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 "qemu-common.h"
  15 #include "qapi/qmp/qerror.h"
  16 #include "qapi/opts-visitor.h"
  17 #include "qemu/queue.h"
  18 #include "qemu/option_int.h"
  19 #include "qapi/visitor-impl.h"
  20
  21
  22 enum ListMode
  23 {
  24     LM_NONE,             /* not traversing a list of repeated options */
  25     LM_STARTED,          /* opts_start_list() succeeded */
  26
  27     LM_IN_PROGRESS,      /* opts_next_list() has been called.
  28                           *
  29                           * Generating the next list link will consume the most
  30                           * recently parsed QemuOpt instance of the repeated
  31                           * option.
  32                           *
  33                           * Parsing a value into the list link will examine the
  34                           * next QemuOpt instance of the repeated option, and
  35                           * possibly enter LM_SIGNED_INTERVAL or
  36                           * LM_UNSIGNED_INTERVAL.
  37                           */
  38
  39     LM_SIGNED_INTERVAL,  /* opts_next_list() has been called.
  40                           *
  41                           * Generating the next list link will consume the most
  42                           * recently stored element from the signed interval,
  43                           * parsed from the most recent QemuOpt instance of the
  44                           * repeated option. This may consume QemuOpt itself
  45                           * and return to LM_IN_PROGRESS.
  46                           *
  47                           * Parsing a value into the list link will store the
  48                           * next element of the signed interval.
  49                           */
  50
  51     LM_UNSIGNED_INTERVAL /* Same as above, only for an unsigned interval. */
  52 };
  53
  54 typedef enum ListMode ListMode;
  55
  56 struct OptsVisitor
  57 {
  58     Visitor visitor;
  59
  60     /* Ownership remains with opts_visitor_new()'s caller. */
  61     const QemuOpts *opts_root;
  62
  63     unsigned depth;
  64
  65     /* Non-null iff depth is positive. Each key is a QemuOpt name. Each value
  66      * is a non-empty GQueue, enumerating all QemuOpt occurrences with that
  67      * name. */
  68     GHashTable *unprocessed_opts;
  69
  70     /* The list currently being traversed with opts_start_list() /
  71      * opts_next_list(). The list must have a struct element type in the
  72      * schema, with a single mandatory scalar member. */
  73     ListMode list_mode;
  74     GQueue *repeated_opts;
  75
  76     /* When parsing a list of repeating options as integers, values of the form
  77      * "a-b", representing a closed interval, are allowed. Elements in the
  78      * range are generated individually.
  79      */
  80     union {
  81         int64_t s;
  82         uint64_t u;
  83     } range_next, range_limit;
  84
  85     /* If "opts_root->id" is set, reinstantiate it as a fake QemuOpt for
  86      * uniformity. Only its "name" and "str" fields are set. "fake_id_opt" does
  87      * not survive or escape the OptsVisitor object.
  88      */
  89     QemuOpt *fake_id_opt;
  90 };
  91
  92
  93 static OptsVisitor *to_ov(Visitor *v)
  94 {
  95     return container_of(v, OptsVisitor, visitor);
  96 }
  97
  98
  99 static void
 100 destroy_list(gpointer list)
 101 {
 102   g_queue_free(list);
 103 }
 104
 105
 106 static void
 107 opts_visitor_insert(GHashTable *unprocessed_opts, const QemuOpt *opt)
 108 {
 109     GQueue *list;
 110
 111     list = g_hash_table_lookup(unprocessed_opts, opt->name);
 112     if (list == NULL) {
 113         list = g_queue_new();
 114
 115         /* GHashTable will never try to free the keys -- we supply NULL as
 116          * "key_destroy_func" in opts_start_struct(). Thus cast away key
 117          * const-ness in order to suppress gcc's warning.
