qapi/qapi-visit-core.c

   1 /*
   2  * Core Definitions for QAPI Visitor Classes
   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/qerror.h"
  18 #include "qapi/visitor.h"
  19 #include "qapi/visitor-impl.h"
  20 #include "trace.h"
  21
  22 /* Zero-initialization must result in default policy */
  23 QEMU_BUILD_BUG_ON(COMPAT_POLICY_INPUT_ACCEPT || COMPAT_POLICY_OUTPUT_ACCEPT);
  24
  25
  26 void visit_complete(Visitor *v, void *opaque)
  27 {
  28     assert(v->type != VISITOR_OUTPUT || v->complete);
  29     trace_visit_complete(v, opaque);
  30     if (v->complete) {
  31         v->complete(v, opaque);
  32     }
  33 }
  34
  35 void visit_free(Visitor *v)
  36 {
  37     trace_visit_free(v);
  38     if (v) {
  39         v->free(v);
  40     }
  41 }
  42
  43 bool visit_start_struct(Visitor *v, const char *name, void **obj,
  44                         size_t size, Error **errp)
  45 {
  46     bool ok;
  47
  48     trace_visit_start_struct(v, name, obj, size);
  49     if (obj) {
  50         assert(size);
  51         assert(!(v->type & VISITOR_OUTPUT) || *obj);
  52     }
  53     ok = v->start_struct(v, name, obj, size, errp);
  54     if (obj && (v->type & VISITOR_INPUT)) {
  55         assert(ok != !*obj);
  56     }
  57     return ok;
  58 }
  59
  60 bool visit_check_struct(Visitor *v, Error **errp)
  61 {
  62     trace_visit_check_struct(v);
  63     return v->check_struct ? v->check_struct(v, errp) : true;
  64 }
  65
  66 void visit_end_struct(Visitor *v, void **obj)
  67 {
  68     trace_visit_end_struct(v, obj);
  69     v->end_struct(v, obj);
  70 }
  71
  72 bool visit_start_list(Visitor *v, const char *name, GenericList **list,
  73                       size_t size, Error **errp)
  74 {
  75     bool ok;
  76
  77     assert(!list || size >= sizeof(GenericList));
  78     trace_visit_start_list(v, name, list, size);
  79     ok = v->start_list(v, name, list, size, errp);
  80     if (list && (v->type & VISITOR_INPUT)) {
  81         assert(ok || !*list);
  82     }
  83     return ok;
  84 }
  85
  86 GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size)
  87 {
  88     assert(tail && size >= sizeof(GenericList));
  89     trace_visit_next_list(v, tail, size);
  90     return v->next_list(v, tail, size);
  91 }
  92
  93 bool visit_check_list(Visitor *v, Error **errp)
  94 {
  95     trace_visit_check_list(v);
  96     return v->check_list ? v->check_list(v, errp) : true;
  97 }
  98
  99 void visit_end_list(Visitor *v, void **obj)
 100 {
 101     trace_visit_end_list(v, obj);
 102     v->end_list(v, obj);
 103 }
 104
 105 bool visit_start_alternate(Visitor *v, const char *name,
 106                            GenericAlternate **obj, size_t size,
 107                            Error **errp)
 108 {
 109     bool ok;
 110
 111     assert(obj && size >= sizeof(GenericAlternate));
 112     assert(!(v->type & VISITOR_OUTPUT) || *obj);
 113     trace_visit_start_alternate(v, name, obj, size);
 114     if (!v->start_alternate) {
 115         assert(!(v->type & VISITOR_INPUT));
 116         return true;
 117     }
 118     ok = v->start_alternate(v, name, obj, size, errp);
 119     if (v->type & VISITOR_INPUT) {
 120         assert(ok != !*obj);
 121     }
 122     return ok;
 123 }
 124
 125 void visit_end_alternate(Visitor *v, void **obj)
 126 {
 127     trace_visit_end_alternate(v, obj);
 128     if (v->end_alternate) {
 129         v->end_alternate(v, obj);
 130     }
 131 }
 132
 133 bool visit_optional(Visitor *v, const char *name, bool *present)
 134 {
 135     trace_visit_optional(v, name, present);
 136     if (v->optional) {
 137         v->optional(v, name, present);
 138     }
 139     return *present;
 140 }
 141
 142 bool visit_policy_reject(Visitor *v, const char *name,
 143                          unsigned special_features, Error **errp)
 144 {
 145     trace_visit_policy_reject(v, name);
 146     if (v->policy_reject) {
 147         return v->policy_reject(v, name, special_features, errp);
 148     }
 149     return false;
 150 }
 151
 152 bool visit_policy_skip(Visitor *v, const char *name,
 153                        unsigned special_features)
 154 {
 155     trace_visit_policy_skip(v, name);
 156     if (v->policy_skip) {
 157         return v->policy_skip(v, name, special_features);
 158     }
 159     return false;
 160 }
 161
 162 void visit_set_policy(Visitor *v, CompatPolicy *policy)
