xref: /freebsd/contrib/openpam/lib/libpam/openpam_readlinev.c (revision 076ad2f836d5f49dc1375f1677335a48fe0d4b82)
1 /*-
2  * Copyright (c) 2012-2016 Dag-Erling Smørgrav
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote
14  *    products derived from this software without specific prior written
15  *    permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $Id: openpam_readlinev.c 890 2016-01-11 16:22:09Z des $
30  */
31 
32 #ifdef HAVE_CONFIG_H
33 # include "config.h"
34 #endif
35 
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 
40 #include <security/pam_appl.h>
41 
42 #include "openpam_impl.h"
43 
44 #define MIN_WORDV_SIZE	32
45 
46 /*
47  * OpenPAM extension
48  *
49  * Read a line from a file and split it into words.
50  */
51 
52 char **
53 openpam_readlinev(FILE *f, int *lineno, int *lenp)
54 {
55 	char *word, **wordv, **tmp;
56 	size_t wordlen, wordvsize;
57 	int ch, serrno, wordvlen;
58 
59 	wordvsize = MIN_WORDV_SIZE;
60 	wordvlen = 0;
61 	if ((wordv = malloc(wordvsize * sizeof *wordv)) == NULL) {
62 		openpam_log(PAM_LOG_ERROR, "malloc(): %m");
63 		errno = ENOMEM;
64 		return (NULL);
65 	}
66 	wordv[wordvlen] = NULL;
67 	while ((word = openpam_readword(f, lineno, &wordlen)) != NULL) {
68 		if ((unsigned int)wordvlen + 1 >= wordvsize) {
69 			/* need to expand the array */
70 			wordvsize *= 2;
71 			tmp = realloc(wordv, wordvsize * sizeof *wordv);
72 			if (tmp == NULL) {
73 				openpam_log(PAM_LOG_ERROR, "malloc(): %m");
74 				errno = ENOMEM;
75 				break;
76 			}
77 			wordv = tmp;
78 		}
79 		/* insert our word */
80 		wordv[wordvlen++] = word;
81 		wordv[wordvlen] = NULL;
82 		word = NULL;
83 	}
84 	if (errno != 0) {
85 		/* I/O error or out of memory */
86 		serrno = errno;
87 		while (wordvlen--)
88 			free(wordv[wordvlen]);
89 		free(wordv);
90 		free(word);
91 		errno = serrno;
92 		return (NULL);
93 	}
94 	/* assert(!ferror(f)) */
95 	ch = fgetc(f);
96 	/* assert(ch == EOF || ch == '\n') */
97 	if (ch == EOF && wordvlen == 0) {
98 		free(wordv);
99 		return (NULL);
100 	}
101 	if (ch == '\n' && lineno != NULL)
102 		++*lineno;
103 	if (lenp != NULL)
104 		*lenp = wordvlen;
105 	return (wordv);
106 }
107 
108 /**
109  * The =openpam_readlinev function reads a line from a file, splits it
110  * into words according to the rules described in the =openpam_readword
111  * manual page, and returns a list of those words.
112  *
113  * If =lineno is not =NULL, the integer variable it points to is
114  * incremented every time a newline character is read.
115  * This includes quoted or escaped newline characters and the newline
116  * character at the end of the line.
117  *
118  * If =lenp is not =NULL, the number of words on the line is stored in the
119  * variable to which it points.
120  *
121  * RETURN VALUES
122  *
123  * If successful, the =openpam_readlinev function returns a pointer to a
124  * dynamically allocated array of pointers to individual dynamically
125  * allocated NUL-terminated strings, each containing a single word, in the
126  * order in which they were encountered on the line.
127  * The array is terminated by a =NULL pointer.
128  *
129  * The caller is responsible for freeing both the array and the individual
130  * strings by passing each of them to =!free.
131  *
132  * If the end of the line was reached before any words were read,
133  * =openpam_readlinev returns a pointer to a dynamically allocated array
134  * containing a single =NULL pointer.
135  *
136  * The =openpam_readlinev function can fail and return =NULL for one of
137  * four reasons:
138  *
139  *  - The end of the file was reached before any words were read; :errno is
140  *    zero, =!ferror returns zero, and =!feof returns a non-zero value.
141  *
142  *  - The end of the file was reached while a quote or backslash escape
143  *    was in effect; :errno is set to =EINVAL, =!ferror returns zero, and
144  *    =!feof returns a non-zero value.
145  *
146  *  - An error occurred while reading from the file; :errno is non-zero,
147  *    =!ferror returns a non-zero value and =!feof returns zero.
148  *
149  *  - A =!malloc or =!realloc call failed; :errno is set to =ENOMEM,
150  *    =!ferror returns a non-zero value, and =!feof may or may not return
151  *    a non-zero value.
152  *
153  * >openpam_readline
154  * >openpam_readword
155  *
156  * AUTHOR DES
157  */
158