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-option.h"
  31
  32 /*
  33  * Extracts the name of an option from the parameter string (p points at the
  34  * first byte of the option name)
  35  *
  36  * The option name is delimited by delim (usually , or =) or the string end
  37  * and is copied into buf. If the option name is longer than buf_size, it is
  38  * truncated. buf is always zero terminated.
  39  *
  40  * The return value is the position of the delimiter/zero byte after the option
  41  * name in p.
  42  */
  43 const char *get_opt_name(char *buf, int buf_size, const char *p, char delim)
  44 {
  45     char *q;
  46
  47     q = buf;
  48     while (*p != '\0' && *p != delim) {
  49         if (q && (q - buf) < buf_size - 1)
  50             *q++ = *p;
  51         p++;
  52     }
  53     if (q)
  54         *q = '\0';
  55
  56     return p;
  57 }
  58
  59 /*
  60  * Extracts the value of an option from the parameter string p (p points at the
  61  * first byte of the option value)
  62  *
  63  * This function is comparable to get_opt_name with the difference that the
  64  * delimiter is fixed to be comma which starts a new option. To specify an
  65  * option value that contains commas, double each comma.
  66  */
  67 const char *get_opt_value(char *buf, int buf_size, const char *p)
  68 {
  69     char *q;
  70
  71     q = buf;
  72     while (*p != '\0') {
  73         if (*p == ',') {
  74             if (*(p + 1) != ',')
  75                 break;
  76             p++;
  77         }
  78         if (q && (q - buf) < buf_size - 1)
  79             *q++ = *p;
  80         p++;
  81     }
  82     if (q)
  83         *q = '\0';
  84
  85     return p;
  86 }
  87
  88 int get_next_param_value(char *buf, int buf_size,
  89                          const char *tag, const char **pstr)
  90 {
  91     const char *p;
  92     char option[128];
  93
  94     p = *pstr;
  95     for(;;) {
  96         p = get_opt_name(option, sizeof(option), p, '=');
  97         if (*p != '=')
  98             break;
  99         p++;
 100         if (!strcmp(tag, option)) {
 101             *pstr = get_opt_value(buf, buf_size, p);
 102             if (**pstr == ',') {
 103                 (*pstr)++;
 104             }
 105             return strlen(buf);
 106         } else {
 107             p = get_opt_value(NULL, 0, p);
 108         }
 109         if (*p != ',')
 110             break;
 111         p++;
 112     }
 113     return 0;
 114 }
 115
 116 int get_param_value(char *buf, int buf_size,
 117                     const char *tag, const char *str)
 118 {
 119     return get_next_param_value(buf, buf_size, tag, &str);
 120 }
 121
 122 int check_params(char *buf, int buf_size,
 123                  const char * const *params, const char *str)
 124 {
 125     const char *p;
 126     int i;
 127
 128     p = str;
 129     while (*p != '\0') {
 130         p = get_opt_name(buf, buf_size, p, '=');
 131         if (*p != '=') {
 132             return -1;
 133         }
 134         p++;
 135         for (i = 0; params[i] != NULL; i++) {
 136             if (!strcmp(params[i], buf)) {
 137                 break;
 138             }
 139         }
 140         if (params[i] == NULL) {
 141             return -1;
 142         }
 143         p = get_opt_value(NULL, 0, p);
 144         if (*p != ',') {
 145             break;
 146         }
 147         p++;
 148     }
 149     return 0;
 150 }
 151
 152 /*
 153  * Searches an option list for an option with the given name
 154  */
 155 QEMUOptionParameter *get_option_parameter(QEMUOptionParameter *list,
 156     const char *name)
 157 {
 158     while (list && list->name) {
 159         if (!strcmp(list->name, name)) {
 160             return list;
 161         }
 162         list++;
 163     }
 164
 165     return NULL;
 166 }
 167
 168 static int parse_option_bool(const char *name, const char *value, int *ret)
 169 {
 170     if (value != NULL) {
 171         if (!strcmp(value, "on")) {
 172             *ret = 1;
 173         } else if (!strcmp(value, "off")) {
 174             *ret = 0;
 175         } else {
 176             fprintf(stderr, "Option '%s': Use 'on' or 'off'\n", name);
 177             return -1;
 178         }
 179     } else {
 180         *ret = 1;
 181     }
 182     return 0;
 183 }
