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 loaded 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 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         PyGILState_STATE gstate;
 156
 157         if (!dec)
 158                 return;
 159
 160         gstate = PyGILState_Ensure();
 161         Py_XDECREF(dec->py_dec);
 162         Py_XDECREF(dec->py_mod);
 163         PyGILState_Release(gstate);
 164
 165         g_slist_free_full(dec->options, &decoder_option_free);
 166         g_slist_free_full(dec->binary, (GDestroyNotify)&g_strfreev);
 167         g_slist_free_full(dec->annotation_rows, &annotation_row_free);
 168         g_slist_free_full(dec->annotations, (GDestroyNotify)&g_strfreev);
 169         g_slist_free_full(dec->opt_channels, &channel_free);
 170         g_slist_free_full(dec->channels, &channel_free);
 171
 172         g_slist_free_full(dec->outputs, g_free);
 173         g_slist_free_full(dec->inputs, g_free);
 174         g_slist_free_full(dec->tags, g_free);
 175         g_free(dec->license);
 176         g_free(dec->desc);
 177         g_free(dec->longname);
 178         g_free(dec->name);
 179         g_free(dec->id);
 180
 181         g_free(dec);
 182 }
 183
 184 static int get_channels(const struct srd_decoder *d, const char *attr,
 185                 GSList **out_pdchl, int offset)
 186 {
 187         PyObject *py_channellist, *py_entry;
 188         struct srd_channel *pdch;
 189         GSList *pdchl;
 190         ssize_t i;
 191         PyGILState_STATE gstate;
 192
 193         gstate = PyGILState_Ensure();
 194
 195         if (!PyObject_HasAttrString(d->py_dec, attr)) {
 196                 /* No channels of this type specified. */
 197                 PyGILState_Release(gstate);
 198                 return SRD_OK;
 199         }
 200
 201         pdchl = NULL;
 202
 203         py_channellist = PyObject_GetAttrString(d->py_dec, attr);
 204         if (!py_channellist)
 205                 goto except_out;
 206
 207         if (!PyTuple_Check(py_channellist)) {
 208                 srd_err("Protocol decoder %s %s attribute is not a tuple.",
 209                         d->name, attr);
 210                 goto err_out;
 211         }
 212
 213         for (i = PyTuple_Size(py_channellist) - 1; i >= 0; i--) {
 214                 py_entry = PyTuple_GetItem(py_channellist, i);
 215                 if (!py_entry)
 216                         goto except_out;
 217
 218                 if (!PyDict_Check(py_entry)) {
 219                         srd_err("Protocol decoder %s %s attribute is not "
 220                                 "a list of dict elements.", d->name, attr);
 221                         goto err_out;
 222                 }
 223                 pdch = g_malloc(sizeof(struct srd_channel));
 224                 /* Add to list right away so it doesn't get lost. */
 225                 pdchl = g_slist_prepend(pdchl, pdch);
 226
 227                 if (py_dictitem_as_str(py_entry, "id", &pdch->id) != SRD_OK)
 228                         goto err_out;
 229                 if (py_dictitem_as_str(py_entry, "name", &pdch->name) != SRD_OK)
 230                         goto err_out;
 231                 if (py_dictitem_as_str(py_entry, "desc", &pdch->desc) != SRD_OK)
 232                         goto err_out;
 233
 234                 pdch->order = offset + i;
 235         }
 236
 237         Py_DECREF(py_channellist);
 238         *out_pdchl = pdchl;
 239
 240         PyGILState_Release(gstate);
 241
 242         return SRD_OK;
 243
 244 except_out:
 245         srd_exception_catch("Failed to get %s list of %s decoder",
 246                         attr, d->name);
 247
 248 err_out:
 249         g_slist_free_full(pdchl, &channel_free);
 250         Py_XDECREF(py_channellist);
 251         PyGILState_Release(gstate);
 252
 253         return SRD_ERR_PYTHON;
 254 }
 255
 256 static int get_options(struct srd_decoder *d)
 257 {
 258         PyObject *py_opts, *py_opt, *py_str, *py_values, *py_default, *py_item;
 259         GSList *options;
 260         struct srd_decoder_option *o;
 261         GVariant *gvar;
 262         ssize_t opt, i;
 263         PyGILState_STATE gstate;
 264
 265         gstate = PyGILState_Ensure();
 266
 267         if (!PyObject_HasAttrString(d->py_dec, "options")) {
 268                 /* No options, that's fine. */
 269                 PyGILState_Release(gstate);
 270                 return SRD_OK;
 271         }
 272
 273         options = NULL;
 274
 275         /* If present, options must be a tuple. */
