/* (C) 2018 by sysmocom s.f.m.c. GmbH
* All Rights Reserved
*
* Author: Harald Welte, Philipp Maier
*
* 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/utils.h>
#include <osmocom/gsm/tlv.h>
#include <osmocom/gsm/protocol/gsm_29_118.h>
#include <osmocom/gsm/gsm29118.h>
#include <osmocom/gsm/apn.h>
#include <osmocom/gsm/gsm48.h>
const struct value_string sgsap_msg_type_names[] = {
{ SGSAP_MSGT_PAGING_REQ, "PAGING-REQUEST" },
{ SGSAP_MSGT_PAGING_REJ, "PAGING-REJECT" },
{ SGSAP_MSGT_SERVICE_REQ, "SERVICE-REQUEST" },
{ SGSAP_MSGT_DL_UD, "DOWNLINK-UNITDATA" },
{ SGSAP_MSGT_UL_UD, "UPLINK-UNITDATA" },
{ SGSAP_MSGT_LOC_UPD_REQ, "LOCATION-UPDATE-REQUEST" },
{ SGSAP_MSGT_LOC_UPD_ACK, "LOCATION-UPDATE-ACCEPT" },
{ SGSAP_MSGT_LOC_UPD_REJ, "LOCATION-UPDATE-REJECT" },
{ SGSAP_MSGT_TMSI_REALL_CMPL, "TMSI-REALLOCATION-COMPLETE" },
{ SGSAP_MSGT_ALERT_REQ, "ALERT-REQQUEST" },
{ SGSAP_MSGT_ALERT_ACK, "ALERT-ACK" },
{ SGSAP_MSGT_ALERT_REJ, "ALERT-REJECT" },
{ SGSAP_MSGT_UE_ACT_IND, "UE-ACTIVITY-INDICATION" },
{ SGSAP_MSGT_EPS_DET_IND, "EPS-DETACH-INDICATION" },
{ SGSAP_MSGT_EPS_DET_ACK, "EPS-DETACH-ACK" },
{ SGSAP_MSGT_IMSI_DET_IND, "IMSI-DETACH-INDICATION" },
{ SGSAP_MSGT_IMSI_DET_ACK, "IMSI-DETACH-ACK" },
{ SGSAP_MSGT_RESET_IND, "RESET-INDICATION" },
{ SGSAP_MSGT_RESET_ACK, "RESET-ACK" },
{ SGSAP_MSGT_SERVICE_ABORT_REQ, "SERVICE-ABORT-REQUEST" },
{ SGSAP_MSGT_MO_CSFB_IND, "MO-CSFB-INDICATION" },
{ SGSAP_MSGT_MM_INFO_REQ, "MM-INFO-REQUEST" },
{ SGSAP_MSGT_RELEASE_REQ, "RELEASE-REQUEST" },
{ SGSAP_MSGT_STATUS, "STATUS" },
{ SGSAP_MSGT_UE_UNREACHABLE, "UE-UNREACHABLE" },
{ 0, NULL }
};
const struct value_string sgsap_iei_names[] = {
{ SGSAP_IE_IMSI, "IMSI" },
{ SGSAP_IE_VLR_NAME, "VLR-NAME" },
{ SGSAP_IE_TMSI, "TMSI" },
{ SGSAP_IE_LAI, "LAI" },
{ SGSAP_IE_CHAN_NEEDED, "CHAN-NEEDED" },
{ SGSAP_IE_EMLPP_PRIORITY, "EMLPP-PRIORITY" },
{ SGSAP_IE_TMSI_STATUS, "TMSI-STATUS" },
{ SGSAP_IE_SGS_CAUSE, "SGS-CAUSE" },
{ SGSAP_IE_MME_NAME, "MME-NAME" },
{ SGSAP_IE_EPS_LU_TYPE, "EPS-LU-TYPE" },
{ SGSAP_IE_GLOBAL_CN_ID, "GLOBAL-CN-ID" },
{ SGSAP_IE_MOBILE_ID, "MOBILE-ID" },
{ SGSAP_IE_REJECT_CAUSE, "REJECT-CAUSE" },
{ SGSAP_IE_IMSI_DET_EPS_TYPE, "IMSI-DET-EPS-TYPE" },
{ SGSAP_IE_IMSI_DET_NONEPS_TYPE, "IMSI-DET-NONEPS-TYPE" },
{ SGSAP_IE_IMEISV, "IMEISV" },
