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libosmocore/src/gsm/gsm0480.c

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/*! \file gsm0480.c
* Format functions for GSM 04.80. */
/*
* (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2009 by Mike Haben <michael.haben@btinternet.com>
* (C) 2018 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* SPDX-License-Identifier: GPL-2.0+
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <osmocom/gsm/gsm48.h>
#include <osmocom/gsm/gsm0480.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/core/logging.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <osmocom/gsm/protocol/gsm_04_80.h>
#include <string.h>
#include <errno.h>
const struct value_string gsm0480_comp_type_names[] = {
{ GSM0480_CTYPE_INVOKE, "Invoke" },
{ GSM0480_CTYPE_RETURN_RESULT, "ReturnResult" },
{ GSM0480_CTYPE_RETURN_ERROR, "ReturnError" },
{ GSM0480_CTYPE_REJECT, "Reject" },
{ 0, NULL }
};
const struct value_string gsm0480_op_code_names[] = {
{ GSM0480_OP_CODE_REGISTER_SS, "RegisterSS" },
{ GSM0480_OP_CODE_ERASE_SS, "EraseSS" },
{ GSM0480_OP_CODE_ACTIVATE_SS, "ActivateSS" },
{ GSM0480_OP_CODE_DEACTIVATE_SS, "DeactivateSS" },
{ GSM0480_OP_CODE_INTERROGATE_SS, "InterrogateSS" },
{ GSM0480_OP_CODE_NOTIFY_SS, "NotifySS" },
{ GSM0480_OP_CODE_REGISTER_PASSWORD, "RegisterPassword" },
{ GSM0480_OP_CODE_GET_PASSWORD, "GetPassword" },
{ GSM0480_OP_CODE_PROCESS_USS_DATA, "ProcessUSSD" },
{ GSM0480_OP_CODE_FORWARD_CHECK_SS_IND, "ForwardCheckSSind" },
{ GSM0480_OP_CODE_PROCESS_USS_REQ, "ProcessUssReq" },
{ GSM0480_OP_CODE_USS_REQUEST, "UssRequest" },
{ GSM0480_OP_CODE_USS_NOTIFY, "UssNotify" },
{ GSM0480_OP_CODE_FORWARD_CUG_INFO, "ForwardCugInfo" },
{ GSM0480_OP_CODE_SPLIT_MPTY, "SplitMPTY" },
{ GSM0480_OP_CODE_RETRIEVE_MPTY, "RetrieveMPTY" },
{ GSM0480_OP_CODE_HOLD_MPTY, "HoldMPTY" },
{ GSM0480_OP_CODE_BUILD_MPTY, "BuildMPTY" },
{ GSM0480_OP_CODE_FORWARD_CHARGE_ADVICE, "ForwardChargeAdvice" },
{ 0, NULL }
};
/* wrap an invoke around it... the other way around
*
* 1.) Invoke Component tag
* 2.) Invoke ID Tag
* 3.) Operation
* 4.) Data
*/
int gsm0480_wrap_invoke(struct msgb *msg, int op, int link_id)
{
/* 3. operation */
msgb_tlv1_push(msg, GSM0480_OPERATION_CODE, op);
/* 2. invoke id tag */
msgb_tlv1_push(msg, GSM0480_COMPIDTAG_INVOKE_ID, link_id);
/* 1. component tag */
msgb_push_tl(msg, GSM0480_CTYPE_INVOKE);
return 0;
}
/* wrap the GSM 04.08 Facility IE around it */
int gsm0480_wrap_facility(struct msgb *msg)
{
msgb_push_tl(msg, GSM0480_IE_FACILITY);
return 0;
}
struct msgb *gsm0480_create_unstructuredSS_Notify(int alertPattern, const char *text)
{
struct msgb *msg;
uint8_t *seq_len_ptr, *ussd_len_ptr, *data;
int len;
msg = gsm0480_msgb_alloc_name("TS 04.80 USSD Notify");
if (!msg)
return NULL;
/* SEQUENCE { */
msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG);
seq_len_ptr = msgb_put(msg, 1);
/* DCS { */
msgb_put_u8(msg, ASN1_OCTET_STRING_TAG);
msgb_put_u8(msg, 1);
msgb_put_u8(msg, 0x0F);
/* } DCS */
/* USSD-String { */
msgb_put_u8(msg, ASN1_OCTET_STRING_TAG);
ussd_len_ptr = msgb_put(msg, 1);
