[Libguestfs] [PATCH] inspect: get windows drive letters for GPT disks.
Richard W.M. Jones
rjones at redhat.com
Fri Feb 5 18:08:59 UTC 2016
On Fri, Feb 05, 2016 at 12:15:32PM -0500, Dawid Zamirski wrote:
> This patch updates the guestfs_inspect_get_drive_mappings API call to
> also return drive letters for GPT paritions. Previously this worked
> only for MBR partitions. This is achieved by matching the GPT partition
> GUID with the info stored in the blob from
> HKLM\SYSTEM\MountedDevices\DosDevices keys. For GPT partions this blob
> contains a "DMIO:ID:" prefix followed by a 16 byte binary GUID.
> ---
> src/inspect-fs-windows.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 96 insertions(+), 2 deletions(-)
Attached is a patch with some stylistic updates. Please combine it
with your patch. More comments below.
> diff --git a/src/inspect-fs-windows.c b/src/inspect-fs-windows.c
> index ccf5cba..6571d37 100644
> --- a/src/inspect-fs-windows.c
> +++ b/src/inspect-fs-windows.c
> @@ -25,6 +25,7 @@
> #include <string.h>
> #include <errno.h>
> #include <iconv.h>
> +#include <inttypes.h>
>
> #ifdef HAVE_ENDIAN_H
> #include <endian.h>
> @@ -57,6 +58,8 @@ static int check_windows_arch (guestfs_h *g, struct inspect_fs *fs);
> static int check_windows_software_registry (guestfs_h *g, struct inspect_fs *fs);
> static int check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs);
> static char *map_registry_disk_blob (guestfs_h *g, const void *blob);
> +static char *map_registry_disk_blob_gpt(guestfs_h *g, const void *blob);
> +static char *extract_guid_from_registry_blob(guestfs_h *g, const void *blob);
>
> /* XXX Handling of boot.ini in the Perl version was pretty broken. It
> * essentially didn't do anything for modern Windows guests.
> @@ -386,6 +389,7 @@ check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs)
> int r;
> size_t len = strlen (fs->windows_systemroot) + 64;
> char system[len];
> + char gpt_prefix[] = "DMIO:ID:";
> snprintf (system, len, "%s/system32/config/system",
> fs->windows_systemroot);
>
> @@ -493,9 +497,14 @@ check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs)
>
> type = guestfs_hivex_value_type (g, v);
> blob = guestfs_hivex_value_value (g, v, &len);
> - if (blob != NULL && type == 3 && len == 12) {
> + bool is_gpt = memcmp(blob, gpt_prefix, 8) == 0;
> + if (blob != NULL && type == 3 && (len == 12 || is_gpt)) {
> /* Try to map the blob to a known disk and partition. */
> - device = map_registry_disk_blob (g, blob);
> + if (is_gpt)
> + device = map_registry_disk_blob_gpt (g, blob);
> + else
> + device = map_registry_disk_blob (g, blob);
> +
> if (device != NULL) {
> fs->drive_mappings[count++] = safe_strndup (g, &key[12], 1);
> fs->drive_mappings[count++] = device;
> @@ -605,6 +614,91 @@ map_registry_disk_blob (guestfs_h *g, const void *blob)
> return safe_asprintf (g, "%s%d", devices[i], partitions->val[j].part_num);
> }
>
> +/* Matches Windows registry HKLM\SYSYTEM\MountedDevices\DosDevices blob to
> + * to libguestfs GPT partition device. For GPT disks, the blob is made of
> + * "DMIO:ID:" prefix followed by the GPT parition GUID.
> + */
> +static char *
> +map_registry_disk_blob_gpt (guestfs_h *g, const void *blob)
> +{
> + CLEANUP_FREE_STRING_LIST char **fses = NULL;
> + size_t i;
> +
> + fses = guestfs_list_filesystems (g);
> + if (fses == NULL)
> + return NULL;
Did you really mean to call guestfs_list_filesystems here? If you're
trying to get the list of partitions, then guestfs_list_partitions is
what you should be calling.
