signaling.c File Reference

Go to the source code of this file.

Data Structures
struct	find_client_context_t
	Context for finding client by participant_id. More...
struct	broadcast_context_t
	Context for broadcasting to session participants. More...

Functions
asciichat_error_t	signaling_relay_sdp (sqlite3 *db, tcp_server_t *tcp_server, const acip_webrtc_sdp_t *sdp, size_t total_packet_len)
	Relay SDP offer/answer to recipient.
asciichat_error_t	signaling_relay_ice (sqlite3 *db, tcp_server_t *tcp_server, const acip_webrtc_ice_t *ice, size_t total_packet_len)
	Relay ICE candidate to recipient.
asciichat_error_t	signaling_broadcast (sqlite3 *db, tcp_server_t *tcp_server, const uint8_t session_id[16], packet_type_t packet_type, const void *packet, size_t packet_len, const uint8_t *exclude_participant_id)
	Broadcast packet to all session participants.
asciichat_error_t	signaling_relay_network_quality (sqlite3 *db, tcp_server_t *tcp_server, const acip_nat_quality_t *quality, size_t total_packet_len)
	Relay NETWORK_QUALITY to session participants.

Function Documentation

signaling_broadcast()

asciichat_error_t signaling_broadcast	(	sqlite3 *	db,
		tcp_server_t *	tcp_server,
		const uint8_t	session_id[16],
		packet_type_t	packet_type,
		const void *	packet,
		size_t	packet_len,
		const uint8_t *	exclude_participant_id
	)

Broadcast packet to all session participants.

Sends packet to all participants in a session (optionally excluding one). Used internally by SDP/ICE relay when recipient_id is all zeros.

Parameters

db	SQLite database handle (for session validation)
tcp_server	TCP server with client registry
session_id	Session UUID
packet_type	Packet type to send
packet	Packet data to broadcast
packet_len	Packet length
exclude_participant_id	Participant to exclude (NULL = no exclusion, typically sender)

Returns

ASCIICHAT_OK on success, error code otherwise

Definition at line 230 of file signaling.c.

                                                                             {
  if (!db || !tcp_server || !session_id || !packet) {
    return SET_ERRNO(ERROR_INVALID_PARAM, "db, tcp_server, session_id, or packet is NULL");
  }
 
  log_info("★ SIGNALING_BROADCAST_START: packet_type=%u, packet_len=%zu, session=%02x%02x...", packet_type, packet_len,
           session_id[0], session_id[1]);
  if (exclude_participant_id) {
    log_debug("★ SIGNALING_BROADCAST: excluding participant=%02x%02x...", exclude_participant_id[0],
              exclude_participant_id[1]);
  }
 
  /* Find session by UUID using database lookup */
  session_entry_t *session = database_session_find_by_id(db, session_id);
  if (!session) {
    return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Session not found for broadcast");
  }
  session_entry_destroy(session); // We only need to validate existence
 
  // Broadcast to all participants in session (excluding sender if specified)
  broadcast_context_t ctx = {.target_session_id = session_id,
                             .exclude_participant_id = exclude_participant_id,
                             .packet_type = packet_type,
                             .packet = packet,
                             .packet_len = packet_len,
                             .sent_count = 0};
 
  tcp_server_foreach_client(tcp_server, broadcast_callback, &ctx);
 
  if (ctx.sent_count == 0) {
    log_warn("★ SIGNALING_BROADCAST_COMPLETE: sent to 0 participants (all offline or not joined yet)");
  } else {
    log_info("★ SIGNALING_BROADCAST_COMPLETE: successfully sent to %zu participants", ctx.sent_count);
  }
 
  return ASCIICHAT_OK;
}

References ASCIICHAT_OK, database_session_find_by_id(), ERROR_INVALID_PARAM, ERROR_NETWORK_PROTOCOL, log_debug, log_info, log_warn, broadcast_context_t::sent_count, session_entry_destroy(), session_id, SET_ERRNO, broadcast_context_t::target_session_id, and tcp_server_foreach_client().

Referenced by signaling_relay_ice(), signaling_relay_network_quality(), and signaling_relay_sdp().

signaling_relay_ice()

asciichat_error_t signaling_relay_ice	(	sqlite3 *	db,
		tcp_server_t *	tcp_server,
		const acip_webrtc_ice_t *	ice,
		size_t	total_packet_len
	)

Relay ICE candidate to recipient.

