xref: /btstack/platform/posix/btstack_tlv_posix.c (revision 08a78038ba366a6a2a2df8fea05d5123880fdff2)
1 /*
2  * Copyright (C) 2017 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  *
17  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
21  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
24  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
27  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  */
31 
32 #define BTSTACK_FILE__ "btstack_tlv_posix.c"
33 
34 #include "btstack_tlv.h"
35 #include "btstack_tlv_posix.h"
36 #include "btstack_debug.h"
37 #include "btstack_util.h"
38 #include "btstack_debug.h"
39 #include "string.h"
40 
41 #include <stdlib.h>
42 #include <string.h>
43 
44 
45 // Header:
46 // - Magic: 'BTstack'
47 // - Status:
48 //   - bits 765432: reserved
49 //	 - bits 10:     epoch
50 
51 // Entries
52 // - Tag: 32 bit
53 // - Len: 32 bit
54 // - Value: Len in bytes
55 
56 #define BTSTACK_TLV_HEADER_LEN 8
57 
58 #define MAX_TLV_VALUE_SIZE 2048
59 
60 static const char * btstack_tlv_header_magic = "BTstack";
61 
62 #define DUMMY_SIZE 4
63 typedef struct tlv_entry {
64 	void   * next;
65 	uint32_t tag;
66 	uint32_t len;
67 	uint8_t  value[DUMMY_SIZE];	// dummy size
68 } tlv_entry_t;
69 
70 // testing support
71 static bool btstack_tlv_posix_read_only = false;
72 
73 static void btstack_tlv_posix_append_tag(btstack_tlv_posix_t * self, uint32_t tag, const uint8_t * data, uint32_t data_size){
74 
75 	if (!self->file) return;
76 
77 	log_info("append tag %04x, len %u", tag, data_size);
78 
79 	uint8_t header[8];
80 	big_endian_store_32(header, 0, tag);
81 	big_endian_store_32(header, 4, data_size);
82 	size_t written_header = fwrite(header, 1, sizeof(header), self->file);
83 	if (written_header != sizeof(header)) return;
84 	if (data_size > 0) {
85 		size_t written_value = fwrite(data, 1, data_size, self->file);
86 		if (written_value != data_size) return;
87 	}
88 	fflush(self->file);
89 }
90 
91 static tlv_entry_t * btstack_tlv_posix_find_entry(btstack_tlv_posix_t * self, uint32_t tag){
92 	btstack_linked_list_iterator_t it;
93 	btstack_linked_list_iterator_init(&it, &self->entry_list);
94 	while (btstack_linked_list_iterator_has_next(&it)){
95 		tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
96 		if (entry->tag != tag) continue;
97 		return entry;
98 	}
99 	return NULL;
100 }
101 
102 /**
103  * Delete Tag
104  * @param tag
105  */
106 static void btstack_tlv_posix_delete_tag(void * context, uint32_t tag){
107 	btstack_tlv_posix_t * self = (btstack_tlv_posix_t *) context;
108 	btstack_linked_list_iterator_t it;
109 	btstack_linked_list_iterator_init(&it, &self->entry_list);
110 	while (btstack_linked_list_iterator_has_next(&it)){
111 		tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
112 		if (entry->tag != tag) continue;
113 		btstack_linked_list_iterator_remove(&it);
114 		free(entry);
115 		btstack_tlv_posix_append_tag(self, tag, NULL, 0);
116 		return;
117 	}
118 }
119 
120 /**
121  * Get Value for Tag
122  * @param tag
123  * @param buffer
124  * @param buffer_size
125  * @returns size of value
126  */
127 static int btstack_tlv_posix_get_tag(void * context, uint32_t tag, uint8_t * buffer, uint32_t buffer_size){
128 	btstack_tlv_posix_t * self = (btstack_tlv_posix_t *) context;
129 	tlv_entry_t * entry = btstack_tlv_posix_find_entry(self, tag);
130 	// not found
131 	if (!entry) return 0;
132 	// return len if buffer = NULL
133 	if (!buffer) return entry->len;
134 	// otherwise copy data into buffer
135 	uint16_t bytes_to_copy = btstack_min(buffer_size, entry->len);
136 	memcpy(buffer, &entry->value[0], bytes_to_copy);
137 	return bytes_to_copy;
138 }
139 
140 /**
141  * Store Tag
142  * @param tag
143  * @param data
144  * @param data_size
145  */
146 static int btstack_tlv_posix_store_tag(void * context, uint32_t tag, const uint8_t * data, uint32_t data_size){
147 	btstack_tlv_posix_t * self = (btstack_tlv_posix_t *) context;
148 
149 	// enforce arbitrary max value size
150 	btstack_assert(data_size <= MAX_TLV_VALUE_SIZE);
151 
152 	// remove old entry
153 	tlv_entry_t * old_entry = btstack_tlv_posix_find_entry(self, tag);
154 	if (old_entry){
155 		btstack_linked_list_remove(&self->entry_list, (btstack_linked_item_t *) old_entry);
156 		free(old_entry);
157 	}
158 
159 	// create new entry
160 	uint32_t entry_size = sizeof(tlv_entry_t) - DUMMY_SIZE + data_size;
161 	tlv_entry_t * new_entry = (tlv_entry_t *) malloc(entry_size);
162 	if (!new_entry) return 0;
163 	memset(new_entry, 0, entry_size);
164 	new_entry->tag = tag;
165 	new_entry->len = data_size;
166 	memcpy(&new_entry->value[0], data, data_size);
167 
168 	// append new entry
169 	btstack_linked_list_add(&self->entry_list, (btstack_linked_item_t *) new_entry);
170 
171 	// write new tag
172 	btstack_tlv_posix_append_tag(self, tag, data, data_size);
173 
174 	return 0;
175 }
176 
177 // returns 0 on success
