xref: /openbmc/qemu/util/qemu-option.c (revision f764718d)
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 "qemu/osdep.h"
27 
28 #include "qapi/error.h"
29 #include "qemu-common.h"
30 #include "qemu/error-report.h"
31 #include "qapi/qmp/types.h"
32 #include "qapi/qmp/qerror.h"
33 #include "qemu/option_int.h"
34 #include "qemu/cutils.h"
35 #include "qemu/id.h"
36 #include "qemu/help_option.h"
37 
38 /*
39  * Extracts the name of an option from the parameter string (p points at the
40  * first byte of the option name)
41  *
42  * The option name is delimited by delim (usually , or =) or the string end
43  * and is copied into buf. If the option name is longer than buf_size, it is
44  * truncated. buf is always zero terminated.
45  *
46  * The return value is the position of the delimiter/zero byte after the option
47  * name in p.
48  */
49 const char *get_opt_name(char *buf, int buf_size, const char *p, char delim)
50 {
51     char *q;
52 
53     q = buf;
54     while (*p != '\0' && *p != delim) {
55         if (q && (q - buf) < buf_size - 1)
56             *q++ = *p;
57         p++;
58     }
59     if (q)
60         *q = '\0';
61 
62     return p;
63 }
64 
65 /*
66  * Extracts the value of an option from the parameter string p (p points at the
67  * first byte of the option value)
68  *
69  * This function is comparable to get_opt_name with the difference that the
70  * delimiter is fixed to be comma which starts a new option. To specify an
71  * option value that contains commas, double each comma.
72  */
73 const char *get_opt_value(char *buf, int buf_size, const char *p)
74 {
75     char *q;
76 
77     q = buf;
78     while (*p != '\0') {
79         if (*p == ',') {
80             if (*(p + 1) != ',')
81                 break;
82             p++;
83         }
84         if (q && (q - buf) < buf_size - 1)
85             *q++ = *p;
86         p++;
87     }
88     if (q)
89         *q = '\0';
90 
91     return p;
92 }
93 
94 static void parse_option_bool(const char *name, const char *value, bool *ret,
95                               Error **errp)
96 {
97     if (!strcmp(value, "on")) {
98         *ret = 1;
99     } else if (!strcmp(value, "off")) {
100         *ret = 0;
101     } else {
102         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
103                    name, "'on' or 'off'");
104     }
105 }
106 
107 static void parse_option_number(const char *name, const char *value,
108                                 uint64_t *ret, Error **errp)
109 {
110     uint64_t number;
111     int err;
112 
113     err = qemu_strtou64(value, NULL, 0, &number);
114     if (err == -ERANGE) {
115         error_setg(errp, "Value '%s' is too large for parameter '%s'",
116                    value, name);
117         return;
118     }
119     if (err) {
120         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
121         return;
122     }
123     *ret = number;
124 }
125 
126 static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,
127                                             const char *name)
128 {
129     int i;
130 
131     for (i = 0; desc[i].name != NULL; i++) {
132         if (strcmp(desc[i].name, name) == 0) {
133             return &desc[i];
134         }
135     }
136 
137     return NULL;
138 }
139 
140 void parse_option_size(const char *name, const char *value,
141                        uint64_t *ret, Error **errp)
142 {
143     uint64_t size;
144     int err;
145 
146     err = qemu_strtosz(value, NULL, &size);
147     if (err == -ERANGE) {
148         error_setg(errp, "Value '%s' is out of range for parameter '%s'",
149                    value, name);
150         return;
151     }
152     if (err) {
153         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
154                    "a non-negative number below 2^64");
155         error_append_hint(errp, "Optional suffix k, M, G, T, P or E means"
