source: branches/stable/cgi-bin/admin.cgi@ 255

Last change on this file since 255 was 252, checked in by Kris Deugau, 19 years ago

/branches/stable

Fixed bug where attempting to allocate a static IP from the
admin tools failed with the wrong error message before it
even let you enter customer info - a section was missing
for static IPs.
Fixed display bug on checking for invalid/unknown actions.

  • Property svn:executable set to *
  • Property svn:keywords set to Date Rev Author
File size: 19.3 KB
Line 
1#!/usr/bin/perl
2# ipdb/cgi-bin/admin.cgi
3# Hack interface to make specific changes to IPDB that (for one reason
4# or another) can't be made through the main interface.
5#
6###
7# SVN revision info
8# $Date: 2005-05-30 15:30:46 +0000 (Mon, 30 May 2005) $
9# SVN revision $Rev: 252 $
10# Last update by $Author: kdeugau $
11###
12# Copyright (C) 2004,2005 - Kris Deugau
13
14use strict;
15use warnings;
16use CGI::Carp qw(fatalsToBrowser);
17use DBI;
18use CommonWeb qw(:ALL);
19use MyIPDB;
20use CustIDCK;
21#use POSIX qw(ceil);
22use NetAddr::IP;
23
24use Sys::Syslog;
25
26openlog "IPDB-admin","pid","local2";
27
28# Collect the username from HTTP auth. If undefined, we're in a test environment.
29my $authuser;
30if (!defined($ENV{'REMOTE_USER'})) {
31 $authuser = '__temptest';
32} else {
33 $authuser = $ENV{'REMOTE_USER'};
34}
35
36syslog "debug", "$authuser active";
37
38# Why not a global DB handle? (And a global statement handle, as well...)
39# Use the connectDB function, otherwise we end up confusing ourselves
40my $ip_dbh;
41my $sth;
42my $errstr;
43($ip_dbh,$errstr) = connectDB_My;
44if (!$ip_dbh) {
45 printAndExit("Database error: $errstr\n");
46}
47initIPDBGlobals($ip_dbh);
48
49if ($IPDBacl{$authuser} !~ /A/) {
50 print "Content-Type: text/html\n\n".
51 "<html><head><title>Access denied</title></head><body>\n".
52 'Access to this tool is restricted. Contact <a href="mailto:kdeugau@vianet.ca">Kris</a> '.
53 "for more information.</body></html>\n";
54 exit;
55}
56
57my %webvar = parse_post();
58cleanInput(\%webvar);
59
60print "Content-type: text/html\n\n".
61 "<html>\n<head>\n\t<title>[IPDB admin tools]</title>\n".
62 qq(\t<link rel="stylesheet" type="text/css" href="/ip/ipdb.css">\n).
63 "</head>\n<body>\n".
64 "<h2>IPDB - Administrative Tools</h2>\n<hr>\n";
65
66if(!defined($webvar{action})) {
67 $webvar{action} = "<NULL>"; #shuts up the warnings.
68
69 my $typelist = '';
70 $sth = $ip_dbh->prepare("select type,listname from alloctypes where listorder < 900 order by listorder");
71 $sth->execute;
72 my @data = $sth->fetchrow_array;
73 $typelist .= "<option value='$data[0]' selected>$data[1]</option>\n";
74 while (my @data = $sth->fetchrow_array) {
75 $typelist .= "<option value='$data[0]'>$data[1]</option>\n";
76 }
77
78 print qq(WARNING: There are FAR fewer controls on what you can do here. Use the
79main interface if at all possible.
80<hr>
81<a href="admin.cgi?action=newalloc">Add allocation</a>
82<hr>
83<form action="admin.cgi" method="POST">
84<input type=hidden name=action value=alloc>
85Allocate block/IP: <input name=cidr> as <select name=alloctype>$typelist</select> to <input name=custid>
86<input type=submit value=" GIMME!! "></form>
87<hr><form action="admin.cgi" method="POST">
88<input type=hidden name=action value=alloctweak>
89Manually update allocation data in this /24: <input name=allocfrom>
90<input type=submit value="Show allocations">
91</form>
92<hr><a href="admin.cgi?action=showpools">List IP Pools</a> for manual tweaking and updates
93<hr><a href="admin.cgi?action=showACL">Change ACLs</a> (change internal access controls -
94note that this does NOT include IP-based limits)
95);
96} else {
97 print '<a href="/ip/cgi-bin/admin.cgi">Back</a> to main<hr>';
98}
99
100
101## Possible actions.
