qapi/qobject-input-visitor.c

   1 /*
   2  * Input Visitor
   3  *
   4  * Copyright (C) 2012-2017 Red Hat, Inc.
   5  * Copyright IBM, Corp. 2011
   6  *
   7  * Authors:
   8  *  Anthony Liguori   <aliguori@us.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  11  * See the COPYING.LIB file in the top-level directory.
  12  *
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "qapi/error.h"
  17 #include "qapi/qobject-input-visitor.h"
  18 #include "qapi/visitor-impl.h"
  19 #include "qemu/queue.h"
  20 #include "qemu-common.h"
  21 #include "qapi/qmp/qjson.h"
  22 #include "qapi/qmp/types.h"
  23 #include "qapi/qmp/qerror.h"
  24 #include "qemu/cutils.h"
  25 #include "qemu/option.h"
  26
  27 typedef struct StackObject {
  28     const char *name;            /* Name of @obj in its parent, if any */
  29     QObject *obj;                /* QDict or QList being visited */
  30     void *qapi; /* sanity check that caller uses same pointer */
  31
  32     GHashTable *h;              /* If @obj is QDict: unvisited keys */
  33     const QListEntry *entry;    /* If @obj is QList: unvisited tail */
  34     unsigned index;             /* If @obj is QList: list index of @entry */
  35
  36     QSLIST_ENTRY(StackObject) node; /* parent */
  37 } StackObject;
  38
  39 struct QObjectInputVisitor {
  40     Visitor visitor;
  41
  42     /* Root of visit at visitor creation. */
  43     QObject *root;
  44
  45     /* Stack of objects being visited (all entries will be either
  46      * QDict or QList). */
  47     QSLIST_HEAD(, StackObject) stack;
  48
  49     GString *errname;           /* Accumulator for full_name() */
  50 };
  51
  52 static QObjectInputVisitor *to_qiv(Visitor *v)
  53 {
  54     return container_of(v, QObjectInputVisitor, visitor);
  55 }
  56
  57 static const char *full_name_nth(QObjectInputVisitor *qiv, const char *name,
  58                                  int n)
  59 {
  60     StackObject *so;
  61     char buf[32];
  62
  63     if (qiv->errname) {
  64         g_string_truncate(qiv->errname, 0);
  65     } else {
  66         qiv->errname = g_string_new("");
  67     }
  68
  69     QSLIST_FOREACH(so , &qiv->stack, node) {
  70         if (n) {
  71             n--;
  72         } else if (qobject_type(so->obj) == QTYPE_QDICT) {
  73             g_string_prepend(qiv->errname, name ?: "<anonymous>");
  74             g_string_prepend_c(qiv->errname, '.');
  75         } else {
  76             snprintf(buf, sizeof(buf), "[%u]", so->index);
  77             g_string_prepend(qiv->errname, buf);
  78         }
  79         name = so->name;
  80     }
  81     assert(!n);
  82
  83     if (name) {
  84         g_string_prepend(qiv->errname, name);
  85     } else if (qiv->errname->str[0] == '.') {
  86         g_string_erase(qiv->errname, 0, 1);
  87     } else if (!qiv->errname->str[0]) {
  88         return "<anonymous>";
  89     }
  90
  91     return qiv->errname->str;
  92 }
  93
  94 static const char *full_name(QObjectInputVisitor *qiv, const char *name)
  95 {
  96     return full_name_nth(qiv, name, 0);
  97 }
  98
  99 static QObject *qobject_input_try_get_object(QObjectInputVisitor *qiv,
 100                                              const char *name,
 101                                              bool consume)
 102 {
 103     StackObject *tos;
 104     QObject *qobj;
 105     QObject *ret;
 106
 107     if (QSLIST_EMPTY(&qiv->stack)) {
 108         /* Starting at root, name is ignored. */
 109         assert(qiv->root);
 110         return qiv->root;
 111     }
 112
 113     /* We are in a container; find the next element. */
 114     tos = QSLIST_FIRST(&qiv->stack);
 115     qobj = tos->obj;
 116     assert(qobj);
 117
 118     if (qobject_type(qobj) == QTYPE_QDICT) {
 119         assert(name);
 120         ret = qdict_get(qobject_to_qdict(qobj), name);
 121         if (tos->h && consume && ret) {
 122             bool removed = g_hash_table_remove(tos->h, name);
 123             assert(removed);
 124         }
 125     } else {
 126         assert(qobject_type(qobj) == QTYPE_QLIST);
 127         assert(!name);
 128         if (tos->entry) {
 129             ret = qlist_entry_obj(tos->entry);
 130             if (consume) {
 131                 tos->entry = qlist_next(tos->entry);
 132             }
 133         } else {
 134             ret = NULL;
 135         }
 136         if (consume) {
 137             tos->index++;
 138         }
 139     }
 140
 141     return ret;
 142 }
 143
 144 static QObject *qobject_input_get_object(QObjectInputVisitor *qiv,
