xref: /btstack/platform/posix/btstack_tlv_posix.c (revision c37cd8f3d1350b92a2f66c31b2a5fcd75f8c91a4)
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 MATTHIAS RINGWALD 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 MATTHIAS
21  * RINGWALD 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 static const char * btstack_tlv_header_magic = "BTstack";
58 
59 #define DUMMY_SIZE 4
60 typedef struct tlv_entry {
61 	void   * next;
62 	uint32_t tag;
63 	uint32_t len;
64 	uint8_t  value[DUMMY_SIZE];	// dummy size
65 } tlv_entry_t;
66 
67 static int btstack_tlv_posix_append_tag(btstack_tlv_posix_t * self, uint32_t tag, const uint8_t * data, uint32_t data_size){
68 
69 	if (!self->file) return 1;
70 
71 	log_info("append tag %04x, len %u", tag, data_size);
72 
73 	uint8_t header[8];
74 	big_endian_store_32(header, 0, tag);
75 	big_endian_store_32(header, 4, data_size);
76 	size_t written_header = fwrite(header, 1, sizeof(header), self->file);
77 	if (written_header != sizeof(header)) return 1;
78 	size_t written_value = fwrite(data, 1, data_size, self->file);
79 	if (written_value != data_size) return 1;
80 	return 1;
81 }
82 
83 static tlv_entry_t * btstack_tlv_posix_find_entry(btstack_tlv_posix_t * self, uint32_t tag){
84 	btstack_linked_list_iterator_t it;
85 	btstack_linked_list_iterator_init(&it, &self->entry_list);
86 	while (btstack_linked_list_iterator_has_next(&it)){
87 		tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
88 		if (entry->tag != tag) continue;
89 		return entry;
90 	}
91 	return NULL;
92 }
93 
94 /**
95  * Delete Tag
96  * @param tag
97  */
98 static void btstack_tlv_posix_delete_tag(void * context, uint32_t tag){
99 	btstack_tlv_posix_t * self = (btstack_tlv_posix_t *) context;
100 	btstack_linked_list_iterator_t it;
101 	btstack_linked_list_iterator_init(&it, &self->entry_list);
102 	while (btstack_linked_list_iterator_has_next(&it)){
103 		tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
104 		if (entry->tag != tag) continue;
105 		btstack_linked_list_iterator_remove(&it);
106 		btstack_tlv_posix_append_tag(self, tag, NULL, 0);
107 		return;
108 	}
109 }
110 
111 /**
112  * Get Value for Tag
113  * @param tag
114  * @param buffer
115  * @param buffer_size
116  * @returns size of value
117  */
118 static int btstack_tlv_posix_get_tag(void * context, uint32_t tag, uint8_t * buffer, uint32_t buffer_size){
119 	btstack_tlv_posix_t * self = (btstack_tlv_posix_t *) context;
120 	tlv_entry_t * entry = btstack_tlv_posix_find_entry(self, tag);
121 	// not found
122 	if (!entry) return 0;
123 	// return len if buffer = NULL
124 	if (!buffer) return entry->len;
125 	// otherwise copy data into buffer
126 	uint16_t bytes_to_copy = btstack_min(buffer_size, entry->len);
127 	memcpy(buffer, &entry->value[0], bytes_to_copy);
128 	return bytes_to_copy;
129 }
130 
131 /**
132  * Store Tag
133  * @param tag
134  * @param data
135  * @param data_size
136  */
137 static int btstack_tlv_posix_store_tag(void * context, uint32_t tag, const uint8_t * data, uint32_t data_size){
138 	btstack_tlv_posix_t * self = (btstack_tlv_posix_t *) context;
139 
140 	// remove old entry
141 	tlv_entry_t * old_entry = btstack_tlv_posix_find_entry(self, tag);
142 	if (old_entry){
143 		btstack_linked_list_remove(&self->entry_list, (btstack_linked_item_t *) old_entry);
144 		free(old_entry);
145 	}
146 
147 	// create new entry
148 	tlv_entry_t * new_entry = (tlv_entry_t *) malloc(sizeof(tlv_entry_t) - DUMMY_SIZE + data_size);
149 	if (!new_entry) return 0;