 276         py_opts = PyObject_GetAttrString(d->py_dec, "options");
 277         if (!py_opts)
 278                 goto except_out;
 279
 280         if (!PyTuple_Check(py_opts)) {
 281                 srd_err("Protocol decoder %s: options attribute is not "
 282                                 "a tuple.", d->id);
 283                 goto err_out;
 284         }
 285
 286         for (opt = PyTuple_Size(py_opts) - 1; opt >= 0; opt--) {
 287                 py_opt = PyTuple_GetItem(py_opts, opt);
 288                 if (!py_opt)
 289                         goto except_out;
 290
 291                 if (!PyDict_Check(py_opt)) {
 292                         srd_err("Protocol decoder %s options: each option "
 293                                         "must consist of a dictionary.", d->name);
 294                         goto err_out;
 295                 }
 296
 297                 o = g_malloc0(sizeof(struct srd_decoder_option));
 298                 /* Add to list right away so it doesn't get lost. */
 299                 options = g_slist_prepend(options, o);
 300
 301                 py_str = PyDict_GetItemString(py_opt, "id");
 302                 if (!py_str) {
 303                         srd_err("Protocol decoder %s option %zd has no ID.",
 304                                 d->name, opt);
 305                         goto err_out;
 306                 }
 307                 if (py_str_as_str(py_str, &o->id) != SRD_OK)
 308                         goto err_out;
 309
 310                 py_str = PyDict_GetItemString(py_opt, "desc");
 311                 if (py_str) {
 312                         if (py_str_as_str(py_str, &o->desc) != SRD_OK)
 313                                 goto err_out;
 314                 }
 315
 316                 py_default = PyDict_GetItemString(py_opt, "default");
 317                 if (py_default) {
 318                         gvar = py_obj_to_variant(py_default);
 319                         if (!gvar) {
 320                                 srd_err("Protocol decoder %s option 'default' has "
 321                                         "invalid default value.", d->name);
 322                                 goto err_out;
 323                         }
 324                         o->def = g_variant_ref_sink(gvar);
 325                 }
 326
 327                 py_values = PyDict_GetItemString(py_opt, "values");
 328                 if (py_values) {
 329                         /*
 330                          * A default is required if a list of values is
 331                          * given, since it's used to verify their type.
 332                          */
 333                         if (!o->def) {
 334                                 srd_err("No default for option '%s'.", o->id);
 335                                 goto err_out;
 336                         }
 337                         if (!PyTuple_Check(py_values)) {
 338                                 srd_err("Option '%s' values should be a tuple.", o->id);
 339                                 goto err_out;
 340                         }
 341
 342                         for (i = PyTuple_Size(py_values) - 1; i >= 0; i--) {
 343                                 py_item = PyTuple_GetItem(py_values, i);
 344                                 if (!py_item)
 345                                         goto except_out;
 346
 347                                 if (py_default && (Py_TYPE(py_default) != Py_TYPE(py_item))) {
 348                                         srd_err("All values for option '%s' must be "
 349                                                 "of the same type as the default.",
 350                                                 o->id);
 351                                         goto err_out;
 352                                 }
 353                                 gvar = py_obj_to_variant(py_item);
 354                                 if (!gvar) {
 355                                         srd_err("Protocol decoder %s option 'values' "
 356                                                 "contains invalid value.", d->name);
 357                                         goto err_out;
 358                                 }
 359                                 o->values = g_slist_prepend(o->values,
 360                                                 g_variant_ref_sink(gvar));
 361                         }
 362                 }
 363         }
 364         d->options = options;
 365         Py_DECREF(py_opts);
 366         PyGILState_Release(gstate);
 367
 368         return SRD_OK;
 369
 370 except_out:
