>Number: 2588 >Category: mod_proxy >Synopsis: ftp proxy adds extra CRs in binary file transfers >Confidential: no >Severity: critical >Priority: medium >Responsible: apache >State: open >Class: sw-bug >Submitter-Id: apache >Arrival-Date: Fri Jul 10 18:40:00 PDT 1998 >Last-Modified: >Originator: [EMAIL PROTECTED] >Organization: apache >Release: 1.3.0 >Environment: Irix 5.3 using gcc-2.7.2.3
[EMAIL PROTECTED] 321: uname -a IRIX d8544-cs 5.3 11091810 IP7 mips >Description: When accessing a ftp site via the ftp proxy and downloading a binary image, the binary image is coorupted with extra CR characters embeded in the file. FTP proxy code is patched with LF corrections patches from bug report # 2412 and additional patches listed in the Jul 1 developers tar file. Accessing the file direct (without apache ftp proxy) the file is of total length 6118 bytes Accessing the file using the apache ftp proxy, the file increases to 61345 bytes. Dumping the file (od -x) I noted the following character string differences File without proxy .... 120c 0b0a 0a0b 1710 File with proxy ..... 120c 0b0d 0a0d 0a0b 1710 Note the extra 0d characters inserted into the file. >How-To-Repeat: Random example url ftp://ftp.sunet.se/pub/pictures/people/faces/angel.gif >Fix: Suspect strongly that the problem lies in bwrite (main/buff.c). That routine always attempts to add CRLF to the end of each buffer write. This is called from ap_proxy_send_fb which is called from proxy_ftp.c. The problem, I believe, originates in ap_proxy_send_fb (called from proxy_ftp when it start to pump data from the incomming connection and sends it both to the cache and the output connection. (see lines 466-490). ap_proxy_send_fb calls ap_bwrite - once for the cache output and a second time to transmit the data to the client. ap_bwrite then calls the bwrite routing which I suspect is doing the real damage. The concept of adding CR/LF should be examined to ensure it is correct. These should be binary transfers - no special processing required (other than the desired buffering for the cache files). >Audit-Trail: >Unformatted: [In order for any reply to be added to the PR database, ] [you need to include <[EMAIL PROTECTED]> in the Cc line ] [and leave the subject line UNCHANGED. This is not done] [automatically because of the potential for mail loops. ]
