In ac9b1df5b246 (1.13.0) we attempted to allow renegotiation in client mode,
but when using OpenSSL 1.0.2 or older versions it was additionally disabled
by SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS.
If initialization of a header failed for some reason after ngx_list_push(),
leaving the header as is can result in uninitialized memory access by
the header filter or the log module. The fix is to clear partially
initialized headers in case of errors.
For the Cache-Control header, the fix is to postpone pushing
r->headers_out.cache_control until its value is completed.
Previously, ngx_http_sub_header_filter() could fail with a partially
initialized context, later accessed in ngx_http_sub_body_filter()
if called from the perl content handler.
The issue had appeared in 2c045e5b8291 (1.9.4).
A better fix would be to handle ngx_http_send_header() errors in
the perl module, though this doesn't seem to be easy enough.
The SSL_CTRL_SET_CURVES_LIST macro is removed in the OpenSSL master branch.
SSL_CTX_set1_curves_list is preserved as compatibility with previous versions.
CVE-2009-3555 is no longer relevant and mitigated by the renegotiation
info extension (secure renegotiation). On the other hand, unexpected
renegotiation still introduces potential security risks, and hence we do
not allow renegotiation on the server side, as we never request renegotiation.
On the client side the situation is different though. There are backends
which explicitly request renegotiation, and disabled renegotiation
introduces interoperability problems. This change allows renegotiation
on the client side, and fixes interoperability problems as observed with
such backends (ticket #872).
Additionally, with TLSv1.3 the SSL_CB_HANDSHAKE_START flag is currently set
by OpenSSL when receiving a NewSessionTicket message, and was detected by
nginx as a renegotiation attempt. This looks like a bug in OpenSSL, though
this change also allows better interoperability till the problem is fixed.
Previously, the source IP address of a response UDP datagram could differ from
the original datagram destination address. This could happen if the server UDP
socket is bound to a wildcard address and the network interface chosen to output
the response packet has a different default address than the destination address
of the original packet. For example, if two addresses from the same network are
configured on an interface.
Now source address is set explicitly if a response is sent for a server UDP
socket bound to a wildcard address.
This change adds "http_429" parameter to "proxy_next_upstream" for
retrying rate-limited requests, and to "proxy_cache_use_stale" for
serving stale cached responses after being rate-limited.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
This change adds reason phrase in status line and pretty response body
when "429" status code is used in "return", "limit_conn_status" and/or
"limit_req_status" directives.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
When a slice subrequest was redirected to a new location, its context was lost.
After its completion, a new slice subrequest for the same slice was created.
This could lead to infinite loop. Now the slice module makes sure each slice
subrequest starts output with the slice context available.
With post_action or subrequests, it is possible that the timer set for
wev->delayed will expire while the active subrequest write event handler
is not ready to handle this. This results in request hangs as observed
with limit_rate / sendfile_max_chunk and post_action (ticket #776) or
subrequests (ticket #1228).
Moving the handling to the connection event handler fixes the hangs observed,
and also slightly simplifies the code.
Since limit_req uses connection's write event to delay request processing,
it can conflict with timers in other subrequests. In particular, even
if applied to an active subrequest, it can break things if wev->delayed
is already set (due to limit_rate or sendfile_max_chunk), since after
limit_req finishes the wev->delayed flag will be set and no timer will be
active.
Fix is to use the wev->delayed flag in limit_req as well. This ensures that
wev->delayed won't be set after limit_req finishes, and also ensures that
limit_req's timers will be properly handled by other subrequests if the one
delayed by limit_req is not active.
All streams in connection must be finalized before the connection
itself can be finalized and all related memory is freed. That's
not always possible on the current event loop iteration.
Thus when the last stream is finalized, it sets the special read
event handler ngx_http_v2_handle_connection_handler() and posts
the event.
Previously, this handler didn't check the connection state and
could call the regular event handler on a connection that was
already in finalization stage. In the worst case that could
lead to a segmentation fault, since some data structures aren't
supposed to be used during connection finalization. Particularly,
the waiting queue can contain already freed streams, so the
WINDOW_UPDATE frame received by that moment could trigger
accessing to these freed streams.
Now, the connection error flag is explicitly checked in
ngx_http_v2_handle_connection_handler().
In order to finalize stream the error flag is set on fake connection and
either "write" or "read" event handler is called. The read events of fake
connections are always ready, but it's not the case with the write events.
When the ready flag isn't set, the error flag can be not checked in some
cases and as a result stream isn't finalized. Now the ready flag is
explicilty set on write events for proper finalization in all cases.
Previously, flow control didn't account for padding in DATA frames,
which meant that its view of the world could drift from peer's view
by up to 256 bytes per received padded DATA frame, which could lead
to a deadlock.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
Previously, its value accounted for payloads of HEADERS, CONTINUATION
and DATA frames, as well as frame headers of HEADERS and DATA frames,
but it didn't account for frame headers of CONTINUATION frames.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
Previously, connection write handler was called, resulting in wake up
of the active subrequest. This change makes it possible to read data
in non-active subrequests as well. For example, this allows SSI to
process instructions in non-active subrequests earlier and start
additional subrequests if needed, reducing overall response time.
If the subrequest is already finalized, the handler set with aio_write
may still be used by sendfile in threads when using range requests
(see also e4c1f5b32868, and the original note in 9fd738b85fad). Calling
already finalized subrequest's r->write_event_handler in practice
results in request hang in some cases.
Fix is to trigger connection event handler if the subrequest was already
finalized.
The ngx_linux_sendfile() function is now used for both normal sendfile()
and sendfile in threads. The ngx_linux_sendfile_thread() function was
modified to use the same interface as ngx_linux_sendfile(), and is simply
called from ngx_linux_sendfile() when threads are enabled.
Special return code NGX_DONE is used to indicate that a thread task was
posted and no further actions are needed.
If number of bytes sent is less that what we were sending, we now always
retry sending. This is needed for sendfile() in threads as the number
of bytes we are sending might have been changed since the thread task
was posted. And this is also needed for Linux 4.3+, as sendfile() might
be interrupted at any time and provides no indication if it was interrupted
or not (ticket #1174).
If of.err is 0, it means that there was a memory allocation error
and no further logging and/or processing is needed. The of.failed
string can be only accessed if of.err is not 0.