156                           " kilo-, mega-, giga-, tera-, peta-\n"
157                           "and exabytes, respectively.\n");
158         return;
159     }
160     *ret = size;
161 }
162 
163 bool has_help_option(const char *param)
164 {
165     size_t buflen = strlen(param) + 1;
166     char *buf = g_malloc(buflen);
167     const char *p = param;
168     bool result = false;
169 
170     while (*p) {
171         p = get_opt_value(buf, buflen, p);
172         if (*p) {
173             p++;
174         }
175 
176         if (is_help_option(buf)) {
177             result = true;
178             goto out;
179         }
180     }
181 
182 out:
183     g_free(buf);
184     return result;
185 }
186 
187 bool is_valid_option_list(const char *param)
188 {
189     size_t buflen = strlen(param) + 1;
190     char *buf = g_malloc(buflen);
191     const char *p = param;
192     bool result = true;
193 
194     while (*p) {
195         p = get_opt_value(buf, buflen, p);
196         if (*p && !*++p) {
197             result = false;
198             goto out;
199         }
200 
201         if (!*buf || *buf == ',') {
202             result = false;
203             goto out;
204         }
205     }
206 
207 out:
208     g_free(buf);
209     return result;
210 }
211 
212 void qemu_opts_print_help(QemuOptsList *list)
213 {
214     QemuOptDesc *desc;
215 
216     assert(list);
217     desc = list->desc;
218     printf("Supported options:\n");
219     while (desc && desc->name) {
220         printf("%-16s %s\n", desc->name,
221                desc->help ? desc->help : "No description available");
222         desc++;
223     }
224 }
225 /* ------------------------------------------------------------------ */
226 
227 QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
228 {
229     QemuOpt *opt;
230 
231     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
232         if (strcmp(opt->name, name) != 0)
233             continue;
234         return opt;
235     }
236     return NULL;
237 }
238 
239 static void qemu_opt_del(QemuOpt *opt)
240 {
241     QTAILQ_REMOVE(&opt->opts->head, opt, next);
242     g_free(opt->name);
243     g_free(opt->str);
244     g_free(opt);
245 }
246 
247 /* qemu_opt_set allows many settings for the same option.
248  * This function deletes all settings for an option.
249  */
250 static void qemu_opt_del_all(QemuOpts *opts, const char *name)
251 {
252     QemuOpt *opt, *next_opt;
253 
254     QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next_opt) {
255         if (!strcmp(opt->name, name)) {
256             qemu_opt_del(opt);
257         }
258     }
259 }
260 
261 const char *qemu_opt_get(QemuOpts *opts, const char *name)
262 {
263     QemuOpt *opt;
264 
265     if (opts == NULL) {
266         return NULL;
267     }
268 
269     opt = qemu_opt_find(opts, name);
270     if (!opt) {
271         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
272         if (desc && desc->def_value_str) {
273             return desc->def_value_str;
274         }
275     }
276     return opt ? opt->str : NULL;
277 }
278 
279 void qemu_opt_iter_init(QemuOptsIter *iter, QemuOpts *opts, const char *name)
280 {
281     iter->opts = opts;
282     iter->opt = QTAILQ_FIRST(&opts->head);
283     iter->name = name;
284 }
285 
286 const char *qemu_opt_iter_next(QemuOptsIter *iter)
287 {
288     QemuOpt *ret = iter->opt;
289     if (iter->name) {
290         while (ret && !g_str_equal(iter->name, ret->name)) {
291             ret = QTAILQ_NEXT(ret, next);
292         }
293     }
294     iter->opt = ret ? QTAILQ_NEXT(ret, next) : NULL;
295     return ret ? ret->str : NULL;
296 }
297 
298 /* Get a known option (or its default) and remove it from the list
299  * all in one action. Return a malloced string of the option value.
300  * Result must be freed by caller with g_free().
