LXR qemu/hw/9pfs/9p-posix-acl.c

   1/*
   2 * 9p system.posix* 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 "qemu/xattr.h"
  16#include "9p.h"
  17#include "fsdev/file-op-9p.h"
  18#include "9p-xattr.h"
  19
  20#define MAP_ACL_ACCESS "user.virtfs.system.posix_acl_access"
  21#define MAP_ACL_DEFAULT "user.virtfs.system.posix_acl_default"
  22#define ACL_ACCESS "system.posix_acl_access"
  23#define ACL_DEFAULT "system.posix_acl_default"
  24
  25static ssize_t mp_pacl_getxattr(FsContext *ctx, const char *path,
  26                                const char *name, void *value, size_t size)
  27{
  28    return local_getxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size);
  29}
  30
  31static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
  32                                 char *name, void *value, size_t osize)
  33{
  34    ssize_t len = sizeof(ACL_ACCESS);
  35
  36    if (!value) {
  37        return len;
  38    }
  39
  40    if (osize < len) {
  41        errno = ERANGE;
  42        return -1;
  43    }
  44
  45    /* len includes the trailing NUL */
  46    memcpy(value, ACL_ACCESS, len);
  47    return 0;
  48}
  49
  50static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
  51                            void *value, size_t size, int flags)
  52{
  53    return local_setxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size,
  54                                   flags);
  55}
  56
  57static int mp_pacl_removexattr(FsContext *ctx,
  58                               const char *path, const char *name)
  59{
  60    int ret;
  61
  62    ret = local_removexattr_nofollow(ctx, path, MAP_ACL_ACCESS);
  63    if (ret == -1 && errno == ENODATA) {
  64        /*
  65         * We don't get ENODATA error when trying to remove a
  66         * posix acl that is not present. So don't throw the error
  67         * even in case of mapped security model
  68         */
  69        errno = 0;
  70        ret = 0;
  71    }
  72    return ret;
  73}
  74
  75static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
  76                                const char *name, void *value, size_t size)
  77{
  78    return local_getxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size);
  79}
  80
  81static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
  82                                 char *name, void *value, size_t osize)
  83{
  84    ssize_t len = sizeof(ACL_DEFAULT);
  85
  86    if (!value) {
  87        return len;
  88    }
  89
  90    if (osize < len) {
  91        errno = ERANGE;
  92        return -1;
  93    }
  94
  95    /* len includes the trailing NUL */
  96    memcpy(value, ACL_DEFAULT, len);
  97    return 0;
  98}
  99
 100static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
 101                            void *value, size_t size, int flags)
 102{
 103    return local_setxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size,
 104                                   flags);
 105}
 106
 107static int mp_dacl_removexattr(FsContext *ctx,
 108                               const char *path, const char *name)
 109{
 110    int ret;
 111
 112    ret = local_removexattr_nofollow(ctx, path, MAP_ACL_DEFAULT);
 113    if (ret == -1 && errno == ENODATA) {
 114        /*
 115         * We don't get ENODATA error when trying to remove a
 116         * posix acl that is not present. So don't throw the error
 117         * even in case of mapped security model
 118         */
 119        errno = 0;
 120        ret = 0;
 121    }
 122    return ret;
 123}
 124
 125
 126XattrOperations mapped_pacl_xattr = {
 127    .name = "system.posix_acl_access",
 128    .getxattr = mp_pacl_getxattr,
 129    .setxattr = mp_pacl_setxattr,
 130    .listxattr = mp_pacl_listxattr,
 131    .removexattr = mp_pacl_removexattr,
 132};
 133
 134XattrOperations mapped_dacl_xattr = {
 135    .name = "system.posix_acl_default",
 136    .getxattr = mp_dacl_getxattr,
 137    .setxattr = mp_dacl_setxattr,
 138    .listxattr = mp_dacl_listxattr,
 139    .removexattr = mp_dacl_removexattr,
 140};
 141
 142XattrOperations passthrough_acl_xattr = {
 143    .name = "system.posix_acl_",
 144    .getxattr = pt_getxattr,
 145    .setxattr = pt_setxattr,
 146    .listxattr = pt_listxattr,
 147    .removexattr = pt_removexattr,
 148};
 149
 150XattrOperations none_acl_xattr = {
 151    .name = "system.posix_acl_",
 152    .getxattr = notsup_getxattr,
 153    .setxattr = notsup_setxattr,
 154    .listxattr = notsup_listxattr,
 155    .removexattr = notsup_removexattr,
 156};
 157