gnupg/util/ttyio.c

/* ttyio.c -  tty i/O functions
 * Copyright (C) 1998, 1999, 2000, 2001, 2002,
 *               2004 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG 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 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#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 _WIN32 /* use the odd Win32 functions */
#include <windows.h>
#ifdef HAVE_TCGETATTR
#error windows and termios
#endif
#endif
#include <errno.h>
#include <ctype.h>
#ifdef HAVE_LIBREADLINE
#include <readline/readline.h>
#include <readline/history.h>
#endif

#include "util.h"
#include "memory.h"
#include "ttyio.h"

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

#ifdef _WIN32 /* use the odd Win32 functions */
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



/* 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;
      s = ctermid (NULL);
      if (s)
        name = strdup (s);
      got_name = 1;
    }
#endif
  /* 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(_WIN32)
    {
	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: %s", w32_strerror (0));
	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: %s", w32_strerror (0));
    }
    SetConsoleMode(con.in, DEF_INPMODE );
    SetConsoleMode(con.out, DEF_OUTMODE );

#elif defined(__EMX__)
    ttyfp = stdout; /* Fixme: replace by the real functions: see wklib */
#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);
    }
#ifdef HAVE_LIBREADLINE
    rl_catch_signals = 0;
    rl_instream = rl_outstream = ttyfp;
    rl_inhibit_completion = 1;
#endif
#endif
#ifdef HAVE_TCGETATTR
    atexit( cleanup );
#endif
    initialized = 1;
}

#ifdef HAVE_LIBREADLINE
void
tty_enable_completion(rl_completion_func_t *completer)
{
  if( !initialized )
    init_ttyfp();
  rl_attempted_completion_function=completer;
  rl_inhibit_completion=0;
}

void
tty_disable_completion(void)
{
  if( !initialized )
    init_ttyfp();
  rl_inhibit_completion=1;
}
#endif /*HAVE_LIBREADLINE*/

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 _WIN32
    {   
        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: %s", w32_strerror (0));
	if( n != nwritten )
	    log_fatal ("WriteConsole failed: %d != %d\n", n, (int)nwritten );
	last_prompt_len += n;
        m_free (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 the standard
   fprintf. */
void
tty_fprintf (FILE *fp, const char *fmt, ... )
{
  va_list arg_ptr;

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

  if (no_terminal)
    return;

  if( !initialized )
    init_ttyfp();

    va_start( arg_ptr, fmt ) ;
#ifdef _WIN32
    {   
        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: %s", w32_strerror (0));
	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.
 */
void
tty_print_string( const byte *p, size_t n )
{
    if (no_terminal)
	return;

    if( !initialized )
	init_ttyfp();

#ifdef _WIN32
    /* 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 (const byte *p, size_t n, size_t max_n )
{
    size_t i;
    char *buf;

    if (no_terminal)
	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( p, n, 0 );
	if( max_n && (strlen( buf ) > max_n )) {
	    buf[max_n] = 0;
	}
	/*(utf8 conversion already does the control character quoting)*/
	tty_printf("%s", buf );
	m_free( buf );
    }
    else {
	if( max_n && (n > max_n) ) {
	    n = max_n;
	}
	tty_print_string( p, n );
    }
}

void
tty_print_utf8_string( const byte *p, size_t n )
{
    tty_print_utf8_string2( 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;
    buf = m_alloc(n=50);
    i = 0;

#ifdef _WIN32 /* windoze version */
    if( hidden )
	SetConsoleMode(con.in, HID_INPMODE );

    tty_printf( "%s", prompt );

    for(;;) {
	DWORD nread;

	if (!ReadConsoleA (con.in, cbuf, 1, &nread, NULL))
	    log_fatal ("ReadConsole failed: %s", w32_strerror (0));
	if( !nread )
	    continue;
	if( *cbuf == '\n' )
	    break;

	if( !hidden )
	    last_prompt_len++;
	c = *cbuf;
	if( c == '\t' )
	    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 = m_realloc( buf, n );
	}
	buf[i++] = c;
    }

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

#elif defined(__riscos__)
    tty_printf( "%s", prompt );
    do {
        c = riscos_getchar();
        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 = m_realloc(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 /* unix version */
    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
    }

    tty_printf( "%s", prompt );

    /* 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 found\n");
	if( c == '\t' )
	    c = ' ';
	else if( c > 0xa0 )
	    ; /* we don't allow 0xa0, as this is a protected blank which may
	       * confuse the user */
        /* Fixme: The above assumption is not bad.  We assum a certain
           character set and even worse, the W32 version behaves
           differently.  It is not clear how we can hix this.  When
           used for passphrases this code path strips off certain
           characters so changing this might invalidate passphrases.  */
	else if( iscntrl(c) )
	    continue;
	if( !(i < n-1) ) {
	    n += 50;
	    buf = m_realloc( 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;
}


char *
tty_get( const char *prompt )
{
#ifdef HAVE_LIBREADLINE
    if (!batchmode && !no_terminal) {
      char *line;
      char *buf;

      if( !initialized )
	init_ttyfp();

      last_prompt_len = 0;

      line = 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 = m_alloc(line? strlen(line)+1:2);
      if (line)
        {
          strcpy (buf, line);
          trim_spaces (buf);
          if (strlen (buf) > 2 )
            add_history (line); /* Note that we test BUF but add LINE. */
          free (line);
        }
      else
        {
          buf[0] = CONTROL_D;
          buf[1] = 0;
        }
      return buf;
    }
    else
#endif /* HAVE_LIBREADLINE */
      return do_get( prompt, 0 );
}

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 _WIN32
    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);
    m_free(p);
    return yes;
}