 163 {
 164     v->compat_policy = *policy;
 165 }
 166
 167 bool visit_is_input(Visitor *v)
 168 {
 169     return v->type == VISITOR_INPUT;
 170 }
 171
 172 bool visit_is_dealloc(Visitor *v)
 173 {
 174     return v->type == VISITOR_DEALLOC;
 175 }
 176
 177 bool visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp)
 178 {
 179     assert(obj);
 180     trace_visit_type_int(v, name, obj);
 181     return v->type_int64(v, name, obj, errp);
 182 }
 183
 184 static bool visit_type_uintN(Visitor *v, uint64_t *obj, const char *name,
 185                              uint64_t max, const char *type, Error **errp)
 186 {
 187     uint64_t value = *obj;
 188
 189     assert(v->type == VISITOR_INPUT || value <= max);
 190
 191     if (!v->type_uint64(v, name, &value, errp)) {
 192         return false;
 193     }
 194     if (value > max) {
 195         assert(v->type == VISITOR_INPUT);
 196         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 197                    name ? name : "null", type);
 198         return false;
 199     }
 200     *obj = value;
 201     return true;
 202 }
 203
 204 bool visit_type_uint8(Visitor *v, const char *name, uint8_t *obj,
 205                       Error **errp)
 206 {
 207     uint64_t value;
 208     bool ok;
 209
 210     trace_visit_type_uint8(v, name, obj);
 211     value = *obj;
 212     ok = visit_type_uintN(v, &value, name, UINT8_MAX, "uint8_t", errp);
 213     *obj = value;
 214     return ok;
 215 }
 216
 217 bool visit_type_uint16(Visitor *v, const char *name, uint16_t *obj,
 218                        Error **errp)
 219 {
 220     uint64_t value;
 221     bool ok;
 222
 223     trace_visit_type_uint16(v, name, obj);
 224     value = *obj;
 225     ok = visit_type_uintN(v, &value, name, UINT16_MAX, "uint16_t", errp);
 226     *obj = value;
 227     return ok;
 228 }
 229
 230 bool visit_type_uint32(Visitor *v, const char *name, uint32_t *obj,
 231                        Error **errp)
 232 {
 233     uint64_t value;
 234     bool ok;
 235
 236     trace_visit_type_uint32(v, name, obj);
 237     value = *obj;
 238     ok = visit_type_uintN(v, &value, name, UINT32_MAX, "uint32_t", errp);
 239     *obj = value;
 240     return ok;
 241 }
 242
 243 bool visit_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 244                        Error **errp)
 245 {
 246     assert(obj);
 247     trace_visit_type_uint64(v, name, obj);
 248     return v->type_uint64(v, name, obj, errp);
 249 }
 250
 251 static bool visit_type_intN(Visitor *v, int64_t *obj, const char *name,
 252                             int64_t min, int64_t max, const char *type,
 253                             Error **errp)
 254 {
 255     int64_t value = *obj;
 256
 257     assert(v->type == VISITOR_INPUT || (value >= min && value <= max));
 258
 259     if (!v->type_int64(v, name, &value, errp)) {
 260         return false;
 261     }
 262     if (value < min || value > max) {
 263         assert(v->type == VISITOR_INPUT);
 264         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 265                    name ? name : "null", type);
 266         return false;
 267     }
 268     *obj = value;
 269     return true;
 270 }
 271
 272 bool visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp)
 273 {
 274     int64_t value;
 275     bool ok;
 276
 277     trace_visit_type_int8(v, name, obj);
 278     value = *obj;
 279     ok = visit_type_intN(v, &value, name, INT8_MIN, INT8_MAX, "int8_t", errp);
 280     *obj = value;
 281     return ok;
 282 }
 283
 284 bool visit_type_int16(Visitor *v, const char *name, int16_t *obj,
 285                       Error **errp)
 286 {
 287     int64_t value;
 288     bool ok;
 289
 290     trace_visit_type_int16(v, name, obj);
 291     value = *obj;
 292     ok = visit_type_intN(v, &value, name, INT16_MIN, INT16_MAX, "int16_t",
 293                          errp);
 294     *obj = value;
 295     return ok;
 296 }
 297
 298 bool visit_type_int32(Visitor *v, const char *name, int32_t *obj,
 299                       Error **errp)
 300 {
 301     int64_t value;
 302     bool ok;
 303
 304     trace_visit_type_int32(v, name, obj);
 305     value = *obj;
 306     ok = visit_type_intN(v, &value, name, INT32_MIN, INT32_MAX, "int32_t",
 307                         errp);
 308     *obj = value;
 309     return ok;
 310 }
 311
 312 bool visit_type_int64(Visitor *v, const char *name, int64_t *obj,
