xref: /btstack/src/classic/btstack_link_key_db_tlv.c (revision cbf509016daa1295a6a8b22d7314db50b88c6c9a)
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
17  *    personal benefit and not for any commercial purpose or for
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 BLUEKITCHEN
24  * GMBH 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
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "btstack_link_key_db_tlv.c"
39 
40 #include <string.h>
41 #include <stdlib.h>
42 
43 #include "classic/btstack_link_key_db_tlv.h"
44 
45 #include "btstack_debug.h"
46 #include "btstack_util.h"
47 #include "classic/core.h"
48 
49 // NVM_NUM_LINK_KEYS defines number of stored link keys
50 #ifndef NVM_NUM_LINK_KEYS
51 #error "Please set NVM_NUM_LINK_KEYS in btstack_config.h - number of link keys that can be stored in TLV"
52 #endif
53 
54 typedef struct {
55     const btstack_tlv_t * btstack_tlv_impl;
56     void * btstack_tlv_context;
57 } btstack_link_key_db_tlv_h;
58 
59 typedef struct link_key_nvm {
60     uint32_t seq_nr;    // used for "least recently stored" eviction strategy
61     bd_addr_t bd_addr;
62     link_key_t link_key;
63     link_key_type_t link_key_type;
64 } link_key_nvm_t;   // sizeof(link_key_nvm_t) = 27 bytes
65 
66 static btstack_link_key_db_tlv_h singleton;
67 static btstack_link_key_db_tlv_h * self = &singleton;
68 
69 static const char tag_0 = 'B';
70 static const char tag_1 = 'T';
71 static const char tag_2 = 'L';
72 
73 static uint32_t btstack_link_key_db_tag_for_index(uint8_t index){
74     return (tag_0 << 24) | (tag_1 << 16) | (tag_2 << 8) | index;
75 }
76 
77 // Device info
78 static void btstack_link_key_db_tlv_open(void){
79 }
80 
81 static void btstack_link_key_db_tlv_set_bd_addr(bd_addr_t bd_addr){
82     (void)bd_addr;
83 }
84 
85 static void btstack_link_key_db_tlv_close(void){
86 }
87 
88 static int btstack_link_key_db_tlv_get_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * link_key_type) {
89     int i;
90     for (i=0;i<NVM_NUM_LINK_KEYS;i++){
91         link_key_nvm_t entry;
92         uint32_t tag = btstack_link_key_db_tag_for_index(i);
93         int size = self->btstack_tlv_impl->get_tag(self->btstack_tlv_context, tag, (uint8_t*) &entry, sizeof(entry));
94         if (size == 0) continue;
95         log_info("tag %x, addr %s", (unsigned int) tag, bd_addr_to_str(entry.bd_addr));
96         if (memcmp(bd_addr, entry.bd_addr, 6)) continue;
97         // found, pass back
98         (void)memcpy(link_key, entry.link_key, 16);
99         *link_key_type = entry.link_key_type;
100         return 1;
101     }
102 	return 0;
103 }
104 
105 static void btstack_link_key_db_tlv_delete_link_key(bd_addr_t bd_addr){
106     int i;
107     for (i=0;i<NVM_NUM_LINK_KEYS;i++){
108         link_key_nvm_t entry;
109         uint32_t tag = btstack_link_key_db_tag_for_index(i);
110         int size = self->btstack_tlv_impl->get_tag(self->btstack_tlv_context, tag, (uint8_t*) &entry, sizeof(entry));
111         if (size == 0) continue;
112         if (memcmp(bd_addr, entry.bd_addr, 6)) continue;
113         // found, delete tag
114         self->btstack_tlv_impl->delete_tag(self->btstack_tlv_context, tag);
115         break;
116     }
117 }
118 
119 static void btstack_link_key_db_tlv_put_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t link_key_type){
120     int i;
121     uint32_t highest_seq_nr = 0;
122     uint32_t lowest_seq_nr = 0;
123     uint32_t tag_for_lowest_seq_nr = 0;
124     uint32_t tag_for_addr = 0;
125     uint32_t tag_for_empty = 0;
126 
127     for (i=0;i<NVM_NUM_LINK_KEYS;i++){
128         link_key_nvm_t entry;
129         uint32_t tag = btstack_link_key_db_tag_for_index(i);
130         int size = self->btstack_tlv_impl->get_tag(self->btstack_tlv_context, tag, (uint8_t*) &entry, sizeof(entry));
131         // empty/deleted tag
132         if (size == 0) {
133             tag_for_empty = tag;
134             continue;
135         }
136         // found addr?
