Expand BSSGP helpers + codec to cover expansion + compaction
diff --git a/gprs_gb/BSSGP_Helper.cc b/gprs_gb/BSSGP_Helper.cc
index 8cf97d2..4665dcd 100644
--- a/gprs_gb/BSSGP_Helper.cc
+++ b/gprs_gb/BSSGP_Helper.cc
@@ -9,7 +9,7 @@
/* convert a buffer filled with TLVs that have variable-length "length" fields (Osmocom TvLV) into a
* buffer filled with TLVs that have fixed 16-bit length values (TL16V format) */
-static OCTETSTRING transcode_tlv_part(OCTETSTRING const &in)
+static OCTETSTRING expand_tlv_part(OCTETSTRING const &in)
{
const unsigned char *in_ptr = (const unsigned char *)in;
int in_len = in.lengthof();
@@ -33,7 +33,7 @@
tl_length = 2;
} else {
/* E bit is not set, 15 bit length field */
- if (in_len < 3) {
+ if (remain_len < 3) {
TTCN_error("Remaining input length insufficient for 2-octet length");
break;
}
@@ -67,12 +67,67 @@
return out;
}
+/* convert a buffer filled with TLVs that have fixed-length "length" fields (Osmocom TL16V) into a
+ * buffer filled with TLVs that have variable-length values (TvLV format) */
+static OCTETSTRING compact_tlv_part(OCTETSTRING const &in)
+{
+ const unsigned char *in_ptr = (const unsigned char *)in;
+ int in_len = in.lengthof();
+ int ofs = 0;
+ uint16_t data_len;
+ OCTETSTRING out(0, (const unsigned char *)"");
+
+ while (ofs < in_len) {
+ int remain_len = in_len - ofs;
+ int tl_length;
+
+ if (remain_len < 3) {
+ TTCN_error("Remaining input length (%d) insufficient for Tag+Length", remain_len);
+ break;
+ }
+
+ data_len = (in_ptr[ofs+1] << 8) | in_ptr[ofs+2];
+
+ /* Tag + 16bit length */
+ uint8_t hdr_buf[3];
+ hdr_buf[0] = in_ptr[ofs+0];
+
+ if (data_len <= 0x7f) {
+ /* E bit is set, 7-bit length field */
+ hdr_buf[1] = 0x80 | data_len;
+ tl_length = 2;
+ } else {
+ /* E bit is not set, 15 bit length field */
+ hdr_buf[1] = data_len >> 8;
+ hdr_buf[2] = data_len & 0xff;
+ tl_length = 3;
+ }
+ if (in_len < 3 + data_len) {
+ TTCN_error("Remaining input length insufficient for TLV value length");
+ break;
+ }
+
+ OCTETSTRING tlv_hdr(tl_length, hdr_buf);
+ out += tlv_hdr;
+
+ if (data_len) {
+ /* append octet string of current TLV to output octetstring */
+ OCTETSTRING tlv_val(data_len, in_ptr + ofs + 3);
+ out += tlv_val;
+ }
+
+ /* advance input offset*/
+ ofs += data_len + 3;
+ }
+
+ return out;
+}
+
#define BSSGP_PDUT_DL_UNITDATA 0x00
#define BSSGP_PDUT_UL_UNITDATA 0x01
-/* expand all the variable-length "length" fields of a BSSGP message (Osmocom TvLV) into
- * statlc TL16V format */
-OCTETSTRING f__BSSGP__preprocess__pdu(OCTETSTRING const &in)
+/* expand all the variable-length "length" fields of a BSSGP message (Osmocom TvLV) into statlc TL16V format */
+OCTETSTRING f__BSSGP__expand__len(OCTETSTRING const &in)
{
const unsigned char *in_ptr = (const unsigned char *)in;
int in_len = in.lengthof();
@@ -90,7 +145,65 @@
OCTETSTRING prefix(static_hdr_len, in_ptr);
OCTETSTRING tlv_part_in(in_len - static_hdr_len, in_ptr + static_hdr_len);
- return prefix + transcode_tlv_part(tlv_part_in);
+ return prefix + expand_tlv_part(tlv_part_in);
+}
+
+OCTETSTRING f__BSSGP__compact__len(OCTETSTRING const &in)
+{
+ const unsigned char *in_ptr = (const unsigned char *)in;
+ int in_len = in.lengthof();
+ uint8_t pdu_type = in_ptr[0];
+ uint8_t static_hdr_len = 1;
+
