Do not emit a CONNECTION_CLOSE on h3s allocation failure. Indeed, this
causes a crash as the calling function qcs_new() will also try to emit a
CONNECTION_CLOSE which triggers a BUG_ON() on qcc_emit_cc().
This was reproduced using -dMfail.
This should be backported up to 2.7.
A H3 unidirectional stream is always opened with its stream type first
encoded as a QUIC variable integer. If the STREAM frame contains some
data but not enough to decode this varint, haproxy would crash due to an
ABORT_NOW() statement.
To fix this, ensure we support an incomplete stream type. In this case,
h3_init_uni_stream() returns 0 and the buffer content is not cleared.
Stream decoding will resume when new data are received for this stream
which should be enough to decode the stream type varint.
This bug has never occured on production because standard H3 stream types
are small enough to be encoded on a single byte.
This should be backported up to 2.6.
When a GOAWAY has been emitted, an ID is announced to represent handled
streams. H3 RFC suggests that higher streams should be resetted with the
error code H3_REQUEST_CANCELLED. This allows the peer to replay requests
on another connection.
For the moment, the impact of this change is limitted as GOAWAY is only
used on connection shutdown just before the MUX is freed. However, for
soft-stop support, a GOAWAY can be emitted in anticipation while keeping
the MUX to finish the active streams. In this case, new streams opened
by the client are resetted.
As a consequence of this change, app_ops.attach() operation has been
delayed at the very end of qcs_new(). This ensure that all qcs members
are initialized to support RESET_STREAM sending.
This should be backported up to 2.7.
h3s stores the current demux frame type and length as a state info. It
should be big enough to store a QUIC variable-length integer which is
the maximum H3 frame type and size.
Without this patch, there is a risk of integer overflow if H3 frame size
is bigger than INT_MAX. This can typically causes demux state mismatch
and demux frame error. However, no occurence has been found yet of this
bug with the current implementation.
This should be backported up to 2.6.
Add traces inside h3_decode_qcs(). Every error path has now its
dedicated trace which should simplify debugging. Each early returns has
been converted to a goto invocation.
To complete the demux tracing, demux frame type and length are now
printed using the h3s instance whenever its possible on trace
invocation. A new internal value H3_FT_UNINIT is used as a frame type to
mark demuxing as inactive.
This should be backported up to 2.7.
Properly handle a STREAM frame with no data but the FIN bit set at the
application layer. H3 and hq-interop decode_qcs() callback have been
adjusted to not return early in this case.
If the FIN bit is accepted, a HTX EOM must be inserted for the upper
stream layer. If the FIN is rejected because the stream cannot be
closed, a proper CONNECTION_CLOSE error will be triggered.
A new utility function qcs_http_handle_standalone_fin() has been
implemented in the qmux_http module. This allows to simply add the HTX
EOM on qcs HTX buffer. If the HTX buffer is empty, a EOT is first added
to ensure it will be transmitted above.
This commit will allow to properly handle FIN notify through an empty
STREAM frame. However, it is not sufficient as currently qcc_recv() skip
the decode_qcs() invocation when the offset is already received. This
will be fixed in the next commit.
This should be backported up to 2.6 along with the next patch.
This commit is identical to the preceeding patch. However, these traces
are from another patch with a different backport scope :
56a86ddfb9
MINOR: h3: add missing traces on closure
This must be backported up to 2.7 where above patch is scheduled.
First H3 traces argument must be a connection instance or a NULL. Some
new traces were added recently with a qcc instance which caused a crash
when traces are activated.
This trace was added by the following patch :
87f8766d3f
BUG/MEDIUM: h3: handle STOP_SENDING on control stream
This must be backported up to 2.6 along with the above patch.
Add traces for function h3_shutdown() / h3_send_goaway(). This should
help to debug problems related to connection closure.
This should be backported up to 2.7.
This commit is similar to the previous one. It reports an error if a
RESET_STREAM is received for the remote control stream. This will
generate a CONNECTION_CLOSE with H3_CLOSED_CRITICAL_STREAM error.
