 0 );
	if( con.out == INVALID_HANDLE_VALUE )
	    log_fatal("open(CONOUT$) failed: rc=%d", (int)GetLastError() );
	memset(&sa, 0, sizeof(sa));
	sa.nLength = sizeof(sa);
	sa.bInheritHandle = TRUE;
	con.in = CreateFileA( "CONIN$", GENERIC_READ|GENERIC_WRITE,
			       FILE_SHARE_READ|FILE_SHARE_WRITE,
			       &sa, OPEN_EXISTING, 0, 0 );
	if( con.in == INVALID_HANDLE_VALUE )
	    log_fatal("open(CONIN$) failed: rc=%d", (int)GetLastError() );
    }
    SetConsoleMode(con.in, DEF_INPMODE );
    SetConsoleMode(con.out, DEF_OUTMODE );

#elif defined(__EMX__)
    ttyfp = stdout; /* Fixme: replace by the real functions: see wklib */
    if (my_rl_init_stream)
      my_rl_init_stream (ttyfp);
#elif defined (HAVE_W32CE_SYSTEM)
    ttyfp = stderr;
#else
    ttyfp = batchmode? stderr : fopen (tty_get_ttyname (), "r+");
    if( !ttyfp ) {
	log_error("cannot open '%s': %s\n", tty_get_ttyname (),
                  strerror(errno) );
	exit(2);
    }
    if (my_rl_init_stream)
      my_rl_init_stream (ttyfp);
#endif


#ifdef HAVE_TCGETATTR
    atexit( cleanup );
#endif
    initialized = 1;
}


int
tty_batchmode( int onoff )
{
    int old = batchmode;
    if( onoff != -1 )
	batchmode = onoff;
    return old;
}

int
tty_no_terminal(int onoff)
{
    int old = no_terminal;
    no_terminal = onoff ? 1 : 0;
    return old;
}

void
tty_printf( const char *fmt, ... )
{
    va_list arg_ptr;

    if (no_terminal)
	return;

    if( !initialized )
	init_ttyfp();

    va_start( arg_ptr, fmt ) ;
#ifdef USE_W32_CONSOLE
    {
        char *buf = NULL;
        int n;
	DWORD nwritten;

	n = vasprintf(&buf, fmt, arg_ptr);
	if( !buf )
	    log_bug("vasprintf() failed\n");

	if( !WriteConsoleA( con.out, buf, n, &nwritten, NULL ) )
	    log_fatal("WriteConsole failed: rc=%d", (int)GetLastError() );
	if( n != nwritten )
	    log_fatal("WriteConsole failed: %d != %d\n", n, (int)nwritten );
	last_prompt_len += n;
        xfree (buf);
    }
#else
    last_prompt_len += vfprintf(ttyfp,fmt,arg_ptr) ;
    fflush(ttyfp);
#endif
    va_end(arg_ptr);
}


/* Same as tty_printf but if FP is not NULL, behave like a regular
   fprintf. */
void
tty_fprintf (estream_t fp, const char *fmt, ... )
{
  va_list arg_ptr;

  if (fp)
    {
      va_start (arg_ptr, fmt) ;
      es_vfprintf (fp, fmt, arg_ptr );
      va_end (arg_ptr);
      return;
    }

  if (no_terminal)
    return;

  if (!initialized)
    init_ttyfp ();

  va_start (arg_ptr, fmt);
#ifdef USE_W32_CONSOLE
  {
    char *buf = NULL;
    int n;
    DWORD nwritten;

    n = vasprintf(&buf, fmt, arg_ptr);
    if (!buf)
      log_bug("vasprintf() failed\n");

    if (!WriteConsoleA( con.out, buf, n, &nwritten, NULL ))
      log_fatal("WriteConsole failed: rc=%d", (int)GetLastError() );
    if (n != nwritten)
      log_fatal("WriteConsole failed: %d != %d\n", n, (int)nwritten );
    last_prompt_len += n;
    xfree (buf);
  }
#else
  last_prompt_len += vfprintf(ttyfp,fmt,arg_ptr) ;
  fflush(ttyfp);
#endif
  va_end(arg_ptr);
}


