hw/9pfs/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 "hw/virtio/virtio.h"
  16 #include "virtio-9p.h"
  17 #include "fsdev/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     char *buffer;
  25     ssize_t ret;
  26
  27     if (strncmp(name, "user.virtfs.", 12) == 0) {
  28         /*
  29          * Don't allow fetch of user.virtfs namesapce
  30          * in case of mapped security
  31          */
  32         errno = ENOATTR;
  33         return -1;
  34     }
  35     buffer = rpath(ctx, path);
  36     ret = lgetxattr(buffer, name, value, size);
  37     g_free(buffer);
  38     return ret;
  39 }
  40
  41 static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
  42                                  char *name, void *value, size_t size)
  43 {
  44     int name_size = strlen(name) + 1;
  45     if (strncmp(name, "user.virtfs.", 12) == 0) {
  46
  47         /*  check if it is a mapped posix acl */
  48         if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
  49             /* adjust the name and size */
  50             name += 12;
  51             name_size -= 12;
  52         } else {
  53             /*
  54              * Don't allow fetch of user.virtfs namesapce
  55              * in case of mapped security
  56              */
  57             return 0;
  58         }
  59     }
  60     if (!value) {
  61         return name_size;
  62     }
  63
  64     if (size < name_size) {
  65         errno = ERANGE;
  66         return -1;
  67     }
  68
  69     /* name_size includes the trailing NUL. */
  70     memcpy(value, name, name_size);
  71     return name_size;
  72 }
  73
  74 static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
  75                             void *value, size_t size, int flags)
  76 {
  77     char *buffer;
  78     int ret;
  79
  80     if (strncmp(name, "user.virtfs.", 12) == 0) {
  81         /*
  82          * Don't allow fetch of user.virtfs namesapce
  83          * in case of mapped security
  84          */
  85         errno = EACCES;
  86         return -1;
  87     }
  88     buffer = rpath(ctx, path);
  89     ret = lsetxattr(buffer, name, value, size, flags);
  90     g_free(buffer);
  91     return ret;
  92 }
  93
  94 static int mp_user_removexattr(FsContext *ctx,
  95                                const char *path, const char *name)
  96 {
  97     char *buffer;
  98     int ret;
  99
 100     if (strncmp(name, "user.virtfs.", 12) == 0) {
 101         /*
 102          * Don't allow fetch of user.virtfs namesapce
 103          * in case of mapped security
 104          */
 105         errno = EACCES;
 106         return -1;
 107     }
 108     buffer = rpath(ctx, path);
 109     ret = lremovexattr(buffer, name);
 110     g_free(buffer);
 111     return ret;
 112 }
 113
 114 XattrOperations mapped_user_xattr = {
 115     .name = "user.",
 116     .getxattr = mp_user_getxattr,
 117     .setxattr = mp_user_setxattr,
 118     .listxattr = mp_user_listxattr,
 119     .removexattr = mp_user_removexattr,
 120 };
 121
 122 XattrOperations passthrough_user_xattr = {
 123     .name = "user.",
 124     .getxattr = pt_getxattr,
 125     .setxattr = pt_setxattr,
 126     .listxattr = pt_listxattr,
 127     .removexattr = pt_removexattr,
 128 };