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1 | /* | |
2 | libloc - A library to determine the location of someone on the Internet | |
3 | ||
4 | Copyright (C) 2017 IPFire Development Team <info@ipfire.org> | |
5 | ||
6 | This library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | This library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <arpa/inet.h> | |
18 | #include <errno.h> | |
19 | #include <stddef.h> | |
20 | #include <stdint.h> | |
21 | #include <stdio.h> | |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <sys/types.h> | |
25 | ||
26 | #include <loc/libloc.h> | |
27 | ||
28 | #include "libloc-private.h" | |
29 | #include "database.h" | |
30 | #include "stringpool.h" | |
31 | ||
32 | struct loc_database { | |
33 | struct loc_ctx* ctx; | |
34 | int refcount; | |
35 | ||
36 | unsigned int version; | |
37 | off_t vendor; | |
38 | off_t description; | |
39 | ||
40 | struct loc_stringpool* pool; | |
41 | }; | |
42 | ||
43 | const char* LOC_DATABASE_MAGIC = "LOCDBXX"; | |
44 | unsigned int LOC_DATABASE_VERSION = 0; | |
45 | ||
46 | struct loc_database_magic { | |
47 | char magic[7]; | |
48 | ||
49 | // Database version information | |
50 | uint8_t version; | |
51 | }; | |
52 | ||
53 | struct loc_database_header_v0 { | |
54 | // Vendor who created the database | |
55 | uint32_t vendor; | |
56 | ||
57 | // Description of the database | |
58 | uint32_t description; | |
59 | ||
60 | // Tells us where the pool starts | |
61 | uint32_t pool_offset; | |
62 | uint32_t pool_length; | |
63 | }; | |
64 | ||
65 | LOC_EXPORT int loc_database_new(struct loc_ctx* ctx, struct loc_database** database, size_t pool_size) { | |
66 | struct loc_database* db = calloc(1, sizeof(*db)); | |
67 | if (!db) | |
68 | return -ENOMEM; | |
69 | ||
70 | // Reference context | |
71 | db->ctx = loc_ref(ctx); | |
72 | db->refcount = 1; | |
73 | ||
74 | DEBUG(db->ctx, "Database allocated at %p\n", db); | |
75 | ||
76 | // Create string pool | |
77 | int r = loc_stringpool_new(db->ctx, &db->pool, pool_size); | |
78 | if (r) { | |
79 | loc_database_unref(db); | |
80 | return r; | |
81 | } | |
82 | ||
83 | *database = db; | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
88 | LOC_EXPORT int loc_database_open(struct loc_ctx* ctx, struct loc_database** database, FILE* f) { | |
89 | int r = loc_database_new(ctx, database, 0); | |
90 | if (r) | |
91 | return r; | |
92 | ||
93 | return loc_database_read(*database, f); | |
94 | } | |
95 | ||
96 | LOC_EXPORT struct loc_database* loc_database_ref(struct loc_database* db) { | |
97 | db->refcount++; | |
98 | ||
99 | return db; | |
100 | } | |
101 | ||
102 | static void loc_database_free(struct loc_database* db) { | |
103 | DEBUG(db->ctx, "Releasing database %p\n", db); | |
104 | ||
105 | loc_stringpool_unref(db->pool); | |
106 | ||
107 | loc_unref(db->ctx); | |
108 | free(db); | |
109 | } | |
110 | ||
111 | LOC_EXPORT struct loc_database* loc_database_unref(struct loc_database* db) { | |
112 | if (--db->refcount > 0) | |
113 | return NULL; | |
114 | ||
115 | loc_database_free(db); | |
116 | return NULL; | |
117 | } | |
118 | ||
119 | LOC_EXPORT const char* loc_database_get_vendor(struct loc_database* db) { | |
120 | return loc_stringpool_get(db->pool, db->vendor); | |
121 | } | |
122 | ||
123 | LOC_EXPORT int loc_database_set_vendor(struct loc_database* db, const char* vendor) { | |
124 | // Add the string to the string pool | |
125 | off_t offset = loc_stringpool_add(db->pool, vendor); | |
126 | if (offset < 0) | |
127 | return offset; | |
128 | ||
129 | db->vendor = offset; | |
130 | return 0; | |
131 | } | |
132 | ||
133 | LOC_EXPORT const char* loc_database_get_description(struct loc_database* db) { | |
134 | return loc_stringpool_get(db->pool, db->description); | |
135 | } | |
136 | ||
137 | LOC_EXPORT int loc_database_set_description(struct loc_database* db, const char* description) { | |
138 | // Add the string to the string pool | |
139 | off_t offset = loc_stringpool_add(db->pool, description); | |
140 | if (offset < 0) | |
141 | return offset; | |
142 | ||
143 | db->description = offset; | |
144 | return 0; | |
145 | } | |
146 | ||
147 | static int loc_database_read_magic(struct loc_database* db, FILE* f) { | |
148 | struct loc_database_magic magic; | |
149 | ||
150 | // Read from file | |
151 | size_t bytes_read = fread(&magic, 1, sizeof(magic), f); | |
152 | ||
