New files to support I/O restructuring and (currently broken) Windows
version.
diff --git a/diskio-unix.cc b/diskio-unix.cc
new file mode 100644
index 0000000..573af56
--- /dev/null
+++ b/diskio-unix.cc
@@ -0,0 +1,366 @@
+//
+// C++ Interface: diskio (Unix components [Linux, FreeBSD, Mac OS X])
+//
+// Description: Class to handle low-level disk I/O for GPT fdisk
+//
+//
+// Author: Rod Smith <rodsmith@rodsbooks.com>, (C) 2009
+//
+// Copyright: See COPYING file that comes with this distribution
+//
+//
+// This program is copyright (c) 2009 by Roderick W. Smith. It is distributed
+// under the terms of the GNU GPL version 2, as detailed in the COPYING file.
+
+#define __STDC_LIMIT_MACROS
+#define __STDC_CONSTANT_MACROS
+
+#include <sys/ioctl.h>
+#include <stdio.h>
+#include <string>
+#include <stdint.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <iostream>
+
+#include "support.h"
+#include "diskio.h"
+
+using namespace std;
+
+// Returns the official "real" name for a shortened version of same.
+// Trivial here; more important in Windows
+void DiskIO::MakeRealName(void) {
+ realFilename = userFilename;
+} // DiskIO::MakeRealName()
+
+// Open the currently on-record file for reading
+int DiskIO::OpenForRead(void) {
+ int shouldOpen = 1;
+
+ if (isOpen) { // file is already open
+ if (openForWrite) {
+ Close();
+ } else {
+ shouldOpen = 0;
+ } // if/else
+ } // if
+
+ if (shouldOpen) {
+ fd = open(realFilename.c_str(), O_RDONLY);
+ if (fd == -1) {
+ fprintf(stderr, "Problem opening %s for reading! Error is %d\n",
+ realFilename.c_str(), errno);
+ if (errno == EACCES) { // User is probably not running as root
+ fprintf(stderr, "You must run this program as root or use sudo!\n");
+ } // if
+ realFilename = "";
+ userFilename = "";
+ isOpen = 0;
+ openForWrite = 0;
+ } else {
+ isOpen = 1;
+ openForWrite = 0;
+ } // if/else
+ } // if
+
+ return isOpen;
+} // DiskIO::OpenForRead(void)
+
+// An extended file-open function. This includes some system-specific checks.
+// Returns 1 if the file is open, 0 otherwise....
+int DiskIO::OpenForWrite(void) {
+ if ((isOpen) && (openForWrite))
+ return 1;
+
+ // Close the disk, in case it's already open for reading only....
+ Close();
+
+ // try to open the device; may fail....
+ fd = open(realFilename.c_str(), O_WRONLY | O_CREAT, S_IWUSR | S_IRUSR | S_IRGRP | S_IROTH);
+#ifdef __APPLE__
+ // MacOS X requires a shared lock under some circumstances....
+ if (fd < 0) {
+ fd = open(realFilename.c_str(), O_WRONLY | O_CREAT, S_IWUSR | S_IRUSR | S_IRGRP | S_IROTH | O_SHLOCK);
+ } // if
+#endif
+ if (fd >= 0) {
+ isOpen = 1;
+ openForWrite = 1;
+ } else {
+ isOpen = 0;
+ openForWrite = 0;
+ } // if/else
+ return isOpen;
+} // DiskIO::OpenForWrite(void)
+
+// Close the disk device. Note that this does NOT erase the stored filenames,
+// so the file can be re-opened without specifying the filename.
+void DiskIO::Close(void) {
+ if (isOpen)
+ close(fd);
+ isOpen = 0;
+ openForWrite = 0;
+} // DiskIO::Close()
+
+// Returns block size of device pointed to by fd file descriptor. If the ioctl
+// returns an error condition, print a warning but return a value of SECTOR_SIZE
+// (512)..
+int DiskIO::GetBlockSize(void) {
+ int err = -1, blockSize = 0;
+
+ // If disk isn't open, try to open it....
+ if (!isOpen) {
+ OpenForRead();
+ } // if
+
+ if (isOpen) {
+#ifdef __APPLE__
+ err = ioctl(fd, DKIOCGETBLOCKSIZE, &blockSize);
+#endif
+#ifdef __FreeBSD__
+ err = ioctl(fd, DIOCGSECTORSIZE, &blockSize);
+#endif
+#ifdef __linux__
+ err = ioctl(fd, BLKSSZGET, &blockSize);
+#endif
+
+ if (err == -1) {
+ blockSize = SECTOR_SIZE;
+ // ENOTTY = inappropriate ioctl; probably being called on a disk image
+ // file, so don't display the warning message....
+ // 32-bit code returns EINVAL, I don't know why. I know I'm treading on
+ // thin ice here, but it should be OK in all but very weird cases....
+ if ((errno != ENOTTY) && (errno != EINVAL)) {
+ printf("\aError %d when determining sector size! Setting sector size to %d\n",
+ errno, SECTOR_SIZE);
+ } // if
+ } // if (err == -1)
+ } // if (isOpen)
+
+ return (blockSize);
+} // DiskIO::GetBlockSize()
+
+// Resync disk caches so the OS uses the new partition table. This code varies
+// a lot from one OS to another.
+void DiskIO::DiskSync(void) {
+ int i, platformFound = 0;
+
+ // If disk isn't open, try to open it....
+ if (!isOpen) {
+ OpenForRead();
+ } // if
+
+ if (isOpen) {
+ sync();
+#ifdef __APPLE__
+ printf("Warning: The kernel may continue to use old or deleted partitions.\n"
+ "You should reboot or remove the drive.\n");
+ /* don't know if this helps
+ * it definitely will get things on disk though:
+ * http://topiks.org/mac-os-x/0321278542/ch12lev1sec8.html */
+ i = ioctl(fd, DKIOCSYNCHRONIZECACHE);
+ platformFound++;
+#endif
+#ifdef __FreeBSD__
+ sleep(2);
+ i = ioctl(fd, DIOCGFLUSH);
+ printf("Warning: The kernel may continue to use old or deleted partitions.\n"
+ "You should reboot or remove the drive.\n");
+ platformFound++;
+#endif
+#ifdef __linux__
+ sleep(2);
+ i = ioctl(fd, BLKRRPART);
+ if (i)
+ printf("Warning: The kernel is still using the old partition table.\n"
+ "The new table will be used at the next reboot.\n");
+ platformFound++;
+#endif
+ if (platformFound == 0)
+ fprintf(stderr, "Warning: Platform not recognized!\n");
+ if (platformFound > 1)
+ fprintf(stderr, "\nWarning: We seem to be running on multiple platforms!\n");
+ } // if (isOpen)
+} // DiskIO::DiskSync()
+
+// Seek to the specified sector. Returns 1 on success, 0 on failure.
+int DiskIO::Seek(uint64_t sector) {
+ int retval = 1;
+ off_t seekTo, sought;
+
+ // If disk isn't open, try to open it....
+ if (!isOpen) {
+ retval = OpenForRead();
+ } // if
+
+ if (isOpen) {
+ seekTo = sector * (uint64_t) GetBlockSize();
+ sought = lseek64(fd, seekTo, SEEK_SET);
+ if (sought != seekTo) {
+ retval = 0;
+ } // if
+ } // if
+ return retval;
+} // DiskIO::Seek()
+
+// A variant on the standard read() function. Done to work around
+// limitations in FreeBSD concerning the matching of the sector
+// size with the number of bytes read.
+// Returns the number of bytes read into buffer.
+int DiskIO::Read(void* buffer, int numBytes) {
+ int blockSize = 512, i, numBlocks, retval = 0;
+ char* tempSpace;
+
+ // If disk isn't open, try to open it....
+ if (!isOpen) {
+ OpenForRead();
+ } // if
+
+ if (isOpen) {
+ // Compute required space and allocate memory
+ blockSize = GetBlockSize();
+ if (numBytes <= blockSize) {
+ numBlocks = 1;
+ tempSpace = (char*) malloc(blockSize);
+ } else {
+ numBlocks = numBytes / blockSize;
+ if ((numBytes % blockSize) != 0) numBlocks++;
+ tempSpace = (char*) malloc(numBlocks * blockSize);
+ } // if/else
+
+ // Read the data into temporary space, then copy it to buffer
+ retval = read(fd, tempSpace, numBlocks * blockSize);
+ memcpy(buffer, tempSpace, numBytes);
+/* for (i = 0; i < numBytes; i++) {
+ ((char*) buffer)[i] = tempSpace[i];
+ } // for */
+
+ // Adjust the return value, if necessary....
+ if (((numBlocks * blockSize) != numBytes) && (retval > 0))
+ retval = numBytes;
+
+ free(tempSpace);
+ } // if (isOpen)
+ return retval;
+} // DiskIO::Read()
+
+// A variant on the standard write() function. Done to work around
+// limitations in FreeBSD concerning the matching of the sector
+// size with the number of bytes read.
