qemu-e2k/util/qemu-option.c

1255 lines
33 KiB
C
Raw Normal View History

/*
* 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 "qemu/osdep.h"
2016-03-14 09:01:28 +01:00
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qerror.h"
#include "qemu/option_int.h"
#include "qemu/cutils.h"
#include "qemu/id.h"
#include "qemu/help_option.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
opts: don't silently truncate long parameter keys The existing QemuOpts parsing code uses a fixed size 128 byte buffer for storing the parameter keys. If a key exceeded this size it was silently truncate and no error reported to the user. This behaviour was reasonable & harmless because traditionally the key names are all statically declared, and it was known that no code was declaring a key longer than 127 bytes. This assumption, however, ceased to be valid once the block layer added support for dot-separate compound keys. This syntax allows for keys that can be arbitrarily long, limited only by the number of block drivers you can stack up. With this usage, silently truncating the key name can never lead to correct behaviour. Hopefully such truncation would turn into an error, when the block code then tried to extract options later, but there's no guarantee that will happen. It is conceivable that an option specified by the user may be truncated and then ignored. This could have serious consequences, possibly even leading to security problems if the ignored option set a security relevant parameter. If the operating system didn't limit the user's argv when spawning QEMU, the code should honour whatever length arguments were given without imposing its own length restrictions. This patch thus changes the code to use a heap allocated buffer for storing the keys during parsing, lifting the arbitrary length restriction. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20180416111743.8473-3-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-04-16 13:17:42 +02:00
* and is copied into option. The caller is responsible for free'ing option
* when no longer required.
*
* The return value is the position of the delimiter/zero byte after the option
* name in p.
*/
opts: don't silently truncate long parameter keys The existing QemuOpts parsing code uses a fixed size 128 byte buffer for storing the parameter keys. If a key exceeded this size it was silently truncate and no error reported to the user. This behaviour was reasonable & harmless because traditionally the key names are all statically declared, and it was known that no code was declaring a key longer than 127 bytes. This assumption, however, ceased to be valid once the block layer added support for dot-separate compound keys. This syntax allows for keys that can be arbitrarily long, limited only by the number of block drivers you can stack up. With this usage, silently truncating the key name can never lead to correct behaviour. Hopefully such truncation would turn into an error, when the block code then tried to extract options later, but there's no guarantee that will happen. It is conceivable that an option specified by the user may be truncated and then ignored. This could have serious consequences, possibly even leading to security problems if the ignored option set a security relevant parameter. If the operating system didn't limit the user's argv when spawning QEMU, the code should honour whatever length arguments were given without imposing its own length restrictions. This patch thus changes the code to use a heap allocated buffer for storing the keys during parsing, lifting the arbitrary length restriction. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20180416111743.8473-3-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-04-16 13:17:42 +02:00
static const char *get_opt_name(const char *p, char **option, char delim)
{
opts: don't silently truncate long parameter keys The existing QemuOpts parsing code uses a fixed size 128 byte buffer for storing the parameter keys. If a key exceeded this size it was silently truncate and no error reported to the user. This behaviour was reasonable & harmless because traditionally the key names are all statically declared, and it was known that no code was declaring a key longer than 127 bytes. This assumption, however, ceased to be valid once the block layer added support for dot-separate compound keys. This syntax allows for keys that can be arbitrarily long, limited only by the number of block drivers you can stack up. With this usage, silently truncating the key name can never lead to correct behaviour. Hopefully such truncation would turn into an error, when the block code then tried to extract options later, but there's no guarantee that will happen. It is conceivable that an option specified by the user may be truncated and then ignored. This could have serious consequences, possibly even leading to security problems if the ignored option set a security relevant parameter. If the operating system didn't limit the user's argv when spawning QEMU, the code should honour whatever length arguments were given without imposing its own length restrictions. This patch thus changes the code to use a heap allocated buffer for storing the keys during parsing, lifting the arbitrary length restriction. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20180416111743.8473-3-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-04-16 13:17:42 +02:00
char *offset = strchr(p, delim);
