/contrib/bind9/bin/named/sortlist.c

  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
 34ns_sortlisttype_t
 35ns_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
116int
117ns_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
132int
133ns_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
144void
145ns_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