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1 | #!/usr/local/bin/perl |
2 | 'di'; | |
3 | 'ig00'; | |
4 | # THIS PROGRAM IS ITS OWN MANUAL PAGE. INSTALL IN man & bin. | |
5 | # groff cannot handle the wrapman constructs, so if you use | |
6 | # groff, you must cut the manual part out and install it | |
7 | # separately. | |
8 | ||
9 | # hardcoded constants, should work fine for BSD-based systems | |
10 | $AF_INET = 2; | |
11 | $SOCK_STREAM = 1; | |
12 | $sockaddr = 'S n a4 x8'; | |
13 | ||
14 | # system requirements: | |
15 | # must have 'nslookup' and 'hostname' programs. | |
16 | ||
17 | # version 3.2, 5/5/93 | |
18 | ||
19 | # TODO: | |
20 | # CERNVM.CERN.CH needs simple logins for the expn command. | |
21 | # format with groff. | |
22 | # less magic should apply to command-line addresses | |
23 | # less magic should apply to local addresses | |
24 | ||
25 | # Checklist: (hard addresses) | |
26 | # harry@hofmann.cs.Berkeley.EDU -> harry@tenet (.berkeley.edu) | |
27 | # bks@cs.berkeley.edu -> shiva.CS (.berkeley.edu) | |
28 | # dan@tc.cornell.edu -> brown@tiberius (.tc.cornell.edu) | |
29 | ||
30 | ############################################################################# | |
31 | # | |
32 | # Copyright (c) 1993 David Muir Sharnoff | |
33 | # All rights reserved. | |
34 | # | |
35 | # Redistribution and use in source and binary forms, with or without | |
36 | # modification, are permitted provided that the following conditions | |
37 | # are met: | |
38 | # 1. Redistributions of source code must retain the above copyright | |
39 | # notice, this list of conditions and the following disclaimer. | |
40 | # 2. Redistributions in binary form must reproduce the above copyright | |
41 | # notice, this list of conditions and the following disclaimer in the | |
42 | # documentation and/or other materials provided with the distribution. | |
43 | # 3. All advertising materials mentioning features or use of this software | |
44 | # must display the following acknowledgement: | |
45 | # This product includes software developed by the David Muir Sharnoff. | |
46 | # 4. The name of David Sharnoff may not be used to endorse or promote products | |
47 | # derived from this software without specific prior written permission. | |
48 | # | |
49 | # THIS SOFTWARE IS PROVIDED BY THE DAVID MUIR SHARNOFF ``AS IS'' AND | |
50 | # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
51 | # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
52 | # ARE DISCLAIMED. IN NO EVENT SHALL DAVID MUIR SHARNOFF BE LIABLE | |
53 | # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
54 | # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
55 | # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
56 | # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
57 | # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
58 | # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
59 | # SUCH DAMAGE. | |
60 | # | |
61 | # This copyright notice derrived from material copyrighted by the Regents | |
62 | # of the University of California. | |
63 | # | |
64 | # Contributions accepted. | |
65 | # | |
66 | ############################################################################# | |
67 | ||
68 | # overall structure: | |
69 | # in an effort to not trace each address individually, but rather | |
70 | # ask each server in turn a whole bunch of questions, addresses to | |
71 | # be expanded are queued up. | |
72 | # | |
73 | # This means that all account w.r.t. an address must be stored in | |
74 | # various arrays. Generally these arrays are indexed by the | |
75 | # string "$addr *** $server" where $addr is the address to be | |
76 | # expanded "foo" or maybe "foo@bar" and $server is the hostname | |
77 | # of the SMTP server to contact. | |
78 | # | |
79 | ||
80 | # important global variables: | |
81 | # | |
82 | # @hosts : list of servers still to be contacted | |
83 | # $server : name of the current we are currently looking at | |
84 | # @users = $users{@hosts[0]} : addresses to expand at this server | |
85 | # $u = $users[0] : the current address being expanded | |
86 | # $names{"$users[0] *** $server"} : the 'name' associated with the address | |
87 | # $mxbacktrace{"$users[0] *** $server"} : record of mx expansion | |
88 | # $mx_secondary{$server} : other mx relays at the same priority | |
89 | # $domainify_fallback{"$users[0] *** $server"} : alternative names to try | |
90 | # instead of $server if $server doesn't work | |
91 | # $temporary_redirect{"$users[0] *** $server"} : when trying alternates, | |
92 | # temporarily channel all tries along current path | |
93 | # $giveup{$server} : do not bother expanding addresses at $server | |
94 | # $verbose : -v | |
95 | # $watch : -w | |
96 | # $vw : -v or -w | |
97 | # $debug : -d | |
98 | # $valid : -a | |
99 | # $levels : -1 | |
100 | # S : the socket connection to $server | |
101 | ||
102 | $have_nslookup = 1; # we have the nslookup program | |
103 | $port = 'smtp'; | |
104 | $av0 = $0; | |
105 | $0 = "$av0 - running hostname"; | |
106 | $ENV{'PATH'} .= ":/usr/etc" unless $ENV{'PATH'} =~ m,/usr/etc,; | |
107 | chop($hostname = `hostname`); | |
108 | select(STDERR); | |
109 | ||
110 | $usage = "Usage: $av0 [-1avwd] user[@host] [user2[host2] ...]"; | |
111 | $0 = "$av0 - parsing args"; | |
112 | for $a (@ARGV) { | |
113 | die $usage if $a eq "-"; | |
114 | while ($a =~ s/^(-.*)([1avwd])/$1/) { | |
115 | eval '$'."flag_$2 += 1"; | |
116 | } | |
117 | next if $a eq "-"; | |
118 | die $usage if $a =~ /^-/; | |
