src/gsm/gsm0808.c

/*
 * (C) 2009,2010 by Holger Hans Peter Freyther <zecke@selfish.org>
 * (C) 2009,2010 by On-Waves
 * All Rights Reserved
 *
 * SPDX-License-Identifier: GPL-2.0+
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <osmocom/core/byteswap.h>
#include <osmocom/gsm/gsm0808.h>
#include <osmocom/gsm/gsm0808_utils.h>
#include <osmocom/gsm/protocol/gsm_08_08.h>
#include <osmocom/gsm/gsm48.h>

/*! \addtogroup gsm0808
 *  @{
 *  \file gsm0808.c
 *  Helper functions regarding the TS 08.08 / 48.008 A interface, primarily
 *  message generation/encoding.
 */

#define BSSMAP_MSG_SIZE 512
#define BSSMAP_MSG_HEADROOM 128

/*! Create "Complete L3 Info" for AoIP
 *  \param[in] msg_l3 msgb containing Layer 3 Message
 *  \param[in] nc Mobile Network Code
 *  \param[in] cc Mobile Country Code
 *  \param[in] lac Location Area Code
 *  \param[in] _ci Cell Identity
 *  \param[in] scl Speech Codec List
 *  \returns callee-allocated msgb with Complete L3 Info message */
struct msgb *gsm0808_create_layer3_aoip(const struct msgb *msg_l3, uint16_t nc,
					uint16_t cc, int lac, uint16_t _ci,
					const struct gsm0808_speech_codec_list
					*scl)
{
	struct msgb* msg;
	struct {
		uint8_t ident;
		struct gsm48_loc_area_id lai;
		uint16_t ci;
	} __attribute__ ((packed)) lai_ci;

	msg  = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
				   "bssmap cmpl l3");
	if (!msg)
		return NULL;

	/* create layer 3 header */
	msgb_v_put(msg, BSS_MAP_MSG_COMPLETE_LAYER_3);

	/* create the cell header */
	lai_ci.ident = CELL_IDENT_WHOLE_GLOBAL;
	gsm48_generate_lai(&lai_ci.lai, cc, nc, lac);
	lai_ci.ci = osmo_htons(_ci);
	msgb_tlv_put(msg, GSM0808_IE_CELL_IDENTIFIER, sizeof(lai_ci),
		     (uint8_t *) &lai_ci);

	/* copy the layer3 data */
	msgb_tlv_put(msg, GSM0808_IE_LAYER_3_INFORMATION,
		     msgb_l3len(msg_l3), msg_l3->l3h);

	/* AoIP: add Codec List (BSS Supported) 3.2.2.103 */
	if (scl)
		gsm0808_enc_speech_codec_list(msg, scl);

	/* push the bssmap header */
	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create "Complete L3 Info" for A
 *  \param[in] msg_l3 msgb containing Layer 3 Message
 *  \param[in] nc Mobile Network Code
 *  \param[in] cc Mobile Country Code
 *  \param[in] lac Location Area Code
 *  \param[in] _ci Cell Identity
 *  \returns callee-allocated msgb with Complete L3 Info message */
struct msgb *gsm0808_create_layer3(struct msgb *msg_l3, uint16_t nc,
				   uint16_t cc, int lac, uint16_t _ci)
{
	return gsm0808_create_layer3_aoip(msg_l3, nc, cc, lac, _ci, NULL);
}

/*! Create BSSMAP RESET message
 *  \returns callee-allocated msgb with BSSMAP Reset message */
struct msgb *gsm0808_create_reset(void)
{
	uint8_t cause = GSM0808_CAUSE_EQUIPMENT_FAILURE;
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: reset");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_RESET);
	msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);
	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP RESET ACK message
 *  \returns callee-allocated msgb with BSSMAP Reset ACK message */
struct msgb *gsm0808_create_reset_ack(void)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: reset ack");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_RESET_ACKNOWLEDGE);
	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Clear Complete message
 *  \returns callee-allocated msgb with BSSMAP Clear Complete message */
struct msgb *gsm0808_create_clear_complete(void)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: clear complete");
	uint8_t val = BSS_MAP_MSG_CLEAR_COMPLETE;
	if (!msg)
		return NULL;

	msg->l3h = msg->data;
	msgb_tlv_put(msg, BSSAP_MSG_BSS_MANAGEMENT, 1, &val);

	return msg;
}

/*! Create BSSMAP Clear Command message
 *  \param[in] reason TS 08.08 cause value
 *  \returns callee-allocated msgb with BSSMAP Clear Command message */
struct msgb *gsm0808_create_clear_command(uint8_t reason)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: clear command");
	if (!msg)
		return NULL;

	msg->l3h = msgb_tv_put(msg, BSSAP_MSG_BSS_MANAGEMENT, 4);
	msgb_v_put(msg, BSS_MAP_MSG_CLEAR_CMD);
	msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &reason);

	return msg;
}

/*! Create BSSMAP Cipher Mode Command message
 *  \param[in] ei Mandatory Encryption Information
 *  \param[in] cipher_response_mode optional 1-byte Cipher Response Mode
 *  \returns callee-allocated msgb with BSSMAP Cipher Mode Command message */
struct msgb *gsm0808_create_cipher(const struct gsm0808_encrypt_info *ei,
				   const uint8_t *cipher_response_mode)
{
	/* See also: 3GPP TS 48.008 3.2.1.30 CIPHER MODE COMMAND */
	struct msgb *msg;

	/* Mandatory emelent! */
	OSMO_ASSERT(ei);

	msg =
	    msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
				"cipher-mode-command");
	if (!msg)
		return NULL;