Note that contrary to the previous bug related to STOP_SENDING, this bug
was not encountered in real environment. As such, it is labelled as
MINOR. However, it could triggered the same crash as the previous patch.
This should be backported up to 2.6.
Before this patch, STOP_SENDING reception was considered valid even on
H3 control stream. This causes the emission in return of RESET_STREAM
and eventually the closure and freeing of the QCS instance. This then
causes a crash during connection closure as a GOAWAY frame is emitted on
the control stream which is now released.
To fix this crash, STOP_SENDING on the control stream is now properly
rejected as specified by RFC 9114. The new app_ops close callback is
used which in turn will generate a CONNECTION_CLOSE with error
H3_CLOSED_CRITICAL_STREAM.
This bug was detected in github issue #2006. Note that however it is
triggered by an incorrect client behavior. It may be useful to determine
which client behaves like this. If this case is too frequent,
STOP_SENDING should probably be silently ignored.
To reproduce this issue, quiche was patched to emit a STOP_SENDING on
its send() function in quiche/src/lib.rs:
pub fn send(&mut self, out: &mut [u8]) -> Result<(usize, SendInfo)> {
- self.send_on_path(out, None, None)
+ let ret = self.send_on_path(out, None, None);
+ self.streams.mark_stopped(3, true, 0);
+ ret
}
This must be backported up to 2.6 along with the preceeding commit :
MINOR: mux-quic/h3: define close callback
Define a new qcc_app_ops callback named close(). This will be used to
notify app-layer about the closure of a stream by the remote peer. Its
main usage is to ensure that the closure is allowed by the application
protocol specification.
For the moment, close is not implemented by H3 layer. However, this
function will be mandatory to properly reject a STOP_SENDING on the
control stream and preventing a later crash. As such, this commit must
be backported with the next one on 2.6.
This is related to github issue #2006.
h3_resp_trailers_send() may be called due to an HTX EOT block present
without preceeding HTX TRAILER block. In this case, no HEADERS frame
will be generated by H3 layer and MUX will emit an empty STREAM frame
with FIN set.
However, before skipping these, some operations are conducted on qcs
buffer to realign it and try to encode the QPACK field section line in a
buffer copy. These operation are thus unneeded if no trailer is
generated. Even worse, the function will fail if there is not enough
space in the buffer for the superfluous QPACK section line.
To improve this situation, this patch adds an early goto statement to
skip most operations in h3_resp_trailers_send() if no HTX trailer block
is found.
This patch is related to github issue #2006.
This should be backported up to 2.7.
Replace ABORT_NOW() by proper error management in
h3_resp_trailers_send() for QPACK encoding operation.
If a QPACK encoding operation fails, it means there is not enough space
in qcs buffer. In this case, flag qcs instance with QC_SF_BLK_MROOM and
return an error. MUX is responsible to remove this flag once buffer
space is available.
This should fix the crash reported by gabrieltz on github issue #2006.
This must be backported up to 2.7.
Since the rework of QUIC streams send scheduling, each stream has to be
inserted in QUIC-mux send-list to be able to emit content. This was not
the case for GOAWAY which prevent it to be sent. This regression has
been introduced by the following patch :
commit 20f2a425ff
MAJOR: mux-quic: rework stream sending priorization
This new patch fixes the issue by inserting H3 control stream in mux
send-list. The impact is deemed minor as for the moment GOAWAY is only
sent just before connection/mux cleanup with a CONNECTION_CLOSE.
However, it might cause some connections to hang up indefinitely.
This should be backported up to 2.7.
As specified by HTTP3 RFC, SETTINGS frame should be sent as soon as
possible. Before this patch, this was only done on the first qc_send()
invocation. This delay significantly SETTINGS emission until the first
H3 response is ready to be transferred.
This patch fixes this by ensuring SETTINGS is emitted when MUX-QUIC is
being setup.
As a side point, return value of finalize operation is checked. This
means that an error during SETTINGS emission will cause the connection
init to fail.
This should be backported up to 2.7.
Implement the conversion of H3 request trailers as HTX blocks. This is
done through a new function h3_trailers_to_htx(). If the request
contains forbidden trailers it is rejected with a stream error.
This should be backported up to 2.7.
