diff --git a/wpa_supplicant/examples/dpp-nfc.py b/wpa_supplicant/examples/dpp-nfc.py index 86d4479b0..a002e08df 100755 --- a/wpa_supplicant/examples/dpp-nfc.py +++ b/wpa_supplicant/examples/dpp-nfc.py @@ -8,6 +8,7 @@ # See README for more details. import os +import struct import sys import time import threading @@ -33,6 +34,8 @@ continue_loop = True terminate_now = False summary_file = None success_file = None +my_crn = None +peer_crn = None def summary(txt): print(txt) @@ -209,11 +212,16 @@ def dpp_handover_client(llc): uri = ndef.UriRecord(uri) print("NFC URI record for DPP: " + str(uri)) carrier = ndef.Record('application/vnd.wfa.dpp', 'A', uri.data) - hr = ndef.HandoverRequestRecord(version="1.4", crn=os.urandom(2)) + crn = os.urandom(2) + hr = ndef.HandoverRequestRecord(version="1.4", crn=crn) hr.add_alternative_carrier('active', carrier.name) message = [hr, carrier] print("NFC Handover Request message for DPP: " + str(message)) + global peer_crn + if peer_crn is not None: + print("NFC handover request from peer was already received - do not send own") + return client = nfc.handover.HandoverClient(llc) try: summary("Trying to initiate NFC connection handover") @@ -228,6 +236,11 @@ def dpp_handover_client(llc): client.close() return + if peer_crn is not None: + print("NFC handover request from peer was already received - do not send own") + client.close() + return + summary("Sending handover request") if not client.send_records(message): @@ -235,6 +248,9 @@ def dpp_handover_client(llc): client.close() return + global my_crn + my_crn, = struct.unpack('>H', crn) + summary("Receiving handover response") message = client.recv_records(timeout=3.0) if message is None: @@ -335,7 +351,32 @@ class HandoverServer(nfc.handover.HandoverServer): clear_raw_mode() print("\nHandoverServer - request received: " + str(records)) - carrier = None + global my_crn, peer_crn + + for carrier in records: + if not isinstance(carrier, ndef.HandoverRequestRecord): + continue + if carrier.collision_resolution_number: + peer_crn = carrier.collision_resolution_number + print("peer_crn:", peer_crn) + + if my_crn is not None: + print("my_crn:", my_crn) + + if my_crn is not None and peer_crn is not None: + if my_crn == peer_crn: + print("Same crn used - automatic collision resolution failed") + # TODO: Should generate a new Handover Request message + return '' + if ((my_crn & 1) == (peer_crn & 1) and my_crn > peer_crn) or \ + ((my_crn & 1) != (peer_crn & 1) and my_crn < peer_crn): + print("I'm the Handover Selector Device") + pass + else: + print("Peer is the Handover Selector device") + print("Ignore the received request.") + return '' + hs = ndef.HandoverSelectRecord('1.4') sel = [hs] @@ -362,7 +403,6 @@ class HandoverServer(nfc.handover.HandoverServer): continue found = True - self.received_carrier = carrier wpas = wpas_connect() if wpas is None: @@ -585,8 +625,10 @@ def llcp_startup(llc): def llcp_connected(llc): print("P2P LLCP connected") - global wait_connection + global wait_connection, my_crn, peer_crn wait_connection = False + my_crn = None + peer_crn = None global srv srv.start() if init_on_touch or not no_input: