1 /*
2 * Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000, 2001 Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* $Id: sortlist.c,v 1.17 2007/09/14 01:46:05 marka Exp $ */
19
20 /*! \file */
21
22 #include <config.h>
23
24 #include <isc/mem.h>
25 #include <isc/util.h>
26
27 #include <dns/acl.h>
28 #include <dns/result.h>
29
30 #include <named/globals.h>
31 #include <named/server.h>
32 #include <named/sortlist.h>
33
34 ns_sortlisttype_t
ns_sortlist_setup(dns_acl_t * acl,isc_netaddr_t * clientaddr,const void ** argp)35 ns_sortlist_setup(dns_acl_t *acl, isc_netaddr_t *clientaddr,
36 const void **argp)
37 {
38 unsigned int i;
39
40 if (acl == NULL)
41 goto dont_sort;
42
43 for (i = 0; i < acl->length; i++) {
44 /*
45 * 'e' refers to the current 'top level statement'
46 * in the sortlist (see ARM).
47 */
48 dns_aclelement_t *e = &acl->elements[i];
49 dns_aclelement_t *try_elt;
50 dns_aclelement_t *order_elt = NULL;
51 const dns_aclelement_t *matched_elt = NULL;
52
53 if (e->type == dns_aclelementtype_nestedacl) {
54 dns_acl_t *inner = e->nestedacl;
55
56 if (inner->length == 0)
57 try_elt = e;
58 else if (inner->length > 2)
59 goto dont_sort;
60 else if (inner->elements[0].negative)
61 goto dont_sort;
62 else {
63 try_elt = &inner->elements[0];
64 if (inner->length == 2)
65 order_elt = &inner->elements[1];
66 }
67 } else {
68 /*
69 * BIND 8 allows bare elements at the top level
70 * as an undocumented feature.
71 */
72 try_elt = e;
73 }
74
75 if (dns_aclelement_match(clientaddr, NULL, try_elt,
76 &ns_g_server->aclenv,
77 &matched_elt)) {
78 if (order_elt != NULL) {
79 if (order_elt->type ==
80 dns_aclelementtype_nestedacl) {
81 *argp = order_elt->nestedacl;
82 return (NS_SORTLISTTYPE_2ELEMENT);
83 } else if (order_elt->type ==
84 dns_aclelementtype_localhost &&
85 ns_g_server->aclenv.localhost != NULL) {
86 *argp = ns_g_server->aclenv.localhost;
87 return (NS_SORTLISTTYPE_2ELEMENT);
88 } else if (order_elt->type ==
89 dns_aclelementtype_localnets &&
90 ns_g_server->aclenv.localnets != NULL) {
91 *argp = ns_g_server->aclenv.localnets;
92 return (NS_SORTLISTTYPE_2ELEMENT);
93 } else {
94 /*
95 * BIND 8 allows a bare IP prefix as
96 * the 2nd element of a 2-element
97 * sortlist statement.
98 */
99 *argp = order_elt;
100 return (NS_SORTLISTTYPE_1ELEMENT);
101 }
102 } else {
103 INSIST(matched_elt != NULL);
104 *argp = matched_elt;
105 return (NS_SORTLISTTYPE_1ELEMENT);
106 }
107 }
108 }
109
110 /* No match; don't sort. */
111 dont_sort:
112 *argp = NULL;
113 return (NS_SORTLISTTYPE_NONE);
114 }
115
116 int
ns_sortlist_addrorder2(const isc_netaddr_t * addr,const void * arg)117 ns_sortlist_addrorder2(const isc_netaddr_t *addr, const void *arg) {
118 const dns_acl_t *sortacl = (const dns_acl_t *) arg;
119 int match;
120
121 (void)dns_acl_match(addr, NULL, sortacl,
122 &ns_g_server->aclenv,
123 &match, NULL);
124 if (match > 0)
125 return (match);
126 else if (match < 0)
127 return (INT_MAX - (-match));
128 else
129 return (INT_MAX / 2);
130 }
131
132 int
ns_sortlist_addrorder1(const isc_netaddr_t * addr,const void * arg)133 ns_sortlist_addrorder1(const isc_netaddr_t *addr, const void *arg) {
134 const dns_aclelement_t *matchelt = (const dns_aclelement_t *) arg;
135 if (dns_aclelement_match(addr, NULL, matchelt,
136 &ns_g_server->aclenv,
137 NULL)) {
138 return (0);
139 } else {
140 return (INT_MAX);
141 }
142 }
143
144 void
ns_sortlist_byaddrsetup(dns_acl_t * sortlist_acl,isc_netaddr_t * client_addr,dns_addressorderfunc_t * orderp,const void ** argp)145 ns_sortlist_byaddrsetup(dns_acl_t *sortlist_acl, isc_netaddr_t *client_addr,
146 dns_addressorderfunc_t *orderp,
147 const void **argp)
148 {
149 ns_sortlisttype_t sortlisttype;
150
151 sortlisttype = ns_sortlist_setup(sortlist_acl, client_addr, argp);
152
153 switch (sortlisttype) {
154 case NS_SORTLISTTYPE_1ELEMENT:
155 *orderp = ns_sortlist_addrorder1;
156 break;
157 case NS_SORTLISTTYPE_2ELEMENT:
158 *orderp = ns_sortlist_addrorder2;
159 break;
160 case NS_SORTLISTTYPE_NONE:
161 *orderp = NULL;
162 break;
163 default:
164 UNEXPECTED_ERROR(__FILE__, __LINE__,
165 "unexpected return from ns_sortlist_setup(): "
166 "%d", sortlisttype);
167 break;
168 }
169 }
170
171