| 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 |