opts: don't silently truncate long parameter keys The existing QemuOpts parsing code uses a fixed size 128 byte buffer for storing the parameter keys. If a key exceeded this size it was silently truncate and no error reported to the user. This behaviour was reasonable & harmless because traditionally the key names are all statically declared, and it was known that no code was declaring a key longer than 127 bytes. This assumption, however, ceased to be valid once the block layer added support for dot-separate compound keys. This syntax allows for keys that can be arbitrarily long, limited only by the number of block drivers you can stack up. With this usage, silently truncating the key name can never lead to correct behaviour. Hopefully such truncation would turn into an error, when the block code then tried to extract options later, but there's no guarantee that will happen. It is conceivable that an option specified by the user may be truncated and then ignored. This could have serious consequences, possibly even leading to security problems if the ignored option set a security relevant parameter. If the operating system didn't limit the user's argv when spawning QEMU, the code should honour whatever length arguments were given without imposing its own length restrictions. This patch thus changes the code to use a heap allocated buffer for storing the keys during parsing, lifting the arbitrary length restriction. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20180416111743.8473-3-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-04-16 13:17:42 +02:00
if (offset) {
*option = g_strndup(p, offset - p);
return offset;
} else {
*option = g_strdup(p);
return p + strlen(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(const char *p, char **value)
{
size_t capacity = 0, length;
const char *offset;
*value = NULL;
while (1) {
offset = qemu_strchrnul(p, ',');
length = offset - p;
if (*offset != '\0' && *(offset + 1) == ',') {
length++;
}
*value = g_renew(char, *value, capacity + length + 1);
strncpy(*value + capacity, p, length);
(*value)[capacity + length] = '\0';
capacity += length;
if (*offset == '\0' ||
*(offset + 1) != ',') {
break;
}
p += (offset - p) + 2;
}
return offset;
}
static void parse_option_bool(const char *name, const char *value, bool *ret,
Error **errp)
{
if (!strcmp(value, "on")) {
*ret = 1;
} else if (!strcmp(value, "off")) {
*ret = 0;
} else {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
name, "'on' or 'off'");
}
}
static void parse_option_number(const char *name, const char *value,
uint64_t *ret, Error **errp)
{
uint64_t number;
int err;
err = qemu_strtou64(value, NULL, 0, &number);
if (err == -ERANGE) {
error_setg(errp, "Value '%s' is too large for parameter '%s'",
value, name);
return;
}
if (err) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name, "a number");
return;
}
*ret = number;
}
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;
}
void parse_option_size(const char *name, const char *value,
uint64_t *ret, Error **errp)
{
uint64_t size;
int err;
err = qemu_strtosz(value, NULL, &size);
if (err == -ERANGE) {
error_setg(errp, "Value '%s' is out of range for parameter '%s'",
value, name);
return;
}
if (err) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
"a non-negative number below 2^64");
error_append_hint(errp, "Optional suffix k, M, G, T, P or E means"
" kilo-, mega-, giga-, tera-, peta-\n"
"and exabytes, respectively.\n");
return;
}
*ret = size;
}
static const char *opt_type_to_string(enum QemuOptType type)
{
switch (type) {
case QEMU_OPT_STRING:
return "str";
case QEMU_OPT_BOOL:
return "bool (on/off)";
case QEMU_OPT_NUMBER:
return "num";
case QEMU_OPT_SIZE:
return "size";
}
g_assert_not_reached();
}
/**
* Print the list of options available in the given list. If
* @print_caption is true, a caption (including the list name, if it
* exists) is printed. The options itself will be indented, so
* @print_caption should only be set to false if the caller prints its
* own custom caption (so that the indentation makes sense).
*/
void qemu_opts_print_help(QemuOptsList *list, bool print_caption)
{
QemuOptDesc *desc;
int i;
GPtrArray *array = g_ptr_array_new();
assert(list);
desc = list->desc;
while (desc && desc->name) {
GString *str = g_string_new(NULL);
g_string_append_printf(str, " %s=<%s>", desc->name,
opt_type_to_string(desc->type));
if (desc->help) {
if (str->len < 24) {
g_string_append_printf(str, "%*s", 24 - (int)str->len, "");
}
g_string_append_printf(str, " - %s", desc->help);
}
g_ptr_array_add(array, g_string_free(str, false));
desc++;
}
g_ptr_array_sort(array, (GCompareFunc)qemu_pstrcmp0);
if (print_caption && array->len > 0) {
if (list->name) {
printf("%s options:\n", list->name);
} else {
printf("Options:\n");
}
} else if (array->len == 0) {
if (list->name) {
printf("There are no options for %s.\n", list->name);
} else {
printf("No options available.\n");
}
}
for (i = 0; i < array->len; i++) {
printf("%s\n", (char *)array->pdata[i]);
}
g_ptr_array_set_free_func(array, g_free);
g_ptr_array_free(array, true);
}
/* ------------------------------------------------------------------ */
QemuOpt *qemu_opt_find(QemuOpts *opts, const char *name)
{
QemuOpt *opt;
QTAILQ_FOREACH_REVERSE(opt, &opts->head, next) {
if (strcmp(opt->name, name) != 0)
continue;
return opt;
}
return NULL;
}
static void qemu_opt_del(QemuOpt *opt)
{
QTAILQ_REMOVE(&opt->opts->head, opt, next);
g_free(opt->name);
g_free(opt->str);
g_free(opt);
}
/* qemu_opt_set allows many settings for the same option.
* This function deletes all settings for an option.
*/
static void qemu_opt_del_all(QemuOpts *opts, const char *name)
{
QemuOpt *opt, *next_opt;
QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next_opt) {
if (!strcmp(opt->name, name)) {
qemu_opt_del(opt);
}
}
}
const char *qemu_opt_get(QemuOpts *opts, const char *name)
{
QemuOpt *opt;
if (opts == NULL) {
return NULL;
}
opt = qemu_opt_find(opts, name);
if (!opt) {
const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
if (desc && desc->def_value_str) {
return desc->def_value_str;
}
}
return opt ? opt->str : NULL;
}
void qemu_opt_iter_init(QemuOptsIter *iter, QemuOpts *opts, const char *name)
{
iter->opts = opts;
iter->opt = QTAILQ_FIRST(&opts->head);
iter->name = name;
}
const char *qemu_opt_iter_next(QemuOptsIter *iter)
{
QemuOpt *ret = iter->opt;
if (iter->name) {
while (ret && !g_str_equal(iter->name, ret->name)) {
ret = QTAILQ_NEXT(ret, next);
}
}
iter->opt = ret ? QTAILQ_NEXT(ret, next) : NULL;
return ret ? ret->str : NULL;
}
/* Get a known option (or its default) and remove it from the list
* all in one action. Return a malloced string of the option value.