 371         srd_exception_catch("Failed to get %s decoder options", d->name);
 372
 373 err_out:
 374         g_slist_free_full(options, &decoder_option_free);
 375         Py_XDECREF(py_opts);
 376         PyGILState_Release(gstate);
 377
 378         return SRD_ERR_PYTHON;
 379 }
 380
 381 /* Convert annotation class attribute to GSList of char **. */
 382 static int get_annotations(struct srd_decoder *dec)
 383 {
 384         PyObject *py_annlist, *py_ann;
 385         GSList *annotations;
 386         char **annpair;
 387         ssize_t i;
 388         PyGILState_STATE gstate;
 389
 390         gstate = PyGILState_Ensure();
 391
 392         if (!PyObject_HasAttrString(dec->py_dec, "annotations")) {
 393                 PyGILState_Release(gstate);
 394                 return SRD_OK;
 395         }
 396
 397         annotations = NULL;
 398
 399         py_annlist = PyObject_GetAttrString(dec->py_dec, "annotations");
 400         if (!py_annlist)
 401                 goto except_out;
 402
 403         if (!PyTuple_Check(py_annlist)) {
 404                 srd_err("Protocol decoder %s annotations should "
 405                         "be a tuple.", dec->name);
 406                 goto err_out;
 407         }
 408
 409         for (i = PyTuple_Size(py_annlist) - 1; i >= 0; i--) {
 410                 py_ann = PyTuple_GetItem(py_annlist, i);
 411                 if (!py_ann)
 412                         goto except_out;
 413
 414                 if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
 415                         srd_err("Protocol decoder %s annotation %zd should "
 416                                 "be a tuple with two elements.",
 417                                 dec->name, i + 1);
 418                         goto err_out;
 419                 }
 420                 if (py_strseq_to_char(py_ann, &annpair) != SRD_OK)
 421                         goto err_out;
 422
 423                 annotations = g_slist_prepend(annotations, annpair);
 424         }
 425         dec->annotations = annotations;
 426         Py_DECREF(py_annlist);
 427         PyGILState_Release(gstate);
 428
 429         return SRD_OK;
 430
 431 except_out:
 432         srd_exception_catch("Failed to get %s decoder annotations", dec->name);
 433
 434 err_out:
 435         g_slist_free_full(annotations, (GDestroyNotify)&g_strfreev);
 436         Py_XDECREF(py_annlist);
 437         PyGILState_Release(gstate);
 438
 439         return SRD_ERR_PYTHON;
 440 }
 441
 442 /* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'. */
 443 static int get_annotation_rows(struct srd_decoder *dec)
 444 {
 445         PyObject *py_ann_rows, *py_ann_row, *py_ann_classes, *py_item;
 446         GSList *annotation_rows;
 447         struct srd_decoder_annotation_row *ann_row;
 448         ssize_t i, k;
 449         size_t class_idx;
 450         PyGILState_STATE gstate;
 451
 452         gstate = PyGILState_Ensure();
 453
 454         if (!PyObject_HasAttrString(dec->py_dec, "annotation_rows")) {
 455                 PyGILState_Release(gstate);
 456                 return SRD_OK;
 457         }
 458
 459         annotation_rows = NULL;
 460
 461         py_ann_rows = PyObject_GetAttrString(dec->py_dec, "annotation_rows");
 462         if (!py_ann_rows)
 463                 goto except_out;
 464
 465         if (!PyTuple_Check(py_ann_rows)) {
 466                 srd_err("Protocol decoder %s annotation_rows "
 467                         "must be a tuple.", dec->name);
 468                 goto err_out;
 469         }
 470
 471         for (i = PyTuple_Size(py_ann_rows) - 1; i >= 0; i--) {
 472                 py_ann_row = PyTuple_GetItem(py_ann_rows, i);
 473                 if (!py_ann_row)
 474                         goto except_out;
 475
 476                 if (!PyTuple_Check(py_ann_row) || PyTuple_Size(py_ann_row) != 3) {
 477                         srd_err("Protocol decoder %s annotation_rows "
 478                                 "must contain only tuples of 3 elements.",
 479                                 dec->name);
 480                         goto err_out;
 481                 }
 482                 ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
 483                 /* Add to list right away so it doesn't get lost. */
 484                 annotation_rows = g_slist_prepend(annotation_rows, ann_row);
 485
 486                 py_item = PyTuple_GetItem(py_ann_row, 0);
 487                 if (!py_item)
 488                         goto except_out;
 489                 if (py_str_as_str(py_item, &ann_row->id) != SRD_OK)
 490                         goto err_out;
