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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"); | |
3ad0308c | 58 | if (env) |
addb7340 SA |
59 | l = g_slist_append(l, g_strdup(env)); |
60 | } | |
61 | ||
62 | l = g_slist_append(l, g_build_filename(g_get_user_data_dir(), subdir, NULL)); | |
63 | ||
64 | #ifdef FIRMWARE_DIR | |
65 | if (res_type == SR_RESOURCE_FIRMWARE) { | |
66 | /* | |
67 | * Scan the hard-coded directory before the system directories to | |
68 | * avoid picking up possibly outdated files from a system install. | |
69 | */ | |
70 | l = g_slist_append(l, g_strdup(FIRMWARE_DIR)); | |
71 | } | |
72 | #endif | |
73 | ||
74 | datadirs = g_get_system_data_dirs(); | |
75 | while (*datadirs) | |
76 | l = g_slist_append(l, g_build_filename(*datadirs++, subdir, NULL)); | |
77 | ||
78 | return l; | |
79 | } | |
80 | ||
81 | /** | |
82 | * Retrieve the size of the open stream @a file. | |
7d89fd60 DE |
83 | * |
84 | * This function only works on seekable streams. However, the set of seekable | |
85 | * streams is generally congruent with the set of streams that have a size. | |
86 | * Code that needs to work with any type of stream (including pipes) should | |
87 | * require neither seekability nor advance knowledge of the size. | |
88 | * On failure, the return value is negative and errno is set. | |
89 | * | |
90 | * @param file An I/O stream opened in binary mode. | |
91 | * @return The size of @a file in bytes, or a negative value on failure. | |
92 | * | |
93 | * @private | |
94 | */ | |
95 | SR_PRIV int64_t sr_file_get_size(FILE *file) | |
96 | { | |
97 | off_t filepos, filesize; | |
98 | ||
99 | /* ftello() and fseeko() are not standard C, but part of POSIX.1-2001. | |
100 | * Thus, if these functions are available at all, they can reasonably | |
101 | * be expected to also conform to POSIX semantics. In particular, this | |
102 | * means that ftello() after fseeko(..., SEEK_END) has a defined result | |
103 | * and can be used to get the size of a seekable stream. | |
104 | * On Windows, the result is fully defined only for binary streams. | |
105 | */ | |
106 | filepos = ftello(file); | |
107 | if (filepos < 0) | |
108 | return -1; | |
109 | ||
110 | if (fseeko(file, 0, SEEK_END) < 0) | |
111 | return -1; | |
112 | ||
113 | filesize = ftello(file); | |
114 | if (filesize < 0) | |
115 | return -1; | |
116 | ||
117 | if (fseeko(file, filepos, SEEK_SET) < 0) | |
118 | return -1; | |
119 | ||
120 | return filesize; | |
121 | } | |
122 | ||
bee24666 DE |
123 | static FILE *try_open_file(const char *datadir, const char *subdir, |
124 | const char *name) | |
125 | { | |
126 | char *filename; | |
127 | FILE *file; | |
128 | ||
366ccb8a SA |
129 | if (subdir) |
130 | filename = g_build_filename(datadir, subdir, name, NULL); | |
131 | else | |
132 | filename = g_build_filename(datadir, name, NULL); | |
133 | ||
bee24666 DE |
134 | file = g_fopen(filename, "rb"); |
135 | ||
136 | if (file) | |
137 | sr_info("Opened '%s'.", filename); | |
138 | else | |
139 | sr_spew("Attempt to open '%s' failed: %s", | |
140 | filename, g_strerror(errno)); | |
141 | g_free(filename); | |
142 | ||
143 | return file; | |
144 | } | |
145 | ||
146 | static int resource_open_default(struct sr_resource *res, | |
147 | const char *name, void *cb_data) | |
148 | { | |
addb7340 | 149 | GSList *paths, *p = NULL; |
bee24666 | 150 | int64_t filesize; |
1503d457 | 151 | FILE *file = NULL; |
bee24666 DE |
152 | |
153 | (void)cb_data; | |
154 | ||
addb7340 SA |
155 | paths = sr_resourcepaths_get(res->type); |
156 | ||
157 | /* Currently, the enum only defines SR_RESOURCE_FIRMWARE. */ | |
158 | if (res->type != SR_RESOURCE_FIRMWARE) { | |
bee24666 DE |
159 | sr_err("%s: unknown type %d.", __func__, res->type); |
160 | return SR_ERR_ARG; | |
161 | } | |
162 | ||
addb7340 SA |
163 | p = paths; |
164 | while (p && !file) { | |
165 | file = try_open_file((const char *)(p->data), NULL, name); | |
166 | p = p->next; | |
bee24666 | 167 | } |
addb7340 SA |
168 | g_slist_free_full(paths, g_free); |
169 | ||
