200 lines
6.7 KiB
C
200 lines
6.7 KiB
C
/* socket.c
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BSD socket interface code... */
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/*
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* Copyright (c) 1995, 1996 The Internet Software Consortium.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of The Internet Software Consortium nor the names
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* of its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
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* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This software has been written for the Internet Software Consortium
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* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
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* Enterprises. To learn more about the Internet Software Consortium,
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* see ``http://www.vix.com/isc''. To learn more about Vixie
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* Enterprises, see ``http://www.vix.com''.
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*/
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#ifndef lint
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static char copyright[] =
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"$Id: socket.c,v 1.1.1.1 1996/10/03 06:33:25 mrg Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
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#endif /* not lint */
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#include "dhcpd.h"
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#ifdef USE_SOCKET_FALLBACK
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# define USE_SOCKET_SEND
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# define if_register_send if_register_fallback
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# define send_packet send_fallback
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#endif
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#if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_RECEIVE)
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/* Generic interface registration routine... */
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int if_register_socket (info, interface)
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struct interface_info *info;
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struct ifreq *interface;
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{
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struct sockaddr_in name;
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int sock;
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int flag;
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static int once = 0;
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/* Make sure only one interface is registered. */
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if (once)
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error ("The standard socket API can only support %s%s%s%s%s",
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"hosts with a single network interface. If you must ",
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"run dhcpd on a host with multiple interfaces, ",
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"you must compile in BPF or NIT support. If neither ",
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"option is supported on your system, please let us ",
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"know.");
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/* Technically, we need to know what interface every packet
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comes in on, which means that we can only operate on a
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machine with a single interface configured. However,
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we generally don't expect to get broadcast packets on
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point-to-point interfaces, so we can bend the rules a bit
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and not count them. This won't allow DHCP-over-PPP,
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but it's probably right in a lot of cases, and the issue
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will have to be revisited when DHCP-over-PPP support is
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done. Currently we determine whether an interface is
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point-to-point by seeing if it has a link-level address.
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This only works on 4.4BSD and derivative networking. */
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#ifdef AF_LINK
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if (info -> hw_address.hlen) /* XXX */
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#endif
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once = 1;
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/* Set up the address we're going to bind to. */
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name.sin_family = AF_INET;
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name.sin_port = server_port;
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name.sin_addr.s_addr = INADDR_ANY;
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memset (name.sin_zero, 0, sizeof (name.sin_zero));
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/* Make a socket... */
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if ((sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
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error ("Can't create dhcp socket: %m");
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/* Set the REUSEADDR option so that we don't fail to start if
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we're being restarted. */
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flag = 1;
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if (setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
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(char *)&flag, sizeof flag) < 0)
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error ("Can't set SO_REUSEADDR option on dhcp socket: %m");
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/* Set the BROADCAST option so that we can broadcast DHCP responses. */
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if (setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
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(char *)&flag, sizeof flag) < 0)
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error ("Can't set SO_BROADCAST option on dhcp socket: %m");
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/* Bind the socket to this interface's IP address. */
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if (bind (sock, (struct sockaddr *)&name, sizeof name) < 0)
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error ("Can't bind to dhcp address: %m");
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return sock;
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}
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#endif /* USE_SOCKET_SEND || USE_SOCKET_RECEIVE */
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#ifdef USE_SOCKET_SEND
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void if_register_send (info, interface)
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struct interface_info *info;
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struct ifreq *interface;
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{
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#ifndef USE_SOCKET_RECEIVE
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info -> wfdesc = if_register_socket (info, interface);
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#else
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info -> wfdesc = info -> rfdesc;
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#endif
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note ("Sending on Socket/%s/%s",
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info -> name,
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(info -> shared_network ?
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info -> shared_network -> name : "unattached"));
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}
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#endif /* USE_SOCKET_SEND */
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#ifdef USE_SOCKET_RECEIVE
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void if_register_receive (info, interface)
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struct interface_info *info;
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struct ifreq *interface;
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{
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/* If we're using the socket API for sending and receiving,
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we don't need to register this interface twice. */
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info -> rfdesc = if_register_socket (info, interface);
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note ("Listening on Socket/%s/%s",
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info -> name,
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(info -> shared_network ?
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info -> shared_network -> name : "unattached"));
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}
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#endif /* USE_SOCKET_RECEIVE */
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#ifdef USE_SOCKET_SEND
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size_t send_packet (interface, packet, raw, len, from, to, hto)
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struct interface_info *interface;
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struct packet *packet;
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struct dhcp_packet *raw;
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size_t len;
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struct in_addr from;
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struct sockaddr_in *to;
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struct hardware *hto;
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{
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return sendto (interface -> wfdesc, (char *)raw, len, 0,
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(struct sockaddr *)to, sizeof *to);
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}
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#endif /* USE_SOCKET_SEND */
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#ifdef USE_SOCKET_RECEIVE
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size_t receive_packet (interface, buf, len, from, hfrom)
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struct interface_info *interface;
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unsigned char *buf;
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size_t len;
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struct sockaddr_in *from;
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struct hardware *hfrom;
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{
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int flen = sizeof *from;
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return recvfrom (interface -> rfdesc, buf, len, 0,
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(struct sockaddr *)from, &flen);
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}
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#endif /* USE_SOCKET_RECEIVE */
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#ifdef USE_SOCKET_FALLBACK
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/* This just reads in a packet and silently discards it. */
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size_t fallback_discard (interface)
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struct interface_info *interface;
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{
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char buf [1540];
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struct sockaddr_in from;
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int flen = sizeof from;
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return recvfrom (interface -> wfdesc, buf, sizeof buf, 0,
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(struct sockaddr *)&from, &flen);
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}
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#endif /* USE_SOCKET_RECEIVE */
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