Now "listen" directve has a new "quic" parameter which enables QUIC protocol
for the address. Further, to enable HTTP/3, a new directive "http3" is
introduced. The hq-interop protocol is enabled by "http3_hq" as before.
Now application protocol is chosen by ALPN.
Previously used "http3" parameter of "listen" is deprecated.
It's called after handshake completion or prior to the first early data stream
creation. The callback should initialize application-level data before
creating streams.
HTTP/3 callback implementation sets keepalive timer and sends SETTINGS.
Also, this allows to limit max handshake time in ngx_http_v3_init_stream().
Now main QUIC connection for HTTP/3 always has c->idle flag set. This allows
the connection to receive worker shutdown notification. It is passed to
application level via a new conf->shutdown() callback.
The HTTP/3 shutdown callback sends GOAWAY to client and gracefully shuts down
the QUIC connection.
Operations like ngx_quic_open_stream(), ngx_http_quic_get_connection(),
ngx_http_v3_finalize_connection(), ngx_http_v3_shutdown_connection() used to
receive a QUIC stream connection. Now they can receive the main QUIC
connection as well. This is useful when calling them from a stream context.
ngx_http_v3_tables.h and ngx_http_v3_tables.c are renamed to
ngx_http_v3_table.h and ngx_http_v3_table.c to better match HTTP/2 code.
ngx_http_v3_streams.h and ngx_http_v3_streams.c are renamed to
ngx_http_v3_uni.h and ngx_http_v3_uni.c to better match their content.
Directives that set transport parameters are removed from the configuration.
Corresponding values are derived from the quic configuration or initialized
to default. Whenever possible, quic configuration parameters are taken from
higher-level protocol settings, i.e. HTTP/3.
A QUIC stream connection is treated as reusable until first bytes of request
arrive, which is also when the request object is now allocated. A connection
closed as a result of draining, is reset with the error code
H3_REQUEST_REJECTED. Such behavior is allowed by quic-http-34:
Once a request stream has been opened, the request MAY be cancelled
by either endpoint. Clients cancel requests if the response is no
longer of interest; servers cancel requests if they are unable to or
choose not to respond.
When the server cancels a request without performing any application
processing, the request is considered "rejected." The server SHOULD
abort its response stream with the error code H3_REQUEST_REJECTED.
The client can treat requests rejected by the server as though they had
never been sent at all, thereby allowing them to be retried later.
With this patch, all traffic over HTTP/3 bidi and uni streams is counted in
the h3c->total_bytes field, and payload traffic is counted in the
h3c->payload_bytes field. As long as total traffic is many times larger than
payload traffic, we consider this to be a flood.
Request header traffic is counted as if all fields are literal. Response
header traffic is counted as is.
Previously it was parsed in ngx_http_v3_streams.c, while the streams were
parsed in ngx_http_v3_parse.c. Now all parsing is done in one file. This
simplifies parsing API and cleans up ngx_http_v3_streams.c.
Previously, an ngx_http_v3_connection_t object was created for HTTP/3 and
then assinged to c->data instead of the generic ngx_http_connection_t object.
Now a direct reference is added to ngx_http_connection_t, which is less
confusing and does not require a flag for http3.
It's used instead of accessing c->quic->parent->data directly. Apart from being
simpler, it allows to change the way session is stored in the future by changing
the macro.
The function ngx_quic_shutdown_connection() waits until all non-cancelable
streams are closed, and then closes the connection. In HTTP/3 cancelable
streams are all unidirectional streams except push streams.
The function is called from HTTP/3 when client reaches keepalive_requests.
The structure is used to parse an HTTP/3 request. An object of this type is
added to ngx_http_request_t instead of h3_parse generic pointer.
Also, the new field is located outside of the request ephemeral zone to keep it
safe after request headers are parsed.
The change reduces diff to the default branch for
src/http/ngx_http_request_body.c.
Also, client Content-Length, if present, is now checked against the real body
size sent by client.
The filter is responsible for creating HTTP/3 response header and body.
The change removes differences to the default branch for
ngx_http_chunked_filter_module and ngx_http_header_filter_module.
Previously errors led only to closing streams.
To simplify closing QUIC connection from a QUIC stream context, new macro
ngx_http_v3_finalize_connection() is introduced. It calls
ngx_quic_finalize_connection() for the parent connection.
Previously dynamic table was not functional because of zero limit on its size
set by default. Now the following changes enable it:
- new directives to set SETTINGS_QPACK_MAX_TABLE_CAPACITY and
SETTINGS_QPACK_BLOCKED_STREAMS
- send settings with SETTINGS_QPACK_MAX_TABLE_CAPACITY and
SETTINGS_QPACK_BLOCKED_STREAMS to the client
- send Insert Count Increment to the client
- send Header Acknowledgement to the client
- evict old dynamic table entries on overflow
- decode Required Insert Count from client
- block stream if Required Insert Count is not reached
Client streams may send literal strings which are now limited in size by the
new directive. The default value is 4096.
The directive is similar to HTTP/2 directive http2_max_field_size.
As per HTTP/3 draft 27, a request or response containing uppercase header
field names MUST be treated as malformed. Also, existing rules applied
when parsing HTTP/1 header names are also applied to HTTP/3 header names:
- null character is not allowed
- underscore character may or may not be treated as invalid depending on the
value of "underscores_in_headers"
- all non-alphanumeric characters with the exception of '-' are treated as
invalid
Also, the r->locase_header field is now filled while parsing an HTTP/3
header.
Error logging for invalid headers is fixed as well.
The first one parses pseudo-headers and is analagous to the request line
parser in HTTP/1. The second one parses regular headers and is analogous to
the header parser in HTTP/1.
Additionally, error handling of client passing malformed uri is now fixed.
Roman Arutyunyan
Sergey Kandaurov
Vladimir Homutov