qapi/opts-visitor.c

   1 /*
   2  * Options Visitor
   3  *
   4  * Copyright Red Hat, Inc. 2012-2016
   5  *
   6  * Author: Laszlo Ersek <lersek@redhat.com>
   7  *
   8  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
   9  * See the COPYING.LIB file in the top-level directory.
  10  *
  11  */
  12
  13 #include "qemu/osdep.h"
  14 #include "qapi/error.h"
  15 #include "qemu/cutils.h"
  16 #include "qapi/qmp/qerror.h"
  17 #include "qapi/opts-visitor.h"
  18 #include "qemu/queue.h"
  19 #include "qemu/option_int.h"
  20 #include "qapi/visitor-impl.h"
  21
  22
  23 enum ListMode
  24 {
  25     LM_NONE,             /* not traversing a list of repeated options */
  26     LM_STARTED,          /* opts_start_list() succeeded */
  27
  28     LM_IN_PROGRESS,      /* opts_next_list() has been called.
  29                           *
  30                           * Generating the next list link will consume the most
  31                           * recently parsed QemuOpt instance of the repeated
  32                           * option.
  33                           *
  34                           * Parsing a value into the list link will examine the
  35                           * next QemuOpt instance of the repeated option, and
  36                           * possibly enter LM_SIGNED_INTERVAL or
  37                           * LM_UNSIGNED_INTERVAL.
  38                           */
  39
  40     LM_SIGNED_INTERVAL,  /* opts_next_list() has been called.
  41                           *
  42                           * Generating the next list link will consume the most
  43                           * recently stored element from the signed interval,
  44                           * parsed from the most recent QemuOpt instance of the
  45                           * repeated option. This may consume QemuOpt itself
  46                           * and return to LM_IN_PROGRESS.
  47                           *
  48                           * Parsing a value into the list link will store the
  49                           * next element of the signed interval.
  50                           */
  51
  52     LM_UNSIGNED_INTERVAL /* Same as above, only for an unsigned interval. */
  53 };
  54
  55 typedef enum ListMode ListMode;
  56
  57 struct OptsVisitor
  58 {
  59     Visitor visitor;
  60
  61     /* Ownership remains with opts_visitor_new()'s caller. */
  62     const QemuOpts *opts_root;
  63
  64     unsigned depth;
  65
  66     /* Non-null iff depth is positive. Each key is a QemuOpt name. Each value
  67      * is a non-empty GQueue, enumerating all QemuOpt occurrences with that
  68      * name. */
  69     GHashTable *unprocessed_opts;
  70
  71     /* The list currently being traversed with opts_start_list() /
  72      * opts_next_list(). The list must have a struct element type in the
  73      * schema, with a single mandatory scalar member. */
  74     ListMode list_mode;
  75     GQueue *repeated_opts;
  76
  77     /* When parsing a list of repeating options as integers, values of the form
  78      * "a-b", representing a closed interval, are allowed. Elements in the
  79      * range are generated individually.
  80      */
  81     union {
  82         int64_t s;
  83         uint64_t u;
  84     } range_next, range_limit;
  85
  86     /* If "opts_root->id" is set, reinstantiate it as a fake QemuOpt for
  87      * uniformity. Only its "name" and "str" fields are set. "fake_id_opt" does
  88      * not survive or escape the OptsVisitor object.
  89      */
  90     QemuOpt *fake_id_opt;
  91 };
  92
  93
  94 static OptsVisitor *to_ov(Visitor *v)
  95 {
  96     return container_of(v, OptsVisitor, visitor);
  97 }
  98
  99
 100 static void
 101 destroy_list(gpointer list)
 102 {
 103   g_queue_free(list);
 104 }
 105
 106
 107 static void
 108 opts_visitor_insert(GHashTable *unprocessed_opts, const QemuOpt *opt)
 109 {
 110     GQueue *list;
 111
 112     list = g_hash_table_lookup(unprocessed_opts, opt->name);
 113     if (list == NULL) {
 114         list = g_queue_new();
 115
 116         /* GHashTable will never try to free the keys -- we supply NULL as
 117          * "key_destroy_func" in opts_start_struct(). Thus cast away key
 118          * const-ness in order to suppress gcc's warning.
