Incorporate lomount from QEMU into tools/misc. This tool makes it easy to mount

individual partitions held within whole disk images.
 
Original source from http://www.dad-answers.com/qemu/utilities/QEMU-HD-Mounter/l
omount/lomount.c
 
 * Copyright (c) 2004 Jim Brown 
 * Copyright (c) 2004 Brad Watson
 * Copyright (c) 2004 Mulyadi Santosa
 
Signed-off-by: ian@xensource.com 
 

3 files changed, 292 insertions, 0 deletions

diff --git a/tools/misc/Makefile b/tools/misc/Makefile
index 5eebbfda12..19bc4fad20 100644
--- a/tools/misc/Makefile
+++ b/tools/misc/Makefile
@@ -23,6 +23,7 @@ build: $(TARGETS)
 	$(MAKE) -C miniterm
 	$(MAKE) -C cpuperf
 	$(MAKE) -C mbootpack
+	$(MAKE) -C lomount
 
 install: build
 	[ -d $(DESTDIR)/usr/bin ] || $(INSTALL_DIR) $(DESTDIR)/usr/bin
@@ -30,6 +31,7 @@ install: build
 	$(INSTALL_PROG) $(INSTALL_BIN) $(DESTDIR)/usr/bin
 	$(INSTALL_PROG) $(INSTALL_SBIN) $(DESTDIR)/usr/sbin
 	$(MAKE) -C cpuperf install
+	$(MAKE) -C lomount install
 #       No sense in installing miniterm on the Xen box.
 #	$(MAKE) -C miniterm install
 #       Likewise mbootpack
@@ -40,6 +42,7 @@ clean:
 	$(MAKE) -C miniterm clean
 	$(MAKE) -C cpuperf clean
 	$(MAKE) -C mbootpack clean
+	$(MAKE) -C lomount clean
 
