While processing a DATA frame, the link to related stream is stored in spdy
connection object as part of connection state. But this stream can be closed
between receiving parts of the frame.
Previously pool->current wasn't moved back to pool, resulting in blocks
not used for further allocations if pool->current was already moved at the
time of ngx_reset_pool(). Additionally, to preserve logic of moving
pool->current, the p->d.failed counters are now properly cleared. While
here, pool->chain is also cleared.
This change is essentially a nop with current code, but generally improves
things.
During the processing of input some control frames can be added to the queue.
And if there were no writing streams at the moment, these control frames might
be left unsent for a long time (or even forever).
This long delay is especially critical for PING replies since a client can
consider connection as broken and then resend exactly the same request over
a new connection, which is not safe in case of non-idempotent HTTP methods.
There is no reason to allocate it from connection pool that more like just
a bug especially since ngx_http_spdy_settings_frame_handler() already uses
sc->pool to free a chain.
The frame->stream pointer should always be initialized for control frames since
the check against it can be performed in ngx_http_spdy_filter_cleanup().
Parameters of ngx_http_spdy_filter_get_shadow() are changed from size_t to off_t
since the last call of the function may get size and offset from the rest of a
file buffer. This fixes possible data loss rightfully complained by MSVC on 32
bits systems where off_t is 8 bytes long while size_t is only 4 bytes.
The other two type casts are needed just to suppress warnings about possible
data loss also complained by MSVC but false positive in these cases.
False positive warning about the "cl" variable may be uninitialized in
the ngx_http_spdy_filter_get_data_frame() call was suppressed.
It is always initialized either in the "while" cycle or in the following
"if" condition since frame_size cannot be zero.
The "delayed" flag always should be set if there are unsent frames,
but this might not be the case if ngx_http_spdy_body_filter() was
called with NULL chain.
As a result, the "send_timeout" timer could be set on a stream in
ngx_http_writer(). And if the timeout occurred before all the stream
data has been sent, then the request was finalized with the "client
timed out" error.
It was used to prevent destroying of request object when there are unsent
frames in queue for the stream. Since it was incremented for each frame
and is only 8 bits long, so it was not very hard to overflow the counter.
Now the stream->queued counter is checked instead.
This adds support so it's possible to explicitly disable SSL Session
Tickets. In order to have good Forward Secrecy support either the
session ticket key has to be reloaded by using nginx' binary upgrade
process or using an external key file and reloading the configuration.
This directive adds another possibility to have good support by
disabling session tickets altogether.
If session tickets are enabled and the process lives for a long a time,
an attacker can grab the session ticket from the process and use that to
decrypt any traffic that occured during the entire lifetime of the
process.
If a request had an empty request body (with Content-Length: 0), and there
were preread data available (e.g., due to a pipelined request in the buffer),
the "zero size buf in output" alert might be logged while proxying the
request to an upstream.
Similar alerts appeared with client_body_in_file_only if a request had an
empty request body.
Not really a strict check (as X-Accel-Expires might be ignored or
contain invalid value), but quite simple to implement and better
than what we have now.
Fallback to synchronous sendfile() now only done on 3rd EBUSY without
any progress in a row. Not falling back is believed to be better
in case of occasional EBUSY, though protection is still needed to
make sure there will be no infinite loop.
This fixes content type set in stub_status and autoindex responses
to be usable in content type checks made by filter modules, such
as charset and sub filters.
There is no need to pass FLAG_FIN as a separate argument since it can always be
detected from the last_buf flag of the last frame buffer.
No functional changes.
Processing events from upstream connection can result in sending queued frames
from other streams. In this case such streams were not added to handling queue
and properly handled.
A global per connection flag was replaced by a per stream flag that indicates
currently sending stream while all other streams can be added to handling
queue.
Conditions for skipping ineligible peers are rewritten to make adding of new
conditions simpler and be in line with the "round_robin" and "least_conn"
modules. No functional changes.
