qemu/qapi/string-input-visitor.c

415 lines
10 KiB
C

/*
* String parsing visitor
*
* Copyright Red Hat, Inc. 2012-2016
*
* Author: Paolo Bonzini <pbonzini@redhat.com>
* David Hildenbrand <david@redhat.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qapi/string-input-visitor.h"
#include "qapi/visitor-impl.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qnull.h"
#include "qemu/option.h"
#include "qemu/cutils.h"
typedef enum ListMode {
/* no list parsing active / no list expected */
LM_NONE,
/* we have an unparsed string remaining */
LM_UNPARSED,
/* we have an unfinished int64 range */
LM_INT64_RANGE,
/* we have an unfinished uint64 range */
LM_UINT64_RANGE,
/* we have parsed the string completely and no range is remaining */
LM_END,
} ListMode;
/* protect against DOS attacks, limit the amount of elements per range */
#define RANGE_MAX_ELEMENTS 65536
typedef union RangeElement {
int64_t i64;
uint64_t u64;
} RangeElement;
struct StringInputVisitor
{
Visitor visitor;
/* List parsing state */
ListMode lm;
RangeElement rangeNext;
RangeElement rangeEnd;
const char *unparsed_string;
void *list;
/* The original string to parse */
const char *string;
};
static StringInputVisitor *to_siv(Visitor *v)
{
return container_of(v, StringInputVisitor, visitor);
}
static bool start_list(Visitor *v, const char *name, GenericList **list,
size_t size, Error **errp)
{
StringInputVisitor *siv = to_siv(v);
assert(siv->lm == LM_NONE);
siv->list = list;
siv->unparsed_string = siv->string;
if (!siv->string[0]) {
if (list) {
*list = NULL;
}
siv->lm = LM_END;
} else {
if (list) {
*list = g_malloc0(size);
}
siv->lm = LM_UNPARSED;
}
return true;
}
static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
{
StringInputVisitor *siv = to_siv(v);
switch (siv->lm) {
case LM_END:
return NULL;
case LM_INT64_RANGE:
case LM_UINT64_RANGE:
case LM_UNPARSED:
/* we have an unparsed string or something left in a range */
break;
default:
abort();
}
tail->next = g_malloc0(size);
return tail->next;
}
static bool check_list(Visitor *v, Error **errp)
{
const StringInputVisitor *siv = to_siv(v);
switch (siv->lm) {
case LM_INT64_RANGE:
case LM_UINT64_RANGE:
case LM_UNPARSED:
error_setg(errp, "Fewer list elements expected");
return false;
case LM_END:
return true;
default:
abort();
}
}
static void end_list(Visitor *v, void **obj)
{
StringInputVisitor *siv = to_siv(v);
assert(siv->lm != LM_NONE);
assert(siv->list == obj);
siv->list = NULL;
siv->unparsed_string = NULL;
siv->lm = LM_NONE;
}
static int try_parse_int64_list_entry(StringInputVisitor *siv, int64_t *obj)
{
const char *endptr;
int64_t start, end;
/* parse a simple int64 or range */
if (qemu_strtoi64(siv->unparsed_string, &endptr, 0, &start)) {
return -EINVAL;
}
end = start;
switch (endptr[0]) {
case '\0':
siv->unparsed_string = endptr;
break;
case ',':
siv->unparsed_string = endptr + 1;
break;
case '-':
/* parse the end of the range */
if (qemu_strtoi64(endptr + 1, &endptr, 0, &end)) {
return -EINVAL;
}
if (start > end || end - start >= RANGE_MAX_ELEMENTS) {
return -EINVAL;
}
switch (endptr[0]) {
case '\0':
siv->unparsed_string = endptr;
break;
case ',':
siv->unparsed_string = endptr + 1;
break;
default:
return -EINVAL;
}
break;
default:
return -EINVAL;
}
/* we have a proper range (with maybe only one element) */
siv->lm = LM_INT64_RANGE;
siv->rangeNext.i64 = start;
siv->rangeEnd.i64 = end;
return 0;
}
static bool parse_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
int64_t val;
switch (siv->lm) {
case LM_NONE:
/* just parse a simple int64, bail out if not completely consumed */
if (qemu_strtoi64(siv->string, NULL, 0, &val)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
name ? name : "null", "int64");
return false;
}
*obj = val;
return true;
case LM_UNPARSED:
if (try_parse_int64_list_entry(siv, obj)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
"list of int64 values or ranges");
return false;
}
assert(siv->lm == LM_INT64_RANGE);
/* fall through */
case LM_INT64_RANGE:
/* return the next element in the range */
assert(siv->rangeNext.i64 <= siv->rangeEnd.i64);
*obj = siv->rangeNext.i64++;
