wpa_supplicant/examples/p2p-nfc.py

   1 #!/usr/bin/python
   2 #
   3 # Example nfcpy to wpa_supplicant wrapper for P2P NFC operations
   4 # Copyright (c) 2012-2013, Jouni Malinen <j@w1.fi>
   5 #
   6 # This software may be distributed under the terms of the BSD license.
   7 # See README for more details.
   8
   9 import os
  10 import sys
  11 import time
  12 import random
  13 import threading
  14 import argparse
  15
  16 import nfc
  17 import nfc.ndef
  18 import nfc.llcp
  19 import nfc.handover
  20
  21 import logging
  22
  23 import wpaspy
  24
  25 wpas_ctrl = '/var/run/wpa_supplicant'
  26 ifname = None
  27 init_on_touch = False
  28 in_raw_mode = False
  29 prev_tcgetattr = 0
  30 include_wps_req = True
  31 include_p2p_req = True
  32 no_input = False
  33 srv = None
  34 continue_loop = True
  35 terminate_now = False
  36 summary_file = None
  37 success_file = None
  38
  39 def summary(txt):
  40     print txt
  41     if summary_file:
  42         with open(summary_file, 'a') as f:
  43             f.write(txt + "\n")
  44
  45 def success_report(txt):
  46     summary(txt)
  47     if success_file:
  48         with open(success_file, 'a') as f:
  49             f.write(txt + "\n")
  50
  51 def wpas_connect():
  52     ifaces = []
  53     if os.path.isdir(wpas_ctrl):
  54         try:
  55             ifaces = [os.path.join(wpas_ctrl, i) for i in os.listdir(wpas_ctrl)]
  56         except OSError as error:
  57             print "Could not find wpa_supplicant: ", error
  58             return None
  59
  60     if len(ifaces) < 1:
  61         print "No wpa_supplicant control interface found"
  62         return None
  63
  64     for ctrl in ifaces:
  65         if ifname:
  66             if ifname not in ctrl:
  67                 continue
  68         try:
  69             print "Trying to use control interface " + ctrl
  70             wpas = wpaspy.Ctrl(ctrl)
  71             return wpas
  72         except Exception as e:
  73             pass
  74     return None
  75
  76
  77 def wpas_tag_read(message):
  78     wpas = wpas_connect()
  79     if (wpas == None):
  80         return False
  81     cmd = "WPS_NFC_TAG_READ " + str(message).encode("hex")
  82     global force_freq
  83     if force_freq:
  84         cmd = cmd + " freq=" + force_freq
  85     if "FAIL" in wpas.request(cmd):
  86         return False
  87     return True
  88
  89
  90 def wpas_get_handover_req():
  91     wpas = wpas_connect()
  92     if (wpas == None):
  93         return None
  94     res = wpas.request("NFC_GET_HANDOVER_REQ NDEF P2P-CR").rstrip()
  95     if "FAIL" in res:
  96         return None
  97     return res.decode("hex")
  98
  99 def wpas_get_handover_req_wps():
 100     wpas = wpas_connect()
 101     if (wpas == None):
 102         return None
 103     res = wpas.request("NFC_GET_HANDOVER_REQ NDEF WPS-CR").rstrip()
 104     if "FAIL" in res:
 105         return None
 106     return res.decode("hex")
 107
 108
 109 def wpas_get_handover_sel(tag=False):
 110     wpas = wpas_connect()
 111     if (wpas == None):
 112         return None
 113     if tag:
 114         res = wpas.request("NFC_GET_HANDOVER_SEL NDEF P2P-CR-TAG").rstrip()
 115     else:
 116         res = wpas.request("NFC_GET_HANDOVER_SEL NDEF P2P-CR").rstrip()
 117     if "FAIL" in res:
 118         return None
 119     return res.decode("hex")
 120
 121
 122 def wpas_get_handover_sel_wps():
 123     wpas = wpas_connect()
 124     if (wpas == None):
 125         return None
 126     res = wpas.request("NFC_GET_HANDOVER_SEL NDEF WPS-CR");
 127     if "FAIL" in res:
 128         return None
 129     return res.rstrip().decode("hex")
 130
 131
 132 def wpas_report_handover(req, sel, type):
 133     wpas = wpas_connect()
 134     if (wpas == None):
 135         return None
 136     cmd = "NFC_REPORT_HANDOVER " + type + " P2P " + str(req).encode("hex") + " " + str(sel).encode("hex")
 137     global force_freq
 138     if force_freq:
 139         cmd = cmd + " freq=" + force_freq