Relays ICE packet to specific participant or broadcasts to all participants in the session if recipient_id is all zeros.

Parameters

db	SQLite database handle (for session validation)
tcp_server	TCP server with client registry
ice	ICE packet to relay (with variable-length candidate data following struct)
total_packet_len	Total packet length including variable data

Returns

ASCIICHAT_OK on success, error code otherwise

Definition at line 187 of file signaling.c.

                                                               {
  if (!db || !tcp_server || !ice) {
    return SET_ERRNO(ERROR_INVALID_PARAM, "db, tcp_server, or ice is NULL");
  }
 
  /* Find session by UUID using database lookup */
  session_entry_t *session = database_session_find_by_id(db, ice->session_id);
  if (!session) {
    return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Session not found for ICE relay");
  }
  session_entry_destroy(session); // We only need to validate existence
 
  // Check if broadcast (recipient_id all zeros) or unicast
  if (is_broadcast_uuid(ice->recipient_id)) {
    // Broadcast to all participants in session (except sender)
    log_debug("Broadcasting ICE candidate to all participants in session (excluding sender)");
    return signaling_broadcast(db, tcp_server, ice->session_id, PACKET_TYPE_ACIP_WEBRTC_ICE, ice, total_packet_len,
                               ice->sender_id);
  } else {
    // Unicast to specific recipient
    find_client_context_t ctx = {
        .target_participant_id = ice->recipient_id, .found_socket = INVALID_SOCKET_VALUE, .found = false};
 
    tcp_server_foreach_client(tcp_server, find_participant_callback, &ctx);
 
    if (!ctx.found) {
      return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Recipient participant not found (may be offline)");
    }
 
    // Send ICE packet to recipient
    asciichat_error_t result =
        packet_send_via_transport(ctx.found_transport, PACKET_TYPE_ACIP_WEBRTC_ICE, ice, total_packet_len, 0);
    if (result != ASCIICHAT_OK) {
      return SET_ERRNO(ERROR_NETWORK, "Failed to send ICE packet to recipient");
    }
 
    log_debug("Relayed ICE candidate from sender to recipient (socket=%d)", ctx.found_socket);
  }
 
  return ASCIICHAT_OK;
}

References ASCIICHAT_OK, database_session_find_by_id(), ERROR_INVALID_PARAM, ERROR_NETWORK, ERROR_NETWORK_PROTOCOL, find_client_context_t::found, find_client_context_t::found_socket, find_client_context_t::found_transport, INVALID_SOCKET_VALUE, log_debug, packet_send_via_transport(), PACKET_TYPE_ACIP_WEBRTC_ICE, session_entry_destroy(), SET_ERRNO, signaling_broadcast(), and tcp_server_foreach_client().

signaling_relay_network_quality()

asciichat_error_t signaling_relay_network_quality	(	sqlite3 *	db,
		tcp_server_t *	tcp_server,
		const acip_nat_quality_t *	quality,
		size_t	total_packet_len
	)

Relay NETWORK_QUALITY to session participants.

Relays NAT quality metrics to all participants in the session (excluding sender). Used during NAT negotiation phase to help peers determine optimal host.

Parameters

db	SQLite database handle (for session validation)
tcp_server	TCP server with client registry
quality	NAT quality packet (includes session_id and participant_id)
total_packet_len	Total packet length

Returns

ASCIICHAT_OK on success, error code otherwise

Definition at line 270 of file signaling.c.

                                                                                                              {
  if (!db || !tcp_server || !quality) {
    return SET_ERRNO(ERROR_INVALID_PARAM, "db, tcp_server, or quality is NULL");
  }
 
  // Validate packet size
  if (total_packet_len < sizeof(acip_nat_quality_t)) {
    return SET_ERRNO(ERROR_NETWORK_SIZE, "NETWORK_QUALITY packet too small");
  }
 
  // Extract session_id and sender_id from the quality packet
  const uint8_t *session_id = quality->session_id;
  const uint8_t *sender_id = quality->participant_id;
 
  // Find session by UUID using database lookup
  log_debug("NETWORK_QUALITY relay: session_id=%02x%02x..., sender_id=%02x%02x...", session_id[0], session_id[1],
            sender_id[0], sender_id[1]);
  session_entry_t *session = database_session_find_by_id(db, session_id);
  if (!session) {
    return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Session not found for NETWORK_QUALITY relay");
  }
  session_entry_destroy(session); // We only need to validate existence
 
