419 lines
13 KiB
C
419 lines
13 KiB
C
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/* bootp.c
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BOOTP Protocol support. */
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/*
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* Copyright (c) 1995-2001 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 in cooperation with Vixie Enterprises and Nominum, Inc.
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* To learn more about the Internet Software Consortium, see
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* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
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* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
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* ``http://www.nominum.com''.
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*/
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#ifndef lint
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static char copyright[] =
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"$Id: bootp.c,v 1.1.1.1 2001/08/03 11:35:40 drochner Exp $ Copyright (c) 1995-2000 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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#if defined (TRACING)
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# define send_packet trace_packet_send
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#endif
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void bootp (packet)
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struct packet *packet;
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{
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int result;
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struct host_decl *hp = (struct host_decl *)0;
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struct host_decl *host = (struct host_decl *)0;
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struct packet outgoing;
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struct dhcp_packet raw;
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struct sockaddr_in to;
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struct in_addr from;
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struct hardware hto;
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struct option_state *options = (struct option_state *)0;
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struct subnet *subnet;
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struct lease *lease;
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struct iaddr ip_address;
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unsigned i;
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struct data_string d1;
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struct option_cache *oc;
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char msgbuf [1024];
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int ignorep;
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int peer_has_leases = 0;
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if (packet -> raw -> op != BOOTREQUEST)
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return;
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sprintf (msgbuf, "BOOTREQUEST from %s via %s",
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print_hw_addr (packet -> raw -> htype,
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packet -> raw -> hlen,
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packet -> raw -> chaddr),
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packet -> raw -> giaddr.s_addr
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? inet_ntoa (packet -> raw -> giaddr)
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: packet -> interface -> name);
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if (!locate_network (packet)) {
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log_info ("%s: network unknown", msgbuf);
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return;
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}
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find_hosts_by_haddr (&hp, packet -> raw -> htype,
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packet -> raw -> chaddr,
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packet -> raw -> hlen, MDL);
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lease = (struct lease *)0;
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find_lease (&lease, packet, packet -> shared_network,
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0, 0, (struct lease *)0, MDL);
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/* Find an IP address in the host_decl that matches the
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specified network. */
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subnet = (struct subnet *)0;
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if (hp)
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find_host_for_network (&subnet, &hp, &ip_address,
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packet -> shared_network);
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if (!subnet) {
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struct host_decl *h;
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/* We didn't find an applicable host declaration.
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Just in case we may be able to dynamically assign
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an address, see if there's a host declaration
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that doesn't have an ip address associated with it. */
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for (h = hp; h; h = h -> n_ipaddr) {
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if (!h -> fixed_addr) {
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host_reference (&host, h, MDL);
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break;
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}
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}
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if (hp) {
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host_dereference (&hp, MDL);
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if (host)
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host_reference (&hp, host, MDL);
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}
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/* If a lease has already been assigned to this client,
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use it. */
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if (lease) {
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if (host && host != lease -> host) {
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if (lease -> host)
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host_dereference (&lease -> host, MDL);
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host_reference (&lease -> host, host, MDL);
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}
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ack_lease (packet, lease, 0, 0, msgbuf, 0);
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goto out;
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}
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/* Otherwise, try to allocate one. */
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allocate_lease (&lease, packet,
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packet -> shared_network -> pools,
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&peer_has_leases);
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if (lease) {
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if (host && host != lease -> host) {
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if (lease -> host)
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host_dereference (&lease -> host, MDL);
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host_reference (&lease -> host, host, MDL);
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} else if (lease -> host)
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host_dereference (&lease -> host, MDL);
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ack_lease (packet, lease, 0, 0, msgbuf, 0);
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goto out;
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}
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/* XXX just ignore BOOTREQUESTS from unknown clients if
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XXX we can't allocate IP addresses for them. */
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#if 0
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log_info ("%s: no available leases", msgbuf);
