contrib/bind-9.5.2/lib/dns/portlist.c

   1 /*
   2  * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2003  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: portlist.c,v 1.13 2007/06/19 23:47:16 tbox Exp $ */
  19
  20 /*! \file */
  21
  22 #include <config.h>
  23
  24 #include <stdlib.h>
  25
  26 #include <isc/magic.h>
  27 #include <isc/mem.h>
  28 #include <isc/mutex.h>
  29 #include <isc/net.h>
  30 #include <isc/refcount.h>
  31 #include <isc/result.h>
  32 #include <isc/string.h>
  33 #include <isc/types.h>
  34 #include <isc/util.h>
  35
  36 #include <dns/types.h>
  37 #include <dns/portlist.h>
  38
  39 #define DNS_PORTLIST_MAGIC      ISC_MAGIC('P','L','S','T')
  40 #define DNS_VALID_PORTLIST(p)   ISC_MAGIC_VALID(p, DNS_PORTLIST_MAGIC)
  41
  42 typedef struct dns_element {
  43         in_port_t       port;
  44         isc_uint16_t    flags;
  45 } dns_element_t;
  46
  47 struct dns_portlist {
  48         unsigned int    magic;
  49         isc_mem_t       *mctx;
  50         isc_refcount_t  refcount;
  51         isc_mutex_t     lock;
  52         dns_element_t   *list;
  53         unsigned int    allocated;
  54         unsigned int    active;
  55 };
  56
  57 #define DNS_PL_INET     0x0001
  58 #define DNS_PL_INET6    0x0002
  59 #define DNS_PL_ALLOCATE 16
  60
  61 static int
  62 compare(const void *arg1, const void *arg2) {
  63         const dns_element_t *e1 = (const dns_element_t *)arg1;
  64         const dns_element_t *e2 = (const dns_element_t *)arg2;
  65
  66         if (e1->port < e2->port)
  67                 return (-1);
  68         if (e1->port > e2->port)
  69                 return (1);
  70         return (0);
  71 }
  72
  73 isc_result_t
  74 dns_portlist_create(isc_mem_t *mctx, dns_portlist_t **portlistp) {
  75         dns_portlist_t *portlist;
  76         isc_result_t result;
  77
  78         REQUIRE(portlistp != NULL && *portlistp == NULL);
  79
  80         portlist = isc_mem_get(mctx, sizeof(*portlist));
  81         if (portlist == NULL)
  82                 return (ISC_R_NOMEMORY);
  83         result = isc_mutex_init(&portlist->lock);
  84         if (result != ISC_R_SUCCESS) {
  85                 isc_mem_put(mctx, portlist, sizeof(*portlist));
  86                 return (result);
  87         }
  88         result = isc_refcount_init(&portlist->refcount, 1);
  89         if (result != ISC_R_SUCCESS) {
  90                 DESTROYLOCK(&portlist->lock);
  91                 isc_mem_put(mctx, portlist, sizeof(*portlist));
  92                 return (result);
  93         }
  94         portlist->list = NULL;
  95         portlist->allocated = 0;
  96         portlist->active = 0;
  97         portlist->mctx = NULL;
  98         isc_mem_attach(mctx, &portlist->mctx);
  99         portlist->magic = DNS_PORTLIST_MAGIC;
 100         *portlistp = portlist;
 101         return (ISC_R_SUCCESS);
 102 }
 103
 104 static dns_element_t *
 105 find_port(dns_element_t *list, unsigned int len, in_port_t port) {
 106         unsigned int xtry = len / 2;
 107         unsigned int min = 0;
 108         unsigned int max = len - 1;
 109         unsigned int last = len;
 110
 111         for (;;) {
 112                 if (list[xtry].port == port)
 113                         return (&list[xtry]);
 114                 if (port > list[xtry].port) {
 115                         if (xtry == max)
 116                                 break;
 117                         min = xtry;
 118                         xtry = xtry + (max - xtry + 1) / 2;
 119                         INSIST(xtry <= max);
 120                         if (xtry == last)
 121                                 break;
 122                         last = min;
 123                 } else {
 124                         if (xtry == min)
 125                                 break;
 126                         max = xtry;
 127                         xtry = xtry - (xtry - min + 1) / 2;
 128                         INSIST(xtry >= min);
 129                         if (xtry == last)
 130                                 break;
 131                         last = max;
 132                 }
 133         }
 134         return (NULL);
 135 }
 136
 137 isc_result_t
 138 dns_portlist_add(dns_portlist_t *portlist, int af, in_port_t port) {
 139         dns_element_t *el;
 140         isc_result_t result;
 141
 142         REQUIRE(DNS_VALID_PORTLIST(portlist));
 143         REQUIRE(af == AF_INET || af == AF_INET6);
 144
 145         LOCK(&portlist->lock);
 146         if (portlist->active != 0) {
 147                 el = find_port(portlist->list, portlist->active, port);
 148                 if (el != NULL) {
 149                         if (af == AF_INET)
 150                                 el->flags |= DNS_PL_INET;
 151                         else
