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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 <endian.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/mman.h> | |
25 | #include <sys/types.h> | |
26 | #include <time.h> | |
27 | #include <unistd.h> | |
28 | ||
29 | #include <loc/libloc.h> | |
30 | #include <loc/format.h> | |
31 | ||
32 | #include "libloc-private.h" | |
33 | #include "as.h" | |
34 | #include "database.h" | |
35 | #include "stringpool.h" | |
36 | ||
37 | struct loc_database { | |
38 | struct loc_ctx* ctx; | |
39 | int refcount; | |
40 | ||
41 | FILE* file; | |
42 | unsigned int version; | |
43 | time_t created_at; | |
44 | off_t vendor; | |
45 | off_t description; | |
46 | ||
47 | // ASes in the database | |
48 | struct loc_database_as_v0* as_v0; | |
49 | size_t as_count; | |
50 | ||
51 | struct loc_stringpool* pool; | |
52 | }; | |
53 | ||
54 | static int loc_database_read_magic(struct loc_database* db) { | |
55 | struct loc_database_magic magic; | |
56 | ||
57 | // Read from file | |
58 | size_t bytes_read = fread(&magic, 1, sizeof(magic), db->file); | |
59 | ||
60 | // Check if we have been able to read enough data | |
61 | if (bytes_read < sizeof(magic)) { | |
62 | ERROR(db->ctx, "Could not read enough data to validate magic bytes\n"); | |
63 | DEBUG(db->ctx, "Read %zu bytes, but needed %zu\n", bytes_read, sizeof(magic)); | |
64 | return -ENOMSG; | |
65 | } | |
66 | ||
67 | // Compare magic bytes | |
68 | if (memcmp(LOC_DATABASE_MAGIC, magic.magic, strlen(LOC_DATABASE_MAGIC)) == 0) { | |
69 | DEBUG(db->ctx, "Magic value matches\n"); | |
70 | ||
71 | // Parse version | |
72 | db->version = be16toh(magic.version); | |
73 | DEBUG(db->ctx, "Database version is %u\n", db->version); | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | ERROR(db->ctx, "Database format is not compatible\n"); | |
79 | ||
80 | // Return an error | |
81 | return 1; | |
82 | } | |
83 | ||
84 | static int loc_database_read_as_section_v0(struct loc_database* db, | |
85 | off_t as_offset, size_t as_length) { | |
86 | DEBUG(db->ctx, "Reading AS section from %jd (%zu bytes)\n", as_offset, as_length); | |
87 | ||
88 | if (as_length > 0) { | |
89 | db->as_v0 = mmap(NULL, as_length, PROT_READ, | |
90 | MAP_SHARED, fileno(db->file), as_offset); | |
91 | ||
92 | if (db->as_v0 == MAP_FAILED) | |
93 | return -errno; | |
94 | } | |
95 | ||
96 | db->as_count = as_length / sizeof(*db->as_v0); | |
97 | ||
98 | INFO(db->ctx, "Read %zu ASes from the database\n", db->as_count); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | static int loc_database_read_header_v0(struct loc_database* db) { | |
104 | struct loc_database_header_v0 header; | |
105 | ||
106 | // Read from file | |
107 | size_t size = fread(&header, 1, sizeof(header), db->file); | |
108 | ||
109 | if (size < sizeof(header)) { | |
110 | ERROR(db->ctx, "Could not read enough data for header\n"); | |
111 | return -ENOMSG; | |
112 | } | |
113 | ||
114 | // Copy over data | |
115 | db->created_at = be64toh(header.created_at); | |
116 | db->vendor = be32toh(header.vendor); | |
117 | db->description = be32toh(header.description); | |
118 | ||
119 | // Open pool | |
120 | off_t pool_offset = be32toh(header.pool_offset); | |
121 | size_t pool_length = be32toh(header.pool_length); | |
122 | ||
123 | int r = loc_stringpool_open(db->ctx, &db->pool, | |
124 | db->file, pool_length, pool_offset); | |
125 | if (r) | |
126 | return r; | |
127 | ||
128 | // AS section | |
129 | off_t as_offset = be32toh(header.as_offset); | |
130 | size_t as_length = be32toh(header.as_length); | |
131 | ||
132 | r = loc_database_read_as_section_v0(db, as_offset, as_length); | |
133 | if (r) | |
134 | return r; | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static int loc_database_read_header(struct loc_database* db) { | |
140 | switch (db->version) { | |
141 | case 0: | |
142 | return loc_database_read_header_v0(db); | |
143 | ||
144 | default: | |
145 | ERROR(db->ctx, "Incompatible database version: %u\n", db->version); | |
146 | return 1; | |
147 | } | |
148 | } | |
149 | ||
150 | static FILE* copy_file_pointer(FILE* f) { | |
151 | int fd = fileno(f); | |
152 | ||
153 | // Make a copy | |
154 | fd = dup(fd); | |
155 | ||
156 | return fdopen(fd, "r"); | |
157 | } | |
158 | ||
159 | static int loc_database_read(struct loc_database* db) { | |
160 | clock_t start = clock(); | |
161 | ||
162 | // Read magic bytes | |
163 | int r = loc_database_read_magic(db); | |
164 | if (r) | |
165 | return r; | |
166 | ||
167 | // Read the header | |
168 | r = loc_database_read_header(db); | |
169 | if (r) | |
170 | return r; | |
171 | ||
