1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1998 Dag-Erling Sm��rgrav
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 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
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
44static void __dead2
45usage(void)
46{
47
48	fprintf(stderr, "usage: chkgrp [-q] [groupfile]\n");
49	exit(EX_USAGE);
50}
51
52int
53main(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