  // Broadcast to all participants in session (except sender)
  log_debug("Broadcasting NETWORK_QUALITY to all participants in session (excluding sender)");
  return signaling_broadcast(db, tcp_server, session_id, PACKET_TYPE_ACIP_NETWORK_QUALITY, quality, total_packet_len,
                             sender_id);
}

References acip_nat_quality_t, database_session_find_by_id(), ERROR_INVALID_PARAM, ERROR_NETWORK_PROTOCOL, ERROR_NETWORK_SIZE, log_debug, PACKET_TYPE_ACIP_NETWORK_QUALITY, session_entry_destroy(), session_id, SET_ERRNO, and signaling_broadcast().

signaling_relay_sdp()

asciichat_error_t signaling_relay_sdp	(	sqlite3 *	db,
		tcp_server_t *	tcp_server,
		const acip_webrtc_sdp_t *	sdp,
		size_t	total_packet_len
	)

Relay SDP offer/answer to recipient.

Relays SDP packet to specific participant or broadcasts to all participants in the session if recipient_id is all zeros.

Parameters

db	SQLite database handle (for session validation)
tcp_server	TCP server with client registry
sdp	SDP packet to relay (with variable-length SDP data following struct)
total_packet_len	Total packet length including variable data

Returns

ASCIICHAT_OK on success, error code otherwise

Definition at line 139 of file signaling.c.

                                                               {
  if (!db || !tcp_server || !sdp) {
    return SET_ERRNO(ERROR_INVALID_PARAM, "db, tcp_server, or sdp is NULL");
  }
 
  /* Find session by UUID using database lookup */
  log_debug("SDP relay: Looking up session_id=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
            sdp->session_id[0], sdp->session_id[1], sdp->session_id[2], sdp->session_id[3], sdp->session_id[4],
            sdp->session_id[5], sdp->session_id[6], sdp->session_id[7], sdp->session_id[8], sdp->session_id[9],
            sdp->session_id[10], sdp->session_id[11], sdp->session_id[12], sdp->session_id[13], sdp->session_id[14],
            sdp->session_id[15]);
  session_entry_t *session = database_session_find_by_id(db, sdp->session_id);
  if (!session) {
    return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Session not found for SDP relay");
  }
  session_entry_destroy(session); // We only need to validate existence
 
  // Check if broadcast (recipient_id all zeros) or unicast
  if (is_broadcast_uuid(sdp->recipient_id)) {
    // Broadcast to all participants in session (except sender)
    log_debug("Broadcasting SDP to all participants in session (excluding sender)");
    return signaling_broadcast(db, tcp_server, sdp->session_id, PACKET_TYPE_ACIP_WEBRTC_SDP, sdp, total_packet_len,
                               sdp->sender_id);
  } else {
    // Unicast to specific recipient
    find_client_context_t ctx = {
        .target_participant_id = sdp->recipient_id, .found_socket = INVALID_SOCKET_VALUE, .found = false};
 
    tcp_server_foreach_client(tcp_server, find_participant_callback, &ctx);
 
    if (!ctx.found) {
      return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Recipient participant not found (may be offline)");
    }
 
    // Send SDP packet to recipient
    asciichat_error_t result =
        packet_send_via_transport(ctx.found_transport, PACKET_TYPE_ACIP_WEBRTC_SDP, sdp, total_packet_len, 0);
    if (result != ASCIICHAT_OK) {
      return SET_ERRNO(ERROR_NETWORK, "Failed to send SDP packet to recipient");
    }
 
    log_debug("Relayed SDP from sender to recipient (socket=%d)", ctx.found_socket);
  }
 
  return ASCIICHAT_OK;
}

References ASCIICHAT_OK, database_session_find_by_id(), ERROR_INVALID_PARAM, ERROR_NETWORK, ERROR_NETWORK_PROTOCOL, find_client_context_t::found, find_client_context_t::found_socket, find_client_context_t::found_transport, INVALID_SOCKET_VALUE, log_debug, packet_send_via_transport(), PACKET_TYPE_ACIP_WEBRTC_SDP, session_entry_destroy(), SET_ERRNO, signaling_broadcast(), and tcp_server_foreach_client().