150 	new_entry->tag = tag;
151 	new_entry->len = data_size;
152 	memcpy(&new_entry->value[0], data, data_size);
153 
154 	// append new entry
155 	btstack_linked_list_add(&self->entry_list, (btstack_linked_item_t *) new_entry);
156 
157 	// write new tag
158 	btstack_tlv_posix_append_tag(self, tag, data, data_size);
159 
160 	return 0;
161 }
162 
163 // returns 0 on success
164 static int btstack_tlv_posix_read_db(btstack_tlv_posix_t * self){
165 	// open file
166 	log_info("open db %s", self->db_path);
167     self->file = fopen(self->db_path,"r+");
168     uint8_t header[BTSTACK_TLV_HEADER_LEN];
169     if (self->file){
170     	// checker header
171 	    size_t objects_read = fread(header, 1, BTSTACK_TLV_HEADER_LEN, self->file );
172 	    int file_valid = 0;
173 	    if (objects_read == BTSTACK_TLV_HEADER_LEN){
174 	    	if (memcmp(header, btstack_tlv_header_magic, strlen(btstack_tlv_header_magic)) == 0){
175 		    	log_info("BTstack Magic Header found");
176 		    	// read entries
177 		    	while (1){
178 					uint8_t entry[8];
179 					size_t 	entries_read = fread(entry, 1, sizeof(entry), self->file);
180 					if (entries_read == 0){
181 						// EOF, we're good
182 						file_valid = 1;
183 						break;
184 					}
185 					if (entries_read == sizeof(entry)){
186 						uint32_t tag = big_endian_read_32(entry, 0);
187 						uint32_t len = big_endian_read_32(entry, 4);
188 						// arbitrary safetly check: values < 1000 bytes each
189 						if (len > 1000) break;
190 						tlv_entry_t * new_entry = (tlv_entry_t *) malloc(sizeof(tlv_entry_t) - DUMMY_SIZE + len);
191 						if (!new_entry) return 0;
192 						new_entry->tag = tag;
193 						new_entry->len = len;
194 						// read
195 						size_t 	value_read = fread(&new_entry->value[0], 1, len, self->file);
196 						if (value_read == len){
197 							// append new entry
198 							btstack_linked_list_add(&self->entry_list, (btstack_linked_item_t *) new_entry);
199 						} else {
200 							// fail
201 							free(new_entry);
202 							break;
203 						}
204 					}
205 		    	}
206 	    	}
207 	    }
208 	    if (!file_valid) {
209 	    	log_info("file invalid, re-create");
210     		fclose(self->file);
211     		self->file = NULL;
212 	    }
213     }
214     if (!self->file){
215     	// create truncate file
216 	    self->file = fopen(self->db_path,"w+");
217 	    memset(header, 0, sizeof(header));
218 	    strcpy((char *)header, btstack_tlv_header_magic);
219 	    fwrite(header, 1, sizeof(header), self->file);
220 	    // write out all valid entries (if any)
221 		btstack_linked_list_iterator_t it;
222 		btstack_linked_list_iterator_init(&it, &self->entry_list);
223 		while (btstack_linked_list_iterator_has_next(&it)){
224 			tlv_entry_t * entry = (tlv_entry_t*) btstack_linked_list_iterator_next(&it);
225 			btstack_tlv_posix_append_tag(self, entry->tag, &entry->value[0], entry->len);
226 		}
227     }
228 	return 0;
229 }
230 
231 static const btstack_tlv_t btstack_tlv_posix = {
232 	/* int  (*get_tag)(..);     */ &btstack_tlv_posix_get_tag,
233 	/* int (*store_tag)(..);    */ &btstack_tlv_posix_store_tag,
234 	/* void (*delete_tag)(v..); */ &btstack_tlv_posix_delete_tag,
235 };
236 
237 /**
238  * Init Tag Length Value Store
239  */
240 const btstack_tlv_t * btstack_tlv_posix_init_instance(btstack_tlv_posix_t * self, const char * db_path){
241 	memset(self, 0, sizeof(btstack_tlv_posix_t));
242 	self->db_path = db_path;
243 
244 	// read DB
245 	btstack_tlv_posix_read_db(self);
246 	return &btstack_tlv_posix;
247 }
248 
249