bee24666 | 170 | if (!file) { |
7ade12b4 | 171 | sr_dbg("Failed to locate '%s'.", name); |
bee24666 DE |
172 | return SR_ERR; |
173 | } | |
174 | ||
175 | filesize = sr_file_get_size(file); | |
176 | if (filesize < 0) { | |
177 | sr_err("Failed to obtain size of '%s': %s", | |
178 | name, g_strerror(errno)); | |
179 | fclose(file); | |
180 | return SR_ERR; | |
181 | } | |
182 | res->size = filesize; | |
183 | res->handle = file; | |
184 | ||
185 | return SR_OK; | |
186 | } | |
187 | ||
188 | static int resource_close_default(struct sr_resource *res, void *cb_data) | |
189 | { | |
190 | FILE *file; | |
191 | ||
192 | (void)cb_data; | |
193 | ||
194 | file = res->handle; | |
195 | if (!file) { | |
196 | sr_err("%s: invalid handle.", __func__); | |
197 | return SR_ERR_ARG; | |
198 | } | |
199 | ||
200 | if (fclose(file) < 0) { | |
201 | sr_err("Failed to close file: %s", g_strerror(errno)); | |
202 | return SR_ERR; | |
203 | } | |
204 | res->handle = NULL; | |
205 | ||
206 | return SR_OK; | |
207 | } | |
208 | ||
32ba0d80 | 209 | static gssize resource_read_default(const struct sr_resource *res, |
bee24666 DE |
210 | void *buf, size_t count, void *cb_data) |
211 | { | |
212 | FILE *file; | |
213 | size_t n_read; | |
214 | ||
215 | (void)cb_data; | |
216 | ||
217 | file = res->handle; | |
218 | if (!file) { | |
219 | sr_err("%s: invalid handle.", __func__); | |
220 | return SR_ERR_ARG; | |
221 | } | |
32ba0d80 | 222 | if (count > G_MAXSSIZE) { |
bee24666 DE |
223 | sr_err("%s: count %zu too large.", __func__, count); |
224 | return SR_ERR_ARG; | |
225 | } | |
226 | ||
227 | n_read = fread(buf, 1, count, file); | |
228 | ||
229 | if (n_read != count && ferror(file)) { | |
230 | sr_err("Failed to read resource file: %s", g_strerror(errno)); | |
231 | return SR_ERR; | |
232 | } | |
233 | return n_read; | |
234 | } | |
235 | ||
236 | /** | |
237 | * Install resource access hooks. | |
238 | * | |
239 | * @param ctx libsigrok context. Must not be NULL. | |
240 | * @param open_cb Resource open callback, or NULL to unset. | |
241 | * @param close_cb Resource close callback, or NULL to unset. | |
242 | * @param read_cb Resource read callback, or NULL to unset. | |
243 | * @param cb_data User data pointer passed to callbacks. | |
244 | * | |
245 | * @retval SR_OK Success. | |
246 | * @retval SR_ERR_ARG Invalid argument. | |
247 | * | |
248 | * @since 0.4.0 | |
249 | */ | |
250 | SR_API int sr_resource_set_hooks(struct sr_context *ctx, | |
251 | sr_resource_open_callback open_cb, | |
252 | sr_resource_close_callback close_cb, | |
253 | sr_resource_read_callback read_cb, void *cb_data) | |
254 | { | |
255 | if (!ctx) { | |
256 | sr_err("%s: ctx was NULL.", __func__); | |
257 | return SR_ERR_ARG; | |
258 | } | |
259 | if (open_cb && close_cb && read_cb) { | |
d9251a2c | 260 | ctx->resource_open_cb = open_cb; |
bee24666 | 261 | ctx->resource_close_cb = close_cb; |
d9251a2c UH |
262 | ctx->resource_read_cb = read_cb; |
263 | ctx->resource_cb_data = cb_data; | |
bee24666 | 264 | } else if (!open_cb && !close_cb && !read_cb) { |
d9251a2c | 265 | ctx->resource_open_cb = &resource_open_default; |
bee24666 | 266 | ctx->resource_close_cb = &resource_close_default; |
d9251a2c UH |
267 | ctx->resource_read_cb = &resource_read_default; |
268 | ctx->resource_cb_data = ctx; | |
bee24666 DE |
269 | } else { |
270 | sr_err("%s: inconsistent callback pointers.", __func__); | |
271 | return SR_ERR_ARG; | |
272 | } | |
273 | return SR_OK; | |
274 | } | |
275 | ||
276 | /** | |
277 | * Open resource. | |
278 | * | |
279 | * @param ctx libsigrok context. Must not be NULL. | |
280 | * @param[out] res Resource descriptor to fill in. Must not be NULL. | |
281 | * @param type Resource type ID. | |
282 | * @param name Name of the resource. Must not be NULL. | |
283 | * | |
284 | * @retval SR_OK Success. | |
285 | * @retval SR_ERR_ARG Invalid argument. | |
286 | * @retval SR_ERR Other error. | |
287 | * | |
288 | * @private | |
289 | */ | |
290 | SR_PRIV int sr_resource_open(struct sr_context *ctx, | |
291 | struct sr_resource *res, int type, const char *name) | |
