decoder.c

   1 /*
   2  * This file is part of the libsigrokdecode project.
   3  *
   4  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
   5  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
  23 #include "libsigrokdecode.h"
  24 #include <glib.h>
  25
  26 /**
  27  * @file
  28  *
  29  * Listing, loading, unloading, and handling protocol decoders.
  30  */
  31
  32 /**
  33  * @defgroup grp_decoder Protocol decoders
  34  *
  35  * Handling protocol decoders.
  36  *
  37  * @{
  38  */
  39
  40 /** @cond PRIVATE */
  41
  42 /* The list of protocol decoders. */
  43 static GSList *pd_list = NULL;
  44
  45 /* srd.c */
  46 extern SRD_PRIV GSList *searchpaths;
  47
  48 /* session.c */
  49 extern SRD_PRIV GSList *sessions;
  50 extern SRD_PRIV int max_session_id;
  51
  52 /* module_sigrokdecode.c */
  53 extern SRD_PRIV PyObject *mod_sigrokdecode;
  54
  55 /** @endcond */
  56
  57 static gboolean srd_check_init(void)
  58 {
  59         if (max_session_id < 0) {
  60                 srd_err("Library is not initialized.");
  61                 return FALSE;
  62         } else
  63                 return TRUE;
  64 }
  65
  66 /**
  67  * Returns the list of supported/loaded protocol decoders.
  68  *
  69  * This is a GSList of pointers to struct srd_decoder items.
  70  *
  71  * @return List of decoders, NULL if none are supported or loaded.
  72  *
  73  * @since 0.2.0
  74  */
  75 SRD_API const GSList *srd_decoder_list(void)
  76 {
  77         return pd_list;
  78 }
  79
  80 /**
  81  * Get the decoder with the specified ID.
  82  *
  83  * @param id The ID string of the decoder to return.
  84  *
  85  * @return The decoder with the specified ID, or NULL if not found.
  86  *
  87  * @since 0.1.0
  88  */
  89 SRD_API struct srd_decoder *srd_decoder_get_by_id(const char *id)
  90 {
  91         GSList *l;
  92         struct srd_decoder *dec;
  93
  94         for (l = pd_list; l; l = l->next) {
  95                 dec = l->data;
  96                 if (!strcmp(dec->id, id))
  97                         return dec;
  98         }
  99
 100         return NULL;
 101 }
 102
 103 static int get_channels(const struct srd_decoder *d, const char *attr,
 104                 GSList **pdchl)
 105 {
 106         PyObject *py_channellist, *py_entry;
 107         struct srd_channel *pdch;
 108         int ret, num_channels, i;
 109
 110         if (!PyObject_HasAttrString(d->py_dec, attr))
 111                 /* No channels of this type specified. */
 112                 return SRD_OK;
 113
 114         py_channellist = PyObject_GetAttrString(d->py_dec, attr);
 115         if (!PyTuple_Check(py_channellist)) {
 116                 srd_err("Protocol decoder %s %s attribute is not a tuple.",
 117                                 d->name, attr);
 118                 return SRD_ERR_PYTHON;
 119         }
 120
 121         if ((num_channels = PyTuple_Size(py_channellist)) == 0)
 122                 /* Empty channellist. */
 123                 return SRD_OK;
 124
 125         ret = SRD_OK;
 126         for (i = 0; i < num_channels; i++) {
 127                 py_entry = PyTuple_GetItem(py_channellist, i);
 128                 if (!PyDict_Check(py_entry)) {
 129                         srd_err("Protocol decoder %s %s attribute is not "
 130                                 "a list with dict elements.", d->name, attr);
 131                         ret = SRD_ERR_PYTHON;
 132                         break;
 133                 }
 134
 135                 pdch = g_malloc(sizeof(struct srd_channel));
 136
 137                 if ((py_dictitem_as_str(py_entry, "id", &pdch->id)) != SRD_OK) {
 138                         ret = SRD_ERR_PYTHON;
 139                         break;
 140                 }
 141                 if ((py_dictitem_as_str(py_entry, "name", &pdch->name)) != SRD_OK) {
 142                         ret = SRD_ERR_PYTHON;
 143                         break;
 144                 }
 145                 if ((py_dictitem_as_str(py_entry, "desc", &pdch->desc)) != SRD_OK) {
 146                         ret = SRD_ERR_PYTHON;
 147                         break;
 148                 }
 149                 pdch->order = i;
 150
 151                 *pdchl = g_slist_append(*pdchl, pdch);
 152         }
 153
 154         Py_DecRef(py_channellist);
 155
 156         return ret;
 157 }
 158
 159 static int get_options(struct srd_decoder *d)
 160 {
 161         PyObject *py_opts, *py_opt, *py_val, *py_default, *py_item;
 162         Py_ssize_t opt, i;
 163         struct srd_decoder_option *o;
 164         GVariant *gvar;
 165         gint64 lval;
 166         double dval;
 167         int overflow;
 168         char *sval;
 169
 170         if (!PyObject_HasAttrString(d->py_dec, "options"))
 171                 /* No options, that's fine. */
 172                 return SRD_OK;
 173
 174         /* If present, options must be a tuple. */
 175         py_opts = PyObject_GetAttrString(d->py_dec, "options");