{ SGSAP_IE_NAS_MSG_CONTAINER, "NAS-MSG-CONTAINER" },
{ SGSAP_IE_MM_INFO, "MM-INFO" },
{ SGSAP_IE_ERR_MSG, "ERR-MSG" },
{ SGSAP_IE_CLI, "CLI" },
{ SGSAP_IE_LCS_CLIENT_ID, "LCS-CLIENT-ID" },
{ SGSAP_IE_LCS_INDICATOR, "LCS-INDICATOR" },
{ SGSAP_IE_SS_CODE, "SS-CODE" },
{ SGSAP_IE_SERVICE_INDICATOR, "SERVICE-INDICATOR" },
{ SGSAP_IE_UE_TIMEZONE, "UE-TIMEZONE" },
{ SGSAP_IE_MS_CLASSMARK2, "MS-CLASSMARK2" },
{ SGSAP_IE_TAI, "TAI" },
{ SGSAP_IE_EUTRAN_CGI, "EUTRAN-CGI" },
{ SGSAP_IE_UE_EMM_MODE, "UE-EMM-MODE" },
{ SGSAP_IE_ADDL_PAGING_INDICATORS, "ADDL-PAGING-INDICATORS" },
{ SGSAP_IE_TMSI_BASED_NRI_CONT, "TMSI-BASED-NRI-CONT" },
{ SGSAP_IE_MO_FALLBACK_VALUE, "MO-FALLBACK-VALUE" },
{ 0, NULL }
};
const struct value_string sgsap_eps_lu_type_names[] = {
{ SGSAP_EPS_LUT_IMSI_ATTACH, "IMSI Attach" },
{ SGSAP_EPS_LUT_NORMAL, "Normal" },
{ 0, NULL }
};
const struct value_string sgsap_ismi_det_eps_type_names[] = {
{ SGSAP_ID_EPS_T_NETWORK_INITIATED, "Network initiated IMSI detach from EPS" },
{ SGSAP_ID_EPS_T_UE_INITIATED, "UE initiated IMSI detach from EPS" },
{ SGSAP_ID_EPS_T_EPS_NOT_ALLOWED, "EPS not allowed" },
{ 0, NULL }
};
const struct value_string sgsap_ismi_det_noneps_type_names[] = {
{ SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS,
"Explicit UE initiated IMSI detach from non-EPS" },
{ SGSAP_ID_NONEPS_T_COMBINED_UE_EPS_NONEPS,
"Combined UE initiated IMSI detach from EPS and non-EPS" },
{ SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS,
"Implicit network initiated IMSI detach from EPS and non-EPS" },
{ 0, NULL }
};
const struct value_string sgsap_service_ind_names[] = {
{ SGSAP_SERV_IND_CS_CALL, "CS Call" },
{ SGSAP_SERV_IND_SMS, "SMS" },
{ 0, NULL }
};
const struct value_string sgsap_sgs_cause_names[] = {
{ SGSAP_SGS_CAUSE_IMSI_DET_EPS, "IMSI detached for EPS" },
{ SGSAP_SGS_CAUSE_IMSI_DET_EPS_NONEPS, "IMSI detached for EPS and non-EPS" },
{ SGSAP_SGS_CAUSE_IMSI_UNKNOWN, "IMSI unknown" },
{ SGSAP_SGS_CAUSE_IMSI_DET_NON_EPS, "IMSI detached for non-EPS" },
{ SGSAP_SGS_CAUSE_IMSI_IMPL_DET_NON_EPS,"IMSI implicitly detached for non-EPS" },
{ SGSAP_SGS_CAUSE_UE_UNREACHABLE, "UE unreachable" },
{ SGSAP_SGS_CAUSE_MSG_INCOMP_STATE, "Message not compatible with protocol state" },
{ SGSAP_SGS_CAUSE_MISSING_MAND_IE, "Missing mandatory IE" },
{ SGSAP_SGS_CAUSE_INVALID_MAND_IE, "Invalid mandatory IE" },
