[PATCH 13/19] util: Add 'luks' to the FileTypeInfo

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Add the ability to detect a luks encrypted device.

This also adding new 16 bit big/little endian macros since the
version of a luks device is stored in a uint16_t.

Signed-off-by: John Ferlan <jferlan@xxxxxxxxxx>
---
 src/util/virendian.h      | 24 ++++++++++++++++++++++++
 src/util/virstoragefile.c | 38 ++++++++++++++++++++++++++++++++------
 src/util/virstoragefile.h |  1 +
 tests/virendiantest.c     | 18 ++++++++++++++++++
 4 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/src/util/virendian.h b/src/util/virendian.h
index eefe48c..97940bd 100644
--- a/src/util/virendian.h
+++ b/src/util/virendian.h
@@ -90,4 +90,28 @@
      ((uint32_t)(uint8_t)((buf)[2]) << 16) |             \
      ((uint32_t)(uint8_t)((buf)[3]) << 24))
 
+/**
+ * virReadBufInt16BE:
+ * @buf: byte to start reading at (can be 'char*' or 'unsigned char*');
+ *       evaluating buf must not have any side effects
+ *
+ * Read 2 bytes at BUF as a big-endian 16-bit number.  Caller is
+ * responsible to avoid reading beyond array bounds.
+ */
+# define virReadBufInt16BE(buf)                          \
+    (((uint16_t)(uint8_t)((buf)[0]) << 8) |              \
+     (uint16_t)(uint8_t)((buf)[1]))
+
+/**
+ * virReadBufInt16LE:
+ * @buf: byte to start reading at (can be 'char*' or 'unsigned char*');
+ *       evaluating buf must not have any side effects
+ *
+ * Read 2 bytes at BUF as a little-endian 16-bit number.  Caller is
+ * responsible to avoid reading beyond array bounds.
+ */
+# define virReadBufInt16LE(buf)                          \
+    ((uint16_t)(uint8_t)((buf)[0]) |                     \
+     ((uint16_t)(uint8_t)((buf)[1]) << 8))
+
 #endif /* __VIR_ENDIAN_H__ */
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 5c2519c..f7a9632 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -63,7 +63,7 @@ VIR_ENUM_IMPL(virStorageFileFormat,
               "cloop", "dmg", "iso",
               "vpc", "vdi",
               /* Not direct file formats, but used for various drivers */
-              "fat", "vhd", "ploop",
+              "fat", "vhd", "ploop", "luks",
               /* Formats with backing file below here */
               "cow", "qcow", "qcow2", "qed", "vmdk")
 
@@ -113,7 +113,8 @@ enum {
 
 enum fi_crypt {
     FI_CRYPT_NONE = 0,
-    FI_CRYPT_QCOW
+    FI_CRYPT_QCOW,
+    FI_CRYPT_LUKS
 };
 
 #define FILE_TYPE_VERSIONS_LAST 2
@@ -193,6 +194,14 @@ qedGetBackingStore(char **, int *, const char *, size_t);
 #define PLOOP_IMAGE_SIZE_OFFSET 36
 #define PLOOP_SIZE_MULTIPLIER 512
 
+#define LUKS_HDR_MAGIC_LEN 6
+#define LUKS_HDR_VERSION_LEN 2
+
+/* Format described by qemu commit id '3e308f20e' */
+#define LUKS_HDR_VERSION_OFFSET LUKS_HDR_MAGIC_LEN
+#define LUKS_HDR_CRYPT_OFFSET LUKS_HDR_MAGIC_LEN + LUKS_HDR_VERSION_LEN
+
+
 static struct FileTypeInfo const fileTypeInfo[] = {
     [VIR_STORAGE_FILE_NONE] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
                                 -1, {0}, 0, 0, 0, FI_CRYPT_NONE, 0, NULL, NULL },
@@ -249,6 +258,13 @@ static struct FileTypeInfo const fileTypeInfo[] = {
                                  PLOOP_SIZE_MULTIPLIER,
                                  FI_CRYPT_NONE, -1, NULL, NULL },
 
