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bee24666 DE |
1 | /* |
2 | * This file is part of the libsigrok project. | |
3 | * | |
4 | * Copyright (C) 2015 Daniel Elstner <daniel.kitta@gmail.com> | |
5 | * | |
6 | * This program is free software: you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation, either version 3 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program 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 | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | ||
20 | #include <config.h> | |
21 | #include <errno.h> | |
22 | #include <stdio.h> | |
23 | #include <glib.h> | |
24 | #include <glib/gstdio.h> | |
25 | #include <libsigrok/libsigrok.h> | |
26 | #include "libsigrok-internal.h" | |
27 | ||
28 | /** @cond PRIVATE */ | |
29 | #define LOG_PREFIX "resource" | |
30 | /** @endcond */ | |
31 | ||
32 | /** | |
33 | * @file | |
34 | * | |
35 | * Access to resource files. | |
36 | */ | |
37 | ||
addb7340 SA |
38 | /** |
39 | * Get a list of paths where we look for resource (e.g. firmware) files. | |
40 | * | |
41 | * @param res_type The type of resource to get the search paths for. | |
42 | * | |
43 | * @return List of strings that must be freed after use, including the strings. | |
44 | * | |
45 | * @since 0.6.0 | |
46 | */ | |
47 | SR_API GSList *sr_resourcepaths_get(int res_type) | |
48 | { | |
49 | const char *subdir = NULL; | |
50 | GSList *l = NULL; | |
51 | const char *env; | |
52 | const char *const *datadirs; | |
53 | ||
54 | if (res_type == SR_RESOURCE_FIRMWARE) { | |
55 | subdir = "sigrok-firmware"; | |
56 | ||
57 | env = g_getenv("SIGROK_FIRMWARE_DIR"); | |
58 | if (!env) | |
59 | sr_dbg("SIGROK_FIRMWARE_DIR environment variable not set, ignoring."); | |
60 | else | |
61 | l = g_slist_append(l, g_strdup(env)); | |
62 | } | |
63 | ||
64 | l = g_slist_append(l, g_build_filename(g_get_user_data_dir(), subdir, NULL)); | |
65 | ||
66 | #ifdef FIRMWARE_DIR | |
67 | if (res_type == SR_RESOURCE_FIRMWARE) { | |
68 | /* | |
69 | * Scan the hard-coded directory before the system directories to | |
70 | * avoid picking up possibly outdated files from a system install. | |
71 | */ | |
72 | l = g_slist_append(l, g_strdup(FIRMWARE_DIR)); | |
73 | } | |
74 | #endif | |
75 | ||
76 | datadirs = g_get_system_data_dirs(); | |
77 | while (*datadirs) | |
78 | l = g_slist_append(l, g_build_filename(*datadirs++, subdir, NULL)); | |
79 | ||
80 | return l; | |
81 | } | |
82 | ||
83 | /** | |
84 | * Retrieve the size of the open stream @a file. | |
7d89fd60 DE |
85 | * |
86 | * This function only works on seekable streams. However, the set of seekable | |
87 | * streams is generally congruent with the set of streams that have a size. | |
88 | * Code that needs to work with any type of stream (including pipes) should | |
89 | * require neither seekability nor advance knowledge of the size. | |
90 | * On failure, the return value is negative and errno is set. | |
91 | * | |
92 | * @param file An I/O stream opened in binary mode. | |
93 | * @return The size of @a file in bytes, or a negative value on failure. | |
94 | * | |
95 | * @private | |
96 | */ | |
97 | SR_PRIV int64_t sr_file_get_size(FILE *file) | |
98 | { | |
99 | off_t filepos, filesize; | |
100 | ||
101 | /* ftello() and fseeko() are not standard C, but part of POSIX.1-2001. | |
102 | * Thus, if these functions are available at all, they can reasonably | |
