Re: Bus error in LWP/Perl5

Roy T. Fielding (fielding@avron.ICS.UCI.EDU)
Sat, 21 Oct 1995 15:58:40 -0700 

> http://alpha.mkn.co.uk/help/flower/info
> #http://anther.learning.cs.cmu.edu/priest.html
> http://artaids.dcs.qmw.ac.uk:8001/entrance/entrance.html
> 
> There might be something strange that happens after we have visited 
> "flower/info".  Some more checking seems to indicate that any URL checked 
> after "flower/info" will give a segmentation fault.
> 
> The server itself seems quite normal to me:
> 
> $ telnet alpha.mkn.co.uk 80
> Trying 193.118.187.101 ...
> Connected to alpha.mkn.co.uk.
> Escape character is '^]'.
> GET /help/flower/info HTTP/1.0
> 
> HTTP/1.0 200 Okeydokey
> Allow: GET POST
> Mime-Version: 1.0
> Content-Type: text/html
> 
> <HTML>
> <TITLE>MarketNet - OnLine Florist</TITLE>
> <H1>Flower<I>Net</I> - OnLine Florist</H1>
> ...

Major weirdness -- I just tried this with the perl4 version of HEAD:

   HEAD http://alpha.mkn.co.uk/help/flower/info HTTP/1.0
   Accept: */*
   User-Agent: HEAD/0.5 libwww-perl/0.40

   HTTP/1.0 200 OK

   <HR> <A HREF="/bank">Banknet:</A> no transaction charges whether in credit
   or overdrawn.<HR><h2>Your communications link is not secure.  To secure it
   please click <A HREF="https://193.118.187.105/HELP/SIGNON">here</A>.</H2>
   <H5>  Original Text and Graphics &copy;
   <A HREF="/HELP/SIGNON">Market<I>Net</I></A> 1995. You are welcome to copy
   this page as long as you say where it came from. Market<I>Net</I>
   User: 204.191.205.19</H5></BODY></HTML>

Note that the response does not include any header fields and illegally
sends a body.  Worse, the body is all one line (I added the line breaks above).
So, I'd say look for a bug that is assuming header fields exist, or that
the HEAD request will never return content, or that the content has
reasonably sized lines [keeping in mind that the bug is triggered on the
request following after this one].


 ...Roy T. Fielding
    Department of Information & Computer Science    (fielding@ics.uci.edu)
    University of California, Irvine, CA 92717-3425    fax:+1(714)824-4056
    http://www.ics.uci.edu/~fielding/