Archipelago » qemu

/*

 * Commandline option parsing functions

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 * Copyright (c) 2009 Kevin Wolf <kwolf@redhat.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdio.h>

#include <string.h>

#include "qemu-common.h"

#include "qemu/error-report.h"

#include "qapi/qmp/types.h"

#include "qapi/error.h"

#include "qapi/qmp/qerror.h"

#include "qemu/option_int.h"

/*

 * Extracts the name of an option from the parameter string (p points at the

 * first byte of the option name)

 *

 * The option name is delimited by delim (usually , or =) or the string end

 * and is copied into buf. If the option name is longer than buf_size, it is

 * truncated. buf is always zero terminated.

 *

 * The return value is the position of the delimiter/zero byte after the option

 * name in p.

 */

const char *get_opt_name(char *buf, int buf_size, const char *p, char delim)

{

    char *q;

    q = buf;

    while (*p != '\0' && *p != delim) {

        if (q && (q - buf) < buf_size - 1)

            *q++ = *p;

        p++;

    }

    if (q)

        *q = '\0';

    return p;

}

/*

 * Extracts the value of an option from the parameter string p (p points at the

 * first byte of the option value)

 *

 * This function is comparable to get_opt_name with the difference that the

 * delimiter is fixed to be comma which starts a new option. To specify an

 * option value that contains commas, double each comma.

 */

const char *get_opt_value(char *buf, int buf_size, const char *p)

{

    char *q;

    q = buf;

    while (*p != '\0') {

        if (*p == ',') {

            if (*(p + 1) != ',')

                break;

            p++;

        }

        if (q && (q - buf) < buf_size - 1)

            *q++ = *p;

        p++;

    }

    if (q)

        *q = '\0';

    return p;

}

int get_next_param_value(char *buf, int buf_size,

                         const char *tag, const char **pstr)

{

    const char *p;

    char option[128];

    p = *pstr;

    for(;;) {

        p = get_opt_name(option, sizeof(option), p, '=');

        if (*p != '=')

            break;

        p++;

        if (!strcmp(tag, option)) {

            *pstr = get_opt_value(buf, buf_size, p);

            if (**pstr == ',') {

                (*pstr)++;

            }

            return strlen(buf);

        } else {

            p = get_opt_value(NULL, 0, p);

        }

        if (*p != ',')

            break;

        p++;

    }

    return 0;

}

int get_param_value(char *buf, int buf_size,

                    const char *tag, const char *str)

{

    return get_next_param_value(buf, buf_size, tag, &str);

}

int check_params(char *buf, int buf_size,

                 const char * const *params, const char *str)

{

    const char *p;

    int i;

    p = str;

    while (*p != '\0') {

        p = get_opt_name(buf, buf_size, p, '=');

        if (*p != '=') {

            return -1;

        }

        p++;

        for (i = 0; params[i] != NULL; i++) {

            if (!strcmp(params[i], buf)) {

                break;

            }

        }

        if (params[i] == NULL) {

            return -1;

        }

        p = get_opt_value(NULL, 0, p);

        if (*p != ',') {

            break;

        }

        p++;

    }

    return 0;

}

/*

 * Searches an option list for an option with the given name

 */

QEMUOptionParameter *get_option_parameter(QEMUOptionParameter *list,

    const char *name)

{

    while (list && list->name) {

        if (!strcmp(list->name, name)) {

            return list;

        }

        list++;

    }

    return NULL;

}

static void parse_option_bool(const char *name, const char *value, bool *ret,

                              Error **errp)

{

    if (value != NULL) {

        if (!strcmp(value, "on")) {

            *ret = 1;

        } else if (!strcmp(value, "off")) {

            *ret = 0;

        } else {

            error_set(errp,QERR_INVALID_PARAMETER_VALUE, name, "'on' or 'off'");

        }

    } else {

        *ret = 1;

    }

}

static void parse_option_number(const char *name, const char *value,

                                uint64_t *ret, Error **errp)

