This commits enables HTTP/2 server push from HTTP/2 backend to be
relayed to HTTP/2 frontend. To use this feature, --http2-bridge or
--client is required. Server push via Link header field contiues to
work.
To validate actual response body length against the value declared in
content-length response header field, we first check request method.
If request method is HEAD, respose body must be 0 regardless of the
value in content-length. nghttp2_session_upgrade() has no parameter
to indicate the request method is HEAD, so we failed to validate
response body if HEAD is used with HTTP Upgrade. New
nghttp2_session_upgrade2() accepts new parameter to indicate that
request method is HEAD or not to fix this issue. Although, this issue
affects client side only, we deprecate nghttp2_session_upgrade() in
favor of nghttp2_session_upgrade2() for both client and server side.
This function is useful for the client application to know that there
is a chance that request can be sent. If this function returns 0,
there is zero chance to make a request.
This commit also set error_code passed to
nghttp2_on_stream_close_callback to NGHTTP2_REFUSED_STREAM if request
is not sent.
The control process handles signals, reads configuration, reads
private keys, and bind port (which may be privileged one). It never
drop privileges, so that it can execute new binary with the same
privilege. It forks worker process. The worker process handles all
incoming connections. It drops privilege.
The intention of this stream API is give server application about
stream dependency information, so that it can utilize it for better
scheduling of stream processing. We have no plan to add object
oriented API based on stream object.
The overall meaning is the same. I added a paragraph to introduce nghttp2_hd_inflate_hd(), and added an explanation of using NGHTTP2_NV_FLAG_NO_INDEX for security sensitive headers.