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.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
  23 #include "libsigrokdecode-internal.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 containing the names of the decoders as strings.
  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                 if (!(pdch = g_try_malloc(sizeof(struct srd_channel)))) {
 136                         srd_err("Failed to g_malloc() struct srd_channel.");
 137                         ret = SRD_ERR_MALLOC;
 138                         break;
 139                 }
 140
 141                 if ((py_dictitem_as_str(py_entry, "id", &pdch->id)) != SRD_OK) {
 142                         ret = SRD_ERR_PYTHON;
 143                         break;
 144                 }
 145                 if ((py_dictitem_as_str(py_entry, "name", &pdch->name)) != SRD_OK) {
 146                         ret = SRD_ERR_PYTHON;
 147                         break;
 148                 }
 149                 if ((py_dictitem_as_str(py_entry, "desc", &pdch->desc)) != SRD_OK) {
 150                         ret = SRD_ERR_PYTHON;
 151                         break;
 152                 }
 153                 pdch->order = i;
 154
 155                 *pdchl = g_slist_append(*pdchl, pdch);
 156         }
 157
 158         Py_DecRef(py_channellist);
 159
 160         return ret;
 161 }
 162
 163 static int get_options(struct srd_decoder *d)
 164 {
 165         PyObject *py_opts, *py_opt, *py_val, *py_default, *py_item;
 166         Py_ssize_t opt, i;
 167         struct srd_decoder_option *o;
 168         GVariant *gvar;
 169         gint64 lval;
 170         double dval;
 171         int overflow;
 172         char *sval;
 173
 174         if (!PyObject_HasAttrString(d->py_dec, "options"))
 175                 /* No options, that's fine. */
 176                 return SRD_OK;
 177
 178         /* If present, options must be a tuple. */
 179         py_opts = PyObject_GetAttrString(d->py_dec, "options");
 180         if (!PyTuple_Check(py_opts)) {
 181                 srd_err("Protocol decoder %s: options attribute is not "
 182                                 "a tuple.", d->id);
 183                 return SRD_ERR_PYTHON;
 184         }
 185
 186         for (opt = 0; opt < PyTuple_Size(py_opts); opt++) {
 187                 py_opt = PyTuple_GetItem(py_opts, opt);
 188                 if (!PyDict_Check(py_opt)) {
 189                         srd_err("Protocol decoder %s options: each option "
 190                                         "must consist of a dictionary.", d->name);
 191                         return SRD_ERR_PYTHON;
 192                 }
 193                 if (!(py_val = PyDict_GetItemString(py_opt, "id"))) {
 194                         srd_err("Protocol decoder %s option %d has no "
 195                                         "id.", d->name);
 196                         return SRD_ERR_PYTHON;
 197                 }
 198                 o = g_malloc0(sizeof(struct srd_decoder_option));
 199                 py_str_as_str(py_val, &o->id);
 200
 201                 if ((py_val = PyDict_GetItemString(py_opt, "desc")))
 202                         py_str_as_str(py_val, &o->desc);
 203
 204                 if ((py_default = PyDict_GetItemString(py_opt, "default"))) {
 205                         if (PyUnicode_Check(py_default)) {
 206                                 /* UTF-8 string */
 207                                 py_str_as_str(py_default, &sval);
 208                                 o->def = g_variant_new_string(sval);
 209                                 g_free(sval);
 210                         } else if (PyLong_Check(py_default)) {
 211                                 /* Long */
 212                                 lval = PyLong_AsLongAndOverflow(py_default, &overflow);
 213                                 if (overflow) {
 214                                         /* Value is < LONG_MIN or > LONG_MAX */
 215                                         PyErr_Clear();
 216                                         srd_err("Protocol decoder %s option 'default' has "
 217                                                         "invalid default value.", d->name);
 218                                         return SRD_ERR_PYTHON;
 219                                 }
 220                                 o->def = g_variant_new_int64(lval);
 221                         } else if (PyFloat_Check(py_default)) {
 222                                 /* Float */
 223                                 if ((dval = PyFloat_AsDouble(py_default)) == -1.0) {
 224                                         PyErr_Clear();
 225                                         srd_err("Protocol decoder %s option 'default' has "
 226                                                         "invalid default value.", d->name);