 119          */
 120         g_hash_table_insert(unprocessed_opts, (gpointer)opt->name, list);
 121     }
 122
 123     /* Similarly, destroy_list() doesn't call g_queue_free_full(). */
 124     g_queue_push_tail(list, (gpointer)opt);
 125 }
 126
 127
 128 static void
 129 opts_start_struct(Visitor *v, const char *name, void **obj,
 130                   size_t size, Error **errp)
 131 {
 132     OptsVisitor *ov = to_ov(v);
 133     const QemuOpt *opt;
 134
 135     if (obj) {
 136         *obj = g_malloc0(size > 0 ? size : 1);
 137     }
 138     if (ov->depth++ > 0) {
 139         return;
 140     }
 141
 142     ov->unprocessed_opts = g_hash_table_new_full(&g_str_hash, &g_str_equal,
 143                                                  NULL, &destroy_list);
 144     QTAILQ_FOREACH(opt, &ov->opts_root->head, next) {
 145         /* ensured by qemu-option.c::opts_do_parse() */
 146         assert(strcmp(opt->name, "id") != 0);
 147
 148         opts_visitor_insert(ov->unprocessed_opts, opt);
 149     }
 150
 151     if (ov->opts_root->id != NULL) {
 152         ov->fake_id_opt = g_malloc0(sizeof *ov->fake_id_opt);
 153
 154         ov->fake_id_opt->name = g_strdup("id");
 155         ov->fake_id_opt->str = g_strdup(ov->opts_root->id);
 156         opts_visitor_insert(ov->unprocessed_opts, ov->fake_id_opt);
 157     }
 158 }
 159
 160
 161 static void
 162 opts_end_struct(Visitor *v, Error **errp)
 163 {
 164     OptsVisitor *ov = to_ov(v);
 165     GHashTableIter iter;
 166     GQueue *any;
 167
 168     if (--ov->depth > 0) {
 169         return;
 170     }
 171
 172     /* we should have processed all (distinct) QemuOpt instances */
 173     g_hash_table_iter_init(&iter, ov->unprocessed_opts);
 174     if (g_hash_table_iter_next(&iter, NULL, (void **)&any)) {
 175         const QemuOpt *first;
 176
 177         first = g_queue_peek_head(any);
 178         error_setg(errp, QERR_INVALID_PARAMETER, first->name);
 179     }
 180     g_hash_table_destroy(ov->unprocessed_opts);
 181     ov->unprocessed_opts = NULL;
 182     if (ov->fake_id_opt) {
 183         g_free(ov->fake_id_opt->name);
 184         g_free(ov->fake_id_opt->str);
 185         g_free(ov->fake_id_opt);
 186     }
 187     ov->fake_id_opt = NULL;
 188 }
 189
 190
 191 static GQueue *
 192 lookup_distinct(const OptsVisitor *ov, const char *name, Error **errp)
 193 {
 194     GQueue *list;
 195
 196     list = g_hash_table_lookup(ov->unprocessed_opts, name);
 197     if (!list) {
 198         error_setg(errp, QERR_MISSING_PARAMETER, name);
 199     }
 200     return list;
 201 }
 202
 203
 204 static void
 205 opts_start_list(Visitor *v, const char *name, Error **errp)
 206 {
 207     OptsVisitor *ov = to_ov(v);
 208
 209     /* we can't traverse a list in a list */
 210     assert(ov->list_mode == LM_NONE);
 211     ov->repeated_opts = lookup_distinct(ov, name, errp);
 212     if (ov->repeated_opts != NULL) {
 213         ov->list_mode = LM_STARTED;
 214     }
 215 }
 216
 217
 218 static GenericList *
 219 opts_next_list(Visitor *v, GenericList **list, size_t size)
 220 {
 221     OptsVisitor *ov = to_ov(v);
 222     GenericList **link;
 223
 224     switch (ov->list_mode) {
 225     case LM_STARTED:
 226         ov->list_mode = LM_IN_PROGRESS;
 227         link = list;
 228         break;
 229
 230     case LM_SIGNED_INTERVAL:
 231     case LM_UNSIGNED_INTERVAL:
 232         link = &(*list)->next;
 233
 234         if (ov->list_mode == LM_SIGNED_INTERVAL) {
 235             if (ov->range_next.s < ov->range_limit.s) {
 236                 ++ov->range_next.s;
 237                 break;
 238             }
 239         } else if (ov->range_next.u < ov->range_limit.u) {
 240             ++ov->range_next.u;
 241             break;
 242         }
 243         ov->list_mode = LM_IN_PROGRESS;
 244         /* range has been completed, fall through in order to pop option */
 245
 246     case LM_IN_PROGRESS: {
 247         const QemuOpt *opt;
 248
 249         opt = g_queue_pop_head(ov->repeated_opts);
 250         if (g_queue_is_empty(ov->repeated_opts)) {
 251             g_hash_table_remove(ov->unprocessed_opts, opt->name);
 252             return NULL;
 253         }
 254         link = &(*list)->next;
 255         break;
 256     }
 257
 258     default:
 259         abort();
 260     }
 261
 262     *link = g_malloc0(size);
 263     return *link;
 264 }
 265
 266
 267 static void
 268 opts_end_list(Visitor *v)
 269 {
 270     OptsVisitor *ov = to_ov(v);
 271
