As was objserved with ngtcp2 client, Finished CRYPTO frame within Handshake
packet may not be sent for some reason if there's nothing to append on 1-RTT.
This results in unnecessary retransmit. To avoid this edge case, a non-zero
active_connection_id_limit transport parameter is now used to append datagram
with NEW_CONNECTION_ID 1-RTT frames.
Now handshake generates frames, and they are queued in c->quic->frames.
The ngx_quic_output() is called from ngx_quic_flush_flight() or manually,
processes the queue and encrypts all frames according to required encryption
level.
ngx_quic_hexdump0(log, format, buffer, buffer_size);
- logs hexdump of buffer to specified error log
ngx_quic_hexdump0(c->log, "this is foo:", foo.data, foo.len);
ngx_quic_hexdump(log, format, buffer, buffer_size, ...)
- same as hexdump0, but more format/args possible:
ngx_quic_hexdump(c->log, "a=%d b=%d, foo is:", foo.data, foo.len, a, b);
When "aio" or "aio threads" is used while processing the response body of an
in-memory background subrequest, the subrequest could be finalized with an aio
operation still in progress. Upon aio completion either parent request is
woken or the old r->write_event_handler is called again. The latter may result
in request errors. In either case post_subrequest handler is never called with
the full response body, which is typically expected when using in-memory
subrequests.
Currently in nginx background subrequests are created by the upstream module
and the mirror module. The issue does not manifest itself with these
subrequests because they are header-only. But it can manifest itself with
third-party modules which create in-memory background subrequests.
We used to have default error_page overwrite for 495, 496, and 497, so
a configuration like
error_page 495 /error;
will result in error 400, much like without any error_page configured.
The 494 status code was introduced later (in 3848:de59ad6bf557, nginx 0.9.4),
and relevant changes to ngx_http_core_error_page() were missed, resulting
in inconsistent behaviour of "error_page 494" - with error_page configured
it results in 494 being returned instead of 400.
Reported by Frank Liu,
http://mailman.nginx.org/pipermail/nginx/2020-February/058957.html.
Introduced ngx_quic_input() and ngx_quic_output() as interface between
nginx and protocol. They are the only functions that are exported.
While there, added copyrights.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
Duplicate "Host" headers were allowed in nginx 0.7.0 (revision b9de93d804ea)
as a workaround for some broken Motorola phones which used to generate
requests with two "Host" headers[1]. It is believed that this workaround
is no longer relevant.
[1] http://mailman.nginx.org/pipermail/nginx-ru/2008-May/017845.html
The "identity" transfer coding has been removed in RFC 7230. It is
believed that it is not used in real life, and at the same time it
provides a potential attack vector.
We anyway do not support more than one transfer encoding, so accepting
requests with multiple Transfer-Encoding headers doesn't make sense.
Further, we do not handle multiple headers, and ignore anything but
the first header.
Reported by Filippo Valsorda.
A connection could get stuck without timers if a client has partially sent
the HEADERS frame such that it was split on the individual header boundary.
In this case, it cannot be processed without the rest of the HEADERS frame.
The fix is to call ngx_http_v2_state_headers_save() in this case. Normally,
it would be called from the ngx_http_v2_state_header_block() handler on the
next iteration, when there is not enough data to continue processing. This
isn't the case if recv_buffer became empty and there's no more data to read.
With the recent change to prevent frames flood in d4448892a294,
nginx will finalize the connection with NGX_HTTP_V2_INTERNAL_ERROR
whenever flood is detected, causing nginx aborting or stopping if
the debug_points directive is used in nginx config.
Previous change 1ce3f01a4355 incorrectly introduced processing of the
ngx_posted_next_events queue at the end of operation, effectively making
posted next events a nop, since at the end of an event loop iteration
the queue is always empty. Correct approach is to move events to the
ngx_posted_events queue at an iteration start, as it was done previously.
Further, in some cases the c->read event might be already in the
ngx_posted_events queue, and calling ngx_post_event() with the
ngx_posted_next_events queue won't do anything. To make sure the event
will be correctly placed into the ngx_posted_next_events queue
we now check if it is already posted.