301  */
302 char *qemu_opt_get_del(QemuOpts *opts, const char *name)
303 {
304     QemuOpt *opt;
305     const QemuOptDesc *desc;
306     char *str = NULL;
307 
308     if (opts == NULL) {
309         return NULL;
310     }
311 
312     opt = qemu_opt_find(opts, name);
313     if (!opt) {
314         desc = find_desc_by_name(opts->list->desc, name);
315         if (desc && desc->def_value_str) {
316             str = g_strdup(desc->def_value_str);
317         }
318         return str;
319     }
320     str = opt->str;
321     opt->str = NULL;
322     qemu_opt_del_all(opts, name);
323     return str;
324 }
325 
326 bool qemu_opt_has_help_opt(QemuOpts *opts)
327 {
328     QemuOpt *opt;
329 
330     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
331         if (is_help_option(opt->name)) {
332             return true;
333         }
334     }
335     return false;
336 }
337 
338 static bool qemu_opt_get_bool_helper(QemuOpts *opts, const char *name,
339                                      bool defval, bool del)
340 {
341     QemuOpt *opt;
342     bool ret = defval;
343 
344     if (opts == NULL) {
345         return ret;
346     }
347 
348     opt = qemu_opt_find(opts, name);
349     if (opt == NULL) {
350         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
351         if (desc && desc->def_value_str) {
352             parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
353         }
354         return ret;
355     }
356     assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
357     ret = opt->value.boolean;
358     if (del) {
359         qemu_opt_del_all(opts, name);
360     }
361     return ret;
362 }
363 
364 bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
365 {
366     return qemu_opt_get_bool_helper(opts, name, defval, false);
367 }
368 
369 bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval)
370 {
371     return qemu_opt_get_bool_helper(opts, name, defval, true);
372 }
373 
374 static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
375                                            uint64_t defval, bool del)
376 {
377     QemuOpt *opt;
378     uint64_t ret = defval;
379 
380     if (opts == NULL) {
381         return ret;
382     }
383 
384     opt = qemu_opt_find(opts, name);
385     if (opt == NULL) {
386         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
387         if (desc && desc->def_value_str) {
388             parse_option_number(name, desc->def_value_str, &ret, &error_abort);
389         }
390         return ret;
391     }
392     assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
393     ret = opt->value.uint;
394     if (del) {
395         qemu_opt_del_all(opts, name);
396     }
397     return ret;
398 }
399 
400 uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
401 {
402     return qemu_opt_get_number_helper(opts, name, defval, false);
403 }
404 
405 uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
406                                  uint64_t defval)
407 {
408     return qemu_opt_get_number_helper(opts, name, defval, true);
409 }
410 
411 static uint64_t qemu_opt_get_size_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_size(name, desc->def_value_str, &ret, &error_abort);
426         }
427         return ret;
428     }
429     assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
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_size(QemuOpts *opts, const char *name, uint64_t defval)
438 {
439     return qemu_opt_get_size_helper(opts, name, defval, false);
440 }
441 
442 uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
443                                uint64_t defval)
444 {
445     return qemu_opt_get_size_helper(opts, name, defval, true);
446 }
447 
448 static void qemu_opt_parse(QemuOpt *opt, Error **errp)
449 {
450     if (opt->desc == NULL)
451         return;
452 
453     switch (opt->desc->type) {
454     case QEMU_OPT_STRING:
455         /* nothing */
456         return;
457     case QEMU_OPT_BOOL:
458         parse_option_bool(opt->name, opt->str, &opt->value.boolean, errp);
459         break;
460     case QEMU_OPT_NUMBER:
461         parse_option_number(opt->name, opt->str, &opt->value.uint, errp);
462         break;
463     case QEMU_OPT_SIZE:
464         parse_option_size(opt->name, opt->str, &opt->value.uint, errp);
465         break;
466     default:
467         abort();
468     }
469 }
470 
471 static bool opts_accepts_any(const QemuOpts *opts)
472 {
473     return opts->list->desc[0].name == NULL;
474 }
475 
476 int qemu_opt_unset(QemuOpts *opts, const char *name)
477 {
478     QemuOpt *opt = qemu_opt_find(opts, name);
479 
480     assert(opts_accepts_any(opts));
481 
482     if (opt == NULL) {
483         return -1;
484     } else {
485         qemu_opt_del(opt);
486         return 0;
487     }
488 }
489 
