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 void channel_free(void *data)
 104 {
 105         struct srd_channel *ch = data;
 106
 107         if (!ch)
 108                 return;
 109
 110         g_free(ch->desc);
 111         g_free(ch->name);
 112         g_free(ch->id);
 113         g_free(ch);
 114 }
 115
 116 static void variant_free(void *data)
 117 {
 118         GVariant *var = data;
 119
 120         if (!var)
 121                 return;
 122
 123         g_variant_unref(var);
 124 }
 125
 126 static void annotation_row_free(void *data)
 127 {
 128         struct srd_decoder_annotation_row *row = data;
 129
 130         if (!row)
 131                 return;
 132
 133         g_slist_free(row->ann_classes);
 134         g_free(row->desc);
 135         g_free(row->id);
 136         g_free(row);
 137 }
 138
 139 static void decoder_option_free(void *data)
 140 {
 141         struct srd_decoder_option *opt = data;
 142
 143         if (!opt)
 144                 return;
 145
 146         g_slist_free_full(opt->values, &variant_free);
 147         variant_free(opt->def);
 148         g_free(opt->desc);
 149         g_free(opt->id);
 150         g_free(opt);
 151 }
 152
 153 static void decoder_free(struct srd_decoder *dec)
 154 {
 155         if (!dec)
 156                 return;
 157
 158         Py_XDECREF(dec->py_dec);
 159         Py_XDECREF(dec->py_mod);
 160
 161         g_slist_free_full(dec->options, &decoder_option_free);
 162         g_slist_free_full(dec->binary, (GDestroyNotify)&g_strfreev);
 163         g_slist_free_full(dec->annotation_rows, &annotation_row_free);
 164         g_slist_free_full(dec->annotations, (GDestroyNotify)&g_strfreev);
 165         g_slist_free_full(dec->opt_channels, &channel_free);
 166         g_slist_free_full(dec->channels, &channel_free);
 167
 168         g_free(dec->license);
 169         g_free(dec->desc);
 170         g_free(dec->longname);
 171         g_free(dec->name);
 172         g_free(dec->id);
 173
 174         g_free(dec);
 175 }
 176
 177 static int get_channels(const struct srd_decoder *d, const char *attr,
 178                 GSList **out_pdchl, int offset)
 179 {
 180         PyObject *py_channellist, *py_entry;
 181         struct srd_channel *pdch;
 182         GSList *pdchl;
 183         ssize_t i;
 184
 185         if (!PyObject_HasAttrString(d->py_dec, attr))
 186                 /* No channels of this type specified. */
 187                 return SRD_OK;
 188
 189         pdchl = NULL;
 190
 191         py_channellist = PyObject_GetAttrString(d->py_dec, attr);
 192         if (!py_channellist)
 193                 goto except_out;
 194
 195         if (!PyTuple_Check(py_channellist)) {
 196                 srd_err("Protocol decoder %s %s attribute is not a tuple.",
 197                         d->name, attr);
 198                 goto err_out;
 199         }
 200
 201         for (i = PyTuple_Size(py_channellist) - 1; i >= 0; i--) {
 202                 py_entry = PyTuple_GetItem(py_channellist, i);
 203                 if (!py_entry)
 204                         goto except_out;
 205
 206                 if (!PyDict_Check(py_entry)) {
 207                         srd_err("Protocol decoder %s %s attribute is not "
 208                                 "a list of dict elements.", d->name, attr);
 209                         goto err_out;
 210                 }
 211                 pdch = g_malloc0(sizeof(struct srd_channel));
 212                 /* Add to list right away so it doesn't get lost. */
 213                 pdchl = g_slist_prepend(pdchl, pdch);
 214
 215                 if (py_dictitem_as_str(py_entry, "id", &pdch->id) != SRD_OK)
 216                         goto err_out;
 217                 if (py_dictitem_as_str(py_entry, "name", &pdch->name) != SRD_OK)
 218                         goto err_out;
 219                 if (py_dictitem_as_str(py_entry, "desc", &pdch->desc) != SRD_OK)
 220                         goto err_out;
 221
 222                 pdch->order = offset + i;
 223         }
 224
 225         Py_DECREF(py_channellist);
 226         *out_pdchl = pdchl;
 227
 228         return SRD_OK;
 229
 230 except_out:
 231         srd_exception_catch("Failed to get %s list of %s decoder",
 232                         attr, d->name);
 233 err_out:
 234         g_slist_free_full(pdchl, &channel_free);
 235         Py_XDECREF(py_channellist);
 236
 237         return SRD_ERR_PYTHON;
 238 }
 239
 240 static int get_options(struct srd_decoder *d)
 241 {
 242         PyObject *py_opts, *py_opt, *py_str, *py_values, *py_default, *py_item;
 243         GSList *options;
 244         struct srd_decoder_option *o;
 245         GVariant *gvar;
 246         ssize_t opt, i;
 247
 248         if (!PyObject_HasAttrString(d->py_dec, "options"))
 249                 /* No options, that's fine. */
 250                 return SRD_OK;
