LXR qemu/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
  20static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
  21                                const char *name, void *value, size_t size)
  22{
  23    if (strncmp(name, "user.virtfs.", 12) == 0) {
  24        /*
  25         * Don't allow fetch of user.virtfs namesapce
  26         * in case of mapped security
  27         */
  28        errno = ENOATTR;
  29        return -1;
  30    }
  31    return local_getxattr_nofollow(ctx, path, name, value, size);
  32}
  33
  34static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
  35                                 char *name, void *value, size_t size)
  36{
  37    int name_size = strlen(name) + 1;
  38    if (strncmp(name, "user.virtfs.", 12) == 0) {
  39
  40        /*  check if it is a mapped posix acl */
  41        if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
  42            /* adjust the name and size */
  43            name += 12;
  44            name_size -= 12;
  45        } else {
  46            /*
  47             * Don't allow fetch of user.virtfs namesapce
  48             * in case of mapped security
  49             */
  50            return 0;
  51        }
  52    }
  53    if (!value) {
  54        return name_size;
  55    }
  56
  57    if (size < name_size) {
  58        errno = ERANGE;
  59        return -1;
  60    }
  61
  62    /* name_size includes the trailing NUL. */
  63    memcpy(value, name, name_size);
  64    return name_size;
  65}
  66
  67static 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 local_setxattr_nofollow(ctx, path, name, value, size, flags);
  79}
  80
  81static 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 local_removexattr_nofollow(ctx, path, name);
  93}
  94
  95XattrOperations 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
 103XattrOperations passthrough_user_xattr = {
 104    .name = "user.",
 105    .getxattr = pt_getxattr,
 106    .setxattr = pt_setxattr,
 107    .listxattr = pt_listxattr,
 108    .removexattr = pt_removexattr,
 109};
 110