{

    char *postfix;

    uint64_t number;

    if (value != NULL) {

        number = strtoull(value, &postfix, 0);

        if (*postfix != '\0') {

            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");

            return;

        }

        *ret = number;

    } else {

        error_set(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");

    }

}

static void parse_option_size(const char *name, const char *value,

                              uint64_t *ret, Error **errp)

{

    char *postfix;

    double sizef;

    if (value != NULL) {

        sizef = strtod(value, &postfix);

        switch (*postfix) {

        case 'T':

            sizef *= 1024;

            /* fall through */

        case 'G':

            sizef *= 1024;

            /* fall through */

        case 'M':

            sizef *= 1024;

            /* fall through */

        case 'K':

        case 'k':

            sizef *= 1024;

            /* fall through */

        case 'b':

        case '\0':

            *ret = (uint64_t) sizef;

            break;

        default:

            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");

            error_printf_unless_qmp("You may use k, M, G or T suffixes for "

                    "kilobytes, megabytes, gigabytes and terabytes.\n");

            return;

        }

    } else {

        error_set(errp, QERR_INVALID_PARAMETER_VALUE, name, "a size");

    }

}

/*

 * Sets the value of a parameter in a given option list. The parsing of the

 * value depends on the type of option:

 *

 * OPT_FLAG (uses value.n):

 *      If no value is given, the flag is set to 1.

 *      Otherwise the value must be "on" (set to 1) or "off" (set to 0)

 *

 * OPT_STRING (uses value.s):

 *      value is strdup()ed and assigned as option value

 *

 * OPT_SIZE (uses value.n):

 *      The value is converted to an integer. Suffixes for kilobytes etc. are

 *      allowed (powers of 1024).

 *

 * Returns 0 on succes, -1 in error cases

 */

int set_option_parameter(QEMUOptionParameter *list, const char *name,

    const char *value)

{

    bool flag;

    Error *local_err = NULL;

    // Find a matching parameter

    list = get_option_parameter(list, name);

    if (list == NULL) {

        fprintf(stderr, "Unknown option '%s'\n", name);

        return -1;

    }

    // Process parameter

    switch (list->type) {

    case OPT_FLAG:

        parse_option_bool(name, value, &flag, &local_err);

        if (!error_is_set(&local_err)) {

            list->value.n = flag;

        }

        break;

    case OPT_STRING:

        if (value != NULL) {

            list->value.s = g_strdup(value);

        } else {

            fprintf(stderr, "Option '%s' needs a parameter\n", name);

            return -1;

        }

        break;

    case OPT_SIZE:

        parse_option_size(name, value, &list->value.n, &local_err);

        break;

    default:

        fprintf(stderr, "Bug: Option '%s' has an unknown type\n", name);

        return -1;

    }

    if (error_is_set(&local_err)) {

        qerror_report_err(local_err);

        error_free(local_err);

        return -1;

    }

    return 0;

}

/*

 * Sets the given parameter to an integer instead of a string.

 * This function cannot be used to set string options.

 *

 * Returns 0 on success, -1 in error cases

 */

int set_option_parameter_int(QEMUOptionParameter *list, const char *name,

    uint64_t value)

{

    // Find a matching parameter

    list = get_option_parameter(list, name);

    if (list == NULL) {

        fprintf(stderr, "Unknown option '%s'\n", name);

        return -1;

    }

    // Process parameter

    switch (list->type) {

    case OPT_FLAG:

    case OPT_NUMBER:

    case OPT_SIZE:

        list->value.n = value;

        break;

    default:

        return -1;

    }

    return 0;

}

/*

 * Frees a option list. If it contains strings, the strings are freed as well.

 */

void free_option_parameters(QEMUOptionParameter *list)

{

    QEMUOptionParameter *cur = list;

    while (cur && cur->name) {

        if (cur->type == OPT_STRING) {

            g_free(cur->value.s);

        }

        cur++;

    }

    g_free(list);

}

/*

 * Count valid options in list

 */

static size_t count_option_parameters(QEMUOptionParameter *list)

{

    size_t num_options = 0;

    while (list && list->name) {

        num_options++;

        list++;

    }

    return num_options;

}

/*

 * Append an option list (list) to an option list (dest).