 184
 185 static int parse_option_number(const char *name, const char *value, uint64_t *ret)
 186 {
 187     char *postfix;
 188     uint64_t number;
 189
 190     if (value != NULL) {
 191         number = strtoull(value, &postfix, 0);
 192         if (*postfix != '\0') {
 193             fprintf(stderr, "Option '%s' needs a number as parameter\n", name);
 194             return -1;
 195         }
 196     } else {
 197         fprintf(stderr, "Option '%s' needs a parameter\n", name);
 198         return -1;
 199     }
 200     return 0;
 201 }
 202
 203 static int parse_option_size(const char *name, const char *value, uint64_t *ret)
 204 {
 205     char *postfix;
 206     double sizef;
 207
 208     if (value != NULL) {
 209         sizef = strtod(value, &postfix);
 210         switch (*postfix) {
 211         case 'T':
 212             sizef *= 1024;
 213         case 'G':
 214             sizef *= 1024;
 215         case 'M':
 216             sizef *= 1024;
 217         case 'K':
 218         case 'k':
 219             sizef *= 1024;
 220         case 'b':
 221         case '\0':
 222             *ret = (uint64_t) sizef;
 223             break;
 224         default:
 225             fprintf(stderr, "Option '%s' needs size as parameter\n", name);
 226             fprintf(stderr, "You may use k, M, G or T suffixes for "
 227                     "kilobytes, megabytes, gigabytes and terabytes.\n");
 228             return -1;
 229         }
 230     } else {
 231         fprintf(stderr, "Option '%s' needs a parameter\n", name);
 232         return -1;
 233     }
 234     return 0;
 235 }
 236
 237 /*
 238  * Sets the value of a parameter in a given option list. The parsing of the
 239  * value depends on the type of option:
 240  *
 241  * OPT_FLAG (uses value.n):
 242  *      If no value is given, the flag is set to 1.
 243  *      Otherwise the value must be "on" (set to 1) or "off" (set to 0)
 244  *
 245  * OPT_STRING (uses value.s):
 246  *      value is strdup()ed and assigned as option value
 247  *
 248  * OPT_SIZE (uses value.n):
 249  *      The value is converted to an integer. Suffixes for kilobytes etc. are
 250  *      allowed (powers of 1024).
 251  *
 252  * Returns 0 on succes, -1 in error cases
 253  */
 254 int set_option_parameter(QEMUOptionParameter *list, const char *name,
 255     const char *value)
 256 {
 257     int flag;
 258
 259     // Find a matching parameter
 260     list = get_option_parameter(list, name);
 261     if (list == NULL) {
 262         fprintf(stderr, "Unknown option '%s'\n", name);
 263         return -1;
 264     }
 265
 266     // Process parameter
 267     switch (list->type) {
 268     case OPT_FLAG:
 269         if (-1 == parse_option_bool(name, value, &flag))
 270             return -1;
 271         list->value.n = flag;
 272         break;
 273
 274     case OPT_STRING:
 275         if (value != NULL) {
 276             list->value.s = strdup(value);
 277         } else {
 278             fprintf(stderr, "Option '%s' needs a parameter\n", name);
 279             return -1;
 280         }
 281         break;
 282
 283     case OPT_SIZE:
 284         if (-1 == parse_option_size(name, value, &list->value.n))
 285             return -1;
 286         break;
 287
 288     default:
 289         fprintf(stderr, "Bug: Option '%s' has an unknown type\n", name);
 290         return -1;
 291     }
 292
 293     return 0;
 294 }
 295
 296 /*
 297  * Sets the given parameter to an integer instead of a string.
 298  * This function cannot be used to set string options.
 299  *
 300  * Returns 0 on success, -1 in error cases
 301  */
 302 int set_option_parameter_int(QEMUOptionParameter *list, const char *name,
 303     uint64_t value)
 304 {
 305     // Find a matching parameter
 306     list = get_option_parameter(list, name);
 307     if (list == NULL) {
 308         fprintf(stderr, "Unknown option '%s'\n", name);
 309         return -1;
 310     }
 311
 312     // Process parameter
 313     switch (list->type) {
 314     case OPT_FLAG:
 315     case OPT_NUMBER:
 316     case OPT_SIZE:
 317         list->value.n = value;
 318         break;
 319
 320     default:
 321         return -1;
 322     }
 323
 324     return 0;
 325 }
 326
 327 /*
 328  * Frees a option list. If it contains strings, the strings are freed as well.