 176         if (!PyTuple_Check(py_opts)) {
 177                 srd_err("Protocol decoder %s: options attribute is not "
 178                                 "a tuple.", d->id);
 179                 return SRD_ERR_PYTHON;
 180         }
 181
 182         for (opt = 0; opt < PyTuple_Size(py_opts); opt++) {
 183                 py_opt = PyTuple_GetItem(py_opts, opt);
 184                 if (!PyDict_Check(py_opt)) {
 185                         srd_err("Protocol decoder %s options: each option "
 186                                         "must consist of a dictionary.", d->name);
 187                         return SRD_ERR_PYTHON;
 188                 }
 189                 if (!(py_val = PyDict_GetItemString(py_opt, "id"))) {
 190                         srd_err("Protocol decoder %s option %zd has no "
 191                                         "id.", d->name, opt);
 192                         return SRD_ERR_PYTHON;
 193                 }
 194                 o = g_malloc0(sizeof(struct srd_decoder_option));
 195                 py_str_as_str(py_val, &o->id);
 196
 197                 if ((py_val = PyDict_GetItemString(py_opt, "desc")))
 198                         py_str_as_str(py_val, &o->desc);
 199
 200                 if ((py_default = PyDict_GetItemString(py_opt, "default"))) {
 201                         if (PyUnicode_Check(py_default)) {
 202                                 /* UTF-8 string */
 203                                 py_str_as_str(py_default, &sval);
 204                                 o->def = g_variant_new_string(sval);
 205                                 g_free(sval);
 206                         } else if (PyLong_Check(py_default)) {
 207                                 /* Long */
 208                                 lval = PyLong_AsLongAndOverflow(py_default, &overflow);
 209                                 if (overflow) {
 210                                         /* Value is < LONG_MIN or > LONG_MAX */
 211                                         PyErr_Clear();
 212                                         srd_err("Protocol decoder %s option 'default' has "
 213                                                         "invalid default value.", d->name);
 214                                         return SRD_ERR_PYTHON;
 215                                 }
 216                                 o->def = g_variant_new_int64(lval);
 217                         } else if (PyFloat_Check(py_default)) {
 218                                 /* Float */
 219                                 if ((dval = PyFloat_AsDouble(py_default)) == -1.0) {
 220                                         PyErr_Clear();
 221                                         srd_err("Protocol decoder %s option 'default' has "
 222                                                         "invalid default value.", d->name);
 223                                         return SRD_ERR_PYTHON;
 224                                 }
 225                                 o->def = g_variant_new_double(dval);
 226                         } else {
 227                                 srd_err("Protocol decoder %s option 'default' has "
 228                                                 "value of unsupported type.", d->name);
 229                                 return SRD_ERR_PYTHON;
 230                         }
 231                         g_variant_ref_sink(o->def);
 232                 }
 233
 234                 if ((py_val = PyDict_GetItemString(py_opt, "values"))) {
 235                         /* A default is required if a list of values is
 236                          * given, since it's used to verify their type. */
 237                         if (!o->def) {
 238                                 srd_err("No default for option '%s'", o->id);
 239                                 return SRD_ERR_PYTHON;
 240                         }
 241                         if (!PyTuple_Check(py_val)) {
 242                                 srd_err("Option '%s' values should be a tuple.", o->id);
 243                                 return SRD_ERR_PYTHON;
 244                         }
 245                         for (i = 0; i < PyTuple_Size(py_val); i++) {
 246                                 py_item = PyTuple_GetItem(py_val, i);
 247                                 if (Py_TYPE(py_default) != Py_TYPE(py_item)) {
 248                                         srd_err("All values for option '%s' must be "
 249                                                         "of the same type as the default.",
 250                                                         o->id);
 251                                         return SRD_ERR_PYTHON;
 252                                 }
 253                                 if (PyUnicode_Check(py_item)) {
 254                                         /* UTF-8 string */
 255                                         py_str_as_str(py_item, &sval);
 256                                         gvar = g_variant_new_string(sval);
