xref: /openbmc/qemu/util/qemu-option.c (revision c8ca2a23)
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/qbool.h"
32 #include "qapi/qmp/qdict.h"
33 #include "qapi/qmp/qnum.h"
34 #include "qapi/qmp/qstring.h"
35 #include "qapi/qmp/qerror.h"
36 #include "qemu/option_int.h"
37 #include "qemu/cutils.h"
38 #include "qemu/id.h"
39 #include "qemu/help_option.h"
40 
41 /*
42  * Extracts the name of an option from the parameter string (p points at the
43  * first byte of the option name)
44  *
45  * The option name is delimited by delim (usually , or =) or the string end
46  * and is copied into buf. If the option name is longer than buf_size, it is
47  * truncated. buf is always zero terminated.
48  *
49  * The return value is the position of the delimiter/zero byte after the option
50  * name in p.
51  */
52 const char *get_opt_name(char *buf, int buf_size, const char *p, char delim)
53 {
54     char *q;
55 
56     q = buf;
57     while (*p != '\0' && *p != delim) {
58         if (q && (q - buf) < buf_size - 1)
59             *q++ = *p;
60         p++;
61     }
62     if (q)
63         *q = '\0';
64 
65     return p;
66 }
67 
68 /*
69  * Extracts the value of an option from the parameter string p (p points at the
70  * first byte of the option value)
71  *
72  * This function is comparable to get_opt_name with the difference that the
73  * delimiter is fixed to be comma which starts a new option. To specify an
74  * option value that contains commas, double each comma.
75  */
76 const char *get_opt_value(char *buf, int buf_size, const char *p)
77 {
78     char *q;
79 
80     q = buf;
81     while (*p != '\0') {
82         if (*p == ',') {
83             if (*(p + 1) != ',')
84                 break;
85             p++;
86         }
87         if (q && (q - buf) < buf_size - 1)
88             *q++ = *p;
89         p++;
90     }
91     if (q)
92         *q = '\0';
93 
94     return p;
95 }
96 
97 static void parse_option_bool(const char *name, const char *value, bool *ret,
98                               Error **errp)
99 {
100     if (!strcmp(value, "on")) {
101         *ret = 1;
102     } else if (!strcmp(value, "off")) {
103         *ret = 0;
104     } else {
105         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
106                    name, "'on' or 'off'");
107     }
108 }
109 
110 static void parse_option_number(const char *name, const char *value,
111                                 uint64_t *ret, Error **errp)
112 {
113     uint64_t number;
114     int err;
115 
116     err = qemu_strtou64(value, NULL, 0, &number);
117     if (err == -ERANGE) {
118         error_setg(errp, "Value '%s' is too large for parameter '%s'",
119                    value, name);
120         return;
121     }
122     if (err) {
123         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
124         return;
125     }
126     *ret = number;
127 }
128 
129 static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,
130                                             const char *name)
131 {
132     int i;
133 
134     for (i = 0; desc[i].name != NULL; i++) {
135         if (strcmp(desc[i].name, name) == 0) {
136             return &desc[i];
137         }
138     }
139 
140     return NULL;
141 }
142 
143 void parse_option_size(const char *name, const char *value,
144                        uint64_t *ret, Error **errp)
145 {
146     uint64_t size;
147     int err;
148 
149     err = qemu_strtosz(value, NULL, &size);
150     if (err == -ERANGE) {
151         error_setg(errp, "Value '%s' is out of range for parameter '%s'",
152                    value, name);
153         return;
154     }
155     if (err) {
156         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
157                    "a non-negative number below 2^64");
158         error_append_hint(errp, "Optional suffix k, M, G, T, P or E means"
