qapi/qobject-input-visitor.c

   1 /*
   2  * Input Visitor
   3  *
   4  * Copyright (C) 2012-2016 Red Hat, Inc.
   5  * Copyright IBM, Corp. 2011
   6  *
   7  * Authors:
   8  *  Anthony Liguori   <[email protected]>
   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/types.h"
  22 #include "qapi/qmp/qerror.h"
  23
  24 typedef struct StackObject {
  25     const char *name;            /* Name of @obj in its parent, if any */
  26     QObject *obj;                /* QDict or QList being visited */
  27     void *qapi; /* sanity check that caller uses same pointer */
  28
  29     GHashTable *h;              /* If @obj is QDict: unvisited keys */
  30     const QListEntry *entry;    /* If @obj is QList: unvisited tail */
  31     unsigned index;             /* If @obj is QList: list index of @entry */
  32
  33     QSLIST_ENTRY(StackObject) node; /* parent */
  34 } StackObject;
  35
  36 struct QObjectInputVisitor {
  37     Visitor visitor;
  38
  39     /* Root of visit at visitor creation. */
  40     QObject *root;
  41
  42     /* Stack of objects being visited (all entries will be either
  43      * QDict or QList). */
  44     QSLIST_HEAD(, StackObject) stack;
  45
  46     GString *errname;           /* Accumulator for full_name() */
  47 };
  48
  49 static QObjectInputVisitor *to_qiv(Visitor *v)
  50 {
  51     return container_of(v, QObjectInputVisitor, visitor);
  52 }
  53
  54 static const char *full_name_nth(QObjectInputVisitor *qiv, const char *name,
  55                                  int n)
  56 {
  57     StackObject *so;
  58     char buf[32];
  59
  60     if (qiv->errname) {
  61         g_string_truncate(qiv->errname, 0);
  62     } else {
  63         qiv->errname = g_string_new("");
  64     }
  65
  66     QSLIST_FOREACH(so , &qiv->stack, node) {
  67         if (n) {
  68             n--;
  69         } else if (qobject_type(so->obj) == QTYPE_QDICT) {
  70             g_string_prepend(qiv->errname, name ?: "<anonymous>");
  71             g_string_prepend_c(qiv->errname, '.');
  72         } else {
  73             snprintf(buf, sizeof(buf), "[%u]", so->index);
  74             g_string_prepend(qiv->errname, buf);
  75         }
  76         name = so->name;
  77     }
  78     assert(!n);
  79
  80     if (name) {
  81         g_string_prepend(qiv->errname, name);
  82     } else if (qiv->errname->str[0] == '.') {
  83         g_string_erase(qiv->errname, 0, 1);
  84     } else if (!qiv->errname->str[0]) {
  85         return "<anonymous>";
  86     }
  87
  88     return qiv->errname->str;
  89 }
  90
  91 static const char *full_name(QObjectInputVisitor *qiv, const char *name)
  92 {
  93     return full_name_nth(qiv, name, 0);
  94 }
  95
  96 static QObject *qobject_input_try_get_object(QObjectInputVisitor *qiv,
  97                                              const char *name,
  98                                              bool consume)
  99 {
 100     StackObject *tos;
 101     QObject *qobj;
 102     QObject *ret;
 103
 104     if (QSLIST_EMPTY(&qiv->stack)) {
 105         /* Starting at root, name is ignored. */
 106         assert(qiv->root);
 107         return qiv->root;
 108     }
 109
 110     /* We are in a container; find the next element. */
 111     tos = QSLIST_FIRST(&qiv->stack);
 112     qobj = tos->obj;
 113     assert(qobj);
 114
 115     if (qobject_type(qobj) == QTYPE_QDICT) {
 116         assert(name);
 117         ret = qdict_get(qobject_to_qdict(qobj), name);
 118         if (tos->h && consume && ret) {
 119             bool removed = g_hash_table_remove(tos->h, name);
 120             assert(removed);
 121         }
 122     } else {
 123         assert(qobject_type(qobj) == QTYPE_QLIST);
 124         assert(!name);
 125         if (tos->entry) {
 126             ret = qlist_entry_obj(tos->entry);
 127             if (consume) {
 128                 tos->entry = qlist_next(tos->entry);
 129             }
 130         } else {
 131             ret = NULL;
 132         }
