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

   1 /*
   2  * 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 "qemu/osdep.h"
  15 #include "9p.h"
  16 #include "fsdev/file-op-9p.h"
  17 #include "9p-xattr.h"
  18
  19
  20 static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
  21                                 const char *name, void *value, size_t size)
  22 {
  23     char *buffer;
  24     ssize_t ret;
  25
  26     if (strncmp(name, "user.virtfs.", 12) == 0) {
  27         /*
  28          * Don't allow fetch of user.virtfs namesapce
  29          * in case of mapped security
  30          */
  31         errno = ENOATTR;
  32         return -1;
  33     }
  34     buffer = rpath(ctx, path);
  35     ret = lgetxattr(buffer, name, value, size);
  36     g_free(buffer);
  37     return ret;
  38 }
  39
  40 static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
  41                                  char *name, void *value, size_t size)
  42 {
  43     int name_size = strlen(name) + 1;
  44     if (strncmp(name, "user.virtfs.", 12) == 0) {
  45
  46         /*  check if it is a mapped posix acl */
  47         if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
  48             /* adjust the name and size */
  49             name += 12;
  50             name_size -= 12;
  51         } else {
  52             /*
  53              * Don't allow fetch of user.virtfs namesapce
  54              * in case of mapped security
  55              */
  56             return 0;
  57         }
  58     }
  59     if (!value) {
  60         return name_size;
  61     }
  62
  63     if (size < name_size) {
  64         errno = ERANGE;
  65         return -1;
  66     }
  67
  68     /* name_size includes the trailing NUL. */
  69     memcpy(value, name, name_size);
  70     return name_size;
  71 }
  72
  73 static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
  74                             void *value, size_t size, int flags)
  75 {
  76     char *buffer;
  77     int ret;
  78
  79     if (strncmp(name, "user.virtfs.", 12) == 0) {
  80         /*
  81          * Don't allow fetch of user.virtfs namesapce
  82          * in case of mapped security
  83          */
  84         errno = EACCES;
  85         return -1;
  86     }
  87     buffer = rpath(ctx, path);
  88     ret = lsetxattr(buffer, name, value, size, flags);
  89     g_free(buffer);
  90     return ret;
  91 }
  92
  93 static int mp_user_removexattr(FsContext *ctx,
  94                                const char *path, const char *name)
  95 {
  96     char *buffer;
  97     int ret;
  98
  99     if (strncmp(name, "user.virtfs.", 12) == 0) {
 100         /*
 101          * Don't allow fetch of user.virtfs namesapce
 102          * in case of mapped security
 103          */
 104         errno = EACCES;
 105         return -1;
 106     }
 107     buffer = rpath(ctx, path);
 108     ret = lremovexattr(buffer, name);
 109     g_free(buffer);
 110     return ret;
 111 }
 112
 113 XattrOperations mapped_user_xattr = {
 114     .name = "user.",
 115     .getxattr = mp_user_getxattr,
 116     .setxattr = mp_user_setxattr,
 117     .listxattr = mp_user_listxattr,
 118     .removexattr = mp_user_removexattr,
 119 };
 120
 121 XattrOperations passthrough_user_xattr = {
 122     .name = "user.",
 123     .getxattr = pt_getxattr,
 124     .setxattr = pt_setxattr,
 125     .listxattr = pt_listxattr,
 126     .removexattr = pt_removexattr,
 127 };