When a message is parsed and copied into the channel buffer, in
h1_process_demux(), more space is requested if some pending data remain
after the parsing while the channel buffer is not empty. To do so,
CS_FL_WANT_ROOM flag is set. It means the H1 parser needs more space in the
channel buffer to continue. In the stream-interface, when this flag is set,
the SI is considered as blocked on the RX path. It is only unblocked when
some data are sent.
However, it is not accurrate because the parsing may be stopped because
there is not enough data to continue. For instance in the middle of a chunk
size. In this case, some data may have been already copied but the parser is
blocked because it must receive more data to continue. If the calling SI is
blocked on RX at this stage when the stream is waiting for the payload
(because http-buffer-request is set for instance), the stream remains stuck
infinitely.
To fix the bug, we must request more space to the app layer only when it is
not possible to copied more data. Actually, this happens when data remain in
the input buffer while the H1 parser is in states MSG_DATA or MSG_TUNNEL, or
when we are unable to copy headers or trailers into a non-empty buffer.
The first condition is quite easy to handle. The second one requires an API
refactoring. h1_parse_msg_hdrs() and h1_parse_msg_tlrs() fnuctions have been
updated. Now it is possible to know when we need more space in the buffer to
copy headers or trailers (-2 is returned). In the H1 mux, a new H1S flag
(H1S_F_RX_CONGESTED) is used to track this state inside h1_process_demux().
This patch is part of a series related to the issue #1362. It should be
backported as far as 2.0, probably with some adaptations. So be careful
during backports.
Replace http_get_path by the http_uri_parser API. The new functions is
renamed http_parse_path. Replace duplicated code for scheme and
authority parsing by invocations to http_parse_scheme/authority.
If no scheme is found for an URI detected as an absolute-uri/authority,
consider it to be an authority format : no path will be found. For an
absolute-uri or absolute-path, use the remaining of the string as the
path. A new http_uri_parser state is declared to mark the path parsing
as done.
h1 parsing functions (h1_parse_msg_*) returns the number of bytes parsed or
0 if nothing is parsed because an error occurred or some data are
missing. But they never return negative values. Thus, instead of a signed
integer, these function now return a size_t value.
The H1 and FCGI muxes are updated accordingly. Note that h1_parse_msg_data()
has been slightly adapted because the parsing of chunked messages still need
to handle negative values when a parsing error is reported by
h1_parse_chunk_size() or h1_skip_chunk_crlf().
A normalized URI is the internal term used to specify an URI is stored using
the absolute format (scheme + authority + path). For now, it is only used
for H2 clients. It is the default and recommended format for H2 request.
However, it is unusual for H1 servers to receive such URI. So in this case,
we only send the path of the absolute URI. It is performed for H1 servers,
but not for FCGI applications. This patch fixes the difference.
Note that it is not a real bug, because FCGI applications should support
abosolute URI.
Note also a normalized URI is only detected for H2 clients when a request is
received. There is no such test on the H1 side. It means an absolute URI
received from an H1 client will be sent without modification to an H1 server
or a FCGI application.
To make it possible, a dedicated function has been added to get the H1
URI. This function is called by the H1 and the FCGI multiplexer when a
request is sent to a server.
This patch should fix the issue #1232. It must be backported as far as 2.2.
The EOM block may be removed. The HTX_FL_EOM flags is enough. Most of time,
to know if the end of the message is reached, we just need to have an empty
HTX message with HTX_FL_EOM flag set. It may also be detected when the last
block of a message with HTX_FL_EOM flag is manipulated.
Removing EOM blocks simplifies the HTX message filling. Indeed, there is no
more edge problems when the message ends but there is no more space to write
the EOM block. However, some part are more tricky. Especially the
compression filter or the FCGI mux. The compression filter must finish the
compression on the last DATA block. Before it was performed on the EOM
block, an extra DATA block with the checksum was added. Now, we must detect
the last DATA block to be sure to finish the compression. The FCGI mux on
its part must be sure to reserve the space for the empty STDIN record on the
last DATA block while this record was inserted on the EOM block.
The H2 multiplexer is probably the part that benefits the most from this
change. Indeed, it is now fairly easier to known when to set the ES flag.
The HTX documentaion has been updated accordingly.