* Result must be freed by caller with g_free().
*/
char *qemu_opt_get_del(QemuOpts *opts, const char *name)
{
QemuOpt *opt;
const QemuOptDesc *desc;
char *str = NULL;
if (opts == NULL) {
return NULL;
}
opt = qemu_opt_find(opts, name);
if (!opt) {
desc = find_desc_by_name(opts->list->desc, name);
if (desc && desc->def_value_str) {
str = g_strdup(desc->def_value_str);
}
return str;
}
str = opt->str;
opt->str = NULL;
qemu_opt_del_all(opts, name);
return str;
}
bool qemu_opt_has_help_opt(QemuOpts *opts)
{
QemuOpt *opt;
QTAILQ_FOREACH_REVERSE(opt, &opts->head, next) {
if (is_help_option(opt->name)) {
return true;
}
}
return false;
}
static bool qemu_opt_get_bool_helper(QemuOpts *opts, const char *name,
bool defval, bool del)
{
QemuOpt *opt;
bool ret = defval;
if (opts == NULL) {
return ret;
}
opt = qemu_opt_find(opts, name);
if (opt == NULL) {
const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
if (desc && desc->def_value_str) {
parse_option_bool(name, desc->def_value_str, &ret, &error_abort);
}
return ret;
}
assert(opt->desc && opt->desc->type == QEMU_OPT_BOOL);
ret = opt->value.boolean;
if (del) {
qemu_opt_del_all(opts, name);
}
return ret;
}
bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
{
return qemu_opt_get_bool_helper(opts, name, defval, false);
}
bool qemu_opt_get_bool_del(QemuOpts *opts, const char *name, bool defval)
{
return qemu_opt_get_bool_helper(opts, name, defval, true);
}
static uint64_t qemu_opt_get_number_helper(QemuOpts *opts, const char *name,
uint64_t defval, bool del)
{
QemuOpt *opt;
uint64_t ret = defval;
if (opts == NULL) {
return ret;
}
opt = qemu_opt_find(opts, name);
if (opt == NULL) {
const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
if (desc && desc->def_value_str) {
parse_option_number(name, desc->def_value_str, &ret, &error_abort);
}
return ret;
}
assert(opt->desc && opt->desc->type == QEMU_OPT_NUMBER);
ret = opt->value.uint;
if (del) {
qemu_opt_del_all(opts, name);
}
return ret;
}
uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
{
return qemu_opt_get_number_helper(opts, name, defval, false);
}
uint64_t qemu_opt_get_number_del(QemuOpts *opts, const char *name,
uint64_t defval)
{
return qemu_opt_get_number_helper(opts, name, defval, true);
}
static uint64_t qemu_opt_get_size_helper(QemuOpts *opts, const char *name,
uint64_t defval, bool del)
{
QemuOpt *opt;
uint64_t ret = defval;
if (opts == NULL) {
return ret;
}
opt = qemu_opt_find(opts, name);
if (opt == NULL) {
const QemuOptDesc *desc = find_desc_by_name(opts->list->desc, name);
if (desc && desc->def_value_str) {
parse_option_size(name, desc->def_value_str, &ret, &error_abort);
}
return ret;
}
assert(opt->desc && opt->desc->type == QEMU_OPT_SIZE);
ret = opt->value.uint;
if (del) {
qemu_opt_del_all(opts, name);
}
return ret;
}
uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
{
return qemu_opt_get_size_helper(opts, name, defval, false);
}
uint64_t qemu_opt_get_size_del(QemuOpts *opts, const char *name,
uint64_t defval)
{
return qemu_opt_get_size_helper(opts, name, defval, true);
}
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 bool opts_accepts_any(const QemuOpts *opts)
{
return opts->list->desc[0].name == NULL;
}
int qemu_opt_unset(QemuOpts *opts, const char *name)
{
QemuOpt *opt = qemu_opt_find(opts, name);
assert(opts_accepts_any(opts));
if (opt == NULL) {
return -1;
} else {
qemu_opt_del(opt);
return 0;
}
}
static void opt_set(QemuOpts *opts, const char *name, char *value,
bool prepend, bool *help_wanted, 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)) {
g_free(value);
error_setg(errp, QERR_INVALID_PARAMETER, name);
if (help_wanted && is_help_option(name)) {
*help_wanted = true;
}
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;
opt->str = value;
qemu_opt_parse(opt, &local_err);
if (local_err) {
error_propagate(errp, local_err);
qemu_opt_del(opt);
}
}
void qemu_opt_set(QemuOpts *opts, const char *name, const char *value,
Error **errp)
{
opt_set(opts, name, g_strdup(value), false, NULL, errp);
}
void qemu_opt_set_bool(QemuOpts *opts, const char *name, bool val,
Error **errp)
{
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)) {
error_setg(errp, QERR_INVALID_PARAMETER, name);
g_free(opt);
return;
}
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);
}
void qemu_opt_set_number(QemuOpts *opts, const char *name, int64_t val,
Error **errp)
{
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)) {
error_setg(errp, QERR_INVALID_PARAMETER, name);
g_free(opt);
return;
}
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);
}
/**
* For each member of @opts, call @func(@opaque, name, value, @errp).