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#endif
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goto out;
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}
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/* Run the executable statements to compute the client and server
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options. */
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option_state_allocate (&options, MDL);
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/* Execute the subnet statements. */
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execute_statements_in_scope ((struct binding_value **)0,
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packet, lease, (struct client_state *)0,
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packet -> options, options,
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&lease -> scope, lease -> subnet -> group,
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(struct group *)0);
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/* Execute statements from class scopes. */
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for (i = packet -> class_count; i > 0; i--) {
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execute_statements_in_scope
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((struct binding_value **)0,
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packet, lease, (struct client_state *)0,
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packet -> options, options,
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&lease -> scope, packet -> classes [i - 1] -> group,
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lease -> subnet -> group);
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}
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/* Execute the host statements. */
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execute_statements_in_scope ((struct binding_value **)0,
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packet, lease, (struct client_state *)0,
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packet -> options, options,
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&lease -> scope,
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hp -> group, subnet -> group);
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/* Drop the request if it's not allowed for this client. */
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if ((oc = lookup_option (&server_universe, options, SV_ALLOW_BOOTP)) &&
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!evaluate_boolean_option_cache (&ignorep, packet, lease,
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(struct client_state *)0,
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packet -> options, options,
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&lease -> scope, oc, MDL)) {
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if (!ignorep)
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log_info ("%s: bootp disallowed", msgbuf);
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goto out;
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}
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if ((oc = lookup_option (&server_universe,
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options, SV_ALLOW_BOOTING)) &&
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!evaluate_boolean_option_cache (&ignorep, packet, lease,
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(struct client_state *)0,
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packet -> options, options,
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&lease -> scope, oc, MDL)) {
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if (!ignorep)
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log_info ("%s: booting disallowed", msgbuf);
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goto out;
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}
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/* Set up the outgoing packet... */
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memset (&outgoing, 0, sizeof outgoing);
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memset (&raw, 0, sizeof raw);
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outgoing.raw = &raw;
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/* If we didn't get a known vendor magic number on the way in,
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just copy the input options to the output. */
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if (!packet -> options_valid &&
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!(evaluate_boolean_option_cache
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(&ignorep, packet, lease, (struct client_state *)0,
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packet -> options, options, &lease -> scope,
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lookup_option (&server_universe, options,
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SV_ALWAYS_REPLY_RFC1048), MDL))) {
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memcpy (outgoing.raw -> options,
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packet -> raw -> options, DHCP_OPTION_LEN);
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outgoing.packet_length = BOOTP_MIN_LEN;
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} else {
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/* Use the subnet mask from the subnet declaration if no other
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mask has been provided. */
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oc = (struct option_cache *)0;
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i = DHO_SUBNET_MASK;
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if (!lookup_option (&dhcp_universe, options, i)) {
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if (option_cache_allocate (&oc, MDL)) {
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if (make_const_data
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(&oc -> expression,
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lease -> subnet -> netmask.iabuf,
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lease -> subnet -> netmask.len,
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0, 0, MDL)) {
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oc -> option =
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dhcp_universe.options [i];
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save_option (&dhcp_universe,
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options, oc);
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}
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option_cache_dereference (&oc, MDL);
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}
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}
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/* Pack the options into the buffer. Unlike DHCP, we
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can't pack options into the filename and server
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name buffers. */
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outgoing.packet_length =
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cons_options (packet, outgoing.raw, lease,
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(struct client_state *)0, 0,
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packet -> options, options,
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&lease -> scope,
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0, 0, 1, (struct data_string *)0,
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(const char *)0);
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if (outgoing.packet_length < BOOTP_MIN_LEN)
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outgoing.packet_length = BOOTP_MIN_LEN;
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}
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/* Take the fields that we care about... */
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raw.op = BOOTREPLY;
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raw.htype = packet -> raw -> htype;
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raw.hlen = packet -> raw -> hlen;
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memcpy (raw.chaddr, packet -> raw -> chaddr, sizeof raw.chaddr);
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raw.hops = packet -> raw -> hops;
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raw.xid = packet -> raw -> xid;
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raw.secs = packet -> raw -> secs;
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raw.flags = packet -> raw -> flags;
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raw.ciaddr = packet -> raw -> ciaddr;