 272     assert(ov->list_mode == LM_STARTED ||
 273            ov->list_mode == LM_IN_PROGRESS ||
 274            ov->list_mode == LM_SIGNED_INTERVAL ||
 275            ov->list_mode == LM_UNSIGNED_INTERVAL);
 276     ov->repeated_opts = NULL;
 277     ov->list_mode = LM_NONE;
 278 }
 279
 280
 281 static const QemuOpt *
 282 lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp)
 283 {
 284     if (ov->list_mode == LM_NONE) {
 285         GQueue *list;
 286
 287         /* the last occurrence of any QemuOpt takes effect when queried by name
 288          */
 289         list = lookup_distinct(ov, name, errp);
 290         return list ? g_queue_peek_tail(list) : NULL;
 291     }
 292     assert(ov->list_mode == LM_IN_PROGRESS);
 293     return g_queue_peek_head(ov->repeated_opts);
 294 }
 295
 296
 297 static void
 298 processed(OptsVisitor *ov, const char *name)
 299 {
 300     if (ov->list_mode == LM_NONE) {
 301         g_hash_table_remove(ov->unprocessed_opts, name);
 302         return;
 303     }
 304     assert(ov->list_mode == LM_IN_PROGRESS);
 305     /* do nothing */
 306 }
 307
 308
 309 static void
 310 opts_type_str(Visitor *v, const char *name, char **obj, Error **errp)
 311 {
 312     OptsVisitor *ov = to_ov(v);
 313     const QemuOpt *opt;
 314
 315     opt = lookup_scalar(ov, name, errp);
 316     if (!opt) {
 317         return;
 318     }
 319     *obj = g_strdup(opt->str ? opt->str : "");
 320     processed(ov, name);
 321 }
 322
 323
 324 /* mimics qemu-option.c::parse_option_bool() */
 325 static void
 326 opts_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
 327 {
 328     OptsVisitor *ov = to_ov(v);
 329     const QemuOpt *opt;
 330
 331     opt = lookup_scalar(ov, name, errp);
 332     if (!opt) {
 333         return;
 334     }
 335
 336     if (opt->str) {
 337         if (strcmp(opt->str, "on") == 0 ||
 338             strcmp(opt->str, "yes") == 0 ||
 339             strcmp(opt->str, "y") == 0) {
 340             *obj = true;
 341         } else if (strcmp(opt->str, "off") == 0 ||
 342             strcmp(opt->str, "no") == 0 ||
 343             strcmp(opt->str, "n") == 0) {
 344             *obj = false;
 345         } else {
 346             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 347                        "on|yes|y|off|no|n");
 348             return;
 349         }
 350     } else {
 351         *obj = true;
 352     }
 353
 354     processed(ov, name);
 355 }
 356
 357
 358 static void
 359 opts_type_int64(Visitor *v, const char *name, int64_t *obj, Error **errp)
 360 {
 361     OptsVisitor *ov = to_ov(v);
 362     const QemuOpt *opt;
 363     const char *str;
 364     long long val;
 365     char *endptr;
 366
 367     if (ov->list_mode == LM_SIGNED_INTERVAL) {
 368         *obj = ov->range_next.s;
 369         return;
 370     }
 371
 372     opt = lookup_scalar(ov, name, errp);
 373     if (!opt) {
 374         return;
 375     }
 376     str = opt->str ? opt->str : "";
 377
 378     /* we've gotten past lookup_scalar() */
 379     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 380
 381     errno = 0;
 382     val = strtoll(str, &endptr, 0);
 383     if (errno == 0 && endptr > str && INT64_MIN <= val && val <= INT64_MAX) {
 384         if (*endptr == '\0') {
 385             *obj = val;
 386             processed(ov, name);
 387             return;
 388         }
 389         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 390             long long val2;
 391
 392             str = endptr + 1;
 393             val2 = strtoll(str, &endptr, 0);
 394             if (errno == 0 && endptr > str && *endptr == '\0' &&
 395                 INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2 &&
 396                 (val > INT64_MAX - OPTS_VISITOR_RANGE_MAX ||
 397                  val2 < val + OPTS_VISITOR_RANGE_MAX)) {
 398                 ov->range_next.s = val;
 399                 ov->range_limit.s = val2;
 400                 ov->list_mode = LM_SIGNED_INTERVAL;
 401
 402                 /* as if entering on the top */
 403                 *obj = ov->range_next.s;
 404                 return;
 405             }
 406         }
 407     }
 408     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 409                (ov->list_mode == LM_NONE) ? "an int64 value" :
 410                                             "an int64 value or range");
 411 }
 412
 413
 414 static void
 415 opts_type_uint64(Visitor *v, const char *name, uint64_t *obj, Error **errp)
 416 {
