qapi/opts-visitor.c

   1 /*
   2  * Options Visitor
   3  *
   4  * Copyright Red Hat, Inc. 2012, 2013
   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-common.h"
  14 #include "qapi/qmp/qerror.h"
  15 #include "qapi/opts-visitor.h"
  16 #include "qemu/queue.h"
  17 #include "qemu/option_int.h"
  18 #include "qapi/visitor-impl.h"
  19
  20
  21 enum ListMode
  22 {
  23     LM_NONE,             /* not traversing a list of repeated options */
  24     LM_STARTED,          /* opts_start_list() succeeded */
  25
  26     LM_IN_PROGRESS,      /* opts_next_list() has been called.
  27                           *
  28                           * Generating the next list link will consume the most
  29                           * recently parsed QemuOpt instance of the repeated
  30                           * option.
  31                           *
  32                           * Parsing a value into the list link will examine the
  33                           * next QemuOpt instance of the repeated option, and
  34                           * possibly enter LM_SIGNED_INTERVAL or
  35                           * LM_UNSIGNED_INTERVAL.
  36                           */
  37
  38     LM_SIGNED_INTERVAL,  /* opts_next_list() has been called.
  39                           *
  40                           * Generating the next list link will consume the most
  41                           * recently stored element from the signed interval,
  42                           * parsed from the most recent QemuOpt instance of the
  43                           * repeated option. This may consume QemuOpt itself
  44                           * and return to LM_IN_PROGRESS.
  45                           *
  46                           * Parsing a value into the list link will store the
  47                           * next element of the signed interval.
  48                           */
  49
  50     LM_UNSIGNED_INTERVAL /* Same as above, only for an unsigned interval. */
  51 };
  52
  53 typedef enum ListMode ListMode;
  54
  55 struct OptsVisitor
  56 {
  57     Visitor visitor;
  58
  59     /* Ownership remains with opts_visitor_new()'s caller. */
  60     const QemuOpts *opts_root;
  61
  62     unsigned depth;
  63
  64     /* Non-null iff depth is positive. Each key is a QemuOpt name. Each value
  65      * is a non-empty GQueue, enumerating all QemuOpt occurrences with that
  66      * name. */
  67     GHashTable *unprocessed_opts;
  68
  69     /* The list currently being traversed with opts_start_list() /
  70      * opts_next_list(). The list must have a struct element type in the
  71      * schema, with a single mandatory scalar member. */
  72     ListMode list_mode;
  73     GQueue *repeated_opts;
  74
  75     /* When parsing a list of repeating options as integers, values of the form
  76      * "a-b", representing a closed interval, are allowed. Elements in the
  77      * range are generated individually.
  78      */
  79     union {
  80         int64_t s;
  81         uint64_t u;
  82     } range_next, range_limit;
  83
  84     /* If "opts_root->id" is set, reinstantiate it as a fake QemuOpt for
  85      * uniformity. Only its "name" and "str" fields are set. "fake_id_opt" does
  86      * not survive or escape the OptsVisitor object.
  87      */
  88     QemuOpt *fake_id_opt;
  89 };
  90
  91
  92 static void
  93 destroy_list(gpointer list)
  94 {
  95   g_queue_free(list);
  96 }
  97
  98
  99 static void
 100 opts_visitor_insert(GHashTable *unprocessed_opts, const QemuOpt *opt)
 101 {
 102     GQueue *list;
 103
 104     list = g_hash_table_lookup(unprocessed_opts, opt->name);
 105     if (list == NULL) {
 106         list = g_queue_new();
 107
 108         /* GHashTable will never try to free the keys -- we supply NULL as
 109          * "key_destroy_func" in opts_start_struct(). Thus cast away key
 110          * const-ness in order to suppress gcc's warning.
