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62b83e6d MT |
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 <errno.h> | |
18 | #include <stddef.h> | |
19 | #include <stdio.h> | |
20 | #include <stdlib.h> | |
21 | #include <string.h> | |
6809d5ac MT |
22 | #include <sys/mman.h> |
23 | #include <unistd.h> | |
62b83e6d MT |
24 | |
25 | #include <loc/libloc.h> | |
c34e76f1 | 26 | #include <loc/format.h> |
9fc7f001 MT |
27 | #include <loc/private.h> |
28 | #include <loc/stringpool.h> | |
62b83e6d | 29 | |
0e974d4b MT |
30 | enum loc_stringpool_mode { |
31 | STRINGPOOL_DEFAULT, | |
32 | STRINGPOOL_MMAP, | |
33 | }; | |
34 | ||
62b83e6d MT |
35 | struct loc_stringpool { |
36 | struct loc_ctx* ctx; | |
62b83e6d | 37 | int refcount; |
0e974d4b MT |
38 | |
39 | enum loc_stringpool_mode mode; | |
40 | ||
62b83e6d | 41 | char* data; |
0e974d4b | 42 | ssize_t length; |
62b83e6d | 43 | |
0e974d4b | 44 | char* pos; |
62b83e6d MT |
45 | }; |
46 | ||
010fe9b6 MT |
47 | static off_t loc_stringpool_get_offset(struct loc_stringpool* pool, const char* pos) { |
48 | if (pos < pool->data) | |
49 | return -EFAULT; | |
50 | ||
51 | if (pos > (pool->data + pool->length)) | |
52 | return -EFAULT; | |
53 | ||
54 | return pos - pool->data; | |
55 | } | |
56 | ||
57 | static char* __loc_stringpool_get(struct loc_stringpool* pool, off_t offset) { | |
58 | if (offset < 0 || offset >= pool->length) | |
59 | return NULL; | |
60 | ||
61 | return pool->data + offset; | |
62 | } | |
63 | ||
64 | static int loc_stringpool_grow(struct loc_stringpool* pool, size_t length) { | |
65 | DEBUG(pool->ctx, "Growing string pool to %zu bytes\n", length); | |
66 | ||
67 | // Save pos pointer | |
68 | off_t pos = loc_stringpool_get_offset(pool, pool->pos); | |
69 | ||
70 | // Reallocate data section | |
71 | pool->data = realloc(pool->data, length); | |
72 | if (!pool->data) | |
73 | return -ENOMEM; | |
74 | ||
75 | pool->length = length; | |
76 | ||
77 | // Restore pos | |
78 | pool->pos = __loc_stringpool_get(pool, pos); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static off_t loc_stringpool_append(struct loc_stringpool* pool, const char* string) { | |
84 | if (!string || !*string) | |
85 | return -EINVAL; | |
86 | ||
87 | DEBUG(pool->ctx, "Appending '%s' to string pool at %p\n", string, pool); | |
88 | ||
89 | // Make sure we have enough space | |
90 | int r = loc_stringpool_grow(pool, pool->length + strlen(string) + 1); | |
91 | if (r) { | |
92 | errno = r; | |
93 | return -1; | |
94 | } | |
95 | ||
96 | off_t offset = loc_stringpool_get_offset(pool, pool->pos); | |
97 | ||
98 | // Copy string byte by byte | |
99 | while (*string) | |
100 | *pool->pos++ = *string++; | |
101 | ||
102 | // Terminate the string | |
103 | *pool->pos++ = '\0'; | |
104 | ||
105 | return offset; | |
106 | } | |
107 | ||
0e974d4b MT |
108 | static int __loc_stringpool_new(struct loc_ctx* ctx, struct loc_stringpool** pool, enum loc_stringpool_mode mode) { |
109 | struct loc_stringpool* p = calloc(1, sizeof(*p)); | |
110 | if (!p) | |
111 | return -ENOMEM; | |
112 | ||
113 | p->ctx = loc_ref(ctx); | |
114 | p->refcount = 1; | |
6809d5ac | 115 | |
0e974d4b MT |
116 | // Save mode |
117 | p->mode = mode; | |
118 | ||
119 | *pool = p; | |
6809d5ac MT |
120 | |
121 | return 0; | |
122 | } | |
123 | ||
0e974d4b | 124 | LOC_EXPORT int loc_stringpool_new(struct loc_ctx* ctx, struct loc_stringpool** pool) { |
010fe9b6 MT |
125 | int r = __loc_stringpool_new(ctx, pool, STRINGPOOL_DEFAULT); |
126 | if (r) | |
127 | return r; | |
128 | ||
129 | // Add an empty string to new string pools | |
130 | loc_stringpool_append(*pool, ""); | |
131 | ||
132 | return r; | |
0e974d4b | 133 | } |
2601e83e | 134 | |
0e974d4b MT |
135 | static int loc_stringpool_mmap(struct loc_stringpool* pool, FILE* f, size_t length, off_t offset) { |
136 | if (pool->mode != STRINGPOOL_MMAP) | |
137 | return -EINVAL; | |
6809d5ac | 138 | |
5c57de03 | 139 | DEBUG(pool->ctx, "Reading string pool starting from %jd (%zu bytes)\n", (intmax_t)offset, length); |
6809d5ac | 140 | |
0e974d4b MT |
141 | // Map file content into memory |
142 | pool->data = pool->pos = mmap(NULL, length, PROT_READ, | |
143 | MAP_PRIVATE, fileno(f), offset); | |
2601e83e | 144 | |
0e974d4b MT |
145 | // Store size of section |
