chkgrp.c revision 149463 
1/*-
2 * Copyright (c) 1998 Dag-Erling Co�dan Sm�rgrav
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: head/usr.sbin/chkgrp/chkgrp.c 149463 2005-08-25 17:01:06Z cperciva $");
31
32#include <err.h>
33#include <ctype.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <sysexits.h>
38
39static char empty[] = { 0 };
40
41static void
42usage(void)
43{
44    fprintf(stderr, "usage: chkgrp [groupfile]\n");
45    exit(EX_USAGE);
46}
47
48int
49main(int argc, char *argv[])
50{
51    unsigned int i;
52    size_t len;
53    int n = 0, k, e = 0;
54    char *line, *f[4], *p;
55    const char *cp, *gfn;
56    FILE *gf;
57
58    /* check arguments */
59    switch (argc) {
60    case 1:
61	gfn = "/etc/group";
62	break;
63    case 2:
64	gfn = argv[1];
65	break;
66    default:
67	gfn = NULL; /* silence compiler */
68	usage();
69    }
70
71    /* open group file */
72    if ((gf = fopen(gfn, "r")) == NULL)
73	err(EX_IOERR, "%s", gfn); /* XXX - is IO_ERR the correct exit code? */
74
75    /* check line by line */
76    while (++n) {
77	if ((line = fgetln(gf, &len)) == NULL)
78	    break;
79	if (len > 0 && line[len - 1] != '\n') {
80	    warnx("%s: line %d: no newline character", gfn, n);
81	    e++;
82	}
83	while (len && isspace(line[len-1]))
84	    len--;
85
86	/* ignore blank lines and comments */
87	for (p = line; p < (line + len); p++)
88	    if (!isspace(*p)) break;
89	if (!len || (*p == '#')) {
90#if 0
91	    /* entry is correct, so print it */
92	    printf("%*.*s\n", len, len, line);
93#endif
94	    continue;
95	}
96
97	/*
98	 * A correct group entry has four colon-separated fields, the third
99	 * of which must be entirely numeric and the fourth of which may
100	 * be empty.
101	 */
102	for (i = k = 0; k < 4; k++) {
103	    for (f[k] = line+i; (i < len) && (line[i] != ':'); i++)
104		/* nothing */ ;
105	    if ((k < 3) && (line[i] != ':'))
106		break;
107	    line[i++] = 0;
108	}
109
110        if (k < 4) {
111            warnx("%s: line %d: missing field(s)", gfn, n);
112	    for ( ; k < 4; k++)
113		f[k] = empty;
114            e++;
115        }
116
117	for (cp = f[0] ; *cp ; cp++) {
118	    if (!isalnum(*cp) && *cp != '.' && *cp != '_' && *cp != '-' &&
119		(cp > f[0] || *cp != '+')) {
120		warnx("%s: line %d: '%c' invalid character", gfn, n, *cp);
121		e++;
122	    }
123	}
124
125	for (cp = f[3] ; *cp ; cp++) {
126	    if (!isalnum(*cp) && *cp != '.' && *cp != '_' && *cp != '-' &&
127			*cp != ',') {
128		warnx("%s: line %d: '%c' invalid character", gfn, n, *cp);
129		e++;
130	    }
131	}
132
133	/* check if fourth field ended with a colon */
134	if (i < len) {
135	    warnx("%s: line %d: too many fields", gfn, n);
136	    e++;
137	}
138
139	/* check that none of the fields contain whitespace */
140	for (k = 0; k < 4; k++) {
141	    if (strcspn(f[k], " \t") != strlen(f[k])) {
142		warnx("%s: line %d: field %d contains whitespace",
143		      gfn, n, k+1);
144		e++;
145	    }
146	}
147
148	/* check that the GID is numeric */
149	if (strspn(f[2], "0123456789") != strlen(f[2])) {
150	    warnx("%s: line %d: GID is not numeric", gfn, n);
151	    e++;
152	}
153
154#if 0
155	/* entry is correct, so print it */
156	printf("%s:%s:%s:%s\n", f[0], f[1], f[2], f[3]);
157#endif
158    }
159
160    /* check what broke the loop */
161    if (ferror(gf))
162	err(EX_IOERR, "%s: line %d", gfn, n);
163
164    /* done */
165    fclose(gf);
166    if (e == 0)
167	printf("%s is fine\n", gfn);
168    exit(e ? EX_DATAERR : EX_OK);
169}
170