xref: /btstack/example/sdp_general_query.c (revision a4fe6467953bdb173fdf96a604f6527ed88f81c3)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
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18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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33  * Please inquire about commercial licensing options at
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36  */
37 
38 #define __BTSTACK_FILE__ "sdp_general_query.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(sdp_general_query): Dump remote SDP Records
42  *
43  * @text The example shows how the SDP Client is used to get a list of
44  * service records on a remote device.
45  */
46 // *****************************************************************************
47 
48 #include "btstack_config.h"
49 
50 #include <stdint.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 
55 #include "btstack.h"
56 
57 int record_id = -1;
58 int attribute_id = -1;
59 
60 static uint8_t   attribute_value[1000];
61 static const int attribute_value_buffer_size = sizeof(attribute_value);
62 static btstack_packet_callback_registration_t hci_event_callback_registration;
63 
64 /* @section SDP Client Setup
65  *
66  * @text SDP is based on L2CAP. To receive SDP query events you must register a
67  * callback, i.e. query handler, with the SPD parser, as shown in
68  * Listing SDPClientInit. Via this handler, the SDP client will receive the following events:
69  * - SDP_EVENT_QUERY_ATTRIBUTE_VALUE containing the results of the query in chunks,
70  * - SDP_EVENT_QUERY_COMPLETE indicating the end of the query and the status
71  */
72 
73 /* LISTING_START(SDPClientInit): SDP client setup */
74 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
75 static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
76 
77 static void sdp_client_init(void){
78     // init L2CAP
79     l2cap_init();
80 
81     // register for HCI events
82     hci_event_callback_registration.callback = &packet_handler;
83     hci_add_event_handler(&hci_event_callback_registration);
84 }
85 /* LISTING_END */
86 
87 /* @section SDP Client Query
88  *
89  * @text To trigger an SDP query to get the a list of service records on a remote device,
90  * you need to call sdp_client_query_uuid16() with the remote address and the
91  * UUID of the public browse group, as shown in Listing SDPQueryUUID.
92  * In this example we used fixed address of the remote device shown in Listing Remote.
93  * Please update it with the address of a device in your vicinity, e.g., one reported
94  * by the GAP Inquiry example in the previous section.
95  */
96 
97 /* LISTING_START(Remote): Address of remote device in big-endian order */
98 static bd_addr_t remote = {0x04,0x0C,0xCE,0xE4,0x85,0xD3};
99 /* LISTING_END */
100 
101 /* LISTING_START(SDPQueryUUID): Querying a list of service records on a remote device. */
102 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
103     UNUSED(channel);
104     UNUSED(size);
105 
106     if (packet_type != HCI_EVENT_PACKET) return;
107     uint8_t event = hci_event_packet_get_type(packet);
108 
109     switch (event) {
110         case BTSTACK_EVENT_STATE:
111             // BTstack activated, get started
112             if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
113                 sdp_client_query_uuid16(&handle_sdp_client_query_result, remote, BLUETOOTH_ATTRIBUTE_PUBLIC_BROWSE_ROOT);
114             }
115             break;
116         default:
117             break;
118     }
119 }
120 /* LISTING_END */
121 
122 static void assertBuffer(int size){
123     if (size > attribute_value_buffer_size){
124         printf("SDP attribute value buffer size exceeded: available %d, required %d", attribute_value_buffer_size, size);
125     }
126 }
127 
128 /* @section Handling SDP Client Query Results
129  *
130  * @text The SDP Client returns the results of the query in chunks. Each result
131  * packet contains the record ID, the Attribute ID, and a chunk of the Attribute
132  * value.
133  * In this example, we append new chunks for the same Attribute ID in a large buffer,
134  * see Listing HandleSDPQUeryResult.
135  *
136  * To save memory, it's also possible to process these chunks directly by a custom stream parser,
137  * similar to the way XML files are parsed by a SAX parser. Have a look at *src/sdp_client_rfcomm.c*
138  * which retrieves the RFCOMM channel number and the service name.
139  */
140 
141 /* LISTING_START(HandleSDPQUeryResult): Handling query result chunks. */
142 static void handle_sdp_client_query_result(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
143     UNUSED(packet_type);
144     UNUSED(channel);
145     UNUSED(size);
146 
147     switch (packet[0]){
148         case SDP_EVENT_QUERY_ATTRIBUTE_VALUE:
149             // handle new record
150             if (sdp_event_query_attribute_byte_get_record_id(packet) != record_id){
151                 record_id = sdp_event_query_attribute_byte_get_record_id(packet);
152                 printf("\n---\nRecord nr. %u\n", record_id);
153             }
154 
155             assertBuffer(sdp_event_query_attribute_byte_get_attribute_length(packet));
156 
157             attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet);
158             if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) == sdp_event_query_attribute_byte_get_attribute_length(packet)){
159                printf("Attribute 0x%04x: ", sdp_event_query_attribute_byte_get_attribute_id(packet));
160                de_dump_data_element(attribute_value);
161             }
162             break;
163         case SDP_EVENT_QUERY_COMPLETE:
164             if (sdp_event_query_complete_get_status(packet)){
165                 printf("SDP query failed 0x%02x\n", sdp_event_query_complete_get_status(packet));
166                 break;
167             }
168             printf("SDP query done.\n");
169             break;
170     }
171 }
172 /* LISTING_END */
173 
174 int btstack_main(int argc, const char * argv[]);
175 int btstack_main(int argc, const char * argv[]){
176     (void)argc;
177     (void)argv;
178 
179     printf("Client HCI init done\r\n");
180 
181     sdp_client_init();
182 
183     // turn on!
184     hci_power_control(HCI_POWER_ON);
185 
186     return 0;
187 }
188 
189 /* EXAMPLE_END */
190