103 | * be expected to also conform to POSIX semantics. In particular, this | |
104 | * means that ftello() after fseeko(..., SEEK_END) has a defined result | |
105 | * and can be used to get the size of a seekable stream. | |
106 | * On Windows, the result is fully defined only for binary streams. | |
107 | */ | |
108 | filepos = ftello(file); | |
109 | if (filepos < 0) | |
110 | return -1; | |
111 | ||
112 | if (fseeko(file, 0, SEEK_END) < 0) | |
113 | return -1; | |
114 | ||
115 | filesize = ftello(file); | |
116 | if (filesize < 0) | |
117 | return -1; | |
118 | ||
119 | if (fseeko(file, filepos, SEEK_SET) < 0) | |
120 | return -1; | |
121 | ||
122 | return filesize; | |
123 | } | |
124 | ||
bee24666 DE |
125 | static FILE *try_open_file(const char *datadir, const char *subdir, |
126 | const char *name) | |
127 | { | |
128 | char *filename; | |
129 | FILE *file; | |
130 | ||
131 | filename = g_build_filename(datadir, subdir, name, NULL); | |
132 | file = g_fopen(filename, "rb"); | |
133 | ||
134 | if (file) | |
135 | sr_info("Opened '%s'.", filename); | |
136 | else | |
137 | sr_spew("Attempt to open '%s' failed: %s", | |
138 | filename, g_strerror(errno)); | |
139 | g_free(filename); | |
140 | ||
141 | return file; | |
142 | } | |
143 | ||
144 | static int resource_open_default(struct sr_resource *res, | |
145 | const char *name, void *cb_data) | |
146 | { | |
addb7340 | 147 | GSList *paths, *p = NULL; |
bee24666 | 148 | int64_t filesize; |
1503d457 | 149 | FILE *file = NULL; |
bee24666 DE |
150 | |
151 | (void)cb_data; | |
152 | ||
addb7340 SA |
153 | paths = sr_resourcepaths_get(res->type); |
154 | ||
155 | /* Currently, the enum only defines SR_RESOURCE_FIRMWARE. */ | |
156 | if (res->type != SR_RESOURCE_FIRMWARE) { | |
bee24666 DE |
157 | sr_err("%s: unknown type %d.", __func__, res->type); |
158 | return SR_ERR_ARG; | |
159 | } | |
160 | ||
addb7340 SA |
161 | p = paths; |
162 | while (p && !file) { | |
163 | file = try_open_file((const char *)(p->data), NULL, name); | |
164 | p = p->next; | |
bee24666 | 165 | } |
addb7340 SA |
166 | g_slist_free_full(paths, g_free); |
167 | ||
bee24666 | 168 | if (!file) { |
7ade12b4 | 169 | sr_dbg("Failed to locate '%s'.", name); |
bee24666 DE |
170 | return SR_ERR; |
171 | } | |
172 | ||
173 | filesize = sr_file_get_size(file); | |
174 | if (filesize < 0) { | |
175 | sr_err("Failed to obtain size of '%s': %s", | |
176 | name, g_strerror(errno)); | |
177 | fclose(file); | |
178 | return SR_ERR; | |
179 | } | |
180 | res->size = filesize; | |
181 | res->handle = file; | |
182 | ||
183 | return SR_OK; | |
184 | } | |
185 | ||
186 | static int resource_close_default(struct sr_resource *res, void *cb_data) | |
187 | { | |
188 | FILE *file; | |
189 | ||
190 | (void)cb_data; | |
191 | ||
192 | file = res->handle; | |
193 | if (!file) { | |
194 | sr_err("%s: invalid handle.", __func__); | |
195 | return SR_ERR_ARG; | |
196 | } | |
197 | ||
198 | if (fclose(file) < 0) { | |
199 | sr_err("Failed to close file: %s", g_strerror(errno)); | |
200 | return SR_ERR; | |
201 | } | |
202 | res->handle = NULL; | |
203 | ||
204 | return SR_OK; | |
205 | } | |
206 | ||
32ba0d80 | 207 | static gssize resource_read_default(const struct sr_resource *res, |
bee24666 DE |
208 | void *buf, size_t count, void *cb_data) |
209 | { | |
210 | FILE *file; | |
211 | size_t n_read; | |
212 | ||
213 | (void)cb_data; | |
214 | ||
215 | file = res->handle; | |
216 | if (!file) { | |
