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_malloc0(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 err_out:
 247         g_slist_free_full(pdchl, &channel_free);
 248         Py_XDECREF(py_channellist);
 249         PyGILState_Release(gstate);
 250
 251         return SRD_ERR_PYTHON;
 252 }
 253
 254 static int get_options(struct srd_decoder *d)
 255 {
 256         PyObject *py_opts, *py_opt, *py_str, *py_values, *py_default, *py_item;
 257         GSList *options;
 258         struct srd_decoder_option *o;
 259         GVariant *gvar;
 260         ssize_t opt, i;
 261         PyGILState_STATE gstate;
 262
 263         gstate = PyGILState_Ensure();
 264
 265         if (!PyObject_HasAttrString(d->py_dec, "options")) {
 266                 /* No options, that's fine. */
 267                 PyGILState_Release(gstate);
 268                 return SRD_OK;
 269         }
 270
 271         options = NULL;
 272
 273         /* If present, options must be a tuple. */
 274         py_opts = PyObject_GetAttrString(d->py_dec, "options");
 275         if (!py_opts)
 276                 goto except_out;
 277
 278         if (!PyTuple_Check(py_opts)) {
 279                 srd_err("Protocol decoder %s: options attribute is not "
 280                                 "a tuple.", d->id);
 281                 goto err_out;
 282         }
 283
 284         for (opt = PyTuple_Size(py_opts) - 1; opt >= 0; opt--) {
 285                 py_opt = PyTuple_GetItem(py_opts, opt);
 286                 if (!py_opt)
 287                         goto except_out;
 288
 289                 if (!PyDict_Check(py_opt)) {
 290                         srd_err("Protocol decoder %s options: each option "
 291                                         "must consist of a dictionary.", d->name);
 292                         goto err_out;
 293                 }
 294
 295                 o = g_malloc0(sizeof(struct srd_decoder_option));
 296                 /* Add to list right away so it doesn't get lost. */
 297                 options = g_slist_prepend(options, o);
 298
 299                 py_str = PyDict_GetItemString(py_opt, "id");
 300                 if (!py_str) {
 301                         srd_err("Protocol decoder %s option %zd has no ID.",
 302                                 d->name, opt);
 303                         goto err_out;
 304                 }
 305                 if (py_str_as_str(py_str, &o->id) != SRD_OK)
 306                         goto err_out;
 307
 308                 py_str = PyDict_GetItemString(py_opt, "desc");
 309                 if (py_str) {
 310                         if (py_str_as_str(py_str, &o->desc) != SRD_OK)
 311                                 goto err_out;
 312                 }
 313
 314                 py_default = PyDict_GetItemString(py_opt, "default");
 315                 if (py_default) {
 316                         gvar = py_obj_to_variant(py_default);
 317                         if (!gvar) {
 318                                 srd_err("Protocol decoder %s option 'default' has "
 319                                         "invalid default value.", d->name);
 320                                 goto err_out;
 321                         }
 322                         o->def = g_variant_ref_sink(gvar);
 323                 }
 324
 325                 py_values = PyDict_GetItemString(py_opt, "values");
 326                 if (py_values) {
 327                         /* A default is required if a list of values is
 328                          * given, since it's used to verify their type. */
 329                         if (!o->def) {
 330                                 srd_err("No default for option '%s'.", o->id);
 331                                 goto err_out;
 332                         }
 333                         if (!PyTuple_Check(py_values)) {
 334                                 srd_err("Option '%s' values should be a tuple.", o->id);
 335                                 goto err_out;
 336                         }
 337
 338                         for (i = PyTuple_Size(py_values) - 1; i >= 0; i--) {
 339                                 py_item = PyTuple_GetItem(py_values, i);
 340                                 if (!py_item)
 341                                         goto except_out;
 342
 343                                 if (Py_TYPE(py_default) != Py_TYPE(py_item)) {
 344                                         srd_err("All values for option '%s' must be "
 345                                                 "of the same type as the default.",
 346                                                 o->id);
 347                                         goto err_out;
 348                                 }
 349                                 gvar = py_obj_to_variant(py_item);
 350                                 if (!gvar) {
 351                                         srd_err("Protocol decoder %s option 'values' "
 352                                                 "contains invalid value.", d->name);
 353                                         goto err_out;
 354                                 }
 355                                 o->values = g_slist_prepend(o->values,
 356                                                 g_variant_ref_sink(gvar));
 357                         }
 358                 }
 359         }
 360         d->options = options;
 361         Py_DECREF(py_opts);
 362         PyGILState_Release(gstate);
 363
 364         return SRD_OK;
 365
 366 except_out:
 367         srd_exception_catch("Failed to get %s decoder options", d->name);
 368 err_out:
 369         g_slist_free_full(options, &decoder_option_free);
 370         Py_XDECREF(py_opts);
 371         PyGILState_Release(gstate);
 372
 373         return SRD_ERR_PYTHON;
 374 }
 375
 376 /* Convert annotation class attribute to GSList of char **.