119 | &expn(&parse($a,$hostname,undef,1,1)); | |
120 | } | |
121 | $verbose = $flag_v; | |
122 | $watch = $flag_w; | |
123 | $vw = $flag_v + $flag_w; | |
124 | $debug = $flag_d; | |
125 | $valid = $flag_a; | |
126 | $levels = $flag_1; | |
127 | ||
128 | die $usage unless @hosts; | |
129 | if ($valid) { | |
130 | if ($valid == 1) { | |
131 | $validRequirement = 0.8; | |
132 | } elsif ($valid == 2) { | |
133 | $validRequirement = 1.0; | |
134 | } elsif ($valid == 3) { | |
135 | $validRequirement = 0.9; | |
136 | } else { | |
137 | $validRequirement = (1 - (1/($valid-3))); | |
138 | print "validRequirement = $validRequirement\n" if $debug; | |
139 | } | |
140 | } | |
141 | ||
142 | $0 = "$av0 - building local socket"; | |
143 | ($name,$aliases,$proto) = getprotobyname('tcp'); | |
144 | ($name,$aliases,$port) = getservbyname($port,'tcp') | |
145 | unless $port =~ /^\d+/; | |
146 | ($name,$aliases,$type,$len,$thisaddr) = gethostbyname($hostname); | |
147 | $this = pack($sockaddr, $AF_INET, 0, $thisaddr); | |
148 | ||
149 | HOST: | |
150 | while (@hosts) { | |
151 | $server = shift(@hosts); | |
152 | @users = split(' ',$users{$server}); | |
153 | delete $users{$server}; | |
154 | ||
155 | # is this server already known to be bad? | |
156 | $0 = "$av0 - looking up $server"; | |
157 | if ($giveup{$server}) { | |
158 | &giveup('mx domainify',$giveup{$server}); | |
159 | next; | |
160 | } | |
161 | ||
162 | # do we already have an mx record for this host? | |
163 | next HOST if &mxredirect($server,*users); | |
164 | ||
165 | # look it up, or try for an mx. | |
166 | $0 = "$av0 - gethostbyname($server)"; | |
167 | ||
168 | ||
169 | ($name,$aliases,$type,$len,$thataddr) = gethostbyname($server); | |
170 | # if we can't get an A record, try for an MX record. | |
171 | unless($thataddr) { | |
172 | &mxlookup(1,$server,"$server: could not resolve name",*users); | |
173 | next HOST; | |
174 | } | |
175 | ||
176 | # get a connection, or look for an mx | |
177 | $0 = "$av0 - socket to $server"; | |
178 | $that = pack($sockaddr, $AF_INET, $port, $thataddr); | |
179 | socket(S, $AF_INET, $SOCK_STREAM, $proto) | |
180 | || die "socket: $!"; | |
181 | $0 = "$av0 - bind to $server"; | |
182 | bind(S, $this) | |
183 | || die "bind $hostname,0: $!"; | |
184 | $0 = "$av0 - connect to $server"; | |
185 | print "debug = $debug server = $server\n" if $debug > 8; | |
186 | if (! connect(S, $that) || ($debug == 10 && $server =~ /relay\d.UU.NET$/i)) { | |
187 | $0 = "$av0 - $server: could not connect: $!\n"; | |
188 | $emsg = $!; | |
189 | unless (&mxlookup(0,$server,"$server: could not connect: $!",*users)) { | |
190 | &giveup('mx',"$server: Could not connect: $emsg"); | |
191 | } | |
192 | next HOST; | |
193 | } | |
194 | select((select(S),$| = 1)[0]); # don't buffer output to S | |
195 | ||
196 | # read the greeting | |
197 | $0 = "$av0 - talking to $server"; | |
198 | while(<S>) { | |
199 | print if $watch; | |
200 | if (/^(\d+)([- ])/) { | |
201 | if ($1 != 220) { | |
202 | $0 = "$av0 - bad numeric responce from $server"; | |
203 | &toss($2); | |
204 | print STDERR "$server: NOT 220 greeting: $_" | |
205 | if ($debug || $vw); | |
206 | if (&mxlookup(0,$server,"$server: did not respond with a 220 greeting",*users)) { | |
207 | close(S); | |
208 | next HOST; | |
209 | } | |
210 | } | |
211 | last if ($2 eq " "); | |
212 | } else { | |
213 | $0 = "$av0 - bad responce from $server"; | |
214 | print STDERR "$server: NOT 220 greeting: $_" | |
215 | if ($debug || $vw); | |
216 | unless (&mxlookup(0,$server,"$server: did not respond with SMTP codes",*users)) { | |
217 | &giveup('',"$server: did not talk SMTP"); | |
218 | } | |
219 | close(S); | |
220 | next HOST; | |
221 | } | |
222 | } | |
223 | ||
224 | # if this causes problems, remove it | |
225 | $0 = "$av0 - sending helo to $server"; | |
226 | &ps("helo $hostname"); | |
227 | while(<S>) { | |
228 | print if $watch; | |
229 | last if /^\d+ /; | |
230 | } | |
231 | ||
232 | # try the users, one by one | |
233 | USER: | |
234 | while(@users) { | |
235 | $u = shift(@users); | |
236 | $0 = "$av0 - expanding $u [\@$server]"; | |
237 | ||
238 | # do we already have a name for this user? | |
239 | $oldname = $names{"$u *** $server"}; | |
240 | ||
241 | print &compact($u,$server)." ->\n" if ($verbose && ! $valid); | |
242 | if ($valid) { | |
243 | # | |
244 | # when running with -a, we delay taking any action | |
245 | # on the results of our query until we have looked | |
246 | # at the complete output. @toFinal stores expansions | |
247 | # that will be final if we take them. @toExpn stores | |
248 | # expnansions that are not final. @isValid keeps | |
249 | # track of our ability to send mail to each of the | |
250 | # expansions. | |
251 | # | |
252 | @isValid = (); | |
253 | @toFinal = (); | |
254 | @toExpn = (); | |
255 | } | |
256 | &ps("expn $u"); | |
257 | $said_something = 0; | |
258 | while($s = <S>) { | |
259 | $said_something = 1; | |
260 | ||
261 | # make sure the server is talking the right language | |
262 | if ($s =~ /^(\d+)([- ])/) { | |
263 | if ($1 != 250 && $1 != 550) { | |
264 | &toss($2); | |
265 | &ps("vrfy $u"); | |
266 | $s = <S>; | |
267 | if ($s =~ /^(\d+)/) { | |
268 | if ($1 != 250 && $1 != 550) { | |
269 | &toss($2); | |
270 | &giveup('',"$server: expn/vrfy not implemented",$u); | |
271 | last USER; | |
272 | } | |
273 | } | |
274 | } | |
275 | } | |
276 | ||
277 | $s =~ s/[\n\r]//g; | |
278 | $0 = "$av0 - parsing $server: $s"; | |
279 | print "$s\n" if $watch; | |
280 | if ($s =~ /^250([- ])(.+)/) { | |
281 | ($done,$addr) = ($1,$2); | |
