external/bsd/dhcp/dist/common/raw.c

   1 /*      $NetBSD: raw.c,v 1.1.1.2 2014/07/12 11:57:46 spz Exp $  */
   2 /* raw.c
   3
   4    BSD raw socket interface code... */
   5
   6 /* XXX
   7
   8    It's not clear how this should work, and that lack of clarity is
   9    terribly detrimental to the NetBSD 1.1 kernel - it crashes and
  10    burns.
  11
  12    Using raw sockets ought to be a big win over using BPF or something
  13    like it, because you don't need to deal with the complexities of
  14    the physical layer, but it appears not to be possible with existing
  15    raw socket implementations.  This may be worth revisiting in the
  16    future.  For now, this code can probably be considered a curiosity.
  17    Sigh. */
  18
  19 /*
  20  * Copyright (c) 2004,2007,2009,2014 by Internet Systems Consortium, Inc. ("ISC")
  21  * Copyright (c) 1995-2003 by Internet Software Consortium
  22  *
  23  * Permission to use, copy, modify, and distribute this software for any
  24  * purpose with or without fee is hereby granted, provided that the above
  25  * copyright notice and this permission notice appear in all copies.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  28  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  29  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  30  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  31  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  32  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  33  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  34  *
  35  *   Internet Systems Consortium, Inc.
  36  *   950 Charter Street
  37  *   Redwood City, CA 94063
  38  *   <info@isc.org>
  39  *   https://www.isc.org/
  40  *
  41  */
  42
  43 #include <sys/cdefs.h>
  44 __RCSID("$NetBSD: raw.c,v 1.1.1.2 2014/07/12 11:57:46 spz Exp $");
  45
  46 #include "dhcpd.h"
  47
  48 #if defined (USE_RAW_SEND)
  49 #include <sys/uio.h>
  50
  51 /* Generic interface registration routine... */
  52 void if_register_send (info)
  53         struct interface_info *info;
  54 {
  55         struct sockaddr_in name;
  56         int sock;
  57         struct socklist *tmp;
  58         int flag;
  59
  60         /* Set up the address we're going to connect to. */
  61         name.sin_family = AF_INET;
  62         name.sin_port = local_port;
  63         name.sin_addr.s_addr = htonl (INADDR_BROADCAST);
  64         memset (name.sin_zero, 0, sizeof (name.sin_zero));
  65
  66         /* List addresses on which we're listening. */
  67         if (!quiet_interface_discovery)
  68                 log_info ("Sending on %s, port %d",
  69                       piaddr (info -> address), htons (local_port));
  70         if ((sock = socket (AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
  71                 log_fatal ("Can't create dhcp socket: %m");
  72
  73         /* Set the BROADCAST option so that we can broadcast DHCP responses. */
  74         flag = 1;
  75         if (setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
  76                         &flag, sizeof flag) < 0)
  77                 log_fatal ("Can't set SO_BROADCAST option on dhcp socket: %m");
  78
  79         /* Set the IP_HDRINCL flag so that we can supply our own IP
  80            headers... */
  81         if (setsockopt (sock, IPPROTO_IP, IP_HDRINCL, &flag, sizeof flag) < 0)
  82                 log_fatal ("Can't set IP_HDRINCL flag: %m");
  83
  84         info -> wfdesc = sock;
  85         if (!quiet_interface_discovery)
  86                 log_info ("Sending on   Raw/%s%s%s",
  87                       info -> name,
  88                       (info -> shared_network ? "/" : ""),
  89                       (info -> shared_network ?
  90                        info -> shared_network -> name : ""));
  91 }
  92
  93 void if_deregister_send (info)
  94         struct interface_info *info;
  95 {
  96         close (info -> wfdesc);
  97         info -> wfdesc = -1;
  98
  99         if (!quiet_interface_discovery)
 100                 log_info ("Disabling output on Raw/%s%s%s",
 101                       info -> name,
 102                       (info -> shared_network ? "/" : ""),
 103                       (info -> shared_network ?
 104                        info -> shared_network -> name : ""));
 105 }
 106
 107 size_t send_packet (interface, packet, raw, len, from, to, hto)
 108         struct interface_info *interface;
 109         struct packet *packet;
 110         struct dhcp_packet *raw;
 111         size_t len;
 112         struct in_addr from;
 113         struct sockaddr_in *to;
 114         struct hardware *hto;
 115 {
 116         unsigned char buf [256];
 117         int bufp = 0;
 118         struct iovec iov [2];
 119         int result;
 120
 121         /* Assemble the headers... */
 122         assemble_udp_ip_header (interface, buf, &bufp, from.s_addr,
 123                                 to -> sin_addr.s_addr, to -> sin_port,
 124                                 (unsigned char *)raw, len);
 125
 126         /* Fire it off */
 127         iov [0].iov_base = (char *)buf;
 128         iov [0].iov_len = bufp;
 129         iov [1].iov_base = (char *)raw;
 130         iov [1].iov_len = len;
 131
 132         result = writev(interface -> wfdesc, iov, 2);
 133         if (result < 0)
 134                 log_error ("send_packet: %m");
 135         return result;
 136 }
 137 #endif /* USE_SOCKET_SEND */