| /* osmo-demo-euse: An External USSD Entity (EUSE) for demo purpose */ |
| |
| /* (C) 2018 by 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/>. |
| */ |
| |
| /* |
| * This program illustrates how to implement an external USSD application using |
| * the existing osmocom libraries, particularly libosmocore, libosmogsm and libosmo-gsup-client. |
| * |
| * It will receive any MS-originated USSD message that is routed to it via the HLR, and |
| * simply respond it quoted in the following string: 'You sent "foobar"' (assuming the original |
| * message was 'foobar'). |
| */ |
| |
| #include <string.h> |
| #include <stdio.h> |
| #include <errno.h> |
| #include <signal.h> |
| |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/select.h> |
| #include <osmocom/core/application.h> |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/logging.h> |
| |
| #include <osmocom/gsm/gsup.h> |
| #include <osmocom/gsm/gsm0480.h> |
| #include <osmocom/gsm/protocol/gsm_04_80.h> |
| |
| #include <osmocom/gsupclient/gsup_client.h> |
| |
| #include <osmocom/hlr/logging.h> |
| |
| static struct osmo_gsup_client *g_gc; |
| |
| /*! send a SS/USSD response to a given imsi/session. |
| * \param[in] gsupc GSUP client connection through which to send |
| * \param[in] imsi IMSI of the subscriber |
| * \param[in] session_id Unique identifier of SS session for which this response is |
| * \param[in] gsup_msg_type GSUP message type (OSMO_GSUP_MSGT_PROC_SS_{REQUEST,RESULT,ERROR}) |
| * \param[in] final Is this the final result (true=END) or an intermediate result (false=CONTINUE) |
| * \param[in] msg Optional binary/BER encoded SS date (for FACILITY IE). Can be NULL. Freed in |
| * this function call. |
| */ |
| static int euse_tx_ss(struct osmo_gsup_client *gsupc, const char *imsi, uint32_t session_id, |
| enum osmo_gsup_message_type gsup_msg_type, bool final, struct msgb *ss_msg) |
| { |
| struct osmo_gsup_message resp = {0}; |
| struct msgb *resp_msg; |
| |
| switch (gsup_msg_type) { |
| case OSMO_GSUP_MSGT_PROC_SS_REQUEST: |
| case OSMO_GSUP_MSGT_PROC_SS_RESULT: |
| case OSMO_GSUP_MSGT_PROC_SS_ERROR: |
| break; |
| default: |
| msgb_free(ss_msg); |
| return -EINVAL; |
| } |
| |
| resp.message_type = gsup_msg_type; |
| OSMO_STRLCPY_ARRAY(resp.imsi, imsi); |
| if (final) |
| resp.session_state = OSMO_GSUP_SESSION_STATE_END; |
| else |
| resp.session_state = OSMO_GSUP_SESSION_STATE_CONTINUE; |
| resp.session_id = 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); |
| return osmo_gsup_client_send(gsupc, resp_msg); |
| } |
| |
| /*! send a SS/USSD reject to a given IMSI/session. |
| * \param[in] gsupc GSUP client connection through which to send |
| * \param[in] imsi IMSI of the subscriber |
| * \param[in] session_id Unique identifier of SS session for which this response is |
| * \param[in] invoke_id InvokeID of the request |
| * \param[in] problem_tag Problem code tag (table 3.13) |
| * \param[in] problem_code Problem code (table 3.14-3.17) |
| */ |
| static int euse_tx_ussd_reject(struct osmo_gsup_client *gsupc, const char *imsi, uint32_t session_id, |
| int invoke_id, uint8_t problem_tag, uint8_t problem_code) |
| { |
| struct msgb *msg = gsm0480_gen_reject(invoke_id, problem_tag, problem_code); |
| LOGP(DMAIN, LOGL_NOTICE, "Tx %s/0x%08x: Reject(%d, 0x%02x, 0x%02x)\n", imsi, session_id, |
| invoke_id, problem_tag, problem_code); |
| OSMO_ASSERT(msg); |
| return euse_tx_ss(gsupc, imsi, session_id, OSMO_GSUP_MSGT_PROC_SS_RESULT, true, msg); |
| } |
| |
| /*! send a SS/USSD response in 7-bit GSM default alphabet o a given imsi/session. |
| * \param[in] gsupc GSUP client connection through which to send |
| * \param[in] imsi IMSI of the subscriber |
| * \param[in] session_id Unique identifier of SS session for which this response is |
| * \param[in] final Is this the final result (true=END) or an intermediate result |
