wifimon as I wrote it.
diff --git a/wifimon.py b/wifimon.py
new file mode 100755
index 0000000..035e2ce
--- /dev/null
+++ b/wifimon.py
@@ -0,0 +1,256 @@
+#!/usr/bin/python
+import csv
+import os
+import string
+import struct
+import subprocess
+import sys
+
+TCPDUMP_MAGIC = 0xa1b2c3d4
+TCPDUMP_VERSION = (2, 4)
+LINKTYPE_IEEE802_11_RADIOTAP = 127
+
+RADIOTAP_FIELDS = [
+ ('mac_usecs', 'Q'),
+ ('flags', 'B'),
+ ('rate', 'B'),
+ ('channel', 'HH'),
+ ('fhss', 'BB'),
+ ('dbm_antsignal', 'b'),
+ ('dbm_antnoise', 'b'),
+ ('lock_quality', 'H'),
+ ('tx_attenuation', 'H'),
+ ('db_tx_attenuation', 'B'),
+ ('dbm_tx_power', 'b'),
+ ('antenna', 'B'),
+ ('db_antsignal', 'B'),
+ ('db_antnoise', 'B'),
+ ('rx_flags', 'H'),
+ ('tx_flags', 'H'),
+ ('rts_retries', 'B'),
+ ('data_retries', 'B'),
+ ('channelplus', 'II'),
+ ('ht', 'BBB'),
+ ('ampdu_status', 'IHBB'),
+ ('vht', 'HBB4sBBH'),
+]
+
+_STDFRAME = ('ra', 'ta', 'xa', 'seq')
+DOT11_TYPES = {
+ # Management
+ 0x00: ('AssocReq', _STDFRAME),
+ 0x01: ('AssocResp', _STDFRAME),
+ 0x02: ('ReassocReq', _STDFRAME),
+ 0x03: ('ReassocResp', _STDFRAME),
+ 0x04: ('ProbeReq', _STDFRAME),
+ 0x05: ('ProbeResp', _STDFRAME),
+ 0x08: ('Beacon', _STDFRAME),
+ 0x09: ('ATIM', _STDFRAME),
+ 0x0a: ('Disassoc', _STDFRAME),
+ 0x0b: ('Auth', _STDFRAME),
+ 0x0c: ('Deauth', _STDFRAME),
+ 0x0d: ('Action', _STDFRAME),
+
+ # Control
+ 0x16: ('CtlExt', ('ra',)),
+ 0x18: ('BlockAckReq', ('ra', 'ta')),
+ 0x19: ('BlockAck', ('ra', 'ta')),
+ 0x1a: ('PsPoll', ('aid', 'ra', 'ta')),
+ 0x1b: ('RTS', ('ra', 'ta')),
+ 0x1c: ('CTS', ('ra',)),
+ 0x1d: ('ACK', ('ra',)),
+ 0x1e: ('CongestionFreeEnd', ('ra', 'ta')),
+ 0x1f: ('CongestionFreeEndAck', ('ra', 'ta')),
+
+ # Data
+ 0x20: ('Data', _STDFRAME),
+ 0x21: ('DataCongestionFreeAck', _STDFRAME),
+ 0x22: ('DataCongestionFreePoll', _STDFRAME),
+ 0x23: ('DataCongestionFreeAckPoll', _STDFRAME),
+ 0x24: ('Null', _STDFRAME),
+ 0x25: ('CongestionFreeAck', _STDFRAME),
+ 0x26: ('CongestionFreePoll', _STDFRAME),
+ 0x27: ('CongestionFreeAckPoll', _STDFRAME),
+ 0x28: ('QosData', _STDFRAME),
+ 0x29: ('QosDataCongestionFreeAck', _STDFRAME),
+ 0x2a: ('QosDataCongestionFreePoll', _STDFRAME),
+ 0x2b: ('QosDataCongestionFreeAckPoll', _STDFRAME),
+ 0x2c: ('QosNull', _STDFRAME),
+ 0x2d: ('QosCongestionFreeAck', _STDFRAME),
+ 0x2e: ('QosCongestionFreePoll', _STDFRAME),
+ 0x2f: ('QosCongestionFreeAckPoll', _STDFRAME),
+}
+
+
+def Align(i, alignment):
+ return i + (alignment - 1) & ~(alignment - 1)
+
+
+def MacAddr(s):
+ return ':'.join(('%02x' % i) for i in struct.unpack('6B', s))
+
+
+def HexDump(s):
+ out = ''
+ for row in xrange(0, len(s), 16):
+ out += '%04x ' % row
+ for col in xrange(16):
+ if len(s) > row + col:
+ out += '%02x ' % ord(s[row + col])
+ else:
+ out += ' '
+ if col == 7:
+ out += ' '
+ out += ' '
+ for col in xrange(16):
+ if len(s) > row + col:
+ c = s[row + col]
+ if len(repr(c)) != 3: # x -> 'x' and newline -> '\\n'
+ c = '.'