 251
 252         options = NULL;
 253
 254         /* If present, options must be a tuple. */
 255         py_opts = PyObject_GetAttrString(d->py_dec, "options");
 256         if (!py_opts)
 257                 goto except_out;
 258
 259         if (!PyTuple_Check(py_opts)) {
 260                 srd_err("Protocol decoder %s: options attribute is not "
 261                                 "a tuple.", d->id);
 262                 goto err_out;
 263         }
 264
 265         for (opt = PyTuple_Size(py_opts) - 1; opt >= 0; opt--) {
 266                 py_opt = PyTuple_GetItem(py_opts, opt);
 267                 if (!py_opt)
 268                         goto except_out;
 269
 270                 if (!PyDict_Check(py_opt)) {
 271                         srd_err("Protocol decoder %s options: each option "
 272                                         "must consist of a dictionary.", d->name);
 273                         goto err_out;
 274                 }
 275
 276                 o = g_malloc0(sizeof(struct srd_decoder_option));
 277                 /* Add to list right away so it doesn't get lost. */
 278                 options = g_slist_prepend(options, o);
 279
 280                 py_str = PyDict_GetItemString(py_opt, "id");
 281                 if (!py_str) {
 282                         srd_err("Protocol decoder %s option %zd has no id.",
 283                                 d->name, opt);
 284                         goto err_out;
 285                 }
 286                 if (py_str_as_str(py_str, &o->id) != SRD_OK)
 287                         goto err_out;
 288
 289                 py_str = PyDict_GetItemString(py_opt, "desc");
 290                 if (py_str) {
 291                         if (py_str_as_str(py_str, &o->desc) != SRD_OK)
 292                                 goto err_out;
 293                 }
 294
 295                 py_default = PyDict_GetItemString(py_opt, "default");
 296                 if (py_default) {
 297                         gvar = py_obj_to_variant(py_default);
 298                         if (!gvar) {
 299                                 srd_err("Protocol decoder %s option 'default' has "
 300                                         "invalid default value.", d->name);
 301                                 goto err_out;
 302                         }
 303                         o->def = g_variant_ref_sink(gvar);
 304                 }
 305
 306                 py_values = PyDict_GetItemString(py_opt, "values");
 307                 if (py_values) {
 308                         /* A default is required if a list of values is
 309                          * given, since it's used to verify their type. */
 310                         if (!o->def) {
 311                                 srd_err("No default for option '%s'.", o->id);
 312                                 goto err_out;
 313                         }
 314                         if (!PyTuple_Check(py_values)) {
 315                                 srd_err("Option '%s' values should be a tuple.", o->id);
 316                                 goto err_out;
 317                         }
 318
 319                         for (i = PyTuple_Size(py_values) - 1; i >= 0; i--) {
 320                                 py_item = PyTuple_GetItem(py_values, i);
 321                                 if (!py_item)
 322                                         goto except_out;
 323
 324                                 if (Py_TYPE(py_default) != Py_TYPE(py_item)) {
 325                                         srd_err("All values for option '%s' must be "
 326                                                 "of the same type as the default.",
 327                                                 o->id);
 328                                         goto err_out;
 329                                 }
 330                                 gvar = py_obj_to_variant(py_item);
 331                                 if (!gvar) {
 332                                         srd_err("Protocol decoder %s option 'values' "
 333                                                 "contains invalid value.", d->name);
 334                                         goto err_out;
 335                                 }
 336                                 o->values = g_slist_prepend(o->values,
 337                                                 g_variant_ref_sink(gvar));
 338                         }
 339                 }
 340         }
 341         d->options = options;
 342         Py_DECREF(py_opts);
 343
 344         return SRD_OK;
 345
 346 except_out:
 347         srd_exception_catch("Failed to get %s decoder options", d->name);
 348 err_out:
 349         g_slist_free_full(options, &decoder_option_free);
 350         Py_XDECREF(py_opts);
 351
 352         return SRD_ERR_PYTHON;
 353 }
 354
 355 /* Convert annotation class attribute to GSList of char **.
