usr.sbin/chkgrp/chkgrp.c

   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 <ctype.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <sysexits.h>
  38
  39 static char empty[] = { 0 };
  40
  41 static void
  42 usage(void)
  43 {
  44     fprintf(stderr, "usage: chkgrp [groupfile]\n");
  45     exit(EX_USAGE);
  46 }
  47
  48 int
  49 main(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 }