 377  */
 378 static int get_annotations(struct srd_decoder *dec)
 379 {
 380         PyObject *py_annlist, *py_ann;
 381         GSList *annotations;
 382         char **annpair;
 383         ssize_t i;
 384         PyGILState_STATE gstate;
 385
 386         gstate = PyGILState_Ensure();
 387
 388         if (!PyObject_HasAttrString(dec->py_dec, "annotations")) {
 389                 PyGILState_Release(gstate);
 390                 return SRD_OK;
 391         }
 392
 393         annotations = NULL;
 394
 395         py_annlist = PyObject_GetAttrString(dec->py_dec, "annotations");
 396         if (!py_annlist)
 397                 goto except_out;
 398
 399         if (!PyTuple_Check(py_annlist)) {
 400                 srd_err("Protocol decoder %s annotations should "
 401                         "be a tuple.", dec->name);
 402                 goto err_out;
 403         }
 404
 405         for (i = PyTuple_Size(py_annlist) - 1; i >= 0; i--) {
 406                 py_ann = PyTuple_GetItem(py_annlist, i);
 407                 if (!py_ann)
 408                         goto except_out;
 409
 410                 if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
 411                         srd_err("Protocol decoder %s annotation %zd should "
 412                                 "be a tuple with two elements.",
 413                                 dec->name, i + 1);
 414                         goto err_out;
 415                 }
 416                 if (py_strseq_to_char(py_ann, &annpair) != SRD_OK)
 417                         goto err_out;
 418
 419                 annotations = g_slist_prepend(annotations, annpair);
 420         }
 421         dec->annotations = annotations;
 422         Py_DECREF(py_annlist);
 423         PyGILState_Release(gstate);
 424
 425         return SRD_OK;
 426
 427 except_out:
 428         srd_exception_catch("Failed to get %s decoder annotations", dec->name);
 429 err_out:
 430         g_slist_free_full(annotations, (GDestroyNotify)&g_strfreev);
 431         Py_XDECREF(py_annlist);
 432         PyGILState_Release(gstate);
 433
 434         return SRD_ERR_PYTHON;
 435 }
 436
 437 /* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'.
