src/libsystemd-network/dhcp6-network.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright (C) 2014 Intel Corporation. All rights reserved.
   6 ***/
   7
   8 #include <errno.h>
   9 #include <netinet/in.h>
  10 #include <netinet/ip6.h>
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <sys/socket.h>
  14 #include <sys/types.h>
  15 #include <unistd.h>
  16 #include <linux/if_packet.h>
  17
  18 #include "dhcp6-internal.h"
  19 #include "dhcp6-protocol.h"
  20 #include "fd-util.h"
  21 #include "socket-util.h"
  22
  23 int dhcp6_network_bind_udp_socket(int index, struct in6_addr *local_address) {
  24         union sockaddr_union src = {
  25                 .in6.sin6_family = AF_INET6,
  26                 .in6.sin6_port = htobe16(DHCP6_PORT_CLIENT),
  27                 .in6.sin6_scope_id = index,
  28         };
  29         _cleanup_close_ int s = -1;
  30         int r, off = 0, on = 1;
  31
  32         assert(index > 0);
  33         assert(local_address);
  34
  35         src.in6.sin6_addr = *local_address;
  36
  37         s = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_UDP);
  38         if (s < 0)
  39                 return -errno;
  40
  41         r = setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
  42         if (r < 0)
  43                 return -errno;
  44
  45         r = setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off, sizeof(off));
  46         if (r < 0)
  47                 return -errno;
  48
  49         r = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
  50         if (r < 0)
  51                 return -errno;
  52
  53         r = bind(s, &src.sa, sizeof(src.in6));
  54         if (r < 0)
  55                 return -errno;
  56
  57         return TAKE_FD(s);
  58 }
  59
  60 int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address,
  61                                   const void *packet, size_t len) {
  62         union sockaddr_union dest = {
  63                 .in6.sin6_family = AF_INET6,
  64                 .in6.sin6_port = htobe16(DHCP6_PORT_SERVER),
  65         };
  66         int r;
  67
  68         assert(server_address);
  69
  70         memcpy(&dest.in6.sin6_addr, server_address, sizeof(dest.in6.sin6_addr));
  71
  72         r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in6));
  73         if (r < 0)
  74                 return -errno;
  75
  76         return 0;
  77 }