src/libsystemd-network/dhcp6-network.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright © 2014 Intel Corporation. All rights reserved.
   4 ***/
   5
   6 #include <errno.h>
   7 #include <netinet/in.h>
   8 #include <netinet/ip6.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sys/types.h>
  12 #include <unistd.h>
  13 #include <linux/if_packet.h>
  14
  15 #include "dhcp6-internal.h"
  16 #include "dhcp6-protocol.h"
  17 #include "fd-util.h"
  18 #include "socket-util.h"
  19
  20 int dhcp6_network_bind_udp_socket(int ifindex, struct in6_addr *local_address) {
  21         union sockaddr_union src = {
  22                 .in6.sin6_family = AF_INET6,
  23                 .in6.sin6_port = htobe16(DHCP6_PORT_CLIENT),
  24                 .in6.sin6_scope_id = ifindex,
  25         };
  26         _cleanup_close_ int s = -1;
  27         int r;
  28
  29         assert(ifindex > 0);
  30         assert(local_address);
  31
  32         src.in6.sin6_addr = *local_address;
  33
  34         s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_UDP);
  35         if (s < 0)
  36                 return -errno;
  37
  38         r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
  39         if (r < 0)
  40                 return r;
  41
  42         r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, false);
  43         if (r < 0)
  44                 return r;
  45
  46         r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
  47         if (r < 0)
  48                 return r;
  49
  50         r = bind(s, &src.sa, sizeof(src.in6));
  51         if (r < 0)
  52                 return -errno;
  53
  54         return TAKE_FD(s);
  55 }
  56
  57 int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address,
  58                                   const void *packet, size_t len) {
  59         union sockaddr_union dest = {
  60                 .in6.sin6_family = AF_INET6,
  61                 .in6.sin6_port = htobe16(DHCP6_PORT_SERVER),
  62         };
  63         int r;
  64
  65         assert(server_address);
  66
  67         memcpy(&dest.in6.sin6_addr, server_address, sizeof(dest.in6.sin6_addr));
  68
  69         r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in6));
  70         if (r < 0)
  71                 return -errno;
  72
  73         return 0;
  74 }