 329  */
 330 void free_option_parameters(QEMUOptionParameter *list)
 331 {
 332     QEMUOptionParameter *cur = list;
 333
 334     while (cur && cur->name) {
 335         if (cur->type == OPT_STRING) {
 336             free(cur->value.s);
 337         }
 338         cur++;
 339     }
 340
 341     free(list);
 342 }
 343
 344 /*
 345  * Parses a parameter string (param) into an option list (dest).
 346  *
 347  * list is the templace is. If dest is NULL, a new copy of list is created for
 348  * it. If list is NULL, this function fails.
 349  *
 350  * A parameter string consists of one or more parameters, separated by commas.
 351  * Each parameter consists of its name and possibly of a value. In the latter
 352  * case, the value is delimited by an = character. To specify a value which
 353  * contains commas, double each comma so it won't be recognized as the end of
 354  * the parameter.
 355  *
 356  * For more details of the parsing see above.
 357  *
 358  * Returns a pointer to the first element of dest (or the newly allocated copy)
 359  * or NULL in error cases
 360  */
 361 QEMUOptionParameter *parse_option_parameters(const char *param,
 362     QEMUOptionParameter *list, QEMUOptionParameter *dest)
 363 {
 364     QEMUOptionParameter *cur;
 365     QEMUOptionParameter *allocated = NULL;
 366     char name[256];
 367     char value[256];
 368     char *param_delim, *value_delim;
 369     char next_delim;
 370     size_t num_options;
 371
 372     if (list == NULL) {
 373         return NULL;
 374     }
 375
 376     if (dest == NULL) {
 377         // Count valid options
 378         num_options = 0;
 379         cur = list;
 380         while (cur->name) {
 381             num_options++;
 382             cur++;
 383         }
 384
 385         // Create a copy of the option list to fill in values
 386         dest = qemu_mallocz((num_options + 1) * sizeof(QEMUOptionParameter));
 387         allocated = dest;
 388         memcpy(dest, list, (num_options + 1) * sizeof(QEMUOptionParameter));
 389     }
 390
 391     while (*param) {
 392
 393         // Find parameter name and value in the string
 394         param_delim = strchr(param, ',');
 395         value_delim = strchr(param, '=');
 396
 397         if (value_delim && (value_delim < param_delim || !param_delim)) {
 398             next_delim = '=';
 399         } else {
 400             next_delim = ',';
 401             value_delim = NULL;
 402         }
 403
 404         param = get_opt_name(name, sizeof(name), param, next_delim);
 405         if (value_delim) {
 406             param = get_opt_value(value, sizeof(value), param + 1);
 407         }
 408         if (*param != '\0') {
 409             param++;
 410         }
 411
 412         // Set the parameter
 413         if (set_option_parameter(dest, name, value_delim ? value : NULL)) {
 414             goto fail;
 415         }
 416     }
 417
 418     return dest;
 419
 420 fail:
 421     // Only free the list if it was newly allocated
 422     free_option_parameters(allocated);
 423     return NULL;
 424 }
 425
 426 /*
 427  * Prints all options of a list that have a value to stdout
 428  */
 429 void print_option_parameters(QEMUOptionParameter *list)
 430 {
 431     while (list && list->name) {
 432         switch (list->type) {
 433             case OPT_STRING:
 434                  if (list->value.s != NULL) {
 435                      printf("%s='%s' ", list->name, list->value.s);
 436                  }
 437                 break;
 438             case OPT_FLAG:
 439                 printf("%s=%s ", list->name, list->value.n ? "on" : "off");
 440                 break;
 441             case OPT_SIZE:
 442             case OPT_NUMBER:
 443                 printf("%s=%" PRId64 " ", list->name, list->value.n);
 444                 break;
 445             default:
 446                 printf("%s=(unkown type) ", list->name);
 447                 break;
 448         }
 449         list++;
 450     }
 451 }
 452
 453 /*
 454  * Prints an overview of all available options
 455  */
 456 void print_option_help(QEMUOptionParameter *list)
 457 {
 458     printf("Supported options:\n");
 459     while (list && list->name) {
 460         printf("%-16s %s\n", list->name,
 461             list->help ? list->help : "No description available");
 462         list++;
 463     }
 464 }
 465
 466 /* ------------------------------------------------------------------ */
