Explicit checks for OPENSSL_VERSION_NUMBER replaced with checks
for X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT, thus allowing X509_check_host()
to be used with other libraries. In particular, X509_check_host() was
introduced in LibreSSL 2.5.0.
IPv6 now compiled-in automatically if support is found. If there is a need
to disable it for some reason, --with-cc-opt="-DNGX_HAVE_INET6=0" can be used
for this.
When the last_buf flag is cleared for add_after_body to append more data from a
subrequest, other filters may still have buffered data, which should be flushed
at this point. For example, the sub_filter may have a partial match buffered,
which will only be flushed after the subrequest is done, ending up with
interleaved data in output.
Setting last_in_chain instead of last_buf flushes the data and fixes the order
of output buffers.
The last_buf flag should only be set in the last buffer of the main request.
Otherwise, several last_buf flags can appear in output. This can, for example,
break the chunked filter, which will include several final chunks in output.
The IPV6_V6ONLY macro is now checked only while parsing appropriate flag
and when using the macro.
The ipv6only field in listen structures is always initialized to 1,
even if not supported on a given platform. This is expected to prevent
a module compiled without IPV6_V6ONLY from accidentally creating dual
sockets if loaded into main binary with proper IPV6_V6ONLY support.
It is to be used as a bitmask with various bits set/reset when appropriate.
Any bit set means that the peer should not be used, that is, exactly what
current checks do, no additional changes required.
Previously flags passed by --with-ld-opt were not used when building perl
module, which meant hardening flags provided by package build systems were not
applied.
All the errors that prevent loading configuration must be printed on the "emerg"
log level. Previously, nginx might silently fail to load configuration in some
cases as the default log level is "error".
The ssl_preread module extracts information from the SSL Client Hello message
without terminating SSL. Currently, only $ssl_preread_server_name variable
is supported, which contains server name from the SNI extension.
In this phase, head of a stream is read and analysed before proceeding to the
content phase. Amount of data read is controlled by the module implementing
the phase, but not more than defined by the "preread_buffer_size" directive.
The time spent on processing preread is controlled by the "preread_timeout"
directive.
The typical preread phase module will parse the beginning of a stream and set
variable that may be used by the content phase, for example to make routing
decision.
Previously, it was not possible to use the stream context
inside ngx_stream_init_connection() handlers. Now, limit_conn,
access handlers, as well as those added later, can create
their own contexts.
Previously, it was possible that some system calls could be
invoked while holding the accept mutex. This is clearly
wrong as it prevents incoming connections from being accepted
as quickly as possible.