	/* Message Type 3.2.2.1 */
	msgb_v_put(msg, BSS_MAP_MSG_CIPHER_MODE_CMD);

	/* Encryption Information 3.2.2.10 */
	gsm0808_enc_encrypt_info(msg, ei);

	/* Cipher Response Mode 3.2.2.34 */
	if (cipher_response_mode)
		msgb_tv_put(msg, GSM0808_IE_CIPHER_RESPONSE_MODE,
			    *cipher_response_mode);

	/* pre-pend the header */
	msg->l3h =
	    msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Cipher Mode Complete message
 *  \param[in] layer3 L3 Message to be included
 *  \param[in] alg_id Chosen Encrpytion Algorithm
 *  \returns callee-allocated msgb with BSSMAP Cipher Mode Complete message */
struct msgb *gsm0808_create_cipher_complete(struct msgb *layer3, uint8_t alg_id)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "cipher-complete");
	if (!msg)
		return NULL;

        /* send response with BSS override for A5/1... cheating */
	msgb_v_put(msg, BSS_MAP_MSG_CIPHER_MODE_COMPLETE);

	/* include layer3 in case we have at least two octets */
	if (layer3 && msgb_l3len(layer3) > 2) {
		msg->l4h = msgb_tlv_put(msg, GSM0808_IE_LAYER_3_MESSAGE_CONTENTS,
					msgb_l3len(layer3), layer3->l3h);
	}

	/* and the optional BSS message */
	msgb_tv_put(msg, GSM0808_IE_CHOSEN_ENCR_ALG, alg_id);

	/* pre-pend the header */
	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Cipher Mode Reject message
 *  \param[in] reason TS 08.08 cause value
 *  \returns callee-allocated msgb with BSSMAP Cipher Mode Reject message */
struct msgb *gsm0808_create_cipher_reject(uint8_t cause)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: clear complete");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_CIPHER_MODE_REJECT);
	msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);

	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Classmark Update message
 *  \param[in] cm2 Classmark 2
 *  \param[in] cm2_len length (in octets) of \a cm2
 *  \param[in] cm3 Classmark 3
 *  \param[in] cm3_len length (in octets) of \a cm3
 *  \returns callee-allocated msgb with BSSMAP Classmark Update message */
struct msgb *gsm0808_create_classmark_update(const uint8_t *cm2, uint8_t cm2_len,
					     const uint8_t *cm3, uint8_t cm3_len)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "classmark-update");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_CLASSMARK_UPDATE);
	msgb_tlv_put(msg, GSM0808_IE_CLASSMARK_INFORMATION_T2, cm2_len, cm2);
	if (cm3)
		msgb_tlv_put(msg, GSM0808_IE_CLASSMARK_INFORMATION_T3,
			     cm3_len, cm3);

	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP SAPI N Reject message
 *  \param[in] link_id Link Identifier
 *  \returns callee-allocated msgb with BSSMAP SAPI N Reject message */
struct msgb *gsm0808_create_sapi_reject(uint8_t link_id)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: sapi 'n' reject");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_SAPI_N_REJECT);
	msgb_v_put(msg, link_id);
	msgb_v_put(msg, GSM0808_CAUSE_BSS_NOT_EQUIPPED);

	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Assignment Request message
 *  \param[in] ct Channel Type
 *  \param[in] cic Circuit Identity Code (Classic A only)
 *  \param[in] ss Socket Address of MSC-side RTP socket (AoIP only)
 *  \param[in] scl Speech Codec List (AoIP only)
 *  \param[in] ci Call Identifier (Optional, LCLS)
 *  \returns callee-allocated msgb with BSSMAP Assignment Request message */
struct msgb *gsm0808_create_ass(const struct gsm0808_channel_type *ct,
				const uint16_t *cic,
				const struct sockaddr_storage *ss,
				const struct gsm0808_speech_codec_list *scl,
				const uint32_t *ci)
{
	/* See also: 3GPP TS 48.008 3.2.1.1 ASSIGNMENT REQUEST */
	struct msgb *msg;
	uint16_t cic_sw;
	uint32_t ci_sw;

	/* Mandatory emelent! */
	OSMO_ASSERT(ct);

	msg =
	    msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
				"bssmap: ass req");
	if (!msg)
		return NULL;

	/* Message Type 3.2.2.1 */
	msgb_v_put(msg, BSS_MAP_MSG_ASSIGMENT_RQST);

	/* Channel Type 3.2.2.11 */
	gsm0808_enc_channel_type(msg, ct);

	/* Circuit Identity Code 3.2.2.2  */
	if (cic) {
		cic_sw = osmo_htons(*cic);
		msgb_tv_fixed_put(msg, GSM0808_IE_CIRCUIT_IDENTITY_CODE,
				  sizeof(cic_sw), (uint8_t *) & cic_sw);
	}

	/* AoIP: AoIP Transport Layer Address (MGW) 3.2.2.102 */
	if (ss) {
		gsm0808_enc_aoip_trasp_addr(msg, ss);
	}

	/* AoIP: Codec List (MSC Preferred) 3.2.2.103 */
	if (scl)
		gsm0808_enc_speech_codec_list(msg, scl);

	/* AoIP: Call Identifier 3.2.2.105 */
	if (ci) {
		ci_sw = osmo_htonl(*ci);
		msgb_tv_fixed_put(msg, GSM0808_IE_CALL_ID, sizeof(ci_sw),
				  (uint8_t *) & ci_sw);
	}