 133         if (consume) {
 134             tos->index++;
 135         }
 136     }
 137
 138     return ret;
 139 }
 140
 141 static QObject *qobject_input_get_object(QObjectInputVisitor *qiv,
 142                                          const char *name,
 143                                          bool consume, Error **errp)
 144 {
 145     QObject *obj = qobject_input_try_get_object(qiv, name, consume);
 146
 147     if (!obj) {
 148         error_setg(errp, QERR_MISSING_PARAMETER, full_name(qiv, name));
 149     }
 150     return obj;
 151 }
 152
 153 static void qdict_add_key(const char *key, QObject *obj, void *opaque)
 154 {
 155     GHashTable *h = opaque;
 156     g_hash_table_insert(h, (gpointer) key, NULL);
 157 }
 158
 159 static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
 160                                             const char *name,
 161                                             QObject *obj, void *qapi)
 162 {
 163     GHashTable *h;
 164     StackObject *tos = g_new0(StackObject, 1);
 165
 166     assert(obj);
 167     tos->name = name;
 168     tos->obj = obj;
 169     tos->qapi = qapi;
 170
 171     if (qobject_type(obj) == QTYPE_QDICT) {
 172         h = g_hash_table_new(g_str_hash, g_str_equal);
 173         qdict_iter(qobject_to_qdict(obj), qdict_add_key, h);
 174         tos->h = h;
 175     } else {
 176         assert(qobject_type(obj) == QTYPE_QLIST);
 177         tos->entry = qlist_first(qobject_to_qlist(obj));
 178         tos->index = -1;
 179     }
 180
 181     QSLIST_INSERT_HEAD(&qiv->stack, tos, node);
 182     return tos->entry;
 183 }
 184
 185
 186 static void qobject_input_check_struct(Visitor *v, Error **errp)
 187 {
 188     QObjectInputVisitor *qiv = to_qiv(v);
 189     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 190     GHashTableIter iter;
 191     const char *key;
 192
 193     assert(tos && !tos->entry);
 194
 195     g_hash_table_iter_init(&iter, tos->h);
 196     if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
 197         error_setg(errp, "Parameter '%s' is unexpected",
 198                    full_name(qiv, key));
 199     }
 200 }
 201
 202 static void qobject_input_stack_object_free(StackObject *tos)
 203 {
 204     if (tos->h) {
 205         g_hash_table_unref(tos->h);
 206     }
 207
 208     g_free(tos);
 209 }
 210
 211 static void qobject_input_pop(Visitor *v, void **obj)
 212 {
 213     QObjectInputVisitor *qiv = to_qiv(v);
 214     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 215
 216     assert(tos && tos->qapi == obj);
 217     QSLIST_REMOVE_HEAD(&qiv->stack, node);
 218     qobject_input_stack_object_free(tos);
 219 }
 220
 221 static void qobject_input_start_struct(Visitor *v, const char *name, void **obj,
 222                                        size_t size, Error **errp)
 223 {
 224     QObjectInputVisitor *qiv = to_qiv(v);
 225     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 226
 227     if (obj) {
 228         *obj = NULL;
 229     }
 230     if (!qobj) {
 231         return;
 232     }
 233     if (qobject_type(qobj) != QTYPE_QDICT) {
 234         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 235                    full_name(qiv, name), "object");
 236         return;
 237     }
 238
 239     qobject_input_push(qiv, name, qobj, obj);
 240
 241     if (obj) {
 242         *obj = g_malloc0(size);
 243     }
 244 }
 245
 246
 247 static void qobject_input_start_list(Visitor *v, const char *name,
 248                                      GenericList **list, size_t size,
 249                                      Error **errp)
 250 {
 251     QObjectInputVisitor *qiv = to_qiv(v);
 252     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 253     const QListEntry *entry;
 254
 255     if (list) {
 256         *list = NULL;
 257     }
 258     if (!qobj) {
 259         return;
 260     }
 261     if (qobject_type(qobj) != QTYPE_QLIST) {
 262         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 263                    full_name(qiv, name), "array");
