| /* OsmoHLR SS/USSD implementation */ |
| |
| /* (C) 2018 Harald Welte <laforge@gnumonks.org> |
| * |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 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 Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| |
| #include <osmocom/core/talloc.h> |
| #include <osmocom/core/timer.h> |
| #include <osmocom/gsm/gsup.h> |
| #include <osmocom/gsm/gsm0480.h> |
| #include <osmocom/gsm/protocol/gsm_04_80.h> |
| #include <stdint.h> |
| #include <string.h> |
| #include <errno.h> |
| |
| #include "hlr.h" |
| #include "hlr_ussd.h" |
| #include "gsup_server.h" |
| #include "gsup_router.h" |
| #include "logging.h" |
| |
| /*********************************************************************** |
| * core data structures expressing config from VTY |
| ***********************************************************************/ |
| |
| struct hlr_euse *euse_find(struct hlr *hlr, const char *name) |
| { |
| struct hlr_euse *euse; |
| |
| llist_for_each_entry(euse, &hlr->euse_list, list) { |
| if (!strcmp(euse->name, name)) |
| return euse; |
| } |
| return NULL; |
| } |
| |
| struct hlr_euse *euse_alloc(struct hlr *hlr, const char *name) |
| { |
| struct hlr_euse *euse = euse_find(hlr, name); |
| if (euse) |
| return NULL; |
| |
| euse = talloc_zero(hlr, struct hlr_euse); |
| euse->name = talloc_strdup(euse, name); |
| euse->hlr = hlr; |
| llist_add_tail(&euse->list, &hlr->euse_list); |
| |
| return euse; |
| } |
| |
| void euse_del(struct hlr_euse *euse) |
| { |
| llist_del(&euse->list); |
| talloc_free(euse); |
| } |
| |
| |
| struct hlr_ussd_route *ussd_route_find_prefix(struct hlr *hlr, const char *prefix) |
| { |
| struct hlr_ussd_route *rt; |
| |
| llist_for_each_entry(rt, &hlr->ussd_routes, list) { |
| if (!strcmp(rt->prefix, prefix)) |
| return rt; |
| } |
| return NULL; |
| } |
| |
| struct hlr_ussd_route *ussd_route_prefix_alloc_int(struct hlr *hlr, const char *prefix, |
| const struct hlr_iuse *iuse) |
| { |
| struct hlr_ussd_route *rt; |
| |
| if (ussd_route_find_prefix(hlr, prefix)) |
| return NULL; |
| |
| rt = talloc_zero(hlr, struct hlr_ussd_route); |
| rt->prefix = talloc_strdup(rt, prefix); |
| rt->u.iuse = iuse; |
| llist_add_tail(&rt->list, &hlr->ussd_routes); |
| |
| return rt; |
| } |
| |
| struct hlr_ussd_route *ussd_route_prefix_alloc_ext(struct hlr *hlr, const char *prefix, |
| struct hlr_euse *euse) |
| { |
| struct hlr_ussd_route *rt; |
| |
| if (ussd_route_find_prefix(hlr, prefix)) |
| return NULL; |
| |
| rt = talloc_zero(hlr, struct hlr_ussd_route); |
| rt->prefix = talloc_strdup(rt, prefix); |
| rt->is_external = true; |
| rt->u.euse = euse; |
| llist_add_tail(&rt->list, &hlr->ussd_routes); |
| |
| return rt; |
| } |
| |
| void ussd_route_del(struct hlr_ussd_route *rt) |
| { |
| llist_del(&rt->list); |
| talloc_free(rt); |
| } |
| |
| static struct hlr_ussd_route *ussd_route_lookup_7bit(struct hlr *hlr, const char *ussd_code) |
| { |
| struct hlr_ussd_route *rt; |
