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