Add EDI dump analyser script

1 files changed, 279 insertions, 0 deletions

diff --git a/edi/edidebug.py b/edi/edidebug.py
new file mode 100755
index 0000000..0b54622
--- /dev/null
+++ b/edi/edidebug.py
@@ -0,0 +1,279 @@
+#!/usr/bin/env python2
+#
+# Decode EDI for debugging
+
+import sys
+import struct
+
+from crc import crc16
+
+class Printer:
+    def __init__(self):
+        self.indent = 0
+    def pr(self, s):
+        print(" " * self.indent + s)
+    def inc(self):
+        self.indent += 1
+    def dec(self):
+        self.indent -= 1
+
+p = Printer()
+
+def decode(stream):
+    p.pr("start")
+    success = False
+
+    pos = stream.tell()
+    sync = stream.read(2)
+    stream.seek(pos)
+
+    if len(sync) < 2:
+        p.pr("EOF")
+        return False
+
+    if sync == "PF":
+        if decode_pft(stream):
+            p.pr("PFT decode success")
+            success = True
+        else:
+            p.pr("PFT decode fail")
+    elif sync == "AF":
+        if decode_af(stream):
+            p.pr("AF decode success")
+            success = True
+        else:
+            p.pr("AF decode fail")
+    return success
+
+
+pft_head_struct = "!2sH3B3BH"
+pft_rs_head_struct = "!2B"
+pft_addr_head_struct = "!2H"
+def decode_pft(stream):
+    p.inc()
+    p.pr("start decoding PF")
+
+    headerdata = stream.read(12)
+    header = struct.unpack(pft_head_struct, headerdata)
+
+    psync, pseq, findex1, findex2, findex3, fcount1, fcount2, fcount3, fec_ad_plen = header
+
+    findex = (findex1 << 16) | (findex2 << 8) | findex3
+    fcount = (fcount1 << 16) | (fcount2 << 8) | fcount3
+
+    fec = (fec_ad_plen & 0x80) != 0x00
+    addr = (fec_ad_plen & 0x40) != 0x00
+    plen = fec_ad_plen & 0x3F
+
+    # try to sync according to TS 102 821 Clause 7.4.1
+    if psync != "PF":
+        p.pr("No PF Sync")
+        p.dec()
+        return False
+
+    rs_k = 0
+    rs_z = 0
+    if fec:
+        rs_head = stream.read(2)
+        rs_k, rs_z = struct.unpack(pft_rs_head_struct, rs_head)
+        headerdata += rs_head
+
+    addr_source = 0
+    addr_dest   = 0
+    if addr:
+        addr_head = stream.read(4)
+        addr_source, addr_dest = struct.unpack(pft_addr_head_struct, addr_head)
+        headerdata += addr_head
+
+    # read CRC
+    headerdata += stream.read(2)
+
+    crc_ok = crc16(headerdata) == 0x1d0f
+
+    if crc_ok:
+        p.pr("CRC ok")
+    else:
+        p.pr("CRC not ok!")
+
+    p.pr("pseq {}".format(pseq))
+    p.pr("findex {}".format(findex))
+    p.pr("fcount {}".format(fcount))
+    if fec:
+        p.pr("with fec:")
+        p.pr(" RSk={}".format(rs_k))
+        p.pr(" RSz={}".format(rs_z))
+    if addr:
+        p.pr("with transport header:")
+        p.pr(" source={}".format(addr_source))
+        p.pr(" dest={}".format(addr_dest))
+    p.pr("payload length={}".format(plen))
+
+    success = False
+    if crc_ok and fec:
+        p.pr("RS PACKET TODO")
+    elif crc_ok:
+        success = decode_af(stream)
+
+    p.dec()
+    return success
+
+af_head_struct = "!2sLHBc"
+def decode_af(stream):
+    p.pr("AF Packet")
+    p.inc()
+
+    headerdata = stream.read(10)
+
+    sync, plen, seq, ar, pt = struct.unpack(af_head_struct, headerdata)
+
+    if sync != "AF":
+        p.pr("No AF Sync")
+        p.dec()
+        return False
+
+    crc_flag = (ar & 0x80) != 0x00
+    revision = ar & 0x7F
+
+    payload = stream.read(plen)
+
+    crc = struct.unpack("!H", stream.read(2))[0]
+
+    crc_calc = crc16(headerdata)
+    crc_calc = crc16(payload, crc_calc)
+    crc_calc ^= 0xFFFF
+    # manual endianness conversion
+    crc_calc = ((crc_calc >> 8) | (crc_calc << 8)) & 0xFFFF
+
+    crc_ok = crc_calc == crc
+
+    if crc_flag and crc_ok:
+        p.pr("CRC ok")
+    elif crc_flag:
+        p.pr("CRC not ok!")
