qapi/qmp-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   <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/qmp-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 #define QIV_STACK_SIZE 1024
  25
  26 typedef struct StackObject
  27 {
  28     QObject *obj; /* Object being visited */
  29
  30     GHashTable *h;           /* If obj is dict: unvisited keys */
  31     const QListEntry *entry; /* If obj is list: unvisited tail */
  32 } StackObject;
  33
  34 struct QmpInputVisitor
  35 {
  36     Visitor visitor;
  37
  38     /* Root of visit at visitor creation. */
  39     QObject *root;
  40
  41     /* Stack of objects being visited (all entries will be either
  42      * QDict or QList). */
  43     StackObject stack[QIV_STACK_SIZE];
  44     int nb_stack;
  45
  46     /* True to reject parse in visit_end_struct() if unvisited keys remain. */
  47     bool strict;
  48 };
  49
  50 static QmpInputVisitor *to_qiv(Visitor *v)
  51 {
  52     return container_of(v, QmpInputVisitor, visitor);
  53 }
  54
  55 static QObject *qmp_input_get_object(QmpInputVisitor *qiv,
  56                                      const char *name,
  57                                      bool consume)
  58 {
  59     StackObject *tos;
  60     QObject *qobj;
  61     QObject *ret;
  62
  63     if (!qiv->nb_stack) {
  64         /* Starting at root, name is ignored. */
  65         return qiv->root;
  66     }
  67
  68     /* We are in a container; find the next element. */
  69     tos = &qiv->stack[qiv->nb_stack - 1];
  70     qobj = tos->obj;
  71     assert(qobj);
  72
  73     if (qobject_type(qobj) == QTYPE_QDICT) {
  74         assert(name);
  75         ret = qdict_get(qobject_to_qdict(qobj), name);
  76         if (tos->h && consume && ret) {
  77             bool removed = g_hash_table_remove(tos->h, name);
  78             assert(removed);
  79         }
  80     } else {
  81         assert(qobject_type(qobj) == QTYPE_QLIST);
  82         assert(!name);
  83         ret = qlist_entry_obj(tos->entry);
  84         if (consume) {
  85             tos->entry = qlist_next(tos->entry);
  86         }
  87     }
  88
  89     return ret;
  90 }
  91
  92 static void qdict_add_key(const char *key, QObject *obj, void *opaque)
  93 {
  94     GHashTable *h = opaque;
  95     g_hash_table_insert(h, (gpointer) key, NULL);
  96 }
  97
  98 static const QListEntry *qmp_input_push(QmpInputVisitor *qiv, QObject *obj,
  99                                         Error **errp)
 100 {
 101     GHashTable *h;
 102     StackObject *tos = &qiv->stack[qiv->nb_stack];
 103
 104     assert(obj);
 105     if (qiv->nb_stack >= QIV_STACK_SIZE) {
 106         error_setg(errp, "An internal buffer overran");
 107         return NULL;
 108     }
 109
 110     tos->obj = obj;
 111     assert(!tos->h);
 112     assert(!tos->entry);
 113
 114     if (qiv->strict && qobject_type(obj) == QTYPE_QDICT) {
 115         h = g_hash_table_new(g_str_hash, g_str_equal);
 116         qdict_iter(qobject_to_qdict(obj), qdict_add_key, h);
 117         tos->h = h;
 118     } else if (qobject_type(obj) == QTYPE_QLIST) {
 119         tos->entry = qlist_first(qobject_to_qlist(obj));
 120     }
 121
 122     qiv->nb_stack++;
 123     return tos->entry;
 124 }
 125
 126
 127 static void qmp_input_check_struct(Visitor *v, Error **errp)
 128 {
 129     QmpInputVisitor *qiv = to_qiv(v);
 130     StackObject *tos = &qiv->stack[qiv->nb_stack - 1];
 131
 132     assert(qiv->nb_stack > 0);
 133
 134     if (qiv->strict) {
 135         GHashTable *const top_ht = tos->h;
 136         if (top_ht) {
 137             GHashTableIter iter;
 138             const char *key;
 139
 140             g_hash_table_iter_init(&iter, top_ht);
 141             if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
 142                 error_setg(errp, QERR_QMP_EXTRA_MEMBER, key);
 143             }
 144         }
 145     }
 146 }
 147
 148 static void qmp_input_pop(Visitor *v)
 149 {
 150     QmpInputVisitor *qiv = to_qiv(v);
 151     StackObject *tos = &qiv->stack[qiv->nb_stack - 1];