data = msgb_put(msg, 0);
gsm_7bit_encode_n_ussd(data, msgb_tailroom(msg), text, &len);
msgb_put(msg, len);
ussd_len_ptr[0] = len;
/* USSD-String } */
/* alertingPattern { */
msgb_put_u8(msg, ASN1_OCTET_STRING_TAG);
msgb_put_u8(msg, 1);
msgb_put_u8(msg, alertPattern);
/* } alertingPattern */
seq_len_ptr[0] = 3 + 2 + ussd_len_ptr[0] + 3;
/* } SEQUENCE */
return msg;
}
struct msgb *gsm0480_create_notifySS(const char *text)
{
struct msgb *msg;
uint8_t *data, *tmp_len;
uint8_t *seq_len_ptr, *cal_len_ptr, *opt_len_ptr, *nam_len_ptr;
int len;
len = strlen(text);
if (len < 1 || len > 160)
return NULL;
msg = gsm0480_msgb_alloc_name("TS 04.80 NotifySS");
if (!msg)
return NULL;
msgb_put_u8(msg, GSM_0480_SEQUENCE_TAG);
seq_len_ptr = msgb_put(msg, 1);
/* ss_code for CNAP { */
msgb_put_u8(msg, 0x81);
msgb_put_u8(msg, 1);
msgb_put_u8(msg, 0x19);
/* } ss_code */
/* nameIndicator { */
msgb_put_u8(msg, 0xB4);
nam_len_ptr = msgb_put(msg, 1);
/* callingName { */
msgb_put_u8(msg, 0xA0);
opt_len_ptr = msgb_put(msg, 1);
msgb_put_u8(msg, 0xA0);
cal_len_ptr = msgb_put(msg, 1);
/* namePresentationAllowed { */
/* add the DCS value */
msgb_put_u8(msg, 0x80);
msgb_put_u8(msg, 1);
msgb_put_u8(msg, 0x0F);
/* add the lengthInCharacters */
msgb_put_u8(msg, 0x81);
msgb_put_u8(msg, 1);
msgb_put_u8(msg, strlen(text));
/* add the actual string */
msgb_put_u8(msg, 0x82);
tmp_len = msgb_put(msg, 1);
data = msgb_put(msg, 0);
gsm_7bit_encode_n_ussd(data, msgb_tailroom(msg), text, &len);
tmp_len[0] = len;
msgb_put(msg, len);
/* }; namePresentationAllowed */
cal_len_ptr[0] = 3 + 3 + 2 + len;
opt_len_ptr[0] = cal_len_ptr[0] + 2;
/* }; callingName */
nam_len_ptr[0] = opt_len_ptr[0] + 2;
/* ); nameIndicator */
/* write the lengths... */
seq_len_ptr[0] = 3 + nam_len_ptr[0] + 2;
return msg;
}
/* Forward declarations */
static int parse_ss(const struct gsm48_hdr *hdr,
uint16_t len, struct ss_request *req);
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_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,
struct ss_request *req);
static int parse_process_uss_data(const uint8_t *uss_req_data, uint16_t length,
struct ss_request *req);
static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length,
struct ss_request *req);
static int parse_ss_for_bs_req(const uint8_t *ss_req_data,
uint16_t length,
struct ss_request *req);
/*! Get pointer to the IE of a given type
* \param[in] hdr Pointer to the message starting from header
* \param[in] msg_len Length of the whole message + header
* \param[out] ie External pointer to be set
* \param[out] ie_len External IE length variable
* \param[in] ie_tag Tag value of the required IE
* \returns 0 in case of success, otherwise -ERRNO
*
* This function iterates over existing IEs within a given
* message (depending on its type), and looks for the one with
* given \ref ie_tag value. If the IE is found, the external
* pointer pointed by \ref ie will be set to its value part
* (omitting TL), and \ref ie_len will be set to the length.
* Otherwise, e.g. in case of parsing error, both \ref ie
* and \ref ie_len are set to NULL and 0 respectively.