159                           " kilo-, mega-, giga-, tera-, peta-\n"
160                           "and exabytes, respectively.\n");
161         return;
162     }
163     *ret = size;
164 }
165 
166 bool has_help_option(const char *param)
167 {
168     size_t buflen = strlen(param) + 1;
169     char *buf = g_malloc(buflen);
170     const char *p = param;
171     bool result = false;
172 
173     while (*p) {
174         p = get_opt_value(buf, buflen, p);
175         if (*p) {
176             p++;
177         }
178 
179         if (is_help_option(buf)) {
180             result = true;
181             goto out;
182         }
183     }
184 
185 out:
186     g_free(buf);
187     return result;
188 }
189 
190 bool is_valid_option_list(const char *param)
191 {
192     size_t buflen = strlen(param) + 1;
193     char *buf = g_malloc(buflen);
194     const char *p = param;
195     bool result = true;
196 
197     while (*p) {
198         p = get_opt_value(buf, buflen, p);
199         if (*p && !*++p) {
200             result = false;
201             goto out;
202         }
203 
204         if (!*buf || *buf == ',') {
205             result = false;
206             goto out;
207         }
208     }
209 
210 out:
211     g_free(buf);
212     return result;
213 }
214 
215 void qemu_opts_print_help(QemuOptsList *list)
216 {
217     QemuOptDesc *desc;
218 
219     assert(list);
220     desc = list->desc;
221     printf("Supported options:\n");
222     while (desc && desc->name) {
223         printf("%-16s %s\n", desc->name,
224                desc->help ? desc->help : "No description available");
225         desc++;
226     }
227 }
228 /* ------------------------------------------------------------------ */
229 
230 QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
231 {
232     QemuOpt *opt;
233 
234     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
235         if (strcmp(opt->name, name) != 0)
236             continue;
237         return opt;
238     }
239     return NULL;
240 }
241 
242 static void qemu_opt_del(QemuOpt *opt)
243 {
244     QTAILQ_REMOVE(&opt->opts->head, opt, next);
245     g_free(opt->name);
246     g_free(opt->str);
247     g_free(opt);
248 }
249 
250 /* qemu_opt_set allows many settings for the same option.
251  * This function deletes all settings for an option.
252  */
253 static void qemu_opt_del_all(QemuOpts *opts, const char *name)
254 {
255     QemuOpt *opt, *next_opt;
256 
257     QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next_opt) {
258         if (!strcmp(opt->name, name)) {
259             qemu_opt_del(opt);
260         }
261     }
262 }
263 
264 const char *qemu_opt_get(QemuOpts *opts, const char *name)
265 {
266     QemuOpt *opt;
267 
268     if (opts == NULL) {
269         return NULL;
270     }
271 
272     opt = qemu_opt_find(opts, name);
273     if (!opt) {
274         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
275         if (desc && desc->def_value_str) {
276             return desc->def_value_str;
277         }
278     }
279     return opt ? opt->str : NULL;
280 }
281 
282 void qemu_opt_iter_init(QemuOptsIter *iter, QemuOpts *opts, const char *name)
283 {
284     iter->opts = opts;
285     iter->opt = QTAILQ_FIRST(&opts->head);
286     iter->name = name;
287 }
288 
289 const char *qemu_opt_iter_next(QemuOptsIter *iter)
290 {
291     QemuOpt *ret = iter->opt;
292     if (iter->name) {
293         while (ret && !g_str_equal(iter->name, ret->name)) {
294             ret = QTAILQ_NEXT(ret, next);
295         }
296     }
297     iter->opt = ret ? QTAILQ_NEXT(ret, next) : NULL;
298     return ret ? ret->str : NULL;
299 }
300 
301 /* Get a known option (or its default) and remove it from the list
302  * all in one action. Return a malloced string of the option value.
303  * Result must be freed by caller with g_free().
