A QUIC stream could be destroyed by handler while in ngx_quic_stream_input().
To detect this, ngx_quic_find_stream() is used to check that it still exists.
Previously, a stream id was passed to this routine off the frame structure.
In case of stream cleanup, it is freed along with other frames belonging to
the stream on cleanup. Then, a cleanup handler reuses last frames to update
MAX_STREAMS and serve other purpose. Thus, ngx_quic_find_stream() is passed
a reused frame with zeroed out part pointed by stream_id. If a stream with
id 0x0 still exists, this leads to use-after-free.
The limits on active bidi and uni client streams are maintained at their
initial values initial_max_streams_bidi and initial_max_streams_uni by sending
a MAX_STREAMS frame upon each client stream closure.
Also, the following is changed for data arriving to non-existing streams:
- if a stream was already closed, such data is ignored
- when creating a new stream, all streams of the same type with lower ids are
created too
The ngx_http_perl_module module doesn't have a notion of including additional
search paths through --with-cc-opt, which results in compile error incomplete
type 'enum ssl_encryption_level_t' when building nginx without QUIC support.
The enum is visible from quic event headers and eventually pollutes ngx_core.h.
The fix is to limit including headers to compile units that are real consumers.
According to quic-transport draft 29, section 21.12.1.1:
Prior to validation, endpoints are limited in what they are able to
send. During the handshake, a server cannot send more than three
times the data it receives; clients that initiate new connections or
migrate to a new network path are limited.
The ngx_quic_queue_frame() functions puts a frame into send queue and
schedules a push timer to actually send data.
The patch adds tracking for data amount in the queue and sends data
immediately if amount of data exceeds limit.
Instead of timer-based retransmissions with constant packet lifetime,
this patch implements ack-based loss detection and probe timeout
for the cases, when no ack is received, according to the quic-recovery
draft 29.
The c->quic->retransmit timer is now called "pto".
The ngx_quic_retransmit() function is renamed to "ngx_quic_detect_lost()".
This is a preparation for the following patches.
According to the quic-recovery 29, Section 5: Estimating the Round-Trip Time.
Currently, integer arithmetics is used, which loses sub-millisecond accuracy.
As long as the "Content-Length" header is given, we now make sure
it exactly matches the size of the response. If it doesn't,
the response is considered malformed and must not be forwarded
(https://tools.ietf.org/html/rfc7540#section-8.1.2.6). While it
is not really possible to "not forward" the response which is already
being forwarded, we generate an error instead, which is the closest
equivalent.
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Also this
directly contradicts HTTP/2 specification requirements.
Note that the new behaviour for the gRPC proxy is more strict than that
applied in other variants of proxying. This is intentional, as HTTP/2
specification requires us to do so, while in other types of proxying
malformed responses from backends are well known and historically
tolerated.
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Fix is to
drop extra data instead, as it naturally happens in most clients.
Additionally, we now also issue a warning if the response is too
short, and make sure the fact it is truncated is propagated to the
client. The u->error flag is introduced to make it possible to
propagate the error to the client in case of unbuffered proxying.
For responses to HEAD requests there is an exception: we do allow
both responses without body and responses with body matching the
Content-Length header.
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Fix is to
drop extra data instead, as it naturally happens in most clients.
This change covers generic buffered and unbuffered filters as used
in the scgi and uwsgi modules. Appropriate input filter init
handlers are provided by the scgi and uwsgi modules to set corresponding
lengths.
Note that for responses to HEAD requests there is an exception:
we do allow any response length. This is because responses to HEAD
requests might be actual full responses, and it is up to nginx
to remove the response body. If caching is enabled, only full
responses matching the Content-Length header will be cached
(see b779728b180c).
Previously, additional data after final chunk was either ignored
(in the same buffer, or during unbuffered proxying) or sent to the
client (in the next buffer already if it was already read from the
socket). Now additional data are properly detected and ignored
in all cases. Additionally, a warning is now logged and keepalive
is disabled in the connection.
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Fix is to
drop extra data instead, as it naturally happens in most clients.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
After sending the GOAWAY frame, a connection is now closed using
the lingering close mechanism.
This allows for the reliable delivery of the GOAWAY frames, while
also fixing connection resets observed when http2_max_requests is
reached (ticket #1250), or with graceful shutdown (ticket #1544),
when some additional data from the client is received on a fully
closed connection.
For HTTP/2, the settings lingering_close, lingering_timeout, and
lingering_time are taken from the "server" level.
Previously, the expression (ch & 0x7f) was promoted to a signed integer.
Depending on the platform, the size of this integer could be less than 8 bytes,
leading to overflow when handling the higher bits of the result. Also, sign
bit of this integer could be replicated when adding to the 64-bit st->value.
