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 "hw/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     char buffer[PATH_MAX];
  30     return lgetxattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS, value, size);
  31 }
  32
  33 static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
  34                                  char *name, void *value, size_t osize)
  35 {
  36     ssize_t len = sizeof(ACL_ACCESS);
  37
  38     if (!value) {
  39         return len;
  40     }
  41
  42     if (osize < len) {
  43         errno = ERANGE;
  44         return -1;
  45     }
  46
  47     strncpy(value, ACL_ACCESS, len);
  48     return 0;
  49 }
  50
  51 static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
  52                             void *value, size_t size, int flags)
  53 {
  54     char buffer[PATH_MAX];
  55     return lsetxattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS, value,
  56             size, flags);
  57 }
  58
  59 static int mp_pacl_removexattr(FsContext *ctx,
  60                                const char *path, const char *name)
  61 {
  62     int ret;
  63     char buffer[PATH_MAX];
  64     ret  = lremovexattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS);
  65     if (ret == -1 && errno == ENODATA) {
  66         /*
  67          * We don't get ENODATA error when trying to remove a
  68          * posix acl that is not present. So don't throw the error
  69          * even in case of mapped security model
  70          */
  71         errno = 0;
  72         ret = 0;
  73     }
  74     return ret;
  75 }
  76
  77 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
  78                                 const char *name, void *value, size_t size)
  79 {
  80     char buffer[PATH_MAX];
  81     return lgetxattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT, value, size);
  82 }
  83
  84 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
  85                                  char *name, void *value, size_t osize)
  86 {
  87     ssize_t len = sizeof(ACL_DEFAULT);
  88
  89     if (!value) {
  90         return len;
  91     }
  92
  93     if (osize < len) {
  94         errno = ERANGE;
  95         return -1;
  96     }
  97
  98     strncpy(value, ACL_DEFAULT, len);
  99     return 0;
 100 }
 101
 102 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
 103                             void *value, size_t size, int flags)
 104 {
 105     char buffer[PATH_MAX];
 106     return lsetxattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT, value,
 107             size, flags);
 108 }
 109
 110 static int mp_dacl_removexattr(FsContext *ctx,
 111                                const char *path, const char *name)
 112 {
 113     int ret;
 114     char buffer[PATH_MAX];
 115     ret  = lremovexattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT);
 116     if (ret == -1 && errno == ENODATA) {
 117         /*
 118          * We don't get ENODATA error when trying to remove a
 119          * posix acl that is not present. So don't throw the error
 120          * even in case of mapped security model
 121          */
 122         errno = 0;
 123         ret = 0;
 124     }
 125     return ret;
 126 }
 127
 128
 129 XattrOperations mapped_pacl_xattr = {
 130     .name = "system.posix_acl_access",
 131     .getxattr = mp_pacl_getxattr,
 132     .setxattr = mp_pacl_setxattr,
 133     .listxattr = mp_pacl_listxattr,
 134     .removexattr = mp_pacl_removexattr,
 135 };
 136
 137 XattrOperations mapped_dacl_xattr = {
 138     .name = "system.posix_acl_default",
 139     .getxattr = mp_dacl_getxattr,
 140     .setxattr = mp_dacl_setxattr,
 141     .listxattr = mp_dacl_listxattr,
 142     .removexattr = mp_dacl_removexattr,
 143 };
 144
 145 XattrOperations passthrough_acl_xattr = {
 146     .name = "system.posix_acl_",
 147     .getxattr = pt_getxattr,
 148     .setxattr = pt_setxattr,
 149     .listxattr = pt_listxattr,
 150     .removexattr = pt_removexattr,
 151 };
 152
 153 XattrOperations none_acl_xattr = {
 154     .name = "system.posix_acl_",
 155     .getxattr = notsup_getxattr,
 156     .setxattr = notsup_setxattr,
 157     .listxattr = notsup_listxattr,
 158     .removexattr = notsup_removexattr,
 159 };