282 | ($newhost, $newaddr, $newname) = &parse($addr,$server,$oldname); | |
283 | print "($newhost, $newaddr, $newname) = &parse($addr, $server, $oldname)\n" if $debug; | |
284 | if (! $newhost) { | |
285 | # no expansion is possible w/o a new server to call | |
286 | if ($valid) { | |
287 | push(@isValid, &validAddr($newaddr)); | |
288 | push(@toFinal,$newaddr,$server,$newname); | |
289 | } else { | |
290 | &verbose(&final($newaddr,$server,$newname)); | |
291 | } | |
292 | } else { | |
293 | $newmxhost = &mx($newhost,$newaddr); | |
294 | print "$newmxhost = &mx($newhost)\n" | |
295 | if ($debug && $newhost ne $newmxhost); | |
296 | $0 = "$av0 - parsing $newaddr [@$newmxhost]"; | |
297 | print "levels = $levels, level{$u *** $server} = ".$level{"$u *** $server"}."\n" if ($debug > 1); | |
298 | # If the new server is the current one, | |
299 | # it would have expanded things for us | |
300 | # if it could have. Mx records must be | |
301 | # followed to compare server names. | |
302 | # We are also done if the recursion | |
303 | # count has been exceeded. | |
304 | if (&trhost($newmxhost) eq &trhost($server) || ($levels && $level{"$u *** $server"} >= $levels)) { | |
305 | if ($valid) { | |
306 | push(@isValid, &validAddr($newaddr)); | |
307 | push(@toFinal,$newaddr,$newmxhost,$newname); | |
308 | } else { | |
309 | &verbose(&final($newaddr,$newmxhost,$newname)); | |
310 | } | |
311 | } else { | |
312 | # more work to do... | |
313 | if ($valid) { | |
314 | push(@isValid, &validAddr($newaddr)); | |
315 | push(@toExpn,$newmxhost,$newaddr,$newname,$level{"$u *** $server"}); | |
316 | } else { | |
317 | &verbose(&expn($newmxhost,$newaddr,$newname,$level{"$u *** $server"})); | |
318 | } | |
319 | } | |
320 | } | |
321 | last if ($done eq " "); | |
322 | next; | |
323 | } | |
324 | # 550 is a known code... Should the be | |
325 | # included in -a output? Might be a bug | |
326 | # here. Does it matter? Can assume that | |
327 | # there won't be UNKNOWN USER responces | |
328 | # mixed with valid users? | |
329 | if ($s =~ /^(550)([- ])/) { | |
330 | if ($valid) { | |
331 | print STDERR "\@$server:$u ($oldname) USER UNKNOWN\n"; | |
332 | } else { | |
333 | &verbose(&final($u,$server,$oldname,"USER UNKNOWN")); | |
334 | } | |
335 | last if ($2 eq " "); | |
336 | next; | |
337 | } | |
338 | &giveup('',"$server: did not grok '$s'",$u); | |
339 | last USER; | |
340 | } | |
341 | if (! $said_something) { | |
342 | &giveup('',"$server: lost connection",$u); | |
343 | last USER; | |
344 | } | |
345 | if ($valid) { | |
346 | # | |
347 | # now we decide if we are going to take these | |
348 | # expansions or roll them back. | |
349 | # | |
350 | $avgValid = &average(@isValid); | |
351 | print "avgValid = $avgValid\n" if $debug; | |
352 | if ($avgValid >= $validRequirement) { | |
353 | print &compact($u,$server)." ->\n" if $verbose; | |
354 | while (@toExpn) { | |
355 | &verbose(&expn(splice(@toExpn,0,4))); | |
356 | } | |
357 | while (@toFinal) { | |
358 | &verbose(&final(splice(@toFinal,0,3))); | |
359 | } | |
360 | } else { | |
361 | print "Tossing some valid to avoid invalid ".&compact($u,$server)."\n" if ($avgValid > 0.0 && ($vw || $debug)); | |
362 | print &compact($u,$server)." ->\n" if $verbose; | |
363 | &verbose(&final($u,$server,$newname)); | |
364 | } | |
365 | } | |
366 | } | |
367 | ||
368 | $0 = "$av0 - sending 'quit' to $server"; | |
369 | &ps("quit"); | |
370 | while(<S>) { | |
371 | print if $watch; | |
372 | last if /^\d+ /; | |
373 | } | |
374 | close(S); | |
375 | } | |
376 | ||
377 | $0 = "$av0 - printing final results"; | |
378 | print "----------\n" if $vw; | |
379 | select(STDOUT); | |
380 | for $f (sort @final) { | |
381 | print "$f\n"; | |
382 | } | |
383 | unlink("/tmp/expn$$"); | |
384 | exit(0); | |
385 | ||
386 | ||
387 | # abandon all attempts deliver to $server | |
388 | # register the current addresses as the final ones | |
389 | sub giveup | |
390 | { | |
391 | local($redirect_okay,$reason,$user) = @_; | |
392 | local($us,@so,$nh,@remaining_users); | |
393 | ||
394 | $0 = "$av0 - giving up on $server: $reason"; | |
395 | # | |
396 | # add back a user if we gave up in the middle | |
397 | # | |
398 | push(@users,$user) if $user; | |
399 | # | |
400 | # don't bother with this system anymore | |
401 | # | |
402 | unless ($giveup{$server}) { | |
403 | $giveup{$server} = $reason; | |
404 | print STDERR "$reason\n"; | |
405 | } | |
406 | print "Giveup!!! redirect okay = $redirect_okay; $reason\n" if $debug; | |
407 | # | |
408 | # Wait! | |
409 | # Before giving up, see if there is a chance that | |
410 | # there is another host to redirect to! | |
411 | # (Kids, don't do this at home! Hacking is a dangerous | |
412 | # crime and you could end up behind bars.) | |
413 | # | |
414 | for $u (@users) { | |
415 | if ($redirect_okay =~ /\bmx\b/) { | |
416 | next if &try_fallback('mx',$u,*server, | |
417 | *mx_secondary, | |
418 | *already_mx_fellback); | |
419 | } | |
420 | if ($redirect_okay =~ /\bdomainify\b/) { | |
421 | next if &try_fallback('domainify',$u,*server, | |
422 | *domainify_fallback, | |
423 | *already_domainify_fellback); | |
424 | } | |
425 | push(@remaining_users,$u); | |
426 | } | |
427 | @users = @remaining_users; | |
428 | for $u (@users) { | |
429 | print &compact($u,$server)." ->\n" if ($verbose && $valid && $u); | |
430 | &verbose(&final($u,$server,$names{"$u *** $server"},$reason)); | |
431 | } | |
432 | } | |
433 | # | |
434 | # This routine is used only within &giveup. It checks to | |
435 | # see if we really have to giveup or if there is a second | |
