GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/dhcpd/bootp.c Lines: 0 153 0.0 %
Date: 2017-11-13 Branches: 0 102 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: bootp.c,v 1.18 2017/02/13 22:33:39 krw Exp $	*/
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3
/*
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 * BOOTP Protocol support.
5
 */
6
7
/*
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 * Copyright (c) 1995, 1996, 1998, 1999 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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#include <sys/socket.h>
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47
#include <arpa/inet.h>
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49
#include <net/if.h>
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#include <netinet/in.h>
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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57
#include "dhcp.h"
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#include "tree.h"
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#include "dhcpd.h"
60
#include "log.h"
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62
void
63
bootp(struct packet *packet)
64
{
65
	struct host_decl *hp, *host = NULL;
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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 tree_cache *options[256];
71
	struct shared_network *s;
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	struct subnet *subnet = NULL;
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	struct lease *lease;
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	struct iaddr ip_address;
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	int i;
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77
	if (packet->raw->op != BOOTREQUEST)
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		return;
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80
	log_info("BOOTREQUEST from %s via %s%s",
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	    print_hw_addr(packet->raw->htype, packet->raw->hlen,
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	    packet->raw->chaddr), packet->raw->giaddr.s_addr ?
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	    inet_ntoa(packet->raw->giaddr) : packet->interface->name,
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	    packet->options_valid ? "" : " (non-rfc1048)");
85
86
	if (!locate_network(packet))
87
		return;
88
89
	hp = find_hosts_by_haddr(packet->raw->htype, packet->raw->chaddr,
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	    packet->raw->hlen);
91
92
	s = packet->shared_network;
93
	lease = find_lease(packet, s, 0);
94
95
	/*
96
	 * Find an IP address in the host_decl that matches the specified
97
	 * network.
98
	 */
99
	if (hp)
100
		subnet = find_host_for_network(&hp, &ip_address, s);
101
102
	if (!subnet) {
103
		/*
104
		 * We didn't find an applicable host declaration. Just in case
105
		 * we may be able to dynamically assign an address, see if
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		 * there's a host declaration that doesn't have an ip address
107
		 * associated with it.
108
		 */
109
		if (hp)
110
			for (; hp; hp = hp->n_ipaddr)
111
				if (!hp->fixed_addr) {
112
					host = hp;
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					break;
114
				}
115
116
		if (host && (!host->group->allow_booting)) {
117
			log_info("Ignoring excluded BOOTP client %s",
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			    host->name ?  host->name :
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			    print_hw_addr (packet->raw->htype,
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			    packet->raw->hlen, packet->raw->chaddr));
121
			return;
122
		}
123
124
		if (host && (!host->group->allow_bootp)) {
125
			log_info("Ignoring BOOTP request from client %s",
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			    host->name ? host->name :
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			    print_hw_addr(packet->raw->htype,
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			    packet->raw->hlen, packet->raw->chaddr));
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			return;
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		}
131
132
		/*
133
		 * If we've been told not to boot unknown clients, and we
134
		 * didn't find any host record for this client, ignore it.
135
		 */
136
		if (!host && !(s->group->boot_unknown_clients)) {
137
			log_info("Ignoring unknown BOOTP client %s via %s",
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			    print_hw_addr(packet->raw->htype,
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			    packet->raw->hlen, packet->raw->chaddr),
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			    packet->raw->giaddr.s_addr ?
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			    inet_ntoa(packet->raw->giaddr) :
142
			    packet->interface->name);
143
			return;
144
		}
145
146
		/*
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		 * If we've been told not to boot with bootp on this network,
148
		 * ignore it.
149
		 */
150
		if (!host && !(s->group->allow_bootp)) {
151
			log_info("Ignoring BOOTP request from client %s via "
152
			    "%s", print_hw_addr(packet->raw->htype,
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			    packet->raw->hlen, 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);
157
			return;
158
		}
159
160
		/*
161
		 * If the packet is from a host we don't know and there are no
162
		 * dynamic bootp addresses on the network it came in on, drop
163
		 * it on the floor.
164
		 */
165
		if (!(s->group->dynamic_bootp)) {
166
lose:
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			log_info("No applicable record for BOOTP host %s via "
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			    "%s", print_hw_addr(packet->raw->htype,
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			    packet->raw->hlen, 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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			return;
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		}
175
176
		/*
177
		 * If a lease has already been assigned to this client and it's
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		 * still okay to use dynamic bootp on that lease, reassign it.
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		 */
180
		if (lease) {
181
			/*
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			 * If this lease can be used for dynamic bootp, do so.
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			 */
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			if ((lease->flags & DYNAMIC_BOOTP_OK)) {
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				/*
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				 * If it's not a DYNAMIC_BOOTP lease, release
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				 * it before reassigning it so that we don't
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				 * get a lease conflict.
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				 */
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				if (!(lease->flags & BOOTP_LEASE))
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					release_lease(lease);
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				lease->host = host;
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				ack_lease(packet, lease, 0, 0);
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				return;
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			}
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			 /*
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			  * If dynamic BOOTP is no longer allowed for this
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			  * lease, set it free.
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			  */
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			release_lease(lease);
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		}
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		/*
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		 * If there are dynamic bootp addresses that might be
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		 * available, try to snag one.
