quic: support QUIC listener filters and ECDS (#29362)

Commit Message: Add interfaces for QUIC listener filter chain. The filters still use the same config API as TCP listener filters and also get installed before connection creation. The difference is that if the iteration through the chain on onAccept() gets paused, the connection will still be created, though the rest filters will be skipped. The contract of returning StopIteration means the connection socket gets closed, the corresponding connection should be closed.

Additional Message: this change introduced a new extension category envoy.filters.quic_listener.

Risk Level: low, not in use
Testing: new unit tests and integration tests.
Docs Changes: yes
Release Notes: yes
Platform Specific Features: N/A

Signed-off-by: Dan Zhang <danzh@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 9d8cb4b0c6892452741fc41e87d50934bf58acc3

envoy/admin/v3/config_dump.proto

@@ -33,6 +33,7 @@ message ConfigDump {
   // * ``bootstrap``: :ref:`BootstrapConfigDump <envoy_v3_api_msg_admin.v3.BootstrapConfigDump>`
   // * ``clusters``: :ref:`ClustersConfigDump <envoy_v3_api_msg_admin.v3.ClustersConfigDump>`
   // * ``ecds_filter_http``: :ref:`EcdsConfigDump <envoy_v3_api_msg_admin.v3.EcdsConfigDump>`
+  // * ``ecds_filter_quic_listener``: :ref:`EcdsConfigDump <envoy_v3_api_msg_admin.v3.EcdsConfigDump>`
   // * ``ecds_filter_tcp_listener``: :ref:`EcdsConfigDump <envoy_v3_api_msg_admin.v3.EcdsConfigDump>`
   // * ``endpoints``:  :ref:`EndpointsConfigDump <envoy_v3_api_msg_admin.v3.EndpointsConfigDump>`
   // * ``listeners``: :ref:`ListenersConfigDump <envoy_v3_api_msg_admin.v3.ListenersConfigDump>`

envoy/config/listener/v3/listener.proto

@@ -199,7 +199,12 @@ message Listener {
   // before a connection is created.
   // UDP Listener filters can be specified when the protocol in the listener socket address in
   // :ref:`protocol <envoy_v3_api_field_config.core.v3.SocketAddress.protocol>` is :ref:`UDP
-  // <envoy_v3_api_enum_value_config.core.v3.SocketAddress.Protocol.UDP>`.
+  // <envoy_v3_api_enum_value_config.core.v3.SocketAddress.Protocol.UDP>` and no
+  // :ref:`quic_options <envoy_v3_api_field_config.listener.v3.UdpListenerConfig.quic_options>` is specified in :ref:`udp_listener_config <envoy_v3_api_field_config.listener.v3.Listener.udp_listener_config>`.
+  // QUIC listener filters can be specified when :ref:`quic_options
+  // <envoy_v3_api_field_config.listener.v3.UdpListenerConfig.quic_options>` is
+  // specified in :ref:`udp_listener_config <envoy_v3_api_field_config.listener.v3.Listener.udp_listener_config>`.
+  // They are processed sequentially right before connection creation. And like TCP Listener filters, they can be used to manipulate the connection metadata and socket. But the difference is that they can't be used to pause connection creation.
   repeated ListenerFilter listener_filters = 9;
 
   // The timeout to wait for all listener filters to complete operation. If the timeout is reached,