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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 | ||
38 | static FILE *try_open_file(const char *datadir, const char *subdir, | |
39 | const char *name) | |
40 | { | |
41 | char *filename; | |
42 | FILE *file; | |
43 | ||
44 | filename = g_build_filename(datadir, subdir, name, NULL); | |
45 | file = g_fopen(filename, "rb"); | |
46 | ||
47 | if (file) | |
48 | sr_info("Opened '%s'.", filename); | |
49 | else | |
50 | sr_spew("Attempt to open '%s' failed: %s", | |
51 | filename, g_strerror(errno)); | |
52 | g_free(filename); | |
53 | ||
54 | return file; | |
55 | } | |
56 | ||
57 | static int resource_open_default(struct sr_resource *res, | |
58 | const char *name, void *cb_data) | |
59 | { | |
60 | int64_t filesize; | |
61 | const char *builtindir, *subdir; | |
62 | const char *const *datadirs; | |
63 | FILE *file; | |
64 | ||
65 | (void)cb_data; | |
66 | ||
67 | switch (res->type) { | |
68 | case SR_RESOURCE_FIRMWARE: | |
69 | builtindir = FIRMWARE_DIR; | |
70 | subdir = "sigrok-firmware"; | |
71 | break; | |
72 | default: | |
73 | sr_err("%s: unknown type %d.", __func__, res->type); | |
74 | return SR_ERR_ARG; | |
75 | } | |
76 | ||
77 | file = try_open_file(g_get_user_data_dir(), subdir, name); | |
78 | /* | |
79 | * Scan the hard-coded directory before the system directories to | |
80 | * avoid picking up possibly outdated files from a system install. | |
81 | */ | |
82 | if (!file) | |
83 | file = try_open_file(builtindir, "", name); | |
84 | ||
85 | if (!file) { | |
86 | datadirs = g_get_system_data_dirs(); | |
87 | while (*datadirs && !file) | |
88 | file = try_open_file(*datadirs++, subdir, name); | |
89 | } | |
90 | if (!file) { | |
91 | sr_err("Failed to locate '%s'.", name); | |
92 | return SR_ERR; | |
93 | } | |
94 | ||
95 | filesize = sr_file_get_size(file); | |
96 | if (filesize < 0) { | |
97 | sr_err("Failed to obtain size of '%s': %s", | |
98 | name, g_strerror(errno)); | |
99 | fclose(file); | |
100 | return SR_ERR; | |
101 | } | |
102 | res->size = filesize; | |
103 | res->handle = file; | |
104 | ||
105 | return SR_OK; | |
106 | } | |
107 | ||
108 | static int resource_close_default(struct sr_resource *res, void *cb_data) | |
109 | { | |
110 | FILE *file; | |
111 | ||
112 | (void)cb_data; | |
113 | ||
114 | file = res->handle; | |
115 | if (!file) { | |
116 | sr_err("%s: invalid handle.", __func__); | |
117 | return SR_ERR_ARG; | |
118 | } | |
119 | ||
120 | if (fclose(file) < 0) { | |
121 | sr_err("Failed to close file: %s", g_strerror(errno)); | |
122 | return SR_ERR; | |
123 | } | |
124 | res->handle = NULL; | |
125 | ||
126 | return SR_OK; | |
127 | } | |
128 | ||
129 | static ssize_t resource_read_default(const struct sr_resource *res, | |
130 | void *buf, size_t count, void *cb_data) | |
131 | { | |
132 | FILE *file; | |
133 | size_t n_read; | |
134 | ||
135 | (void)cb_data; | |
136 | ||
137 | file = res->handle; | |
138 | if (!file) { | |
139 | sr_err("%s: invalid handle.", __func__); | |
140 | return SR_ERR_ARG; | |
141 | } | |
142 | if (count > SSIZE_MAX) { | |
143 | sr_err("%s: count %zu too large.", __func__, count); | |
144 | return SR_ERR_ARG; | |
145 | } | |
146 | ||
147 | n_read = fread(buf, 1, count, file); | |
148 | ||
149 | if (n_read != count && ferror(file)) { | |
150 | sr_err("Failed to read resource file: %s", g_strerror(errno)); | |
151 | return SR_ERR; | |
152 | } | |
153 | return n_read; | |
154 | } | |
155 | ||
156 | /** | |
157 | * Install resource access hooks. | |
158 | * | |
159 | * @param ctx libsigrok context. Must not be NULL. | |
160 | * @param open_cb Resource open callback, or NULL to unset. | |
161 | * @param close_cb Resource close callback, or NULL to unset. | |
162 | * @param read_cb Resource read callback, or NULL to unset. | |
163 | * @param cb_data User data pointer passed to callbacks. | |
164 | * | |
165 | * @retval SR_OK Success. | |
166 | * @retval SR_ERR_ARG Invalid argument. | |
167 | * | |
168 | * @since 0.4.0 | |
169 | */ | |
170 | SR_API int sr_resource_set_hooks(struct sr_context *ctx, | |
171 | sr_resource_open_callback open_cb, | |
172 | sr_resource_close_callback close_cb, | |
173 | sr_resource_read_callback read_cb, void *cb_data) | |
174 | { | |
175 | if (!ctx) { | |
176 | sr_err("%s: ctx was NULL.", __func__); | |
177 | return SR_ERR_ARG; | |
178 | } | |
179 | if (open_cb && close_cb && read_cb) { | |
180 | ctx->resource_open_cb = open_cb; | |
181 | ctx->resource_close_cb = close_cb; | |
182 | ctx->resource_read_cb = read_cb; | |
183 | ctx->resource_cb_data = cb_data; | |
184 | } else if (!open_cb && !close_cb && !read_cb) { | |
185 | ctx->resource_open_cb = &resource_open_default; | |