This patch implement the conversion of an HTX response containing
trailer into a H3 HEADERS frame. This is done through a new function
named h3_resp_trailers_send().
This was tested with a nginx configuration using <add_trailer>
statement.
It may be possible that HTX buffer only contains a EOT block without
preceeding trailer. In this case, the conversion will produce nothing
but fin will be reported. This causes QUIC mux to generate an empty
STREAM frame with FIN bit set.
This should be backported up to 2.7.
Slighty adjust b_quic_enc_int(). This function is used to encode an
integer as a QUIC varint in a struct buffer.
A new parameter is added to the function API to specify the width of the
encoded integer. By default, 0 should be use to ensure that the minimum
space is used. Other valid values are 1, 2, 4 or 8. An error is reported
if the width is not large enough.
This new parameter will be useful when buffer space is reserved prior to
encode an unknown integer value. The maximum size of 8 bytes will be
reserved and some data can be put after. When finally encoding the
integer, the width can be requested to be 8 bytes.
With this new parameter, a small refactoring of the function has been
conducted to remove some useless internal variables.
This should be backported up to 2.7. It will be mostly useful to
implement H3 trailers encoding.
Connection headers are not used in HTTP/3. As specified by RFC 9114, a
received message containing one of those is considered as malformed and
rejected. When converting an HTX message to HTTP/3, these headers are
silently skipped.
This must be backported up to 2.6. Note that assignment to <h3s.err>
must be removed on 2.6 as stream level error has been introduced in 2.7
so this field does not exist in 2.6 A connection error will be used
instead automatically.
Complete qcc_send_stream() function to allow to specify if the stream
should be handled in priority. Internally this will insert the qcs
instance in front of <qcc.send_list> to be able to treat it before other
streams.
This functionality is useful when some QUIC streams should be sent
before others. Most notably, this is used to guarantee that H3 SETTINGS
is done first via the control stream.
This must be backported up to 2.7.
Implement a mechanism to register streams ready to send data in new
STREAM frames. Internally, this is implemented with a new list
<qcc.send_list> which contains qcs instances.
A qcs can be registered safely using the new function qcc_send_stream().
This is done automatically in qc_send_buf() which covers most cases.
Also, application layer is free to use it for internal usage streams.
This is currently the case for H3 control stream with SETTINGS sending.
The main point of this patch is to handle stream sending fairly. This is
in stark contrast with previous code where streams with lower ID were
always prioritized. This could cause other streams to be indefinitely
blocked behind a stream which has a lot of data to transfer. Now,
streams are handled in an order scheduled by se_desc layer.
This commit is the first one of a serie which will bring other
improvments which also relied on the send_list implementation.
This must be backported up to 2.7 when deemed sufficiently stable.
Use a stream error when possible instead of always closing the whole
connection. This requires a new field <err> in h3s structure.
Change slightly the decoding loop to facilitate error propagation. It
will be interrupted as soon as <h3s.err> or <h3c.err> is non null. In
the later case, a CONNECTION_CLOSE is requested through
qcc_emit_cc_app().
For stream error, H3 layer uses qcc_abort_stream_read() coupled with
qcc_reset_stream(). This is in conformance with RFC 9114 which
recommends to use STOP_SENDING + RESET_STREAM emission on stream error.
This commit is part of implementing H3 errors at the stream level.
This should be backported up to 2.7.
Implement STOP_SENDING. This is divided in two main functions :
* qcc_abort_stream_read() which can be used by application protocol to
request for a STOP_SENDING. This set the flag QC_SF_READ_ABORTED.
* qcs_send_reset() is a static function called after the preceding one.
It will send a STOP_SENDING via qcc_send().
QC_SF_READ_ABORTED flag is now properly used : if activated on a stream
during qcc_recv(), <qcc.app_ops.decode_qcs> callback is skipped. Also,
abort reading on unknown unidirection remote stream is now fully
supported with the emission of a STOP_SENDING as specified by RFC 9000.
This commit is part of implementing H3 errors at the stream level. This
will allows the H3 layer to request the peer to close its endpoint for
an error on a stream.
This should be backported up to 2.7.
