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NetBSD/dist/dhcp/server/bootp.c

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/* bootp.c
BOOTP Protocol support. */
/*
* Copyright (c) 2004-2005 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1995-2003 by Internet Software Consortium
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Internet Systems Consortium, Inc.
* 950 Charter Street
* Redwood City, CA 94063
* <info@isc.org>
* http://www.isc.org/
*
* This software has been written for Internet Systems Consortium
* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
* To learn more about Internet Systems Consortium, see
* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
* ``http://www.nominum.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: bootp.c,v 1.4 2005/08/11 17:13:30 drochner Exp $ Copyright (c) 2004 Internet Systems Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
#if defined (TRACING)
# define send_packet trace_packet_send
#endif
void bootp (packet)
struct packet *packet;
{
int result;
struct host_decl *hp = (struct host_decl *)0;
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 option_state *options = (struct option_state *)0;
struct lease *lease = (struct lease *)0;
unsigned i;
struct data_string d1;
struct option_cache *oc;
char msgbuf [1024];
int ignorep;
int peer_has_leases = 0;
if (packet -> raw -> op != BOOTREQUEST)
return;
/* %Audit% This is log output. %2004.06.17,Safe%
* If we truncate we hope the user can get a hint from the log.
*/
snprintf (msgbuf, sizeof msgbuf, "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)) {
log_info ("%s: network unknown", msgbuf);
return;
}
find_lease (&lease, packet, packet -> shared_network,
0, 0, (struct lease *)0, MDL);
if (lease && lease->host)
host_reference(&hp, lease->host, MDL);
if (!lease || ((lease->flags & STATIC_LEASE) == 0)) {
struct host_decl *h;
/* We didn't find an applicable fixed-address 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)
find_hosts_by_haddr(&hp, packet->raw->htype,
packet->raw->chaddr,
packet->raw->hlen, MDL);
for (h = hp; h; h = h -> n_ipaddr) {
if (!h -> fixed_addr) {
host_reference(&host, h, MDL);
break;
}
}
if (hp)
host_dereference(&hp, MDL);
if (host) {
host_reference(&hp, host, MDL);
host_dereference(&host, MDL);
}
/* Allocate a lease if we have not yet found one. */
if (!lease)
allocate_lease (&lease, packet,
packet -> shared_network -> pools,
&peer_has_leases);
if (lease)
ack_lease (packet, lease, 0, 0, msgbuf, 0, hp);
else
log_info ("%s: BOOTP from dynamic client and no "
"dynamic leases", msgbuf);
goto out;
}
/* Run the executable statements to compute the client and server
options. */
option_state_allocate (&options, MDL);
/* Execute the subnet statements. */
execute_statements_in_scope ((struct binding_value **)0,
packet, lease, (struct client_state *)0,
packet -> options, options,
&lease -> scope, lease -> subnet -> group,
(struct group *)0);
/* Execute statements from class scopes. */
for (i = packet -> class_count; i > 0; i--) {
execute_statements_in_scope
((struct binding_value **)0,
packet, lease, (struct client_state *)0,
packet -> options, options,
&lease -> scope, packet -> classes [i - 1] -> group,
lease -> subnet -> group);
}
/* Execute the host statements. */
execute_statements_in_scope ((struct binding_value **)0,
packet, lease, (struct client_state *)0,
packet -> options, options,
&lease -> scope,
hp -> group, lease -> subnet -> group);
/* Drop the request if it's not allowed for this client. */
if ((oc = lookup_option (&server_universe, options, SV_ALLOW_BOOTP)) &&
!evaluate_boolean_option_cache (&ignorep, packet, lease,
(struct client_state *)0,
packet -> options, options,
&lease -> scope, oc, MDL)) {
if (!ignorep)
log_info ("%s: bootp disallowed", msgbuf);
goto out;
}
if ((oc = lookup_option (&server_universe,
options, SV_ALLOW_BOOTING)) &&
!evaluate_boolean_option_cache (&ignorep, packet, lease,
(struct client_state *)0,
packet -> options, options,
&lease -> scope, oc, MDL)) {
if (!ignorep)
log_info ("%s: booting disallowed", msgbuf);
goto out;
}
/* 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 &&
!(evaluate_boolean_option_cache
(&ignorep, packet, lease, (struct client_state *)0,
packet -> options, options, &lease -> scope,