 438  */
 439 static int get_annotation_rows(struct srd_decoder *dec)
 440 {
 441         PyObject *py_ann_rows, *py_ann_row, *py_ann_classes, *py_item;
 442         GSList *annotation_rows;
 443         struct srd_decoder_annotation_row *ann_row;
 444         ssize_t i, k;
 445         size_t class_idx;
 446         PyGILState_STATE gstate;
 447
 448         gstate = PyGILState_Ensure();
 449
 450         if (!PyObject_HasAttrString(dec->py_dec, "annotation_rows")) {
 451                 PyGILState_Release(gstate);
 452                 return SRD_OK;
 453         }
 454
 455         annotation_rows = NULL;
 456
 457         py_ann_rows = PyObject_GetAttrString(dec->py_dec, "annotation_rows");
 458         if (!py_ann_rows)
 459                 goto except_out;
 460
 461         if (!PyTuple_Check(py_ann_rows)) {
 462                 srd_err("Protocol decoder %s annotation_rows "
 463                         "must be a tuple.", dec->name);
 464                 goto err_out;
 465         }
 466
 467         for (i = PyTuple_Size(py_ann_rows) - 1; i >= 0; i--) {
 468                 py_ann_row = PyTuple_GetItem(py_ann_rows, i);
 469                 if (!py_ann_row)
 470                         goto except_out;
 471
 472                 if (!PyTuple_Check(py_ann_row) || PyTuple_Size(py_ann_row) != 3) {
 473                         srd_err("Protocol decoder %s annotation_rows "
 474                                 "must contain only tuples of 3 elements.",
 475                                 dec->name);
 476                         goto err_out;
 477                 }
 478                 ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
 479                 /* Add to list right away so it doesn't get lost. */
 480                 annotation_rows = g_slist_prepend(annotation_rows, ann_row);
 481
 482                 py_item = PyTuple_GetItem(py_ann_row, 0);
 483                 if (!py_item)
 484                         goto except_out;
 485                 if (py_str_as_str(py_item, &ann_row->id) != SRD_OK)
 486                         goto err_out;
 487
 488                 py_item = PyTuple_GetItem(py_ann_row, 1);
 489                 if (!py_item)
 490                         goto except_out;
 491                 if (py_str_as_str(py_item, &ann_row->desc) != SRD_OK)
 492                         goto err_out;
 493
 494                 py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
 495                 if (!py_ann_classes)
 496                         goto except_out;
 497
 498                 if (!PyTuple_Check(py_ann_classes)) {
 499                         srd_err("Protocol decoder %s annotation_rows tuples "
 500                                 "must have a tuple of numbers as 3rd element.",
 501                                 dec->name);
 502                         goto err_out;
 503                 }
 504
 505                 for (k = PyTuple_Size(py_ann_classes) - 1; k >= 0; k--) {
 506                         py_item = PyTuple_GetItem(py_ann_classes, k);
 507                         if (!py_item)
 508                                 goto except_out;
 509
 510                         if (!PyLong_Check(py_item)) {
 511                                 srd_err("Protocol decoder %s annotation row "
 512                                         "class tuple must only contain numbers.",
 513                                         dec->name);
 514                                 goto err_out;
 515                         }
 516                         class_idx = PyLong_AsSize_t(py_item);
 517                         if (PyErr_Occurred())
 518                                 goto except_out;
 519
 520                         ann_row->ann_classes = g_slist_prepend(ann_row->ann_classes,
 521                                         GSIZE_TO_POINTER(class_idx));
 522                 }
 523         }
 524         dec->annotation_rows = annotation_rows;
 525         Py_DECREF(py_ann_rows);
 526         PyGILState_Release(gstate);
 527
 528         return SRD_OK;
 529
 530 except_out:
 531         srd_exception_catch("Failed to get %s decoder annotation rows",
 532                         dec->name);
 533 err_out:
 534         g_slist_free_full(annotation_rows, &annotation_row_free);
 535         Py_XDECREF(py_ann_rows);
 536         PyGILState_Release(gstate);
 537
 538         return SRD_ERR_PYTHON;
 539 }
 540
 541 /* Convert binary classes to GSList of char **.
 542  */
 543 static int get_binary_classes(struct srd_decoder *dec)
 544 {
 545         PyObject *py_bin_classes, *py_bin_class;
 546         GSList *bin_classes;
 547         char **bin;
 548         ssize_t i;
 549         PyGILState_STATE gstate;
 550
 551         gstate = PyGILState_Ensure();
 552
 553         if (!PyObject_HasAttrString(dec->py_dec, "binary")) {
 554                 PyGILState_Release(gstate);
 555                 return SRD_OK;
 556         }
 557
 558         bin_classes = NULL;
 559
 560         py_bin_classes = PyObject_GetAttrString(dec->py_dec, "binary");
 561         if (!py_bin_classes)
 562                 goto except_out;
 563
 564         if (!PyTuple_Check(py_bin_classes)) {
 565                 srd_err("Protocol decoder %s binary classes should "
 566                         "be a tuple.", dec->name);
 567                 goto err_out;
 568         }
 569
 570         for (i = PyTuple_Size(py_bin_classes) - 1; i >= 0; i--) {
 571                 py_bin_class = PyTuple_GetItem(py_bin_classes, i);
 572                 if (!py_bin_class)
 573                         goto except_out;
 574
 575                 if (!PyTuple_Check(py_bin_class)
 576                                 || PyTuple_Size(py_bin_class) != 2) {
 577                         srd_err("Protocol decoder %s binary classes should "
 578                                 "consist only of tuples of 2 elements.",
 579                                 dec->name);
 580                         goto err_out;
 581                 }
 582                 if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK)
 583                         goto err_out;
 584
 585                 bin_classes = g_slist_prepend(bin_classes, bin);
 586         }
 587         dec->binary = bin_classes;
 588         Py_DECREF(py_bin_classes);
 589         PyGILState_Release(gstate);
 590
 591         return SRD_OK;
 592
 593 except_out:
 594         srd_exception_catch("Failed to get %s decoder binary classes",
 595                         dec->name);
 596 err_out:
 597         g_slist_free_full(bin_classes, (GDestroyNotify)&g_strfreev);
 598         Py_XDECREF(py_bin_classes);
 599         PyGILState_Release(gstate);
 600
 601         return SRD_ERR_PYTHON;
 602 }
 603
 604 /* Check whether the Decoder class defines the named method.
