util/qemu-option.c

   1 /*
   2  * Commandline option parsing functions
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  * Copyright (c) 2009 Kevin Wolf <kwolf@redhat.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include <stdio.h>
  27 #include <string.h>
  28
  29 #include "qemu-common.h"
  30 #include "qemu/error-report.h"
  31 #include "qapi/qmp/types.h"
  32 #include "qapi/error.h"
  33 #include "qapi/qmp/qerror.h"
  34 #include "qemu/option_int.h"
  35
  36 /*
  37  * Extracts the name of an option from the parameter string (p points at the
  38  * first byte of the option name)
  39  *
  40  * The option name is delimited by delim (usually , or =) or the string end
  41  * and is copied into buf. If the option name is longer than buf_size, it is
  42  * truncated. buf is always zero terminated.
  43  *
  44  * The return value is the position of the delimiter/zero byte after the option
  45  * name in p.
  46  */
  47 const char *get_opt_name(char *buf, int buf_size, const char *p, char delim)
  48 {
  49     char *q;
  50
  51     q = buf;
  52     while (*p != '\0' && *p != delim) {
  53         if (q && (q - buf) < buf_size - 1)
  54             *q++ = *p;
  55         p++;
  56     }
  57     if (q)
  58         *q = '\0';
  59
  60     return p;
  61 }
  62
  63 /*
  64  * Extracts the value of an option from the parameter string p (p points at the
  65  * first byte of the option value)
  66  *
  67  * This function is comparable to get_opt_name with the difference that the
  68  * delimiter is fixed to be comma which starts a new option. To specify an
  69  * option value that contains commas, double each comma.
  70  */
  71 const char *get_opt_value(char *buf, int buf_size, const char *p)
  72 {
  73     char *q;
  74
  75     q = buf;
  76     while (*p != '\0') {
  77         if (*p == ',') {
  78             if (*(p + 1) != ',')
  79                 break;
  80             p++;
  81         }
  82         if (q && (q - buf) < buf_size - 1)
  83             *q++ = *p;
  84         p++;
  85     }
  86     if (q)
  87         *q = '\0';
  88
  89     return p;
  90 }
  91
  92 int get_next_param_value(char *buf, int buf_size,
  93                          const char *tag, const char **pstr)
  94 {
  95     const char *p;
  96     char option[128];
  97
  98     p = *pstr;
  99     for(;;) {
 100         p = get_opt_name(option, sizeof(option), p, '=');
 101         if (*p != '=')
 102             break;
 103         p++;
 104         if (!strcmp(tag, option)) {
 105             *pstr = get_opt_value(buf, buf_size, p);
 106             if (**pstr == ',') {
 107                 (*pstr)++;
 108             }
 109             return strlen(buf);
 110         } else {
 111             p = get_opt_value(NULL, 0, p);
 112         }
 113         if (*p != ',')
 114             break;
 115         p++;
 116     }
 117     return 0;
 118 }
 119
 120 int get_param_value(char *buf, int buf_size,
 121                     const char *tag, const char *str)
 122 {
 123     return get_next_param_value(buf, buf_size, tag, &str);
 124 }
 125
 126 static void parse_option_bool(const char *name, const char *value, bool *ret,
 127                               Error **errp)
 128 {
 129     if (value != NULL) {
 130         if (!strcmp(value, "on")) {
 131             *ret = 1;
 132         } else if (!strcmp(value, "off")) {
 133             *ret = 0;
 134         } else {
 135             error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
 136                        name, "'on' or 'off'");
 137         }
 138     } else {
 139         *ret = 1;
 140     }
 141 }
 142
 143 static void parse_option_number(const char *name, const char *value,
 144                                 uint64_t *ret, Error **errp)
 145 {
 146     char *postfix;
 147     uint64_t number;
 148
 149     if (value != NULL) {
 150         number = strtoull(value, &postfix, 0);
 151         if (*postfix != '\0') {
 152             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
 153             return;
 154         }
 155         *ret = number;
 156     } else {
 157         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
 158     }
 159 }
 160
 161 static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,
 162                                             const char *name)
 163 {
 164     int i;
 165
 166     for (i = 0; desc[i].name != NULL; i++) {
 167         if (strcmp(desc[i].name, name) == 0) {
 168             return &desc[i];
 169         }
 170     }
 171
 172     return NULL;
 173 }
 174
 175 void parse_option_size(const char *name, const char *value,
 176                        uint64_t *ret, Error **errp)
 177 {
 178     char *postfix;
 179     double sizef;
 180
 181     if (value != NULL) {
 182         sizef = strtod(value, &postfix);
 183         if (sizef < 0 || sizef > UINT64_MAX) {
 184             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
 185                              "a non-negative number below 2^64");
 186             return;
 187         }
 188         switch (*postfix) {
 189         case 'T':
 190             sizef *= 1024;
 191             /* fall through */
 192         case 'G':
 193             sizef *= 1024;
 194             /* fall through */
 195         case 'M':
 196             sizef *= 1024;
 197             /* fall through */
 198         case 'K':
 199         case 'k':
 200             sizef *= 1024;
 201             /* fall through */
 202         case 'b':
 203         case '\0':
 204             *ret = (uint64_t) sizef;
 205             break;
 206         default:
 207             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");
 208 #if 0 /* conversion from qerror_report() to error_set() broke this: */
 209             error_printf_unless_qmp("You may use k, M, G or T suffixes for "
 210                     "kilobytes, megabytes, gigabytes and terabytes.\n");
 211 #endif
 212             return;
 213         }
 214     } else {
 215         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");
 216     }
 217 }
 218
 219 bool has_help_option(const char *param)
 220 {
 221     size_t buflen = strlen(param) + 1;
 222     char *buf = g_malloc(buflen);
 223     const char *p = param;
 224     bool result = false;
 225
 226     while (*p) {
 227         p = get_opt_value(buf, buflen, p);
 228         if (*p) {
 229             p++;
 230         }
 231
 232         if (is_help_option(buf)) {
 233             result = true;
 234             goto out;
 235         }
 236     }
 237
 238 out:
 239     g_free(buf);
 240     return result;
 241 }
 242
 243 bool is_valid_option_list(const char *param)
 244 {
 245     size_t buflen = strlen(param) + 1;
 246     char *buf = g_malloc(buflen);
 247     const char *p = param;
 248     bool result = true;
 249
 250     while (*p) {
 251         p = get_opt_value(buf, buflen, p);
 252         if (*p && !*++p) {
 253             result = false;
 254             goto out;
 255         }
 256
 257         if (!*buf || *buf == ',') {
 258             result = false;
 259             goto out;
 260         }
 261     }
 262
 263 out:
 264     g_free(buf);
 265     return result;
 266 }
 267
 268 void qemu_opts_print_help(QemuOptsList *list)
 269 {
 270     QemuOptDesc *desc;
 271
 272     assert(list);
 273     desc = list->desc;
 274     printf("Supported options:\n");
 275     while (desc && desc->name) {
 276         printf("%-16s %s\n", desc->name,
 277                desc->help ? desc->help : "No description available");
 278         desc++;
 279     }
 280 }
 281 /* ------------------------------------------------------------------ */
 282
 283 QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
 284 {
 285     QemuOpt *opt;
 286
 287     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
 288         if (strcmp(opt->name, name) != 0)
 289             continue;
 290         return opt;
 291     }
 292     return NULL;
 293 }
 294
 295 static void qemu_opt_del(QemuOpt *opt)
 296 {
 297     QTAILQ_REMOVE(&opt->opts->head, opt, next);
 298     g_free(opt->name);
 299     g_free(opt->str);
 300     g_free(opt);
 301 }
 302
 303 /* qemu_opt_set allows many settings for the same option.
 304  * This function deletes all settings for an option.
 305  */
 306 static void qemu_opt_del_all(QemuOpts *opts, const char *name)
 307 {
 308     QemuOpt *opt, *next_opt;
 309
 310     QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next_opt) {
 311         if (!strcmp(opt->name, name)) {
 312             qemu_opt_del(opt);
 313         }
 314     }
 315 }
 316
 317 const char *qemu_opt_get(QemuOpts *opts, const char *name)
 318 {
 319     QemuOpt *opt;
 320
 321     if (opts == NULL) {
 322         return NULL;
 323     }
 324
 325     opt = qemu_opt_find(opts, name);
 326     if (!opt) {
 327         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
 328         if (desc && desc->def_value_str) {
 329             return desc->def_value_str;
 330         }
 331     }
 332     return opt ? opt->str : NULL;
 333 }
 334
 335 /* Get a known option (or its default) and remove it from the list
 336  * all in one action. Return a malloced string of the option value.
 337  * Result must be freed by caller with g_free().