Check return values of htx_add_header()/htx_add_eof() during H3 HEADERS
conversion to HTX. In case of error, the connection is interrupted with
a CONNECTION_CLOSE.
This commit is useful to detect abnormal situation on headers parsing.
It should be backported up to 2.7.
If an error is triggered on H3 HEADERS parsing, the allocated buffer for
HTX data is not freed.
To prevent this memleak, all return path have been centralized using
goto statements.
Also, as a small bonus, offer_buffers() is not called anymore if buffer
is not freed because sedesc has taken it. However this change has
probably no noticeable effect as dynamic buffers management is not
functional currently.
This should be backported up to 2.6.
Cookie header are treated specifically to merge multiple occurences in a
single HTX header. This is treated in a if-block condition inside the
'while (1)' loop for headers parsing. The length value of ist
representing cookie header is set to -1 by http_cookie_register(). The
problem is that then a continue statement is used but without
incrementing 'hdr_idx' to pass on the next header.
This issue was revealed by the introduction of commit :
commit d6fb7a0e0f
BUG/MEDIUM: h3: reject request with invalid header name
Before the aformentionned patch, the bug was hidden : on the next while
iteration, all isteq() invocations won't match with cookie header length
now set to -1. htx_add_header() fails silently because length is
invalid. hdr_idx is finally incremented which allows parsing to proceed
normally with the next header.
Now, a cookie header with length -1 do not pass the test on header name
conformance introduced by the above patch. Thus, a spurrious
RESET_STREAM is emitted. This behavior has been reported on the mailing
list by Shawn Heisey who found out that browsers disabled H3 usage due
to the RESET_STREAM received. Big thanks to him for his testing on the
master branch.
This issue is simply resolved by incrementing hdr_idx before continue
statement. It could have been detected earlier if htx_add_header()
return value was checked. This will be the subject of a dedicated commit
outside of the backport scope.
This must be backported up to 2.6.
Ensure that if a request contains a content-length header it matches
with the total size of following DATA frames. This is conformance with
HTTP/3 RFC 9114.
For the moment, this kind of errors triggers a connection close. In the
future, it should be handled only with a stream reset. To reduce
backport surface, this will be implemented in another commit.
This must be backported up to 2.6. It relies on the previous commit :
MINOR: http: extract content-length parsing from H2
RFC 9114 dictates several requirements for pseudo header usage in H3
request. Previously only minimal checks were implemented. Enforce all
the following requirements with this patch :
* reject request with undefined or invalid pseudo header
* reject request with duplicated pseudo header
* reject non-CONNECT request with missing mandatory pseudo header
* reject request with pseudo header after standard ones
For the moment, this kind of errors triggers a connection close. In the
future, it should be handled only with a stream reset. To reduce
backport surface, this will be implemented in another commit.
This must be backported up to 2.6.
Reject request containing invalid header name. This concerns every
header containing uppercase letter or a non HTTP token such as a space.
For the moment, this kind of errors triggers a connection close. In the
future, it should be handled only with a stream reset. To reduce
backport surface, this will be implemented in another commit.
Thanks to Yuki Mogi from FFRI Security, Inc. for having reported this.
This must be backported up to 2.6.
xprt_quic module was too large and did not reflect the true architecture
by contrast to the other protocols in haproxy.
Extract code related to XPRT layer and keep it under xprt_quic module.
This code should only contains a simple API to communicate between QUIC
lower layer and connection/MUX.
The vast majority of the code has been moved into a new module named
quic_conn. This module is responsible to the implementation of QUIC
lower layer. Conceptually, it overlaps with TCP kernel implementation
when comparing QUIC and HTTP1/2 stacks of haproxy.
This should be backported up to 2.6.
Clean up quic sources by adjusting headers list included depending
on the actual dependency of each source file.
On some occasion, xprt_quic.h was removed from included list. This is
useful to help reducing the dependency on this single file and cleaning
up QUIC haproxy architecture.
This should be backported up to 2.6.
Factorize common code between h3 and hq-interop snd_buf operation. This
is inserted in MUX QUIC snd_buf own callback.