	/* push the bssmap header */
	msg->l3h =
	    msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Assignment Completed message
 *  \param[in] rr_cause GSM 04.08 RR Cause value
 *  \param[in] chosen_channel Chosen Channel
 *  \param[in] encr_alg_id Encryption Algorithm ID
 *  \param[in] speech_mode Speech Mode
 *  \param[in] ss Socket Address of BSS-side RTP socket
 *  \param[in] sc Speech Codec (current)
 *  \param[in] scl Speech Codec List (permitted)
 *  \returns callee-allocated msgb with BSSMAP Assignment Complete message */
struct msgb *gsm0808_create_ass_compl(uint8_t rr_cause, uint8_t chosen_channel,
				      uint8_t encr_alg_id, uint8_t speech_mode,
				      const struct sockaddr_storage *ss,
				      const struct gsm0808_speech_codec *sc,
				      const struct gsm0808_speech_codec_list
				      *scl)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
						"bssmap: ass compl");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_ASSIGMENT_COMPLETE);

	/* write 3.2.2.22 */
	msgb_tv_put(msg, GSM0808_IE_RR_CAUSE, rr_cause);

	/* write cirtcuit identity  code 3.2.2.2 */
	/* write cell identifier 3.2.2.17 */
	/* write chosen channel 3.2.2.33 when BTS picked it */
	msgb_tv_put(msg, GSM0808_IE_CHOSEN_CHANNEL, chosen_channel);

	/* write chosen encryption algorithm 3.2.2.44 */
	msgb_tv_put(msg, GSM0808_IE_CHOSEN_ENCR_ALG, encr_alg_id);

	/* write circuit pool 3.2.2.45 */
	/* write speech version chosen: 3.2.2.51 when BTS picked it */
	if (speech_mode != 0)
		msgb_tv_put(msg, GSM0808_IE_SPEECH_VERSION, speech_mode);

	/* AoIP: AoIP Transport Layer Address (BSS) 3.2.2.102 */
	if (ss)
		gsm0808_enc_aoip_trasp_addr(msg, ss);

	/* AoIP: Speech Codec (Chosen) 3.2.2.104 */
	if (sc)
		gsm0808_enc_speech_codec(msg, sc);

	/* AoIP: add Codec List (BSS Supported) 3.2.2.103 */
	if (scl)
		gsm0808_enc_speech_codec_list(msg, scl);

	/* write LSA identifier 3.2.2.15 */

	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Assignment Completed message
 *  \param[in] rr_cause GSM 04.08 RR Cause value
 *  \param[in] chosen_channel Chosen Channel
 *  \param[in] encr_alg_id Encryption Algorithm ID
 *  \param[in] speech_mode Speech Mode
 *  \returns callee-allocated msgb with BSSMAP Assignment Complete message */
struct msgb *gsm0808_create_assignment_completed(uint8_t rr_cause,
						 uint8_t chosen_channel,
						 uint8_t encr_alg_id,
						 uint8_t speech_mode)
{
	return gsm0808_create_ass_compl(rr_cause, chosen_channel, encr_alg_id,
					speech_mode, NULL, NULL, NULL);
}

/*! Create BSSMAP Assignment Failure message
 *  \param[in] cause BSSMAP Cause value
 *  \param[in] rr_cause GSM 04.08 RR Cause value
 *  \param[in] scl Optional Speech Cdec List (AoIP)
 *  \returns callee-allocated msgb with BSSMAP Assignment Failure message */
struct msgb *gsm0808_create_ass_fail(uint8_t cause, const uint8_t *rr_cause,
				     const struct gsm0808_speech_codec_list
				     *scl)
{
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "bssmap: ass fail");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_ASSIGMENT_FAILURE);
	msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);

	/* RR cause 3.2.2.22 */
	if (rr_cause)
		msgb_tv_put(msg, GSM0808_IE_RR_CAUSE, *rr_cause);

	/* Circuit pool 3.22.45 */
	/* Circuit pool list 3.2.2.46 */

	/* AoIP: add Codec List (BSS Supported) 3.2.2.103 */
	if (scl)
		gsm0808_enc_speech_codec_list(msg, scl);

	/* update the size */
	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP Assignment Failure message
 *  \param[in] cause BSSMAP Cause value
 *  \param[in] rr_cause GSM 04.08 RR Cause value
 *  \returns callee-allocated msgb with BSSMAP Assignment Failure message */
struct msgb *gsm0808_create_assignment_failure(uint8_t cause,
					       uint8_t *rr_cause)
{
	return gsm0808_create_ass_fail(cause, rr_cause, NULL);
}

/*! Create BSSMAP Clear Request message
 *  \param[in] cause BSSMAP Cause value
 *  \returns callee-allocated msgb with BSSMAP Clear Request message */
struct msgb *gsm0808_create_clear_rqst(uint8_t cause)
{
	struct msgb *msg;

	msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
				  "bssmap: clear rqst");
	if (!msg)
		return NULL;

	msgb_v_put(msg, BSS_MAP_MSG_CLEAR_RQST);
	msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);
	msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Create BSSMAP PAGING message
 *  \param[in] imsi Mandatory paged IMSI in string representation
 *  \param[in] tmsi Optional paged TMSI
 *  \param[in] cil Cell Identity List (where to page)
 *  \param[in] chan_needed Channel Type needed
 *  \returns callee-allocated msgb with BSSMAP PAGING message */
struct msgb *gsm0808_create_paging(const char *imsi, const uint32_t *tmsi,
				   const struct gsm0808_cell_id_list *cil,
				   const uint8_t *chan_needed)
{
	struct msgb *msg;
	uint8_t mid_buf[GSM48_MI_SIZE + 2];
	int mid_len;
	uint32_t tmsi_sw;

