[Mimedefang] filter_before
Jonas Eckerman
jonas_lists at frukt.org
Thu Oct 23 06:05:35 EDT 2008
Jonas Eckerman wrote:
> I think I'll put in a check for $TerminateAndDiscard as well (so that we
> can restream before parsing as well), and then I'll start using it here
> (should be within the next couple of days).
Been running with filter_before here for a couple of days now. It
now checks $TerminateAndDiscard so that restreaming can be done
before parsing the mail as well.
It seems to work. Patches attached. I hope the man page patch
isn't too bad (it was done quickly).
Regards
/Jonas
--
Jonas Eckerman, FSDB & Fruktträdet
http://whatever.frukt.org/
http://www.fsdb.org/
http://www.frukt.org/
-------------- next part --------------
--- mimedefang.pl Fri Aug 15 20:03:41 2008
+++ mimedefang.pl.data Mon Oct 20 17:41:08 2008
@@ -5517,10 +5517,32 @@
if (!open(RESULTS, ">RESULTS")) {
fatal("$MsgID: Could not open RESULTS file: $!");
return -1;
}
+ # Call pre-pre-scan filter if defined
+ if (defined(&filter_before)) {
+ push_status_tag("In filter_before");
+ filter_before();
+ pop_status_tag();
+ # Have we allreeady decided to reject or discard?
+ if (message_rejected()) {
+ md_syslog('debug', "$MsgID: filter_before rejected or discarded.");
+ signal_unchanged();
+ signal_complete();
+ return 0;
+ }
+ # If stream_by_domain tells us to discard, do so...
+ if ($TerminateAndDiscard) {
+ write_result_line("D", "");
+ signal_unchanged();
+ md_syslog('debug', "$MsgID: filter_before set TerminateAndDiscard flag.");
+ signal_complete();
+ return 0;
+ }
+ }
+
my $entity;
my $parser;
if (defined(&filter_create_parser)) {
$parser = filter_create_parser();
if (!defined($parser) ||
-------------- next part --------------
--- mimedefang-filter.5.in Fri Aug 15 20:03:41 2008
+++ mimedefang-filter.5.in.data Tue Oct 21 13:20:44 2008
@@ -19,16 +19,21 @@
directory and the e-mail message is split into parts in this directory.
Each part is represented internally as an instance of MIME::Entity.
.PP
2) If the file \fB at CONFDIR_EVAL@/mimedefang-filter.pl\fR defines a
+Perl function called \fBfilter_before\fR, it is called before an
+e-mail is parsed. Any return value is ignored.
+
+.PP
+3) If the file \fB at CONFDIR_EVAL@/mimedefang-filter.pl\fR defines a
Perl function called \fBfilter_begin\fR, it is called with a single
argument consisting of a MIME::Entity representing the parsed e-mail
message. Any return value is ignored.
.PP
-3) For each \fIleaf\fR part of the mail message, \fBfilter\fR is
+4) For each \fIleaf\fR part of the mail message, \fBfilter\fR is
called with four arguments: \fBentity\fR, a MIME::Entity object;
\fBfname\fR, the suggested filename taken from the MIME
Content-Disposition header; \fBext\fR, the file extension, and
\fBtype\fR, the MIME Content-Type value. For each \fInon-leaf\fR
part of the mail message, \fBfilter_multipart\fR is called with the
@@ -44,11 +49,11 @@
Note that both \fBfilter\fR and \fBfilter_multipart\fR are optional.
If you do not define them, a default function that simply accepts each
part is used.
.PP
-4) After all parts have been processed, the function \fBfilter_end\fR
+5) After all parts have been processed, the function \fBfilter_end\fR
is called if it has been defined. It is passed a single argument consisting
of the (possibly modified) MIME::Entity object representing the message
about to be delivered.
.SH DISPOSITION
@@ -694,12 +699,12 @@
.SH GLOBAL VARIABLES SET BY MIMEDEFANG.PL
The following global variables are set by \fBmimedefang.pl\fR and are
available for use in your filter. All of these variables are always
-available to filter_begin, filter, filter_multipart and filter_end.
