hw/virtio-9p-xattr-user.c

   1 /*
   2  * Virtio 9p user. xattr callback
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include <sys/types.h>
  15 #include "virtio.h"
  16 #include "virtio-9p.h"
  17 #include "file-op-9p.h"
  18 #include "virtio-9p-xattr.h"
  19
  20
  21 static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
  22                                 const char *name, void *value, size_t size)
  23 {
  24     if (strncmp(name, "user.virtfs.", 12) == 0) {
  25         /*
  26          * Don't allow fetch of user.virtfs namesapce
  27          * in case of mapped security
  28          */
  29         errno = ENOATTR;
  30         return -1;
  31     }
  32     return lgetxattr(rpath(ctx, path), name, value, size);
  33 }
  34
  35 static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
  36                                  char *name, void *value, size_t size)
  37 {
  38     int name_size = strlen(name) + 1;
  39     if (strncmp(name, "user.virtfs.", 12) == 0) {
  40
  41         /*  check if it is a mapped posix acl */
  42         if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
  43             /* adjust the name and size */
  44             name += 12;
  45             name_size -= 12;
  46         } else {
  47             /*
  48              * Don't allow fetch of user.virtfs namesapce
  49              * in case of mapped security
  50              */
  51             return 0;
  52         }
  53     }
  54     if (!value) {
  55         return name_size;
  56     }
  57
  58     if (size < name_size) {
  59         errno = ERANGE;
  60         return -1;
  61     }
  62
  63     strncpy(value, name, name_size);
  64     return name_size;
  65 }
  66
  67 static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
  68                             void *value, size_t size, int flags)
  69 {
  70     if (strncmp(name, "user.virtfs.", 12) == 0) {
  71         /*
  72          * Don't allow fetch of user.virtfs namesapce
  73          * in case of mapped security
  74          */
  75         errno = EACCES;
  76         return -1;
  77     }
  78     return lsetxattr(rpath(ctx, path), name, value, size, flags);
  79 }
  80
  81 static int mp_user_removexattr(FsContext *ctx,
  82                                const char *path, const char *name)
  83 {
  84     if (strncmp(name, "user.virtfs.", 12) == 0) {
  85         /*
  86          * Don't allow fetch of user.virtfs namesapce
  87          * in case of mapped security
  88          */
  89         errno = EACCES;
  90         return -1;
  91     }
  92     return lremovexattr(rpath(ctx, path), name);
  93 }
  94
  95 XattrOperations mapped_user_xattr = {
  96     .name = "user.",
  97     .getxattr = mp_user_getxattr,
  98     .setxattr = mp_user_setxattr,
  99     .listxattr = mp_user_listxattr,
 100     .removexattr = mp_user_removexattr,
 101 };
 102
 103 XattrOperations passthrough_user_xattr = {
 104     .name = "user.",
 105     .getxattr = pt_getxattr,
 106     .setxattr = pt_setxattr,
 107     .listxattr = pt_listxattr,
 108     .removexattr = pt_removexattr,
 109 };