diff options
Diffstat (limited to 'src/gsm/gsm0480.c')
| -rw-r--r-- | src/gsm/gsm0480.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/src/gsm/gsm0480.c b/src/gsm/gsm0480.c index dfd98773..300c0ede 100644 --- a/src/gsm/gsm0480.c +++ b/src/gsm/gsm0480.c @@ -201,8 +201,6 @@ static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len, struct ss_request *req); static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, struct ss_request *req); -static int parse_facility_ie(const uint8_t *facility_ie, uint16_t length, - struct ss_request *req); static int parse_ss_invoke(const uint8_t *invoke_data, uint16_t length, struct ss_request *req); static int parse_ss_return_result(const uint8_t *rr_data, uint16_t length, @@ -419,7 +417,7 @@ static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len, if (len - 1 < facility_length) return 0; - return parse_facility_ie(ss_facility + 1, facility_length, req); + return !gsm0480_parse_facility_ie(ss_facility + 1, facility_length, req); } static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, @@ -445,7 +443,7 @@ static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, case GSM48_IE_CAUSE: break; case GSM0480_IE_FACILITY: - rc = parse_facility_ie(ss_ie + 2, iei_length, req); + rc = !gsm0480_parse_facility_ie(ss_ie + 2, iei_length, req); break; case GSM0480_IE_SS_VERSION: break; @@ -464,31 +462,40 @@ static int parse_ss_info_elements(const uint8_t *ss_ie, uint16_t len, return rc; } -static int parse_facility_ie(const uint8_t *facility_ie, uint16_t length, - struct ss_request *req) +/*! Parse the components of a given Facility IE + * \param[in] facility_ie The Facility IE + * \param[in] length The length of Facility IE + * \param[out] req Abstract representation of SS message + * \return 0 in case of success, otherwise -ERRNO + */ +int gsm0480_parse_facility_ie(const uint8_t *facility_ie, uint16_t length, + struct ss_request *req) { - int rc = 1; + uint8_t component_length; + uint8_t component_type; uint8_t offset = 0; + int rc = 1; + /* Iterate over components within IE */ while (offset + 2 <= length) { /* Component Type tag - table 3.7 */ - uint8_t component_type = facility_ie[offset]; - uint8_t component_length = facility_ie[offset+1]; + component_type = facility_ie[offset]; + component_length = facility_ie[offset + 1]; - /* size check */ + /* Make sure that there is no overflow */ if (offset + 2 + component_length > length) { LOGP(0, LOGL_ERROR, "Component does not fit.\n"); - return 0; + return -EINVAL; } switch (component_type) { case GSM0480_CTYPE_INVOKE: - rc &= parse_ss_invoke(facility_ie+2, + rc &= parse_ss_invoke(facility_ie + 2, component_length, req); break; case GSM0480_CTYPE_RETURN_RESULT: - rc &= parse_ss_return_result(facility_ie+2, + rc &= parse_ss_return_result(facility_ie + 2, component_length, req); break; @@ -502,10 +509,17 @@ static int parse_facility_ie(const uint8_t *facility_ie, uint16_t length, rc = 0; break; } - offset += (component_length+2); - }; - return rc; + offset += (component_length + 2); + } + + /** + * The internal functions are using inverted return + * codes, where '0' means error/failure. While a + * common approach is to return negative errno in + * case of any failure, and '0' if all is ok. + */ + return (rc == 0) ? -EINVAL : 0; } /* Parse an Invoke component - see table 3.3 */ |