[USSD] eliminate static global variables
This patch removes the need of static global variables and introduces a new,
caller-allocated 'struct ussd_request' that needs to be passed to the various
functions.
diff --git a/openbsc/src/gsm_04_80.c b/openbsc/src/gsm_04_80.c
index 052b0a7..5d85c82 100644
--- a/openbsc/src/gsm_04_80.c
+++ b/openbsc/src/gsm_04_80.c
@@ -37,16 +37,16 @@
#include <openbsc/gsm_04_08.h>
#include <openbsc/gsm_04_80.h>
-static char ussd_string_buff[32];
-static u_int8_t last_transaction_id;
-static u_int8_t last_invoke_id;
-
/* Forward declarations */
-static int parse_ussd(u_int8_t *ussd);
-static int parse_ussd_information_elements(u_int8_t *ussd_ie);
-static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length);
-static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length);
-static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length);
+static int parse_ussd(u_int8_t *ussd, struct ussd_request *req);
+static int parse_ussd_info_elements(u_int8_t *ussd_ie,
+ struct ussd_request *req);
+static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length,
+ struct ussd_request *req);
+static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length,
+ struct ussd_request *req);
+static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length,
+ struct ussd_request *req);
static inline unsigned char *msgb_wrap_with_TL(struct msgb *msgb, u_int8_t tag)
{
@@ -69,26 +69,24 @@
}
-/* Receive a mobile-originated USSD message and return the decoded text */
-char *gsm0480_rcv_ussd(struct msgb *msg)
+/* Decode a mobile-originated USSD-request message */
+int gsm0480_decode_ussd_request(struct msgb *msg, struct ussd_request *req)
{
int rc = 0;
u_int8_t *parse_ptr = msgb_l3(msg);
- memset(ussd_string_buff, 0, sizeof(ussd_string_buff));
-
if ((*parse_ptr & 0x0F) == GSM48_PDISC_NC_SS) {
- last_transaction_id = *parse_ptr & 0x70;
- rc = parse_ussd(parse_ptr + 1);
+ req->transaction_id = *parse_ptr & 0x70;
+ rc = parse_ussd(parse_ptr+1, req);
}
if (!rc)
DEBUGP(DMM, "Error occurred while parsing received USSD!\n");
- return ussd_string_buff;
+ return rc;
}
-static int parse_ussd(u_int8_t *ussd)
+static int parse_ussd(u_int8_t *ussd, struct ussd_request *req)
{
int rc = 1;
u_int8_t msg_type = ussd[0] & 0xBF; /* message-type - section 3.4 */
@@ -97,11 +95,11 @@
case GSM0480_MTYPE_RELEASE_COMPLETE:
DEBUGP(DMM, "USS Release Complete\n");
/* could also parse out the optional Cause/Facility data */
- ussd_string_buff[0] = 0xFF;
+ req->text[0] = 0xFF;
break;
case GSM0480_MTYPE_REGISTER:
case GSM0480_MTYPE_FACILITY:
- rc &= parse_ussd_information_elements(ussd+1);
+ rc &= parse_ussd_info_elements(ussd+1, req);
break;
default:
fprintf(stderr, "Unknown GSM 04.80 message-type field 0x%02x\n",
@@ -113,7 +111,7 @@
return rc;
}
-static int parse_ussd_information_elements(u_int8_t *ussd_ie)
+static int parse_ussd_info_elements(u_int8_t *ussd_ie, struct ussd_request *req)
{
int rc;
/* Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 */
@@ -124,7 +122,7 @@
case GSM48_IE_CAUSE:
break;
case GSM0480_IE_FACILITY:
- rc = parse_facility_ie(ussd_ie+2, iei_length);
+ rc = parse_facility_ie(ussd_ie+2, iei_length, req);
break;
case GSM0480_IE_SS_VERSION:
break;
@@ -138,7 +136,8 @@
return rc;
}
-static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length)
+static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length,
+ struct ussd_request *req)
{
int rc = 1;
u_int8_t offset = 0;
@@ -150,7 +149,9 @@
switch (component_type) {
case GSM0480_CTYPE_INVOKE:
- rc &= parse_ss_invoke(facility_ie+2, component_length);
+ rc &= parse_ss_invoke(facility_ie+2,
+ component_length,
+ req);
break;
case GSM0480_CTYPE_RETURN_RESULT:
break;
@@ -171,7 +172,8 @@
}
/* Parse an Invoke component - see table 3.3 */
-static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length)
+static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length,
+ struct ussd_request *req)
{
int rc = 1;
u_int8_t offset;
@@ -183,7 +185,7 @@
}
offset = invoke_data[1] + 2;
- last_invoke_id = invoke_data[2];
+ req->invoke_id = invoke_data[2];
/* optional part */
if (invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID)
@@ -195,7 +197,8 @@
switch (operation_code) {
case GSM0480_OP_CODE_PROCESS_USS_REQ:
rc = parse_process_uss_req(invoke_data + offset + 3,
- length - offset - 3);
+ length - offset - 3,
+ req);
break;
default:
fprintf(stderr, "GSM 04.80 operation code 0x%02x "
@@ -214,36 +217,33 @@
}
/* Parse the parameters of a Process UnstructuredSS Request */
-static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length)
+static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length,
+ struct ussd_request *req)
{
- int rc = 1;
+ int rc = 0;
int num_chars;
u_int8_t dcs;
- /* 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];
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,
+ gsm_7bit_decode(req->text,
&(uss_req_data[7]), num_chars);
+ /* append null-terminator */
+ req->text[num_chars+1] = 0;
+ rc = 1;
}
}
- } else if (uss_req_data[0] == ASN1_IA5_STRING_TAG) {
- num_chars = uss_req_data[1];
- memcpy(ussd_string_buff, &(uss_req_data[2]), num_chars);
- }
-
+ }
return rc;
}
/* Send response to a mobile-originated ProcessUnstructuredSS-Request */
-int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text)
+int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text,
+ const struct ussd_request *req)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
@@ -278,7 +278,7 @@
msgb_wrap_with_TL(msg, GSM_0480_SEQUENCE_TAG);
/* Pre-pend the invoke ID */
- msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, last_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);
@@ -288,13 +288,15 @@
/* And finally pre-pend the L3 header */
gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh));
- gh->proto_discr = GSM48_PDISC_NC_SS | last_transaction_id | (1<<7); /* TI direction = 1 */
+ gh->proto_discr = GSM48_PDISC_NC_SS | req->transaction_id
+ | (1<<7); /* TI direction = 1 */
gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE;
return gsm48_sendmsg(msg, NULL);
}
-int gsm0480_send_ussd_reject(struct msgb *in_msg)
+int gsm0480_send_ussd_reject(struct msgb *in_msg,
+ const struct ussd_request *req)
{
struct msgb *msg = gsm48_msgb_alloc();
struct gsm48_hdr *gh;
@@ -307,7 +309,7 @@
GSM_0480_GEN_PROB_CODE_UNRECOGNISED);
/* Before it insert the invoke ID */
- msgb_push_TLV1(msg, GSM0480_COMPIDTAG_INVOKE_ID, last_invoke_id);
+ 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);
@@ -318,7 +320,7 @@
/* And finally pre-pend the L3 header */
gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh));
gh->proto_discr = GSM48_PDISC_NC_SS;
- gh->proto_discr |= last_transaction_id | (1<<7); /* TI direction = 1 */
+ gh->proto_discr |= req->transaction_id | (1<<7); /* TI direction = 1 */
gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE;
return gsm48_sendmsg(msg, NULL);