nginx/1.3.2 - 4xx responses are returned without HTTP headers, bug?

[Igor Sysoev]

On Mon, Jul 09, 2012 at 01:01:21PM +0200, Sjon Hortensius wrote:
> On 07/09/2012 11:52 AM, Maxim Dounin wrote:
> > Hello!
> >
> > On Mon, Jul 09, 2012 at 10:41:19AM +0200, Sjon Hortensius wrote:
> >
> >> Hi,
> >>
> >> I think I stumbled upon a bug in nginx but I would like to get
> >> someone else's opinion on this.
> >>
> >> It seems all 4xx errors are not prefixed by headers in HTTP
> >> responses. I have a simple test-script in bash which you can run to
> >> verify this behavior:
> >>
> >> function req { echo -n "GET /bugtest?id="; for i in `seq 15000
> >> 17100` ; do echo -n "%7C$i" ; done ; echo -en "HTTP/1.1\nUser-Agent:
> >> Mozilla/5.0\nConnection: Close\nHost: wiki.nginx.org\r\n\r\n" ; } ;
> >> req | nc wiki.nginx.org 80
> >>
> >> I can also reproduce this for other 4xx responses. My interpretation
> >> of the RFC is that this is unwanted, see
> >> http://tools.ietf.org/html/rfc2616#section-6.1
> >
> > Headers aren't sent if nginx assumes the request is in HTTP/0.9
> > format.  The above script makes nginx to think it's HTTP/0.9 as
> > uri used dosn't fit into header buffer and nginx isn't able to
> > see "HTTP/1.1" before it returns 414.
> >
> > Maxim Dounin
> 
> Thanks for your reply! I have been looking for RFC documents describing 
> the maximum request-length in HTTP/0.9, but I cannot find any. I found 
> http://www.w3.org/Protocols/HTTP/Request.html (which links to 
> http://www.w3.org/Addressing/URL/5_BNF.html to describe URLs) and 
> http://www.ietf.org/rfc/rfc1738.txt, both of which describe no maximum 
> length.
> 
> If nginx assumes HTTP/0.9 for the request, it doesn't seem very logical 
> to return an error which cannot exist within that very protocol?

Well, it does not return error. It just returns a page with text:
"414 Request-URI Too Large". What can you suggest to return for
a request larger than configured buffer ?


-- 
Igor Sysoev