-In addition, some of them are available in \fBfilter_relay\fR,
+available to filter_before, filter_begin, filter, filter_multipart and
+filter_end. In addition, some of them are available in \fBfilter_relay\fR,
\fBfilter_sender\fR or \fBfilter_recipient\fR. If this is the case,
it will be noted below.
.TP
.B %Features
@@ -1327,11 +1332,11 @@
directory is created and its pathname returned.
.TP
.B change_sender($sender)
This function changes the envelope sender to $sender. It can only
-be called from \fBfilter_begin\fR or any later function. Please note
+be called from \fBfilter_before\fR or any later function. Please note
that this function is \fIonly\fR supported with Sendmail/Milter 8.14.0
or newer. It has \fIno effect\fR if you're running older versions.
.TP
.B add_recipient($recip)
@@ -1405,11 +1410,11 @@
.B stream_by_domain()
\fIDo not use this function unless you have Sendmail 8.12 and locally-
submitted e-mail is submitted using SMTP.\fR
This function should \fIonly\fR be called at the very beginning of
-filter_begin(), like this:
+filter_before() or filter_begin(), like this:
.nf
sub filter_begin {
if (stream_by_domain()) {
return;
@@ -1462,11 +1467,11 @@
.B stream_by_recipient()
\fIDo not use this function unless you have Sendmail 8.12 and locally-
submitted e-mail is submitted using SMTP.\fR
This function should \fIonly\fR be called at the very beginning of
-filter_begin(), like this:
+filter_before() or filter_begin(), like this:
.nf
sub filter_begin {
if (stream_by_recipient()) {
return;
@@ -1993,12 +1998,12 @@
If you invoked \fBmimedefang\fR with the \fB\-t\fR option and have
defined a filter_recipient routine, it is called.
.TP
.B 5. END OF SMTP DATA
-filter_begin is called. For each MIME part, filter is called. Then
-filter_end is called.
+filter_before is called. filter_begin is called. For each MIME part,
+filter is called. Then filter_end is called.
.SH PRESERVING RELAY INFORMATION
.PP
Most organizations have more than one machine handling internet
@@ -2043,11 +2048,11 @@
When the secondary MX hosts relay to the primary MX host, $RelayAddr
and $RelayHostname will be set based on the IP validation header. If
MIMEDefang notices this header, it sets the global variable $WasResent
to 1. Since you don't want to trust the header unless it was set by
one of your secondary MX hosts, you should put this code in
-filter_begin:
+filter_before:
.nf
if ($WasResent) {
if ($RealRelayAddr ne "ip.of.secondary.mx" and
$RealRelayAddr ne "ip.of.tertiary.mx") {
@@ -2094,10 +2099,14 @@
Not guaranteed to be available to any other function, not even
from one filter_recipient call to the next, when receiving a
multi-recipient email message.
.TP
+.B In filter_before
+Available to filter_before, filter_begin, filter and filter_end
+
+.TP
.B In filter_begin
Available to filter_begin, filter and filter_end
.TP
.B In filter
@@ -2107,13 +2116,13 @@
.B In filter_end
Available within filter_end
.PP
The "built-in" globals like $Subject, $Sender, etc. are always available
-to filter_begin, filter and filter_end. Some are available to filter_relay,
-filter_sender or filter_recipient, but you should check the documentation
-of the variable above for details.
+to filter_before, filter_begin, filter and filter_end. Some are available to
+filter_relay, filter_sender or filter_recipient, but you should check the
+documentation of the variable above for details.
.SH MAINTAINING STATE
.PP
There are four basic groups of filtering functions:
@@ -2130,11 +2139,11 @@
.B 3
filter_recipient
.TP
.B 4
-filter_begin, filter, filter_multipart, filter_end
+filter_before, filter_begin, filter, filter_multipart, filter_end
.PP
In general, for a given mail message, these groups of functions may
be called in completely different Perl processes. Thus, there is
\fIno way\fR to maintain state inside Perl between groups of functions.
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