153 | // Check if we have been able to read enough data | |
154 | if (bytes_read < sizeof(magic)) { | |
155 | ERROR(db->ctx, "Could not read enough data to validate magic bytes\n"); | |
156 | DEBUG(db->ctx, "Read %zu bytes, but needed %zu\n", bytes_read, sizeof(magic)); | |
157 | return -ENOMSG; | |
158 | } | |
159 | ||
160 | // Compare magic bytes | |
161 | if (memcmp(LOC_DATABASE_MAGIC, magic.magic, strlen(LOC_DATABASE_MAGIC)) == 0) { | |
162 | DEBUG(db->ctx, "Magic value matches\n"); | |
163 | ||
164 | // Parse version | |
165 | db->version = ntohs(magic.version); | |
166 | DEBUG(db->ctx, "Database version is %u\n", db->version); | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
171 | ERROR(db->ctx, "Database format is not compatible\n"); | |
172 | ||
173 | // Return an error | |
174 | return 1; | |
175 | } | |
176 | ||
177 | static int loc_database_read_header_v0(struct loc_database* db, FILE* f) { | |
178 | struct loc_database_header_v0 header; | |
179 | ||
180 | // Read from file | |
181 | size_t size = fread(&header, 1, sizeof(header), f); | |
182 | ||
183 | if (size < sizeof(header)) { | |
184 | ERROR(db->ctx, "Could not read enough data for header\n"); | |
185 | return -ENOMSG; | |
186 | } | |
187 | ||
188 | // Copy over data | |
189 | db->vendor = ntohl(header.vendor); | |
190 | db->description = ntohl(header.description); | |
191 | ||
192 | // Open pool | |
193 | off_t pool_offset = ntohl(header.pool_offset); | |
194 | size_t pool_length = ntohl(header.pool_length); | |
195 | ||
196 | int r = loc_stringpool_read(db->pool, f, pool_offset, pool_length); | |
197 | if (r) | |
198 | return r; | |
199 | ||
200 | return 0; | |
201 | } | |
202 | ||
203 | static int loc_database_read_header(struct loc_database* db, FILE* f) { | |
204 | switch (db->version) { | |
205 | case 0: | |
206 | return loc_database_read_header_v0(db, f); | |
207 | ||
208 | default: | |
209 | ERROR(db->ctx, "Incompatible database version: %u\n", db->version); | |
210 | return 1; | |
211 | } | |
212 | } | |
213 | ||
214 | LOC_EXPORT int loc_database_read(struct loc_database* db, FILE* f) { | |
215 | int r = fseek(f, 0, SEEK_SET); | |
216 | if (r) | |
217 | return r; | |
218 | ||
219 | // Read magic bytes | |
220 | r = loc_database_read_magic(db, f); | |
221 | if (r) | |
222 | return r; | |
223 | ||
224 | // Read the header | |
225 | r = loc_database_read_header(db, f); | |
226 | if (r) | |
227 | return r; | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
232 | static void loc_database_make_magic(struct loc_database* db, struct loc_database_magic* magic) { | |
233 | // Copy magic bytes | |
234 | for (unsigned int i = 0; i < strlen(LOC_DATABASE_MAGIC); i++) | |
235 | magic->magic[i] = LOC_DATABASE_MAGIC[i]; | |
236 | ||
237 | // Set version | |
238 | magic->version = htons(LOC_DATABASE_VERSION); | |
239 | } | |
240 | ||
241 | LOC_EXPORT int loc_database_write(struct loc_database* db, FILE* f) { | |
242 | struct loc_database_magic magic; | |
243 | loc_database_make_magic(db, &magic); | |
244 | ||
245 | // Make the header | |
246 | struct loc_database_header_v0 header; | |
247 | header.vendor = htonl(db->vendor); | |
248 | header.description = htonl(db->description); | |
249 | ||
250 | int r; | |
251 | off_t offset = 0; | |
252 | ||
253 | // Start writing at the beginning of the file | |
254 | r = fseek(f, 0, SEEK_SET); | |
255 | if (r) | |
256 | return r; | |
257 | ||
258 | // Write the magic | |
259 | offset += fwrite(&magic, 1, sizeof(magic), f); | |
260 | ||
261 | // Skip the space we need to write the header later | |
262 | r = fseek(f, sizeof(header), SEEK_CUR); | |
263 | if (r) { | |
264 | DEBUG(db->ctx, "Could not seek to position after header\n"); | |
265 | return r; | |
266 | } | |
267 | offset += sizeof(header); | |
268 | ||
269 | // Save the offset of the pool section | |
270 | DEBUG(db->ctx, "Pool starts at %jd bytes\n", offset); | |
271 | header.pool_offset = htonl(offset); | |
272 | ||
273 | // Size of the pool | |
274 | size_t pool_length = loc_stringpool_write(db->pool, f); | |
275 | DEBUG(db->ctx, "Pool has a length of %zu bytes\n", pool_length); | |
276 | header.pool_length = htonl(pool_length); | |
277 | ||
278 | // Write the header | |
279 | r = fseek(f, sizeof(magic), SEEK_SET); | |
280 | if (r) | |
281 | return r; | |
282 | ||
283 | offset += fwrite(&header, 1, sizeof(header), f); | |
284 | ||
285 | return 0; | |
286 | } |