XGW.Peer.Turn (xgw v0.1.0)

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Peer-side TURN lifecycle: allocate, refresh, unwrap, and encode relay traffic.

How this fits

When local candidates include relay addresses, the Peer must keep TURN allocations alive, create permissions / channel bindings toward the selected remote, and wrap outbound UDP (including DTLS/SRTP) as Send Indication or ChannelData. Inbound TURN Data Indications are unwrapped before demux.

Pure helpers and state transforms used by XGW.Peer (not a GenServer).

RFCs

  • RFC 8656 -- TURN allocations, permissions, ChannelBind, Send Indication, ChannelData
  • RFC 8489 -- STUN encoding of TURN methods

Summary

Functions

allocations_cover_relay_locals?(allocs, locals)

Returns true when every relay local candidate has a covering TURN allocation.

allocations_cover_relays?(arg1)

Returns true when peer state allocations cover current ICE relay locals.

apply_relay_results(state, relay_results)

Merges gather_relay results into ICE/allocations and notifies the handler.

cancel_refresh_timer(state)

Cancels the TURN refresh timer when present.

clear_channels(state)

Resets channel number maps.

delete_allocations(state)

Deletes all TURN allocations and clears channel maps.

encode_relay_app_data(state, alloc, peer, data)

Encodes app data as Send Indication or ChannelData for the peer.

find_allocation(arg1, arg2)

Looks up a TURN allocation by relay local candidate.

gather_relay(map)

Synchronous relay gather for prefetch.

maybe_create_permission(state, ice)

After nomination on a relay pair, create permission + ChannelBind.

maybe_delete_allocations(state, config)

Deletes allocations when they do not cover answer relay locals.

refresh_allocations(state)

Best-effort TURN Refresh for each live allocation.

relay_send_allocation(state)

Allocation used for outbound relay send, or nil when host path should win.

schedule_refresh_tick(state)

Arms :turn_refresh_tick from the first allocation lifetime.

unwrap_data_indication(data)

Unwraps a TURN Data Indication to {inner, peer_from} or :not_turn_data.

Functions

allocations_cover_relay_locals?(allocs, locals)

@spec allocations_cover_relay_locals?(list(), list()) :: boolean()

Returns true when every relay local candidate has a covering TURN allocation.

allocations_cover_relays?(arg1)

@spec allocations_cover_relays?(map()) :: boolean()

Returns true when peer state allocations cover current ICE relay locals.

apply_relay_results(state, relay_results)

@spec apply_relay_results(map(), list()) :: map()

Merges gather_relay results into ICE/allocations and notifies the handler.

Schedules TURN refresh; caller schedules connectivity-check ticks.

cancel_refresh_timer(state)

@spec cancel_refresh_timer(map()) :: map()

Cancels the TURN refresh timer when present.

clear_channels(state)

@spec clear_channels(map()) :: map()

Resets channel number maps.

delete_allocations(state)

@spec delete_allocations(map()) :: map()

Deletes all TURN allocations and clears channel maps.

encode_relay_app_data(state, alloc, peer, data)

@spec encode_relay_app_data(map(), map(), term(), binary()) :: binary()

Encodes app data as Send Indication or ChannelData for the peer.

find_allocation(arg1, arg2)

@spec find_allocation(map(), map()) :: map() | nil

Looks up a TURN allocation by relay local candidate.

gather_relay(map)

@spec gather_relay(map()) :: list()

Synchronous relay gather for prefetch.

maybe_create_permission(state, ice)

@spec maybe_create_permission(map(), map()) :: map()

After nomination on a relay pair, create permission + ChannelBind.

maybe_delete_allocations(state, config)

@spec maybe_delete_allocations(map(), map()) :: map()

Deletes allocations when they do not cover answer relay locals.

refresh_allocations(state)

@spec refresh_allocations(map()) :: map()

Best-effort TURN Refresh for each live allocation.

relay_send_allocation(state)

@spec relay_send_allocation(map()) :: map() | nil

Allocation used for outbound relay send, or nil when host path should win.

schedule_refresh_tick(state)

@spec schedule_refresh_tick(map()) :: map()

Arms :turn_refresh_tick from the first allocation lifetime.

unwrap_data_indication(data)

@spec unwrap_data_indication(binary()) ::
  {:ok, binary(), {tuple(), integer()}} | :not_turn_data

Unwraps a TURN Data Indication to {inner, peer_from} or :not_turn_data.