102if ($webvar{action} eq 'alloc') {
103 # OK, we know what we're allocating.
104
105 if ($webvar{cidr} !~ /^\s*(\d{1,3}\.){3}\d{1,3}(\/\d{2})?\s*$/) {
106 printAndExit("Can't allocate something that's not a netblock/ip");
107 }
108
109 $sth = $ip_dbh->prepare("select def_custid from alloctypes where type='$webvar{alloctype}'");
110 $sth->execute;
111 my @data = $sth->fetchrow_array;
112 my $custid = $data[0];
113 if ($custid eq '') {
114 if ($webvar{custid} !~ /^(?:\d{10}|\d{7}|STAFF)(?:-\d\d?)?$/) {
115 # Force uppercase for now...
116 $webvar{custid} =~ tr/a-z/A-Z/;
117 # Crosscheck with ... er... something.
118 my $status = CustIDCK->custid_exist($webvar{custid});
119 if ($CustIDCK::Error) {
120 printError("Error verifying customer ID: ".$CustIDCK::ErrMsg);
121 return;
122 }
123 if (!$status) {
124 printError("Customer ID not valid. Make sure the Customer ID ".
125 "is correct.<br>\nUse STAFF for staff static IPs, and 6750400 for any other ".
126 "non-customer assignments.");
127 return;
128 }
129 }
130 # Type that doesn't have a default custid
131 $custid = $webvar{custid};
132 }
133
134 my $cidr = new NetAddr::IP $webvar{cidr};
135 my @data;
136 if ($webvar{alloctype} eq 'rm') {
137 $sth = $ip_dbh->prepare("select cidr from freeblocks where cidr >>='$cidr' and routed='n'");
138 $sth->execute;
139 @data = $sth->fetchrow_array;
140# User deserves errors if user can't be bothered to find the free block first.
141 printAndExit("Can't allocate from outside a free block!!\n")
142 if !$data[0];
143 } elsif ($webvar{alloctype} =~ /^(.)i$/) {
144 $sth = $ip_dbh->prepare("select cidr from allocations where cidr >>='$cidr' and (type like '_d' or type like '_p')");
145 $sth->execute;
146 @data = $sth->fetchrow_array;
147# User deserves errors if user can't be bothered to find the pool and a free IP first.
148 printAndExit("Can't allocate static IP from outside a pool!!\n")
149 if !$data[0];
150 } else {
151 $sth = $ip_dbh->prepare("select cidr from freeblocks where cidr >>='$cidr' and not (routed='n')");
152 $sth->execute;
153 @data = $sth->fetchrow_array;
154# User deserves errors if user can't be bothered to find the free block first.
155 printAndExit("Can't allocate from outside a routed block!!\n")
156 if !$data[0];
157 }
158
159 my $alloc_from = new NetAddr::IP $data[0];
160 $sth->finish;
161
162 my $cities = '';
163 foreach my $city (@citylist) {
164 $cities .= "<option>$city</option>\n";
165 }
166
167 print qq(<table class=regular>
168<form method=POST action=admin.cgi>
169<tr class=color1>
170<td>Allocating:</td>
171<td>$cidr<input type=hidden name=cidr value="$cidr"></td>
172</tr><tr class=color2>
173<td>Type:</td><td>$disp_alloctypes{$webvar{alloctype}}
174<input type=hidden name=alloctype value="$webvar{alloctype}"></td>
175</tr><tr class=color1>
176<td>Allocated from:</td>
177<td>$alloc_from<input type=hidden name=alloc_from value="$alloc_from"></td>
178</tr><tr class="color2">
179<td>Customer ID:</td><td>$custid<input type=hidden name=custid value="$custid"></td>
180</tr><tr class=color1>
181<td>Customer location:</td><td>
182<select name="city"><option selected>-</option>
183$cities
184</select>
185&nbsp;<a href="javascript:popNotes('/ip/newcity.html')">Add new location</a>
186</td>
187</tr>
188<tr class="color2">
189<td>Circuit ID:</td><td><input name=circid size=40></td>
190</tr><tr class="color1">
191<td>Description/Name:</td><td><input name="desc" size=40></td>
192</tr><tr class="color2">
193<td>Notes:</td><td><textarea name="notes" rows="3" cols="40"></textarea></td>
194</tr><tr class="warning">
195<td colspan=2><center>WARNING: This will IMMEDIATELY assign this block!!</center></td>
196</tr><tr class="color2">
197<td class="center" colspan="2"><input type="submit" value=" Assign "></td>
198<input type="hidden" name="action" value="confirm">
199</tr>
200</table>
201);
202
203
204} elsif ($webvar{action} eq 'confirm') {
205
206 print "Assigning $webvar{cidr} to $webvar{custid} (\"$webvar{desc}\") as ".