| llist_for_each_entry(rt, &hlr->ussd_routes, list) { |
| if (!strncmp(ussd_code, rt->prefix, strlen(rt->prefix))) { |
| LOGP(DSS, LOGL_DEBUG, "Found %s '%s' (prefix '%s') for USSD " |
| "Code '%s'\n", rt->is_external ? "EUSE" : "IUSE", |
| rt->is_external ? rt->u.euse->name : rt->u.iuse->name, |
| rt->prefix, ussd_code); |
| return rt; |
| } |
| } |
| |
| LOGP(DSS, LOGL_DEBUG, "Could not find Route for USSD Code '%s'\n", ussd_code); |
| return NULL; |
| } |
| |
| /*********************************************************************** |
| * handling functions for individual GSUP messages |
| ***********************************************************************/ |
| |
| #define LOGPSS(ss, lvl, fmt, args...) \ |
| LOGP(DSS, lvl, "%s/0x%08x: " fmt, (ss)->imsi, (ss)->session_id, ## args) |
| |
| struct ss_session { |
| /* link us to hlr->ss_sessions */ |
| struct llist_head list; |
| /* imsi of this session */ |
| char imsi[GSM23003_IMSI_MAX_DIGITS+2]; |
| /* ID of this session (unique per IMSI) */ |
| uint32_t session_id; |
| /* state of the session */ |
| enum osmo_gsup_session_state state; |
| /* time-out when we will delete the session */ |
| struct osmo_timer_list timeout; |
| |
| /* is this USSD for an external handler (EUSE): true */ |
| bool is_external; |
| union { |
| /* external USSD Entity responsible for this session */ |
| struct hlr_euse *euse; |
| /* internal USSD Entity responsible for this session */ |
| const struct hlr_iuse *iuse; |
| } u; |
| |
| /* we don't keep a pointer to the osmo_gsup_{route,conn} towards the MSC/VLR here, |
| * as this might change during inter-VLR hand-over, and we simply look-up the serving MSC/VLR |
| * every time we receive an USSD component from the EUSE */ |
| }; |
| |
| struct ss_session *ss_session_find(struct hlr *hlr, const char *imsi, uint32_t session_id) |
| { |
| struct ss_session *ss; |
| llist_for_each_entry(ss, &hlr->ss_sessions, list) { |
| if (!strcmp(ss->imsi, imsi) && ss->session_id == session_id) |
| return ss; |
| } |
| return NULL; |
| } |
| |
| void ss_session_free(struct ss_session *ss) |
| { |
| osmo_timer_del(&ss->timeout); |
| llist_del(&ss->list); |
| talloc_free(ss); |
| } |
| |
| static void ss_session_timeout(void *data) |
| { |
| struct ss_session *ss = data; |
| |
| LOGPSS(ss, LOGL_NOTICE, "SS Session Timeout, destroying\n"); |
| /* FIXME: should we send a ReturnError component to the MS? */ |
| ss_session_free(ss); |
| } |
| |
| struct ss_session *ss_session_alloc(struct hlr *hlr, const char *imsi, uint32_t session_id) |
| { |
| struct ss_session *ss; |
| |
| OSMO_ASSERT(!ss_session_find(hlr, imsi, session_id)); |
| |
| ss = talloc_zero(hlr, struct ss_session); |
| OSMO_ASSERT(ss); |
| |
| OSMO_STRLCPY_ARRAY(ss->imsi, imsi); |
| ss->session_id = session_id; |
| |
| /* Schedule self-destruction timer */ |
| osmo_timer_setup(&ss->timeout, ss_session_timeout, ss); |
| if (g_hlr->ncss_guard_timeout > 0) |
| osmo_timer_schedule(&ss->timeout, g_hlr->ncss_guard_timeout, 0); |