+    /* Magic is 'L','U','K','S', 0xBA, 0xBE
+     * Set sizeOffset = -1 and let hypervisor handle */
+    [VIR_STORAGE_FILE_LUKS] = {
+        0, "\x4c\x55\x4b\x53\xba\xbe", NULL,
+        LV_BIG_ENDIAN, LUKS_HDR_VERSION_OFFSET, {1},
+        -1, 0, 0, FI_CRYPT_LUKS, LUKS_HDR_CRYPT_OFFSET, NULL, NULL
+    },
     /* All formats with a backing store probe below here */
     [VIR_STORAGE_FILE_COW] = {
         0, "OOOM", NULL,
@@ -634,7 +650,7 @@ virStorageFileMatchesVersion(int format,
                              char *buf,
                              size_t buflen)
 {
-    int version;
+    int version = 0;
     size_t i;
 
     /* Validate version number info */
@@ -648,10 +664,16 @@ virStorageFileMatchesVersion(int format,
     if ((fileTypeInfo[format].versionOffset + 4) > buflen)
         return false;
 
-    if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN)
+    if (fileTypeInfo[format].endian == LV_LITTLE_ENDIAN) {
         version = virReadBufInt32LE(buf + fileTypeInfo[format].versionOffset);
-    else
-        version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);
+    } else {
+        if (format == VIR_STORAGE_FILE_LUKS)
+            version = virReadBufInt16BE(buf +
+                                        fileTypeInfo[format].versionOffset);
+        else
+            version = virReadBufInt32BE(buf +
+                                        fileTypeInfo[format].versionOffset);
+    }
 
     for (i = 0;
          i < FILE_TYPE_VERSIONS_LAST && fileTypeInfo[format].versionNumbers[i];
@@ -832,6 +854,10 @@ virStorageFileGetMetadataInternal(virStorageSourcePtr meta,
         if (crypt_format && !meta->encryption &&
             VIR_ALLOC(meta->encryption) < 0)
             goto cleanup;
+    } else if (fileTypeInfo[meta->format].cryptType == FI_CRYPT_LUKS) {
+        /* By definition, this is encrypted */
+        if (!meta->encryption && VIR_ALLOC(meta->encryption) < 0)
+            goto cleanup;
     }
 
     VIR_FREE(meta->backingStoreRaw);
diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
index 9424fed..8d5c45a 100644
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@@ -74,6 +74,7 @@ typedef enum {
     VIR_STORAGE_FILE_FAT,
     VIR_STORAGE_FILE_VHD,
     VIR_STORAGE_FILE_PLOOP,
+    VIR_STORAGE_FILE_LUKS,
 
     /* Not a format, but a marker: all formats below this point have
      * libvirt support for following a backing chain */
diff --git a/tests/virendiantest.c b/tests/virendiantest.c
index 4072507..f858e5c 100644
--- a/tests/virendiantest.c
+++ b/tests/virendiantest.c
@@ -50,6 +50,15 @@ test1(const void *data ATTRIBUTE_UNUSED)
     if (virReadBufInt32LE(array + 9) != 0x8d8c8b8aU)
         goto cleanup;
 
+    if (virReadBufInt16BE(array) != 0x0102U)
+        goto cleanup;
+    if (virReadBufInt16BE(array + 11) != 0x8c8dU)
+        goto cleanup;
+    if (virReadBufInt16LE(array) != 0x0201U)
+        goto cleanup;
+    if (virReadBufInt16LE(array + 11) != 0x8d8cU)
+        goto cleanup;
+
     ret = 0;
  cleanup:
     return ret;
@@ -81,6 +90,15 @@ test2(const void *data ATTRIBUTE_UNUSED)
     if (virReadBufInt32LE(array + 9) != 0x8d8c8b8aU)
         goto cleanup;
 
+    if (virReadBufInt16BE(array) != 0x0102U)
+        goto cleanup;
+    if (virReadBufInt16BE(array + 11) != 0x8c8dU)
+        goto cleanup;
+    if (virReadBufInt16LE(array) != 0x0201U)
+        goto cleanup;
+    if (virReadBufInt16LE(array + 11) != 0x8d8cU)
+        goto cleanup;
+
     ret = 0;
  cleanup:
     return ret;
-- 
2.5.5

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list



[Index of Archives]     [Virt Tools]     [Libvirt Users]     [Lib OS Info]     [Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Big List of Linux Books]     [Yosemite News]     [KDE Users]     [Fedora Tools]