/* Print a string, but filter all control characters out.  If FP is
 * not NULL print to that stream instead to the tty.  */
static void
do_print_string (estream_t fp, const byte *p, size_t n )
{
  if (no_terminal && !fp)
    return;

  if (!initialized && !fp)
    init_ttyfp();

  if (fp)
    {
      print_utf8_buffer (fp, p, n);
      return;
    }

#ifdef USE_W32_CONSOLE
  /* Not so effective, change it if you want */
  for (; n; n--, p++)
    {
      if (iscntrl (*p))
        {
          if( *p == '\n' )
            tty_printf ("\\n");
          else if( !*p )
            tty_printf ("\\0");
          else
            tty_printf ("\\x%02x", *p);
        }
      else
        tty_printf ("%c", *p);
    }
#else
  for (; n; n--, p++)
    {
      if (iscntrl (*p))
        {
          putc ('\\', ttyfp);
          if ( *p == '\n' )
            putc ('n', ttyfp);
          else if ( !*p )
            putc ('0', ttyfp);
          else
            fprintf (ttyfp, "x%02x", *p );
        }
      else
        putc (*p, ttyfp);
    }
#endif
}


void
tty_print_utf8_string2 (estream_t fp, const byte *p, size_t n, size_t max_n)
{
    size_t i;
    char *buf;

    if (no_terminal && !fp)
	return;

    /* we can handle plain ascii simpler, so check for it first */
    for(i=0; i < n; i++ ) {
	if( p[i] & 0x80 )
	    break;
    }
    if( i < n ) {
	buf = utf8_to_native( (const char *)p, n, 0 );
	if( max_n && (strlen( buf ) > max_n )) {
	    buf[max_n] = 0;
	}
	/*(utf8 conversion already does the control character quoting)*/
	tty_fprintf (fp, "%s", buf);
	xfree (buf);
    }
    else {
	if( max_n && (n > max_n) ) {
	    n = max_n;
	}
	do_print_string (fp, p, n );
    }
}


void
tty_print_utf8_string( const byte *p, size_t n )
{
  tty_print_utf8_string2 (NULL, p, n, 0);
}


static char *
do_get( const char *prompt, int hidden )
{
  char *buf;
#ifndef __riscos__
  byte cbuf[1];
#endif
  int c, n, i;

  if (batchmode)
    {
      log_error ("Sorry, we are in batchmode - can't get input\n");
      exit (2);
    }

  if (no_terminal)
    {
      log_error ("Sorry, no terminal at all requested - can't get input\n");
      exit (2);
    }

  if (!initialized)
    init_ttyfp ();

  last_prompt_len = 0;
  tty_printf ("%s", prompt);
  buf = xmalloc ((n=50));
  i = 0;

#ifdef USE_W32_CONSOLE
  if (hidden)
    SetConsoleMode(con.in, HID_INPMODE );

  for (;;)
    {
      DWORD nread;

      if (!ReadConsoleA( con.in, cbuf, 1, &nread, NULL))
        log_fatal ("ReadConsole failed: rc=%d", (int)GetLastError ());
      if (!nread)
        continue;
      if (*cbuf == '\n')
        break;

      if (!hidden)
        last_prompt_len++;
      c = *cbuf;
      if (c == '\t')
        c = ' ';
      else if ( (c >= 0 && c <= 0x1f) || c == 0x7f)
        continue;
      if (!(i < n-1))
        {
          n += 50;
          buf = xrealloc (buf, n);
        }
      buf[i++] = c;
    }

  if (hidden)
    SetConsoleMode(con.in, DEF_INPMODE );

