tools/usb_gadget/server.py

   1 # Copyright 2014 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """WSGI application to manage a USB gadget.
   6 """
   7
   8 import datetime
   9 import hashlib
  10 import re
  11 import subprocess
  12 import sys
  13 import time
  14 import urllib2
  15
  16 from tornado import httpserver
  17 from tornado import ioloop
  18 from tornado import web
  19
  20 import default_gadget
  21
  22 VERSION_PATTERN = re.compile(r'.*usb_gadget-([a-z0-9]{32})\.zip')
  23
  24 address = None
  25 chip = None
  26 claimed_by = None
  27 default = default_gadget.DefaultGadget()
  28 gadget = None
  29 hardware = None
  30 interface = None
  31 port = None
  32
  33
  34 def SwitchGadget(new_gadget):
  35   if chip.IsConfigured():
  36     chip.Destroy()
  37
  38   global gadget
  39   gadget = new_gadget
  40   gadget.AddStringDescriptor(3, address)
  41   chip.Create(gadget)
  42
  43
  44 class VersionHandler(web.RequestHandler):
  45
  46   def get(self):
  47     version = 'unpackaged'
  48     for path in sys.path:
  49       match = VERSION_PATTERN.match(path)
  50       if match:
  51         version = match.group(1)
  52         break
  53
  54     self.write(version)
  55
  56
  57 class UpdateHandler(web.RequestHandler):
  58
  59   def post(self):
  60     fileinfo = self.request.files['file'][0]
  61
  62     match = VERSION_PATTERN.match(fileinfo['filename'])
  63     if match is None:
  64       self.write('Filename must contain MD5 hash.')
  65       self.set_status(400)
  66       return
  67
  68     content = fileinfo['body']
  69     md5sum = hashlib.md5(content).hexdigest()
  70     if md5sum != match.group(1):
  71       self.write('File hash does not match.')
  72       self.set_status(400)
  73       return
  74
  75     filename = 'usb_gadget-{}.zip'.format(md5sum)
  76     with open(filename, 'wb') as f:
  77       f.write(content)
  78
  79     args = ['/usr/bin/python', filename,
  80             '--interface', interface,
  81             '--port', str(port),
  82             '--hardware', hardware]
  83     if claimed_by is not None:
  84       args.extend(['--start-claimed', claimed_by])
  85
  86     print 'Reloading with version {}...'.format(md5sum)
  87
  88     global http_server
  89     if chip.IsConfigured():
  90       chip.Destroy()
  91     http_server.stop()
  92
  93     child = subprocess.Popen(args, close_fds=True)
  94
  95     while True:
  96       child.poll()
  97       if child.returncode is not None:
  98         self.write('New package exited with error {}.'
  99                    .format(child.returncode))
 100         self.set_status(500)
 101
 102         http_server = httpserver.HTTPServer(app)
 103         http_server.listen(port)
 104         SwitchGadget(gadget)
 105         return
 106
 107       try:
 108         f = urllib2.urlopen('http://{}/version'.format(address))
 109         if f.getcode() == 200:
 110           # Update complete, wait 1 second to make sure buffers are flushed.
 111           io_loop = ioloop.IOLoop.instance()
 112           io_loop.add_timeout(datetime.timedelta(seconds=1), io_loop.stop)
 113           return
 114       except urllib2.URLError:
 115         pass
 116       time.sleep(0.1)
 117
 118
 119 class ClaimHandler(web.RequestHandler):
 120
 121   def post(self):
 122     global claimed_by
 123
 124     if claimed_by is None:
 125       claimed_by = self.get_argument('session_id')
 126     else:
 127       self.write('Device is already claimed by "{}".'.format(claimed_by))
 128       self.set_status(403)
 129
 130
 131 class UnclaimHandler(web.RequestHandler):
 132
 133   def post(self):
 134     global claimed_by
 135     claimed_by = None
 136     if gadget != default:
 137       SwitchGadget(default)
 138
 139
 140 class UnconfigureHandler(web.RequestHandler):
 141
 142   def post(self):
 143     SwitchGadget(default)
 144
 145
 146 class DisconnectHandler(web.RequestHandler):
 147
 148   def post(self):
 149     if chip.IsConfigured():
 150       chip.Destroy()
 151
 152
 153 class ReconnectHandler(web.RequestHandler):
 154
 155   def post(self):
 156     if not chip.IsConfigured():
 157       chip.Create(gadget)
 158
 159
 160 app = web.Application([
 161     (r'/version', VersionHandler),
 162     (r'/update', UpdateHandler),
 163     (r'/claim', ClaimHandler),
 164     (r'/unclaim', UnclaimHandler),
 165     (r'/unconfigure', UnconfigureHandler),
 166     (r'/disconnect', DisconnectHandler),
 167     (r'/reconnect', ReconnectHandler),
 168 ])
 169
 170 http_server = httpserver.HTTPServer(app)