# -*- perl -*- # # INetSim::NTP - A fake NTP server # # RFC 1305, 2030 - (Simple) Network Time Protocol v1-4 # # (c)2007-2013 Matthias Eckert, Thomas Hungenberg # # Version 0.49 (2009-08-28) # # For history/changelog see bottom of this file. # ############################################################# package INetSim::NTP; use strict; use warnings; use Time::HiRes; use base qw(INetSim::GenericServer); use constant NTP_ADJ => 2208988800; sub configure_hook { my $self = shift; $self->{server}->{host} = &INetSim::Config::getConfigParameter("Default_BindAddress"); # bind to address $self->{server}->{port} = &INetSim::Config::getConfigParameter("NTP_BindPort"); # bind to port $self->{server}->{proto} = 'udp'; # UDP protocol $self->{server}->{user} = &INetSim::Config::getConfigParameter("Default_RunAsUser"); # user to run as $self->{server}->{group} = &INetSim::Config::getConfigParameter("Default_RunAsGroup"); # group to run as $self->{server}->{setsid} = 0; # do not daemonize $self->{server}->{no_client_stdout} = 1; # do not attach client to STDOUT $self->{server}->{log_level} = 0; # do not log anything # $self->{server}->{udp_recv_len} = 960; # default is 4096 $self->{servicename} = &INetSim::Config::getConfigParameter("NTP_ServiceName"); $self->{max_childs} = &INetSim::Config::getConfigParameter("Default_MaxChilds"); $self->{server_ip} = &INetSim::Config::getConfigParameter("NTP_Server_IP"); $self->{strict_checks} = &INetSim::Config::getConfigParameter("NTP_StrictChecks"); } sub pre_loop_hook { my $self = shift; $0 = "inetsim_$self->{servicename}"; &INetSim::Log::MainLog("started (PID $$)", $self->{servicename}); } sub pre_server_close_hook { my $self = shift; &INetSim::Log::MainLog("stopped (PID $$)", $self->{servicename}); } sub fatal_hook { my $self = shift; &INetSim::Log::MainLog("failed!", $self->{servicename}); exit 0; } sub process_request { my $self = shift; my $client = $self->{server}->{client}; my $rhost = $self->{server}->{peeraddr}; my $rport = $self->{server}->{peerport}; my $stat_success = 0; my $diff_seconds = 0; ##### init for variables my $recvmsg = ""; my $sendmsg = ""; my $ReceiveTime = 0; my $cur_time = 0; my $valid = 1; ##### client my $C_Byte1 = 0; my $C_Leap_Indicator = 0; my $C_NTP_Version = 0; my $C_Mode = 0; my $C_Stratum = 0; my $C_Poll = 0; my $C_Precision = 0; my $C_Root_Delay_w1 = 0; my $C_Root_Delay_w2 = 0; my $C_Root_Delay = 0; my $C_Root_Dispersion_w1 = 0; my $C_Root_Dispersion_w2 = 0; my $C_Root_Dispersion = 0; my $C_Reference_Clock_Identifier = 0; my $C_Reference_Time_w1 = 0; my $C_Reference_Time_w2 = 0; my $C_Reference_Time = 0; my $C_Originate_Time_w1 = 0; my $C_Originate_Time_w2 = 0; my $C_Originate_Time = 0; my $C_Receive_Time_w1 = 0; my $C_Receive_Time_w2 = 0; my $C_Receive_Time = 0; my $C_Transmit_Time_w1 = 0; my $C_Transmit_Time_w2 = 0; my $C_Transmit_Time = 0; ##### server my $S_Byte1 = 0; my $S_Leap_Indicator = 0; my $S_NTP_Version = 4; my $S_Mode = 2; my $S_Stratum = 2; my $S_Poll = 6; my $S_Precision = -20; my $S_Root_Delay_w1 = 0; my $S_Root_Delay_w2 = 0; my $S_Root_Delay = 0; my $S_Root_Dispersion_w1 = 0; my $S_Root_Dispersion_w2 = 0; my $S_Root_Dispersion = 0; my $S_Reference_Clock_Identifier = unpack("N", pack("C4", split(/\./, $self->{server_ip}))); my $S_Reference_Time_w1 = 0; my $S_Reference_Time_w2 = 0; my $S_Reference_Time = 0; my $S_Originate_Time_w1 = 0; my $S_Originate_Time_w2 = 0; my $S_Originate_Time = 0; my $S_Receive_Time_w1 = 0; my $S_Receive_Time_w2 = 0; my $S_Receive_Time = 0; my $S_Transmit_Time_w1 = 0; my $S_Transmit_Time_w2 = 0; my $S_Transmit_Time = 0; &INetSim::Log::SubLog("[$rhost:$rport] connect", $self->{servicename}, $$); if ($self->{server}->{numchilds} >= $self->{max_childs}) { print $client "Maximum number of connections ($self->{max_childs}) exceeded.