 152
 153     assert(qiv->nb_stack > 0);
 154
 155     if (qiv->strict) {
 156         GHashTable * const top_ht = qiv->stack[qiv->nb_stack - 1].h;
 157         if (top_ht) {
 158             g_hash_table_unref(top_ht);
 159         }
 160         tos->h = NULL;
 161     }
 162
 163     qiv->nb_stack--;
 164 }
 165
 166 static void qmp_input_start_struct(Visitor *v, const char *name, void **obj,
 167                                    size_t size, Error **errp)
 168 {
 169     QmpInputVisitor *qiv = to_qiv(v);
 170     QObject *qobj = qmp_input_get_object(qiv, name, true);
 171     Error *err = NULL;
 172
 173     if (obj) {
 174         *obj = NULL;
 175     }
 176     if (!qobj || qobject_type(qobj) != QTYPE_QDICT) {
 177         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 178                    "QDict");
 179         return;
 180     }
 181
 182     qmp_input_push(qiv, qobj, &err);
 183     if (err) {
 184         error_propagate(errp, err);
 185         return;
 186     }
 187
 188     if (obj) {
 189         *obj = g_malloc0(size);
 190     }
 191 }
 192
 193
 194 static void qmp_input_start_list(Visitor *v, const char *name,
 195                                  GenericList **list, size_t size, Error **errp)
 196 {
 197     QmpInputVisitor *qiv = to_qiv(v);
 198     QObject *qobj = qmp_input_get_object(qiv, name, true);
 199     const QListEntry *entry;
 200
 201     if (!qobj || qobject_type(qobj) != QTYPE_QLIST) {
 202         if (list) {
 203             *list = NULL;
 204         }
 205         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 206                    "list");
 207         return;
 208     }
 209
 210     entry = qmp_input_push(qiv, qobj, errp);
 211     if (list) {
 212         if (entry) {
 213             *list = g_malloc0(size);
 214         } else {
 215             *list = NULL;
 216         }
 217     }
 218 }
 219
 220 static GenericList *qmp_input_next_list(Visitor *v, GenericList *tail,
 221                                         size_t size)
 222 {
 223     QmpInputVisitor *qiv = to_qiv(v);
 224     StackObject *so = &qiv->stack[qiv->nb_stack - 1];
 225
 226     if (!so->entry) {
 227         return NULL;
 228     }
 229     tail->next = g_malloc0(size);
 230     return tail->next;
 231 }
 232
 233
 234 static void qmp_input_start_alternate(Visitor *v, const char *name,
 235                                       GenericAlternate **obj, size_t size,
 236                                       bool promote_int, Error **errp)
 237 {
 238     QmpInputVisitor *qiv = to_qiv(v);
 239     QObject *qobj = qmp_input_get_object(qiv, name, false);
 240
 241     if (!qobj) {
 242         *obj = NULL;
 243         error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
 244         return;
 245     }
 246     *obj = g_malloc0(size);
 247     (*obj)->type = qobject_type(qobj);
 248     if (promote_int && (*obj)->type == QTYPE_QINT) {
 249         (*obj)->type = QTYPE_QFLOAT;
 250     }
 251 }
 252
 253 static void qmp_input_type_int64(Visitor *v, const char *name, int64_t *obj,
 254                                  Error **errp)
 255 {
 256     QmpInputVisitor *qiv = to_qiv(v);
 257     QInt *qint = qobject_to_qint(qmp_input_get_object(qiv, name, true));
 258
 259     if (!qint) {
 260         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 261                    "integer");
 262         return;
 263     }
 264
 265     *obj = qint_get_int(qint);
 266 }
 267
 268 static void qmp_input_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 269                                   Error **errp)
 270 {
 271     /* FIXME: qobject_to_qint mishandles values over INT64_MAX */
 272     QmpInputVisitor *qiv = to_qiv(v);
 273     QInt *qint = qobject_to_qint(qmp_input_get_object(qiv, name, true));
 274
 275     if (!qint) {
 276         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 277                    "integer");
 278         return;
 279     }
 280
 281     *obj = qint_get_int(qint);
 282 }
 283
