2 * This file is part of the libsigrok project.
4 * Copyright (C) 2015 Daniel Elstner <daniel.kitta@gmail.com>
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.
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.
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/>.
24 #include <glib/gstdio.h>
25 #include <libsigrok/libsigrok.h>
26 #include "libsigrok-internal.h"
29 #define LOG_PREFIX "resource"
35 * Access to resource files.
39 * Get a list of paths where we look for resource (e.g. firmware) files.
41 * @param res_type The type of resource to get the search paths for.
43 * @return List of strings that must be freed after use, including the strings.
47 SR_API GSList *sr_resourcepaths_get(int res_type)
49 const char *subdir = NULL;
52 const char *const *datadirs;
54 if (res_type == SR_RESOURCE_FIRMWARE) {
55 subdir = "sigrok-firmware";
57 env = g_getenv("SIGROK_FIRMWARE_DIR");
59 sr_dbg("SIGROK_FIRMWARE_DIR environment variable not set, ignoring.");
61 l = g_slist_append(l, g_strdup(env));
64 l = g_slist_append(l, g_build_filename(g_get_user_data_dir(), subdir, NULL));
67 if (res_type == SR_RESOURCE_FIRMWARE) {
69 * Scan the hard-coded directory before the system directories to
70 * avoid picking up possibly outdated files from a system install.
72 l = g_slist_append(l, g_strdup(FIRMWARE_DIR));
76 datadirs = g_get_system_data_dirs();
78 l = g_slist_append(l, g_build_filename(*datadirs++, subdir, NULL));
84 * Retrieve the size of the open stream @a file.
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.
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.
97 SR_PRIV int64_t sr_file_get_size(FILE *file)
99 off_t filepos, filesize;
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.
108 filepos = ftello(file);
112 if (fseeko(file, 0, SEEK_END) < 0)
115 filesize = ftello(file);
119 if (fseeko(file, filepos, SEEK_SET) < 0)
125 static FILE *try_open_file(const char *datadir, const char *subdir,
132 filename = g_build_filename(datadir, subdir, name, NULL);
134 filename = g_build_filename(datadir, name, NULL);
136 file = g_fopen(filename, "rb");
139 sr_info("Opened '%s'.", filename);
141 sr_spew("Attempt to open '%s' failed: %s",
142 filename, g_strerror(errno));
148 static int resource_open_default(struct sr_resource *res,
149 const char *name, void *cb_data)
151 GSList *paths, *p = NULL;
157 paths = sr_resourcepaths_get(res->type);
159 /* Currently, the enum only defines SR_RESOURCE_FIRMWARE. */
160 if (res->type != SR_RESOURCE_FIRMWARE) {
161 sr_err("%s: unknown type %d.", __func__, res->type);
167 file = try_open_file((const char *)(p->data), NULL, name);
170 g_slist_free_full(paths, g_free);
173 sr_dbg("Failed to locate '%s'.", name);
177 filesize = sr_file_get_size(file);
179 sr_err("Failed to obtain size of '%s': %s",
180 name, g_strerror(errno));
184 res->size = filesize;
190 static int resource_close_default(struct sr_resource *res, void *cb_data)
198 sr_err("%s: invalid handle.", __func__);
202 if (fclose(file) < 0) {
203 sr_err("Failed to close file: %s", g_strerror(errno));
211 static gssize resource_read_default(const struct sr_resource *res,
212 void *buf, size_t count, void *cb_data)
221 sr_err("%s: invalid handle.", __func__);
224 if (count > G_MAXSSIZE) {
225 sr_err("%s: count %zu too large.", __func__, count);
229 n_read = fread(buf, 1, count, file);
231 if (n_read != count && ferror(file)) {
232 sr_err("Failed to read resource file: %s", g_strerror(errno));
239 * Install resource access hooks.
241 * @param ctx libsigrok context. Must not be NULL.
242 * @param open_cb Resource open callback, or NULL to unset.
243 * @param close_cb Resource close callback, or NULL to unset.