 356  */
 357 static int get_annotations(struct srd_decoder *dec)
 358 {
 359         PyObject *py_annlist, *py_ann;
 360         GSList *annotations;
 361         char **annpair;
 362         ssize_t i;
 363
 364         if (!PyObject_HasAttrString(dec->py_dec, "annotations"))
 365                 return SRD_OK;
 366
 367         annotations = NULL;
 368
 369         py_annlist = PyObject_GetAttrString(dec->py_dec, "annotations");
 370         if (!py_annlist)
 371                 goto except_out;
 372
 373         if (!PyTuple_Check(py_annlist)) {
 374                 srd_err("Protocol decoder %s annotations should "
 375                         "be a tuple.", dec->name);
 376                 goto err_out;
 377         }
 378
 379         for (i = PyTuple_Size(py_annlist) - 1; i >= 0; i--) {
 380                 py_ann = PyTuple_GetItem(py_annlist, i);
 381                 if (!py_ann)
 382                         goto except_out;
 383
 384                 if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
 385                         srd_err("Protocol decoder %s annotation %zd should "
 386                                 "be a tuple with two elements.",
 387                                 dec->name, i + 1);
 388                         goto err_out;
 389                 }
 390                 if (py_strseq_to_char(py_ann, &annpair) != SRD_OK)
 391                         goto err_out;
 392
 393                 annotations = g_slist_prepend(annotations, annpair);
 394         }
 395         dec->annotations = annotations;
 396         Py_DECREF(py_annlist);
 397
 398         return SRD_OK;
 399
 400 except_out:
 401         srd_exception_catch("Failed to get %s decoder annotations", dec->name);
 402 err_out:
 403         g_slist_free_full(annotations, (GDestroyNotify)&g_strfreev);
 404         Py_XDECREF(py_annlist);
 405
 406         return SRD_ERR_PYTHON;
 407 }
 408
 409 /* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'.
 410  */
 411 static int get_annotation_rows(struct srd_decoder *dec)
 412 {
 413         PyObject *py_ann_rows, *py_ann_row, *py_ann_classes, *py_item;
 414         GSList *annotation_rows;
 415         struct srd_decoder_annotation_row *ann_row;
 416         ssize_t i, k;
 417         size_t class_idx;
 418
 419         if (!PyObject_HasAttrString(dec->py_dec, "annotation_rows"))
 420                 return SRD_OK;
 421
 422         annotation_rows = NULL;
 423
 424         py_ann_rows = PyObject_GetAttrString(dec->py_dec, "annotation_rows");
 425         if (!py_ann_rows)
 426                 goto except_out;
 427
 428         if (!PyTuple_Check(py_ann_rows)) {
 429                 srd_err("Protocol decoder %s annotation_rows "
 430                         "must be a tuple.", dec->name);
 431                 goto err_out;
 432         }
 433
 434         for (i = PyTuple_Size(py_ann_rows) - 1; i >= 0; i--) {
 435                 py_ann_row = PyTuple_GetItem(py_ann_rows, i);
 436                 if (!py_ann_row)
 437                         goto except_out;
 438
 439                 if (!PyTuple_Check(py_ann_row) || PyTuple_Size(py_ann_row) != 3) {
 440                         srd_err("Protocol decoder %s annotation_rows "
 441                                 "must contain only tuples of 3 elements.",
 442                                 dec->name);
 443                         goto err_out;
 444                 }
 445                 ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
 446                 /* Add to list right away so it doesn't get lost. */
 447                 annotation_rows = g_slist_prepend(annotation_rows, ann_row);
 448
 449                 py_item = PyTuple_GetItem(py_ann_row, 0);
 450                 if (!py_item)
 451                         goto except_out;
 452                 if (py_str_as_str(py_item, &ann_row->id) != SRD_OK)
 453                         goto err_out;
 454
 455                 py_item = PyTuple_GetItem(py_ann_row, 1);
 456                 if (!py_item)
 457                         goto except_out;
 458                 if (py_str_as_str(py_item, &ann_row->desc) != SRD_OK)
 459                         goto err_out;
 460
 461                 py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
 462                 if (!py_ann_classes)
 463                         goto except_out;
 464
 465                 if (!PyTuple_Check(py_ann_classes)) {
 466                         srd_err("Protocol decoder %s annotation_rows tuples "
 467                                 "must have a tuple of numbers as 3rd element.",
 468                                 dec->name);
 469                         goto err_out;
 470                 }
 471
 472                 for (k = PyTuple_Size(py_ann_classes) - 1; k >= 0; k--) {
 473                         py_item = PyTuple_GetItem(py_ann_classes, k);
 474                         if (!py_item)
 475                                 goto except_out;
 476
 477                         if (!PyLong_Check(py_item)) {
 478                                 srd_err("Protocol decoder %s annotation row "
 479                                         "class tuple must only contain numbers.",
 480                                         dec->name);
 481                                 goto err_out;
 482                         }
 483                         class_idx = PyLong_AsSize_t(py_item);
 484                         if (PyErr_Occurred())
 485                                 goto except_out;
 486
 487                         ann_row->ann_classes = g_slist_prepend(ann_row->ann_classes,
 488                                         GSIZE_TO_POINTER(class_idx));
 489                 }
 490         }
 491         dec->annotation_rows = annotation_rows;
 492         Py_DECREF(py_ann_rows);
 493
 494         return SRD_OK;
 495
 496 except_out:
 497         srd_exception_catch("Failed to get %s decoder annotation rows",
 498                         dec->name);
 499 err_out:
 500         g_slist_free_full(annotation_rows, &annotation_row_free);
 501         Py_XDECREF(py_ann_rows);
 502
 503         return SRD_ERR_PYTHON;
 504 }
 505
 506 /* Convert binary classes to GSList of char **.
 507  */
 508 static int get_binary_classes(struct srd_decoder *dec)
 509 {
 510         PyObject *py_bin_classes, *py_bin_class;
 511         GSList *bin_classes;
 512         char **bin;
 513         ssize_t i;
 514
 515         if (!PyObject_HasAttrString(dec->py_dec, "binary"))
 516                 return SRD_OK;
 517
 518         bin_classes = NULL;
 519
 520         py_bin_classes = PyObject_GetAttrString(dec->py_dec, "binary");
 521         if (!py_bin_classes)
 522                 goto except_out;
 523
 524         if (!PyTuple_Check(py_bin_classes)) {
 525                 srd_err("Protocol decoder %s binary classes should "
 526                         "be a tuple.", dec->name);
 527                 goto err_out;
 528         }
 529
 530         for (i = PyTuple_Size(py_bin_classes) - 1; i >= 0; i--) {
 531                 py_bin_class = PyTuple_GetItem(py_bin_classes, i);
 532                 if (!py_bin_class)
 533                         goto except_out;
 534
 535                 if (!PyTuple_Check(py_bin_class)
 536                                 || PyTuple_Size(py_bin_class) != 2) {
 537                         srd_err("Protocol decoder %s binary classes should "
 538                                 "consist only of tuples of 2 elements.",
 539                                 dec->name);
 540                         goto err_out;
 541                 }
 542                 if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK)
 543                         goto err_out;
 544
 545                 bin_classes = g_slist_prepend(bin_classes, bin);
 546         }
 547         dec->binary = bin_classes;
 548         Py_DECREF(py_bin_classes);
 549
 550         return SRD_OK;
 551
 552 except_out:
 553         srd_exception_catch("Failed to get %s decoder binary classes",
 554                         dec->name);
 555 err_out:
 556         g_slist_free_full(bin_classes, (GDestroyNotify)&g_strfreev);
 557         Py_XDECREF(py_bin_classes);
 558
 559         return SRD_ERR_PYTHON;
 560 }
 561
 562 /* Check whether the Decoder class defines the named method.
