library: S1AP encoding/decoding using libfftranscode and ASN.1 from V15.5.0
This allows us to encode/decode 3GPP S1AP messages, as used on the S1
interface control plane between eNodeB and MME.
Change-Id: Ie019bef1f3ef9cc5f6c94a64c7f352c510fb5633
diff --git a/library/s1ap/S1AP_EncDec.cc b/library/s1ap/S1AP_EncDec.cc
new file mode 100644
index 0000000..a17f20e
--- /dev/null
+++ b/library/s1ap/S1AP_EncDec.cc
@@ -0,0 +1,64 @@
+
+#include <string.h>
+#include <stdarg.h>
+#include "S1AP_PDU_Descriptions.hh"
+
+extern "C" {
+#include <fftranscode/transcode.h>
+}
+
+namespace S1AP__Types {
+
+TTCN_Module S1AP__EncDec("S1AP_EncDec", __DATE__, __TIME__);
+
+OCTETSTRING enc__S1AP__PDU(const S1AP__PDU__Descriptions::S1AP__PDU &pdu)
+{
+ uint8_t *aper_buf;
+ int aper_buf_len;
+ TTCN_Buffer TTCN_buf;
+ TTCN_buf.clear();
+
+ /* Encode from abstract data type into BER/DER */
+ pdu.encode(S1AP__PDU__Descriptions::S1AP__PDU_descr_, TTCN_buf,
+ TTCN_EncDec::CT_BER, BER_ENCODE_DER);
+
+ aper_buf_len = fftranscode_ber2aper(FFTRANSC_T_S1AP, &aper_buf, TTCN_buf.get_data(), TTCN_buf.get_len());
+ if (aper_buf_len < 0) {
+ TTCN_error("fftranscode failed.");
+ }
+
+ /* make octetstring from output buffer */
+ OCTETSTRING ret_val(aper_buf_len, aper_buf);
+
+ /* release dynamically-allocated output buffer */
+ fftranscode_free(aper_buf);
+
+ return ret_val;
+}
+
+S1AP__PDU__Descriptions::S1AP__PDU dec__S1AP__PDU(const OCTETSTRING &stream)
+{
+ uint8_t *ber_buf;
+ int ber_buf_len;
+
+ /* First, decode APER + re-encode as BER */
+ ber_buf_len = fftranscode_aper2ber(FFTRANSC_T_S1AP, &ber_buf, (const unsigned char *)stream, stream.lengthof());
+ if (ber_buf_len < 0) {
+ TTCN_error("fftranscode failed.");
+ }
+
+ /* Then, re-encode from BER to TITAN representation */
+ S1AP__PDU__Descriptions::S1AP__PDU ret_dcc;
+ TTCN_Buffer TTCN_buf;
+ TTCN_buf.clear();
+ TTCN_buf.put_s(ber_buf_len, ber_buf);
+
+ ret_dcc.decode(S1AP__PDU__Descriptions::S1AP__PDU_descr_, TTCN_buf,
+ TTCN_EncDec::CT_BER, BER_ACCEPT_ALL);
+
+ fftranscode_free(ber_buf);
+
+ return ret_dcc;
+}
+
+}