 *

 * If dest is NULL, a new copy of list is created.

 *

 * Returns a pointer to the first element of dest (or the newly allocated copy)

 */

QEMUOptionParameter *append_option_parameters(QEMUOptionParameter *dest,

    QEMUOptionParameter *list)

{

    size_t num_options, num_dest_options;

    num_options = count_option_parameters(dest);

    num_dest_options = num_options;

    num_options += count_option_parameters(list);

    dest = g_realloc(dest, (num_options + 1) * sizeof(QEMUOptionParameter));

    dest[num_dest_options].name = NULL;

    while (list && list->name) {

        if (get_option_parameter(dest, list->name) == NULL) {

            dest[num_dest_options++] = *list;

            dest[num_dest_options].name = NULL;

        }

        list++;

    }

    return dest;

}

/*

 * Parses a parameter string (param) into an option list (dest).

 *

 * list is the template option list. If dest is NULL, a new copy of list is

 * created. If list is NULL, this function fails.

 *

 * A parameter string consists of one or more parameters, separated by commas.

 * Each parameter consists of its name and possibly of a value. In the latter

 * case, the value is delimited by an = character. To specify a value which

 * contains commas, double each comma so it won't be recognized as the end of

 * the parameter.

 *

 * For more details of the parsing see above.

 *

 * Returns a pointer to the first element of dest (or the newly allocated copy)

 * or NULL in error cases

 */

QEMUOptionParameter *parse_option_parameters(const char *param,

    QEMUOptionParameter *list, QEMUOptionParameter *dest)

{

    QEMUOptionParameter *allocated = NULL;

    char name[256];

    char value[256];

    char *param_delim, *value_delim;

    char next_delim;

    if (list == NULL) {

        return NULL;

    }

    if (dest == NULL) {

        dest = allocated = append_option_parameters(NULL, list);

    }

    while (*param) {

        // Find parameter name and value in the string

        param_delim = strchr(param, ',');

        value_delim = strchr(param, '=');

        if (value_delim && (value_delim < param_delim || !param_delim)) {

            next_delim = '=';

        } else {

            next_delim = ',';

            value_delim = NULL;

        }

        param = get_opt_name(name, sizeof(name), param, next_delim);

        if (value_delim) {

            param = get_opt_value(value, sizeof(value), param + 1);

        }

        if (*param != '\0') {

            param++;

        }

        // Set the parameter

        if (set_option_parameter(dest, name, value_delim ? value : NULL)) {

            goto fail;

        }

    }

    return dest;

fail:

    // Only free the list if it was newly allocated

    free_option_parameters(allocated);

    return NULL;

}

/*

 * Prints all options of a list that have a value to stdout

 */

void print_option_parameters(QEMUOptionParameter *list)

{

    while (list && list->name) {

        switch (list->type) {

            case OPT_STRING:

                 if (list->value.s != NULL) {

                     printf("%s='%s' ", list->name, list->value.s);

                 }

                break;

            case OPT_FLAG:

                printf("%s=%s ", list->name, list->value.n ? "on" : "off");

                break;

            case OPT_SIZE:

            case OPT_NUMBER:

                printf("%s=%" PRId64 " ", list->name, list->value.n);

                break;

            default:

                printf("%s=(unknown type) ", list->name);

                break;

        }

        list++;

    }

}

/*

 * Prints an overview of all available options

 */

void print_option_help(QEMUOptionParameter *list)

{

    printf("Supported options:\n");

    while (list && list->name) {

        printf("%-16s %s\n", list->name,

            list->help ? list->help : "No description available");

        list++;

    }

}

/* ------------------------------------------------------------------ */

static QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)

{

    QemuOpt *opt;

    QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {

        if (strcmp(opt->name, name) != 0)

            continue;

        return opt;

    }

    return NULL;

}

const char *qemu_opt_get(QemuOpts *opts, const char *name)

