3 * $Id: acl.c,v 1.3 1999/07/27 18:30:53 mdw Exp $
5 * Access control list handling
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the `fw' port forwarder.
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.3 1999/07/27 18:30:53 mdw
33 * Various minor portability fixes.
35 * Revision 1.2 1999/07/26 23:28:15 mdw
36 * Minor modifications for new design.
38 * Revision 1.1.1.1 1999/07/01 08:56:23 mdw
43 /*----- Header files ------------------------------------------------------*/
52 #include <sys/types.h>
55 #include <sys/socket.h>
56 #include <netinet/in.h>
57 #include <arpa/inet.h>
64 /*----- Static variables --------------------------------------------------*/
66 static acl_entry
*global
= 0;
67 static acl_entry
**gtail
= &global
;
69 /*----- Main code ---------------------------------------------------------*/
71 /* --- @acl_check@ --- *
73 * Arguments: @acl_entry *a@ = pointer to ACL to check against
74 * @struct in_addr addr@ = address to check
76 * Returns: Nonzero if allowed.
78 * Use: Checks an address against an ACL.
81 int acl_check(acl_entry
*a
, struct in_addr addr
)
86 for (i
= 0; i
< 2; i
++) {
87 for (; a
; a
= a
->next
) {
88 if ((addr
.s_addr
& a
->mask
.s_addr
) == a
->addr
.s_addr
)
89 return (a
->act
& ACL_PERM
);
90 act
= (a
->act
& ACL_PERM
) ^ 1;
98 /* --- @acl_dump@ --- *
100 * Arguments: @acl_entry *a@ = pointer to ACL to dump
101 * @FILE *fp@ = pointer to stream to dump on
105 * Use: Dumps an access control list to an output stream.
108 void acl_dump(acl_entry
*a
, FILE *fp
)
112 for (; a
; a
= a
->next
) {
113 fprintf(fp
, " %s from ",
114 (a
->act
& ACL_PERM
) == ACL_ALLOW ?
"allow" : "deny");
115 fputs(inet_ntoa(a
->addr
), fp
);
117 fputs(inet_ntoa(a
->mask
), fp
);
122 /* --- @acl_free@ --- *
124 * Arguments: @acl_entry *a@ = pointer to a list of ACLs
128 * Use: Frees all of the memory used by an ACL.
131 void acl_free(acl_entry
*a
)
140 /* --- @acl_add@ --- *
142 * Arguments: @acl_entry ***a@ = address of pointer to list tail
143 * @unsigned act@ = what to do with matching addresses
144 * @struct in_addr addr, mask@ = address and mask to match
148 * Use: Adds an entry to the end of an access control list.
151 void acl_add(acl_entry
***a
, unsigned act
,
152 struct in_addr addr
, struct in_addr mask
)
154 acl_entry
*aa
= CREATE(acl_entry
);
156 aa
->addr
.s_addr
= addr
.s_addr
& mask
.s_addr
;
165 /*----- That's all, folks -------------------------------------------------*/