{ SGSAP_SGS_CAUSE_COND_IE_ERROR, "Conditional IE error" },
{ SGSAP_SGS_CAUSE_SEMANT_INCORR_MSG, "Semantically incorrect message" },
{ SGSAP_SGS_CAUSE_MSG_UNKNOWN, "Message unknown" },
{ SGSAP_SGS_CAUSE_MT_CSFB_REJ_USER, "MT CSFB call rejected by user" },
{ SGSAP_SGS_CAUSE_UE_TEMP_UNREACHABLE, "UE temporarily unreachable" },
{ 0, NULL }
};
const struct value_string sgsap_ue_emm_mode_names[] = {
{ SGSAP_UE_EMM_MODE_IDLE, "EMM-IDLE" },
{ SGSAP_UE_EMM_MODE_CONNECTED, "EMM-CONNECTED" },
{ 0, NULL }
};
const struct tlv_definition sgsap_ie_tlvdef = {
.def = {
[SGSAP_IE_IMSI] = { TLV_TYPE_TLV },
[SGSAP_IE_VLR_NAME] = { TLV_TYPE_TLV },
[SGSAP_IE_TMSI] = { TLV_TYPE_TLV },
[SGSAP_IE_LAI] = { TLV_TYPE_TLV },
[SGSAP_IE_CHAN_NEEDED] = { TLV_TYPE_TLV },
[SGSAP_IE_EMLPP_PRIORITY] = { TLV_TYPE_TLV },
[SGSAP_IE_TMSI_STATUS] = { TLV_TYPE_TLV },
[SGSAP_IE_SGS_CAUSE] = { TLV_TYPE_TLV },
[SGSAP_IE_MME_NAME] = { TLV_TYPE_TLV },
[SGSAP_IE_EPS_LU_TYPE] = { TLV_TYPE_TLV },
[SGSAP_IE_GLOBAL_CN_ID] = { TLV_TYPE_TLV },
[SGSAP_IE_MOBILE_ID] = { TLV_TYPE_TLV },
[SGSAP_IE_REJECT_CAUSE] = { TLV_TYPE_TLV },
[SGSAP_IE_IMSI_DET_EPS_TYPE] = { TLV_TYPE_TLV },
[SGSAP_IE_IMSI_DET_NONEPS_TYPE] = { TLV_TYPE_TLV },
[SGSAP_IE_IMEISV] = { TLV_TYPE_TLV },
[SGSAP_IE_NAS_MSG_CONTAINER] = { TLV_TYPE_TLV },
[SGSAP_IE_MM_INFO] = { TLV_TYPE_TLV },
[SGSAP_IE_ERR_MSG] = { TLV_TYPE_TLV },
[SGSAP_IE_CLI] = { TLV_TYPE_TLV },
[SGSAP_IE_LCS_CLIENT_ID] = { TLV_TYPE_TLV },
[SGSAP_IE_LCS_INDICATOR] = { TLV_TYPE_TLV },
[SGSAP_IE_SS_CODE] = { TLV_TYPE_TLV },
[SGSAP_IE_SERVICE_INDICATOR] = { TLV_TYPE_TLV },
[SGSAP_IE_UE_TIMEZONE] = { TLV_TYPE_TLV },
[SGSAP_IE_MS_CLASSMARK2] = { TLV_TYPE_TLV },
[SGSAP_IE_TAI] = { TLV_TYPE_TLV },
[SGSAP_IE_EUTRAN_CGI] = { TLV_TYPE_TLV },
[SGSAP_IE_UE_EMM_MODE] = { TLV_TYPE_TLV },
[SGSAP_IE_ADDL_PAGING_INDICATORS]={ TLV_TYPE_TLV },
[SGSAP_IE_TMSI_BASED_NRI_CONT] = { TLV_TYPE_TLV },
[SGSAP_IE_MO_FALLBACK_VALUE] = { TLV_TYPE_TLV },
},
};
/* Allocate an empty message buffer, suitable to hold a complete SGsAP msg. */
struct msgb *gsm29118_msgb_alloc(void)
{
/* by far sufficient for the maximum size message of 298 bytes
* (9+7+5+3+10+253+10+1) SGsAP-UP-UD */
return msgb_alloc_headroom(1024, 512, "SGsAP");
}
/* Encode VLR/MME name from string and append to SGsAP msg */