+ if (pdu_type == BSSGP_PDUT_DL_UNITDATA || pdu_type == BSSGP_PDUT_UL_UNITDATA)
+ static_hdr_len = 8;
+
+ if (in_len < static_hdr_len)
+ TTCN_error("BSSGP message is shorter (%u bytes) than minimum header length (%u bytes) for msg_type 0x%02x",
+ in_len, static_hdr_len, pdu_type);
+
+ /* prefix = non-TLV section of header */
+ OCTETSTRING prefix(static_hdr_len, in_ptr);
+ OCTETSTRING tlv_part_in(in_len - static_hdr_len, in_ptr + static_hdr_len);
+
+ return prefix + compact_tlv_part(tlv_part_in);
+}
+
+/* expand all the variable-length "length" fields of a NS message (Osmocom TvLV) into statlc TL16V format */
+OCTETSTRING f__NS__expand__len(OCTETSTRING const &in)
+{
+ const unsigned char *in_ptr = (const unsigned char *)in;
+ int in_len = in.lengthof();
+ uint8_t pdu_type = in_ptr[0];
+ uint8_t static_hdr_len = 1;
+
+ if (in_len < static_hdr_len)
+ TTCN_error("NS message is shorter (%u bytes) than minimum header length (%u bytes) for msg_type 0x%02x",
+ in_len, static_hdr_len, pdu_type);
+
+ /* prefix = non-TLV section of header */
+ OCTETSTRING prefix(static_hdr_len, in_ptr);
+ OCTETSTRING tlv_part_in(in_len - static_hdr_len, in_ptr + static_hdr_len);
+
+ return prefix + expand_tlv_part(tlv_part_in);
+}
+
+OCTETSTRING f__NS__compact__len(OCTETSTRING const &in)
+{
+ const unsigned char *in_ptr = (const unsigned char *)in;
+ int in_len = in.lengthof();
+ uint8_t pdu_type = in_ptr[0];
+ uint8_t static_hdr_len = 1;
+
+ if (in_len < static_hdr_len)
+ TTCN_error("NS message is shorter (%u bytes) than minimum header length (%u bytes) for msg_type 0x%02x",
+ in_len, static_hdr_len, pdu_type);
+
+ /* prefix = non-TLV section of header */
+ OCTETSTRING prefix(static_hdr_len, in_ptr);
+ OCTETSTRING tlv_part_in(in_len - static_hdr_len, in_ptr + static_hdr_len);
+
+ return prefix + compact_tlv_part(tlv_part_in);
}
}
diff --git a/gprs_gb/BSSGP_Helper_Functions.ttcn b/gprs_gb/BSSGP_Helper_Functions.ttcn
index 9c8af92..731d2ab 100644
--- a/gprs_gb/BSSGP_Helper_Functions.ttcn
+++ b/gprs_gb/BSSGP_Helper_Functions.ttcn
@@ -1,3 +1,6 @@
module BSSGP_Helper_Functions {
- external function f_BSSGP_preprocess_pdu(in octetstring inp) return octetstring;
+ external function f_BSSGP_expand_len(in octetstring inp) return octetstring;
+ external function f_BSSGP_compact_len(in octetstring inp) return octetstring;
+ external function f_NS_expand_len(in octetstring inp) return octetstring;
+ external function f_NS_compact_len(in octetstring inp) return octetstring;
};
diff --git a/gprs_gb/NS_Types.ttcn b/gprs_gb/NS_Types.ttcn
new file mode 100644
index 0000000..ee2444d
--- /dev/null
+++ b/gprs_gb/NS_Types.ttcn
@@ -0,0 +1,103 @@
+module NS_Types {
+ import from General_Types all;
+ import from Osmocom_Types all;
+ import from GSM_Types all;
+ import from BSSGP_Types all;
+
+ /* TS 48.016 10.3.7 */
+ type enumerated NsPduType {
+ NS_PDUT_NS_UNITDATA ('00000000'B),
+ NS_PDUT_NS_RESET ('00000010'B),
+ NS_PDUT_NS_RESET_ACK ('00000011'B),
+ NS_PDUT_NS_BLOCK ('00000100'B),
+ NS_PDUT_NS_BLOCK_ACK ('00000101'B),
+ NS_PDUT_NS_UNBLOCK ('00000110'B),
+ NS_PDUT_NS_UNBLOCK_ACK ('00000111'B),
+ NS_PDUT_NS_STATUS ('00001000'B),
+ NS_PDUT_NS_ALIVE ('00001010'B),
+ NS_PDUT_NS_ALIVE_ACK ('00001011'B)
+ /* FIXME: SNS */
+ } with { variant "FIELDLENGTH(8)" };
+