 338  */
 339 char *qemu_opt_get_del(QemuOpts *opts, const char *name)
 340 {
 341     QemuOpt *opt;
 342     const QemuOptDesc *desc;
 343     char *str = NULL;
 344
 345     if (opts == NULL) {
 346         return NULL;
 347     }
 348
 349     opt = qemu_opt_find(opts, name);
 350     if (!opt) {
 351         desc = find_desc_by_name(opts->list->desc, name);
 352         if (desc && desc->def_value_str) {
 353             str = g_strdup(desc->def_value_str);
 354         }
 355         return str;
 356     }
 357     str = opt->str;
 358     opt->str = NULL;
 359     qemu_opt_del_all(opts, name);
 360     return str;
 361 }
 362
 363 bool qemu_opt_has_help_opt(QemuOpts *opts)
 364 {
 365     QemuOpt *opt;
 366
 367     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
 368         if (is_help_option(opt->name)) {
 369             return true;
 370         }
 371     }
 372     return false;
 373 }
 374
 375 static bool qemu_opt_get_bool_helper(QemuOpts *opts, const char *name,
 376                                      bool defval, bool del)
 377 {
 378     QemuOpt *opt;
 379     bool ret = defval;
 380
 381     if (opts == NULL) {
 382         return ret;
 383     }
 384
 385     opt = qemu_opt_find(opts, name);
 386     if (opt == NULL) {
 387         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
 388         if (desc && desc->def_value_str) {
 389             parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
 390         }
 391         return ret;
 392     }
 393     assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
 394     ret = opt->value.boolean;
 395     if (del) {
 396         qemu_opt_del_all(opts, name);
 397     }
 398     return ret;
 399 }
 400
 401 bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
 402 {
 403     return qemu_opt_get_bool_helper(opts, name, defval, false);
 404 }
 405
 406 bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval)
 407 {
 408     return qemu_opt_get_bool_helper(opts, name, defval, true);
 409 }
 410
 411 static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
 412                                            uint64_t defval, bool del)
 413 {
 414     QemuOpt *opt;
 415     uint64_t ret = defval;
 416
 417     if (opts == NULL) {
 418         return ret;
 419     }
 420
 421     opt = qemu_opt_find(opts, name);
 422     if (opt == NULL) {
 423         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
 424         if (desc && desc->def_value_str) {
 425             parse_option_number(name, desc->def_value_str, &ret, &error_abort);
 426         }
 427         return ret;
 428     }
 429     assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
 430     ret = opt->value.uint;
 431     if (del) {
 432         qemu_opt_del_all(opts, name);
 433     }
 434     return ret;
 435 }
 436
 437 uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
 438 {
 439     return qemu_opt_get_number_helper(opts, name, defval, false);
 440 }
 441
 442 uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
 443                                  uint64_t defval)
 444 {
 445     return qemu_opt_get_number_helper(opts, name, defval, true);
 446 }
 447
 448 static uint64_t qemu_opt_get_size_helper(QemuOpts *opts, const char *name,
 449                                          uint64_t defval, bool del)
 450 {
 451     QemuOpt *opt;
 452     uint64_t ret = defval;
 453
 454     if (opts == NULL) {
 455         return ret;
 456     }
 457
 458     opt = qemu_opt_find(opts, name);
 459     if (opt == NULL) {
 460         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
 461         if (desc && desc->def_value_str) {
 462             parse_option_size(name, desc->def_value_str, &ret, &error_abort);
 463         }
 464         return ret;
 465     }
 466     assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
 467     ret = opt->value.uint;
 468     if (del) {
 469         qemu_opt_del_all(opts, name);
 470     }
 471     return ret;
 472 }
 473
 474 uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
 475 {
 476     return qemu_opt_get_size_helper(opts, name, defval, false);
