+/*
+ * Copyright (c) 2008 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+//
+// wipefs.cpp
+//
+
+#include <fcntl.h>
+#include <sys/uio.h>
+#include <sys/ioctl.h>
+#include <sys/disk.h>
+#include <sys/stat.h>
+
+#include "ExtentManager.h"
+#include "wipefs.h"
+
+#define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
+
+struct __wipefs_ctx {
+ int fd;
+ class ExtentManager extMan;
+};
+
+void
+AddExtentsForFutureFS(class ExtentManager *extMan)
+{
+ // we don't know what blocks future FS will use to recognize itself. But we'd better be safe than sorry and write
+ // the first and last 2MB of the volume
+ off_t size = 2 * 1024 * 1024;
+ extMan->AddByteRangeExtent(0, size);
+ extMan->AddByteRangeExtent(extMan->totalBytes - size, size);
+}
+
+void
+AddExtentsForHFS(class ExtentManager *extMan)
+{
+ // first 1KB is boot block, last 512B is reserved
+ // the Volume Header (512B) is after 1KB and before the last 512B
+ extMan->AddByteRangeExtent(0, 1024 + 512);
+ extMan->AddByteRangeExtent(extMan->totalBytes - 1024, 1024);
+}
+
+void
+AddExtentsForMSDOS(class ExtentManager *extMan)
+{
+ // MSDOS needs the first block (in theory, up to 32KB)
+ extMan->AddByteRangeExtent(0, 32 * 1024);
+}
+
+void
+AddExtentsForNTFS(class ExtentManager *extMan)
+{
+ // NTFS supports block size from 256B to 32768B. The first, middle and last block are needed
+ extMan->AddByteRangeExtent(0, 32 * 1024);
+ extMan->AddByteRangeExtent(extMan->totalBytes - 32 * 1024, 32 * 1024);
+ // to be safe, add the rage from (mid_point - 32KB) to (mid_point + 32KB)
+ extMan->AddByteRangeExtent(extMan->totalBytes / 2 - 32 * 1024, 64 * 1024);
+}
+
+void
+AddExtentsForUDF(class ExtentManager *extMan)
+{
+ off_t lastBlockAddr = extMan->totalBlocks - 1;
+
+ // Volume Recognization Sequence (VRS) starts at 32KB, usually less than 7 Volume Structure Descriptors (2KB each)
+ extMan->AddByteRangeExtent(32 * 1024, 14 * 1024);
+
+ // AVDP is on 256, 512, last block, last block - 256
+ extMan->AddBlockRangeExtent(256, 1);
+ extMan->AddBlockRangeExtent(512, 1);
+ extMan->AddBlockRangeExtent(lastBlockAddr, 1);
+ extMan->AddBlockRangeExtent(lastBlockAddr - 256, 1);
+
+ // to be safe, assume the device has 2KB block size and do it again
+ if (extMan->blockSize != 2048) {
+ off_t blockSize = 2048;
+ // AVDP is on 256, 512, last block, last block - 256
+ extMan->AddByteRangeExtent(256 * blockSize, blockSize);
+ extMan->AddByteRangeExtent(512 * blockSize, blockSize);
+ extMan->AddByteRangeExtent(extMan->totalBytes - blockSize, blockSize);
+ extMan->AddByteRangeExtent(extMan->totalBytes - 256 * blockSize, blockSize);
+ }
+}
+
+void
+AddExtentsForUFS(class ExtentManager *extMan)
+{
+ // UFS super block is 8KB at offset 8KB
+ extMan->AddByteRangeExtent(8192, 8192);
+}
+
+void
+AddExtentsForZFS(class ExtentManager *extMan)
+{
+ // ZFS needs the first 512KB and last 512KB for all the 4 disk labels
+ extMan->AddByteRangeExtent(0, 512 * 1024);
+ extMan->AddByteRangeExtent(extMan->totalBytes - 512 * 1024, 512 * 1024);
+}
+
+void
+AddExtentsForPartitions(class ExtentManager *extMan)
+{
+ // MBR (Master Boot Record) needs the first sector
+ // APM (Apple Partition Map) needs the second sector
+ // GPT (GUID Partition Table) needs the first 34 and last 33 sectors
+ extMan->AddByteRangeExtent(0, 512 * 34);
+ extMan->AddByteRangeExtent(extMan->totalBytes - 512 * 33, 512 * 33);
+}
+
+extern "C" int
+wipefs_alloc(int fd, size_t block_size, wipefs_ctx *handle)
+{
+ int err = 0;
+ uint64_t numBlocks = 0;
+ uint32_t nativeBlockSize = 0;
+ off_t totalSizeInBytes = 0;
+ class ExtentManager *extMan = NULL;
+ struct stat sbuf = { 0 };
+
+ *handle = NULL;
+ (void)fstat(fd, &sbuf);