186 | ctx->resource_close_cb = &resource_close_default; | |
187 | ctx->resource_read_cb = &resource_read_default; | |
188 | ctx->resource_cb_data = ctx; | |
189 | } else { | |
190 | sr_err("%s: inconsistent callback pointers.", __func__); | |
191 | return SR_ERR_ARG; | |
192 | } | |
193 | return SR_OK; | |
194 | } | |
195 | ||
196 | /** | |
197 | * Open resource. | |
198 | * | |
199 | * @param ctx libsigrok context. Must not be NULL. | |
200 | * @param[out] res Resource descriptor to fill in. Must not be NULL. | |
201 | * @param type Resource type ID. | |
202 | * @param name Name of the resource. Must not be NULL. | |
203 | * | |
204 | * @retval SR_OK Success. | |
205 | * @retval SR_ERR_ARG Invalid argument. | |
206 | * @retval SR_ERR Other error. | |
207 | * | |
208 | * @private | |
209 | */ | |
210 | SR_PRIV int sr_resource_open(struct sr_context *ctx, | |
211 | struct sr_resource *res, int type, const char *name) | |
212 | { | |
213 | int ret; | |
214 | ||
215 | res->size = 0; | |
216 | res->handle = NULL; | |
217 | res->type = type; | |
218 | ||
219 | ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data); | |
220 | ||
221 | if (ret != SR_OK) | |
222 | sr_err("Failed to open resource '%s'.", name); | |
223 | ||
224 | return ret; | |
225 | } | |
226 | ||
227 | /** | |
228 | * Close resource. | |
229 | * | |
230 | * @param ctx libsigrok context. Must not be NULL. | |
231 | * @param[inout] res Resource descriptor. Must not be NULL. | |
232 | * | |
233 | * @retval SR_OK Success. | |
234 | * @retval SR_ERR_ARG Invalid argument. | |
235 | * @retval SR_ERR Other error. | |
236 | * | |
237 | * @private | |
238 | */ | |
239 | SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res) | |
240 | { | |
241 | int ret; | |
242 | ||
243 | ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data); | |
244 | ||
245 | if (ret != SR_OK) | |
246 | sr_err("Failed to close resource."); | |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | /** | |
252 | * Read resource data. | |
253 | * | |
254 | * @param ctx libsigrok context. Must not be NULL. | |
255 | * @param[in] res Resource descriptor. Must not be NULL. | |
256 | * @param[out] buf Buffer to store @a count bytes into. Must not be NULL. | |
257 | * @param count Number of bytes to read. | |
258 | * | |
259 | * @return The number of bytes actually read, or a negative value on error. | |
260 | * @retval SR_ERR_ARG Invalid argument. | |
261 | * @retval SR_ERR Other error. | |
262 | * | |
263 | * @private | |
264 | */ | |
265 | SR_PRIV ssize_t sr_resource_read(struct sr_context *ctx, | |
266 | const struct sr_resource *res, void *buf, size_t count) | |
267 | { | |
268 | ssize_t n_read; | |
269 | ||
270 | n_read = (*ctx->resource_read_cb)(res, buf, count, | |
271 | ctx->resource_cb_data); | |
272 | if (n_read < 0) | |
273 | sr_err("Failed to read resource."); | |
274 | ||
275 | return n_read; | |
276 | } | |
277 | ||
278 | /** | |
279 | * Load a resource into memory. | |
280 | * | |
281 | * @param ctx libsigrok context. Must not be NULL. | |
282 | * @param type Resource type ID. | |
283 | * @param name Name of the resource. Must not be NULL. | |
284 | * @param[out] size Size in bytes of the returned buffer. Must not be NULL. | |
285 | * @param max_size Size limit. Error out if the resource is larger than this. | |
286 | * | |
287 | * @return A buffer containing the resource data, or NULL on failure. Must | |
288 | * be freed by the caller using g_free(). | |
289 | * | |
290 | * @private | |
291 | */ | |
292 | SR_PRIV void *sr_resource_load(struct sr_context *ctx, | |
293 | int type, const char *name, size_t *size, size_t max_size) | |
294 | { | |
295 | struct sr_resource res; | |
296 | void *buf; | |
297 | ssize_t n_read; | |
298 | ||
299 | if (sr_resource_open(ctx, &res, type, name) != SR_OK) | |
300 | return NULL; | |
301 | ||
302 | if (res.size > max_size) { | |
303 | sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.", | |
304 | res.size, name, max_size); | |
305 | sr_resource_close(ctx, &res); | |
306 | return NULL; | |
307 | } | |
308 | buf = g_try_malloc(res.size); | |
309 | if (!buf) { | |
310 | sr_err("Failed to allocate buffer for '%s'.", name); | |
311 | sr_resource_close(ctx, &res); | |
312 | return NULL; | |
313 | } | |
314 | ||
315 | n_read = sr_resource_read(ctx, &res, buf, res.size); | |
316 | sr_resource_close(ctx, &res); | |
317 | ||
318 | if (n_read < 0 || (size_t)n_read != res.size) { | |
319 | if (n_read >= 0) | |
320 | sr_err("Failed to read '%s': premature end of file.", | |
321 | name); | |
322 | g_free(buf); | |
323 | return NULL; | |
324 | } | |
325 | ||
326 | *size = res.size; | |
327 | return buf; | |
328 | } | |
329 | ||
330 | /** @} */ |