| |
| llist_add_tail(&ss->list, &hlr->ss_sessions); |
| return ss; |
| } |
| |
| /*********************************************************************** |
| * handling functions for encoding SS messages + wrapping them in GSUP |
| ***********************************************************************/ |
| |
| static int ss_tx_to_ms(struct ss_session *ss, enum osmo_gsup_message_type gsup_msg_type, |
| bool final, struct msgb *ss_msg) |
| |
| { |
| struct osmo_gsup_message resp = {0}; |
| struct msgb *resp_msg; |
| |
| resp.message_type = gsup_msg_type; |
| OSMO_STRLCPY_ARRAY(resp.imsi, ss->imsi); |
| if (final) |
| resp.session_state = OSMO_GSUP_SESSION_STATE_END; |
| else |
| resp.session_state = OSMO_GSUP_SESSION_STATE_CONTINUE; |
| resp.session_id = ss->session_id; |
| if (ss_msg) { |
| resp.ss_info = msgb_data(ss_msg); |
| resp.ss_info_len = msgb_length(ss_msg); |
| } |
| |
| resp_msg = gsm0480_msgb_alloc_name(__func__); |
| OSMO_ASSERT(resp_msg); |
| osmo_gsup_encode(resp_msg, &resp); |
| msgb_free(ss_msg); |
| |
| /* FIXME: resolve this based on the database vlr_addr */ |
| return osmo_gsup_addr_send(g_hlr->gs, (uint8_t *)"MSC-00-00-00-00-00-00", 22, resp_msg); |
| } |
| |
| #if 0 |
| static int ss_tx_reject(struct ss_session *ss, int invoke_id, uint8_t problem_tag, |
| uint8_t problem_code) |
| { |
| struct msgb *msg = gsm0480_gen_reject(invoke_id, problem_tag, problem_code); |
| LOGPSS(ss, LOGL_NOTICE, "Tx Reject(%u, 0x%02x, 0x%02x)\n", invoke_id, |
| problem_tag, problem_code); |
| OSMO_ASSERT(msg); |
| return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, true, msg); |
| } |
| #endif |
| |
| static int ss_tx_error(struct ss_session *ss, uint8_t invoke_id, uint8_t error_code) |
| { |
| struct msgb *msg = gsm0480_gen_return_error(invoke_id, error_code); |
| LOGPSS(ss, LOGL_NOTICE, "Tx ReturnError(%u, 0x%02x)\n", invoke_id, error_code); |
| OSMO_ASSERT(msg); |
| return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, true, msg); |
| } |
| |
| static int ss_tx_ussd_7bit(struct ss_session *ss, bool final, uint8_t invoke_id, const char *text) |
| { |
| struct msgb *msg = gsm0480_gen_ussd_resp_7bit(invoke_id, text); |
| LOGPSS(ss, LOGL_INFO, "Tx USSD '%s'\n", text); |
| OSMO_ASSERT(msg); |
| return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, final, msg); |
| } |
| |
| /*********************************************************************** |
| * Internal USSD Handlers |
| ***********************************************************************/ |
| |
| #include "db.h" |
| |
| static int handle_ussd_own_msisdn(struct osmo_gsup_conn *conn, struct ss_session *ss, |
| const struct osmo_gsup_message *gsup, const struct ss_request *req) |
| { |
| struct hlr_subscriber subscr; |
| char buf[GSM0480_USSD_7BIT_STRING_LEN+1]; |
| int rc; |
| |
| rc = db_subscr_get_by_imsi(g_hlr->dbc, ss->imsi, &subscr); |
| switch (rc) { |
| case 0: |
| if (strlen(subscr.msisdn) == 0) |
| snprintf(buf, sizeof(buf), "You have no MSISDN!"); |