{

    QemuOpt *opt = qemu_opt_find(opts, name);

    return opt ? opt->str : NULL;

}

bool qemu_opt_has_help_opt(QemuOpts *opts)

{

    QemuOpt *opt;

    QTAILQ_FOREACH_REVERSE(opt, &opts->head, QemuOptHead, next) {

        if (is_help_option(opt->name)) {

            return true;

        }

    }

    return false;

}

bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)

{

    QemuOpt *opt = qemu_opt_find(opts, name);

    if (opt == NULL)

        return defval;

    assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);

    return opt->value.boolean;

}

uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)

{

    QemuOpt *opt = qemu_opt_find(opts, name);

    if (opt == NULL)

        return defval;

    assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);

    return opt->value.uint;

}

uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)

{

    QemuOpt *opt = qemu_opt_find(opts, name);

    if (opt == NULL)

        return defval;

    assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);

    return opt->value.uint;

}

static void qemu_opt_parse(QemuOpt *opt, Error **errp)

{

    if (opt->desc == NULL)

        return;

    switch (opt->desc->type) {

    case QEMU_OPT_STRING:

        /* nothing */

        return;

    case QEMU_OPT_BOOL:

        parse_option_bool(opt->name, opt->str, &opt->value.boolean, errp);

        break;

    case QEMU_OPT_NUMBER:

        parse_option_number(opt->name, opt->str, &opt->value.uint, errp);

        break;

    case QEMU_OPT_SIZE:

        parse_option_size(opt->name, opt->str, &opt->value.uint, errp);

        break;

    default:

        abort();

    }

}

static void qemu_opt_del(QemuOpt *opt)

{

    QTAILQ_REMOVE(&opt->opts->head, opt, next);

    g_free((/* !const */ char*)opt->name);

    g_free((/* !const */ char*)opt->str);

    g_free(opt);

}

static bool opts_accepts_any(const QemuOpts *opts)

{

    return opts->list->desc[0].name == NULL;

}

static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,

                                            const char *name)

{

    int i;

    for (i = 0; desc[i].name != NULL; i++) {

        if (strcmp(desc[i].name, name) == 0) {

            return &desc[i];

        }

    }

    return NULL;

}

static void opt_set(QemuOpts *opts, const char *name, const char *value,

                    bool prepend, Error **errp)

{

    QemuOpt *opt;

    const QemuOptDesc *desc;

    Error *local_err = NULL;

    desc = find_desc_by_name(opts->list->desc, name);

    if (!desc && !opts_accepts_any(opts)) {

        error_set(errp, QERR_INVALID_PARAMETER, name);

        return;

    }

    opt = g_malloc0(sizeof(*opt));

    opt->name = g_strdup(name);

    opt->opts = opts;

    if (prepend) {

        QTAILQ_INSERT_HEAD(&opts->head, opt, next);

    } else {

        QTAILQ_INSERT_TAIL(&opts->head, opt, next);

    }

    opt->desc = desc;

    if (value) {

        opt->str = g_strdup(value);

    }

    qemu_opt_parse(opt, &local_err);

    if (error_is_set(&local_err)) {

        error_propagate(errp, local_err);

        qemu_opt_del(opt);

    }

}

int qemu_opt_set(QemuOpts *opts, const char *name, const char *value)

{

    Error *local_err = NULL;

    opt_set(opts, name, value, false, &local_err);

    if (error_is_set(&local_err)) {

        qerror_report_err(local_err);

        error_free(local_err);

        return -1;

    }

    return 0;

}

void qemu_opt_set_err(QemuOpts *opts, const char *name, const char *value,

                      Error **errp)

{

    opt_set(opts, name, value, false, errp);

}

int qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val)

{

    QemuOpt *opt;

    const QemuOptDesc *desc = opts->list->desc;

    opt = g_malloc0(sizeof(*opt));

    opt->desc = find_desc_by_name(desc, name);

    if (!opt->desc && !opts_accepts_any(opts)) {

        qerror_report(QERR_INVALID_PARAMETER, name);

        g_free(opt);

        return -1;

