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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 | ||
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 | l = g_slist_append(l, g_strdup(env)); | |
60 | ||
61 | env = g_getenv("SIGROK_FIRMWARE_PATH"); | |
62 | if (env) { | |
63 | char **dir_list, **dir_iter, *dir_item; | |
64 | dir_list = g_strsplit(env, G_SEARCHPATH_SEPARATOR_S, 0); | |
65 | for (dir_iter = dir_list; *dir_iter; dir_iter++) { | |
66 | dir_item = *dir_iter; | |
67 | if (!dir_item || !*dir_item) | |
68 | continue; | |
69 | l = g_slist_append(l, g_strdup(dir_item)); | |
70 | } | |
71 | g_strfreev(dir_list); | |
72 | } | |
73 | } | |
74 | ||
75 | l = g_slist_append(l, g_build_filename(g_get_user_data_dir(), subdir, NULL)); | |
76 | ||
77 | #ifdef FIRMWARE_DIR | |
78 | if (res_type == SR_RESOURCE_FIRMWARE) { | |
79 | /* | |
80 | * Scan the hard-coded directory before the system directories to | |
81 | * avoid picking up possibly outdated files from a system install. | |
82 | */ | |
83 | l = g_slist_append(l, g_strdup(FIRMWARE_DIR)); | |
84 | } | |
85 | #endif | |
86 | ||
87 | datadirs = g_get_system_data_dirs(); | |
88 | while (*datadirs) | |
89 | l = g_slist_append(l, g_build_filename(*datadirs++, subdir, NULL)); | |
90 | ||
91 | return l; | |
92 | } | |
93 | ||
94 | /** | |
95 | * Retrieve the size of the open stream @a file. | |
96 | * | |
97 | * This function only works on seekable streams. However, the set of seekable | |
98 | * streams is generally congruent with the set of streams that have a size. | |
99 | * Code that needs to work with any type of stream (including pipes) should | |
100 | * require neither seekability nor advance knowledge of the size. | |
101 | * On failure, the return value is negative and errno is set. | |
102 | * | |
103 | * @param file An I/O stream opened in binary mode. | |
104 | * @return The size of @a file in bytes, or a negative value on failure. | |
105 | * | |
106 | * @private | |
107 | */ | |
108 | SR_PRIV int64_t sr_file_get_size(FILE *file) | |
109 | { | |
110 | off_t filepos, filesize; | |
111 | ||
112 | /* ftello() and fseeko() are not standard C, but part of POSIX.1-2001. | |
113 | * Thus, if these functions are available at all, they can reasonably | |
114 | * be expected to also conform to POSIX semantics. In particular, this | |
115 | * means that ftello() after fseeko(..., SEEK_END) has a defined result | |
116 | * and can be used to get the size of a seekable stream. | |
117 | * On Windows, the result is fully defined only for binary streams. | |
118 | */ | |
119 | filepos = ftello(file); | |
120 | if (filepos < 0) | |
121 | return -1; | |
122 | ||
123 | if (fseeko(file, 0, SEEK_END) < 0) | |
124 | return -1; | |
125 | ||
126 | filesize = ftello(file); | |
127 | if (filesize < 0) | |
128 | return -1; | |
129 | ||
130 | if (fseeko(file, filepos, SEEK_SET) < 0) | |
131 | return -1; | |
132 | ||
133 | return filesize; | |
134 | } | |
135 | ||
136 | static FILE *try_open_file(const char *datadir, const char *subdir, | |
137 | const char *name) | |
138 | { | |
139 | char *filename; | |
140 | FILE *file; | |
141 | ||
142 | if (subdir) | |
143 | filename = g_build_filename(datadir, subdir, name, NULL); | |
144 | else | |
145 | filename = g_build_filename(datadir, name, NULL); | |
146 | ||
147 | file = g_fopen(filename, "rb"); | |
148 | ||
149 | if (file) | |
150 | sr_info("Opened '%s'.", filename); | |
151 | else | |
152 | sr_spew("Attempt to open '%s' failed: %s", | |
153 | filename, g_strerror(errno)); | |
154 | g_free(filename); | |
155 | ||
156 | return file; | |
157 | } | |
158 | ||
159 | static int resource_open_default(struct sr_resource *res, | |
160 | const char *name, void *cb_data) | |
161 | { | |
162 | GSList *paths, *p = NULL; | |
163 | int64_t filesize; | |
164 | FILE *file = NULL; | |
165 | ||
166 | (void)cb_data; | |
167 | ||
168 | paths = sr_resourcepaths_get(res->type); | |
169 | ||
170 | /* Currently, the enum only defines SR_RESOURCE_FIRMWARE. */ | |
171 | if (res->type != SR_RESOURCE_FIRMWARE) { | |