*/
int gsm0480_extract_ie_by_tag(const struct gsm48_hdr *hdr, uint16_t msg_len,
uint8_t **ie, uint16_t *ie_len, uint8_t ie_tag)
{
uint8_t pdisc, msg_type;
uint8_t *tlv, len;
/* Init external variables */
*ie_len = 0;
*ie = NULL;
/* Drop incomplete / corrupted messages */
if (msg_len < sizeof(*hdr))
return -EINVAL;
pdisc = gsm48_hdr_pdisc(hdr);
msg_type = gsm48_hdr_msg_type(hdr);
/* Drop non-SS related messages */
if (pdisc != GSM48_PDISC_NC_SS)
return -EINVAL;
len = msg_len - sizeof(*hdr);
tlv = (uint8_t *) hdr->data;
/* Parse a message depending on its type */
switch (msg_type) {
/* See table 2.5: RELEASE COMPLETE message content */
case GSM0480_MTYPE_RELEASE_COMPLETE:
/* See tables 2.3 and 2.4: REGISTER message content */
case GSM0480_MTYPE_REGISTER:
/* Iterate over TLV-based IEs */
while (len > 2) {
if (tlv[0] == ie_tag) {
*ie_len = tlv[1];
*ie = tlv + 2;
return 0;
}
len -= tlv[1] + 2;
tlv += tlv[1] + 2;
continue;
}
/* The Facility IE is mandatory for REGISTER */
if (msg_type == GSM0480_MTYPE_REGISTER)
if (ie_tag == GSM0480_IE_FACILITY)
return -EINVAL;
break;
/* See table 2.2: FACILITY message content */
case GSM0480_MTYPE_FACILITY:
/* There is no other IEs */
if (ie_tag != GSM0480_IE_FACILITY)
break;
/* Mandatory LV-based Facility IE */
if (len < 2)
return -EINVAL;
*ie_len = tlv[0];
*ie = tlv + 1;
return 0;
default:
/* Wrong message type, out of specs */
return -EINVAL;
}
return 0;
}
/* Decode a mobile-originated USSD-request message */
int gsm0480_decode_ussd_request(const struct gsm48_hdr *hdr, uint16_t len,
struct ussd_request *req)
{
struct ss_request ss;
int rc = 0;
memset(&ss, 0, sizeof(ss));
if (len < sizeof(*hdr) + 2) {
LOGP(DLGLOBAL, LOGL_ERROR, "USSD Request is too short.\n");
return 0;
}
if (gsm48_hdr_pdisc(hdr) == GSM48_PDISC_NC_SS) {
req->transaction_id = hdr->proto_discr & 0x70;
ss.transaction_id = req->transaction_id;
rc = parse_ss(hdr, len - sizeof(*hdr), &ss);
/* convert from ss_request to legacy ussd_request */
req->transaction_id = ss.transaction_id;
req->invoke_id = ss.invoke_id;
if (ss.ussd_text[0] == 0xFF)
req->text[0] = '\0';
else {
memcpy(req->text, ss.ussd_text, sizeof(req->text));
req->text[sizeof(req->text)-1] = '\0';
}
}
if (!rc)
LOGP(DLGLOBAL, LOGL_ERROR, "Error occurred while parsing received USSD!\n");
return rc;
}
/* Decode a mobile-originated SS request message */
int gsm0480_decode_ss_request(const struct gsm48_hdr *hdr, uint16_t len,
struct ss_request *req)
{
uint8_t pdisc;
/**
* Check Protocol Discriminator
* see TS GSM 04.07 and GSM 04.80
*/
pdisc = gsm48_hdr_pdisc(hdr);
if (pdisc != GSM48_PDISC_NC_SS) {
LOGP(DLGLOBAL, LOGL_ERROR, "Dropping message with "
"unsupported pdisc=%02x\n", pdisc);
return 0;
}
/* GSM 04.80 3.3 Transaction Identifier */
req->transaction_id = hdr->proto_discr & 0x70;
/* Parse SS request */
return parse_ss(hdr, len - sizeof(*hdr), req);
}
static int parse_ss(const struct gsm48_hdr *hdr, uint16_t len, struct ss_request *req)
{
int rc = 1;
uint8_t msg_type = hdr->msg_type & 0x3F; /* message-type - section 3.4 */
/**
* GSM 04.80 Section 2.5 'Release complete' Table 2.5
* payload is optional for 'RELEASE COMPLETE' message
*/
if (msg_type != GSM0480_MTYPE_RELEASE_COMPLETE) {
if (len < 2) {
LOGP(DLGLOBAL, LOGL_ERROR, "SS Request is too short.\n");
return 0;
}
}
/* Table 2.1: Messages for call independent SS control */
switch (msg_type) {
case GSM0480_MTYPE_RELEASE_COMPLETE:
/**
* Indicates that there is no decoded message.