436 | # chance because we did something before that can be | |
437 | # backtracked. | |
438 | # | |
439 | # %fallback{"$user *** $host"} tracks what is able to fallback | |
440 | # %fellback{"$user *** $host"} tracks what has fallen back | |
441 | # | |
442 | # If there is a valid backtrack, then queue up the new possibility | |
443 | # | |
444 | sub try_fallback | |
445 | { | |
446 | local($method,$user,*host,*fall_table,*fellback) = @_; | |
447 | local($us,$fallhost,$oldhost,$ft,$i); | |
448 | ||
449 | if ($debug > 8) { | |
450 | print "Fallback table $method:\n"; | |
451 | for $i (sort keys %fall_table) { | |
452 | print "\t'$i'\t\t'$fall_table{$i}'\n"; | |
453 | } | |
454 | print "Fellback table $method:\n"; | |
455 | for $i (sort keys %fellback) { | |
456 | print "\t'$i'\t\t'$fellback{$i}'\n"; | |
457 | } | |
458 | print "U: $user H: $host\n"; | |
459 | } | |
460 | ||
461 | $us = "$user *** $host"; | |
462 | if (defined $fellback{$us}) { | |
463 | # | |
464 | # Undo a previous fallback so that we can try again | |
465 | # Nest fallbacks are avoided because they could | |
466 | # lead to infinite loops | |
467 | # | |
468 | $fallhost = $fellback{$us}; | |
469 | print "Already $method fell back from $us -> \n" if $debug; | |
470 | $us = "$user *** $fallhost"; | |
471 | $oldhost = $fallhost; | |
472 | } elsif (($method eq 'mx') && (defined $mxbacktrace{$us}) && (defined $mx_secondary{$mxbacktrace{$us}})) { | |
473 | print "Fallback an MX expansion $us -> \n" if $debug; | |
474 | $oldhost = $mxbacktrace{$us}; | |
475 | } else { | |
476 | print "Oldhost(host, $us) = " if $debug; | |
477 | $oldhost = $host; | |
478 | } | |
479 | print "$oldhost\n" if $debug; | |
480 | if (((defined $fall_table{$us}) && ($ft = $us)) || ((defined $fall_table{$oldhost}) && ($ft = $oldhost))) { | |
481 | print "$method Fallback = ".$fall_table{$ft}."\n" if $debug; | |
482 | local(@so,$newhost); | |
483 | @so = split(' ',$fall_table{$ft}); | |
484 | $newhost = shift(@so); | |
485 | print "Falling back ($method) $us -> $newhost (from $oldhost)\n" if $debug; | |
486 | if ($method eq 'mx') { | |
487 | if (! defined ($mxbacktrace{"$user *** $newhost"})) { | |
488 | if (defined $mxbacktrace{"$user *** $oldhost"}) { | |
489 | print "resetting oldhost $oldhost to the original: " if $debug; | |
490 | $oldhost = $mxbacktrace{"$user *** $oldhost"}; | |
491 | print "$oldhost\n" if $debug; | |
492 | } | |
493 | $mxbacktrace{"$user *** $newhost"} = $oldhost; | |
494 | print "mxbacktrace $user *** $newhost -> $oldhost\n" if $debug; | |
495 | } | |
496 | $mx{&trhost($oldhost)} = $newhost; | |
497 | } else { | |
498 | $temporary_redirect{$us} = $newhost; | |
499 | } | |
500 | if (@so) { | |
501 | print "Can still $method $us: @so\n" if $debug; | |
502 | $fall_table{$ft} = join(' ',@so); | |
503 | } else { | |
504 | print "No more fallbacks for $us\n" if $debug; | |
505 | delete $fall_table{$ft}; | |
506 | } | |
507 | if (defined $create_host_backtrack{$us}) { | |
508 | $create_host_backtrack{"$user *** $newhost"} | |
509 | = $create_host_backtrack{$us}; | |
510 | } | |
511 | $fellback{"$user *** $newhost"} = $oldhost; | |
512 | &expn($newhost,$user,$names{$us},$level{$us}); | |
513 | return 1; | |
514 | } | |
515 | delete $temporary_redirect{$us}; | |
516 | $host = $oldhost; | |
517 | return 0; | |
518 | } | |
519 | # return 1 if you could send mail to the address as is. | |
520 | sub validAddr | |
521 | { | |
522 | local($addr) = @_; | |
523 | $res = &do_validAddr($addr); | |
524 | print "validAddr($addr) = $res\n" if $debug; | |
525 | $res; | |
526 | } | |
527 | sub do_validAddr | |
528 | { | |
529 | local($addr) = @_; | |
530 | local($urx) = "[-A-Za-z_.0-9+]+"; | |
531 | ||
532 | # \u | |
533 | return 0 if ($addr =~ /^\\/); | |
534 | # ?@h | |
535 | return 1 if ($addr =~ /.\@$urx$/); | |
536 | # @h:? | |
537 | return 1 if ($addr =~ /^\@$urx\:./); | |
538 | # h!u | |
539 | return 1 if ($addr =~ /^$urx!./); | |
540 | # u | |
541 | return 1 if ($addr =~ /^$urx$/); | |
542 | # ? | |
543 | print "validAddr($addr) = ???\n" if $debug; | |
544 | return 0; | |
545 | } | |
546 | # returns ($new_smtp_server,$new_address,$new_name) | |
547 | # given a responce from a SMTP server ($newaddr), the | |
548 | # current host ($server), the old "name" and a flag that | |
549 | # indicates if it is being called during the initial | |
550 | # command line parsing ($parsing_args) | |
551 | sub parse | |
552 | { | |
553 | local($newaddr,$context_host,$old_name,$parsing_args) = @_; | |
554 | local(@names) = $old_name; | |
555 | local($urx) = "[-A-Za-z_.0-9+]+"; | |
556 | ||
557 | # | |
558 | # first, separate out the address part. | |
559 | # | |
560 | ||
561 | # | |
562 | # [NAME] <ADDR [(NAME)]> | |
563 | # [NAME] <[(NAME)] ADDR | |
564 | # ADDR [(NAME)] | |
565 | # (NAME) ADDR | |
566 | # [(NAME)] <ADDR> | |
567 | # | |
568 | if ($newaddr =~ /^\<(.*)\>$/) { | |
569 | print "<A:$1>\n" if $debug; | |
570 | $newaddr = &trim($1); | |
571 | print "na = $newaddr\n" if $debug; | |
572 | } | |
573 | if ($newaddr =~ /^([^\<\>]*)\<([^\<\>]*)\>([^\<\>]*)$/) { | |
574 | # address has a < > pair in it. | |
575 | print "N:$1 <A:$2> N:$3\n" if $debug; | |
576 | $newaddr = &trim($2); | |
577 | unshift(@names, &trim($3,$1)); | |
578 | print "na = $newaddr\n" if $debug; | |
579 | } | |
580 | if ($newaddr =~ /^([^\(\)]*)\(([^\(\)]*)\)([^\(\)]*)$/) { | |
581 | # address has a ( ) pair in it. | |
582 | print "A:$1 (N:$2) A:$3\n" if $debug; | |
583 | unshift(@names,&trim($2)); | |