* @func() may store an Error through @errp, but must return non-zero then.
* When @func() returns non-zero, break the loop and return that value.
* Return zero when the loop completes.
*/
int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
Error **errp)
{
QemuOpt *opt;
int rc;
QTAILQ_FOREACH(opt, &opts->head, next) {
rc = func(opaque, opt->name, opt->str, errp);
if (rc) {
return rc;
}
assert(!errp || !*errp);
}
return 0;
}
QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id)
{
QemuOpts *opts;
QTAILQ_FOREACH(opts, &list->head, next) {
if (!opts->id && !id) {
return opts;
}
if (opts->id && id && !strcmp(opts->id, id)) {
return opts;
}
}
return NULL;
}
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_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
"an identifier");
error_append_hint(errp, "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_setg(errp, "Duplicate ID '%s' for %s", 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));
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;
}
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);
}
void qemu_opts_set(QemuOptsList *list, const char *id,
const char *name, const char *value, Error **errp)
{
QemuOpts *opts;
Error *local_err = NULL;
opts = qemu_opts_create(list, id, 1, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
qemu_opt_set(opts, name, value, errp);
}
const char *qemu_opts_id(QemuOpts *opts)
{
return opts->id;
}
/* The id string will be g_free()d by qemu_opts_del */
void qemu_opts_set_id(QemuOpts *opts, char *id)
{
opts->id = id;
}
void qemu_opts_del(QemuOpts *opts)
{
QemuOpt *opt;
if (opts == NULL) {
return;
}
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);
}
/* print value, escaping any commas in value */
static void escaped_print(const char *value)
{
const char *ptr;
for (ptr = value; *ptr; ++ptr) {
if (*ptr == ',') {
putchar(',');
}
putchar(*ptr);
}
}
void qemu_opts_print(QemuOpts *opts, const char *separator)
{
QemuOpt *opt;
QemuOptDesc *desc = opts->list->desc;
const char *sep = "";
if (opts->id) {
printf("id=%s", opts->id); /* passed id_wellformed -> no commas */
sep = separator;
}
if (desc[0].name == NULL) {
QTAILQ_FOREACH(opt, &opts->head, next) {
printf("%s%s=", sep, opt->name);
escaped_print(opt->str);
sep = separator;
}
return;
}
for (; desc && desc->name; desc++) {
const char *value;
opt = qemu_opt_find(opts, desc->name);
value = opt ? opt->str : desc->def_value_str;
if (!value) {
continue;
}
if (desc->type == QEMU_OPT_STRING) {
printf("%s%s=", sep, desc->name);
escaped_print(value);
} else if ((desc->type == QEMU_OPT_SIZE ||
desc->type == QEMU_OPT_NUMBER) && opt) {
printf("%s%s=%" PRId64, sep, desc->name, opt->value.uint);
} else {
printf("%s%s=%s", sep, desc->name, value);
}
sep = separator;
}
}
static const char *get_opt_name_value(const char *params,
const char *firstname,
char **name, char **value)
{
const char *p, *pe, *pc;
pe = strchr(params, '=');
pc = strchr(params, ',');
if (!pe || (pc && pc < pe)) {
/* found "foo,more" */
if (firstname) {
/* implicitly named first option */
*name = g_strdup(firstname);
p = get_opt_value(params, value);
} else {
/* option without value, must be a flag */
p = get_opt_name(params, name, ',');
if (strncmp(*name, "no", 2) == 0) {
memmove(*name, *name + 2, strlen(*name + 2) + 1);
*value = g_strdup("off");
} else {
*value = g_strdup("on");
}
}
} else {
/* found "foo=bar,more" */
p = get_opt_name(params, name, '=');
assert(*p == '=');
p++;
p = get_opt_value(p, value);
}
assert(!*p || *p == ',');
if (*p == ',') {
p++;
}
return p;
}
static void opts_do_parse(QemuOpts *opts, const char *params,
const char *firstname, bool prepend,
bool *help_wanted, Error **errp)
{
Error *local_err = NULL;
char *option, *value;
const char *p;
for (p = params; *p;) {
p = get_opt_name_value(p, firstname, &option, &value);
firstname = NULL;
if (!strcmp(option, "id")) {
g_free(option);
g_free(value);
continue;
}
opt_set(opts, option, value, prepend, help_wanted, &local_err);
opts: don't silently truncate long parameter keys The existing QemuOpts parsing code uses a fixed size 128 byte buffer for storing the parameter keys. If a key exceeded this size it was silently truncate and no error reported to the user. This behaviour was reasonable & harmless because traditionally the key names are all statically declared, and it was known that no code was declaring a key longer than 127 bytes. This assumption, however, ceased to be valid once the block layer added support for dot-separate compound keys. This syntax allows for keys that can be arbitrarily long, limited only by the number of block drivers you can stack up. With this usage, silently truncating the key name can never lead to correct behaviour. Hopefully such truncation would turn into an error, when the block code then tried to extract options later, but there's no guarantee that will happen. It is conceivable that an option specified by the user may be truncated and then ignored. This could have serious consequences, possibly even leading to security problems if the ignored option set a security relevant parameter. If the operating system didn't limit the user's argv when spawning QEMU, the code should honour whatever length arguments were given without imposing its own length restrictions. This patch thus changes the code to use a heap allocated buffer for storing the keys during parsing, lifting the arbitrary length restriction. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20180416111743.8473-3-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-04-16 13:17:42 +02:00
g_free(option);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}
static char *opts_parse_id(const char *params)
{
const char *p;
char *name, *value;
for (p = params; *p;) {
p = get_opt_name_value(p, NULL, &name, &value);
if (!strcmp(name, "id")) {
g_free(name);
return value;
}
g_free(name);
g_free(value);
}
return NULL;
}
bool has_help_option(const char *params)
{
const char *p;
char *name, *value;
bool ret;
for (p = params; *p;) {
p = get_opt_name_value(p, NULL, &name, &value);
ret = is_help_option(name);
g_free(name);
g_free(value);
if (ret) {
return true;
}
}
return false;
}
/**
* Store options parsed from @params into @opts.
* If @firstname is non-null, the first key=value in @params may omit
* key=, and is treated as if key was @firstname.
* On error, store an error object through @errp if non-null.
*/
void qemu_opts_do_parse(QemuOpts *opts, const char *params,
const char *firstname, Error **errp)
{
opts_do_parse(opts, params, firstname, false, NULL, errp);
}
static QemuOpts *opts_parse(QemuOptsList *list, const char *params,
bool permit_abbrev, bool defaults,
bool *help_wanted, Error **errp)
{
const char *firstname;
char *id = opts_parse_id(params);
QemuOpts *opts;
Error *local_err = NULL;
assert(!permit_abbrev || list->implied_opt_name);
firstname = permit_abbrev ? list->implied_opt_name : NULL;
/*
* This code doesn't work for defaults && !list->merge_lists: when
* params has no id=, and list has an element with !opts->id, it
* appends a new element instead of returning the existing opts.
* However, we got no use for this case. Guard against possible
* (if unlikely) future misuse:
*/
assert(!defaults || list->merge_lists);
opts = qemu_opts_create(list, id, !defaults, &local_err);
g_free(id);
if (opts == NULL) {
error_propagate(errp, local_err);
return NULL;
}
opts_do_parse(opts, params, firstname, defaults, help_wanted, &local_err);
if (local_err) {
error_propagate(errp, local_err);
qemu_opts_del(opts);
return NULL;
}
return opts;
}
/**
* Create a QemuOpts in @list and with options parsed from @params.
* If @permit_abbrev, the first key=value in @params may omit key=,
* and is treated as if key was @list->implied_opt_name.
QemuOpts: Wean off qerror_report_err() qerror_report_err() is a transitional interface to help with converting existing monitor commands to QMP. It should not be used elsewhere. The only remaining user in qemu-option.c is qemu_opts_parse(). Is it used in QMP context? If not, we can simply replace qerror_report_err() by error_report_err(). The uses in qemu-img.c, qemu-io.c, qemu-nbd.c and under tests/ are clearly not in QMP context. The uses in vl.c aren't either, because the only QMP command handlers there are qmp_query_status() and qmp_query_machines(), and they don't call it. Remaining uses: * drive_def(): Command line -drive and such, HMP drive_add and pci_add * hmp_chardev_add(): HMP chardev-add * monitor_parse_command(): HMP core * tmp_config_parse(): Command line -tpmdev * net_host_device_add(): HMP host_net_add * net_client_parse(): Command line -net and -netdev * qemu_global_option(): Command line -global * vnc_parse_func(): Command line -display, -vnc, default display, HMP change, QMP change. Bummer. * qemu_pci_hot_add_nic(): HMP pci_add * usb_net_init(): Command line -usbdevice, HMP usb_add Propagate errors through qemu_opts_parse(). Create a convenience function qemu_opts_parse_noisily() that passes errors to error_report_err(). Switch all non-QMP users outside tests to it. That leaves vnc_parse_func(). Propagate errors through it. Since I'm touching it anyway, rename it to vnc_parse(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-02-13 12:50:26 +01:00
* On error, store an error object through @errp if non-null.
* Return the new QemuOpts on success, null pointer on error.
