Contents of /trunk/bin/dhcp-edit

#! /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
1	lange	5816	#! /usr/bin/perl
2
3			# $Id$
4			#*********************************************************************
5			#
6			# dhcp-edit -- managing dhcpd entries made easy
7			#
8			# This script is part of FAI (Fully Automatic Installation)
9			# Copyright (C) 2010 Thomas Lange, lange@informatik.uni-koeln.de
10			# Universitaet zu Koeln
11			#
12			#*********************************************************************
13			# This program is free software; you can redistribute it and/or modify
14			# it under the terms of the GNU General Public License as published by
15			# the Free Software Foundation; either version 2 of the License, or
16			# (at your option) any later version.
17			#*********************************************************************
18
19			# TODO
20			# -q quiet: do not print error if host/mac entry not found, exit code 0
21
22	lange	5916	$dhcpdconf=(-d "/etc/dhcp") ? "/etc/dhcp/dhcpd.conf" : "/etc/dhcp3/dhcpd.conf";
23	lange	5816
24	lange	5843	$modified=0; # 1 if dhcpd.conf was modified
25	lange	5816	our ($opt_p,$opt_d,$opt_h,$opt_n,$opt_r);
26
27			use Pod::Usage;
28			use Getopt::Std;
29
30	lange	5872	getopts('p:dhnr') \|\| pod2usage(-msg => "edit-dhcp", -verbose => 2);
31			$opt_h && pod2usage(-msg => "edit-dhcp",-verbose => 1);
32	lange	5816	($hostname,$mac,$ip)= @ARGV;
33	lange	5872	$hostname \|\| pod2usage(-msg => "edit-dhcp",-verbose => 1);
34	lange	5816	$ip && merror(4,"$ip is not a correct IP address") unless $ip =~ /^[.0-9]{7,15}$/i;
35
36			read_dhcpd_conf();
37
38			if ($opt_r) {
39
40			$mac=$hostname;
41	lange	5843	# create empty entry, remove entry
42	lange	5816
43			# set flag if an entry was found. print warning if entry not found
44			foreach (@dhcpd) {
45			next if /^\s*#/; # do not change comments
46	lange	5843	do {$_="XXX ENTRY DELETED XXX\n";$modified++} if m/host\s+$hostname\b.+hardware\s+ethernet.+;/;
47			do {$_="XXX ENTRY DELETED XXX\n";$modified++} if m/host\s+.+hardware\s+ethernet\s+$mac[\s+;]/i;
48	lange	5816	}
49	lange	5843	merror(6,"Entry $hostname can not be removed. Not found.\n") unless $modified;
50			print "$modified entry/entries removed.\n" if $modified;
51	lange	5816
52			} else {
53
54			$mac \|\| merror(5,"Please specify hostname and MAC address.");
55			merror(4,"$hostname is not a correct host name") unless $hostname =~ /^[.0-9a-z-]+$/i;
56			merror(4,"$mac is not a correct MAC address") unless $mac =~ /^([0-9a-f]{1,2}(:\|$)){6}$/i;
57			# grep all lines if the entry already exists
58			foreach (@dhcpd) {
59			next if /^\s*#/; # do not change comments
60			merror(7,"$hostname already exists in dhcpd.conf") if m/host\s+$hostname\b/;
61			merror(7,"MAC address $mac already exists in dhcpd.conf") if m/hardware\s+ethernet\s+$mac[\s+;]/i;
62			}
63			}
64
65			# check if executed as root
66			merror(3,"Terminated. $0 can only be run as root.") unless ($< == 0);
67			add_entry($hostname,$ip) unless $opt_r;
68			write_dhcpd();
69	lange	5843	restart_dhcpd();
70	lange	5816
71			exit 0;
72			# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
73			sub merror {
74
75			$error = shift;
76			warn "$0 ERROR: @_\n";
77			exit $error;
78			}
79			# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
80			sub read_dhcpd_conf {
81
82			# read the whole dhcpd.conf
83			open(DHCP,"$dhcpdconf") \|\| die "Can't read $dhcpdconf. $!\n";