244 * @param read_cb Resource read callback, or NULL to unset.
245 * @param cb_data User data pointer passed to callbacks.
247 * @retval SR_OK Success.
248 * @retval SR_ERR_ARG Invalid argument.
252 SR_API int sr_resource_set_hooks(struct sr_context *ctx,
253 sr_resource_open_callback open_cb,
254 sr_resource_close_callback close_cb,
255 sr_resource_read_callback read_cb, void *cb_data)
258 sr_err("%s: ctx was NULL.", __func__);
261 if (open_cb && close_cb && read_cb) {
262 ctx->resource_open_cb = open_cb;
263 ctx->resource_close_cb = close_cb;
264 ctx->resource_read_cb = read_cb;
265 ctx->resource_cb_data = cb_data;
266 } else if (!open_cb && !close_cb && !read_cb) {
267 ctx->resource_open_cb = &resource_open_default;
268 ctx->resource_close_cb = &resource_close_default;
269 ctx->resource_read_cb = &resource_read_default;
270 ctx->resource_cb_data = ctx;
272 sr_err("%s: inconsistent callback pointers.", __func__);
281 * @param ctx libsigrok context. Must not be NULL.
282 * @param[out] res Resource descriptor to fill in. Must not be NULL.
283 * @param type Resource type ID.
284 * @param name Name of the resource. Must not be NULL.
286 * @retval SR_OK Success.
287 * @retval SR_ERR_ARG Invalid argument.
288 * @retval SR_ERR Other error.
292 SR_PRIV int sr_resource_open(struct sr_context *ctx,
293 struct sr_resource *res, int type, const char *name)
301 ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data);
304 sr_err("Failed to open resource '%s' (use loglevel 5/spew for"
313 * @param ctx libsigrok context. Must not be NULL.
314 * @param[inout] res Resource descriptor. Must not be NULL.
316 * @retval SR_OK Success.
317 * @retval SR_ERR_ARG Invalid argument.
318 * @retval SR_ERR Other error.
322 SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res)
326 ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data);
329 sr_err("Failed to close resource.");
335 * Read resource data.
337 * @param ctx libsigrok context. Must not be NULL.
338 * @param[in] res Resource descriptor. Must not be NULL.
339 * @param[out] buf Buffer to store @a count bytes into. Must not be NULL.
340 * @param count Number of bytes to read.
342 * @return The number of bytes actually read, or a negative value on error.
343 * @retval SR_ERR_ARG Invalid argument.
344 * @retval SR_ERR Other error.
348 SR_PRIV gssize sr_resource_read(struct sr_context *ctx,
349 const struct sr_resource *res, void *buf, size_t count)
353 n_read = (*ctx->resource_read_cb)(res, buf, count,
354 ctx->resource_cb_data);
356 sr_err("Failed to read resource.");
362 * Load a resource into memory.
364 * @param ctx libsigrok context. Must not be NULL.
365 * @param type Resource type ID.
366 * @param name Name of the resource. Must not be NULL.
367 * @param[out] size Size in bytes of the returned buffer. Must not be NULL.
368 * @param max_size Size limit. Error out if the resource is larger than this.
370 * @return A buffer containing the resource data, or NULL on failure. Must
371 * be freed by the caller using g_free().
375 SR_PRIV void *sr_resource_load(struct sr_context *ctx,
376 int type, const char *name, size_t *size, size_t max_size)
378 struct sr_resource res;
383 if (sr_resource_open(ctx, &res, type, name) != SR_OK)
386 if (res.size > max_size) {
387 sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.",
388 res.size, name, max_size);
389 sr_resource_close(ctx, &res);
394 buf = g_try_malloc(res_size);
396 sr_err("Failed to allocate buffer for '%s'.", name);
397 sr_resource_close(ctx, &res);
401 n_read = sr_resource_read(ctx, &res, buf, res_size);
402 sr_resource_close(ctx, &res);
404 if (n_read < 0 || (size_t)n_read != res_size) {
406 sr_err("Failed to read '%s': premature end of file.",