| else |
| snprintf(buf, sizeof(buf), "Your extension is %s", subscr.msisdn); |
| ss_tx_ussd_7bit(ss, true, req->invoke_id, buf); |
| break; |
| case -ENOENT: |
| ss_tx_error(ss, true, GSM0480_ERR_CODE_UNKNOWN_SUBSCRIBER); |
| break; |
| case -EIO: |
| default: |
| ss_tx_error(ss, true, GSM0480_ERR_CODE_SYSTEM_FAILURE); |
| break; |
| } |
| return 0; |
| } |
| |
| static int handle_ussd_own_imsi(struct osmo_gsup_conn *conn, struct ss_session *ss, |
| const struct osmo_gsup_message *gsup, const struct ss_request *req) |
| { |
| char buf[GSM0480_USSD_7BIT_STRING_LEN+1]; |
| snprintf(buf, sizeof(buf), "Your IMSI is %s", ss->imsi); |
| ss_tx_ussd_7bit(ss, true, req->invoke_id, buf); |
| return 0; |
| } |
| |
| |
| static const struct hlr_iuse hlr_iuses[] = { |
| { |
| .name = "own-msisdn", |
| .handle_ussd = handle_ussd_own_msisdn, |
| }, |
| { |
| .name = "own-imsi", |
| .handle_ussd = handle_ussd_own_imsi, |
| }, |
| }; |
| |
| const struct hlr_iuse *iuse_find(const char *name) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < ARRAY_SIZE(hlr_iuses); i++) { |
| const struct hlr_iuse *iuse = &hlr_iuses[i]; |
| if (!strcmp(name, iuse->name)) |
| return iuse; |
| } |
| return NULL; |
| } |
| |
| |
| /*********************************************************************** |
| * handling functions for individual GSUP messages |
| ***********************************************************************/ |
| |
| static bool ss_op_is_ussd(uint8_t opcode) |
| { |
| switch (opcode) { |
| case GSM0480_OP_CODE_PROCESS_USS_DATA: |
| case GSM0480_OP_CODE_PROCESS_USS_REQ: |
| case GSM0480_OP_CODE_USS_REQUEST: |
| case GSM0480_OP_CODE_USS_NOTIFY: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /* is this GSUP connection an EUSE (true) or not (false)? */ |
| static bool conn_is_euse(struct osmo_gsup_conn *conn) |
| { |
| int rc; |
| uint8_t *addr; |
| |
| rc = osmo_gsup_conn_ccm_get(conn, &addr, IPAC_IDTAG_SERNR); |
| if (rc <= 5) |
| return false; |
| if (!strncmp((char *)addr, "EUSE-", 5)) |
| return true; |
| else |
| return false; |
| } |
| |
| static struct hlr_euse *euse_by_conn(struct osmo_gsup_conn *conn) |
| { |
| int rc; |
| char *addr; |
| struct hlr *hlr = conn->server->priv; |
| |
| rc = osmo_gsup_conn_ccm_get(conn, (uint8_t **) &addr, IPAC_IDTAG_SERNR); |
| if (rc <= 5) |
| return NULL; |
| if (strncmp(addr, "EUSE-", 5)) |
| return NULL; |
| |
| return euse_find(hlr, addr+5); |
| } |
| |
| static int handle_ss(struct ss_session *ss, const struct osmo_gsup_message *gsup, |
| const struct ss_request *req) |
| { |
| uint8_t comp_type = gsup->ss_info[0]; |
| |
| LOGPSS(ss, LOGL_INFO, "SS CompType=%s, OpCode=%s\n", |
| gsm0480_comp_type_name(comp_type), gsm0480_op_code_name(req->opcode)); |
| |
| /** |
| * FIXME: As we don't store any SS related information |
| * (e.g. call forwarding preferences) in the database, |
| * we don't handle "structured" SS requests at all. |
| */ |
| LOGPSS(ss, LOGL_NOTICE, "Structured SS requests are not supported, rejecting...\n"); |