 491
 492                 py_item = PyTuple_GetItem(py_ann_row, 1);
 493                 if (!py_item)
 494                         goto except_out;
 495                 if (py_str_as_str(py_item, &ann_row->desc) != SRD_OK)
 496                         goto err_out;
 497
 498                 py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
 499                 if (!py_ann_classes)
 500                         goto except_out;
 501
 502                 if (!PyTuple_Check(py_ann_classes)) {
 503                         srd_err("Protocol decoder %s annotation_rows tuples "
 504                                 "must have a tuple of numbers as 3rd element.",
 505                                 dec->name);
 506                         goto err_out;
 507                 }
 508
 509                 for (k = PyTuple_Size(py_ann_classes) - 1; k >= 0; k--) {
 510                         py_item = PyTuple_GetItem(py_ann_classes, k);
 511                         if (!py_item)
 512                                 goto except_out;
 513
 514                         if (!PyLong_Check(py_item)) {
 515                                 srd_err("Protocol decoder %s annotation row "
 516                                         "class tuple must only contain numbers.",
 517                                         dec->name);
 518                                 goto err_out;
 519                         }
 520                         class_idx = PyLong_AsSize_t(py_item);
 521                         if (PyErr_Occurred())
 522                                 goto except_out;
 523
 524                         ann_row->ann_classes = g_slist_prepend(ann_row->ann_classes,
 525                                         GSIZE_TO_POINTER(class_idx));
 526                 }
 527         }
 528         dec->annotation_rows = annotation_rows;
 529         Py_DECREF(py_ann_rows);
 530         PyGILState_Release(gstate);
 531
 532         return SRD_OK;
 533
 534 except_out:
 535         srd_exception_catch("Failed to get %s decoder annotation rows",
 536                         dec->name);
 537
 538 err_out:
 539         g_slist_free_full(annotation_rows, &annotation_row_free);
 540         Py_XDECREF(py_ann_rows);
 541         PyGILState_Release(gstate);
 542
 543         return SRD_ERR_PYTHON;
 544 }
 545
 546 /* Convert binary classes to GSList of char **. */
 547 static int get_binary_classes(struct srd_decoder *dec)
 548 {
 549         PyObject *py_bin_classes, *py_bin_class;
 550         GSList *bin_classes;
 551         char **bin;
 552         ssize_t i;
 553         PyGILState_STATE gstate;
 554
 555         gstate = PyGILState_Ensure();
 556
 557         if (!PyObject_HasAttrString(dec->py_dec, "binary")) {
 558                 PyGILState_Release(gstate);
 559                 return SRD_OK;
 560         }
 561
 562         bin_classes = NULL;
 563
 564         py_bin_classes = PyObject_GetAttrString(dec->py_dec, "binary");
 565         if (!py_bin_classes)
 566                 goto except_out;
 567
 568         if (!PyTuple_Check(py_bin_classes)) {
 569                 srd_err("Protocol decoder %s binary classes should "
 570                         "be a tuple.", dec->name);
 571                 goto err_out;
 572         }
 573
 574         for (i = PyTuple_Size(py_bin_classes) - 1; i >= 0; i--) {
 575                 py_bin_class = PyTuple_GetItem(py_bin_classes, i);
 576                 if (!py_bin_class)
 577                         goto except_out;
 578
 579                 if (!PyTuple_Check(py_bin_class)
 580                                 || PyTuple_Size(py_bin_class) != 2) {
 581                         srd_err("Protocol decoder %s binary classes should "
 582                                 "consist only of tuples of 2 elements.",
 583                                 dec->name);
 584                         goto err_out;
 585                 }
 586                 if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK)
 587                         goto err_out;
 588
 589                 bin_classes = g_slist_prepend(bin_classes, bin);
 590         }
 591         dec->binary = bin_classes;
 592         Py_DECREF(py_bin_classes);
 593         PyGILState_Release(gstate);
 594
 595         return SRD_OK;
 596
 597 except_out:
 598         srd_exception_catch("Failed to get %s decoder binary classes",
 599                         dec->name);
 600
 601 err_out:
 602         g_slist_free_full(bin_classes, (GDestroyNotify)&g_strfreev);
 603         Py_XDECREF(py_bin_classes);
 604         PyGILState_Release(gstate);
 605
 606         return SRD_ERR_PYTHON;
 607 }
 608
 609 /* Check whether the Decoder class defines the named method. */
 610 static int check_method(PyObject *py_dec, const char *mod_name,
 611                 const char *method_name)
 612 {
 613         PyObject *py_method;
 614         int is_callable;
 615         PyGILState_STATE gstate;
 616
 617         gstate = PyGILState_Ensure();
 618
 619         py_method = PyObject_GetAttrString(py_dec, method_name);
 620         if (!py_method) {
 621                 srd_exception_catch("Protocol decoder %s Decoder class "
 622                                 "has no %s() method", mod_name, method_name);
 623                 PyGILState_Release(gstate);
 624                 return SRD_ERR_PYTHON;
 625         }
 626
 627         is_callable = PyCallable_Check(py_method);
 628         Py_DECREF(py_method);
 629
 630         PyGILState_Release(gstate);
 631
 632         if (!is_callable) {
 633                 srd_err("Protocol decoder %s Decoder class attribute '%s' "
 634                         "is not a method.", mod_name, method_name);
 635                 return SRD_ERR_PYTHON;
 636         }
 637
 638         return SRD_OK;
 639 }
 640
 641 /**
 642  * Get the API version of the specified decoder.
 643  *
 644  * @param d The decoder to use. Must not be NULL.
 645  *
 646  * @return The API version of the decoder, or 0 upon errors.
 647  *
 648  * @private
 649  */
 650 SRD_PRIV long srd_decoder_apiver(const struct srd_decoder *d)
 651 {
 652         PyObject *py_apiver;
 653         long apiver;
 654         PyGILState_STATE gstate;
 655
 656         if (!d)
 657                 return 0;
 658
 659         gstate = PyGILState_Ensure();
 660
 661         py_apiver = PyObject_GetAttrString(d->py_dec, "api_version");
 662         apiver = (py_apiver && PyLong_Check(py_apiver))
 663                         ? PyLong_AsLong(py_apiver) : 0;
 664         Py_XDECREF(py_apiver);
 665
 666         PyGILState_Release(gstate);
 667
 668         return apiver;
 669 }
 670
 671 /**
 672  * Load a protocol decoder module into the embedded Python interpreter.
 673  *
 674  * @param module_name The module name to be loaded.
 675  *
 676  * @return SRD_OK upon success, a (negative) error code otherwise.
 677  *
 678  * @since 0.1.0
 679  */
 680 SRD_API int srd_decoder_load(const char *module_name)
 681 {
 682         PyObject *py_basedec;
 683         struct srd_decoder *d;
 684         long apiver;
 685         int is_subclass;
 686         const char *fail_txt;
 687         PyGILState_STATE gstate;
 688
 689         if (!srd_check_init())
 690                 return SRD_ERR;
 691
 692         if (!module_name)
 693                 return SRD_ERR_ARG;
 694
 695         gstate = PyGILState_Ensure();
 696
 697         if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
 698                 /* Module was already imported. */
 699                 PyGILState_Release(gstate);
 700                 return SRD_OK;
 701         }
 702
 703         d = g_malloc0(sizeof(struct srd_decoder));
 704         fail_txt = NULL;
 705
 706         d->py_mod = py_import_by_name(module_name);
 707         if (!d->py_mod) {
 708                 fail_txt = "import by name failed";
 709                 goto except_out;
 710         }
 711
 712         if (!mod_sigrokdecode) {
 713                 srd_err("sigrokdecode module not loaded.");
 714                 fail_txt = "sigrokdecode(3) not loaded";
 715                 goto err_out;
 716         }
 717
 718         /* Get the 'Decoder' class as Python object. */
 719         d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder");
 720         if (!d->py_dec) {
 721                 fail_txt = "no 'Decoder' attribute in imported module";
 722                 goto except_out;
 723         }
 724
 725         py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder");
 726         if (!py_basedec) {
 727                 fail_txt = "no 'Decoder' attribute in sigrokdecode(3)";
 728                 goto except_out;
 729         }
 730
 731         is_subclass = PyObject_IsSubclass(d->py_dec, py_basedec);
 732         Py_DECREF(py_basedec);
 733
 734         if (!is_subclass) {
 735                 srd_err("Decoder class in protocol decoder module %s is not "
 736                         "a subclass of sigrokdecode.Decoder.", module_name);
 737                 fail_txt = "not a subclass of sigrokdecode.Decoder";
 738                 goto err_out;
 739         }
 740
 741         /*
 742          * Check that this decoder has the correct PD API version.