217 | sr_err("%s: invalid handle.", __func__); | |
218 | return SR_ERR_ARG; | |
219 | } | |
32ba0d80 | 220 | if (count > G_MAXSSIZE) { |
bee24666 DE |
221 | sr_err("%s: count %zu too large.", __func__, count); |
222 | return SR_ERR_ARG; | |
223 | } | |
224 | ||
225 | n_read = fread(buf, 1, count, file); | |
226 | ||
227 | if (n_read != count && ferror(file)) { | |
228 | sr_err("Failed to read resource file: %s", g_strerror(errno)); | |
229 | return SR_ERR; | |
230 | } | |
231 | return n_read; | |
232 | } | |
233 | ||
234 | /** | |
235 | * Install resource access hooks. | |
236 | * | |
237 | * @param ctx libsigrok context. Must not be NULL. | |
238 | * @param open_cb Resource open callback, or NULL to unset. | |
239 | * @param close_cb Resource close callback, or NULL to unset. | |
240 | * @param read_cb Resource read callback, or NULL to unset. | |
241 | * @param cb_data User data pointer passed to callbacks. | |
242 | * | |
243 | * @retval SR_OK Success. | |
244 | * @retval SR_ERR_ARG Invalid argument. | |
245 | * | |
246 | * @since 0.4.0 | |
247 | */ | |
248 | SR_API int sr_resource_set_hooks(struct sr_context *ctx, | |
249 | sr_resource_open_callback open_cb, | |
250 | sr_resource_close_callback close_cb, | |
251 | sr_resource_read_callback read_cb, void *cb_data) | |
252 | { | |
253 | if (!ctx) { | |
254 | sr_err("%s: ctx was NULL.", __func__); | |
255 | return SR_ERR_ARG; | |
256 | } | |
257 | if (open_cb && close_cb && read_cb) { | |
d9251a2c | 258 | ctx->resource_open_cb = open_cb; |
bee24666 | 259 | ctx->resource_close_cb = close_cb; |
d9251a2c UH |
260 | ctx->resource_read_cb = read_cb; |
261 | ctx->resource_cb_data = cb_data; | |
bee24666 | 262 | } else if (!open_cb && !close_cb && !read_cb) { |
d9251a2c | 263 | ctx->resource_open_cb = &resource_open_default; |
bee24666 | 264 | ctx->resource_close_cb = &resource_close_default; |
d9251a2c UH |
265 | ctx->resource_read_cb = &resource_read_default; |
266 | ctx->resource_cb_data = ctx; | |
bee24666 DE |
267 | } else { |
268 | sr_err("%s: inconsistent callback pointers.", __func__); | |
269 | return SR_ERR_ARG; | |
270 | } | |
271 | return SR_OK; | |
272 | } | |
273 | ||
274 | /** | |
275 | * Open resource. | |
276 | * | |
277 | * @param ctx libsigrok context. Must not be NULL. | |
278 | * @param[out] res Resource descriptor to fill in. Must not be NULL. | |
279 | * @param type Resource type ID. | |
280 | * @param name Name of the resource. Must not be NULL. | |
281 | * | |
282 | * @retval SR_OK Success. | |
283 | * @retval SR_ERR_ARG Invalid argument. | |
284 | * @retval SR_ERR Other error. | |
285 | * | |
286 | * @private | |
287 | */ | |
288 | SR_PRIV int sr_resource_open(struct sr_context *ctx, | |
289 | struct sr_resource *res, int type, const char *name) | |
290 | { | |
291 | int ret; | |
292 | ||
293 | res->size = 0; | |
294 | res->handle = NULL; | |
295 | res->type = type; | |
296 | ||
297 | ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data); | |
298 | ||
299 | if (ret != SR_OK) | |
7ade12b4 UH |
300 | sr_err("Failed to open resource '%s' (use loglevel 5/spew for" |
301 | " details).", name); | |
bee24666 DE |
302 | |
303 | return ret; | |
304 | } | |
305 | ||
306 | /** | |
307 | * Close resource. | |
308 | * | |
309 | * @param ctx libsigrok context. Must not be NULL. | |
310 | * @param[inout] res Resource descriptor. Must not be NULL. | |
311 | * | |
312 | * @retval SR_OK Success. | |