	/* Mandatory emelents! */
	OSMO_ASSERT(imsi);
	OSMO_ASSERT(cil);

	/* Malformed IMSI */
	OSMO_ASSERT(strlen(imsi) <= GSM48_MI_SIZE);

	msg =
	    msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM, "paging");
	if (!msg)
		return NULL;

	/* Message Type 3.2.2.1 */
	msgb_v_put(msg, BSS_MAP_MSG_PAGING);

	/* IMSI 3.2.2.6 */
	mid_len = gsm48_generate_mid_from_imsi(mid_buf, imsi);
	msgb_tlv_put(msg, GSM0808_IE_IMSI, mid_len - 2, mid_buf + 2);

	/* TMSI 3.2.2.7 */
	if (tmsi) {
		tmsi_sw = osmo_htonl(*tmsi);
		msgb_tlv_put(msg, GSM0808_IE_TMSI, sizeof(*tmsi),
			     (uint8_t *) & tmsi_sw);
	}

	/* Cell Identifier List 3.2.2.27 */
	if (cil)
		gsm0808_enc_cell_id_list(msg, cil);

	/* Channel Needed 3.2.2.36 */
	if (chan_needed) {
		msgb_tv_put(msg, GSM0808_IE_CHANNEL_NEEDED,
			    (*chan_needed) & 0x03);
	}

	/* pre-pend the header */
	msg->l3h =
	    msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));

	return msg;
}

/*! Prepend a DTAP header to given Message Buffer
 *  \param[in] msgb Message Buffer
 *  \param[in] link_id Link Identifier */
void gsm0808_prepend_dtap_header(struct msgb *msg, uint8_t link_id)
{
	uint8_t *hh = msgb_push(msg, 3);
	hh[0] = BSSAP_MSG_DTAP;
	hh[1] = link_id;
	hh[2] = msg->len - 3;
}

/*! Create BSSMAP DTAP message
 *  \param[in] msg_l3 Messge Buffer containing Layer3 message
 *  \param[in] link_id Link Identifier
 *  \returns callee-allocated msgb with BSSMAP DTAP message */
struct msgb *gsm0808_create_dtap(struct msgb *msg_l3, uint8_t link_id)
{
	struct dtap_header *header;
	uint8_t *data;
	struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
					       "dtap");
	if (!msg)
		return NULL;

	/* DTAP header */
	msg->l3h = msgb_put(msg, sizeof(*header));
	header = (struct dtap_header *) &msg->l3h[0];
	header->type = BSSAP_MSG_DTAP;
	header->link_id = link_id;
	header->length = msgb_l3len(msg_l3);

	/* Payload */
	data = msgb_put(msg, header->length);
	memcpy(data, msg_l3->l3h, header->length);