 477 }
 478
 479 uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
 480                                uint64_t defval)
 481 {
 482     return qemu_opt_get_size_helper(opts, name, defval, true);
 483 }
 484
 485 static void qemu_opt_parse(QemuOpt *opt, Error **errp)
 486 {
 487     if (opt->desc == NULL)
 488         return;
 489
 490     switch (opt->desc->type) {
 491     case QEMU_OPT_STRING:
 492         /* nothing */
 493         return;
 494     case QEMU_OPT_BOOL:
 495         parse_option_bool(opt->name, opt->str, &opt->value.boolean, errp);
 496         break;
 497     case QEMU_OPT_NUMBER:
 498         parse_option_number(opt->name, opt->str, &opt->value.uint, errp);
 499         break;
 500     case QEMU_OPT_SIZE:
 501         parse_option_size(opt->name, opt->str, &opt->value.uint, errp);
 502         break;
 503     default:
 504         abort();
 505     }
 506 }
 507
 508 static bool opts_accepts_any(const QemuOpts *opts)
 509 {
 510     return opts->list->desc[0].name == NULL;
 511 }
 512
 513 int qemu_opt_unset(QemuOpts *opts, const char *name)
 514 {
 515     QemuOpt *opt = qemu_opt_find(opts, name);
 516
 517     assert(opts_accepts_any(opts));
 518
 519     if (opt == NULL) {
 520         return -1;
 521     } else {
 522         qemu_opt_del(opt);
 523         return 0;
 524     }
 525 }
 526
 527 static void opt_set(QemuOpts *opts, const char *name, const char *value,
 528                     bool prepend, Error **errp)
 529 {
 530     QemuOpt *opt;
 531     const QemuOptDesc *desc;
 532     Error *local_err = NULL;
 533
 534     desc = find_desc_by_name(opts->list->desc, name);
 535     if (!desc && !opts_accepts_any(opts)) {
 536         error_setg(errp, QERR_INVALID_PARAMETER, name);
 537         return;
 538     }
 539
 540     opt = g_malloc0(sizeof(*opt));
 541     opt->name = g_strdup(name);
 542     opt->opts = opts;
 543     if (prepend) {
 544         QTAILQ_INSERT_HEAD(&opts->head, opt, next);
 545     } else {
 546         QTAILQ_INSERT_TAIL(&opts->head, opt, next);
 547     }
 548     opt->desc = desc;
 549     opt->str = g_strdup(value);
 550     qemu_opt_parse(opt, &local_err);
 551     if (local_err) {
 552         error_propagate(errp, local_err);
 553         qemu_opt_del(opt);
 554     }
 555 }
 556
 557 void qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
 558                   Error **errp)
 559 {
 560     opt_set(opts, name, value, false, errp);
 561 }
 562
 563 void qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val,
 564                        Error **errp)
 565 {
 566     QemuOpt *opt;
 567     const QemuOptDesc *desc = opts->list->desc;
 568
 569     opt = g_malloc0(sizeof(*opt));
 570     opt->desc = find_desc_by_name(desc, name);
 571     if (!opt->desc && !opts_accepts_any(opts)) {
 572         error_setg(errp, QERR_INVALID_PARAMETER, name);
 573         g_free(opt);
 574         return;
 575     }
 576
 577     opt->name = g_strdup(name);
 578     opt->opts = opts;
 579     opt->value.boolean = !!val;
 580     opt->str = g_strdup(val ? "on" : "off");
 581     QTAILQ_INSERT_TAIL(&opts->head, opt, next);
 582 }
 583
 584 void qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val,
 585                          Error **errp)
 586 {
 587     QemuOpt *opt;
 588     const QemuOptDesc *desc = opts->list->desc;
 589
 590     opt = g_malloc0(sizeof(*opt));
 591     opt->desc = find_desc_by_name(desc, name);
 592     if (!opt->desc && !opts_accepts_any(opts)) {
 593         error_setg(errp, QERR_INVALID_PARAMETER, name);
 594         g_free(opt);
 595         return;
 596     }
 597
 598     opt->name = g_strdup(name);
 599     opt->opts = opts;
 600     opt->value.uint = val;
 601     opt->str = g_strdup_printf("%" PRId64, val);
 602     QTAILQ_INSERT_TAIL(&opts->head, opt, next);
 603 }
 604
 605 /**
 606  * For each member of @opts, call @func(@opaque, name, value, @errp).
 607  * @func() may store an Error through @errp, but must return non-zero then.
 608  * When @func() returns non-zero, break the loop and return that value.
 609  * Return zero when the loop completes.
