1#! /usr/bin/perl -w 2 3# Copyright (C) 2007-2022 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# PO Box 360 19# Newmarket, NH 03857 USA 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_DECLINE); 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 $option_data = pack("NNN", ++$iaid, 0, 0); 75 $msg->add_option($OPT_IA_NA, $option_data); 76} 77 78# timeout parameters, from DOCSIS 79my $IRT = $SOL_TIMEOUT; 80my $MRT = $SOL_MAX_RT; 81my $MRC = 4; # DOCSIS says 4, RFC 3315 says it SHOULD be 0 82my $MRD = 0; 83 84# sleep a random amount of time between 0 and 1 second, required by RFC 3315 85# XXX: this seems pretty stupid 86sleep(rand($SOL_MAX_DELAY)); 87 88my $RT; 89my $count = 0; 90my $mrd_end_time; 91if ($MRD != 0) { 92 $mrd_end_time = time() + $MRD; 93} 94my $reply_msg; 95do { 96 # create our socket, and send our Solicit 97 socket(SOCK, PF_INET6, SOCK_DGRAM, getprotobyname('udp')) || die; 98 my $addr = inet_pton(AF_INET6, $All_DHCP_Servers); 99 my $packet = $msg->packet(); 100 my $send_ret = send(SOCK, $packet, 0, 101 pack_sockaddr_in6($server_port, $addr)); 102 if (not defined($send_ret)) { 103 printf STDERR 104 "Error \%d sending DHCPv6 Solicit message;\n\%s\n", 105 0+$ERRNO, $ERRNO; 106 exit(1); 107 } elsif ($send_ret != length($packet)) { 108 print STDERR "Unable to send entire DHCPv6 Solicit message.\n"; 109 exit(1); 110 } 111 $count++; 112 113 my $RAND = rand(0.2) - 0.1; 114 if (defined $RT) { 115 $RT = 2*$RT + $RAND*$RT; 116 if (($RT > $MRT) && ($MRT != 0)) { 117 $RT = $MRT + $RAND*$RT; 118 } 119 } else { 120 $RT = $IRT + $RAND*$IRT; 121 } 122 123 my $rt_end_time = time() + $RT; 124 if (defined($mrd_end_time) && ($mrd_end_time > $rt_end_time)) { 125 $rt_end_time = $mrd_end_time; 126 } 127 128 for (;;) { 129 my $timeout = $rt_end_time - time(); 130 if ($timeout < 0) { 131# print STDERR "Timeout waiting for DHCPv6 Advertise ", 132# "or Reply message.\n"; 133 last; 134 } 135 136 my @ready = IO::Select->new(\*SOCK)->can_read($timeout); 137 138 if (@ready) { 139 my $reply; 140 my $recv_ret; 141 142 $recv_ret = recv(SOCK, $reply, 1500, 0); 143 if (not defined $recv_ret) { 144 printf STDERR 145 "Error \%d receiving DHCPv6 " . 146 "message;\n\%s\n", 147 0+$ERRNO, $ERRNO; 148 exit(1); 149 } 150 151 $reply_msg = dhcp_client::msg::decode($reply, 1); 152 if (($reply_msg->{msg_type} == $MSG_ADVERTISE) || 153 ($reply_msg->{msg_type} == $MSG_REPLY)) { 154 last; 155 } 156 } 157 } 158 159} until ($reply_msg || 160 (($MRC != 0) && ($count > $MRC)) || 161 (defined($mrd_end_time) && ($mrd_end_time > time()))); 162 163unless ($reply_msg) { 164 if (($MRC != 0) && ($count >= $MRC)) { 165 print STDERR 166 "No reply after maximum retransmission count.\n"; 167 } else { 168 print STDERR 169 "No reply after maximum retransmission duration.\n"; 170 } 171} 172 173if ($reply_msg && ($reply_msg->{msg_type} == $MSG_REPLY)) { 174 print "Got DHCPv6 Reply message.\n"; 175 exit(0); 176} 177 178#$Data::Dumper::Useqq = 1; 179#print Dumper($msg), "\n"; 180#print Dumper($msg->packet()), "\n"; 181# 182#print "packet length: ", length($msg->packet()), "\n"; 183