 140     return wpas.request(cmd)
 141
 142
 143 def wpas_report_handover_wsc(req, sel, type):
 144     wpas = wpas_connect()
 145     if (wpas == None):
 146         return None
 147     cmd = "NFC_REPORT_HANDOVER " + type + " WPS " + str(req).encode("hex") + " " + str(sel).encode("hex")
 148     if force_freq:
 149         cmd = cmd + " freq=" + force_freq
 150     return wpas.request(cmd)
 151
 152
 153 def p2p_handover_client(llc):
 154     message = nfc.ndef.HandoverRequestMessage(version="1.2")
 155     message.nonce = random.randint(0, 0xffff)
 156
 157     global include_p2p_req
 158     if include_p2p_req:
 159         data = wpas_get_handover_req()
 160         if (data == None):
 161             summary("Could not get handover request carrier record from wpa_supplicant")
 162             return
 163         print "Handover request carrier record from wpa_supplicant: " + data.encode("hex")
 164         datamsg = nfc.ndef.Message(data)
 165         message.add_carrier(datamsg[0], "active", datamsg[1:])
 166
 167     global include_wps_req
 168     if include_wps_req:
 169         print "Handover request (pre-WPS):"
 170         try:
 171             print message.pretty()
 172         except Exception as e:
 173             print e
 174
 175         data = wpas_get_handover_req_wps()
 176         if data:
 177             print "Add WPS request in addition to P2P"
 178             datamsg = nfc.ndef.Message(data)
 179             message.add_carrier(datamsg[0], "active", datamsg[1:])
 180
 181     print "Handover request:"
 182     try:
 183         print message.pretty()
 184     except Exception as e:
 185         print e
 186     print str(message).encode("hex")
 187
 188     client = nfc.handover.HandoverClient(llc)
 189     try:
 190         summary("Trying to initiate NFC connection handover")
 191         client.connect()
 192         summary("Connected for handover")
 193     except nfc.llcp.ConnectRefused:
 194         summary("Handover connection refused")
 195         client.close()
 196         return
 197     except Exception as e:
 198         summary("Other exception: " + str(e))
 199         client.close()
 200         return
 201
 202     summary("Sending handover request")
 203
 204     if not client.send(message):
 205         summary("Failed to send handover request")
 206         client.close()
 207         return
 208
 209     summary("Receiving handover response")
 210     message = client._recv()
 211     if message is None:
 212         summary("No response received")
 213         client.close()
 214         return
 215     if message.type != "urn:nfc:wkt:Hs":
 216         summary("Response was not Hs - received: " + message.type)
 217         client.close()
 218         return
 219
 220     print "Received message"
 221     try:
 222         print message.pretty()
 223     except Exception as e:
 224         print e
 225     print str(message).encode("hex")
 226     message = nfc.ndef.HandoverSelectMessage(message)
 227     summary("Handover select received")
 228     try:
 229         print message.pretty()
 230     except Exception as e:
 231         print e
 232
 233     for carrier in message.carriers:
 234         print "Remote carrier type: " + carrier.type
 235         if carrier.type == "application/vnd.wfa.p2p":
 236             print "P2P carrier type match - send to wpa_supplicant"
 237             if "OK" in wpas_report_handover(data, carrier.record, "INIT"):
 238                 success_report("P2P handover reported successfully (initiator)")
 239             else:
 240                 summary("P2P handover report rejected")
 241             break
 242
 243     print "Remove peer"
 244     client.close()
 245     print "Done with handover"
 246     global only_one
 247     if only_one:
 248         print "only_one -> stop loop"
 249         global continue_loop
 250         continue_loop = False
 251
 252     global no_wait
 253     if no_wait:
 254         print "Trying to exit.."