304  */
305 char *qemu_opt_get_del(QemuOpts *opts, const char *name)
306 {
307     QemuOpt *opt;
308     const QemuOptDesc *desc;
309     char *str = NULL;
310 
311     if (opts == NULL) {
312         return NULL;
313     }
314 
315     opt = qemu_opt_find(opts, name);
316     if (!opt) {
317         desc = find_desc_by_name(opts->list->desc, name);
318         if (desc && desc->def_value_str) {
319             str = g_strdup(desc->def_value_str);
320         }
321         return str;
322     }
323     str = opt->str;
324     opt->str = NULL;
325     qemu_opt_del_all(opts, name);
326     return str;
327 }
328 
329 bool qemu_opt_has_help_opt(QemuOpts *opts)
330 {
331     QemuOpt *opt;
332 
333     QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {
334         if (is_help_option(opt->name)) {
335             return true;
336         }
337     }
338     return false;
339 }
340 
341 static bool qemu_opt_get_bool_helper(QemuOpts *opts, const char *name,
342                                      bool defval, bool del)
343 {
344     QemuOpt *opt;
345     bool ret = defval;
346 
347     if (opts == NULL) {
348         return ret;
349     }
350 
351     opt = qemu_opt_find(opts, name);
352     if (opt == NULL) {
353         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
354         if (desc && desc->def_value_str) {
355             parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
356         }
357         return ret;
358     }
359     assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
360     ret = opt->value.boolean;
361     if (del) {
362         qemu_opt_del_all(opts, name);
363     }
364     return ret;
365 }
366 
367 bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
368 {
369     return qemu_opt_get_bool_helper(opts, name, defval, false);
370 }
371 
372 bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval)
373 {
374     return qemu_opt_get_bool_helper(opts, name, defval, true);
375 }
376 
377 static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
378                                            uint64_t defval, bool del)
379 {
380     QemuOpt *opt;
381     uint64_t ret = defval;
382 
383     if (opts == NULL) {
384         return ret;
385     }
386 
387     opt = qemu_opt_find(opts, name);
388     if (opt == NULL) {
389         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
390         if (desc && desc->def_value_str) {
391             parse_option_number(name, desc->def_value_str, &ret, &error_abort);
392         }
393         return ret;
394     }
395     assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
396     ret = opt->value.uint;
397     if (del) {
398         qemu_opt_del_all(opts, name);
399     }
400     return ret;
401 }
402 
403 uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
404 {
405     return qemu_opt_get_number_helper(opts, name, defval, false);
406 }
407 
408 uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
409                                  uint64_t defval)
410 {
411     return qemu_opt_get_number_helper(opts, name, defval, true);
412 }
413 
414 static uint64_t qemu_opt_get_size_helper(QemuOpts *opts, const char *name,
415                                          uint64_t defval, bool del)
416 {
417     QemuOpt *opt;
418     uint64_t ret = defval;
419 
420     if (opts == NULL) {
421         return ret;
422     }
423 
424     opt = qemu_opt_find(opts, name);
425     if (opt == NULL) {
426         const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
427         if (desc && desc->def_value_str) {
428             parse_option_size(name, desc->def_value_str, &ret, &error_abort);
429         }
430         return ret;
431     }
432     assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
433     ret = opt->value.uint;
434     if (del) {
435         qemu_opt_del_all(opts, name);
436     }
437     return ret;
438 }
439 
440 uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
441 {
442     return qemu_opt_get_size_helper(opts, name, defval, false);
443 }
444 
445 uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
446                                uint64_t defval)
447 {
448     return qemu_opt_get_size_helper(opts, name, defval, true);
449 }
450 
451 static void qemu_opt_parse(QemuOpt *opt, Error **errp)
452 {
453     if (opt->desc == NULL)
454         return;
455 
456     switch (opt->desc->type) {
457     case QEMU_OPT_STRING:
458         /* nothing */
459         return;
460     case QEMU_OPT_BOOL:
461         parse_option_bool(opt->name, opt->str, &opt->value.boolean, errp);
462         break;
463     case QEMU_OPT_NUMBER:
464         parse_option_number(opt->name, opt->str, &opt->value.uint, errp);
465         break;
466     case QEMU_OPT_SIZE:
467         parse_option_size(opt->name, opt->str, &opt->value.uint, errp);
468         break;
469     default:
470         abort();
471     }
472 }
473 
474 static bool opts_accepts_any(const QemuOpts *opts)
475 {
476     return opts->list->desc[0].name == NULL;
477 }