+ switch (sbuf.st_mode & S_IFMT) {
+ case S_IFCHR:
+ case S_IFBLK:
+ if (ioctl(fd, DKIOCGETBLOCKSIZE, (char *)&nativeBlockSize) < 0) {
+ err = errno;
+ goto labelExit;
+ }
+ if (ioctl(fd, DKIOCGETBLOCKCOUNT, (char *)&numBlocks) < 0) {
+ err = errno;
+ goto labelExit;
+ }
+ totalSizeInBytes = numBlocks * nativeBlockSize;
+ break;
+ case S_IFREG:
+ nativeBlockSize = sbuf.st_blksize;
+ numBlocks = sbuf.st_size / sbuf.st_blksize;
+ totalSizeInBytes = sbuf.st_size;
+ break;
+ default:
+ errno = EINVAL;
+ goto labelExit;
+ }
+ if (block_size == 0) {
+ block_size = nativeBlockSize;
+ }
+ if (block_size == 0 || totalSizeInBytes == 0) {
+ err = EINVAL;
+ goto labelExit;
+ }
+
+ try {
+ *handle = new __wipefs_ctx;
+ if (*handle == NULL) {
+ bad_alloc e;
+ throw e;
+ }
+
+ (*handle)->fd = fd;
+ extMan = &(*handle)->extMan;
+
+ extMan->Init(block_size, nativeBlockSize, totalSizeInBytes);
+ AddExtentsForFutureFS(extMan);
+ AddExtentsForHFS(extMan);
+ AddExtentsForMSDOS(extMan);
+ AddExtentsForNTFS(extMan);
+ AddExtentsForUDF(extMan);
+ AddExtentsForUFS(extMan);
+ AddExtentsForZFS(extMan);
+ AddExtentsForPartitions(extMan);
+ }
+ catch (bad_alloc &e) {
+ err = ENOMEM;
+ }
+ catch (...) { // currently only ENOMEM is possible
+ err = ENOMEM;
+ }
+
+ labelExit:
+ if (err != 0) {
+ wipefs_free(handle);
+ }
+ return err;
+} // wipefs_alloc
+
+extern "C" int
+wipefs_except_blocks(wipefs_ctx handle, off_t block_offset, off_t nblocks)
+{
+ int err = 0;
+ try {
+ handle->extMan.RemoveBlockRangeExtent(block_offset, nblocks);
+ }
+ catch (bad_alloc &e) {
+ err = ENOMEM;
+ }
+ catch (...) { // currently only ENOMEM is possible
+ err = ENOMEM;
+ }
+ return err;
+}
+
+extern "C" int
+wipefs_wipe(wipefs_ctx handle)
+{
+ int err = 0;
+ uint8_t *bufZero = NULL;
+ ListExtIt curExt;
+ size_t bufSize;
+ dk_discard_t discard;
+
+ memset(&discard, 0, sizeof(dk_discard_t));
+ discard.length = handle->extMan.totalBytes;
+
+ //
+ // Don't bother to check the return value since this is mostly
+ // informational for the lower-level drivers.
+ //
+ ioctl(handle->fd, DKIOCDISCARD, (caddr_t)&discard);
+
+
+ bufSize = 256 * 1024; // issue large I/O to get better performance
+ bufZero = new uint8_t[bufSize];
+ bzero(bufZero, bufSize);
+
+ off_t byteOffset, totalBytes;
+ size_t numBytes, numBytesToWrite, blockSize;
+
+ blockSize = handle->extMan.blockSize;
+ totalBytes = handle->extMan.totalBytes;
+ // write zero to all extents
+ for (curExt = handle->extMan.extentList.begin(); curExt != handle->extMan.extentList.end(); curExt++) {
+ byteOffset = curExt->blockAddr * blockSize;
+ numBytes = curExt->numBlocks * blockSize;
+ // make both offset and numBytes on native block boundary
+ if (byteOffset % handle->extMan.nativeBlockSize != 0 ||
+ numBytes % handle->extMan.nativeBlockSize != 0) {
+ size_t nativeBlockSize = handle->extMan.nativeBlockSize;
+ off_t newOffset, newEndOffset;
+ newOffset = byteOffset / nativeBlockSize * nativeBlockSize;
+ newEndOffset = roundup(byteOffset + numBytes, nativeBlockSize);
+ byteOffset = newOffset;
+ numBytes = newEndOffset - newOffset;
+ }
+ if (byteOffset + (off_t)numBytes > totalBytes) {
+ numBytes = totalBytes - byteOffset;
+ }
+ while (numBytes > 0) {
+ numBytesToWrite = min(numBytes, bufSize);
+ if (pwrite(handle->fd, bufZero, numBytesToWrite, byteOffset) != (ssize_t)numBytesToWrite) {
+ err = errno;
+ goto labelExit;
+ }
+ numBytes -= numBytesToWrite;
+ byteOffset += numBytesToWrite;
+ }
+ }
+
+ labelExit:
+ if (bufZero != NULL)
+ delete[] bufZero;
+ return err;
+} // wipefs_wipe
+
+extern "C" void
+wipefs_free(wipefs_ctx *handle)
+{
+ if (*handle != NULL) {
+ delete *handle;
+ *handle = NULL;
+ }
+}
projects / apple / libutil.git / commitdiff