 255         global terminate_now
 256         terminate_now = True
 257
 258
 259 class HandoverServer(nfc.handover.HandoverServer):
 260     def __init__(self, llc):
 261         super(HandoverServer, self).__init__(llc)
 262         self.sent_carrier = None
 263         self.ho_server_processing = False
 264         self.success = False
 265
 266     # override to avoid parser error in request/response.pretty() in nfcpy
 267     # due to new WSC handover format
 268     def _process_request(self, request):
 269         summary("received handover request {}".format(request.type))
 270         response = nfc.ndef.Message("\xd1\x02\x01Hs\x12")
 271         if not request.type == 'urn:nfc:wkt:Hr':
 272             summary("not a handover request")
 273         else:
 274             try:
 275                 request = nfc.ndef.HandoverRequestMessage(request)
 276             except nfc.ndef.DecodeError as e:
 277                 summary("error decoding 'Hr' message: {}".format(e))
 278             else:
 279                 response = self.process_request(request)
 280         summary("send handover response {}".format(response.type))
 281         return response
 282
 283     def process_request(self, request):
 284         self.ho_server_processing = True
 285         clear_raw_mode()
 286         print "HandoverServer - request received"
 287         try:
 288             print "Parsed handover request: " + request.pretty()
 289         except Exception as e:
 290             print e
 291
 292         sel = nfc.ndef.HandoverSelectMessage(version="1.2")
 293
 294         found = False
 295
 296         for carrier in request.carriers:
 297             print "Remote carrier type: " + carrier.type
 298             if carrier.type == "application/vnd.wfa.p2p":
 299                 print "P2P carrier type match - add P2P carrier record"
 300                 found = True
 301                 self.received_carrier = carrier.record
 302                 print "Carrier record:"
 303                 try:
 304                     print carrier.record.pretty()
 305                 except Exception as e:
 306                     print e
 307                 data = wpas_get_handover_sel()
 308                 if data is None:
 309                     print "Could not get handover select carrier record from wpa_supplicant"
 310                     continue
 311                 print "Handover select carrier record from wpa_supplicant:"
 312                 print data.encode("hex")
 313                 self.sent_carrier = data
 314                 if "OK" in wpas_report_handover(self.received_carrier, self.sent_carrier, "RESP"):
 315                     success_report("P2P handover reported successfully (responder)")
 316                 else:
 317                     summary("P2P handover report rejected")
 318                     break
 319
 320                 message = nfc.ndef.Message(data);
 321                 sel.add_carrier(message[0], "active", message[1:])
 322                 break
 323
 324         for carrier in request.carriers:
 325             if found:
 326                 break
 327             print "Remote carrier type: " + carrier.type
 328             if carrier.type == "application/vnd.wfa.wsc":
 329                 print "WSC carrier type match - add WSC carrier record"
 330                 found = True
 331                 self.received_carrier = carrier.record
 332                 print "Carrier record:"
 333                 try:
 334                     print carrier.record.pretty()
 335                 except Exception as e:
 336                     print e
 337                 data = wpas_get_handover_sel_wps()
 338                 if data is None:
 339                     print "Could not get handover select carrier record from wpa_supplicant"
 340                     continue
 341                 print "Handover select carrier record from wpa_supplicant:"
 342                 print data.encode("hex")
 343                 self.sent_carrier = data
 344                 if "OK" in wpas_report_handover_wsc(self.received_carrier, self.sent_carrier, "RESP"):
 345                     success_report("WSC handover reported successfully")
 346                 else:
 347                     summary("WSC handover report rejected")
 348                     break
 349
 350                 message = nfc.ndef.Message(data);
 351                 sel.add_carrier(message[0], "active", message[1:])
 352                 found = True
 353                 break
 354
 355         print "Handover select:"
 356         try:
 357             print sel.pretty()
 358         except Exception as e:
 359             print e
 360         print str(sel).encode("hex")
 361
 362         summary("Sending handover select")
 363         self.success = True
 364         return sel
 365
 366
 367 def clear_raw_mode():
 368     import sys, tty, termios
 369     global prev_tcgetattr, in_raw_mode
 370     if not in_raw_mode:
 371         return
 372     fd = sys.stdin.fileno()
 373     termios.tcsetattr(fd, termios.TCSADRAIN, prev_tcgetattr)
 374     in_raw_mode = False