 111          */
 112         g_hash_table_insert(unprocessed_opts, (gpointer)opt->name, list);
 113     }
 114
 115     /* Similarly, destroy_list() doesn't call g_queue_free_full(). */
 116     g_queue_push_tail(list, (gpointer)opt);
 117 }
 118
 119
 120 static void
 121 opts_start_struct(Visitor *v, void **obj, const char *kind,
 122                   const char *name, size_t size, Error **errp)
 123 {
 124     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 125     const QemuOpt *opt;
 126
 127     if (obj) {
 128         *obj = g_malloc0(size > 0 ? size : 1);
 129     }
 130     if (ov->depth++ > 0) {
 131         return;
 132     }
 133
 134     ov->unprocessed_opts = g_hash_table_new_full(&g_str_hash, &g_str_equal,
 135                                                  NULL, &destroy_list);
 136     QTAILQ_FOREACH(opt, &ov->opts_root->head, next) {
 137         /* ensured by qemu-option.c::opts_do_parse() */
 138         assert(strcmp(opt->name, "id") != 0);
 139
 140         opts_visitor_insert(ov->unprocessed_opts, opt);
 141     }
 142
 143     if (ov->opts_root->id != NULL) {
 144         ov->fake_id_opt = g_malloc0(sizeof *ov->fake_id_opt);
 145
 146         ov->fake_id_opt->name = g_strdup("id");
 147         ov->fake_id_opt->str = g_strdup(ov->opts_root->id);
 148         opts_visitor_insert(ov->unprocessed_opts, ov->fake_id_opt);
 149     }
 150 }
 151
 152
 153 static gboolean
 154 ghr_true(gpointer ign_key, gpointer ign_value, gpointer ign_user_data)
 155 {
 156     return TRUE;
 157 }
 158
 159
 160 static void
 161 opts_end_struct(Visitor *v, Error **errp)
 162 {
 163     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 164     GQueue *any;
 165
 166     if (--ov->depth > 0) {
 167         return;
 168     }
 169
 170     /* we should have processed all (distinct) QemuOpt instances */
 171     any = g_hash_table_find(ov->unprocessed_opts, &ghr_true, NULL);
 172     if (any) {
 173         const QemuOpt *first;
 174
 175         first = g_queue_peek_head(any);
 176         error_setg(errp, QERR_INVALID_PARAMETER, first->name);
 177     }
 178     g_hash_table_destroy(ov->unprocessed_opts);
 179     ov->unprocessed_opts = NULL;
 180     if (ov->fake_id_opt) {
 181         g_free(ov->fake_id_opt->name);
 182         g_free(ov->fake_id_opt->str);
 183         g_free(ov->fake_id_opt);
 184     }
 185     ov->fake_id_opt = NULL;
 186 }
 187
 188
 189 static GQueue *
 190 lookup_distinct(const OptsVisitor *ov, const char *name, Error **errp)
 191 {
 192     GQueue *list;
 193
 194     list = g_hash_table_lookup(ov->unprocessed_opts, name);
 195     if (!list) {
 196         error_setg(errp, QERR_MISSING_PARAMETER, name);
 197     }
 198     return list;
 199 }
 200
 201
 202 static void
 203 opts_start_list(Visitor *v, const char *name, Error **errp)
 204 {
 205     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 206
 207     /* we can't traverse a list in a list */
 208     assert(ov->list_mode == LM_NONE);
 209     ov->repeated_opts = lookup_distinct(ov, name, errp);
 210     if (ov->repeated_opts != NULL) {
 211         ov->list_mode = LM_STARTED;
 212     }
 213 }
 214
 215
 216 static GenericList *
 217 opts_next_list(Visitor *v, GenericList **list, Error **errp)
 218 {
 219     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 220     GenericList **link;
 221
 222     switch (ov->list_mode) {
 223     case LM_STARTED:
 224         ov->list_mode = LM_IN_PROGRESS;
 225         link = list;
 226         break;
 227
 228     case LM_SIGNED_INTERVAL:
 229     case LM_UNSIGNED_INTERVAL:
 230         link = &(*list)->next;
 231
 232         if (ov->list_mode == LM_SIGNED_INTERVAL) {
 233             if (ov->range_next.s < ov->range_limit.s) {
 234                 ++ov->range_next.s;
 235                 break;
 236             }
 237         } else if (ov->range_next.u < ov->range_limit.u) {
 238             ++ov->range_next.u;
 239             break;
 240         }
 241         ov->list_mode = LM_IN_PROGRESS;
 242         /* range has been completed, fall through in order to pop option */
 243
 244     case LM_IN_PROGRESS: {
 245         const QemuOpt *opt;
 246
 247         opt = g_queue_pop_head(ov->repeated_opts);
 248         if (g_queue_is_empty(ov->repeated_opts)) {
 249             g_hash_table_remove(ov->unprocessed_opts, opt->name);
 250             return NULL;
 251         }
 252         link = &(*list)->next;
 253         break;
 254     }
 255
 256     default:
 257         abort();
 258     }
 259
 260     *link = g_malloc0(sizeof **link);
 261     return *link;
 262 }
 263
 264
 265 static void