 152                                 el->flags |= DNS_PL_INET6;
 153                         result = ISC_R_SUCCESS;
 154                         goto unlock;
 155                 }
 156         }
 157
 158         if (portlist->allocated <= portlist->active) {
 159                 unsigned int allocated;
 160                 allocated = portlist->allocated + DNS_PL_ALLOCATE;
 161                 el = isc_mem_get(portlist->mctx, sizeof(*el) * allocated);
 162                 if (el == NULL) {
 163                         result = ISC_R_NOMEMORY;
 164                         goto unlock;
 165                 }
 166                 if (portlist->list != NULL) {
 167                         memcpy(el, portlist->list,
 168                                portlist->allocated * sizeof(*el));
 169                         isc_mem_put(portlist->mctx, portlist->list,
 170                                     portlist->allocated * sizeof(*el));
 171                 }
 172                 portlist->list = el;
 173                 portlist->allocated = allocated;
 174         }
 175         portlist->list[portlist->active].port = port;
 176         if (af == AF_INET)
 177                 portlist->list[portlist->active].flags = DNS_PL_INET;
 178         else
 179                 portlist->list[portlist->active].flags = DNS_PL_INET6;
 180         portlist->active++;
 181         qsort(portlist->list, portlist->active, sizeof(*el), compare);
 182         result = ISC_R_SUCCESS;
 183  unlock:
 184         UNLOCK(&portlist->lock);
 185         return (result);
 186 }
 187
 188 void
 189 dns_portlist_remove(dns_portlist_t *portlist, int af, in_port_t port) {
 190         dns_element_t *el;
 191
 192         REQUIRE(DNS_VALID_PORTLIST(portlist));
 193         REQUIRE(af == AF_INET || af == AF_INET6);
 194
 195         LOCK(&portlist->lock);
 196         if (portlist->active != 0) {
 197                 el = find_port(portlist->list, portlist->active, port);
 198                 if (el != NULL) {
 199                         if (af == AF_INET)
 200                                 el->flags &= ~DNS_PL_INET;
 201                         else
 202                                 el->flags &= ~DNS_PL_INET6;
 203                         if (el->flags == 0) {
 204                                 *el = portlist->list[portlist->active];
 205                                 portlist->active--;
 206                                 qsort(portlist->list, portlist->active,
 207                                       sizeof(*el), compare);
 208                         }
 209                 }
 210         }
 211         UNLOCK(&portlist->lock);
 212 }
 213
 214 isc_boolean_t
 215 dns_portlist_match(dns_portlist_t *portlist, int af, in_port_t port) {
 216         dns_element_t *el;
 217         isc_boolean_t result = ISC_FALSE;
 218
 219         REQUIRE(DNS_VALID_PORTLIST(portlist));
 220         REQUIRE(af == AF_INET || af == AF_INET6);
 221         LOCK(&portlist->lock);
 222         if (portlist->active != 0) {
 223                 el = find_port(portlist->list, portlist->active, port);
 224                 if (el != NULL) {
 225                         if (af == AF_INET && (el->flags & DNS_PL_INET) != 0)
 226                                 result = ISC_TRUE;
 227                         if (af == AF_INET6 && (el->flags & DNS_PL_INET6) != 0)
 228                                 result = ISC_TRUE;
 229                 }
 230         }
 231         UNLOCK(&portlist->lock);
 232         return (result);
 233 }
 234
 235 void
 236 dns_portlist_attach(dns_portlist_t *portlist, dns_portlist_t **portlistp) {
 237
 238         REQUIRE(DNS_VALID_PORTLIST(portlist));
 239         REQUIRE(portlistp != NULL && *portlistp == NULL);
 240
 241         isc_refcount_increment(&portlist->refcount, NULL);
 242         *portlistp = portlist;
 243 }
 244
 245 void
 246 dns_portlist_detach(dns_portlist_t **portlistp) {
 247         dns_portlist_t *portlist;
 248         unsigned int count;
 249
 250         REQUIRE(portlistp != NULL);
 251         portlist = *portlistp;
 252         REQUIRE(DNS_VALID_PORTLIST(portlist));
 253         *portlistp = NULL;
 254         isc_refcount_decrement(&portlist->refcount, &count);
 255         if (count == 0) {
 256                 portlist->magic = 0;
 257                 isc_refcount_destroy(&portlist->refcount);
 258                 if (portlist->list != NULL)
 259                         isc_mem_put(portlist->mctx, portlist->list,
 260                                     portlist->allocated *
 261                                     sizeof(*portlist->list));
 262                 DESTROYLOCK(&portlist->lock);
 263                 isc_mem_putanddetach(&portlist->mctx, portlist,
 264                                      sizeof(*portlist));
 265         }
 266 }