Proxied output is corrupted by extraneous numbers

Hello,

While preparing to upgrade our production servers, I encountered
a problem that may involve mod_proxy code. When html code is
generated and printed by our mod_perl handler initiated directly
from the back end the output is correct. When the same operation
is initiated via the front end proxy server the output is corrupted
by extraneous numbers. I have set up a test scenario to isolate
the problem. Our new server configurations include this software:

Front End Back End
--------- --------
kernel-2.4.9-31 kernel-2.4.9-31
apache_1.3.24 apache_1.3.24
mod_ssl-2.8.8-1.3.24 mod_perl-1.26
openssl-0.9.6c
mm-1.1.3

The front end apache configuration includes:


ServerName gelco5.yvod.com
DocumentRoot /www/gelcompany/html

RewriteEngine On
RewriteLogLevel 9
RewriteOptions 'inherit'

RewriteRule ^/$ http://192.168.20.111:8089/ [proxy,last]

RewriteRule ^/(.+)$ /www/gelcompany/html/$1 [last]


The back end apache configuration includes:

NameVirtualHost 192.168.20.111:8089
Listen 8089

ServerName gelco5.yvod.com
DocumentRoot /www/gelcompany/html

Alias / /www/gelcompany/modperl


SetHandler perl-script
PerlHandler YVOD::welcome



The test handler code looks like this:

#!/usr/bin/perl -w -d
package YVOD::welcome;
use strict;

sub handler{
my $r = shift;
$r->send_http_header('text/html');
print qq|\n|;
print "You are Welcome at ", $r->get_remote_host, "

\n";
while (my ($key, $val) = each %ENV) {
print "$key = $val
\n"; }
print "";
return 1;
}
1;

The outout source looks like this when initiated directly from the
back end (http://192.168.20.111:8089/):


You are Welcome at 192.168.20.98


QUERY_STRING =

HTTP_ACCEPT_LANGUAGE = en

TZ = PST8PDT

REMOTE_PORT = 3201

HTTP_USER_AGENT = Mozilla/4.76 [en] (X11; U; Linux 2.2.14-5.0 i686)

HTTP_ACCEPT = image/gif, image/x-xbitmap, image/jpeg, image/pjpeg,
image/png, */*

HTTP_HOST = 192.168.20.111:8089

GATEWAY_INTERFACE = CGI-Perl/1.1

SCRIPT_NAME = /

SERVER_NAME = gelco5.yvod.com

HTTP_ACCEPT_ENCODING = gzip

MOD_PERL = mod_perl/1.26

HTTP_ACCEPT_CHARSET = iso-8859-1,*,utf-8

HTTP_COOKIE = YVOD_SESSION_ID=2e4046b477f9374f

SCRIPT_FILENAME = /www/gelcompany/modperl

PATH = /bin:/usr/bin

SERVER_ADDR = 192.168.20.111

MOD_PERL_TRACE = all

SERVER_PROTOCOL = HTTP/1.0

HTTP_CONNECTION = Keep-Alive

SERVER_SIGNATURE =

Re: Proxied output is corrupted by extraneous numbers

This is a cryptographically signed message in MIME format.

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Content-Transfer-Encoding: 7bit

"Michael E. Lewis" wrote:

> While preparing to upgrade our production servers, I encountered
> a problem that may involve mod_proxy code.

This is a known bug, which is fixed in v1.3.25-dev.

What Apache is doing is not dechunking incoming requests properly.
"chunking" refers to a special encoding that allows an HTTP client to
know how much to download from the server without there having to be a
valid Content-Length on the request. The numbers you see are the
"lengths" within the protocol, which are supposed to be stripped out.

There should be a release of 1.2.25 shortly, which will fix this
problem.

Regards,
Graham
--
-----------------------------------------
minfrin@sharp.fm "There's a moon
over Bourbon Street
tonight..."
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RE : Proxied output is corrupted by extraneous numbers

HI,
I think the HTML page you create via the front end proxy server is =
serving using chunked encoding (new support for HTTP/1.1 for mod_proxy =
since 1.3.23).

