xref: /btstack/platform/posix/btstack_link_key_db_fs.c (revision bc37f7b0d0a3eaa5763a873c5730bc14b849aaa0)
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 #define LINK_KEY_PATH "/tmp/"
49 #define LINK_KEY_PREFIX "btstack_at_"
50 #define LINK_KEY_FOR "_link_key_for_"
51 #define LINK_KEY_SUFFIX ".txt"
52 #define LINK_KEY_STRING_LEN 17
53 
54 static bd_addr_t local_addr;
55 // note: sizeof for string literals works at compile time while strlen only works with some optimizations turned on. sizeof inlcudes the  \0
56 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];
57 
58 static char bd_addr_to_dash_str_buffer[6*3];  // 12-45-78-01-34-67\0
59 static char * bd_addr_to_dash_str(bd_addr_t addr){
60     char * p = bd_addr_to_dash_str_buffer;
61     int i;
62     for (i = 0; i < 6 ; i++) {
63         *p++ = char_for_nibble((addr[i] >> 4) & 0x0F);
64         *p++ = char_for_nibble((addr[i] >> 0) & 0x0F);
65         *p++ = '-';
66     }
67     *--p = 0;
68     return (char *) bd_addr_to_dash_str_buffer;
69 }
70 
71 static char link_key_to_str_buffer[LINK_KEY_STR_LEN+1];  // 11223344556677889900112233445566\0
72 char *link_key_to_str(link_key_t link_key){
73     char * p = link_key_to_str_buffer;
74     int i;
75     for (i = 0; i < LINK_KEY_LEN ; i++) {
76         *p++ = char_for_nibble((link_key[i] >> 4) & 0x0F);
77         *p++ = char_for_nibble((link_key[i] >> 0) & 0x0F);
78     }
79     *p = 0;
80     return (char *) link_key_to_str_buffer;
81 }
82 
83 static char link_key_type_to_str_buffer[2];
84 char *link_key_type_to_str(link_key_type_t link_key){
85     snprintf(link_key_type_to_str_buffer, sizeof(link_key_type_to_str_buffer), "%d", link_key);
86     return (char *) link_key_type_to_str_buffer;
87 }
88 
89 int sscanf_link_key(char * addr_string, link_key_t link_key){
90     unsigned int buffer[LINK_KEY_LEN];
91 
92     // reset result buffer
93     memset(&buffer, 0, sizeof(buffer));
94 
95     // parse
96     int result = sscanf( (char *) addr_string, "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
97                                     &buffer[0], &buffer[1], &buffer[2], &buffer[3],
98                                     &buffer[4], &buffer[5], &buffer[6], &buffer[7],
99                                     &buffer[8], &buffer[9], &buffer[10], &buffer[11],
100                                     &buffer[12], &buffer[13], &buffer[14], &buffer[15] );
101 
102     if (result != LINK_KEY_LEN) return 0;
103 
104     // store
105     int i;
106     uint8_t *p = (uint8_t *) link_key;
107     for (i=0; i<LINK_KEY_LEN; i++ ) {
108         *p++ = (uint8_t) buffer[i];
109     }
110     return 1;
111 }
112 
113 static void set_path(bd_addr_t bd_addr){
114     strcpy(keypath, LINK_KEY_PATH);
115     strcat(keypath, LINK_KEY_PREFIX);
116     strcat(keypath, bd_addr_to_dash_str(local_addr));
117     strcat(keypath, LINK_KEY_FOR);
118     strcat(keypath, bd_addr_to_dash_str(bd_addr));
119     strcat(keypath, LINK_KEY_SUFFIX);
120 }
121 
122 // Device info
123 static void db_open(void){
124 }
125 
126 static void db_set_local_bd_addr(bd_addr_t bd_addr){
127     memcpy(local_addr, bd_addr, 6);
128 }
129 
130 static void db_close(void){
131 }
132 
133 static void put_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t link_key_type){
134     set_path(bd_addr);
135     char * link_key_str = link_key_to_str(link_key);
136     char * link_key_type_str = link_key_type_to_str(link_key_type);
137 
138     FILE * wFile = fopen(keypath,"w+");
139     fwrite(link_key_str, strlen(link_key_str), 1, wFile);
140     fwrite(link_key_type_str, strlen(link_key_type_str), 1, wFile);
141     fclose(wFile);
142 }
143 
144 static int get_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * link_key_type) {
145     set_path(bd_addr);
146     if (access(keypath, R_OK)) return 0;
147 
148     char link_key_str[LINK_KEY_STR_LEN + 1];
149     char link_key_type_str[2];
150 
151     FILE * rFile = fopen(keypath,"r+");
152     size_t objects_read = fread(link_key_str, LINK_KEY_STR_LEN, 1, rFile );
153     if (objects_read == 1){
154         link_key_str[LINK_KEY_STR_LEN] = 0;
155         log_info("Found link key %s\n", link_key_str);
156         objects_read = fread(link_key_type_str, 1, 1, rFile );
157     }
158     fclose(rFile);
159 
160     if (objects_read != 1) return 0;
161     link_key_type_str[1] = 0;
162     log_info("Found link key type %s\n", link_key_type_str);
163 
164     int scan_result = sscanf_link_key(link_key_str, link_key);
165     if (scan_result == 0 ) return 0;
166 
167     int link_key_type_buffer;
168     scan_result = sscanf( (char *) link_key_type_str, "%d", &link_key_type_buffer);
169     if (scan_result == 0 ) return 0;
170     *link_key_type = (link_key_type_t) link_key_type_buffer;
171     return 1;
172 }
173 
174 static void delete_link_key(bd_addr_t bd_addr){
175     set_path(bd_addr);
176     if (access(keypath, R_OK)) return;
177 
178     if(remove(keypath) != 0){
179         log_error("File %s could not be deleted.\n", keypath);
180     }
181 }
182 
183 const btstack_link_key_db_t btstack_link_key_db_fs = {
184     &db_open,
185     &db_set_local_bd_addr,
186     &db_close,
187     &get_link_key,
188     &put_link_key,
189     &delete_link_key,
190 };
191 
192 const btstack_link_key_db_t * btstack_link_key_db_fs_instance(void){
193     return &btstack_link_key_db_fs;
194 }
195 
196 
197