 145                                          const char *name,
 146                                          bool consume, Error **errp)
 147 {
 148     QObject *obj = qobject_input_try_get_object(qiv, name, consume);
 149
 150     if (!obj) {
 151         error_setg(errp, QERR_MISSING_PARAMETER, full_name(qiv, name));
 152     }
 153     return obj;
 154 }
 155
 156 static const char *qobject_input_get_keyval(QObjectInputVisitor *qiv,
 157                                             const char *name,
 158                                             Error **errp)
 159 {
 160     QObject *qobj;
 161     QString *qstr;
 162
 163     qobj = qobject_input_get_object(qiv, name, true, errp);
 164     if (!qobj) {
 165         return NULL;
 166     }
 167
 168     qstr = qobject_to_qstring(qobj);
 169     if (!qstr) {
 170         switch (qobject_type(qobj)) {
 171         case QTYPE_QDICT:
 172         case QTYPE_QLIST:
 173             error_setg(errp, "Parameters '%s.*' are unexpected",
 174                        full_name(qiv, name));
 175             return NULL;
 176         default:
 177             /* Non-string scalar (should this be an assertion?) */
 178             error_setg(errp, "Internal error: parameter %s invalid",
 179                        full_name(qiv, name));
 180             return NULL;
 181         }
 182     }
 183
 184     return qstring_get_str(qstr);
 185 }
 186
 187 static void qdict_add_key(const char *key, QObject *obj, void *opaque)
 188 {
 189     GHashTable *h = opaque;
 190     g_hash_table_insert(h, (gpointer) key, NULL);
 191 }
 192
 193 static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
 194                                             const char *name,
 195                                             QObject *obj, void *qapi)
 196 {
 197     GHashTable *h;
 198     StackObject *tos = g_new0(StackObject, 1);
 199
 200     assert(obj);
 201     tos->name = name;
 202     tos->obj = obj;
 203     tos->qapi = qapi;
 204
 205     if (qobject_type(obj) == QTYPE_QDICT) {
 206         h = g_hash_table_new(g_str_hash, g_str_equal);
 207         qdict_iter(qobject_to_qdict(obj), qdict_add_key, h);
 208         tos->h = h;
 209     } else {
 210         assert(qobject_type(obj) == QTYPE_QLIST);
 211         tos->entry = qlist_first(qobject_to_qlist(obj));
 212         tos->index = -1;
 213     }
 214
 215     QSLIST_INSERT_HEAD(&qiv->stack, tos, node);
 216     return tos->entry;
 217 }
 218
 219
 220 static void qobject_input_check_struct(Visitor *v, Error **errp)
 221 {
 222     QObjectInputVisitor *qiv = to_qiv(v);
 223     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 224     GHashTableIter iter;
 225     const char *key;
 226
 227     assert(tos && !tos->entry);
 228
 229     g_hash_table_iter_init(&iter, tos->h);
 230     if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
 231         error_setg(errp, "Parameter '%s' is unexpected",
 232                    full_name(qiv, key));
 233     }
 234 }
 235
 236 static void qobject_input_stack_object_free(StackObject *tos)
 237 {
 238     if (tos->h) {
 239         g_hash_table_unref(tos->h);
 240     }
 241
 242     g_free(tos);
 243 }
 244
 245 static void qobject_input_pop(Visitor *v, void **obj)
 246 {
 247     QObjectInputVisitor *qiv = to_qiv(v);
 248     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 249
 250     assert(tos && tos->qapi == obj);
 251     QSLIST_REMOVE_HEAD(&qiv->stack, node);
 252     qobject_input_stack_object_free(tos);
 253 }
 254
 255 static void qobject_input_start_struct(Visitor *v, const char *name, void **obj,
 256                                        size_t size, Error **errp)
 257 {
 258     QObjectInputVisitor *qiv = to_qiv(v);
 259     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 260
 261     if (obj) {
 262         *obj = NULL;
 263     }
 264     if (!qobj) {
 265         return;
 266     }
 267     if (qobject_type(qobj) != QTYPE_QDICT) {
 268         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 269                    full_name(qiv, name), "object");
 270         return;
 271     }
 272
 273     qobject_input_push(qiv, name, qobj, obj);
 274
 275     if (obj) {
 276         *obj = g_malloc0(size);
 277     }
 278 }
 279
 280
 281 static void qobject_input_start_list(Visitor *v, const char *name,
 282                                      GenericList **list, size_t size,
 283                                      Error **errp)
 284 {
 285     QObjectInputVisitor *qiv = to_qiv(v);