207 "$disp_alloctypes{$webvar{alloctype}}...<br>\n";
208 # Only need to check city here.
209 if ($webvar{city} eq '-') {
210 printError("Invalid customer location! Go back and select customer's location.");
211 } else {
212 my ($retcode,$msg) = allocateBlock($ip_dbh, $webvar{cidr}, $webvar{alloc_from},
213 $webvar{custid}, $webvar{alloctype}, $webvar{city}, $webvar{desc}, $webvar{notes},
214 $webvar{circid});
215 if ($retcode eq 'OK') {
216 print "Allocation OK!\n";
217
218 if ($webvar{alloctype} =~ /^.i$/) {
219 # Notify tech@example.com
220 mailNotify('tech@example.com',"$disp_alloctypes{$webvar{alloctype}} allocation",
221 "$disp_alloctypes{$webvar{alloctype}} $msg allocated to customer $webvar{custid}\n".
222 "Description: $webvar{desc}\n\nAllocated by: $authuser\n");
223 }
224 syslog "notice", "$authuser allocated '$webvar{cidr}' to '$webvar{custid}' as ".
225 "'$webvar{alloctype}'";
226 } else {
227 print "Allocation failed! IPDB::allocateBlock said:\n$msg\n";
228 syslog "err", "($authuser) Allocation of '$webvar{cidr}' to '$webvar{custid}' as ".
229 "'$webvar{alloctype}' failed: '$msg'";
230 }
231 } # done city check
232
233} elsif ($webvar{action} eq 'alloctweak') {
234 fix_allocfrom();
235 showAllocs($webvar{allocfrom});
236} elsif ($webvar{action} eq 'update') {
237 update();
238} elsif ($webvar{action} eq 'assign') {
239 # Display a list of possible blocks within the requested block.
240 open (HTML, "../admin_alloc.html")
241 or croak "Could not open admin_alloc.html :$!";
242 my $html = join('', <HTML>);
243 $html =~ s/\$\$MASK\$\$/$webvar{masklen}/g;
244 $html =~ s/\$\$ALLOCFROM\$\$/$webvar{allocfrom}/g;
245
246 my $from = new NetAddr::IP $webvar{allocfrom};
247 my @blocklist = $from->split($webvar{masklen});
248 my $availblocks;
249 foreach (@blocklist) {
250 $availblocks .= qq(<tr><td colspan=2 align=center><input type=radio name=block value="$_">$_</td></tr>\n);
251 }
252 $html =~ s/\$\$BLOCKLIST\$\$/$availblocks/g;
253
254 print $html;
255} elsif ($webvar{action} eq 'showpools') {
256 print "IP Pools currently allocated:\n".
257 "<table border=1>\n<tr><td>Pool</td><td># of free IPs</td></tr>\n";
258 $sth = $ip_dbh->prepare("select cidr from allocations where type like '%p' or type like '%d' order by cidr");
259 $sth->execute;
260 my %poolfree;
261 while (my @data = $sth->fetchrow_array) {
262 $poolfree{$data[0]} = 0;
263 }
264 $sth = $ip_dbh->prepare("select pool,ip from poolips where available='y' order by ip");
265 $sth->execute;
266 while (my @data = $sth->fetchrow_array) {
267 $poolfree{$data[0]}++;
268 }
269 foreach my $key (keys %poolfree) {
270 print qq(<tr><td><a href="admin.cgi?action=tweakpool&pool=$key">$key</a></td>).