 118          */
 119         g_hash_table_insert(unprocessed_opts, (gpointer)opt->name, list);
 120     }
 121
 122     /* Similarly, destroy_list() doesn't call g_queue_free_full(). */
 123     g_queue_push_tail(list, (gpointer)opt);
 124 }
 125
 126
 127 static void
 128 opts_start_struct(Visitor *v, const char *name, void **obj,
 129                   size_t size, Error **errp)
 130 {
 131     OptsVisitor *ov = to_ov(v);
 132     const QemuOpt *opt;
 133
 134     if (obj) {
 135         *obj = g_malloc0(size > 0 ? size : 1);
 136     }
 137     if (ov->depth++ > 0) {
 138         return;
 139     }
 140
 141     ov->unprocessed_opts = g_hash_table_new_full(&g_str_hash, &g_str_equal,
 142                                                  NULL, &destroy_list);
 143     QTAILQ_FOREACH(opt, &ov->opts_root->head, next) {
 144         /* ensured by qemu-option.c::opts_do_parse() */
 145         assert(strcmp(opt->name, "id") != 0);
 146
 147         opts_visitor_insert(ov->unprocessed_opts, opt);
 148     }
 149
 150     if (ov->opts_root->id != NULL) {
 151         ov->fake_id_opt = g_malloc0(sizeof *ov->fake_id_opt);
 152
 153         ov->fake_id_opt->name = g_strdup("id");
 154         ov->fake_id_opt->str = g_strdup(ov->opts_root->id);
 155         opts_visitor_insert(ov->unprocessed_opts, ov->fake_id_opt);
 156     }
 157 }
 158
 159
 160 static gboolean
 161 ghr_true(gpointer ign_key, gpointer ign_value, gpointer ign_user_data)
 162 {
 163     return TRUE;
 164 }
 165
 166
 167 static void
 168 opts_end_struct(Visitor *v, Error **errp)
 169 {
 170     OptsVisitor *ov = to_ov(v);
 171     GQueue *any;
 172
 173     if (--ov->depth > 0) {
 174         return;
 175     }
 176
 177     /* we should have processed all (distinct) QemuOpt instances */
 178     any = g_hash_table_find(ov->unprocessed_opts, &ghr_true, NULL);
 179     if (any) {
 180         const QemuOpt *first;
 181
 182         first = g_queue_peek_head(any);
 183         error_setg(errp, QERR_INVALID_PARAMETER, first->name);
 184     }
 185     g_hash_table_destroy(ov->unprocessed_opts);
 186     ov->unprocessed_opts = NULL;
 187     if (ov->fake_id_opt) {
 188         g_free(ov->fake_id_opt->name);
 189         g_free(ov->fake_id_opt->str);
 190         g_free(ov->fake_id_opt);
 191     }
 192     ov->fake_id_opt = NULL;
 193 }
 194
 195
 196 static GQueue *
 197 lookup_distinct(const OptsVisitor *ov, const char *name, Error **errp)
 198 {
 199     GQueue *list;
 200
 201     list = g_hash_table_lookup(ov->unprocessed_opts, name);
 202     if (!list) {
 203         error_setg(errp, QERR_MISSING_PARAMETER, name);
 204     }
 205     return list;
 206 }
 207
 208
 209 static void
 210 opts_start_list(Visitor *v, const char *name, Error **errp)
 211 {
 212     OptsVisitor *ov = to_ov(v);
 213
 214     /* we can't traverse a list in a list */
 215     assert(ov->list_mode == LM_NONE);
 216     ov->repeated_opts = lookup_distinct(ov, name, errp);
 217     if (ov->repeated_opts != NULL) {
 218         ov->list_mode = LM_STARTED;
 219     }
 220 }
 221
 222
 223 static GenericList *
 224 opts_next_list(Visitor *v, GenericList **list)
 225 {
 226     OptsVisitor *ov = to_ov(v);
 227     GenericList **link;
 228
 229     switch (ov->list_mode) {
 230     case LM_STARTED:
 231         ov->list_mode = LM_IN_PROGRESS;
 232         link = list;
 233         break;
 234
 235     case LM_SIGNED_INTERVAL:
 236     case LM_UNSIGNED_INTERVAL:
 237         link = &(*list)->next;
 238
 239         if (ov->list_mode == LM_SIGNED_INTERVAL) {
 240             if (ov->range_next.s < ov->range_limit.s) {
 241                 ++ov->range_next.s;
 242                 break;
 243             }
 244         } else if (ov->range_next.u < ov->range_limit.u) {
 245             ++ov->range_next.u;
 246             break;
 247         }
 248         ov->list_mode = LM_IN_PROGRESS;
 249         /* range has been completed, fall through in order to pop option */
 250
 251     case LM_IN_PROGRESS: {
 252         const QemuOpt *opt;
 253
 254         opt = g_queue_pop_head(ov->repeated_opts);
 255         if (g_queue_is_empty(ov->repeated_opts)) {
 256             g_hash_table_remove(ov->unprocessed_opts, opt->name);
 257             return NULL;
 258         }
 259         link = &(*list)->next;
 260         break;
 261     }
 262
 263     default:
 264         abort();
 265     }
 266
 267     *link = g_malloc0(sizeof **link);
 268     return *link;
 269 }
 270
 271
 272 static void
 273 opts_end_list(Visitor *v)
 274 {