313 | * @retval SR_ERR_ARG Invalid argument. | |
314 | * @retval SR_ERR Other error. | |
315 | * | |
316 | * @private | |
317 | */ | |
318 | SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res) | |
319 | { | |
320 | int ret; | |
321 | ||
322 | ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data); | |
323 | ||
324 | if (ret != SR_OK) | |
325 | sr_err("Failed to close resource."); | |
326 | ||
327 | return ret; | |
328 | } | |
329 | ||
330 | /** | |
331 | * Read resource data. | |
332 | * | |
333 | * @param ctx libsigrok context. Must not be NULL. | |
334 | * @param[in] res Resource descriptor. Must not be NULL. | |
335 | * @param[out] buf Buffer to store @a count bytes into. Must not be NULL. | |
336 | * @param count Number of bytes to read. | |
337 | * | |
338 | * @return The number of bytes actually read, or a negative value on error. | |
339 | * @retval SR_ERR_ARG Invalid argument. | |
340 | * @retval SR_ERR Other error. | |
341 | * | |
342 | * @private | |
343 | */ | |
32ba0d80 | 344 | SR_PRIV gssize sr_resource_read(struct sr_context *ctx, |
bee24666 DE |
345 | const struct sr_resource *res, void *buf, size_t count) |
346 | { | |
32ba0d80 | 347 | gssize n_read; |
bee24666 DE |
348 | |
349 | n_read = (*ctx->resource_read_cb)(res, buf, count, | |
350 | ctx->resource_cb_data); | |
351 | if (n_read < 0) | |
352 | sr_err("Failed to read resource."); | |
353 | ||
354 | return n_read; | |
355 | } | |
356 | ||
357 | /** | |
358 | * Load a resource into memory. | |
359 | * | |
360 | * @param ctx libsigrok context. Must not be NULL. | |
361 | * @param type Resource type ID. | |
362 | * @param name Name of the resource. Must not be NULL. | |
363 | * @param[out] size Size in bytes of the returned buffer. Must not be NULL. | |
364 | * @param max_size Size limit. Error out if the resource is larger than this. | |
365 | * | |
366 | * @return A buffer containing the resource data, or NULL on failure. Must | |
d9251a2c | 367 | * be freed by the caller using g_free(). |
bee24666 DE |
368 | * |
369 | * @private | |
370 | */ | |
371 | SR_PRIV void *sr_resource_load(struct sr_context *ctx, | |
372 | int type, const char *name, size_t *size, size_t max_size) | |
373 | { | |
374 | struct sr_resource res; | |
375 | void *buf; | |
45d835ed | 376 | size_t res_size; |
32ba0d80 | 377 | gssize n_read; |
bee24666 DE |
378 | |
379 | if (sr_resource_open(ctx, &res, type, name) != SR_OK) | |
380 | return NULL; | |
381 | ||
382 | if (res.size > max_size) { | |
383 | sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.", | |
384 | res.size, name, max_size); | |
385 | sr_resource_close(ctx, &res); | |
386 | return NULL; | |
387 | } | |
45d835ed DE |
388 | res_size = res.size; |
389 | ||
390 | buf = g_try_malloc(res_size); | |
bee24666 DE |
391 | if (!buf) { |
392 | sr_err("Failed to allocate buffer for '%s'.", name); | |
393 | sr_resource_close(ctx, &res); | |
394 | return NULL; | |
395 | } | |
396 | ||
45d835ed | 397 | n_read = sr_resource_read(ctx, &res, buf, res_size); |
bee24666 DE |
398 | sr_resource_close(ctx, &res); |
399 | ||
45d835ed | 400 | if (n_read < 0 || (size_t)n_read != res_size) { |
bee24666 DE |
401 | if (n_read >= 0) |
402 | sr_err("Failed to read '%s': premature end of file.", | |
403 | name); | |
404 | g_free(buf); | |
405 | return NULL; | |
406 | } | |
407 | ||
45d835ed | 408 | *size = res_size; |
bee24666 DE |
409 | return buf; |
410 | } | |
411 | ||
412 | /** @} */ |