SNDCP: add SNDCP-XID encoder/decoder and unit test
The SNDCP-XID (or layer-3 xid) is used to exchange layer-3 parameters
such as compression. The encoder encodes a bytestream that is then
sent as regular XID field from LLC.
We will need the SNDCP-XID to negotiate the parameters for our
upcomming GPRS data and header compression features
Change-Id: If2d63fe2550864cafef3156b1dc0629037c49c1e
diff --git a/openbsc/tests/sndcp_xid/sndcp_xid_test.ok b/openbsc/tests/sndcp_xid/sndcp_xid_test.ok
new file mode 100644
index 0000000..f357282
--- /dev/null
+++ b/openbsc/tests/sndcp_xid/sndcp_xid_test.ok
@@ -0,0 +1,11 @@
+Testing SNDCP XID-Decoder/Encoder (real world data)
+Decoded:
+Result length=54
+Encoded: 000100023182022789ffe0000f00a8000000010101000201020003010300040104000501050006000701070008010880000412004007
+Rencoded: 000100023182022789ffe0000f00a8000000010101000201020003010300040104000501050006000701070008010880000412004007
+
+Testing SNDCP XID-Encoder/Decoder
+Test input data:
+Encoded: 000100011a83010dab00208003012c012c02580258830007a000200308001402408000041200200781010c3456700040010005a80f000f82022789ffe0000f00a80000000101010002010200030103000401040005010500060007010700080108 (97 bytes)
+Decoded:
+Done