 286     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 287     const QListEntry *entry;
 288
 289     if (list) {
 290         *list = NULL;
 291     }
 292     if (!qobj) {
 293         return;
 294     }
 295     if (qobject_type(qobj) != QTYPE_QLIST) {
 296         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 297                    full_name(qiv, name), "array");
 298         return;
 299     }
 300
 301     entry = qobject_input_push(qiv, name, qobj, list);
 302     if (entry && list) {
 303         *list = g_malloc0(size);
 304     }
 305 }
 306
 307 static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
 308                                             size_t size)
 309 {
 310     QObjectInputVisitor *qiv = to_qiv(v);
 311     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 312
 313     assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
 314
 315     if (!tos->entry) {
 316         return NULL;
 317     }
 318     tail->next = g_malloc0(size);
 319     return tail->next;
 320 }
 321
 322 static void qobject_input_check_list(Visitor *v, Error **errp)
 323 {
 324     QObjectInputVisitor *qiv = to_qiv(v);
 325     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 326
 327     assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
 328
 329     if (tos->entry) {
 330         error_setg(errp, "Only %u list elements expected in %s",
 331                    tos->index + 1, full_name_nth(qiv, NULL, 1));
 332     }
 333 }
 334
 335
 336 static void qobject_input_start_alternate(Visitor *v, const char *name,
 337                                           GenericAlternate **obj, size_t size,
 338                                           bool promote_int, Error **errp)
 339 {
 340     QObjectInputVisitor *qiv = to_qiv(v);
 341     QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
 342
 343     if (!qobj) {
 344         *obj = NULL;
 345         return;
 346     }
 347     *obj = g_malloc0(size);
 348     (*obj)->type = qobject_type(qobj);
 349     if (promote_int && (*obj)->type == QTYPE_QINT) {
 350         (*obj)->type = QTYPE_QFLOAT;
 351     }
 352 }
 353
 354 static void qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
 355                                      Error **errp)
 356 {
 357     QObjectInputVisitor *qiv = to_qiv(v);
 358     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 359     QInt *qint;
 360
 361     if (!qobj) {
 362         return;
 363     }
 364     qint = qobject_to_qint(qobj);
 365     if (!qint) {
 366         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 367                    full_name(qiv, name), "integer");
 368         return;
 369     }
 370
 371     *obj = qint_get_int(qint);
 372 }
 373
 374
 375 static void qobject_input_type_int64_keyval(Visitor *v, const char *name,
 376                                             int64_t *obj, Error **errp)
 377 {
 378     QObjectInputVisitor *qiv = to_qiv(v);
 379     const char *str = qobject_input_get_keyval(qiv, name, errp);
 380
 381     if (!str) {
 382         return;
 383     }
 384
 385     if (qemu_strtoi64(str, NULL, 0, obj) < 0) {
 386         /* TODO report -ERANGE more nicely */
 387         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 388                    full_name(qiv, name), "integer");
 389     }
 390 }
 391
 392 static void qobject_input_type_uint64(Visitor *v, const char *name,
 393                                       uint64_t *obj, Error **errp)
 394 {
 395     /* FIXME: qobject_to_qint mishandles values over INT64_MAX */
 396     QObjectInputVisitor *qiv = to_qiv(v);
 397     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 398     QInt *qint;
 399
 400     if (!qobj) {
 401         return;
 402     }
 403     qint = qobject_to_qint(qobj);
 404     if (!qint) {
 405         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 406                    full_name(qiv, name), "integer");
 407         return;
 408     }
 409
 410     *obj = qint_get_int(qint);
 411 }
 412
 413 static void qobject_input_type_uint64_keyval(Visitor *v, const char *name,
 414                                              uint64_t *obj, Error **errp)
 415 {
 416     QObjectInputVisitor *qiv = to_qiv(v);
 417     const char *str = qobject_input_get_keyval(qiv, name, errp);
 418
 419     if (!str) {
 420         return;
 421     }
 422
 423     if (qemu_strtou64(str, NULL, 0, obj) < 0) {
 424         /* TODO report -ERANGE more nicely */
 425         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 426                    full_name(qiv, name), "integer");
 427     }
 428 }
 429
