Previously, when input ended on a QUIC buffer boundary, input chain was not
advanced to the next buffer. As a result, ngx_quic_write_chain() returned
a chain with an empty buffer instead of NULL. This broke HTTP write filter,
preventing it from closing the HTTP request and eventually timing out.
Now input chain is always advanced to a buffer that has data, before checking
QUIC buffer boundary condition.
Chrome only uses TLS session tickets once with TLS 1.3, likely following
RFC 8446 Appendix C.4 recommendation. With OpenSSL, this works fine with
built-in session tickets, since these are explicitly renewed in case of
TLS 1.3 on each session reuse, but results in only two connections being
reused after an initial handshake when using ssl_session_ticket_key.
Fix is to always renew TLS session tickets in case of TLS 1.3 when using
ssl_session_ticket_key, similarly to how it is done by OpenSSL internally.
Line continuation as used in the syntax file might be broken if "compatible"
is set or "C" is added to cpoptions. Fix is to set the "cpoptions" option
to vim default value at script start and restore it later, see
":help use-cpo-save".
RFC 9000, 9.3. Responding to Connection Migration:
An endpoint only changes the address to which it sends packets in
response to the highest-numbered non-probing packet.
The patch extends this requirement to probing packets. Although it may
seem excessive, it helps with mitigation of reply attacks (when an off-path
attacker has copied packet with PATH_CHALLENGE and uses different
addresses to exhaust available connection ids).
The quic connection now holds active, backup and probe paths instead
of sockets. The number of migration paths is now limited and cannot
be inflated by a bad client or an attacker.
The client id is now associated with path rather than socket. This allows
to simplify processing of output and connection ids handling.
New migration abandons any previously started migrations. This allows to
free consumed client ids and request new for use in future migrations and
make progress in case when connection id limit is hit during migration.
A path now can be revalidated without losing its state.
The patch also fixes various issues with NAT rebinding case handling:
- paths are now validated (previously, there was no validation
and paths were left in limited state)
- attempt to reuse id on different path is now again verified
(this was broken in 40445fc7c403)
- former path is now validated in case of apparent migration
The function splits a buffer at given offset. The function is now
called from ngx_quic_read_chain() and ngx_quic_write_chain(), which
simplifies both functions.
After 9ae239d2547d, ngx_quic_handle_write_event() no longer runs into
ngx_send_lowat() for QUIC connections, so the check became excessive.
It is assumed that external modules operating with SO_SNDLOWAT
(I'm not aware of any) should do this check on their own.
Previously, ngx_quic_write_chain() treated each input buffer as a memory
buffer, which is not always the case. Special buffers were not skipped, which
is especially important when hitting the input byte limit.
The issue manifested itself with ngx_quic_write_chain() returning a non-empty
chain consisting of a special last_buf buffer when called from QUIC stream
send_chain(). In order for this to happen, input byte limit should be equal to
the chain length, and the input chain should end with an empty last_buf buffer.
An easy way to achieve this is the following:
location /empty {
return 200;
}
When this non-empty chain was returned from send_chain(), it signalled to the
caller that input was blocked, while in fact it wasn't. This prevented HTTP
request from finalization, which prevented QUIC from sending STREAM FIN to
the client. The QUIC stream was then reset after a timeout.
Now special buffers are skipped and send_chain() returns NULL in the case
above, which signals to the caller a successful operation.
Also, original byte limit is now passed to ngx_quic_write_chain() from
send_chain() instead of actual chain length to make sure it's never zero.
Previously, when a STREAM FIN frame with no data bytes was received after all
prior stream data were already read by the application layer, the frame was
ignored and eof was not reported to the application.
When a worker process is shutting down, keepalive is not used: this is checked
before the ngx_http_set_keepalive() call in ngx_http_finalize_connection().
Yet the "Connection: keep-alive" header was still sent, even if we know that
the worker process is shutting down, potentially resulting in additional
requests being sent to the connection which is going to be closed anyway.
While clients are expected to be able to handle asynchronous close events
(see ticket #1022), it is certainly possible to send the "Connection: close"
header instead, informing the client that the connection is going to be closed
and potentially saving some unneeded work.
With this change, we additionally check for worker process shutdown just
before sending response headers, and disable keepalive accordingly.
Linux with EPOLLEXCLUSIVE usually notifies only the process which was first
to add the listening socket to the epoll instance. As a result most of the
connections are handled by the first worker process (ticket #2285). To fix
this, we re-add the socket periodically, so other workers will get a chance
to accept connections.
The SF_NOCACHE flag, introduced in FreeBSD 11 along with the new non-blocking
sendfile() implementation by glebius@, makes it possible to use sendfile()
along with the "directio" directive.
Starting with FreeBSD 11, there is no need to use AIO operations to preload
data into cache for sendfile(SF_NODISKIO) to work. Instead, sendfile()
handles non-blocking loading data from disk by itself. It still can, however,
return EBUSY if a page is already being loaded (for example, by a different
process). If this happens, we now post an event for the next event loop
iteration, so sendfile() is retried "after a short period", as manpage
recommends.
The limit of the number of EBUSY tolerated without any progress is preserved,
but now it does not result in an alert, since on an idle system event loop
iteration might be very short and EBUSY can happen many times in a row.
Instead, SF_NODISKIO is simply disabled for one call once the limit is
reached.
With this change, sendfile(SF_NODISKIO) is now used automatically as long as
sendfile() is enabled, and no longer requires "aio on;".
It was mostly copy of the ngx_quic_listen(). Now ngx_quic_listen() no
longer generates server id and increments seqnum. Instead, the server
id is generated when the socket is created.
The ngx_quic_alloc_socket() function is renamed to ngx_quic_create_socket().
Notably, NAXSI is known to misuse ngx_regex_compile() with rc.options set
to PCRE_CASELESS | PCRE_MULTILINE. With PCRE2 support, and notably binary
compatibility changes, it is no longer possible to set PCRE[2]_MULTILINE
option without using proper interface. To facilitate correct usage,
this change adds the NGX_REGEX_MULTILINE option.
With this change, dynamic modules using nginx regex interface can be used
regardless of the variant of the PCRE library nginx was compiled with.
If a module is compiled with different PCRE library variant, in case of
ngx_regex_exec() errors it will report wrong function name in error
messages. This is believed to be tolerable, given that fixing this will
require interface changes.
The PCRE2 library is now used by default if found, instead of the
original PCRE library. If needed for some reason, this can be disabled
with the --without-pcre2 configure option.
To make it possible to specify paths to the library and include files
via --with-cc-opt / --with-ld-opt, the library is first tested without
any additional paths and options. If this fails, the pcre2-config script
is used.
Similarly to the original PCRE library, it is now possible to build PCRE2
from sources with nginx configure, by using the --with-pcre= option.
It automatically detects if PCRE or PCRE2 sources are provided.
Note that compiling PCRE2 10.33 and later requires inttypes.h. When
compiling on Windows with MSVC, inttypes.h is only available starting
with MSVC 2013. In older versions some replacement needs to be provided
("echo '#include <stdint.h>' > pcre2-10.xx/src/inttypes.h" is good enough
for MSVC 2010).
The interface on nginx side remains unchanged.
