xref: /btstack/example/sm_pairing_central.c (revision bc37f7b0d0a3eaa5763a873c5730bc14b849aaa0)
1 /*
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37 
38 
39 // *****************************************************************************
40 /* EXAMPLE_START(sm_pairing_central): LE Peripheral - Test pairing combinations
41  *
42  * @text Depending on the Authentication requiremens and IO Capabilities,
43  * the pairing process uses different short and long term key generation method.
44  * This example helps explore the different options incl. LE Secure Connections.
45  * It scans for advertisements and connects to the first device that lists a
46  * random service.
47  */
48  // *****************************************************************************
49 
50 
51 #include <stdint.h>
52 #include <inttypes.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 
57 #include "btstack.h"
58 
59 
60 // We're looking for a remote device that lists this service in the advertisement
61 // LightBlue assigns 0x1111 as the UUID for a Blank service.
62 #define REMOTE_SERVICE 0x1111
63 
64 
65 static btstack_packet_callback_registration_t hci_event_callback_registration;
66 static btstack_packet_callback_registration_t sm_event_callback_registration;
67 
68 /* @section GAP LE setup for receiving advertisements
69  *
70  * @text GAP LE advertisements are received as custom HCI events of the
71  * GAP_EVENT_ADVERTISING_REPORT type. To receive them, you'll need to register
72  * the HCI packet handler, as shown in Listing GAPLEAdvSetup.
73  */
74 
75 /* LISTING_START(GAPLEAdvSetup): Setting up GAP LE client for receiving advertisements */
76 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
77 
78 static void sm_pairing_central_setup(void){
79     hci_event_callback_registration.callback = &packet_handler;
80     hci_add_event_handler(&hci_event_callback_registration);
81 
82     l2cap_init();
83 
84     // setup le device db
85     le_device_db_init();
86 
87     // setup SM: Display only
88     sm_init();
89     sm_event_callback_registration.callback = &packet_handler;
90     sm_add_event_handler(&sm_event_callback_registration);
91 
92     /**
93      * Choose ONE of the following configurations
94      */
95 
96     // LE Legacy Pairing, Just Works
97     sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
98     sm_set_authentication_requirements(0);
99 
100     // LE Legacy Pairing, Passkey entry initiator enter, responder (us) displays
101     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);
102     // sm_set_authentication_requirements(SM_AUTHREQ_MITM_PROTECTION);
103 
104 #ifdef ENABLE_LE_SECURE_CONNECTIONS
105     // LE Secure Connetions, Just Works
106     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
107     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION);
108 
109     // LE Secure Connections, Numeric Comparison
110     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
111     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
112 
113     // LE Legacy Pairing, Passkey entry initiator enter, responder (us) displays
114     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);
115     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
116 #endif
117 }
118 
119 /* LISTING_END */
120 
121 /* @section HCI packet handler
122  *
123  * @text The HCI packet handler has to start the scanning,
124  * and to handle received advertisements. Advertisements are received
125  * as HCI event packets of the GAP_EVENT_ADVERTISING_REPORT type,
126  * see Listing GAPLEAdvPacketHandler.
127  */
128 
129 /* LISTING_START(GAPLEAdvPacketHandler): Scanning and receiving advertisements */
130 
131 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
132     if (packet_type != HCI_EVENT_PACKET) return;
133     hci_con_handle_t con_handle;
134 
135     switch (hci_event_packet_get_type(packet)) {
136         case BTSTACK_EVENT_STATE:
137             // BTstack activated, get started
138             if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
139                 printf("Start scaning!\n");
140                 gap_set_scan_parameters(1,0x0030, 0x0030);
141                 gap_start_scan();
142             }
143             break;
144         case GAP_EVENT_ADVERTISING_REPORT:{
145             bd_addr_t address;
146             gap_event_advertising_report_get_address(packet, address);
147             uint8_t address_type = gap_event_advertising_report_get_address_type(packet);
148             uint8_t length = gap_event_advertising_report_get_data_length(packet);
149             const uint8_t * data = gap_event_advertising_report_get_data(packet);
150             printf("Advertisement event: addr-type %u, addr %s, data[%u] ",
151                address_type, bd_addr_to_str(address), length);
152             printf_hexdump(data, length);
153             if (!ad_data_contains_uuid16(length, (uint8_t *) data, REMOTE_SERVICE)) break;
154             printf("Found remote with UUID %04x, connecting...\n", REMOTE_SERVICE);
155             gap_stop_scan();
156             gap_connect(address,address_type);
157             break;
158         }
159         case SM_EVENT_JUST_WORKS_REQUEST:
160             printf("Just works requested\n");
161             sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));
162             break;
163         case SM_EVENT_NUMERIC_COMPARISON_REQUEST:
164             printf("Confirming numeric comparison: %u\n", sm_event_numeric_comparison_request_get_passkey(packet));
165             sm_numeric_comparison_confirm(sm_event_passkey_display_number_get_handle(packet));
166             break;
167         case SM_EVENT_PASSKEY_DISPLAY_NUMBER:
168             printf("Display Passkey: %u\n", sm_event_passkey_display_number_get_passkey(packet));
169             break;
170 
171         case HCI_EVENT_LE_META:
172             // wait for connection complete
173             if (hci_event_le_meta_get_subevent_code(packet) != HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
174             con_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
175             // start pairing
176             sm_request_pairing(con_handle);
177             break;
178         default:
179             break;
180     }
181 }
182 /* LISTING_END */
183 
184 int btstack_main(void);
185 int btstack_main(void)
186 {
187     sm_pairing_central_setup();
188 
189     // turn on!
190     hci_power_control(HCI_POWER_ON);
191 
192     return 0;
193 }
194 
195 /* EXAMPLE_END */
196