* To be overwriten by the message otherwise.
*/
req->ussd_text[0] = 0xFF;
/* Parse optional Cause and/or Facility data */
if (len >= 2)
rc &= parse_ss_info_elements(&hdr->data[0], len, req);
break;
case GSM0480_MTYPE_REGISTER:
rc &= parse_ss_info_elements(&hdr->data[0], len, req);
break;
case GSM0480_MTYPE_FACILITY:
rc &= parse_ss_facility(&hdr->data[0], len, req);
break;
default:
LOGP(DLGLOBAL, LOGL_ERROR, "Unknown GSM 04.80 message-type field 0x%02x\n",
hdr->msg_type);
rc = 0;
break;
}
return rc;
}
static int parse_ss_facility(const uint8_t *ss_facility, uint16_t len,
struct ss_request *req)
{
uint8_t facility_length;
facility_length = ss_facility[0];
if (len - 1 < facility_length)
return 0;
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,
struct ss_request *req)
{
int rc = -1;
/* Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 */
uint8_t iei;
uint8_t iei_length;
/* We need at least two bytes */
if (len < 2)
return 0;
iei = ss_ie[0];
iei_length = ss_ie[1];
/* If the data does not fit, report an error */
if (iei_length + 2 > len)
return 0;
switch (iei) {
case GSM48_IE_CAUSE:
break;
case GSM0480_IE_FACILITY:
rc = !gsm0480_parse_facility_ie(ss_ie + 2, iei_length, req);
break;
case GSM0480_IE_SS_VERSION:
break;
default:
LOGP(DLGLOBAL, LOGL_ERROR, "Unhandled GSM 04.08 or 04.80 IEI 0x%02x\n",
iei);
rc = 0;
break;
}
/* A message may contain multiple IEs */
if (iei_length + 2 + 2 < len)
rc &= parse_ss_info_elements(ss_ie + iei_length + 2,
len - iei_length - 2, req);
return rc;
}
/*! 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)
{
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 */
component_type = facility_ie[offset];
component_length = facility_ie[offset + 1];
/* Make sure that there is no overflow */
if (offset + 2 + component_length > length) {
LOGP(DLGLOBAL, LOGL_ERROR, "Component does not fit.\n");
return -EINVAL;
}
switch (component_type) {
case GSM0480_CTYPE_INVOKE:
rc &= parse_ss_invoke(facility_ie + 2,
component_length,
req);
break;
case GSM0480_CTYPE_RETURN_RESULT:
rc &= parse_ss_return_result(facility_ie + 2,
component_length,
req);
break;
case GSM0480_CTYPE_RETURN_ERROR:
break;
case GSM0480_CTYPE_REJECT:
break;
default:
LOGP(DLGLOBAL, LOGL_ERROR, "Unknown GSM 04.80 Facility "
"Component Type 0x%02x\n", component_type);
rc = 0;
break;
}
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 */
static int parse_ss_invoke(const uint8_t *invoke_data, uint16_t length,
struct ss_request *req)
{
int rc = 1;
uint8_t offset;
if (length < 3)
return 0;
/* mandatory part */
if (invoke_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) {
LOGP(DLGLOBAL, LOGL_ERROR, "Unexpected GSM 04.80 Component-ID tag "
"0x%02x (expecting Invoke ID tag)\n", invoke_data[0]);
}
offset = invoke_data[1] + 2;
req->invoke_id = invoke_data[2];
/* look ahead once */
if (offset + 1 > length)
return 0;
/* optional part */
if (invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID)
offset += invoke_data[offset+1] + 2; /* skip over it */
/* mandatory part */
if (invoke_data[offset] == GSM0480_OPERATION_CODE) {
if (offset + 2 > length)
return 0;
uint8_t operation_code = invoke_data[offset+2];
req->opcode = operation_code;