271 "<td>$poolfree{$key}</td></tr>\n";
272 }
273 print "</table>\n";
274} elsif ($webvar{action} eq 'tweakpool') {
275 showPool($webvar{pool});
276} elsif ($webvar{action} eq 'updatepool') {
277
278 $sth = $ip_dbh->prepare("update poolips set custid='$webvar{custid}', ".
279 "city='$webvar{city}', type='$webvar{type}', available='".
280 (($webvar{available} eq 'y') ? 'y' : 'n').
281 "', notes='$webvar{notes}', description='$webvar{desc}' ".
282 "where ip='$webvar{ip}'");
283 $sth->execute;
284 if ($sth->err) {
285 print "Error updating pool IP $webvar{ip}: $@<hr>\n";
286 syslog "err", "$authuser could not update pool IP $webvar{ip}: $@";
287 } else {
288 $sth = $ip_dbh->prepare("select pool from poolips where ip='$webvar{ip}'");
289 $sth->execute;
290 my @data = $sth->fetchrow_array;
291 print "$webvar{ip} in $data[0] updated\n<hr>\n";
292 syslog "notice", "$authuser updated pool IP $webvar{ip}";
293 }
294} elsif ($webvar{action} eq 'showACL') {
295 print "Notes:<br>\n".
296 "<li>Users must be added to .htpasswd from the shell, for the time being.\n".
297 "<li>New accounts will be added to the ACL here every time this page is loaded.\n".
298 "<li>Old accounts will NOT be automatically deleted; they must be removed via shell.\n".
299 "<li>Admin users automatically get all other priviledges.\n";
300# open .htpasswd, and snag the userlist.
301 $sth = $ip_dbh->prepare("select count (*) from users where username=?");
302 open HTPASS, "<../../.htpasswd" or carp "BOO! No .htpasswd file!";
303 while (<HTPASS>) {
304 chomp;
305 my ($username,$encpwd) = split /:/;
306 $sth->execute($username);
307 my @data = $sth->fetchrow_array;
308 if ($data[0] eq '0') {
309 my $sth2 = $ip_dbh->prepare("insert into users (username,password) values ('$username','$encpwd')");
310 $sth2->execute;
311 print "$username added with read-only privs to ACL<br>\n";
312 }
313 }
314
315 print "<hr>Users with access:\n<table border=1>\n";
316 print "<tr><td>Username</td><td>Add new</td><td>Change</td>".
317 "<td>Delete</td><td>Admin user</td></tr>\n".
318 "<form action=admin.cgi method=POST>\n";
319 $sth = $ip_dbh->prepare("select username,acl from users order by username");
320 $sth->execute;
321 while (my @data = $sth->fetchrow_array) {
322 print "<form action=admin.cgi method=POST><input type=hidden name=action value=updacl>".
323 qq(<tr><td>$data[0]<input type=hidden name=username value="$data[0]"></td><td>).
324 # Now for the fun bit. We have to pull apart the ACL field and
325 # output a bunch of checkboxes.
326 "<input type=checkbox name=add".($data[1] =~ /a/ ? ' checked=y' : '').
327 "></td><td><input type=checkbox name=change".($data[1] =~ /c/ ? ' checked=y' : '').
328 "></td><td><input type=checkbox name=del".($data[1] =~ /d/ ? ' checked=y' : '').
329 "></td><td><input type=checkbox name=admin".($data[1] =~ /A/ ? ' checked=y' : '').
330 qq(></td><td><input type=submit value="Update"></td></tr></form>\n);
331
332 }
333 print "</table>\n";
334} elsif ($webvar{action} eq 'updacl') {
335 print "Updating ACL for $webvar{username}:<br>\n";
336 my $acl = 'b';
337 if ($webvar{admin} eq 'on') {
338 $acl .= "acdA";
339 } else {
340 $acl .= ($webvar{add} eq 'on' ? 'a' : '').
341 ($webvar{change} eq 'on' ? 'c' : '').
342 ($webvar{del} eq 'on' ? 'd' : '');
343 }
344 print "New ACL: $acl<br>\n";
345
346 $sth = $ip_dbh->prepare("update users set acl='$acl' where username='$webvar{username}'");
347 $sth->execute;
348 print "OK\n" if !$sth->err;
349
350 print qq(<hr><a href="admin.cgi?action=showACL">Back</a> to ACL listing\n);
351
352} elsif ($webvar{action} ne '<NULL>') {
353 print "webvar{action} check failed: Don't know how to $webvar{action}";
354}
355
356# Hokay. This is a little different. We have a few specific functions here:
357# -> Assign arbitrary subnet from arbitrary free space
358# -> Tweak individual DB fields
359#
360
361
362printFooter;
363
364$ip_dbh->disconnect;
365
366exit;
367
368
369# Tweak allocfrom into shape.