\n"; &INetSim::Log::SubLog("[$rhost:$rport] Connection refused - maximum number of connections ($self->{max_childs}) exceeded.", $self->{servicename}, $$); } else { $recvmsg = $self->{server}->{udp_data}; # check packet length - valid packets must be 48 or 68 bytes long if (length($recvmsg) != 48 && length($recvmsg) != 68) { &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (packet length is not 48 or 68 bytes)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # if packet size equals to 68, drop the last 20 bytes if (length($recvmsg) == 68) { $recvmsg = substr($recvmsg, 0, 48); } # arrival time of the client packet $ReceiveTime = &INetSim::FakeTime::get_faketime(); # split the packet ( $C_Byte1, $C_Stratum, $C_Poll, $C_Precision, $C_Root_Delay_w1, $C_Root_Delay_w2, $C_Root_Dispersion_w1, $C_Root_Dispersion_w2, $C_Reference_Clock_Identifier, $C_Reference_Time_w1, $C_Reference_Time_w2, $C_Originate_Time_w1, $C_Originate_Time_w2, $C_Receive_Time_w1, $C_Receive_Time_w2, $C_Transmit_Time_w1, $C_Transmit_Time_w2 ) = unpack ("C3 c n B16 n B16 a4 N B32 N B32 N B32 N B32", $recvmsg); # if byte 1 is zero -> abort if (! $C_Byte1) { &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (first byte is zero)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # originate timestamp AND receive timestamp must not be zero if ($self->{strict_checks} && ($C_Originate_Time_w1 || $C_Receive_Time_w1)) { &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (originate and/or receive timestamps are not zero)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # split byte 1 $C_Leap_Indicator = ($C_Byte1 & 192) >> 6; $C_NTP_Version = ($C_Byte1 & 56) >> 3; $C_Mode = $C_Byte1 & 7; # if leap indicator not 0 or 3 -> abort if ($self->{strict_checks} && ($C_Leap_Indicator != 0 && $C_Leap_Indicator != 3)) { &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (wrong leap indicator value)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # according to the rfc, ntp version must be taken from client packet, therefore it should be between 1 and 4 if ($C_NTP_Version >= 1 && $C_NTP_Version <= 4) { $S_NTP_Version = $C_NTP_Version; } else { &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (wrong ntp version)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # mode must be 4 (server), if client mode was 3 (client), else 2 (symmetric passive) if ($C_Mode == 3) { $S_Mode = 4; } elsif ($C_Mode == 1 || $C_Mode == 2) { $S_Mode = 2; } else { # if mode is not between 1 and 3 -> abort &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (wrong client mode)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # stratum should be 0 (unspecified) if ($self->{strict_checks} && ($C_Stratum != 0)) { &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (wrong stratum)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } # poll is taken from client and should be in range 1-14 if ($C_Poll) { # set to 1..17 as temp. workaround ==> ToDo if ($C_Poll >= 1 && $C_Poll <= 17) { $S_Poll = $C_Poll; } else { # poll not in range and not 0 -> abort &INetSim::Log::SubLog("[$rhost:$rport] recv: invalid ntp packet (poll interval out of range)", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); return; } } else { # else set poll to 6 (64s) $S_Poll = 6; } $S_Root_Delay_w2 = &frac2bin($S_Root_Delay_w1); $S_Root_Dispersion_w2 = &frac2bin($S_Root_Dispersion_w1); $cur_time = &INetSim::FakeTime::get_faketime(); # last sync time for server clock $S_Reference_Time_w1 = $cur_time + NTP_ADJ - 59; ##### fraction to ^^^ $S_Reference_Time_w2 = &frac2bin($S_Reference_Time_w1); #### RFC-konform ??? ToDo !!!!!!! # #if ($S_NTP_Version == 4 && $S_Stratum >= 2){ # $S_Reference_Clock_Identifier = $S_Reference_Time_w2 >> 33; #} # # Reference Identifier: # ... In NTP Version 3 secondary servers, this is the 32-bit IPv4 # address of the reference source. In NTP Version 4 secondary servers, # this is the low order 32 bits of the latest transmit timestamp of the # reference source.... (rfc 2030, page 10) # # ^^^^^^^^^^^ #### # hmm, could be another check built in here !? if ($C_Transmit_Time_w1) { # check transmit timestamp from client $S_Originate_Time_w1 = $C_Transmit_Time_w1; # last packet from other connection endpoint. Servers have to take the transmit timestamp from client $S_Originate_Time_w2 = $C_Transmit_Time_w2; # fraction to transmit timestamp } else { $S_Originate_Time_w1 = 0; $S_Originate_Time_w2 = &frac2bin($S_Originate_Time_w1); } $S_Receive_Time_w1 = $ReceiveTime + NTP_ADJ; # arrival time of the last packet $S_Receive_Time_w2 = &frac2bin($S_Receive_Time_w1); # fraction to ^^^ $S_Transmit_Time_w1 = $cur_time + NTP_ADJ; # packet sending time $S_Transmit_Time_w2 = &frac2bin($S_Transmit_Time_w1); # fraction to ^^^ # build byte 1 $S_Leap_Indicator = ($S_Leap_Indicator << 6) ^ 63; # bits 0+1, => SHL 6, XOR with 00111111 $S_NTP_Version = ($S_NTP_Version << 3) ^ 199; # bits 2+3+4 => SHL 3, XOR with 11000111 $S_Mode = $S_Mode ^ 248; # bits 5+6+7 => XOR with 11111000 $S_Byte1 = ($S_Leap_Indicator & $S_NTP_Version & $S_Mode); # put it all together wit AND # build response packet $sendmsg = pack ("C3 c n B16 n B16 N N B32 N B32 N B32 N B32", $S_Byte1, $S_Stratum, $S_Poll, $S_Precision, $S_Root_Delay_w1, $S_Root_Delay_w2, $S_Root_Dispersion_w1, $S_Root_Dispersion_w2, $S_Reference_Clock_Identifier, $S_Reference_Time_w1, $S_Reference_Time_w2, $S_Originate_Time_w1, $S_Originate_Time_w2, $S_Receive_Time_w1, $S_Receive_Time_w2, $S_Transmit_Time_w1, $S_Transmit_Time_w2 ); # send out as fast as possible $client->send($sendmsg); $stat_success = 1; # analyse and log the client packet if ($C_Precision) { $C_Precision = sprintf("%1.4e",2**$C_Precision); } else { $C_Precision = 0; } if ($C_Root_Delay_w1 && $C_Root_Delay_w2) { $C_Root_Delay_w1 += bin2frac($C_Root_Delay_w2); $C_Root_Delay = sprintf("%.4f", $C_Root_Delay_w1); } else { $C_Root_Delay = 0; } if ($C_Root_Dispersion_w1 && $C_Root_Dispersion_w2) { $C_Root_Dispersion_w1 += bin2frac($C_Root_Dispersion_w2); $C_Root_Dispersion = sprintf("%.4f", $C_Root_Dispersion_w1); } else { $C_Root_Dispersion = 0; } if ($C_Stratum && $C_Reference_Clock_Identifier) { if ($C_Stratum == 2 && $C_NTP_Version) { if ($C_NTP_Version >= 1 && $C_NTP_Version <= 3) { $C_Reference_Clock_Identifier = join(".", unpack("C4", pack("N", $C_Reference_Clock_Identifier))); } elsif ($C_NTP_Version == 4) { $C_Reference_Clock_Identifier = "low 32bits of latest TX timestamp of reference src"; } } } if ($C_Reference_Clock_Identifier) { # replace non-printable characters with "." $C_Reference_Clock_Identifier =~ s/([^\x20-\x7e])/\./g; if (! $C_Reference_Clock_Identifier || $C_Reference_Clock_Identifier =~ /^\x00/){$C_Reference_Clock_Identifier = "unspec"}; } else{ $C_Reference_Clock_Identifier = "unspec" } if ($C_Reference_Time_w1 && $C_Reference_Time_w2) { $C_Reference_Time_w1 += bin2frac($C_Reference_Time_w2); $C_Reference_Time = sprintf("%10.5f", $C_Reference_Time_w1 - NTP_ADJ); } else { $C_Reference_Time = sprintf("%10.5f", 0); } if ($C_Originate_Time_w1 && $C_Originate_Time_w2) { $C_Originate_Time_w1 += bin2frac($C_Originate_Time_w2); $C_Originate_Time = sprintf("%10.5f", $C_Originate_Time_w1 - NTP_ADJ); } else { $C_Originate_Time = sprintf("%10.5f", 0); } if ($C_Receive_Time_w1 && $C_Receive_Time_w2) { $C_Receive_Time_w1 += bin2frac($C_Receive_Time_w2); $C_Receive_Time = sprintf("%10.5f", $C_Receive_Time_w1 - NTP_ADJ); } else { $C_Receive_Time = sprintf("%10.5f", 0); } if ($C_Transmit_Time_w1 && $C_Transmit_Time_w2) { $C_Transmit_Time_w1 += bin2frac($C_Transmit_Time_w2); $C_Transmit_Time = sprintf("%10.5f", $C_Transmit_Time_w1 - NTP_ADJ); } else { $C_Transmit_Time = sprintf("%10.5f", 0); } &INetSim::Log::SubLog("[$rhost:$rport] recv: VN = $C_NTP_Version, Mode = $C_Mode, LI = $C_Leap_Indicator", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Stratum = $C_Stratum, Poll = $C_Poll, Precision = $C_Precision", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Root Delay = $C_Root_Delay, Root Dispersion = $C_Root_Dispersion", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Reference Identifier = $C_Reference_Clock_Identifier", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Reference Timestamp = $C_Reference_Time", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Originate Timestamp = $C_Originate_Time", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Receive Timestamp = $C_Receive_Time", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] recv: Transmit Timestamp = $C_Transmit_Time", $self->{servicename}, $$); # log the response packet $S_Leap_Indicator = $S_Leap_Indicator >> 6; $S_NTP_Version = ($S_NTP_Version & 56) >> 3; $S_Mode = $S_Mode & 7; $S_Precision = sprintf("%1.4e",2**$S_Precision); $S_Root_Delay_w1 += bin2frac($S_Root_Delay_w2); $S_Root_Delay = sprintf("%.4f", $S_Root_Delay_w1); $S_Root_Dispersion_w1 += bin2frac($S_Root_Dispersion_w2); $S_Root_Dispersion = sprintf("%.4f", $S_Root_Dispersion_w1); $S_Reference_Time_w1 += bin2frac($S_Reference_Time_w2); $S_Reference_Time = sprintf("%10.5f",$S_Reference_Time_w1 - NTP_ADJ); $S_Originate_Time_w1 += bin2frac($S_Originate_Time_w2); $S_Originate_Time = sprintf("%10.5f",$S_Originate_Time_w1 - NTP_ADJ); $S_Receive_Time_w1 += bin2frac($S_Receive_Time_w2); $S_Receive_Time = sprintf("%10.5f",$S_Receive_Time_w1 - NTP_ADJ); $S_Transmit_Time_w1 += bin2frac($S_Transmit_Time_w2); $S_Transmit_Time = sprintf("%10.5f",$S_Transmit_Time_w1 - NTP_ADJ); &INetSim::Log::SubLog("[$rhost:$rport] send: VN = $S_NTP_Version, Mode = $S_Mode, LI = $S_Leap_Indicator", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Stratum = $S_Stratum, Poll = $S_Poll, Precision = $S_Precision", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Root Delay = $S_Root_Delay, Root Dispersion = $S_Root_Dispersion", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Reference Identifier = $S_Reference_Clock_Identifier", $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Reference Timestamp = $S_Reference_Time ".scalar(localtime($S_Reference_Time)), $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Originate Timestamp = $S_Originate_Time ".scalar(localtime($S_Originate_Time)), $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Receive Timestamp = $S_Receive_Time ".scalar(localtime($S_Receive_Time)), $self->{servicename}, $$); &INetSim::Log::SubLog("[$rhost:$rport] send: Transmit