 275     OptsVisitor *ov = to_ov(v);
 276
 277     assert(ov->list_mode == LM_STARTED ||
 278            ov->list_mode == LM_IN_PROGRESS ||
 279            ov->list_mode == LM_SIGNED_INTERVAL ||
 280            ov->list_mode == LM_UNSIGNED_INTERVAL);
 281     ov->repeated_opts = NULL;
 282     ov->list_mode = LM_NONE;
 283 }
 284
 285
 286 static const QemuOpt *
 287 lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp)
 288 {
 289     if (ov->list_mode == LM_NONE) {
 290         GQueue *list;
 291
 292         /* the last occurrence of any QemuOpt takes effect when queried by name
 293          */
 294         list = lookup_distinct(ov, name, errp);
 295         return list ? g_queue_peek_tail(list) : NULL;
 296     }
 297     assert(ov->list_mode == LM_IN_PROGRESS);
 298     return g_queue_peek_head(ov->repeated_opts);
 299 }
 300
 301
 302 static void
 303 processed(OptsVisitor *ov, const char *name)
 304 {
 305     if (ov->list_mode == LM_NONE) {
 306         g_hash_table_remove(ov->unprocessed_opts, name);
 307         return;
 308     }
 309     assert(ov->list_mode == LM_IN_PROGRESS);
 310     /* do nothing */
 311 }
 312
 313
 314 static void
 315 opts_type_str(Visitor *v, const char *name, char **obj, Error **errp)
 316 {
 317     OptsVisitor *ov = to_ov(v);
 318     const QemuOpt *opt;
 319
 320     opt = lookup_scalar(ov, name, errp);
 321     if (!opt) {
 322         return;
 323     }
 324     *obj = g_strdup(opt->str ? opt->str : "");
 325     processed(ov, name);
 326 }
 327
 328
 329 /* mimics qemu-option.c::parse_option_bool() */
 330 static void
 331 opts_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
 332 {
 333     OptsVisitor *ov = to_ov(v);
 334     const QemuOpt *opt;
 335
 336     opt = lookup_scalar(ov, name, errp);
 337     if (!opt) {
 338         return;
 339     }
 340
 341     if (opt->str) {
 342         if (strcmp(opt->str, "on") == 0 ||
 343             strcmp(opt->str, "yes") == 0 ||
 344             strcmp(opt->str, "y") == 0) {
 345             *obj = true;
 346         } else if (strcmp(opt->str, "off") == 0 ||
 347             strcmp(opt->str, "no") == 0 ||
 348             strcmp(opt->str, "n") == 0) {
 349             *obj = false;
 350         } else {
 351             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 352                        "on|yes|y|off|no|n");
 353             return;
 354         }
 355     } else {
 356         *obj = true;
 357     }
 358
 359     processed(ov, name);
 360 }
 361
 362
 363 static void
 364 opts_type_int64(Visitor *v, const char *name, int64_t *obj, Error **errp)
 365 {
 366     OptsVisitor *ov = to_ov(v);
 367     const QemuOpt *opt;
 368     const char *str;
 369     long long val;
 370     char *endptr;
 371
 372     if (ov->list_mode == LM_SIGNED_INTERVAL) {
 373         *obj = ov->range_next.s;
 374         return;
 375     }
 376
 377     opt = lookup_scalar(ov, name, errp);
 378     if (!opt) {
 379         return;
 380     }
 381     str = opt->str ? opt->str : "";
 382
 383     /* we've gotten past lookup_scalar() */
 384     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 385
 386     errno = 0;
 387     val = strtoll(str, &endptr, 0);
 388     if (errno == 0 && endptr > str && INT64_MIN <= val && val <= INT64_MAX) {
 389         if (*endptr == '\0') {
 390             *obj = val;
 391             processed(ov, name);
 392             return;
 393         }
 394         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 395             long long val2;
 396
 397             str = endptr + 1;
 398             val2 = strtoll(str, &endptr, 0);
 399             if (errno == 0 && endptr > str && *endptr == '\0' &&
 400                 INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2 &&
 401                 (val > INT64_MAX - OPTS_VISITOR_RANGE_MAX ||
 402                  val2 < val + OPTS_VISITOR_RANGE_MAX)) {
 403                 ov->range_next.s = val;
 404                 ov->range_limit.s = val2;
 405                 ov->list_mode = LM_SIGNED_INTERVAL;
 406
 407                 /* as if entering on the top */
 408                 *obj = ov->range_next.s;
 409                 return;
 410             }
 411         }
 412     }
 413     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 414                (ov->list_mode == LM_NONE) ? "an int64 value" :
 415                                             "an int64 value or range");
 416 }
 417
 418
 419 static void
 420 opts_type_uint64(Visitor *v, const char *name, uint64_t *obj, Error **errp)