switch (operation_code) {
case GSM0480_OP_CODE_USS_NOTIFY:
case GSM0480_OP_CODE_USS_REQUEST:
case GSM0480_OP_CODE_PROCESS_USS_REQ:
rc = parse_process_uss_req(invoke_data + offset + 3,
length - offset - 3,
req);
break;
case GSM0480_OP_CODE_PROCESS_USS_DATA:
rc = parse_process_uss_data(invoke_data + offset + 3,
length - offset - 3,
req);
break;
case GSM0480_OP_CODE_ACTIVATE_SS:
case GSM0480_OP_CODE_DEACTIVATE_SS:
case GSM0480_OP_CODE_INTERROGATE_SS:
rc = parse_ss_for_bs_req(invoke_data + offset + 3,
length - offset - 3,
req);
break;
default:
LOGP(DLGLOBAL, LOGL_ERROR, "GSM 04.80 operation code 0x%02x "
"is not yet handled\n", operation_code);
rc = 0;
break;
}
} else {
LOGP(DLGLOBAL, LOGL_ERROR, "Unexpected GSM 04.80 Component-ID tag 0x%02x "
"(expecting Operation Code tag)\n",
invoke_data[0]);
rc = 0;
}
return rc;
}
/* Parse a Return Result component - see table 3.4 */
static int parse_ss_return_result(const uint8_t *rr_data, uint16_t length,
struct ss_request *req)
{
uint8_t operation_code;
uint8_t offset;
if (length < 3)
return 0;
/* Mandatory part */
if (rr_data[0] != GSM0480_COMPIDTAG_INVOKE_ID) {
LOGP(DLGLOBAL, LOGL_ERROR, "Unexpected GSM 04.80 Component-ID tag "
"0x%02x (expecting Invoke ID tag)\n", rr_data[0]);
return 0;
}
offset = rr_data[1] + 2;
req->invoke_id = rr_data[2];
if (offset >= length)
return 0;
if (rr_data[offset] != GSM_0480_SEQUENCE_TAG)
return 0;
if (offset + 2 > length)
return 0;
offset += 2;
operation_code = rr_data[offset + 2];
req->opcode = operation_code;
switch (operation_code) {
case GSM0480_OP_CODE_USS_NOTIFY:
case GSM0480_OP_CODE_USS_REQUEST:
case GSM0480_OP_CODE_PROCESS_USS_REQ:
return parse_process_uss_req(rr_data + offset + 3,
length - offset - 3, req);
case GSM0480_OP_CODE_PROCESS_USS_DATA:
return parse_process_uss_data(rr_data + offset + 3,
length - offset - 3, req);
default:
LOGP(DLGLOBAL, LOGL_ERROR, "GSM 04.80 operation code 0x%02x "
"is not yet handled\n", operation_code);
return 0;
}
return 1;
}
static int parse_process_uss_data(const uint8_t *uss_req_data, uint16_t length,
struct ss_request *req)
{
uint8_t num_chars;
/* we need at least that much */
if (length < 3)
return 0;
if (uss_req_data[0] != ASN1_IA5_STRING_TAG)
return 0;
num_chars = uss_req_data[1];
if (num_chars > length - 2)
return 0;
/* Drop messages with incorrect length */
if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) {
LOGP(DLGLOBAL, LOGL_ERROR, "Incorrect USS_DATA data length=%u, "
"dropping message", num_chars);
return 0;
}
memcpy(req->ussd_text, uss_req_data + 2, num_chars);
/* Copy the data 'as is' */
memcpy(req->ussd_data, uss_req_data + 2, num_chars);
req->ussd_data_len = num_chars;
req->ussd_data_dcs = 0x00;
return 1;
}
/* Parse the parameters of a Process UnstructuredSS Request */
static int parse_process_uss_req(const uint8_t *uss_req_data, uint16_t length,
struct ss_request *req)
{
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;
/* Get DCS (Data Coding Scheme) */
dcs = uss_req_data[4];
/* Get the amount of bytes */
num_chars = uss_req_data[6];
/* Drop messages with incorrect length */
if (num_chars > GSM0480_USSD_OCTET_STRING_LEN) {
LOGP(DLGLOBAL, LOGL_ERROR, "Incorrect USS_REQ data length=%u, "