 284 static void qmp_input_type_bool(Visitor *v, const char *name, bool *obj,
 285                                 Error **errp)
 286 {
 287     QmpInputVisitor *qiv = to_qiv(v);
 288     QBool *qbool = qobject_to_qbool(qmp_input_get_object(qiv, name, true));
 289
 290     if (!qbool) {
 291         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 292                    "boolean");
 293         return;
 294     }
 295
 296     *obj = qbool_get_bool(qbool);
 297 }
 298
 299 static void qmp_input_type_str(Visitor *v, const char *name, char **obj,
 300                                Error **errp)
 301 {
 302     QmpInputVisitor *qiv = to_qiv(v);
 303     QString *qstr = qobject_to_qstring(qmp_input_get_object(qiv, name, true));
 304
 305     if (!qstr) {
 306         *obj = NULL;
 307         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 308                    "string");
 309         return;
 310     }
 311
 312     *obj = g_strdup(qstring_get_str(qstr));
 313 }
 314
 315 static void qmp_input_type_number(Visitor *v, const char *name, double *obj,
 316                                   Error **errp)
 317 {
 318     QmpInputVisitor *qiv = to_qiv(v);
 319     QObject *qobj = qmp_input_get_object(qiv, name, true);
 320     QInt *qint;
 321     QFloat *qfloat;
 322
 323     qint = qobject_to_qint(qobj);
 324     if (qint) {
 325         *obj = qint_get_int(qobject_to_qint(qobj));
 326         return;
 327     }
 328
 329     qfloat = qobject_to_qfloat(qobj);
 330     if (qfloat) {
 331         *obj = qfloat_get_double(qobject_to_qfloat(qobj));
 332         return;
 333     }
 334
 335     error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 336                "number");
 337 }
 338
 339 static void qmp_input_type_any(Visitor *v, const char *name, QObject **obj,
 340                                Error **errp)
 341 {
 342     QmpInputVisitor *qiv = to_qiv(v);
 343     QObject *qobj = qmp_input_get_object(qiv, name, true);
 344
 345     qobject_incref(qobj);
 346     *obj = qobj;
 347 }
 348
 349 static void qmp_input_type_null(Visitor *v, const char *name, Error **errp)
 350 {
 351     QmpInputVisitor *qiv = to_qiv(v);
 352     QObject *qobj = qmp_input_get_object(qiv, name, true);
 353
 354     if (qobject_type(qobj) != QTYPE_QNULL) {
 355         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
 356                    "null");
 357     }
 358 }
 359
 360 static void qmp_input_optional(Visitor *v, const char *name, bool *present)
 361 {
 362     QmpInputVisitor *qiv = to_qiv(v);
 363     QObject *qobj = qmp_input_get_object(qiv, name, false);
 364
 365     if (!qobj) {
 366         *present = false;
 367         return;
 368     }
 369
 370     *present = true;
 371 }
 372
 373 Visitor *qmp_input_get_visitor(QmpInputVisitor *v)
 374 {
 375     return &v->visitor;
 376 }
 377
 378 void qmp_input_visitor_cleanup(QmpInputVisitor *v)
 379 {
 380     qobject_decref(v->root);
 381     g_free(v);
 382 }
 383
 384 QmpInputVisitor *qmp_input_visitor_new(QObject *obj, bool strict)
 385 {
 386     QmpInputVisitor *v;
 387
 388     v = g_malloc0(sizeof(*v));
 389
 390     v->visitor.type = VISITOR_INPUT;
 391     v->visitor.start_struct = qmp_input_start_struct;
 392     v->visitor.check_struct = qmp_input_check_struct;
 393     v->visitor.end_struct = qmp_input_pop;
 394     v->visitor.start_list = qmp_input_start_list;
 395     v->visitor.next_list = qmp_input_next_list;
 396     v->visitor.end_list = qmp_input_pop;
 397     v->visitor.start_alternate = qmp_input_start_alternate;
 398     v->visitor.type_int64 = qmp_input_type_int64;
 399     v->visitor.type_uint64 = qmp_input_type_uint64;
 400     v->visitor.type_bool = qmp_input_type_bool;
 401     v->visitor.type_str = qmp_input_type_str;
 402     v->visitor.type_number = qmp_input_type_number;
 403     v->visitor.type_any = qmp_input_type_any;
 404     v->visitor.type_null = qmp_input_type_null;
 405     v->visitor.optional = qmp_input_optional;
 406     v->strict = strict;
 407
 408     v->root = obj;
 409     qobject_incref(obj);
 410
 411     return v;
 412 }