NetBSD/usr.sbin/dhcp/server/bootp.c

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/* bootp.c
BOOTP Protocol support. */
/*
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* Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium.
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* 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 1.9 1999/12/07 23:23:16 soren Exp $ Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium. All rights reserved.\n";
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#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;
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if (packet -> raw -> op != BOOTREQUEST)
return;
note ("BOOTREQUEST from %s via %s%s",
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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,
packet -> options_valid ? "" : " (non-rfc1048)");
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if (!locate_network (packet))
return;
hp = find_hosts_by_haddr (packet -> raw -> htype,
packet -> raw -> chaddr,
packet -> raw -> hlen);
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lease = find_lease (packet, packet -> shared_network, 0);
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/* 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;
break;
}
}
}
if (host && (!host -> group -> allow_booting)) {
note ("Ignoring excluded BOOTP client %s",
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host -> name
? host -> name
: print_hw_addr (packet -> raw -> htype,
packet -> raw -> hlen,
packet -> raw -> chaddr));
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return;
}
if (host && (!host -> group -> allow_bootp)) {
note ("Ignoring BOOTP request from client %s",
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host -> name
? host -> name
: print_hw_addr (packet -> raw -> htype,
packet -> raw -> hlen,
packet -> raw -> chaddr));
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return;
}
/* If we've been told not to boot unknown clients,
and we didn't find any host record for this client,
ignore it. */
if (!host && !(packet -> shared_network ->
group -> boot_unknown_clients)) {
note ("Ignoring unknown BOOTP client %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);
return;
}
/* If we've been told not to boot with bootp on this
network, ignore it. */
if (!host &&
!(packet -> shared_network -> group -> allow_bootp)) {
note ("Ignoring BOOTP request from client %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);
return;
}
/* 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 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);
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;
}
/* Make sure we're allowed to boot this client. */
if (hp && (!hp -> group -> allow_booting)) {
note ("Ignoring excluded BOOTP client %s",
hp -> name);
return;
}
/* Make sure we're allowed to boot this client with bootp. */
if (hp && (!hp -> group -> allow_bootp)) {
note ("Ignoring BOOTP request from client %s",
hp -> name);
return;
}
/* Set up the outgoing packet... */
memset (&outgoing, 0, sizeof outgoing);
memset (&raw, 0, sizeof raw);
outgoing.raw = &raw;
/* If we didn't get a known vendor magic number on the way in,
just copy the input options to the output. */
if (!packet -> options_valid &&
!subnet -> group -> always_reply_rfc1048 &&
(!hp || !hp -> group -> always_reply_rfc1048)) {
memcpy (outgoing.raw -> options,
packet -> raw -> options, DHCP_OPTION_LEN);
outgoing.packet_length = BOOTP_MIN_LEN;
} else {
struct tree_cache netmask_tree; /* -- RBF */
/* 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. */
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memcpy (options, subnet -> group -> options, sizeof options);
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for (i = 0; i < 256; i++) {
if (hp -> group -> options [i])
options [i] = hp -> group -> options [i];
}
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/* Use the subnet mask from the subnet declaration if no other
mask has been provided. */
if (!options [DHO_SUBNET_MASK]) {
options [DHO_SUBNET_MASK] = &netmask_tree;
netmask_tree.flags = TC_TEMPORARY;
netmask_tree.value = lease -> subnet -> netmask.iabuf;
netmask_tree.len = lease -> subnet -> netmask.len;
netmask_tree.buf_size = lease -> subnet -> netmask.len;
netmask_tree.timeout = 0xFFFFFFFF;
netmask_tree.tree = (struct tree *)0;
}
/* Pack the options into the buffer. Unlike DHCP, we
can't pack options into the filename and server
name buffers. */
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outgoing.packet_length =
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cons_options (packet, outgoing.raw,
0, options, 0, 0, 1, (u_int8_t *)0, 0);
if (outgoing.packet_length < BOOTP_MIN_LEN)
outgoing.packet_length = BOOTP_MIN_LEN;
}
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/* Take the fields that we care about... */
raw.op = BOOTREPLY;
raw.htype = packet -> raw -> htype;
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;
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
raw.siaddr = packet -> interface -> primary_address;
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) {
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strncpy (raw.file, hp -> group -> filename,
(sizeof raw.file) - 1);
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raw.file [(sizeof raw.file) - 1] = 0;
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} else
memcpy (raw.file, packet -> raw -> file, sizeof raw.file);
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/* Set up the hardware destination address... */
hto.htype = packet -> raw -> htype;
hto.hlen = packet -> raw -> hlen;
memcpy (hto.haddr, packet -> raw -> chaddr, hto.hlen);
from = packet -> interface -> primary_address;
/* 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 = local_port;
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if (fallback_interface) {
result = send_packet (fallback_interface,
(struct packet *)0,
&raw, outgoing.packet_length,
from, &to, &hto);
return;
}
/* 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()) {
to.sin_addr = raw.yiaddr;
to.sin_port = remote_port;
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/* Otherwise, broadcast it on the local network. */
} else {
to.sin_addr.s_addr = INADDR_BROADCAST;
to.sin_port = remote_port; /* XXX */
}
errno = 0;
result = send_packet (packet -> interface,
packet, &raw, outgoing.packet_length,
from, &to, &hto);
}