From 5b0790df523b82f327ddc8e7d538380101ac2cae Mon Sep 17 00:00:00 2001 From: Vadim Yanitskiy Date: Sat, 29 Jul 2017 04:26:21 +0600 Subject: gsm0480: clean up the parse_process_uss_req() code This change reduces the degree of code nesting... Change-Id: I467f75794c5ac9df75c001245b18bbdfcfaadd88 --- src/gsm/gsm0480.c | 39 ++++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-) (limited to 'src') diff --git a/src/gsm/gsm0480.c b/src/gsm/gsm0480.c index dcf487af..11c66e94 100644 --- a/src/gsm/gsm0480.c +++ b/src/gsm/gsm0480.c @@ -439,33 +439,34 @@ static int parse_ss_invoke(const uint8_t *invoke_data, uint16_t length, static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length, struct ss_request *req) { - int rc = 0; - int num_chars; + uint8_t num_chars; uint8_t dcs; - /* we need at least that much */ if (length < 8) return 0; + if (uss_req_data[0] != GSM_0480_SEQUENCE_TAG) + return 0; + + /* Both 2th and 5th should be equal to ASN1_OCTET_STRING_TAG */ + if ((uss_req_data[2] & uss_req_data[5]) != ASN1_OCTET_STRING_TAG) + return 0; - if (uss_req_data[0] == GSM_0480_SEQUENCE_TAG) { - if (uss_req_data[2] == ASN1_OCTET_STRING_TAG) { - dcs = uss_req_data[4]; - if ((dcs == 0x0F) && - (uss_req_data[5] == ASN1_OCTET_STRING_TAG)) { - 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; - gsm_7bit_decode_n_ussd((char *)req->ussd_text, - sizeof(req->ussd_text), - &(uss_req_data[7]), num_chars); - rc = 1; - } - } + dcs = uss_req_data[4]; + if (dcs == 0x0F) { + 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; + + gsm_7bit_decode_n_ussd((char *)req->ussd_text, + sizeof(req->ussd_text), &(uss_req_data[7]), num_chars); + + return 1; } - return rc; + + return 0; } /* Parse the parameters of a Interrogate/Activate/DeactivateSS Request */ -- cgit v1.2.3