xref: /btstack/platform/posix/btstack_link_key_db_fs.c (revision ceed67ffe68ea5103bbc5647a2e000ed0e08b747)
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_fs.c"
39 
40 #include <string.h>
41 #include <stdlib.h>
42 #include <stdio.h>
43 #include <unistd.h>
44 
45 #include "tinydir.h"
46 
47 #include "btstack_config.h"
48 #include "btstack_link_key_db_fs.h"
49 #include "btstack_debug.h"
50 #include "btstack_util.h"
51 
52 // allow to pre-set LINK_KEY_PATH from btstack_config.h
53 #ifndef LINK_KEY_PATH
54 #ifdef _WIN32
55 #define LINK_KEY_PATH ""
56 #else
57 #define LINK_KEY_PATH "/tmp/"
58 #endif
59 #endif
60 
61 #define LINK_KEY_PREFIX "btstack_at_"
62 #define LINK_KEY_FOR "_link_key_for_"
63 #define LINK_KEY_SUFFIX ".txt"
64 #define LINK_KEY_STRING_LEN 17
65 
66 static bd_addr_t local_addr;
67 // note: sizeof for string literals works at compile time while strlen only works with some optimizations turned on. sizeof includes the  \0
68 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];
69 
70 static char * bd_addr_to_dash_str(bd_addr_t addr){
71     return bd_addr_to_str_with_delimiter(addr, '-');
72 }
73 
74 static char link_key_to_str_buffer[LINK_KEY_STR_LEN+1];  // 11223344556677889900112233445566\0
75 static char *link_key_to_str(link_key_t link_key){
76     char * p = link_key_to_str_buffer;
77     int i;
78     for (i = 0; i < LINK_KEY_LEN ; i++) {
79         *p++ = char_for_nibble((link_key[i] >> 4) & 0x0F);
80         *p++ = char_for_nibble((link_key[i] >> 0) & 0x0F);
81     }
82     *p = 0;
83     return (char *) link_key_to_str_buffer;
84 }
85 
86 static char link_key_type_to_str_buffer[2];
87 static char *link_key_type_to_str(link_key_type_t link_key){
88     btstack_snprintf_assert_complete(link_key_type_to_str_buffer, sizeof(link_key_type_to_str_buffer), "%d", link_key);
89     return (char *) link_key_type_to_str_buffer;
90 }
91 
92 static int sscanf_link_key(char * addr_string, link_key_t link_key){
93     unsigned int buffer[LINK_KEY_LEN];
94 
95     // reset result buffer
96     memset(&buffer, 0, sizeof(buffer));
97 
98     // parse
99     int result = sscanf( (char *) addr_string, "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
100                                     &buffer[0], &buffer[1], &buffer[2], &buffer[3],
101                                     &buffer[4], &buffer[5], &buffer[6], &buffer[7],
102                                     &buffer[8], &buffer[9], &buffer[10], &buffer[11],
103                                     &buffer[12], &buffer[13], &buffer[14], &buffer[15] );
104 
105     if (result != LINK_KEY_LEN) return 0;
106 
107     // store
108     int i;
109     uint8_t *p = (uint8_t *) link_key;
110     for (i=0; i<LINK_KEY_LEN; i++ ) {
111         *p++ = (uint8_t) buffer[i];
112     }
113     return 1;
114 }
115 
116 static void set_path(bd_addr_t bd_addr){
117     strcpy(keypath, LINK_KEY_PATH);
118     strcat(keypath, LINK_KEY_PREFIX);
119     strcat(keypath, bd_addr_to_dash_str(local_addr));
120     strcat(keypath, LINK_KEY_FOR);
121     strcat(keypath, bd_addr_to_dash_str(bd_addr));
122     strcat(keypath, LINK_KEY_SUFFIX);
123 }
124 
125 // Device info
126 static void db_open(void){
127 }
128 
129 static void db_set_local_bd_addr(bd_addr_t bd_addr){
130     memcpy(local_addr, bd_addr, 6);
131 }
132 
133 static void db_close(void){
134 }
135 
136 static void put_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t link_key_type){
137     set_path(bd_addr);
138     char * link_key_str = link_key_to_str(link_key);
139     char * link_key_type_str = link_key_type_to_str(link_key_type);
140 
141     FILE * wFile = fopen(keypath,"w+");
142     if (wFile == NULL){
143         log_error("failed to create file");
144         return;
