Re: Proposal: a new WRAP UP capsule

[Tommy Pauly <[e-mail]>]

> On Jul 9, 2024, at 6:10 PM, Martin Thomson <[e-mail]> wrote:
> 
> Hi David,
> 
> I think that this is reasonable - if your goal is to suggest that clients terminate a single CONNECT flow, rather than the entire connection.  This could also be achieved with GOAWAY, but it will affect multiple flows.  The draft doesn't say this, so maybe I'm missing something important.
> 
> How common is it to establish multiple flows through a single proxy?  That might depend on use case (CONNECT-IP might be more profligate than CONNECT-UDP, say).

I think you'd generally see the most for CONNECT-TCP and CONNECT-UDP, when you’re proxying an application like a web browser. CONNECT-IP would generally be much more limited, and in some cases just be a big VPN tunnel.

Tommy

> 
> Cheers,
> Martin
> 
> On Sat, Jul 6, 2024, at 08:29, David Schinazi wrote:
>> Hi HTTP enthusiasts,
>> 
>> Over in MASQUE land, as we're deploying our two-hop proxies, we decided 
>> we needed to put a cap on how many bytes we'd allow per 
>> token-authenticated connect-udp tunnel. Enforcing a hard limit is easy, 
>> but the issue is that if the proxy aborts the tunnel halfway through, 
>> the web browser could be halfway through a proxied request. Since the 
>> browser doesn't know if the half-finished request was acted on or not, 
>> it can't retry it, so it has to surface the error to the user. Instead, 
>> we want the proxy to be able to warn the browser that this will happen 
>> soon, so that the browser can establish a new tunnel with a new token, 
>> and start sending new requests there. Conceptually this is a little 
>> like GOAWAY, but instead of "please wrap up this connection", it's 
>> "please wrap up this tunnel stream". It uses capsules, since this is a 
>> message from proxy to client. Here's a draft with diagrams:
>> 
>> https://datatracker.ietf.org/doc/draft-schinazi-httpbis-wrap-up/
>> https://davidschinazi.github.io/draft-schinazi-httpbis-wrap-up/draft-schinazi-httpbis-wrap-up.html
>> 
>> I'd love to hear your thoughts.
>> 
>> Thanks,
>> David
>