source: rtems/cpukit/libmisc/shell/login_prompt.c @ cbd1e87

4.104.11
Last change on this file since cbd1e87 was cbd1e87, checked in by Thomas Doerfler <Thomas.Doerfler@…>, on Apr 14, 2009 at 8:50:03 AM

adapt copyright statements

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File size: 6.3 KB
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[2649eef]1/**
2 * @file
3 *
4 * @brief Shell login prompt functions.
5 */
6
7/*
[cbd1e87]8 * Authorship
9 * ----------
10 * Parts of this software was created by
11 *     Till Straumann <strauman@slac.stanford.edu>, 2003-2007
12 *         Stanford Linear Accelerator Center, Stanford University.
13 *                                                                 
14 * Acknowledgement of sponsorship                                 
15 * ------------------------------                                 
16 * Parts of this software was produced by                                   
17 *     the Stanford Linear Accelerator Center, Stanford University,
18 *         under Contract DE-AC03-76SFO0515 with the Department of Energy.
19 *                                                                       
20 * Government disclaimer of liability                                     
21 * ----------------------------------                                     
22 * Neither the United States nor the United States Department of Energy, 
23 * nor any of their employees, makes any warranty, express or implied, or
24 * assumes any legal liability or responsibility for the accuracy,       
25 * completeness, or usefulness of any data, apparatus, product, or process
26 * disclosed, or represents that its use would not infringe privately owned
27 * rights.                                                                 
28 *                                                                         
29 * Stanford disclaimer of liability                                       
30 * --------------------------------                                       
31 * Stanford University makes no representations or warranties, express or 
32 * implied, nor assumes any liability for the use of this software.       
33 *                                                                         
34 * Stanford disclaimer of copyright                                       
35 * --------------------------------                                       
36 * Stanford University, owner of the copyright, hereby disclaims its       
37 * copyright and all other rights in this software.  Hence, anyone may     
38 * freely use it for any purpose without restriction.                     
39 *                                                                         
40 * Maintenance of notices                                                 
41 * ----------------------                                                 
42 * In the interest of clarity regarding the origin and status of this     
43 * SLAC software, this and all the preceding Stanford University notices   
44 * are to remain affixed to any copy or derivative of this software made   
45 * or distributed by the recipient and are to be affixed to any copy of   
46 * software made or distributed by the recipient that contains a copy or   
47 * derivative of this software.                                           
48 *                                                                         
49 * ------------------ SLAC Software Notices, Set 4 OTT.002a, 2004 FEB 03
50 *
51 * Copyright (c) 2009 embedded brains GmbH and others.
52 *
[2649eef]53 * embedded brains GmbH
54 * Obere Lagerstr. 30
55 * D-82178 Puchheim
56 * Germany
57 * <rtems@embedded-brains.de>
58 *
59 * Based on work from Chris Johns, Fernando Ruiz and Till Straumann.
60 *
[cbd1e87]61 * Derived from files "cpukit/libmisc/shell/shell.c" and
62 * "cpukit/telnetd/check_passwd.c".
63 *
[2649eef]64 * The license and distribution terms for this file may be
65 * found in the file LICENSE in this distribution or at
66 * http://www.rtems.com/license/LICENSE.
67 */
68
69#include <stdio.h>
70#include <termios.h>
71#include <unistd.h>
72#include <ctype.h>
73
[cbd1e87]74#include <rtems/shell.h>
[2649eef]75
76static int rtems_shell_discard( int c, FILE *stream)
77{
78  return c;
79}
80
81static void rtems_shell_get_text(
82  FILE *in,
83  FILE *out,
84  char *line,
85  size_t size
86)
87{
88  int fd_in = fileno( in);
89  int (*put)( int, FILE *) =
90    out != NULL && isatty( fd_in)
91      ? fputc
92      : rtems_shell_discard;
93  size_t i = 0;
94
95  if (size < 1) {
96    return;
97  }
98
99  tcdrain( fd_in);
100  if (out != NULL){
101    tcdrain( fileno( out));
102  }
103
104  while (true) {
105    int c = fgetc( in);
106
107    switch (c) {
108      case EOF:
109        /* Here comes an ugly hack: The Termios driver's read() handler returns
110         * 0 to the C library's fgets() if it times out.  fgets() interprets
111         * this (correctly) as EOF, a condition we want to undo since it's not
112         * really true since we really have a read error (Termios bug?).
113         *
114         * As a workaround we push something back and read it again.  This
115         * should simply reset the EOF condition.
116         */
117        if (ungetc( '?', in) == '?') {
118          fgetc( in);
119        }
120        break;
121      case '\n':
122      case '\r':
123        put( '\n', out);
124        line [i] = '\0';
125        return;
126      case  127:
127      case '\b':
128        if (i > 0) {
129          put( '\b', out);
130          put( ' ', out);
131          put( '\b', out);
132          --i;
133        } else {
134          put( '\a', out);
135        }
136        break;
137      default:
138        if (!iscntrl( c)) {
139          if (i < size - 1) {
140            line [i] = (char) c;
141            ++i;
142            put( c, out);
143          } else {
144            put( '\a', out);
145          }
146        } else {
147          put( '\a', out);
148        }
149        break;
150    }
151  }
152}
153
154bool rtems_shell_login_prompt(
155  FILE *in,
156  FILE *out,
157  const char *device,
[cbd1e87]158  rtems_shell_login_check_t check
[2649eef]159)
160{
161  int fd_in = fileno( in);
162  struct termios termios_previous;
163  bool restore_termios = false;
164  int i = 0;
165  bool result = false;
166
167  if (tcgetattr( fd_in, &termios_previous) == 0) {
168    struct termios termios_new = termios_previous;
169
170    termios_new.c_lflag &= ~ECHO;
171    termios_new.c_lflag &= ~ICANON;
172    termios_new.c_cc [VTIME] = 255;
173    termios_new.c_cc [VMIN] = 0;
174
175    restore_termios = tcsetattr( fd_in, TCSANOW, &termios_new) == 0;
176  }
177
178  for (i = 0; i < 3; ++i) {
179    char user [32];
180    char passphrase [128];
181
182    fprintf( out, "%s login: ", device);
183    fflush( out);
184    rtems_shell_get_text( in, out, user, sizeof( user));
185
186    fflush( in);
187    fprintf( out, "Password: ");
188    fflush( out);
189    rtems_shell_get_text( in, NULL, passphrase, sizeof( passphrase));
190    fputc( '\n', out);
191
192    result = check( user, passphrase);
193    if (result) {
194      break;
195    }
196
197    fprintf( out, "Login incorrect\n\n");
198    sleep( 2);
199  }
200
201  if (restore_termios) {
202    /* What to do if restoring the flags fails? */
203    tcsetattr( fd_in, TCSANOW, &termios_previous);
204  }
205
206  return result;
207}
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