int nghttp2_session_upgrade(nghttp2_session *session, const uint8_t *settings_payload, size_t settings_payloadlen, void *stream_user_data)
Performs post-process of HTTP Upgrade request. This function can be called from both client and server, but the behavior is very different in each other.
This function is deprecated in favor of
nghttp2_session_upgrade2(), because this function lacks the parameter to tell the library the request method used in the original HTTP request. This information is required for client to validate actual response body length against content-length header field (see
nghttp2_option_set_no_http_messaging()). If HEAD is used in request, the length of response body must be 0 regardless of value included in content-length header field.
If called from client side, the settings_payload must be the value sent in
HTTP2-Settingsheader field and must be decoded by base64url decoder. The settings_payloadlen is the length of settings_payload. The settings_payload is unpacked and its setting values will be submitted using
nghttp2_submit_settings(). This means that the client application code does not need to submit SETTINGS by itself. The stream with stream ID=1 is opened and the stream_user_data is used for its stream_user_data. The opened stream becomes half-closed (local) state.
If called from server side, the settings_payload must be the value received in
HTTP2-Settingsheader field and must be decoded by base64url decoder. The settings_payloadlen is the length of settings_payload. It is treated as if the SETTINGS frame with that payload is received. Thus, callback functions for the reception of SETTINGS frame will be invoked. The stream with stream ID=1 is opened. The stream_user_data is ignored. The opened stream becomes half-closed (remote).
This function returns 0 if it succeeds, or one of the following negative error codes: