From d926f32560cb7996b6a5ec08545d946bf0594fe8 Mon Sep 17 00:00:00 2001

Message-Id: <d926f32560cb7996b6a5ec08545d946bf0594fe8@dist-git>

From: Peter Krempa <pkrempa@redhat.com>

Date: Fri, 28 Feb 2020 10:24:28 +0100

Subject: [PATCH] util: storagefile: Drop image format probing by file suffix

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Probing by file suffix was meant to be a last resort if probing by

contents fails or is not supported. For most formats we never specified

any suffix. There's a few formats implementing both magic bytes and

suffix and finally DMG which had only suffix probing. Since suffix

probing is nowhere reliable and only one format depends on in which has a

comment that qemu doesn't do the probing either drop the whole

infrastructure.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>

Reviewed-by: Eric Blake <eblake@redhat.com>

(cherry picked from commit 181fccc2ed67a79d462dfcf5b6fcfd2fbb1702b9)

https://bugzilla.redhat.com/show_bug.cgi?id=1798148

Message-Id: <113e583f0c032b616ea5c691fe36540ebb8e7c8f.1582881363.git.pkrempa@redhat.com>

Reviewed-by: Ján Tomko <jtomko@redhat.com>

---

 src/util/virstoragefile.c | 58 ++++++++++++---------------------------

 1 file changed, 17 insertions(+), 41 deletions(-)

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c

index fcbc97d96a..6b83fc0e24 100644

--- a/src/util/virstoragefile.c

+++ b/src/util/virstoragefile.c

@@ -146,12 +146,10 @@ struct FileEncryptionInfo {

     int payloadOffset; /* start offset of the volume data (in 512 byte sectors) */

 };

-/* Either 'magic' or 'extension' *must* be provided */

 struct FileTypeInfo {

     int magicOffset;    /* Byte offset of the magic */

     const char *magic;  /* Optional string of file magic

                          * to check at head of file */

-    const char *extension; /* Optional file extension to check */

     enum lv_endian endian; /* Endianness of file format */

     int versionOffset;    /* Byte offset from start of file

@@ -297,17 +295,17 @@ static struct FileEncryptionInfo const qcow2EncryptionInfo[] = {

 };

 static struct FileTypeInfo const fileTypeInfo[] = {

-    [VIR_STORAGE_FILE_NONE] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,

+    [VIR_STORAGE_FILE_NONE] = { 0, NULL, LV_LITTLE_ENDIAN,

                                 -1, 0, {0}, 0, 0, 0, NULL, NULL, NULL },

-    [VIR_STORAGE_FILE_RAW] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,

+    [VIR_STORAGE_FILE_RAW] = { 0, NULL, LV_LITTLE_ENDIAN,

                                -1, 0, {0}, 0, 0, 0,

                                luksEncryptionInfo,

                                NULL, NULL },

-    [VIR_STORAGE_FILE_DIR] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,

+    [VIR_STORAGE_FILE_DIR] = { 0, NULL, LV_LITTLE_ENDIAN,

                                -1, 0, {0}, 0, 0, 0, NULL, NULL, NULL },

     [VIR_STORAGE_FILE_BOCHS] = {

         /*"Bochs Virtual HD Image", */ /* Untested */

-        0, NULL, NULL,

+        0, NULL,

         LV_LITTLE_ENDIAN, 64, 4, {0x20000},

         32+16+16+4+4+4+4+4, 8, 1, NULL, NULL, NULL

     },

@@ -316,7 +314,7 @@ static struct FileTypeInfo const fileTypeInfo[] = {

            #V2.0 Format

            modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1

         */ /* Untested */

-        0, NULL, NULL,

+        0, NULL,

         LV_LITTLE_ENDIAN, -1, 0, {0},

         -1, 0, 0, NULL, NULL, NULL

     },

@@ -324,50 +322,50 @@ static struct FileTypeInfo const fileTypeInfo[] = {

         /* XXX QEMU says there's no magic for dmg,

          * /usr/share/misc/magic lists double magic (both offsets

          * would have to match) but then disables that check. */

-        0, NULL, ".dmg",

+        0, NULL,

         0, -1, 0, {0},

         -1, 0, 0, NULL, NULL, NULL

     },

     [VIR_STORAGE_FILE_ISO] = {

-        32769, "CD001", ".iso",

+        32769, "CD001",

         LV_LITTLE_ENDIAN, -2, 0, {0},

         -1, 0, 0, NULL, NULL, NULL

     },

     [VIR_STORAGE_FILE_VPC] = {

-        0, "conectix", NULL,

+        0, "conectix",

         LV_BIG_ENDIAN, 12, 4, {0x10000},

         8 + 4 + 4 + 8 + 4 + 4 + 2 + 2 + 4, 8, 1, NULL, NULL, NULL

     },

     /* TODO: add getBackingStore function */

     [VIR_STORAGE_FILE_VDI] = {

-        64, "\x7f\x10\xda\xbe", ".vdi",

+        64, "\x7f\x10\xda\xbe",

         LV_LITTLE_ENDIAN, 68, 4, {0x00010001},

         64 + 5 * 4 + 256 + 7 * 4, 8, 1, NULL, NULL, NULL},

     /* Not direct file formats, but used for various drivers */

-    [VIR_STORAGE_FILE_FAT] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,

+    [VIR_STORAGE_FILE_FAT] = { 0, NULL, LV_LITTLE_ENDIAN,

                                -1, 0, {0}, 0, 0, 0, NULL, NULL, NULL },

-    [VIR_STORAGE_FILE_VHD] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,

+    [VIR_STORAGE_FILE_VHD] = { 0, NULL, LV_LITTLE_ENDIAN,

                                -1, 0, {0}, 0, 0, 0, NULL, NULL, NULL },

-    [VIR_STORAGE_FILE_PLOOP] = { 0, "WithouFreSpacExt", NULL, LV_LITTLE_ENDIAN,

+    [VIR_STORAGE_FILE_PLOOP] = { 0, "WithouFreSpacExt", LV_LITTLE_ENDIAN,

                                  -2, 0, {0}, PLOOP_IMAGE_SIZE_OFFSET, 0,

                                  PLOOP_SIZE_MULTIPLIER, NULL, NULL, NULL },

     /* All formats with a backing store probe below here */

     [VIR_STORAGE_FILE_COW] = {

-        0, "OOOM", NULL,

+        0, "OOOM",

         LV_BIG_ENDIAN, 4, 4, {2},

         4+4+1024+4, 8, 1, NULL, cowGetBackingStore, NULL

     },

     [VIR_STORAGE_FILE_QCOW] = {

-        0, "QFI", NULL,

+        0, "QFI",

         LV_BIG_ENDIAN, 4, 4, {1},

         QCOWX_HDR_IMAGE_SIZE, 8, 1,

         qcow1EncryptionInfo,

         qcowXGetBackingStore, NULL

     },

     [VIR_STORAGE_FILE_QCOW2] = {

-        0, "QFI", NULL,

+        0, "QFI",

         LV_BIG_ENDIAN, 4, 4, {2, 3},

         QCOWX_HDR_IMAGE_SIZE, 8, 1,

         qcow2EncryptionInfo,

@@ -376,12 +374,12 @@ static struct FileTypeInfo const fileTypeInfo[] = {

     },

     [VIR_STORAGE_FILE_QED] = {

         /* https://wiki.qemu.org/Features/QED */

-        0, "QED", NULL,

+        0, "QED",

         LV_LITTLE_ENDIAN, -2, 0, {0},

         QED_HDR_IMAGE_SIZE, 8, 1, NULL, qedGetBackingStore, NULL

     },

     [VIR_STORAGE_FILE_VMDK] = {

-        0, "KDMV", NULL,

+        0, "KDMV",

         LV_LITTLE_ENDIAN, 4, 4, {1, 2, 3},

         4+4+4, 8, 512, NULL, vmdk4GetBackingStore, NULL

     },

@@ -707,20 +705,6 @@ virStorageFileMatchesMagic(int magicOffset,

 }

-static bool

-virStorageFileMatchesExtension(const char *extension,

-                               const char *path)

-{

-    if (extension == NULL)

-        return false;

-

-    if (virStringHasCaseSuffix(path, extension))

-        return true;

-

-    return false;

-}

-

-

 static bool

 virStorageFileMatchesVersion(int versionOffset,

                              int versionSize,

@@ -842,14 +826,6 @@ virStorageFileProbeFormatFromBuf(const char *path,

                  "Please report new version to libvir-list@redhat.com",

                  path, virStorageFileFormatTypeToString(possibleFormat));

-    /* No magic, so check file extension */

-    for (i = 0; i < VIR_STORAGE_FILE_LAST; i++) {

-        if (virStorageFileMatchesExtension(fileTypeInfo[i].extension, path)) {

-            format = i;

-            goto cleanup;

-        }

-    }

-

  cleanup:

     VIR_DEBUG("format=%d", format);

     return format;

-- 

2.25.1