| * (false=CONTINUE) |
| * \param[in] invoke_id InvokeID of the request |
| */ |
| static int euse_tx_ussd_resp_7bit(struct osmo_gsup_client *gsupc, const char *imsi, uint32_t session_id, |
| bool final, uint8_t invoke_id, const char *text) |
| { |
| struct msgb *ss_msg; |
| |
| /* encode response; remove L3 header */ |
| ss_msg = gsm0480_gen_ussd_resp_7bit(invoke_id, text); |
| LOGP(DMAIN, LOGL_DEBUG, "Tx %s/0x%08x: USSD Result(%d, %s, '%s')\n", imsi, session_id, |
| invoke_id, final ? "END" : "CONTINUE", text); |
| OSMO_ASSERT(ss_msg); |
| return euse_tx_ss(gsupc, imsi, session_id, OSMO_GSUP_MSGT_PROC_SS_RESULT, final, ss_msg); |
| } |
| |
| static int euse_rx_proc_ss_req(struct osmo_gsup_client *gsupc, const struct osmo_gsup_message *gsup) |
| { |
| char buf[GSM0480_USSD_7BIT_STRING_LEN+1]; |
| struct ss_request req = {0}; |
| |
| if (gsup->ss_info && gsup->ss_info_len) { |
| if (gsm0480_parse_facility_ie(gsup->ss_info, gsup->ss_info_len, &req)) { |
| return euse_tx_ussd_reject(gsupc, gsup->imsi, gsup->session_id, -1, |
| GSM_0480_PROBLEM_CODE_TAG_GENERAL, |
| GSM_0480_GEN_PROB_CODE_BAD_STRUCTURE); |
| } |
| } |
| |
| LOGP(DMAIN, LOGL_INFO, "Rx %s/0x%08x: USSD SessionState=%s, OpCode=%s, '%s'\n", gsup->imsi, |
| gsup->session_id, osmo_gsup_session_state_name(gsup->session_state), |
| gsm0480_op_code_name(req.opcode), req.ussd_text); |
| |
| /* we only handle single-request-response USSD in this demo */ |
| if (gsup->session_state != OSMO_GSUP_SESSION_STATE_BEGIN) { |
| return euse_tx_ussd_reject(gsupc, gsup->imsi, gsup->session_id, req.invoke_id, |
| GSM_0480_PROBLEM_CODE_TAG_GENERAL, |
| GSM_0480_GEN_PROB_CODE_UNRECOGNISED); |
| } |
| |
| snprintf(buf, sizeof(buf), "You sent \"%s\"", req.ussd_text); |
| return euse_tx_ussd_resp_7bit(gsupc, gsup->imsi, gsup->session_id, true, req.invoke_id, buf); |
| } |
| |
| static int gsupc_read_cb(struct osmo_gsup_client *gsupc, struct msgb *msg) |
| { |
| struct osmo_gsup_message gsup_msg = {0}; |
| int rc; |
| |
| rc = osmo_gsup_decode(msgb_l2(msg), msgb_l2len(msg), &gsup_msg); |
| if (rc < 0) { |
| LOGP(DMAIN, LOGL_ERROR, "Error decoding GSUP: %s\n", msgb_hexdump(msg)); |
| return rc; |
| } |
| DEBUGP(DMAIN, "Rx GSUP %s: %s\n", osmo_gsup_message_type_name(gsup_msg.message_type), |
| msgb_hexdump(msg)); |
| |
| switch (gsup_msg.message_type) { |
| case OSMO_GSUP_MSGT_PROC_SS_REQUEST: |
| case OSMO_GSUP_MSGT_PROC_SS_RESULT: |
| euse_rx_proc_ss_req(gsupc, &gsup_msg); |
| break; |
| case OSMO_GSUP_MSGT_PROC_SS_ERROR: |
| break; |
| default: |
| LOGP(DMAIN, LOGL_DEBUG, "Unhandled GSUP message type %s\n", |
| osmo_gsup_message_type_name(gsup_msg.message_type)); |
| break; |
| } |
| |
| msgb_free(msg); |
| return 0; |
| } |
| |
| |
| static struct log_info_cat default_categories[] = { |
| [DMAIN] = { |
| .name = "DMAIN", |
| .description = "Main Program", |
| .enabled = 1, .loglevel = LOGL_DEBUG, |
| }, |
| }; |
| |
| static const struct log_info gsup_log_info = { |
| .cat = default_categories, |
| .num_cat = ARRAY_SIZE(default_categories), |
| }; |
| |
| static void print_usage(void) |
| { |
| printf("Usage: osmo-euse-demo [hlr-ip [hlr-gsup-port]]\n"); |
| } |
| |
| int main(int argc, char **argv) |
| { |
| char *server_host = "127.0.0.1"; |
| uint16_t server_port = OSMO_GSUP_PORT; |
| void *ctx = talloc_named_const(NULL, 0, "demo-euse"); |
| |
| osmo_init_logging2(ctx, &gsup_log_info); |
| |
| printf("argc=%d\n", argc); |
| |
| if (argc > 1) { |
| if (!strcmp(argv[1], "--help") || !strcmp(argv[1], "-h")) { |
| print_usage(); |
| exit(0); |
| } else |
| server_host = argv[1]; |
| } |
| if (argc > 2) |
| server_port = atoi(argv[2]); |
| |
| g_gc = osmo_gsup_client_create(ctx, "EUSE-foobar", server_host, server_port, gsupc_read_cb, NULL); |
| |
| while (1) { |
| osmo_select_main(0); |
| } |
| |
| exit(0); |
| } |
| |