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