 421 {
 422     OptsVisitor *ov = to_ov(v);
 423     const QemuOpt *opt;
 424     const char *str;
 425     unsigned long long val;
 426     char *endptr;
 427
 428     if (ov->list_mode == LM_UNSIGNED_INTERVAL) {
 429         *obj = ov->range_next.u;
 430         return;
 431     }
 432
 433     opt = lookup_scalar(ov, name, errp);
 434     if (!opt) {
 435         return;
 436     }
 437     str = opt->str;
 438
 439     /* we've gotten past lookup_scalar() */
 440     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 441
 442     if (parse_uint(str, &val, &endptr, 0) == 0 && val <= UINT64_MAX) {
 443         if (*endptr == '\0') {
 444             *obj = val;
 445             processed(ov, name);
 446             return;
 447         }
 448         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 449             unsigned long long val2;
 450
 451             str = endptr + 1;
 452             if (parse_uint_full(str, &val2, 0) == 0 &&
 453                 val2 <= UINT64_MAX && val <= val2 &&
 454                 val2 - val < OPTS_VISITOR_RANGE_MAX) {
 455                 ov->range_next.u = val;
 456                 ov->range_limit.u = val2;
 457                 ov->list_mode = LM_UNSIGNED_INTERVAL;
 458
 459                 /* as if entering on the top */
 460                 *obj = ov->range_next.u;
 461                 return;
 462             }
 463         }
 464     }
 465     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 466                (ov->list_mode == LM_NONE) ? "a uint64 value" :
 467                                             "a uint64 value or range");
 468 }
 469
 470
 471 static void
 472 opts_type_size(Visitor *v, const char *name, uint64_t *obj, Error **errp)
 473 {
 474     OptsVisitor *ov = to_ov(v);
 475     const QemuOpt *opt;
 476     int64_t val;
 477     char *endptr;
 478
 479     opt = lookup_scalar(ov, name, errp);
 480     if (!opt) {
 481         return;
 482     }
 483
 484     val = qemu_strtosz_suffix(opt->str ? opt->str : "", &endptr,
 485                          QEMU_STRTOSZ_DEFSUFFIX_B);
 486     if (val < 0 || *endptr) {
 487         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 488                    "a size value representible as a non-negative int64");
 489         return;
 490     }
 491
 492     *obj = val;
 493     processed(ov, name);
 494 }
 495
 496
 497 static void
 498 opts_optional(Visitor *v, const char *name, bool *present)
 499 {
 500     OptsVisitor *ov = to_ov(v);
 501
 502     /* we only support a single mandatory scalar field in a list node */
 503     assert(ov->list_mode == LM_NONE);
 504     *present = (lookup_distinct(ov, name, NULL) != NULL);
 505 }
 506
 507
 508 OptsVisitor *
 509 opts_visitor_new(const QemuOpts *opts)
 510 {
 511     OptsVisitor *ov;
 512
 513     ov = g_malloc0(sizeof *ov);
 514
 515     ov->visitor.start_struct = &opts_start_struct;
 516     ov->visitor.end_struct   = &opts_end_struct;
 517
 518     ov->visitor.start_list = &opts_start_list;
 519     ov->visitor.next_list  = &opts_next_list;
 520     ov->visitor.end_list   = &opts_end_list;
 521
 522     /* input_type_enum() covers both "normal" enums and union discriminators.
 523      * The union discriminator field is always generated as "type"; it should
 524      * match the "type" QemuOpt child of any QemuOpts.
 525      *
 526      * input_type_enum() will remove the looked-up key from the
 527      * "unprocessed_opts" hash even if the lookup fails, because the removal is
 528      * done earlier in opts_type_str(). This should be harmless.
 529      */
 530     ov->visitor.type_enum = &input_type_enum;
 531
 532     ov->visitor.type_int64  = &opts_type_int64;
 533     ov->visitor.type_uint64 = &opts_type_uint64;
 534     ov->visitor.type_size   = &opts_type_size;
 535     ov->visitor.type_bool   = &opts_type_bool;
 536     ov->visitor.type_str    = &opts_type_str;
 537
 538     /* type_number() is not filled in, but this is not the first visitor to
 539      * skip some mandatory methods... */
 540
 541     ov->visitor.optional = &opts_optional;
 542
 543     ov->opts_root = opts;
 544
 545     return ov;
 546 }
 547
 548
 549 void
 550 opts_visitor_cleanup(OptsVisitor *ov)
 551 {
 552     if (ov->unprocessed_opts != NULL) {
 553         g_hash_table_destroy(ov->unprocessed_opts);
 554     }
 555     g_free(ov->fake_id_opt);
 556     g_free(ov);
 557 }
 558
 559
 560 Visitor *
 561 opts_get_visitor(OptsVisitor *ov)
 562 {
 563     return &ov->visitor;
 564 }