platform_system_core/libcutils/partition_utils.cpp

71 lines
1.5 KiB
C++

/*
* Copyright 2011, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <cutils/partition_utils.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mount.h> /* for BLKGETSIZE */
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <cutils/properties.h>
static int only_one_char(char *buf, int len, char c)
{
int i, ret;
ret = 1;
for (i=0; i<len; i++) {
if (buf[i] != c) {
ret = 0;
break;
}
}
return ret;
}
int partition_wiped(char *source)
{
char buf[4096];
int fd, ret;
if ((fd = open(source, O_RDONLY)) < 0) {
return 0;
}
ret = read(fd, buf, sizeof(buf));
close(fd);
if (ret != sizeof(buf)) {
return 0;
}
/* Check for all zeros */
if (only_one_char(buf, sizeof(buf), 0)) {
return 1;
}
/* Check for all ones */
if (only_one_char(buf, sizeof(buf), 0xff)) {
return 1;
}
return 0;
}