 257                                         g_variant_ref_sink(gvar);
 258                                         g_free(sval);
 259                                         o->values = g_slist_append(o->values, gvar);
 260                                 } else if (PyLong_Check(py_item)) {
 261                                         /* Long */
 262                                         lval = PyLong_AsLongAndOverflow(py_item, &overflow);
 263                                         if (overflow) {
 264                                                 /* Value is < LONG_MIN or > LONG_MAX */
 265                                                 PyErr_Clear();
 266                                                 srd_err("Protocol decoder %s option 'values' "
 267                                                                 "has invalid value.", d->name);
 268                                                 return SRD_ERR_PYTHON;
 269                                         }
 270                                         gvar = g_variant_new_int64(lval);
 271                                         g_variant_ref_sink(gvar);
 272                                         o->values = g_slist_append(o->values, gvar);
 273                                 } else if (PyFloat_Check(py_item)) {
 274                                         /* Float */
 275                                         if ((dval = PyFloat_AsDouble(py_item)) == -1.0) {
 276                                                 PyErr_Clear();
 277                                                 srd_err("Protocol decoder %s option 'default' has "
 278                                                                 "invalid default value.", d->name);
 279                                                 return SRD_ERR_PYTHON;
 280                                         }
 281                                         gvar = g_variant_new_double(dval);
 282                                         g_variant_ref_sink(gvar);
 283                                         o->values = g_slist_append(o->values, gvar);
 284                                 }
 285                         }
 286                 }
 287                 d->options = g_slist_append(d->options, o);
 288         }
 289
 290         return SRD_OK;
 291 }
 292
 293 /**
 294  * Load a protocol decoder module into the embedded Python interpreter.
 295  *
 296  * @param module_name The module name to be loaded.
 297  *
 298  * @return SRD_OK upon success, a (negative) error code otherwise.
 299  *
 300  * @since 0.1.0
 301  */
 302 SRD_API int srd_decoder_load(const char *module_name)
 303 {
 304         PyObject *py_basedec, *py_method, *py_attr, *py_annlist, *py_ann;
 305         PyObject *py_bin_classes, *py_bin_class, *py_ann_rows, *py_ann_row;
 306         PyObject *py_ann_classes, *py_long;
 307         struct srd_decoder *d;
 308         int ret, i, j;
 309         char **ann, **bin, *ann_row_id, *ann_row_desc;
 310         struct srd_channel *pdch;
 311         GSList *l, *ann_classes;
 312         struct srd_decoder_annotation_row *ann_row;
 313
 314         if (!srd_check_init())
 315                 return SRD_ERR;
 316
 317         if (!module_name)
 318                 return SRD_ERR_ARG;
 319
 320         if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
 321                 /* Module was already imported. */
 322                 return SRD_OK;
 323         }
 324
 325         srd_dbg("Loading protocol decoder '%s'.", module_name);
 326
 327         py_basedec = py_method = py_attr = NULL;
 328
 329         d = g_malloc0(sizeof(struct srd_decoder));
 330
 331         ret = SRD_ERR_PYTHON;
 332
 333         /* Import the Python module. */
 334         if (!(d->py_mod = PyImport_ImportModule(module_name))) {
 335                 srd_exception_catch("Import of '%s' failed", module_name);
 336                 goto err_out;
 337         }
 338
 339         /* Get the 'Decoder' class as Python object. */
 340         if (!(d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder"))) {
 341                 /* This generated an AttributeError exception. */
 342                 PyErr_Clear();
 343                 srd_err("Decoder class not found in protocol decoder %s.",
 344                         module_name);
 345                 goto err_out;
 346         }
 347
 348         if (!(py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder"))) {
 349                 srd_dbg("sigrokdecode module not loaded.");
 350                 goto err_out;
 351         }
 352
 353         if (!PyObject_IsSubclass(d->py_dec, py_basedec)) {
 354                 srd_err("Decoder class in protocol decoder module %s is not "
 355                         "a subclass of sigrokdecode.Decoder.", module_name);
 356                 goto err_out;
 357         }
 358         Py_CLEAR(py_basedec);
 359
 360         /*
 361          * Check that this decoder has the correct PD API version.