| ss_tx_error(ss, req->invoke_id, GSM0480_ERR_CODE_FACILITY_NOT_SUPPORTED); |
| return -ENOTSUP; |
| } |
| |
| /* Handle a USSD GSUP message for a given SS Session received from VLR or EUSE */ |
| static int handle_ussd(struct osmo_gsup_conn *conn, struct ss_session *ss, |
| const struct osmo_gsup_message *gsup, const struct ss_request *req) |
| { |
| uint8_t comp_type = gsup->ss_info[0]; |
| struct msgb *msg_out; |
| bool is_euse_originated = conn_is_euse(conn); |
| |
| LOGPSS(ss, LOGL_INFO, "USSD CompType=%s, OpCode=%s '%s'\n", |
| gsm0480_comp_type_name(comp_type), gsm0480_op_code_name(req->opcode), |
| req->ussd_text); |
| |
| if ((ss->is_external && !ss->u.euse) || !ss->u.iuse) { |
| LOGPSS(ss, LOGL_NOTICE, "USSD for unknown code '%s'\n", req->ussd_text); |
| ss_tx_error(ss, req->invoke_id, GSM0480_ERR_CODE_SS_NOT_AVAILABLE); |
| return 0; |
| } |
| |
| if (is_euse_originated) { |
| msg_out = msgb_alloc_headroom(1024+16, 16, "GSUP USSD FW"); |
| OSMO_ASSERT(msg_out); |
| /* Received from EUSE, Forward to VLR */ |
| osmo_gsup_encode(msg_out, gsup); |
| /* FIXME: resolve this based on the database vlr_addr */ |
| osmo_gsup_addr_send(conn->server, (uint8_t *)"MSC-00-00-00-00-00-00", 22, msg_out); |
| } else { |
| /* Received from VLR (MS) */ |
| if (ss->is_external) { |
| /* Forward to EUSE */ |
| char addr[128]; |
| strcpy(addr, "EUSE-"); |
| osmo_strlcpy(addr+5, ss->u.euse->name, sizeof(addr)-5); |
| conn = gsup_route_find(conn->server, (uint8_t *)addr, strlen(addr)+1); |
| if (!conn) { |
| LOGPSS(ss, LOGL_ERROR, "Cannot find conn for EUSE %s\n", addr); |
| ss_tx_error(ss, req->invoke_id, GSM0480_ERR_CODE_SYSTEM_FAILURE); |
| } else { |
| msg_out = msgb_alloc_headroom(1024+16, 16, "GSUP USSD FW"); |
| OSMO_ASSERT(msg_out); |
| osmo_gsup_encode(msg_out, gsup); |
| osmo_gsup_conn_send(conn, msg_out); |
| } |
| } else { |
| /* Handle internally */ |
| ss->u.iuse->handle_ussd(conn, ss, gsup, req); |
| /* Release session immediately */ |
| ss_session_free(ss); |
| } |
| } |
| |
| return 0; |
| } |
| |
| |
| /* this function is called for any SS_REQ/SS_RESP messages from both the MSC/VLR side as well |
| * as from the EUSE side */ |
| int rx_proc_ss_req(struct osmo_gsup_conn *conn, const struct osmo_gsup_message *gsup) |
| { |
| struct hlr *hlr = conn->server->priv; |
| struct ss_session *ss; |
| struct ss_request req = {0}; |
| |
| LOGP(DSS, LOGL_DEBUG, "%s/0x%08x: Process SS (%s)\n", gsup->imsi, gsup->session_id, |
| osmo_gsup_session_state_name(gsup->session_state)); |
| |
| /* decode and find out what kind of SS message it is */ |
| if (gsup->ss_info && gsup->ss_info_len) { |
| if (gsm0480_parse_facility_ie(gsup->ss_info, gsup->ss_info_len, &req)) { |
| LOGP(DSS, LOGL_ERROR, "%s/0x%082x: Unable to parse SS request: %s\n", |
| gsup->imsi, gsup->session_id, |
| osmo_hexdump(gsup->ss_info, gsup->ss_info_len)); |
| /* FIXME: Send a Reject component? */ |
| goto out_err; |
| } |
| } |
| |
| switch (gsup->session_state) { |
