moqsess.h File Reference

draft-ietf-moq-transport-19 3.3 / 5.1: session establishment/control- stream discipline, and 5.1 SUBSCRIBE/PUBLISH lifecycle. More...

#include "common/platform/sys/syscall.h"

Go to the source code of this file.

Data Structures
struct	moqsess
	Session state including the GOAWAY-lifecycle flags (5.1: GOAWAY may be sent/received at most once per direction; violations and shutdown decisions read these). More...
struct	moqsub
	One subscription's lifecycle state plus the flags moqsub_step keeps. More...

Macros
#define	MOQSESS_CLOSE_NONE   0
	Close reasons a step can produce (0 = still open).
#define	MOQSESS_CLOSE_PROTOCOL_VIOLATION   1
	Close with PROTOCOL_VIOLATION: a control-stream or GOAWAY rule was broken (e.g.
#define	MOQSESS_CLOSE_INVALID_REQUEST_ID   2
	Close with INVALID_REQUEST_ID: wrong-parity or reused Request ID.
#define	MOQSESS_CLOSE_GOAWAY_TIMEOUT   3
	Close with GOAWAY_TIMEOUT: the peer did not close after GOAWAY.
#define	MOQSESS_CLOSE_NO_ERROR   4
	Clean close (NO_ERROR); no moqsess_step event produces it.
#define	MOQSUB_TERM_NONE   0
	Terminated reasons (informational; a subscription's own close does not imply the session closes).
#define	MOQSUB_TERM_STOP_SENDING   1
	Cancelled via STOP_SENDING.
#define	MOQSUB_TERM_PUBLISH_DONE   2
	Publisher finished normally (PUBLISH_DONE).
#define	MOQSUB_TERM_ERROR   3
	REQUEST_ERROR (reject or fault).
#define	MOQSUB_TERM_EARLY_FIN   4
	Peer FIN'd before responding (not set by moqsub_step).
#define	MOQSUB_TERM_DUP_RESPONSE   5
	A second response arrived; moqsub_step flags session_fault instead and never sets this.

Enumerations
enum	moqsess_state { MOQSESS_IDLE = 0 , MOQSESS_SETUP_HALF = 1 , MOQSESS_ESTABLISHED = 2 , MOQSESS_CLOSED = 3 }
	Session state (draft 3.3: each endpoint opens one uni control stream and sends SETUP first; the session is established once both sides have done so).
enum	moqsess_event {   MOQSESS_EV_SENT_SETUP = 0 , MOQSESS_EV_RECV_SETUP = 1 , MOQSESS_EV_CTRL_CLOSED = 2 , MOQSESS_EV_UNKNOWN_UNI = 3 ,   MOQSESS_EV_SECOND_CTRL = 4 , MOQSESS_EV_MALFORMED_CTRL = 5 , MOQSESS_EV_SEND_GOAWAY = 6 , MOQSESS_EV_RECV_GOAWAY = 7 ,   MOQSESS_EV_RECV_GOAWAY_BAD_URI = 8 , MOQSESS_EV_GOAWAY_TIMEOUT = 9 , MOQSESS_EV_BAD_FIRST = 10 , MOQSESS_EV_BAD_REQUEST_ID = 11 }
	Events the run layer feeds in as it decodes the wire.
enum	moqsub_state { MOQSUB_IDLE = 0 , MOQSUB_PENDING = 1 , MOQSUB_ESTABLISHED = 2 , MOQSUB_TERMINATED = 3 }
	One subscription's state (draft 5.1: SUBSCRIBE/PUBLISH -> response -> termination, one instance per request stream).
enum	moqsub_role { MOQSUB_ROLE_SUBSCRIBER = 0 , MOQSUB_ROLE_PUBLISHER = 1 }
	Which side opened the request stream with its First message.
enum	moqsub_event {   MOQSUB_EV_OPEN = 0 , MOQSUB_EV_OK = 1 , MOQSUB_EV_ERROR = 2 , MOQSUB_EV_UPDATE = 3 ,   MOQSUB_EV_STOP_SENDING = 4 , MOQSUB_EV_PUBLISH_DONE = 5 , MOQSUB_EV_FIN_RESP = 6 , MOQSUB_EV_FIN_REQ = 7 }
	Events moqsub_step applies, each sent or received on the request stream.

