Previously the preread phase code ignored NGX_AGAIN value returned from
c->recv() and relied only on c->read->ready. But this flag is not reliable and
should only be checked for optimization purposes. For example, when using
SSL, c->read->ready may be set when no input is available. This can lead to
calling preread handler infinitely in a loop.
The problem does not manifest itself currently, because in case of
non-buffered reading, chain link created by u->create_request method
consists of a single element.
Found by PVS-Studio.
The directive configures maximum number of requests allowed on
a connection kept in the cache. Once a connection reaches the number
of requests configured, it is no longer saved to the cache.
The default is 100.
Much like keepalive_requests for client connections, this is mostly
a safeguard to make sure connections are closed periodically and the
memory allocated from the connection pool is freed.
The directive configures maximum time a connection can be kept in the
cache. By configuring a time which is smaller than the corresponding
timeout on the backend side one can avoid the race between closing
a connection by the backend and nginx trying to use the same connection
to send a request at the same time.
LibreSSL 2.8.0 "added const annotations to many existing APIs from OpenSSL,
making interoperability easier for downstream applications". This includes
the const change in the SSL_CTX_sess_set_get_cb() callback function (see
9dd43f4ef67e), which breaks compilation.
To fix this, added a condition on how we redefine OPENSSL_VERSION_NUMBER
when working with LibreSSL (see 382fc7069e3a). With LibreSSL 2.8.0,
we now set OPENSSL_VERSION_NUMBER to 0x1010000fL (OpenSSL 1.1.0), so the
appropriate conditions in the code will use "const" as it happens with
OpenSSL 1.1.0 and later versions.
There are clients which cannot handle HPACK's dynamic table size updates
as added in 12cadc4669a7 (1.13.6). Notably, old versions of OkHttp library
are known to fail on it (ticket #1397).
This change makes it possible to work with such clients by only sending
dynamic table size updates in response to SETTINGS_HEADER_TABLE_SIZE. As
a downside, clients which do not use SETTINGS_HEADER_TABLE_SIZE will
continue to maintain default 4k table.
Previously, a chunk of spaces larger than NGX_CONF_BUFFER (4096 bytes)
resulted in the "too long parameter" error during parsing such a
configuration. This was because the code only set start and start_line
on non-whitespace characters, and hence adjacent whitespace characters
were preserved when reading additional data from the configuration file.
Fix is to always move start and start_line if the last character was
a space.
Early data AKA 0-RTT mode is enabled as long as "ssl_early_data on" is
specified in the configuration (default is off).
The $ssl_early_data variable evaluates to "1" if the SSL handshake
isn't yet completed, and can be used to set the Early-Data header as
per draft-ietf-httpbis-replay-04.
BoringSSL currently requires SSL_CTX_set_max_proto_version(TLS1_3_VERSION)
to be able to enable TLS 1.3. This is because by default max protocol
version is set to TLS 1.2, and the SSL_OP_NO_* options are merely used
as a blacklist within the version range specified using the
SSL_CTX_set_min_proto_version() and SSL_CTX_set_max_proto_version()
functions.
With this change, we now call SSL_CTX_set_max_proto_version() with an
explicit maximum version set. This enables TLS 1.3 with BoringSSL.
As a side effect, this change also limits maximum protocol version to
the newest protocol we know about, TLS 1.3. This seems to be a good
change, as enabling unknown protocols might have unexpected results.
Additionally, we now explicitly call SSL_CTX_set_min_proto_version()
with 0. This is expected to help with Debian system-wide default
of MinProtocol set to TLSv1.2, see
http://mailman.nginx.org/pipermail/nginx-ru/2017-October/060411.html.
Note that there is no SSL_CTX_set_min_proto_version macro in BoringSSL,
so we call SSL_CTX_set_min_proto_version() and SSL_CTX_set_max_proto_version()
as long as the TLS1_3_VERSION macro is defined.
The behaviour is now in line with COPY of a directory with contents,
which preserves access masks on individual files, as well as the "cp"
command.
Requested by Roman Arutyunyan.
This fixes wrong permissions and file time after cross-device MOVE
in the DAV module (ticket #1577). Broken in 8101d9101ed8 (0.8.9) when
cross-device copying was introduced in ngx_ext_rename_file().
With this change, ngx_copy_file() always calls ngx_set_file_time(),
either with the time provided, or with the time from the original file.
This is considered acceptable given that copying the file is costly anyway,
and optimizing cases when we do not need to preserve time will require
interface changes.
Previously, ngx_open_file(NGX_FILE_CREATE_OR_OPEN) was used, resulting
in destination file being partially rewritten if exists. Notably,
this affected WebDAV COPY command (ticket #1576).
Previously, "%uA" was used, which corresponds to ngx_atomic_uint_t.
Size of ngx_atomic_uint_t can be easily different from uint64_t,
leading to undefined results.
In TLSv1.3, NewSessionTicket messages arrive after the handshake and
can come at any time. Therefore we use a callback to save the session
when we know about it. This approach works for < TLSv1.3 as well.
The callback function is set once per location on merge phase.
Since SSL_get_session() in BoringSSL returns an unresumable session for
TLSv1.3, peer save_session() methods have been updated as well to use a
session supplied within the callback. To preserve API, the session is
cached in c->ssl->session. It is preferably accessed in save_session()
methods by ngx_ssl_get_session() and ngx_ssl_get0_session() wrappers.
In OpenSSL 1.1.0 the SSL_CTRL_CLEAR_OPTIONS macro was removed, so
conditional compilation test on it results in SSL_clear_options()
and SSL_CTX_clear_options() not being used. Notably, this caused
"ssl_prefer_server_ciphers off" to not work in SNI-based virtual
servers if server preference was switched on in the default server.
It looks like the only possible fix is to test OPENSSL_VERSION_NUMBER
explicitly.
Starting with OpenSSL 1.1.0, SSL_R_UNSUPPORTED_PROTOCOL instead of
SSL_R_UNKNOWN_PROTOCOL is reported when a protocol is disabled via
an SSL_OP_NO_* option.
Additionally, SSL_R_VERSION_TOO_LOW is reported when using MinProtocol
or when seclevel checks (as set by @SECLEVEL=n in the cipher string)
rejects a protocol, and this is what happens with SSLv3 and @SECLEVEL=1,
which is the default.
There is also the SSL_R_VERSION_TOO_HIGH error code, but it looks like
it is not possible to trigger it.
There should be at least one worker connection for each listening socket,
plus an additional connection for channel between worker and master,
or starting worker processes will fail.
Previously, listenings sockets were not cloned if the worker_processes
directive was specified after "listen ... reuseport".
This also simplifies upcoming configuration check on the number
of worker connections, as it needs to know the number of listening
sockets before cloning.
The variable keeps the latest SSL protocol version supported by the client.
The variable has the same format as $ssl_protocol.
The version is read from the client_version field of ClientHello. If the
supported_versions extension is present in the ClientHello, then the version
is set to TLSv1.3.
Errors when sending UDP datagrams can happen, e.g., when local IP address
changes (see fa0e093b64d7), or an unavailable DNS server on the LAN can cause
send() to fail with EHOSTDOWN on BSD systems. If this happens during
initial query, retry sending immediately, to a different DNS server when
possible. If this is not enough, allow normal resend to happen by ignoring
the return code of the second ngx_resolver_send_query() call, much like we
do in ngx_resolver_resend().
The "http request" and "https proxy request" errors cannot happen
with HTTP due to pre-handshake checks in ngx_http_ssl_handshake(),
but can happen when SSL is used in stream and mail modules.
With gRPC it is possible that a request sending is blocked due to flow
control. Moreover, further sending might be only allowed once the
backend sees all the data we've already sent. With such a backend
it is required to clear the TCP_NOPUSH socket option to make sure all
the data we've sent are actually delivered to the backend.
As such, we now clear TCP_NOPUSH in ngx_http_upstream_send_request()
also on NGX_AGAIN if c->write->ready is set. This fixes a test (which
waits for all the 64k bytes as per initial window before allowing more
bytes) with sendfile enabled when the body was written to a file
in a different context.
Now tcp_nopush on peer connections is disabled if it is disabled on
the client connection, similar to how we handle c->sendfile. Previously,
tcp_nopush was always used on upstream connections, regardless of
the "tcp_nopush" directive.
We copy input buffers to our buffers, so various flags might be
unexpectedly set in buffers returned by ngx_chain_get_free_buf().
