lib/replace/getpass.c

   1 /* Copyright (C) 1992-1998 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Lesser General Public License as
   6 published by the Free Software Foundation; either version 3 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Lesser General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, see <http://www.gnu.org/licenses/>.  */
  17
  18 /* Modified to use with samba by Jeremy Allison, 8th July 1995. */
  19
  20 #include "replace.h"
  21 #include "system/filesys.h"
  22 #include "system/wait.h"
  23 #include "system/terminal.h"
  24 #include "system/passwd.h"
  25
  26 /*
  27  * Define additional missing types
  28  */
  29 #ifndef HAVE_SIG_ATOMIC_T_TYPE
  30 typedef int sig_atomic_t;
  31 #endif
  32
  33 #ifndef SIGCLD
  34 #define SIGCLD SIGCHLD
  35 #endif
  36
  37 #ifdef SYSV_TERMIO
  38
  39 /* SYSTEM V TERMIO HANDLING */
  40
  41 static struct termio t;
  42
  43 #define ECHO_IS_ON(t) ((t).c_lflag & ECHO)
  44 #define TURN_ECHO_OFF(t) ((t).c_lflag &= ~ECHO)
  45 #define TURN_ECHO_ON(t) ((t).c_lflag |= ECHO)
  46
  47 #ifndef TCSAFLUSH
  48 #define TCSAFLUSH 1
  49 #endif
  50
  51 #ifndef TCSANOW
  52 #define TCSANOW 0
  53 #endif
  54
  55 static int tcgetattr(int fd, struct termio *_t)
  56 {
  57         return ioctl(fd, TCGETA, _t);
  58 }
  59
  60 static int tcsetattr(int fd, int flags, struct termio *_t)
  61 {
  62         if(flags & TCSAFLUSH)
  63                 ioctl(fd, TCFLSH, TCIOFLUSH);
  64         return ioctl(fd, TCSETS, _t);
  65 }
  66
  67 #elif !defined(TCSAFLUSH)
  68
  69 /* BSD TERMIO HANDLING */
  70
  71 static struct sgttyb t;
  72
  73 #define ECHO_IS_ON(t) ((t).sg_flags & ECHO)
  74 #define TURN_ECHO_OFF(t) ((t).sg_flags &= ~ECHO)
  75 #define TURN_ECHO_ON(t) ((t).sg_flags |= ECHO)
  76
  77 #define TCSAFLUSH 1
  78 #define TCSANOW 0
  79
  80 static int tcgetattr(int fd, struct sgttyb *_t)
  81 {
  82         return ioctl(fd, TIOCGETP, (char *)_t);
  83 }
  84
  85 static int tcsetattr(int fd, int flags, struct sgttyb *_t)
  86 {
  87         return ioctl(fd, TIOCSETP, (char *)_t);
  88 }
  89
  90 #else /* POSIX TERMIO HANDLING */
  91 #define ECHO_IS_ON(t) ((t).c_lflag & ECHO)
  92 #define TURN_ECHO_OFF(t) ((t).c_lflag &= ~ECHO)
  93 #define TURN_ECHO_ON(t) ((t).c_lflag |= ECHO)
  94
  95 static struct termios t;
  96 #endif /* SYSV_TERMIO */
  97
  98 static void catch_signal(int signum, void (*handler)(int ))
  99 {
 100 #ifdef HAVE_SIGACTION
 101         struct sigaction act;
 102         struct sigaction oldact;
 103
 104         memset(&act, 0, sizeof(act));
 105
 106         act.sa_handler = handler;
 107 #ifdef SA_RESTART
 108         /*
 109          * We *want* SIGALRM to interrupt a system call.
 110          */
 111         if(signum != SIGALRM)
 112                 act.sa_flags = SA_RESTART;
 113 #endif
 114         sigemptyset(&act.sa_mask);
 115         sigaddset(&act.sa_mask,signum);
 116         sigaction(signum,&act,&oldact);
 117 #else /* !HAVE_SIGACTION */
 118         /* FIXME: need to handle sigvec and systems with broken signal() */
 119         signal(signum, handler);
 120 #endif
 121 }
 122
 123 static sig_atomic_t gotintr;
 124 static int in_fd = -1;
 125
 126 /***************************************************************
 127  Signal function to tell us were ^C'ed.
 128 ****************************************************************/
 129
 130 static void gotintr_sig(int signum)
 131 {
 132         gotintr = 1;
 133         if (in_fd != -1)
 134                 close(in_fd); /* Safe way to force a return. */
 135         in_fd = -1;
 136 }
 137
 138 char *rep_getpass(const char *prompt)
 139 {
 140         FILE *in, *out;
 141         int echo_off;
 142         static char buf[256];
 143         static size_t bufsize = sizeof(buf);
 144         size_t nread;
 145
 146         /* Catch problematic signals */
 147         catch_signal(SIGINT, gotintr_sig);
 148
 149         /* Try to write to and read from the terminal if we can.
 150                 If we can't open the terminal, use stderr and stdin.  */
 151
 152         in = fopen ("/dev/tty", "w+");
 153         if (in == NULL) {
 154                 in = stdin;
 155                 out = stderr;
 156         } else {
 157                 out = in;
 158         }
 159
 160         setvbuf(in, NULL, _IONBF, 0);
 161
 162         /* Turn echoing off if it is on now.  */
 163
 164         if (tcgetattr (fileno (in), &t) == 0) {
 165                 if (ECHO_IS_ON(t)) {
 166                         TURN_ECHO_OFF(t);
 167                         echo_off = tcsetattr (fileno (in), TCSAFLUSH, &t) == 0;
 168                         TURN_ECHO_ON(t);
 169                 } else {
 170                         echo_off = 0;
 171                 }
 172         } else {
 173                 echo_off = 0;
 174         }
 175
 176         /* Write the prompt.  */
 177         fputs(prompt, out);
 178         fflush(out);
 179
 180         /* Read the password.  */
 181         buf[0] = 0;
 182         if (!gotintr) {
 183                 in_fd = fileno(in);
 184                 if (fgets(buf, bufsize, in) == NULL) {
 185                         buf[0] = 0;
 186                 }
 187         }
 188         nread = strlen(buf);
 189         if (nread) {
 190                 if (buf[nread - 1] == '\n')
 191                         buf[nread - 1] = '\0';
 192         }
 193
 194         /* Restore echoing.  */
 195         if (echo_off) {
 196                 if (gotintr && in_fd == -1) {
 197                         in = fopen ("/dev/tty", "w+");
 198                 }
 199                 if (in != NULL)
 200                         tcsetattr (fileno (in), TCSANOW, &t);
 201         }
 202
 203         fprintf(out, "\n");
 204         fflush(out);
 205
 206         if (in && in != stdin) /* We opened the terminal; now close it.  */
 207                 fclose(in);
 208
 209         /* Catch problematic signals */
 210         catch_signal(SIGINT, SIG_DFL);
 211
 212         if (gotintr) {
 213                 printf("Interrupted by signal.\n");
 214                 fflush(stdout);
 215                 exit(1);
 216         }
 217         return buf;
 218 }