 743          * PDs of different API versions are incompatible and cannot work.
 744          */
 745         apiver = srd_decoder_apiver(d);
 746         if (apiver != 3) {
 747                 srd_exception_catch("Only PD API version 3 is supported, "
 748                         "decoder %s has version %ld", module_name, apiver);
 749                 fail_txt = "API version mismatch";
 750                 goto err_out;
 751         }
 752
 753         /* Check Decoder class for required methods. */
 754
 755         if (check_method(d->py_dec, module_name, "reset") != SRD_OK) {
 756                 fail_txt = "no 'reset()' method";
 757                 goto err_out;
 758         }
 759
 760         if (check_method(d->py_dec, module_name, "start") != SRD_OK) {
 761                 fail_txt = "no 'start()' method";
 762                 goto err_out;
 763         }
 764
 765         if (check_method(d->py_dec, module_name, "decode") != SRD_OK) {
 766                 fail_txt = "no 'decode()' method";
 767                 goto err_out;
 768         }
 769
 770         /* Store required fields in newly allocated strings. */
 771         if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK) {
 772                 fail_txt = "no 'id' attribute";
 773                 goto err_out;
 774         }
 775
 776         if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK) {
 777                 fail_txt = "no 'name' attribute";
 778                 goto err_out;
 779         }
 780
 781         if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK) {
 782                 fail_txt = "no 'longname' attribute";
 783                 goto err_out;
 784         }
 785
 786         if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK) {
 787                 fail_txt = "no 'desc' attribute";
 788                 goto err_out;
 789         }
 790
 791         if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK) {
 792                 fail_txt = "no 'license' attribute";
 793                 goto err_out;
 794         }
 795
 796         if (py_attr_as_strlist(d->py_dec, "inputs", &(d->inputs)) != SRD_OK) {
 797                 fail_txt = "missing or malformed 'inputs' attribute";
 798                 goto err_out;
 799         }
 800
 801         if (py_attr_as_strlist(d->py_dec, "outputs", &(d->outputs)) != SRD_OK) {
 802                 fail_txt = "missing or malformed 'outputs' attribute";
 803                 goto err_out;
 804         }
 805
 806         if (py_attr_as_strlist(d->py_dec, "tags", &(d->tags)) != SRD_OK) {
 807                 fail_txt = "missing or malformed 'tags' attribute";
 808                 goto err_out;
 809         }
 810
 811         /* All options and their default values. */
 812         if (get_options(d) != SRD_OK) {
 813                 fail_txt = "cannot get options";
 814                 goto err_out;
 815         }
 816
 817         /* Check and import required channels. */
 818         if (get_channels(d, "channels", &d->channels, 0) != SRD_OK) {
 819                 fail_txt = "cannot get channels";
 820                 goto err_out;
 821         }
 822
 823         /* Check and import optional channels. */
 824         if (get_channels(d, "optional_channels", &d->opt_channels,
 825                                 g_slist_length(d->channels)) != SRD_OK) {
 826                 fail_txt = "cannot get optional channels";
 827                 goto err_out;
 828         }
 829
 830         if (get_annotations(d) != SRD_OK) {
 831                 fail_txt = "cannot get annotations";
 832                 goto err_out;
 833         }
 834
 835         if (get_annotation_rows(d) != SRD_OK) {
 836                 fail_txt = "cannot get annotation rows";
 837                 goto err_out;
 838         }
 839
 840         if (get_binary_classes(d) != SRD_OK) {
 841                 fail_txt = "cannot get binary classes";
 842                 goto err_out;
 843         }
 844
 845         PyGILState_Release(gstate);
 846
 847         /* Append it to the list of loaded decoders. */
 848         pd_list = g_slist_append(pd_list, d);
 849
 850         return SRD_OK;
 851
 852 except_out:
 853         /* Don't show a message for the "common" directory, it's not a PD. */
 854         if (strcmp(module_name, "common")) {
 855                 srd_exception_catch("Failed to load decoder %s: %s",
 856                                     module_name, fail_txt);
 857         }
 858         fail_txt = NULL;
 859
 860 err_out:
 861         if (fail_txt)
 862                 srd_err("Failed to load decoder %s: %s", module_name, fail_txt);
 863         decoder_free(d);
 864         PyGILState_Release(gstate);
 865
 866         return SRD_ERR_PYTHON;
 867 }
 868
 869 /**
 870  * Return a protocol decoder's docstring.