584 | local($f,$l) = (&trim($1),&trim($3)); | |
585 | if (($f && $l) || !($f || $l)) { | |
586 | # address looks like: | |
587 | # foo (bar) baz or (bar) | |
588 | # not allowed! | |
589 | print STDERR "Could not parse $newaddr\n" if $vw; | |
590 | return(undef,$newaddr,&firstname(@names)); | |
591 | } | |
592 | $newaddr = $f if $f; | |
593 | $newaddr = $l if $l; | |
594 | print "newaddr now = $newaddr\n" if $debug; | |
595 | } | |
596 | # | |
597 | # @foo:bar | |
598 | # j%k@l | |
599 | # a@b | |
600 | # b!a | |
601 | # a | |
602 | # | |
603 | if ($newaddr =~ /^\@($urx)\:(.+)$/) { | |
604 | print "(\@:)" if $debug; | |
605 | # this is a bit of a cheat, but it seems necessary | |
606 | return (&domainify($1,$context_host,$2),$2,&firstname(@names)); | |
607 | } | |
608 | if ($newaddr =~ /^(.+)\@($urx)$/) { | |
609 | print "(\@)" if $debug; | |
610 | return (&domainify($2,$context_host,$newaddr),$newaddr,&firstname(@names)); | |
611 | } | |
612 | if ($parsing_args) { | |
613 | if ($newaddr =~ /^($urx)\!(.+)$/) { | |
614 | return (&domainify($1,$context_host,$newaddr),$newaddr,&firstname(@names)); | |
615 | } | |
616 | if ($newaddr =~ /^($urx)$/) { | |
617 | return ($context_host,$newaddr,&firstname(@names)); | |
618 | } | |
619 | print STDERR "Could not parse $newaddr\n"; | |
620 | } | |
621 | print "(?)" if $debug; | |
622 | return(undef,$newaddr,&firstname(@names)); | |
623 | } | |
624 | # return $u (@$server) unless $u includes reference to $server | |
625 | sub compact | |
626 | { | |
627 | local($u, $server) = @_; | |
628 | local($se) = $server; | |
629 | local($sp); | |
630 | $se =~ s/(\W)/\\$1/g; | |
631 | $sp = " (\@$server)"; | |
632 | if ($u !~ /$se/i) { | |
633 | return "$u$sp"; | |
634 | } | |
635 | return $u; | |
636 | } | |
637 | # remove empty (spaces don't count) members from an array | |
638 | sub trim | |
639 | { | |
640 | local(@v) = @_; | |
641 | local($v,@r); | |
642 | for $v (@v) { | |
643 | $v =~ s/^\s+//; | |
644 | $v =~ s/\s+$//; | |
645 | push(@r,$v) if ($v =~ /\S/); | |
646 | } | |
647 | return(@r); | |
648 | } | |
649 | # using the host part of an address, and the server name, add the | |
650 | # servers' domain to the address if it doesn't already have a | |
651 | # domain. Since this sometimes failes, save a back reference so | |
652 | # it can be unrolled. | |
653 | sub domainify | |
654 | { | |
655 | local($host,$domain_host,$u) = @_; | |
656 | local($domain,$newhost); | |
657 | ||
658 | # cut of trailing dots | |
659 | $host =~ s/\.$//; | |
660 | $domain_host =~ s/\.$//; | |
661 | ||
662 | if ($domain_host !~ /\./) { | |
663 | # | |
664 | # domain host isn't, keep $host whatever it is | |
665 | # | |
666 | print "domainify($host,$domain_host) = $host\n" if $debug; | |
667 | return $host; | |
668 | } | |
669 | ||
670 | # | |
671 | # There are several weird situtations that need to be | |
672 | # accounted for. They have to do with domain relay hosts. | |
673 | # | |
674 | # Examples: | |
675 | # host server "right answer" | |
676 | # | |
677 | # shiva.cs cs.berkeley.edu shiva.cs.berkeley.edu | |
678 | # shiva cs.berkeley.edu shiva.cs.berekley.edu | |
679 | # cumulus reed.edu @reed.edu:cumulus.uucp | |
680 | # tiberius tc.cornell.edu tiberius.tc.cornell.edu | |
681 | # | |
682 | # The first try must always be to cut the domain part out of | |
683 | # the server and tack it onto the host. | |
684 | # | |
685 | # A reasonable second try is to tack the whole server part onto | |
686 | # the host and for each possible repeated element, eliminate | |
687 | # just that part. | |
688 | # | |
689 | # These extra "guesses" get put into the %domainify_fallback | |
690 | # array. They will be used to give addresses a second chance | |
691 | # in the &giveup routine | |
692 | # | |
693 | ||
694 | local(%fallback); | |
695 | ||
696 | local($long); | |
697 | $long = "$host $domain_host"; | |
698 | $long =~ tr/A-Z/a-z/; | |
699 | print "long = $long\n" if $debug; | |
700 | if ($long =~ s/^([^ ]+\.)([^ ]+) \2(\.[^ ]+\.[^ ]+)/$1$2$3/) { | |
701 | # matches shiva.cs cs.berkeley.edu and returns shiva.cs.berkeley.edu | |
702 | print "condensed fallback $host $domain_host -> $long\n" if $debug; | |
703 | $fallback{$long} = 9; | |
704 | } | |
705 | ||
706 | local($fh); | |
707 | $fh = $domain_host; | |
708 | while ($fh =~ /\./) { | |
709 | print "FALLBACK $host.$fh = 1\n" if $debug > 7; | |
710 | $fallback{"$host.$fh"} = 1; | |
711 | $fh =~ s/^[^\.]+\.//; | |
712 | } | |
713 | ||
714 | $fallback{"$host.$domain_host"} = 2; | |
715 | ||
716 | ($domain = $domain_host) =~ s/^[^\.]+//; | |
717 | $fallback{"$host$domain"} = 6 | |
718 | if ($domain =~ /\./); | |
719 | ||
720 | if ($host =~ /\./) { | |
721 | # | |
722 | # Host is already okay, but let's look for multiple | |
723 | # interpretations | |
724 | # | |
725 | print "domainify($host,$domain_host) = $host\n" if $debug; | |
726 | delete $fallback{$host}; | |
727 | $domainify_fallback{"$u *** $host"} = join(' ',sort {$fallback{$b} <=> $fallback{$a};} keys %fallback) if %fallback; | |
728 | return $host; | |
729 | } | |
730 | ||
731 | $domain = ".$domain_host" | |
732 | if ($domain !~ /\..*\./); | |
733 | $newhost = "$host$domain"; | |
734 | ||
735 | $create_host_backtrack{"$u *** $newhost"} = $domain_host; | |
736 | print "domainify($host,$domain_host) = $newhost\n" if $debug; | |
737 | delete $fallback{$newhost}; | |
738 | $domainify_fallback{"$u *** $newhost"} = join(' ',sort {$fallback{$b} <=> $fallback{$a};} keys %fallback) if %fallback; | |
739 | if ($debug) { | |
740 | print "fallback = "; | |