In particular, the b->in_file flag might be set when the body was
written to a file in a different context. With sendfile enabled this
in turn might result in protocol corruption if such a buffer was reused
for a control frame.
Make sure to clear buffers and set only fields we really need to be set.
The module implements random load-balancing algorithm with optional second
choice. In the latter case, the best of two servers is chosen, accounting
number of connections and server weight.
Example:
upstream u {
random [two [least_conn]];
server 127.0.0.1:8080;
server 127.0.0.1:8081;
server 127.0.0.1:8082;
server 127.0.0.1:8083;
}
Before 4a8c9139e579, ngx_resolver_create() didn't use configuration
pool, and allocations were done using malloc().
In 016352c19049, when resolver gained support of several servers,
new allocations were done from the pool.
With u->conf->preserve_output set the request body file might be used
after the response header is sent, so avoid cleaning it. (Normally
this is not a problem as u->conf->preserve_output is only set with
r->request_body_no_buffering, but the request body might be already
written to a file in a different context.)
Previously, only one client packet could be processed in a udp stream session
even though multiple response packets were supported. Now multiple packets
coming from the same client address and port are delivered to the same stream
session.
If it's required to maintain a single stream of data, nginx should be
configured in a way that all packets from a client are delivered to the same
worker. On Linux and DragonFly BSD the "reuseport" parameter should be
specified for this. Other systems do not currently provide appropriate
mechanisms. For these systems a single stream of udp packets is only
guaranteed in single-worker configurations.
The proxy_response directive now specifies how many packets are expected in
response to a single client packet.
Previously, ngx_event_recvmsg() got remote socket addresses after creating
the connection object. In preparation to handling multiple UDP packets in a
single session, this code was moved up.
On Linux recvmsg() syscall may return a zero-length client address when
receiving a datagram from an unbound unix datagram socket. It is usually
assumed that socket address has at least the sa_family member. Zero-length
socket address caused buffer over-read in functions which receive socket
address, for example ngx_sock_ntop(). Typically the over-read resulted in
unexpected socket family followed by session close. Now a fake socket address
is allocated instead of a zero-length client address.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
The bug in question was fixed in glibc 2.3.2 and is no longer expected
to manifest itself on real servers. On the other hand, the workaround
causes compilation problems on various systems. Previously, we've
already fixed the code to compile with musl libc (fd6fd02f6a4d), and
now it is broken on Fedora 28 where glibc's crypt library was replaced
by libxcrypt. So the workaround was removed.
FreeBSD returns EINVAL when getsockopt(TCP_FASTOPEN) is called on a unix
domain socket, resulting in "getsockopt(TCP_FASTOPEN) ... failed" messages
during binary upgrade when unix domain listen sockets are present in
the configuration. Added EINVAL to the list of ignored error codes.
Previously, only unix domain sockets were reopened to tolerate cases when
local syslog server was restarted. It makes sense to treat other cases
(for example, local IP address changes) similarly.
Cast to intermediate "void *" to lose compiler knowledge about the original
type and pass the warning. This is not a real fix but rather a workaround.
Found by gcc8.
In mail and stream modules, no certificate provided is a fatal condition,
much like with the "ssl" and "starttls" directives.
In http, "listen ... ssl" can be used in a non-default server without
certificates as long as there is a certificate in the default one, so
missing certificate is only fatal for default servers.
In 51e1f047d15d, the "ssl" directive name was incorrectly hardcoded
in the error message shown when there are some SSL keys defined, but
not for all certificates. Right approach is to use the "mode" variable,
which can be either "ssl" or "starttls".
Previously, result of ngx_atoi() was assigned to an ngx_uint_t variable,
and errors reported by ngx_atoi() became positive, so the following check
in "status < 100" failed to catch them. This resulted in the configurations
like "proxy_cache_valid 2xx 30s" being accepted as correct, while they
in fact do nothing. Changing type to ngx_int_t fixes this, and such
configurations are now properly rejected.
Previously, ngx_http_upstream_process_header() might be called after
we've finished reading response headers and switched to a different read
event handler, leading to errors with gRPC proxying. Additionally,
the u->conf->read_timeout timer might be re-armed during reading response
headers (while this is expected to be a single timeout on reading
the whole response header).