 227                                         return SRD_ERR_PYTHON;
 228                                 }
 229                                 o->def = g_variant_new_double(dval);
 230                         } else {
 231                                 srd_err("Protocol decoder %s option 'default' has "
 232                                                 "value of unsupported type '%s'.", d->name,
 233                                                 Py_TYPE(py_default)->tp_name);
 234                                 return SRD_ERR_PYTHON;
 235                         }
 236                         g_variant_ref_sink(o->def);
 237                 }
 238
 239                 if ((py_val = PyDict_GetItemString(py_opt, "values"))) {
 240                         /* A default is required if a list of values is
 241                          * given, since it's used to verify their type. */
 242                         if (!o->def) {
 243                                 srd_err("No default for option '%s'", o->id);
 244                                 return SRD_ERR_PYTHON;
 245                         }
 246                         if (!PyTuple_Check(py_val)) {
 247                                 srd_err("Option '%s' values should be a tuple.", o->id);
 248                                 return SRD_ERR_PYTHON;
 249                         }
 250                         for (i = 0; i < PyTuple_Size(py_val); i++) {
 251                                 py_item = PyTuple_GetItem(py_val, i);
 252                                 if (Py_TYPE(py_default) != Py_TYPE(py_item)) {
 253                                         srd_err("All values for option '%s' must be "
 254                                                         "of the same type as the default.",
 255                                                         o->id);
 256                                         return SRD_ERR_PYTHON;
 257                                 }
 258                                 if (PyUnicode_Check(py_item)) {
 259                                         /* UTF-8 string */
 260                                         py_str_as_str(py_item, &sval);
 261                                         gvar = g_variant_new_string(sval);
 262                                         g_variant_ref_sink(gvar);
 263                                         g_free(sval);
 264                                         o->values = g_slist_append(o->values, gvar);
 265                                 } else if (PyLong_Check(py_item)) {
 266                                         /* Long */
 267                                         lval = PyLong_AsLongAndOverflow(py_item, &overflow);
 268                                         if (overflow) {
 269                                                 /* Value is < LONG_MIN or > LONG_MAX */
 270                                                 PyErr_Clear();
 271                                                 srd_err("Protocol decoder %s option 'values' "
 272                                                                 "has invalid value.", d->name);
 273                                                 return SRD_ERR_PYTHON;
 274                                         }
 275                                         gvar = g_variant_new_int64(lval);
 276                                         g_variant_ref_sink(gvar);
 277                                         o->values = g_slist_append(o->values, gvar);
 278                                 } else if (PyFloat_Check(py_item)) {
 279                                         /* Float */
 280                                         if ((dval = PyFloat_AsDouble(py_item)) == -1.0) {
 281                                                 PyErr_Clear();
 282                                                 srd_err("Protocol decoder %s option 'default' has "
 283                                                                 "invalid default value.", d->name);
 284                                                 return SRD_ERR_PYTHON;
 285                                         }
 286                                         gvar = g_variant_new_double(dval);
 287                                         g_variant_ref_sink(gvar);
 288                                         o->values = g_slist_append(o->values, gvar);
 289                                 }
 290                         }
 291                 }
 292                 d->options = g_slist_append(d->options, o);
 293         }
 294
 295         return SRD_OK;
 296 }
 297
 298 /**
 299  * Load a protocol decoder module into the embedded Python interpreter.
 300  *
 301  * @param module_name The module name to be loaded.
 302  *
 303  * @return SRD_OK upon success, a (negative) error code otherwise.
 304  *
 305  * @since 0.1.0
 306  */
 307 SRD_API int srd_decoder_load(const char *module_name)
 308 {
 309         PyObject *py_basedec, *py_method, *py_attr, *py_annlist, *py_ann;
 310         PyObject *py_bin_classes, *py_bin_class, *py_ann_rows, *py_ann_row;
 311         PyObject *py_ann_classes, *py_long;
 312         struct srd_decoder *d;
 313         int ret, i, j;
 314         char **ann, **bin, *ann_row_id, *ann_row_desc;
 315         struct srd_channel *pdch;
 316         GSList *l, *ann_classes;
 317         struct srd_decoder_annotation_row *ann_row;
 318
 319         if (!srd_check_init())
 320                 return SRD_ERR;
 321
 322         if (!module_name)
 323                 return SRD_ERR_ARG;
 324
 325         if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
 326                 /* Module was already imported. */
 327                 return SRD_OK;
 328         }
 329
 330         srd_dbg("Loading protocol decoder '%s'.", module_name);
 331
 332         py_basedec = py_method = py_attr = NULL;
 333
 334         if (!(d = g_try_malloc0(sizeof(struct srd_decoder)))) {
 335                 srd_dbg("Failed to g_malloc() struct srd_decoder.");
 336                 ret = SRD_ERR_MALLOC;
 337                 goto err_out;
 338         }
 339
 340         ret = SRD_ERR_PYTHON;
 341
 342         /* Import the Python module. */
 343         if (!(d->py_mod = PyImport_ImportModule(module_name))) {
 344                 srd_exception_catch("Import of '%s' failed.", module_name);
 345                 goto err_out;
 346         }
 347
 348         /* Get the 'Decoder' class as Python object. */
 349         if (!(d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder"))) {
 350                 /* This generated an AttributeError exception. */
 351                 PyErr_Clear();
 352                 srd_err("Decoder class not found in protocol decoder %s.",
 353                         module_name);
 354                 goto err_out;
 355         }
 356
 357         if (!(py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder"))) {
 358                 srd_dbg("sigrokdecode module not loaded.");
 359                 goto err_out;
 360         }
 361
 362         if (!PyObject_IsSubclass(d->py_dec, py_basedec)) {
 363                 srd_err("Decoder class in protocol decoder module %s is not "
 364                         "a subclass of sigrokdecode.Decoder.", module_name);
 365                 goto err_out;
 366         }
 367         Py_CLEAR(py_basedec);
 368
 369         /*
 370          * Check that thіs decoder has the correct PD API version.
 371          * PDs of different API versions are incompatible and cannot work.
 372          */
 373         py_long = PyObject_GetAttrString(d->py_dec, "api_version");
 374         if (PyLong_AsLong(py_long) != 2) {
 375                 srd_err("Only PDs of API version 2 are supported.");
 376                 goto err_out;
 377         }
 378         Py_CLEAR(py_long);
 379
 380         /* Check for a proper start() method. */
 381         if (!PyObject_HasAttrString(d->py_dec, "start")) {
 382                 srd_err("Protocol decoder %s has no start() method Decoder "
 383                         "class.", module_name);
 384                 goto err_out;
 385         }
 386         py_method = PyObject_GetAttrString(d->py_dec, "start");
 387         if (!PyFunction_Check(py_method)) {
 388                 srd_err("Protocol decoder %s Decoder class attribute 'start' "
 389                         "is not a method.", module_name);
 390                 goto err_out;
 391         }
 392         Py_CLEAR(py_method);
 393
 394         /* Check for a proper decode() method. */
 395         if (!PyObject_HasAttrString(d->py_dec, "decode")) {
 396                 srd_err("Protocol decoder %s has no decode() method Decoder "
 397                         "class.", module_name);
 398                 goto err_out;
 399         }
 400         py_method = PyObject_GetAttrString(d->py_dec, "decode");
 401         if (!PyFunction_Check(py_method)) {
 402                 srd_err("Protocol decoder %s Decoder class attribute 'decode' "
 403                         "is not a method.", module_name);
 404                 goto err_out;
 405         }
 406         Py_CLEAR(py_method);
 407
 408         /* Store required fields in newly allocated strings. */
 409         if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
 410                 goto err_out;
 411
 412         if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
 413                 goto err_out;
 414
 415         if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
 416                 goto err_out;
 417
 418         if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
 419                 goto err_out;
 420
 421         if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
 422                 goto err_out;
 423
 424         /* All options and their default values. */
 425         if (get_options(d) != SRD_OK)
 426                 goto err_out;
 427
 428         /* Check and import required channels. */
 429         if (get_channels(d, "channels", &d->channels) != SRD_OK)
 430                 goto err_out;
 431
 432         /* Check and import optional channels. */
 433         if (get_channels(d, "optional_channels", &d->opt_channels) != SRD_OK)
 434                 goto err_out;
 435
 436         /*
 437          * Fix order numbers for the optional channels.