 264         return;
 265     }
 266
 267     entry = qobject_input_push(qiv, name, qobj, list);
 268     if (entry && list) {
 269         *list = g_malloc0(size);
 270     }
 271 }
 272
 273 static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
 274                                             size_t size)
 275 {
 276     QObjectInputVisitor *qiv = to_qiv(v);
 277     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 278
 279     assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
 280
 281     if (!tos->entry) {
 282         return NULL;
 283     }
 284     tail->next = g_malloc0(size);
 285     return tail->next;
 286 }
 287
 288 static void qobject_input_check_list(Visitor *v, Error **errp)
 289 {
 290     QObjectInputVisitor *qiv = to_qiv(v);
 291     StackObject *tos = QSLIST_FIRST(&qiv->stack);
 292
 293     assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
 294
 295     if (tos->entry) {
 296         error_setg(errp, "Only %u list elements expected in %s",
 297                    tos->index + 1, full_name_nth(qiv, NULL, 1));
 298     }
 299 }
 300
 301
 302 static void qobject_input_start_alternate(Visitor *v, const char *name,
 303                                           GenericAlternate **obj, size_t size,
 304                                           bool promote_int, Error **errp)
 305 {
 306     QObjectInputVisitor *qiv = to_qiv(v);
 307     QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
 308
 309     if (!qobj) {
 310         *obj = NULL;
 311         return;
 312     }
 313     *obj = g_malloc0(size);
 314     (*obj)->type = qobject_type(qobj);
 315     if (promote_int && (*obj)->type == QTYPE_QINT) {
 316         (*obj)->type = QTYPE_QFLOAT;
 317     }
 318 }
 319
 320 static void qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
 321                                      Error **errp)
 322 {
 323     QObjectInputVisitor *qiv = to_qiv(v);
 324     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 325     QInt *qint;
 326
 327     if (!qobj) {
 328         return;
 329     }
 330     qint = qobject_to_qint(qobj);
 331     if (!qint) {
 332         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 333                    full_name(qiv, name), "integer");
 334         return;
 335     }
 336
 337     *obj = qint_get_int(qint);
 338 }
 339
 340 static void qobject_input_type_uint64(Visitor *v, const char *name,
 341                                       uint64_t *obj, Error **errp)
 342 {
 343     /* FIXME: qobject_to_qint mishandles values over INT64_MAX */
 344     QObjectInputVisitor *qiv = to_qiv(v);
 345     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 346     QInt *qint;
 347
 348     if (!qobj) {
 349         return;
 350     }
 351     qint = qobject_to_qint(qobj);
 352     if (!qint) {
 353         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 354                    full_name(qiv, name), "integer");
 355         return;
 356     }
 357
 358     *obj = qint_get_int(qint);
 359 }
 360
 361 static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
 362                                     Error **errp)
 363 {
 364     QObjectInputVisitor *qiv = to_qiv(v);
 365     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 366     QBool *qbool;
 367
 368     if (!qobj) {
 369         return;
 370     }
 371     qbool = qobject_to_qbool(qobj);
 372     if (!qbool) {
 373         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 374                    full_name(qiv, name), "boolean");
 375         return;
 376     }
 377
 378     *obj = qbool_get_bool(qbool);
 379 }
 380
 381 static void qobject_input_type_str(Visitor *v, const char *name, char **obj,
 382                                    Error **errp)
 383 {
 384     QObjectInputVisitor *qiv = to_qiv(v);
 385     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 386     QString *qstr;
 387
 388     *obj = NULL;
 389     if (!qobj) {
 390         return;
 391     }
 392     qstr = qobject_to_qstring(qobj);