static int msgb_sgsap_name_put(struct msgb *msg, enum sgsap_iei iei, const char *name)
{
uint8_t buf[APN_MAXLEN];
uint8_t len;
int rc;
/* encoding is like DNS names, which is like APN fields */
memset(buf, 0, sizeof(buf));
rc = osmo_apn_from_str(buf, sizeof(buf), name);
if (rc < 0)
return -1;
len = (uint8_t)rc;
/* Note: While the VLR-Name (see 3GPP TS 29.118, chapter 9.4.22) has
* a flexible length, the MME-Name has a fixed size of 55 octets. (see
* 3GPP TS 29.118, chapter 9.4.13). */
if (iei == SGSAP_IE_MME_NAME && len != SGS_MME_NAME_LEN)
return -1;
msgb_tlv_put(msg, iei, len, buf);
return 0;
}
/* Encode IMSI from string representation and append to SGSaAP msg */
static void msgb_sgsap_imsi_put(struct msgb *msg, const char *imsi)
{
uint8_t buf[16];
uint8_t len;
/* encoding is just like TS 04.08 */
len = gsm48_generate_mid_from_imsi(buf, imsi);
/* skip first two bytes (tag+length) so we can use msgb_tlv_put */
msgb_tlv_put(msg, SGSAP_IE_IMSI, len - 2, buf + 2);
}
/* Encode LAI from struct representation and append to SGSaAP msg */
static void msgb_sgsap_lai_put(struct msgb *msg, const struct osmo_location_area_id *lai)
{
struct gsm48_loc_area_id lai_enc;
gsm48_generate_lai2(&lai_enc, lai);
msgb_tlv_put(msg, SGSAP_IE_LAI, sizeof(lai_enc), (uint8_t *) & lai_enc);
}
/* Many messages consist only of a message type and an imsi */
static struct msgb *create_simple_msg(enum sgsap_msg_type msg_type, const char *imsi)
{
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, imsi);
msgb_push_u8(msg, msg_type);
return msg;
}
/* 8.3 SGsAP-ALERT-REQUEST.
* \param[in] imsi IMSI of the subscriber.
* \returns callee-allocated msgb with the encoded message.*/
struct msgb *gsm29118_create_alert_req(const char *imsi)
{
return create_simple_msg(SGSAP_MSGT_ALERT_REQ, imsi);
}
/* 8.4 SGsAP-DOWNLINK-UNITDATA.
* \param[in] imsi IMSI of the subscriber.
* \param[in] nas_msg user provided message buffer with L3 message.
* \returns callee-allocated msgb with the encoded message. */
struct msgb *gsm29118_create_dl_ud(const char *imsi, struct msgb *nas_msg)
{
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, imsi);
msgb_tlv_put(msg, SGSAP_IE_NAS_MSG_CONTAINER, nas_msg->len, nas_msg->data);
msgb_push_u8(msg, SGSAP_MSGT_DL_UD);
return msg;
}
/* 8.5 SGsAP-EPS-DETACH-ACK.
* \param[in] imsi IMSI of the subscriber.
* \returns callee-allocated msgb with the encoded message. */
struct msgb *gsm29118_create_eps_det_ack(const char *imsi)
{
return create_simple_msg(SGSAP_MSGT_EPS_DET_ACK, imsi);
}
/* 8.7 SGsAP-IMSI-DETACH-ACK.
* \param[in] imsi IMSI of the subscriber.
* \returns callee-allocated msgb with the encoded message. */
struct msgb *gsm29118_create_imsi_det_ack(const char *imsi)
{
return create_simple_msg(SGSAP_MSGT_IMSI_DET_ACK, imsi);
}
/*! 8.9 SGsAP-LOCATION-UPDATE-ACCEPT.
* \param[in] imsi IMSI of the subscriber.
* \param[in] lai Location Area Identity (optional, may be NULL).
* \param[in] new_id value part of new Mobile Identity (optional, may be NULL).
* \param[in] new_id_len length of \a new_id in octets.
* \returns callee-allocated msgb with the encoded message */
struct msgb *gsm29118_create_lu_ack(const char *imsi, const struct osmo_location_area_id *lai, const uint8_t *new_id,
unsigned int new_id_len)
{
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, imsi);
msgb_sgsap_lai_put(msg, lai);
if (new_id && new_id_len)
msgb_tlv_put(msg, SGSAP_IE_MOBILE_ID, new_id_len, new_id);
msgb_push_u8(msg, SGSAP_MSGT_LOC_UPD_ACK);
return msg;
}
/* 8.10 SGsAP-LOCATION-UPDATE-REJECT.
* \param[in] imsi IMSI of the subscriber.
* \param[in] rej_cause LU cause code, see also 3GPP TS 29.018, subclause 18.4.21.
* \param[in] lai location area identifier.
* \returns callee-allocated msgb with the encoded message */
struct msgb *gsm29118_create_lu_rej(const char *imsi, uint8_t rej_cause, const struct osmo_location_area_id *lai)
{
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, imsi);
msgb_tlv_put(msg, SGSAP_IE_REJECT_CAUSE, 1, &rej_cause);
if (lai)
msgb_sgsap_lai_put(msg, lai);
msgb_push_u8(msg, SGSAP_MSGT_LOC_UPD_REJ);
return msg;
}
/* 8.12 SGsAP-MM-INFORMATION-REQUEST.
* \param[in] imsi IMSI of the subscriber.
* \param[in] mm_info MM information, see also 3GPP TS 29.018, subclause 18.4.16.
* \param[in] mm_info_len length of \a mm_info in octets.
* \returns callee-allocated msgb with the encoded message. */
struct msgb *gsm29118_create_mm_info_req(const char *imsi, const uint8_t *mm_info, uint8_t mm_info_len)
{
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, imsi);
msgb_tlv_put(msg, SGSAP_IE_MM_INFO, mm_info_len, mm_info);
msgb_push_u8(msg, SGSAP_MSGT_MM_INFO_REQ);
return msg;
}
/* 8.14 SGsAP-PAGING-REQUEST.
* \param[in] params user provided memory with message contents to encode.
* \returns callee-allocated msgb with the encoded message or NULL on error. */
struct msgb *gsm29118_create_paging_req(struct gsm29118_paging_req *params)
{
int rc;
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, params->imsi);
rc = msgb_sgsap_name_put(msg, SGSAP_IE_VLR_NAME, params->vlr_name);
if (rc < 0)
goto error;
msgb_tlv_put(msg, SGSAP_IE_SERVICE_INDICATOR, 1, ¶ms->serv_ind);
if (params->lai_present)
msgb_sgsap_lai_put(msg, ¶ms->lai);
msgb_push_u8(msg, SGSAP_MSGT_PAGING_REQ);
return msg;
error:
msgb_free(msg);
return NULL;
}
/* 8.15 SGsAP-RESET-ACK.