478 
479 int qemu_opt_unset(QemuOpts *opts, const char *name)
480 {
481     QemuOpt *opt = qemu_opt_find(opts, name);
482 
483     assert(opts_accepts_any(opts));
484 
485     if (opt == NULL) {
486         return -1;
487     } else {
488         qemu_opt_del(opt);
489         return 0;
490     }
491 }
492 
493 static void opt_set(QemuOpts *opts, const char *name, const char *value,
494                     bool prepend, Error **errp)
495 {
496     QemuOpt *opt;
497     const QemuOptDesc *desc;
498     Error *local_err = NULL;
499 
500     desc = find_desc_by_name(opts->list->desc, name);
501     if (!desc && !opts_accepts_any(opts)) {
502         error_setg(errp, QERR_INVALID_PARAMETER, name);
503         return;
504     }
505 
506     opt = g_malloc0(sizeof(*opt));
507     opt->name = g_strdup(name);
508     opt->opts = opts;
509     if (prepend) {
510         QTAILQ_INSERT_HEAD(&opts->head, opt, next);
511     } else {
512         QTAILQ_INSERT_TAIL(&opts->head, opt, next);
513     }
514     opt->desc = desc;
515     opt->str = g_strdup(value);
516     assert(opt->str);
517     qemu_opt_parse(opt, &local_err);
518     if (local_err) {
519         error_propagate(errp, local_err);
520         qemu_opt_del(opt);
521     }
522 }
523 
524 void qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
525                   Error **errp)
526 {
527     opt_set(opts, name, value, false, errp);
528 }
529 
530 void qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val,
531                        Error **errp)
532 {
533     QemuOpt *opt;
534     const QemuOptDesc *desc = opts->list->desc;
535 
536     opt = g_malloc0(sizeof(*opt));
537     opt->desc = find_desc_by_name(desc, name);
538     if (!opt->desc && !opts_accepts_any(opts)) {
539         error_setg(errp, QERR_INVALID_PARAMETER, name);
540         g_free(opt);
541         return;
542     }
543 
544     opt->name = g_strdup(name);
545     opt->opts = opts;
546     opt->value.boolean = !!val;
547     opt->str = g_strdup(val ? "on" : "off");
548     QTAILQ_INSERT_TAIL(&opts->head, opt, next);
549 }
550 
551 void qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val,
552                          Error **errp)
553 {
554     QemuOpt *opt;
555     const QemuOptDesc *desc = opts->list->desc;
556 
557     opt = g_malloc0(sizeof(*opt));
558     opt->desc = find_desc_by_name(desc, name);
559     if (!opt->desc && !opts_accepts_any(opts)) {
560         error_setg(errp, QERR_INVALID_PARAMETER, name);
561         g_free(opt);
562         return;
563     }
564 
565     opt->name = g_strdup(name);
566     opt->opts = opts;
567     opt->value.uint = val;
568     opt->str = g_strdup_printf("%" PRId64, val);
569     QTAILQ_INSERT_TAIL(&opts->head, opt, next);
570 }
571 
572 /**
573  * For each member of @opts, call @func(@opaque, name, value, @errp).
574  * @func() may store an Error through @errp, but must return non-zero then.
575  * When @func() returns non-zero, break the loop and return that value.
576  * Return zero when the loop completes.
577  */
578 int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
579                      Error **errp)
580 {
581     QemuOpt *opt;
582     int rc;
583 
584     QTAILQ_FOREACH(opt, &opts->head, next) {
585         rc = func(opaque, opt->name, opt->str, errp);
586         if (rc) {
587             return rc;
588         }
589         assert(!errp || !*errp);
590     }
591     return 0;
592 }
593 
594 QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
595 {
596     QemuOpts *opts;
597 
598     QTAILQ_FOREACH(opts, &list->head, next) {
599         if (!opts->id && !id) {
600             return opts;
601         }
602         if (opts->id && id && !strcmp(opts->id, id)) {
603             return opts;
604         }
605     }
606     return NULL;
607 }
608 
609 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
610                            int fail_if_exists, Error **errp)
611 {
612     QemuOpts *opts = NULL;
613 
614     if (id) {
615         if (!id_wellformed(id)) {
616             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
617                        "an identifier");
618             error_append_hint(errp, "Identifiers consist of letters, digits, "
619                               "'-', '.', '_', starting with a letter.\n");
620             return NULL;
621         }
622         opts = qemu_opts_find(list, id);
623         if (opts != NULL) {
624             if (fail_if_exists && !list->merge_lists) {
625                 error_setg(errp, "Duplicate ID '%s' for %s", id, list->name);
626                 return NULL;
627             } else {
628                 return opts;
629             }
630         }
631     } else if (list->merge_lists) {
632         opts = qemu_opts_find(list, NULL);
633         if (opts) {
634             return opts;
635         }
636     }
637     opts = g_malloc0(sizeof(*opts));
638     opts->id = g_strdup(id);
639     opts->list = list;
640     loc_save(&opts->loc);