    }

    opt->name = g_strdup(name);

    opt->opts = opts;

    opt->value.boolean = !!val;

    opt->str = g_strdup(val ? "on" : "off");

    QTAILQ_INSERT_TAIL(&opts->head, opt, next);

    return 0;

}

int qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val)

{

    QemuOpt *opt;

    const QemuOptDesc *desc = opts->list->desc;

    opt = g_malloc0(sizeof(*opt));

    opt->desc = find_desc_by_name(desc, name);

    if (!opt->desc && !opts_accepts_any(opts)) {

        qerror_report(QERR_INVALID_PARAMETER, name);

        g_free(opt);

        return -1;

    }

    opt->name = g_strdup(name);

    opt->opts = opts;

    opt->value.uint = val;

    opt->str = g_strdup_printf("%" PRId64, val);

    QTAILQ_INSERT_TAIL(&opts->head, opt, next);

    return 0;

}

int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,

                     int abort_on_failure)

{

    QemuOpt *opt;

    int rc = 0;

    QTAILQ_FOREACH(opt, &opts->head, next) {

        rc = func(opt->name, opt->str, opaque);

        if (abort_on_failure  &&  rc != 0)

            break;

    }

    return rc;

}

QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)

{

    QemuOpts *opts;

    QTAILQ_FOREACH(opts, &list->head, next) {

        if (!opts->id) {

            if (!id) {

                return opts;

            }

            continue;

        }

        if (strcmp(opts->id, id) != 0) {

            continue;

        }

        return opts;

    }

    return NULL;

}

static int id_wellformed(const char *id)

{

    int i;

    if (!qemu_isalpha(id[0])) {

        return 0;

    }

    for (i = 1; id[i]; i++) {

        if (!qemu_isalnum(id[i]) && !strchr("-._", id[i])) {

            return 0;

        }

    }

    return 1;

}

QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,

                           int fail_if_exists, Error **errp)

{

    QemuOpts *opts = NULL;

    if (id) {

        if (!id_wellformed(id)) {

            error_set(errp,QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");

            error_printf_unless_qmp("Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.\n");

            return NULL;

        }

        opts = qemu_opts_find(list, id);

        if (opts != NULL) {

            if (fail_if_exists && !list->merge_lists) {

                error_set(errp, QERR_DUPLICATE_ID, id, list->name);

                return NULL;

            } else {

                return opts;

            }

        }

    } else if (list->merge_lists) {

        opts = qemu_opts_find(list, NULL);

        if (opts) {

            return opts;

        }

    }

    opts = g_malloc0(sizeof(*opts));

    if (id) {

        opts->id = g_strdup(id);

    }

    opts->list = list;

    loc_save(&opts->loc);

    QTAILQ_INIT(&opts->head);

    QTAILQ_INSERT_TAIL(&list->head, opts, next);

    return opts;

}

QemuOpts *qemu_opts_create_nofail(QemuOptsList *list)

{

    QemuOpts *opts;

    Error *errp = NULL;

    opts = qemu_opts_create(list, NULL, 0, &errp);

    assert_no_error(errp);

    return opts;

}

void qemu_opts_reset(QemuOptsList *list)

{

    QemuOpts *opts, *next_opts;

    QTAILQ_FOREACH_SAFE(opts, &list->head, next, next_opts) {

        qemu_opts_del(opts);

    }

}

void qemu_opts_loc_restore(QemuOpts *opts)

{

    loc_restore(&opts->loc);

}

int qemu_opts_set(QemuOptsList *list, const char *id,

                  const char *name, const char *value)

{

    QemuOpts *opts;

    Error *local_err = NULL;

    opts = qemu_opts_create(list, id, 1, &local_err);

    if (error_is_set(&local_err)) {

        qerror_report_err(local_err);

        error_free(local_err);

        return -1;

    }

    return qemu_opt_set(opts, name, value);

}

const char *qemu_opts_id(QemuOpts *opts)

{

    return opts->id;

}

void qemu_opts_del(QemuOpts *opts)

