xref: /btstack/platform/posix/btstack_link_key_db_fs.c (revision f12924e0a61c0582b548a1e70cea1bd59ba21f1d)
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 #include <string.h>
39 #include <stdlib.h>
40 #include <stdio.h>
41 #include <unistd.h>
42 
43 #include "btstack_link_key_db_fs.h"
44 #include "btstack_debug.h"
45 
46 #include "btstack_util.h"
47 
48 #ifdef _WIN32
49 #define LINK_KEY_PATH ""
50 #else
51 #define LINK_KEY_PATH "/tmp/"
52 #endif
53 #define LINK_KEY_PREFIX "btstack_at_"
54 #define LINK_KEY_FOR "_link_key_for_"
55 #define LINK_KEY_SUFFIX ".txt"
56 #define LINK_KEY_STRING_LEN 17
57 
58 static bd_addr_t local_addr;
59 // note: sizeof for string literals works at compile time while strlen only works with some optimizations turned on. sizeof inlcudes the  \0
60 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];
61 
62 static char bd_addr_to_dash_str_buffer[6*3];  // 12-45-78-01-34-67\0
63 static char * bd_addr_to_dash_str(bd_addr_t addr){
64     char * p = bd_addr_to_dash_str_buffer;
65     int i;
66     for (i = 0; i < 6 ; i++) {
67         *p++ = char_for_nibble((addr[i] >> 4) & 0x0F);
68         *p++ = char_for_nibble((addr[i] >> 0) & 0x0F);
69         *p++ = '-';
70     }
71     *--p = 0;
72     return (char *) bd_addr_to_dash_str_buffer;
73 }
74 
75 static char link_key_to_str_buffer[LINK_KEY_STR_LEN+1];  // 11223344556677889900112233445566\0
76 char *link_key_to_str(link_key_t link_key){
77     char * p = link_key_to_str_buffer;
78     int i;
79     for (i = 0; i < LINK_KEY_LEN ; i++) {
80         *p++ = char_for_nibble((link_key[i] >> 4) & 0x0F);
81         *p++ = char_for_nibble((link_key[i] >> 0) & 0x0F);
82     }
83     *p = 0;
84     return (char *) link_key_to_str_buffer;
85 }
86 
87 static char link_key_type_to_str_buffer[2];
88 char *link_key_type_to_str(link_key_type_t link_key){
89     snprintf(link_key_type_to_str_buffer, sizeof(link_key_type_to_str_buffer), "%d", link_key);
90     return (char *) link_key_type_to_str_buffer;
91 }
92 
93 int sscanf_link_key(char * addr_string, link_key_t link_key){
94     unsigned int buffer[LINK_KEY_LEN];
95 
96     // reset result buffer
97     memset(&buffer, 0, sizeof(buffer));
98 
99     // parse
100     int result = sscanf( (char *) addr_string, "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
101                                     &buffer[0], &buffer[1], &buffer[2], &buffer[3],
102                                     &buffer[4], &buffer[5], &buffer[6], &buffer[7],
103                                     &buffer[8], &buffer[9], &buffer[10], &buffer[11],
104                                     &buffer[12], &buffer[13], &buffer[14], &buffer[15] );
105 
106     if (result != LINK_KEY_LEN) return 0;
107 
108     // store
109     int i;
110     uint8_t *p = (uint8_t *) link_key;
111     for (i=0; i<LINK_KEY_LEN; i++ ) {
112         *p++ = (uint8_t) buffer[i];
113     }
114     return 1;
115 }
116 
117 static void set_path(bd_addr_t bd_addr){
118     strcpy(keypath, LINK_KEY_PATH);
119     strcat(keypath, LINK_KEY_PREFIX);
120     strcat(keypath, bd_addr_to_dash_str(local_addr));
121     strcat(keypath, LINK_KEY_FOR);
122     strcat(keypath, bd_addr_to_dash_str(bd_addr));
123     strcat(keypath, LINK_KEY_SUFFIX);
124 }
125 
126 // Device info
127 static void db_open(void){
128 }
129 
130 static void db_set_local_bd_addr(bd_addr_t bd_addr){
131     memcpy(local_addr, bd_addr, 6);
132 }
133 
134 static void db_close(void){
135 }
136 
137 static void put_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t link_key_type){
138     set_path(bd_addr);
139     char * link_key_str = link_key_to_str(link_key);
140     char * link_key_type_str = link_key_type_to_str(link_key_type);
141 
142     FILE * wFile = fopen(keypath,"w+");
143     fwrite(link_key_str, strlen(link_key_str), 1, wFile);
144     fwrite(link_key_type_str, strlen(link_key_type_str), 1, wFile);
145     fclose(wFile);
146 }
147 
148 static int get_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * link_key_type) {
149     set_path(bd_addr);
150     if (access(keypath, R_OK)) return 0;
151 
152     char link_key_str[LINK_KEY_STR_LEN + 1];
153     char link_key_type_str[2];
154 
155     FILE * rFile = fopen(keypath,"r+");
156     size_t objects_read = fread(link_key_str, LINK_KEY_STR_LEN, 1, rFile );
157     if (objects_read == 1){
158         link_key_str[LINK_KEY_STR_LEN] = 0;
159         log_info("Found link key %s\n", link_key_str);
160         objects_read = fread(link_key_type_str, 1, 1, rFile );
161     }
162     fclose(rFile);
163 
164     if (objects_read != 1) return 0;
165     link_key_type_str[1] = 0;
166     log_info("Found link key type %s\n", link_key_type_str);
167 
168     int scan_result = sscanf_link_key(link_key_str, link_key);
169     if (scan_result == 0 ) return 0;
170 
171     int link_key_type_buffer;
172     scan_result = sscanf( (char *) link_key_type_str, "%d", &link_key_type_buffer);
173     if (scan_result == 0 ) return 0;
174     *link_key_type = (link_key_type_t) link_key_type_buffer;
175     return 1;
176 }
177 
178 static void delete_link_key(bd_addr_t bd_addr){
179     set_path(bd_addr);
180     if (access(keypath, R_OK)) return;
181 
182     if(remove(keypath) != 0){
183         log_error("File %s could not be deleted.\n", keypath);
184     }
185 }
186 
187 const btstack_link_key_db_t btstack_link_key_db_fs = {
188     &db_open,
189     &db_set_local_bd_addr,
190     &db_close,
191     &get_link_key,
192     &put_link_key,
193     &delete_link_key,
194 };
195 
196 const btstack_link_key_db_t * btstack_link_key_db_fs_instance(void){
197     return &btstack_link_key_db_fs;
198 }
199 
200 
201