+ /* TS 48.016 10.3 */
+ type enumerated NsIEI {
+ NS_IEI_CAUSE ('00000000'B),
+ NS_IEI_NSVCI ('00000001'B),
+ NS_IEI_NS_PDU ('00000010'B),
+ NS_IEI_BVCI ('00000011'B),
+ NS_IEI_NSEI ('00000100'B),
+ NS_IEI_LIST_IPv4 ('00000101'B),
+ NS_IEI_LIST_IPv6 ('00000110'B),
+ NS_IEI_MAX_NUM_NSVC ('00000111'B),
+ NS_IEI_NUM_IPv4_EP ('00001000'B),
+ NS_IEI_NUM_IPv6_EP ('00001001'B),
+ NS_IEI_RESET_FLAG ('00001010'B),
+ NS_IEI_IP_ADDRESS ('00001011'B)
+ } with { variant "FIELDLENGTH(8)" };
+
+ /* TS 48.016 10.3.2 */
+ type enumerated NsCause {
+ NS_CAUSE_TRANSIT_NETWORK_FAILURE ('00000000'B),
+ NS_CAUSE_OM_INTERVENTION ('00000001'B),
+ NS_CAUSE_EQUIPMENT_FAILURE ('00000010'B),
+ NS_CAUSE_NSVC_BLOCKED ('00000011'B),
+ NS_CAUSE_NSVC_UNKNOWN ('00000100'B),
+ NS_CAUSE_BVCI_UNKNOWN_AT_NSE ('00000101'B),
+ NS_CAUSE_SEMANTICALLY_INCORRECT_PDU ('00001000'B),
+ NS_CAUSE_PDU_NOT_COMPATIBLE_WITH_PROTOCOL_STATE ('00001010'B),
+ NS_CAUSE_PROTOCOL_ERROR_UNSPEIFIED ('00001011'B),
+ NS_CAUSE_INVALID_ESSENTIAL_IE ('00001100'B),
+ NS_CAUSE_MISSING_ESSENTIAL_IE ('00001101'B),
+ NS_CAUSE_INVALID_NR_OF_IPv4_ENDPOINTS ('00001110'B),
+ NS_CAUSE_INVALID_NR_OF_IPv6_ENDPOINTS ('00001111'B),
+ NS_CAUSE_INVALID_NR_OF_NSVCS ('00010000'B),
+ NS_CAUSE_INVALID_WEIGHTS ('00010001'B),
+ NS_CAUSE_UNKNOWN_IP_ENDPOINT ('00010010'B),
+ NS_CAUSE_UNKNOWN_IP_ADDRESS ('00010011'B),
+ NS_CAUSE_IP_TEST_FAILEDA ('00010100'B)
+ } with { variant "FIELDLENGTH(8)" };
+
+ type uint16_t Nsvci;
+ type uint16_t Nsei;
+
+ type union NsIeUnion {
+ BssgpBvci bvci, /* 10.3.1 */
+ NsCause cause, /* 10.3.2 */
+ uint16_t max_num_nsvc, /* 10.3.2e */
+ uint16_t num_ipv4_ep, /* 10.3.2f */
+ uint16_t num_ipv6_ep, /* 10.3.2g */
+ Nsvci nsvci, /* 10.3.5 */
+ Nsei nsei, /* 10.3.6 */
+ octetstring other
+ };
+
+ type record NsTLV {
+ NsIEI iei,
+ uint16_t len,
+ NsIeUnion u
+ } with {
+ variant (u) "CROSSTAG(
+ bvci, iei = NS_IEI_BVCI;
+ cause, iei = NS_IEI_CAUSE;
+ max_num_nsvc, iei = NS_IEI_MAX_NUM_NSVC;
+ num_ipv4_ep, iei = NS_IEI_NUM_IPv4_EP;
+ num_ipv6_ep, iei = NS_IEI_NUM_IPv6_EP;
+ nsvci, iei = NS_IEI_NSVCI;
+ nsei, iei = NS_IEI_NSEI;
+ other, OTHERWISE)"
+ variant (len) "LENGTHTO(u)"
+ };
+
+ type record of NsTLV NsTLVs;
+
+ type record NsPdu {
+ NsPduType pdu_type,
+ NsTLVs tlvs optional
+ } with { variant "" };
+
+ external function enc_NsPdu(in NsPdu pdu) return octetstring
+ with { extension "prototype(convert) encode(RAW)" };
+ external function dec_NsPdu(in octetstring stream) return NsPdu
+ with { extension "prototype(convert) decode(RAW)" };
+
+} with { encode "RAW" };
diff --git a/gprs_gb/Test.ttcn b/gprs_gb/Test.ttcn
index 88a78a8..33d43bf 100644
--- a/gprs_gb/Test.ttcn
+++ b/gprs_gb/Test.ttcn
@@ -9,7 +9,7 @@
function f_assert_prepr(in octetstring a, in octetstring b) {
log ("Input: ", a);
log ("Expected: ", b);
- var octetstring a_preprocessed := f_BSSGP_preprocess_pdu(a);
+ var octetstring a_preprocessed := f_BSSGP_expand_len(a);
log ("Preprocessed: ", a_preprocessed);
if (a_preprocessed != b) {
@@ -21,7 +21,7 @@
function f_dec_and_log(in octetstring inp) {
log("Input: ", inp);
- var octetstring inp_p := f_BSSGP_preprocess_pdu(inp);
+ var octetstring inp_p := f_BSSGP_expand_len(inp);
log ("Preprocessed: ", inp_p);
var BssgpPdu dec := dec_BssgpPdu(inp_p);
log("Decoded: ", dec);