| Current File : //usr/local/share/man/man3/Mail::DKIM::DNS.3 |
.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.30)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings. \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote. \*(C+ will
.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
. ds -- \(*W-
. ds PI pi
. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
. ds L" ""
. ds R" ""
. ds C` ""
. ds C' ""
'br\}
.el\{\
. ds -- \|\(em\|
. ds PI \(*p
. ds L" ``
. ds R" ''
. ds C`
. ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD. Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{
. if \nF \{
. de IX
. tm Index:\\$1\t\\n%\t"\\$2"
..
. if !\nF==2 \{
. nr % 0
. nr F 2
. \}
. \}
.\}
.rr rF
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff
.if n \{\
. ds #H 0
. ds #V .8m
. ds #F .3m
. ds #[ \f1
. ds #] \fP
.\}
.if t \{\
. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
. ds #V .6m
. ds #F 0
. ds #[ \&
. ds #] \&
.\}
. \" simple accents for nroff and troff
.if n \{\
. ds ' \&
. ds ` \&
. ds ^ \&
. ds , \&
. ds ~ ~
. ds /
.\}
.if t \{\
. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
. \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
. \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
. \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
. ds : e
. ds 8 ss
. ds o a
. ds d- d\h'-1'\(ga
. ds D- D\h'-1'\(hy
. ds th \o'bp'
. ds Th \o'LP'
. ds ae ae
. ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "Mail::DKIM::DNS 3"
.TH Mail::DKIM::DNS 3 "2013-02-08" "perl v5.20.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
Mail::DKIM::DNS \- performs DNS queries for Mail::DKIM
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This is the module that performs \s-1DNS\s0 queries for Mail::DKIM.
.SH "CONFIGURATION"
.IX Header "CONFIGURATION"
This module has a couple configuration settings that the caller
may want to use to customize the behavior of this module.
.ie n .SS "$Mail::DKIM::DNS::TIMEOUT"
.el .SS "\f(CW$Mail::DKIM::DNS::TIMEOUT\fP"
.IX Subsection "$Mail::DKIM::DNS::TIMEOUT"
This global variable specifies the maximum amount of time (in seconds)
to wait for a single \s-1DNS\s0 query to complete. The default is 10.
.SS "\fIMail::DKIM::DNS::resolver()\fP"
.IX Subsection "Mail::DKIM::DNS::resolver()"
Use this global subroutine to get or replace the instance of
Net::DNS::Resolver that Mail::DKIM uses. If set to undef (the default),
then a brand new default instance of Net::DNS::Resolver will be
created the first time a \s-1DNS\s0 query is needed.
.PP
You will call this subroutine if you want to specify non-default options
to Net::DNS::Resolver, such as different timeouts, or to enable use
of a persistent socket. For example:
.PP
.Vb 6
\& # first, construct a custom DNS resolver
\& my $res = Net::DNS::Resolver\->new(
\& udp_timeout => 3, tcp_timeout => 3, retry => 2,
\& );
\& $res\->udppacketsize(1240);
\& $res\->persistent_udp(1);
\&
\& # then, tell Mail::DKIM to use this resolver
\& Mail::DKIM::DNS::resolver($res);
.Ve
.SS "\fIMail::DKIM::DNS::enable_EDNS0()\fP"
.IX Subsection "Mail::DKIM::DNS::enable_EDNS0()"
This is a convenience subroutine that will construct an appropriate \s-1DNS\s0
resolver that uses \s-1EDNS0 \s0(Extension mechanisms for \s-1DNS\s0) to support large
\&\s-1DNS\s0 replies, and configure Mail::DKIM to use it. (As such, it should \s-1NOT\s0
be used in conjunction with the \fIresolver()\fR subroutine described above.)
.PP
.Vb 1
\& Mail::DKIM::DNS::enable_EDNS0();
.Ve
.PP
Use of \s-1EDNS0\s0 is recommended, since it reduces the need for falling back to \s-1TCP\s0
when dealing with large \s-1DNS\s0 packets. However, it is not enabled by default
because some Internet firewalls which do deep inspection of packets are not able
to process EDNS0\-enabled packets. When there is a firewall on a path to a \s-1DNS\s0
resolver, the \s-1EDNS0\s0 feature should be specifically tested before enabling.
.SH "AUTHOR"
.IX Header "AUTHOR"
Jason Long, <jlong@messiah.edu>
.SH "COPYRIGHT AND LICENSE"
.IX Header "COPYRIGHT AND LICENSE"
Copyright (C) 2006\-2007, 2012\-2013 by Messiah College
.PP
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.6 or,
at your option, any later version of Perl 5 you may have available.