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 = "id";
 147         ov->fake_id_opt->str = 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_set(errp, QERR_INVALID_PARAMETER, first->name);
 177     }
 178     g_hash_table_destroy(ov->unprocessed_opts);
 179     ov->unprocessed_opts = NULL;
 180     g_free(ov->fake_id_opt);
 181     ov->fake_id_opt = NULL;
 182 }
 183
 184
 185 static GQueue *
 186 lookup_distinct(const OptsVisitor *ov, const char *name, Error **errp)
 187 {
 188     GQueue *list;
 189
 190     list = g_hash_table_lookup(ov->unprocessed_opts, name);
 191     if (!list) {
 192         error_set(errp, QERR_MISSING_PARAMETER, name);
 193     }
 194     return list;
 195 }
 196
 197
 198 static void
 199 opts_start_list(Visitor *v, const char *name, Error **errp)
 200 {
 201     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 202
 203     /* we can't traverse a list in a list */
 204     assert(ov->list_mode == LM_NONE);
 205     ov->repeated_opts = lookup_distinct(ov, name, errp);
 206     if (ov->repeated_opts != NULL) {
 207         ov->list_mode = LM_STARTED;
 208     }
 209 }
 210
 211
 212 static GenericList *
 213 opts_next_list(Visitor *v, GenericList **list, Error **errp)
 214 {
 215     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 216     GenericList **link;
 217
 218     switch (ov->list_mode) {
 219     case LM_STARTED:
 220         ov->list_mode = LM_IN_PROGRESS;
 221         link = list;
 222         break;
 223
 224     case LM_SIGNED_INTERVAL:
 225     case LM_UNSIGNED_INTERVAL:
 226         link = &(*list)->next;
 227
 228         if (ov->list_mode == LM_SIGNED_INTERVAL) {
 229             if (ov->range_next.s < ov->range_limit.s) {
 230                 ++ov->range_next.s;
 231                 break;
 232             }
 233         } else if (ov->range_next.u < ov->range_limit.u) {
 234             ++ov->range_next.u;
 235             break;
 236         }
 237         ov->list_mode = LM_IN_PROGRESS;
 238         /* range has been completed, fall through in order to pop option */
 239
 240     case LM_IN_PROGRESS: {
 241         const QemuOpt *opt;
 242
 243         opt = g_queue_pop_head(ov->repeated_opts);
 244         if (g_queue_is_empty(ov->repeated_opts)) {
 245             g_hash_table_remove(ov->unprocessed_opts, opt->name);
 246             return NULL;
 247         }
 248         link = &(*list)->next;
 249         break;
 250     }
 251
 252     default:
 253         abort();
 254     }
 255
 256     *link = g_malloc0(sizeof **link);
 257     return *link;
 258 }
 259
 260
 261 static void
 262 opts_end_list(Visitor *v, Error **errp)
 263 {
 264     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 265
 266     assert(ov->list_mode == LM_STARTED ||
 267            ov->list_mode == LM_IN_PROGRESS ||
 268            ov->list_mode == LM_SIGNED_INTERVAL ||
 269            ov->list_mode == LM_UNSIGNED_INTERVAL);
 270     ov->repeated_opts = NULL;
 271     ov->list_mode = LM_NONE;
 272 }
 273
 274
 275 static const QemuOpt *
 276 lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp)
 277 {
 278     if (ov->list_mode == LM_NONE) {
 279         GQueue *list;
 280
 281         /* the last occurrence of any QemuOpt takes effect when queried by name
 282          */
 283         list = lookup_distinct(ov, name, errp);
 284         return list ? g_queue_peek_tail(list) : NULL;
 285     }
 286     assert(ov->list_mode == LM_IN_PROGRESS);
 287     return g_queue_peek_head(ov->repeated_opts);
 288 }
 289
 290
 291 static void
 292 processed(OptsVisitor *ov, const char *name)
 293 {
 294     if (ov->list_mode == LM_NONE) {
 295         g_hash_table_remove(ov->unprocessed_opts, name);
 296         return;
 297     }
 298     assert(ov->list_mode == LM_IN_PROGRESS);
 299     /* do nothing */
 300 }
 301
 302
 303 static void
 304 opts_type_str(Visitor *v, char **obj, const char *name, Error **errp)
 305 {