145     }
146     fwrite(link_key_str, strlen(link_key_str), 1, wFile);
147     fwrite(link_key_type_str, strlen(link_key_type_str), 1, wFile);
148     fclose(wFile);
149 }
150 
151 static int read_link_key(const char * path, link_key_t link_key, link_key_type_t * link_key_type){
152     if (access(path, 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(path,"r+");
158     if (rFile == NULL) return 0;
159     size_t objects_read = fread(link_key_str, LINK_KEY_STR_LEN, 1, rFile );
160     if (objects_read == 1){
161         link_key_str[LINK_KEY_STR_LEN] = 0;
162         log_info("Found link key %s\n", link_key_str);
163         objects_read = fread(link_key_type_str, 1, 1, rFile );
164     }
165     fclose(rFile);
166 
167     if (objects_read != 1) return 0;
168     link_key_type_str[1] = 0;
169     log_info("Found link key type %s\n", link_key_type_str);
170 
171     int scan_result = sscanf_link_key(link_key_str, link_key);
172     if (scan_result == 0 ) return 0;
173 
174     int link_key_type_buffer;
175     scan_result = sscanf( (char *) link_key_type_str, "%d", &link_key_type_buffer);
176     if (scan_result == 0 ) return 0;
177     *link_key_type = (link_key_type_t) link_key_type_buffer;
178     return 1;
179 }
180 
181 static int get_link_key(bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * link_key_type) {
182     set_path(bd_addr);
183     return read_link_key(keypath, link_key, link_key_type);
184 }
185 
186 static void delete_link_key(bd_addr_t bd_addr){
187     set_path(bd_addr);
188     if (access(keypath, R_OK)) return;
189     if(remove(keypath) != 0){
190         log_error("File %s could not be deleted.\n", keypath);
191     }
192 }
193 
194 static int iterator_init(btstack_link_key_iterator_t * it){
195     tinydir_dir * dir = (tinydir_dir *) malloc(sizeof(tinydir_dir));
196     if (!dir) return 0;
197     it->context = dir;
198     tinydir_open(dir, LINK_KEY_PATH);
199     return 1;
200 }
201 
202 static int  iterator_get_next(btstack_link_key_iterator_t * it, bd_addr_t bd_addr, link_key_t link_key, link_key_type_t * type){
203     (void)bd_addr;
204     (void)link_key;
205     UNUSED(type);
206     tinydir_dir * dir = (tinydir_dir*) it->context;
207 
208     // construct prefix
209     strcpy(keypath, LINK_KEY_PREFIX);
210     strcat(keypath, bd_addr_to_dash_str(local_addr));
211     strcat(keypath, LINK_KEY_FOR);
212 
213     while (dir->has_next) {
214         tinydir_file file;
215         tinydir_readfile(dir, &file);
216         tinydir_next(dir);
217         // compare
218         if (strncmp(keypath, file.name, strlen(keypath)) == 0){
219             // parse bd_addr
220             const int addr_offset = sizeof(LINK_KEY_PREFIX) + LINK_KEY_STRING_LEN + sizeof(LINK_KEY_FOR) - 2;   // -1 for each sizeof
221             sscanf_bd_addr(&file.name[addr_offset], bd_addr);
222             // path found, read file
223             strcpy(keypath, LINK_KEY_PATH);
224             strcat(keypath, file.name);
225             read_link_key(keypath, link_key, type);
226             return 1;
227         }
228     }
229     return 0;
230 }
231 
232 static void iterator_done(btstack_link_key_iterator_t * it){
233     tinydir_close((tinydir_dir*)it->context);
234     free(it->context);
235     it->context = NULL;
236 }
237 
238 static const btstack_link_key_db_t btstack_link_key_db_fs = {
239     &db_open,
240     &db_set_local_bd_addr,
241     &db_close,
242     &get_link_key,
243     &put_link_key,
244     &delete_link_key,
245     &iterator_init,
246     &iterator_get_next,
247     &iterator_done,
248 };
249 
250 const btstack_link_key_db_t * btstack_link_key_db_fs_instance(void){
251     return &btstack_link_key_db_fs;
252 }
253 
254 
255