xref: /freebsd/usr.sbin/chkgrp/chkgrp.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
1 /*-
2  * Copyright (c) 1998 Dag-Erling Coïdan 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  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <err.h>
33 #include <errno.h>
34 #include <ctype.h>
35 #include <inttypes.h>
36 #include <limits.h>
37 #include <stdint.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 #include <sysexits.h>
43 
44 static void __dead2
45 usage(void)
46 {
47 
48 	fprintf(stderr, "usage: chkgrp [-q] [groupfile]\n");
49 	exit(EX_USAGE);
50 }
51 
52 int
53 main(int argc, char *argv[])
54 {
55 	FILE *gf;
56 	unsigned long gid;
57 	unsigned int i;
58 	size_t len;
59 	int opt, quiet;
60 	int n = 0, k, e = 0;
61 	const char *cp, *f[4], *gfn, *p;
62 	char *line;
63 
64 	quiet = 0;
65 	while ((opt = getopt(argc, argv, "q")) != -1) {
66 		switch (opt) {
67 		case 'q':
68 			quiet = 1;
69 			break;
70 		default:
71 			usage();
72 		}
73 	}
74 
75 	argc -= optind;
76 	argv += optind;
77 
78 	if (argc == 0)
79 		gfn = "/etc/group";
80 	else if (argc == 1)
81 		gfn = argv[0];
82 	else
83 		usage();
84 
85 	/* open group file */
86 	if ((gf = fopen(gfn, "r")) == NULL)
87 		err(EX_NOINPUT, "%s", gfn);
88 
89 	/* check line by line */
90 	while (++n) {
91 		if ((line = fgetln(gf, &len)) == NULL)
92 			break;
93 		if (len > 0 && line[len - 1] != '\n') {
94 			warnx("%s: line %d: no newline character", gfn, n);
95 			e = 1;
96 		}
97 		while (len && isspace(line[len-1]))
98 			len--;
99 
100 		/* ignore blank lines and comments */
101 		for (p = line; p < line + len; p++)
102 			if (!isspace(*p)) break;
103 		if (!len || *p == '#')
104 			continue;
105 
106 		/*
107 		 * Hack: special case for + line
108 		 */
109 		if (strncmp(line, "+:::", len) == 0 ||
110 		    strncmp(line, "+:*::", len) == 0)
111 			continue;
112 
113 		/*
114 		 * A correct group entry has four colon-separated fields,
115 		 * the third of which must be entirely numeric and the
116 		 * fourth of which may be empty.
117 		 */
118 		for (i = k = 0; k < 4; k++) {
119 			for (f[k] = line + i; i < len && line[i] != ':'; i++)
120 				/* nothing */ ;
121 			if (k < 3 && line[i] != ':')
122 				break;
123 			line[i++] = 0;
124 		}
125 
126 		if (k < 4) {
127 			warnx("%s: line %d: missing field(s)", gfn, n);
128 			while (k < 4)
129 				f[k++] = "";
130 			e = 1;
131 		}
132 
133 		for (cp = f[0] ; *cp ; cp++) {
134 			if (!isalnum(*cp) && *cp != '.' && *cp != '_' &&
135 			    *cp != '-' && (cp > f[0] || *cp != '+')) {
136 				warnx("%s: line %d: '%c' invalid character",
137 				    gfn, n, *cp);
138 				e = 1;
139 			}
140 		}
141 
142 		for (cp = f[3] ; *cp ; cp++) {
143 			if (!isalnum(*cp) && *cp != '.' && *cp != '_' &&
144 			    *cp != '-' && *cp != ',') {
145 				warnx("%s: line %d: '%c' invalid character",
146 				    gfn, n, *cp);
147 				e = 1;
148 			}
149 		}
150 
151 		/* check if fourth field ended with a colon */
152 		if (i < len) {
153 			warnx("%s: line %d: too many fields", gfn, n);
154 			e = 1;
155 		}
156 
157 		/* check that none of the fields contain whitespace */
158 		for (k = 0; k < 4; k++) {
159 			if (strcspn(f[k], " \t") != strlen(f[k])) {
160 				warnx("%s: line %d: field %d contains whitespace",
161 				    gfn, n, k+1);
162 				e = 1;
163 			}
164 		}
165 
166 		/* check that the GID is numeric */
167 		if (strspn(f[2], "0123456789") != strlen(f[2])) {
168 			warnx("%s: line %d: group id is not numeric", gfn, n);
169 			e = 1;
170 		}
171 
172 		/* check the range of the group id */
173 		errno = 0;
174 		gid = strtoul(f[2], NULL, 10);
175 		if (errno != 0) {
176 			warnx("%s: line %d: strtoul failed", gfn, n);
177 		} else if (gid > GID_MAX) {
178 			warnx("%s: line %d: group id is too large (%ju > %ju)",
179 			    gfn, n, (uintmax_t)gid, (uintmax_t)GID_MAX);
180 			e = 1;
181 		}
182 	}
183 
184 	/* check what broke the loop */
185 	if (ferror(gf))
186 		err(EX_IOERR, "%s: line %d", gfn, n);
187 
188 	/* done */
189 	fclose(gf);
190 	if (e == 0 && quiet == 0)
191 		printf("%s is fine\n", gfn);
192 	exit(e ? EX_DATAERR : EX_OK);
193 }
194