"dropping message", num_chars);
return 0;
}
/* Copy the data 'as is' */
memcpy(req->ussd_data, uss_req_data + 7, num_chars);
req->ussd_data_len = num_chars;
req->ussd_data_dcs = dcs;
/**
* 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 = (num_chars * 8) / 7;
gsm_7bit_decode_n_ussd((char *)req->ussd_text,
sizeof(req->ussd_text), &(uss_req_data[7]), num_chars);
return 1;
} else {
memcpy(req->ussd_text, &(uss_req_data[7]), num_chars);
return 1;
}
return 0;
}
/* Parse the parameters of a Interrogate/Activate/DeactivateSS Request */
static int parse_ss_for_bs_req(const uint8_t *ss_req_data,
uint16_t length,
struct ss_request *req)
{
int rc = 0;
/* we need at least that much */
if (length < 5)
return 0;
if (ss_req_data[0] == GSM_0480_SEQUENCE_TAG) {
if ((ss_req_data[2] == ASN1_OCTET_STRING_TAG) &&
ss_req_data[3] == 1) {
req->ss_code = ss_req_data[4];
rc = 1;
}
}
return rc;
}
struct msgb *gsm0480_msgb_alloc_name(const char *name)
{
return msgb_alloc_headroom(1024, 128, name);
}
/*! Generate a USSD ReturnResult component containing a string in default GSM alphabet.
* \param[in] invoke_id InvokeID of the request to which we respond
* \param[in] text USSD text in ASCII; to be encoded as GSM 7-but alphabet
*/
struct msgb *gsm0480_gen_ussd_resp_7bit(uint8_t invoke_id, const char *text)
{
struct msgb *msg;
uint8_t *ptr8;
int response_len;
msg = gsm0480_msgb_alloc_name("TS 04.80 USSD Resp");
if (!msg)
return NULL;
/* First put the payload text into the message */
ptr8 = msgb_put(msg, 0);
gsm_7bit_encode_n_ussd(ptr8, msgb_tailroom(msg), text, &response_len);
msgb_put(msg, response_len);
/* Then wrap it as an Octet String */
msgb_push_tl(msg, ASN1_OCTET_STRING_TAG);
/* Pre-pend the DCS octet string */
msgb_tlv1_push(msg, ASN1_OCTET_STRING_TAG, 0x0F);
/* Then wrap these as a Sequence */
msgb_push_tl(msg, GSM_0480_SEQUENCE_TAG);
/* Pre-pend the operation code */
msgb_tlv1_push(msg, GSM0480_OPERATION_CODE,
GSM0480_OP_CODE_PROCESS_USS_REQ);
/* Wrap the operation code and IA5 string as a sequence */
msgb_push_tl(msg, GSM_0480_SEQUENCE_TAG);
/* Pre-pend the invoke ID */
msgb_tlv1_push(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id);
/* Wrap this up as a Return Result component */
msgb_push_tl(msg, GSM0480_CTYPE_RETURN_RESULT);
return msg;
}
/*! Legacy helper: Generate USSD response including FACILITY IE + L3 header.
*
* This function is just like \ref gsm0480_gen_ussd_resp_7bit, but it generates
* not only the FACILITY value, but the full L3 message including message header
* and FACILITY IE Tag+Length.
*/
OSMO_DEPRECATED("Use gsm0480_gen_ussd_resp_7bit() instead")
struct msgb *gsm0480_create_ussd_resp(uint8_t invoke_id, uint8_t trans_id, const char *text)
{
struct msgb *msg;
msg = gsm0480_gen_ussd_resp_7bit(invoke_id, text);
if (!msg)
return NULL;
/* Wrap the component in a Facility message */
msgb_push_tl(msg, GSM0480_IE_FACILITY);
/* And finally pre-pend the L3 header */
gsm48_push_l3hdr_tid(msg, GSM48_PDISC_NC_SS,
/* FIXME: TI direction is always 1 ?!? */
trans_id | (1 << 7),
GSM0480_MTYPE_RELEASE_COMPLETE);
return msg;
}
/*! Generate a ReturnError component (see section 3.6.1) and given error code (see section 3.6.6).