 605  */
 606 static int check_method(PyObject *py_dec, const char *mod_name,
 607                 const char *method_name)
 608 {
 609         PyObject *py_method;
 610         int is_callable;
 611         PyGILState_STATE gstate;
 612
 613         gstate = PyGILState_Ensure();
 614
 615         py_method = PyObject_GetAttrString(py_dec, method_name);
 616         if (!py_method) {
 617                 srd_exception_catch("Protocol decoder %s Decoder class "
 618                                 "has no %s() method", mod_name, method_name);
 619                 PyGILState_Release(gstate);
 620                 return SRD_ERR_PYTHON;
 621         }
 622
 623         is_callable = PyCallable_Check(py_method);
 624         Py_DECREF(py_method);
 625
 626         PyGILState_Release(gstate);
 627
 628         if (!is_callable) {
 629                 srd_err("Protocol decoder %s Decoder class attribute '%s' "
 630                         "is not a method.", mod_name, method_name);
 631                 return SRD_ERR_PYTHON;
 632         }
 633
 634         return SRD_OK;
 635 }
 636
 637 /**
 638  * Get the API version of the specified decoder.
 639  *
 640  * @param d The decoder to use. Must not be NULL.
 641  *
 642  * @return The API version of the decoder, or 0 upon errors.
 643  *
 644  * @private
 645  */
 646 SRD_PRIV long srd_decoder_apiver(const struct srd_decoder *d)
 647 {
 648         PyObject *py_apiver;
 649         long apiver;
 650         PyGILState_STATE gstate;
 651
 652         if (!d)
 653                 return 0;
 654
 655         gstate = PyGILState_Ensure();
 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         PyGILState_Release(gstate);
 663
 664         return apiver;
 665 }
 666
 667 /**
 668  * Load a protocol decoder module into the embedded Python interpreter.
 669  *
 670  * @param module_name The module name to be loaded.
 671  *
 672  * @return SRD_OK upon success, a (negative) error code otherwise.
 673  *
 674  * @since 0.1.0
 675  */
 676 SRD_API int srd_decoder_load(const char *module_name)
 677 {
 678         PyObject *py_basedec;
 679         struct srd_decoder *d;
 680         long apiver;
 681         int is_subclass;
 682         const char *fail_txt;
 683         PyGILState_STATE gstate;
 684
 685         if (!srd_check_init())
 686                 return SRD_ERR;
 687
 688         if (!module_name)
 689                 return SRD_ERR_ARG;
 690
 691         gstate = PyGILState_Ensure();
 692
 693         if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
 694                 /* Module was already imported. */
 695                 PyGILState_Release(gstate);
 696                 return SRD_OK;
 697         }
 698
 699         d = g_malloc0(sizeof(struct srd_decoder));
 700         fail_txt = NULL;
 701
 702         d->py_mod = py_import_by_name(module_name);
 703         if (!d->py_mod) {
 704                 fail_txt = "import by name failed";
 705                 goto except_out;
 706         }
 707
 708         if (!mod_sigrokdecode) {
 709                 srd_err("sigrokdecode module not loaded.");
 710                 fail_txt = "sigrokdecode(3) not loaded";
 711                 goto err_out;
 712         }
 713
 714         /* Get the 'Decoder' class as Python object. */
 715         d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder");
 716         if (!d->py_dec) {
 717                 fail_txt = "no 'Decoder' attribute in imported module";
 718                 goto except_out;
 719         }
 720
 721         py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder");
 722         if (!py_basedec) {
 723                 fail_txt = "no 'Decoder' attribute in sigrokdecode(3)";
 724                 goto except_out;
 725         }
 726
 727         is_subclass = PyObject_IsSubclass(d->py_dec, py_basedec);
 728         Py_DECREF(py_basedec);
 729
 730         if (!is_subclass) {
 731                 srd_err("Decoder class in protocol decoder module %s is not "
 732                         "a subclass of sigrokdecode.Decoder.", module_name);
 733                 fail_txt = "not a subclass of sigrokdecode.Decoder";
 734                 goto err_out;
 735         }
 736
 737         /*
 738          * Check that this decoder has the correct PD API version.
