xref: /btstack/example/sm_pairing_central.c (revision bace42effc5c76e7dcfa3189abae51fe2b9ebfe2)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
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15  *    from this software without specific prior written permission.
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36  */
37 
38 #define __BTSTACK_FILE__ "sm_pairing_central.c"
39 
40 
41 // *****************************************************************************
42 /* EXAMPLE_START(sm_pairing_central): LE Peripheral - Test pairing combinations
43  *
44  * @text Depending on the Authentication requiremens and IO Capabilities,
45  * the pairing process uses different short and long term key generation method.
46  * This example helps explore the different options incl. LE Secure Connections.
47  * It scans for advertisements and connects to the first device that lists a
48  * random service.
49  */
50  // *****************************************************************************
51 
52 
53 #include <stdint.h>
54 #include <inttypes.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 
59 #include "btstack.h"
60 
61 
62 // We're looking for a remote device that lists this service in the advertisement
63 // LightBlue assigns 0x1111 as the UUID for a Blank service.
64 #define REMOTE_SERVICE 0x1111
65 
66 
67 static btstack_packet_callback_registration_t hci_event_callback_registration;
68 static btstack_packet_callback_registration_t sm_event_callback_registration;
69 
70 /* @section GAP LE setup for receiving advertisements
71  *
72  * @text GAP LE advertisements are received as custom HCI events of the
73  * GAP_EVENT_ADVERTISING_REPORT type. To receive them, you'll need to register
74  * the HCI packet handler, as shown in Listing GAPLEAdvSetup.
75  */
76 
77 /* LISTING_START(GAPLEAdvSetup): Setting up GAP LE client for receiving advertisements */
78 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
79 
80 static void sm_pairing_central_setup(void){
81     hci_event_callback_registration.callback = &packet_handler;
82     hci_add_event_handler(&hci_event_callback_registration);
83 
84     l2cap_init();
85 
86     // setup le device db
87     le_device_db_init();
88 
89     // setup SM: Display only
90     sm_init();
91     sm_event_callback_registration.callback = &packet_handler;
92     sm_add_event_handler(&sm_event_callback_registration);
93 
94     /**
95      * Choose ONE of the following configurations
96      */
97 
98     // LE Legacy Pairing, Just Works
99     sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
100     sm_set_authentication_requirements(0);
101 
102     // LE Legacy Pairing, Passkey entry initiator enter, responder (us) displays
103     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);
104     // sm_set_authentication_requirements(SM_AUTHREQ_MITM_PROTECTION);
105 
106 #ifdef ENABLE_LE_SECURE_CONNECTIONS
107     // LE Secure Connetions, Just Works
108     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
109     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION);
110 
111     // LE Secure Connections, Numeric Comparison
112     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
113     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
114 
115     // LE Legacy Pairing, Passkey entry initiator enter, responder (us) displays
116     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);
117     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
118 #endif
119 }
120 
121 /* LISTING_END */
122 
123 /* @section HCI packet handler
124  *
125  * @text The HCI packet handler has to start the scanning,
126  * and to handle received advertisements. Advertisements are received
127  * as HCI event packets of the GAP_EVENT_ADVERTISING_REPORT type,
128  * see Listing GAPLEAdvPacketHandler.
129  */
130 
131 /* LISTING_START(GAPLEAdvPacketHandler): Scanning and receiving advertisements */
132 
133 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
134     UNUSED(channel);
135     UNUSED(size);
136 
137     if (packet_type != HCI_EVENT_PACKET) return;
138     hci_con_handle_t con_handle;
139 
140     switch (hci_event_packet_get_type(packet)) {
141         case BTSTACK_EVENT_STATE:
142             // BTstack activated, get started
143             if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
144                 printf("Start scaning!\n");
145                 gap_set_scan_parameters(1,0x0030, 0x0030);
146                 gap_start_scan();
147             }
148             break;
149         case GAP_EVENT_ADVERTISING_REPORT:{
150             bd_addr_t address;
151             gap_event_advertising_report_get_address(packet, address);
152             uint8_t address_type = gap_event_advertising_report_get_address_type(packet);
153             uint8_t length = gap_event_advertising_report_get_data_length(packet);
154             const uint8_t * data = gap_event_advertising_report_get_data(packet);
155             printf("Advertisement event: addr-type %u, addr %s, data[%u] ",
156                address_type, bd_addr_to_str(address), length);
157             printf_hexdump(data, length);
158             if (!ad_data_contains_uuid16(length, (uint8_t *) data, REMOTE_SERVICE)) break;
159             printf("Found remote with UUID %04x, connecting...\n", REMOTE_SERVICE);
160             gap_stop_scan();
161             gap_connect(address,address_type);
162             break;
163         }
164         case SM_EVENT_JUST_WORKS_REQUEST:
165             printf("Just works requested\n");
166             sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));
167             break;
168         case SM_EVENT_NUMERIC_COMPARISON_REQUEST:
169             printf("Confirming numeric comparison: %"PRIu32"\n", sm_event_numeric_comparison_request_get_passkey(packet));
170             sm_numeric_comparison_confirm(sm_event_passkey_display_number_get_handle(packet));
171             break;
172         case SM_EVENT_PASSKEY_DISPLAY_NUMBER:
173             printf("Display Passkey: %"PRIu32"\n", sm_event_passkey_display_number_get_passkey(packet));
174             break;
175 
176         case HCI_EVENT_LE_META:
177             // wait for connection complete
178             if (hci_event_le_meta_get_subevent_code(packet) != HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
179             con_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
180             // start pairing
181             sm_request_pairing(con_handle);
182             break;
183         default:
184             break;
185     }
186 }
187 /* LISTING_END */
188 
189 int btstack_main(void);
190 int btstack_main(void)
191 {
192     sm_pairing_central_setup();
193 
194     // turn on!
195     hci_power_control(HCI_POWER_ON);
196 
197     return 0;
198 }
199 
200 /* EXAMPLE_END */
201