HDFS-6456. Merging change r1610840 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1610843 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/nfs/NfsExports.java

@@ -72,6 +72,15 @@ public class NfsExports {
   private static final Pattern CIDR_FORMAT_LONG = 
       Pattern.compile(SLASH_FORMAT_LONG);
 
+  // Hostnames are composed of series of 'labels' concatenated with dots.
+  // Labels can be between 1-63 characters long, and can only take
+  // letters, digits & hyphens. They cannot start and end with hyphens. For
+  // more details, refer RFC-1123 & http://en.wikipedia.org/wiki/Hostname
+  private static final String LABEL_FORMAT =
+      "[a-zA-Z0-9]([a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])?";
+  private static final Pattern HOSTNAME_FORMAT =
+      Pattern.compile("^(" + LABEL_FORMAT + "\\.)*" + LABEL_FORMAT + "$");
+
   static class AccessCacheEntry implements LightWeightCache.Entry{
     private final String hostAddr;
     private AccessPrivilege access;
@@ -381,10 +390,14 @@ public class NfsExports {
         LOG.debug("Using Regex match for '" + host + "' and " + privilege);
       }
       return new RegexMatch(privilege, host);
-    }
+    } else if (HOSTNAME_FORMAT.matcher(host).matches()) {
       if (LOG.isDebugEnabled()) {
         LOG.debug("Using exact match for '" + host + "' and " + privilege);
       }
       return new ExactMatch(privilege, host);
+    } else {
+      throw new IllegalArgumentException("Invalid hostname provided '" + host
+          + "'");
+    }
   }
 }

hadoop-common-project/hadoop-nfs/src/test/java/org/apache/hadoop/nfs/TestNfsExports.java

@@ -194,4 +194,16 @@ public class TestNfsExports {
     } while ((System.nanoTime() - startNanos) / NanosPerMillis < 5000);
     Assert.assertEquals(AccessPrivilege.NONE, ap);
   }
+
+  @Test(expected=IllegalArgumentException.class)
+  public void testInvalidHost() {
+      NfsExports matcher = new NfsExports(CacheSize, ExpirationPeriod,
+        "foo#bar");
+  }
+
+  @Test(expected=IllegalArgumentException.class)
+  public void testInvalidSeparator() {
+      NfsExports matcher = new NfsExports(CacheSize, ExpirationPeriod,
+        "foo ro : bar rw");
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -59,6 +59,9 @@ Release 2.6.0 - UNRELEASED
     HDFS-5809. BlockPoolSliceScanner and high speed hdfs appending make
     datanode to drop into infinite loop (cmccabe)
 
+    HDFS-6456. NFS should throw error for invalid entry in 
+    dfs.nfs.exports.allowed.hosts (Abhiraj Butala via brandonli)
+
 Release 2.5.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES