By default, nghttp2 library only handles HTTP/2 frames and does not
recognize first 24 bytes of client connection preface. This design
choice is done due to the fact that server may want to detect the
application protocol based on first few bytes on clear text
communication. But for simple servers which only speak HTTP/2, it is
easier for developers if nghttp2 library takes care of client
connection preface.
If this option is used with nonzero val, nghttp2 library checks first
24 bytes client connection preface. If it is not a valid one,
nghttp2_session_recv() and nghttp2_session_mem_recv() will return
error NGHTTP2_ERR_BAD_PREFACE, which is fatal error.
This commit moves frame_type parameter of
nghttp2_data_soruce_read_length_callback in front of stream_id
parameter. The motivation is that other callback is generally put
frame related parameters first. To make it consistent, we move
frame_type, which is frame ralted parameter, to the left.
Previously we always call on_frame_send_callback before calling
nghttp2_stream_detach_data() after sending DATA frame. As a result,
even if DATA frame has END_STREAM, application cannot call
nghttp2_submit_data() in on_frame_send_callback because previous data
is still attached. This commit makes a change so that
nghttp2_stream_detach_data() is called before on_frame_send_callback
so that application can issue nghttp2_submit_data() in the callback.
Now it returns only stream's available remote window size, without
considering connection level window size. For connection-level window
size, nghttp2_session_get_remote_window_size() is added by this
commit. To get old behavior of
nghttp2_session_get_stream_remote_window_size() is use
min(nghttp2_session_get_stream_remote_window_size(),
nghttp2_session_get_remote_window_size()). The reason of this change
is that it is desirable to know just stream level window size without
taking into connection level window size. This is useful for
debugging purpose.
It is not used by library for a while. It could be used to pass
unsupported extension frames to application, but its interface
requires library to buffer entire frame, which we'd like to avoid.
For unsupported extension frames, we will add new callbacks which does
not require buffering if they are required.
h2-14 now allows extensions to define new error codes. To allow
application callback to access such error codes, we uses uint32_t as
error_code type for structs and function parameters. Previously we
treated unknown error code as INTERNAL_ERROR, but this change removes
this and unknown error code is passed to application callback as is.
To make it possible to add new callbacks without bumping so name, we
decided to hide details of nghttp2_session_callbacks. We provide
setter like functions to set individual callback function.
Motivation:
The send window size is currently fixed by a macro at compile time.
In order for users of the library to impact the send window size they
would have to change a macro at compile time. The window size may be dynamic
depending on the environment and deployment scheme. The library users
currently have no way to change this parameter.
Modifications:
Add a new optional callback method which is called before data is sent to
obtain the desired send window size. The callback return value will be
subject to a range check for the current session, stream, and settings
limits defined by flow control.
Result:
Library users have control over their send sizes.
Previously returning NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE from
on_header_callback moves input offset badly and it causes header
decompression error on the subsequent frames. This commit fix this
bug.
This is partial revert of bbe4f5a3d1.
Only documentation is reverted. Since we have 2 queues to handle
maximum concurrent streams, we are not ready to allow immediate frame
submission for pending new frames.
This commit makes handling of outgoing HEADERS and PUSH_PROMISE in the
same priority of other frames on the stream, so these frames are
processed in the order they are submitted. This allows application to
submit frames to a stream returned by nghttp2_submit_{request,
headers, push_promise} immediately. The only exception is
WINDOW_UPDATA frame, which requires nghttp2_stream object, which is
not created yet.
The application should be responsible for the size of incoming header
block size. Framing layer just passes everything (we have size limit
for one header/field though) to application.
Reworked no automatic WINDOW_UPDATE feature. We added new API
nghttp2_session_consume() which tells the library how many bytes are
consumed by the application. Instead of submitting WINDOW_UPDATE by
the application, the library is now responsible to submit
WINDOW_UPDATE based on consumed bytes. This is more reliable method,
since it enables us to properly send WINDOW_UPDATE for stream and
connection individually. The previous implementation of nghttpx had
broken connection window management.
Previously we just assumed that if same settings ID is found in
SETTINGS, it is enough to process last seen entry. But it turns out
it is not enough for SETTINGS_HEADER_TABLE_SIZE. If we have 0 and
4096 for SETTINGS_HEADER_TABLE_SIZE in one SETTINGS, we must first
shrink dynamic table to 0 and then enlarge it to 4096. This means
that we have to remember the minimum value and last value.
Since we do not call on_data_chunk_recv_callback for ignored DATA
chunk, if nghttp2_option_set_no_auto_connection_window_update is used,
application may not have a chance to send connection WINDOW_UPDATE.
To fix this, we accumulate those received bytes, and if it exceeds
certain number, we automatically send connection-level WINDOW_UPDATE.
This commits changes the upper bound of one header field size (the sum
of the length of name and value) to 64KiB by default. We may add an
option to change this upper bound in the future.
Previously in inflater we reserve new ringbuffer when table size is
changed. This may be potentially a problem if new table size is very
large number. When inflater is not used directly by application, this
is not a problem because application can choose the buffer size. On
the other hand, if application uses inflater directly and it does not
have control of new buffer size (e.g., protocol dissector), then we
just fail to allocate large buffer in
nghttp2_hd_inflate_change_table_size() without actually use such huge
buffer. This change defers the actual allocation of buffer when it is
actually needed so that we will fail when it is absolutely needed.
Add last_stream_id parameter to nghttp2_submit_goaway(). To terminate
connection immediately with application chosen last stream ID,
nghttp2_session_terminate_session2() was added.
ALTSVC and BLOCKED frames are now extension frames. To add new
extension frame without modifying nghttp2_frame union, which causes so
name bump, we separated extension frames from core frames.
nghttp2_frame includes generic nghttp2_extension. The payload member
of nghttp2_extension will point to the structure of extension frame
payload. The frame types of extension frames are defined in
nghttp2_ext_frame_type.
Previously we have uint16_t as state member variable in
nghttp2_huff_decode structure to express -1 as failure. This is
because we have 256 valid states. However, we can express failed
state using flags member variable and make state uint8_t. This commit
does this and as a result the size of decoding table is reduced.
Previously we use 2 separate buffer for each name and value. The
problem is we would waste buffer space for name because it is usually
small. Also tuning buffer size for each buffer separately is not
elegant and current HTTP server practice is that one buffer for 1
name/value pair. This commit unifies 2 buffers into 1.
pending_local_max_concurrent_stream is, once local settings applied,
becomes NGHTTP2_INITIAL_MAX_CONCURRENT_STREAMS, which is very large
number. When adjusting number of streams, we have to take min of
local effective SETTINGS_MAX_CONCURRENT_STREAMS and pending one.
It is generally useful to know what is the cause of the error. Since
we expose HPACK API, it is friendly to tell application the
insufficient buffer size is a culprit.
Use this macro in Python sources. Python module constant
HD_DEFLATE_HD_TABLE_BUFSIZE_MAX was renamed as
DEFLATE_MAX_HEADER_TABLE_SIZE since the previous name was awkward.
We simulate resource sharing by decreasing weight. The thing is if
weight is wrapped, that item continues to send DATA until its weight
gets lowered under the other items. This commits fix this issue.
Tatsuhiro Tsujikawa
Scott Mitchell
Alexis La Goutte