Google Wifi diagnostic report parser

parser.py

#!/usr/bin/python
import os, sys, gzip
from StringIO import StringIO
from datetime import datetime

def readByte(f):
	return ord(f.read(1))

def readInt(f):
	l = 0
	shift = 0
	while True:
		b = readByte(f)
		l |= (b & 0x7F) << shift
		shift += 7
		if (b & 0x80) == 0: break
	return l

def readString(f):
	l = readInt(f)
	return f.read(l).decode("utf-8")

def readDict(f):
	l = readInt(f)
	end = f.tell() + l
	
	d = dict()
	
	while f.tell() < end:
		et = readByte(f)
		el = readInt(f)
		if et == 0x0A:
			d['name'] = f.read(el).decode("utf-8")
		elif et == 0x12:
			d['value'] = f.read(el)
		elif et == 0x10:
			d['size'] = el
		elif et == 0x18:
			d['retcode'] = el
		elif et == 0x1A:
			d['extra'] = f.read(el).decode("utf-8")
		else:
			print "Unknown dict entry type:", hex(et)
			f.seek(el, os.SEEK_CUR)
			
	f.seek(end) # just in case
	
	return d
	
if len(sys.argv) < 2:
	print "Usage:", sys.argv[0], "<report-filename>"
	exit(0)

fsroot = os.path.abspath(sys.argv[1] + "-files")

with gzip.open(sys.argv[1], "rb") as f:
	t = f.read(1)
	while t:
		t = ord(t)
    
		if t == 0x0A:
			s = readString(f)
			print "SoftwareVersion:", s
			
		elif t == 0x12:
			d = readDict(f)
			
			fname = fsroot + d['name']
			dname = os.path.dirname(fname)
			if not os.path.exists(dname):
				os.makedirs(dname)
			
			data = d['value']
			if len(data) > 10 and ord(data[0]) == 0x1F and ord(data[1]) == 0x8B:
				try:
					with gzip.GzipFile(fileobj=StringIO(data)) as x:
						data = x.read()
				except:
					pass
			
			with open(fname, "wb") as o:
				o.write(data)
		
		elif t == 0x1A:
			s = readString(f)
			print "OriginalSoftwareId:", s
			
		elif t == 0x22:
			s = readString(f)
			print "HardwareId:", s
			
		elif t == 0x2A:
			s = readString(f)
			print ""
			print "Configuration Info:"
			print s
			
		elif t == 0x3A:
			d = readDict(f)
			print "Large File:", d['name'], "(" + str(d['size']) + " bytes)"
			
		elif t == 0x42:
			s = readString(f)
			print ""
			print "Network Info:"
			print s
			
		elif t == 0x4A:
			d = readDict(f)
			print ""
			print "Command:", d['name'], "(status = " + str(d['retcode']) + ")"
			print d['value']
			
		elif t == 0x52:
			s = readString(f)
			print ""
			print "Information:"
			print s
			
		elif t == 0x58:
			print "Unknown 0x58:", readByte(f)
			
		elif t == 0x62:
			d = readDict(f)
			print "Id2mac:", d['name'], "=", d['value']
			
		elif t == 0x68:
			timestamp = readInt(f)
			print "Generated:", datetime.fromtimestamp(timestamp)
		
		elif t == 0x72:
			l = readInt(f)
			print "Previous Report (" + str(l) + " bytes)"
			f.seek(l, os.SEEK_CUR)
		
		else:
			print "Unknown tag:", hex(t)
			l = readInt(f)
			f.seek(l, os.SEEK_CUR)
		
		t = f.read(1)

Hi Guys,

I bought a few Google Wifi’s, which have an old 8688.0.0 version of firmware from the test image channel (instead of the usual stable channel) and having field updateRequired = 0.

It seems that some kind of write protection / restriction were in force in the test image firmware, preventing the execution of Recovery Mode when trying to flash a newer stable image firmware.

Since I am not familiar with CrOS development, could you please advise the procedure for me to flash the Google Wifi to 9334.x.x steady channel image (downloaded from OnHub Recovery Utility).

Below is my posting seeking for help in Google Help Forum, for your reference:

https://groups.google.com/a/chromium.org/forum/m/#!topic/chromium-os-dev/98yOPE3UEBo

https://productforums.google.com/forum/#!topic/googlewifi/etya6Mqeo-Y

https://productforums.google.com/forum/#!topic/googlewifi/-AvwS-S-h2Q

https://productforums.google.com/forum/#!topic/googlewifi/IH16V17l6J4

I also attached the status page of the Google Wifi (http://192.168.86.1/api/v1/status) below for your information, many thanks!

{
softwareStatus = {
updateChannel = "testimage-channel";
updateProgress = 0;
updateRequired = 0;
updateStatus = 1;
version = "8688.0.0";
};
systemStatus = {
deviceId = "ed6640ea-ccbd-8c48-a02f-6c9102300f44";
hardware = 4;
hardwareId = "GALE A2A-A2A-E3A-A4Q-A9C";
uptime = 19893;
};
wanStatus = {
captivePortal = 0;
ethernetLink = 1;
invalidCredentials = 0;
online = 1;
pppoeDetected = 0;
};
}

https://gist.github.com/booth-f/72832e05252eb89dbdbe644e2a0a9a92

Modified parser code to work with Python3. Looks like in the latest dumps there are some errors towards the end which somebody else might be able to figure out.

Unknown tag: 0x7a
Unknown tag: 0x7a
Unknown tag: 0x7a
Unknown tag: 0x82
Unknown tag: 0xcf
Unknown tag: 0x74
Unknown tag: 0x20
Unknown tag: 0x69
Unknown tag: 0x70
Unknown dict entry type: 0x74
Unknown dict entry type: 0x36
Traceback (most recent call last):
File "wifi-parser.py", line 125, in
print("Id2mac:", d['name'], "=", d['value'])
KeyError: 'name'