 375
 376
 377 def getch():
 378     import sys, tty, termios, select
 379     global prev_tcgetattr, in_raw_mode
 380     fd = sys.stdin.fileno()
 381     prev_tcgetattr = termios.tcgetattr(fd)
 382     ch = None
 383     try:
 384         tty.setraw(fd)
 385         in_raw_mode = True
 386         [i, o, e] = select.select([fd], [], [], 0.05)
 387         if i:
 388             ch = sys.stdin.read(1)
 389     finally:
 390         termios.tcsetattr(fd, termios.TCSADRAIN, prev_tcgetattr)
 391         in_raw_mode = False
 392     return ch
 393
 394
 395 def p2p_tag_read(tag):
 396     success = False
 397     if len(tag.ndef.message):
 398         for record in tag.ndef.message:
 399             print "record type " + record.type
 400             if record.type == "application/vnd.wfa.wsc":
 401                 summary("WPS tag - send to wpa_supplicant")
 402                 success = wpas_tag_read(tag.ndef.message)
 403                 break
 404             if record.type == "application/vnd.wfa.p2p":
 405                 summary("P2P tag - send to wpa_supplicant")
 406                 success = wpas_tag_read(tag.ndef.message)
 407                 break
 408     else:
 409         summary("Empty tag")
 410
 411     if success:
 412         success_report("Tag read succeeded")
 413
 414     return success
 415
 416
 417 def rdwr_connected_p2p_write(tag):
 418     summary("Tag found - writing - " + str(tag))
 419     global p2p_sel_data
 420     tag.ndef.message = str(p2p_sel_data)
 421     success_report("Tag write succeeded")
 422     print "Done - remove tag"
 423     global only_one
 424     if only_one:
 425         global continue_loop
 426         continue_loop = False
 427     global p2p_sel_wait_remove
 428     return p2p_sel_wait_remove
 429
 430 def wps_write_p2p_handover_sel(clf, wait_remove=True):
 431     print "Write P2P handover select"
 432     data = wpas_get_handover_sel(tag=True)
 433     if (data == None):
 434         summary("Could not get P2P handover select from wpa_supplicant")
 435         return
 436
 437     global p2p_sel_wait_remove
 438     p2p_sel_wait_remove = wait_remove
 439     global p2p_sel_data
 440     p2p_sel_data = nfc.ndef.HandoverSelectMessage(version="1.2")
 441     message = nfc.ndef.Message(data);
 442     p2p_sel_data.add_carrier(message[0], "active", message[1:])
 443     print "Handover select:"
 444     try:
 445         print p2p_sel_data.pretty()
 446     except Exception as e:
 447         print e
 448     print str(p2p_sel_data).encode("hex")
 449
 450     print "Touch an NFC tag"
 451     clf.connect(rdwr={'on-connect': rdwr_connected_p2p_write})
 452
 453
 454 def rdwr_connected(tag):
 455     global only_one, no_wait
 456     summary("Tag connected: " + str(tag))
 457
 458     if tag.ndef:
 459         print "NDEF tag: " + tag.type
 460         try:
 461             print tag.ndef.message.pretty()
 462         except Exception as e:
 463             print e
 464         success = p2p_tag_read(tag)
 465         if only_one and success:
 466             global continue_loop
 467             continue_loop = False
 468     else:
 469         summary("Not an NDEF tag - remove tag")
 470         return True
 471
 472     return not no_wait
 473
 474
 475 def llcp_worker(llc):
 476     global init_on_touch
 477     if init_on_touch:
 478             print "Starting handover client"
 479             p2p_handover_client(llc)
 480             return
 481
 482     global no_input
 483     if no_input:
 484         print "Wait for handover to complete"
 485     else:
 486         print "Wait for handover to complete - press 'i' to initiate ('w' for WPS only, 'p' for P2P only)"
 487     global srv
 488     global wait_connection
 489     while not wait_connection and srv.sent_carrier is None:
 490         if srv.ho_server_processing:
 491             time.sleep(0.025)
 492         elif no_input:
 493             time.sleep(0.5)
 494         else:
 495             global include_wps_req, include_p2p_req
 496             res = getch()
 497             if res == 'i':
 498                 include_wps_req = True
 499                 include_p2p_req = True
 500             elif res == 'p':
 501                 include_wps_req = False
 502                 include_p2p_req = True
 503             elif res == 'w':
 504                 include_wps_req = True
 505                 include_p2p_req = False
 506             else:
 507                 continue
 508             clear_raw_mode()
 509             print "Starting handover client"
 510             p2p_handover_client(llc)
 511             return
 512
 513     clear_raw_mode()
 514     print "Exiting llcp_worker thread"
 515
 516 def llcp_startup(clf, llc):
 517     print "Start LLCP server"
 518     global srv
 519     srv = HandoverServer(llc)
 520     return llc
 521
 522 def llcp_connected(llc):
 523     print "P2P LLCP connected"
 524     global wait_connection
 525     wait_connection = False
 526     global init_on_touch
 527     if not init_on_touch:
 528         global srv
 529         srv.start()
 530     if init_on_touch or not no_input:
 531         threading.Thread(target=llcp_worker, args=(llc,)).start()
 532     return True
 533
 534 def terminate_loop():
 535     global terminate_now
 536     return terminate_now
 537
 538 def main():
 539     clf = nfc.ContactlessFrontend()
 540
 541     parser = argparse.ArgumentParser(description='nfcpy to wpa_supplicant integration for P2P and WPS NFC operations')
 542     parser.add_argument('-d', const=logging.DEBUG, default=logging.INFO,
 543                         action='store_const', dest='loglevel',
 544                         help='verbose debug output')
 545     parser.add_argument('-q', const=logging.WARNING, action='store_const',
 546                         dest='loglevel', help='be quiet')
 547     parser.add_argument('--only-one', '-1', action='store_true',
 548                         help='run only one operation and exit')
 549     parser.add_argument('--init-on-touch', '-I', action='store_true',
 550                         help='initiate handover on touch')
 551     parser.add_argument('--no-wait', action='store_true',
 552                         help='do not wait for tag to be removed before exiting')
 553     parser.add_argument('--ifname', '-i',
 554                         help='network interface name')
 555     parser.add_argument('--no-wps-req', '-N', action='store_true',
 556                         help='do not include WPS carrier record in request')
 557     parser.add_argument('--no-input', '-a', action='store_true',
 558                         help='do not use stdout input to initiate handover')
 559     parser.add_argument('--tag-read-only', '-t', action='store_true',
 560                         help='tag read only (do not allow connection handover)')
 561     parser.add_argument('--handover-only', action='store_true',
 562                         help='connection handover only (do not allow tag read)')
 563     parser.add_argument('--freq', '-f',
 564                         help='forced frequency of operating channel in MHz')
 565     parser.add_argument('--summary',
 566                         help='summary file for writing status updates')
 567     parser.add_argument('--success',
 568                         help='success file for writing success update')
 569     parser.add_argument('command', choices=['write-p2p-sel'],
 570                         nargs='?')
 571     args = parser.parse_args()
 572
 573     global only_one
 574     only_one = args.only_one
 575
 576     global no_wait
 577     no_wait = args.no_wait
 578
 579     global force_freq
 580     force_freq = args.freq
 581
 582     logging.basicConfig(level=args.loglevel)
 583
 584     global init_on_touch
 585     init_on_touch = args.init_on_touch
 586
 587     if args.ifname:
 588         global ifname
 589         ifname = args.ifname
 590         print "Selected ifname " + ifname
 591
 592     if args.no_wps_req:
 593         global include_wps_req
 594         include_wps_req = False
 595
 596     if args.summary:
 597         global summary_file
 598         summary_file = args.summary
 599
 600     if args.success:
 601         global success_file
 602         success_file = args.success
 603
 604     if args.no_input:
 605         global no_input
 606         no_input = True
 607
 608     clf = nfc.ContactlessFrontend()
 609     global wait_connection
 610
 611     try:
 612         if not clf.open("usb"):
 613             print "Could not open connection with an NFC device"
 614             raise SystemExit
 615
 616         if args.command == "write-p2p-sel":
 617             wps_write_p2p_handover_sel(clf, wait_remove=not args.no_wait)
 618             raise SystemExit
 619
 620         global continue_loop
 621         while continue_loop:
 622             print "Waiting for a tag or peer to be touched"
 623             wait_connection = True
 624             try:
 625                 if args.tag_read_only:
 626                     if not clf.connect(rdwr={'on-connect': rdwr_connected}):
 627                         break
 628                 elif args.handover_only:
 629                     if not clf.connect(llcp={'on-startup': llcp_startup,
 630                                              'on-connect': llcp_connected},
 631                                        terminate=terminate_loop):
 632                         break
 633                 else:
 634                     if not clf.connect(rdwr={'on-connect': rdwr_connected},
 635                                        llcp={'on-startup': llcp_startup,
 636                                              'on-connect': llcp_connected},
 637                                        terminate=terminate_loop):
 638                         break
 639             except Exception as e:
 640                 print "clf.connect failed"
 641
 642             global srv
 643             if only_one and srv and srv.success:
 644                 raise SystemExit
 645
 646     except KeyboardInterrupt:
 647         raise SystemExit
 648     finally:
 649         clf.close()
 650
 651     raise SystemExit
 652
 653 if __name__ == '__main__':
 654     main()