137         if (memcmp(bd_addr, entry.bd_addr, 6) == 0){
138             tag_for_addr = tag;
139         }
140         // update highest seq nr
141         if (entry.seq_nr > highest_seq_nr){
142             highest_seq_nr = entry.seq_nr;
143         }
144         // find entry with lowest seq nr
145         if ((tag_for_lowest_seq_nr == 0) || (entry.seq_nr < lowest_seq_nr)){
146             tag_for_lowest_seq_nr = tag;
147             lowest_seq_nr = entry.seq_nr;
148         }
149     }
150 
151     log_info("tag_for_addr %x, tag_for_empy %x, tag_for_lowest_seq_nr %x",
152              (unsigned int) tag_for_addr, (unsigned int) tag_for_empty, (unsigned int) tag_for_lowest_seq_nr);
153 
154     uint32_t tag_to_use = 0;
155     if (tag_for_addr){
156         tag_to_use = tag_for_addr;
157     } else if (tag_for_empty){
158         tag_to_use = tag_for_empty;
159     } else if (tag_for_lowest_seq_nr){
160         tag_to_use = tag_for_lowest_seq_nr;
161     } else {
162         // should not happen
163         return;
164     }
165 
166     log_info("store with tag %x", (unsigned int) tag_to_use);
167 
168     link_key_nvm_t entry;
169 
170     (void)memcpy(entry.bd_addr, bd_addr, 6);
171     (void)memcpy(entry.link_key, link_key, 16);
172     entry.link_key_type = link_key_type;
173     entry.seq_nr = highest_seq_nr + 1;
174 
175     int result = self->btstack_tlv_impl->store_tag(self->btstack_tlv_context, tag_to_use, (uint8_t*) &entry, sizeof(entry));
176     if (result != 0){
177         log_error("store link key failed");
178     }
179 }
180 
181 static int btstack_link_key_db_tlv_iterator_init(btstack_link_key_iterator_t * it){
182     it->context = (void*) 0;
183     return 1;
184 }
185 
186 static int  btstack_link_key_db_tlv_iterator_get_next(btstack_link_key_iterator_t * it, bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * link_key_type){
187     uint8_t i = (uint8_t)(uintptr_t) it->context;
188     int found = 0;
189     while (i<NVM_NUM_LINK_KEYS){
190         link_key_nvm_t entry;
191         uint32_t tag = btstack_link_key_db_tag_for_index(i++);
192         int size = self->btstack_tlv_impl->get_tag(self->btstack_tlv_context, tag, (uint8_t*) &entry, sizeof(entry));
193         if (size == 0) continue;
194         (void)memcpy(bd_addr, entry.bd_addr, 6);
195         (void)memcpy(link_key, entry.link_key, 16);
196         *link_key_type = entry.link_key_type;
197         found = 1;
198         break;
199     }
200     it->context = (void*)(uintptr_t) i;
201     return found;
202 }
203 
204 static void btstack_link_key_db_tlv_iterator_done(btstack_link_key_iterator_t * it){
205     UNUSED(it);
206 }
207 
208 static const btstack_link_key_db_t btstack_link_key_db_tlv = {
209     btstack_link_key_db_tlv_open,
210     btstack_link_key_db_tlv_set_bd_addr,
211     btstack_link_key_db_tlv_close,
212     btstack_link_key_db_tlv_get_link_key,
213     btstack_link_key_db_tlv_put_link_key,
214     btstack_link_key_db_tlv_delete_link_key,
215     btstack_link_key_db_tlv_iterator_init,
216     btstack_link_key_db_tlv_iterator_get_next,
217     btstack_link_key_db_tlv_iterator_done,
218 };
219 
220 const btstack_link_key_db_t * btstack_link_key_db_tlv_get_instance(const btstack_tlv_t * btstack_tlv_impl, void * btstack_tlv_context){
221     self->btstack_tlv_impl = btstack_tlv_impl;
222     self->btstack_tlv_context = btstack_tlv_context;
223     return &btstack_link_key_db_tlv;
224 }
225 
226 
227