This file is indexed.

/usr/sbin/dhcp-edit is in fai-server 3.4.8ubuntu5.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

  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
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 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
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
#! /usr/bin/perl

# $Id$
#*********************************************************************
#
# dhcp-edit -- managing dhcpd entries made easy
#
# This script is part of FAI (Fully Automatic Installation)
# Copyright (C) 2010 Thomas Lange, lange@informatik.uni-koeln.de
# Universitaet zu Koeln
#
#*********************************************************************
# 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.
#*********************************************************************

# TODO
# -q quiet: do not print error if host/mac entry not found, exit code 0

$dhcpdconf=(-d "/etc/dhcp") ? "/etc/dhcp/dhcpd.conf" : "/etc/dhcp3/dhcpd.conf";

$modified=0; # 1 if dhcpd.conf was modified
our ($opt_p,$opt_d,$opt_h,$opt_n,$opt_r);

use Pod::Usage;
use Getopt::Std;

getopts('p:dhnr') || pod2usage(-msg => "edit-dhcp", -verbose => 2);
$opt_h && pod2usage(-msg => "edit-dhcp",-verbose => 1);
($hostname,$mac,$ip)= @ARGV;
$hostname || pod2usage(-msg => "edit-dhcp",-verbose => 1);
$ip && merror(4,"$ip is not a correct IP address") unless $ip =~ /^[.0-9]{7,15}$/i;

read_dhcpd_conf();

if ($opt_r) {

  $mac=$hostname;
  # create empty entry, remove entry

  # set flag if an entry was found. print warning if entry not found
  foreach (@dhcpd) {
    next if /^\s*#/;  # do not change comments
    do {$_="XXX ENTRY DELETED XXX\n";$modified++} if m/host\s+$hostname\b.+hardware\s+ethernet.+;/;
    do {$_="XXX ENTRY DELETED XXX\n";$modified++} if m/host\s+.+hardware\s+ethernet\s+$mac[\s+;]/i;
  }
  merror(6,"Entry $hostname can not be removed. Not found.\n") unless $modified;
  print "$modified entry/entries removed.\n" if $modified;

} else {

  $mac || merror(5,"Please specify hostname and MAC address.");
  merror(4,"$hostname is not a correct host name") unless $hostname =~ /^[.0-9a-z-]+$/i;
  merror(4,"$mac is not a correct MAC address") unless $mac =~ /^([0-9a-f]{1,2}(:|$)){6}$/i;
  # grep all lines if the entry already exists
  foreach (@dhcpd) {
    next if /^\s*#/;  # do not change comments
    merror(7,"$hostname already exists in dhcpd.conf") if m/host\s+$hostname\b/;
    merror(7,"MAC address $mac already exists in dhcpd.conf") if m/hardware\s+ethernet\s+$mac[\s+;]/i;
  }
}

# check if executed as root
merror(3,"Terminated. $0 can only be run as root.") unless ($< == 0);
add_entry($hostname,$ip) unless $opt_r;
write_dhcpd();
restart_dhcpd();

exit 0;
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
sub merror {

  $error = shift;
  warn "$0 ERROR: @_\n";
  exit $error;
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
sub read_dhcpd_conf {

  # read the whole dhcpd.conf
  open(DHCP,"$dhcpdconf") || die "Can't read $dhcpdconf. $!\n";
  @dhcpd = <DHCP>;
  close(DHCP);
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
sub add_entry {

  my @new;

  my ($hostname,$ip) = @_;
  $ip=$hostname unless $ip;

  # if -p was not given
  unless (defined $opt_p) {
    $modified=1;
    push @dhcpd, "host $hostname {hardware ethernet $mac;fixed-address $ip;}\n";
    print "Entry added: host $hostname {hardware ethernet $mac;fixed-address $ip;}\n" if $modified;
    return;
  }

  # add new entry before line matching $opt_p
  # if $opt_p matches multiple times, also the new entry is added multiple times
  foreach (@dhcpd) {
    if ($_ =~ /$opt_p/o) {
      push @new, "host $hostname {hardware ethernet $mac;fixed-address $ip;}\n";
      print "Entry added: host $hostname {hardware ethernet $mac;fixed-address $ip;}\n";
      $modified=1;
    }
    push @new,$_;
  }
  @dhcpd = @new;
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
sub write_dhcpd {

  if ($opt_d) {
    print "DRY RUN. Nothing changed.";
    return;
  }

  unless ($modified) {
    print "Nothing changed.";
    return;
  }

  @dhcpd = grep(!/^XXX ENTRY DELETED XXX\n$/, @dhcpd);
#  print @dhcpd;
  open(DHCP," >$dhcpdconf") || die "Can't write $dhcpdconf. $!\n";
  print DHCP @dhcpd;
  close(DHCP);
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
sub restart_dhcpd {

  if ($opt_d) {
    print "DRY RUN. Did not restart dhcp daemon.\n";
  }
  if ($opt_n) {
    print "Did not restart dhcp daemon.\n";
  }
  unless ($modified) {
    print "No modifications.\n";
  }

  if ($opt_d || $opt_n || $modified==0) {
    print "Did not restart dhcp daemon.\n";
    return;
  }

  (-x "/etc/init.d/isc-dhcp-server") and print qx#/etc/init.d/isc-dhcp-server# or
    print qx#/etc/init.d/dhcp3-server restart#;
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

__END__

=head1 NAME

dhcp-edit - add or and remove entries to/from dhcpd.conf

=head1 SYNOPSIS

dhcp-edit [OPTION] HOST MAC [IP]

=head1 DESCRIPTION

Add a new host entry to dhcpd.conf or remove an existing entry.
Additionally restart DHCP daemon.

=head1 OPTIONS

=over 8

=item B<-d>

Dry run. Do not change files.

=item B<-h>

Print help.

=item B<-n>

Do not restart DHCP daemon.

=item B<-p> PATTERN

Add new entry before line matching PATTERN

=item B<-r> HOST|MAC

Remove entry contain HOST or MAC address.

=back

=head1 EXAMPLES

dhcp-edit host mac

   Add entry using host and mac address using a fixed IP address. You
   have to define the IP address in /etc/hosts or similar service.


dhcp-edit host mac ip

   Add entry using host and mac address using the numerical IP address.


dhcp-edit -r hostname|mac

   Remove line containing this hostname or mac address.

=head1 COPYRIGHT

This program is Copyright (C) 2010 by Thomas Lange <lange@informatik.uni-koeln.de>

=cut