xref: /btstack/platform/posix/btstack_link_key_db_fs.c (revision ab2c6ae4b737d5e801d3defe4117331eb244ebb7)
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 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
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_fs.c"
39 
40 #include <string.h>
41 #include <stdlib.h>
42 #include <stdio.h>
43 #include <unistd.h>
44 
45 #include "btstack_link_key_db_fs.h"
46 #include "btstack_debug.h"
47 
48 #include "btstack_util.h"
49 
50 #ifdef _WIN32
51 #define LINK_KEY_PATH ""
52 #else
53 #define LINK_KEY_PATH "/tmp/"
54 #endif
55 #define LINK_KEY_PREFIX "btstack_at_"
56 #define LINK_KEY_FOR "_link_key_for_"
57 #define LINK_KEY_SUFFIX ".txt"
58 #define LINK_KEY_STRING_LEN 17
59 
60 static bd_addr_t local_addr;
61 // note: sizeof for string literals works at compile time while strlen only works with some optimizations turned on. sizeof inlcudes the  \0
62 static char keypath[sizeof(LINK_KEY_PATH) + sizeof(LINK_KEY_PREFIX) + LINK_KEY_STRING_LEN + sizeof(LINK_KEY_FOR) + LINK_KEY_STRING_LEN + sizeof(LINK_KEY_SUFFIX) + 1];
63 
64 static char bd_addr_to_dash_str_buffer[6*3];  // 12-45-78-01-34-67\0
65 static char * bd_addr_to_dash_str(bd_addr_t addr){
66     char * p = bd_addr_to_dash_str_buffer;
67     int i;
68     for (i = 0; i < 6 ; i++) {
69         *p++ = char_for_nibble((addr[i] >> 4) & 0x0F);
70         *p++ = char_for_nibble((addr[i] >> 0) & 0x0F);
71         *p++ = '-';
72     }
73     *--p = 0;
74     return (char *) bd_addr_to_dash_str_buffer;
75 }
76 
77 static char link_key_to_str_buffer[LINK_KEY_STR_LEN+1];  // 11223344556677889900112233445566\0
78 char *link_key_to_str(link_key_t link_key){
79     char * p = link_key_to_str_buffer;
80     int i;
81     for (i = 0; i < LINK_KEY_LEN ; i++) {
82         *p++ = char_for_nibble((link_key[i] >> 4) & 0x0F);
83         *p++ = char_for_nibble((link_key[i] >> 0) & 0x0F);
84     }
85     *p = 0;
86     return (char *) link_key_to_str_buffer;
87 }
88 
89 static char link_key_type_to_str_buffer[2];
90 char *link_key_type_to_str(link_key_type_t link_key){
91     snprintf(link_key_type_to_str_buffer, sizeof(link_key_type_to_str_buffer), "%d", link_key);
92     return (char *) link_key_type_to_str_buffer;
93 }
94 
95 int sscanf_link_key(char * addr_string, link_key_t link_key){
96     unsigned int buffer[LINK_KEY_LEN];
97 
98     // reset result buffer
99     memset(&buffer, 0, sizeof(buffer));
100 
101     // parse
102     int result = sscanf( (char *) addr_string, "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
103                                     &buffer[0], &buffer[1], &buffer[2], &buffer[3],
104                                     &buffer[4], &buffer[5], &buffer[6], &buffer[7],
105                                     &buffer[8], &buffer[9], &buffer[10], &buffer[11],
106                                     &buffer[12], &buffer[13], &buffer[14], &buffer[15] );
107 
108     if (result != LINK_KEY_LEN) return 0;
109 
110     // store
111     int i;
112     uint8_t *p = (uint8_t *) link_key;
113     for (i=0; i<LINK_KEY_LEN; i++ ) {
114         *p++ = (uint8_t) buffer[i];
115     }
116     return 1;
117 }
118 
119 static void set_path(bd_addr_t bd_addr){
120     strcpy(keypath, LINK_KEY_PATH);
121     strcat(keypath, LINK_KEY_PREFIX);
122     strcat(keypath, bd_addr_to_dash_str(local_addr));
123     strcat(keypath, LINK_KEY_FOR);
124     strcat(keypath, bd_addr_to_dash_str(bd_addr));
125     strcat(keypath, LINK_KEY_SUFFIX);
126 }
127 
128 // Device info
129 static void db_open(void){
130 }
131 
132 static void db_set_local_bd_addr(bd_addr_t bd_addr){
133     memcpy(local_addr, bd_addr, 6);
134 }
135 
136 static void db_close(void){
137 }
138 
139 static void put_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t link_key_type){
140     set_path(bd_addr);
141     char * link_key_str = link_key_to_str(link_key);
142     char * link_key_type_str = link_key_type_to_str(link_key_type);
143 
144     FILE * wFile = fopen(keypath,"w+");
145     fwrite(link_key_str, strlen(link_key_str), 1, wFile);
146     fwrite(link_key_type_str, strlen(link_key_type_str), 1, wFile);
147     fclose(wFile);
148 }
149 
150 static int get_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * link_key_type) {
151     set_path(bd_addr);
152     if (access(keypath, R_OK)) return 0;
153 
154     char link_key_str[LINK_KEY_STR_LEN + 1];
155     char link_key_type_str[2];
156 
157     FILE * rFile = fopen(keypath,"r+");
158     size_t objects_read = fread(link_key_str, LINK_KEY_STR_LEN, 1, rFile );
159     if (objects_read == 1){
160         link_key_str[LINK_KEY_STR_LEN] = 0;
161         log_info("Found link key %s\n", link_key_str);
162         objects_read = fread(link_key_type_str, 1, 1, rFile );
163     }
164     fclose(rFile);
165 
166     if (objects_read != 1) return 0;
167     link_key_type_str[1] = 0;
168     log_info("Found link key type %s\n", link_key_type_str);
169 
170     int scan_result = sscanf_link_key(link_key_str, link_key);
171     if (scan_result == 0 ) return 0;
172 
173     int link_key_type_buffer;
174     scan_result = sscanf( (char *) link_key_type_str, "%d", &link_key_type_buffer);
175     if (scan_result == 0 ) return 0;
176     *link_key_type = (link_key_type_t) link_key_type_buffer;
177     return 1;
178 }
179 
180 static void delete_link_key(bd_addr_t bd_addr){
181     set_path(bd_addr);
182     if (access(keypath, R_OK)) return;
183 
184     if(remove(keypath) != 0){
185         log_error("File %s could not be deleted.\n", keypath);
186     }
187 }
188 
189 const btstack_link_key_db_t btstack_link_key_db_fs = {
190     &db_open,
191     &db_set_local_bd_addr,
192     &db_close,
193     &get_link_key,
194     &put_link_key,
195     &delete_link_key,
196 };
197 
198 const btstack_link_key_db_t * btstack_link_key_db_fs_instance(void){
199     return &btstack_link_key_db_fs;
200 }
201 
202 
203