 393     if (!qstr) {
 394         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 395                    full_name(qiv, name), "string");
 396         return;
 397     }
 398
 399     *obj = g_strdup(qstring_get_str(qstr));
 400 }
 401
 402 static void qobject_input_type_number(Visitor *v, const char *name, double *obj,
 403                                       Error **errp)
 404 {
 405     QObjectInputVisitor *qiv = to_qiv(v);
 406     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 407     QInt *qint;
 408     QFloat *qfloat;
 409
 410     if (!qobj) {
 411         return;
 412     }
 413     qint = qobject_to_qint(qobj);
 414     if (qint) {
 415         *obj = qint_get_int(qobject_to_qint(qobj));
 416         return;
 417     }
 418
 419     qfloat = qobject_to_qfloat(qobj);
 420     if (qfloat) {
 421         *obj = qfloat_get_double(qobject_to_qfloat(qobj));
 422         return;
 423     }
 424
 425     error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 426                full_name(qiv, name), "number");
 427 }
 428
 429 static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
 430                                    Error **errp)
 431 {
 432     QObjectInputVisitor *qiv = to_qiv(v);
 433     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 434
 435     *obj = NULL;
 436     if (!qobj) {
 437         return;
 438     }
 439
 440     qobject_incref(qobj);
 441     *obj = qobj;
 442 }
 443
 444 static void qobject_input_type_null(Visitor *v, const char *name, Error **errp)
 445 {
 446     QObjectInputVisitor *qiv = to_qiv(v);
 447     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
 448
 449     if (!qobj) {
 450         return;
 451     }
 452
 453     if (qobject_type(qobj) != QTYPE_QNULL) {
 454         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
 455                    full_name(qiv, name), "null");
 456     }
 457 }
 458
 459 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
 460 {
 461     QObjectInputVisitor *qiv = to_qiv(v);
 462     QObject *qobj = qobject_input_try_get_object(qiv, name, false);
 463
 464     if (!qobj) {
 465         *present = false;
 466         return;
 467     }
 468
 469     *present = true;
 470 }
 471
 472 static void qobject_input_free(Visitor *v)
 473 {
 474     QObjectInputVisitor *qiv = to_qiv(v);
 475
 476     while (!QSLIST_EMPTY(&qiv->stack)) {
 477         StackObject *tos = QSLIST_FIRST(&qiv->stack);
 478
 479         QSLIST_REMOVE_HEAD(&qiv->stack, node);
 480         qobject_input_stack_object_free(tos);
 481     }
 482
 483     qobject_decref(qiv->root);
 484     if (qiv->errname) {
 485         g_string_free(qiv->errname, TRUE);
 486     }
 487     g_free(qiv);
 488 }
 489
 490 Visitor *qobject_input_visitor_new(QObject *obj)
 491 {
 492     QObjectInputVisitor *v;
 493
 494     assert(obj);
 495     v = g_malloc0(sizeof(*v));
 496
 497     v->visitor.type = VISITOR_INPUT;
 498     v->visitor.start_struct = qobject_input_start_struct;
 499     v->visitor.check_struct = qobject_input_check_struct;
 500     v->visitor.end_struct = qobject_input_pop;
 501     v->visitor.start_list = qobject_input_start_list;
 502     v->visitor.next_list = qobject_input_next_list;
 503     v->visitor.check_list = qobject_input_check_list;
 504     v->visitor.end_list = qobject_input_pop;
 505     v->visitor.start_alternate = qobject_input_start_alternate;
 506     v->visitor.type_int64 = qobject_input_type_int64;
 507     v->visitor.type_uint64 = qobject_input_type_uint64;
 508     v->visitor.type_bool = qobject_input_type_bool;
 509     v->visitor.type_str = qobject_input_type_str;
 510     v->visitor.type_number = qobject_input_type_number;
 511     v->visitor.type_any = qobject_input_type_any;
 512     v->visitor.type_null = qobject_input_type_null;
 513     v->visitor.optional = qobject_input_optional;
 514     v->visitor.free = qobject_input_free;
 515
 516     v->root = obj;
 517     qobject_incref(obj);
 518
 519     return &v->visitor;
 520 }