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/* This inspects a block device and produces an XML representation of
* the partitions, LVM, filesystems that we find there. This could be
* useful as example code of how to do this sort of probing, or to
* feed the XML to other programs.
*
* Usage:
* to-xml guest.img [guest.img ...]
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <guestfs.h>
/* Note that if any API call fails, we can just exit. The
* standard error handler will have printed the error message
* to stderr already.
*/
#define CALL(call,errcode) \
if ((call) == (errcode)) exit (1);
static void display_partition (guestfs_h *g, const char *dev);
static void display_partitions (guestfs_h *g, const char *dev);
static void display_ext23 (guestfs_h *g, const char *dev, const char *fstype);
int
main (int argc, char *argv[])
{
guestfs_h *g;
int i;
if (argc < 2 || access (argv[1], F_OK) != 0) {
fprintf (stderr, "Usage: to-xml guest.img [guest.img ...]\n");
exit (1);
}
if (!(g = guestfs_create ())) {
fprintf (stderr, "Cannot create libguestfs handle.\n");
exit (1);
}
for (i = 1; i < argc; ++i)
CALL (guestfs_add_drive (g, argv[i]), -1);
CALL (guestfs_launch (g), -1);
CALL (guestfs_wait_ready (g), -1);
printf ("<guestfs-system>\n");
/* list-devices should return the devices that we just attached?
* Better to find out what the kernel thinks are devices anyway ...
*/
char **devices;
CALL (devices = guestfs_list_devices (g), NULL);
printf ("<devices>\n");
for (i = 0; devices[i] != NULL; ++i) {
printf ("<device dev=\"%s\">\n", devices[i]);
display_partition (g, devices[i]);
free (devices[i]);
printf ("</device>\n");
}
free (devices);
printf ("</devices>\n");
/* Now do the same for VGs and LVs. Note that a VG may span
* multiple PVs / block devices, in arbitrary ways, which is
* why VGs are in a separate top-level XML class.
*/
char **vgs;
char **lvs;
printf ("<volgroups>\n");
CALL (vgs = guestfs_vgs (g), NULL);
CALL (lvs = guestfs_lvs (g), NULL);
for (i = 0; vgs[i] != NULL; ++i) {
printf ("<volgroup name=\"%s\">\n", vgs[i]);
/* Just the LVs in this VG. */
int len = strlen (vgs[i]);
int j;
for (j = 0; lvs[j] != NULL; ++j) {
if (strncmp (lvs[j], "/dev/", 5) == 0 &&
strncmp (&lvs[j][5], vgs[i], len) == 0 &&
lvs[j][len+5] == '/') {
printf ("<logvol name=\"%s\">\n", lvs[j]);
display_partition (g, lvs[j]);
printf ("</logvol>\n");
free (lvs[j]);
}
}
free (vgs[i]);
printf ("</volgroup>\n");
}
free (vgs);
free (lvs);
printf ("</volgroups>\n");
guestfs_close (g);
printf ("</guestfs-system>\n");
return 0;
}
/* Display a partition or LV. */
static void
display_partition (guestfs_h *g, const char *dev)
{
char *what;
CALL (what = guestfs_file (g, dev), NULL);
if (strstr (what, "boot sector") != NULL)
display_partitions (g, dev);
else if (strncmp (what, "LVM2", 4) == 0)
printf ("<physvol/>\n");
else if (strstr (what, "ext2 filesystem data") != NULL)
display_ext23 (g, dev, "ext2");
else if (strstr (what, "ext3 filesystem data") != NULL)
display_ext23 (g, dev, "ext3");
else if (strstr (what, "Linux/i386 swap file") != NULL)
printf ("<linux-swap/>\n");
else
printf ("<unknown/>\n");
free (what);
}
/* Display an MBR-formatted boot sector. */
static void
display_partitions (guestfs_h *g, const char *dev)
{
/* We can't look into a boot sector which is an LV. That's
* a limitation of sorts of the Linux kernel. (Actually, we
* could do this if we add the kpartx program to libguestfs).
*/
if (strncmp (dev, "/dev/sd", 7) != 0) {
printf ("<vm-image dev=\"%s\"/>\n", dev);
return;
}
char **parts;
int i, len;
CALL (parts = guestfs_list_partitions (g), NULL);
printf ("<partitions>\n");
len = strlen (dev);
for (i = 0; parts[i] != NULL; ++i) {
/* Only display partition if it's in the device. */
if (strncmp (parts[i], dev, len) == 0) {
printf ("<partition dev=\"%s\">\n", parts[i]);
display_partition (g, parts[i]);
printf ("</partition>\n");
}
free (parts[i]);
}
free (parts);
printf ("</partitions>\n");
}
/* Display some details on the ext2/3 filesystem on dev. */
static void
display_ext23 (guestfs_h *g, const char *dev, const char *fstype)
{
char **sbfields;
int i;
printf ("<fs type=\"%s\">\n", fstype);
CALL (sbfields = guestfs_tune2fs_l (g, dev), NULL);
for (i = 0; sbfields[i] != NULL; i += 2) {
/* Just pick out a few important fields to display. There
* is much more that could be displayed here.
*/
if (strcmp (sbfields[i], "Filesystem UUID") == 0)
printf ("<uuid>%s</uuid>\n", sbfields[i+1]);
else if (strcmp (sbfields[i], "Block size") == 0)
printf ("<blocksize>%s</blocksize>\n", sbfields[i+1]);
free (sbfields[i]);
free (sbfields[i+1]);
}
free (sbfields);
printf ("</fs>\n");
}
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