 266 opts_end_list(Visitor *v, Error **errp)
 267 {
 268     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 269
 270     assert(ov->list_mode == LM_STARTED ||
 271            ov->list_mode == LM_IN_PROGRESS ||
 272            ov->list_mode == LM_SIGNED_INTERVAL ||
 273            ov->list_mode == LM_UNSIGNED_INTERVAL);
 274     ov->repeated_opts = NULL;
 275     ov->list_mode = LM_NONE;
 276 }
 277
 278
 279 static const QemuOpt *
 280 lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp)
 281 {
 282     if (ov->list_mode == LM_NONE) {
 283         GQueue *list;
 284
 285         /* the last occurrence of any QemuOpt takes effect when queried by name
 286          */
 287         list = lookup_distinct(ov, name, errp);
 288         return list ? g_queue_peek_tail(list) : NULL;
 289     }
 290     assert(ov->list_mode == LM_IN_PROGRESS);
 291     return g_queue_peek_head(ov->repeated_opts);
 292 }
 293
 294
 295 static void
 296 processed(OptsVisitor *ov, const char *name)
 297 {
 298     if (ov->list_mode == LM_NONE) {
 299         g_hash_table_remove(ov->unprocessed_opts, name);
 300         return;
 301     }
 302     assert(ov->list_mode == LM_IN_PROGRESS);
 303     /* do nothing */
 304 }
 305
 306
 307 static void
 308 opts_type_str(Visitor *v, char **obj, const char *name, Error **errp)
 309 {
 310     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 311     const QemuOpt *opt;
 312
 313     opt = lookup_scalar(ov, name, errp);
 314     if (!opt) {
 315         return;
 316     }
 317     *obj = g_strdup(opt->str ? opt->str : "");
 318     processed(ov, name);
 319 }
 320
 321
 322 /* mimics qemu-option.c::parse_option_bool() */
 323 static void
 324 opts_type_bool(Visitor *v, bool *obj, const char *name, Error **errp)
 325 {
 326     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 327     const QemuOpt *opt;
 328
 329     opt = lookup_scalar(ov, name, errp);
 330     if (!opt) {
 331         return;
 332     }
 333
 334     if (opt->str) {
 335         if (strcmp(opt->str, "on") == 0 ||
 336             strcmp(opt->str, "yes") == 0 ||
 337             strcmp(opt->str, "y") == 0) {
 338             *obj = true;
 339         } else if (strcmp(opt->str, "off") == 0 ||
 340             strcmp(opt->str, "no") == 0 ||
 341             strcmp(opt->str, "n") == 0) {
 342             *obj = false;
 343         } else {
 344             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 345                        "on|yes|y|off|no|n");
 346             return;
 347         }
 348     } else {
 349         *obj = true;
 350     }
 351
 352     processed(ov, name);
 353 }
 354
 355
 356 static void
 357 opts_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
 358 {
 359     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 360     const QemuOpt *opt;
 361     const char *str;
 362     long long val;
 363     char *endptr;
 364
 365     if (ov->list_mode == LM_SIGNED_INTERVAL) {
 366         *obj = ov->range_next.s;
 367         return;
 368     }
 369
 370     opt = lookup_scalar(ov, name, errp);
 371     if (!opt) {
 372         return;
 373     }
 374     str = opt->str ? opt->str : "";
 375
 376     /* we've gotten past lookup_scalar() */
 377     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 378
 379     errno = 0;
 380     val = strtoll(str, &endptr, 0);
 381     if (errno == 0 && endptr > str && INT64_MIN <= val && val <= INT64_MAX) {
 382         if (*endptr == '\0') {
 383             *obj = val;
 384             processed(ov, name);
 385             return;
 386         }
 387         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 388             long long val2;
 389
 390             str = endptr + 1;
 391             val2 = strtoll(str, &endptr, 0);
 392             if (errno == 0 && endptr > str && *endptr == '\0' &&
 393                 INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2 &&
 394                 (val > INT64_MAX - OPTS_VISITOR_RANGE_MAX ||
 395                  val2 < val + OPTS_VISITOR_RANGE_MAX)) {
 396                 ov->range_next.s = val;
 397                 ov->range_limit.s = val2;
 398                 ov->list_mode = LM_SIGNED_INTERVAL;
 399
 400                 /* as if entering on the top */
 401                 *obj = ov->range_next.s;
 402                 return;
 403             }
 404         }
 405     }
 406     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 407                (ov->list_mode == LM_NONE) ? "an int64 value" :
 408                                             "an int64 value or range");
 409 }
 410
 411
 412 static void
