Bug 106454

Summary:

ProxyPass modifies http header removing Content-Length field

Product:

[Retired] Red Hat Linux

Reporter:

Pedro Bezunartea <pedro>

Component:

httpd

Assignee:

Joe Orton <jorton>

Status:

CLOSED ERRATA

QA Contact:

David Lawrence <dkl>

Severity:

medium

Docs Contact:

Priority:

low

Version:

CC:

pedro

Target Milestone:

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Keywords:

FutureFeature

Target Release:

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Hardware:

All

OS:

Linux

Whiteboard:

Fixed In Version:

Doc Type:

Enhancement

Doc Text:

Story Points:

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Clone Of:

Environment:

Last Closed:

2003-12-16 21:45:24 UTC

Type:

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Regression:

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Mount Type:

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Documentation:

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CRM:

Verified Versions:

Category:

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oVirt Team:

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RHEL 7.3 requirements from Atomic Host:

Cloudforms Team:

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Target Upstream Version:

Embargoed:

Attachments:

Description	Flags
This is a tcpdump from the client with the browser	none
tcpdump from the server to the camera	none
tcpdump from the server to the camera	none
Tcpdump of comm. from the client to the server	none
Tcpdump of comm. from apache server to the camera.	none
Tcpdump client-server with downgrade-1.0 directive	none
Tcpdump server-camera with downgrade-1.0 directive	none

Description Pedro Bezunartea 2003-10-07 10:05:39 UTC

From Bugzilla Helper:
User-Agent: Mozilla/5.0 Galeon/1.2.5 (X11; Linux i686; U;) Gecko/0

Description of problem:
I use the ProxyPass to access several JVC VNetwork Cameras connected to a Linux
Server (RH 9). I use the following lines in httpd.conf:
ProxyPass /camera1 http://192.168.0.1
ProxyPass /camera2 http://192.168.0.2
...

The problem started when I updated the httpd server from version 2.0.40-21.3 to
2.0.40-21.5. The request was http://server/camera2/java.jpg which is a live
image taken from the JVC VN-C10U camera internal web server, and the http header
changed from version 2.0.40-21.3:
-----------------------------
HTTP/1.1 200 OK
Date: Fro, 03 Oct 2003 11:02:33 GMT
Server: JVC/1.1
Content-Type: image/jpeg
Cache-Control: no-cache
Pragma: no-cache
ETag: "54651516"
Content-Length: 18932
Connection: close
-----------------------------

To version 2.0.40-21.5:
-----------------------------
HTTP/1.1 200 OK
(... same as before)
ETag: "54447730"
Connection: close
Transfer-Encoding: chunked
-----------------------------

If you try to load the image from a browser it works fine, but the Java applet
the camera includes to see live images doesn't. I guess it needs a
Content-Length http header field. All the applet does is to load via
http://server/camera2/java.jpg and show it in the applet.


Version-Release number of selected component (if applicable):
2.0.40-21.5

How reproducible:
Always

Steps to Reproduce:
1. Add the following line in httpd.conf:
ProxyPass /camera http://80.25.71.40:4001
(I've setup a camera to be available at that address.)
2. Restart apache web server (2.0.40-21.5)
3. With a java-ready browser load the following:
http://your-server/camera/java-e.html


Actual Results:  The applet loads fine, but the images don't.

Expected Results:  The applet should be able to load the images the same way as
if you were directly connected to the camera: http://80.25.71.40:4001/java-e.html


Additional info:

Comment 1 Joe Orton 2003-10-07 10:11:49 UTC

That in itself is not a bug - it may be that the applet is buggy.

Can you capture a complete network trace between the applet and the server (and
applet and proxy) with "tcpdump -w" and attach that?

It may be you need a BrowserMatch to force an HTTP/1.0 response to the applet, try 
something like the existing:

BrowserMatch "Java/1\.0" force-response-1.0
BrowserMatch "JDK/1\.0" force-response-1.0

Comment 2 Pedro Bezunartea 2003-10-07 11:23:11 UTC

Created attachment 94976 [details]
This is a tcpdump from the client with the browser

Comment 3 Pedro Bezunartea 2003-10-07 11:24:16 UTC

Created attachment 94977 [details]
tcpdump from the server to the camera

Comment 4 Pedro Bezunartea 2003-10-07 11:25:34 UTC

Created attachment 94978 [details]
tcpdump from the server to the camera

Both dumps were made with apache version 2.0.40-21.5.

Comment 5 Joe Orton 2003-10-07 12:34:58 UTC

Sorry, that needs to be "tcpdump -s0 -w" otherwise tcpdump only captures a few
bytes of packet data.  Can you redo?

Comment 6 Pedro Bezunartea 2003-10-07 14:58:58 UTC

Created attachment 94987 [details]
Tcpdump of comm. from the client to the server

I added the line 'BrowserMatch "Java/1" force-response-1.0' first, and
'BrowserMatch "Java/1.4.2_01" force-response-1.0' later, but neither made a
difference.

Comment 7 Pedro Bezunartea 2003-10-07 15:01:47 UTC

Created attachment 94988 [details]
Tcpdump of comm. from apache server to the camera.

This file is related to the previous attachment #94987 [details].

Comment 8 Joe Orton 2003-10-08 09:31:07 UTC

Try "downgrade-1.0" in the BrowserMatch line as well.  The traces seem to show
the server acting correctly, but the Java client is closing the connection as
soon as it receives the chunked response.

Comment 9 Pedro Bezunartea 2003-10-09 08:45:08 UTC

Added the following line to httpd.conf:
BrowserMatch "Java/1" force-response-1.0 downgrade-1.0
But the applet still doesn't work. Is there a way to make the ProxyPass work
like the previous version?

Comment 10 Joe Orton 2003-10-09 09:05:45 UTC

Can you attach the tcpdump between client and server in that configuration?

Comment 11 Pedro Bezunartea 2003-10-09 10:30:28 UTC

Created attachment 95067 [details]
Tcpdump client-server with downgrade-1.0 directive

Comment 12 Pedro Bezunartea 2003-10-09 10:31:28 UTC

Created attachment 95068 [details]
Tcpdump server-camera with downgrade-1.0 directive

Comment 13 Joe Orton 2003-10-09 10:45:52 UTC

The bottom line is that the proxy is compliant with the HTTP specification, but
the Java applet is not at all compliant.

We'll look into adding a workaround for this to preserve the Content-Length
header if possible; apparently the "Windows Update" client has the same, severe,
problem.

Comment 14 Joe Orton 2003-11-04 14:31:16 UTC

There are packages here which might fix this problem:

http://people.redhat.com/jorton/9-httpd/

can you try these out?

Comment 15 Pedro Bezunartea 2003-11-04 18:27:08 UTC

Tryed and worked just fine :)

Thanks, Pedro.

Comment 16 Mark J. Cox 2003-12-16 21:45:24 UTC

An errata has been issued which should help the problem described in this bug report. 
This report is therefore being closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files, please follow the link below. You may reopen 
this bug report if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2003-320.html