 739          * PDs of different API versions are incompatible and cannot work.
 740          */
 741         apiver = srd_decoder_apiver(d);
 742         if (apiver != 3) {
 743                 srd_exception_catch("Only PD API version 3 is supported, "
 744                         "decoder %s has version %ld", module_name, apiver);
 745                 fail_txt = "API version mismatch";
 746                 goto err_out;
 747         }
 748
 749         /* Check Decoder class for required methods.
 750          */
 751         if (check_method(d->py_dec, module_name, "start") != SRD_OK) {
 752                 fail_txt = "no 'start()' method";
 753                 goto err_out;
 754         }
 755
 756         if (check_method(d->py_dec, module_name, "decode") != SRD_OK) {
 757                 fail_txt = "no 'decode()' method";
 758                 goto err_out;
 759         }
 760
 761         /* Store required fields in newly allocated strings. */
 762         if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK) {
 763                 fail_txt = "no 'id' attribute";
 764                 goto err_out;
 765         }
 766
 767         if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK) {
 768                 fail_txt = "no 'name' attribute";
 769                 goto err_out;
 770         }
 771
 772         if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK) {
 773                 fail_txt = "no 'longname' attribute";
 774                 goto err_out;
 775         }
 776
 777         if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK) {
 778                 fail_txt = "no 'desc' attribute";
 779                 goto err_out;
 780         }
 781
 782         if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK) {
 783                 fail_txt = "no 'license' attribute";
 784                 goto err_out;
 785         }
 786
 787         if (py_attr_as_strlist(d->py_dec, "inputs", &(d->inputs)) != SRD_OK) {
 788                 fail_txt = "missing or malformed 'inputs' attribute";
 789                 goto err_out;
 790         }
 791
 792         if (py_attr_as_strlist(d->py_dec, "outputs", &(d->outputs)) != SRD_OK) {
 793                 fail_txt = "missing or malformed 'outputs' attribute";
 794                 goto err_out;
 795         }
 796
 797         /* All options and their default values. */
 798         if (get_options(d) != SRD_OK) {
 799                 fail_txt = "cannot get options";
 800                 goto err_out;
 801         }
 802
 803         /* Check and import required channels. */
 804         if (get_channels(d, "channels", &d->channels, 0) != SRD_OK) {
 805                 fail_txt = "cannot get channels";
 806                 goto err_out;
 807         }
 808
 809         /* Check and import optional channels. */
 810         if (get_channels(d, "optional_channels", &d->opt_channels,
 811                                 g_slist_length(d->channels)) != SRD_OK) {
 812                 fail_txt = "cannot get optional channels";
 813                 goto err_out;
 814         }
 815
 816         if (get_annotations(d) != SRD_OK) {
 817                 fail_txt = "cannot get annotations";
 818                 goto err_out;
 819         }
 820
 821         if (get_annotation_rows(d) != SRD_OK) {
 822                 fail_txt = "cannot get annotation rows";
 823                 goto err_out;
 824         }
 825
 826         if (get_binary_classes(d) != SRD_OK) {
 827                 fail_txt = "cannot get binary classes";
 828                 goto err_out;
 829         }
 830
 831         PyGILState_Release(gstate);
 832
 833         /* Append it to the list of loaded decoders. */
 834         pd_list = g_slist_append(pd_list, d);
 835
 836         return SRD_OK;
 837
 838 except_out:
 839         /* Don't show a message for the "common" directory, it's not a PD. */
 840         if (strcmp(module_name, "common")) {
 841                 srd_exception_catch("Failed to load decoder %s: %s",
 842                                     module_name, fail_txt);
 843         }
 844         fail_txt = NULL;
 845 err_out:
 846         if (fail_txt)
 847                 srd_err("Failed to load decoder %s: %s", module_name, fail_txt);
 848         decoder_free(d);
 849         PyGILState_Release(gstate);
 850
 851         return SRD_ERR_PYTHON;
 852 }
 853
 854 /**
 855  * Return a protocol decoder's docstring.
