Begin parsing wifi packets for airtime report.
Also try to improve PHY report accuracy by detecting what network
packets are associated with and only counting those.
Change-Id: I2861b1111332b3fcc0a4a90ed0cfc1f429f7e26f
diff --git a/wifitables/ifstats/__init__.py b/wifitables/ifstats/__init__.py
new file mode 100644
index 0000000..cedb8cb
--- /dev/null
+++ b/wifitables/ifstats/__init__.py
@@ -0,0 +1,9 @@
+import fabric
+import skids
+
+fabric = fabric
+skids = skids
+
+InterfaceStats = fabric.InterfaceStats
+Parse = fabric.Parse
+Restore = fabric.Restore
diff --git a/wifitables/ifstats.py b/wifitables/ifstats/fabric.py
similarity index 96%
rename from wifitables/ifstats.py
rename to wifitables/ifstats/fabric.py
index a148f72..06608c7 100644
--- a/wifitables/ifstats.py
+++ b/wifitables/ifstats/fabric.py
@@ -184,9 +184,10 @@
# the scan sometimes includes comment lines. assume that anything that has
# a valid channel isn't a comment line.
if chre.match(channel):
- result += [[ssid, bssid, int(rssi), channel, ht, cc, security]]
+ result += [dict(zip(header,
+ [ssid, bssid, int(rssi), channel, ht, cc, security]))]
- return [header] + result
+ return result
def Parse(system, cache):
@@ -213,18 +214,18 @@
'Linux': ['ipaddr', 'iwlink', 'iwscan'],
}
+ read = set()
for system, names in system_results.items():
- read = 0
for name in names:
try:
with open(os.path.join(report_dir, name)) as infile:
cache[name] = infile.read()
- read += 1
+ read.add(system)
except IOError:
cache[name] = ''
- if read:
- return system, cache
+ if read:
+ return read, cache
raise IOError('Could not open report in {}'.format(report_dir))
diff --git a/wifitables/ifstats_skids.py b/wifitables/ifstats/skids.py
similarity index 100%
rename from wifitables/ifstats_skids.py
rename to wifitables/ifstats/skids.py
diff --git a/wifitables/ifstats_skids_test.py b/wifitables/ifstats_test.py
similarity index 91%
rename from wifitables/ifstats_skids_test.py
rename to wifitables/ifstats_test.py
index 4e4e287..11ca13a 100755
--- a/wifitables/ifstats_skids_test.py
+++ b/wifitables/ifstats_test.py
@@ -1,7 +1,7 @@
#!/usr/bin/python2.7
"""Tests for ifstats_skids."""
-import ifstats_skids
+import ifstats
from wvtest import wvtest
@@ -9,7 +9,7 @@
def ParseSavedStatusWireless():
with open('testdata/skids/status_wireless.html') as status_wireless:
text = status_wireless.read()
- res = ifstats_skids.ParseStatusWireless(text)
+ res = ifstats.skids.ParseStatusWireless(text)
wvtest.WVPASSEQ(res, {
'Wireless Band': '802.11ac',
'AP Mac Address (BSSID)': '00:26:86:F0:22:C9',
diff --git a/wifitables/report.py b/wifitables/report.py
index b5770c6..2d4a1a5 100755
--- a/wifitables/report.py
+++ b/wifitables/report.py
@@ -86,6 +86,64 @@
return counter.most_common()[0][0], phy / alltimes
+def ParsePcap(stream, known_ssids):
+ """ParsePcap computes PHY performance for a packet capture in `stream`.
+
+ Args:
+ stream: an open `file` object pointing to a file with pcap data.
+ known_ssids: a dict mapping known BSSIDs to SSIDs.
+
+ Returns:
+ a dict containing PHY performance information. keys are descriptive strings,
+ values are strings or numbers in Mbit/s.
+ """
+
+ rates = collections.defaultdict(list)
+ times_seen = collections.Counter()
+ start_secs = None
+
+ for opt, frame in wifipacket.Packetize(stream):
+ if start_secs is None:
+ start_secs = opt.pcap_secs
+
+ # Fill in known SSIDs array if our scan didn't see anything.