641     QTAILQ_INIT(&opts->head);
642     QTAILQ_INSERT_TAIL(&list->head, opts, next);
643     return opts;
644 }
645 
646 void qemu_opts_reset(QemuOptsList *list)
647 {
648     QemuOpts *opts, *next_opts;
649 
650     QTAILQ_FOREACH_SAFE(opts, &list->head, next, next_opts) {
651         qemu_opts_del(opts);
652     }
653 }
654 
655 void qemu_opts_loc_restore(QemuOpts *opts)
656 {
657     loc_restore(&opts->loc);
658 }
659 
660 void qemu_opts_set(QemuOptsList *list, const char *id,
661                    const char *name, const char *value, Error **errp)
662 {
663     QemuOpts *opts;
664     Error *local_err = NULL;
665 
666     opts = qemu_opts_create(list, id, 1, &local_err);
667     if (local_err) {
668         error_propagate(errp, local_err);
669         return;
670     }
671     qemu_opt_set(opts, name, value, errp);
672 }
673 
674 const char *qemu_opts_id(QemuOpts *opts)
675 {
676     return opts->id;
677 }
678 
679 /* The id string will be g_free()d by qemu_opts_del */
680 void qemu_opts_set_id(QemuOpts *opts, char *id)
681 {
682     opts->id = id;
683 }
684 
685 void qemu_opts_del(QemuOpts *opts)
686 {
687     QemuOpt *opt;
688 
689     if (opts == NULL) {
690         return;
691     }
692 
693     for (;;) {
694         opt = QTAILQ_FIRST(&opts->head);
695         if (opt == NULL)
696             break;
697         qemu_opt_del(opt);
698     }
699     QTAILQ_REMOVE(&opts->list->head, opts, next);
700     g_free(opts->id);
701     g_free(opts);
702 }
703 
704 /* print value, escaping any commas in value */
705 static void escaped_print(const char *value)
706 {
707     const char *ptr;
708 
709     for (ptr = value; *ptr; ++ptr) {
710         if (*ptr == ',') {
711             putchar(',');
712         }
713         putchar(*ptr);
714     }
715 }
716 
717 void qemu_opts_print(QemuOpts *opts, const char *separator)
718 {
719     QemuOpt *opt;
720     QemuOptDesc *desc = opts->list->desc;
721     const char *sep = "";
722 
723     if (opts->id) {
724         printf("id=%s", opts->id); /* passed id_wellformed -> no commas */
725         sep = separator;
726     }
727 
728     if (desc[0].name == NULL) {
729         QTAILQ_FOREACH(opt, &opts->head, next) {
730             printf("%s%s=", sep, opt->name);
731             escaped_print(opt->str);
732             sep = separator;
733         }
734         return;
735     }
736     for (; desc && desc->name; desc++) {
737         const char *value;
738         opt = qemu_opt_find(opts, desc->name);
739 
740         value = opt ? opt->str : desc->def_value_str;
741         if (!value) {
742             continue;
743         }
744         if (desc->type == QEMU_OPT_STRING) {
745             printf("%s%s=", sep, desc->name);
746             escaped_print(value);
747         } else if ((desc->type == QEMU_OPT_SIZE ||
748                     desc->type == QEMU_OPT_NUMBER) && opt) {
749             printf("%s%s=%" PRId64, sep, desc->name, opt->value.uint);
750         } else {
751             printf("%s%s=%s", sep, desc->name, value);
752         }
753         sep = separator;
754     }
755 }
756 
757 static void opts_do_parse(QemuOpts *opts, const char *params,
758                           const char *firstname, bool prepend, Error **errp)
759 {
760     char option[128], value[1024];
761     const char *p,*pe,*pc;
762     Error *local_err = NULL;
763 
764     for (p = params; *p != '\0'; p++) {
765         pe = strchr(p, '=');
766         pc = strchr(p, ',');
767         if (!pe || (pc && pc < pe)) {
768             /* found "foo,more" */
769             if (p == params && firstname) {
770                 /* implicitly named first option */
771                 pstrcpy(option, sizeof(option), firstname);
772                 p = get_opt_value(value, sizeof(value), p);
773             } else {
774                 /* option without value, probably a flag */
775                 p = get_opt_name(option, sizeof(option), p, ',');
776                 if (strncmp(option, "no", 2) == 0) {
777                     memmove(option, option+2, strlen(option+2)+1);
778                     pstrcpy(value, sizeof(value), "off");
779                 } else {
780                     pstrcpy(value, sizeof(value), "on");
781                 }
782             }
783         } else {
784             /* found "foo=bar,more" */
785             p = get_opt_name(option, sizeof(option), p, '=');
786             if (*p != '=') {
787                 break;
788             }
789             p++;
790             p = get_opt_value(value, sizeof(value), p);
791         }
792         if (strcmp(option, "id") != 0) {
793             /* store and parse */
794             opt_set(opts, option, value, prepend, &local_err);
795             if (local_err) {
796                 error_propagate(errp, local_err);
797                 return;
798             }
799         }
800         if (*p != ',') {
801             break;
802         }
803     }
804 }
805 
806 /**
807  * Store options parsed from @params into @opts.
