Previously, when a buffer was processed by the sub filter, its final bytes could be buffered by the filter even if they don't match any pattern. This happened because the Boyer-Moore algorithm, employed by the sub filter since b9447fc457b4 (1.9.4), matches the last characters of patterns prior to checking other characters. If the last character is out of scope, initial bytes of a potential match are buffered until the last character is available. Now, after receiving a flush or recycled buffer, the filter performs additional checks to reduce the number of buffered bytes. The potential match is checked against the initial parts of all patterns. Non-matching bytes are not buffered. This improves processing of a chunked response from upstream by sending the entire chunks without buffering unless a partial match is found at the end of a chunk.
No functional changes.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
This patch moves various OpenSSL-specific function calls into the OpenSSL module and introduces ngx_ssl_ciphers() to make nginx more crypto-library-agnostic.
When the stream is terminated the HEADERS frame can still wait in the output queue. This frame can't be removed and must be sent to the client anyway, since HTTP/2 uses stateful compression for headers. So in order to postpone closing and freeing memory of such stream the special close stream handler is set to the write event. After the HEADERS frame is sent the write event is called and the stream will be finally closed. Some events like receiving a RST_STREAM can trigger the read handler of such stream in closing state and cause unexpected processing that can result in another attempt to finalize the request. To prevent it the read handler is now set to ngx_http_empty_handler. Thanks to Amazon.
There is no reason to add the "Content-Length: 0" header to a proxied request without body if the header isn't presented in the original request. Thanks to Amazon.
According to RFC 7540, an endpoint should not send more than one RST_STREAM frame for any stream. Also, now all the data frames will be skipped while termination.
The ngx_http_v2_finalize_connection() closes current stream, but that is an invalid operation while processing unbuffered upload. This results in access to already freed memory, since the upstream module sets a cleanup handler that also finalizes the request.