 856  *
 857  * @param dec The loaded protocol decoder.
 858  *
 859  * @return A newly allocated buffer containing the protocol decoder's
 860  *         documentation. The caller is responsible for free'ing the buffer.
 861  *
 862  * @since 0.1.0
 863  */
 864 SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
 865 {
 866         PyObject *py_str;
 867         char *doc;
 868         PyGILState_STATE gstate;
 869
 870         if (!srd_check_init())
 871                 return NULL;
 872
 873         if (!dec)
 874                 return NULL;
 875
 876         gstate = PyGILState_Ensure();
 877
 878         if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
 879                 goto err;
 880
 881         if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
 882                 srd_exception_catch("Failed to get docstring");
 883                 goto err;
 884         }
 885
 886         doc = NULL;
 887         if (py_str != Py_None)
 888                 py_str_as_str(py_str, &doc);
 889         Py_DECREF(py_str);
 890
 891         PyGILState_Release(gstate);
 892
 893         return doc;
 894
 895 err:
 896         PyGILState_Release(gstate);
 897
 898         return NULL;
 899 }
 900
 901 /**
 902  * Unload the specified protocol decoder.
 903  *
 904  * @param dec The struct srd_decoder to be unloaded.
 905  *
 906  * @return SRD_OK upon success, a (negative) error code otherwise.
 907  *
 908  * @since 0.1.0
 909  */
 910 SRD_API int srd_decoder_unload(struct srd_decoder *dec)
 911 {
 912         struct srd_session *sess;
 913         GSList *l;
 914
 915         if (!srd_check_init())
 916                 return SRD_ERR;
 917
 918         if (!dec)
 919                 return SRD_ERR_ARG;
 920
 921         /*
 922          * Since any instances of this decoder need to be released as well,
 923          * but they could be anywhere in the stack, just free the entire
 924          * stack. A frontend reloading a decoder thus has to restart all
 925          * instances, and rebuild the stack.
 926          */
 927         for (l = sessions; l; l = l->next) {
 928                 sess = l->data;
 929                 srd_inst_free_all(sess);
 930         }
 931
 932         /* Remove the PD from the list of loaded decoders. */
 933         pd_list = g_slist_remove(pd_list, dec);
 934
 935         decoder_free(dec);
 936
 937         return SRD_OK;
 938 }
 939
 940 static void srd_decoder_load_all_zip_path(char *path)
 941 {
 942         PyObject *zipimport_mod, *zipimporter_class, *zipimporter;
 943         PyObject *prefix_obj, *files, *key, *value, *set, *modname;
 944         Py_ssize_t pos = 0;
 945         char *prefix;
 946         size_t prefix_len;
 947         PyGILState_STATE gstate;
 948
 949         set = files = prefix_obj = zipimporter = zipimporter_class = NULL;
 950
 951         gstate = PyGILState_Ensure();
 952
 953         zipimport_mod = py_import_by_name("zipimport");
 954         if (zipimport_mod == NULL)
 955                 goto err_out;
 956
 957         zipimporter_class = PyObject_GetAttrString(zipimport_mod, "zipimporter");
 958         if (zipimporter_class == NULL)
 959                 goto err_out;
 960
 961         zipimporter = PyObject_CallFunction(zipimporter_class, "s", path);
 962         if (zipimporter == NULL)
 963                 goto err_out;
 964
 965         prefix_obj = PyObject_GetAttrString(zipimporter, "prefix");
 966         if (prefix_obj == NULL)
 967                 goto err_out;
 968
 969         files = PyObject_GetAttrString(zipimporter, "_files");
 970         if (files == NULL || !PyDict_Check(files))
 971                 goto err_out;
 972
 973         set = PySet_New(NULL);
 974         if (set == NULL)