146 | pool->length = length; | |
6809d5ac | 147 | |
0e974d4b | 148 | if (pool->data == MAP_FAILED) |
6809d5ac | 149 | return -errno; |
2601e83e MT |
150 | |
151 | return 0; | |
152 | } | |
153 | ||
0e974d4b MT |
154 | LOC_EXPORT int loc_stringpool_open(struct loc_ctx* ctx, struct loc_stringpool** pool, |
155 | FILE* f, size_t length, off_t offset) { | |
156 | int r = __loc_stringpool_new(ctx, pool, STRINGPOOL_MMAP); | |
157 | if (r) | |
158 | return r; | |
62b83e6d | 159 | |
0e974d4b | 160 | // Map data into memory |
2a30e4de MT |
161 | if (length > 0) { |
162 | r = loc_stringpool_mmap(*pool, f, length, offset); | |
163 | if (r) | |
164 | return r; | |
165 | } | |
62b83e6d MT |
166 | |
167 | return 0; | |
168 | } | |
169 | ||
170 | LOC_EXPORT struct loc_stringpool* loc_stringpool_ref(struct loc_stringpool* pool) { | |
171 | pool->refcount++; | |
172 | ||
173 | return pool; | |
174 | } | |
175 | ||
176 | static void loc_stringpool_free(struct loc_stringpool* pool) { | |
177 | DEBUG(pool->ctx, "Releasing string pool %p\n", pool); | |
0e974d4b MT |
178 | int r; |
179 | ||
180 | switch (pool->mode) { | |
181 | case STRINGPOOL_DEFAULT: | |
182 | if (pool->data) | |
183 | free(pool->data); | |
184 | break; | |
185 | ||
186 | case STRINGPOOL_MMAP: | |
187 | if (pool->data) { | |
188 | r = munmap(pool->data, pool->length); | |
189 | if (r) | |
190 | ERROR(pool->ctx, "Could not unmap data at %p: %s\n", | |
191 | pool->data, strerror(errno)); | |
192 | } | |
193 | break; | |
194 | } | |
62b83e6d MT |
195 | |
196 | loc_unref(pool->ctx); | |
62b83e6d MT |
197 | free(pool); |
198 | } | |
199 | ||
200 | LOC_EXPORT struct loc_stringpool* loc_stringpool_unref(struct loc_stringpool* pool) { | |
201 | if (--pool->refcount > 0) | |
202 | return NULL; | |
203 | ||
204 | loc_stringpool_free(pool); | |
205 | ||
206 | return NULL; | |
207 | } | |
208 | ||
62b83e6d MT |
209 | static off_t loc_stringpool_get_next_offset(struct loc_stringpool* pool, off_t offset) { |
210 | const char* string = loc_stringpool_get(pool, offset); | |
211 | ||
212 | return offset + strlen(string) + 1; | |
213 | } | |
214 | ||
0e974d4b MT |
215 | LOC_EXPORT const char* loc_stringpool_get(struct loc_stringpool* pool, off_t offset) { |
216 | return __loc_stringpool_get(pool, offset); | |
62b83e6d MT |
217 | } |
218 | ||
2601e83e MT |
219 | LOC_EXPORT size_t loc_stringpool_get_size(struct loc_stringpool* pool) { |
220 | return loc_stringpool_get_offset(pool, pool->pos); | |
221 | } | |
222 | ||
62b83e6d MT |
223 | static off_t loc_stringpool_find(struct loc_stringpool* pool, const char* s) { |
224 | if (!s || !*s) | |
225 | return -EINVAL; | |
226 | ||
227 | off_t offset = 0; | |
0e974d4b | 228 | while (offset < pool->length) { |
62b83e6d MT |
229 | const char* string = loc_stringpool_get(pool, offset); |
230 | if (!string) | |
231 | break; | |
232 | ||
233 | int r = strcmp(s, string); | |
234 | if (r == 0) | |
235 | return offset; | |
236 | ||
237 | offset = loc_stringpool_get_next_offset(pool, offset); | |
238 | } | |
239 | ||
240 | return -ENOENT; | |
241 | } | |
242 | ||
62b83e6d MT |
243 | LOC_EXPORT off_t loc_stringpool_add(struct loc_stringpool* pool, const char* string) { |
244 | off_t offset = loc_stringpool_find(pool, string); | |
245 | if (offset >= 0) { | |
5c57de03 | 246 | DEBUG(pool->ctx, "Found '%s' at position %jd\n", string, (intmax_t)offset); |
62b83e6d MT |
247 | return offset; |
248 | } | |
249 | ||
250 | return loc_stringpool_append(pool, string); | |
251 | } | |
252 | ||
253 | LOC_EXPORT void loc_stringpool_dump(struct loc_stringpool* pool) { | |
254 | off_t offset = 0; | |
255 | ||
0e974d4b | 256 | while (offset < pool->length) { |
62b83e6d MT |
257 | const char* string = loc_stringpool_get(pool, offset); |
258 | if (!string) | |
259 | break; | |
260 | ||
5c57de03 | 261 | printf("%jd (%zu): %s\n", (intmax_t)offset, strlen(string), string); |
62b83e6d MT |
262 | |
263 | offset = loc_stringpool_get_next_offset(pool, offset); | |
264 | } | |
265 | } | |
2601e83e | 266 | |
2601e83e MT |
267 | LOC_EXPORT size_t loc_stringpool_write(struct loc_stringpool* pool, FILE* f) { |
268 | size_t size = loc_stringpool_get_size(pool); | |
269 | ||
8f5b676a | 270 | return fwrite(pool->data, sizeof(*pool->data), size, f); |
2601e83e | 271 | } |