741 | print $domainify_fallback{"$u *** $newhost"} | |
742 | if defined($domainify_fallback{"$u *** $newhost"}); | |
743 | print "\n"; | |
744 | } | |
745 | return $newhost; | |
746 | } | |
747 | # return the first non-empty element of an array | |
748 | sub firstname | |
749 | { | |
750 | local(@names) = @_; | |
751 | local($n); | |
752 | while(@names) { | |
753 | $n = shift(@names); | |
754 | return $n if $n =~ /\S/; | |
755 | } | |
756 | return undef; | |
757 | } | |
758 | # queue up more addresses to expand | |
759 | sub expn | |
760 | { | |
761 | local($host,$addr,$name,$level) = @_; | |
762 | if ($host) { | |
763 | $host = &trhost($host); | |
764 | ||
765 | if (($debug > 3) || (defined $giveup{$host})) { | |
766 | unshift(@hosts,$host) unless $users{$host}; | |
767 | } else { | |
768 | push(@hosts,$host) unless $users{$host}; | |
769 | } | |
770 | $users{$host} .= " $addr"; | |
771 | $names{"$addr *** $host"} = $name; | |
772 | $level{"$addr *** $host"} = $level + 1; | |
773 | print "expn($host,$addr,$name)\n" if $debug; | |
774 | return "\t$addr\n"; | |
775 | } else { | |
776 | return &final($addr,'NONE',$name); | |
777 | } | |
778 | } | |
779 | # compute the numerical average value of an array | |
780 | sub average | |
781 | { | |
782 | local(@e) = @_; | |
783 | return 0 unless @e; | |
784 | local($e,$sum); | |
785 | for $e (@e) { | |
786 | $sum += $e; | |
787 | } | |
788 | $sum / @e; | |
789 | } | |
790 | # print to the server (also to stdout, if -w) | |
791 | sub ps | |
792 | { | |
793 | local($p) = @_; | |
794 | print ">>> $p\n" if $watch; | |
795 | print S "$p\n"; | |
796 | } | |
797 | # return case-adjusted name for a host (for comparison purposes) | |
798 | sub trhost | |
799 | { | |
800 | # treat foo.bar as an alias for Foo.BAR | |
801 | local($host) = @_; | |
802 | local($trhost) = $host; | |
803 | $trhost =~ tr/A-Z/a-z/; | |
804 | if ($trhost{$trhost}) { | |
805 | $host = $trhost{$trhost}; | |
806 | } else { | |
807 | $trhost{$trhost} = $host; | |
808 | } | |
809 | $trhost{$trhost}; | |
810 | } | |
811 | # re-queue users if an mx record dictates a redirect | |
812 | # don't allow a user to be redirected more than once | |
813 | sub mxredirect | |
814 | { | |
815 | local($server,*users) = @_; | |
816 | local($u,$nserver,@still_there); | |
817 | ||
818 | $nserver = &mx($server); | |
819 | ||
820 | if (&trhost($nserver) ne &trhost($server)) { | |
821 | $0 = "$av0 - mx redirect $server -> $nserver\n"; | |
822 | for $u (@users) { | |
823 | if (defined $mxbacktrace{"$u *** $nserver"}) { | |
824 | push(@still_there,$u); | |
825 | } else { | |
826 | $mxbacktrace{"$u *** $nserver"} = $server; | |
827 | print "mxbacktrace{$u *** $nserver} = $server\n" | |
828 | if ($debug > 1); | |
829 | &expn($nserver,$u,$names{"$u *** $server"}); | |
830 | } | |
831 | } | |
832 | @users = @still_there; | |
833 | if (! @users) { | |
834 | return $nserver; | |
835 | } else { | |
836 | return undef; | |
837 | } | |
838 | } | |
839 | return undef; | |
840 | } | |
841 | # follow mx records, return a hostname | |
842 | # also follow temporary redirections comming from &domainify and | |
843 | # &mxlookup | |
844 | sub mx | |
845 | { | |
846 | local($h,$u) = @_; | |
847 | ||
848 | for (;;) { | |
849 | if (defined $mx{&trhost($h)} && $h ne $mx{&trhost($h)}) { | |
850 | $0 = "$av0 - mx expand $h"; | |
851 | $h = $mx{&trhost($h)}; | |
852 | return $h; | |
853 | } | |
854 | if ($u) { | |
855 | if (defined $temporary_redirect{"$u *** $h"}) { | |
856 | $0 = "$av0 - internal redirect $h"; | |
857 | print "Temporary redirect taken $u *** $h -> " if $debug; | |
858 | $h = $temporary_redirect{"$u *** $h"}; | |
859 | print "$h\n" if $debug; | |
860 | next; | |
861 | } | |
862 | $htr = &trhost($h); | |
863 | if (defined $temporary_redirect{"$u *** $htr"}) { | |
864 | $0 = "$av0 - internal redirect $h"; | |
865 | print "temporary redirect taken $u *** $h -> " if $debug; | |
866 | $h = $temporary_redirect{"$u *** $htr"}; | |
867 | print "$h\n" if $debug; | |
868 | next; | |
869 | } | |
870 | } | |
871 | return $h; | |
872 | } | |
873 | } | |
874 | # look up mx records with the name server. | |
875 | # re-queue expansion requests if possible | |
876 | # optionally give up on this host. | |
877 | sub mxlookup | |
878 | { | |
879 | local($lastchance,$server,$giveup,*users) = @_; | |
880 | local(*T); | |
881 | local(*NSLOOKUP); | |
882 | local($nh, $pref,$cpref); | |
883 | local($o0) = $0; | |
884 | local($nserver); | |
885 | local($name,$aliases,$type,$len,$thataddr); | |
886 | local(%fallback); | |
887 | ||
888 | return 1 if &mxredirect($server,*users); | |
889 | ||
890 | if ((defined $mx{$server}) || (! $have_nslookup)) { | |
891 | return 0 unless $lastchance; | |
892 | &giveup('mx domainify',$giveup); | |
893 | return 0; | |
894 | } | |
895 | ||
896 | $0 = "$av0 - nslookup of $server"; | |
897 | open(T,">/tmp/expn$$") || die "open > /tmp/expn$$: $!\n"; | |
898 | print T "set querytype=MX\n"; | |
899 | print T "$server\n"; | |
900 | close(T); | |
901 | $cpref = 1.0E12; | |
902 | undef $nserver; | |
903 | open(NSLOOKUP,"nslookup < /tmp/expn$$ 2>&1 |") || die "open nslookup: $!"; | |
904 | while(<NSLOOKUP>) { | |
905 | print if ($debug > 2); | |
906 | if (/mail exchanger = ([-A-Za-z_.0-9+]+)/) { | |
907 | $nh = $1; | |
908 | if (/preference = (\d+)/) { | |
909 | $pref = $1; | |
910 | if ($pref < $cpref) { | |
911 | $nserver = $nh; | |
912 | $cpref = $pref; | |
913 | } elsif ($pref) { | |
914 | $fallback{$pref} .= " $nh"; | |
915 | } | |
916 | } | |
917 | } | |
918 | if (/Non-existent domain/) { | |
919 | # | |
