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