mdw@git.distorted.org.uk Git - fwd/blob - acl.h

   1 /* -*-c-*-
   2  *
   3  * $Id: acl.h,v 1.4 2003/11/25 14:08:23 mdw Exp $
   4  *
   5  * Access control list handling
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: acl.h,v $
  32  * Revision 1.4  2003/11/25 14:08:23  mdw
  33  * Debianization.  Socket target options.  Internet binding.
  34  *
  35  * Revision 1.3  1999/07/27 18:30:53  mdw
  36  * Various minor portability fixes.
  37  *
  38  * Revision 1.2  1999/07/26 23:28:16  mdw
  39  * Minor modifications for new design.
  40  *
  41  * Revision 1.1.1.1  1999/07/01 08:56:23  mdw
  42  * Initial revision.
  43  *
  44  */
  45
  46 #ifndef ACL_H
  47 #define ACL_H
  48
  49 #ifdef __cplusplus
  50   extern "C" {
  51 #endif
  52
  53 /*----- Header files ------------------------------------------------------*/
  54
  55 #include <stdio.h>
  56
  57 #include <sys/types.h>
  58 #include <sys/socket.h>
  59 #include <netinet/in.h>
  60
  61 /*----- Data structures ---------------------------------------------------*/
  62
  63 /* --- An access control entry --- */
  64
  65 typedef struct acl_entry {
  66   struct acl_entry *next;               /* Next entry in the list */
  67   const struct acl_ops *ops;            /* Operations for the ACL entry */
  68   unsigned act;                         /* What to do with matching hosts */
  69 } acl_entry;
  70
  71 #define ACL_DENY 0                      /* Deny access to matching conns */
  72 #define ACL_ALLOW 1                     /* Allow access to matching conns */
  73 #define ACL_PERM 1u                     /* Bit mask for permission bit */
  74
  75 /* --- Host-based access control --- */
  76
  77 typedef struct acl_host {
  78   acl_entry a;                          /* Base structure */
  79   struct in_addr addr, mask;            /* Address and netmask */
  80 } acl_host;
  81
  82 /* --- ACL methods --- */
  83
  84 typedef struct acl_ops {
  85   int (*check)(void */*a*/, struct in_addr /*addr*/, unsigned /*port*/);
  86   void (*dump)(void */*a*/, FILE */*fp*/);
  87   void (*free)(void */*a*/);
  88 } acl_ops;
  89
  90 /*----- Functions provided ------------------------------------------------*/
  91
  92 /* --- @acl_check@ --- *
  93  *
  94  * Arguments:   @acl_entry *a@ = pointer to ACL to check against
  95  *              @struct in_addr addr@ = address to check
  96  *              @unsigned port@ = port number to check
  97  *              @int *act@ = verdict (should initially be @ACT_ALLOW@)
  98  *
  99  * Returns:     Zero if undecided, nonzero if a rule matched.
 100  *
 101  * Use:         Checks an address against an ACL.
 102  */
 103
 104 extern int acl_check(acl_entry */*a*/,
 105                      struct in_addr /*addr*/, unsigned /*port*/,
 106                      int */*act*/);
 107
 108 /* --- @acl_dump@ --- *
 109  *
 110  * Arguments:   @acl_entry *a@ = pointer to ACL to dump
 111  *              @FILE *fp@ = pointer to stream to dump on
 112  *
 113  * Returns:     ---
 114  *
 115  * Use:         Dumps an access control list to an output stream.
 116  */
 117
 118 extern void acl_dump(acl_entry */*a*/, FILE */*fp*/);
 119
 120 /* --- @acl_free@ --- *
 121  *
 122  * Arguments:   @acl_entry *a@ = pointer to a list of ACLs
 123  *
 124  * Returns:     ---
 125  *
 126  * Use:         Frees all of the memory used by an ACL.
 127  */
 128
 129 extern void acl_free(acl_entry */*a*/);
 130
 131 /* --- @acl_addhost@ --- *
 132  *
 133  * Arguments:   @acl_entry ***a@ = address of pointer to list tail
 134  *              @unsigned act@ = what to do with matching addresses
 135  *              @struct in_addr addr, mask@ = address and mask to match
 136  *
 137  * Returns:     ---
 138  *
 139  * Use:         Adds a host-authentication entry to the end of an access
 140  *              control list.
 141  */
 142
 143 extern void acl_addhost(acl_entry ***/*a*/, unsigned /*act*/,
 144                         struct in_addr /*addr*/, struct in_addr /*mask*/);
 145
 146 /* --- @acl_addpriv@ --- *
 147  *
 148  * Arguments:   @acl_entry ***a@ = address of pointer to list tail
 149  *              @unsigned act@ = what to do with matching addresses
 150  *
 151  * Returns:     ---
 152  *
 153  * Use:         Adds a privileged-port check to the end of an access control
 154  *              list.
 155  */
 156
 157 extern void acl_addpriv(acl_entry ***/*a*/, unsigned /*act*/);
 158
 159 /*----- That's all, folks -------------------------------------------------*/
 160
 161 #ifdef __cplusplus
 162   }
 163 #endif
 164
 165 #endif