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1 | /* | |
2 | * This file is part of the sigrok project. | |
3 | * | |
4 | * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de> | |
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 2 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, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | */ | |
20 | ||
21 | #include <sigrokdecode.h> /* First, so we avoid a _POSIX_C_SOURCE warning. */ | |
22 | #include <stdio.h> | |
23 | #include <string.h> | |
24 | #include <dirent.h> | |
25 | #include <config.h> | |
26 | ||
27 | /* Re-define some string functions for Python >= 3.0. */ | |
28 | #if PY_VERSION_HEX >= 0x03000000 | |
29 | #define PyString_AsString PyBytes_AsString | |
30 | #define PyString_FromString PyBytes_FromString | |
31 | #define PyString_Check PyBytes_Check | |
32 | #endif | |
33 | ||
34 | /* The list of protocol decoders. */ | |
35 | GSList *list_pds = NULL; | |
36 | ||
37 | /* | |
38 | * Here's a quick overview of Python/C API reference counting. | |
39 | * | |
40 | * Check the Python/C API docs for what type of reference a function returns. | |
41 | * | |
42 | * - If it returns a "new reference", you're responsible to Py_XDECREF() it. | |
43 | * | |
44 | * - If it returns a "borrowed reference", you MUST NOT Py_XDECREF() it. | |
45 | * | |
46 | * - If a function "steals" a reference, you no longer are responsible for | |
47 | * Py_XDECREF()ing it (someone else will do it for you at some point). | |
48 | */ | |
49 | ||
50 | static int sigrokdecode_load_decoder(const char *name, | |
51 | struct sigrokdecode_decoder **dec); | |
52 | ||
53 | /** | |
54 | * Initialize libsigrokdecode. | |
55 | * | |
56 | * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. | |
57 | */ | |
58 | int sigrokdecode_init(void) | |
59 | { | |
60 | DIR *dir; | |
61 | struct dirent *dp; | |
62 | char *decodername; | |
63 | struct sigrokdecode_decoder *dec; | |
64 | int ret; | |
65 | ||
66 | /* Py_Initialize() returns void and usually cannot fail. */ | |
67 | Py_Initialize(); | |
68 | ||
69 | /* Add search directory for the protocol decoders. */ | |
70 | /* FIXME: Check error code. */ | |
71 | /* FIXME: What happens if this function is called multiple times? */ | |
72 | PyRun_SimpleString("import sys;" | |
73 | "sys.path.append(r'" DECODERS_DIR "');"); | |
74 | ||
75 | if (!(dir = opendir(DECODERS_DIR))) | |
76 | return SIGROKDECODE_ERR_DECODERS_DIR; | |
77 | ||
78 | while ((dp = readdir(dir)) != NULL) { | |
79 | if (!g_str_has_suffix(dp->d_name, ".py")) | |
80 | continue; | |
81 | ||
82 | /* Decoder name == filename (without .py suffix). */ | |
83 | decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3); | |
84 | ||
85 | /* TODO: Error handling. */ | |
86 | dec = malloc(sizeof(struct sigrokdecode_decoder)); | |
87 | ||
88 | /* Load the decoder. */ | |
89 | ret = sigrokdecode_load_decoder(decodername, &dec); | |
90 | ||
91 | /* Append it to the list of supported/loaded decoders. */ | |
92 | list_pds = g_slist_append(list_pds, dec); | |
93 | } | |
94 | closedir(dir); | |
95 | ||
96 | return SIGROKDECODE_OK; | |
97 | } | |
98 | ||
99 | /** | |
100 | * Returns the list of supported/loaded protocol decoders. | |
101 | * | |
102 | * This is a GSList containing the names of the decoders as strings. | |
103 | * | |
104 | * @return List of decoders, NULL if none are supported or loaded. | |