Timestamp = $S_Transmit_Time ".scalar(localtime($S_Transmit_Time)), $self->{servicename}, $$); } &INetSim::Log::SubLog("[$rhost:$rport] disconnect", $self->{servicename}, $$); if ($stat_success == 1) { $S_Originate_Time = sprintf("%d", $S_Originate_Time); $S_Transmit_Time = sprintf("%d", $S_Transmit_Time); if ($S_Originate_Time > $S_Transmit_Time) { $diff_seconds = $S_Originate_Time - $S_Transmit_Time; } elsif ($S_Originate_Time < $S_Transmit_Time) { $diff_seconds = $S_Transmit_Time - $S_Originate_Time; } &INetSim::Log::SubLog("[$rhost:$rport] stat: $stat_success client=$S_Originate_Time server=$S_Transmit_Time secsdiff=$diff_seconds", $self->{servicename}, $$); } else { &INetSim::Log::SubLog("[$rhost:$rport] stat: $stat_success", $self->{servicename}, $$); } } sub bin2frac { # convert a binary string to fraction my $input = shift; my @bin = split '', $input; my $frac = 0; while (@bin) { $frac = ($frac + pop @bin)/2; } $frac; } sub frac2bin{ # convert a fraction to binary string (B32) my $input = shift; my $frac = $input; my $bin =""; while (length($bin) < 32) { $bin = $bin . int($frac*2); $frac = $frac*2 - int($frac*2); } $bin; } 1; ############################################################# # # History: # # Version 0.49 (2013-08-28) me # - changed allowed poll range to 1..17 as temp. workaround # # Version 0.48 (2009-10-28) me # - improved some code parts # # Version 0.47 (2009-09-01) me # - changed comments # # Version 0.46 (2008-08-27) me # - added logging of process id # # Version 0.45 (2008-03-15) me # - added configuration option 'NTP_StrictChecks' to enable/disable # strict packet checks # - changed check for non-printable characters in $C_Reference_Clock_Identifier # variable # # Version 0.44 (2008-03-15) me # - removed check for given reference timestamp from client, # because some operating systems sets this to a non-zero value # - changed logging messages for invalid packets # # Version 0.43 (2007-12-31) th # - change process name # # Version 0.42 (2007-04-29) me # - added some checks for valid packets # - added logging of every invalid packet # # Version 0.41 (2007-04-26) th # - use getConfigParameter # # Version 0.40 (2007-04-21) me # - added logging of status for use with &INetSim::Report::GenReport() # # Version 0.39 (2007-04-20) me # - fixed a ugly bug with byte 1 # - added check for byte 1 # - added flag for invalid packets # # # Version 0.38 (2007-04-10) th # - get fake time via &INetSim::FakeTime::get_faketime() # instead of accessing $INetSim::Config::FakeTimeDelta # # Version 0.37 (2007-04-05) me # - changed check for MaxChilds, BindAddress, RunAsUser and # RunAsGroup # # Version 0.36b-c (2007-03-30) me # - forgotten debug output removed *argh* # - fixed a typo # # Version 0.36 (2007-03-30) me # - small bug fixes with variables # # Version 0.35 (2007-03-29) me # - complete rewrite :-/ # - now checking some ranges from client packet # - ToDo: the if-condition at lines 189-191 # # Version 0.34 (2007-03-27) th # - fixed logging if *_Time_H undefined # - $S_Precision is negative, therefore cannot be pack'ed as # "C", so "C3" changed to "C2 c" when generating $send_msg # # Version 0.33 (2007-03-18) th # - added configuration option $INetSim::Config::NTP_Server_IP # - fixed double declaration of $S_Mode # # Version 0.32 (2007-03-16) th # - added configuration option $INetSim::Config::FakeTimeDelta # # Version 0.31 (2007-03-15) th # - small bug fixes with variables # # Version 0.3 (2007-03-14) me # #############################################################