source: openpam/trunk/lib/openpam_readline.c @ 380

Last change on this file since 380 was 380, checked in by Dag-Erling Smørgrav, 13 years ago

Fix signedness mismatch, and use an explicit cast when calling ctype functions.

  • Property svn:keywords set to Id
File size: 4.3 KB
Line 
1/*-
2 * Copyright (c) 2003 Networks Associates Technology, Inc.
3 * All rights reserved.
4 *
5 * This software was developed for the FreeBSD Project by ThinkSec AS and
6 * Network Associates Laboratories, the Security Research Division of
7 * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
8 * ("CBOSS"), as part of the DARPA CHATS research program.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote
19 *    products derived from this software without specific prior written
20 *    permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $Id: openpam_readline.c 380 2006-03-14 14:42:09Z des $
35 */
36
37#include <ctype.h>
38#include <stdio.h>
39#include <stdlib.h>
40
41#include <security/pam_appl.h>
42#include "openpam_impl.h"
43
44#define MIN_LINE_LENGTH 128
45
46/*
47 * OpenPAM extension
48 *
49 * Read a line from a file.
50 */
51
52char *
53openpam_readline(FILE *f, int *lineno, size_t *lenp)
54{
55        char *line;
56        size_t len, size;
57        int ch;
58
59        if ((line = malloc(MIN_LINE_LENGTH)) == NULL)
60                return (NULL);
61        size = MIN_LINE_LENGTH;
62        len = 0;
63
64#define line_putch(ch) do { \
65        if (len >= size - 1) { \
66                char *tmp = realloc(line, size *= 2); \
67                if (tmp == NULL) \
68                        goto fail; \
69                line = tmp; \
70        } \
71        line[len++] = ch; \
72        line[len] = '\0'; \
73} while (0)
74
75        for (;;) {
76                ch = fgetc(f);
77                /* strip comment */
78                if (ch == '#') {
79                        do {
80                                ch = fgetc(f);
81                        } while (ch != EOF && ch != '\n');
82                }
83                /* eof */
84                if (ch == EOF) {
85                        /* remove trailing whitespace */
86                        while (len > 0 && isspace((int)line[len - 1]))
87                                --len;
88                        line[len] = '\0';
89                        if (len == 0)
90                                goto fail;
91                        break;
92                }
93                /* eol */
94                if (ch == '\n') {
95                        if (lineno != NULL)
96                                ++*lineno;
97
98                        /* remove trailing whitespace */
99                        while (len > 0 && isspace((int)line[len - 1]))
100                                --len;
101                        line[len] = '\0';
102                        /* skip blank lines */
103                        if (len == 0)
104                                continue;
105                        /* continuation */
106                        if (line[len - 1] == '\\') {
107                                line[--len] = '\0';
108                                /* fall through to whitespace case */
109                        } else {
110                                break;
111                        }
112                }
113                /* whitespace */
114                if (isspace(ch)) {
115                        /* ignore leading whitespace */
116                        /* collapse linear whitespace */
117                        if (len > 0 && line[len - 1] != ' ')
118                                line_putch(' ');
119                        continue;
120                }
121                /* anything else */
122                line_putch(ch);
123        }
124
125        if (lenp != NULL)
126                *lenp = len;
127        return (line);
128 fail:
129        FREE(line);
130        return (NULL);
131}
132
133/**
134 * The =openpam_readline function reads a line from a file, and returns it
135 * in a NUL-terminated buffer allocated with =malloc.
136 *
137 * The =openpam_readline function performs a certain amount of processing
138 * on the data it reads.
139 * Comments (introduced by a hash sign) are stripped, as is leading and
140 * trailing whitespace.
141 * Any amount of linear whitespace is collapsed to a single space.
142 * Blank lines are ignored.
143 * If a line ends in a backslash, the backslash is stripped and the next
144 * line is appended.
145 *
146 * If =lineno is not =NULL, the integer variable it points to is
147 * incremented every time a newline character is read.
148 *
149 * If =lenp is not =NULL, the length of the line (not including the
150 * terminating NUL character) is stored in the variable it points to.
151 *
152 * The caller is responsible for releasing the returned buffer by passing
153 * it to =free.
154 */
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