 438          *
 439          * Example:
 440          * Required channels: r1, r2, r3. Optional: o1, o2, o3, o4.
 441          * 'order' fields in the d->channels list = 0, 1, 2.
 442          * 'order' fields in the d->opt_channels list = 3, 4, 5, 6.
 443          */
 444         for (l = d->opt_channels; l; l = l->next) {
 445                 pdch = l->data;
 446                 pdch->order += g_slist_length(d->channels);
 447         }
 448
 449         /* Convert annotation class attribute to GSList of char **. */
 450         d->annotations = NULL;
 451         if (PyObject_HasAttrString(d->py_dec, "annotations")) {
 452                 py_annlist = PyObject_GetAttrString(d->py_dec, "annotations");
 453                 if (!PyTuple_Check(py_annlist)) {
 454                         srd_err("Protocol decoder %s annotations should "
 455                                         "be a tuple.", module_name);
 456                         goto err_out;
 457                 }
 458                 for (i = 0; i < PyTuple_Size(py_annlist); i++) {
 459                         py_ann = PyTuple_GetItem(py_annlist, i);
 460                         if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
 461                                 srd_err("Protocol decoder %s annotation %d should "
 462                                                 "be a tuple with two elements.", module_name, i + 1);
 463                                 goto err_out;
 464                         }
 465
 466                         if (py_strseq_to_char(py_ann, &ann) != SRD_OK) {
 467                                 goto err_out;
 468                         }
 469                         d->annotations = g_slist_append(d->annotations, ann);
 470                 }
 471         }
 472
 473         /* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'. */
 474         d->annotation_rows = NULL;
 475         if (PyObject_HasAttrString(d->py_dec, "annotation_rows")) {
 476                 py_ann_rows = PyObject_GetAttrString(d->py_dec, "annotation_rows");
 477                 if (!PyTuple_Check(py_ann_rows)) {
 478                         srd_err("Protocol decoder %s annotation row list "
 479                                 "must be a tuple.", module_name);
 480                         goto err_out;
 481                 }
 482                 for (i = 0; i < PyTuple_Size(py_ann_rows); i++) {
 483                         py_ann_row = PyTuple_GetItem(py_ann_rows, i);
 484                         if (!PyTuple_Check(py_ann_row)) {
 485                                 srd_err("Protocol decoder %s annotation rows "
 486                                         "must be tuples.", module_name);
 487                                 goto err_out;
 488                         }
 489                         if (PyTuple_Size(py_ann_row) != 3
 490                                         || !PyUnicode_Check(PyTuple_GetItem(py_ann_row, 0))
 491                                         || !PyUnicode_Check(PyTuple_GetItem(py_ann_row, 1))
 492                                         || !PyTuple_Check(PyTuple_GetItem(py_ann_row, 2))) {
 493                                 srd_err("Protocol decoder %s annotation rows "
 494                                         "must contain tuples containing two "
 495                                         "strings and a tuple.", module_name);
 496                                 goto err_out;
 497                         }
 498
 499                         if (py_str_as_str(PyTuple_GetItem(py_ann_row, 0), &ann_row_id) != SRD_OK)
 500                                 goto err_out;
 501
 502                         if (py_str_as_str(PyTuple_GetItem(py_ann_row, 1), &ann_row_desc) != SRD_OK)
 503                                 goto err_out;
 504
 505                         py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
 506                         ann_classes = NULL;
 507                         for (j = 0; j < PyTuple_Size(py_ann_classes); j++) {
 508                                 py_long = PyTuple_GetItem(py_ann_classes, j);
 509                                 if (!PyLong_Check(py_long)) {
 510                                         srd_err("Protocol decoder %s annotation row class "
 511                                                 "list must only contain numbers.", module_name);
 512                                         goto err_out;
 513                                 }