 430 static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
 431                                     Error **errp)
 432 {
 433     QObjectInputVisitor *qiv = to_qiv(v);
 434     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 435     QBool *qbool;
 436
 437     if (!qobj) {
 438         return;
 439     }
 440     qbool = qobject_to_qbool(qobj);
 441     if (!qbool) {
 442         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 443                    full_name(qiv, name), "boolean");
 444         return;
 445     }
 446
 447     *obj = qbool_get_bool(qbool);
 448 }
 449
 450 static void qobject_input_type_bool_keyval(Visitor *v, const char *name,
 451                                            bool *obj, Error **errp)
 452 {
 453     QObjectInputVisitor *qiv = to_qiv(v);
 454     const char *str = qobject_input_get_keyval(qiv, name, errp);
 455
 456     if (!str) {
 457         return;
 458     }
 459
 460     if (!strcmp(str, "on")) {
 461         *obj = true;
 462     } else if (!strcmp(str, "off")) {
 463         *obj = false;
 464     } else {
 465         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 466                    full_name(qiv, name), "'on' or 'off'");
 467     }
 468 }
 469
 470 static void qobject_input_type_str(Visitor *v, const char *name, char **obj,
 471                                    Error **errp)
 472 {
 473     QObjectInputVisitor *qiv = to_qiv(v);
 474     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 475     QString *qstr;
 476
 477     *obj = NULL;
 478     if (!qobj) {
 479         return;
 480     }
 481     qstr = qobject_to_qstring(qobj);
 482     if (!qstr) {
 483         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 484                    full_name(qiv, name), "string");
 485         return;
 486     }
 487
 488     *obj = g_strdup(qstring_get_str(qstr));
 489 }
 490
 491 static void qobject_input_type_str_keyval(Visitor *v, const char *name,
 492                                           char **obj, Error **errp)
 493 {
 494     QObjectInputVisitor *qiv = to_qiv(v);
 495     const char *str = qobject_input_get_keyval(qiv, name, errp);
 496
 497     *obj = g_strdup(str);
 498 }
 499
 500 static void qobject_input_type_number(Visitor *v, const char *name, double *obj,
 501                                       Error **errp)
 502 {
 503     QObjectInputVisitor *qiv = to_qiv(v);
 504     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 505     QInt *qint;
 506     QFloat *qfloat;
 507
 508     if (!qobj) {
 509         return;
 510     }
 511     qint = qobject_to_qint(qobj);
 512     if (qint) {
 513         *obj = qint_get_int(qobject_to_qint(qobj));
 514         return;
 515     }
 516
 517     qfloat = qobject_to_qfloat(qobj);
 518     if (qfloat) {
 519         *obj = qfloat_get_double(qobject_to_qfloat(qobj));
 520         return;
 521     }
 522
 523     error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 524                full_name(qiv, name), "number");
 525 }
 526
 527 static void qobject_input_type_number_keyval(Visitor *v, const char *name,
 528                                              double *obj, Error **errp)
 529 {
 530     QObjectInputVisitor *qiv = to_qiv(v);
 531     const char *str = qobject_input_get_keyval(qiv, name, errp);
 532     char *endp;
 533
 534     if (!str) {
 535         return;
 536     }
 537
 538     errno = 0;
 539     *obj = strtod(str, &endp);
 540     if (errno || endp == str || *endp) {
 541         /* TODO report -ERANGE more nicely */
 542         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 543                    full_name(qiv, name), "number");
 544     }
 545 }
 546
 547 static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
 548                                    Error **errp)
 549 {
 550     QObjectInputVisitor *qiv = to_qiv(v);
 551     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 552
 553     *obj = NULL;
 554     if (!qobj) {
 555         return;
 556     }
 557
 558     qobject_incref(qobj);
 559     *obj = qobj;
 560 }
 561
 562 static void qobject_input_type_null(Visitor *v, const char *name, Error **errp)
 563 {
 564     QObjectInputVisitor *qiv = to_qiv(v);
 565     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 566
 567     if (!qobj) {
 568         return;
 569     }
 570
 571     if (qobject_type(qobj) != QTYPE_QNULL) {
 572         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 573                    full_name(qiv, name), "null");
 574     }
 575 }
 576
 577 static void qobject_input_type_size_keyval(Visitor *v, const char *name,