808  * If @firstname is non-null, the first key=value in @params may omit
809  * key=, and is treated as if key was @firstname.
810  * On error, store an error object through @errp if non-null.
811  */
812 void qemu_opts_do_parse(QemuOpts *opts, const char *params,
813                        const char *firstname, Error **errp)
814 {
815     opts_do_parse(opts, params, firstname, false, errp);
816 }
817 
818 static QemuOpts *opts_parse(QemuOptsList *list, const char *params,
819                             bool permit_abbrev, bool defaults, Error **errp)
820 {
821     const char *firstname;
822     char value[1024], *id = NULL;
823     const char *p;
824     QemuOpts *opts;
825     Error *local_err = NULL;
826 
827     assert(!permit_abbrev || list->implied_opt_name);
828     firstname = permit_abbrev ? list->implied_opt_name : NULL;
829 
830     if (strncmp(params, "id=", 3) == 0) {
831         get_opt_value(value, sizeof(value), params+3);
832         id = value;
833     } else if ((p = strstr(params, ",id=")) != NULL) {
834         get_opt_value(value, sizeof(value), p+4);
835         id = value;
836     }
837 
838     /*
839      * This code doesn't work for defaults && !list->merge_lists: when
840      * params has no id=, and list has an element with !opts->id, it
841      * appends a new element instead of returning the existing opts.
842      * However, we got no use for this case.  Guard against possible
843      * (if unlikely) future misuse:
844      */
845     assert(!defaults || list->merge_lists);
846     opts = qemu_opts_create(list, id, !defaults, &local_err);
847     if (opts == NULL) {
848         error_propagate(errp, local_err);
849         return NULL;
850     }
851 
852     opts_do_parse(opts, params, firstname, defaults, &local_err);
853     if (local_err) {
854         error_propagate(errp, local_err);
855         qemu_opts_del(opts);
856         return NULL;
857     }
858 
859     return opts;
860 }
861 
862 /**
863  * Create a QemuOpts in @list and with options parsed from @params.
864  * If @permit_abbrev, the first key=value in @params may omit key=,
865  * and is treated as if key was @list->implied_opt_name.
866  * On error, store an error object through @errp if non-null.
867  * Return the new QemuOpts on success, null pointer on error.
868  */
869 QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
870                           bool permit_abbrev, Error **errp)
871 {
872     return opts_parse(list, params, permit_abbrev, false, errp);
873 }
874 
875 /**
876  * Create a QemuOpts in @list and with options parsed from @params.
877  * If @permit_abbrev, the first key=value in @params may omit key=,
878  * and is treated as if key was @list->implied_opt_name.
879  * Report errors with error_report_err().  This is inappropriate in
880  * QMP context.  Do not use this function there!
881  * Return the new QemuOpts on success, null pointer on error.
882  */
883 QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
884                                   bool permit_abbrev)
885 {
886     Error *err = NULL;
887     QemuOpts *opts;
888 
889     opts = opts_parse(list, params, permit_abbrev, false, &err);
890     if (err) {
891         error_report_err(err);
892     }
893     return opts;
894 }
895 
896 void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
897                             int permit_abbrev)
898 {
899     QemuOpts *opts;
900 
901     opts = opts_parse(list, params, permit_abbrev, true, NULL);
902     assert(opts);
903 }
904 
905 typedef struct OptsFromQDictState {
906     QemuOpts *opts;
907     Error **errp;
908 } OptsFromQDictState;
909 
910 static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)
911 {
912     OptsFromQDictState *state = opaque;
913     char buf[32], *tmp = NULL;
914     const char *value;
915 
916     if (!strcmp(key, "id") || *state->errp) {
917         return;
918     }
919 
920     switch (qobject_type(obj)) {
921     case QTYPE_QSTRING:
922         value = qstring_get_str(qobject_to_qstring(obj));
923         break;
924     case QTYPE_QNUM:
925         tmp = qnum_to_string(qobject_to_qnum(obj));
926         value = tmp;
927         break;
928     case QTYPE_QBOOL:
929         pstrcpy(buf, sizeof(buf),
930                 qbool_get_bool(qobject_to_qbool(obj)) ? "on" : "off");
931         value = buf;
932         break;
933     default:
934         return;
935     }
936 
937     qemu_opt_set(state->opts, key, value, state->errp);
938     g_free(tmp);
939 }
940 
941 /*
942  * Create QemuOpts from a QDict.