 413 opts_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp)
 414 {
 415     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 416     const QemuOpt *opt;
 417     const char *str;
 418     unsigned long long val;
 419     char *endptr;
 420
 421     if (ov->list_mode == LM_UNSIGNED_INTERVAL) {
 422         *obj = ov->range_next.u;
 423         return;
 424     }
 425
 426     opt = lookup_scalar(ov, name, errp);
 427     if (!opt) {
 428         return;
 429     }
 430     str = opt->str;
 431
 432     /* we've gotten past lookup_scalar() */
 433     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 434
 435     if (parse_uint(str, &val, &endptr, 0) == 0 && val <= UINT64_MAX) {
 436         if (*endptr == '\0') {
 437             *obj = val;
 438             processed(ov, name);
 439             return;
 440         }
 441         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 442             unsigned long long val2;
 443
 444             str = endptr + 1;
 445             if (parse_uint_full(str, &val2, 0) == 0 &&
 446                 val2 <= UINT64_MAX && val <= val2 &&
 447                 val2 - val < OPTS_VISITOR_RANGE_MAX) {
 448                 ov->range_next.u = val;
 449                 ov->range_limit.u = val2;
 450                 ov->list_mode = LM_UNSIGNED_INTERVAL;
 451
 452                 /* as if entering on the top */
 453                 *obj = ov->range_next.u;
 454                 return;
 455             }
 456         }
 457     }
 458     error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 459                (ov->list_mode == LM_NONE) ? "a uint64 value" :
 460                                             "a uint64 value or range");
 461 }
 462
 463
 464 static void
 465 opts_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp)
 466 {
 467     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 468     const QemuOpt *opt;
 469     int64_t val;
 470     char *endptr;
 471
 472     opt = lookup_scalar(ov, name, errp);
 473     if (!opt) {
 474         return;
 475     }
 476
 477     val = strtosz_suffix(opt->str ? opt->str : "", &endptr,
 478                          STRTOSZ_DEFSUFFIX_B);
 479     if (val < 0 || *endptr) {
 480         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 481                    "a size value representible as a non-negative int64");
 482         return;
 483     }
 484
 485     *obj = val;
 486     processed(ov, name);
 487 }
 488
 489
 490 static void
 491 opts_optional(Visitor *v, bool *present, const char *name, Error **errp)
 492 {
 493     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 494
 495     /* we only support a single mandatory scalar field in a list node */
 496     assert(ov->list_mode == LM_NONE);
 497     *present = (lookup_distinct(ov, name, NULL) != NULL);
 498 }
 499
 500
 501 OptsVisitor *
 502 opts_visitor_new(const QemuOpts *opts)
 503 {
 504     OptsVisitor *ov;
 505
 506     ov = g_malloc0(sizeof *ov);
 507
 508     ov->visitor.start_struct = &opts_start_struct;
 509     ov->visitor.end_struct   = &opts_end_struct;
 510
 511     ov->visitor.start_list = &opts_start_list;
 512     ov->visitor.next_list  = &opts_next_list;
 513     ov->visitor.end_list   = &opts_end_list;
 514
 515     /* input_type_enum() covers both "normal" enums and union discriminators.
 516      * The union discriminator field is always generated as "type"; it should
 517      * match the "type" QemuOpt child of any QemuOpts.
 518      *
 519      * input_type_enum() will remove the looked-up key from the
 520      * "unprocessed_opts" hash even if the lookup fails, because the removal is
 521      * done earlier in opts_type_str(). This should be harmless.
 522      */
 523     ov->visitor.type_enum = &input_type_enum;
 524
 525     ov->visitor.type_int    = &opts_type_int;
 526     ov->visitor.type_uint64 = &opts_type_uint64;
 527     ov->visitor.type_size   = &opts_type_size;
 528     ov->visitor.type_bool   = &opts_type_bool;
 529     ov->visitor.type_str    = &opts_type_str;
 530
 531     /* type_number() is not filled in, but this is not the first visitor to
 532      * skip some mandatory methods... */
 533
 534     ov->visitor.optional = &opts_optional;
 535
 536     ov->opts_root = opts;
 537
 538     return ov;
 539 }
 540
 541
 542 void
 543 opts_visitor_cleanup(OptsVisitor *ov)
 544 {
 545     if (ov->unprocessed_opts != NULL) {
 546         g_hash_table_destroy(ov->unprocessed_opts);
 547     }
 548     g_free(ov->fake_id_opt);
 549     g_free(ov);
 550 }
 551
 552
 553 Visitor *
 554 opts_get_visitor(OptsVisitor *ov)
 555 {
 556     return &ov->visitor;
 557 }