*/
QemuOpts *qemu_opts_parse(QemuOptsList *list, const char *params,
QemuOpts: Wean off qerror_report_err() qerror_report_err() is a transitional interface to help with converting existing monitor commands to QMP. It should not be used elsewhere. The only remaining user in qemu-option.c is qemu_opts_parse(). Is it used in QMP context? If not, we can simply replace qerror_report_err() by error_report_err(). The uses in qemu-img.c, qemu-io.c, qemu-nbd.c and under tests/ are clearly not in QMP context. The uses in vl.c aren't either, because the only QMP command handlers there are qmp_query_status() and qmp_query_machines(), and they don't call it. Remaining uses: * drive_def(): Command line -drive and such, HMP drive_add and pci_add * hmp_chardev_add(): HMP chardev-add * monitor_parse_command(): HMP core * tmp_config_parse(): Command line -tpmdev * net_host_device_add(): HMP host_net_add * net_client_parse(): Command line -net and -netdev * qemu_global_option(): Command line -global * vnc_parse_func(): Command line -display, -vnc, default display, HMP change, QMP change. Bummer. * qemu_pci_hot_add_nic(): HMP pci_add * usb_net_init(): Command line -usbdevice, HMP usb_add Propagate errors through qemu_opts_parse(). Create a convenience function qemu_opts_parse_noisily() that passes errors to error_report_err(). Switch all non-QMP users outside tests to it. That leaves vnc_parse_func(). Propagate errors through it. Since I'm touching it anyway, rename it to vnc_parse(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-02-13 12:50:26 +01:00
bool permit_abbrev, Error **errp)
{
return opts_parse(list, params, permit_abbrev, false, NULL, errp);
QemuOpts: Wean off qerror_report_err() qerror_report_err() is a transitional interface to help with converting existing monitor commands to QMP. It should not be used elsewhere. The only remaining user in qemu-option.c is qemu_opts_parse(). Is it used in QMP context? If not, we can simply replace qerror_report_err() by error_report_err(). The uses in qemu-img.c, qemu-io.c, qemu-nbd.c and under tests/ are clearly not in QMP context. The uses in vl.c aren't either, because the only QMP command handlers there are qmp_query_status() and qmp_query_machines(), and they don't call it. Remaining uses: * drive_def(): Command line -drive and such, HMP drive_add and pci_add * hmp_chardev_add(): HMP chardev-add * monitor_parse_command(): HMP core * tmp_config_parse(): Command line -tpmdev * net_host_device_add(): HMP host_net_add * net_client_parse(): Command line -net and -netdev * qemu_global_option(): Command line -global * vnc_parse_func(): Command line -display, -vnc, default display, HMP change, QMP change. Bummer. * qemu_pci_hot_add_nic(): HMP pci_add * usb_net_init(): Command line -usbdevice, HMP usb_add Propagate errors through qemu_opts_parse(). Create a convenience function qemu_opts_parse_noisily() that passes errors to error_report_err(). Switch all non-QMP users outside tests to it. That leaves vnc_parse_func(). Propagate errors through it. Since I'm touching it anyway, rename it to vnc_parse(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-02-13 12:50:26 +01:00
}
/**
* Create a QemuOpts in @list and with options parsed from @params.
* If @permit_abbrev, the first key=value in @params may omit key=,
* and is treated as if key was @list->implied_opt_name.
* Report errors with error_report_err(). This is inappropriate in
* QMP context. Do not use this function there!
* Return the new QemuOpts on success, null pointer on error.
*/
QemuOpts *qemu_opts_parse_noisily(QemuOptsList *list, const char *params,
bool permit_abbrev)
{
Error *err = NULL;
QemuOpts *opts;
bool help_wanted = false;
opts = opts_parse(list, params, permit_abbrev, false, &help_wanted, &err);
QemuOpts: Wean off qerror_report_err() qerror_report_err() is a transitional interface to help with converting existing monitor commands to QMP. It should not be used elsewhere. The only remaining user in qemu-option.c is qemu_opts_parse(). Is it used in QMP context? If not, we can simply replace qerror_report_err() by error_report_err(). The uses in qemu-img.c, qemu-io.c, qemu-nbd.c and under tests/ are clearly not in QMP context. The uses in vl.c aren't either, because the only QMP command handlers there are qmp_query_status() and qmp_query_machines(), and they don't call it. Remaining uses: * drive_def(): Command line -drive and such, HMP drive_add and pci_add * hmp_chardev_add(): HMP chardev-add * monitor_parse_command(): HMP core * tmp_config_parse(): Command line -tpmdev * net_host_device_add(): HMP host_net_add * net_client_parse(): Command line -net and -netdev * qemu_global_option(): Command line -global * vnc_parse_func(): Command line -display, -vnc, default display, HMP change, QMP change. Bummer. * qemu_pci_hot_add_nic(): HMP pci_add * usb_net_init(): Command line -usbdevice, HMP usb_add Propagate errors through qemu_opts_parse(). Create a convenience function qemu_opts_parse_noisily() that passes errors to error_report_err(). Switch all non-QMP users outside tests to it. That leaves vnc_parse_func(). Propagate errors through it. Since I'm touching it anyway, rename it to vnc_parse(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-02-13 12:50:26 +01:00
if (err) {
if (help_wanted) {
qemu_opts_print_help(list, true);
error_free(err);
} else {
error_report_err(err);
}
}
return opts;
}
void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
int permit_abbrev)
{
QemuOpts *opts;
opts = opts_parse(list, params, permit_abbrev, true, NULL, NULL);
assert(opts);
}
static void qemu_opts_from_qdict_entry(QemuOpts *opts,
const QDictEntry *entry,
Error **errp)
{
const char *key = qdict_entry_key(entry);
QObject *obj = qdict_entry_value(entry);
char buf[32], *tmp = NULL;
const char *value;
if (!strcmp(key, "id")) {
return;
}
switch (qobject_type(obj)) {
case QTYPE_QSTRING:
value = qstring_get_str(qobject_to(QString, obj));
break;
case QTYPE_QNUM:
tmp = qnum_to_string(qobject_to(QNum, obj));
value = tmp;
break;
case QTYPE_QBOOL:
pstrcpy(buf, sizeof(buf),
qbool_get_bool(qobject_to(QBool, obj)) ? "on" : "off");
value = buf;
break;
default:
return;
}
qemu_opt_set(opts, key, value, errp);
g_free(tmp);
}
/*
* Create QemuOpts from a QDict.
* Use value of key "id" as ID if it exists and is a QString. Only
* QStrings, QNums and QBools are copied. Entries with other types
* are silently ignored.