 563  */
 564 static int check_method(PyObject *py_dec, const char *mod_name,
 565                 const char *method_name)
 566 {
 567         PyObject *py_method;
 568         int is_callable;
 569
 570         py_method = PyObject_GetAttrString(py_dec, method_name);
 571         if (!py_method) {
 572                 srd_exception_catch("Protocol decoder %s Decoder class "
 573                                 "has no %s() method", mod_name, method_name);
 574                 return SRD_ERR_PYTHON;
 575         }
 576
 577         is_callable = PyCallable_Check(py_method);
 578         Py_DECREF(py_method);
 579
 580         if (!is_callable) {
 581                 srd_err("Protocol decoder %s Decoder class attribute '%s' "
 582                         "is not a method.", mod_name, method_name);
 583                 return SRD_ERR_PYTHON;
 584         }
 585
 586         return SRD_OK;
 587 }
 588
 589 /**
 590  * Load a protocol decoder module into the embedded Python interpreter.
 591  *
 592  * @param module_name The module name to be loaded.
 593  *
 594  * @return SRD_OK upon success, a (negative) error code otherwise.
 595  *
 596  * @since 0.1.0
 597  */
 598 SRD_API int srd_decoder_load(const char *module_name)
 599 {
 600         PyObject *py_modname, *py_basedec, *py_apiver;
 601         struct srd_decoder *d;
 602         long apiver;
 603         int is_subclass;
 604
 605         if (!srd_check_init())
 606                 return SRD_ERR;
 607
 608         if (!module_name)
 609                 return SRD_ERR_ARG;
 610
 611         if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
 612                 /* Module was already imported. */
 613                 return SRD_OK;
 614         }
 615
 616         srd_dbg("Loading protocol decoder '%s'.", module_name);
 617
 618         d = g_malloc0(sizeof(struct srd_decoder));
 619
 620         /* Import the Python module. */
 621         py_modname = PyUnicode_FromString(module_name);
 622         if (!py_modname)
 623                 goto except_out;
 624
 625         d->py_mod = PyImport_Import(py_modname);
 626         Py_DECREF(py_modname);
 627         if (!d->py_mod)
 628                 goto except_out;
 629
 630         if (!mod_sigrokdecode) {
 631                 srd_err("sigrokdecode module not loaded.");
 632                 goto err_out;
 633         }
 634
 635         /* Get the 'Decoder' class as Python object. */
 636         d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder");
 637         if (!d->py_dec)
 638                 goto except_out;
 639
 640         py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder");
 641         if (!py_basedec)
 642                 goto except_out;
 643
 644         is_subclass = PyObject_IsSubclass(d->py_dec, py_basedec);
 645         Py_DECREF(py_basedec);
 646
 647         if (!is_subclass) {
 648                 srd_err("Decoder class in protocol decoder module %s is not "
 649                         "a subclass of sigrokdecode.Decoder.", module_name);
 650                 goto err_out;
 651         }
 652
 653         /*
 654          * Check that this decoder has the correct PD API version.
 655          * PDs of different API versions are incompatible and cannot work.
 656          */
 657         py_apiver = PyObject_GetAttrString(d->py_dec, "api_version");
 658         apiver = (py_apiver && PyLong_Check(py_apiver))
 659                         ? PyLong_AsLong(py_apiver) : 0;
 660         Py_XDECREF(py_apiver);
 661
 662         if (apiver != 2) {
 663                 srd_exception_catch("Only PDs of API version 2 are supported");
 664                 goto err_out;
 665         }
 666
 667         /* Check Decoder class for required methods.