105 | */ | |
106 | GSList *sigrokdecode_list_decoders(void) | |
107 | { | |
108 | return list_pds; | |
109 | } | |
110 | ||
111 | /** | |
112 | * Get the decoder with the specified ID. | |
113 | * | |
114 | * @param id The ID string of the decoder to return. | |
115 | * @return The decoder with the specified ID, or NULL if not found. | |
116 | */ | |
117 | struct sigrokdecode_decoder *sigrokdecode_get_decoder_by_id(const char *id) | |
118 | { | |
119 | GSList *l; | |
120 | struct sigrokdecode_decoder *dec; | |
121 | ||
122 | for (l = sigrokdecode_list_decoders(); l; l = l->next) { | |
123 | dec = l->data; | |
124 | if (!strcmp(dec->id, id)) | |
125 | return dec; | |
126 | } | |
127 | ||
128 | return NULL; | |
129 | } | |
130 | ||
131 | /** | |
132 | * Helper function to handle Python strings. | |
133 | * | |
134 | * TODO: @param entries. | |
135 | * | |
136 | * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. | |
137 | * The 'outstr' argument points to a malloc()ed string upon success. | |
138 | */ | |
139 | static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, | |
140 | const char *key, char **outstr) | |
141 | { | |
142 | PyObject *py_str; | |
143 | char *str; | |
144 | int ret; | |
145 | ||
146 | py_str = PyMapping_GetItemString(py_res, (char *)key); | |
147 | if (!py_str || !PyString_Check(py_str)) { | |
148 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
149 | goto err_h_decref_func; | |
150 | } | |
151 | ||
152 | /* | |
153 | * PyString_AsString()'s returned string refers to an internal buffer | |
154 | * (not a copy), i.e. the data must not be modified, and the memory | |
155 | * must not be free()'d. | |
156 | */ | |
157 | if (!(str = PyString_AsString(py_str))) { | |
158 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
159 | goto err_h_decref_str; | |
160 | } | |
161 | ||
162 | if (!(*outstr = g_strdup(str))) { | |
163 | ret = SIGROKDECODE_ERR_MALLOC; | |
164 | goto err_h_decref_str; | |
165 | } | |
166 | ||
167 | Py_XDECREF(py_str); | |
168 | ||
169 | return SIGROKDECODE_OK; | |
170 | ||
171 | err_h_decref_str: | |
172 | Py_XDECREF(py_str); | |
173 | err_h_decref_func: | |
174 | Py_XDECREF(py_func); | |
175 | Py_XDECREF(py_mod); | |
176 | ||
177 | if (PyErr_Occurred()) | |
178 | PyErr_Print(); /* Returns void. */ | |
179 | ||
180 | return ret; | |
181 | } | |
182 | ||
183 | /** | |
184 | * TODO | |
185 | * | |
186 | * @param name TODO | |
187 | * | |
188 | * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. | |
189 | */ | |
190 | static int sigrokdecode_load_decoder(const char *name, | |
191 | struct sigrokdecode_decoder **dec) | |
192 | { | |
193 | struct sigrokdecode_decoder *d; | |
194 | PyObject *py_mod, *py_func, *py_res /* , *py_tuple */; | |
195 | int r; | |
196 | ||
197 | /* "Import" the Python module. */ | |
198 | if (!(py_mod = PyImport_ImportModule(name))) { /* NEWREF */ | |
199 | PyErr_Print(); /* Returns void. */ | |
200 | return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
201 | } | |
202 | ||
203 | /* Get the 'register' function name as Python callable object. */ | |
204 | py_func = PyObject_GetAttrString(py_mod, "register"); /* NEWREF */ | |
205 | if (!py_func || !PyCallable_Check(py_func)) { | |
206 | if (PyErr_Occurred()) | |
207 | PyErr_Print(); /* Returns void. */ | |
208 | Py_XDECREF(py_mod); | |
209 | return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
210 | } | |
211 | ||
212 | /* Call the 'register' function without arguments, get the result. */ | |
213 | if (!(py_res = PyObject_CallFunction(py_func, NULL))) { /* NEWREF */ | |
214 | PyErr_Print(); /* Returns void. */ | |
215 | Py_XDECREF(py_func); | |
216 | Py_XDECREF(py_mod); | |
217 | return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
218 | } | |
219 | ||
220 | if (!(d = malloc(sizeof(struct sigrokdecode_decoder)))) | |
221 | return SIGROKDECODE_ERR_MALLOC; | |
222 | ||
223 | if ((r = h_str(py_res, py_func, py_mod, "id", &(d->id))) < 0) | |
224 | return r; | |
225 | ||
226 | if ((r = h_str(py_res, py_func, py_mod, "name", &(d->name))) < 0) | |
227 | return r; | |
228 | ||
229 | if ((r = h_str(py_res, py_func, py_mod, "desc", &(d->desc))) < 0) | |
230 | return r; | |
231 | ||
232 | d->py_mod = py_mod; | |
233 | ||
234 | Py_XDECREF(py_res); | |
235 | Py_XDECREF(py_func); | |
236 | ||
237 | /* Get the 'decode' function name as Python callable object. */ | |
238 | py_func = PyObject_GetAttrString(py_mod, "decode"); /* NEWREF */ | |
239 | if (!py_func || !PyCallable_Check(py_func)) { | |
240 | if (PyErr_Occurred()) | |
241 | PyErr_Print(); /* Returns void. */ | |
242 | Py_XDECREF(py_mod); | |
243 | return SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
244 | } | |
245 | ||
246 | d->py_func = py_func; | |
247 | ||
248 | /* TODO: Handle func, inputformats, outputformats. */ | |
249 | /* Note: They must at least be set to NULL, will segfault otherwise. */ | |
250 | d->func = NULL; | |
251 | d->inputformats = NULL; | |
252 | d->outputformats = NULL; | |
253 | ||
254 | *dec = d; | |
255 | ||
256 | return SIGROKDECODE_OK; | |
257 | } | |
258 | ||
259 | /** | |
260 | * Run the specified decoder function. | |
261 | * | |
262 | * @param dec TODO | |
263 | * @param inbuf TODO | |
264 | * @param inbuflen TODO | |
265 | * @param outbuf TODO | |
266 | * @param outbuflen TODO | |
267 | * | |
268 | * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. | |
269 | */ | |
270 | int sigrokdecode_run_decoder(struct sigrokdecode_decoder *dec, | |
271 | uint8_t *inbuf, uint64_t inbuflen, | |
272 | uint8_t **outbuf, uint64_t *outbuflen) | |
273 | { | |
274 | PyObject *py_mod, *py_func, *py_args, *py_value, *py_res; | |
275 | int r, ret; | |
276 | ||
277 | /* TODO: Use #defines for the return codes. */ | |
278 | ||
279 | /* Return an error upon unusable input. */ | |
280 | if (dec == NULL) | |
281 | return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ | |
282 | if (inbuf == NULL) | |
283 | return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ | |
284 | if (inbuflen == 0) /* No point in working on empty buffers. */ | |
285 | return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ | |
286 | if (outbuf == NULL) | |
287 | return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ | |
288 | if (outbuflen == NULL) | |
289 | return SIGROKDECODE_ERR_ARGS; /* TODO: More specific error? */ | |
290 | ||
291 | /* TODO: Error handling. */ | |
292 | py_mod = dec->py_mod; | |
293 | Py_XINCREF(py_mod); | |
294 | py_func = dec->py_func; | |
295 | Py_XINCREF(py_func); | |
296 | ||
297 | /* Create a Python tuple of size 1. */ | |
298 | if (!(py_args = PyTuple_New(1))) { /* NEWREF */ | |
299 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
300 | goto err_run_decref_func; | |