+// Returns the number of bytes written.
+int DiskIO::Write(void* buffer, int numBytes) {
+ int blockSize = 512, i, numBlocks, retval = 0;
+ char* tempSpace;
+
+ // If disk isn't open, try to open it....
+ if ((!isOpen) || (!openForWrite)) {
+ OpenForWrite();
+ } // if
+
+ if (isOpen) {
+ // Compute required space and allocate memory
+ blockSize = GetBlockSize();
+ if (numBytes <= blockSize) {
+ numBlocks = 1;
+ tempSpace = (char*) malloc(blockSize);
+ } else {
+ numBlocks = numBytes / blockSize;
+ if ((numBytes % blockSize) != 0) numBlocks++;
+ tempSpace = (char*) malloc(numBlocks * blockSize);
+ } // if/else
+
+ // Copy the data to my own buffer, then write it
+/* for (i = 0; i < numBytes; i++) {
+ tempSpace[i] = ((char*) buffer)[i];
+ } // for */
+ memcpy(tempSpace, buffer, numBytes);
+ for (i = numBytes; i < numBlocks * blockSize; i++) {
+ tempSpace[i] = 0;
+ } // for
+ retval = write(fd, tempSpace, numBlocks * blockSize);
+
+ // Adjust the return value, if necessary....
+ if (((numBlocks * blockSize) != numBytes) && (retval > 0))
+ retval = numBytes;
+
+ free(tempSpace);
+ } // if (isOpen)
+ return retval;
+} // DiskIO:Write()
+
+/**************************************************************************************
+ * *
+ * Below functions are lifted from various sources, as documented in comments before *
+ * each one. *
+ * *
+ **************************************************************************************/
+
+// The disksize function is taken from the Linux fdisk code and modified
+// greatly since then to enable FreeBSD and MacOS support, as well as to
+// return correct values for disk image files.
+uint64_t DiskIO::DiskSize(int *err) {
+ long sz; // Do not delete; needed for Linux
+ long long b; // Do not delete; needed for Linux
+ uint64_t sectors = 0; // size in sectors
+ off_t bytes = 0; // size in bytes
+ struct stat64 st;
+ int platformFound = 0;
+
+ // If disk isn't open, try to open it....
+ if (!isOpen) {
+ OpenForRead();
+ } // if
+
+ if (isOpen) {
+ // Note to self: I recall testing a simplified version of
+ // this code, similar to what's in the __APPLE__ block,
+ // on Linux, but I had some problems. IIRC, it ran OK on 32-bit
+ // systems but not on 64-bit. Keep this in mind in case of
+ // 32/64-bit issues on MacOS....
+#ifdef __APPLE__
+ *err = ioctl(fd, DKIOCGETBLOCKCOUNT, §ors);
+ platformFound++;
+#endif
+#ifdef __FreeBSD__
+ *err = ioctl(fd, DIOCGMEDIASIZE, &bytes);
+ b = GetBlockSize();
+ sectors = bytes / b;
+ platformFound++;
+#endif
+#ifdef __linux__
+ *err = ioctl(fd, BLKGETSIZE, &sz);
+ if (*err) {
+ sectors = sz = 0;
+ } // if
+ if ((errno == EFBIG) || (!*err)) {
+ *err = ioctl(fd, BLKGETSIZE64, &b);
+ if (*err || b == 0 || b == sz)
+ sectors = sz;
+ else
+ sectors = (b >> 9);
+ } // if
+ // Unintuitively, the above returns values in 512-byte blocks, no
+ // matter what the underlying device's block size. Correct for this....
+ sectors /= (GetBlockSize() / 512);
+ platformFound++;
+#endif
+ if (platformFound != 1)
+ fprintf(stderr, "Warning! We seem to be running on no known platform!\n");
+
+ // The above methods have failed, so let's assume it's a regular
+ // file (a QEMU image, dd backup, or what have you) and see what
+ // fstat() gives us....
+ if ((sectors == 0) || (*err == -1)) {
+ if (fstat64(fd, &st) == 0) {
+ bytes = (off_t) st.st_size;
+ if ((bytes % UINT64_C(512)) != 0)
+ fprintf(stderr, "Warning: File size is not a multiple of 512 bytes!"
+ " Misbehavior is likely!\n\a");
+ sectors = bytes / UINT64_C(512);
+ } // if
+ } // if
+ } // if (isOpen)
+ return sectors;
+} // DiskIO::DiskSize()