 668          */
 669         if (check_method(d->py_dec, module_name, "start") != SRD_OK)
 670                 goto err_out;
 671
 672         if (check_method(d->py_dec, module_name, "decode") != SRD_OK)
 673                 goto err_out;
 674
 675         /* Store required fields in newly allocated strings. */
 676         if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK)
 677                 goto err_out;
 678
 679         if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK)
 680                 goto err_out;
 681
 682         if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK)
 683                 goto err_out;
 684
 685         if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK)
 686                 goto err_out;
 687
 688         if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK)
 689                 goto err_out;
 690
 691         /* All options and their default values. */
 692         if (get_options(d) != SRD_OK)
 693                 goto err_out;
 694
 695         /* Check and import required channels. */
 696         if (get_channels(d, "channels", &d->channels, 0) != SRD_OK)
 697                 goto err_out;
 698
 699         /* Check and import optional channels. */
 700         if (get_channels(d, "optional_channels", &d->opt_channels,
 701                                 g_slist_length(d->channels)) != SRD_OK)
 702                 goto err_out;
 703
 704         if (get_annotations(d) != SRD_OK)
 705                 goto err_out;
 706
 707         if (get_annotation_rows(d) != SRD_OK)
 708                 goto err_out;
 709
 710         if (get_binary_classes(d) != SRD_OK)
 711                 goto err_out;
 712
 713         /* Append it to the list of supported/loaded decoders. */
 714         pd_list = g_slist_append(pd_list, d);
 715
 716         return SRD_OK;
 717
 718 except_out:
 719         srd_exception_catch("Failed to load decoder %s", module_name);
 720 err_out:
 721         decoder_free(d);
 722
 723         return SRD_ERR_PYTHON;
 724 }
 725
 726 /**
 727  * Return a protocol decoder's docstring.
 728  *
 729  * @param dec The loaded protocol decoder.
 730  *
 731  * @return A newly allocated buffer containing the protocol decoder's
 732  *         documentation. The caller is responsible for free'ing the buffer.
 733  *
 734  * @since 0.1.0
 735  */
 736 SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
 737 {
 738         PyObject *py_str;
 739         char *doc;
 740
 741         if (!srd_check_init())
 742                 return NULL;
 743
 744         if (!dec)
 745                 return NULL;
 746
 747         if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
 748                 return NULL;
 749
 750         if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
 751                 srd_exception_catch("Failed to get docstring");
 752                 return NULL;
 753         }
 754
 755         doc = NULL;
 756         if (py_str != Py_None)
 757                 py_str_as_str(py_str, &doc);
 758         Py_DECREF(py_str);
 759
 760         return doc;
 761 }
 762
 763 /**
 764  * Unload the specified protocol decoder.
 765  *
 766  * @param dec The struct srd_decoder to be unloaded.
 767  *
 768  * @return SRD_OK upon success, a (negative) error code otherwise.
 769  *
 770  * @since 0.1.0
 771  */
 772 SRD_API int srd_decoder_unload(struct srd_decoder *dec)
 773 {
 774         struct srd_session *sess;
 775         GSList *l;
 776
 777         if (!srd_check_init())
 778                 return SRD_ERR;
 779
 780         if (!dec)
 781                 return SRD_ERR_ARG;
 782
 783         srd_dbg("Unloading protocol decoder '%s'.", dec->name);
 784
 785         /*
 786          * Since any instances of this decoder need to be released as well,
 787          * but they could be anywhere in the stack, just free the entire
 788          * stack. A frontend reloading a decoder thus has to restart all
 789          * instances, and rebuild the stack.
 790          */
 791         for (l = sessions; l; l = l->next) {
 792                 sess = l->data;
 793                 srd_inst_free_all(sess, NULL);
 794         }
 795
 796         decoder_free(dec);
 797
 798         return SRD_OK;
 799 }
 800
 801 static void srd_decoder_load_all_zip_path(char *path)
 802 {
 803         PyObject *zipimport_mod, *zipimporter_class, *zipimporter;
 804         PyObject *prefix_obj, *files, *key, *value, *set, *modname;
 805         Py_ssize_t pos = 0;
 806         char *prefix;
 807         size_t prefix_len;
 808
 809         zipimport_mod = NULL;
 810         set = files = prefix_obj = zipimporter = zipimporter_class = NULL;
 811
 812         modname = PyUnicode_FromString("zipimport");
 813         if (!modname)