370sub fix_allocfrom {
371 if ($webvar{allocfrom} =~ /^(\d+\.){2}\d+$/) {
372 # 3-octet class C specified
373 $webvar{allocfrom} .= ".0/24";
374 } elsif ($webvar{allocfrom} =~ /^(\d+\.){3}\d+$/) {
375 # 4-octet IP specified;
376 $webvar{allocfrom} .= "/24";
377 }
378}
379
380
381# List free blocks in a /24 for arbitrary manual allocation
382sub showfree($) {
383 my $cidr = new NetAddr::IP $_[0];
384 print "Showing free blocks in $cidr<br>\n".
385 "<table border=1>\n";
386 $sth = $ip_dbh->prepare("select * from freeblocks where cidr <<= '$cidr' order by cidr");
387 $sth->execute;
388 while (my @data = $sth->fetchrow_array) {
389 my $temp = new NetAddr::IP $data[0];
390 print "<tr><form action=admin.cgi method=POST><input type=hidden name=action value=assign>\n".
391 qq(<td>$temp<input type=hidden name=allocfrom value="$temp"></td>\n).
392 "<td>".
393 (($temp->masklen == 30) ? '<input type=hidden name=masklen value=30>30'
394 : "<select name=masklen><option>30</option>\n<option>29</option>\n") .
395 (($temp->masklen < 29) ? "<option>28</option>\n" : '') .
396 (($temp->masklen < 28) ? "<option>27</option>\n" : '') .
397 (($temp->masklen < 27) ? "<option>26</option>\n" : '') .
398 (($temp->masklen < 26) ? "<option>25</option>\n" : '') .
399 (($temp->masklen < 25) ? "<option>24</option>\n" : '') .
400 "</td>".
401 qq(<td>$data[2]</td><td><input type=submit value="Allocate from here"></td>).
402 "\n</form></tr>\n";
403 }
404 print "</table>\n";
405}
406
407
408# Show allocations to allow editing.
409sub showAllocs($) {
410 my $cidr = new NetAddr::IP $_[0];
411 print "Edit custID, allocation type, city for allocations in ".
412 "$cidr:\n<table border=1>";
413 $sth = $ip_dbh->prepare("select * from allocations where cidr <<= '$cidr' order by cidr");
414 $sth->execute;
415 while (my @data = $sth->fetchrow_array) {
416 print "<tr><form action=admin.cgi method=POST><input type=hidden name=action value=update>\n".
417 qq(<td>$data[0]<input type=hidden value="$data[0]" name=block></td>\n).
418 qq(<td><input name=custid value="$data[1]"></td>\n);
419
420 print "<td><select name=alloctype><option".
421 (($data[2] eq 'cn') ? ' selected' : '') ." value='cn'>Customer netblock</option>\n<option".
422 (($data[2] eq 'si') ? ' selected' : '') ." value='si'>Static IP - Server pool</option>\n<option".
423 (($data[2] eq 'ci') ? ' selected' : '') ." value='ci'>Static IP - Cable</option>\n<option".
424 (($data[2] eq 'di') ? ' selected' : '') ." value='di'>Static IP - DSL</option>\n<option".
425 (($data[2] eq 'mi') ? ' selected' : '') ." value='mi'>Static IP - Dialup</option>\n<option".
426 (($data[2] eq 'wi') ? ' selected' : '') ." value='wi'>Static IP - Wireless</option>\n<option".
427 (($data[2] eq 'sd') ? ' selected' : '') ." value='sd'>Static Pool - Server pool</option>\n<option".
428 (($data[2] eq 'cd') ? ' selected' : '') ." value='cd'>Static Pool - Cable</option>\n<option".
429 (($data[2] eq 'dp') ? ' selected' : '') ." value='dp'>Static Pool - DSL</option>\n<option".
430 (($data[2] eq 'mp') ? ' selected' : '') ." value='mp'>Static Pool - Dialup</option>\n<option".
