[whatwg] WebSocket sub protocol name.
ian at hixie.ch
Mon Dec 7 02:25:09 PST 2009
On Mon, 7 Dec 2009, Fumitoshi Ukai (éµ~\é£¼æ~V~Gæ~U~O) wrote:
> On Mon, Dec 7, 2009 at 5:05 PM, Ian Hickson <ian at hixie.ch> wrote:
> > On Mon, 7 Dec 2009, Fumitoshi Ukai (æ¦~\æ¤å
> > > > > >
> > > > > > Control characters are allowed (though using them would be
> > > > > > silly).
> > > > >
> > > > > Why are control characters (except LF and CR) allowed?
> > > >
> > > > There doesn't seem to be a good reason to exclude them, and
> > > > excluding them would lead to a more complicated processing model.
> > >
> > > In HTTP, field-content is TEXT or combinations of token, separators,
> > > and quoted-string. TEXT, or token, separators excludes CTLs. So, we
> > > must use quoted-string in WebSocket-Protocol: if protocol contains
> > > CTLs?
> > Oh, I forgot that HTTP had the no-CTL restriction. Good point. I've
> > updated the spec to be consistent with this.
> In "The Web Sockets API", could you fix the following statement?
> The second, protocol, if present, specifies a sub-protocol that the server
> must support for the connection to be successful. The sub-protocol name must
> be an ASCII string with no U+000A LINE FEED (LF) or U+000D CARRIAGE RETURN
> (CR) characters in it.
> IIRC, in old spec draft, protocol should not be an empty string, but
> current spec draft accepts it?
Man, I'm just incompetent today. Sorry about that. Fixed.
> > > And, why is it limited to ASCII instead of UTF-8?
> > Because the HTTP working group refuse to allow UTF-8 in HTTP headers
> > for reasons that I don't really understand, and the handshake is
> > supposed to be valid HTTP.
> Hmm, then it should be mentioned in The Web Socket protocol 1.2 Protocol
> overview? It looks websocket message accept UTF-8 in handshake message.
There should be no way to _send_ UTF-8 in the handshake at this point,
given the requirements in the spec, but once you _receive_ the handshake,
it's no longer HTTP, it's just WebSocket, so you can use UTF-8 fine. (In
practice it doesn't mean much, since there's nothing in the
server-to-client handshake other than the client-to-server handshake, so
if there ever was UTF-8 in the server-to-client handshake, it would either
be ignored, or the connection would be dropped, depending on where exactly
the UTF-8 was found.)
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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