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 l = g_slist_append(l, g_strdup(env));
61 env = g_getenv("SIGROK_FIRMWARE_PATH");
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++) {
67 if (!dir_item || !*dir_item)
69 l = g_slist_append(l, g_strdup(dir_item));
75 l = g_slist_append(l, g_build_filename(g_get_user_data_dir(), subdir, NULL));
78 if (res_type == SR_RESOURCE_FIRMWARE) {
80 * Scan the hard-coded directory before the system directories to
81 * avoid picking up possibly outdated files from a system install.
83 l = g_slist_append(l, g_strdup(FIRMWARE_DIR));
87 datadirs = g_get_system_data_dirs();
89 l = g_slist_append(l, g_build_filename(*datadirs++, subdir, NULL));
95 * Retrieve the size of the open stream @a file.
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.
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.
108 SR_PRIV int64_t sr_file_get_size(FILE *file)
110 off_t filepos, filesize;
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.
119 filepos = ftello(file);
123 if (fseeko(file, 0, SEEK_END) < 0)
126 filesize = ftello(file);
130 if (fseeko(file, filepos, SEEK_SET) < 0)
136 static FILE *try_open_file(const char *datadir, const char *subdir,
143 filename = g_build_filename(datadir, subdir, name, NULL);
145 filename = g_build_filename(datadir, name, NULL);
147 file = g_fopen(filename, "rb");
150 sr_info("Opened '%s'.", filename);
152 sr_spew("Attempt to open '%s' failed: %s",
153 filename, g_strerror(errno));
159 static int resource_open_default(struct sr_resource *res,
160 const char *name, void *cb_data)
162 GSList *paths, *p = NULL;
168 paths = sr_resourcepaths_get(res->type);
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);
178 file = try_open_file((const char *)(p->data), NULL, name);
181 g_slist_free_full(paths, g_free);
184 sr_dbg("Failed to locate '%s'.", name);
188 filesize = sr_file_get_size(file);
190 sr_err("Failed to obtain size of '%s': %s",
191 name, g_strerror(errno));
195 res->size = filesize;
201 static int resource_close_default(struct sr_resource *res, void *cb_data)
209 sr_err("%s: invalid handle.", __func__);
213 if (fclose(file) < 0) {
214 sr_err("Failed to close file: %s", g_strerror(errno));
222 static gssize resource_read_default(const struct sr_resource *res,
223 void *buf, size_t count, void *cb_data)
232 sr_err("%s: invalid handle.", __func__);
235 if (count > G_MAXSSIZE) {
236 sr_err("%s: count %zu too large.", __func__, count);
240 n_read = fread(buf, 1, count, file);
242 if (n_read != count && ferror(file)) {
243 sr_err("Failed to read resource file: %s", g_strerror(errno));
250 * Install resource access hooks.
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.
258 * @retval SR_OK Success.
259 * @retval SR_ERR_ARG Invalid argument.
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)
269 sr_err("%s: ctx was NULL.", __func__);
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;
283 sr_err("%s: inconsistent callback pointers.", __func__);
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.
297 * @retval SR_OK Success.
298 * @retval SR_ERR_ARG Invalid argument.
299 * @retval SR_ERR Other error.
303 SR_PRIV int sr_resource_open(struct sr_context *ctx,
304 struct sr_resource *res, int type, const char *name)
312 ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data);
315 sr_err("Failed to open resource '%s' (use loglevel 5/spew for"
324 * @param ctx libsigrok context. Must not be NULL.
325 * @param[inout] res Resource descriptor. Must not be NULL.
327 * @retval SR_OK Success.
328 * @retval SR_ERR_ARG Invalid argument.
329 * @retval SR_ERR Other error.
333 SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res)
337 ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data);
340 sr_err("Failed to close resource.");
346 * Read resource data.
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.
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.
359 SR_PRIV gssize sr_resource_read(struct sr_context *ctx,
360 const struct sr_resource *res, void *buf, size_t count)
364 n_read = (*ctx->resource_read_cb)(res, buf, count,
365 ctx->resource_cb_data);
367 sr_err("Failed to read resource.");
373 * Load a resource into memory.
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.
381 * @return A buffer containing the resource data, or NULL on failure. Must
382 * be freed by the caller using g_free().
386 SR_PRIV void *sr_resource_load(struct sr_context *ctx,
387 int type, const char *name, size_t *size, size_t max_size)
389 struct sr_resource res;
394 if (sr_resource_open(ctx, &res, type, name) != SR_OK)
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);
405 buf = g_try_malloc(res_size);
407 sr_err("Failed to allocate buffer for '%s'.", name);
408 sr_resource_close(ctx, &res);
412 n_read = sr_resource_read(ctx, &res, buf, res_size);
413 sr_resource_close(ctx, &res);
415 if (n_read < 0 || (size_t)n_read != res_size) {
417 sr_err("Failed to read '%s': premature end of file.",