 467
 468 struct QemuOpt {
 469     const char   *name;
 470     const char   *str;
 471
 472     QemuOptDesc  *desc;
 473     union {
 474         int      bool;
 475         uint64_t uint;
 476     } value;
 477
 478     QemuOpts     *opts;
 479     TAILQ_ENTRY(QemuOpt) next;
 480 };
 481
 482 struct QemuOpts {
 483     const char *id;
 484     QemuOptsList *list;
 485     TAILQ_HEAD(, QemuOpt) head;
 486     TAILQ_ENTRY(QemuOpts) next;
 487 };
 488
 489 static QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
 490 {
 491     QemuOpt *opt;
 492
 493     TAILQ_FOREACH(opt, &opts->head, next) {
 494         if (strcmp(opt->name, name) != 0)
 495             continue;
 496         return opt;
 497     }
 498     return NULL;
 499 }
 500
 501 const char *qemu_opt_get(QemuOpts *opts, const char *name)
 502 {
 503     QemuOpt *opt = qemu_opt_find(opts, name);
 504     return opt ? opt->str : NULL;
 505 }
 506
 507 int qemu_opt_get_bool(QemuOpts *opts, const char *name, int defval)
 508 {
 509     QemuOpt *opt = qemu_opt_find(opts, name);
 510
 511     if (opt == NULL)
 512         return defval;
 513     assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
 514     return opt->value.bool;
 515 }
 516
 517 uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
 518 {
 519     QemuOpt *opt = qemu_opt_find(opts, name);
 520
 521     if (opt == NULL)
 522         return defval;
 523     assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
 524     return opt->value.uint;
 525 }
 526
 527 uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
 528 {
 529     QemuOpt *opt = qemu_opt_find(opts, name);
 530
 531     if (opt == NULL)
 532         return defval;
 533     assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
 534     return opt->value.uint;
 535 }
 536
 537 static int qemu_opt_parse(QemuOpt *opt)
 538 {
 539     if (opt->desc == NULL)
 540         return 0;
 541     switch (opt->desc->type) {
 542     case QEMU_OPT_STRING:
 543         /* nothing */
 544         return 0;
 545     case QEMU_OPT_BOOL:
 546         return parse_option_bool(opt->name, opt->str, &opt->value.bool);
 547     case QEMU_OPT_NUMBER:
 548         return parse_option_number(opt->name, opt->str, &opt->value.uint);
 549     case QEMU_OPT_SIZE:
 550         return parse_option_size(opt->name, opt->str, &opt->value.uint);
 551     default:
 552         abort();
 553     }
 554 }
 555
 556 static void qemu_opt_del(QemuOpt *opt)
 557 {
 558     TAILQ_REMOVE(&opt->opts->head, opt, next);
 559     qemu_free((/* !const */ char*)opt->name);
 560     qemu_free((/* !const */ char*)opt->str);
 561     qemu_free(opt);
 562 }
 563
 564 int qemu_opt_set(QemuOpts *opts, const char *name, const char *value)
 565 {
 566     QemuOpt *opt;
 567
 568     opt = qemu_opt_find(opts, name);
 569     if (!opt) {
 570         QemuOptDesc *desc = opts->list->desc;
 571         int i;
 572
 573         for (i = 0; desc[i].name != NULL; i++) {
 574             if (strcmp(desc[i].name, name) == 0) {
 575                 break;
 576             }
 577         }
 578         if (desc[i].name == NULL) {
 579             if (i == 0) {
 580                 /* empty list -> allow any */;
 581             } else {
 582                 fprintf(stderr, "option \"%s\" is not valid for %s\n",
 583                         name, opts->list->name);
 584                 return -1;
 585             }
 586         }
 587         opt = qemu_mallocz(sizeof(*opt));
 588         opt->name = qemu_strdup(name);
 589         opt->opts = opts;
 590         TAILQ_INSERT_TAIL(&opts->head, opt, next);
 591         if (desc[i].name != NULL) {
 592             opt->desc = desc+i;
 593         }
 594     }
 595     qemu_free((/* !const */ char*)opt->str);
 596     opt->str = NULL;
 597     if (value) {
 598         opt->str = qemu_strdup(value);
 599     }
 600     if (qemu_opt_parse(opt) < 0) {
 601         fprintf(stderr, "Failed to parse \"%s\" for \"%s.%s\"\n", opt->str,
 602                 opts->list->name, opt->name);
 603         qemu_opt_del(opt);
 604         return -1;
 605     }
 606     return 0;
 607 }
 608
 609 QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
 610 {
 611     QemuOpts *opts;
 612
 613     TAILQ_FOREACH(opts, &list->head, next) {
 614         if (!opts->id) {
 615             continue;
 616         }
 617         if (strcmp(opts->id, id) != 0) {
