sip-in hold/retr error handling: simply send BYE Because we know that the SIP state is CONNECTED at the time of any such error event, we can call initiate_bye() instead of disconnect_sip(), and thereby get rid of struct gsm_mncc_cause which will never be used in this scenario anyway.

/*
 * This header file defines structures written into the binary form
 * of the number database file.
 */

struct numdb_file_hdr {
	uint32_t	owned_number_count;
	uint32_t	short_number_count;
};

struct short_number_map {
	uint32_t	short_code;
	uint32_t	prefix;
};