Gael



> -----Message d'origine-----
> De : Michael E. Lewis [mailto:mlewis@comprehend.com]=20
> Envoy=E9 : vendredi 3 mai 2002 13:24
> =C0 : modproxy-dev@apache.org
> Objet : Proxied output is corrupted by extraneous numbers
>=20
>=20
> Hello,
>=20
> While preparing to upgrade our production servers, I=20
> encountered a problem that may involve mod_proxy code. When=20
> html code is generated and printed by our mod_perl handler=20
> initiated directly from the back end the output is correct. =20
> When the same operation is initiated via the front end proxy=20
> server the output is corrupted by extraneous numbers. I have=20
> set up a test scenario to isolate the problem. Our new=20
> server configurations include this software:
>=20
> Front End Back End
> --------- --------
> kernel-2.4.9-31 kernel-2.4.9-31
> apache_1.3.24 apache_1.3.24
> mod_ssl-2.8.8-1.3.24 mod_perl-1.26
> openssl-0.9.6c
> mm-1.1.3
>=20
> The front end apache configuration includes:
>=20
>
> ServerName gelco5.yvod.com
> DocumentRoot /www/gelcompany/html
>=20
> RewriteEngine On
> RewriteLogLevel 9
> RewriteOptions 'inherit'
>=20
> RewriteRule ^/$ http://192.168.20.111:8089/ [proxy,last]
>=20
> RewriteRule ^/(.+)$ /www/gelcompany/html/$1 [last]
>
>=20
> The back end apache configuration includes:
>=20
> NameVirtualHost 192.168.20.111:8089
> Listen 8089
>
> ServerName gelco5.yvod.com
> DocumentRoot /www/gelcompany/html
>=20
> Alias / /www/gelcompany/modperl
>=20
>
> SetHandler perl-script
> PerlHandler YVOD::welcome
>
>
>=20
> The test handler code looks like this:
>=20
> #!/usr/bin/perl -w -d
> package YVOD::welcome;
> use strict;
>=20
> sub handler{
> my $r =3D shift;
> $r->send_http_header('text/html');
> print qq|\n|;
> print "You are Welcome at ", $r->get_remote_host,=20
> "

\n";
> while (my ($key, $val) =3D each %ENV) {
> print "$key =3D $val
\n"; }
> print "";
> return 1;
> }
> 1;
>=20
> The outout source looks like this when initiated directly=20
> from the back end (http://192.168.20.111:8089/):
>=20
>
> You are Welcome at 192.168.20.98


> QUERY_STRING =3D

> HTTP_ACCEPT_LANGUAGE =3D en

> TZ =3D PST8PDT

> REMOTE_PORT =3D 3201

> HTTP_USER_AGENT =3D Mozilla/4.76 [en] (X11; U; Linux=20
> 2.2.14-5.0 i686)

> HTTP_ACCEPT =3D image/gif, image/x-xbitmap, image/jpeg,=20
> image/pjpeg, image/png, */*

> HTTP_HOST =3D 192.168.20.111:8089

> GATEWAY_INTERFACE =3D CGI-Perl/1.1

> SCRIPT_NAME =3D /

> SERVER_NAME =3D gelco5.yvod.com

> HTTP_ACCEPT_ENCODING =3D gzip

> MOD_PERL =3D mod_perl/1.26

> HTTP_ACCEPT_CHARSET =3D iso-8859-1,*,utf-8

> HTTP_COOKIE =3D YVOD_SESSION_ID=3D2e4046b477f9374f

> SCRIPT_FILENAME =3D /www/gelcompany/modperl

> PATH =3D /bin:/usr/bin

> SERVER_ADDR =3D 192.168.20.111

> MOD_PERL_TRACE =3D all

> SERVER_PROTOCOL =3D HTTP/1.0

> HTTP_CONNECTION =3D Keep-Alive

> SERVER_SIGNATURE =3D

Re: Proxied output is corrupted by extraneous numbers - WAS: proxy for HTTP 1.0 clients

I should have dug a little deeper into the archives.

