hw/9pfs/virtio-9p-posix-acl.c

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