> + for (i = 0; fses[i] != NULL; i += 2) {
> + CLEANUP_FREE char *fs_guid = NULL;
> + CLEANUP_FREE char *blob_guid = NULL;
> + CLEANUP_FREE char *fs_dev = NULL;
> +
> + fs_dev = guestfs_canonical_device_name (g, fses[i]);
> +
> + if (fs_dev == NULL)
> + continue;
> +
> + int partnum = guestfs_part_to_partnum (g, fs_dev);
Need to check that partnum != -1 and do something.
> + CLEANUP_FREE char *device = guestfs_part_to_dev (g, fs_dev);
> + CLEANUP_FREE char *type = guestfs_part_get_parttype (g, device);
> +
> + if (STRCASENEQ(type, "gpt"))
> + continue;
> +
> + /* get the GPT parition GUID from the partition block device */
> + fs_guid = guestfs_part_get_gpt_guid (g, device, partnum);
> +
> + if (fs_guid == NULL)
> + continue;
> +
> + /* extract the GUID from the Windows registry blob */
> + blob_guid = extract_guid_from_registry_blob (g, blob);
> +
> + /* if both GUIDs match, we have found mapping for out device */
> + if (STRCASEEQ (fs_guid, blob_guid))
> + return safe_strdup (g, fs_dev);
> + }
> +
> + return NULL;
> +}
> +
> +/* Extracts the binary GUID stored in blob from Windows registry
> + * HKLM\SYSTYEM\MountedDevices\DosDevices value and converts it to a GUID string
> + * so that it can be matched against libguestfs partition device GPT GUID.
> + */
> +static char *
> +extract_guid_from_registry_blob (guestfs_h *g, const void *blob)
> +{
> + char guid_bytes[16];
> + size_t len = 37;
> + uint32_t data1;
> + uint16_t data2, data3;
> + uint64_t data4;
> +
> + char *guid = (char *) safe_calloc(g, len, sizeof (char * ));
> +
> + /* get the GUID bytes from blob (skip 8 byte "DMIO:ID:" prefix) */
> + memcpy (&guid_bytes, (char *) blob + 8, sizeof (guid_bytes));
> +
> + /* copy relevant sections from blob to respective ints */
> + memcpy (&data1, guid_bytes, sizeof (data1));
> + memcpy (&data2, guid_bytes + 4, sizeof (data2));
> + memcpy (&data3, guid_bytes + 6, sizeof (data3));
> + memcpy (&data4, guid_bytes + 8, sizeof (data4));
> +
> + /* ensure proper endianness */
> + data1 = htole32 (data1);
Did you mean to use htole32? Surely it should be le32toh?
> + data2 = htole16 (data2);
> + data3 = htole16 (data3);
> + data4 = htobe64 (data4);
And is this really big endian?
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages. http://libguestfs.org
-------------- next part --------------
>From 9bc43ef03944b6b2e1dfe0f7306a30e61a3f339d Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones at redhat.com>
Date: Fri, 5 Feb 2016 18:02:16 +0000
Subject: [PATCH] Update styles
---
src/inspect-fs-windows.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/src/inspect-fs-windows.c b/src/inspect-fs-windows.c
index 6571d37..48670ce 100644
--- a/src/inspect-fs-windows.c
+++ b/src/inspect-fs-windows.c
@@ -58,8 +58,8 @@ static int check_windows_arch (guestfs_h *g, struct inspect_fs *fs);
static int check_windows_software_registry (guestfs_h *g, struct inspect_fs *fs);
static int check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs);
static char *map_registry_disk_blob (guestfs_h *g, const void *blob);
-static char *map_registry_disk_blob_gpt(guestfs_h *g, const void *blob);
-static char *extract_guid_from_registry_blob(guestfs_h *g, const void *blob);
+static char *map_registry_disk_blob_gpt (guestfs_h *g, const void *blob);
+static char *extract_guid_from_registry_blob (guestfs_h *g, const void *blob);
/* XXX Handling of boot.ini in the Perl version was pretty broken. It
* essentially didn't do anything for modern Windows guests.