 306     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 307     const QemuOpt *opt;
 308
 309     opt = lookup_scalar(ov, name, errp);
 310     if (!opt) {
 311         return;
 312     }
 313     *obj = g_strdup(opt->str ? opt->str : "");
 314     processed(ov, name);
 315 }
 316
 317
 318 /* mimics qemu-option.c::parse_option_bool() */
 319 static void
 320 opts_type_bool(Visitor *v, bool *obj, const char *name, Error **errp)
 321 {
 322     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 323     const QemuOpt *opt;
 324
 325     opt = lookup_scalar(ov, name, errp);
 326     if (!opt) {
 327         return;
 328     }
 329
 330     if (opt->str) {
 331         if (strcmp(opt->str, "on") == 0 ||
 332             strcmp(opt->str, "yes") == 0 ||
 333             strcmp(opt->str, "y") == 0) {
 334             *obj = true;
 335         } else if (strcmp(opt->str, "off") == 0 ||
 336             strcmp(opt->str, "no") == 0 ||
 337             strcmp(opt->str, "n") == 0) {
 338             *obj = false;
 339         } else {
 340             error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 341                 "on|yes|y|off|no|n");
 342             return;
 343         }
 344     } else {
 345         *obj = true;
 346     }
 347
 348     processed(ov, name);
 349 }
 350
 351
 352 static void
 353 opts_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
 354 {
 355     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 356     const QemuOpt *opt;
 357     const char *str;
 358     long long val;
 359     char *endptr;
 360
 361     if (ov->list_mode == LM_SIGNED_INTERVAL) {
 362         *obj = ov->range_next.s;
 363         return;
 364     }
 365
 366     opt = lookup_scalar(ov, name, errp);
 367     if (!opt) {
 368         return;
 369     }
 370     str = opt->str ? opt->str : "";
 371
 372     /* we've gotten past lookup_scalar() */
 373     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 374
 375     errno = 0;
 376     val = strtoll(str, &endptr, 0);
 377     if (errno == 0 && endptr > str && INT64_MIN <= val && val <= INT64_MAX) {
 378         if (*endptr == '\0') {
 379             *obj = val;
 380             processed(ov, name);
 381             return;
 382         }
 383         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 384             long long val2;
 385
 386             str = endptr + 1;
 387             val2 = strtoll(str, &endptr, 0);
 388             if (errno == 0 && endptr > str && *endptr == '\0' &&
 389                 INT64_MIN <= val2 && val2 <= INT64_MAX && val <= val2 &&
 390                 (val > INT64_MAX - OPTS_VISITOR_RANGE_MAX ||
 391                  val2 < val + OPTS_VISITOR_RANGE_MAX)) {
 392                 ov->range_next.s = val;
 393                 ov->range_limit.s = val2;
 394                 ov->list_mode = LM_SIGNED_INTERVAL;
 395
 396                 /* as if entering on the top */
 397                 *obj = ov->range_next.s;
 398                 return;
 399             }
 400         }
 401     }
 402     error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 403               (ov->list_mode == LM_NONE) ? "an int64 value" :
 404                                            "an int64 value or range");
 405 }
 406
 407
 408 static void
 409 opts_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp)
 410 {
 411     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 412     const QemuOpt *opt;
 413     const char *str;
 414     unsigned long long val;
 415     char *endptr;
 416
 417     if (ov->list_mode == LM_UNSIGNED_INTERVAL) {
 418         *obj = ov->range_next.u;
 419         return;
 420     }
 421
 422     opt = lookup_scalar(ov, name, errp);
 423     if (!opt) {
 424         return;
 425     }
 426     str = opt->str;
 427
 428     /* we've gotten past lookup_scalar() */
 429     assert(ov->list_mode == LM_NONE || ov->list_mode == LM_IN_PROGRESS);
 430
 431     if (parse_uint(str, &val, &endptr, 0) == 0 && val <= UINT64_MAX) {