 578                                            uint64_t *obj, Error **errp)
 579 {
 580     QObjectInputVisitor *qiv = to_qiv(v);
 581     const char *str = qobject_input_get_keyval(qiv, name, errp);
 582
 583     if (!str) {
 584         return;
 585     }
 586
 587     if (qemu_strtosz(str, NULL, obj) < 0) {
 588         /* TODO report -ERANGE more nicely */
 589         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 590                    full_name(qiv, name), "size");
 591     }
 592 }
 593
 594 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
 595 {
 596     QObjectInputVisitor *qiv = to_qiv(v);
 597     QObject *qobj = qobject_input_try_get_object(qiv, name, false);
 598
 599     if (!qobj) {
 600         *present = false;
 601         return;
 602     }
 603
 604     *present = true;
 605 }
 606
 607 static void qobject_input_free(Visitor *v)
 608 {
 609     QObjectInputVisitor *qiv = to_qiv(v);
 610
 611     while (!QSLIST_EMPTY(&qiv->stack)) {
 612         StackObject *tos = QSLIST_FIRST(&qiv->stack);
 613
 614         QSLIST_REMOVE_HEAD(&qiv->stack, node);
 615         qobject_input_stack_object_free(tos);
 616     }
 617
 618     qobject_decref(qiv->root);
 619     if (qiv->errname) {
 620         g_string_free(qiv->errname, TRUE);
 621     }
 622     g_free(qiv);
 623 }
 624
 625 static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
 626 {
 627     QObjectInputVisitor *v = g_malloc0(sizeof(*v));
 628
 629     assert(obj);
 630
 631     v->visitor.type = VISITOR_INPUT;
 632     v->visitor.start_struct = qobject_input_start_struct;
 633     v->visitor.check_struct = qobject_input_check_struct;
 634     v->visitor.end_struct = qobject_input_pop;
 635     v->visitor.start_list = qobject_input_start_list;
 636     v->visitor.next_list = qobject_input_next_list;
 637     v->visitor.check_list = qobject_input_check_list;
 638     v->visitor.end_list = qobject_input_pop;
 639     v->visitor.start_alternate = qobject_input_start_alternate;
 640     v->visitor.optional = qobject_input_optional;
 641     v->visitor.free = qobject_input_free;
 642
 643     v->root = obj;
 644     qobject_incref(obj);
 645
 646     return v;
 647 }
 648
 649 Visitor *qobject_input_visitor_new(QObject *obj)
 650 {
 651     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
 652
 653     v->visitor.type_int64 = qobject_input_type_int64;
 654     v->visitor.type_uint64 = qobject_input_type_uint64;
 655     v->visitor.type_bool = qobject_input_type_bool;
 656     v->visitor.type_str = qobject_input_type_str;
 657     v->visitor.type_number = qobject_input_type_number;
 658     v->visitor.type_any = qobject_input_type_any;
 659     v->visitor.type_null = qobject_input_type_null;
 660
 661     return &v->visitor;
 662 }
 663
 664 Visitor *qobject_input_visitor_new_keyval(QObject *obj)
 665 {
 666     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
 667
 668     v->visitor.type_int64 = qobject_input_type_int64_keyval;
 669     v->visitor.type_uint64 = qobject_input_type_uint64_keyval;
 670     v->visitor.type_bool = qobject_input_type_bool_keyval;
 671     v->visitor.type_str = qobject_input_type_str_keyval;
 672     v->visitor.type_number = qobject_input_type_number_keyval;
 673     v->visitor.type_any = qobject_input_type_any;
 674     v->visitor.type_null = qobject_input_type_null;
 675     v->visitor.type_size = qobject_input_type_size_keyval;
 676
 677     return &v->visitor;
 678 }
 679
 680 Visitor *qobject_input_visitor_new_str(const char *str,
 681                                        const char *implied_key,
 682                                        Error **errp)
 683 {
 684     bool is_json = str[0] == '{';
 685     QObject *obj;
 686     QDict *args;
 687     Visitor *v;
 688
 689     if (is_json) {
 690         obj = qobject_from_json(str, errp);
 691         if (!obj) {
 692             /* Work around qobject_from_json() lossage TODO fix that */
 693             if (errp && !*errp) {
 694                 error_setg(errp, "JSON parse error");
 695                 return NULL;
 696             }
 697             return NULL;
 698         }
 699         args = qobject_to_qdict(obj);
 700         assert(args);
 701         v = qobject_input_visitor_new(QOBJECT(args));
 702     } else {
 703         args = keyval_parse(str, implied_key, errp);
 704         if (!args) {
 705             return NULL;
 706         }
 707         v = qobject_input_visitor_new_keyval(QOBJECT(args));
 708     }
 709     QDECREF(args);
 710
 711     return v;
 712 }