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kraxelAnthony Liguori
kraxel
authored and
Anthony Liguori
committed
QemuOpts: framework for storing and parsing options.
This stores device parameters in a better way than unparsed strings. New types: QemuOpt - one key-value pair. QemuOpts - group of key-value pairs, belonging to one device, i.e. one drive. QemuOptsList - list of some kind of devices, i.e. all drives. Functions are provided to work with these types. The plan is that some day we will pass around QemuOpts pointers instead of strings filled with "key1=value1,key2=value2". Check out the next patch to see all this in action ;) Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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‎qemu-option.c

Lines changed: 314 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -182,6 +182,24 @@ static int parse_option_bool(const char *name, const char *value, int *ret)
182182
return 0;
183183
}
184184

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+
185203
static int parse_option_size(const char *name, const char *value, uint64_t *ret)
186204
{
187205
char *postfix;
@@ -444,3 +462,299 @@ void print_option_help(QEMUOptionParameter *list)
444462
list++;
445463
}
446464
}
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+
}

‎qemu-option.h

Lines changed: 45 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -26,6 +26,8 @@
2626
#ifndef QEMU_OPTIONS_H
2727
#define QEMU_OPTIONS_H
2828

29+
#include "sys-queue.h"
30+
2931
enum QEMUOptionParType {
3032
OPT_FLAG,
3133
OPT_NUMBER,
@@ -72,4 +74,47 @@ void free_option_parameters(QEMUOptionParameter *list);
7274
void print_option_parameters(QEMUOptionParameter *list);
7375
void print_option_help(QEMUOptionParameter *list);
7476

77+
/* ------------------------------------------------------------------ */
78+
79+
typedef struct QemuOpt QemuOpt;
80+
typedef struct QemuOpts QemuOpts;
81+
typedef struct QemuOptsList QemuOptsList;
82+
83+
enum QemuOptType {
84+
QEMU_OPT_STRING = 0, /* no parsing (use string as-is) */
85+
QEMU_OPT_BOOL, /* on/off */
86+
QEMU_OPT_NUMBER, /* simple number */
87+
QEMU_OPT_SIZE, /* size, accepts (K)ilo, (M)ega, (G)iga, (T)era postfix */
88+
};
89+
90+
typedef struct QemuOptDesc {
91+
const char *name;
92+
enum QemuOptType type;
93+
const char *help;
94+
} QemuOptDesc;
95+
96+
struct QemuOptsList {
97+
const char *name;
98+
TAILQ_HEAD(, QemuOpts) head;
99+
QemuOptDesc desc[];
100+
};
101+
102+
const char *qemu_opt_get(QemuOpts *opts, const char *name);
103+
int qemu_opt_get_bool(QemuOpts *opts, const char *name, int defval);
104+
uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval);
105+
uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval);
106+
int qemu_opt_set(QemuOpts *opts, const char *name, const char *value);
107+
108+
QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id);
109+
QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, int fail_if_exists);
110+
int qemu_opts_set(QemuOptsList *list, const char *id,
111+
const char *name, const char *value);
112+
void qemu_opts_del(QemuOpts *opts);
113+
QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params, const char *firstname);
114+
115+
typedef int (*qemu_opts_loopfunc)(QemuOpts *opts, void *opaque);
116+
int qemu_opts_print(QemuOpts *opts, void *dummy);
117+
int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
118+
int abort_on_failure);
119+
75120
#endif

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