*/
QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
Error **errp)
{
Error *local_err = NULL;
QemuOpts *opts;
const QDictEntry *entry;
opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,
&local_err);
if (local_err) {
error_propagate(errp, local_err);
return NULL;
}
assert(opts != NULL);
for (entry = qdict_first(qdict);
entry;
entry = qdict_next(qdict, entry)) {
qemu_opts_from_qdict_entry(opts, entry, &local_err);
if (local_err) {
error_propagate(errp, local_err);
qemu_opts_del(opts);
return NULL;
}
}
return opts;
}
/*
* Adds all QDict entries to the QemuOpts that can be added and removes them
* from the QDict. When this function returns, the QDict contains only those
* entries that couldn't be added to the QemuOpts.
*/
void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
{
const QDictEntry *entry, *next;
entry = qdict_first(qdict);
while (entry != NULL) {
Error *local_err = NULL;
next = qdict_next(qdict, entry);
if (find_desc_by_name(opts->list->desc, entry->key)) {
qemu_opts_from_qdict_entry(opts, entry, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
qdict_del(qdict, entry->key);
}
entry = next;
}
}
/*
* Convert from QemuOpts to QDict. The QDict values are of type QString.
*
* If @list is given, only add those options to the QDict that are contained in
* the list. If @del is true, any options added to the QDict are removed from
* the QemuOpts, otherwise they remain there.
*
* If two options in @opts have the same name, they are processed in order
* so that the last one wins (consistent with the reverse iteration in
* qemu_opt_find()), but all of them are deleted if @del is true.
*
* TODO We'll want to use types appropriate for opt->desc->type, but
* this is enough for now.
*/
QDict *qemu_opts_to_qdict_filtered(QemuOpts *opts, QDict *qdict,
QemuOptsList *list, bool del)
{
QemuOpt *opt, *next;
if (!qdict) {
qdict = qdict_new();
}
if (opts->id) {
qdict_put_str(qdict, "id", opts->id);
}
QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next) {
if (list) {
QemuOptDesc *desc;
bool found = false;
for (desc = list->desc; desc->name; desc++) {
if (!strcmp(desc->name, opt->name)) {
found = true;
break;
}
}
if (!found) {
continue;
}
}
qdict_put_str(qdict, opt->name, opt->str);
if (del) {
qemu_opt_del(opt);
}
}
return qdict;
}
/* Copy all options in a QemuOpts to the given QDict. See
* qemu_opts_to_qdict_filtered() for details. */
QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
{
return qemu_opts_to_qdict_filtered(opts, qdict, NULL, false);
}
/* 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_setg(errp, QERR_INVALID_PARAMETER, opt->name);
return;
}
qemu_opt_parse(opt, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
}
/**
* For each member of @list, call @func(@opaque, member, @errp).
* Call it with the current location temporarily set to the member's.
* @func() may store an Error through @errp, but must return non-zero then.
* When @func() returns non-zero, break the loop and return that value.
* Return zero when the loop completes.
*/
int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func,
void *opaque, Error **errp)
{
Location loc;
QemuOpts *opts;
int rc = 0;
loc_push_none(&loc);
QTAILQ_FOREACH(opts, &list->head, next) {
loc_restore(&opts->loc);
rc = func(opaque, opts, errp);
if (rc) {
break;
}
assert(!errp || !*errp);
}
loc_pop(&loc);
return rc;
}
static size_t count_opts_list(QemuOptsList *list)
{
QemuOptDesc *desc = NULL;
size_t num_opts = 0;
if (!list) {
return 0;
}
desc = list->desc;
while (desc && desc->name) {
num_opts++;
desc++;
}
return num_opts;
}
void qemu_opts_free(QemuOptsList *list)
{
g_free(list);
}
/* Realloc dst option list and append options from an option list (list)
* to it. dst could be NULL or a malloced list.
* The lifetime of dst must be shorter than the input list because the
* QemuOptDesc->name, ->help, and ->def_value_str strings are shared.
*/
QemuOptsList *qemu_opts_append(QemuOptsList *dst,
QemuOptsList *list)
{
size_t num_opts, num_dst_opts;
QemuOptDesc *desc;
bool need_init = false;
qemu_opts_append: Play nicely with QemuOptsList's head When running a libvirt test suite I've noticed the qemu-img is crashing occasionally. Tracing the problem down led me to the following valgrind output: qemu.git $ valgrind -q ./qemu-img create -f qed -obacking_file=/dev/null,backing_fmt=raw qed ==14881== Invalid write of size 8 ==14881== at 0x1D263F: qemu_opts_create (qemu-option.c:692) ==14881== by 0x130782: bdrv_img_create (block.c:5531) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd ==14881== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==14881== by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2) ==14881== by 0x1D38D8: qemu_opts_append (qemu-option.c:1129) ==14881== by 0x13075E: bdrv_img_create (block.c:5528) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Formatting 'qed', fmt=qed size=0 backing_file='/dev/null' backing_fmt='raw' cluster_size=65536 ==14881== Invalid write of size 8 ==14881== at 0x1D28BE: qemu_opts_del (qemu-option.c:750) ==14881== by 0x130BF3: bdrv_img_create (block.c:5638) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd ==14881== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==14881== by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2) ==14881== by 0x1D38D8: qemu_opts_append (qemu-option.c:1129) ==14881== by 0x13075E: bdrv_img_create (block.c:5528) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== The problem is apparently in the qemu_opts_append(). Well, if it gets called twice or more. On the first call, when @dst is NULL some initialization is done during which @dst->head list gets initialized. The list is initialized in a way, so that the list tail points at the list head. However, the next time qemu_opts_append() is called for new options to be added, g_realloc() may move @dst to a new address making the old list tail point at an invalid address. If that's the case, we must update the list pointers. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-25 10:38:41 +02:00
bool need_head_update;
if (!list) {
return dst;
}
/* If dst is NULL, after realloc, some area of dst should be initialized
* before adding options to it.