 514                                 ann_classes = g_slist_append(ann_classes,
 515                                         GINT_TO_POINTER(PyLong_AsLong(py_long)));
 516                         }
 517
 518                         ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
 519                         ann_row->id = ann_row_id;
 520                         ann_row->desc = ann_row_desc;
 521                         ann_row->ann_classes = ann_classes;
 522                         d->annotation_rows = g_slist_append(d->annotation_rows, ann_row);
 523                 }
 524         }
 525
 526         /* Convert binary class to GSList of char *. */
 527         d->binary = NULL;
 528         if (PyObject_HasAttrString(d->py_dec, "binary")) {
 529                 py_bin_classes = PyObject_GetAttrString(d->py_dec, "binary");
 530                 if (!PyTuple_Check(py_bin_classes)) {
 531                         srd_err("Protocol decoder %s binary classes should "
 532                                         "be a tuple.", module_name);
 533                         goto err_out;
 534                 }
 535                 for (i = 0; i < PyTuple_Size(py_bin_classes); i++) {
 536                         py_bin_class = PyTuple_GetItem(py_bin_classes, i);
 537                         if (!PyTuple_Check(py_bin_class)) {
 538                                 srd_err("Protocol decoder %s binary classes "
 539                                                 "should consist of tuples.", module_name);
 540                                 goto err_out;
 541                         }
 542                         if (PyTuple_Size(py_bin_class) != 2
 543                                         || !PyUnicode_Check(PyTuple_GetItem(py_bin_class, 0))
 544                                         || !PyUnicode_Check(PyTuple_GetItem(py_bin_class, 1))) {
 545                                 srd_err("Protocol decoder %s binary classes should "
 546                                                 "contain tuples with two strings.", module_name);
 547                                 goto err_out;
 548                         }
 549
 550                         if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK) {
 551                                 goto err_out;
 552                         }
 553                         d->binary = g_slist_append(d->binary, bin);
 554                 }
 555         }
 556
 557         /* Append it to the list of supported/loaded decoders. */
 558         pd_list = g_slist_append(pd_list, d);
 559
 560         ret = SRD_OK;
 561
 562 err_out:
 563         if (ret != SRD_OK) {
 564                 Py_XDECREF(py_method);
 565                 Py_XDECREF(py_basedec);
 566                 Py_XDECREF(d->py_dec);
 567                 Py_XDECREF(d->py_mod);
 568                 g_free(d);
 569         }
 570
 571         return ret;
 572 }
 573
 574 /**
 575  * Return a protocol decoder's docstring.
 576  *
 577  * @param dec The loaded protocol decoder.
 578  *
 579  * @return A newly allocated buffer containing the protocol decoder's
 580  *         documentation. The caller is responsible for free'ing the buffer.
 581  *
 582  * @since 0.1.0
 583  */
 584 SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
 585 {
 586         PyObject *py_str;
 587         char *doc;
 588
 589         if (!srd_check_init())
 590                 return NULL;
 591
 592         if (!dec)
 593                 return NULL;
 594
 595         if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
 596                 return NULL;
 597
 598         if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
 599                 srd_exception_catch("");
 600                 return NULL;
 601         }
 602
 603         doc = NULL;
 604         if (py_str != Py_None)
 605                 py_str_as_str(py_str, &doc);
 606         Py_DecRef(py_str);
 607
 608         return doc;
 609 }
 610
 611 static void free_channels(GSList *channellist)
 612 {
 613         GSList *l;
 614         struct srd_channel *pdch;
 615
 616         if (channellist == NULL)
 617                 return;
 618
 619         for (l = channellist; l; l = l->next) {
 620                 pdch = l->data;
 621                 g_free(pdch->id);
 622                 g_free(pdch->name);
 623                 g_free(pdch->desc);
 624                 g_free(pdch);
 625         }
 626         g_slist_free(channellist);
 627 }
 628
 629 /**
 630  * Unload the specified protocol decoder.