{

    QemuOpt *opt;

    for (;;) {

        opt = QTAILQ_FIRST(&opts->head);

        if (opt == NULL)

            break;

        qemu_opt_del(opt);

    }

    QTAILQ_REMOVE(&opts->list->head, opts, next);

    g_free(opts->id);

    g_free(opts);

}

int qemu_opts_print(QemuOpts *opts, void *dummy)

{

    QemuOpt *opt;

    fprintf(stderr, "%s: %s:", opts->list->name,

            opts->id ? opts->id : "<noid>");

    QTAILQ_FOREACH(opt, &opts->head, next) {

        fprintf(stderr, " %s=\"%s\"", opt->name, opt->str);

    }

    fprintf(stderr, "\n");

    return 0;

}

static int opts_do_parse(QemuOpts *opts, const char *params,

                         const char *firstname, bool prepend)

{

    char option[128], value[1024];

    const char *p,*pe,*pc;

    Error *local_err = NULL;

    for (p = params; *p != '\0'; p++) {

        pe = strchr(p, '=');

        pc = strchr(p, ',');

        if (!pe || (pc && pc < pe)) {

            /* found "foo,more" */

            if (p == params && firstname) {

                /* implicitly named first option */

                pstrcpy(option, sizeof(option), firstname);

                p = get_opt_value(value, sizeof(value), p);

            } else {

                /* option without value, probably a flag */

                p = get_opt_name(option, sizeof(option), p, ',');

                if (strncmp(option, "no", 2) == 0) {

                    memmove(option, option+2, strlen(option+2)+1);

                    pstrcpy(value, sizeof(value), "off");

                } else {

                    pstrcpy(value, sizeof(value), "on");

                }

            }

        } else {

            /* found "foo=bar,more" */

            p = get_opt_name(option, sizeof(option), p, '=');

            if (*p != '=') {

                break;

            }

            p++;

            p = get_opt_value(value, sizeof(value), p);

        }

        if (strcmp(option, "id") != 0) {

            /* store and parse */

            opt_set(opts, option, value, prepend, &local_err);

            if (error_is_set(&local_err)) {

                qerror_report_err(local_err);

                error_free(local_err);

                return -1;

            }

        }

        if (*p != ',') {

            break;

        }

    }

    return 0;

}

int qemu_opts_do_parse(QemuOpts *opts, const char *params, const char *firstname)

{

    return opts_do_parse(opts, params, firstname, false);

}

static QemuOpts *opts_parse(QemuOptsList *list, const char *params,

                            int permit_abbrev, bool defaults)

{

    const char *firstname;

    char value[1024], *id = NULL;

    const char *p;

    QemuOpts *opts;

    Error *local_err = NULL;

    assert(!permit_abbrev || list->implied_opt_name);

    firstname = permit_abbrev ? list->implied_opt_name : NULL;

    if (strncmp(params, "id=", 3) == 0) {

        get_opt_value(value, sizeof(value), params+3);

        id = value;

    } else if ((p = strstr(params, ",id=")) != NULL) {

        get_opt_value(value, sizeof(value), p+4);

        id = value;

    }

    if (defaults) {

        if (!id && !QTAILQ_EMPTY(&list->head)) {

            opts = qemu_opts_find(list, NULL);

        } else {

            opts = qemu_opts_create(list, id, 0, &local_err);

        }

    } else {

        opts = qemu_opts_create(list, id, 1, &local_err);

    }

    if (opts == NULL) {

        if (error_is_set(&local_err)) {

            qerror_report_err(local_err);

            error_free(local_err);

        }

        return NULL;

    }

    if (opts_do_parse(opts, params, firstname, defaults) != 0) {

        qemu_opts_del(opts);

        return NULL;

    }

    return opts;

}

QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,

                          int permit_abbrev)

{

    return opts_parse(list, params, permit_abbrev, false);

}

void qemu_opts_set_defaults(QemuOptsList *list, const char *params,

                            int permit_abbrev)

