Annotation of embedaddon/dnsmasq/contrib/dnslist/dnslist.pl, revision 1.1.1.1
1.1 misho 1: #!/usr/bin/perl
2:
3: # dnslist - Read state file from dnsmasq and create a nice web page to display
4: # a list of DHCP clients.
5: #
6: # Copyright (C) 2004 Thomas Tuttle
7: #
8: # This program is free software; you can redistribute it and/or modify
9: # it under the terms of the GNU General Public License as published by
10: # the Free Software Foundation; either version 2 of the License, or
11: # (at your option) any later version.
12: #
13: # This program is distributed in the hope that it will be useful,
14: # but WITHOUT ANY WARRANTY; without even the implied warranty of
15: # MERCHANTIBILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16: # GNU General Public License for more details.
17: #
18: # You should have received a copy of the GNU General Public License
19: # along with this program*; if not, write to the Free Software
20: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21: #
22: # * The license is in fact included at the end of this file, and can
23: # either be viewed by reading everything after "__DATA__" or by
24: # running dnslist with the '-l' option.
25: #
26: # Version: 0.2
27: # Author: Thomas Tuttle
28: # Email: dnslist.20.thinkinginbinary@spamgourmet.org
29: # License: GNU General Public License, version 2.0
30: #
31: # v. 0.0: Too ugly to publish, thrown out.
32: #
33: # v. 0.1: First rewrite.
34: # Added master host list so offline hosts can still be displayed.
35: # Fixed modification detection (a newer modification time is lower.)
36: #
37: # v. 0.2: Fixed Client ID = "*" => "None"
38: # Fixed HTML entities (a client ID of ????<? screwed it up)
39: # Fixed command-line argument processing (apparently, "shift @ARGV" !=
40: # "$_ = shift @ARGV"...)
41: # Added license information.
42:
43: use Template;
44:
45: # Location of state file. (This is the dnsmasq default.)
46: # Change with -s <file>
47: my $dnsmasq_state_file = '/var/lib/misc/dnsmasq.leases';
48: # Location of template. (Assumed to be in current directory.)
49: # Change with -t <file>
50: my $html_template_file = 'dnslist.tt2';
51: # File to write HTML page to. (This is where Slackware puts WWW pages. It may
52: # be different on other systems. Make sure the permissions are set correctly
53: # for it.)
54: my $html_output_file = '/var/www/htdocs/dhcp.html';
55: # Time to wait after each page update. (The state file is checked for changes
56: # before each update but is not read in each time, in case it is very big. The
57: # page is rewritten just so the "(updated __/__ __:__:__)" text changes ;-)
58: my $wait_time = 2;
59:
60: # Read command-line arguments.
61: while ($_ = shift @ARGV) {
62: if (/-s/) { $dnsmasq_state_file = shift; next; }
63: if (/-t/) { $html_template_file = shift; next; }
64: if (/-o/) { $html_output_file = shift; next; }
65: if (/-d/) { $wait_time = shift; next; }
66: if (/-l/) { show_license(); exit; }
67: die "usage: dnslist [-s state_file] [-t template_file] [-o output_file] [-d delay_time]\n";
68: }
69:
70: # Master list of clients, offline and online.
71: my $list = {};
72: # Sorted host list. (It's actually sorted by IP--the sub &byip() compares two
73: # IP addresses, octet by octet, and figures out which is higher.)
74: my @hosts = ();
75: # Last time the state file was changed.
76: my $last_state_change;
77:
78: # Check for a change to the state file.
79: sub check_state {
80: if (defined $last_state_change) {
81: if (-M $dnsmasq_state_file < $last_state_change) {
82: print "check_state: state file has been changed.\n";
83: $last_state_change = -M $dnsmasq_state_file;
84: return 1;
85: } else {
86: return 0;
87: }
88: } else {
89: # Last change undefined, so we are running for the first time.
90: print "check_state: reading state file at startup.\n";
91: read_state();
92: $last_state_change = -M $dnsmasq_state_file;
93: return 1;
94: }
95: }
96:
97: # Read data in state file.
98: sub read_state {
99: my $old;
100: my $new;
101: # Open file.
102: unless (open STATE, $dnsmasq_state_file) {
103: warn "read_state: can't open $dnsmasq_state_file!\n";
104: return 0;
105: }
106: # Mark all hosts as offline, saving old state.
107: foreach $ether (keys %{$list}) {
108: $list->{$ether}->{'old_online'} = $list->{$ether}->{'online'};
109: $list->{$ether}->{'online'} = 0;
110: }
111: # Read hosts.
112: while (<STATE>) {
113: chomp;
114: @host{qw/raw_lease ether_addr ip_addr hostname raw_client_id/} = split /\s+/;
115: $ether = $host{ether_addr};
116: # Mark each online host as online.
117: $list->{$ether}->{'online'} = 1;
118: # Copy data to master list.
119: foreach $key (keys %host) {
120: $list->{$ether}->{$key} = $host{$key};
121: }
122: }
123: close STATE;
124: # Handle changes in offline/online state. (The sub &do_host() handles
125: # all of the extra stuff to do with a host's data once it is read.
126: foreach $ether (keys %{$list}) {
127: $old = $list->{$ether}->{'old_online'};
128: $new = $list->{$ether}->{'online'};
129: if (not $old) {
130: if (not $new) {
131: do_host($ether, 'offline');
132: } else {
133: do_host($ether, 'join');
134: }
135: } else {
136: if (not $new) {
137: do_host($ether, 'leave');
138: } else {
139: do_host($ether, 'online');
140: }
141: }
142: }
143: # Sort hosts by IP ;-)
144: @hosts = sort byip values %{$list};
145: # Copy sorted list to template data store.
