xref: /netbsd-src/external/bsd/openpam/dist/lib/libpam/openpam_readlinev.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: openpam_readlinev.c,v 1.3 2017/05/06 19:50:09 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2012-2016 Dag-Erling Smørgrav
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote
16  *    products derived from this software without specific prior written
17  *    permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $OpenPAM: openpam_readlinev.c 938 2017-04-30 21:34:42Z des $
32  */
33 
34 #ifdef HAVE_CONFIG_H
35 # include "config.h"
36 #endif
37 
38 #include <sys/cdefs.h>
39 __RCSID("$NetBSD: openpam_readlinev.c,v 1.3 2017/05/06 19:50:09 christos Exp $");
40 
41 #include <errno.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 
45 #include <security/pam_appl.h>
46 
47 #include "openpam_impl.h"
48 
49 #define MIN_WORDV_SIZE	32
50 
51 /*
52  * OpenPAM extension
53  *
54  * Read a line from a file and split it into words.
55  */
56 
57 char **
58 openpam_readlinev(FILE *f, int *lineno, int *lenp)
59 {
60 	char *word, **wordv, **tmp;
61 	size_t wordlen, wordvsize;
62 	int ch, serrno, wordvlen;
63 
64 	wordvsize = MIN_WORDV_SIZE;
65 	wordvlen = 0;
66 	if ((wordv = malloc(wordvsize * sizeof *wordv)) == NULL) {
67 		openpam_log(PAM_LOG_ERROR, "malloc(): %m");
68 		errno = ENOMEM;
69 		return (NULL);
70 	}
71 	wordv[wordvlen] = NULL;
72 	while ((word = openpam_readword(f, lineno, &wordlen)) != NULL) {
73 		if ((unsigned int)wordvlen + 1 >= wordvsize) {
74 			/* need to expand the array */
75 			wordvsize *= 2;
76 			tmp = realloc(wordv, wordvsize * sizeof *wordv);
77 			if (tmp == NULL) {
78 				openpam_log(PAM_LOG_ERROR, "malloc(): %m");
79 				errno = ENOMEM;
80 				break;
81 			}
82 			wordv = tmp;
83 		}
84 		/* insert our word */
85 		wordv[wordvlen++] = word;
86 		wordv[wordvlen] = NULL;
87 		word = NULL;
88 	}
89 	if (errno != 0) {
90 		/* I/O error or out of memory */
91 		serrno = errno;
92 		while (wordvlen--)
93 			free(wordv[wordvlen]);
94 		free(wordv);
95 		free(word);
96 		errno = serrno;
97 		return (NULL);
98 	}
99 	/* assert(!ferror(f)) */
100 	ch = fgetc(f);
101 	/* assert(ch == EOF || ch == '\n') */
102 	if (ch == EOF && wordvlen == 0) {
103 		free(wordv);
104 		return (NULL);
105 	}
106 	if (ch == '\n' && lineno != NULL)
107 		++*lineno;
108 	if (lenp != NULL)
109 		*lenp = wordvlen;
110 	return (wordv);
111 }
112 
113 /**
114  * The =openpam_readlinev function reads a line from a file, splits it
115  * into words according to the rules described in the =openpam_readword
116  * manual page, and returns a list of those words.
117  *
118  * If =lineno is not =NULL, the integer variable it points to is
119  * incremented every time a newline character is read.
120  * This includes quoted or escaped newline characters and the newline
121  * character at the end of the line.
122  *
123  * If =lenp is not =NULL, the number of words on the line is stored in the
124  * variable to which it points.
125  *
126  * RETURN VALUES
127  *
128  * If successful, the =openpam_readlinev function returns a pointer to a
129  * dynamically allocated array of pointers to individual dynamically
130  * allocated NUL-terminated strings, each containing a single word, in the
131  * order in which they were encountered on the line.
132  * The array is terminated by a =NULL pointer.
133  *
134  * The caller is responsible for freeing both the array and the individual
135  * strings by passing each of them to =!free.
136  *
137  * If the end of the line was reached before any words were read,
138  * =openpam_readlinev returns a pointer to a dynamically allocated array
139  * containing a single =NULL pointer.
140  *
141  * The =openpam_readlinev function can fail and return =NULL for one of
142  * four reasons:
143  *
144  *  - The end of the file was reached before any words were read; :errno is
145  *    zero, =!ferror returns zero, and =!feof returns a non-zero value.
146  *
147  *  - The end of the file was reached while a quote or backslash escape
148  *    was in effect; :errno is set to =EINVAL, =!ferror returns zero, and
149  *    =!feof returns a non-zero value.
150  *
151  *  - An error occurred while reading from the file; :errno is non-zero,
152  *    =!ferror returns a non-zero value and =!feof returns zero.
153  *
154  *  - A =!malloc or =!realloc call failed; :errno is set to =ENOMEM,
155  *    =!ferror returns a non-zero value, and =!feof may or may not return
156  *    a non-zero value.
157  *
158  * >openpam_readline
159  * >openpam_readword
160  *
161  * AUTHOR DES
162  */
163