490 static void opt_set(QemuOpts *opts, const char *name, const char *value,
491                     bool prepend, Error **errp)
492 {
493     QemuOpt *opt;
494     const QemuOptDesc *desc;
495     Error *local_err = NULL;
496 
497     desc = find_desc_by_name(opts->list->desc, name);
498     if (!desc && !opts_accepts_any(opts)) {
499         error_setg(errp, QERR_INVALID_PARAMETER, name);
500         return;
501     }
502 
503     opt = g_malloc0(sizeof(*opt));
504     opt->name = g_strdup(name);
505     opt->opts = opts;
506     if (prepend) {
507         QTAILQ_INSERT_HEAD(&opts->head, opt, next);
508     } else {
509         QTAILQ_INSERT_TAIL(&opts->head, opt, next);
510     }
511     opt->desc = desc;
512     opt->str = g_strdup(value);
513     assert(opt->str);
514     qemu_opt_parse(opt, &local_err);
515     if (local_err) {
516         error_propagate(errp, local_err);
517         qemu_opt_del(opt);
518     }
519 }
520 
521 void qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
522                   Error **errp)
523 {
524     opt_set(opts, name, value, false, errp);
525 }
526 
527 void qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val,
528                        Error **errp)
529 {
530     QemuOpt *opt;
531     const QemuOptDesc *desc = opts->list->desc;
532 
533     opt = g_malloc0(sizeof(*opt));
534     opt->desc = find_desc_by_name(desc, name);
535     if (!opt->desc && !opts_accepts_any(opts)) {
536         error_setg(errp, QERR_INVALID_PARAMETER, name);
537         g_free(opt);
538         return;
539     }
540 
541     opt->name = g_strdup(name);
542     opt->opts = opts;
543     opt->value.boolean = !!val;
544     opt->str = g_strdup(val ? "on" : "off");
545     QTAILQ_INSERT_TAIL(&opts->head, opt, next);
546 }
547 
548 void qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val,
549                          Error **errp)
550 {
551     QemuOpt *opt;
552     const QemuOptDesc *desc = opts->list->desc;
553 
554     opt = g_malloc0(sizeof(*opt));
555     opt->desc = find_desc_by_name(desc, name);
556     if (!opt->desc && !opts_accepts_any(opts)) {
557         error_setg(errp, QERR_INVALID_PARAMETER, name);
558         g_free(opt);
559         return;
560     }
561 
562     opt->name = g_strdup(name);
563     opt->opts = opts;
564     opt->value.uint = val;
565     opt->str = g_strdup_printf("%" PRId64, val);
566     QTAILQ_INSERT_TAIL(&opts->head, opt, next);
567 }
568 
569 /**
570  * For each member of @opts, call @func(@opaque, name, value, @errp).
571  * @func() may store an Error through @errp, but must return non-zero then.
572  * When @func() returns non-zero, break the loop and return that value.
573  * Return zero when the loop completes.
574  */
575 int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
576                      Error **errp)
577 {
578     QemuOpt *opt;
579     int rc;
580 
581     QTAILQ_FOREACH(opt, &opts->head, next) {
582         rc = func(opaque, opt->name, opt->str, errp);
583         if (rc) {
584             return rc;
585         }
586         assert(!errp || !*errp);
587     }
588     return 0;
589 }
590 
591 QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
592 {
593     QemuOpts *opts;
594 
595     QTAILQ_FOREACH(opts, &list->head, next) {
596         if (!opts->id && !id) {
597             return opts;
598         }
599         if (opts->id && id && !strcmp(opts->id, id)) {
600             return opts;
601         }
602     }
603     return NULL;
604 }
605 
606 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
607                            int fail_if_exists, Error **errp)
608 {
609     QemuOpts *opts = NULL;
610 
611     if (id) {
612         if (!id_wellformed(id)) {
613             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
614                        "an identifier");
615             error_append_hint(errp, "Identifiers consist of letters, digits, "
616                               "'-', '.', '_', starting with a letter.\n");
617             return NULL;
618         }
619         opts = qemu_opts_find(list, id);
620         if (opts != NULL) {
621             if (fail_if_exists && !list->merge_lists) {
622                 error_setg(errp, "Duplicate ID '%s' for %s", id, list->name);
623                 return NULL;
624             } else {
625                 return opts;
626             }
627         }
628     } else if (list->merge_lists) {
629         opts = qemu_opts_find(list, NULL);
630         if (opts) {
631             return opts;
632         }
633     }
634     opts = g_malloc0(sizeof(*opts));
635     opts->id = g_strdup(id);
636     opts->list = list;
637     loc_save(&opts->loc);
638     QTAILQ_INIT(&opts->head);
639     QTAILQ_INSERT_TAIL(&list->head, opts, next);
640     return opts;
641 }
642 
643 void qemu_opts_reset(QemuOptsList *list)
644 {
