contrib/bind-9.3/bin/named/sortlist.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000, 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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 1.5.12.4 2004/03/08 04:04:19 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <isc/mem.h>
  23 #include <isc/util.h>
  24
  25 #include <dns/acl.h>
  26 #include <dns/result.h>
  27
  28 #include <named/globals.h>
  29 #include <named/server.h>
  30 #include <named/sortlist.h>
  31
  32 ns_sortlisttype_t
  33 ns_sortlist_setup(dns_acl_t *acl, isc_netaddr_t *clientaddr, void **argp) {
  34         unsigned int i;
  35
  36         if (acl == NULL)
  37                 goto dont_sort;
  38
  39         for (i = 0; i < acl->length; i++) {
  40                 /*
  41                  * 'e' refers to the current 'top level statement'
  42                  * in the sortlist (see ARM).
  43                  */
  44                 dns_aclelement_t *e = &acl->elements[i];
  45                 dns_aclelement_t *try_elt;
  46                 dns_aclelement_t *order_elt = NULL;
  47                 dns_aclelement_t *matched_elt = NULL;
  48
  49                 if (e->type == dns_aclelementtype_nestedacl) {
  50                         dns_acl_t *inner = e->u.nestedacl;
  51
  52                         if (inner->length < 1 || inner->length > 2)
  53                                 goto dont_sort;
  54                         if (inner->elements[0].negative)
  55                                 goto dont_sort;
  56                         try_elt = &inner->elements[0];
  57                         if (inner->length == 2)
  58                                 order_elt = &inner->elements[1];
  59                 } else {
  60                         /*
  61                          * BIND 8 allows bare elements at the top level
  62                          * as an undocumented feature.
  63                          */
  64                         try_elt = e;
  65                 }
  66
  67                 if (dns_aclelement_match(clientaddr, NULL, try_elt,
  68                                          &ns_g_server->aclenv,
  69                                          &matched_elt)) {
  70                         if (order_elt != NULL) {
  71                                 if (order_elt->type ==
  72                                     dns_aclelementtype_nestedacl) {
  73                                         *argp = order_elt->u.nestedacl;
  74                                         return (NS_SORTLISTTYPE_2ELEMENT);
  75                                 } else if (order_elt->type ==
  76                                            dns_aclelementtype_localhost &&
  77                                            ns_g_server->aclenv.localhost != NULL) {
  78                                         *argp = ns_g_server->aclenv.localhost;
  79                                         return (NS_SORTLISTTYPE_2ELEMENT);
  80                                 } else if (order_elt->type ==
  81                                            dns_aclelementtype_localnets &&
  82                                            ns_g_server->aclenv.localnets != NULL) {
  83                                         *argp = ns_g_server->aclenv.localnets;
  84                                         return (NS_SORTLISTTYPE_2ELEMENT);
  85                                 } else {
  86                                         /*
  87                                          * BIND 8 allows a bare IP prefix as
  88                                          * the 2nd element of a 2-element
  89                                          * sortlist statement.
  90                                          */
  91                                         *argp = order_elt;
  92                                         return (NS_SORTLISTTYPE_1ELEMENT);
  93                                 }
  94                         } else {
  95                                 INSIST(matched_elt != NULL);
  96                                 *argp = matched_elt;
  97                                 return (NS_SORTLISTTYPE_1ELEMENT);
  98                         }
  99                 }
 100         }
 101
 102         /* No match; don't sort. */
 103  dont_sort:
 104         *argp = NULL;
 105         return (NS_SORTLISTTYPE_NONE);
 106 }
 107
 108 int
 109 ns_sortlist_addrorder2(isc_netaddr_t *addr, void *arg) {
 110         dns_acl_t *sortacl = (dns_acl_t *) arg;
 111         int match;
 112
 113         (void)dns_acl_match(addr, NULL, sortacl,
 114                             &ns_g_server->aclenv,
 115                             &match, NULL);
 116         if (match > 0)
 117                 return (match);
 118         else if (match < 0)
 119                 return (INT_MAX - (-match));
 120         else
 121                 return (INT_MAX / 2);
 122 }
 123
 124 int
 125 ns_sortlist_addrorder1(isc_netaddr_t *addr, void *arg) {
 126         dns_aclelement_t *matchelt = (dns_aclelement_t *) arg;
 127         if (dns_aclelement_match(addr, NULL, matchelt,
 128                                  &ns_g_server->aclenv,
 129                                  NULL)) {
 130                 return (0);
 131         } else {
 132                 return (INT_MAX);
 133         }
 134 }
 135
 136 void
 137 ns_sortlist_byaddrsetup(dns_acl_t *sortlist_acl, isc_netaddr_t *client_addr,
 138                        dns_addressorderfunc_t *orderp,
 139                        void **argp)
 140 {
 141         ns_sortlisttype_t sortlisttype;
 142
 143         sortlisttype = ns_sortlist_setup(sortlist_acl, client_addr, argp);
 144
 145         switch (sortlisttype) {
 146         case NS_SORTLISTTYPE_1ELEMENT:
 147                 *orderp = ns_sortlist_addrorder1;
 148                 break;
 149         case NS_SORTLISTTYPE_2ELEMENT:
 150                 *orderp = ns_sortlist_addrorder2;
 151                 break;
 152         case NS_SORTLISTTYPE_NONE:
 153                 *orderp = NULL;
 154                 break;
 155         default:
 156                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 157                                  "unexpected return from ns_sortlist_setup(): "
 158                                  "%d", sortlisttype);
 159                 break;
 160         }
 161 }
 162