hangup-greylist(1)

1HANGUP-GREYLIST(1)                   NCID                   HANGUP-GREYLIST(1)
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NAME

6       hangup-greylist
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SYNOPSIS

9       hangup-greylist [-h]
10       hangup-greylist [-v] <string>
11
12       where string is in this format:
13       "*DATE*<mmddyyyy>*TIME*<hhmm>*LINE*<lineid>\
14       *NMBR*<number>*NAME*<name>*MODE*<hupmode>\
15       *FNMBR*<formatted number>*NTYPE*<type of device>\
16       *CTRY*<country code>*LOCA*<location>*CARI*<carrier>\
17       *NAME*<name>*
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DESCRIPTION

20       hangup-greylist  blocks  most  robocalls by requiring an unknown caller
21       hang up and call again from the same number.  The  assumption  is  that
22       automated calls will be unlikely to call back.
23
24       Script is not called if caller number or name is in ncidd.whitelist.
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26       Callers from unknown numbers will optionally have a recording played to
27       them after which ncidd hangs up. If using  a  recording,  a  customized
28       recording should be provided by the user and should instruct the caller
29       to call again from the same number within the user-defined time  limit.
30       Hupmode  3 is required for the recording to be played. If Hupmode is 1,
31       ncidd will hang up without playing a recording.  If Hupmode is  2,  the
32       extension will abort and allow the call.
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34       The goal is to encourage a human caller to call again. Hupmode 1 causes
35       an immediate hangup and the caller may just assume there was a  problem
36       and  call right back. Hupmode 3 uses a recording to give the caller ex‐
37       plicit instructions.  Hupmode 2 would play a FAX tone. This is not  ap‐
38       propriate  for  greylisting  as it would make the caller think they had
39       the wrong  number.   hangup-greylist  adds  the  unknown  number  to  a
40       "greylist" file along with an expiration time.
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42       Incoming  calls  from  numbers that are in the greylist are accepted if
43       the expiration time has not been reached. The expiration  time  may  be
44       optionally extended each time a call is accepted. An incoming call from
45       a number in the list where the expiration  time  has  been  reached  is
46       treated as an unknown call.
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48       Entries  in the greylist file with expired time limits are removed from
49       the file whenever a call is processed. The user should occasionally re‐
50       view  the  greylist  file and add numbers to the whitelist or blacklist
51       files as appropriate.  ncidd does not call this script  if  the  caller
52       number or name is in ncidd.whitelist.
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54       Server  hangup  extensions are only executed by the server unless test‐
55       ing.
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OPTIONS

58       -h     show help message
59
60       -v     turn on verbose and send additional data  to  STDOUT  for  trou‐
61              bleshooting
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REQUIREMENTS

64       Set hupname to the name of this script ncidd.conf.
65       Set hupmode to 1, 2 or 3 in ncidd.conf.
66       Set huprmd to a unique voice file in ncidd.conf, if hupmode set to 3.
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FILES

69       /usr/share/ncid/extensions/hangup-greylist
70       /usr/share/ncid/recording/*.rmd
71       /etc/ncid/ncidd.conf
72       /etc/ncid/ncidd.whitelist
73       /var/cache/ncid/ncidd.greylist
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NAME

SYNOPSIS

DESCRIPTION

OPTIONS

REQUIREMENTS

FILES

SEE ALSO