#elif defined(__riscos__) || defined(HAVE_W32CE_SYSTEM)
  do
    {
#ifdef HAVE_W32CE_SYSTEM
      /* Using getchar is not a correct solution but for now it
         doesn't matter because we have no real console at all.  We
         should rework this as soon as we have switched this entire
         module to estream.  */
      c = getchar();
#else
      c = riscos_getchar();
#endif
      if (c == 0xa || c == 0xd)  /* Return || Enter */
        {
          c = (int) '\n';
        }
      else if (c == 0x8 || c == 0x7f) /* Backspace || Delete */
        {
          if (i>0)
            {
              i--;
              if (!hidden)
                {
                  last_prompt_len--;
                  fputc(8, ttyfp);
                  fputc(32, ttyfp);
                  fputc(8, ttyfp);
                  fflush(ttyfp);
                }
            }
          else
            {
              fputc(7, ttyfp);
              fflush(ttyfp);
            }
          continue;
        }
      else if (c == (int) '\t')  /* Tab */
        {
          c = ' ';
        }
      else if (c > 0xa0)
        {
          ; /* we don't allow 0xa0, as this is a protected blank which may
             * confuse the user */
        }
      else if (iscntrl(c))
        {
          continue;
        }
      if (!(i < n-1))
        {
          n += 50;
          buf = xrealloc (buf, n);
        }
      buf[i++] = c;
      if (!hidden)
        {
          last_prompt_len++;
          fputc(c, ttyfp);
          fflush(ttyfp);
        }
    }
  while (c != '\n');
  i = (i>0) ? i-1 : 0;

#else /* Other systems. */

  if (hidden)
    {
#ifdef HAVE_TCGETATTR
      struct termios term;

      if (tcgetattr(fileno(ttyfp), &termsave))
        log_fatal("tcgetattr() failed: %s\n", strerror(errno));
      restore_termios = 1;
      term = termsave;
      term.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
      if (tcsetattr( fileno(ttyfp), TCSAFLUSH, &term ) )
        log_fatal("tcsetattr() failed: %s\n", strerror(errno));
#endif
    }

  /* fixme: How can we avoid that the \n is echoed w/o disabling
   * canonical mode - w/o this kill_prompt can't work */
  while (read(fileno(ttyfp), cbuf, 1) == 1 && *cbuf != '\n')
    {
      if (!hidden)
        last_prompt_len++;
      c = *cbuf;
      if (c == CONTROL_D)
        log_info ("Control-D detected\n");

      if (c == '\t') /* Map tab to a space.  */
        c = ' ';
      else if ( (c >= 0 && c <= 0x1f) || c == 0x7f)
        continue; /* Skip all other ASCII control characters.  */
      if (!(i < n-1))
        {
          n += 50;
          buf = xrealloc (buf, n);
        }
      buf[i++] = c;
    }
  if (*cbuf != '\n')
    {
      buf[0] = CONTROL_D;
      i = 1;
    }

  if (hidden)
    {
#ifdef HAVE_TCGETATTR
      if (tcsetattr(fileno(ttyfp), TCSAFLUSH, &termsave))
        log_error ("tcsetattr() failed: %s\n", strerror(errno));
      restore_termios = 0;
#endif
    }
#endif /* end unix version */

  buf[i] = 0;
  return buf;
}



/* Note: This function never returns NULL. */
char *
tty_get( const char *prompt )
{
  if (!batchmode && !no_terminal && my_rl_readline && my_rl_add_history)
    {
      char *line;
      char *buf;

      if (!initialized)
	init_ttyfp();

      last_prompt_len = 0;

      line = my_rl_readline (prompt?prompt:"");

      /* We need to copy it to memory controlled by our malloc
         implementations; further we need to convert an EOF to our
         convention. */
      buf = xmalloc(line? strlen(line)+1:2);
      if (line)
        {
          strcpy (buf, line);
          trim_spaces (buf);
          if (strlen (buf) > 2 )
            my_rl_add_history (line); /* Note that we test BUF but add LINE. */
          free (line);
        }
      else
        {
          buf[0] = CONTROL_D;
          buf[1] = 0;
        }
      return buf;
    }
  else
    return do_get ( prompt, 0 );
}

