Changeset 9e3dc95 in mainline

Timestamp:

2011-03-01T22:10:16Z (14 years ago)

Author:

Maurizio Lombardi <m.lombardi85@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

9a9a58e

Parents:

819450a

Message:

check superblock magic numbers

Location:

uspace/srv/fs/minixfs

Files:

• Makefile (modified) (1 diff)
• mfs_const.h (modified) (1 diff)
• mfs_super.c (modified) (3 diffs)
• mfs_super.h (modified) (2 diffs)
• mfs_utils.c (modified) (1 diff)

uspace/srv/fs/minixfs/Makefile

@@ -34 +34 @@
 
 SOURCES = \
-        mfs.c
+        mfs.c \
+        mfs_super.c \
+        mfs_utils.c
 
 include $(USPACE_PREFIX)/Makefile.common

uspace/srv/fs/minixfs/mfs_const.h

@@ -38 +38 @@
 #include <bool.h>
 
-#define MFS_MAGIC_V1            0x137F
-#define MFS_MAGIC_V2            0x2468
-#define MFS_MAGIC_V3            0x4D5A
-
 #define MFS_ROOT_INO            1
 #define MFS_SUPER_BLOCK         0

uspace/srv/fs/minixfs/mfs_super.c

@@ -31 +31 @@
  */
 
+#include <libfs.h>
+#include <stdlib.h>
+#include <libblock.h>
+#include <errno.h>
+#include <str.h>
 #include "mfs_super.h"
+#include "mfs_utils.h"
+#include "../../vfs/vfs.h"
+
+static bool check_magic_number(int16_t magic, bool *native, mfs_version_t *version);
 
 void mfs_mounted(ipc_callid_t rid, ipc_call_t *request)
@@ -38 +47 @@
         enum cache_mode cmode;  
         struct mfs_superblock *sp;
+        bool native;
+        mfs_version_t version;
 
         /* Accept the mount options */
@@ -73 +84 @@
         /* get the buffer with the superblock */
         sp = block_bb_get(devmap_handle);
+
+        if (!check_magic_number(sp->s_magic, &native, &version)) {
+                /*Magic number is invalid!*/
+                block_fini(devmap_handle);
+                async_answer_0(rid, ENOTSUP);
+                return;
+        }
+}
+
+static bool check_magic_number(int16_t magic, bool *native, mfs_version_t *version)
+{
+        *native = true;
+
+repeat_check:
+
+        switch (*native ? magic : conv16(false, magic)) {
+        case MFS_MAGIC_V1:
+                *version = MFS_VERSION_V1;
+                return true;
+        case MFS_MAGIC_V2:
+                *version = MFS_VERSION_V2;
+                return true;
+        case MFS_MAGIC_V3:
+                *version = MFS_VERSION_V3;
+                return true;
+        default:
+                ;
+        }
+
+        if (*native) {
+                *native = false;
+                goto repeat_check;
+        } else {
+                return false;
+        }
+
+        /*Should never happens*/
+        return false;
 }
 

uspace/srv/fs/minixfs/mfs_super.h

@@ -37 +37 @@
 #include "../../vfs/vfs.h"
 
+#define MFS_MAGIC_V1            0x137F
+#define MFS_MAGIC_V2            0x2468
+#define MFS_MAGIC_V3            0x4D5A
+
 struct mfs_superblock {
         /*Total number of inodes on the device*/
@@ -67 +71 @@
 } __attribute__ ((packed));
 
+typedef enum {
+        MFS_VERSION_V1 = 1,
+        MFS_VERSION_V2,
+        MFS_VERSION_V3
+} mfs_version_t;
+
 void mfs_mounted(ipc_callid_t rid, ipc_call_t *request);
 

uspace/srv/fs/minixfs/mfs_utils.c

@@ -38 +38 @@
                 return n;
 
-        return r = (n << 8) | (n >> 8);
+        return (n << 8) | (n >> 8);
 }