84			@dhcpd = <DHCP>;
85			close(DHCP);
86			}
87			# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
88			sub add_entry {
89
90			my @new;
91
92			my ($hostname,$ip) = @_;
93			$ip=$hostname unless $ip;
94
95	lange	5843	# if -p was not given
96			unless (defined $opt_p) {
97			$modified=1;
98			push @dhcpd, "host $hostname {hardware ethernet $mac;fixed-address $ip;}\n";
99			print "Entry added: host $hostname {hardware ethernet $mac;fixed-address $ip;}\n" if $modified;
100			return;
101			}
102
103			# add new entry before line matching $opt_p
104			# if $opt_p matches multiple times, also the new entry is added multiple times
105	lange	5816	foreach (@dhcpd) {
106			if ($_ =~ /$opt_p/o) {
107			push @new, "host $hostname {hardware ethernet $mac;fixed-address $ip;}\n";
108			print "Entry added: host $hostname {hardware ethernet $mac;fixed-address $ip;}\n";
109	lange	5843	$modified=1;
110	lange	5816	}
111			push @new,$_;
112			}
113			@dhcpd = @new;
114			}
115			# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
116			sub write_dhcpd {
117
118			if ($opt_d) {
119			print "DRY RUN. Nothing changed.";
120			return;
121			}
122
123	lange	5843	unless ($modified) {
124			print "Nothing changed.";
125			return;
126			}
127
128	lange	5816	@dhcpd = grep(!/^XXX ENTRY DELETED XXX\n$/, @dhcpd);
129			# print @dhcpd;
130			open(DHCP," >$dhcpdconf") \|\| die "Can't write $dhcpdconf. $!\n";
131			print DHCP @dhcpd;
132			close(DHCP);
133			}
134			# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
135	lange	5843	sub restart_dhcpd {
136	lange	5816
137	lange	5843	if ($opt_d) {
138			print "DRY RUN. Did not restart dhcp daemon.\n";
139			}
140			if ($opt_n) {
141			print "Did not restart dhcp daemon.\n";
142			}
143			unless ($modified) {
144			print "No modifications.\n";
145			}
146
147			if ($opt_d \|\| $opt_n \|\| $modified==0) {
148			print "Did not restart dhcp daemon.\n";
149			return;
150			}
151
152	lange	5916	(-x "/etc/init.d/isc-dhcp-server") and print qx#/etc/init.d/isc-dhcp-server# or
153			print qx#/etc/init.d/dhcp3-server restart#;
154	lange	5843	}
155			# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
156
157	lange	5816	__END__
158
159			=head1 NAME
160
161			dhcp-edit - add or and remove entries to/from dhcpd.conf
162
163			=head1 SYNOPSIS
164
165			dhcp-edit [OPTION] HOST MAC [IP]
166
167			=head1 DESCRIPTION
168
169			Add a new host entry to dhcpd.conf or remove an existing entry.
170			Additionally restart DHCP daemon.
171
172			=head1 OPTIONS
173
174			=over 8
175
176			=item B<-d>
177
178			Dry run. Do not change files.
179
180			=item B<-h>
181
182			Print help.
183
184			=item B<-n>
185
186			Do not restart DHCP daemon.
187
188			=item B<-p> PATTERN
189
190			Add new entry before line matching PATTERN
191
192			=item B<-r> HOST\|MAC
193
194			Remove entry contain HOST or MAC address.
195
196			=back
197
198			=head1 EXAMPLES
199
200			dhcp-edit host mac
201
202			Add entry using host and mac address using a fixed IP address. You
203			have to define the IP address in /etc/hosts or similar service.
204
205
206			dhcp-edit host mac ip
207
208			Add entry using host and mac address using the numerical IP address.
209
210
211			dhcp-edit -r hostname\|mac
212
213			Remove line containing this hostname or mac address.
214
215			=head1 COPYRIGHT
216
217			This program is Copyright (C) 2010 by Thomas Lange <lange@informatik.uni-koeln.de>
218
219			=cut