 %.o: %.c $(HDRS) Makefile
 	$(CC) -c $(CFLAGS) -o $@ $<
diff --git a/tools/misc/lomount/Makefile b/tools/misc/lomount/Makefile
new file mode 100644
index 0000000000..32d9db41a4
--- /dev/null
+++ b/tools/misc/lomount/Makefile
@@ -0,0 +1,27 @@
+INSTALL		= install
+INSTALL_PROG	= $(INSTALL) -m0755
+INSTALL_DIR	= $(INSTALL) -d -m0755
+INSTALL_DATA	= $(INSTALL) -m0644
+
+XEN_ROOT=../../..
+include $(XEN_ROOT)/tools/Rules.mk
+
+CFLAGS  += -Wall -Werror -O3
+
+HDRS     = $(wildcard *.h)
+OBJS     = $(patsubst %.c,%.o,$(wildcard *.c))
+
+BIN      = lomount
+
+all: build
+build: $(BIN)
+
+install: build
+	$(INSTALL_PROG) $(BIN) $(SCRIPTS) $(DESTDIR)/usr/bin
+
+clean:
+	$(RM) *.a *.so *.o *.rpm $(BIN)
+
+%: %.c $(HDRS) Makefile
+	$(CC) $(CFLAGS) -o $@ $< 
+
diff --git a/tools/misc/lomount/lomount.c b/tools/misc/lomount/lomount.c
new file mode 100644
index 0000000000..308b772d46
--- /dev/null
+++ b/tools/misc/lomount/lomount.c
@@ -0,0 +1,262 @@
+/*
+ * lomount - utility to mount partitions in a hard disk image
+ *
+ * Copyright (c) 2004 Jim Brown
+ * Copyright (c) 2004 Brad Watson
+ * Copyright (c) 2004 Mulyadi Santosa
+ *
+ * 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 <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+
+#define BUF 4096
+
+//#define SECSIZE 4096    /* arbitrarilly large (it's probably just 512) */
+#define SECSIZE 512
+
+struct pentry 
+{
+	unsigned char bootable; 
+	unsigned char start_head;
+	unsigned int start_cylinder;
+	unsigned char start_sector;
+	unsigned char system;
+	unsigned char end_head;
+	unsigned int  end_cylinder;
+	unsigned char end_sector;
+	unsigned long start_sector_abs;
+	unsigned long no_of_sectors_abs;
+};
+
+char * progname;
+
+int loadptable(const char *argv, struct pentry parttbl[], struct pentry **exttbl)
+{
+	FILE *fd; 
+	int i, valid, total_known_sectors = 0;
+	unsigned char *pi; 
+	unsigned char data [SECSIZE]; 
+	unsigned long extent = 0, old_extent = 0, e_count = 1;
+	struct pentry exttbls[4];
+
+	fd = fopen(argv, "r");
+	if (fd == NULL)
+	{
+		perror ("lomount"); 
+		return 1;
+	}
+	i = fread (&data, 1, sizeof (data), fd); 
+	if (i < SECSIZE)
+	{
+		fprintf (stderr, "%s: could not read the entire first sector\n", progname); 
+		return 1;
+	}
+	for (i = 0;i < 4;i++)
+	{
+		pi = &data [446 + 16 * i];
+		parttbl [i].bootable = *pi; 
+		parttbl [i].start_head  = *(pi + 1); 
+		parttbl [i].start_cylinder = *(pi + 3) | ((*(pi + 2) << 2) & 0x300);
+		parttbl [i].start_sector = *(pi + 2) & 0x3f;
+		parttbl [i].system = *(pi + 4);
+		parttbl [i].end_head = *(pi + 5);
+		parttbl [i].end_cylinder = *(pi + 7) | ((*(pi + 6) << 2) & 0x300);
+		parttbl [i].end_sector = *(pi + 6) & 0x3f;
+		parttbl [i].start_sector_abs = 
+			(unsigned long) *(pi + 8) | ((unsigned long) *(pi + 9) << 8) | ((unsigned long) *(pi + 10) << 16) | ((unsigned long) *(pi + 11) << 24);
+		parttbl [i].no_of_sectors_abs = 
+			(unsigned long) *(pi + 12) | ((unsigned long) *(pi + 13) << 8) | ((unsigned long) *(pi + 14) << 16) | ((unsigned long) *(pi + 15) << 24);
+		if (parttbl[i].system == 0xF || parttbl[i].system == 0x5)
+		{
+			extent = parttbl[i].start_sector_abs * SECSIZE;
+			/* save the location of the "real" extended partition */
+			old_extent = extent;
+		}
+	}
+	valid = (data [510] == 0x55 && data [511] == 0xaa) ? 1 : 0;
+	for (i = 0; i < 4; i++)
+	{
+		total_known_sectors += parttbl[i].no_of_sectors_abs;
+	}
+	/* Extended Partition layout format was obtained from
+	http://wigner.cped.ornl.gov/the-gang/att-0520/03-Partition.htm */
+#ifdef DEBUG
+	if (extent != 0)
+	{
+		printf("extended partition detected at offset %d\n", extent);
+	}
+#endif
+	while (extent != 0)
+	{
+/* according to realloc(3) passing NULL as pointer is same as calling malloc() */
+		exttbl[0] = realloc(exttbl[0], e_count * sizeof(struct pentry));
+		fseek(fd, extent, SEEK_SET);
+		i = fread (&data, 1, sizeof (data), fd); 
+		if (i < SECSIZE)
+		{
+			fprintf (stderr, "%s: could not read the entire first sector\n", progname); 
+			return 1;
+		}
+	/* only first 2 entrys are used in extented partition tables */
+		for (i = 0;i < 2;i++)
+		{
+			pi = &data [446 + 16 * i];
+			exttbls [i].bootable = *pi; 
+			exttbls [i].start_head  = *(pi + 1); 
+			exttbls [i].start_cylinder = *(pi + 3) | ((*(pi + 2) << 2) & 0x300);
+			exttbls [i].start_sector = *(pi + 2) & 0x3f;
