This is a partial backport of cb9da0bf and a backport of c9635349.
Because C doesn't like us to declare identifiers starting with an
underscore, Libevent 2.1 has renamed every such identifier. The
only change that affects a public API is that the _EVENT_LOG_*
macros have been renamed to start with EVENT_LOG instead. The old
names are still present, but deprecated.
I'm doing this backport because it represents the deprecation of a
Libevent 2.0 interface, and folks should have the opportunity to
write code that isn't deprecated and works with both 2.0 and 2.1.
The sendfile() implementation for evbuffer_add_file is potentially more
efficient, but it has a problem: you can only use it to send bytes over
a socket using sendfile(). If you are writing bytes via SSL_send() or
via a filter, or if you need to be able to inspect your buffer, it
doesn't work.
As an easy fix, this patch disables the sendfile-based implementation of
evbuffer_add_file on an evbuffer unless the user sets a new
EVBUFFER_FLAG_DRAINS_TO_FD flag on that evbuffer, indicating that the
evbuffer will not be inspected, but only written out via
evbuffer_write(), evbuffer_write_atmost(), or drained with stuff like
evbuffer_drain() or evbuffer_add_buffer(). This flag is off by
default, except for evbuffers used for output on bufferevent_socket.
In the future, it could be interesting to make a best-effort file
segment implementation that tries to send via sendfile, but mmaps on
demand. That's too much complexity for a stable release series, though.
https://sourceforge.net/tracker/index.php?func=detail&aid=3078187&group_id=50884&atid=461324
The problem is that bufferevent_disable() doesn't disable EV_WRITE
when 'connecting' flag is set. However from evhttp_connection_reset()
we want to disable EV_WRITE for sure (we are closing the socket next).
So we add bufferevent_disable_hard(), which acts like
bufferevent_disable(), but resets 'connecting' flag before the call to
the actual handler.
TODO: bufferevent_disable_hard() shouldn't be public, remove it from
event2/bufferevent.h.
If the EVHTTP_URI_NONCONFORMANT flag is passed in (which it is when
parsing URIs we get over the wire), then we relax our checks a lot.
Specifically, we do nothing to check for correct characters in the
path, query, and fragment parts of such a URI.
We could do much more here: we could relax our hostname requirements,
deal with spaces differently/better, trap some errors but not others,
etc. But this should solve the worst user-agent compatibility issues
for now; the other issues can wait for a later release.
evhttp needs to be mindful of all hostnames and addresses that clients
use to contact the main server and vhosts to know the difference between
proxy requests and non-proxy requests.
