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[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.
This commit is contained in:
Mike Haben 2009-10-22 09:56:44 +02:00 committed by Harald Welte
parent 6307b85700
commit dc329a6cdb
3 changed files with 68 additions and 56 deletions
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15
openbsc/include/openbsc/gsm_04_80.h
View File

@ -125,8 +125,17 @@
#include <openbsc/msgb.h>
char* gsm0480_rcv_ussd(struct msgb *msg);
int gsm0480_send_ussd_response(struct msgb *msg, const char* response_text);
int gsm0480_send_ussd_reject(struct msgb *msg);
struct ussd_request {
char text[32];
u_int8_t transaction_id;
u_int8_t invoke_id;
};
int gsm0480_decode_ussd_request(struct msgb *msg,
struct ussd_request *request);
int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text,
const struct ussd_request *req);
int gsm0480_send_ussd_reject(struct msgb *msg,
const struct ussd_request *request);
#endif

90
openbsc/src/gsm_04_80.c
View File

@ -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 @@ static inline unsigned char *msgb_push_TLV1(struct msgb *msgb, u_int8_t tag,
}
/* 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 @@ static int parse_ussd(u_int8_t *ussd)
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 @@ static int parse_ussd(u_int8_t *ussd)
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 @@ static int parse_ussd_information_elements(u_int8_t *ussd_ie)
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 @@ static int parse_ussd_information_elements(u_int8_t *ussd_ie)
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 @@ static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length)
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 @@ static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length)
}
/* 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 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length)
}
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 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length)
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 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length)
}
/* 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 @@ int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text)
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 @@ int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text)
/* 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 @@ int gsm0480_send_ussd_reject(struct msgb *in_msg)
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 @@ int gsm0480_send_ussd_reject(struct msgb *in_msg)
/* 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);

19
openbsc/src/ussd.c
View File

@ -38,33 +38,34 @@
const char USSD_TEXT_OWN_NUMBER[] = "*#100#";
/* Forward declarations of network-specific handler functions */
static int send_own_number(struct msgb *msg);
static int send_own_number(const struct msgb *msg, const struct ussd_request *req);
/* Entrypoint - handler function common to all mobile-originated USSDs */
int handle_rcv_ussd(struct msgb *msg)
{
char *ussd_text_rcvd = gsm0480_rcv_ussd(msg);
struct ussd_request req;
if (ussd_text_rcvd[0] == 0xFF) /* Release-Complete */
gsm0480_decode_ussd_request(msg, &req);
if (req.text[0] == 0xFF) /* Release-Complete */
return 0;
if (strstr(USSD_TEXT_OWN_NUMBER, ussd_text_rcvd) != NULL) {
if (strstr(USSD_TEXT_OWN_NUMBER, req.text) != NULL) {
DEBUGP(DMM, "USSD: Own number requested\n");
return send_own_number(msg);
return send_own_number(msg, &req);
} else {
DEBUGP(DMM, "Unhandled USSD %s\n", ussd_text_rcvd);
return gsm0480_send_ussd_reject(msg);
DEBUGP(DMM, "Unhandled USSD %s\n", req.text);
return gsm0480_send_ussd_reject(msg, &req);
}
}
/* A network-specific handler function */
static int send_own_number(struct msgb *msg)
static int send_own_number(const struct msgb *msg, const struct ussd_request *req)
{
char *own_number = msg->lchan->subscr->extension;
/* Need trailing CR as EOT character */
char response_string[] = "Your extension is xxxxx\r";
memcpy(response_string + 18, own_number, 5);
return gsm0480_send_ussd_response(msg, response_string);
return gsm0480_send_ussd_response(msg, response_string, req);
}