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  * $FreeBSD: src/usr.sbin/chkgrp/chkgrp.c,v 1.3.2.2 2001/07/12 22:57:35 mjacob Exp $
  29  * $DragonFly: src/usr.sbin/chkgrp/chkgrp.c,v 1.6 2005/08/25 17:09:32 liamfoy Exp $
  30  */
  31 #include <sys/types.h>
  32
  33 #include <ctype.h>
  34 #include <err.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <sysexits.h>
  39
  40 #define DEFAULTGFILE "/etc/group"
  41
  42 static void     usage(void);
  43 static char empty[] = { 0 };
  44
  45 static void
  46 usage(void)
  47 {
  48         fprintf(stderr, "usage: chkgrp [groupfile]\n");
  49         exit(EX_USAGE);
  50 }
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55         size_t len;
  56         int n = 0, i, k, e = 0;
  57         char *line, *f[4], *p;
  58         const char *cp, *gfn;
  59         FILE *gf;
  60
  61         /* check arguments */
  62         switch (argc) {
  63         case 1:
  64                 gfn = DEFAULTGFILE;
  65                 break;
  66         case 2:
  67                 gfn = argv[1];
  68                 break;
  69         default:
  70                 gfn = NULL;     /* silence compiler */
  71                 usage();
  72         }
  73
  74         /* open group file */
  75         if ((gf = fopen(gfn, "r")) == NULL)
  76                 err(EX_IOERR, "%s", gfn);
  77
  78         /* check line by line */
  79         while (++n) {
  80                 if ((line = fgetln(gf, &len)) == NULL)
  81                         break;
  82                 if (len > 0 && line[len - 1] != '\n') {
  83                         warnx("%s: line %d: no newline character", gfn, n);
  84                         e++;
  85                 }
  86                 while (len && isspace(line[len - 1]))
  87                         len--;
  88
  89                 /* ignore blank lines and comments */
  90                 for (p = line; p < (line + len); p++)
  91                         if (!isspace(*p))
  92                                 break;
  93                 if (!len || (*p == '#')) {
  94 #if 0
  95                         /* entry is correct, so print it */
  96                         printf("%*.*s\n", len, len, line);
  97 #endif
  98                         continue;
  99                 }
 100                 /*
 101                  * A correct group entry has four colon-separated fields, the
 102                  * third of which must be entirely numeric and the fourth of
 103                  * which may be empty. We also check for any incorrect characters.
 104                  */
 105                 for (i = k = 0; k < 4; k++) {
 106                         for (f[k] = line + i; (i < (int)len) && (line[i] != ':'); i++)
 107                                  /* nothing */ ;
 108                         if ((k < 3) && (line[i] != ':'))
 109                                 break;
 110                         line[i++] = 0;
 111                 }
 112
 113                 if (k < 4) {
 114                         warnx("%s: line %d: missing field(s)", gfn, n);
 115                         for ( ; k < 4; k++)
 116                                 f[k] = empty;
 117                         e++;
 118                 }
 119
 120                 for (cp = f[0] ; *cp ; cp++) {
 121                         if (!isalnum(*cp) && *cp != '.' && *cp != '_' && *cp != '-' &&
 122                                 (cp > f[0] || *cp != '+')) {
 123                                 warnx("%s: line %d: '%c' invalid character", gfn, n, *cp);
 124                                 e++;
 125                         }
 126                 }
 127
 128                 for (cp = f[3] ; *cp ; cp++) {
 129                         if (!isalnum(*cp) && *cp != ',' && *cp != '.' && *cp != '_' && *cp != '-') {
 130                                 warnx("%s: line %d: '%c' invalid character", gfn, n, *cp);
 131                                 e++;
 132                         }
 133                 }
 134
 135                 /* check if fourth field ended with a colon */
 136                 if (i < (int)len) {
 137                         warnx("%s: line %d: too many fields", gfn, n);
 138                         e++;
 139                 }
 140                 /* check that none of the fields contain whitespace */
 141                 for (k = 0; k < 4; k++) {
 142                         if (strcspn(f[k], " \t") != strlen(f[k])) {
 143                                 warnx("%s: line %d: field %d contains whitespace",
 144                                       gfn, n, k + 1);
 145                                 e++;
 146                         }
 147                 }
 148
 149                 /* check that the GID is numeric */
 150                 if (strspn(f[2], "0123456789") != strlen(f[2])) {
 151                         warnx("%s: line %d: GID is not numeric", gfn, n);
 152                         e++;
 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 }