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.
Keeps the full address of the upstream server. If several servers were
contacted during proxying, their addresses are separated by commas,
e.g. "192.168.1.1:80, 192.168.1.2:80".
The stream session status is one of the following:
200 - normal completion
403 - access forbidden
500 - internal server error
502 - bad gateway
503 - limit conn
If the range includes two or more /16 networks and does
not start at the /16 boundary, the last subrange was not
removed (see 91cff7f97a50 for details).
If PCRE is disabled, captures were treated as normal variables in
ngx_http_script_compile(), while code calculating flushes array length in
ngx_http_compile_complex_value() did not account captures as variables.
This could lead to write outside of the array boundary when setting
last element to -1.
Found with AddressSanitizer.
The following two types of bind addresses are supported in addition to
$remote_addr and address literals:
- $remote_addr:$remote_port
- [$remote_addr]:$remote_port
In both cases client remote address with port is used in upstream socket bind.
This patch moves various OpenSSL-specific function calls into the
OpenSSL module and introduces ngx_ssl_ciphers() to make nginx more
crypto-library-agnostic.
The 6f8254ae61b8 change inadvertently fixed the duplicate port
detection similar to how it was fixed for mail in b2920b517490.
It also revealed another issue: the socket type (tcp vs. udp)
wasn't taken into account.
OpenSSL 1.0.2+ allows configuring a curve list instead of a single curve
previously supported. This allows use of different curves depending on
what client supports (as available via the elliptic_curves extension),
and also allows use of different curves in an ECDHE key exchange and
in the ECDSA certificate.
The special value "auto" was introduced (now the default for ssl_ecdh_curve),
which means "use an internal list of curves as available in the OpenSSL
library used". For versions prior to OpenSSL 1.0.2 it maps to "prime256v1"
as previously used. The default in 1.0.2b+ prefers prime256v1 as well
(and X25519 in OpenSSL 1.1.0+).
As client vs. server preference of curves is controlled by the
same option as used for ciphers (SSL_OP_CIPHER_SERVER_PREFERENCE),
the ssl_prefer_server_ciphers directive now controls both.
This parameter lets binding the proxy connection to a non-local address.
Upstream will see the connection as coming from that address.
When used with $remote_addr, upstream will accept the connection from real
client address.
Example:
proxy_bind $remote_addr transparent;
The main proxy function ngx_stream_proxy_process() can terminate the stream
session. The code, following it, should check its return code to make sure the
session still exists. This happens in client and upstream initialization
functions. Swapping ngx_stream_proxy_process() call with the code, that
follows it, leaves the same problem vice versa.
In future ngx_stream_proxy_process() will call ngx_stream_proxy_next_upstream()
making it too complicated to know if stream session still exists after this
call.
Now ngx_stream_proxy_process() is called from posted event handlers in both
places with no code following it. The posted event is automatically removed
once session is terminated.
Resolved warnings about declarations that hide previous local declarations.
Warnings about WSASocketA() being deprecated resolved by explicit use of
WSASocketW() instead of WSASocket(). When compiling without IPv6 support,
WinSock deprecated warnings are disabled to allow use of gethostbyname().
Once upstream is connected, the upstream buffer is allocated. Previously, the
proxy module used the buffer allocation status to check if upstream is
connected. Now it's enough to check the flag.
When configured, an individual listen socket on a given address is
created for each worker process. This allows to reduce in-kernel lock
contention on configurations with high accept rates, resulting in better
performance. As of now it works on Linux and DragonFly BSD.
Note that on Linux incoming connection requests are currently tied up
to a specific listen socket, and if some sockets are closed, connection
requests will be reset, see https://lwn.net/Articles/542629/. With
nginx, this may happen if the number of worker processes is reduced.
There is no such problem on DragonFly BSD.
Based on previous work by Sepherosa Ziehau and Yingqi Lu.
There is no need to set "i" to 0, as it's expected to be 0 assuming
the bindings are properly sorted, and we already rely on this when
explicitly set hport->naddrs to 1. Remaining conditional code is
replaced with identical "hport->naddrs = i + 1".
Identical modifications are done in the mail and stream modules,
in the ngx_mail_optimize_servers() and ngx_stream_optimize_servers()
functions, respectively.
No functional changes.
When client or upstream connection is closed, level-triggered read event
remained active until the end of the session leading to cpu hog. Now the flag
NGX_CLOSE_EVENT is used to unschedule the event.