lookup_option (&server_universe, options,
SV_ALWAYS_REPLY_RFC1048), MDL))) {
memcpy (outgoing.raw -> options,
packet -> raw -> options, DHCP_OPTION_LEN);
outgoing.packet_length = BOOTP_MIN_LEN;
} else {
/* Use the subnet mask from the subnet declaration if no other
mask has been provided. */
oc = (struct option_cache *)0;
i = DHO_SUBNET_MASK;
if (!lookup_option (&dhcp_universe, options, i)) {
if (option_cache_allocate (&oc, MDL)) {
if (make_const_data
(&oc -> expression,
lease -> subnet -> netmask.iabuf,
lease -> subnet -> netmask.len,
0, 0, MDL)) {
oc -> option =
dhcp_universe.options [i];
save_option (&dhcp_universe,
options, oc);
}
option_cache_dereference (&oc, MDL);
}
}
/* Pack the options into the buffer. Unlike DHCP, we
can't pack options into the filename and server
name buffers. */
outgoing.packet_length =
cons_options (packet, outgoing.raw, lease,
(struct client_state *)0, 0,
packet -> options, options,
&lease -> scope,
0, 0, 1, (struct data_string *)0,
(const char *)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, sizeof raw.chaddr);
raw.hops = packet -> raw -> hops;
raw.xid = packet -> raw -> xid;
raw.secs = packet -> raw -> secs;
raw.flags = packet -> raw -> flags;
raw.ciaddr = packet -> raw -> ciaddr;
/* yiaddr is an ipv4 address, it must be 4 octets. */
memcpy (&raw.yiaddr, lease->ip_addr.iabuf, 4);
/* If we're always supposed to broadcast to this client, set
the broadcast bit in the bootp flags field. */
if ((oc = lookup_option (&server_universe,
options, SV_ALWAYS_BROADCAST)) &&
evaluate_boolean_option_cache (&ignorep, packet, lease,
(struct client_state *)0,
packet -> options, options,
&lease -> scope, oc, MDL))
raw.flags |= htons (BOOTP_BROADCAST);
/* Figure out the address of the next server. */
memset (&d1, 0, sizeof d1);
oc = lookup_option (&server_universe, options, SV_NEXT_SERVER);
if (oc &&
evaluate_option_cache (&d1, packet, lease,
(struct client_state *)0,
packet -> options, options,
&lease -> scope, oc, MDL)) {
/* If there was more than one answer, take the first. */
if (d1.len >= 4 && d1.data)
memcpy (&raw.siaddr, d1.data, 4);
data_string_forget (&d1, MDL);
} else {
if (lease -> subnet -> shared_network -> interface)
raw.siaddr = (lease -> subnet -> shared_network ->
interface -> primary_address);
else
raw.siaddr = packet -> interface -> primary_address;
}
raw.giaddr = packet -> raw -> giaddr;
/* Figure out the filename. */
oc = lookup_option (&server_universe, options, SV_FILENAME);
if (oc &&
evaluate_option_cache (&d1, packet, lease,
(struct client_state *)0,
packet -> options, options,
&lease -> scope, oc, MDL)) {
memcpy (raw.file, d1.data,
d1.len > sizeof raw.file ? sizeof raw.file : d1.len);
if (sizeof raw.file > d1.len)
memset (&raw.file [d1.len],
0, (sizeof raw.file) - d1.len);
data_string_forget (&d1, MDL);
} else
memcpy (raw.file, packet -> raw -> file, sizeof raw.file);
/* Choose a server name as above. */
oc = lookup_option (&server_universe, options, SV_SERVER_NAME);
if (oc &&
evaluate_option_cache (&d1, packet, lease,
(struct client_state *)0,
packet -> options, options,
&lease -> scope, oc, MDL)) {
memcpy (raw.sname, d1.data,
d1.len > sizeof raw.sname ? sizeof raw.sname : d1.len);
if (sizeof raw.sname > d1.len)
memset (&raw.sname [d1.len],
0, (sizeof raw.sname) - d1.len);
data_string_forget (&d1, MDL);
}
/* Execute the commit statements, if there are any. */
execute_statements ((struct binding_value **)0,
packet, lease, (struct client_state *)0,
packet -> options,
options, &lease -> scope, lease -> on_commit);
/* We're done with the option state. */
option_state_dereference (&options, MDL);
/* Set up the hardware destination address... */
hto.hbuf [0] = packet -> raw -> htype;
hto.hlen = packet -> raw -> hlen + 1;
memcpy (&hto.hbuf [1], packet -> raw -> chaddr, packet -> raw -> hlen);
from = packet -> interface -> primary_address;
/* Report what we're doing... */
log_info ("%s", msgbuf);
log_info ("BOOTREPLY for %s to %s (%s) via %s",
piaddr (lease->ip_addr), 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. */
memset (&to, 0, sizeof to);
to.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
to.sin_len = sizeof to;
#endif
/* 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);
}
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