645     QemuOpts *opts, *next_opts;
646 
647     QTAILQ_FOREACH_SAFE(opts, &list->head, next, next_opts) {
648         qemu_opts_del(opts);
649     }
650 }
651 
652 void qemu_opts_loc_restore(QemuOpts *opts)
653 {
654     loc_restore(&opts->loc);
655 }
656 
657 void qemu_opts_set(QemuOptsList *list, const char *id,
658                    const char *name, const char *value, Error **errp)
659 {
660     QemuOpts *opts;
661     Error *local_err = NULL;
662 
663     opts = qemu_opts_create(list, id, 1, &local_err);
664     if (local_err) {
665         error_propagate(errp, local_err);
666         return;
667     }
668     qemu_opt_set(opts, name, value, errp);
669 }
670 
671 const char *qemu_opts_id(QemuOpts *opts)
672 {
673     return opts->id;
674 }
675 
676 /* The id string will be g_free()d by qemu_opts_del */
677 void qemu_opts_set_id(QemuOpts *opts, char *id)
678 {
679     opts->id = id;
680 }
681 
682 void qemu_opts_del(QemuOpts *opts)
683 {
684     QemuOpt *opt;
685 
686     if (opts == NULL) {
687         return;
688     }
689 
690     for (;;) {
691         opt = QTAILQ_FIRST(&opts->head);
692         if (opt == NULL)
693             break;
694         qemu_opt_del(opt);
695     }
696     QTAILQ_REMOVE(&opts->list->head, opts, next);
697     g_free(opts->id);
698     g_free(opts);
699 }
700 
701 /* print value, escaping any commas in value */
702 static void escaped_print(const char *value)
703 {
704     const char *ptr;
705 
706     for (ptr = value; *ptr; ++ptr) {
707         if (*ptr == ',') {
708             putchar(',');
709         }
710         putchar(*ptr);
711     }
712 }
713 
714 void qemu_opts_print(QemuOpts *opts, const char *separator)
715 {
716     QemuOpt *opt;
717     QemuOptDesc *desc = opts->list->desc;
718     const char *sep = "";
719 
720     if (opts->id) {
721         printf("id=%s", opts->id); /* passed id_wellformed -> no commas */
722         sep = separator;
723     }
724 
725     if (desc[0].name == NULL) {
726         QTAILQ_FOREACH(opt, &opts->head, next) {
727             printf("%s%s=", sep, opt->name);
728             escaped_print(opt->str);
729             sep = separator;
730         }
731         return;
732     }
733     for (; desc && desc->name; desc++) {
734         const char *value;
735         opt = qemu_opt_find(opts, desc->name);
736 
737         value = opt ? opt->str : desc->def_value_str;
738         if (!value) {
739             continue;
740         }
741         if (desc->type == QEMU_OPT_STRING) {
742             printf("%s%s=", sep, desc->name);
743             escaped_print(value);
744         } else if ((desc->type == QEMU_OPT_SIZE ||
745                     desc->type == QEMU_OPT_NUMBER) && opt) {
746             printf("%s%s=%" PRId64, sep, desc->name, opt->value.uint);
747         } else {
748             printf("%s%s=%s", sep, desc->name, value);
749         }
750         sep = separator;
751     }
752 }
753 
754 static void opts_do_parse(QemuOpts *opts, const char *params,
755                           const char *firstname, bool prepend, Error **errp)
756 {
757     char option[128], value[1024];
758     const char *p,*pe,*pc;
759     Error *local_err = NULL;
760 
761     for (p = params; *p != '\0'; p++) {
762         pe = strchr(p, '=');
763         pc = strchr(p, ',');
764         if (!pe || (pc && pc < pe)) {
765             /* found "foo,more" */
766             if (p == params && firstname) {
767                 /* implicitly named first option */
768                 pstrcpy(option, sizeof(option), firstname);
769                 p = get_opt_value(value, sizeof(value), p);
770             } else {
771                 /* option without value, probably a flag */
772                 p = get_opt_name(option, sizeof(option), p, ',');
773                 if (strncmp(option, "no", 2) == 0) {
774                     memmove(option, option+2, strlen(option+2)+1);
775                     pstrcpy(value, sizeof(value), "off");
776                 } else {
777                     pstrcpy(value, sizeof(value), "on");
778                 }
779             }
780         } else {
781             /* found "foo=bar,more" */
782             p = get_opt_name(option, sizeof(option), p, '=');
783             if (*p != '=') {
784                 break;
785             }
786             p++;
787             p = get_opt_value(value, sizeof(value), p);
788         }
789         if (strcmp(option, "id") != 0) {
790             /* store and parse */
791             opt_set(opts, option, value, prepend, &local_err);
792             if (local_err) {
793                 error_propagate(errp, local_err);
794                 return;
795             }
796         }
797         if (*p != ',') {
798             break;
799         }
800     }
801 }
802 
803 /**
804  * Store options parsed from @params into @opts.