 432         if (*endptr == '\0') {
 433             *obj = val;
 434             processed(ov, name);
 435             return;
 436         }
 437         if (*endptr == '-' && ov->list_mode == LM_IN_PROGRESS) {
 438             unsigned long long val2;
 439
 440             str = endptr + 1;
 441             if (parse_uint_full(str, &val2, 0) == 0 &&
 442                 val2 <= UINT64_MAX && val <= val2 &&
 443                 val2 - val < OPTS_VISITOR_RANGE_MAX) {
 444                 ov->range_next.u = val;
 445                 ov->range_limit.u = val2;
 446                 ov->list_mode = LM_UNSIGNED_INTERVAL;
 447
 448                 /* as if entering on the top */
 449                 *obj = ov->range_next.u;
 450                 return;
 451             }
 452         }
 453     }
 454     error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 455               (ov->list_mode == LM_NONE) ? "a uint64 value" :
 456                                            "a uint64 value or range");
 457 }
 458
 459
 460 static void
 461 opts_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp)
 462 {
 463     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 464     const QemuOpt *opt;
 465     int64_t val;
 466     char *endptr;
 467
 468     opt = lookup_scalar(ov, name, errp);
 469     if (!opt) {
 470         return;
 471     }
 472
 473     val = strtosz_suffix(opt->str ? opt->str : "", &endptr,
 474                          STRTOSZ_DEFSUFFIX_B);
 475     if (val < 0 || *endptr) {
 476         error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
 477                   "a size value representible as a non-negative int64");
 478         return;
 479     }
 480
 481     *obj = val;
 482     processed(ov, name);
 483 }
 484
 485
 486 static void
 487 opts_optional(Visitor *v, bool *present, const char *name, Error **errp)
 488 {
 489     OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
 490
 491     /* we only support a single mandatory scalar field in a list node */
 492     assert(ov->list_mode == LM_NONE);
 493     *present = (lookup_distinct(ov, name, NULL) != NULL);
 494 }
 495
 496
 497 OptsVisitor *
 498 opts_visitor_new(const QemuOpts *opts)
 499 {
 500     OptsVisitor *ov;
 501
 502     ov = g_malloc0(sizeof *ov);
 503
 504     ov->visitor.start_struct = &opts_start_struct;
 505     ov->visitor.end_struct   = &opts_end_struct;
 506
 507     ov->visitor.start_list = &opts_start_list;
 508     ov->visitor.next_list  = &opts_next_list;
 509     ov->visitor.end_list   = &opts_end_list;
 510
 511     /* input_type_enum() covers both "normal" enums and union discriminators.
 512      * The union discriminator field is always generated as "type"; it should
 513      * match the "type" QemuOpt child of any QemuOpts.
 514      *
 515      * input_type_enum() will remove the looked-up key from the
 516      * "unprocessed_opts" hash even if the lookup fails, because the removal is
 517      * done earlier in opts_type_str(). This should be harmless.
 518      */
 519     ov->visitor.type_enum = &input_type_enum;
 520
 521     ov->visitor.type_int    = &opts_type_int;
 522     ov->visitor.type_uint64 = &opts_type_uint64;
 523     ov->visitor.type_size   = &opts_type_size;
 524     ov->visitor.type_bool   = &opts_type_bool;
 525     ov->visitor.type_str    = &opts_type_str;
 526
 527     /* type_number() is not filled in, but this is not the first visitor to
 528      * skip some mandatory methods... */
 529
 530     ov->visitor.optional = &opts_optional;
 531
 532     ov->opts_root = opts;
 533
 534     return ov;
 535 }
 536
 537
 538 void
 539 opts_visitor_cleanup(OptsVisitor *ov)
 540 {
 541     if (ov->unprocessed_opts != NULL) {
 542         g_hash_table_destroy(ov->unprocessed_opts);
 543     }
 544     g_free(ov->fake_id_opt);
 545     g_free(ov);
 546 }
 547
 548
 549 Visitor *
 550 opts_get_visitor(OptsVisitor *ov)
 551 {
 552     return &ov->visitor;
 553 }