int nghttp2_submit_extension(nghttp2_session *session, uint8_t type, uint8_t flags, int32_t stream_id, void *payload)
Submits extension frame.
Application can pass arbitrary frame flags and stream ID in flags and stream_id respectively. The payload is opaque pointer, and it can be accessible though
nghttp2_pack_extension_callback. The library will not own passed payload pointer.
The application must set
The application should retain the memory pointed by payload until the transmission of extension frame is done (which is indicated by
nghttp2_on_frame_send_callback), or transmission fails (which is indicated by
nghttp2_on_frame_not_send_callback). If application does not touch this memory region after packing it into a wire format, application can free it inside
The standard HTTP/2 frame cannot be sent with this function, so type must be strictly grater than 0x9. Otherwise, this function will fail with error code
This function returns 0 if it succeeds, or one of the following negative error codes:
nghttp2_pack_extension_callbackis not set.
If type specifies standard HTTP/2 frame type. The frame types in the rage [0x0, 0x9], both inclusive, are standard HTTP/2 frame type, and cannot be sent using this function.
Out of memory