The h3/hq-interop API has been adjusted to directly receive a HTX
message instead of a plain buf. This led to extracting part of MUX QUIC
snd_buf in qmux_http module.
This should be backported up to 2.6.
Small cleanup on snd_buf for application protocol layer.
* do not export h3_snd_buf
* replace stconn by a qcs argument. This is better as h3/hq-interop only
uses the qcs instance.
This should be backported up to 2.6.
H3 SETTINGS emission has recently been delayed. The idea is to send it
with the first STREAM to reduce sendto syscall invocation. This was
implemented in the following patch :
3dd79d378c
MINOR: h3: Send the h3 settings with others streams (requests)
This patch works fine under nominal conditions. However, it will cause a
crash if a HTTP/3 connection is released before having sent any data,
for example when receiving an invalid first request. In this case,
qc_release will first free qcc.app_ops HTTP/3 application protocol layer
via release callback. Then qc_send is called to emit any closing frames
built by app_ops release invocation. However, in qc_send, as no data has
been sent, it will try to complete application layer protocol
intialization, with a SETTINGS emission for HTTP/3. Thus, qcc.app_ops is
reused, which is invalid as it has been just freed. This will cause a
crash with h3_finalize in the call stack.
This bug can be reproduced artificially by generating incomplete HTTP/3
requests. This will in time trigger http-request timeout without any
data send. This is done by editing qc_handle_strm_frm function.
- ret = qcc_recv(qc->qcc, strm_frm->id, strm_frm->len,
+ ret = qcc_recv(qc->qcc, strm_frm->id, strm_frm->len - 1,
strm_frm->offset.key, strm_frm->fin,
(char *)strm_frm->data);
To fix this, application layer closing API has been adjusted to be done
in two-steps. A new shutdown callback is implemented : it is used by the
HTTP/3 layer to generate GOAWAY frame in qc_release prologue.
Application layer context qcc.app_ops is then freed later in qc_release
via the release operation which is now only used to liberate app layer
ressources. This fixes the problem as the intermediary qc_send
invocation will be able to reuse app_ops before it is freed.
This patch fixes the crash, but it would be better to adjust H3 SETTINGS
emission in case of early connection closing : in this case, there is no
need to send it. This should be implemented in a future patch.
This should fix the crash recently experienced by Tristan in github
issue #1801.
This must be backported up to 2.6.
This is the ->finalize application callback which prepares the unidirectional STREAM
frames for h3 settings and wakeup the mux I/O handler to send them. As haproxy is
at the same time always waiting for the client request, this makes haproxy
call sendto() to send only about 20 bytes of stream data. Furthermore in case
of heavy loss, this give less chances to short h3 requests to succeed.
Drawback: as at this time the mux sends its streams by their IDs ascending order
the stream 0 is always embedded before the unidirectional stream 3 for h3 settings.
Nevertheless, as these settings may be lost and received after other h3 request
streams, this is permitted by the RFC.
Perhaps there is a better way to do. This will have to be checked with Amaury.
Must be backported to 2.6.
This was due to a missing check in h3_trace() about the first argument
presence (connection) and h3_parse_settings_frm() which calls TRACE_LEAVE()
without any argument. Then this argument was dereferenced.
Must be backported to 2.6
As specified by RFC 9114, multiple cookie headers must be concatenated
into a single entry before passing it to a HTTP/1.1 connection. To
implement this, reuse the same function as already used for HTTP/2
module.
This should answer to feature requested in github issue #1818.
As specified by RFC 9204, encoder and decoder streams must not be
closed. If the peer behaves incorrectly and closes one of them, emit a
H3_CLOSED_CRITICAL_STREAM connection error.
To implement this, QPACK stream decoding API has been slightly adjusted.
Firstly, fin parameter is passed to notify about FIN STREAM bit.
Secondly, qcs instance is passed via unused void* context. This allows
to use qcc_emit_cc_app() function to report a CONNECTION_CLOSE error.
As specified by RFC 9114 the control stream must not be closed. If the
peer behaves incorrectly and closes it, emit a H3_CLOSED_CRITICAL_STREAM
connection error.