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memcpy (&raw.yiaddr, ip_address.iabuf, sizeof raw.yiaddr);
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/* If we're always supposed to broadcast to this client, set
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the broadcast bit in the bootp flags field. */
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if ((oc = lookup_option (&server_universe,
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options, SV_ALWAYS_BROADCAST)) &&
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evaluate_boolean_option_cache (&ignorep, packet, lease,
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(struct client_state *)0,
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packet -> options, options,
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&lease -> scope, oc, MDL))
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raw.flags |= htons (BOOTP_BROADCAST);
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/* Figure out the address of the next server. */
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memset (&d1, 0, sizeof d1);
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oc = lookup_option (&server_universe, options, SV_NEXT_SERVER);
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if (oc &&
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evaluate_option_cache (&d1, packet, lease,
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(struct client_state *)0,
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packet -> options, options,
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&lease -> scope, oc, MDL)) {
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/* If there was more than one answer, take the first. */
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if (d1.len >= 4 && d1.data)
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memcpy (&raw.siaddr, d1.data, 4);
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data_string_forget (&d1, MDL);
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} else {
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if (lease -> subnet -> shared_network -> interface)
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raw.siaddr = (lease -> subnet -> shared_network ->
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interface -> primary_address);
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else
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raw.siaddr = packet -> interface -> primary_address;
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}
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raw.giaddr = packet -> raw -> giaddr;
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/* Figure out the filename. */
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oc = lookup_option (&server_universe, options, SV_FILENAME);
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if (oc &&
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evaluate_option_cache (&d1, packet, lease,
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(struct client_state *)0,
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packet -> options, options,
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&lease -> scope, oc, MDL)) {
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memcpy (raw.file, d1.data,
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d1.len > sizeof raw.file ? sizeof raw.file : d1.len);
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if (sizeof raw.file > d1.len)
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memset (&raw.file [d1.len],
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0, (sizeof raw.file) - d1.len);
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data_string_forget (&d1, MDL);
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} else
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memcpy (raw.file, packet -> raw -> file, sizeof raw.file);
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/* Choose a server name as above. */
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oc = lookup_option (&server_universe, options, SV_SERVER_NAME);
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if (oc &&
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evaluate_option_cache (&d1, packet, lease,
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(struct client_state *)0,
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packet -> options, options,
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&lease -> scope, oc, MDL)) {
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memcpy (raw.sname, d1.data,
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d1.len > sizeof raw.sname ? sizeof raw.sname : d1.len);
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if (sizeof raw.sname > d1.len)
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memset (&raw.sname [d1.len],
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0, (sizeof raw.sname) - d1.len);
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data_string_forget (&d1, MDL);
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}
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/* Execute the commit statements, if there are any. */
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execute_statements ((struct binding_value **)0,
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packet, lease, (struct client_state *)0,
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packet -> options,
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options, &lease -> scope, lease -> on_commit);
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/* We're done with the option state. */
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option_state_dereference (&options, MDL);
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/* Set up the hardware destination address... */
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hto.hbuf [0] = packet -> raw -> htype;
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hto.hlen = packet -> raw -> hlen + 1;
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memcpy (&hto.hbuf [1], packet -> raw -> chaddr, packet -> raw -> hlen);
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from = packet -> interface -> primary_address;
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/* Report what we're doing... */
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log_info ("%s", msgbuf);
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log_info ("BOOTREPLY for %s to %s (%s) via %s",
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piaddr (ip_address), hp -> name,
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print_hw_addr (packet -> raw -> htype,
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packet -> raw -> hlen,
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|
|
packet -> raw -> chaddr),
|
||
|
|
packet -> raw -> giaddr.s_addr
|
||
|
|
? inet_ntoa (packet -> raw -> giaddr)
|
||
|
|
: packet -> interface -> name);
|
||
|
|
|
||
|
|
/* Set up the parts of the address that are in common. */
|
||
|
|
to.sin_family = AF_INET;
|
||
|
|
#ifdef HAVE_SA_LEN
|
||
|
|
to.sin_len = sizeof to;
|
||
|
|
#endif
|
||
|
|
memset (to.sin_zero, 0, sizeof to.sin_zero);
|
||
|
|
|
||
|
|
/* If this was gatewayed, send it back to the gateway... */
|
||
|
|
if (raw.giaddr.s_addr) {
|
||
|
|
to.sin_addr = raw.giaddr;
|
||
|
|
to.sin_port = local_port;
|
||
|
|
|
||
|
|
if (fallback_interface) {
|
||
|
|
result = send_packet (fallback_interface,
|
||
|
|
(struct packet *)0,
|
||
|
|
&raw, outgoing.packet_length,
|
||
|
|
from, &to, &hto);
|
||
|
|
goto out;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* If it comes from a client that already knows its address
|
||
|
|
and is not requesting a broadcast response, and we can
|
||
|
|
unicast to a client without using the ARP protocol, sent it
|
||
|
|
directly to that client. */
|
||
|
|
} else if (!(raw.flags & htons (BOOTP_BROADCAST)) &&
|
||
|
|
can_unicast_without_arp (packet -> interface)) {
|
||
|
|
to.sin_addr = raw.yiaddr;
|
||
|
|
to.sin_port = remote_port;
|
||
|
|
|
||
|
|
/* Otherwise, broadcast it on the local network. */
|
||
|
|
} else {
|
||
|
|
to.sin_addr = limited_broadcast;
|
||
|
|
to.sin_port = remote_port; /* XXX */
|
||
|
|
}
|
||
|
|
|
||
|
|
errno = 0;
|
||
|
|
result = send_packet (packet -> interface,
|
||
|
|
packet, &raw, outgoing.packet_length,
|
||
|
|
from, &to, &hto);
|
||
|
|
out:
|
||
|
|
if (options)
|
||
|
|
option_state_dereference (&options, MDL);
|
||
|
|
if (lease)
|
||
|
|
lease_dereference (&lease, MDL);
|
||
|
|
if (hp)
|
||
|
|
host_dereference (&hp, MDL);
|
||
|
|
if (host)
|
||
|
|
host_dereference (&host, MDL);
|
||
|
|
if (subnet)
|
||
|
|
subnet_dereference (&subnet, MDL);
|
||
|
|
}
|