301 | } | |
302 | ||
303 | /* Get the input buffer as Python "string" (byte array). */ | |
304 | /* TODO: int vs. uint64_t for 'inbuflen'? */ | |
305 | if (!(py_value = Py_BuildValue("s#", inbuf, inbuflen))) { /* NEWREF */ | |
306 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
307 | goto err_run_decref_args; | |
308 | } | |
309 | ||
310 | /* | |
311 | * IMPORTANT: PyTuple_SetItem() "steals" a reference to py_value! | |
312 | * That means we are no longer responsible for Py_XDECREF()'ing it. | |
313 | * It will automatically be free'd when the 'py_args' tuple is free'd. | |
314 | */ | |
315 | if (PyTuple_SetItem(py_args, 0, py_value) != 0) { /* STEAL */ | |
316 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
317 | Py_XDECREF(py_value); /* TODO: Ref. stolen upon error? */ | |
318 | goto err_run_decref_args; | |
319 | } | |
320 | ||
321 | if (!(py_res = PyObject_CallObject(py_func, py_args))) { /* NEWREF */ | |
322 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
323 | goto err_run_decref_args; | |
324 | } | |
325 | ||
326 | if ((r = PyObject_AsCharBuffer(py_res, (const char **)outbuf, | |
327 | (Py_ssize_t *)outbuflen))) { | |
328 | ret = SIGROKDECODE_ERR_PYTHON; /* TODO: More specific error? */ | |
329 | Py_XDECREF(py_res); | |
330 | goto err_run_decref_args; | |
331 | } | |
332 | ||
333 | ret = SIGROKDECODE_OK; | |
334 | ||
335 | Py_XDECREF(py_res); | |
336 | ||
337 | err_run_decref_args: | |
338 | Py_XDECREF(py_args); | |
339 | err_run_decref_func: | |
340 | Py_XDECREF(py_func); | |
341 | Py_XDECREF(py_mod); | |
342 | ||
343 | if (PyErr_Occurred()) | |
344 | PyErr_Print(); /* Returns void. */ | |
345 | ||
346 | return ret; | |
347 | } | |
348 | ||
349 | /** | |
350 | * TODO | |
351 | */ | |
352 | static int sigrokdecode_unload_decoder(struct sigrokdecode_decoder *dec) | |
353 | { | |
354 | g_free(dec->id); | |
355 | g_free(dec->name); | |
356 | g_free(dec->desc); | |
357 | g_free(dec->func); | |
358 | ||
359 | /* TODO: Free everything in inputformats and outputformats. */ | |
360 | ||
361 | if (dec->inputformats != NULL) | |
362 | g_slist_free(dec->inputformats); | |
363 | if (dec->outputformats != NULL) | |
364 | g_slist_free(dec->outputformats); | |
365 | ||
366 | Py_XDECREF(dec->py_func); | |
367 | Py_XDECREF(dec->py_mod); | |
368 | ||
369 | return SIGROKDECODE_OK; | |
370 | } | |
371 | ||
372 | /** | |
373 | * TODO | |
374 | */ | |
375 | static int sigrokdecode_unload_all_decoders(void) | |
376 | { | |
377 | GSList *l; | |
378 | struct sigrokdecode_decoder *dec; | |
379 | ||
380 | for (l = sigrokdecode_list_decoders(); l; l = l->next) { | |
381 | dec = l->data; | |
382 | /* TODO: Error handling. */ | |
383 | sigrokdecode_unload_decoder(dec); | |
384 | } | |
385 | ||
386 | return SIGROKDECODE_OK; | |
387 | } | |
388 | ||
389 | /** | |
390 | * Shutdown libsigrokdecode. | |
391 | * | |
392 | * @return SIGROKDECODE_OK upon success, a (negative) error code otherwise. | |
393 | */ | |
394 | int sigrokdecode_shutdown(void) | |
395 | { | |
396 | /* Unload/free all decoders, and then the list of decoders itself. */ | |
397 | /* TODO: Error handling. */ | |
398 | sigrokdecode_unload_all_decoders(); | |
399 | g_slist_free(list_pds); | |
400 | ||
401 | /* Py_Finalize() returns void, any finalization errors are ignored. */ | |
402 | Py_Finalize(); | |
403 | ||
404 | return SIGROKDECODE_OK; | |
405 | } |