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     /* Note that we consume a string even if this is called as part of
 321      * an enum visit that later fails because the string is not a
 322      * valid enum value; this is harmless because tracking what gets
 323      * consumed only matters to visit_end_struct() as the final error
 324      * check if there were no other failures during the visit.  */
 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.type = VISITOR_INPUT;
 516
 517     ov->visitor.start_struct = &opts_start_struct;
 518     ov->visitor.end_struct   = &opts_end_struct;
 519
 520     ov->visitor.start_list = &opts_start_list;
 521     ov->visitor.next_list  = &opts_next_list;
 522     ov->visitor.end_list   = &opts_end_list;
 523
 524     ov->visitor.type_int64  = &opts_type_int64;
 525     ov->visitor.type_uint64 = &opts_type_uint64;
 526     ov->visitor.type_size   = &opts_type_size;
 527     ov->visitor.type_bool   = &opts_type_bool;
 528     ov->visitor.type_str    = &opts_type_str;
 529
 530     /* type_number() is not filled in, but this is not the first visitor to
 531      * skip some mandatory methods... */
 532
 533     ov->visitor.optional = &opts_optional;
 534
 535     ov->opts_root = opts;
 536
 537     return ov;
 538 }
 539
 540
 541 void
 542 opts_visitor_cleanup(OptsVisitor *ov)
 543 {
 544     if (ov->unprocessed_opts != NULL) {
 545         g_hash_table_destroy(ov->unprocessed_opts);
 546     }
 547     g_free(ov->fake_id_opt);
 548     g_free(ov);
 549 }
 550
 551
 552 Visitor *
 553 opts_get_visitor(OptsVisitor *ov)
 554 {
 555     return &ov->visitor;
 556 }