 610  */
 611 int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
 612                      Error **errp)
 613 {
 614     QemuOpt *opt;
 615     int rc;
 616
 617     QTAILQ_FOREACH(opt, &opts->head, next) {
 618         rc = func(opaque, opt->name, opt->str, errp);
 619         if (rc) {
 620             return rc;
 621         }
 622         assert(!errp || !*errp);
 623     }
 624     return 0;
 625 }
 626
 627 QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
 628 {
 629     QemuOpts *opts;
 630
 631     QTAILQ_FOREACH(opts, &list->head, next) {
 632         if (!opts->id && !id) {
 633             return opts;
 634         }
 635         if (opts->id && id && !strcmp(opts->id, id)) {
 636             return opts;
 637         }
 638     }
 639     return NULL;
 640 }
 641
 642 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
 643                            int fail_if_exists, Error **errp)
 644 {
 645     QemuOpts *opts = NULL;
 646
 647     if (id) {
 648         if (!id_wellformed(id)) {
 649             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
 650                        "an identifier");
 651 #if 0 /* conversion from qerror_report() to error_set() broke this: */
 652             error_printf_unless_qmp("Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.\n");
 653 #endif
 654             return NULL;
 655         }
 656         opts = qemu_opts_find(list, id);
 657         if (opts != NULL) {
 658             if (fail_if_exists && !list->merge_lists) {
 659                 error_setg(errp, "Duplicate ID '%s' for %s", id, list->name);
 660                 return NULL;
 661             } else {
 662                 return opts;
 663             }
 664         }
 665     } else if (list->merge_lists) {
 666         opts = qemu_opts_find(list, NULL);
 667         if (opts) {
 668             return opts;
 669         }
 670     }
 671     opts = g_malloc0(sizeof(*opts));
 672     opts->id = g_strdup(id);
 673     opts->list = list;
 674     loc_save(&opts->loc);
 675     QTAILQ_INIT(&opts->head);
 676     QTAILQ_INSERT_TAIL(&list->head, opts, next);
 677     return opts;
 678 }
 679
 680 void qemu_opts_reset(QemuOptsList *list)
 681 {
 682     QemuOpts *opts, *next_opts;
 683
 684     QTAILQ_FOREACH_SAFE(opts, &list->head, next, next_opts) {
 685         qemu_opts_del(opts);
 686     }
 687 }
 688
 689 void qemu_opts_loc_restore(QemuOpts *opts)
 690 {
 691     loc_restore(&opts->loc);
 692 }
 693
 694 void qemu_opts_set(QemuOptsList *list, const char *id,
 695                    const char *name, const char *value, Error **errp)
 696 {
 697     QemuOpts *opts;
 698     Error *local_err = NULL;
 699
 700     opts = qemu_opts_create(list, id, 1, &local_err);
 701     if (local_err) {
 702         error_propagate(errp, local_err);
 703         return;
 704     }
 705     qemu_opt_set(opts, name, value, errp);
 706 }
 707
 708 const char *qemu_opts_id(QemuOpts *opts)
 709 {
 710     return opts->id;
 711 }
 712
 713 /* The id string will be g_free()d by qemu_opts_del */
 714 void qemu_opts_set_id(QemuOpts *opts, char *id)
 715 {
 716     opts->id = id;
 717 }
 718
 719 void qemu_opts_del(QemuOpts *opts)
 720 {
 721     QemuOpt *opt;
 722
 723     if (opts == NULL) {
 724         return;
 725     }
 726
 727     for (;;) {
 728         opt = QTAILQ_FIRST(&opts->head);
 729         if (opt == NULL)
 730             break;
 731         qemu_opt_del(opt);
 732     }
 733     QTAILQ_REMOVE(&opts->list->head, opts, next);
 734     g_free(opts->id);
 735     g_free(opts);
 736 }
 737
 738 /* print value, escaping any commas in value */
 739 static void escaped_print(const char *value)
 740 {
 741     const char *ptr;
 742
 743     for (ptr = value; *ptr; ++ptr) {
 744         if (*ptr == ',') {
 745             putchar(',');
 746         }
 747         putchar(*ptr);
 748     }
 749 }
 750
 751 void qemu_opts_print(QemuOpts *opts, const char *separator)
 752 {
 753     QemuOpt *opt;
 754     QemuOptDesc *desc = opts->list->desc;
 755     const char *sep = "";
 756
 757     if (opts->id) {
 758         printf("id=%s", opts->id); /* passed id_wellformed -> no commas */
 759         sep = separator;
 760     }
 761
 762     if (desc[0].name == NULL) {
 763         QTAILQ_FOREACH(opt, &opts->head, next) {
 764             printf("%s%s=", sep, opt->name);
 765             escaped_print(opt->str);
 766             sep = separator;
 767         }
 768         return;
 769     }
 770     for (; desc && desc->name; desc++) {
 771         const char *value;
 772         QemuOpt *opt = qemu_opt_find(opts, desc->name);
 773
 774         value = opt ? opt->str : desc->def_value_str;
 775         if (!value) {
 776             continue;
 777         }
 778         if (desc->type == QEMU_OPT_STRING) {
 779             printf("%s%s=", sep, desc->name);
 780             escaped_print(value);
 781         } else if ((desc->type == QEMU_OPT_SIZE ||
 782                     desc->type == QEMU_OPT_NUMBER) && opt) {
 783             printf("%s%s=%" PRId64, sep, desc->name, opt->value.uint);