146: $data->{'hosts'} = [ @hosts ];
147: }
148:
149: # Do stuff per host.
150: sub do_host {
151: my ($ether, $status) = @_;
152:
153: # Find textual representation of DHCP client ID.
154: if ($list->{$ether}->{'raw_client_id'} eq '*') {
155: $list->{$ether}->{'text_client_id'} = 'None';
156: } else {
157: my $text = "";
158: foreach $char (split /:/, $list->{$ether}->{'raw_client_id'}) {
159: $char = pack('H2', $char);
160: if (ord($char) >= 32 and ord($char) <= 127) {
161: $text .= $char;
162: } else {
163: $text .= "?";
164: }
165: }
166: $list->{$ether}->{'text_client_id'} = $text;
167: }
168:
169: # Convert lease expiration date/time to text.
170: if ($list->{$ether}->{'raw_lease'} == 0) {
171: $list->{$ether}->{'text_lease'} = 'Never';
172: } else {
173: $list->{$ether}->{'text_lease'} = nice_time($list->{$ether}->{'raw_lease'});
174: }
175:
176: if ($status eq 'offline') {
177: # Nothing to do.
178: } elsif ($status eq 'online') {
179: # Nothing to do.
180: } elsif ($status eq 'join') {
181: # Update times for joining host.
182: print "do_host: $ether joined the network.\n";
183: $list->{$ether}->{'join_time'} = time;
184: $list->{$ether}->{'since'} = nice_time(time);
185: } elsif ($status eq 'leave') {
186: # Update times for leaving host.
187: print "do_host: $ether left the network.\n";
188: $list->{$ether}->{'leave_time'} = time;
189: $list->{$ether}->{'since'} = nice_time(time);
190: }
191:
192: }
193:
194: # Convert time to a string representation.
195: sub nice_time {
196: my $time = shift;
197: my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $dst) = localtime($time);
198: $sec = pad($sec, '0', 2);
199: $min = pad($min, '0', 2);
200: $hour = pad($hour, '0', 2);
201: $mon = pad($mon, '0', 2);
202: $mday = pad($mday, '0', 2);
203: return "$mon/$mday $hour:$min:$sec";
204: }
205:
206: # Pad string to a certain length by repeatedly prepending another string.
207: sub pad {
208: my ($text, $pad, $length) = @_;
209: while (length($text) < $length) {
210: $text = "$pad$text";
211: }
212: return $text;
213: }
214:
215: # Compare two IP addresses. (Uses $a and $b from sort.)
216: sub byip {
217: # Split into octets.
218: my @a = split /\./, $a->{ip_addr};
219: my @b = split /\./, $b->{ip_addr};
220: # Compare octets.
221: foreach $n (0..3) {
222: return $a[$n] <=> $b[$n] if ($a[$n] != $b[$n]);
223: }
224: # If we get here there is no difference.
225: return 0;
226: }
227:
228: # Output HTML file.
229: sub write_output {
230: # Create new template object.
231: my $template = Template->new(
232: {
233: ABSOLUTE => 1, # /var/www/... is an absolute path
234: OUTPUT => $html_output_file # put it here, not STDOUT
235: }
236: );
237: $data->{'updated'} = nice_time(time); # add "(updated ...)" to file
238: unless ($template->process($html_template_file, $data)) { # do it
239: warn "write_output: Template Toolkit error: " . $template->error() . "\n";
240: return 0;
241: }
242: print "write_output: page updated.\n";
243: return 1;
244: }
245:
246: sub show_license {
247: while (<DATA>) {
248: print;
249: $line++;
250: if ($line == 24) { <>; $line = 1; }
251: }
252: }
253:
254: # Main loop.
255: while (1) {
256: # Check for state change.
257: if (check_state()) {
258: read_state();
259: sleep 1; # Sleep for a second just so we don't wear anything
260: # out. (By not sleeping the whole time after a change
261: # we can detect rapid changes more easily--like if 300
262: # hosts all come back online, they show up quicker.)
263: } else {
264: sleep $wait_time; # Take a nap.
265: }
266: write_output(); # Write the file anyway.
267: }
268: __DATA__
269: GNU GENERAL PUBLIC LICENSE
270: Version 2, June 1991
271:
272: Copyright (C) 1989, 1991 Free Software Foundation, Inc.
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590: parts of the General Public License. Of course, the commands you use may
591: be called something other than `show w' and `show c'; they could even be
592: mouse-clicks or menu items--whatever suits your program.
593:
594: You should also get your employer (if you work as a programmer) or your
595: school, if any, to sign a "copyright disclaimer" for the program, if
596: necessary. Here is a sample; alter the names:
597:
598: Yoyodyne, Inc., hereby disclaims all copyright interest in the program
599: `Gnomovision' (which makes passes at compilers) written by James Hacker.
600:
601: <signature of Ty Coon>, 1 April 1989
602: Ty Coon, President of Vice
603:
604: This General Public License does not permit incorporating your program into
605: proprietary programs. If your program is a subroutine library, you may
606: consider it more useful to permit linking proprietary applications with the
607: library. If this is what you want to do, use the GNU Library General
608: Public License instead of this License.
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