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/socket.h>
  12 #include <sys/types.h>
  13 #include <unistd.h>
  14 #include <linux/if_packet.h>
  15
  16 #include "dhcp6-internal.h"
  17 #include "dhcp6-protocol.h"
  18 #include "fd-util.h"
  19 #include "socket-util.h"
  20
  21 int dhcp6_network_bind_udp_socket(int index, struct in6_addr *local_address) {
  22         union sockaddr_union src = {
  23                 .in6.sin6_family = AF_INET6,
  24                 .in6.sin6_port = htobe16(DHCP6_PORT_CLIENT),
  25                 .in6.sin6_scope_id = index,
  26         };
  27         _cleanup_close_ int s = -1;
  28         int r;
  29
  30         assert(index > 0);
  31         assert(local_address);
  32
  33         src.in6.sin6_addr = *local_address;
  34
  35         s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_UDP);
  36         if (s < 0)
  37                 return -errno;
  38
  39         r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
  40         if (r < 0)
  41                 return r;
  42
  43         r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, false);
  44         if (r < 0)
  45                 return r;
  46
  47         r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
  48         if (r < 0)
  49                 return r;
  50
  51         r = bind(s, &src.sa, sizeof(src.in6));
  52         if (r < 0)
  53                 return -errno;
  54
  55         return TAKE_FD(s);
  56 }
  57
  58 int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address,
  59                                   const void *packet, size_t len) {
  60         union sockaddr_union dest = {
  61                 .in6.sin6_family = AF_INET6,
  62                 .in6.sin6_port = htobe16(DHCP6_PORT_SERVER),
  63         };
  64         int r;
  65
  66         assert(server_address);
  67
  68         memcpy(&dest.in6.sin6_addr, server_address, sizeof(dest.in6.sin6_addr));
  69
  70         r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in6));
  71         if (r < 0)
  72                 return -errno;
  73
  74         return 0;
  75 }