*/
if (!dst) {
need_init = true;
qemu_opts_append: Play nicely with QemuOptsList's head When running a libvirt test suite I've noticed the qemu-img is crashing occasionally. Tracing the problem down led me to the following valgrind output: qemu.git $ valgrind -q ./qemu-img create -f qed -obacking_file=/dev/null,backing_fmt=raw qed ==14881== Invalid write of size 8 ==14881== at 0x1D263F: qemu_opts_create (qemu-option.c:692) ==14881== by 0x130782: bdrv_img_create (block.c:5531) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd ==14881== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==14881== by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2) ==14881== by 0x1D38D8: qemu_opts_append (qemu-option.c:1129) ==14881== by 0x13075E: bdrv_img_create (block.c:5528) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Formatting 'qed', fmt=qed size=0 backing_file='/dev/null' backing_fmt='raw' cluster_size=65536 ==14881== Invalid write of size 8 ==14881== at 0x1D28BE: qemu_opts_del (qemu-option.c:750) ==14881== by 0x130BF3: bdrv_img_create (block.c:5638) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd ==14881== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==14881== by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2) ==14881== by 0x1D38D8: qemu_opts_append (qemu-option.c:1129) ==14881== by 0x13075E: bdrv_img_create (block.c:5528) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== The problem is apparently in the qemu_opts_append(). Well, if it gets called twice or more. On the first call, when @dst is NULL some initialization is done during which @dst->head list gets initialized. The list is initialized in a way, so that the list tail points at the list head. However, the next time qemu_opts_append() is called for new options to be added, g_realloc() may move @dst to a new address making the old list tail point at an invalid address. If that's the case, we must update the list pointers. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-25 10:38:41 +02:00
need_head_update = true;
} else {
/* Moreover, even if dst is not NULL, the realloc may move it to a
* different address in which case we may get a stale tail pointer
* in dst->head. */
need_head_update = QTAILQ_EMPTY(&dst->head);
}
num_opts = count_opts_list(dst);
num_dst_opts = num_opts;
num_opts += count_opts_list(list);
dst = g_realloc(dst, sizeof(QemuOptsList) +
(num_opts + 1) * sizeof(QemuOptDesc));
if (need_init) {
dst->name = NULL;
dst->implied_opt_name = NULL;
dst->merge_lists = false;
}
qemu_opts_append: Play nicely with QemuOptsList's head When running a libvirt test suite I've noticed the qemu-img is crashing occasionally. Tracing the problem down led me to the following valgrind output: qemu.git $ valgrind -q ./qemu-img create -f qed -obacking_file=/dev/null,backing_fmt=raw qed ==14881== Invalid write of size 8 ==14881== at 0x1D263F: qemu_opts_create (qemu-option.c:692) ==14881== by 0x130782: bdrv_img_create (block.c:5531) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd ==14881== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==14881== by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2) ==14881== by 0x1D38D8: qemu_opts_append (qemu-option.c:1129) ==14881== by 0x13075E: bdrv_img_create (block.c:5528) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Formatting 'qed', fmt=qed size=0 backing_file='/dev/null' backing_fmt='raw' cluster_size=65536 ==14881== Invalid write of size 8 ==14881== at 0x1D28BE: qemu_opts_del (qemu-option.c:750) ==14881== by 0x130BF3: bdrv_img_create (block.c:5638) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== Address 0x11fedd38 is 24 bytes inside a block of size 232 free'd ==14881== at 0x4C2CA5E: realloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==14881== by 0x592D35E: g_realloc (in /usr/lib64/libglib-2.0.so.0.3800.2) ==14881== by 0x1D38D8: qemu_opts_append (qemu-option.c:1129) ==14881== by 0x13075E: bdrv_img_create (block.c:5528) ==14881== by 0x118DE0: img_create (qemu-img.c:462) ==14881== by 0x11E7E4: main (qemu-img.c:2830) ==14881== The problem is apparently in the qemu_opts_append(). Well, if it gets called twice or more. On the first call, when @dst is NULL some initialization is done during which @dst->head list gets initialized. The list is initialized in a way, so that the list tail points at the list head. However, the next time qemu_opts_append() is called for new options to be added, g_realloc() may move @dst to a new address making the old list tail point at an invalid address. If that's the case, we must update the list pointers. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-25 10:38:41 +02:00
if (need_head_update) {
QTAILQ_INIT(&dst->head);
}
dst->desc[num_dst_opts].name = NULL;
/* append list->desc to dst->desc */
if (list) {
desc = list->desc;
while (desc && desc->name) {
if (find_desc_by_name(dst->desc, desc->name) == NULL) {
dst->desc[num_dst_opts++] = *desc;
dst->desc[num_dst_opts].name = NULL;
}
desc++;
}
}
return dst;
}