292 | { | |
293 | int ret; | |
294 | ||
295 | res->size = 0; | |
296 | res->handle = NULL; | |
297 | res->type = type; | |
298 | ||
299 | ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data); | |
300 | ||
301 | if (ret != SR_OK) | |
7ade12b4 UH |
302 | sr_err("Failed to open resource '%s' (use loglevel 5/spew for" |
303 | " details).", name); | |
bee24666 DE |
304 | |
305 | return ret; | |
306 | } | |
307 | ||
308 | /** | |
309 | * Close resource. | |
310 | * | |
311 | * @param ctx libsigrok context. Must not be NULL. | |
312 | * @param[inout] res Resource descriptor. Must not be NULL. | |
313 | * | |
314 | * @retval SR_OK Success. | |
315 | * @retval SR_ERR_ARG Invalid argument. | |
316 | * @retval SR_ERR Other error. | |
317 | * | |
318 | * @private | |
319 | */ | |
320 | SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res) | |
321 | { | |
322 | int ret; | |
323 | ||
324 | ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data); | |
325 | ||
326 | if (ret != SR_OK) | |
327 | sr_err("Failed to close resource."); | |
328 | ||
329 | return ret; | |
330 | } | |
331 | ||
332 | /** | |
333 | * Read resource data. | |
334 | * | |
335 | * @param ctx libsigrok context. Must not be NULL. | |
336 | * @param[in] res Resource descriptor. Must not be NULL. | |
337 | * @param[out] buf Buffer to store @a count bytes into. Must not be NULL. | |
338 | * @param count Number of bytes to read. | |
339 | * | |
340 | * @return The number of bytes actually read, or a negative value on error. | |
341 | * @retval SR_ERR_ARG Invalid argument. | |
342 | * @retval SR_ERR Other error. | |
343 | * | |
344 | * @private | |
345 | */ | |
32ba0d80 | 346 | SR_PRIV gssize sr_resource_read(struct sr_context *ctx, |
bee24666 DE |
347 | const struct sr_resource *res, void *buf, size_t count) |
348 | { | |
32ba0d80 | 349 | gssize n_read; |
bee24666 DE |
350 | |
351 | n_read = (*ctx->resource_read_cb)(res, buf, count, | |
352 | ctx->resource_cb_data); | |
353 | if (n_read < 0) | |
354 | sr_err("Failed to read resource."); | |
355 | ||
356 | return n_read; | |
357 | } | |
358 | ||
359 | /** | |
360 | * Load a resource into memory. | |
361 | * | |
362 | * @param ctx libsigrok context. Must not be NULL. | |
363 | * @param type Resource type ID. | |
364 | * @param name Name of the resource. Must not be NULL. | |
365 | * @param[out] size Size in bytes of the returned buffer. Must not be NULL. | |
366 | * @param max_size Size limit. Error out if the resource is larger than this. | |
367 | * | |
368 | * @return A buffer containing the resource data, or NULL on failure. Must | |
d9251a2c | 369 | * be freed by the caller using g_free(). |
bee24666 DE |
370 | * |
371 | * @private | |
372 | */ | |
373 | SR_PRIV void *sr_resource_load(struct sr_context *ctx, | |
374 | int type, const char *name, size_t *size, size_t max_size) | |
375 | { | |
376 | struct sr_resource res; | |
377 | void *buf; | |
45d835ed | 378 | size_t res_size; |
32ba0d80 | 379 | gssize n_read; |
bee24666 DE |
380 | |
381 | if (sr_resource_open(ctx, &res, type, name) != SR_OK) | |
382 | return NULL; | |
383 | ||
384 | if (res.size > max_size) { | |
385 | sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.", | |
386 | res.size, name, max_size); | |
387 | sr_resource_close(ctx, &res); | |
388 | return NULL; | |
389 | } | |
45d835ed DE |
390 | res_size = res.size; |
391 | ||
392 | buf = g_try_malloc(res_size); | |
bee24666 DE |
393 | if (!buf) { |
394 | sr_err("Failed to allocate buffer for '%s'.", name); | |
395 | sr_resource_close(ctx, &res); | |
396 | return NULL; | |
397 | } | |
398 | ||
45d835ed | 399 | n_read = sr_resource_read(ctx, &res, buf, res_size); |
bee24666 DE |
400 | sr_resource_close(ctx, &res); |
401 | ||
45d835ed | 402 | if (n_read < 0 || (size_t)n_read != res_size) { |
bee24666 DE |
403 | if (n_read >= 0) |
404 | sr_err("Failed to read '%s': premature end of file.", | |
405 | name); | |
406 | g_free(buf); | |
407 | return NULL; | |
408 | } | |
409 | ||
45d835ed | 410 | *size = res_size; |
bee24666 DE |
411 | return buf; |
412 | } |