@@ -494,10 +494,11 @@ check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs)
CLEANUP_FREE char *blob = NULL;
char *device;
int64_t type;
+ bool is_gpt;
type = guestfs_hivex_value_type (g, v);
blob = guestfs_hivex_value_value (g, v, &len);
- bool is_gpt = memcmp(blob, gpt_prefix, 8) == 0;
+ is_gpt = memcmp (blob, gpt_prefix, 8) == 0;
if (blob != NULL && type == 3 && (len == 12 || is_gpt)) {
/* Try to map the blob to a known disk and partition. */
if (is_gpt)
@@ -616,7 +617,7 @@ map_registry_disk_blob (guestfs_h *g, const void *blob)
/* Matches Windows registry HKLM\SYSYTEM\MountedDevices\DosDevices blob to
* to libguestfs GPT partition device. For GPT disks, the blob is made of
- * "DMIO:ID:" prefix followed by the GPT parition GUID.
+ * "DMIO:ID:" prefix followed by the GPT partition GUID.
*/
static char *
map_registry_disk_blob_gpt (guestfs_h *g, const void *blob)
@@ -632,22 +633,25 @@ map_registry_disk_blob_gpt (guestfs_h *g, const void *blob)
CLEANUP_FREE char *fs_guid = NULL;
CLEANUP_FREE char *blob_guid = NULL;
CLEANUP_FREE char *fs_dev = NULL;
+ int partnum;
+ CLEANUP_FREE char *device = NULL;
+ CLEANUP_FREE char *type = NULL;
fs_dev = guestfs_canonical_device_name (g, fses[i]);
if (fs_dev == NULL)
continue;
- int partnum = guestfs_part_to_partnum (g, fs_dev);
- CLEANUP_FREE char *device = guestfs_part_to_dev (g, fs_dev);
- CLEANUP_FREE char *type = guestfs_part_get_parttype (g, device);
+ partnum = guestfs_part_to_partnum (g, fs_dev);
+ device = guestfs_part_to_dev (g, fs_dev);
+ type = guestfs_part_get_parttype (g, device);
- if (STRCASENEQ(type, "gpt"))
+ if (STRCASENEQ (type, "gpt"))
continue;
/* get the GPT parition GUID from the partition block device */
fs_guid = guestfs_part_get_gpt_guid (g, device, partnum);
-
+
if (fs_guid == NULL)
continue;
@@ -662,21 +666,19 @@ map_registry_disk_blob_gpt (guestfs_h *g, const void *blob)
return NULL;
}
-/* Extracts the binary GUID stored in blob from Windows registry
- * HKLM\SYSTYEM\MountedDevices\DosDevices value and converts it to a GUID string
- * so that it can be matched against libguestfs partition device GPT GUID.
+/* Extracts the binary GUID stored in blob from Windows registry
+ * HKLM\SYSTYEM\MountedDevices\DosDevices value and converts it to a
+ * GUID string so that it can be matched against libguestfs partition
+ * device GPT GUID.
*/
static char *
extract_guid_from_registry_blob (guestfs_h *g, const void *blob)
{
char guid_bytes[16];
- size_t len = 37;
uint32_t data1;
uint16_t data2, data3;
uint64_t data4;
- char *guid = (char *) safe_calloc(g, len, sizeof (char * ));
-
/* get the GUID bytes from blob (skip 8 byte "DMIO:ID:" prefix) */
memcpy (&guid_bytes, (char *) blob + 8, sizeof (guid_bytes));
@@ -689,14 +691,12 @@ extract_guid_from_registry_blob (guestfs_h *g, const void *blob)
/* ensure proper endianness */
data1 = htole32 (data1);
data2 = htole16 (data2);
- data3 = htole16 (data3);
+ data3 = htole16 (data3);
data4 = htobe64 (data4);
- snprintf (guid, len,
+ return safe_asprintf (g,
"%08" PRIX32 "-%04" PRIX16 "-%04" PRIX16 "-%04" PRIX64 "-%06" PRIX64,
data1, data2, data3, (data4 >> 48), (data4 << 16));
-
- return guid;
}
/* NB: This function DOES NOT test for the existence of the file. It
--
2.5.0
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