--- openbsc/src/gsm_04_80.c | 31 +++++++++++++++++++------------ openbsc/src/ussd.c | 4 ++-- 2 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/openbsc/src/gsm_04_80.c b/openbsc/src/gsm_04_80.c index d922ae5..d0dcbc2 100755 --- a/openbsc/src/gsm_04_80.c +++ b/openbsc/src/gsm_04_80.c @@ -90,11 +90,11 @@ char* gsm0480_rcv_ussd(struct msgb *msg) static int parse_ussd(u_int8_t *ussd) { int rc = 1; - u_int8_t msg_type = ussd[0] & 0xBF; // message-type - section 3.4 + u_int8_t msg_type = ussd[0] & 0xBF; /* message-type - section 3.4 */

switch(msg_type) { case GSM0480_MTYPE_RELEASE_COMPLETE: - DEBUGP(DMM, "USS Release Complete\n"); // could also parse out the optional Cause/Facility data + DEBUGP(DMM, "USS Release Complete\n"); /* could also parse out the optional Cause/Facility data */ ussd_string_buff[0] = 0xFF; break; case GSM0480_MTYPE_REGISTER: @@ -115,7 +115,7 @@ static int parse_ussd_information_elements(u_int8_t *ussd_ie) { int rc;

- u_int8_t iei = ussd_ie[0]; // Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 + u_int8_t iei = ussd_ie[0]; /* Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 */ u_int8_t iei_length = ussd_ie[1]; switch(iei) { case GSM48_IE_CAUSE: @@ -141,7 +141,7 @@ static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length) u_int8_t offset = 0;

do { - u_int8_t component_type = facility_ie[offset]; // Component Type tag - table 3.7 + u_int8_t component_type = facility_ie[offset]; /* Component Type tag - table 3.7 */ u_int8_t component_length = facility_ie[offset+1]; switch(component_type) { case GSM0480_CTYPE_INVOKE: @@ -178,7 +178,7 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length) last_invoke_id = invoke_data[2];

if (invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID) /* optional part */ - offset += invoke_data[offset+1] + 2; // skip over it + offset += invoke_data[offset+1] + 2; /* skip over it */ if (invoke_data[offset] == GSM0480_OPERATION_CODE) { /* mandatory part */ u_int8_t operation_code = invoke_data[offset+2]; @@ -208,13 +208,11 @@ static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length) int num_chars; u_int8_t dcs;

-// DEBUGP(DMM, "USSD request params %s\n", hexdump(uss_req_data, length)); /* FIXME: most phones send USSD text as a 7-bit encoded octet string; the following code also handles the case of plain ASCII text (IA5String), but other encodings might be used */ if (uss_req_data[0] == GSM_0480_SEQUENCE_TAG) { if (uss_req_data[2] == ASN1_OCTET_STRING_TAG) { dcs = uss_req_data[4]; -// DEBUGP(DMM, "Data coding scheme = 0x%2.2X\n", dcs); if ((dcs == 0x0F) && (uss_req_data[5] == ASN1_OCTET_STRING_TAG)) { num_chars = (uss_req_data[6] * 8) / 7; gsm_7bit_decode(ussd_string_buff, &(uss_req_data[7]), num_chars); @@ -228,6 +226,7 @@ static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length) return rc; }

+/* Send response to a mobile-originated ProcessUnstructuredSS-Request */ int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text) { struct msgb *msg = gsm48_msgb_alloc(); @@ -235,20 +234,28 @@ int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text) u_int8_t *ptr8; int response_len;

- response_len = strlen(response_text); + response_len = (strlen(response_text) * 7) / 8; + if (((strlen(response_text) * 7) % 8) != 0) + response_len += 1;

msg->bts_link = in_msg->bts_link; msg->lchan = in_msg->lchan;

/* First put the payload text into the message */ ptr8 = msgb_put(msg, response_len); - memcpy(ptr8, response_text, response_len); + gsm_7bit_encode(ptr8, response_text);

- /* Then wrap it as an IA5 String */ - msgb_wrap_with_TL(msg, ASN1_IA5_STRING_TAG); + /* Then wrap it as an Octet String */ + msgb_wrap_with_TL(msg, ASN1_OCTET_STRING_TAG); + + /* Pre-pend the DCS octet string */ + msgb_push_TLV1(msg, ASN1_OCTET_STRING_TAG, 0x0F); + + /* 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_DATA); + 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); diff --git a/openbsc/src/ussd.c b/openbsc/src/ussd.c index ba2f045..5f9a457 100755 --- a/openbsc/src/ussd.c +++ b/openbsc/src/ussd.c @@ -45,7 +45,7 @@ int handle_rcv_ussd(struct msgb *msg) { char* ussd_text_rcvd = gsm0480_rcv_ussd(msg);

- if(ussd_text_rcvd[0] == 0xFF) // Release-Complete + if(ussd_text_rcvd[0] == 0xFF) /* Release-Complete */ return 0;

if(strstr(USSD_TEXT_OWN_NUMBER, ussd_text_rcvd) != NULL) { @@ -60,7 +60,7 @@ int handle_rcv_ussd(struct msgb *msg) /* A network-specific handler function */ static int send_own_number(struct msgb *msg) { - char response_string[] = "Your extension is xxxxx"; + char response_string[] = "Your extension is xxxxx\r"; /* Need trailing CR as EOT character */

char* own_number = msg->lchan->subscr->extension; memcpy(response_string + 18, own_number, 5);