805  * If @firstname is non-null, the first key=value in @params may omit
806  * key=, and is treated as if key was @firstname.
807  * On error, store an error object through @errp if non-null.
808  */
809 void qemu_opts_do_parse(QemuOpts *opts, const char *params,
810                        const char *firstname, Error **errp)
811 {
812     opts_do_parse(opts, params, firstname, false, errp);
813 }
814 
815 static QemuOpts *opts_parse(QemuOptsList *list, const char *params,
816                             bool permit_abbrev, bool defaults, Error **errp)
817 {
818     const char *firstname;
819     char value[1024], *id = NULL;
820     const char *p;
821     QemuOpts *opts;
822     Error *local_err = NULL;
823 
824     assert(!permit_abbrev || list->implied_opt_name);
825     firstname = permit_abbrev ? list->implied_opt_name : NULL;
826 
827     if (strncmp(params, "id=", 3) == 0) {
828         get_opt_value(value, sizeof(value), params+3);
829         id = value;
830     } else if ((p = strstr(params, ",id=")) != NULL) {
831         get_opt_value(value, sizeof(value), p+4);
832         id = value;
833     }
834 
835     /*
836      * This code doesn't work for defaults && !list->merge_lists: when
837      * params has no id=, and list has an element with !opts->id, it
838      * appends a new element instead of returning the existing opts.
839      * However, we got no use for this case.  Guard against possible
840      * (if unlikely) future misuse:
841      */
842     assert(!defaults || list->merge_lists);
843     opts = qemu_opts_create(list, id, !defaults, &local_err);
844     if (opts == NULL) {
845         error_propagate(errp, local_err);
846         return NULL;
847     }
848 
849     opts_do_parse(opts, params, firstname, defaults, &local_err);
850     if (local_err) {
851         error_propagate(errp, local_err);
852         qemu_opts_del(opts);
853         return NULL;
854     }
855 
856     return opts;
857 }
858 
859 /**
860  * Create a QemuOpts in @list and with options parsed from @params.
861  * If @permit_abbrev, the first key=value in @params may omit key=,
862  * and is treated as if key was @list->implied_opt_name.
863  * On error, store an error object through @errp if non-null.
864  * Return the new QemuOpts on success, null pointer on error.
865  */
866 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
867                           bool permit_abbrev, Error **errp)
868 {
869     return opts_parse(list, params, permit_abbrev, false, errp);
870 }
871 
872 /**
873  * Create a QemuOpts in @list and with options parsed from @params.
874  * If @permit_abbrev, the first key=value in @params may omit key=,
875  * and is treated as if key was @list->implied_opt_name.
876  * Report errors with error_report_err().  This is inappropriate in
877  * QMP context.  Do not use this function there!
878  * Return the new QemuOpts on success, null pointer on error.
