NetBSD/usr.sbin/dhcpd/bootp.c

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1996-10-03 10:33:24 +04:00
/* bootp.c
BOOTP Protocol support. */
/*
* Copyright (c) 1995, 1996 The Internet Software Consortium.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of The Internet Software Consortium nor the names
* of its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: bootp.c,v 1.1.1.1 1996/10/03 06:33:24 mrg Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
void bootp (packet)
struct packet *packet;
{
int result;
struct host_decl *hp;
struct host_decl *host = (struct host_decl *)0;
struct packet outgoing;
struct dhcp_packet raw;
struct sockaddr_in to;
struct in_addr from;
struct hardware hto;
struct tree_cache *options [256];
struct subnet *subnet;
struct lease *lease;
struct iaddr ip_address;
int i;
note ("BOOTREQUEST from %s via %s",
print_hw_addr (packet -> raw -> htype,
packet -> raw -> hlen,
packet -> raw -> chaddr),
packet -> raw -> giaddr.s_addr
? inet_ntoa (packet -> raw -> giaddr)
: packet -> interface -> name);
if (!locate_network (packet))
return;
hp = find_hosts_by_haddr (packet -> raw -> htype,
packet -> raw -> chaddr,
packet -> raw -> hlen);
lease = find_lease (packet, packet -> shared_network);
/* Find an IP address in the host_decl that matches the
specified network. */
if (hp)
subnet = find_host_for_network (&hp, &ip_address,
packet -> shared_network);
else
subnet = (struct subnet *)0;
if (!subnet) {
/* We didn't find an applicable host declaration.
Just in case we may be able to dynamically assign
an address, see if there's a host declaration
that doesn't have an ip address associated with it. */
if (hp) {
for (; hp; hp = hp -> n_ipaddr) {
if (!hp -> fixed_addr) {
host = hp;
}
}
}
/* If we've been told not to boot unknown clients,
and we didn't find any host record for this client,
ignore it. */
if (!hp && !(packet -> shared_network ->
group -> boot_unknown_clients)) {
note ("Ignoring unknown BOOTP client %s",
print_hw_addr (packet -> raw -> htype,
packet -> raw -> hlen,
packet -> raw -> chaddr));
}
/* If the packet is from a host we don't know and there
are no dynamic bootp addresses on the network it came
in on, drop it on the floor. */
if (!(packet -> shared_network -> group -> dynamic_bootp)) {
lose:
note ("No applicable record for BOOTP host %s",
print_hw_addr (packet -> raw -> htype,
packet -> raw -> hlen,
packet -> raw -> chaddr));
return;
}
/* If a lease has already been assigned to this client
and it's still okay to use dynamic bootp on
that lease, reassign it. */
if (lease) {
/* If this lease can be used for dynamic bootp,
do so. */
if ((lease -> flags & DYNAMIC_BOOTP_OK)) {
/* If it's not a DYNAMIC_BOOTP lease,
release it before reassigning it
so that we don't get a lease
conflict. */
if (!(lease -> flags & BOOTP_LEASE))
release_lease (lease);
lease -> host = host;
ack_lease (packet, lease, 0, 0);
return;
}
/* If dynamic BOOTP is no longer allowed for
this lease, set it free. */
release_lease (lease);
}
/* If there are dynamic bootp addresses that might be
available, try to snag one. */
for (lease = packet -> shared_network -> last_lease;
lease && lease -> ends <= cur_time;
lease = lease -> prev) {
if ((lease -> flags & DYNAMIC_BOOTP_OK)) {
lease -> host = host;
ack_lease (packet, lease, 0, 0);
return;
}
}
goto lose;
}
/* Set up the outgoing packet... */
memset (&outgoing, 0, sizeof outgoing);
memset (&raw, 0, sizeof raw);
outgoing.raw = &raw;
/* Come up with a list of options that we want to send to this
client. Start with the per-subnet options, and then override
those with client-specific options. */
memcpy (options, subnet -> group -> options, sizeof options);
for (i = 0; i < 256; i++) {
if (hp -> group -> options [i])
options [i] = hp -> group -> options [i];
}
/* Pack the options into the buffer. Unlike DHCP, we can't
pack options into the filename and server name buffers. */
cons_options (packet, &outgoing, options, 0, 0);
if (outgoing.packet_length < BOOTP_MIN_LEN)
outgoing.packet_length = BOOTP_MIN_LEN;
/* Take the fields that we care about... */
raw.op = BOOTREPLY;
raw.htype = packet -> raw -> htype;
raw.hlen = packet -> raw -> hlen;
memcpy (raw.chaddr, packet -> raw -> chaddr, raw.hlen);
memset (&raw.chaddr [raw.hlen], 0,
(sizeof raw.chaddr) - raw.hlen);
raw.hops = packet -> raw -> hops;
raw.xid = packet -> raw -> xid;
raw.secs = packet -> raw -> secs;
raw.flags = 0;
raw.ciaddr = packet -> raw -> ciaddr;
memcpy (&raw.yiaddr, ip_address.iabuf, sizeof raw.yiaddr);
/* Figure out the address of the next server. */
if (hp && hp -> group -> next_server.len)
memcpy (&raw.siaddr, hp -> group -> next_server.iabuf, 4);
else if (subnet -> group -> next_server.len)
memcpy (&raw.siaddr, subnet -> group -> next_server.iabuf, 4);
else if (subnet -> interface_address.len)
memcpy (&raw.siaddr, subnet -> interface_address.iabuf, 4);
else
memcpy (&raw.siaddr, server_identifier.iabuf, 4);
raw.giaddr = packet -> raw -> giaddr;
if (hp -> group -> server_name) {
strncpy (raw.sname, hp -> group -> server_name,
(sizeof raw.sname) - 1);
raw.sname [(sizeof raw.sname) - 1] = 0;
}
if (hp -> group -> filename) {
strncpy (raw.file, hp -> group -> filename,
(sizeof raw.file) - 1);
raw.file [(sizeof raw.file) - 1] = 0;
}
/* Set up the hardware destination address... */
hto.htype = packet -> raw -> htype;
hto.hlen = packet -> raw -> hlen;
memcpy (hto.haddr, packet -> raw -> chaddr, hto.hlen);
if (server_identifier.len)
memcpy (&from, server_identifier.iabuf, 4);
else
memset (&from, 0, 4);
/* Report what we're doing... */
note ("BOOTREPLY for %s to %s (%s) via %s",
piaddr (ip_address), hp -> name,
print_hw_addr (packet -> raw -> htype,
packet -> raw -> hlen,
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 = server_port;
#ifdef USE_FALLBACK
result = send_fallback (&fallback_interface,
(struct packet *)0,
&raw, outgoing.packet_length,
from, &to, &hto);
if (result < 0)
warn ("send_fallback: %m");
return;
#endif
/* Otherwise, broadcast it on the local network. */
} else {
to.sin_addr.s_addr = INADDR_BROADCAST;
to.sin_port = htons (ntohs (server_port) + 1); /* XXX */
}
errno = 0;
result = send_packet (packet -> interface,
packet, &raw, outgoing.packet_length,
from, &to, &hto);
if (result < 0)
warn ("send_packet: %m");
}