xref: /nrf52832-nimble/packages/NimBLE-latest/nimble/host/services/gatt/src/ble_svc_gatt.c (revision 042d53a763ad75cb1465103098bb88c245d95138)
1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements.  See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership.  The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License.  You may obtain a copy of the License at
9  *
10  *  http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied.  See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  */
19 
20 #include <assert.h>
21 
22 #include "sysinit/sysinit.h"
23 #include "host/ble_hs.h"
24 #include "services/gatt/ble_svc_gatt.h"
25 
26 static uint16_t ble_svc_gatt_changed_val_handle;
27 static uint16_t ble_svc_gatt_start_handle;
28 static uint16_t ble_svc_gatt_end_handle;
29 
30 static int
31 ble_svc_gatt_access(uint16_t conn_handle, uint16_t attr_handle,
32                     struct ble_gatt_access_ctxt *ctxt, void *arg);
33 
34 static const struct ble_gatt_svc_def ble_svc_gatt_defs[] = {
35     {
36         /*** Service: GATT */
37         .type = BLE_GATT_SVC_TYPE_PRIMARY,
38         .uuid = BLE_UUID16_DECLARE(BLE_GATT_SVC_UUID16),
39         .characteristics = (struct ble_gatt_chr_def[]) { {
40             .uuid = BLE_UUID16_DECLARE(BLE_SVC_GATT_CHR_SERVICE_CHANGED_UUID16),
41             .access_cb = ble_svc_gatt_access,
42             .val_handle = &ble_svc_gatt_changed_val_handle,
43             .flags = BLE_GATT_CHR_F_INDICATE,
44         }, {
45             0, /* No more characteristics in this service. */
46         } },
47     },
48 
49     {
50         0, /* No more services. */
51     },
52 };
53 
54 static int
ble_svc_gatt_access(uint16_t conn_handle,uint16_t attr_handle,struct ble_gatt_access_ctxt * ctxt,void * arg)55 ble_svc_gatt_access(uint16_t conn_handle, uint16_t attr_handle,
56                     struct ble_gatt_access_ctxt *ctxt, void *arg)
57 {
58     uint8_t *u8p;
59 
60     /* The only operation allowed for this characteristic is indicate.  This
61      * access callback gets called by the stack when it needs to read the
62      * characteristic value to populate the outgoing indication command.
63      * Therefore, this callback should only get called during an attempt to
64      * read the characteristic.
65      */
66     assert(ctxt->op == BLE_GATT_ACCESS_OP_READ_CHR);
67     assert(ctxt->chr == &ble_svc_gatt_defs[0].characteristics[0]);
68 
69     u8p = os_mbuf_extend(ctxt->om, 4);
70     if (u8p == NULL) {
71         return BLE_HS_ENOMEM;
72     }
73 
74     put_le16(u8p + 0, ble_svc_gatt_start_handle);
75     put_le16(u8p + 2, ble_svc_gatt_end_handle);
76 
77     return 0;
78 }
79 
80 /**
81  * Indicates a change in attribute assignment to all subscribed peers.
82  * Unconnected bonded peers receive an indication when they next connect.
83  *
84  * @param start_handle          The start of the affected handle range.
85  * @param end_handle            The end of the affected handle range.
86  */
87 void
ble_svc_gatt_changed(uint16_t start_handle,uint16_t end_handle)88 ble_svc_gatt_changed(uint16_t start_handle, uint16_t end_handle)
89 {
90     ble_svc_gatt_start_handle = start_handle;
91     ble_svc_gatt_end_handle = end_handle;
92     ble_gatts_chr_updated(ble_svc_gatt_changed_val_handle);
93 }
94 
95 void
ble_svc_gatt_init(void)96 ble_svc_gatt_init(void)
97 {
98     int rc;
99 
100     /* Ensure this function only gets called by sysinit. */
101     SYSINIT_ASSERT_ACTIVE();
102 
103     rc = ble_gatts_count_cfg(ble_svc_gatt_defs);
104     SYSINIT_PANIC_ASSERT(rc == 0);
105 
106     rc = ble_gatts_add_svcs(ble_svc_gatt_defs);
107     SYSINIT_PANIC_ASSERT(rc == 0);
108 }
109