879  */
880 QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
881                                   bool permit_abbrev)
882 {
883     Error *err = NULL;
884     QemuOpts *opts;
885 
886     opts = opts_parse(list, params, permit_abbrev, false, &err);
887     if (err) {
888         error_report_err(err);
889     }
890     return opts;
891 }
892 
893 void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
894                             int permit_abbrev)
895 {
896     QemuOpts *opts;
897 
898     opts = opts_parse(list, params, permit_abbrev, true, NULL);
899     assert(opts);
900 }
901 
902 typedef struct OptsFromQDictState {
903     QemuOpts *opts;
904     Error **errp;
905 } OptsFromQDictState;
906 
907 static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)
908 {
909     OptsFromQDictState *state = opaque;
910     char buf[32], *tmp = NULL;
911     const char *value;
912 
913     if (!strcmp(key, "id") || *state->errp) {
914         return;
915     }
916 
917     switch (qobject_type(obj)) {
918     case QTYPE_QSTRING:
919         value = qstring_get_str(qobject_to_qstring(obj));
920         break;
921     case QTYPE_QNUM:
922         tmp = qnum_to_string(qobject_to_qnum(obj));
923         value = tmp;
924         break;
925     case QTYPE_QBOOL:
926         pstrcpy(buf, sizeof(buf),
927                 qbool_get_bool(qobject_to_qbool(obj)) ? "on" : "off");
928         value = buf;
929         break;
930     default:
931         return;
932     }
933 
934     qemu_opt_set(state->opts, key, value, state->errp);
935     g_free(tmp);
936 }
937 
938 /*
939  * Create QemuOpts from a QDict.
940  * Use value of key "id" as ID if it exists and is a QString.  Only
941  * QStrings, QNums and QBools are copied.  Entries with other types
942  * are silently ignored.
943  */
944 QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
945                                Error **errp)
946 {
947     OptsFromQDictState state;
948     Error *local_err = NULL;
949     QemuOpts *opts;
950 
951     opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,
952                             &local_err);
953     if (local_err) {
954         error_propagate(errp, local_err);
955         return NULL;
956     }
957 
958     assert(opts != NULL);
959 
960     state.errp = &local_err;
961     state.opts = opts;
962     qdict_iter(qdict, qemu_opts_from_qdict_1, &state);
963     if (local_err) {
964         error_propagate(errp, local_err);
965         qemu_opts_del(opts);
966         return NULL;
967     }
968 
969     return opts;
970 }
971 
972 /*
973  * Adds all QDict entries to the QemuOpts that can be added and removes them
974  * from the QDict. When this function returns, the QDict contains only those
975  * entries that couldn't be added to the QemuOpts.
976  */
977 void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
978 {
979     const QDictEntry *entry, *next;
980 
981     entry = qdict_first(qdict);
982 
983     while (entry != NULL) {
984         Error *local_err = NULL;
985         OptsFromQDictState state = {
986             .errp = &local_err,
987             .opts = opts,
988         };
989 
990         next = qdict_next(qdict, entry);
991 
992         if (find_desc_by_name(opts->list->desc, entry->key)) {
993             qemu_opts_from_qdict_1(entry->key, entry->value, &state);
994             if (local_err) {
995                 error_propagate(errp, local_err);
996                 return;
997             } else {
998                 qdict_del(qdict, entry->key);
999             }
1000         }
1001 
1002         entry = next;
1003     }
1004 }
1005 
1006 /*
1007  * Convert from QemuOpts to QDict.
1008  * The QDict values are of type QString.
1009  * TODO We'll want to use types appropriate for opt->desc->type, but
1010  * this is enough for now.
1011  */
1012 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
1013 {
1014     QemuOpt *opt;
1015 
1016     if (!qdict) {
1017         qdict = qdict_new();
1018     }
1019     if (opts->id) {
1020         qdict_put_str(qdict, "id", opts->id);
1021     }
1022     QTAILQ_FOREACH(opt, &opts->head, next) {
1023         qdict_put_str(qdict, opt->name, opt->str);
1024     }
1025     return qdict;
1026 }
1027 
1028 /* Validate parsed opts against descriptions where no
1029  * descriptions were provided in the QemuOptsList.
