Previously, for Via, X-Forwarded-For, and X-Forwarded-Proto header
field, nghttpx only forwarded the last header field of each. With
this commit, nghttpx forwards all of them if it is configured to do
so.
This commit removes frontend-tls parameter, and adds
redirect-if-not-tls parameter parameter to --backend option. nghttpx
now responds to the request with 308 status code to redirect the
request to https URI if frontend connection is not TLS encrypted, and
redirect-if-no-tls parameter is used in --backend option. The port
number in Location header field is 443 by default (thus omitted), but
it can be configurable using --redirect-https-port option.
Previously, we have dedicated read buffer for each frontend
connection. With this commit, the buffer spaces are only used when
needed, and pooled if they are not used. This reduces memory usage
for idle client connections.
on_read may fail, but we failed to check its return value most of the
places. This is because failure means deletion of ClientHandler, but
because of architecture, we cannot delete it. Feeding read event is
better since we can move call on_read from libev callback. We can
delete ClientHandler form there.
Because of bidirectional nature of TCP, we may fail write(2), but have
still pending read in TCP buffer, which may contain response body. To
forward them, we should keep reading until get EOF from backend.
To avoid stalling HTTP/1 upload when request buffer is full, and we
have received complete response from backend, drop connection in that
case.
Previously we wrongly handles stream per connection when h2 backend
failed or closed. If upstream is h2 or spdy, streams which are not
associated to the failed h2 backend are also handled, which is
unnecessary.
For HTTP/2, read timer starts when there is no downstream, and timer
stops when there is at least one downstream. For HTTP/1, read timer
starts when request handling finished, and timer stops when request
handling starts.