[PATCH 3/8] libmsc: Update USSD to use new ss_request structure

From: Sergey Kostanbaev &lt;sergey.kostanbaev(a)gmail.com&gt; Use new ss_request structure to support long messages and handle FACILITY message type to support USSD menus. --- openbsc/include/openbsc/gsm_04_80.h | 11 ++-- openbsc/src/libmsc/gsm_04_80.c | 119 +++++++++++++++++++++++++++--------- openbsc/src/libmsc/ussd.c | 44 ++++++++----- 3 files changed, 128 insertions(+), 46 deletions(-) diff --git a/openbsc/include/openbsc/gsm_04_80.h b/openbsc/include/openbsc/gsm_04_80.h index 0a60652..08f974f 100644 --- a/openbsc/include/openbsc/gsm_04_80.h +++ b/openbsc/include/openbsc/gsm_04_80.h @@ -7,12 +7,15 @@ struct gsm_subscriber_connection; +int gsm0480_send_ussd(struct gsm_subscriber_connection *conn, + struct ss_request *req); + int gsm0480_send_ussd_response(struct gsm_subscriber_connection *conn, - const struct msgb *in_msg, const char* response_text, - const struct ussd_request *req); + const char *resp_string, + const struct ss_request *req); + int gsm0480_send_ussd_reject(struct gsm_subscriber_connection *conn, - const struct msgb *msg, - const struct ussd_request *request); + const struct ss_request *request); int gsm0480_send_ussdNotify(struct gsm_subscriber_connection *conn, int level, const char *text); int gsm0480_send_releaseComplete(struct gsm_subscriber_connection *conn); diff --git a/openbsc/src/libmsc/gsm_04_80.c b/openbsc/src/libmsc/gsm_04_80.c index b30f9ee..4585202 100644 --- a/openbsc/src/libmsc/gsm_04_80.c +++ b/openbsc/src/libmsc/gsm_04_80.c @@ -39,6 +39,22 @@ #include <osmocom/core/msgb.h> #include <osmocom/gsm/tlv.h> +/* This function can handle ASN1 length up to 255 which is enough for USSD */ +static inline unsigned char *msgb_wrap_with_ASN1_TL(struct msgb *msgb, uint8_t tag) +{ + uint16_t origlen = msgb->len; + uint8_t *data = msgb_push(msgb, (origlen > 0x7f) ? 3 : 2); + data[0] = tag; + if (origlen > 0x7f) { + data[1] = 0x81; + data[2] = origlen; + } else { + data[1] = origlen; + } + return data; +} + + static inline unsigned char *msgb_wrap_with_TL(struct msgb *msgb, uint8_t tag) { uint8_t *data = msgb_push(msgb, 2); @@ -59,59 +75,106 @@ static inline unsigned char *msgb_push_TLV1(struct msgb *msgb, uint8_t tag, return data; } +static inline unsigned char *msgb_wrap_with_L(struct msgb *msgb) +{ + uint8_t *data = msgb_push(msgb, 1); + + data[0] = msgb->len - 1; + return data; +} /* Send response to a mobile-originated ProcessUnstructuredSS-Request */ int gsm0480_send_ussd_response(struct gsm_subscriber_connection *conn, - const struct msgb *in_msg, const char *response_text, - const struct ussd_request *req) + const char *resp_string, + const struct ss_request* req) +{ + struct ss_request rss; + int response_len; + + memset(&rss, 0, sizeof(rss)); + + gsm_7bit_encode_n_ussd(rss.ussd_text, MAX_LEN_USSD_STRING, resp_string, &response_len); + rss.ussd_text_len = response_len; + rss.ussd_text_language = 0x0f; + + rss.transaction_id = req->transaction_id; + rss.message_type = GSM0480_MTYPE_RELEASE_COMPLETE; + rss.component_type = GSM0480_CTYPE_RETURN_RESULT; + rss.invoke_id = req->invoke_id; + rss.opcode = GSM0480_OP_CODE_PROCESS_USS_REQ; + + return gsm0480_send_ussd(conn, &rss); +} + +/* Compose universial SS packet except Reject opcodes */ +int gsm0480_send_ussd(struct gsm_subscriber_connection *conn, + struct ss_request* req) { struct msgb *msg = gsm48_msgb_alloc(); struct