Go to this URL: http://www.apache.org/mail/modproxy-dev/200204.gz
And search for: proxy for HTTP 1.0 clients


Graham Leggett wrote: (on 05/03/2002)
>
> This problem is fixed in v1.3.25-dev in CVS - I've asked that a new
> release of Apache be made, which should be ready in about a week or so
> (according to the release manager...).
>
> In the mean time, the latest CVS version of apache will solve the
> problem.

And: (on 04/10/2002)
> The 1.3.24 proxy did not know how to dechunk incoming responses from
> HTTP/1.1 servers, which meant the chunked encoding was being sent as is
> to the client. If the client was HTTP/1.1 it didn't complain, but
> obviously HTTP/1.0 clients have a problem. Now the proxy dechunks
> incoming chunked responses as required by RFC2616.


"Michael E. Lewis" wrote:
>
> While preparing to upgrade our production servers, I encountered
> a problem that may involve mod_proxy code. When html code is
> generated and printed by our mod_perl handler initiated directly
> from the back end the output is correct. When the same operation
> is initiated via the front end proxy server the output is corrupted
> by extraneous numbers. I have set up a test scenario to isolate
> the problem. Our new server configurations include this software:
>
> Front End Back End
> --------- --------
> kernel-2.4.9-31 kernel-2.4.9-31
> apache_1.3.24 apache_1.3.24
> mod_ssl-2.8.8-1.3.24 mod_perl-1.26
> openssl-0.9.6c
> mm-1.1.3
>
> The front end apache configuration includes:
>
>
> ServerName gelco5.yvod.com
> DocumentRoot /www/gelcompany/html
>
> RewriteEngine On
> RewriteLogLevel 9
> RewriteOptions 'inherit'
>
> RewriteRule ^/$ http://192.168.20.111:8089/ [proxy,last]
>
> RewriteRule ^/(.+)$ /www/gelcompany/html/$1 [last]
>
>
> The back end apache configuration includes:
>
> NameVirtualHost 192.168.20.111:8089
> Listen 8089
>
> ServerName gelco5.yvod.com
> DocumentRoot /www/gelcompany/html
>
> Alias / /www/gelcompany/modperl
>
>
> SetHandler perl-script
> PerlHandler YVOD::welcome
>
>
>
> The test handler code looks like this:
>
> #!/usr/bin/perl -w -d
> package YVOD::welcome;
> use strict;
>
> sub handler{
> my $r = shift;
> $r->send_http_header('text/html');
> print qq|\n|;
> print "You are Welcome at ", $r->get_remote_host, "

\n";
> while (my ($key, $val) = each %ENV) {
> print "$key = $val
\n"; }
> print "";
> return 1;
> }
> 1;
>
> The output source looks like this when initiated directly from the
> back end (http://192.168.20.111:8089/):
>
>
> You are Welcome at 192.168.20.98


> QUERY_STRING =

> HTTP_ACCEPT_LANGUAGE = en

> TZ = PST8PDT

> REMOTE_PORT = 3201

> HTTP_USER_AGENT = Mozilla/4.76 [en] (X11; U; Linux 2.2.14-5.0 i686)

> HTTP_ACCEPT = image/gif, image/x-xbitmap, image/jpeg, image/pjpeg,
> image/png, */*

> HTTP_HOST = 192.168.20.111:8089

> GATEWAY_INTERFACE = CGI-Perl/1.1

> SCRIPT_NAME = /

> SERVER_NAME = gelco5.yvod.com

> HTTP_ACCEPT_ENCODING = gzip

> MOD_PERL = mod_perl/1.26

> HTTP_ACCEPT_CHARSET = iso-8859-1,*,utf-8

> HTTP_COOKIE = YVOD_SESSION_ID=2e4046b477f9374f

> SCRIPT_FILENAME = /www/gelcompany/modperl

> PATH = /bin:/usr/bin

> SERVER_ADDR = 192.168.20.111

> MOD_PERL_TRACE = all

> SERVER_PROTOCOL = HTTP/1.0

> HTTP_CONNECTION = Keep-Alive

> SERVER_SIGNATURE =