943  * Use value of key "id" as ID if it exists and is a QString.  Only
944  * QStrings, QNums and QBools are copied.  Entries with other types
945  * are silently ignored.
946  */
947 QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
948                                Error **errp)
949 {
950     OptsFromQDictState state;
951     Error *local_err = NULL;
952     QemuOpts *opts;
953 
954     opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,
955                             &local_err);
956     if (local_err) {
957         error_propagate(errp, local_err);
958         return NULL;
959     }
960 
961     assert(opts != NULL);
962 
963     state.errp = &local_err;
964     state.opts = opts;
965     qdict_iter(qdict, qemu_opts_from_qdict_1, &state);
966     if (local_err) {
967         error_propagate(errp, local_err);
968         qemu_opts_del(opts);
969         return NULL;
970     }
971 
972     return opts;
973 }
974 
975 /*
976  * Adds all QDict entries to the QemuOpts that can be added and removes them
977  * from the QDict. When this function returns, the QDict contains only those
978  * entries that couldn't be added to the QemuOpts.
979  */
980 void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
981 {
982     const QDictEntry *entry, *next;
983 
984     entry = qdict_first(qdict);
985 
986     while (entry != NULL) {
987         Error *local_err = NULL;
988         OptsFromQDictState state = {
989             .errp = &local_err,
990             .opts = opts,
991         };
992 
993         next = qdict_next(qdict, entry);
994 
995         if (find_desc_by_name(opts->list->desc, entry->key)) {
996             qemu_opts_from_qdict_1(entry->key, entry->value, &state);
997             if (local_err) {
998                 error_propagate(errp, local_err);
999                 return;
1000             } else {
1001                 qdict_del(qdict, entry->key);
1002             }
1003         }
1004 
1005         entry = next;
1006     }
1007 }
1008 
1009 /*
1010  * Convert from QemuOpts to QDict. The QDict values are of type QString.
1011  *
1012  * If @list is given, only add those options to the QDict that are contained in
1013  * the list. If @del is true, any options added to the QDict are removed from
1014  * the QemuOpts, otherwise they remain there.
1015  *
1016  * If two options in @opts have the same name, they are processed in order
1017  * so that the last one wins (consistent with the reverse iteration in
1018  * qemu_opt_find()), but all of them are deleted if @del is true.
1019  *
1020  * TODO We'll want to use types appropriate for opt->desc->type, but
1021  * this is enough for now.
1022  */
1023 QDict *qemu_opts_to_qdict_filtered(QemuOpts *opts, QDict *qdict,
1024                                    QemuOptsList *list, bool del)
1025 {
1026     QemuOpt *opt, *next;
1027 
1028     if (!qdict) {
1029         qdict = qdict_new();
1030     }
1031     if (opts->id) {
1032         qdict_put_str(qdict, "id", opts->id);
1033     }
1034     QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next) {
1035         if (list) {
1036             QemuOptDesc *desc;
1037             bool found = false;
1038             for (desc = list->desc; desc->name; desc++) {
1039                 if (!strcmp(desc->name, opt->name)) {
1040                     found = true;
1041                     break;
1042                 }
1043             }
1044             if (!found) {
1045                 continue;
1046             }
1047         }
1048         qdict_put_str(qdict, opt->name, opt->str);
1049         if (del) {
1050             qemu_opt_del(opt);
1051         }
1052     }
1053     return qdict;
1054 }
1055 
1056 /* Copy all options in a QemuOpts to the given QDict. See
1057  * qemu_opts_to_qdict_filtered() for details. */
1058 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
1059 {
1060     return qemu_opts_to_qdict_filtered(opts, qdict, NULL, false);
1061 }
1062 
1063 /* Validate parsed opts against descriptions where no
1064  * descriptions were provided in the QemuOptsList.
