1#! @PATH_PERL@ -w 2 3# Copyright (C) 2015 Network Time Foundation 4# Author: Harlan Stenn 5 6# Original shell version: 7# Copyright (C) 2014 Timothe Litt litt at acm dot org 8 9# This script may be freely copied, used and modified providing that 10# this notice and the copyright statement are included in all copies 11# and derivative works. No warranty is offered, and use is entirely at 12# your own risk. Bugfixes and improvements would be appreciated by the 13# author. 14 15use strict; 16 17use Digest::SHA qw(sha1_hex); 18use File::Copy qw(move); 19use File::Fetch; 20use Getopt::Long qw(:config auto_help no_ignore_case bundling); 21use Sys::Syslog; 22 23my $VERSION="1.003"; 24 25# leap-seconds file manager/updater 26 27# ########## Default configuration ########## 28# 29 30my $CRONJOB = $ENV{'CRONJOB'}; 31$CRONJOB = "" unless defined($CRONJOB); 32my $LOGGER; 33my $QUIET = ""; 34my $VERBOSE = ""; 35 36# Where to get the file 37# Choices: 38# https://www.ietf.org/timezones/data/leap-seconds.list 39# ftp://time.nist.gov/pub/leap-seconds.list 40my $LEAPSRC="https://www.ietf.org/timezones/data/leap-seconds.list"; 41my $LEAPFILE; 42 43# How many times to try to download new file 44my $MAXTRIES=6; 45my $INTERVAL=10; 46 47# Where to find ntp config file 48my $NTPCONF="/etc/ntp.conf"; 49 50# How long (in days) before expiration to get updated file 51my $PREFETCH="60"; 52 53# How to restart NTP - older NTP: service ntpd? try-restart | condrestart 54# Recent NTP checks for new file daily, so there's nothing to do 55my $RESTART=""; 56 57my $EXPIRES; 58my $FORCE = ""; 59 60# Where to put temporary copy before it's validated 61my $TMPFILE="/tmp/leap-seconds.$$.tmp"; 62 63# Syslog facility 64my $LOGFAC="daemon"; 65 66# ########################################### 67 68=item update-leap 69 70Usage: $0 [options] [leapfile] 71 72Verifies and if necessary, updates leap-second definition file 73 74All arguments are optional: Default (or current value) shown: 75 -s Specify the URL of the master copy to download 76 $LEAPSRC 77 -d Specify the filename on the local system 78 $LEAPFILE 79 -e Specify how long (in days) before expiration the file is to be 80 refreshed. Note that larger values imply more frequent refreshes. 81 "$PREFETCH" 82 -f Specify location of ntp.conf (used to make sure leapfile directive is 83 present and to default leapfile) 84 $NTPCONF 85 -F Force update even if current file is OK and not close to expiring. 86 -r Specify number of times to retry on get failure 87 $MAXTRIES 88 -i Specify number of minutes between retries 89 $INTERVAL 90 -l Use syslog for output (Implied if CRONJOB is set) 91 -L Don't use syslog for output 92 -P Specify the syslog facility for logging 93 $LOGFAC 94 -t Name of temporary file used in validation 95 $TMPFILE 96 -q Only report errors to stdout 97 -v Verbose output 98 99The following options are not (yet) implemented in the perl version: 100 -4 Use only IPv4 101 -6 Use only IPv6 102 -c Command to restart NTP after installing a new file 103 <none> - ntpd checks file daily 104 -p 4|6 105 Prefer IPv4 or IPv6 (as specified) addresses, but use either 106 -z Specify path for utilities 107 $PATHLIST 108 -Z Only use system path 109 110$0 will validate the file currently on the local system 111 112Ordinarily, the file is found using the "leapfile" directive in $NTPCONF. 113However, an alternate location can be specified on the command line. 114 115If the file does not exist, is not valid, has expired, or is expiring soon, 116a new copy will be downloaded. If the new copy validates, it is installed and 117NTP is (optionally) restarted. 118 119If the current file is acceptable, no download or restart occurs. 120 121-c can also be used to invoke another script to perform administrative 122functions, e.g. to copy the file to other local systems. 123 124This can be run as a cron job. As the file is rarely updated, and leap 125seconds are announced at least one month in advance (usually longer), it 126need not be run more frequently than about once every three weeks. 