172 | sr_err("%s: unknown type %d.", __func__, res->type); | |
173 | return SR_ERR_ARG; | |
174 | } | |
175 | ||
176 | p = paths; | |
177 | while (p && !file) { | |
178 | file = try_open_file((const char *)(p->data), NULL, name); | |
179 | p = p->next; | |
180 | } | |
181 | g_slist_free_full(paths, g_free); | |
182 | ||
183 | if (!file) { | |
184 | sr_dbg("Failed to locate '%s'.", name); | |
185 | return SR_ERR; | |
186 | } | |
187 | ||
188 | filesize = sr_file_get_size(file); | |
189 | if (filesize < 0) { | |
190 | sr_err("Failed to obtain size of '%s': %s", | |
191 | name, g_strerror(errno)); | |
192 | fclose(file); | |
193 | return SR_ERR; | |
194 | } | |
195 | res->size = filesize; | |
196 | res->handle = file; | |
197 | ||
198 | return SR_OK; | |
199 | } | |
200 | ||
201 | static int resource_close_default(struct sr_resource *res, void *cb_data) | |
202 | { | |
203 | FILE *file; | |
204 | ||
205 | (void)cb_data; | |
206 | ||
207 | file = res->handle; | |
208 | if (!file) { | |
209 | sr_err("%s: invalid handle.", __func__); | |
210 | return SR_ERR_ARG; | |
211 | } | |
212 | ||
213 | if (fclose(file) < 0) { | |
214 | sr_err("Failed to close file: %s", g_strerror(errno)); | |
215 | return SR_ERR; | |
216 | } | |
217 | res->handle = NULL; | |
218 | ||
219 | return SR_OK; | |
220 | } | |
221 | ||
222 | static gssize resource_read_default(const struct sr_resource *res, | |
223 | void *buf, size_t count, void *cb_data) | |
224 | { | |
225 | FILE *file; | |
226 | size_t n_read; | |
227 | ||
228 | (void)cb_data; | |
229 | ||
230 | file = res->handle; | |
231 | if (!file) { | |
232 | sr_err("%s: invalid handle.", __func__); | |
233 | return SR_ERR_ARG; | |
234 | } | |
235 | if (count > G_MAXSSIZE) { | |
236 | sr_err("%s: count %zu too large.", __func__, count); | |
237 | return SR_ERR_ARG; | |
238 | } | |
239 | ||
240 | n_read = fread(buf, 1, count, file); | |
241 | ||
242 | if (n_read != count && ferror(file)) { | |
243 | sr_err("Failed to read resource file: %s", g_strerror(errno)); | |
244 | return SR_ERR; | |
245 | } | |
246 | return n_read; | |
247 | } | |
248 | ||
249 | /** | |
250 | * Install resource access hooks. | |
251 | * | |
252 | * @param ctx libsigrok context. Must not be NULL. | |
253 | * @param open_cb Resource open callback, or NULL to unset. | |
254 | * @param close_cb Resource close callback, or NULL to unset. | |
255 | * @param read_cb Resource read callback, or NULL to unset. | |
256 | * @param cb_data User data pointer passed to callbacks. | |
257 | * | |
258 | * @retval SR_OK Success. | |
259 | * @retval SR_ERR_ARG Invalid argument. | |
260 | * | |
261 | * @since 0.4.0 | |
262 | */ | |
263 | SR_API int sr_resource_set_hooks(struct sr_context *ctx, | |
264 | sr_resource_open_callback open_cb, | |
265 | sr_resource_close_callback close_cb, | |
266 | sr_resource_read_callback read_cb, void *cb_data) | |
267 | { | |
268 | if (!ctx) { | |
269 | sr_err("%s: ctx was NULL.", __func__); | |
270 | return SR_ERR_ARG; | |
271 | } | |
272 | if (open_cb && close_cb && read_cb) { | |
273 | ctx->resource_open_cb = open_cb; | |
274 | ctx->resource_close_cb = close_cb; | |
275 | ctx->resource_read_cb = read_cb; | |
276 | ctx->resource_cb_data = cb_data; | |
277 | } else if (!open_cb && !close_cb && !read_cb) { | |
278 | ctx->resource_open_cb = &resource_open_default; | |
279 | ctx->resource_close_cb = &resource_close_default; | |
280 | ctx->resource_read_cb = &resource_read_default; | |
281 | ctx->resource_cb_data = ctx; | |
282 | } else { | |
283 | sr_err("%s: inconsistent callback pointers.", __func__); | |
284 | return SR_ERR_ARG; | |
285 | } | |
286 | return SR_OK; | |
287 | } | |
288 | ||
289 | /** | |
290 | * Open resource. | |
291 | * | |
292 | * @param ctx libsigrok context. Must not be NULL. | |
293 | * @param[out] res Resource descriptor to fill in. Must not be NULL. | |
294 | * @param type Resource type ID. | |
295 | * @param name Name of the resource. Must not be NULL. | |
296 | * | |
297 | * @retval SR_OK Success. | |
298 | * @retval SR_ERR_ARG Invalid argument. | |