Implement http-request timeout for QUIC MUX. It is used when the
connection is opened and is triggered if no HTTP request is received in
time. By HTTP request we mean at least a QUIC stream with a full header
section. Then qcs instance is attached to a sedesc and upper layer is
then responsible to wait for the rest of the request.
This timeout is also used when new QUIC streams are opened during the
connection lifetime to wait for full HTTP request on them. As it's
possible to demux multiple streams in parallel with QUIC, each waiting
stream is registered in a list <opening_list> stored in qcc with <start>
as timestamp in qcs for the stream opening. Once a qcs is attached to a
sedesc, it is removed from <opening_list>. When refreshing MUX timeout,
if <opening_list> is not empty, the first waiting stream is used to set
MUX timeout.
This is efficient as streams are stored in the list in their creation
order so CPU usage is minimal. Also, the size of the list is
automatically restricted by flow control limitation so it should not
grow too much.
Streams are insert in <opening_list> by application protocol layer. This
is because only application protocol can differentiate streams for HTTP
messaging from internal usage. A function qcs_wait_http_req() has been
added to register a request stream by app layer. QUIC MUX can then
remove it from the list in qc_attach_sc().
As a side-note, it was necessary to implement attach qcc_app_ops
callback on hq-interop module to be able to insert a stream in waiting
list. Without this, a BUG_ON statement would be triggered when trying to
remove the stream on sedesc attach. This is to ensure that every
requests streams are registered for http-request timeout.
MUX timeout is explicitely refreshed on MAX_STREAM_DATA and STOP_SENDING
frame parsing to schedule http-request timeout if a new stream has been
instantiated. It was already done on STREAM parsing due to a previous
patch.
Store the current step of HTTP message in h3s stream. This reports if we
are in the parsing of headers, content or trailers section. A new enum
h3s_st_req is defined for this.
This field is stored in h3s struct but only used for request stream. It
is left undefined for other streams (control or QPACK streams).
h3_is_frame_valid() has been extended to take into account this state
information. A connection error H3_FRAME_UNEXPECTED is reported if an
invalid frame according to the current state is received; for example a
DATA frame at the beginning of a stream.
Timeout in QUIC MUX has evolved from the simple first implementation. At
the beginning, a connection was considered dead unless bidirectional
streams were opened. This was abstracted through an app callback
is_active().
Now this paradigm has been reversed and a connection is considered alive
by default, unless an error has been reported or a timeout has already
been fired. The callback is_active() is thus not used anymore and can be
safely removed to simplify qcc_is_dead().
This commit should be backported to 2.6.
Implement graceful shutdown as specified in RFC 9114. A GOAWAY frame is
generated with stream ID to indicate range of processed requests.
This process is done via the release app protocol operation. The MUX
is responsible to emit the generated GOAWAY frame after app release. A
CONNECTION_CLOSE will be emitted once there is no unacknowledged STREAM
frames.
Store a reference to the HTTP/3 control stream in h3c context.
This will be useful to implement GOAWAY emission without having to store
the control stream ID on opening.
When MUX is released, a CONNECTION_CLOSE frame should be emitted. This
will ensure that the client does not use anymore a half-dead connection.
App protocol layer is responsible to provide the error code via release
callback. For HTTP/3 NO_ERROR is used as specified in RFC 9114. If no
release callback is provided, generic QUIC NO_ERROR code is used. Note
that a graceful shutdown is used : quic_conn must emit CONNECTION_CLOSE
frame when possible. This will be provided in another patch.
This change should limit the risk of browsers stuck on webpage loading
if MUX has been released. On CONNECTION_CLOSE reception, the client will
reopen a new QUIC connection.
Adjust qcc_emit_cc_app() to allow the delay of emission of a
CONNECTION_CLOSE. This will only set the error code but the quic-conn
layer is not flagged for immediate close. The quic-conn will be
responsible to shut the connection when deemed suitable.
This change will allow to implement application graceful shutdown, such
as HTTP/3 with GOAWAY emission. This will allow to emit closing frames
on MUX release. Once all work is done at the lower layer, the quic-conn
should emit a CONNECTION_CLOSE with the registered error code.