127 128For cron-friendly behavior, define CRONJOB=1 in the crontab. 129 130Version $VERSION 131=cut 132 133# Default: Use syslog for logging if running under cron 134 135my $SYSLOG = $CRONJOB; 136 137# Parse options 138 139our(%opt); 140 141GetOptions(\%opt, 142 'c=s', 143 'e:60', 144 'F', 145 'f=s', 146 'i:10', 147 'L', 148 'l', 149 'P=s', 150 'q', 151 'r:6', 152 's=s', 153 't=s', 154 'v' 155 ); 156 157$LOGFAC=$opt{P} if (defined($opt{P})); 158$LEAPSRC=$opt{s} if (defined($opt{s})); 159$PREFETCH=$opt{e} if (defined($opt{e})); 160$NTPCONF=$opt{f} if (defined($opt{f})); 161$FORCE="Y" if (defined($opt{F})); 162$RESTART=$opt{c} if (defined($opt{c})); 163$MAXTRIES=$opt{r} if (defined($opt{r})); 164$INTERVAL=$opt{i} if (defined($opt{i})); 165$TMPFILE=$opt{t} if (defined($opt{t})); 166$SYSLOG="Y" if (defined($opt{l})); 167$SYSLOG="" if (defined($opt{L})); 168$QUIET="Y" if (defined($opt{q})); 169$VERBOSE="Y" if (defined($opt{v})); 170 171# export PATH="$PATHLIST$PATH" 172 173# Handle logging 174 175openlog($0, 'pid', $LOGFAC); 176 177sub logger { 178 my ($priority, $message) = @_; 179 180 # "priority" "message" 181 # 182 # Stdout unless syslog specified or logger isn't available 183 # 184 if ($SYSLOG eq "" or $LOGGER eq "") { 185 if ($QUIET ne "" and ( $priority eq "info" or $priority eq "notice" or $priority eq "debug" ) ) { 186 return 0 187 } 188 printf "%s: $message\n", uc $priority; 189 return 0; 190 } 191 192 # Also log to stdout if cron job && notice or higher 193 if (($CRONJOB ne "" and ($priority ne "info" ) and ($priority ne "debug" )) || ($VERBOSE ne "")) { 194 # Log to stderr as well 195 print STDERR "$0: $priority: $message\n"; 196 } 197 syslog($priority, $message); 198} 199 200# Verify interval 201# INTERVAL=$(( $INTERVAL *1 )) 202 203# Validate a leap-seconds file checksum 204# 205# File format: (full description in files) 206# # marks comments, except: 207# #$ number : the NTP date of the last update 208# #@ number : the NTP date that the file expires 209# Date (seconds since 1900) leaps : leaps is the # of seconds to add for times >= Date 210# Date lines have comments. 211# #h hex hex hex hex hex is the SHA-1 checksum of the data & dates, excluding whitespace w/o leading zeroes 212# 213# Returns: 214# 0 File is valid 215# 1 Invalid Checksum 216# 2 Expired 217 218sub verifySHA { 219 my ($file, $verbose) = @_; 220 221 my $raw = ""; 222 my $data = ""; 223 my $FSHA; 224 225 # Remove comments, except those that are markers for last update, 226 # expires and hash 227 228 unless (open(LF, $file)) { 229 warn "Can't open <$file>: $!\n"; 230 print "Will try and create that file.\n"; 231 return 1; 232 }; 233 while (<LF>) { 234 if (/^#\$/) { 235 $raw .= $_; 236 s/^..//; 237 $data .= $_; 238 } 239 elsif (/^#\@/) { 240 $raw .= $_; 241 s/^..//; 242 $data .= $_; 243 s/\s+//g; 244 $EXPIRES = $_ - 2208988800; 245 } 246 elsif (/^#h\s+([[:xdigit:]]+)\s+([[:xdigit:]]+)\s+([[:xdigit:]]+)\s+([[:xdigit:]]+)\s+([[:xdigit:]]+)/) { 247 chomp; 248 $raw .= $_; 249 $FSHA = sprintf("%08s%08s%08s%08s%08s", $1, $2, $3, $4, $5); 250 } 251 elsif (/^#/) { 252 # ignore it 253 } 254 elsif (/^\d/) { 255 s/#.*$//; 256 $raw .= $_; 257 $data .= $_; 258 } else { 259 chomp; 260 print "Unexpected line: <$_>\n"; 261 } 262 } 263 close LF; 264 265 # Remove all white space 266 $data =~ s/\s//g; 267 268 # Compute the SHA hash of the data, removing the marker and filename 269 # Computed in binary mode, which shouldn't matter since whitespace has been removed 270 271 my $DSHA = sha1_hex($data); 272 273 # Extract the file's hash. Restore any leading zeroes in hash segments. 