 871  *
 872  * @param dec The loaded protocol decoder.
 873  *
 874  * @return A newly allocated buffer containing the protocol decoder's
 875  *         documentation. The caller is responsible for free'ing the buffer.
 876  *
 877  * @since 0.1.0
 878  */
 879 SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
 880 {
 881         PyObject *py_str;
 882         char *doc;
 883         PyGILState_STATE gstate;
 884
 885         if (!srd_check_init())
 886                 return NULL;
 887
 888         if (!dec)
 889                 return NULL;
 890
 891         gstate = PyGILState_Ensure();
 892
 893         if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
 894                 goto err;
 895
 896         if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
 897                 srd_exception_catch("Failed to get docstring");
 898                 goto err;
 899         }
 900
 901         doc = NULL;
 902         if (py_str != Py_None)
 903                 py_str_as_str(py_str, &doc);
 904         Py_DECREF(py_str);
 905
 906         PyGILState_Release(gstate);
 907
 908         return doc;
 909
 910 err:
 911         PyGILState_Release(gstate);
 912
 913         return NULL;
 914 }
 915
 916 /**
 917  * Unload the specified protocol decoder.
 918  *
 919  * @param dec The struct srd_decoder to be unloaded.
 920  *
 921  * @return SRD_OK upon success, a (negative) error code otherwise.
 922  *
 923  * @since 0.1.0
 924  */
 925 SRD_API int srd_decoder_unload(struct srd_decoder *dec)
 926 {
 927         struct srd_session *sess;
 928         GSList *l;
 929
 930         if (!srd_check_init())
 931                 return SRD_ERR;
 932
 933         if (!dec)
 934                 return SRD_ERR_ARG;
 935
 936         /*
 937          * Since any instances of this decoder need to be released as well,
 938          * but they could be anywhere in the stack, just free the entire
 939          * stack. A frontend reloading a decoder thus has to restart all
 940          * instances, and rebuild the stack.
 941          */
 942         for (l = sessions; l; l = l->next) {
 943                 sess = l->data;
 944                 srd_inst_free_all(sess);
 945         }
 946
 947         /* Remove the PD from the list of loaded decoders. */
 948         pd_list = g_slist_remove(pd_list, dec);
 949
 950         decoder_free(dec);
 951
 952         return SRD_OK;
 953 }
 954
 955 static void srd_decoder_load_all_zip_path(char *zip_path)
 956 {
 957         PyObject *zipimport_mod, *zipimporter_class, *zipimporter;
 958         PyObject *prefix_obj, *files, *key, *value, *set, *modname;
 959         Py_ssize_t pos = 0;
 960         char *prefix;
 961         size_t prefix_len;
 962         PyGILState_STATE gstate;
 963
 964         set = files = prefix_obj = zipimporter = zipimporter_class = NULL;
 965
 966         gstate = PyGILState_Ensure();
 967
 968         zipimport_mod = py_import_by_name("zipimport");
 969         if (zipimport_mod == NULL)
 970                 goto err_out;
 971
 972         zipimporter_class = PyObject_GetAttrString(zipimport_mod, "zipimporter");
 973         if (zipimporter_class == NULL)
 974                 goto err_out;
 975
 976         zipimporter = PyObject_CallFunction(zipimporter_class, "s", zip_path);
 977         if (zipimporter == NULL)
 978                 goto err_out;
 979
 980         prefix_obj = PyObject_GetAttrString(zipimporter, "prefix");
 981         if (prefix_obj == NULL)
 982                 goto err_out;
 983
 984         files = PyObject_GetAttrString(zipimporter, "_files");
 985         if (files == NULL || !PyDict_Check(files))
 986                 goto err_out;
 987
 988         set = PySet_New(NULL);
 989         if (set == NULL)
 990                 goto err_out;
 991
 992         if (py_str_as_str(prefix_obj, &prefix) != SRD_OK)
