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70 * avoid picking up possibly outdated files from a system install.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,
131 filename = g_build_filename(datadir, subdir, name, NULL);
132 file = g_fopen(filename, "rb");
135 sr_info("Opened '%s'.", filename);
137 sr_spew("Attempt to open '%s' failed: %s",
138 filename, g_strerror(errno));
144 static int resource_open_default(struct sr_resource *res,
145 const char *name, void *cb_data)
147 GSList *paths, *p = NULL;
153 paths = sr_resourcepaths_get(res->type);
155 /* Currently, the enum only defines SR_RESOURCE_FIRMWARE. */
156 if (res->type != SR_RESOURCE_FIRMWARE) {
157 sr_err("%s: unknown type %d.", __func__, res->type);
163 file = try_open_file((const char *)(p->data), NULL, name);
166 g_slist_free_full(paths, g_free);
169 sr_dbg("Failed to locate '%s'.", name);
173 filesize = sr_file_get_size(file);
175 sr_err("Failed to obtain size of '%s': %s",
176 name, g_strerror(errno));
180 res->size = filesize;
186 static int resource_close_default(struct sr_resource *res, void *cb_data)
194 sr_err("%s: invalid handle.", __func__);
198 if (fclose(file) < 0) {
199 sr_err("Failed to close file: %s", g_strerror(errno));
207 static gssize resource_read_default(const struct sr_resource *res,
208 void *buf, size_t count, void *cb_data)
217 sr_err("%s: invalid handle.", __func__);
220 if (count > G_MAXSSIZE) {
221 sr_err("%s: count %zu too large.", __func__, count);
225 n_read = fread(buf, 1, count, file);
227 if (n_read != count && ferror(file)) {
228 sr_err("Failed to read resource file: %s", g_strerror(errno));
235 * Install resource access hooks.
237 * @param ctx libsigrok context. Must not be NULL.
238 * @param open_cb Resource open callback, or NULL to unset.
239 * @param close_cb Resource close callback, or NULL to unset.
240 * @param read_cb Resource read callback, or NULL to unset.
241 * @param cb_data User data pointer passed to callbacks.
243 * @retval SR_OK Success.
244 * @retval SR_ERR_ARG Invalid argument.
248 SR_API int sr_resource_set_hooks(struct sr_context *ctx,
249 sr_resource_open_callback open_cb,
250 sr_resource_close_callback close_cb,
251 sr_resource_read_callback read_cb, void *cb_data)
254 sr_err("%s: ctx was NULL.", __func__);
257 if (open_cb && close_cb && read_cb) {
258 ctx->resource_open_cb = open_cb;
259 ctx->resource_close_cb = close_cb;
260 ctx->resource_read_cb = read_cb;
261 ctx->resource_cb_data = cb_data;
262 } else if (!open_cb && !close_cb && !read_cb) {
263 ctx->resource_open_cb = &resource_open_default;
264 ctx->resource_close_cb = &resource_close_default;
265 ctx->resource_read_cb = &resource_read_default;
266 ctx->resource_cb_data = ctx;
268 sr_err("%s: inconsistent callback pointers.", __func__);
277 * @param ctx libsigrok context. Must not be NULL.
278 * @param[out] res Resource descriptor to fill in. Must not be NULL.
279 * @param type Resource type ID.
280 * @param name Name of the resource. Must not be NULL.
282 * @retval SR_OK Success.
283 * @retval SR_ERR_ARG Invalid argument.
284 * @retval SR_ERR Other error.
288 SR_PRIV int sr_resource_open(struct sr_context *ctx,
289 struct sr_resource *res, int type, const char *name)
297 ret = (*ctx->resource_open_cb)(res, name, ctx->resource_cb_data);
300 sr_err("Failed to open resource '%s' (use loglevel 5/spew for"
309 * @param ctx libsigrok context. Must not be NULL.
310 * @param[inout] res Resource descriptor. Must not be NULL.
312 * @retval SR_OK Success.
313 * @retval SR_ERR_ARG Invalid argument.
314 * @retval SR_ERR Other error.
318 SR_PRIV int sr_resource_close(struct sr_context *ctx, struct sr_resource *res)
322 ret = (*ctx->resource_close_cb)(res, ctx->resource_cb_data);
325 sr_err("Failed to close resource.");
331 * Read resource data.
333 * @param ctx libsigrok context. Must not be NULL.
334 * @param[in] res Resource descriptor. Must not be NULL.
335 * @param[out] buf Buffer to store @a count bytes into. Must not be NULL.
336 * @param count Number of bytes to read.
338 * @return The number of bytes actually read, or a negative value on error.
339 * @retval SR_ERR_ARG Invalid argument.
340 * @retval SR_ERR Other error.
344 SR_PRIV gssize sr_resource_read(struct sr_context *ctx,
345 const struct sr_resource *res, void *buf, size_t count)
349 n_read = (*ctx->resource_read_cb)(res, buf, count,
350 ctx->resource_cb_data);
352 sr_err("Failed to read resource.");
358 * Load a resource into memory.
360 * @param ctx libsigrok context. Must not be NULL.
361 * @param type Resource type ID.
362 * @param name Name of the resource. Must not be NULL.
363 * @param[out] size Size in bytes of the returned buffer. Must not be NULL.
364 * @param max_size Size limit. Error out if the resource is larger than this.
366 * @return A buffer containing the resource data, or NULL on failure. Must
367 * be freed by the caller using g_free().
371 SR_PRIV void *sr_resource_load(struct sr_context *ctx,
372 int type, const char *name, size_t *size, size_t max_size)
374 struct sr_resource res;
379 if (sr_resource_open(ctx, &res, type, name) != SR_OK)
382 if (res.size > max_size) {
383 sr_err("Size %" PRIu64 " of '%s' exceeds limit %zu.",
384 res.size, name, max_size);
385 sr_resource_close(ctx, &res);
390 buf = g_try_malloc(res_size);
392 sr_err("Failed to allocate buffer for '%s'.", name);
393 sr_resource_close(ctx, &res);
397 n_read = sr_resource_read(ctx, &res, buf, res_size);
398 sr_resource_close(ctx, &res);
400 if (n_read < 0 || (size_t)n_read != res_size) {
402 sr_err("Failed to read '%s': premature end of file.",