274 275 if ( ( "$FSHA" ne "" ) && ( $FSHA eq $DSHA ) ) { 276 if ( $verbose ne "" ) { 277 logger("info", "Checksum of $file validated"); 278 } 279 } else { 280 logger("error", "Checksum of $file is invalid:"); 281 $FSHA="(no checksum record found in file)" 282 if ( $FSHA eq ""); 283 logger("error", "EXPECTED: $FSHA"); 284 logger("error", "COMPUTED: $DSHA"); 285 return 1; 286 } 287 288 # Check the expiration date, converting NTP epoch to Unix epoch used by date 289 290 if ( $EXPIRES < time() ) { 291 logger("notice", "File expired on " . gmtime($EXPIRES)); 292 return 2; 293 } 294 return 0; 295} 296 297# Verify ntp.conf 298 299-r $NTPCONF || die "Missing ntp configuration: $NTPCONF\n"; 300 301# Parse ntp.conf for leapfile directive 302 303open(LF, $NTPCONF) || die "Can't open <$NTPCONF>: $!\n"; 304while (<LF>) { 305 chomp; 306 if (/^ *leapfile\s+"(\S+)"/) { 307 $LEAPFILE = $1; 308 } 309} 310close LF; 311 312-s $LEAPFILE || warn "$NTPCONF specifies $LEAPFILE as a leapfile, which is empty.\n"; 313 314# Allow placing the file someplace else - testing 315 316if ( defined $ARGV[0] ) { 317 if ( $ARGV[0] ne $LEAPFILE ) { 318 logger("notice", "Requested install to $ARGV[0], but $NTPCONF specifies $LEAPFILE"); 319 } 320 $LEAPFILE = $ARGV[0]; 321} 322 323# Verify the current file 324# If it is missing, doesn't validate or expired 325# Or is expiring soon 326# Download a new one 327 328if ( $FORCE ne "" || verifySHA($LEAPFILE, $VERBOSE) || ( $EXPIRES lt ( $PREFETCH * 86400 + time() ) )) { 329 my $TRY = 0; 330 my $ff = File::Fetch->new(uri => $LEAPSRC) || die "Fetch failed.\n"; 331 while (1) { 332 ++$TRY; 333 logger("info", "Attempting download from $LEAPSRC, try $TRY..") 334 if ($VERBOSE ne ""); 335 my $where = $ff->fetch( to => '/tmp' ); 336 337 if ($where) { 338 logger("info", "Download of $LEAPSRC succeeded"); 339 340 if ( verifySHA($where, $VERBOSE )) { 341 # There is no point in retrying, as the file on the 342 # server is almost certainly corrupt. 343 344 logger("warning", "Downloaded file $where rejected -- saved for diagnosis"); 345 exit 1; 346 } 347 348 # While the shell script version will set correct permissions 349 # on temporary file, for the perl version that's harder, so 350 # for now at least one should run this script as the 351 # appropriate user. 352 353 # REFFILE="$LEAPFILE" 354 # if [ ! -f $LEAPFILE ]; then 355 # logger "notice" "$LEAPFILE was missing, creating new copy - check permissions" 356 # touch $LEAPFILE 357 # # Can't copy permissions from old file, copy from NTPCONF instead 358 # REFFILE="$NTPCONF" 359 # fi 360 # chmod --reference $REFFILE $TMPFILE 361 # chown --reference $REFFILE $TMPFILE 362 # ( which selinuxenabled && selinuxenabled && which chcon ) >/dev/null 2>&1 363 # if [ $? == 0 ] ; then 364 # chcon --reference $REFFILE $TMPFILE 365 # fi 366 367 # Replace current file with validated new one 368 369 if ( move $where, $LEAPFILE ) { 370 logger("notice", "Installed new $LEAPFILE from $LEAPSRC"); 371 } else { 372 logger("error", "Install $where => $LEAPFILE failed -- saved for diagnosis: $!"); 373 exit 1; 374 } 375 376 # Restart NTP (or whatever else is specified) 377 378 if ( $RESTART ne "" ) { 379 if ( $VERBOSE ne "" ) { 380 logger("info", "Attempting restart action: $RESTART"); 381 } 382 383# XXX 384 #R="$( 2>&1 $RESTART )" 385 #if [ $? -eq 0 ]; then 386 # logger "notice" "Restart action succeeded" 387 # if [ -n "$VERBOSE" -a -n "$R" ]; then 388 # logger "info" "$R" 389 # fi 390 #else 391 # logger "error" "Restart action failed" 392 # if [ -n "$R" ]; then 393 # logger "error" "$R" 394 # fi 395 # exit 2 396 #fi 397 } 398 exit 0; 399 } 400 401 # Failed to download. See about trying again 402 403 # rm -f $TMPFILE 404 if ( $TRY ge $MAXTRIES ) { 405 last; 406 } 407 if ( $VERBOSE ne "" ) { 408 logger("info", "Waiting $INTERVAL minutes before retrying..."); 409 } 410 sleep $INTERVAL * 60 ; 411 } 412 413 # Failed and out of retries 414 415 logger("warning", "Download from $LEAPSRC failed after $TRY attempts"); 416 exit 1; 417} 418 419print "FORCE is <$FORCE>\n"; 420print "verifySHA is " . verifySHA($LEAPFILE, "") . "\n"; 421print "EXPIRES <$EXPIRES> vs ". ( $PREFETCH * 86400 + time() ) . "\n"; 422 423logger("info", "Not time to replace $LEAPFILE"); 424 425exit 0; 426 427# EOF 428