 993                 goto err_out;
 994
 995         prefix_len = strlen(prefix);
 996
 997         while (PyDict_Next(files, &pos, &key, &value)) {
 998                 char *path, *slash;
 999                 if (py_str_as_str(key, &path) == SRD_OK) {
1000                         if (strlen(path) > prefix_len
1001                                         && memcmp(path, prefix, prefix_len) == 0
1002                                         && (slash = strchr(path + prefix_len, '/'))) {
1003
1004                                 modname = PyUnicode_FromStringAndSize(path + prefix_len,
1005                                                         slash - (path + prefix_len));
1006                                 if (modname == NULL) {
1007                                         PyErr_Clear();
1008                                 } else {
1009                                         PySet_Add(set, modname);
1010                                         Py_DECREF(modname);
1011                                 }
1012                         }
1013                         g_free(path);
1014                 }
1015         }
1016         g_free(prefix);
1017
1018         while ((modname = PySet_Pop(set))) {
1019                 char *modname_str;
1020                 if (py_str_as_str(modname, &modname_str) == SRD_OK) {
1021                         /* The directory name is the module name (e.g. "i2c"). */
1022                         srd_decoder_load(modname_str);
1023                         g_free(modname_str);
1024                 }
1025                 Py_DECREF(modname);
1026         }
1027
1028 err_out:
1029         Py_XDECREF(set);
1030         Py_XDECREF(files);
1031         Py_XDECREF(prefix_obj);
1032         Py_XDECREF(zipimporter);
1033         Py_XDECREF(zipimporter_class);
1034         Py_XDECREF(zipimport_mod);
1035         PyErr_Clear();
1036         PyGILState_Release(gstate);
1037 }
1038
1039 static void srd_decoder_load_all_path(char *path)
1040 {
1041         GDir *dir;
1042         const gchar *direntry;
1043
1044         if (!(dir = g_dir_open(path, 0, NULL))) {
1045                 /* Not really fatal. Try zipimport method too. */
1046                 srd_decoder_load_all_zip_path(path);
1047                 return;
1048         }
1049
1050         /*
1051          * This ignores errors returned by srd_decoder_load(). That
1052          * function will have logged the cause, but in any case we
1053          * want to continue anyway.
1054          */
1055         while ((direntry = g_dir_read_name(dir)) != NULL) {
1056                 /* The directory name is the module name (e.g. "i2c"). */
1057                 srd_decoder_load(direntry);
1058         }
1059         g_dir_close(dir);
1060 }
1061
1062 /**
1063  * Load all installed protocol decoders.
1064  *
1065  * @return SRD_OK upon success, a (negative) error code otherwise.
1066  *
1067  * @since 0.1.0
1068  */
1069 SRD_API int srd_decoder_load_all(void)
1070 {
1071         GSList *l;
1072
1073         if (!srd_check_init())
1074                 return SRD_ERR;
1075
1076         for (l = searchpaths; l; l = l->next)
1077                 srd_decoder_load_all_path(l->data);
1078
1079         return SRD_OK;
1080 }
1081
1082 static void srd_decoder_unload_cb(void *arg, void *ignored)
1083 {
1084         (void)ignored;
1085
1086         srd_decoder_unload((struct srd_decoder *)arg);
1087 }
1088
1089 /**
1090  * Unload all loaded protocol decoders.
1091  *
1092  * @return SRD_OK upon success, a (negative) error code otherwise.
1093  *
1094  * @since 0.1.0
1095  */
1096 SRD_API int srd_decoder_unload_all(void)
1097 {
1098         g_slist_foreach(pd_list, srd_decoder_unload_cb, NULL);
1099         g_slist_free(pd_list);
1100         pd_list = NULL;
1101
1102         return SRD_OK;
1103 }
1104
1105 /** @} */