Access to Request Body

[Tim Gustafson <tj...@soe.ucsc.edu>]

Hello,

I'm writing a mod_perl logging module, and I can't seem to find anywhere in
the documentation that talks about how I can access the request body
(basically, the POST data) of a request during the logging phase.  Is this
not possible?

I'm using mod_perl 2.0 and Apache 2.2 on a CentOS 5.1 box.

Thanks! 

Tim Gustafson
SOE Webmaster
UC Santa Cruz
tjg@soe.ucsc.edu
(831) 459-5354

Re: Access to Request Body

[Torsten Foertsch <to...@gmx.net>]

On Mon 28 Apr 2008, Tim Gustafson wrote:
> I'm writing a mod_perl logging module, and I can't seem to find anywhere in
> the documentation that talks about how I can access the request body
> (basically, the POST data) of a request during the logging phase.  Is this
> not possible?

It is but you'd have to use an input filter. Something like this:

use Apache2::Const -compile=>qw/M_POST OK/;
use APR::Const -compile=>qw/SUCCESS/;
use Apache2::Filter ();
use APR::Bucket ();
use APR::Brigade ();

if( $r->method_number==Apache2::Const::M_POST ) {
  my @content;
  my $cl=0;
  my $rc=$r->add_input_filter( sub {
    my ($f, $bb, $mode, $block, $readbytes) = @_;

    my $rv = $f->next->get_brigade($bb, $mode, $block, $readbytes);
    return $rv unless $rv == APR::Const::SUCCESS;

    for (my $b = $bb->first; $b; $b = $bb->next($b)) {
      $b->read(my $bdata);
      $cl+=length $bdata;
      push @content, $bdata;
    }

    return Apache2::Const::OK;
  } );
  $r->discard_request_body;
  $r->pnotes->{rbody}=\@content;
  $r->pnotes->{rbody_length}=$cl;
}

Remember this is just an example not production code. For production you'd 
want to put the data chunks into a temporary file / files. This way you'll 
get the request body stripped of all transfer-encoding.

Torsten

--
Need professional mod_perl support?
Just hire me: torsten.foertsch@gmx.net

RE: Access to Request Body

[ad...@utoronto.ca]

Quoting Tim Gustafson <tj...@soe.ucsc.edu>:

> Hrmm, that doesn't seem to work.  In my code, I have:
>
> print $fh $r->body . "\n";
>
> And in my error log, I get:
>
> Can't locate object method "body" via package "Apache2::RequestRec" at
> /var/www/lib/Log.pm line 31.

It's part of Apache2::Request, see the documentation below

http://httpd.apache.org/apreq/docs/libapreq2/group__apreq__xs__request.html#body

It gives you access to the content through an APR::Table derived  
class, so you can do stuff like:

my $name = $r->body("name");

or

my $table = $r->body();

It doesn't give you access to the whole, unaltered POST data (afaik).

Adam

RE: Access to Request Body

[Tim Gustafson <tj...@soe.ucsc.edu>]

Hrmm, that doesn't seem to work.  In my code, I have:

print $fh $r->body . "\n";

And in my error log, I get:

Can't locate object method "body" via package "Apache2::RequestRec" at
/var/www/lib/Log.pm line 31. 

Tim Gustafson
SOE Webmaster
UC Santa Cruz
tjg@soe.ucsc.edu
(831) 459-5354


-----Original Message-----
From: adam.prime@utoronto.ca [mailto:adam.prime@utoronto.ca] 
Sent: Monday, April 28, 2008 1:47 PM
To: modperl@perl.apache.org
Subject: Re: Access to Request Body

Quoting Tim Gustafson <tj...@soe.ucsc.edu>:

> Hello,
>
> I'm writing a mod_perl logging module, and I can't seem to find anywhere
in
> the documentation that talks about how I can access the request body
> (basically, the POST data) of a request during the logging phase.  Is this
> not possible?

do you want access to the unmodified post data, or do you want access  
to the content?  Apache2::Request parses the POST data, and makes it  
available though $r->body.  (and possibly $r->upload) If you want the  
unparsed body, i'm not sure what you'd have to do offhand.

Adam

Re: Access to Request Body

[ad...@utoronto.ca]

Quoting Tim Gustafson <tj...@soe.ucsc.edu>:

> Hello,
>
> I'm writing a mod_perl logging module, and I can't seem to find anywhere in
> the documentation that talks about how I can access the request body
> (basically, the POST data) of a request during the logging phase.  Is this
> not possible?

do you want access to the unmodified post data, or do you want access  
to the content?  Apache2::Request parses the POST data, and makes it  
available though $r->body.  (and possibly $r->upload) If you want the  
unparsed body, i'm not sure what you'd have to do offhand.

Adam