 417     OptsVisitor *ov = to_ov(v);
 418     const QemuOpt *opt;
 419     const char *str;
 420     unsigned long long val;
 421     char *endptr;
 422
 423     if (ov->list_mode == LM_UNSIGNED_INTERVAL) {
 424         *obj = ov->range_next.u;
 425         return;
 426     }
 427
 428     opt = lookup_scalar(ov, name, errp);
 429     if (!opt) {
 430         return;
 431     }
 432     str = opt->str;
 433
 434     /* we've gotten past lookup_scalar() */
 435     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 436
 437     if (parse_uint(str, &val, &endptr, 0) == 0 && val <= UINT64_MAX) {
 438         if (*endptr == '\0') {
 439             *obj = val;
 440             processed(ov, name);
 441             return;
 442         }
 443         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 444             unsigned long long val2;
 445
 446             str = endptr + 1;
 447             if (parse_uint_full(str, &val2, 0) == 0 &&
 448                 val2 <= UINT64_MAX && val <= val2 &&
 449                 val2 - val < OPTS_VISITOR_RANGE_MAX) {
 450                 ov->range_next.u = val;
 451                 ov->range_limit.u = val2;
 452                 ov->list_mode = LM_UNSIGNED_INTERVAL;
 453
 454                 /* as if entering on the top */
 455                 *obj = ov->range_next.u;
 456                 return;
 457             }
 458         }
 459     }
 460     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 461                (ov->list_mode == LM_NONE) ? "a uint64 value" :
 462                                             "a uint64 value or range");
 463 }
 464
 465
 466 static void
 467 opts_type_size(Visitor *v, const char *name, uint64_t *obj, Error **errp)
 468 {
 469     OptsVisitor *ov = to_ov(v);
 470     const QemuOpt *opt;
 471     int64_t val;
 472     char *endptr;
 473
 474     opt = lookup_scalar(ov, name, errp);
 475     if (!opt) {
 476         return;
 477     }
 478
 479     val = qemu_strtosz_suffix(opt->str ? opt->str : "", &endptr,
 480                          QEMU_STRTOSZ_DEFSUFFIX_B);
 481     if (val < 0 || *endptr) {
 482         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 483                    "a size value representible as a non-negative int64");
 484         return;
 485     }
 486
 487     *obj = val;
 488     processed(ov, name);
 489 }
 490
 491
 492 static void
 493 opts_optional(Visitor *v, const char *name, bool *present)
 494 {
 495     OptsVisitor *ov = to_ov(v);
 496
 497     /* we only support a single mandatory scalar field in a list node */
 498     assert(ov->list_mode == LM_NONE);
 499     *present = (lookup_distinct(ov, name, NULL) != NULL);
 500 }
 501
 502
 503 OptsVisitor *
 504 opts_visitor_new(const QemuOpts *opts)
 505 {
 506     OptsVisitor *ov;
 507
 508     ov = g_malloc0(sizeof *ov);
 509
 510     ov->visitor.start_struct = &opts_start_struct;
 511     ov->visitor.end_struct   = &opts_end_struct;
 512
 513     ov->visitor.start_list = &opts_start_list;
 514     ov->visitor.next_list  = &opts_next_list;
 515     ov->visitor.end_list   = &opts_end_list;
 516
 517     /* input_type_enum() covers both "normal" enums and union discriminators.
 518      * The union discriminator field is always generated as "type"; it should
 519      * match the "type" QemuOpt child of any QemuOpts.
 520      *
 521      * input_type_enum() will remove the looked-up key from the
 522      * "unprocessed_opts" hash even if the lookup fails, because the removal is
 523      * done earlier in opts_type_str(). This should be harmless.
 524      */
 525     ov->visitor.type_enum = &input_type_enum;
 526
 527     ov->visitor.type_int64  = &opts_type_int64;
 528     ov->visitor.type_uint64 = &opts_type_uint64;
 529     ov->visitor.type_size   = &opts_type_size;
 530     ov->visitor.type_bool   = &opts_type_bool;
 531     ov->visitor.type_str    = &opts_type_str;
 532
 533     /* type_number() is not filled in, but this is not the first visitor to
 534      * skip some mandatory methods... */
 535
 536     ov->visitor.optional = &opts_optional;
 537
 538     ov->opts_root = opts;
 539
 540     return ov;
 541 }
 542
 543
 544 void
 545 opts_visitor_cleanup(OptsVisitor *ov)
 546 {
 547     if (ov->unprocessed_opts != NULL) {
 548         g_hash_table_destroy(ov->unprocessed_opts);
 549     }
 550     g_free(ov->fake_id_opt);
 551     g_free(ov);
 552 }
 553
 554
 555 Visitor *
 556 opts_get_visitor(OptsVisitor *ov)
 557 {
 558     return &ov->visitor;
 559 }