920 | # These addresss are hosed. Kaput! Dead! | |
921 | # However, if we created the address in the | |
922 | # first place then there is a chance of | |
923 | # salvation. | |
924 | # | |
925 | 1 while(<NSLOOKUP>); | |
926 | close(NSLOOKUP); | |
927 | return 0 unless $lastchance; | |
928 | &giveup('domainify',"$server: Non-existent domain",undef,1); | |
929 | return 0; | |
930 | } | |
931 | ||
932 | } | |
933 | close(NSLOOKUP); | |
934 | unlink("/tmp/expn$$"); | |
935 | unless ($nserver) { | |
936 | $0 = "$o0 - finished mxlookup"; | |
937 | return 0 unless $lastchance; | |
938 | &giveup('mx domainify',"$server: Could not resolve address"); | |
939 | return 0; | |
940 | } | |
941 | ||
942 | # provide fallbacks in case $nserver doesn't work out | |
943 | if (defined $fallback{$cpref}) { | |
944 | # for $u (@users) { | |
945 | # print "mx_secondary{$u *** $nserver} = ".$fallback{$cpref}."\n" | |
946 | # if $debug; | |
947 | # $mx_secondary{"$u *** $nserver"} = $fallback{$cpref}; | |
948 | # } | |
949 | $mx_secondary{$server} = $fallback{$cpref}; | |
950 | } | |
951 | ||
952 | $0 = "$av0 - gethostbyname($nserver)"; | |
953 | ($name,$aliases,$type,$len,$thataddr) = gethostbyname($nserver); | |
954 | ||
955 | unless ($thataddr) { | |
956 | $0 = $o0; | |
957 | return 0 unless $lastchance; | |
958 | &giveup('mx domainify',"$nserver: could not resolve address"); | |
959 | return 0; | |
960 | } | |
961 | print "MX($server) = $nserver\n" if $debug; | |
962 | print "$server -> $nserver\n" if $vw && !$debug; | |
963 | $mx{&trhost($server)} = $nserver; | |
964 | # redeploy the users | |
965 | unless (&mxredirect($server,*users)) { | |
966 | return 0 unless $lastchance; | |
967 | &giveup('mx domainify',"$nserver: only one level of mx redirect allowed"); | |
968 | return 0; | |
969 | } | |
970 | $0 = "$o0 - finished mxlookup"; | |
971 | return 1; | |
972 | } | |
973 | # if mx expansion did not help to resolve an address | |
974 | # (ie: foo@bar became @baz:foo@bar, then undo the | |
975 | # expansion). | |
976 | # this is only used by &final | |
977 | sub mxunroll | |
978 | { | |
979 | local(*host,*addr) = @_; | |
980 | local($r) = 0; | |
981 | print "looking for mxbacktrace{$addr *** $host}\n" | |
982 | if ($debug > 1); | |
983 | while (defined $mxbacktrace{"$addr *** $host"}) { | |
984 | print "Unrolling MX expnasion: \@$host:$addr -> " | |
985 | if ($debug || $verbose); | |
986 | $host = $mxbacktrace{"$addr *** $host"}; | |
987 | print "\@$host:$addr\n" | |
988 | if ($debug || $verbose); | |
989 | $r = 1; | |
990 | } | |
991 | return 1 if $r; | |
992 | $addr = "\@$host:$addr" | |
993 | if ($host =~ /\./); | |
994 | return 0; | |
995 | } | |
996 | # register a completed expnasion. Make the final address as | |
997 | # simple as possible. | |
998 | sub final | |
999 | { | |
1000 | local($addr,$host,$name,$error) = @_; | |
1001 | local($he); | |
1002 | local($hb,$hr); | |
1003 | local($au,$ah); | |
1004 | ||
1005 | if ($error =~ /Non-existent domain/) { | |
1006 | # | |
1007 | # If we created the domain, then let's undo the | |
1008 | # damage... | |
1009 | # | |
1010 | if (defined $create_host_backtrack{"$addr *** $host"}) { | |
1011 | while (defined $create_host_backtrack{"$addr *** $host"}) { | |
1012 | print "Un&domainifying($host) = " if $debug; | |
1013 | $host = $create_host_backtrack{"$addr *** $host"}; | |
1014 | print "$host\n" if $debug; | |
1015 | } | |
1016 | $error = "$host: could not locate"; | |
1017 | } else { | |
1018 | # | |
1019 | # If we only want valid addresses, toss out | |
1020 | # bad host names. | |
1021 | # | |
1022 | if ($valid) { | |
1023 | print STDERR "\@$host:$addr ($name) Non-existent domain\n"; | |
1024 | return ""; | |
1025 | } | |
1026 | } | |
1027 | } | |
1028 | ||
1029 | MXUNWIND: { | |
1030 | $0 = "$av0 - final parsing of \@$host:$addr"; | |
1031 | ($he = $host) =~ s/(\W)/\\$1/g; | |
1032 | if ($addr !~ /@/) { | |
1033 | # addr does not contain any host | |
1034 | $addr = "$addr@$host"; | |
1035 | } elsif ($addr !~ /$he/i) { | |
1036 | # if host part really something else, use the something | |
1037 | # else. | |
1038 | if ($addr =~ m/(.*)\@([^\@]+)$/) { | |
1039 | ($au,$ah) = ($1,$2); | |
1040 | print "au = $au ah = $ah\n" if $debug; | |
1041 | if (defined $temporary_redirect{"$addr *** $ah"}) { | |
1042 | $addr = "$au\@".$temporary_redirect{"$addr *** $ah"}; | |
1043 | print "Rewrite! to $addr\n" if $debug; | |
1044 | next MXUNWIND; | |
1045 | } | |
1046 | } | |
1047 | # addr does not contain full host | |
1048 | if ($valid) { | |
1049 | if ($host =~ /^([^\.]+)(\..+)$/) { | |
1050 | # host part has a . in it - foo.bar | |
1051 | ($hb, $hr) = ($1, $2); | |
1052 | if ($addr =~ /\@([^\.\@]+)$/ && ($1 eq $hb)) { | |
1053 | # addr part has not . | |
1054 | # and matches beginning of | |
1055 | # host part -- tack on a | |
1056 | # domain name. | |
1057 | $addr .= $hr; | |
1058 | } else { | |
1059 | &mxunroll(*host,*addr) | |
1060 | && redo MXUNWIND; | |
1061 | } | |
1062 | } else { | |
1063 | &mxunroll(*host,*addr) | |
1064 | && redo MXUNWIND; | |
1065 | } | |
1066 | } else { | |
1067 | $addr = "${addr}[\@$host]" | |
1068 | if ($host =~ /\./); | |
1069 | } | |
1070 | } | |
1071 | } | |
1072 | $name = "$name " if $name; | |
1073 | $error = " $error" if $error; | |
1074 | if ($valid) { | |
1075 | push(@final,"$name<$addr>"); | |
1076 | } else { | |
1077 | push(@final,"$name<$addr>$error"); | |
1078 | } | |
1079 | "\t$name<$addr>$error\n"; | |
1080 | } | |
1081 | # read the rest of the current smtp daemon's responce (and toss it away) | |