 631  *
 632  * @param dec The struct srd_decoder to be unloaded.
 633  *
 634  * @return SRD_OK upon success, a (negative) error code otherwise.
 635  *
 636  * @since 0.1.0
 637  */
 638 SRD_API int srd_decoder_unload(struct srd_decoder *dec)
 639 {
 640         struct srd_decoder_option *o;
 641         struct srd_session *sess;
 642         GSList *l;
 643
 644         if (!srd_check_init())
 645                 return SRD_ERR;
 646
 647         if (!dec)
 648                 return SRD_ERR_ARG;
 649
 650         srd_dbg("Unloading protocol decoder '%s'.", dec->name);
 651
 652         /*
 653          * Since any instances of this decoder need to be released as well,
 654          * but they could be anywhere in the stack, just free the entire
 655          * stack. A frontend reloading a decoder thus has to restart all
 656          * instances, and rebuild the stack.
 657          */
 658         for (l = sessions; l; l = l->next) {
 659                 sess = l->data;
 660                 srd_inst_free_all(sess, NULL);
 661         }
 662
 663         for (l = dec->options; l; l = l->next) {
 664                 o = l->data;
 665                 g_free(o->id);
 666                 g_free(o->desc);
 667                 g_variant_unref(o->def);
 668                 g_free(o);
 669         }
 670         g_slist_free(dec->options);
 671
 672         free_channels(dec->channels);
 673         free_channels(dec->opt_channels);
 674         g_free(dec->id);
 675         g_free(dec->name);
 676         g_free(dec->longname);
 677         g_free(dec->desc);
 678         g_free(dec->license);
 679
 680         /* The module's Decoder class. */
 681         Py_XDECREF(dec->py_dec);
 682         /* The module itself. */
 683         Py_XDECREF(dec->py_mod);
 684
 685         g_free(dec);
 686
 687         return SRD_OK;
 688 }
 689
 690 static void srd_decoder_load_all_path(char *path)
 691 {
 692         GDir *dir;
 693         const gchar *direntry;
 694
 695         if (!(dir = g_dir_open(path, 0, NULL)))
 696                 /* Not really fatal */
 697                 return;
 698
 699         /* This ignores errors returned by srd_decoder_load(). That
 700          * function will have logged the cause, but in any case we
 701          * want to continue anyway. */
 702         while ((direntry = g_dir_read_name(dir)) != NULL) {
 703                 /* The directory name is the module name (e.g. "i2c"). */
 704                 srd_decoder_load(direntry);
 705         }
 706         g_dir_close(dir);
 707
 708 }
 709
 710 /**
 711  * Load all installed protocol decoders.
 712  *
 713  * @return SRD_OK upon success, a (negative) error code otherwise.
 714  *
 715  * @since 0.1.0
 716  */
 717 SRD_API int srd_decoder_load_all(void)
 718 {
 719         GSList *l;
 720
 721         if (!srd_check_init())
 722                 return SRD_ERR;
 723
 724         for (l = searchpaths; l; l = l->next)
 725                 srd_decoder_load_all_path(l->data);
 726
 727         return SRD_OK;
 728 }
 729
 730 /**
 731  * Unload all loaded protocol decoders.
 732  *
 733  * @return SRD_OK upon success, a (negative) error code otherwise.
 734  *
 735  * @since 0.1.0
 736  */
 737 SRD_API int srd_decoder_unload_all(void)
 738 {
 739         GSList *l;
 740         struct srd_decoder *dec;
 741
 742         for (l = pd_list; l; l = l->next) {
 743                 dec = l->data;
 744                 srd_decoder_unload(dec);
 745         }
 746         g_slist_free(pd_list);
 747         pd_list = NULL;
 748
 749         return SRD_OK;
 750 }
 751
 752 /** @} */