[PATCH] Basic support for checking NFSv4 ACLs in Linux

[Ondrej Valousek]

---
 lib/file-has-acl.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c
index e02f0626a..a6144e52e 100644
--- a/lib/file-has-acl.c
+++ b/lib/file-has-acl.c
@@ -32,6 +32,10 @@
 #if GETXATTR_WITH_POSIX_ACLS
 # include <sys/xattr.h>
 # include <linux/xattr.h>
+# include <arpa/inet.h>
+#ifndef XATTR_NAME_NFSV4_ACL
+#define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
+#endif
 #endif
 
 /* Return 1 if NAME has a nontrivial access control list,
@@ -67,6 +71,26 @@ file_has_acl (char const *name, struct stat const *sb)
             return 1;
         }
 
+      if (ret < 0) { /* we might be on NFS, so try to check NFSv4 ACLs too */
+         ret = getxattr (name, XATTR_NAME_NFSV4_ACL, NULL, 0);
+         if (ret < 0 && errno == ENODATA)
+              ret = 0;
+         else if (ret > 0) {
+              char *xattr;
+             xattr = malloc(ret);
+             if (!xattr) {
+               ret = -1;
+             } else {
+                ret = getxattr (name, XATTR_NAME_NFSV4_ACL, xattr, ret);
+               if (ret < 0) ret = -1;
+               else {
+                   u_int32_t num_aces = 
(u_int32_t)ntohl(*((u_int32_t*)(xattr))); /* Grab the number of aces in the acl 
*/
+                   ret = num_aces > 3;
+               }
+               free(xattr);
+            }
+         }
+      }  
       if (ret < 0)
         return - acl_errno_valid (errno);
       return ret;
-- 
2.37.3