src/libsystemd-network/dhcp6-network.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright (C) 2014 Intel Corporation. All rights reserved.
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <sys/types.h>
  22 #include <sys/socket.h>
  23 #include <string.h>
  24 #include <linux/if_packet.h>
  25 #include <stdio.h>
  26 #include <unistd.h>
  27 #include <netinet/ip6.h>
  28 #include <netinet/in.h>
  29
  30 #include "socket-util.h"
  31
  32 #include "dhcp6-internal.h"
  33 #include "dhcp6-protocol.h"
  34
  35 int dhcp6_network_bind_udp_socket(int index, struct in6_addr *local_address) {
  36         struct in6_pktinfo pktinfo = {
  37                 .ipi6_ifindex = index,
  38         };
  39         union sockaddr_union src = {
  40                 .in6.sin6_family = AF_INET6,
  41                 .in6.sin6_port = htobe16(DHCP6_PORT_CLIENT),
  42                 .in6.sin6_addr = IN6ADDR_ANY_INIT,
  43         };
  44         _cleanup_close_ int s = -1;
  45         int r, off = 0, on = 1;
  46
  47         if (local_address)
  48                 memcpy(&src.in6.sin6_addr, local_address,
  49                        sizeof(src.in6.sin6_addr));
  50
  51         s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
  52                    IPPROTO_UDP);
  53         if (s < 0)
  54                 return -errno;
  55
  56         r = setsockopt(s, IPPROTO_IPV6, IPV6_PKTINFO, &pktinfo,
  57                        sizeof(pktinfo));
  58         if (r < 0)
  59                 return -errno;
  60
  61         r = setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
  62         if (r < 0)
  63                 return -errno;
  64
  65         r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off, sizeof(off));
  66         if (r < 0)
  67                 return -errno;
  68
  69         r = bind(s, &src.sa, sizeof(src.in6));
  70         if (r < 0)
  71                 return -errno;
  72
  73         r = s;
  74         s = -1;
  75         return r;
  76 }
  77
  78 int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address,
  79                                   const void *packet, size_t len) {
  80         union sockaddr_union dest = {
  81                 .in6.sin6_family = AF_INET6,
  82                 .in6.sin6_port = htobe16(DHCP6_PORT_SERVER),
  83         };
  84         int r;
  85
  86         assert(server_address);
  87
  88         memcpy(&dest.in6.sin6_addr, server_address, sizeof(dest.in6.sin6_addr));
  89
  90         r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in6));
  91         if (r < 0)
  92                 return -errno;
  93
  94         return 0;
  95 }