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