 362          * PDs of different API versions are incompatible and cannot work.
 363          */
 364         py_long = PyObject_GetAttrString(d->py_dec, "api_version");
 365         if (PyLong_AsLong(py_long) != 2) {
 366                 srd_err("Only PDs of API version 2 are supported.");
 367                 goto err_out;
 368         }
 369         Py_CLEAR(py_long);
 370
 371         /* Check for a proper start() method. */
 372         if (!PyObject_HasAttrString(d->py_dec, "start")) {
 373                 srd_err("Protocol decoder %s has no start() method Decoder "
 374                         "class.", module_name);
 375                 goto err_out;
 376         }
 377         py_method = PyObject_GetAttrString(d->py_dec, "start");
 378         if (!PyCallable_Check(py_method)) {
 379                 srd_err("Protocol decoder %s Decoder class attribute 'start' "
 380                         "is not a method.", module_name);
 381                 goto err_out;
 382         }
 383         Py_CLEAR(py_method);
 384
 385         /* Check for a proper decode() method. */
 386         if (!PyObject_HasAttrString(d->py_dec, "decode")) {
 387                 srd_err("Protocol decoder %s has no decode() method Decoder "
 388                         "class.", module_name);
 389                 goto err_out;
 390         }
 391         py_method = PyObject_GetAttrString(d->py_dec, "decode");
 392         if (!PyCallable_Check(py_method)) {
 393                 srd_err("Protocol decoder %s Decoder class attribute 'decode' "
 394                         "is not a method.", module_name);
 395                 goto err_out;
 396         }
 397         Py_CLEAR(py_method);
 398
 399         /* Store required fields in newly allocated strings. */
 400         if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
 401                 goto err_out;
 402
 403         if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
 404                 goto err_out;
 405
 406         if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
 407                 goto err_out;
 408
 409         if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
 410                 goto err_out;
 411
 412         if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
 413                 goto err_out;
 414
 415         /* All options and their default values. */
 416         if (get_options(d) != SRD_OK)
 417                 goto err_out;
 418
 419         /* Check and import required channels. */
 420         if (get_channels(d, "channels", &d->channels) != SRD_OK)
 421                 goto err_out;
 422
 423         /* Check and import optional channels. */
 424         if (get_channels(d, "optional_channels", &d->opt_channels) != SRD_OK)
 425                 goto err_out;
 426
 427         /*
 428          * Fix order numbers for the optional channels.
 429          *
 430          * Example:
 431          * Required channels: r1, r2, r3. Optional: o1, o2, o3, o4.
 432          * 'order' fields in the d->channels list = 0, 1, 2.
 433          * 'order' fields in the d->opt_channels list = 3, 4, 5, 6.
 434          */
 435         for (l = d->opt_channels; l; l = l->next) {
 436                 pdch = l->data;
 437                 pdch->order += g_slist_length(d->channels);
 438         }
 439
 440         /* Convert annotation class attribute to GSList of char **. */
 441         d->annotations = NULL;
 442         if (PyObject_HasAttrString(d->py_dec, "annotations")) {
 443                 py_annlist = PyObject_GetAttrString(d->py_dec, "annotations");
 444                 if (!PyTuple_Check(py_annlist)) {
 445                         srd_err("Protocol decoder %s annotations should "
 446                                         "be a tuple.", module_name);
 447                         goto err_out;
 448                 }
 449                 for (i = 0; i < PyTuple_Size(py_annlist); i++) {
 450                         py_ann = PyTuple_GetItem(py_annlist, i);
 451                         if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
 452                                 srd_err("Protocol decoder %s annotation %d should "
 453                                                 "be a tuple with two elements.", module_name, i + 1);
 454                                 goto err_out;
 455                         }
 456
 457                         if (py_strseq_to_char(py_ann, &ann) != SRD_OK) {
 458                                 goto err_out;
 459                         }
 460                         d->annotations = g_slist_append(d->annotations, ann);
 461                 }
 462         }
 463
 464         /* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'. */
 465         d->annotation_rows = NULL;
 466         if (PyObject_HasAttrString(d->py_dec, "annotation_rows")) {
 467                 py_ann_rows = PyObject_GetAttrString(d->py_dec, "annotation_rows");
 468                 if (!PyTuple_Check(py_ann_rows)) {
 469                         srd_err("Protocol decoder %s annotation row list "
 470                                 "must be a tuple.", module_name);