178 static int btstack_tlv_posix_read_db(btstack_tlv_posix_t * self){
179 	// open file
180 	log_info("open db %s", self->db_path);
181     const char * mode = btstack_tlv_posix_read_only ? "r" : "r+";
182     self->file = fopen(self->db_path, mode);
183     uint8_t header[BTSTACK_TLV_HEADER_LEN];
184     if (self->file){
185     	// checker header
186 	    size_t objects_read = fread(header, 1, BTSTACK_TLV_HEADER_LEN, self->file );
187 	    int file_valid = 0;
188 	    if (objects_read == BTSTACK_TLV_HEADER_LEN){
189 	    	if (memcmp(header, btstack_tlv_header_magic, strlen(btstack_tlv_header_magic)) == 0){
190 		    	log_info("BTstack Magic Header found");
191 		    	// read entries
192 		    	while (true){
193 					uint8_t entry[8];
194 					size_t 	entries_read = fread(entry, 1, sizeof(entry), self->file);
195 					if (entries_read == 0){
196 						// EOF, we're good
197 						file_valid = 1;
198 						break;
199 					}
200 					if (entries_read != sizeof(entry)) break;
201 
202                     uint32_t tag = big_endian_read_32(entry, 0);
203                     uint32_t len = big_endian_read_32(entry, 4);
204 
205                     // arbitrary safety check: values <= MAX_TLV_VALUE_SIZE
206                     if (len > MAX_TLV_VALUE_SIZE) break;
207 
208                     // create new entry for regular tag
209                     tlv_entry_t * new_entry = NULL;
210                     if (len > 0) {
211                         new_entry = (tlv_entry_t *) malloc(sizeof(tlv_entry_t) - DUMMY_SIZE + len);
212                         if (!new_entry) return 0;
213                         new_entry->tag = tag;
214                         new_entry->len = len;
215 
216                         // read
217                         size_t value_read = fread(&new_entry->value[0], 1, len, self->file);
218                         if (value_read != len) break;
219                     }
220 
221                     // remove old entry
222                     tlv_entry_t * old_entry = btstack_tlv_posix_find_entry(self, tag);
223                     if (old_entry){
224                         btstack_linked_list_remove(&self->entry_list, (btstack_linked_item_t *) old_entry);
225                         free(old_entry);
226                     }
227 
228                     // append new entry
229                     if (new_entry){
230 	                    btstack_linked_list_add(&self->entry_list, (btstack_linked_item_t *) new_entry);
231                     }
232 		    	}
233 	    	}
234 	    }
235 	    if (!file_valid) {
236 	    	log_info("file invalid, re-create");
237     		fclose(self->file);
238     		self->file = NULL;
239 	    }
240     }
241 
242     // close file in read-only mode
243     if (btstack_tlv_posix_read_only && (self->file != NULL)){
244         fclose(self->file);
245         self->file = NULL;
246         return 0;
247     }
248 
249     if (!self->file){
250     	// create truncate file
251 	    self->file = fopen(self->db_path,"w+");
252         if (!self->file) {
253             log_error("failed to create file");
254             return -1;
255         }
256 	    memset(header, 0, sizeof(header));
257 	    strcpy((char *)header, btstack_tlv_header_magic);
258 	    fwrite(header, 1, sizeof(header), self->file);
259 	    // write out all valid entries (if any)
260 		btstack_linked_list_iterator_t it;
261 		btstack_linked_list_iterator_init(&it, &self->entry_list);
262 		while (btstack_linked_list_iterator_has_next(&it)){
263 			tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
264 			btstack_tlv_posix_append_tag(self, entry->tag, &entry->value[0], entry->len);
265 		}
266     }
267 	return 0;
268 }
269 
270 static const btstack_tlv_t btstack_tlv_posix = {
271 	/* int  (*get_tag)(..);     */ &btstack_tlv_posix_get_tag,
272 	/* int (*store_tag)(..);    */ &btstack_tlv_posix_store_tag,
273 	/* void (*delete_tag)(v..); */ &btstack_tlv_posix_delete_tag,
274 };
275 
276 /**
277  * Init Tag Length Value Store
278  */
279 const btstack_tlv_t * btstack_tlv_posix_init_instance(btstack_tlv_posix_t * self, const char * db_path){
280 	memset(self, 0, sizeof(btstack_tlv_posix_t));
281 	self->db_path = db_path;
282 
283 	// read DB
284     if (db_path != NULL){
285         btstack_tlv_posix_read_db(self);
286     }
287 	return &btstack_tlv_posix;
288 }
289 
290 void btstack_tlv_posix_set_read_only(void){
291     btstack_tlv_posix_read_only = true;
292 }
293 
294 /**
295  * Free TLV entries
296  * @param self
297  */
298 void btstack_tlv_posix_deinit(btstack_tlv_posix_t * self){
299     // free all entries
300     btstack_linked_list_iterator_t it;
301     btstack_linked_list_iterator_init(&it, &self->entry_list);
302     while (btstack_linked_list_iterator_has_next(&it)){
303         tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
304 		btstack_linked_list_iterator_remove(&it);
305 		free(entry);
306     }
307     btstack_tlv_posix_read_only = true;
308 }
309