Functions
void	moqsess_init (moqsess *s)
	Zero-initialize (equivalent to = {0}; provided for callers that build the struct at runtime rather than with a static initializer).
int	moqsess_step (moqsess *s, moqsess_event ev)
	Apply one event.
int	moqsess_should_buffer (const moqsess *s)
	True while SETUP has not yet completed both directions: requests and data streams that arrive now must be buffered, not delivered to the application (3.3 / draft 5.1 buffering discipline).
int	moqsess_established (const moqsess *s)
	True once SETUP is fully established (both directions done).
int	moqsess_may_reject_request (const moqsess *s)
	True if a newly arriving request MAY be rejected with GOING_AWAY (either side sent or received GOAWAY: draft 5.1 GOAWAY discipline).
int	moqsess_suppress_own_requests (const moqsess *s)
	True if this endpoint SHOULD NOT initiate new requests of its own (GOAWAY received on the control stream: draft 5.1, SHOULD NOT).
void	moqsub_init (moqsub *s, moqsub_role role)
	Initialize a fresh subscription: role is fixed by which message (SUBSCRIBE vs PUBLISH) opened the request stream.
int	moqsub_step (moqsub *s, moqsub_event ev)
	Apply one event.
int	moqsub_established (const moqsub *s)
	True once the subscription is Established (SS10.6/10.9 semantics apply: REQUEST_UPDATE legal, Object forwarding gated by moqsub_may_forward).
int	moqsub_terminated (const moqsub *s)
	True once Terminated (state machine done; s->term_reason explains why).
int	moqsub_may_forward (const moqsub *s, int forward)
	Forward State gate (5.1 / SS10.2 FORWARD parameter, subscribe notes decision 9): Object sending toward this subscription is permitted only while pending or established AND not yet errored.
int	moqsub_may_send_publish_done (usz open_stream_count)
	PUBLISH_DONE precondition (draft 8.9): a publisher may only send PUBLISH_DONE once every data stream it opened for this subscription has been closed.

Detailed Description

draft-ietf-moq-transport-19 3.3 / 5.1: session establishment/control- stream discipline, and 5.1 SUBSCRIBE/PUBLISH lifecycle.

Pure state machines: callers (the run layer, decoding wire bytes via moqctl) drive these with events; no wire codec is invoked here.

Macro Definition Documentation

MOQSESS_CLOSE_PROTOCOL_VIOLATION

#define MOQSESS_CLOSE_PROTOCOL_VIOLATION   1

Close with PROTOCOL_VIOLATION: a control-stream or GOAWAY rule was broken (e.g.

a second GOAWAY, a malformed control message).

MOQSUB_TERM_NONE

#define MOQSUB_TERM_NONE   0

Terminated reasons (informational; a subscription's own close does not imply the session closes).

0 = not terminated.

Function Documentation

moqsess_step()

int moqsess_step	(	moqsess *	s,
		moqsess_event	ev )

Apply one event.

Returns the resulting close_reason (MOQSESS_CLOSE_ NONE if the session is still open). Once state == CLOSED, further events are no-ops (idempotent close).

moqsub_may_forward()

int moqsub_may_forward	(	const moqsub *	s,
		int	forward )

Forward State gate (5.1 / SS10.2 FORWARD parameter, subscribe notes decision 9): Object sending toward this subscription is permitted only while pending or established AND not yet errored.

forward is the negotiated FORWARD value (0 = never send Objects, 1 = normal gate).

moqsub_may_send_publish_done()

int moqsub_may_send_publish_done

(

usz

open_stream_count

)

PUBLISH_DONE precondition (draft 8.9): a publisher may only send PUBLISH_DONE once every data stream it opened for this subscription has been closed.

Callers pass their own open-stream count; this only encodes the gate, not the count itself.

moqsub_step()

int moqsub_step	(	moqsub *	s,
		moqsub_event	ev )

Apply one event.

Returns 1 if the event was legal for the current state (state/flags updated), 0 if it violates the subscribe discipline (e.g. a duplicate response) – callers read s->session_fault to distinguish a subscription-local termination from a session-level protocol error.