gsm48_hdr *gh; uint8_t *ptr8; - int response_len; /* First put the payload text into the message */ ptr8 = msgb_put(msg, 0); - gsm_7bit_encode_n_ussd(ptr8, msgb_tailroom(msg), response_text, &response_len); - msgb_put(msg, response_len); + + memcpy(ptr8, req->ussd_text, req->ussd_text_len); + msgb_put(msg, req->ussd_text_len); /* Then wrap it as an Octet String */ - msgb_wrap_with_TL(msg, ASN1_OCTET_STRING_TAG); + msgb_wrap_with_ASN1_TL(msg, ASN1_OCTET_STRING_TAG); /* Pre-pend the DCS octet string */ - msgb_push_TLV1(msg, ASN1_OCTET_STRING_TAG, 0x0F); + msgb_push_TLV1(msg, ASN1_OCTET_STRING_TAG, req->ussd_text_language); /* Then wrap these as a Sequence */ - msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); - - /* Pre-pend the operation code */ - msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, - GSM0480_OP_CODE_PROCESS_USS_REQ); - - /* Wrap the operation code and IA5 string as a sequence */ - msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG); - - /* Pre-pend the invoke ID */ - msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, req->invoke_id); - - /* Wrap this up as a Return Result component */ - msgb_wrap_with_TL(msg, GSM0480_CTYPE_RETURN_RESULT); - - /* Wrap the component in a Facility message */ - msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); + msgb_wrap_with_ASN1_TL(msg, GSM_0480_SEQUENCE_TAG); + + if (req->component_type == GSM0480_CTYPE_RETURN_RESULT) { + /* Pre-pend the operation code */ + msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, req->opcode); + + /* Wrap the operation code and IA5 string as a sequence */ + msgb_wrap_with_ASN1_TL(msg, GSM_0480_SEQUENCE_TAG); + + /* Pre-pend the invoke ID */ + msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, req->invoke_id); + } else if (req->component_type == GSM0480_CTYPE_INVOKE) { + /* Pre-pend the operation code */ + msgb_push_TLV1(msg, GSM0480_OPERATION_CODE, req->opcode); + + /* Pre-pend the invoke ID */ + msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, req->invoke_id); + } else { + abort(); + } + + /* Wrap this up as an Invoke or a Return Result component */ + msgb_wrap_with_ASN1_TL(msg, req->component_type); + + if (req->message_type == GSM0480_MTYPE_REGISTER || + req->message_type == GSM0480_MTYPE_RELEASE_COMPLETE) { + /* Wrap the component in a Facility message, it's not ASN1 */ + msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); + } else if (req->message_type == GSM0480_MTYPE_FACILITY) { + /* For GSM0480_MTYPE_FACILITY it's LV not TLV */ + msgb_wrap_with_L(msg); + } else { + abort(); + } /* And finally pre-pend the L3 header */ gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh)); gh->proto_discr = GSM48_PDISC_NC_SS | req->transaction_id | (1<<7); /* TI direction = 1 */ - gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE; + gh->msg_type = req->message_type; + + DEBUGP(DSS, "Sending USSD to mobile: %s\n", msgb_hexdump(msg)); return gsm0808_submit_dtap(conn, msg, 0, 0); } int gsm0480_send_ussd_reject(struct gsm_subscriber_connection *conn, - const struct msgb *in_msg, - const struct ussd_request *req) + const struct ss_request *req) { struct msgb *msg = gsm48_msgb_alloc(); struct gsm48_hdr *gh; @@ -124,7 +187,7 @@ int gsm0480_send_ussd_reject(struct gsm_subscriber_connection *conn, msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, req->invoke_id); /* Wrap this up as a Reject component */ - msgb_wrap_with_TL(msg, GSM0480_CTYPE_REJECT); + msgb_wrap_with_ASN1_TL(msg, GSM0480_CTYPE_REJECT); /* Wrap the component in a Facility message */ msgb_wrap_with_TL(msg, GSM0480_IE_FACILITY); diff --git a/openbsc/src/libmsc/ussd.c b/openbsc/src/libmsc/ussd.c index 7f01eae..f0426c4 100644 --- a/openbsc/src/libmsc/ussd.c +++ b/openbsc/src/libmsc/ussd.c @@ -33,41 +33,57 @@ #include <openbsc/gsm_subscriber.h> #include <openbsc/debug.h> #include <openbsc/osmo_msc.h> +#include <openbsc/ussd.h> +#include <osmocom/gsm/gsm_utils.h> +#include <osmocom/gsm/gsm0480.h> /* Declarations of USSD strings to be recognised */ const char USSD_TEXT_OWN_NUMBER[] = "*#100#"; /* Forward declarations of network-specific handler functions */ -static int send_own_number(struct gsm_subscriber_connection *conn, const struct msgb *msg, const struct ussd_request *req); +static int send_own_number(struct gsm_subscriber_connection *conn, const struct ss_request *req); /* Entrypoint - handler function common to all mobile-originated USSDs */ int handle_rcv_ussd(struct gsm_subscriber_connection *conn, struct msgb *msg) { int rc; - struct ussd_request req; + struct ss_request req; + char request_string[MAX_LEN_USSD_STRING + 1]; struct gsm48_hdr *gh; memset(&req, 0, sizeof(req)); gh = msgb_l3(msg); - rc = gsm0480_decode_ussd_request(gh, msgb_l3len(msg), &req); + rc = gsm0480_decode_ss_request(gh, msgb_l3len(msg), &req); if (!rc) { - DEBUGP(DMM, "Unhandled SS\n"); - rc = gsm0480_send_ussd_reject(conn, msg, &req); + DEBUGP(DSS, "Unhandled SS\n"); + rc = gsm0480_send_ussd_reject(conn, &req); msc_release_connection(conn); return rc; } - /* Release-Complete */ - if (req.text[0] == '\0') + if (req.message_type == GSM0480_MTYPE_RELEASE_COMPLETE) return 0; - if (!strcmp(USSD_TEXT_OWN_NUMBER, (const char *)req.text)) { - DEBUGP(DMM, "USSD: Own number requested\n"); - rc = send_own_number(conn, msg, &req); + if (req.message_type != GSM0480_MTYPE_REGISTER || + req.component_type != GSM0480_CTYPE_INVOKE || + req.opcode != GSM0480_OP_CODE_PROCESS_USS_REQ || + req.ussd_text_language != 0x0f) + { + DEBUGP(DSS, "Unexpected SS\n"); + rc = gsm0480_send_ussd_reject(conn, &req); + msc_release_connection(conn); + return rc; + } + + gsm_7bit_decode_n_ussd(request_string, MAX_LEN_USSD_STRING, req.ussd_text, req.ussd_text_len); + + if (!strcmp(USSD_TEXT_OWN_NUMBER, (const char *)request_string)) { + DEBUGP(DSS, "USSD: Own number requested\n"); + rc = send_own_number(conn, &req); } else { - DEBUGP(DMM, "Unhandled USSD %s\n", req.text); - rc = gsm0480_send_ussd_reject(conn, msg, &req); + DEBUGP(DSS, "Unhandled USSD %s\n", request_string); + rc = gsm0480_send_ussd_reject(conn, &req); } /* check if we can release it */ @@ -76,12 +92,12 @@ int handle_rcv_ussd(struct gsm_subscriber_connection *conn, struct msgb *msg) } /* A network-specific handler function */ -static int send_own_number(struct gsm_subscriber_connection *conn, const struct msgb *msg, const struct ussd_request *req) +static int send_own_number(struct gsm_subscriber_connection *conn, const struct ss_request *req) { char *own_number = conn->subscr->extension; char response_string[GSM_EXTENSION_LENGTH + 20]; /* Need trailing CR as EOT character */ snprintf(response_string, sizeof(response_string), "Your extension is %s\r", own_number); - return gsm0480_send_ussd_response(conn, msg, response_string, req); + return gsm0480_send_ussd_response(conn, response_string, req); } -- 1.9.1