 784         } else {
 785             printf("%s%s=%s", sep, desc->name, value);
 786         }
 787         sep = separator;
 788     }
 789 }
 790
 791 static void opts_do_parse(QemuOpts *opts, const char *params,
 792                           const char *firstname, bool prepend, Error **errp)
 793 {
 794     char option[128], value[1024];
 795     const char *p,*pe,*pc;
 796     Error *local_err = NULL;
 797
 798     for (p = params; *p != '\0'; p++) {
 799         pe = strchr(p, '=');
 800         pc = strchr(p, ',');
 801         if (!pe || (pc && pc < pe)) {
 802             /* found "foo,more" */
 803             if (p == params && firstname) {
 804                 /* implicitly named first option */
 805                 pstrcpy(option, sizeof(option), firstname);
 806                 p = get_opt_value(value, sizeof(value), p);
 807             } else {
 808                 /* option without value, probably a flag */
 809                 p = get_opt_name(option, sizeof(option), p, ',');
 810                 if (strncmp(option, "no", 2) == 0) {
 811                     memmove(option, option+2, strlen(option+2)+1);
 812                     pstrcpy(value, sizeof(value), "off");
 813                 } else {
 814                     pstrcpy(value, sizeof(value), "on");
 815                 }
 816             }
 817         } else {
 818             /* found "foo=bar,more" */
 819             p = get_opt_name(option, sizeof(option), p, '=');
 820             if (*p != '=') {
 821                 break;
 822             }
 823             p++;
 824             p = get_opt_value(value, sizeof(value), p);
 825         }
 826         if (strcmp(option, "id") != 0) {
 827             /* store and parse */
 828             opt_set(opts, option, value, prepend, &local_err);
 829             if (local_err) {
 830                 error_propagate(errp, local_err);
 831                 return;
 832             }
 833         }
 834         if (*p != ',') {
 835             break;
 836         }
 837     }
 838 }
 839
 840 /**
 841  * Store options parsed from @params into @opts.
 842  * If @firstname is non-null, the first key=value in @params may omit
 843  * key=, and is treated as if key was @firstname.
 844  * On error, store an error object through @errp if non-null.
 845  */
 846 void qemu_opts_do_parse(QemuOpts *opts, const char *params,
 847                        const char *firstname, Error **errp)
 848 {
 849     opts_do_parse(opts, params, firstname, false, errp);
 850 }
 851
 852 static QemuOpts *opts_parse(QemuOptsList *list, const char *params,
 853                             bool permit_abbrev, bool defaults, Error **errp)
 854 {
 855     const char *firstname;
 856     char value[1024], *id = NULL;
 857     const char *p;
 858     QemuOpts *opts;
 859     Error *local_err = NULL;
 860
 861     assert(!permit_abbrev || list->implied_opt_name);
 862     firstname = permit_abbrev ? list->implied_opt_name : NULL;
 863
 864     if (strncmp(params, "id=", 3) == 0) {
 865         get_opt_value(value, sizeof(value), params+3);
 866         id = value;
 867     } else if ((p = strstr(params, ",id=")) != NULL) {
 868         get_opt_value(value, sizeof(value), p+4);
 869         id = value;
 870     }
 871
 872     /*
 873      * This code doesn't work for defaults && !list->merge_lists: when
 874      * params has no id=, and list has an element with !opts->id, it
 875      * appends a new element instead of returning the existing opts.
 876      * However, we got no use for this case.  Guard against possible
 877      * (if unlikely) future misuse:
 878      */
 879     assert(!defaults || list->merge_lists);
 880     opts = qemu_opts_create(list, id, !defaults, &local_err);
 881     if (opts == NULL) {
 882         error_propagate(errp, local_err);
 883         return NULL;
 884     }
 885
 886     opts_do_parse(opts, params, firstname, defaults, &local_err);
 887     if (local_err) {
 888         error_propagate(errp, local_err);
 889         qemu_opts_del(opts);
 890         return NULL;
 891     }
 892
 893     return opts;
 894 }
 895
 896 /**
 897  * Create a QemuOpts in @list and with options parsed from @params.
 898  * If @permit_abbrev, the first key=value in @params may omit key=,
 899  * and is treated as if key was @list->implied_opt_name.
 900  * On error, store an error object through @errp if non-null.
 901  * Return the new QemuOpts on success, null pointer on error.
 902  */
 903 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
 904                           bool permit_abbrev, Error **errp)
 905 {
 906     return opts_parse(list, params, permit_abbrev, false, errp);
 907 }
 908
 909 /**
 910  * Create a QemuOpts in @list and with options parsed from @params.
 911  * If @permit_abbrev, the first key=value in @params may omit key=,
 912  * and is treated as if key was @list->implied_opt_name.
 913  * Report errors with error_report_err().  This is inappropriate in
 914  * QMP context.  Do not use this function there!
