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authorMatthias P. Braendli <matthias.braendli@mpb.li>2014-06-06 18:06:49 +0200
committerMatthias P. Braendli <matthias.braendli@mpb.li>2014-06-06 18:06:49 +0200
commita13a871ade41bbebf85760acf598eecabe7dc0c5 (patch)
treebe801b509ba9aa379509d80a21e7e39d6848888a /edi/edidebug.py
parent27beb269d01744c0c1aeff078c720feca8cb3977 (diff)
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Add EDI dump analyser script
Diffstat (limited to 'edi/edidebug.py')
-rwxr-xr-xedi/edidebug.py279
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
+