* \param[in] params user provided memory with message contents to encode.
* \returns callee-allocated msgb with the encoded message or NULL on error. */
struct msgb *gsm29118_create_reset_ack(struct gsm29118_reset_msg *params)
{
int rc;
struct msgb *msg = gsm29118_msgb_alloc();
if (params->vlr_name_present && params->mme_name_present == false)
rc = msgb_sgsap_name_put(msg, SGSAP_IE_VLR_NAME, params->vlr_name);
else if (params->mme_name_present && params->vlr_name_present == false)
rc = msgb_sgsap_name_put(msg, SGSAP_IE_MME_NAME, params->mme_name);
else
goto error;
if (rc < 0)
goto error;
msgb_push_u8(msg, SGSAP_MSGT_RESET_ACK);
return msg;
error:
msgb_free(msg);
return NULL;
}
/* 8.16 SGsAP-RESET-INDICATION.
* \param[in] params user provided memory with message contents to encode.
* \returns callee-allocated msgb with the encoded message or NULL on error. */
struct msgb *gsm29118_create_reset_ind(struct gsm29118_reset_msg *params)
{
int rc;
struct msgb *msg = gsm29118_msgb_alloc();
if (params->vlr_name_present && params->mme_name_present == false)
rc = msgb_sgsap_name_put(msg, SGSAP_IE_VLR_NAME, params->vlr_name);
else if (params->mme_name_present && params->vlr_name_present == false)
rc = msgb_sgsap_name_put(msg, SGSAP_IE_MME_NAME, params->mme_name);
else
goto error;
if (rc < 0)
goto error;
msgb_push_u8(msg, SGSAP_MSGT_RESET_IND);
return msg;
error:
msgb_free(msg);
return NULL;
}
/* 8.18 SGsAP-STATUS.
* \param[in] imsi IMSI of the subscriber.
* \param[in] cause sgs related cause code.
* \param[in] err_msg user provided message buffer containing the errornous message.
* \returns callee-allocated msgb with the encoded message */
struct msgb *gsm29118_create_status(const char *imsi, enum sgsap_sgs_cause cause, const struct msgb *err_msg)
{
struct msgb *msg = gsm29118_msgb_alloc();
uint8_t c8 = cause;
unsigned int err_msg_len;
msgb_tlv_put(msg, SGSAP_IE_SGS_CAUSE, 1, &c8);
if (imsi)
msgb_sgsap_imsi_put(msg, imsi);
if (err_msg) {
err_msg_len = msgb_l2len(err_msg);
if (err_msg_len > 255)
err_msg_len = 255;
msgb_tlv_put(msg, SGSAP_IE_ERR_MSG, err_msg_len, msgb_l2(err_msg));
}
msgb_push_u8(msg, SGSAP_MSGT_STATUS);
return msg;
}
/* 8.23 SGsAP-RELEASE-REQUEST.
* \param[in] imsi IMSI of the subscriber.
* \param[in] cause sgs related cause code.
* \returns callee-allocated msgb with the encoded message. */
struct msgb *gsm29118_create_release_req(const char *imsi, const uint8_t sgs_cause)
{
struct msgb *msg = gsm29118_msgb_alloc();
msgb_sgsap_imsi_put(msg, imsi);
if (sgs_cause)
msgb_tlv_put(msg, SGSAP_IE_SGS_CAUSE, 1, &sgs_cause);
msgb_push_u8(msg, SGSAP_MSGT_RELEASE_REQ);
return msg;
}
/* 8.24 SGsAP-SERVICE-ABORT-REQUEST.
* \param[in] imsi IMSI of the subscriber.
* \returns callee-allocated msgb with the encoded message. */
struct msgb *gsm29118_create_service_abort_req(const char *imsi)
{
return create_simple_msg(SGSAP_MSGT_SERVICE_ABORT_REQ, imsi);
}