htpdate 7.23 KB
Newer Older
amnesia's avatar
amnesia committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
#!/usr/bin/perl
#
# htpdate time poller version 0.9.3
# Copyright (C) 2005 Eddy Vervest
# Copyright (C) 2010 T(A)ILS dev team <amnesia@boum.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# http://www.gnu.org/copyleft/gpl.html

# Proxy setting are read from environment 
# e.g. in bash for setting environment variables:
#
# export HTTP_PROXY='http://wwwproxy.xs4all.nl:8080'
#
# or set the proxy value here
#
# $ENV{HTTP_PROXY} = 'http://wwwproxy.xs4all.nl:8080';
#
# If proxy authentication is required, specify your userid and password below.

use strict;
use warnings;

use version; our $VERSION = qv('0.9.3');

use Carp;
use Cwd;
use DateTime;
use DateTime::Format::DateParse;
amnesia's avatar
amnesia committed
33
use English qw( -no_match_vars );
amnesia's avatar
amnesia committed
34 35 36 37 38 39 40 41 42 43
use Fatal qw( open close );
use File::Temp qw/tempdir/;
use Getopt::Std;
use open qw{:utf8 :std};
use POSIX qw( WIFEXITED );

my $datecommand = '/bin/date';  # "date" command to set time
my $dateparam   = '-s';         # "date" parameter to set time
my $debug       = 0;
my $fullrequest = 0;
amnesia's avatar
amnesia committed
44
my $log         = '';
amnesia's avatar
amnesia committed
45 46 47 48 49 50 51 52 53
my $maxadjust   = 1800;         # maximum time step in seconds
my $minadjust   = 1;            # minimum time step in seconds
my $password    = '';           # password for proxy server
my $quiet       = 0;
my $set_date    = 1;
my $ssl_protocol = 'TLSv1';     # will be passed to wget's --secure-protocol
my $useragent   = "htpdate/$VERSION";
my $userid      = '';           # userid for proxy servers

amnesia's avatar
amnesia committed
54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
our ($opt_d, $opt_h, $opt_q, $opt_x, $opt_u, $opt_a, $opt_f, $opt_l);

sub message {
    my @msg = @_;

    if ($log) {
        open my $h, '>>', $log;
        print $h "@msg\n";
        close $h;
    }
    else {
        print "@msg\n" unless $quiet;
    }
}

sub debug {
    message(@_) if $debug;
}

sub error (@_) {
    my @msg = @_;

    debug(@msg);
    croak @msg;
}
amnesia's avatar
amnesia committed
79 80 81

sub parseCommandLine () {
    # specify valid switches
amnesia's avatar
amnesia committed
82
    getopts('dhqxfu:a:l:') || usage();
amnesia's avatar
amnesia committed
83 84 85 86 87 88 89 90

    usage() if $opt_h;
    usage() unless $ARGV[0];

    $> = getpwnam($opt_u)   if $opt_u;
    $useragent = $opt_a     if $opt_a;
    $debug = 1              if $opt_d;
    $fullrequest = 1        if $opt_f;
amnesia's avatar
amnesia committed
91
    $log = $opt_l           if $opt_l;
amnesia's avatar
amnesia committed
92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
    $quiet = 1              if $opt_q;
    $set_date = 0           if $opt_x;

    my @urls;
    foreach my $url (@ARGV) {
        unless ( $url =~ /^http/i ) {
            $url = 'https://'.$url;
        }
        push @urls, $url;
    }

    return @urls;
}

sub usage () {

    print STDERR <<USAGE;

htpdate version $VERSION
Usage: $0 [-dhqxf] [-u userid] [-a useragent] <URL> [<URL> ...]

        -d      debug
        -h      show this help
        -q      quiet
        -u      userid to run as
        -x      do not set the time (only show)
        -a      http user agent to use
        -f      request the full page and referenced resources rather than only its header
amnesia's avatar
amnesia committed
120
        -l      log to this file rather than to STDOUT
amnesia's avatar
amnesia committed
121 122 123 124 125 126 127 128 129 130 131 132 133 134

        e.g. $0 -x http://www.microsoft.com/ https://check.torproject.org/

USAGE

    exit;
}

sub newestDateHeader {
    my ($dir) = @_;

    my $origdir = getcwd;
    chdir $dir;

amnesia's avatar
amnesia committed
135
    my @files = grep { ! ( $_ =~ m/^\.{1,2}$/ ) } glob('.* *');
amnesia's avatar
amnesia committed
136
    @files or error "No downloaded files can be found";
amnesia's avatar
amnesia committed
137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166

    my $newestdt;

    foreach my $file (@files) {
        next if -l $file || -d _;
        my $date;
        open(my $file_h, '<', $file);
        while (my $line = <$file_h>) {
            chomp $line;
            # empty line == we leave the headers to go into the content
            last if $line eq '';
            last if ($date) = ($line =~ m/^Date:\s+(.*)$/m);
        }
        close $file_h;
        if (defined $date) {
            # RFC 2616 (3.3.1) says Date headers MUST be represented in GMT
            my $dt = DateTime::Format::DateParse->parse_datetime( $date, 'GMT' );
            if (! defined $newestdt || DateTime->compare($dt, $newestdt) > 0) {
                $newestdt = $dt;
            }
        }
    }

