MUX streams can now allocate multiple buffers for sending. quic-conn is
responsible to limit the total count of allowed allocated buffers. A
counter is stored in the new field <stream_buf_count>.
For the moment, the value is hardcoded to 30.
On stream buffer allocation failure, the qcc MUX is flagged with
QC_CF_CONN_FULL. The MUX is then woken up as soon as a buffer is freed,
most notably on ACK reception.
Acknowledge of STREAM has been complexified with the introduction of
stream multi buffers. Two functions are executing roughly the same set
of instructions in xprt_quic.c.
To simplify this, move the code complexity in a new function
qc_stream_desc_ack(). It will handle offset calculation, removal of
data, freeing oldest buffer and freeing stream instance if required.
The qc_stream_desc API is cleaner as qc_stream_desc_free_buf() ambiguous
function has been removed.
Complete the qc_stream_desc type to support multiple buffers on
emission. The main objective is to increase the transfer throughput.
The MUX is now able to transfer more data without having to wait ACKs.
To implement this feature, a new type qc_stream_buf is declared. it
encapsulates a buffer with a list element. New functions are defined to
retrieve the current buffer, release it or allocate a new one. Each
buffer is kept in the qc_stream_desc list until all of its data is
acknowledged.
On the MUX side, a qcs uses the current stream buffer to transfer data.
Once the buffer is full, it is released and a new one will be allocated
on a future qc_send() invocation.
Simplify the model qcs/qc_stream_desc. Each types has now its own tree
node, stored respectively in qcc and quic-conn trees. It is still
necessary to mark the stream as detached by the MUX once all data is
transfered to the lower layer.
This might improve slightly the performance on ACK management as now
only the lookup in quic-conn is necessary. On the other hand, memory
size of qcs structure is increased.
Regroup all type definitions and functions related to qc_stream_desc in
the source file src/quic_stream.c.
qc_stream_desc complexity will be increased with the development of Tx
multi-buffers. Having a dedicated module is useful to mix it with
pure transport/quic-conn code.
A released qc_stream_desc is freed as soon as all its buffer content has
been acknowledged. However, it may still contains other frames waiting
for ACK pointing to deleted buffer content. This can happen on
retransmission.
When freeing a qc_stream_desc, free all its frames in acked_frms tree to
fix memory leak. This may also possibly fix a crash on retransmission.
Now, the frames are properly removed from a packet. This ensure we do
not retransmit a frame whose buffer is deallocated.
Emit a CONNECTION_CLOSE if the app layer cannot be properly initialized
on qc_xprt_start. This force the quic-conn to enter the closing state
before being closed.
Without this, quic-conn normal operations continue, despite the
app-layer reported as not initialized. This behavior is undefined, in
particular when handling STREAM frames.
Fix the return value used in quic-conn start callback for error. The
caller expects a negative value in this case.
Without this patch, the quic-conn and the connection stack are not
closed despite an initialization failure error, which is an undefined
behavior and may cause a crash in the end.
If the client does not sent an ALPN, the SSL ALPN negotiation callback
is not called. However, the handshake is reported as successful. Check
just after SSL_do_handshake if an ALPN was negotiated. If not, emit a
CONNECTION_CLOSE with a TLS alert to close the connection.
This prevent a crash in qcc_install_app_ops() called with null as second
parameter value.
It was supposed to be there, and probably was not placed there due to
historic limitations in listener_accept(), but now there does not seem
to be a remaining valid reason for keeping the quic_conn out of the
handle. In addition in new_quic_cli_conn() the handle->fd was incorrectly
set to the listener's FD.
By being able to return the ssl_sock_ctx, we're now enabling the whole
set of SSL sample fetch methods to work on the current SSL context of
the QUIC connection, as seen in the following test showing a request
forwarded to an HTTP/1 server with plenty of SSL headers filled:
00000001:decrypt.clireq[000f:ffffffff]: GET / HTTP/1.1
00000001:decrypt.clihdr[000f:ffffffff]: host: localhost
00000001:decrypt.clihdr[000f:ffffffff]: user-agent: nghttp3/ngtcp2 client
00000001:decrypt.clihdr[000f:ffffffff]: x-src: 127.0.0.1
00000001:decrypt.clihdr[000f:ffffffff]: x-dst: 127.0.0.4
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_f_serial: D16197E7D3E634E9
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_f_key_alg: rsaEncryption
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_f_sig_alg: RSA-SHA1
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc: 1
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_has_sni: 1
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_sni: blah
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_alpn: h3
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_protocol: TLSv1.3
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_cipher: TLS_AES_256_GCM_SHA384
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_alg_keysize: 256
00000001:decrypt.clihdr[000f:ffffffff]: x-ssl_fc_use_keysize: 256
00000001:decrypt.clihdr[000f:ffffffff]: x-forwarded-for: 127.0.0.1
The code is trivial, but this is marked as medium as there's always
the risk that some of the callable functions do not like being called
on such SSL contexts.
OpenSSL 3.0 warns that ERR_func_error_string() is deprecated. Using
ERR_peek_error_func() solves it instead, and this function was added to
the compat layer by commit 1effd9aa0 ("MINOR: ssl: Remove call to
ERR_func_error_string with OpenSSLv3").
We modify the key update feature implementation to support reusable cipher contexts
as this is done for the other cipher contexts for packet decryption and encryption.
To do so we attach a context to the quic_tls_kp struct and initialize it each time
the underlying secret key is updated. Same thing when we rotate the secrets keys,
we rotate the contexts as the same time.
These settings are potentially cancelled by others setting initialization shared
with SSL sock bindings. This will have to be clarified when we will adapt the
QUIC bindings configuration.
Add ->ctx new member field to quic_tls_secrets struct to store the cipher context
for each QUIC TLS context TX/RX parts.
Add quic_tls_rx_ctx_init() and quic_tls_tx_ctx_init() functions to initialize
these cipher context for RX and TX parts respectively.
Make qc_new_isecs() call these two functions to initialize the cipher contexts
of the Initial secrets. Same thing for ha_quic_set_encryption_secrets() to
initialize the cipher contexts of the subsequent derived secrets (ORTT, Handshake,
1RTT).
Modify quic_tls_decrypt() and quic_tls_encrypt() to always use the same cipher
context without allocating it each time they are called.
Define a new API to notify the MUX from the quic-conn when the
connection is about to be closed. This happens in the following cases :
- on idle timeout
- on CONNECTION_CLOSE emission or reception
The MUX wake callback is called on these conditions. The quic-conn
QUIC_FL_NOTIFY_CLOSE is set to only report once. On the MUX side,
connection flags CO_FL_SOCK_RD_SH|CO_FL_SOCK_WR_SH are set to interrupt
future emission/reception.
This patch is the counterpart to
"MEDIUM: mux-quic: report CO_FL_ERROR on send".
Now the quic-conn is able to report its closing, which may be translated
by the MUX into a CO_FL_ERROR on the connection for the upper layer.
This allows the MUX to properly react to the QUIC closing mechanism for
both idle-timeout and closing/draining states.
When freeing a quic-conn, the streams resources attached to it must be
cleared. This code is already implemented but the streams buffer was not
deallocated.
Fix this by using the function qc_stream_desc_free. This existing
function centralize all operations to properly free all streams
elements, attached both to the MUX and the quic-conn.
This fixes a memory leak which can happen for each released connection.
This flag was used to notify the MUX about a CONNECTION_CLOSE frame
reception. It is now unused on the MUX side and can be removed. A new
mechanism to detect quic-conn closing will be soon implemented.
Rationalize the lifetime of the quic-conn regarding with the MUX. The
quic-conn must not be freed if the MUX is still allocated.
This simplify the MUX code when accessing the quic-conn and removed
possible segfaults.
To implement this, if the quic-conn timer expired, the quic-conn is
released only if the MUX is not allocated. Else, the quic-conn is
flagged with QUIC_FL_CONN_EXP_TIMER. The MUX is then responsible
to call quic_close() which will free the flagged quic-conn.
New received packets after sending CONNECTION_CLOSE frame trigger a new
CONNECTION_CLOSE frame to be sent. Each time such a frame is sent we
increase the number of packet required to send another CONNECTION_CLOSE
frame.
Rearm only one time the idle timer when sending a CONNECTION_CLOSE frame.
This should be useful to have an idea of the list of frames which could be built
towards the list of available frames when building packets.
Same thing about the frames which could not be built because of a lack of room
in the TX buffer.
During a handshake, after having prepared a probe upon a PTO expiration from
process_timer(), we wake up the I/O handler to make it send probing packets.
This handler first treat incoming packets which trigger a fast retransmission
leading to send too much probing (duplicated) packets. In this cas we cancel
the fast retranmission.
When discarding a packet number space, we at least reset the PTO backoff counter.