1082 | sub toss | |
1083 | { | |
1084 | local($done) = @_; | |
1085 | print $s if $watch; | |
1086 | while(($done eq "-") && ($s = <S>) && ($s =~ /^\d+([- ])/)) { | |
1087 | print $s if $watch; | |
1088 | $done = $1; | |
1089 | } | |
1090 | } | |
1091 | # print args if verbose. Return them in any case | |
1092 | sub verbose | |
1093 | { | |
1094 | local(@tp) = @_; | |
1095 | print "@tp" if $verbose; | |
1096 | } | |
1097 | # to pass perl -w: | |
1098 | @tp; | |
1099 | $flag_a; | |
1100 | $flag_d; | |
1101 | $flag_1; | |
1102 | %already_domainify_fellback; | |
1103 | %already_mx_fellback; | |
1104 | ################### BEGIN PERL/TROFF TRANSITION | |
1105 | .00; | |
1106 | ||
1107 | 'di \\ " finish diversion--previous line must be blank | |
1108 | .nr nl 0-1 \\ " fake up transition to first page again | |
1109 | .nr % 0 \\ " start at page 1 | |
1110 | '; __END__ | |
1111 | .\" ############### END PERL/TROFF TRANSITION | |
1112 | .TH EXPN 1 "March 11, 1993" | |
1113 | .AT 3 | |
1114 | .SH NAME | |
1115 | expn \- recursively expand mail aliases | |
1116 | .SH SYNOPSIS | |
1117 | .B expn | |
1118 | .RI [ -a ] | |
1119 | .RI [ -v ] | |
1120 | .RI [ -w ] | |
1121 | .RI [ -d ] | |
1122 | .IR user [@ hostname ] | |
1123 | .RI [ user [@ hostname ]]... | |
1124 | .SH DESCRIPTION | |
1125 | .B expn | |
1126 | will use the SMTP | |
1127 | .B expn | |
1128 | and | |
1129 | .B vrfy | |
1130 | commands to expand mail aliases. | |
1131 | It will first look up the addresses you provide on the command line. | |
1132 | If those expand into addresses on other systems, it will | |
1133 | connect to the other systems and expand again. It will keep | |
1134 | doing this until no further expansion is possible. | |
1135 | .SH OPTIONS | |
1136 | The default output of | |
1137 | .B expn | |
1138 | can contain many lines which are not valid | |
1139 | email addresses. With the | |
1140 | .I -aa | |
1141 | flag, only expansions that result in legal addresses | |
1142 | are used. Since many mailing lists have an illegal | |
1143 | address or two, the single | |
1144 | .IR -a , | |
1145 | address, flag specifies that a few illegal addresses can | |
1146 | be mixed into the results. More | |
1147 | .I -a | |
1148 | flags vary the ratio. Read the source to track down | |
1149 | the formula. With the | |
1150 | .I -a | |
1151 | option, you should be able to construct a new mailing | |
1152 | list out of an existing one. | |
1153 | .LP | |
1154 | If you wish to limit the number of levels deep that | |
1155 | .B expn | |
1156 | will recurse as it traces addresses, use the | |
1157 | .I -1 | |
1158 | option. For each | |
1159 | .I -1 | |
1160 | another level will be traversed. So, | |
1161 | .I -111 | |
1162 | will traverse no more than three levels deep. | |
1163 | .LP | |
1164 | The normal mode of operation for | |
1165 | .B expn | |
1166 | is to do all of its work silently. | |
1167 | The following options make it more verbose. | |
1168 | It is not necessary to make it verbose to see what it is | |
1169 | doing because as it works, it changes its | |
1170 | .BR argv [0] | |
1171 | variable to reflect its current activity. | |
1172 | To see how it is expanding things, the | |
1173 | .IR -v , | |
1174 | verbose, flag will cause | |
1175 | .B expn | |
1176 | to show each address before | |
1177 | and after translation as it works. | |
1178 | The | |
1179 | .IR -w , | |
1180 | watch, flag will cause | |
1181 | .B expn | |
1182 | to show you its conversations with the mail daemons. | |
1183 | Finally, the | |
1184 | .IR -d , | |
1185 | debug, flag will expose many of the inner workings so that | |
1186 | it is possible to eliminate bugs. | |
1187 | .SH ENVIRONMENT | |
1188 | No enviroment variables are used. | |
1189 | .SH FILES | |
1190 | .PD 0 | |
1191 | .B /tmp/expn$$ | |
1192 | .B temporary file used as input to | |
1193 | .BR nslookup . | |
1194 | .SH SEE ALSO | |
1195 | .BR aliases (5), | |
1196 | .BR sendmail (8), | |
1197 | .BR nslookup (8), | |
1198 | RFC 823, and RFC 1123. | |
1199 | .SH BUGS | |
1200 | Not all mail daemons will implement | |
1201 | .B expn | |
1202 | or | |
1203 | .BR vrfy . | |
1204 | It is not possible to verify addresses that are served | |
1205 | by such daemons. | |
1206 | .LP | |
1207 | When attempting to connect to a system to verify an address, | |
1208 | .B expn | |
1209 | only tries one IP address. Most mail daemons | |
1210 | will try harder. | |
1211 | .LP | |
1212 | It is assumed that you are running domain names and that | |
1213 | the | |
1214 | .BR nslookup (8) | |
1215 | program is available. If not, | |
1216 | .B expn | |
1217 | will not be able to verify many addresses. It will also pause | |
1218 | for a long time unless you change the code where it says | |
1219 | .I $have_nslookup = 1 | |
1220 | to read | |
1221 | .I $have_nslookup = | |
1222 | .IR 0 . | |
1223 | .LP | |
1224 | Lastly, | |
1225 | .B expn | |
1226 | does not handle every valid address. If you have an example, | |
1227 | please submit a bug report. | |
1228 | .SH CREDITS | |
1229 | In 1986 or so, Jon Broome wrote a program of the same name | |
1230 | that did about the same thing. It has since suffered bit rot | |
1231 | and Jon Broome has dropped off the face of the earth! | |
1232 | (Jon, if you are out there, drop me a line) | |
1233 | .SH AVAILABILITY | |
1234 | The latest version of | |
1235 | .B expn | |
1236 | is available through anonymous ftp to | |
1237 | .IR idiom.berkeley.ca.us . | |
1238 | .SH AUTHOR | |
1239 | .I David Muir Sharnoff\ \ \ \ <muir@idiom.berkeley.ca.us> |