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 "qemu/xattr.h"
  16 #include "hw/virtio/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;
  30     ssize_t ret;
  31
  32     buffer = rpath(ctx, path);
  33     ret = lgetxattr(buffer, MAP_ACL_ACCESS, value, size);
  34     g_free(buffer);
  35     return ret;
  36 }
  37
  38 static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path,
  39                                  char *name, void *value, size_t osize)
  40 {
  41     ssize_t len = sizeof(ACL_ACCESS);
  42
  43     if (!value) {
  44         return len;
  45     }
  46
  47     if (osize < len) {
  48         errno = ERANGE;
  49         return -1;
  50     }
  51
  52     /* len includes the trailing NUL */
  53     memcpy(value, ACL_ACCESS, len);
  54     return 0;
  55 }
  56
  57 static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
  58                             void *value, size_t size, int flags)
  59 {
  60     char *buffer;
  61     int ret;
  62
  63     buffer = rpath(ctx, path);
  64     ret = lsetxattr(buffer, MAP_ACL_ACCESS, value, size, flags);
  65     g_free(buffer);
  66     return ret;
  67 }
  68
  69 static int mp_pacl_removexattr(FsContext *ctx,
  70                                const char *path, const char *name)
  71 {
  72     int ret;
  73     char *buffer;
  74
  75     buffer = rpath(ctx, path);
  76     ret  = lremovexattr(buffer, MAP_ACL_ACCESS);
  77     if (ret == -1 && errno == ENODATA) {
  78         /*
  79          * We don't get ENODATA error when trying to remove a
  80          * posix acl that is not present. So don't throw the error
  81          * even in case of mapped security model
  82          */
  83         errno = 0;
  84         ret = 0;
  85     }
  86     g_free(buffer);
  87     return ret;
  88 }
  89
  90 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
  91                                 const char *name, void *value, size_t size)
  92 {
  93     char *buffer;
  94     ssize_t ret;
  95
  96     buffer = rpath(ctx, path);
  97     ret = lgetxattr(buffer, MAP_ACL_DEFAULT, value, size);
  98     g_free(buffer);
  99     return ret;
 100 }
 101
 102 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
 103                                  char *name, void *value, size_t osize)
 104 {
 105     ssize_t len = sizeof(ACL_DEFAULT);
 106
 107     if (!value) {
 108         return len;
 109     }
 110
 111     if (osize < len) {
 112         errno = ERANGE;
 113         return -1;
 114     }
 115
 116     /* len includes the trailing NUL */
 117     memcpy(value, ACL_ACCESS, len);
 118     return 0;
 119 }
 120
 121 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
 122                             void *value, size_t size, int flags)
 123 {
 124     char *buffer;
 125     int ret;
 126
 127     buffer = rpath(ctx, path);
 128     ret = lsetxattr(buffer, MAP_ACL_DEFAULT, value, size, flags);
 129     g_free(buffer);
 130     return ret;
 131 }
 132
 133 static int mp_dacl_removexattr(FsContext *ctx,
 134                                const char *path, const char *name)
 135 {
 136     int ret;
 137     char *buffer;
 138
 139     buffer = rpath(ctx, path);
 140     ret  = lremovexattr(buffer, MAP_ACL_DEFAULT);
 141     if (ret == -1 && errno == ENODATA) {
 142         /*
 143          * We don't get ENODATA error when trying to remove a
 144          * posix acl that is not present. So don't throw the error
 145          * even in case of mapped security model
 146          */
 147         errno = 0;
 148         ret = 0;
 149     }
 150     g_free(buffer);
 151     return ret;
 152 }
 153
 154
 155 XattrOperations mapped_pacl_xattr = {
 156     .name = "system.posix_acl_access",
 157     .getxattr = mp_pacl_getxattr,
 158     .setxattr = mp_pacl_setxattr,
 159     .listxattr = mp_pacl_listxattr,
 160     .removexattr = mp_pacl_removexattr,
 161 };
 162
 163 XattrOperations mapped_dacl_xattr = {
 164     .name = "system.posix_acl_default",
 165     .getxattr = mp_dacl_getxattr,
 166     .setxattr = mp_dacl_setxattr,
 167     .listxattr = mp_dacl_listxattr,
 168     .removexattr = mp_dacl_removexattr,
 169 };
 170
 171 XattrOperations passthrough_acl_xattr = {
 172     .name = "system.posix_acl_",
 173     .getxattr = pt_getxattr,
 174     .setxattr = pt_setxattr,
 175     .listxattr = pt_listxattr,
 176     .removexattr = pt_removexattr,
 177 };
 178
 179 XattrOperations none_acl_xattr = {
 180     .name = "system.posix_acl_",
 181     .getxattr = notsup_getxattr,
 182     .setxattr = notsup_setxattr,
 183     .listxattr = notsup_listxattr,
 184     .removexattr = notsup_removexattr,
 185 };