+ out += c
+ else:
+ out += ' '
+ if col == 7:
+ out += ' '
+ out += '\n'
+ return out
+
+
+def Packetize(stream):
+ # pcap global header
+ magicbytes = stream.read(4)
+ if struct.unpack('<I', magicbytes) == (TCPDUMP_MAGIC,):
+ byteorder = '<'
+ elif struct.unpack('>I', magicbytes) == (TCPDUMP_MAGIC,):
+ byteorder = '>'
+ else:
+ raise ValueError('unexpected tcpdump magic %r' % magicbytes)
+ (version_major, version_minor,
+ unused_thiszone,
+ unused_sigfigs,
+ snaplen,
+ network) = struct.unpack(byteorder + 'HHiIII', stream.read(20))
+ version = (version_major, version_minor)
+ if version != TCPDUMP_VERSION:
+ raise ValueError('unexpected tcpdump version %r' % version)
+ if network != LINKTYPE_IEEE802_11_RADIOTAP:
+ raise ValueError('unexpected tcpdump network type %r' % network)
+
+ while 1:
+ opt = {}
+
+ # pcap packet header
+ bytes = stream.read(16)
+ if len(bytes) < 16: break # EOF
+ (ts_sec, ts_usec,
+ incl_len, orig_len) = struct.unpack(byteorder + 'IIII', bytes)
+ if incl_len > orig_len:
+ raise ValueError('packet incl_len(%d) > orig_len(%d): invalid'
+ % (incl_len, orig_len))
+ if incl_len > snaplen:
+ raise ValueError('packet incl_len(%d) > snaplen(%d): invalid'
+ % (incl_len, snaplen))
+
+ opt['pcap_secs'] = ts_sec + (ts_usec / 1e6)
+
+ # pcap packet data
+ radiotap = stream.read(incl_len)
+
+ # radiotap header (always little-endian)
+ (it_version, unused_it_pad,
+ it_len, it_present) = struct.unpack('<BBHI', radiotap[:8])
+ if it_version != 0:
+ raise ValueError('unknown radiotap version %d' % it_version)
+ frame = radiotap[it_len:]
+ optbytes = radiotap[8:it_len]
+
+ ofs = 0
+ for i, (name, format) in enumerate(RADIOTAP_FIELDS):
+ if it_present & (1 << i):
+ ofs = Align(ofs, struct.calcsize(format[0]))
+ sz = struct.calcsize(format)
+ v = struct.unpack(format, optbytes[ofs:ofs+sz])
+ if name == 'mac_usecs':
+ opt['mac_usecs'] = v[0]
+ opt['mac_secs'] = v[0] / 1e6
+ elif name == 'channel':
+ opt['freq'] = v[0]
+ opt['channel_flags'] = v[1]
+ elif name == 'ht':
+ opt['ht'] = v
+ opt['mcs'] = v[2]
+ else:
+ opt[name] = v if len(v) > 1 else v[0]
+ ofs += sz
+
+ (fctl, duration) = struct.unpack('<HH', frame[0:4])
+ dot11ver = fctl & 0x0003
+ dot11type = (fctl & 0x000c) >> 2
+ dot11subtype = (fctl & 0x00f0) >> 4
+ dot11dsmode = (fctl & 0x0300) >> 8
+ dot11morefrag = (fctl & 0x0400) >> 10
+ dot11retry = (fctl & 0x0800) >> 11
+ dot11powerman = (fctl & 0x1000) >> 12
+ dot11moredata = (fctl & 0x2000) >> 13
+ dot11wep = (fctl & 0x4000) >> 14
+ dot11order = (fctl & 0x8000) >> 15
+ fulltype = (dot11type << 4) | dot11subtype
+ opt['type'] = fulltype
+ (typename, typefields) = DOT11_TYPES.get(fulltype, ('Unknown', ('ra',)))
+ opt['typestr'] = '%02X %s' % (fulltype, typename)
+ opt['dsmode'] = dot11dsmode
+ opt['retry'] = dot11retry
+ opt['powerman'] = dot11powerman
+ opt['order'] = dot11order
+
+ ofs = 4
+ for i, fieldname in enumerate(typefields):
+ if fieldname == 'seq':
+ seq = struct.unpack('<H', frame[ofs:ofs+2])[0]
+ opt['seq'] = (seq & 0xfff0) >> 4
+ opt['frag'] = (seq & 0x000f)
+ ofs += 2
+ else:
+ opt[fieldname] = MacAddr(frame[ofs:ofs+6])
+ ofs += 6
+
+ yield opt, frame
+
+
+def main():
+ if 0:
+ for opt, frame in Packetize(sys.stdin):
+ print opt
+ print HexDump(frame)
+ else:
+ want_fields = [
+ 'ta',
+ 'ra',
+# 'xa',
+# 'freq',
+ 'seq',
+ 'mcs',
+ 'rate',
+ 'retry',
+ 'dbm_antsignal',
+ 'dbm_antnoise',
+# 'frag',
+ 'typestr',
+# 'powerman',
+# 'order',
+# 'dsmode',
+ ]
+ co = csv.writer(sys.stdout)
+ co.writerow(['pcap_secs'] + want_fields)
+ sys.stdout.flush()
+ tbase_pcap = 0
+ tbase_mac = 0
+ for opt, frame in Packetize(sys.stdin):
+ t_pcap = opt.get('pcap_secs', 0)
+ if not tbase_pcap: tbase_pcap = t_pcap
+ co.writerow(['%.6f' % (t_pcap - tbase_pcap)] +
+ [opt.get(f, None) for f in want_fields])
+ sys.stdout.flush()
+
+if __name__ == '__main__':
+ main()
