qemu/hw/9pfs/virtio-9p-xattr.h
Chen Gang 4fa4ce7107 hw/9pfs: use g_strdup_printf() instead of PATH_MAX limitation
When path is truncated by PATH_MAX limitation, it causes QEMU to access
incorrect file. So use original full path instead of PATH_MAX within
9pfs (need check/process ENOMEM for related memory allocation).

The related test:

 - Environments (for qemu-devel):

   - Host is under fedora17 desktop with ext4fs:

     qemu-system-x86_64 -hda test.img -m 1024 \
       -net nic,vlan=4,model=virtio,macaddr=00:16:35:AF:94:04 \
       -net tap,vlan=4,ifname=tap4,script=no,downscript=no \
       -device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=hostshare \
       -fsdev local,security_model=passthrough,id=fsdev0,\
         path=/upstream/vm/data/share/1234567890abcdefghijklmnopqrstuvwxyz\
           ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmnopqrstuvwxyz\
           ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111111111\
           1111111111111111111111111111111111111111111111111111222222222222\
           2222222222222222222222222222222222222222222222222222222222222222\
           2222222222222222222222222222222222233333333333333333333333333333\
           3333333333333333333333333333333333

    - Guest is ubuntu12 server with 9pfs.

      mount -t 9p -o trans=virtio,version=9p2000.L hostshare /share

    - Limitations:

      full path limitation is PATH_MAX (4096B include nul) under Linux.
      file/dir node name maximized length is 256 (include nul) under ext4.

 - Special test:

    Under host, modify the file: "/upstream/vm/data/share/1234567890abcdefg\
      hijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890acdefghijklmno\
      pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890/111111111111111111111\
      111111111111111111111111111111111111111111111111111111111122222222222\
      222222222222222222222222222222222222222222222222222222222222222222222\
      222222222222222222222222222222233333333333333333333333333333333333333\
      3333333333333333333333333/4444444444444444444444444444444444444444444\
      444444444444444444444444444444444444444444444444444444444444444444444\
      444444444444444444444444444444444444444444444444444444444444444444444\
      444444444444444444444444444444444444444/55555555555555555555555555555\
      555555555555555555555555555555555555555555555555555555555555555555555\
      555555555555555555555555555555555555555555555555555555555555555555555\
      555555555555555555555555555555555555555555555555555555555555555555555\
      55555555/666666666666666666666666666666666666666666666666666666666666\
      666666666666666666666666666666666666666666666666666666666666666666666\
      666666666666666666666666666666666666666666666666666666666666666666666\
      666666666666666666666/77777777777777777777777777777777777777777777777\
      777777777777777777777777777777777777777777777777777777777777777777777\
      777777777777777777777777777777777777777777777777777777777777777777777\
      77777777777777777777777777777777777777777777777777777777777/888888888\
      888888888888888888888888888888888888888888888888888888888888888888888\
      888888888888888888888888888888888888888888888888888888888888888888888\
      888888888888888888888888888888888888888888888888888888888888888888888\
      888888888/99999999999999999999999999999999999999999999999999999999999\
      999999999999999999999999999999999999999999999999999999999999999999999\
      999999999999999999999999999999999999999999999999999999999999999999999\
      99999999999999999999999999999999999999999/000000000000000000000000000\
      000000000000000000000000000000000000000000000000000000000000000000000\
      000000000000000000000000000000000000000000000000000000000000000000000\
      000000000000000000000000000000000000000000000000/aaaaaaaaaaaaaaaaaaaa\
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\
      aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbb\
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\
      bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/ccccccccc\
      ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
      ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
      ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc\
      cccccccccc/dddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
      ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
      ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd\
      dddddddddddddddddddddd/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\
      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee/fffffffffffffff\
      fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\
      fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff\
      ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff/gggggggggg\
      ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
      ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
      ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg\
      ggggggggggggggggggggggg/iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
      iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
      iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\
      iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii/jjjjjjjjjjjjj\
      jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj\
      jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj/ppppppppppppppppppppp\
      ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp\
      ppppppppppppppppppppppppppppppppppppppp/test1234567890file.log"
        (need enter dir firstly, then modify file, or can not open it).

   Under guest, still allow modify "test1234567890file.log" (will generate
   "test123456" file with contents).

   After apply this patch, can not open "test1234567890file.log" under guest
   (permission denied).

 - Common test:

   All are still OK after apply this path.

     "mkdir -p", "create/open file/dir", "modify file/dir", "rm file/dir".
     change various mount point paths under host and/or guest.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2014-03-04 00:57:57 +05:30

121 lines
3.5 KiB
C

/*
* Virtio 9p
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef _QEMU_VIRTIO_9P_XATTR_H
#define _QEMU_VIRTIO_9P_XATTR_H
#include "qemu/xattr.h"
typedef struct xattr_operations
{
const char *name;
ssize_t (*getxattr)(FsContext *ctx, const char *path,
const char *name, void *value, size_t size);
ssize_t (*listxattr)(FsContext *ctx, const char *path,
char *name, void *value, size_t size);
int (*setxattr)(FsContext *ctx, const char *path, const char *name,
void *value, size_t size, int flags);
int (*removexattr)(FsContext *ctx,
const char *path, const char *name);
} XattrOperations;
extern XattrOperations mapped_user_xattr;
extern XattrOperations passthrough_user_xattr;
extern XattrOperations mapped_pacl_xattr;
extern XattrOperations mapped_dacl_xattr;
extern XattrOperations passthrough_acl_xattr;
extern XattrOperations none_acl_xattr;
extern XattrOperations *mapped_xattr_ops[];
extern XattrOperations *passthrough_xattr_ops[];
extern XattrOperations *none_xattr_ops[];
ssize_t v9fs_get_xattr(FsContext *ctx, const char *path, const char *name,
void *value, size_t size);
ssize_t v9fs_list_xattr(FsContext *ctx, const char *path, void *value,
size_t vsize);
int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name,
void *value, size_t size, int flags);
int v9fs_remove_xattr(FsContext *ctx, const char *path, const char *name);
ssize_t pt_listxattr(FsContext *ctx, const char *path, char *name, void *value,
size_t size);
static inline ssize_t pt_getxattr(FsContext *ctx, const char *path,
const char *name, void *value, size_t size)
{
char *buffer;
ssize_t ret;
buffer = rpath(ctx, path);
ret = lgetxattr(buffer, name, value, size);
g_free(buffer);
return ret;
}
static inline int pt_setxattr(FsContext *ctx, const char *path,
const char *name, void *value,
size_t size, int flags)
{
char *buffer;
int ret;
buffer = rpath(ctx, path);
ret = lsetxattr(buffer, name, value, size, flags);
g_free(buffer);
return ret;
}
static inline int pt_removexattr(FsContext *ctx,
const char *path, const char *name)
{
char *buffer;
int ret;
buffer = rpath(ctx, path);
ret = lremovexattr(path, name);
g_free(buffer);
return ret;
}
static inline ssize_t notsup_getxattr(FsContext *ctx, const char *path,
const char *name, void *value,
size_t size)
{
errno = ENOTSUP;
return -1;
}
static inline int notsup_setxattr(FsContext *ctx, const char *path,
const char *name, void *value,
size_t size, int flags)
{
errno = ENOTSUP;
return -1;
}
static inline ssize_t notsup_listxattr(FsContext *ctx, const char *path,
char *name, void *value, size_t size)
{
return 0;
}
static inline int notsup_removexattr(FsContext *ctx,
const char *path, const char *name)
{
errno = ENOTSUP;
return -1;
}
#endif