1#! /usr/bin/perl -w
2
3# Copyright (c) 2007,2009 by Internet Systems Consortium, Inc. ("ISC")
4#
5# Permission to use, copy, modify, and distribute this software for any
6# purpose with or without fee is hereby granted, provided that the above
7# copyright notice and this permission notice appear in all copies.
8#
9# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11# MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16#
17#   Internet Systems Consortium, Inc.
18#   950 Charter Street
19#   Redwood City, CA 94063
20#   <info@isc.org>
21#   https://www.isc.org/
22
23use strict;
24use English;
25use Time::HiRes qw( sleep );
26use Socket;
27use Socket6;
28use IO::Select;
29
30use dhcp_client;
31
32# XXX: for debugging
33use Data::Dumper;
34
35# not-yet-standard options
36my $OPT_TIME_SERVERS = 40;
37my $OPT_TIME_OFFSET = 41;
38
39# DOCSIS sub-options
40my $DOCSIS_OPT_ORO = 1;
41# 2 to 31 are reserved
42my $DOCSIS_OPT_TFTP_SERVERS = 32;
43my $DOCSIS_OPT_CONFIG_FILE_NAME = 33;
44my $DOCSIS_OPT_SYSLOG_SERVERS = 34;
45my $DOCSIS_OPT_TLV5 = 35;
46my $DOCSIS_OPT_DEVICE_ID = 36;
47my $DOCSIS_OPT_CCC = 37;
48my $DOCSIS_OPT_VERS = 38;
49
50# well-known addresses
51my $All_DHCP_Relay_Agents_and_Servers = "ff02::1:2";
52my $All_DHCP_Servers = "ff05::1:3";
53
54# ports
55my $client_port = 546;
56my $server_port = 547;
57
58# create a new Solicit message
59my $msg = dhcp_client::msg->new($MSG_RELEASE);
60
61# add the Client Identifier (required by DOCSIS and RFC 3315)
62$msg->add_option($OPT_CLIENTID, dhcp_client::duid());
63
64# add the Server identifier (required by RFC 3315)
65$msg->add_option($OPT_SERVERID, "InfiniteEntropy");
66
67# add Elapsed Time, set to 0 on first packet (required by RFC 3315)
68$msg->add_option($OPT_ELAPSED_TIME, "\x00\x00");
69
70# add IA_NA for each interface (required by DOCSIS and RFC 3315)
71# XXX: should this be a single interface only?
72my $iaid = 0;
73foreach my $iface (dhcp_client::iface()) {
74	my $iaaddr_option = inet_pton(AF_INET6, "1:2:3:4::");
75	$iaaddr_option .= pack("NN", 0, 0);
76	my $option_data = pack("NNN", ++$iaid, 0, 0);
77	$option_data .= pack("nn", $OPT_IAADDR, length($iaaddr_option)-8);
78	$option_data .= $iaaddr_option;
79	$msg->add_option($OPT_IA_NA, $option_data);
80}
81
82# timeout parameters, from DOCSIS
83my $IRT = $SOL_TIMEOUT;
84my $MRT = $SOL_MAX_RT;
85my $MRC = 4;	# DOCSIS says 4, RFC 3315 says it SHOULD be 0
86my $MRD = 0;
87
88# sleep a random amount of time between 0 and 1 second, required by RFC 3315
89# XXX: this seems pretty stupid
90sleep(rand($SOL_MAX_DELAY));
91
92my $RT;
93my $count = 0;
94my $mrd_end_time;
95if ($MRD != 0) {
96	$mrd_end_time = time() + $MRD;
97}
98my $reply_msg;
99do {
100	# create our socket, and send our Solicit
101	socket(SOCK, PF_INET6, SOCK_DGRAM, getprotobyname('udp')) || die;
102	my $addr = inet_pton(AF_INET6, $All_DHCP_Servers);
103	my $packet = $msg->packet();
104	my $send_ret = send(SOCK, $packet, 0,
105			    pack_sockaddr_in6($server_port, $addr));
106	if (not defined($send_ret)) {
107		printf STDERR
108			"Error \%d sending DHCPv6 Solicit message;\n\%s\n",
109			0+$ERRNO, $ERRNO;
110		exit(1);
111	} elsif ($send_ret != length($packet)) {
112		print STDERR "Unable to send entire DHCPv6 Solicit message.\n";
113		exit(1);
114	}
115	$count++;
116
117	my $RAND = rand(0.2) - 0.1;
118	if (defined $RT) {
119		$RT = 2*$RT + $RAND*$RT;
120		if (($RT > $MRT) && ($MRT != 0)) {
121			$RT = $MRT + $RAND*$RT;
122		}
123	} else {
124		$RT = $IRT + $RAND*$IRT;
125	}
126
127	my $rt_end_time = time() + $RT;
128	if (defined($mrd_end_time) && ($mrd_end_time > $rt_end_time)) {
129		$rt_end_time = $mrd_end_time;
130	}
131
132	for (;;) {
133		my $timeout = $rt_end_time - time();
134		if ($timeout < 0) {
135#			print STDERR "Timeout waiting for DHCPv6 Advertise ",
136#				"or Reply message.\n";
137			last;
138		}
139
140		my @ready = IO::Select->new(\*SOCK)->can_read($timeout);
141
142		if (@ready) {
143			my $reply;
144			my $recv_ret;
145
146			$recv_ret = recv(SOCK, $reply, 1500, 0);
147			if (not defined $recv_ret) {
148				printf STDERR
149					"Error \%d receiving DHCPv6 " .
150						"message;\n\%s\n",
151					0+$ERRNO, $ERRNO;
152				exit(1);
153			}
154
155			$reply_msg = dhcp_client::msg::decode($reply, 1);
156			if (($reply_msg->{msg_type} == $MSG_ADVERTISE) ||
157			    ($reply_msg->{msg_type} == $MSG_REPLY)) {
158			    	last;
159			}
160		}
161	}
162
163} until ($reply_msg ||
164	 (($MRC != 0) && ($count > $MRC)) ||
165	 (defined($mrd_end_time) && ($mrd_end_time > time())));
166
167unless ($reply_msg) {
168	if (($MRC != 0) && ($count >= $MRC)) {
169		print STDERR
170			"No reply after maximum retransmission count.\n";
171	} else {
172		print STDERR
173			"No reply after maximum retransmission duration.\n";
174	}
175}
176
177if ($reply_msg && ($reply_msg->{msg_type} == $MSG_REPLY)) {
178	print "Got DHCPv6 Reply message.\n";
179	exit(0);
180}
181
182#$Data::Dumper::Useqq = 1;
183#print Dumper($msg), "\n";
184#print Dumper($msg->packet()), "\n";
185#
186#print "packet length: ", length($msg->packet()), "\n";
187
188