	return msg;
}

/* As per 3GPP TS 48.008 version 11.7.0 Release 11 */
static const struct tlv_definition bss_att_tlvdef = {
	.def = {
		[GSM0808_IE_CIRCUIT_IDENTITY_CODE]  = { TLV_TYPE_FIXED, 2 },
		[GSM0808_IE_CONNECTION_RELEASE_RQSTED]	= { TLV_TYPE_TV },
		[GSM0808_IE_RESOURCE_AVAILABLE]		= { TLV_TYPE_FIXED, 21 },
		[GSM0808_IE_CAUSE]			= { TLV_TYPE_TLV },
		[GSM0808_IE_IMSI]		    = { TLV_TYPE_TLV },
		[GSM0808_IE_TMSI]		    = { TLV_TYPE_TLV },
		[GSM0808_IE_NUMBER_OF_MSS]		= { TLV_TYPE_TV },
		[GSM0808_IE_LAYER_3_HEADER_INFORMATION] = { TLV_TYPE_TLV },
		[GSM0808_IE_ENCRYPTION_INFORMATION] = { TLV_TYPE_TLV },
		[GSM0808_IE_CHANNEL_TYPE]	    = { TLV_TYPE_TLV },
		[GSM0808_IE_PERIODICITY]		= { TLV_TYPE_TV },
		[GSM0808_IE_EXTENDED_RESOURCE_INDICATOR]= { TLV_TYPE_TV },
		[GSM0808_IE_TOTAL_RESOURCE_ACCESSIBLE]	= { TLV_TYPE_FIXED, 4 },
		[GSM0808_IE_LSA_IDENTIFIER]		= { TLV_TYPE_TLV },
		[GSM0808_IE_LSA_IDENTIFIER_LIST]	= { TLV_TYPE_TLV },
		[GSM0808_IE_LSA_INFORMATION]	= { TLV_TYPE_TLV },
		[GSM0808_IE_CELL_IDENTIFIER]	    = { TLV_TYPE_TLV },
		[GSM0808_IE_PRIORITY]		    = { TLV_TYPE_TLV },
		[GSM0808_IE_CLASSMARK_INFORMATION_T2] = { TLV_TYPE_TLV },
		[GSM0808_IE_CLASSMARK_INFORMATION_T3] = { TLV_TYPE_TLV },
		[GSM0808_IE_INTERFERENCE_BAND_TO_USE] = { TLV_TYPE_TV },
		[GSM0808_IE_RR_CAUSE]			= { TLV_TYPE_TV },
		[GSM0808_IE_LAYER_3_INFORMATION]    = { TLV_TYPE_TLV },
		[GSM0808_IE_DLCI]			= { TLV_TYPE_TV },
		[GSM0808_IE_DOWNLINK_DTX_FLAG]	    = { TLV_TYPE_TV },
		[GSM0808_IE_CELL_IDENTIFIER_LIST]   = { TLV_TYPE_TLV },
		[GSM0808_IE_CELL_ID_LIST_SEGMENT]	= { TLV_TYPE_TLV },
		[GSM0808_IE_CELL_ID_LIST_SEG_EST_CELLS]	= { TLV_TYPE_TLV },
		[GSM0808_IE_CELL_ID_LIST_SEG_CELLS_TBE]	= { TLV_TYPE_TLV },
		[GSM0808_IE_CELL_ID_LIST_SEG_REL_CELLS]	= { TLV_TYPE_TLV },
		[GSM0808_IE_CELL_ID_LIST_SEG_NE_CELLS]	= { TLV_TYPE_TLV },
		[GSM0808_IE_RESPONSE_RQST]		= { TLV_TYPE_T },
		[GSM0808_IE_RESOURCE_INDICATION_METHOD]	= { TLV_TYPE_TV },
		[GSM0808_IE_CLASSMARK_INFORMATION_TYPE_1] = { TLV_TYPE_TV },
		[GSM0808_IE_CIRCUIT_IDENTITY_CODE_LIST]	= { TLV_TYPE_TLV },
		[GSM0808_IE_DIAGNOSTIC]			= { TLV_TYPE_TLV },
		[GSM0808_IE_CHOSEN_CHANNEL]	    = { TLV_TYPE_TV },
		[GSM0808_IE_CIPHER_RESPONSE_MODE]   = { TLV_TYPE_TV },
		[GSM0808_IE_LAYER_3_MESSAGE_CONTENTS] = { TLV_TYPE_TLV },
		[GSM0808_IE_CHANNEL_NEEDED]	    = { TLV_TYPE_TV },
		[GSM0808_IE_TRACE_TYPE]			= { TLV_TYPE_TV },
		[GSM0808_IE_TRIGGERID]			= { TLV_TYPE_TLV },
		[GSM0808_IE_TRACE_REFERENCE]		= { TLV_TYPE_TV },
		[GSM0808_IE_TRANSACTIONID]		= { TLV_TYPE_TLV },
		[GSM0808_IE_MOBILE_IDENTITY]		= { TLV_TYPE_TLV },
		[GSM0808_IE_OMCID]			= { TLV_TYPE_TLV },
		[GSM0808_IE_FORWARD_INDICATOR]		= { TLV_TYPE_TV },
		[GSM0808_IE_CHOSEN_ENCR_ALG]        = { TLV_TYPE_TV },
		[GSM0808_IE_CIRCUIT_POOL]		= { TLV_TYPE_TV },
		[GSM0808_IE_CIRCUIT_POOL_LIST]		= { TLV_TYPE_TLV },
		[GSM0808_IE_TIME_INDICATION]		= { TLV_TYPE_TV },
		[GSM0808_IE_RESOURCE_SITUATION]		= { TLV_TYPE_TLV },
		[GSM0808_IE_CURRENT_CHANNEL_TYPE_1]	= { TLV_TYPE_TV },
		[GSM0808_IE_QUEUEING_INDICATOR]		= { TLV_TYPE_TV },
		[GSM0808_IE_SPEECH_VERSION]         = { TLV_TYPE_TV },
		[GSM0808_IE_ASSIGNMENT_REQUIREMENT]	= { TLV_TYPE_TV },
		[GSM0808_IE_TALKER_FLAG]	    = { TLV_TYPE_T },
		[GSM0808_IE_GROUP_CALL_REFERENCE]   = { TLV_TYPE_TLV },
		[GSM0808_IE_EMLPP_PRIORITY]	    = { TLV_TYPE_TV },
		[GSM0808_IE_CONFIG_EVO_INDI]	    = { TLV_TYPE_TV },
		[GSM0808_IE_OLD_BSS_TO_NEW_BSS_INFORMATION] = { TLV_TYPE_TLV },
		[GSM0808_IE_LCS_QOS]			= { TLV_TYPE_TLV },