* \param[in] invoke_id InvokeID of the request
* \param[in] error_code Error code (section 4.5)
* \return message buffer containing the Reject component
*/
struct msgb *gsm0480_gen_return_error(uint8_t invoke_id, uint8_t error_code)
{
struct msgb *msg;
msg = gsm0480_msgb_alloc_name("TS 04.80 ReturnError");
if (!msg)
return NULL;
/* First insert the problem code */
msgb_tlv1_push(msg, GSM_0480_ERROR_CODE_TAG, error_code);
/* Before it, insert the invoke ID */
msgb_tlv1_push(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id);
/* Wrap this up as a Reject component */
msgb_push_tl(msg, GSM0480_CTYPE_RETURN_ERROR);
/* FIXME: Wrap in Facility + L3? */
return msg;
}
/*! Generate a Reject component (see section 3.6.1) and given error code (see section 3.6.7).
* \param[in] invoke_id InvokeID of the request
* \param[in] problem_tag Problem code tag (table 3.13)
* \param[in] problem_code Problem code (table 3.14-3.17)
* \return message buffer containing the Reject component
*
* Note: if InvokeID is not available, e.g. when message parsing failed, any incorrect vlue
* can be passed (0x00 > x > 0xff), so the universal NULL-tag (see table 3.6) will be used instead.
*/
struct msgb *gsm0480_gen_reject(int invoke_id, uint8_t problem_tag, uint8_t problem_code)
{
struct msgb *msg;
msg = gsm0480_msgb_alloc_name("TS 04.80 Reject");
if (!msg)
return NULL;
/* First insert the problem code */
msgb_tlv1_push(msg, problem_tag, problem_code);
/* If the Invoke ID is not available, Universal NULL (table 3.9) with length=0 shall be used */
if (invoke_id < 0 || invoke_id > 255)
msgb_tv_push(msg, ASN1_NULL_TYPE_TAG, 0);
else
msgb_tlv1_push(msg, GSM0480_COMPIDTAG_INVOKE_ID, invoke_id);
/* Wrap this up as a Reject component */
msgb_push_tl(msg, GSM0480_CTYPE_REJECT);
/* FIXME: Wrap in Facility + L3? */
return msg;
}
struct msgb *gsm0480_create_ussd_notify(int level, const char *text)
{
struct msgb *msg;
msg = gsm0480_create_unstructuredSS_Notify(level, text);
if (!msg)
return NULL;
gsm0480_wrap_invoke(msg, GSM0480_OP_CODE_USS_NOTIFY, 0);
gsm0480_wrap_facility(msg);
/* And finally pre-pend the L3 header */
gsm48_push_l3hdr(msg, GSM48_PDISC_NC_SS,
/* FIXME: no transactionID?!? */
GSM0480_MTYPE_REGISTER);
return msg;
}
/*! Deprecated, use gsm0480_create_release_complete() instead. */
struct msgb *gsm0480_create_ussd_release_complete(void)
{
struct msgb *msg;
msg = gsm0480_msgb_alloc_name("TS 04.80 USSD REL COMPL");
if (!msg)
return NULL;
/* And finally pre-pend the L3 header */
gsm48_push_l3hdr(msg, GSM48_PDISC_NC_SS,
/* FIXME: no transactionID?!? */
GSM0480_MTYPE_RELEASE_COMPLETE);
return msg;
}
/*! Create a GSM 04.80 Release complete (see 2.5) message, prefixed
* by GSM 04.08 L3 header with a given transaction ID.
* \param[in] trans_id GSM 04.07 transaction identifier (and TI flag)
* \return message buffer containing the Release complete message
*/
struct msgb *gsm0480_create_release_complete(uint8_t trans_id)
{
struct msgb *msg;
msg = gsm0480_msgb_alloc_name("TS 04.80 USSD REL COMPL");
if (!msg)
return NULL;
/* Push the L3 header */
gsm48_push_l3hdr_tid(msg, GSM48_PDISC_NC_SS,
trans_id, GSM0480_MTYPE_RELEASE_COMPLETE);
return msg;
}
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