 471                         goto err_out;
 472                 }
 473                 for (i = 0; i < PyTuple_Size(py_ann_rows); i++) {
 474                         py_ann_row = PyTuple_GetItem(py_ann_rows, i);
 475                         if (!PyTuple_Check(py_ann_row)) {
 476                                 srd_err("Protocol decoder %s annotation rows "
 477                                         "must be tuples.", module_name);
 478                                 goto err_out;
 479                         }
 480                         if (PyTuple_Size(py_ann_row) != 3
 481                                         || !PyUnicode_Check(PyTuple_GetItem(py_ann_row, 0))
 482                                         || !PyUnicode_Check(PyTuple_GetItem(py_ann_row, 1))
 483                                         || !PyTuple_Check(PyTuple_GetItem(py_ann_row, 2))) {
 484                                 srd_err("Protocol decoder %s annotation rows "
 485                                         "must contain tuples containing two "
 486                                         "strings and a tuple.", module_name);
 487                                 goto err_out;
 488                         }
 489
 490                         if (py_str_as_str(PyTuple_GetItem(py_ann_row, 0), &ann_row_id) != SRD_OK)
 491                                 goto err_out;
 492
 493                         if (py_str_as_str(PyTuple_GetItem(py_ann_row, 1), &ann_row_desc) != SRD_OK)
 494                                 goto err_out;
 495
 496                         py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
 497                         ann_classes = NULL;
 498                         for (j = 0; j < PyTuple_Size(py_ann_classes); j++) {
 499                                 py_long = PyTuple_GetItem(py_ann_classes, j);
 500                                 if (!PyLong_Check(py_long)) {
 501                                         srd_err("Protocol decoder %s annotation row class "
 502                                                 "list must only contain numbers.", module_name);
 503                                         goto err_out;
 504                                 }
 505                                 ann_classes = g_slist_append(ann_classes,
 506                                         GINT_TO_POINTER(PyLong_AsLong(py_long)));
 507                         }
 508
 509                         ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
 510                         ann_row->id = ann_row_id;
 511                         ann_row->desc = ann_row_desc;
 512                         ann_row->ann_classes = ann_classes;
 513                         d->annotation_rows = g_slist_append(d->annotation_rows, ann_row);
 514                 }
 515         }
 516
 517         /* Convert binary class to GSList of char *. */
 518         d->binary = NULL;
 519         if (PyObject_HasAttrString(d->py_dec, "binary")) {
 520                 py_bin_classes = PyObject_GetAttrString(d->py_dec, "binary");
 521                 if (!PyTuple_Check(py_bin_classes)) {
 522                         srd_err("Protocol decoder %s binary classes should "
 523                                         "be a tuple.", module_name);
 524                         goto err_out;
 525                 }
 526                 for (i = 0; i < PyTuple_Size(py_bin_classes); i++) {
 527                         py_bin_class = PyTuple_GetItem(py_bin_classes, i);
 528                         if (!PyTuple_Check(py_bin_class)) {
 529                                 srd_err("Protocol decoder %s binary classes "
 530                                                 "should consist of tuples.", module_name);
 531                                 goto err_out;
 532                         }
 533                         if (PyTuple_Size(py_bin_class) != 2
 534                                         || !PyUnicode_Check(PyTuple_GetItem(py_bin_class, 0))
 535                                         || !PyUnicode_Check(PyTuple_GetItem(py_bin_class, 1))) {
 536                                 srd_err("Protocol decoder %s binary classes should "
 537                                                 "contain tuples with two strings.", module_name);
 538                                 goto err_out;
 539                         }
 540
 541                         if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK) {
 542                                 goto err_out;
 543                         }
 544                         d->binary = g_slist_append(d->binary, bin);
 545                 }
 546         }
 547
 548         /* Append it to the list of supported/loaded decoders. */
 549         pd_list = g_slist_append(pd_list, d);
 550
 551         ret = SRD_OK;
 552
 553 err_out:
 554         if (ret != SRD_OK) {
 555                 Py_XDECREF(py_method);
 556                 Py_XDECREF(py_basedec);
 557                 Py_XDECREF(d->py_dec);
 558                 Py_XDECREF(d->py_mod);
 559                 g_free(d);
 560         }
 561
 562         return ret;
 563 }
 564
 565 /**
 566  * Return a protocol decoder's docstring.
