at.tproj/perm.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  *  perm.c - check user permission for at(1)
  27  *  Copyright (C) 1994  Thomas Koenig
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. The name of the author(s) may not be used to endorse or promote
  35  *    products derived from this software without specific prior written
  36  *    permission.
  37  *
  38  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  39  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  40  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  41  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  42  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  43  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  44  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  45  * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  46  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  47  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  48  */
  49
  50 /* System Headers */
  51
  52 #include <sys/types.h>
  53 #include <errno.h>
  54 #include <pwd.h>
  55 #include <stddef.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include <unistd.h>
  60
  61 /* Local headers */
  62
  63 #include "privs.h"
  64 #include "at.h"
  65 #include "pathnames.h"
  66
  67 /* Macros */
  68
  69 #define MAXUSERID 10
  70
  71 /* Structures and unions */
  72
  73 /* File scope variables */
  74
  75 static char rcsid[] = "$Id: perm.c,v 1.1.1.2 2000/01/11 02:10:05 wsanchez Exp $";
  76
  77 /* Function declarations */
  78
  79 static int check_for_user(FILE *fp,const char *name);
  80
  81 /* Local functions */
  82
  83 static int check_for_user(FILE *fp,const char *name)
  84 {
  85     char *buffer;
  86     size_t len;
  87     int found = 0;
  88
  89     len = strlen(name);
  90     if ((buffer = malloc(sizeof (char) * (len+2))) == NULL) {
  91         fprintf(stderr, "malloc error!");
  92         exit(EXIT_FAILURE);
  93     }
  94
  95     while(fgets(buffer, len+2, fp) != NULL)
  96     {
  97         if ((strncmp(name, buffer, len) == 0) &&
  98             (buffer[len] == '\n'))
  99         {
 100             found = 1;
 101             break;
 102         }
 103     }
 104     fclose(fp);
 105     free(buffer);
 106     return found;
 107 }
 108 /* Global functions */
 109 int check_permission()
 110 {
 111     FILE *fp;
 112     uid_t uid = geteuid();
 113     struct passwd *pentry;
 114
 115     if (uid==0)
 116         return 1;
 117
 118     if ((pentry = getpwuid(uid)) == NULL)
 119     {
 120         perror("Cannot access user database");
 121         exit(EXIT_FAILURE);
 122     }
 123
 124     PRIV_START
 125
 126     fp=fopen(_PATH_AT "at.allow","r");
 127
 128     PRIV_END
 129
 130     if (fp != NULL)
 131     {
 132         return check_for_user(fp, pentry->pw_name);
 133     }
 134     else
 135     {
 136
 137         PRIV_START
 138
 139         fp=fopen(_PATH_AT "at.deny", "r");
 140
 141         PRIV_END
 142
 143         if (fp != NULL)
 144         {
 145             return !check_for_user(fp, pentry->pw_name);
 146         }
 147         perror("at.deny");
 148     }
 149     return 0;
 150 }