 915  * Return the new QemuOpts on success, null pointer on error.
 916  */
 917 QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
 918                                   bool permit_abbrev)
 919 {
 920     Error *err = NULL;
 921     QemuOpts *opts;
 922
 923     opts = opts_parse(list, params, permit_abbrev, false, &err);
 924     if (err) {
 925         error_report_err(err);
 926     }
 927     return opts;
 928 }
 929
 930 void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
 931                             int permit_abbrev)
 932 {
 933     QemuOpts *opts;
 934
 935     opts = opts_parse(list, params, permit_abbrev, true, NULL);
 936     assert(opts);
 937 }
 938
 939 typedef struct OptsFromQDictState {
 940     QemuOpts *opts;
 941     Error **errp;
 942 } OptsFromQDictState;
 943
 944 static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)
 945 {
 946     OptsFromQDictState *state = opaque;
 947     char buf[32];
 948     const char *value;
 949     int n;
 950
 951     if (!strcmp(key, "id") || *state->errp) {
 952         return;
 953     }
 954
 955     switch (qobject_type(obj)) {
 956     case QTYPE_QSTRING:
 957         value = qstring_get_str(qobject_to_qstring(obj));
 958         break;
 959     case QTYPE_QINT:
 960         n = snprintf(buf, sizeof(buf), "%" PRId64,
 961                      qint_get_int(qobject_to_qint(obj)));
 962         assert(n < sizeof(buf));
 963         value = buf;
 964         break;
 965     case QTYPE_QFLOAT:
 966         n = snprintf(buf, sizeof(buf), "%.17g",
 967                      qfloat_get_double(qobject_to_qfloat(obj)));
 968         assert(n < sizeof(buf));
 969         value = buf;
 970         break;
 971     case QTYPE_QBOOL:
 972         pstrcpy(buf, sizeof(buf),
 973                 qbool_get_bool(qobject_to_qbool(obj)) ? "on" : "off");
 974         value = buf;
 975         break;
 976     default:
 977         return;
 978     }
 979
 980     qemu_opt_set(state->opts, key, value, state->errp);
 981 }
 982
 983 /*
 984  * Create QemuOpts from a QDict.
 985  * Use value of key "id" as ID if it exists and is a QString.
 986  * Only QStrings, QInts, QFloats and QBools are copied.  Entries with
 987  * other types are silently ignored.
 988  */
 989 QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
 990                                Error **errp)
 991 {
 992     OptsFromQDictState state;
 993     Error *local_err = NULL;
 994     QemuOpts *opts;
 995
 996     opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,
 997                             &local_err);
 998     if (local_err) {
 999         error_propagate(errp, local_err);
1000         return NULL;
1001     }
1002
1003     assert(opts != NULL);
1004
1005     state.errp = &local_err;
1006     state.opts = opts;
1007     qdict_iter(qdict, qemu_opts_from_qdict_1, &state);
1008     if (local_err) {
1009         error_propagate(errp, local_err);
1010         qemu_opts_del(opts);
1011         return NULL;
1012     }
1013
1014     return opts;
1015 }
1016
1017 /*
1018  * Adds all QDict entries to the QemuOpts that can be added and removes them
1019  * from the QDict. When this function returns, the QDict contains only those
1020  * entries that couldn't be added to the QemuOpts.
1021  */
1022 void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
1023 {
1024     const QDictEntry *entry, *next;
1025
1026     entry = qdict_first(qdict);
1027
1028     while (entry != NULL) {
1029         Error *local_err = NULL;
1030         OptsFromQDictState state = {
1031             .errp = &local_err,
1032             .opts = opts,
1033         };
1034
1035         next = qdict_next(qdict, entry);
1036
1037         if (find_desc_by_name(opts->list->desc, entry->key)) {
1038             qemu_opts_from_qdict_1(entry->key, entry->value, &state);
1039             if (local_err) {
1040                 error_propagate(errp, local_err);
1041                 return;
1042             } else {
1043                 qdict_del(qdict, entry->key);
1044             }
1045         }
1046
1047         entry = next;
1048     }
1049 }
1050
1051 /*
1052  * Convert from QemuOpts to QDict.
1053  * The QDict values are of type QString.
1054  * TODO We'll want to use types appropriate for opt->desc->type, but
1055  * this is enough for now.