if (siv->rangeNext.i64 > siv->rangeEnd.i64 || *obj == INT64_MAX) {
/* end of range, check if there is more to parse */
siv->lm = siv->unparsed_string[0] ? LM_UNPARSED : LM_END;
}
return true;
case LM_END:
error_setg(errp, "Fewer list elements expected");
return false;
default:
abort();
}
}
static int try_parse_uint64_list_entry(StringInputVisitor *siv, uint64_t *obj)
{
const char *endptr;
uint64_t start, end;
/* parse a simple uint64 or range */
if (qemu_strtou64(siv->unparsed_string, &endptr, 0, &start)) {
return -EINVAL;
}
end = start;
switch (endptr[0]) {
case '\0':
siv->unparsed_string = endptr;
break;
case ',':
siv->unparsed_string = endptr + 1;
break;
case '-':
/* parse the end of the range */
if (qemu_strtou64(endptr + 1, &endptr, 0, &end)) {
return -EINVAL;
}
if (start > end || end - start >= RANGE_MAX_ELEMENTS) {
return -EINVAL;
}
switch (endptr[0]) {
case '\0':
siv->unparsed_string = endptr;
break;
case ',':
siv->unparsed_string = endptr + 1;
break;
default:
return -EINVAL;
}
break;
default:
return -EINVAL;
}
/* we have a proper range (with maybe only one element) */
siv->lm = LM_UINT64_RANGE;
siv->rangeNext.u64 = start;
siv->rangeEnd.u64 = end;
return 0;
}
static bool parse_type_uint64(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
uint64_t val;
switch (siv->lm) {
case LM_NONE:
/* just parse a simple uint64, bail out if not completely consumed */
if (qemu_strtou64(siv->string, NULL, 0, &val)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
"uint64");
return false;
}
*obj = val;
return true;
case LM_UNPARSED:
if (try_parse_uint64_list_entry(siv, obj)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
"list of uint64 values or ranges");
return false;
}
assert(siv->lm == LM_UINT64_RANGE);
/* fall through */
case LM_UINT64_RANGE:
/* return the next element in the range */
assert(siv->rangeNext.u64 <= siv->rangeEnd.u64);
*obj = siv->rangeNext.u64++;
if (siv->rangeNext.u64 > siv->rangeEnd.u64 || *obj == UINT64_MAX) {
/* end of range, check if there is more to parse */
siv->lm = siv->unparsed_string[0] ? LM_UNPARSED : LM_END;
}
return true;
case LM_END:
error_setg(errp, "Fewer list elements expected");
return false;
default:
abort();
}
}
static bool parse_type_size(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
uint64_t val;
assert(siv->lm == LM_NONE);
if (!parse_option_size(name, siv->string, &val, errp)) {
return false;
}
*obj = val;
return true;
}
static bool parse_type_bool(Visitor *v, const char *name, bool *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
assert(siv->lm == LM_NONE);
return qapi_bool_parse(name ? name : "null", siv->string, obj, errp);
}
static bool parse_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
assert(siv->lm == LM_NONE);
*obj = g_strdup(siv->string);
return true;
}
static bool parse_type_number(Visitor *v, const char *name, double *obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
double val;
assert(siv->lm == LM_NONE);
if (qemu_strtod_finite(siv->string, NULL, &val)) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"number");
return false;
}
*obj = val;
return true;
}
static bool parse_type_null(Visitor *v, const char *name, QNull **obj,
Error **errp)
{
StringInputVisitor *siv = to_siv(v);
assert(siv->lm == LM_NONE);
*obj = NULL;
if (siv->string[0]) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"null");
return false;
}
*obj = qnull();
return true;
}
static void string_input_free(Visitor *v)
{
StringInputVisitor *siv = to_siv(v);
g_free(siv);
}
Visitor *string_input_visitor_new(const char *str)
{
StringInputVisitor *v;
assert(str);
v = g_malloc0(sizeof(*v));
v->visitor.type = VISITOR_INPUT;
v->visitor.type_int64 = parse_type_int64;
v->visitor.type_uint64 = parse_type_uint64;
v->visitor.type_size = parse_type_size;
v->visitor.type_bool = parse_type_bool;
v->visitor.type_str = parse_type_str;
v->visitor.type_number = parse_type_number;
v->visitor.type_null = parse_type_null;
v->visitor.start_list = start_list;
v->visitor.next_list = next_list;
v->visitor.check_list = check_list;
v->visitor.end_list = end_list;
v->visitor.free = string_input_free;
v->string = str;
v->lm = LM_NONE;
return &v->visitor;
}