Application Layer Entity (ALE) — NON-VITAL, runs in the Gateway. More...

#include <stdbool.h>
#include <stdint.h>
#include "safecomm/status.h"
#include "safecomm/config/config.h"

Include dependency graph for ale.h:

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Data Structures
struct	safecomm_ale_peer_t
	One routed peer: external bearer <-> the A/B endpoint pair. More...
struct	safecomm_ale_t
	An ALE instance. Caller-allocated, opaque. More...

Macros
#define	SAFECOMM_ALE_MAX_PEERS 64U
	Max concurrent peer connections one ALE instance tracks.

Functions
safecomm_status_t	safecomm_ale_from_config (const safecomm_config_t cfg, safecomm_ale_t out)
	Build an ALE from a loaded config (ale.* keys) + its peer map.
const safecomm_ale_peer_t *	safecomm_ale_lookup (const safecomm_ale_t *ale, uint32_t peer_id)
	Resolve a peer id to its A/B endpoint pair.

Detailed Description

Application Layer Entity (ALE) — NON-VITAL, runs in the Gateway.

The ALE is the concentration / routing point between the outside world and the vital A/B channels (ADR-002):

Accepts inbound bearer connections (EVCs for SS-037, the peer RBC for SS-098) on ale.listen_host:ale.listen_port.
Identifies the peer (NID_ENGINE for a train, RBC-ID for a neighbour) and looks it up in ale.peer_map_file.
Relays the raw bearer byte stream to BOTH A and B for that peer — it does NOT hold KSMAC and cannot read or alter a SaF PDU; the SFM in A/B is the only thing that authenticates.
Multiplexes many peers over the A/B internal links.

Because the ALE cannot forge an authenticated message, it stays outside the safety case: a fault here can drop or misroute a connection (the SFM's supervision timer then fires safe-side) but cannot inject a false MA or handover message.

REQ-SC-ALE-001..012 — see docs/requirements/SRS.md.

Definition in file ale.h.

Macro Definition Documentation

◆ SAFECOMM_ALE_MAX_PEERS

#define SAFECOMM_ALE_MAX_PEERS 64U

Max concurrent peer connections one ALE instance tracks.

Definition at line 38 of file ale.h.

Function Documentation

◆ safecomm_ale_from_config()

safecomm_status_t safecomm_ale_from_config	(	const safecomm_config_t *	cfg,
		safecomm_ale_t *	out )

Build an ALE from a loaded config (ale.* keys) + its peer map.

Parameters

cfg	loaded configuration (ale.listen_host, ale.listen_port, ale.peer_map_file). Non-NULL.
out	receives the ALE. Non-NULL.

Returns: SAFECOMM_STATUS_OK / _INVALID_PARAM / _TRANSPORT (peer map unreadable) / _NOT_IMPLEMENTED.

Note: REQ-SC-ALE-003.

Definition at line 72 of file ale.c.

◆ safecomm_ale_lookup()

const safecomm_ale_peer_t * safecomm_ale_lookup	(	const safecomm_ale_t *	ale,
		uint32_t	peer_id )

Resolve a peer id to its A/B endpoint pair.

Returns: the peer entry, or NULL if peer_id is not in the map.

Note: REQ-SC-ALE-006.

Definition at line 104 of file ale.c.

Data Structures