diff options
Diffstat (limited to 'src/gsm/gsm29118.c')
| -rw-r--r-- | src/gsm/gsm29118.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/src/gsm/gsm29118.c b/src/gsm/gsm29118.c index 3898be64..ca210fbf 100644 --- a/src/gsm/gsm29118.c +++ b/src/gsm/gsm29118.c @@ -1,7 +1,32 @@ +/* (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" }, @@ -156,3 +181,253 @@ const struct tlv_definition sgsap_ie_tlvdef = { [SGSAP_IE_TMSI_BASED_NRI_CONT] = { 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; + /* encoding is like DNS names, which is like APN fields */ + memset(buf, 0, sizeof(buf)); + len = osmo_apn_from_str(buf, sizeof(buf), name); + + /* 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); +} |