299 | * @retval SR_ERR Other error. | |
300 | * | |
301 | * @private | |
302 | */ | |
303 | SR_PRIV int sr_resource_open(struct sr_context *ctx, | |
304 | struct sr_resource *res, int type, const char *name) | |
305 | { | |
306 | int ret; | |
307 | ||
308 | res->size = 0; | |
309 | res->handle = NULL; | |
310 | res->type = type; | |
311 | ||
312 | ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data); | |
313 | ||
314 | if (ret != SR_OK) | |
315 | sr_err("Failed to open resource '%s' (use loglevel 5/spew for" | |
316 | " details).", name); | |
317 | ||
318 | return ret; | |
319 | } | |
320 | ||
321 | /** | |
322 | * Close resource. | |
323 | * | |
324 | * @param ctx libsigrok context. Must not be NULL. | |
325 | * @param[inout] res Resource descriptor. Must not be NULL. | |
326 | * | |
327 | * @retval SR_OK Success. | |
328 | * @retval SR_ERR_ARG Invalid argument. | |
329 | * @retval SR_ERR Other error. | |
330 | * | |
331 | * @private | |
332 | */ | |
333 | SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res) | |
334 | { | |
335 | int ret; | |
336 | ||
337 | ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data); | |
338 | ||
339 | if (ret != SR_OK) | |
340 | sr_err("Failed to close resource."); | |
341 | ||
342 | return ret; | |
343 | } | |
344 | ||
345 | /** | |
346 | * Read resource data. | |
347 | * | |
348 | * @param ctx libsigrok context. Must not be NULL. | |
349 | * @param[in] res Resource descriptor. Must not be NULL. | |
350 | * @param[out] buf Buffer to store @a count bytes into. Must not be NULL. | |
351 | * @param count Number of bytes to read. | |
352 | * | |
353 | * @return The number of bytes actually read, or a negative value on error. | |
354 | * @retval SR_ERR_ARG Invalid argument. | |
355 | * @retval SR_ERR Other error. | |
356 | * | |
357 | * @private | |
358 | */ | |
359 | SR_PRIV gssize sr_resource_read(struct sr_context *ctx, | |
360 | const struct sr_resource *res, void *buf, size_t count) | |
361 | { | |
362 | gssize n_read; | |
363 | ||
364 | n_read = (*ctx->resource_read_cb)(res, buf, count, | |
365 | ctx->resource_cb_data); | |
366 | if (n_read < 0) | |
367 | sr_err("Failed to read resource."); | |
368 | ||
369 | return n_read; | |
370 | } | |
371 | ||
372 | /** | |
373 | * Load a resource into memory. | |
374 | * | |
375 | * @param ctx libsigrok context. Must not be NULL. | |
376 | * @param type Resource type ID. | |
377 | * @param name Name of the resource. Must not be NULL. | |
378 | * @param[out] size Size in bytes of the returned buffer. Must not be NULL. | |
379 | * @param max_size Size limit. Error out if the resource is larger than this. | |
380 | * | |
381 | * @return A buffer containing the resource data, or NULL on failure. Must | |
382 | * be freed by the caller using g_free(). | |
383 | * | |
384 | * @private | |
385 | */ | |
386 | SR_PRIV void *sr_resource_load(struct sr_context *ctx, | |
387 | int type, const char *name, size_t *size, size_t max_size) | |
388 | { | |
389 | struct sr_resource res; | |
390 | void *buf; | |
391 | size_t res_size; | |
392 | gssize n_read; | |
393 | ||
394 | if (sr_resource_open(ctx, &res, type, name) != SR_OK) | |
395 | return NULL; | |
396 | ||
397 | if (res.size > max_size) { | |
398 | sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.", | |
399 | res.size, name, max_size); | |
400 | sr_resource_close(ctx, &res); | |
401 | return NULL; | |
402 | } | |
403 | res_size = res.size; | |
404 | ||
405 | buf = g_try_malloc(res_size); | |
406 | if (!buf) { | |
407 | sr_err("Failed to allocate buffer for '%s'.", name); | |
408 | sr_resource_close(ctx, &res); | |
409 | return NULL; | |
410 | } | |
411 | ||
412 | n_read = sr_resource_read(ctx, &res, buf, res_size); | |
413 | sr_resource_close(ctx, &res); | |
414 | ||
415 | if (n_read < 0 || (size_t)n_read != res_size) { | |
416 | if (n_read >= 0) | |
417 | sr_err("Failed to read '%s': premature end of file.", | |
418 | name); | |
419 | g_free(buf); | |
420 | return NULL; | |
421 | } | |
422 | ||
423 | *size = res_size; | |
424 | return buf; | |
425 | } |