xref: /freebsd/libexec/mknetid/parse_group.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 
32 /*
33  * This is a slightly modified chunk of getgrent(3). All the YP support
34  * and unneeded functions have been stripped out.
35  */
36 
37 #include <sys/types.h>
38 #include <grp.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 
43 FILE *_gr_fp;
44 static struct group _gr_group;
45 static int _gr_stayopen;
46 static int grscan(int, int);
47 static int start_gr(void);
48 
49 #define	MAXGRP		200
50 static char *members[MAXGRP];
51 #define	MAXLINELENGTH	1024
52 static char line[MAXLINELENGTH];
53 
54 struct group *
55 _getgrent(void)
56 {
57 	if (!_gr_fp && !start_gr()) {
58 		return NULL;
59 	}
60 
61 
62 	if (!grscan(0, 0))
63 		return(NULL);
64 	return(&_gr_group);
65 }
66 
67 static int
68 start_gr(void)
69 {
70 	return 1;
71 }
72 
73 int
74 _setgroupent(int stayopen)
75 {
76 	if (!start_gr())
77 		return(0);
78 	_gr_stayopen = stayopen;
79 	return(1);
80 }
81 
82 int
83 _setgrent(void)
84 {
85 	return(_setgroupent(0));
86 }
87 
88 void
89 _endgrent(void)
90 {
91 	if (_gr_fp) {
92 		(void)fclose(_gr_fp);
93 		_gr_fp = NULL;
94 	}
95 }
96 
97 static int
98 grscan(int search, int gid)
99 {
100 	char *cp, **m;
101 	char *bp;
102 	for (;;) {
103 		if (!fgets(line, sizeof(line), _gr_fp))
104 			return(0);
105 		bp = line;
106 		/* skip lines that are too big */
107 		if (!strchr(line, '\n')) {
108 			int ch;
109 
110 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
111 				;
112 			continue;
113 		}
114 		if ((_gr_group.gr_name = strsep(&bp, ":\n")) == NULL)
115 			break;
116 		if (_gr_group.gr_name[0] == '+')
117 			continue;
118 		if ((_gr_group.gr_passwd = strsep(&bp, ":\n")) == NULL)
119 			break;
120 		if (!(cp = strsep(&bp, ":\n")))
121 			continue;
122 		_gr_group.gr_gid = atoi(cp);
123 		if (search && _gr_group.gr_gid != gid)
124 			continue;
125 		cp = NULL;
126 		if (bp == NULL) /* !! Must check for this! */
127 			break;
128 		for (m = _gr_group.gr_mem = members;; bp++) {
129 			if (m == &members[MAXGRP - 1])
130 				break;
131 			if (*bp == ',') {
132 				if (cp) {
133 					*bp = '\0';
134 					*m++ = cp;
135 					cp = NULL;
136 				}
137 			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
138 				if (cp) {
139 					*bp = '\0';
140 					*m++ = cp;
141 			}
142 				break;
143 			} else if (cp == NULL)
144 				cp = bp;
145 		}
146 		*m = NULL;
147 		return(1);
148 	}
149 	/* NOTREACHED */
150 	return (0);
151 }
152