src/libsystemd-network/dhcp-network.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright (C) 2013 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 <net/ethernet.h>
  26 #include <stdio.h>
  27 #include <unistd.h>
  28
  29 #include "socket-util.h"
  30
  31 #include "dhcp-internal.h"
  32
  33 int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link)
  34 {
  35         int s, one = 1;
  36
  37         assert(index > 0);
  38         assert(link);
  39
  40         s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
  41                    htons(ETH_P_IP));
  42         if (s < 0)
  43                 return -errno;
  44
  45         link->ll.sll_family = AF_PACKET;
  46         link->ll.sll_protocol = htons(ETH_P_IP);
  47         link->ll.sll_ifindex =  index;
  48         link->ll.sll_halen = ETH_ALEN;
  49         memset(link->ll.sll_addr, 0xff, ETH_ALEN);
  50
  51         if (setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one)) < 0)
  52                 return -errno;
  53
  54         if (bind(s, &link->sa, sizeof(link->ll)) < 0) {
  55                 close_nointr_nofail(s);
  56                 return -errno;
  57         }
  58
  59         return s;
  60 }
  61
  62 int dhcp_network_bind_udp_socket(int index, be32_t address, uint16_t port)
  63 {
  64         int s;
  65         union sockaddr_union src = {
  66                 .in.sin_family = AF_INET,
  67                 .in.sin_port = htobe16(port),
  68                 .in.sin_addr.s_addr = address,
  69         };
  70
  71         s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
  72         if (s < 0)
  73                 return -errno;
  74
  75         if (bind(s, &src.sa, sizeof(src.in)) < 0) {
  76                 close_nointr_nofail(s);
  77                 return -errno;
  78         }
  79
  80         return s;
  81 }
  82
  83 int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
  84                                  const void *packet, size_t len)
  85 {
  86         assert(link);
  87         assert(packet);
  88         assert(len);
  89
  90         if (sendto(s, packet, len, 0, &link->sa, sizeof(link->ll)) < 0)
  91                 return -errno;
  92
  93         return 0;
  94 }
  95
  96 int dhcp_network_send_udp_socket(int s, be32_t address, uint16_t port,
  97                                  const void *packet, size_t len)
  98 {
  99         union sockaddr_union dest = {
 100                 .in.sin_family = AF_INET,
 101                 .in.sin_port = htobe16(port),
 102                 .in.sin_addr.s_addr = address,
 103         };
 104
 105         if (sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)) < 0)
 106                 return -errno;
 107
 108         return 0;
 109 }