Le mer. 3 févr. 2021 à 17:10, Mark Thomas <ma...@apache.org> a écrit :
> On 03/02/2021 16:06, Romain Manni-Bucau wrote: > > Hi, > > > > Why not just adding a tomcat-application-fixer module (a more ugly name > can > > be relevant ;)) application could add in their WEB-INF/lib through web > > resource definition (ie plain context.xml config or programmatic > > equivalent) which would have a @WebFilter(/*, asyncSupported=true) which > > would wrap the response to do the fixes you want for these apps but it > > wouldnt be seen in the most common case at all (or if there is only this > > small fix it can be a default filter of tomcat, depends the number of > fixes > > and related code IMHO). > > Primarily because of the risk that wrapping the request breaks the > application. > > While a well-behaved app should be unaffected by a Filter adding a > wrapped response, we already know that these applications are not > well-behaved - else they wouldn't be setting these headers in the first > place. > > Hence I am looking at solutions further down the stack in the Tomcat > internals. > So you mean the application uses tomcat internals (like casting the Response/Request) but does not work on Tomcat? :s Otherwise there is no real way a filter and wrapper breaks a "broken" application since the application will take the wrapped instance as a standard servlet instance - as tomcat already do with its facade layer. The only constraint is to ensure the filter is first which can require another solution than @WebFilter but web.xml solves it. > > Mark > > > > > > Romain Manni-Bucau > > @rmannibucau <https://twitter.com/rmannibucau> | Blog > > <https://rmannibucau.metawerx.net/> | Old Blog > > <http://rmannibucau.wordpress.com> | Github < > https://github.com/rmannibucau> | > > LinkedIn <https://www.linkedin.com/in/rmannibucau> | Book > > < > https://www.packtpub.com/application-development/java-ee-8-high-performance > > > > > > > > Le mer. 3 févr. 2021 à 16:50, Rémy Maucherat <r...@apache.org> a écrit : > > > >> On Wed, Feb 3, 2021 at 1:03 PM Mark Thomas <ma...@apache.org> wrote: > >> > >>> Hi all, > >>> > >>> We have an open PR related to this for HTTP/2 (#277) and I am seeing > >>> related issues at $work with HTTP. > >>> > >>> In short, applications are doing things like: > >>> > >>> response.setHeader("Transfer-Encoding", "chunked"); > >>> > >>> which, as you'd expect is causing problems if: > >>> - Tomcat doesn't chunk the response > >>> - Tomcat does chunk the response, adds its own "chunked" value and the > >>> user agent rightly objects to "chunked" appearing twice > >>> > >>> And so on. > >>> > >>> I'd like to put something into Tomcat to address this. > >>> > >>> I think it should be disabled by default so correctly written > >>> applications pay a very small penalty. Along the lines of > >>> > >>> if (someSetting != null) { > >>> // Do header checks > >>> } > >>> > >>> In terms of options I think we need: > >>> - something representing the current, allow anything, behaviour > >>> - an option to log (with a stack trace so the offending code can be > >>> identified) attempts to set such headers > >>> - an option to ignore attempts to set such headers > >>> > >>> Do we need an option that throws an exception if there is an attempt to > >>> set such headers? > >>> > >>> Do we need an option to control which headers and which values will > >>> trigger this behaviour? This would make the configuration rather more > >>> complex. You'd need to be able to set multiple combinations of header, > >>> value and action. > >>> > >>> Is adding debug (no stacktrace) and trace (with stacktrace) logging to > >>> addHeader() sufficient? For identifying faulty code this helps but it > >>> doesn't provide a way to work-around the problem. For that you need > >>> something that blocks the adding of the header. > >>> > >>> I'm still considering what might be the best way to fix this. Hence the > >>> brain dump above. Thoughts? > >>> > >> > >> There has been some debate about this before, and you did add quite a > bit > >> of code to catch things that would break the protocol. So it seems this > >> would go above and beyond, and attempt to catch *anything* that could > make > >> a response non compliant with the underlying protocol ? > >> > >> Rémy > >> > >> > >>> > >>> Mark > >>> > >>> > >>> --------------------------------------------------------------------- > >>> To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org > >>> For additional commands, e-mail: dev-h...@tomcat.apache.org > >>> > >>> > >> > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org > For additional commands, e-mail: dev-h...@tomcat.apache.org > >