		[GSM0808_IE_LSA_ACCESS_CTRL_SUPPR]  = { TLV_TYPE_TV },
		[GSM0808_IE_LCS_PRIORITY]		= { TLV_TYPE_TLV },
		[GSM0808_IE_LOCATION_TYPE]		= { TLV_TYPE_TLV },
		[GSM0808_IE_LOCATION_ESTIMATE]		= { TLV_TYPE_TLV },
		[GSM0808_IE_POSITIONING_DATA]		= { TLV_TYPE_TLV },
		[GSM0808_IE_LCS_CAUSE]			= { TLV_TYPE_TLV },
		[GSM0808_IE_APDU]			= { TLV_TYPE_TLV },
		[GSM0808_IE_NETWORK_ELEMENT_IDENTITY]	= { TLV_TYPE_TLV },
		[GSM0808_IE_GPS_ASSISTANCE_DATA]	= { TLV_TYPE_TLV },
		[GSM0808_IE_DECIPHERING_KEYS]		= { TLV_TYPE_TLV },
		[GSM0808_IE_RETURN_ERROR_RQST]		= { TLV_TYPE_TLV },
		[GSM0808_IE_RETURN_ERROR_CAUSE]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SEGMENTATION]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SERVICE_HANDOVER]	    = { TLV_TYPE_TLV },
		[GSM0808_IE_SOURCE_RNC_TO_TARGET_RNC_TRANSPARENT_UMTS]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SOURCE_RNC_TO_TARGET_RNC_TRANSPARENT_CDMA2000]	= { TLV_TYPE_TLV },
		[GSM0808_IE_GERAN_CLASSMARK]		= { TLV_TYPE_TLV },
		[GSM0808_IE_GERAN_BSC_CONTAINER]	= { TLV_TYPE_TLV },
		[GSM0808_IE_NEW_BSS_TO_OLD_BSS_INFO]	= { TLV_TYPE_TLV },
		[GSM0800_IE_INTER_SYSTEM_INFO]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SNA_ACCESS_INFO]		= { TLV_TYPE_TLV },
		[GSM0808_IE_VSTK_RAND_INFO]		= { TLV_TYPE_TLV },
		[GSM0808_IE_PAGING_INFO]		= { TLV_TYPE_TV },
		[GSM0808_IE_IMEI]			= { TLV_TYPE_TLV },
		[GSM0808_IE_VELOCITY_ESTIMATE]		= { TLV_TYPE_TLV },
		[GSM0808_IE_VGCS_FEATURE_FLAGS]		= { TLV_TYPE_TLV },
		[GSM0808_IE_TALKER_PRIORITY]		= { TLV_TYPE_TV },
		[GSM0808_IE_EMERGENCY_SET_INDICATION]	= { TLV_TYPE_T },
		[GSM0808_IE_TALKER_IDENTITY]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SMS_TO_VGCS]		= { TLV_TYPE_TLV },
		[GSM0808_IE_VGCS_TALKER_MODE]		= { TLV_TYPE_TLV },
		[GSM0808_IE_VGCS_VBS_CELL_STATUS]	= { TLV_TYPE_TLV },
		[GSM0808_IE_GANSS_ASSISTANCE_DATA]	= { TLV_TYPE_TLV },
		[GSM0808_IE_GANSS_POSITIONING_DATA]	= { TLV_TYPE_TLV },
		[GSM0808_IE_GANSS_LOCATION_TYPE]	= { TLV_TYPE_TLV },
		[GSM0808_IE_APP_DATA]			= { TLV_TYPE_TLV },
		[GSM0808_IE_DATA_IDENTITY]		= { TLV_TYPE_TLV },
		[GSM0808_IE_APP_DATA_INFO]		= { TLV_TYPE_TLV },
		[GSM0808_IE_MSISDN]			= { TLV_TYPE_TLV },
		[GSM0808_IE_AOIP_TRASP_ADDR]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SPEECH_CODEC_LIST]		= { TLV_TYPE_TLV },
		[GSM0808_IE_SPEECH_CODEC]		= { TLV_TYPE_TLV },
		[GSM0808_IE_CALL_ID]			= { TLV_TYPE_FIXED, 4 },
		[GSM0808_IE_CALL_ID_LIST]		= { TLV_TYPE_TLV },
		[GSM0808_IE_A_IF_SEL_FOR_RESET]		= { TLV_TYPE_TV },
		[GSM0808_IE_KC_128]			= { TLV_TYPE_FIXED, 16 },
		[GSM0808_IE_CSG_IDENTIFIER]		= { TLV_TYPE_TLV },
		[GSM0808_IE_REDIR_ATTEMPT_FLAG]		= { TLV_TYPE_T },
		[GSM0808_IE_REROUTE_REJ_CAUSE]		= { TLV_TYPE_TV },
		[GSM0808_IE_SEND_SEQ_NUM]		= { TLV_TYPE_TV },
		[GSM0808_IE_REROUTE_COMPL_OUTCOME]	= { TLV_TYPE_TV },
		[GSM0808_IE_GLOBAL_CALL_REF]		= { TLV_TYPE_TLV },
		[GSM0808_IE_LCLS_CONFIG]		= { TLV_TYPE_TV },
		[GSM0808_IE_LCLS_CONN_STATUS_CTRL]	= { TLV_TYPE_TV },
		[GSM0808_IE_LCLS_CORR_NOT_NEEDED]	= { TLV_TYPE_TV },
		[GSM0808_IE_LCLS_BSS_STATUS]		= { TLV_TYPE_TV },
		[GSM0808_IE_LCLS_BREAK_REQ]		= { TLV_TYPE_TV },
		[GSM0808_IE_CSFB_INDICATION]		= { TLV_TYPE_T },
		[GSM0808_IE_CS_TO_PS_SRVCC]		= { TLV_TYPE_T },
		[GSM0808_IE_SRC_ENB_TO_TGT_ENB_TRANSP]	= { TLV_TYPE_TLV },
		[GSM0808_IE_CS_TO_PS_SRVCC_IND]		= { TLV_TYPE_T },
		[GSM0808_IE_CN_TO_MS_TRANSP_INFO]	= { TLV_TYPE_TLV },
		[GSM0808_IE_SELECTED_PLMN_ID]		= { TLV_TYPE_FIXED, 3 },
		[GSM0808_IE_LAST_USED_EUTRAN_PLMN_ID]	= { TLV_TYPE_FIXED, 3 },
	},
};