 313                       Error **errp)
 314 {
 315     assert(obj);
 316     trace_visit_type_int64(v, name, obj);
 317     return v->type_int64(v, name, obj, errp);
 318 }
 319
 320 bool visit_type_size(Visitor *v, const char *name, uint64_t *obj,
 321                      Error **errp)
 322 {
 323     assert(obj);
 324     trace_visit_type_size(v, name, obj);
 325     if (v->type_size) {
 326         return v->type_size(v, name, obj, errp);
 327     }
 328     return v->type_uint64(v, name, obj, errp);
 329 }
 330
 331 bool visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
 332 {
 333     assert(obj);
 334     trace_visit_type_bool(v, name, obj);
 335     return v->type_bool(v, name, obj, errp);
 336 }
 337
 338 bool visit_type_str(Visitor *v, const char *name, char **obj, Error **errp)
 339 {
 340     bool ok;
 341
 342     assert(obj);
 343     /* TODO: Fix callers to not pass NULL when they mean "", so that we
 344      * can enable:
 345     assert(!(v->type & VISITOR_OUTPUT) || *obj);
 346      */
 347     trace_visit_type_str(v, name, obj);
 348     ok = v->type_str(v, name, obj, errp);
 349     if (v->type & VISITOR_INPUT) {
 350         assert(ok != !*obj);
 351     }
 352     return ok;
 353 }
 354
 355 bool visit_type_number(Visitor *v, const char *name, double *obj,
 356                        Error **errp)
 357 {
 358     assert(obj);
 359     trace_visit_type_number(v, name, obj);
 360     return v->type_number(v, name, obj, errp);
 361 }
 362
 363 bool visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp)
 364 {
 365     bool ok;
 366
 367     assert(obj);
 368     assert(v->type != VISITOR_OUTPUT || *obj);
 369     trace_visit_type_any(v, name, obj);
 370     ok = v->type_any(v, name, obj, errp);
 371     if (v->type == VISITOR_INPUT) {
 372         assert(ok != !*obj);
 373     }
 374     return ok;
 375 }
 376
 377 bool visit_type_null(Visitor *v, const char *name, QNull **obj,
 378                      Error **errp)
 379 {
 380     trace_visit_type_null(v, name, obj);
 381     return v->type_null(v, name, obj, errp);
 382 }
 383
 384 static bool output_type_enum(Visitor *v, const char *name, int *obj,
 385                              const QEnumLookup *lookup, Error **errp)
 386 {
 387     int value = *obj;
 388     char *enum_str;
 389
 390     enum_str = (char *)qapi_enum_lookup(lookup, value);
 391     return visit_type_str(v, name, &enum_str, errp);
 392 }
 393
 394 static bool input_type_enum(Visitor *v, const char *name, int *obj,
 395                             const QEnumLookup *lookup, Error **errp)
 396 {
 397     int64_t value;
 398     g_autofree char *enum_str = NULL;
 399
 400     if (!visit_type_str(v, name, &enum_str, errp)) {
 401         return false;
 402     }
 403
 404     value = qapi_enum_parse(lookup, enum_str, -1, NULL);
 405     if (value < 0) {
 406         error_setg(errp, "Parameter '%s' does not accept value '%s'",
 407                    name ? name : "null", enum_str);
 408         return false;
 409     }
 410
 411     if (lookup->special_features
 412         && (lookup->special_features[value] & QAPI_DEPRECATED)) {
 413         switch (v->compat_policy.deprecated_input) {
 414         case COMPAT_POLICY_INPUT_ACCEPT:
 415             break;
 416         case COMPAT_POLICY_INPUT_REJECT:
 417             error_setg(errp, "Deprecated value '%s' disabled by policy",
 418                        enum_str);
 419             return false;
 420         case COMPAT_POLICY_INPUT_CRASH:
 421         default:
 422             abort();
 423         }
 424     }
 425
 426     *obj = value;
 427     return true;
 428 }
 429
 430 bool visit_type_enum(Visitor *v, const char *name, int *obj,
 431                      const QEnumLookup *lookup, Error **errp)
 432 {
 433     assert(obj && lookup);
 434     trace_visit_type_enum(v, name, obj);
 435     switch (v->type) {
 436     case VISITOR_INPUT:
 437         return input_type_enum(v, name, obj, lookup, errp);
 438     case VISITOR_OUTPUT:
 439         return output_type_enum(v, name, obj, lookup, errp);
 440     case VISITOR_CLONE:
 441         /* nothing further to do, scalar value was already copied by
 442          * g_memdup() during visit_start_*() */
 443         return true;
 444     case VISITOR_DEALLOC:
 445         /* nothing to deallocate for a scalar */
 446         return true;
 447     default:
 448         abort();
 449     }
 450 }