Security

• server: Stop reading from the connection when flooded by HTTP/2 frames. The default value for this limit is 100 frames, excluding DATA and HEADERS, and may be changed by setting environment variable GRPC_GO_EXPERIMENTAL_CONTROL_BUFFER_THROTTLE_LIMIT.
• xds/rbac: Support Metadata and RequestedServerName permissions matcher fields. If present in a DENY rule, previously these would be ignored and fail-open.
• xds/rbac: Fix panic when parsing unsupported fields in NotRule/NotId permissions.
• xds/rbac: Support the deprecated source_ip principal identifier by treating it as equivalent to direct_remote_ip.