 618             continue;
 619         }
 620         return opts;
 621     }
 622     return NULL;
 623 }
 624
 625 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, int fail_if_exists)
 626 {
 627     QemuOpts *opts = NULL;
 628
 629     if (id) {
 630         opts = qemu_opts_find(list, id);
 631         if (opts != NULL) {
 632             if (fail_if_exists) {
 633                 fprintf(stderr, "tried to create id \"%s\" twice for \"%s\"\n",
 634                         id, list->name);
 635                 return NULL;
 636             } else {
 637                 return opts;
 638             }
 639         }
 640     }
 641     opts = qemu_mallocz(sizeof(*opts));
 642     if (id) {
 643         opts->id = qemu_strdup(id);
 644     }
 645     opts->list = list;
 646     TAILQ_INIT(&opts->head);
 647     TAILQ_INSERT_TAIL(&list->head, opts, next);
 648     return opts;
 649 }
 650
 651 int qemu_opts_set(QemuOptsList *list, const char *id,
 652                   const char *name, const char *value)
 653 {
 654     QemuOpts *opts;
 655
 656     opts = qemu_opts_create(list, id, 1);
 657     if (opts == NULL) {
 658         fprintf(stderr, "id \"%s\" not found for \"%s\"\n",
 659                 id, list->name);
 660         return -1;
 661     }
 662     return qemu_opt_set(opts, name, value);
 663 }
 664
 665 void qemu_opts_del(QemuOpts *opts)
 666 {
 667     QemuOpt *opt;
 668
 669     for (;;) {
 670         opt = TAILQ_FIRST(&opts->head);
 671         if (opt == NULL)
 672             break;
 673         qemu_opt_del(opt);
 674     }
 675     TAILQ_REMOVE(&opts->list->head, opts, next);
 676     qemu_free(opts);
 677 }
 678
 679 int qemu_opts_print(QemuOpts *opts, void *dummy)
 680 {
 681     QemuOpt *opt;
 682
 683     fprintf(stderr, "%s: %s:", opts->list->name,
 684             opts->id ? opts->id : "<noid>");
 685     TAILQ_FOREACH(opt, &opts->head, next) {
 686         fprintf(stderr, " %s=\"%s\"", opt->name, opt->str);
 687     }
 688     fprintf(stderr, "\n");
 689     return 0;
 690 }
 691
 692 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, const char *firstname)
 693 {
 694     char option[128], value[128], *id = NULL;
 695     QemuOpts *opts;
 696     const char *p,*pe,*pc;
 697
 698     if (get_param_value(value, sizeof(value), "id", params))
 699         id = qemu_strdup(value);
 700     opts = qemu_opts_create(list, id, 1);
 701     if (opts == NULL)
 702         return NULL;
 703
 704     p = params;
 705     for(;;) {
 706         pe = strchr(p, '=');
 707         pc = strchr(p, ',');
 708         if (!pe || (pc && pc < pe)) {
 709             /* found "foo,more" */
 710             if (p == params && firstname) {
 711                 /* implicitly named first option */
 712                 pstrcpy(option, sizeof(option), firstname);
 713                 p = get_opt_value(value, sizeof(value), p);
 714             } else {
 715                 /* option without value, probably a flag */
 716                 p = get_opt_name(option, sizeof(option), p, ',');
 717                 if (strncmp(p, "no", 2) == 0) {
 718                     memmove(option, option+2, strlen(option+2)+1);
 719                     pstrcpy(value, sizeof(value), "off");
 720                 } else {
 721                     pstrcpy(value, sizeof(value), "on");
 722                 }
 723             }
 724         } else {
 725             /* found "foo=bar,more" */
 726             p = get_opt_name(option, sizeof(option), p, '=');
 727             if (*p != '=') {
 728                 break;
 729             }
 730             p++;
 731             p = get_opt_value(value, sizeof(value), p);
 732         }
 733         if (strcmp(option, "id") != 0) {
 734             /* store and parse */
 735             if (-1 == qemu_opt_set(opts, option, value)) {
 736                 qemu_opts_del(opts);
 737                 return NULL;
 738             }
 739         }
 740         if (*p != ',') {
 741             break;
 742         }
 743         p++;
 744     }
 745     return opts;
 746 }
 747
 748 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
 749                       int abort_on_failure)
 750 {
 751     QemuOpts *opts;
 752     int rc = 0;
 753
 754     TAILQ_FOREACH(opts, &list->head, next) {
 755         rc = func(opts, opaque);
 756         if (abort_on_failure  &&  rc != 0)
 757             break;
 758     }
 759     return rc;
 760 }