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[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     /* len includes the trailing NUL */
  48     memcpy(value, ACL_ACCESS, len);
  49     return 0;
  50 }
  51
  52 static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name,
  53                             void *value, size_t size, int flags)
  54 {
  55     char buffer[PATH_MAX];
  56     return lsetxattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS, value,
  57             size, flags);
  58 }
  59
  60 static int mp_pacl_removexattr(FsContext *ctx,
  61                                const char *path, const char *name)
  62 {
  63     int ret;
  64     char buffer[PATH_MAX];
  65     ret  = lremovexattr(rpath(ctx, path, buffer), MAP_ACL_ACCESS);
  66     if (ret == -1 && errno == ENODATA) {
  67         /*
  68          * We don't get ENODATA error when trying to remove a
  69          * posix acl that is not present. So don't throw the error
  70          * even in case of mapped security model
  71          */
  72         errno = 0;
  73         ret = 0;
  74     }
  75     return ret;
  76 }
  77
  78 static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path,
  79                                 const char *name, void *value, size_t size)
  80 {
  81     char buffer[PATH_MAX];
  82     return lgetxattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT, value, size);
  83 }
  84
  85 static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path,
  86                                  char *name, void *value, size_t osize)
  87 {
  88     ssize_t len = sizeof(ACL_DEFAULT);
  89
  90     if (!value) {
  91         return len;
  92     }
  93
  94     if (osize < len) {
  95         errno = ERANGE;
  96         return -1;
  97     }
  98
  99     /* len includes the trailing NUL */
 100     memcpy(value, ACL_ACCESS, len);
 101     return 0;
 102 }
 103
 104 static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name,
 105                             void *value, size_t size, int flags)
 106 {
 107     char buffer[PATH_MAX];
 108     return lsetxattr(rpath(ctx, path, buffer), MAP_ACL_DEFAULT, value,
 109             size, flags);
 110 }
 111
 112 static int mp_dacl_removexattr(FsContext *ctx,
 113                                const char *path, const char *name)
 114 {
 115     int ret;
 116     char buffer[PATH_MAX];
 117     ret  = lremovexattr(rpath(ctx, path, buffer), 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
 131 XattrOperations 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
 139 XattrOperations 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
 147 XattrOperations 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
 155 XattrOperations 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 };