/* Variable argument version of tty_get.  The prompt is actually a
   format string with arguments.  */
char *
tty_getf (const char *promptfmt, ... )
{
  va_list arg_ptr;
  char *prompt;
  char *answer;

  va_start (arg_ptr, promptfmt);
  if (gpgrt_vasprintf (&prompt, promptfmt, arg_ptr) < 0)
    log_fatal ("estream_vasprintf failed: %s\n", strerror (errno));
  va_end (arg_ptr);
  answer = tty_get (prompt);
  xfree (prompt);
  return answer;
}



char *
tty_get_hidden( const char *prompt )
{
    return do_get( prompt, 1 );
}


void
tty_kill_prompt()
{
    if ( no_terminal )
	return;

    if( !initialized )
	init_ttyfp();

    if( batchmode )
	last_prompt_len = 0;
    if( !last_prompt_len )
	return;
#ifdef USE_W32_CONSOLE
    tty_printf("\r%*s\r", last_prompt_len, "");
#else
    {
	int i;
	putc('\r', ttyfp);
	for(i=0; i < last_prompt_len; i ++ )
	    putc(' ', ttyfp);
	putc('\r', ttyfp);
	fflush(ttyfp);
    }
#endif
    last_prompt_len = 0;
}


int
tty_get_answer_is_yes( const char *prompt )
{
    int yes;
    char *p = tty_get( prompt );
    tty_kill_prompt();
    yes = answer_is_yes(p);
    xfree(p);
    return yes;
}


/* Called by gnupg_rl_initialize to setup the readline support. */
void
tty_private_set_rl_hooks (void (*init_stream) (FILE *),
                          void (*set_completer) (rl_completion_func_t*),
                          void (*inhibit_completion) (int),
                          void (*cleanup_after_signal) (void),
                          char *(*readline_fun) (const char*),
                          void (*add_history_fun) (const char*),
                          int (*rw_history_fun)(const char *, int, int))
{
  my_rl_init_stream = init_stream;
  my_rl_set_completer = set_completer;
  my_rl_inhibit_completion = inhibit_completion;
  my_rl_cleanup_after_signal = cleanup_after_signal;
  my_rl_readline = readline_fun;
  my_rl_add_history = add_history_fun;
  my_rl_rw_history = rw_history_fun;
}


/* Read the history from FILENAME or limit the size of the history.
 * If FILENAME is NULL and NLINES is zero the current history is
 * cleared.  Returns 0 on success or -1 on error and sets ERRNO.  No
 * error is return if readline support is not available.  */
int
tty_read_history (const char *filename, int nlines)
{
  int rc;

  if (!my_rl_rw_history)
    return 0;

  rc = my_rl_rw_history (filename, 0, nlines);
  if (rc && gpg_err_code_from_syserror () == GPG_ERR_ENOENT)
    rc = 0;

  return rc;
}


/* Write the current history to the file FILENAME.  Returns 0 on
 * success or -1 on error and sets ERRNO.  No error is return if
 * readline support is not available.  */
int
tty_write_history (const char *filename)
{
  if (!my_rl_rw_history)
    return 0;

  return my_rl_rw_history (filename, 1, 0);
}


#ifdef HAVE_LIBREADLINE
void
tty_enable_completion (rl_completion_func_t *completer)
{
  if (no_terminal || !my_rl_set_completer )
    return;

  if (!initialized)
    init_ttyfp();

  my_rl_set_completer (completer);
}

void
tty_disable_completion (void)
{
  if (no_terminal || !my_rl_inhibit_completion)
    return;

  if (!initialized)
    init_ttyfp();

  my_rl_inhibit_completion (1);
}
#endif

void
tty_cleanup_after_signal (void)
{
#ifdef HAVE_TCGETATTR
  cleanup ();
#endif
}

void
tty_cleanup_rl_after_signal (void)
{
  if (my_rl_cleanup_after_signal)
    my_rl_cleanup_after_signal ();
}