common/dhcp4o6.c

   1 /* dhcp4o6.c
   2
   3    DHCPv4 over DHCPv6 shared code... */
   4
   5 /*
   6  * Copyright (c) 2016-2017 by Internet Systems Consortium, Inc. ("ISC")
   7  *
   8  * This Source Code Form is subject to the terms of the Mozilla Public
   9  * License, v. 2.0. If a copy of the MPL was not distributed with this
  10  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  14  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  18  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  19  *
  20  *   Internet Systems Consortium, Inc.
  21  *   PO Box 360
  22  *   Newmarket, NH 03857 USA
  23  *   <info@isc.org>
  24  *   https://www.isc.org/
  25  *
  26  */
  27
  28 #include "dhcpd.h"
  29
  30 #ifdef DHCP4o6
  31
  32 int dhcp4o6_fd = -1;
  33 omapi_object_t *dhcp4o6_object = NULL;
  34 omapi_object_type_t *dhcp4o6_type = NULL;
  35
  36 static int dhcp4o6_readsocket(omapi_object_t *);
  37
  38 /*
  39  * DHCPv4 over DHCPv6 Inter Process Communication setup
  40  *
  41  * A UDP socket is created between ::1 port and ::1 port + 1
  42  * (port is given in network order, the DHCPv6 side is bound to port,
  43  *  the DHCPv4 side to port + 1. The socket descriptor is stored into
  44  *  dhcp4o6_fd and an OMAPI handler is registered. Any failure is fatal.)
  45  */
  46 void dhcp4o6_setup(u_int16_t port) {
  47         struct sockaddr_in6 local6, remote6;
  48         int flag;
  49         isc_result_t status;
  50
  51         /* Register DHCPv4 over DHCPv6 forwarding. */
  52         memset(&local6, 0, sizeof(local6));
  53         local6.sin6_family = AF_INET6;
  54         if (local_family == AF_INET6)
  55                 local6.sin6_port = port;
  56         else
  57                 local6.sin6_port = htons(ntohs(port) + 1);
  58         local6.sin6_addr.s6_addr[15] = 1;
  59 #ifdef HAVE_SA_LEN
  60         local6.sin6_len = sizeof(local6);
  61 #endif
  62         memset(&remote6, 0, sizeof(remote6));
  63         remote6.sin6_family = AF_INET6;
  64         if (local_family == AF_INET6)
  65                 remote6.sin6_port = htons(ntohs(port) + 1);
  66         else
  67                 remote6.sin6_port = port;
  68         remote6.sin6_addr.s6_addr[15] = 1;
  69 #ifdef HAVE_SA_LEN
  70         remote6.sin6_len = sizeof(remote6);
  71 #endif
  72
  73         dhcp4o6_fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
  74         if (dhcp4o6_fd < 0)
  75                 log_fatal("Can't create dhcp4o6 socket: %m");
  76         flag = 1;
  77         if (setsockopt(dhcp4o6_fd, SOL_SOCKET, SO_REUSEADDR,
  78                        (char *)&flag, sizeof(flag)) < 0)
  79                 log_fatal("Can't set SO_REUSEADDR option "
  80                           "on dhcp4o6 socket: %m");
  81         if (bind(dhcp4o6_fd,
  82                  (struct sockaddr *)&local6,
  83                  sizeof(local6)) < 0)
  84                 log_fatal("Can't bind dhcp4o6 socket: %m");
  85         if (connect(dhcp4o6_fd,
  86                     (struct sockaddr *)&remote6,
  87                     sizeof(remote6)) < 0)
  88                 log_fatal("Can't connect dhcp4o6 socket: %m");
  89
  90         /* Omapi stuff. */
  91         /* TODO: add tracing support. */
  92         status = omapi_object_type_register(&dhcp4o6_type,
  93                                             "dhcp4o6",
  94                                             0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  95                                             sizeof(*dhcp4o6_object),
  96                                             0, RC_MISC);
  97         if (status != ISC_R_SUCCESS)
  98                 log_fatal("Can't register dhcp4o6 type: %s",
  99                           isc_result_totext(status));
 100         status = omapi_object_allocate(&dhcp4o6_object, dhcp4o6_type, 0, MDL);
 101         if (status != ISC_R_SUCCESS)
 102                 log_fatal("Can't allocate dhcp4o6 object: %s",
 103                           isc_result_totext(status));
 104         status = omapi_register_io_object(dhcp4o6_object,
 105                                           dhcp4o6_readsocket, 0,
 106                                           dhcpv4o6_handler, 0, 0);
 107         if (status != ISC_R_SUCCESS)
 108                 log_fatal("Can't register dhcp4o6 handle: %s",
 109                           isc_result_totext(status));
 110 }
 111
 112 static int dhcp4o6_readsocket(omapi_object_t *h) {
 113         IGNORE_UNUSED(h);
 114         return dhcp4o6_fd;
 115 }
 116 #endif /* DHCP4o6 */