172 | clock_t end = clock(); | |
173 | ||
174 | INFO(db->ctx, "Opened database in %.8fs\n", | |
175 | (double)(end - start) / CLOCKS_PER_SEC); | |
176 | ||
177 | return 0; | |
178 | } | |
179 | ||
180 | LOC_EXPORT int loc_database_new(struct loc_ctx* ctx, struct loc_database** database, FILE* f) { | |
181 | struct loc_database* db = calloc(1, sizeof(*db)); | |
182 | if (!db) | |
183 | return -ENOMEM; | |
184 | ||
185 | // Reference context | |
186 | db->ctx = loc_ref(ctx); | |
187 | db->refcount = 1; | |
188 | ||
189 | DEBUG(db->ctx, "Database object allocated at %p\n", db); | |
190 | ||
191 | // Copy the file pointer and work on that so we don't care if | |
192 | // the calling function closes the file | |
193 | db->file = copy_file_pointer(f); | |
194 | if (!db->file) | |
195 | goto FAIL; | |
196 | ||
197 | int r = loc_database_read(db); | |
198 | if (r) { | |
199 | loc_database_unref(db); | |
200 | return r; | |
201 | } | |
202 | ||
203 | *database = db; | |
204 | ||
205 | return 0; | |
206 | ||
207 | FAIL: | |
208 | loc_database_unref(db); | |
209 | ||
210 | return -errno; | |
211 | } | |
212 | ||
213 | LOC_EXPORT struct loc_database* loc_database_ref(struct loc_database* db) { | |
214 | db->refcount++; | |
215 | ||
216 | return db; | |
217 | } | |
218 | ||
219 | static void loc_database_free(struct loc_database* db) { | |
220 | DEBUG(db->ctx, "Releasing database %p\n", db); | |
221 | ||
222 | // Removing all ASes | |
223 | if (db->as_v0) { | |
224 | int r = munmap(db->as_v0, db->as_count * sizeof(*db->as_v0)); | |
225 | if (r) | |
226 | ERROR(db->ctx, "Could not unmap AS section: %s\n", strerror(errno)); | |
227 | } | |
228 | ||
229 | loc_stringpool_unref(db->pool); | |
230 | ||
231 | // Close file | |
232 | if (db->file) | |
233 | fclose(db->file); | |
234 | ||
235 | loc_unref(db->ctx); | |
236 | free(db); | |
237 | } | |
238 | ||
239 | LOC_EXPORT struct loc_database* loc_database_unref(struct loc_database* db) { | |
240 | if (--db->refcount > 0) | |
241 | return NULL; | |
242 | ||
243 | loc_database_free(db); | |
244 | return NULL; | |
245 | } | |
246 | ||
247 | LOC_EXPORT time_t loc_database_created_at(struct loc_database* db) { | |
248 | return db->created_at; | |
249 | } | |
250 | ||
251 | LOC_EXPORT const char* loc_database_get_vendor(struct loc_database* db) { | |
252 | return loc_stringpool_get(db->pool, db->vendor); | |
253 | } | |
254 | ||
255 | LOC_EXPORT const char* loc_database_get_description(struct loc_database* db) { | |
256 | return loc_stringpool_get(db->pool, db->description); | |
257 | } | |
258 | ||
259 | LOC_EXPORT size_t loc_database_count_as(struct loc_database* db) { | |
260 | return db->as_count; | |
261 | } | |
262 | ||
263 | // Returns the AS at position pos | |
264 | static int loc_database_fetch_as(struct loc_database* db, struct loc_as** as, off_t pos) { | |
265 | if ((size_t)pos >= db->as_count) | |
266 | return -EINVAL; | |
267 | ||
268 | DEBUG(db->ctx, "Fetching AS at position %jd\n", pos); | |
269 | ||
270 | int r; | |
271 | switch (db->version) { | |
272 | case 0: | |
273 | r = loc_as_new_from_database_v0(db->ctx, db->pool, as, db->as_v0 + pos); | |
274 | break; | |
275 | ||
276 | default: | |
277 | return -1; | |
278 | } | |
279 | ||
280 | if (r == 0) { | |
281 | DEBUG(db->ctx, "Got AS%u\n", loc_as_get_number(*as)); | |
282 | } | |
283 | ||
284 | return r; | |
285 | } | |
286 | ||
287 | // Performs a binary search to find the AS in the list | |
288 | LOC_EXPORT int loc_database_get_as(struct loc_database* db, struct loc_as** as, uint32_t number) { | |
289 | off_t lo = 0; | |
290 | off_t hi = db->as_count - 1; | |
291 | ||
292 | // Save start time | |
293 | clock_t start = clock(); | |
294 | ||
295 | while (lo <= hi) { | |
296 | off_t i = (lo + hi) / 2; | |
297 | ||
298 | // Fetch AS in the middle between lo and hi | |
299 | int r = loc_database_fetch_as(db, as, i); | |
300 | if (r) | |
301 | return r; | |
302 | ||
303 | // Check if this is a match | |
304 | uint32_t as_number = loc_as_get_number(*as); | |
305 | if (as_number == number) { | |
306 | clock_t end = clock(); | |
307 | ||
308 | // Log how fast this has been | |
309 | DEBUG(db->ctx, "Found AS%u in %.8fs\n", as_number, | |
310 | (double)(end - start) / CLOCKS_PER_SEC); | |
311 | ||
312 | return 0; | |
313 | } | |
314 | ||
315 | // If it wasn't, we release the AS and | |
316 | // adjust our search pointers | |
317 | loc_as_unref(*as); | |
318 | ||
319 | if (as_number < number) { | |
320 | lo = i + 1; | |
321 | } else | |
322 | hi = i - 1; | |
323 | } | |
324 | ||
325 | // Nothing found | |
326 | *as = NULL; | |
327 | ||
328 | return 1; | |
329 | } |