Previously, ngx_http_upstream_test_next() used an outdated condition on
whether it will be possible to switch to a different server or not. It
did not take into account restrictions on non-idempotent requests, requests
with non-buffered request body, and the next upstream timeout.
For such requests, switching to the next upstream server was rejected
later in ngx_http_upstream_next(), resulting in nginx own error page
being returned instead of the original upstream response.
- use normal prefixes for types and macros
- removed some macros and types
- revised debug messages
- removed useless check of ngx_sock_ntop() returning 0
- removed special processing of AF_UNSPEC
The protocol used on inbound connection is auto-detected and corresponding
parser is used to extract passed addresses. TLV parameters are ignored.
The maximum supported size of PROXY protocol header is 107 bytes
(similar to version 1).
All cases are harmless and should not happen on valid values, though can
result in bad values being shown incorrectly in logs.
Found by Coverity (CID 1430311, 1430312, 1430313).
The fields "uri", "location", and "url" from ngx_http_upstream_conf_t
moved to ngx_http_proxy_loc_conf_t and ngx_http_proxy_vars_t, reflect
this change in create_loc_conf comments.
The gRPC protocol makes a distinction between HEADERS frame with
the END_STREAM flag set, and a HEADERS frame followed by an empty
DATA frame with the END_STREAM flag. The latter is not permitted,
and results in errors not being propagated through nginx. Instead,
gRPC clients complain that "server closed the stream without sending
trailers" (seen in grpc-go) or "13: Received RST_STREAM with error
code 2" (seen in grpc-c).
To fix this, nginx now returns HEADERS with the END_STREAM flag if
the response length is known to be 0, and we are not expecting
any trailer headers to be added. And the response length is
explicitly set to 0 in the gRPC proxy if we see initial HEADERS frame
with the END_STREAM flag set.
According to the gRPC protocol specification, the "TE" header is used
to detect incompatible proxies, and at least grpc-c server rejects
requests without "TE: trailers".
To preserve the logic, we have to pass "TE: trailers" to the backend if
and only if the original request contains "trailers" in the "TE" header.
Note that no other TE values are allowed in HTTP/2, so we have to remove
anything else.
The module allows passing requests to upstream gRPC servers.
The module is built by default as long as HTTP/2 support is compiled in.
Example configuration:
grpc_pass 127.0.0.1:9000;
Alternatively, the "grpc://" scheme can be used:
grpc_pass grpc://127.0.0.1:9000;
Keepalive support is available via the upstream keepalive module. Note
that keepalive connections won't currently work with grpc-go as it fails
to handle SETTINGS_HEADER_TABLE_SIZE.
To use with SSL:
grpc_pass grpcs://127.0.0.1:9000;
SSL connections use ALPN "h2" when available. At least grpc-go works fine
without ALPN, so if ALPN is not available we just establish a connection
without it.
Tested with grpc-c++ and grpc-go.
The flag can be used to continue sending request body even after we've
got a response from the backend. In particular, this is needed for gRPC
proxying of bidirectional streaming RPCs, and also to send control frames
in other forms of RPCs.
The flag indicates whether last ngx_output_chain() returned NGX_AGAIN
or not. If the flag is set, we arm the u->conf->send_timeout timer.
The flag complements c->write->ready test, and allows to stop sending
the request body in an output filter due to protocol-specific flow
control.
Basic trailer headers support allows one to access response trailers
via the $upstream_trailer_* variables.
Additionally, the u->conf->pass_trailers flag was introduced. When the
flag is set, trailer headers from the upstream response are passed to
the client. Like normal headers, trailer headers will be hidden
if present in u->conf->hide_headers_hash.
When clock_gettime(CLOCK_MONOTONIC) (or faster variants, _FAST on FreeBSD,
and _COARSE on Linux) is available, we now use it for ngx_current_msec.
This should improve handling of timers if system time changes (ticket #189).
The r->out chain link could be left uninitialized in case of error.
A segfault could happen if the subrequest handler accessed it.
The issue was introduced in commit 20f139e9ffa8.
Previously, only the upstream response body could be accessed with the
NGX_HTTP_SUBREQUEST_IN_MEMORY feature. Now any response body from a subrequest
can be saved in a memory buffer. It is available as a single buffer in r->out
and the buffer size is configured by the subrequest_output_buffer_size
directive.
Upstream, proxy and fastcgi code used to handle the old-style feature is
removed.