1030  */
1031 void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp)
1032 {
1033     QemuOpt *opt;
1034     Error *local_err = NULL;
1035 
1036     assert(opts_accepts_any(opts));
1037 
1038     QTAILQ_FOREACH(opt, &opts->head, next) {
1039         opt->desc = find_desc_by_name(desc, opt->name);
1040         if (!opt->desc) {
1041             error_setg(errp, QERR_INVALID_PARAMETER, opt->name);
1042             return;
1043         }
1044 
1045         qemu_opt_parse(opt, &local_err);
1046         if (local_err) {
1047             error_propagate(errp, local_err);
1048             return;
1049         }
1050     }
1051 }
1052 
1053 /**
1054  * For each member of @list, call @func(@opaque, member, @errp).
1055  * Call it with the current location temporarily set to the member's.
1056  * @func() may store an Error through @errp, but must return non-zero then.
1057  * When @func() returns non-zero, break the loop and return that value.
1058  * Return zero when the loop completes.
1059  */
1060 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
1061                       void *opaque, Error **errp)
1062 {
1063     Location loc;
1064     QemuOpts *opts;
1065     int rc = 0;
1066 
1067     loc_push_none(&loc);
1068     QTAILQ_FOREACH(opts, &list->head, next) {
1069         loc_restore(&opts->loc);
1070         rc = func(opaque, opts, errp);
1071         if (rc) {
1072             break;
1073         }
1074         assert(!errp || !*errp);
1075     }
1076     loc_pop(&loc);
1077     return rc;
1078 }
1079 
1080 static size_t count_opts_list(QemuOptsList *list)
1081 {
1082     QemuOptDesc *desc = NULL;
1083     size_t num_opts = 0;
1084 
1085     if (!list) {
1086         return 0;
1087     }
1088 
1089     desc = list->desc;
1090     while (desc && desc->name) {
1091         num_opts++;
1092         desc++;
1093     }
1094 
1095     return num_opts;
1096 }
1097 
1098 void qemu_opts_free(QemuOptsList *list)
1099 {
1100     g_free(list);
1101 }
1102 
1103 /* Realloc dst option list and append options from an option list (list)
1104  * to it. dst could be NULL or a malloced list.
1105  * The lifetime of dst must be shorter than the input list because the
1106  * QemuOptDesc->name, ->help, and ->def_value_str strings are shared.
1107  */
1108 QemuOptsList *qemu_opts_append(QemuOptsList *dst,
1109                                QemuOptsList *list)
1110 {
1111     size_t num_opts, num_dst_opts;
1112     QemuOptDesc *desc;
1113     bool need_init = false;
1114     bool need_head_update;
1115 
1116     if (!list) {
1117         return dst;
1118     }
1119 
1120     /* If dst is NULL, after realloc, some area of dst should be initialized
1121      * before adding options to it.
1122      */
1123     if (!dst) {
1124         need_init = true;
1125         need_head_update = true;
1126     } else {
1127         /* Moreover, even if dst is not NULL, the realloc may move it to a
1128          * different address in which case we may get a stale tail pointer
1129          * in dst->head. */
1130         need_head_update = QTAILQ_EMPTY(&dst->head);
1131     }
1132 
1133     num_opts = count_opts_list(dst);
1134     num_dst_opts = num_opts;
1135     num_opts += count_opts_list(list);
1136     dst = g_realloc(dst, sizeof(QemuOptsList) +
1137                     (num_opts + 1) * sizeof(QemuOptDesc));
1138     if (need_init) {
1139         dst->name = NULL;
1140         dst->implied_opt_name = NULL;
1141         dst->merge_lists = false;
1142     }
1143     if (need_head_update) {
1144         QTAILQ_INIT(&dst->head);
1145     }
1146     dst->desc[num_dst_opts].name = NULL;
1147 
1148     /* append list->desc to dst->desc */
1149     if (list) {
1150         desc = list->desc;
1151         while (desc && desc->name) {
1152             if (find_desc_by_name(dst->desc, desc->name) == NULL) {
1153                 dst->desc[num_dst_opts++] = *desc;
1154                 dst->desc[num_dst_opts].name = NULL;
1155             }
1156             desc++;
1157         }
1158     }
1159 
1160     return dst;
1161 }
1162