 567  *
 568  * @param dec The loaded protocol decoder.
 569  *
 570  * @return A newly allocated buffer containing the protocol decoder's
 571  *         documentation. The caller is responsible for free'ing the buffer.
 572  *
 573  * @since 0.1.0
 574  */
 575 SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
 576 {
 577         PyObject *py_str;
 578         char *doc;
 579
 580         if (!srd_check_init())
 581                 return NULL;
 582
 583         if (!dec)
 584                 return NULL;
 585
 586         if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
 587                 return NULL;
 588
 589         if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
 590                 srd_exception_catch("Failed to get docstring");
 591                 return NULL;
 592         }
 593
 594         doc = NULL;
 595         if (py_str != Py_None)
 596                 py_str_as_str(py_str, &doc);
 597         Py_DecRef(py_str);
 598
 599         return doc;
 600 }
 601
 602 static void free_channels(GSList *channellist)
 603 {
 604         GSList *l;
 605         struct srd_channel *pdch;
 606
 607         if (channellist == NULL)
 608                 return;
 609
 610         for (l = channellist; l; l = l->next) {
 611                 pdch = l->data;
 612                 g_free(pdch->id);
 613                 g_free(pdch->name);
 614                 g_free(pdch->desc);
 615                 g_free(pdch);
 616         }
 617         g_slist_free(channellist);
 618 }
 619
 620 /**
 621  * Unload the specified protocol decoder.
 622  *
 623  * @param dec The struct srd_decoder to be unloaded.
 624  *
 625  * @return SRD_OK upon success, a (negative) error code otherwise.
 626  *
 627  * @since 0.1.0
 628  */
 629 SRD_API int srd_decoder_unload(struct srd_decoder *dec)
 630 {
 631         struct srd_decoder_option *o;
 632         struct srd_session *sess;
 633         GSList *l;
 634
 635         if (!srd_check_init())
 636                 return SRD_ERR;
 637
 638         if (!dec)
 639                 return SRD_ERR_ARG;
 640
 641         srd_dbg("Unloading protocol decoder '%s'.", dec->name);
 642
 643         /*
 644          * Since any instances of this decoder need to be released as well,
 645          * but they could be anywhere in the stack, just free the entire
 646          * stack. A frontend reloading a decoder thus has to restart all
 647          * instances, and rebuild the stack.
 648          */
 649         for (l = sessions; l; l = l->next) {
 650                 sess = l->data;
 651                 srd_inst_free_all(sess, NULL);
 652         }
 653
 654         for (l = dec->options; l; l = l->next) {
 655                 o = l->data;
 656                 g_free(o->id);
 657                 g_free(o->desc);
 658                 g_variant_unref(o->def);
 659                 g_free(o);
 660         }
 661         g_slist_free(dec->options);
 662
 663         free_channels(dec->channels);
 664         free_channels(dec->opt_channels);
 665         g_free(dec->id);
 666         g_free(dec->name);
 667         g_free(dec->longname);
 668         g_free(dec->desc);
 669         g_free(dec->license);
 670
 671         /* The module's Decoder class. */
 672         Py_XDECREF(dec->py_dec);
 673         /* The module itself. */
 674         Py_XDECREF(dec->py_mod);
 675
 676         g_free(dec);
 677
 678         return SRD_OK;
 679 }
 680
 681 static void srd_decoder_load_all_zip_path(char *path)
 682 {
 683         PyObject *zipimport_mod, *zipimporter_class, *zipimporter;
 684         PyObject *prefix_obj, *files, *key, *value, *set, *modname;
 685         Py_ssize_t pos = 0;
 686         char *prefix;
 687         size_t prefix_len;
 688
 689         set = files = prefix_obj = zipimporter = zipimporter_class = NULL;
 690
 691         zipimport_mod = PyImport_ImportModule("zipimport");
 692         if (zipimport_mod == NULL)
 693                 goto err_out;
 694
 695         zipimporter_class = PyObject_GetAttrString(zipimport_mod, "zipimporter");
 696         if (zipimporter_class == NULL)
 697                 goto err_out;
 698
 699         zipimporter = PyObject_CallFunction(zipimporter_class, "s", path);
 700         if (zipimporter == NULL)