 975                 goto err_out;
 976
 977         if (py_str_as_str(prefix_obj, &prefix) != SRD_OK)
 978                 goto err_out;
 979
 980         prefix_len = strlen(prefix);
 981
 982         while (PyDict_Next(files, &pos, &key, &value)) {
 983                 char *path, *slash;
 984                 if (py_str_as_str(key, &path) == SRD_OK) {
 985                         if (strlen(path) > prefix_len
 986                                         && memcmp(path, prefix, prefix_len) == 0
 987                                         && (slash = strchr(path + prefix_len, '/'))) {
 988
 989                                 modname = PyUnicode_FromStringAndSize(path + prefix_len,
 990                                                         slash - (path + prefix_len));
 991                                 if (modname == NULL) {
 992                                         PyErr_Clear();
 993                                 } else {
 994                                         PySet_Add(set, modname);
 995                                         Py_DECREF(modname);
 996                                 }
 997                         }
 998                         g_free(path);
 999                 }
1000         }
1001         g_free(prefix);
1002
1003         while ((modname = PySet_Pop(set))) {
1004                 char *modname_str;
1005                 if (py_str_as_str(modname, &modname_str) == SRD_OK) {
1006                         /* The directory name is the module name (e.g. "i2c"). */
1007                         srd_decoder_load(modname_str);
1008                         g_free(modname_str);
1009                 }
1010                 Py_DECREF(modname);
1011         }
1012
1013 err_out:
1014         Py_XDECREF(set);
1015         Py_XDECREF(files);
1016         Py_XDECREF(prefix_obj);
1017         Py_XDECREF(zipimporter);
1018         Py_XDECREF(zipimporter_class);
1019         Py_XDECREF(zipimport_mod);
1020         PyErr_Clear();
1021         PyGILState_Release(gstate);
1022 }
1023
1024 static void srd_decoder_load_all_path(char *path)
1025 {
1026         GDir *dir;
1027         const gchar *direntry;
1028
1029         if (!(dir = g_dir_open(path, 0, NULL))) {
1030                 /* Not really fatal */
1031                 /* Try zipimport method too */
1032                 srd_decoder_load_all_zip_path(path);
1033                 return;
1034         }
1035
1036         /* This ignores errors returned by srd_decoder_load(). That
1037          * function will have logged the cause, but in any case we
1038          * want to continue anyway. */
1039         while ((direntry = g_dir_read_name(dir)) != NULL) {
1040                 /* The directory name is the module name (e.g. "i2c"). */
1041                 srd_decoder_load(direntry);
1042         }
1043         g_dir_close(dir);
1044
1045 }
1046
1047 /**
1048  * Load all installed protocol decoders.
1049  *
1050  * @return SRD_OK upon success, a (negative) error code otherwise.
1051  *
1052  * @since 0.1.0
1053  */
1054 SRD_API int srd_decoder_load_all(void)
1055 {
1056         GSList *l;
1057
1058         if (!srd_check_init())
1059                 return SRD_ERR;
1060
1061         for (l = searchpaths; l; l = l->next)
1062                 srd_decoder_load_all_path(l->data);
1063
1064         return SRD_OK;
1065 }
1066
1067 /**
1068  * Unload all loaded protocol decoders.
1069  *
1070  * @return SRD_OK upon success, a (negative) error code otherwise.
1071  *
1072  * @since 0.1.0
1073  */
1074 SRD_API int srd_decoder_unload_all(void)
1075 {
1076         g_slist_foreach(pd_list, (GFunc)srd_decoder_unload, NULL);
1077         g_slist_free(pd_list);
1078         pd_list = NULL;
1079
1080         return SRD_OK;
1081 }
1082
1083 /** @} */