 814                 goto err_out;
 815
 816         zipimport_mod = PyImport_Import(modname);
 817         Py_DECREF(modname);
 818         if (zipimport_mod == NULL)
 819                 goto err_out;
 820
 821         zipimporter_class = PyObject_GetAttrString(zipimport_mod, "zipimporter");
 822         if (zipimporter_class == NULL)
 823                 goto err_out;
 824
 825         zipimporter = PyObject_CallFunction(zipimporter_class, "s", path);
 826         if (zipimporter == NULL)
 827                 goto err_out;
 828
 829         prefix_obj = PyObject_GetAttrString(zipimporter, "prefix");
 830         if (prefix_obj == NULL)
 831                 goto err_out;
 832
 833         files = PyObject_GetAttrString(zipimporter, "_files");
 834         if (files == NULL || !PyDict_Check(files))
 835                 goto err_out;
 836
 837         set = PySet_New(NULL);
 838         if (set == NULL)
 839                 goto err_out;
 840
 841         if (py_str_as_str(prefix_obj, &prefix) != SRD_OK)
 842                 goto err_out;
 843
 844         prefix_len = strlen(prefix);
 845
 846         while (PyDict_Next(files, &pos, &key, &value)) {
 847                 char *path, *slash;
 848                 if (py_str_as_str(key, &path) == SRD_OK) {
 849                         if (strlen(path) > prefix_len
 850                                         && memcmp(path, prefix, prefix_len) == 0
 851                                         && (slash = strchr(path + prefix_len, '/'))) {
 852
 853                                 modname = PyUnicode_FromStringAndSize(path + prefix_len,
 854                                                         slash - (path + prefix_len));
 855                                 if (modname == NULL) {
 856                                         PyErr_Clear();
 857                                 } else {
 858                                         PySet_Add(set, modname);
 859                                         Py_DECREF(modname);
 860                                 }
 861                         }
 862                         g_free(path);
 863                 }
 864         }
 865         g_free(prefix);
 866
 867         while ((modname = PySet_Pop(set))) {
 868                 char *modname_str;
 869                 if (py_str_as_str(modname, &modname_str) == SRD_OK) {
 870                         /* The directory name is the module name (e.g. "i2c"). */
 871                         srd_decoder_load(modname_str);
 872                         g_free(modname_str);
 873                 }
 874                 Py_DECREF(modname);
 875         }
 876
 877 err_out:
 878         Py_XDECREF(set);
 879         Py_XDECREF(files);
 880         Py_XDECREF(prefix_obj);
 881         Py_XDECREF(zipimporter);
 882         Py_XDECREF(zipimporter_class);
 883         Py_XDECREF(zipimport_mod);
 884         PyErr_Clear();
 885 }
 886
 887 static void srd_decoder_load_all_path(char *path)
 888 {
 889         GDir *dir;
 890         const gchar *direntry;
 891
 892         if (!(dir = g_dir_open(path, 0, NULL))) {
 893                 /* Not really fatal */
 894                 /* Try zipimport method too */
 895                 srd_decoder_load_all_zip_path(path);
 896                 return;
 897         }
 898
 899         /* This ignores errors returned by srd_decoder_load(). That
 900          * function will have logged the cause, but in any case we
 901          * want to continue anyway. */
 902         while ((direntry = g_dir_read_name(dir)) != NULL) {
 903                 /* The directory name is the module name (e.g. "i2c"). */
 904                 srd_decoder_load(direntry);
 905         }
 906         g_dir_close(dir);
 907
 908 }
 909
 910 /**
 911  * Load all installed protocol decoders.
 912  *
 913  * @return SRD_OK upon success, a (negative) error code otherwise.
 914  *
 915  * @since 0.1.0
 916  */
 917 SRD_API int srd_decoder_load_all(void)
 918 {
 919         GSList *l;
 920
 921         if (!srd_check_init())
 922                 return SRD_ERR;
 923
 924         for (l = searchpaths; l; l = l->next)
 925                 srd_decoder_load_all_path(l->data);
 926
 927         return SRD_OK;
 928 }
 929
 930 /**
 931  * Unload all loaded protocol decoders.
 932  *
 933  * @return SRD_OK upon success, a (negative) error code otherwise.
 934  *
 935  * @since 0.1.0
 936  */
 937 SRD_API int srd_decoder_unload_all(void)
 938 {
 939         GSList *l;
 940         struct srd_decoder *dec;
 941
 942         for (l = pd_list; l; l = l->next) {
 943                 dec = l->data;
 944                 srd_decoder_unload(dec);
 945         }
 946         g_slist_free(pd_list);
 947         pd_list = NULL;
 948
 949         return SRD_OK;
 950 }
 951
 952 /** @} */