 701                 goto err_out;
 702
 703         prefix_obj = PyObject_GetAttrString(zipimporter, "prefix");
 704         if (prefix_obj == NULL)
 705                 goto err_out;
 706
 707         files = PyObject_GetAttrString(zipimporter, "_files");
 708         if (files == NULL)
 709                 goto err_out;
 710
 711         set = PySet_New(NULL);
 712         if (set == NULL)
 713                 goto err_out;
 714
 715         if (py_str_as_str(prefix_obj, &prefix) != SRD_OK)
 716                 goto err_out;
 717
 718         prefix_len = strlen(prefix);
 719
 720         while (PyDict_Next(files, &pos, &key, &value)) {
 721                 char *path, *slash;
 722                 if (py_str_as_str(key, &path) == SRD_OK) {
 723                         if (strlen(path) > prefix_len &&
 724                             !memcmp(path, prefix, prefix_len) &&
 725                             (slash = strchr(path+prefix_len, '/'))) {
 726                                 modname =
 727                                   PyUnicode_FromStringAndSize(path+prefix_len,
 728                                                               slash-(path+prefix_len));
 729                                 if (modname == NULL) {
 730                                         PyErr_Clear();
 731                                 } else {
 732                                         PySet_Add(set, modname);
 733                                         Py_XDECREF(modname);
 734                                 }
 735                         }
 736                         free(path);
 737                 }
 738         }
 739
 740         free(prefix);
 741
 742         while ((modname = PySet_Pop(set))) {
 743                 char *modname_str;
 744                 if (py_str_as_str(modname, &modname_str) == SRD_OK) {
 745                         /* The directory name is the module name (e.g. "i2c"). */
 746                         srd_decoder_load(modname_str);
 747                         free(modname_str);
 748                 }
 749                 Py_XDECREF(modname);
 750         }
 751
 752 err_out:
 753         Py_XDECREF(set);
 754         Py_XDECREF(files);
 755         Py_XDECREF(prefix_obj);
 756         Py_XDECREF(zipimporter);
 757         Py_XDECREF(zipimporter_class);
 758         Py_XDECREF(zipimport_mod);
 759         PyErr_Clear();
 760 }
 761
 762 static void srd_decoder_load_all_path(char *path)
 763 {
 764         GDir *dir;
 765         const gchar *direntry;
 766
 767         if (!(dir = g_dir_open(path, 0, NULL))) {
 768                 /* Not really fatal */
 769                 /* Try zipimport method too */
 770                 srd_decoder_load_all_zip_path(path);
 771                 return;
 772         }
 773
 774         /* This ignores errors returned by srd_decoder_load(). That
 775          * function will have logged the cause, but in any case we
 776          * want to continue anyway. */
 777         while ((direntry = g_dir_read_name(dir)) != NULL) {
 778                 /* The directory name is the module name (e.g. "i2c"). */
 779                 srd_decoder_load(direntry);
 780         }
 781         g_dir_close(dir);
 782
 783 }
 784
 785 /**
 786  * Load all installed protocol decoders.
 787  *
 788  * @return SRD_OK upon success, a (negative) error code otherwise.
 789  *
 790  * @since 0.1.0
 791  */
 792 SRD_API int srd_decoder_load_all(void)
 793 {
 794         GSList *l;
 795
 796         if (!srd_check_init())
 797                 return SRD_ERR;
 798
 799         for (l = searchpaths; l; l = l->next)
 800                 srd_decoder_load_all_path(l->data);
 801
 802         return SRD_OK;
 803 }
 804
 805 /**
 806  * Unload all loaded protocol decoders.
 807  *
 808  * @return SRD_OK upon success, a (negative) error code otherwise.
 809  *
 810  * @since 0.1.0
 811  */
 812 SRD_API int srd_decoder_unload_all(void)
 813 {
 814         GSList *l;
 815         struct srd_decoder *dec;
 816
 817         for (l = pd_list; l; l = l->next) {
 818                 dec = l->data;
 819                 srd_decoder_unload(dec);
 820         }
 821         g_slist_free(pd_list);
 822         pd_list = NULL;
 823
 824         return SRD_OK;
 825 }
 826
 827 /** @} */