diff options
Diffstat (limited to 'src/gsm/gsm0480.c')
| -rw-r--r-- | src/gsm/gsm0480.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/gsm/gsm0480.c b/src/gsm/gsm0480.c index 11c66e94..b0b28e43 100644 --- a/src/gsm/gsm0480.c +++ b/src/gsm/gsm0480.c @@ -453,9 +453,18 @@ static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length, if ((uss_req_data[2] & uss_req_data[5]) != ASN1_OCTET_STRING_TAG) return 0; + /* Get DCS (Data Coding Scheme) */ dcs = uss_req_data[4]; + + /** + * According to GSM 04.08, 4.4.2 "ASN.1 data types": + * the USSD-DataCodingScheme shall indicate use of + * the default alphabet using the 0x0F value. + */ if (dcs == 0x0F) { + /* Calculate the amount of 7-bit characters */ num_chars = (uss_req_data[6] * 8) / 7; + /* Prevent a mobile-originated buffer-overrun! */ if (num_chars > GSM0480_USSD_7BIT_STRING_LEN) num_chars = GSM0480_USSD_7BIT_STRING_LEN; @@ -464,6 +473,17 @@ static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length, sizeof(req->ussd_text), &(uss_req_data[7]), num_chars); return 1; + } else { + /* Get the amount of 8-bit characters */ + num_chars = uss_req_data[6]; + + /* Prevent a mobile-originated buffer-overrun! */ + if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) + num_chars = GSM0480_USSD_OCTET_STRING_LEN; + + memcpy(req->ussd_text, &(uss_req_data[7]), num_chars); + + return 1; } return 0; |