+        p.pr(" CRC: is 0x{0:04x}, calculated 0x{1:04x}".format(crc, crc_calc))
+    else:
+        p.pr("No CRC")
+
+    p.pr("plen {}".format(plen))
+    p.pr("seq {}".format(seq))
+    p.pr("revision {}".format(revision))
+    p.pr("protocol type {}".format(pt))
+
+    success = False
+    if pt == "T":
+        success = decode_tag(payload)
+
+    p.dec()
+    return success
+
+tag_item_head_struct = "!4sL"
+def tagitems(tagpacket):
+    i = 0
+    while i+8 < len(tagpacket):
+        name, length = struct.unpack(tag_item_head_struct, tagpacket[i:i+8])
+
+        # length is in bits, because it's more annoying this way
+        assert(length % 8 == 0)
+        length /= 8
+
+        tag_value = tagpacket[i+8:i+8+length]
+        yield {'name': name, 'length': length, 'value': tag_value}
+
+        i += 8 + length
+
+def decode_tag(tagpacket):
+    p.pr("Tag packet len={}".format(len(tagpacket)))
+    p.inc()
+    for item in tagitems(tagpacket):
+        if item['name'] == "deti":
+            decode_deti(item)
+        elif item['name'].startswith("est"):
+            decode_estn(item)
+        else:
+            p.pr("Tag item '{}' ({})".format(item['name'], item['length']))
+
+    p.dec()
+    return True
+
+item_deti_header_struct = "!BBBBH"
+def decode_deti(item):
+    p.pr("TAG item {} ({})".format(item['name'], item['length']))
+    p.inc()
+    tag_value = item['value']
+
+    unpacked = struct.unpack(item_deti_header_struct, tag_value[:6])
+    flag_fcth, fctl, stat, mid_fp, mnsc = unpacked
+
+
+    atstf = flag_fcth & 0x80 != 0
+    if atstf:
+        utco, seconds, tsta1, tsta2, tsta3 = struct.unpack("!BL3B", tag_value[6:6+8])
+        tsta = (tsta1 << 16) | (tsta2 << 8) | tsta3
+
+    ficf  = flag_fcth & 0x40 != 0
+    rfudf = flag_fcth & 0x20 != 0
+    fcth  = flag_fcth & 0x1F
+    fct = fcth << 5 | fctl
+
+    mid = (mid_fp >> 6) & 0x03
+    fp  = (mid_fp >> 3) & 0x07
+
+
+    p.pr("FICF        = {}".format(ficf))
+    p.pr("ATST        = {}".format(atstf))
+    p.pr("RFUDF       = {}".format(rfudf))
+    p.pr("FCT         = {} (0x{:02x} 0x{:02x})".format(fct, fcth, fctl))
+    p.pr("STAT        = 0x{:02x}".format(stat))
+    p.pr("Mode id     = {}".format(mid))
+    p.pr("Frame phase = {}".format(fp))
+    p.pr("MNSC        = 0x{:02x}".format(mnsc))
+    if atstf:
+        p.pr("UTCOffset   = {}".format(utco))
+        p.pr("Seconds     = {}".format(seconds))
+        p.pr("TSTA        = {}".format(tsta))
+
+
+    len_fic = len(tag_value) - 2 - 4
+
+    if atstf:
+        len_fic -= 8
+
+    if rfudf:
+        len_fic -= 3
+
+    p.pr("FIC data len  {}".format(len_fic))
+
+    p.dec()
+
+item_estn_head_struct = "!HB"
+def decode_estn(item):
+    estN = chr(ord("0") + ord(item['name'][3]))
+    p.pr("TAG item EST{} ({})".format(estN, item['length']))
+    p.inc()
+    tag_value = item['value']
+
+    scid_sad, tpl_rfa = struct.unpack(item_estn_head_struct, tag_value[:3])
+    scid = scid_sad >> 10
+    sad  = scid_sad & 0x3F
+    tpl  = tpl_rfa >> 2
+
+    p.pr("SCID = {}".format(scid))
+    p.pr("SAD  = {}".format(sad))
+    p.pr("TPL  = {}".format(tpl))
+
+    assert(item['length'] == len(tag_value))
+
+    p.pr("MST len = {}".format(len(tag_value) - 3))
+
+    p.dec()
+
+if len(sys.argv) < 2:
+    print("Filename expected")
+    sys.exit(1)
+
+filename = sys.argv[1]
+
+edi_fd = open(filename, "r")
+while decode(edi_fd):
+    pass
+