431 (($data[2] eq 'wp') ? ' selected' : '') ." value='wp'>Static Pool - Wireless</option>\n<option".
432 (($data[2] eq 'en') ? ' selected' : '') ." value='en'>End-use netblock</option>\n<option".
433 (($data[2] eq 'me') ? ' selected' : '') ." value='me'>Dialup netblock</option>\n<option".
434 (($data[2] eq 'de') ? ' selected' : '') ." value='de'>Dynamic DSL netblock</option>\n<option".
435 (($data[2] eq 'ce') ? ' selected' : '') ." value='ce'>Dynamic cable netblock</option>\n<option".
436 (($data[2] eq 'we') ? ' selected' : '') ." value='we'>Dynamic WiFi netblock</option>\n<option".
437 (($data[2] eq 'in') ? ' selected' : '') ." value='in'>Internal netblock</option>\n".
438 "</select></td>\n";
439 print qq(<td><input name=city value="$data[3]"></td>\n).
440 "<td>$data[4]</td><td>$data[5]</td>".
441 qq(<td><input type=submit value="Update"></td></form></tr>\n);
442 }
443 print "</table>\n";
444
445 # notes
446 print "<hr><b>Notes:</b>\n".
447 "<ul>\n<li>Use the main interface to update description and notes fields\n".
448 "<li>Changing the allocation type here will NOT affect IP pool data.\n".
449 "</ul>\n";
450}
451
452
453# Stuff updates into DB
454sub update {
455 eval {
456 # Relatively simple SQL transaction here. Note that we're deliberately NOT
457 # updating notes/desc here as it's available through the main interface.
458 $sth = $ip_dbh->prepare("update allocations set custid='$webvar{custid}',".
459 "city='$webvar{city}',type='$webvar{alloctype}' where cidr='$webvar{block}'");
460 $sth->execute;
461 $ip_dbh->commit;
462 };
463 if ($@) {
464 carp "Transaction aborted because $@";
465 eval { $ip_dbh->rollback; };
466 syslog "err", "$authuser could not update block '$webvar{block}': '$@'";
467 } else {
468 # If we get here, the operation succeeded.
469 syslog "notice", "$authuser updated $webvar{block}";
470 print "Allocation $webvar{block} updated<hr>\n";
471 }
472 # need to get /24 that block is part of
473 my @bits = split /\./, $webvar{block};
474 $bits[3] = "0/24";
475 showAllocs((join ".", @bits));
476}
477
478
479# showPool()
480# List all IPs in a pool, and allow arbitrary admin changes to each
481# Allow changes to ALL fields
482sub showPool($) {
483 my $pool = new NetAddr::IP $_[0];
484 print qq(Listing pool $pool:\n<table border=1>
485<form action=admin.cgi method=POST>
486<input type=hidden name=action value=updatepool>
487<tr><td align=right>Customer ID:</td><td><input name=custid></td></tr>
488<tr><td align=right>Customer location:</td><td><input name=city></td></tr>
489<tr><td align=right>Type:</td><td><select name=type><option selected>-</option>
490<option value="si">Static IP - Server pool</option>
491<option value="ci">Static IP - Cable</option>
492<option value="di">Static IP - DSL</option>
493<option value="mi">Static IP - Dialup</option>
494<option value="wi">Static IP - Wireless</option>
495</select></td></tr>
496<tr><td align=right>Available?</td><td><input type=checkbox value=y></td></tr>
497<tr><td align=right>Description/name:</td><td><input name=desc size=40></td></tr>
498<tr><td align=right>Notes:</td><td><textarea name=notes rows=3 cols=40></textarea></td></tr>
499<tr><td colspan=2 align=center><input type=submit value="Update"></td></tr>
500).
501 "</table>Update the following record:<table border=1>\n";
502 $sth = $ip_dbh->prepare("select pool,ip,custid,city,type,available,description,notes from poolips where pool='$pool' order by ip");
503 $sth->execute;
504 while (my @data = $sth->fetchrow_array) {
505 print qq(<tr><td><input type=radio name=ip value="$data[1]">$data[1]</td>).
506 "<td>$data[2]</td><td>$data[3]</td><td>$data[4]</td>".
507 "<td>$data[5]</td><td>$data[6]</td><td>$data[7]</td></tr>\n";
508 }
509 print "</form></table>\n";
510}
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