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/*
  15 * Not so fast! You might want to read the 9p developer docs first:
  16 * https://wiki.qemu.org/Documentation/9p
  17 */
  18
  19#include "qemu/osdep.h"
  20#include "qemu/xattr.h"
  21#include "9p.h"
  22#include "fsdev/file-op-9p.h"
  23#include "9p-xattr.h"
  24
  25#define MAP_ACL_ACCESS "user.virtfs.system.posix_acl_access"
  26#define MAP_ACL_DEFAULT "user.virtfs.system.posix_acl_default"
  27#define ACL_ACCESS "system.posix_acl_access"
  28#define ACL_DEFAULT "system.posix_acl_default"
  29
  30static ssize_t mp_pacl_getxattr(FsContext *ctx, const char *path,
  31                                const char *name, void *value, size_t size)
  32{
  33    return local_getxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size);
  34}
  35
  36static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
  37                                 char *name, void *value, size_t osize)
  38{
  39    ssize_t len = sizeof(ACL_ACCESS);
  40
  41    if (!value) {
  42        return len;
  43    }
  44
  45    if (osize < len) {
  46        errno = ERANGE;
  47        return -1;
  48    }
  49
  50    /* len includes the trailing NUL */
  51    memcpy(value, ACL_ACCESS, len);
  52    return 0;
  53}
  54
  55static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
  56                            void *value, size_t size, int flags)
  57{
  58    return local_setxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size,
  59                                   flags);
  60}
  61
  62static int mp_pacl_removexattr(FsContext *ctx,
  63                               const char *path, const char *name)
  64{
  65    int ret;
  66
  67    ret = local_removexattr_nofollow(ctx, path, MAP_ACL_ACCESS);
  68    if (ret == -1 && errno == ENODATA) {
  69        /*
  70         * We don't get ENODATA error when trying to remove a
  71         * posix acl that is not present. So don't throw the error
  72         * even in case of mapped security model
  73         */
  74        errno = 0;
  75        ret = 0;
  76    }
  77    return ret;
  78}
  79
  80static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
  81                                const char *name, void *value, size_t size)
  82{
  83    return local_getxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size);
  84}
  85
  86static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
  87                                 char *name, void *value, size_t osize)
  88{
  89    ssize_t len = sizeof(ACL_DEFAULT);
  90
  91    if (!value) {
  92        return len;
  93    }
  94
  95    if (osize < len) {
  96        errno = ERANGE;
  97        return -1;
  98    }
  99
 100    /* len includes the trailing NUL */
 101    memcpy(value, ACL_DEFAULT, len);
 102    return 0;
 103}
 104
 105static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
 106                            void *value, size_t size, int flags)
 107{
 108    return local_setxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size,
 109                                   flags);
 110}
 111
 112static int mp_dacl_removexattr(FsContext *ctx,
 113                               const char *path, const char *name)
 114{
 115    int ret;
 116
 117    ret = local_removexattr_nofollow(ctx, path, MAP_ACL_DEFAULT);
 118    if (ret == -1 && errno == ENODATA) {
 119        /*
 120         * We don't get ENODATA error when trying to remove a
 121         * posix acl that is not present. So don't throw the error
 122         * even in case of mapped security model
 123         */
 124        errno = 0;
 125        ret = 0;
 126    }
 127    return ret;
 128}
 129
 130
 131XattrOperations mapped_pacl_xattr = {
 132    .name = "system.posix_acl_access",
 133    .getxattr = mp_pacl_getxattr,
 134    .setxattr = mp_pacl_setxattr,
 135    .listxattr = mp_pacl_listxattr,
 136    .removexattr = mp_pacl_removexattr,
 137};
 138
 139XattrOperations mapped_dacl_xattr = {
 140    .name = "system.posix_acl_default",
 141    .getxattr = mp_dacl_getxattr,
 142    .setxattr = mp_dacl_setxattr,
 143    .listxattr = mp_dacl_listxattr,
 144    .removexattr = mp_dacl_removexattr,
 145};
 146
 147XattrOperations passthrough_acl_xattr = {
 148    .name = "system.posix_acl_",
 149    .getxattr = pt_getxattr,
 150    .setxattr = pt_setxattr,
 151    .listxattr = pt_listxattr,
 152    .removexattr = pt_removexattr,
 153};
 154
 155XattrOperations none_acl_xattr = {
 156    .name = "system.posix_acl_",
 157    .getxattr = notsup_getxattr,
 158    .setxattr = notsup_setxattr,
 159    .listxattr = notsup_listxattr,
 160    .removexattr = notsup_removexattr,
 161};
 162