1056  */
1057 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
1058 {
1059     QemuOpt *opt;
1060     QObject *val;
1061
1062     if (!qdict) {
1063         qdict = qdict_new();
1064     }
1065     if (opts->id) {
1066         qdict_put(qdict, "id", qstring_from_str(opts->id));
1067     }
1068     QTAILQ_FOREACH(opt, &opts->head, next) {
1069         val = QOBJECT(qstring_from_str(opt->str));
1070         qdict_put_obj(qdict, opt->name, val);
1071     }
1072     return qdict;
1073 }
1074
1075 /* Validate parsed opts against descriptions where no
1076  * descriptions were provided in the QemuOptsList.
1077  */
1078 void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp)
1079 {
1080     QemuOpt *opt;
1081     Error *local_err = NULL;
1082
1083     assert(opts_accepts_any(opts));
1084
1085     QTAILQ_FOREACH(opt, &opts->head, next) {
1086         opt->desc = find_desc_by_name(desc, opt->name);
1087         if (!opt->desc) {
1088             error_setg(errp, QERR_INVALID_PARAMETER, opt->name);
1089             return;
1090         }
1091
1092         qemu_opt_parse(opt, &local_err);
1093         if (local_err) {
1094             error_propagate(errp, local_err);
1095             return;
1096         }
1097     }
1098 }
1099
1100 /**
1101  * For each member of @list, call @func(@opaque, member, @errp).
1102  * Call it with the current location temporarily set to the member's.
1103  * @func() may store an Error through @errp, but must return non-zero then.
1104  * When @func() returns non-zero, break the loop and return that value.
1105  * Return zero when the loop completes.
1106  */
1107 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
1108                       void *opaque, Error **errp)
1109 {
1110     Location loc;
1111     QemuOpts *opts;
1112     int rc;
1113
1114     loc_push_none(&loc);
1115     QTAILQ_FOREACH(opts, &list->head, next) {
1116         loc_restore(&opts->loc);
1117         rc = func(opaque, opts, errp);
1118         if (rc) {
1119             return rc;
1120         }
1121         assert(!errp || !*errp);
1122     }
1123     loc_pop(&loc);
1124     return 0;
1125 }
1126
1127 static size_t count_opts_list(QemuOptsList *list)
1128 {
1129     QemuOptDesc *desc = NULL;
1130     size_t num_opts = 0;
1131
1132     if (!list) {
1133         return 0;
1134     }
1135
1136     desc = list->desc;
1137     while (desc && desc->name) {
1138         num_opts++;
1139         desc++;
1140     }
1141
1142     return num_opts;
1143 }
1144
1145 void qemu_opts_free(QemuOptsList *list)
1146 {
1147     g_free(list);
1148 }
1149
1150 /* Realloc dst option list and append options from an option list (list)
1151  * to it. dst could be NULL or a malloced list.
1152  * The lifetime of dst must be shorter than the input list because the
1153  * QemuOptDesc->name, ->help, and ->def_value_str strings are shared.
1154  */
1155 QemuOptsList *qemu_opts_append(QemuOptsList *dst,
1156                                QemuOptsList *list)
1157 {
1158     size_t num_opts, num_dst_opts;
1159     QemuOptDesc *desc;
1160     bool need_init = false;
1161     bool need_head_update;
1162
1163     if (!list) {
1164         return dst;
1165     }
1166
1167     /* If dst is NULL, after realloc, some area of dst should be initialized
1168      * before adding options to it.
1169      */
1170     if (!dst) {
1171         need_init = true;
1172         need_head_update = true;
1173     } else {
1174         /* Moreover, even if dst is not NULL, the realloc may move it to a
1175          * different address in which case we may get a stale tail pointer
1176          * in dst->head. */
1177         need_head_update = QTAILQ_EMPTY(&dst->head);
1178     }
1179
1180     num_opts = count_opts_list(dst);
1181     num_dst_opts = num_opts;
1182     num_opts += count_opts_list(list);
1183     dst = g_realloc(dst, sizeof(QemuOptsList) +
1184                     (num_opts + 1) * sizeof(QemuOptDesc));
1185     if (need_init) {
1186         dst->name = NULL;
1187         dst->implied_opt_name = NULL;
1188         dst->merge_lists = false;
1189     }
1190     if (need_head_update) {
1191         QTAILQ_INIT(&dst->head);
1192     }
1193     dst->desc[num_dst_opts].name = NULL;
1194
1195     /* append list->desc to dst->desc */
1196     if (list) {
1197         desc = list->desc;
1198         while (desc && desc->name) {
1199             if (find_desc_by_name(dst->desc, desc->name) == NULL) {
1200                 dst->desc[num_dst_opts++] = *desc;
1201                 dst->desc[num_dst_opts].name = NULL;
1202             }
1203             desc++;
1204         }
1205     }
1206
1207     return dst;
1208 }