+			exttbls [i].system = *(pi + 4);
+			exttbls [i].end_head = *(pi + 5);
+			exttbls [i].end_cylinder = *(pi + 7) | ((*(pi + 6) << 2) & 0x300);
+			exttbls [i].end_sector = *(pi + 6) & 0x3f;
+			exttbls [i].start_sector_abs = 
+				(unsigned long) *(pi + 8) | ((unsigned long) *(pi + 9) << 8) | ((unsigned long) *(pi + 10) << 16) | ((unsigned long) *(pi + 11) << 24);
+			exttbls [i].no_of_sectors_abs = 
+				(unsigned long) *(pi + 12) | ((unsigned long) *(pi + 13) << 8) | ((unsigned long) *(pi + 14) << 16) | ((unsigned long) *(pi + 15) << 24);
+			if (i == 0)
+			{
+				//memmove((void *)exttbl[e_count-1], (void *)exttbls[i], sizeof(struct pentry));
+				//memmove() seems broken!
+				exttbl[0][e_count-1].bootable = exttbls [i].bootable;
+				exttbl[0][e_count-1].start_head  = exttbls [i].start_head;
+				exttbl[0][e_count-1].start_cylinder = exttbls [i].start_cylinder;
+				exttbl[0][e_count-1].start_sector = exttbls [i].start_sector;
+				exttbl[0][e_count-1].system = exttbls [i].system;
+				exttbl[0][e_count-1].end_head = exttbls [i].end_head;
+				exttbl[0][e_count-1].end_cylinder = exttbls [i].end_cylinder;
+				exttbl[0][e_count-1].end_sector = exttbls [i].end_sector;
+				exttbl[0][e_count-1].start_sector_abs = exttbls [i].start_sector_abs;
+				exttbl[0][e_count-1].no_of_sectors_abs = exttbls [i].no_of_sectors_abs;
+			/* adjust for start of image instead of start of ext partition */
+				exttbl[0][e_count-1].start_sector_abs += (extent/SECSIZE);
+#ifdef DEBUG
+				printf("extent %d start_sector_abs %d\n", extent, exttbl[0][e_count-1].start_sector_abs);
+#endif
+			//else if (parttbl[i].system == 0x5)
+			}
+			else if (i == 1)
+			{
+				extent = (exttbls[i].start_sector_abs * SECSIZE);
+				if (extent)
+					extent += old_extent;
+			}
+		}
+		e_count ++;
+	}
+	//fclose (fd);
+	//the above segfaults (?!!!)
+#ifdef DEBUG
+	printf("e_count = %d\n", e_count);
+#endif
+	return valid;
+}
+
+int main(int argc, char ** argv)
+{
+	struct pentry perttbl [4];
+	struct pentry *exttbl[1], *parttbl;
+	char buf[BUF], argv2[BUF], diskimage[BUF];
+	int partition = 1, sec, num = 0, pnum = 0, len = BUF, i, f = 0, valid;
+	progname = argv[0];
+	exttbl[0] = NULL;
+	for (i = 1; i < argc; i ++)
+	{
+		if (strncmp(argv[i], "-diskimage", BUF)==0)
+		{
+			strncpy(diskimage, argv[i+1], BUF);
+			i++; f = 1;
+		}
+		else if (strncmp(argv[i], "-partition", BUF)==0)
+		{
+			partition = atoi(argv[i+1]);
+			i++;
+			if (partition < 1) partition = 1;
+		}
+		else
+		{
+			strncat(argv2, argv[i], len);
+			strncat(argv2, " ", len-1);
+			len -= strlen(argv[i]);
+			len--;
+		}
+	}
+	if (!f)
+	{
+		printf("You must specify -diskimage and -partition\n");
+		printf("ex. lomount -t fs-type -diskimage hda.img -partition 1 /mnt\n");
+		return 0;
+	}
+	valid = loadptable(diskimage, perttbl, exttbl);
+	if (!valid)
+	{
+		printf("Warning: disk image does not appear to describe a valid partition table.\n");
+	}
+	/* NOTE: need to make sure this always rounds down */
+	//sec = total_known_sectors / sizeof_diskimage;
+/* The above doesn't work unless the disk image is completely filled by
+partitions ... unused space will thrown off the sector size. The calculation
+assumes the disk image is completely filled, and that the few sectors used
+to store the partition table/MBR are few enough that the calculated value is
+off by (larger than) a value less than one. */
+	sec = 512; /* TODO: calculate real sector size */
+#ifdef DEBUG
+	printf("sec: %d\n", sec);
+#endif
+	if (partition > 4)
+	{
+		if (exttbl[0] == NULL)
+		{
+		    printf("No extended partitions were found in %s.\n", diskimage);
+		    return 2;
+		}
+		parttbl = exttbl[0];
+		if (parttbl[partition-5].no_of_sectors_abs == 0)
+		{
+			printf("Partition %d was not found in %s.\n", partition, diskimage);
+			return 3;
+		}
+		partition -= 4;
+	}
+	else
+	{
+		parttbl = perttbl;
+		if (parttbl[partition-1].no_of_sectors_abs == 0)
+		{
+			printf("Partition %d was not found in %s.\n", partition, diskimage);
+			return 3;
+		}
+	}
+	num = parttbl[partition-1].start_sector_abs;
+	pnum = sec * num;
+#ifdef DEBUG
+	printf("offset = %d\n", pnum);
+#endif
+	snprintf(buf, BUF, "mount -oloop,offset=%d %s %s", pnum, diskimage, argv2);
+#ifdef DEBUG
+	printf("%s\n", buf);
+#endif
+	system(buf);
+	return 0;
+}