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		 */
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		for (lease = s->last_lease;
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		    lease && lease->ends <= cur_time;
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		    lease = lease->prev) {
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			if ((lease->flags & DYNAMIC_BOOTP_OK)) {
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				lease->host = host;
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				ack_lease(packet, lease, 0, 0);
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				return;
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			}
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		}
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		goto lose;
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	}
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	/* Make sure we're allowed to boot this client. */
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	if (hp && (!hp->group->allow_booting)) {
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		log_info("Ignoring excluded BOOTP client %s", hp->name);
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		return;
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	}
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	/* Make sure we're allowed to boot this client with bootp. */
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	if (hp && (!hp->group->allow_bootp)) {
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		log_info("Ignoring BOOTP request from client %s", hp->name);
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		return;
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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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	/*
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	 * If we didn't get a known vendor magic number on the way in, just
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	 * copy the input options to the output.
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	 */
242
	if (!packet->options_valid && !subnet->group->always_reply_rfc1048 &&
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	    (!hp || !hp->group->always_reply_rfc1048)) {
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		memcpy(outgoing.raw->options, packet->raw->options,
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		    DHCP_OPTION_LEN);
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		outgoing.packet_length = BOOTP_MIN_LEN;
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	} else {
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		struct tree_cache netmask_tree;   /*  -- RBF */
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		/*
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		 * Come up with a list of options that we want to send to this
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		 * client. Start with the per-subnet options, and then override
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		 * those with client-specific options.
254
		 */
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		memcpy(options, subnet->group->options, sizeof(options));
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		for (i = 0; i < 256; i++)
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			if (hp->group->options[i])
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				options[i] = hp->group->options[i];
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		/*
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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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		 */
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		if (!options[DHO_SUBNET_MASK]) {
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			options[DHO_SUBNET_MASK] = &netmask_tree;
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			netmask_tree.flags = TC_TEMPORARY;
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			netmask_tree.value = lease->subnet->netmask.iabuf;
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			netmask_tree.len = lease->subnet->netmask.len;
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			netmask_tree.buf_size = lease->subnet->netmask.len;
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			netmask_tree.timeout = -1;
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			netmask_tree.tree = NULL;
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		}
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		/*
277
		 * Pack the options into the buffer. Unlike DHCP, we can't pack
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		 * options into the filename and server name buffers.
279
		 */
280
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		outgoing.packet_length = cons_options(packet, outgoing.raw,
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		    0, options, 0, 0, 1, NULL, 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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	}
287
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	/* Take the fields that we care about... */
289
	raw.op = BOOTREPLY;
290
	raw.htype = packet->raw->htype;
291
	raw.hlen = packet->raw->hlen;
292
	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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	/* Figure out the address of the next server. */
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	if (hp && hp->group->next_server.len)
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		memcpy(&raw.siaddr, hp->group->next_server.iabuf, 4);
303
	else if (subnet->group->next_server.len)
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		memcpy(&raw.siaddr, subnet->group->next_server.iabuf, 4);
305
	else if (subnet->interface_address.len)
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		memcpy(&raw.siaddr, subnet->interface_address.iabuf, 4);
307
	else
308
		raw.siaddr = packet->interface->primary_address;
309
310
	raw.giaddr = packet->raw->giaddr;
311
	if (hp->group->server_name)
312
		strncpy(raw.sname, hp->group->server_name, sizeof(raw.sname));
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	else if (subnet->group->server_name)
314
		strncpy(raw.sname, subnet->group->server_name,
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		    sizeof(raw.sname));
316
317
	if (hp->group->filename)
318
		strncpy(raw.file, hp->group->filename, sizeof(raw.file));
319
	else if (subnet->group->filename)
320
		strncpy(raw.file, subnet->group->filename, sizeof(raw.file));
321
	else
322
		memcpy(raw.file, packet->raw->file, sizeof(raw.file));
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	from = packet->interface->primary_address;
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	/* Report what we're doing... */
327
	log_info("BOOTREPLY for %s to %s (%s) via %s", piaddr(ip_address),
328
	    hp->name, print_hw_addr(packet->raw->htype, packet->raw->hlen,
329
	    packet->raw->chaddr), packet->raw->giaddr.s_addr ?
330
	    inet_ntoa(packet->raw->giaddr) : packet->interface->name);
331
332
	/* Set up the parts of the address that are in common. */
333
	memset(&to, 0, sizeof(to));
334
	to.sin_family = AF_INET;
335
#ifdef HAVE_SA_LEN
336
	to.sin_len = sizeof(to);
337
#endif
338
339
	/* If this was gatewayed, send it back to the gateway... */
340
	if (raw.giaddr.s_addr) {
341
		to.sin_addr = raw.giaddr;
342
		to.sin_port = server_port;
343
344
		(void) packet->interface->send_packet(packet->interface, &raw,
345
		    outgoing.packet_length, from, &to, packet->haddr);
346
		return;
347
	}
348
349
	/*
350
	 * If it comes from a client that already knows its address and is not
351
	 * requesting a broadcast response, and we can unicast to a client
352
	 * without using the ARP protocol, sent it directly to that client.
353
	 */
354
	else if (!(raw.flags & htons(BOOTP_BROADCAST))) {
355
		to.sin_addr = raw.yiaddr;
356
		to.sin_port = client_port;
357
	} else {
358
		/* Otherwise, broadcast it on the local network. */
359
		to.sin_addr.s_addr = INADDR_BROADCAST;
360
		to.sin_port = client_port; /* XXX */
361
	}
362
363
	errno = 0;
364
	(void) packet->interface->send_packet(packet->interface, &raw,
365
	    outgoing.packet_length, from, &to, packet->haddr);
366
}