1065  */
1066 void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp)
1067 {
1068     QemuOpt *opt;
1069     Error *local_err = NULL;
1070 
1071     assert(opts_accepts_any(opts));
1072 
1073     QTAILQ_FOREACH(opt, &opts->head, next) {
1074         opt->desc = find_desc_by_name(desc, opt->name);
1075         if (!opt->desc) {
1076             error_setg(errp, QERR_INVALID_PARAMETER, opt->name);
1077             return;
1078         }
1079 
1080         qemu_opt_parse(opt, &local_err);
1081         if (local_err) {
1082             error_propagate(errp, local_err);
1083             return;
1084         }
1085     }
1086 }
1087 
1088 /**
1089  * For each member of @list, call @func(@opaque, member, @errp).
1090  * Call it with the current location temporarily set to the member's.
1091  * @func() may store an Error through @errp, but must return non-zero then.
1092  * When @func() returns non-zero, break the loop and return that value.
1093  * Return zero when the loop completes.
1094  */
1095 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
1096                       void *opaque, Error **errp)
1097 {
1098     Location loc;
1099     QemuOpts *opts;
1100     int rc = 0;
1101 
1102     loc_push_none(&loc);
1103     QTAILQ_FOREACH(opts, &list->head, next) {
1104         loc_restore(&opts->loc);
1105         rc = func(opaque, opts, errp);
1106         if (rc) {
1107             break;
1108         }
1109         assert(!errp || !*errp);
1110     }
1111     loc_pop(&loc);
1112     return rc;
1113 }
1114 
1115 static size_t count_opts_list(QemuOptsList *list)
1116 {
1117     QemuOptDesc *desc = NULL;
1118     size_t num_opts = 0;
1119 
1120     if (!list) {
1121         return 0;
1122     }
1123 
1124     desc = list->desc;
1125     while (desc && desc->name) {
1126         num_opts++;
1127         desc++;
1128     }
1129 
1130     return num_opts;
1131 }
1132 
1133 void qemu_opts_free(QemuOptsList *list)
1134 {
1135     g_free(list);
1136 }
1137 
1138 /* Realloc dst option list and append options from an option list (list)
1139  * to it. dst could be NULL or a malloced list.
1140  * The lifetime of dst must be shorter than the input list because the
1141  * QemuOptDesc->name, ->help, and ->def_value_str strings are shared.
1142  */
1143 QemuOptsList *qemu_opts_append(QemuOptsList *dst,
1144                                QemuOptsList *list)
1145 {
1146     size_t num_opts, num_dst_opts;
1147     QemuOptDesc *desc;
1148     bool need_init = false;
1149     bool need_head_update;
1150 
1151     if (!list) {
1152         return dst;
1153     }
1154 
1155     /* If dst is NULL, after realloc, some area of dst should be initialized
1156      * before adding options to it.
1157      */
1158     if (!dst) {
1159         need_init = true;
1160         need_head_update = true;
1161     } else {
1162         /* Moreover, even if dst is not NULL, the realloc may move it to a
1163          * different address in which case we may get a stale tail pointer
1164          * in dst->head. */
1165         need_head_update = QTAILQ_EMPTY(&dst->head);
1166     }
1167 
1168     num_opts = count_opts_list(dst);
1169     num_dst_opts = num_opts;
1170     num_opts += count_opts_list(list);
1171     dst = g_realloc(dst, sizeof(QemuOptsList) +
1172                     (num_opts + 1) * sizeof(QemuOptDesc));
1173     if (need_init) {
1174         dst->name = NULL;
1175         dst->implied_opt_name = NULL;
1176         dst->merge_lists = false;
1177     }
1178     if (need_head_update) {
1179         QTAILQ_INIT(&dst->head);
1180     }
1181     dst->desc[num_dst_opts].name = NULL;
1182 
1183     /* append list->desc to dst->desc */
1184     if (list) {
1185         desc = list->desc;
1186         while (desc && desc->name) {
1187             if (find_desc_by_name(dst->desc, desc->name) == NULL) {
1188                 dst->desc[num_dst_opts++] = *desc;
1189                 dst->desc[num_dst_opts].name = NULL;
1190             }
1191             desc++;
1192         }
1193     }
1194 
1195     return dst;
1196 }
1197