+ ssid = wifipacket.IdentifySSID(opt, frame)
+ if ssid is not None:
+ known_ssids[opt.ta] = ssid
+
+ for sta, direction in [('ra', 'up'), ('ta', 'down'), ('xa', 'across')]:
+ bssid = opt.get(sta)
+ ssid = known_ssids.get(bssid)
+ if ssid:
+ rates[ssid].append((opt.pcap_secs - start_secs,
+ direction,
+ opt.rate,
+ len(frame)))
+ times_seen[ssid] += 1
+ break
+
+ if not times_seen:
+ return {}
+
+ modal_ssid, _ = times_seen.most_common(1)[0]
+ summary = {}
+ for _, direction, rate, size in rates[modal_ssid]:
+ size_weighted_rate = rate * float(size)
+ if direction not in summary:
+ summary[direction] = [size_weighted_rate, size]
+ else:
+ summary[direction][0] += size_weighted_rate
+ summary[direction][1] += size
+
+ line = {'PHY ssid': modal_ssid}
+ for direction, accum in summary.items():
+ size_weighted_rate, size = accum
+ line['PHY {}'.format(direction)] = ((size_weighted_rate / size) if size
+ else 0.0)
+
+ return line
+
+
def Channel(text_channel):
"""Given a text channel spec like 149,+1 return the central freq and width."""
LoadChannels()
@@ -122,11 +180,12 @@
line['Steps'] = int(steps)
system, cache = ifstats.Restore(report_dir)
- result = ifstats.Parse(system, cache)
- if not result.get('link'):
- pass
- elif system == 'Darwin':
+ # known_ssids is a map from BSSID(string) => SSID(string)
+ known_ssids = {}
+
+ if 'Darwin' in system:
+ result = ifstats.Parse('Darwin', cache)
airport = result.get('link')
channel, width = Channel(airport['channel'])
shared = 0
@@ -134,13 +193,15 @@
scan = result.get('scan')
if len(scan) > 1:
- for row in scan[1:]:
- oc, ow = Channel(row[3])
+ for row in scan:
+ oc, ow = Channel(row['CHANNEL'])
if channel == oc and width == ow:
shared += 1
if Overlap(channel, width, oc, ow):
overlap += 1
+ known_ssids[row['BSSID']] = row['SSID']
+
line.update({
'Channel': channel,
'Width': width,
@@ -149,7 +210,9 @@
'Shared': shared,
'Interfering': overlap - shared
})
- elif system == 'Linux':
+
+ if 'Linux' in system:
+ result = ifstats.Parse('Linux', cache)
iwlink = result.get('link')
signal = int(iwlink.get('signal', '0 dBm').split()[0])
channel = int(iwlink.get('freq', '0'))
@@ -165,14 +228,24 @@
'RSSI': signal,
})
+ # TODO(willangley): integrate skid statistics with the rest of the benchmark
+ # framework system detection.
+ try:
+ with open(os.path.join(report_dir, 'status_wireless')) as status_wireless:
+ result = ifstats.skids.ParseStatusWireless(status_wireless.read())
+ width = result['Bandwidth'].split()[0]
+ line.update({
+ 'Channel': result['Channel'],
+ 'Width': width,
+ 'RSSI': result['RSSI'],
+ })
+ except IOError:
+ pass
+
try:
ppath = os.path.join(report_dir, 'testnetwork.pcap')
with open(ppath) as stream:
- rates = [float(opt.rate) for opt, _ in wifipacket.Packetize(stream)]
-
- # TODO(willangley): come up with a meaningful modal MCS for mixed
- # 802.11n/802.11ac captures like we have here.
- line['PHY'] = sum(rates)/max(len(rates), 1)
+ line.update(ParsePcap(stream, known_ssids))
except IOError:
try:
mpath = os.path.join(report_dir, 'mcs')
@@ -262,10 +335,11 @@
"""Write a network testing report in .tsv format to stdout."""
