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
  25 static 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
  31 static 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
  50 static 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
  57 static 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
  75 static 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
  81 static 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
 100 static 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
 107 static 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
 126 XattrOperations 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
 134 XattrOperations 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
 142 XattrOperations 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
 150 XattrOperations 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 };