const struct tlv_definition *gsm0808_att_tlvdef(void)
{
	return &bss_att_tlvdef;
}

static const struct value_string gsm0808_msgt_names[] = {
	{ BSS_MAP_MSG_ASSIGMENT_RQST,		"ASSIGNMENT REQ" },
	{ BSS_MAP_MSG_ASSIGMENT_COMPLETE,	"ASSIGNMENT COMPL" },
	{ BSS_MAP_MSG_ASSIGMENT_FAILURE,	"ASSIGNMENT FAIL" },
	{ BSS_MAP_MSG_CHAN_MOD_RQST,		"CHANNEL MODIFY REQUEST" },

	{ BSS_MAP_MSG_HANDOVER_RQST,		"HANDOVER REQ" },
	{ BSS_MAP_MSG_HANDOVER_REQUIRED,	"HANDOVER REQUIRED" },
	{ BSS_MAP_MSG_HANDOVER_RQST_ACKNOWLEDGE,"HANDOVER REQ ACK" },
	{ BSS_MAP_MSG_HANDOVER_CMD,		"HANDOVER CMD" },
	{ BSS_MAP_MSG_HANDOVER_COMPLETE,	"HANDOVER COMPLETE" },
	{ BSS_MAP_MSG_HANDOVER_SUCCEEDED,	"HANDOVER SUCCESS" },
	{ BSS_MAP_MSG_HANDOVER_FAILURE,		"HANDOVER FAILURE" },
	{ BSS_MAP_MSG_HANDOVER_PERFORMED,	"HANDOVER PERFORMED" },
	{ BSS_MAP_MSG_HANDOVER_CANDIDATE_ENQUIRE, "HANDOVER CAND ENQ" },
	{ BSS_MAP_MSG_HANDOVER_CANDIDATE_RESPONSE, "HANDOVER CAND RESP" },
	{ BSS_MAP_MSG_HANDOVER_REQUIRED_REJECT,	"HANDOVER REQ REJ" },
	{ BSS_MAP_MSG_HANDOVER_DETECT,		"HANDOVER DETECT" },
	{ BSS_MAP_MSG_INT_HANDOVER_REQUIRED,	"INT HANDOVER REQ" },
	{ BSS_MAP_MSG_INT_HANDOVER_REQUIRED_REJ,"INT HANDOVER REQ REJ" },
	{ BSS_MAP_MSG_INT_HANDOVER_CMD,		"INT HANDOVER CMD" },
	{ BSS_MAP_MSG_INT_HANDOVER_ENQUIRY,	"INT HANDOVER ENQ" },

	{ BSS_MAP_MSG_CLEAR_CMD,		"CLEAR COMMAND" },
	{ BSS_MAP_MSG_CLEAR_COMPLETE,		"CLEAR COMPLETE" },
	{ BSS_MAP_MSG_CLEAR_RQST,		"CLEAR REQUEST" },
	{ BSS_MAP_MSG_SAPI_N_REJECT,		"SAPI N REJECT" },
	{ BSS_MAP_MSG_CONFUSION,		"CONFUSION" },

	{ BSS_MAP_MSG_SUSPEND,			"SUSPEND" },
	{ BSS_MAP_MSG_RESUME,			"RESUME" },
	{ BSS_MAP_MSG_CONNECTION_ORIENTED_INFORMATION, "CONN ORIENT INFO" },
	{ BSS_MAP_MSG_PERFORM_LOCATION_RQST,	"PERFORM LOC REQ" },
	{ BSS_MAP_MSG_LSA_INFORMATION,		"LSA INFORMATION" },
	{ BSS_MAP_MSG_PERFORM_LOCATION_RESPONSE, "PERFORM LOC RESP" },
	{ BSS_MAP_MSG_PERFORM_LOCATION_ABORT,	"PERFORM LOC ABORT" },
	{ BSS_MAP_MSG_COMMON_ID,		"COMMON ID" },
	{ BSS_MAP_MSG_REROUTE_CMD,		"REROUTE COMMAND" },
	{ BSS_MAP_MSG_REROUTE_COMPLETE,		"REROUTE COMPLETE" },

	{ BSS_MAP_MSG_RESET,			"RESET" },
	{ BSS_MAP_MSG_RESET_ACKNOWLEDGE,	"RESET ACK" },
	{ BSS_MAP_MSG_OVERLOAD,			"OVERLOAD" },
	{ BSS_MAP_MSG_RESET_CIRCUIT,		"RESET CIRCUIT" },
	{ BSS_MAP_MSG_RESET_CIRCUIT_ACKNOWLEDGE, "RESET CIRCUIT ACK" },
	{ BSS_MAP_MSG_MSC_INVOKE_TRACE,		"MSC INVOKE TRACE" },
	{ BSS_MAP_MSG_BSS_INVOKE_TRACE,		"BSS INVOKE TRACE" },
	{ BSS_MAP_MSG_CONNECTIONLESS_INFORMATION, "CONNLESS INFO" },
	{ BSS_MAP_MSG_RESET_IP_RSRC,		"RESET IP RESOURCE" },
	{ BSS_MAP_MSG_RESET_IP_RSRC_ACK,	"RESET IP RESOURCE ACK" },

	{ BSS_MAP_MSG_BLOCK,			"BLOCK" },
	{ BSS_MAP_MSG_BLOCKING_ACKNOWLEDGE,	"BLOCK ACK" },
	{ BSS_MAP_MSG_UNBLOCK,			"UNBLOCK" },
	{ BSS_MAP_MSG_UNBLOCKING_ACKNOWLEDGE,	"UNBLOCK ACK" },
	{ BSS_MAP_MSG_CIRCUIT_GROUP_BLOCK,	"CIRC GROUP BLOCK" },
	{ BSS_MAP_MSG_CIRCUIT_GROUP_BLOCKING_ACKNOWLEDGE, "CIRC GORUP BLOCK ACK" },
	{ BSS_MAP_MSG_CIRCUIT_GROUP_UNBLOCK,	"CIRC GROUP UNBLOCK" },
	{ BSS_MAP_MSG_CIRCUIT_GROUP_UNBLOCKING_ACKNOWLEDGE, "CIRC GROUP UNBLOCK ACK" },
	{ BSS_MAP_MSG_UNEQUIPPED_CIRCUIT,	"UNEQUIPPED CIRCUIT" },
	{ BSS_MAP_MSG_CHANGE_CIRCUIT,		"CHANGE CIRCUIT" },
	{ BSS_MAP_MSG_CHANGE_CIRCUIT_ACKNOWLEDGE, "CHANGE CIRCUIT ACK" },