# include every field we can write in the header row
header = ['Series', 'Time', 'Steps', 'Channel', 'Width', 'RSSI', 'Noise',
- 'Shared', 'Interfering', 'MCS', 'PHY', 'TCP BW up',
- 'TCP BW up units', 'UDP BW up', 'UDP BW up units', 'TCP BW down',
- 'TCP BW down units', 'UDP BW down', 'UDP BW down units',
- 'isostream']
+ 'Shared', 'Interfering',
+ 'MCS', 'PHY', 'PHY ssid', 'PHY up', 'PHY down', 'PHY across',
+ 'TCP BW up', 'TCP BW up units', 'UDP BW up', 'UDP BW up units',
+ 'TCP BW down', 'TCP BW down units', 'UDP BW down',
+ 'UDP BW down units', 'isostream']
writer = csv.DictWriter(sys.stdout, header, dialect=csv.excel_tab)
writer.writeheader()
diff --git a/wifitables/report_test.py b/wifitables/report_test.py
index a7d5a87..e4b6e98 100755
--- a/wifitables/report_test.py
+++ b/wifitables/report_test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.7 -S
+#!/usr/bin/python2.7
"""Tests for report."""
import ifstats
@@ -39,15 +39,16 @@
print 'Restoring report'
system, cache = ifstats.Restore(rpt)
- wvtest.WVPASSEQ(system, 'Linux')
+ wvtest.WVPASSEQ(len(system), 1)
+ wvtest.WVPASS('Linux' in system)
print 'Checking IP address'
- addrmap = ifstats.ParseIpAddr(cache['ipaddr'])
+ addrmap = ifstats.fabric.ParseIpAddr(cache['ipaddr'])
wvtest.WVPASSEQ(addrmap.get('lo'), '127.0.0.1/32')
wvtest.WVPASSEQ(addrmap.get('wcli0'), '192.168.1.222/24')
print 'Checking for link information'
- data = ifstats.ParseIwLink(cache['iwlink'])
+ data = ifstats.fabric.ParseIwLink(cache['iwlink'])
wvtest.WVPASSEQ(data.get('SSID'), 'GSAFNS1441P0208_TestWifi')
wvtest.WVPASSEQ(data.get('BSSID'), 'f4:f5:e8:80:f3:d0')
diff --git a/wifitables/sample.py b/wifitables/sample.py
index 6bebbdd..ddcef21 100755
--- a/wifitables/sample.py
+++ b/wifitables/sample.py
@@ -17,7 +17,7 @@
from fabric import utils
import ifstats
-import ifstats_skids
+import ifstats.skids as ifstats_skids
import iperf
import isostream
import options
diff --git a/wifitables/wifipacket.py b/wifitables/wifipacket.py
index 68f8596..b50d0fb 100644
--- a/wifitables/wifipacket.py
+++ b/wifitables/wifipacket.py
@@ -16,6 +16,7 @@
"""Functions for decoding wifi pcap files."""
from __future__ import print_function
+import binascii
import bz2
import csv
import gzip
@@ -384,6 +385,45 @@
yield opt, frame
+def CheckFrame(frame):
+ """CheckFrame returns True if the frame checksum is good, False otherwise."""
+ crc = struct.pack('<I', binascii.crc32(frame[:-4]) & 0xffffffff)
+ return crc == frame[-4:]
+
+
+def IdentifySSID(opt, frame):
+ """Given an opt and frame from `Packetize`, report any SSIDs found.
+
+ These are currently only expected to be in ProbeResponse frames.
+
+ Args:
+ opt: dict of options computed by Packetize
+ frame: an 802.11 frame as a str
+ Returns:
+ SSID found as a string, or None.
+ """
+ # only look at ProbeResponse frames
+ if opt.type != 0x05:
+ return None
+
+ # ignore invalid frames
+ if not CheckFrame(frame):
+ return None
+
+ # timestamp, bi, capabilities = struct.unpack('<QHH', frame[24:36])
+ rawtagged = frame[36:-4]
+ tagged = {}
+ start = 0
+ while start < len(rawtagged):
+ tnum, tlen = struct.unpack('<BB', rawtagged[start:start+2])
+ start += 2
+ tagged[tnum] = rawtagged[start:start+tlen]
+ start += tlen
+
+ ssid = tagged.get(0)
+ return ssid
+
+
def Example(p):
if 0:
basetime = 0