| case OSMO_GSUP_SESSION_STATE_BEGIN: |
| /* Check for overlapping Session ID usage */ |
| if (ss_session_find(hlr, gsup->imsi, gsup->session_id)) { |
| LOGP(DSS, LOGL_ERROR, "%s/0x%08x: BEGIN with non-unique session ID!\n", |
| gsup->imsi, gsup->session_id); |
| goto out_err; |
| } |
| ss = ss_session_alloc(hlr, gsup->imsi, gsup->session_id); |
| if (!ss) { |
| LOGP(DSS, LOGL_ERROR, "%s/0x%08x: Unable to allocate SS session\n", |
| gsup->imsi, gsup->session_id); |
| goto out_err; |
| } |
| if (ss_op_is_ussd(req.opcode)) { |
| if (conn_is_euse(conn)) { |
| /* EUSE->VLR: MT USSD. EUSE is known ('conn'), VLR is to be resolved */ |
| ss->u.euse = euse_by_conn(conn); |
| } else { |
| /* VLR->EUSE: MO USSD. VLR is known ('conn'), EUSE is to be resolved */ |
| struct hlr_ussd_route *rt; |
| rt = ussd_route_lookup_7bit(hlr, (const char *) req.ussd_text); |
| if (rt) { |
| if (rt->is_external) { |
| ss->is_external = true; |
| ss->u.euse = rt->u.euse; |
| } else if (rt) { |
| ss->is_external = false; |
| ss->u.iuse = rt->u.iuse; |
| } |
| } else { |
| if (hlr->euse_default) { |
| ss->is_external = true; |
| ss->u.euse = hlr->euse_default; |
| } |
| } |
| } |
| /* dispatch unstructured SS to routing */ |
| handle_ussd(conn, ss, gsup, &req); |
| } else { |
| /* dispatch non-call SS to internal code */ |
| handle_ss(ss, gsup, &req); |
| } |
| break; |
| case OSMO_GSUP_SESSION_STATE_CONTINUE: |
| ss = ss_session_find(hlr, gsup->imsi, gsup->session_id); |
| if (!ss) { |
| LOGP(DSS, LOGL_ERROR, "%s/0x%08x: CONTINUE for unknown SS session\n", |
| gsup->imsi, gsup->session_id); |
| goto out_err; |
| } |
| |
| /* Reschedule self-destruction timer */ |
| if (g_hlr->ncss_guard_timeout > 0) |
| osmo_timer_schedule(&ss->timeout, g_hlr->ncss_guard_timeout, 0); |
| |
| if (ss_op_is_ussd(req.opcode)) { |
| /* dispatch unstructured SS to routing */ |
| handle_ussd(conn, ss, gsup, &req); |
| } else { |
| /* dispatch non-call SS to internal code */ |
| handle_ss(ss, gsup, &req); |
| } |
| break; |
| case OSMO_GSUP_SESSION_STATE_END: |
| ss = ss_session_find(hlr, gsup->imsi, gsup->session_id); |
| if (!ss) { |
| LOGP(DSS, LOGL_ERROR, "%s/0x%08x: END for unknown SS session\n", |
| gsup->imsi, gsup->session_id); |
| goto out_err; |
| } |
| if (ss_op_is_ussd(req.opcode)) { |
| /* dispatch unstructured SS to routing */ |
| handle_ussd(conn, ss, gsup, &req); |
| } else { |
| /* dispatch non-call SS to internal code */ |
| handle_ss(ss, gsup, &req); |
| } |
| ss_session_free(ss); |
| break; |
| default: |
| LOGP(DSS, LOGL_ERROR, "%s/0x%08x: Unknown SS State %d\n", gsup->imsi, |
| gsup->session_id, gsup->session_state); |
| goto out_err; |
| } |
| |
| return 0; |
| |
| out_err: |
| return 0; |
| } |
| |
| int rx_proc_ss_error(struct osmo_gsup_conn *conn, const struct osmo_gsup_message *gsup) |
| { |
| LOGP(DSS, LOGL_NOTICE, "%s/0x%08x: Process SS ERROR (%s)\n", gsup->imsi, gsup->session_id, |
| osmo_gsup_session_state_name(gsup->session_state)); |
| return 0; |
| } |