	{ BSS_MAP_MSG_RESOURCE_RQST,		"RESOURCE REQ" },
	{ BSS_MAP_MSG_RESOURCE_INDICATION,	"RESOURCE IND" },
	{ BSS_MAP_MSG_PAGING,			"PAGING" },
	{ BSS_MAP_MSG_CIPHER_MODE_CMD,		"CIPHER MODE CMD" },
	{ BSS_MAP_MSG_CLASSMARK_UPDATE,		"CLASSMARK UPDATE" },
	{ BSS_MAP_MSG_CIPHER_MODE_COMPLETE,	"CIPHER MODE COMPLETE" },
	{ BSS_MAP_MSG_QUEUING_INDICATION,	"QUEUING INDICATION" },
	{ BSS_MAP_MSG_COMPLETE_LAYER_3,		"COMPLETE LAYER 3" },
	{ BSS_MAP_MSG_CLASSMARK_RQST,		"CLASSMARK REQ" },
	{ BSS_MAP_MSG_CIPHER_MODE_REJECT,	"CIPHER MODE REJECT" },
	{ BSS_MAP_MSG_LOAD_INDICATION,		"LOAD IND" },

	{ BSS_MAP_MSG_VGCS_VBS_SETUP,		"VGCS/VBS SETUP" },
	{ BSS_MAP_MSG_VGCS_VBS_SETUP_ACK,	"VGCS/VBS SETUP ACK" },
	{ BSS_MAP_MSG_VGCS_VBS_SETUP_REFUSE,	"VGCS/VBS SETUP REFUSE" },
	{ BSS_MAP_MSG_VGCS_VBS_ASSIGNMENT_RQST,	"VGCS/VBS ASSIGN REQ" },
	{ BSS_MAP_MSG_VGCS_VBS_ASSIGNMENT_RESULT, "VGCS/VBS ASSIGN RES" },
	{ BSS_MAP_MSG_VGCS_VBS_ASSIGNMENT_FAILURE, "VGCS/VBS ASSIGN FAIL" },
	{ BSS_MAP_MSG_VGCS_VBS_QUEUING_INDICATION, "VGCS/VBS QUEUING IND" },
	{ BSS_MAP_MSG_UPLINK_RQST,		"UPLINK REQ" },
	{ BSS_MAP_MSG_UPLINK_RQST_ACKNOWLEDGE,	"UPLINK REQ ACK" },
	{ BSS_MAP_MSG_UPLINK_RQST_CONFIRMATION,	"UPLINK REQ CONF" },
	{ BSS_MAP_MSG_UPLINK_RELEASE_INDICATION,"UPLINK REL IND" },
	{ BSS_MAP_MSG_UPLINK_REJECT_CMD,	"UPLINK REJ CMD" },
	{ BSS_MAP_MSG_UPLINK_RELEASE_CMD,	"UPLINK REL CMD" },
	{ BSS_MAP_MSG_UPLINK_SEIZED_CMD,	"UPLINK SEIZED CMD" },
	{ BSS_MAP_MSG_VGCS_ADDL_INFO,		"VGCS ADDL INFO" },
	{ BSS_MAP_MSG_NOTIFICATION_DATA,	"NOTIF DATA" },
	{ BSS_MAP_MSG_UPLINK_APP_DATA,		"UPLINK APP DATA" },

	{ BSS_MAP_MSG_LCLS_CONNECT_CTRL,	"LCLS-CONNECT-CONTROL" },
	{ BSS_MAP_MSG_LCLS_CONNECT_CTRL_ACK,	"CLS-CONNECT-CONTROL-ACK" },
	{ BSS_MAP_MSG_LCLS_NOTIFICATION,	"LCLS-NOTIFICATION" },

	{ 0, NULL }
};

/*! Return string name of BSSMAP Message Type */
const char *gsm0808_bssmap_name(uint8_t msg_type)
{
	return get_value_string(gsm0808_msgt_names, msg_type);
}

static const struct value_string gsm0808_bssap_names[] = {
	{ BSSAP_MSG_BSS_MANAGEMENT, 		"MANAGEMENT" },
	{ BSSAP_MSG_DTAP,			"DTAP" },
	{ 0, NULL }
};

/*! Return string name of BSSAP Message Type */
const char *gsm0808_bssap_name(uint8_t msg_type)
{
	return get_value_string(gsm0808_bssap_names, msg_type);
}

const struct value_string gsm0808_speech_codec_type_names[] = {
	{ GSM0808_SCT_FR1, "FR1" },
	{ GSM0808_SCT_FR2, "FR2" },
	{ GSM0808_SCT_FR3, "FR3" },
	{ GSM0808_SCT_FR4, "FR4" },
	{ GSM0808_SCT_FR5, "FR5" },
	{ GSM0808_SCT_HR1, "HR1" },
	{ GSM0808_SCT_HR3, "HR3" },
	{ GSM0808_SCT_HR4, "HR4" },
	{ GSM0808_SCT_HR6, "HR6" },
	{ GSM0808_SCT_CSD, "CSD" },
	{ 0, NULL }
};

/*! @} */