    chdir $origdir;
    return $newestdt;
}

sub getRemoteDateDiff {
    my ($url, $fullrequest) = @_;

amnesia's avatar
amnesia committed
167
    defined $url or error "getRemoteDateDiff must be passed an URL";
amnesia's avatar
amnesia committed
168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186
    $fullrequest = defined $fullrequest ? $fullrequest : 0;

    my $origdir = getcwd;

    my @wget_options = ( '-U', $useragent, '--quiet', '--no-cache',
                         '-e', 'robots=off', '--save-headers',
                         '--no-directories',
                         '--secure-protocol', $ssl_protocol,
                     );
    if ($fullrequest) {
        push @wget_options, ('--page-requisites', '--span-hosts');
    }
    my @cmdline = ('wget', @wget_options, $url);

    my $tmpdir = tempdir("XXXXXXXXXX", TMPDIR => 1);
    chdir $tmpdir;

    # fetch (the page and) referenced resources:
    # images, stylesheets, scripts, etc.
amnesia's avatar
amnesia committed
187
    WIFEXITED(system(@cmdline)) or error "Failed to fetch content from $url: $!";
amnesia's avatar
amnesia committed
188
    my $localdt = DateTime->now;
amnesia's avatar
amnesia committed
189 190 191
    my $newestdt;
    eval { $newestdt = newestDateHeader($tmpdir) };
    if ($EVAL_ERROR =~ m/No downloaded files can be found/) {
amnesia's avatar
amnesia committed
192
        error "No file could be downloaded from $url.";
amnesia's avatar
amnesia committed
193
    }
amnesia's avatar
amnesia committed
194

amnesia's avatar
amnesia committed
195
    defined $newestdt or error "Could not get any Date header";
amnesia's avatar
amnesia committed
196 197 198

    my $diffdt = $newestdt - $localdt;
    my $diff   = $diffdt->in_units('seconds');
amnesia's avatar
amnesia committed
199
    debug("$url => $diff second(s)");
amnesia's avatar
amnesia committed
200 201 202 203 204 205 206 207

    chdir $origdir;
    return $diffdt;
}

sub adjustDate {
    my ($diffdt) = @_;

amnesia's avatar
amnesia committed
208
    defined $diffdt or error "adjustDate was passed an undefined diff";
amnesia's avatar
amnesia committed
209 210 211 212 213

    my $localdt = DateTime->now;
    my $absdiffdt = $diffdt->is_positive() ? $diffdt : $diffdt->inverse();
    my $diff      = $diffdt->in_units('seconds');

amnesia's avatar
amnesia committed
214
    debug("Median diff: $diff second(s)");
amnesia's avatar
amnesia committed
215 216 217 218 219

    if ( DateTime::Duration->compare( $absdiffdt,
                                      DateTime::Duration->new(seconds => $maxadjust),
                                      $localdt )
          > 0 ) {
amnesia's avatar
amnesia committed
220
        message("Not setting clock as diff ($diff seconds) is too large.");
amnesia's avatar
amnesia committed
221 222 223 224 225
    }
    elsif ( DateTime::Duration->compare($absdiffdt,
                                        DateTime::Duration->new(seconds => $minadjust),
                                        $localdt, )
          <= 0 ) {
amnesia's avatar
amnesia committed
226
        message("Not setting clock as diff ($diff seconds) is too small.");
amnesia's avatar
amnesia committed
227 228 229 230
    }
    else {
        my $newtimedt = DateTime->now + $diffdt;
        my $newtime = scalar localtime($newtimedt->epoch);
amnesia's avatar
amnesia committed
231
        message("Setting time to $newtime...");
amnesia's avatar
amnesia committed
232 233 234 235
        if ($set_date) {
            $> = 0 if $opt_u;
            open(my $fd, "-|", $datecommand, $dateparam, $newtime);
            if ( $? != 0 ) {
amnesia's avatar
amnesia committed
236 237
                my @output = <$fd>;
                error "An error occured setting the time\n@output";
amnesia's avatar
amnesia committed
238 239 240 241 242 243 244 245 246 247
            }
            close($fd);
            $> = getpwnam($opt_u) if $opt_u;
        }
    }
}

my @urls = parseCommandLine();
my @diffdts;
foreach my $url (@urls) {
amnesia's avatar
amnesia committed
248 249 250 251 252 253 254 255
    my $diffdt;
    eval { $diffdt = getRemoteDateDiff($url, $fullrequest) };
    if ($EVAL_ERROR) {
        print STDERR "$EVAL_ERROR\n";
    }
    else {
        push @diffdts, $diffdt;
    }
amnesia's avatar
amnesia committed
256
}
amnesia's avatar
amnesia committed
257
@diffdts or error "No Date header could be received.";
amnesia's avatar
amnesia committed
258 259 260 261
my @sorted_diffdts = sort {
    $a->in_units('seconds') <=> $b->in_units('seconds')
} @diffdts;
adjustDate($sorted_diffdts[int(@sorted_diffdts / 2)]);