{

    QemuOpts *opts;

    opts = opts_parse(list, params, permit_abbrev, true);

    assert(opts);

}

typedef struct OptsFromQDictState {

    QemuOpts *opts;

    Error **errp;

} OptsFromQDictState;

static void qemu_opts_from_qdict_1(const char *key, QObject *obj, void *opaque)

{

    OptsFromQDictState *state = opaque;

    char buf[32];

    const char *value;

    int n;

    if (!strcmp(key, "id") || error_is_set(state->errp)) {

        return;

    }

    switch (qobject_type(obj)) {

    case QTYPE_QSTRING:

        value = qstring_get_str(qobject_to_qstring(obj));

        break;

    case QTYPE_QINT:

        n = snprintf(buf, sizeof(buf), "%" PRId64,

                     qint_get_int(qobject_to_qint(obj)));

        assert(n < sizeof(buf));

        value = buf;

        break;

    case QTYPE_QFLOAT:

        n = snprintf(buf, sizeof(buf), "%.17g",

                     qfloat_get_double(qobject_to_qfloat(obj)));

        assert(n < sizeof(buf));

        value = buf;

        break;

    case QTYPE_QBOOL:

        pstrcpy(buf, sizeof(buf),

                qbool_get_int(qobject_to_qbool(obj)) ? "on" : "off");

        value = buf;

        break;

    default:

        return;

    }

    qemu_opt_set_err(state->opts, key, value, state->errp);

}

/*

 * Create QemuOpts from a QDict.

 * Use value of key "id" as ID if it exists and is a QString.

 * Only QStrings, QInts, QFloats and QBools are copied.  Entries with

 * other types are silently ignored.

 */

QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,

                               Error **errp)

{

    OptsFromQDictState state;

    Error *local_err = NULL;

    QemuOpts *opts;

    opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,

                            &local_err);

    if (error_is_set(&local_err)) {

        error_propagate(errp, local_err);

        return NULL;

    }

    assert(opts != NULL);

    state.errp = &local_err;

    state.opts = opts;

    qdict_iter(qdict, qemu_opts_from_qdict_1, &state);

    if (error_is_set(&local_err)) {

        error_propagate(errp, local_err);

        qemu_opts_del(opts);

        return NULL;

    }

    return opts;

}

/*

 * Convert from QemuOpts to QDict.

 * The QDict values are of type QString.

 * TODO We'll want to use types appropriate for opt->desc->type, but

 * this is enough for now.

 */

QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)

{

    QemuOpt *opt;

    QObject *val;

    if (!qdict) {

        qdict = qdict_new();

    }

    if (opts->id) {

        qdict_put(qdict, "id", qstring_from_str(opts->id));

    }

    QTAILQ_FOREACH(opt, &opts->head, next) {

        val = QOBJECT(qstring_from_str(opt->str));

        qdict_put_obj(qdict, opt->name, val);

    }

    return qdict;

}

/* Validate parsed opts against descriptions where no

 * descriptions were provided in the QemuOptsList.

 */

void qemu_opts_validate(QemuOpts *opts, const QemuOptDesc *desc, Error **errp)

{

    QemuOpt *opt;

    Error *local_err = NULL;

    assert(opts_accepts_any(opts));

    QTAILQ_FOREACH(opt, &opts->head, next) {

        opt->desc = find_desc_by_name(desc, opt->name);

        if (!opt->desc) {

            error_set(errp, QERR_INVALID_PARAMETER, opt->name);

            return;

        }

        qemu_opt_parse(opt, &local_err);

        if (error_is_set(&local_err)) {

            error_propagate(errp, local_err);

            return;

        }

    }

}

int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,

                      int abort_on_failure)

{

    Location loc;

    QemuOpts *opts;

    int rc = 0;

    loc_push_none(&loc);

    QTAILQ_FOREACH(opts, &list->head, next) {

        loc_restore(&opts->loc);

        rc |= func(opts, opaque);

        if (abort_on_failure  &&  rc != 0)

            break;

    }

    loc_pop(&loc);

    return rc;

}