Doing this several times have an impact on the PTO duration calculation.
We must not discard a packet number space several times (this is already the case
for the handshake packet number space).
Before having a look at the next encryption level to build packets if there is
no more ack-eliciting frames to send we must check we have not to probe from
the current encryption level anymore. If not, we only send one datagram instead
of sending two datagrams giving less chance to recover from packet loss.
Due to a erroneous interpretation of the RFC 9000 (quic-transport), ACKs frames
were always sent only after having received two ack-eliciting packets.
This could trigger useless retransmissions for tail packets on the peer side.
For now on, we send as soon as possible ACK frames as soon as we have ACK to send,
in the same packets as the ack-eliciting frame packets, and we also send ACK
frames after having received 2 ack-eliciting packets since the last time we sent
an ACK frame with other ack-eliciting frames.
As such variables are handled by the QUIC connection I/O handler which runs
always on the thread, there is no need to continue to use such atomic operations
This bug has come with this commit:
1fc5e16c4 MINOR: quic: More accurate immediately close
As mentionned in this commit we do not want to derive anymore secret when in closing
state. But the flag which denote secrets were derived was set. Add a label at
the correct flag to skip the secrets derivation without setting this flag.
The new qc_stream_desc type has a tree node for storage. Thus, we can
remove the node in the qcs structure.
When initializing a new stream, it is stored into the qcc streams_by_id
tree. When the MUX releases it, it will freed as soon as its buffer is
emptied. Before this, the quic-conn is responsible to store it inside
its own streams_by_id tree.
Move the xprt-buf and ack related fields from qcs to the qc_stream_desc
structure. In exchange, qcs has a pointer to the low-level stream. For
each new qcs, a qc_stream_desc is automatically allocated.
This simplify the transport layer by removing qcs/mux manipulation
during ACK frame parsing. An additional check is done to not notify the
MUX on sending if the stream is already released : this case may now
happen on retransmission.
To complete this change, the quic_stream frame now references the
quic_stream instance instead of a qcs.
Currently, the mux qcs streams manage the Tx buffering, even after
sending it to the transport layer. Buffers are emptied when
acknowledgement are treated by the transport layer. This complicates the
MUX liberation and we may loose some data after the MUX free.
Change this paradigm by moving the buffering on the transport layer. For
this goal, a new type is implemented as low-level stream at the
transport layer, as a counterpart of qcs mux instances. This structure
is called qc_stream_desc. This will allow to free the qcs/qcc instances
without having to wait for acknowledge reception.
For the moment, the quic-conn is responsible to store the qc_stream_desc
in a new tree named streams_by_id. This will sligthly change in the next
commits to remove the qcs node which has a similar purpose :
qc_stream_desc instances will be shared between the qcc MUX and the
quic-conn.
This patch only introduces the new type definition and the function to
manipulate it. The following commit will bring the rearchitecture in the
qcs structure.
The quic_stream frame stores the qcs instance. On ACK parsing, qcs is
accessed to clear the stream buffer. This can cause a segfault if the
MUX or the qcs is already released.
Consider the following scenario :
1. a STREAM frame is generated by the MUX
transport layer emits the frame with PKN=1
upper layer has finished the transfer so related qcs is detached
2. transport layer reemits the frame with PKN=2 because ACK was not
received
3. ACK for PKN=1 is received, stream buffer is cleared
at this stage, qcs may be freed by the MUX as it is detached
4. ACK for PKN=2 is received
qcs for STREAM frame is dereferenced which will lead to a crash
To prevent this, qcs is never accessed from the quic_stream during ACK
parsing. Instead, a lookup is done on the MUX streams tree. If the MUX
is already released, no lookup is done. These checks prevents a possible
segfault.
This change may have an impact on the perf as now we are forced to use a
tree lookup operation. If this is the case, an alternative solution may
be to implement a refcount on qcs instances.
After having consumed <i> bytes from <buf>, the remaining available room to be
passed to generate_retry_token() is sizeof(buf) - i.
This bug could be easily reproduced with quic-qo as client which chooses a random
value as ODCID length.
This commit is similar to the previous one but with MAX_DATA frames.
This allows to increase the connection level flow-control limit. If the
connection was blocked due to QC_CF_BLK_MFCTL flag, the flag is reseted.
Implement a MUX method to parse MAX_STREAM_DATA. If the limit is greater
than the previous one and the stream was blocked, the flag
QC_SF_BLK_SFCTL is removed.
