Raw path and IP parsing (#77)

* Raw path and IP parsing --------- Co-authored-by: Tilmann Zäschke <tilmann.zaeschke@inf.ethz.ch>
scionproto-contrib · May 27, 2024 · 79c3490 · 79c3490
1 parent 983eece
commit 79c3490
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -23,6 +23,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   [#72](https://github.com/scionproto-contrib/jpan/issues/72)
 - Fixed path lookup error when destination isn't reachable.
   [#70](https://github.com/scionproto-contrib/jpan/issues/70)
+- Fixed internal raw path parsing and IP parsing.
+  [#77](https://github.com/scionproto-contrib/jpan/pull/77)
 
 ## [0.1.1] - 2024-05-10
 

diff --git a/src/main/java/org/scion/jpan/ScionUtil.java b/src/main/java/org/scion/jpan/ScionUtil.java
@@ -14,7 +14,6 @@
 
 package org.scion.jpan;
 
-import java.nio.ByteBuffer;
 import org.scion.jpan.internal.PathRawParser;
 
 /** Scion utility functions. */
@@ -103,11 +102,7 @@ public static String toStringIA(int isd, long as) {
    * @return The sequence or border router interface IDs.
    */
   public static String toStringPath(byte[] raw) {
-    if (raw.length == 0) {
-      return "[]";
-    }
-    PathRawParser ph = new PathRawParser();
-    ph.read(ByteBuffer.wrap(raw));
+    PathRawParser ph = PathRawParser.create(raw);
     StringBuilder sb = new StringBuilder();
     sb.append("[");
     int[] segLen = {ph.getSegLen(0), ph.getSegLen(1), ph.getSegLen(2)};

diff --git a/src/main/java/org/scion/jpan/internal/IPHelper.java b/src/main/java/org/scion/jpan/internal/IPHelper.java
@@ -49,8 +49,8 @@ public static byte[] toByteArray(String s) {
     if ("localhost".equals(s)) {
       return new byte[] {127, 0, 0, 1};
     }
-    if ("localhost-ip6".equals(s)) {
-      return new byte[] {127, 0, 0, 1};
+    if ("ip6-localhost".equals(s)) {
+      return new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
     }
     if (s.startsWith("[")) {
       if (s.endsWith("]")) {

diff --git a/src/main/java/org/scion/jpan/internal/PathRawParser.java b/src/main/java/org/scion/jpan/internal/PathRawParser.java
@@ -47,18 +47,20 @@ public class PathRawParser {
 
   public static PathRawParser create(byte[] rawPath) {
     PathRawParser p = new PathRawParser();
-    p.read(ByteBuffer.wrap(rawPath));
+    if (rawPath.length != 0) {
+      p.read(ByteBuffer.wrap(rawPath));
+    }
     return p;
   }
 
-  public PathRawParser() {
+  private PathRawParser() {
     this.info[0] = new InfoField();
     this.info[1] = new InfoField();
     this.info[2] = new InfoField();
     Arrays.setAll(hops, value -> new HopField());
   }
 
-  public void read(ByteBuffer data) {
+  private void read(ByteBuffer data) {
     int start = data.position();
     // 2 bit : (C)urrINF : 2-bits index (0-based) pointing to the current info field (see offset
     // calculations below).

diff --git a/src/test/java/org/scion/jpan/api/ScionUtilTest.java b/src/test/java/org/scion/jpan/api/ScionUtilTest.java
@@ -129,5 +129,6 @@ private RequestPath createRequestPathRemote() throws UnknownHostException {
   void toStringPath_raw() {
     assertEquals("[]", ScionUtil.toStringPath(new byte[] {}));
     assertEquals("[2>1]", ScionUtil.toStringPath(ExamplePacket.PATH_RAW_TINY_110_112));
+    assertEquals("[1>5 30>5 7>3 6>1]", ScionUtil.toStringPath(ExamplePacket.PATH_RAW_UP_CORE_DOWN));
   }
 }
diff --git a/src/test/java/org/scion/jpan/internal/IPHelperTest.java b/src/test/java/org/scion/jpan/internal/IPHelperTest.java
@@ -0,0 +1,84 @@
+// Copyright 2024 ETH Zurich
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package org.scion.jpan.internal;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.net.UnknownHostException;
+import org.junit.jupiter.api.Test;
+
+class IPHelperTest {
+
+  @Test
+  void isLocalhost() {
+    assertTrue(IPHelper.isLocalhost("localhost"));
+    assertTrue(IPHelper.isLocalhost("127.0.0.42"));
+
+    assertTrue(IPHelper.isLocalhost("::1"));
+    assertTrue(IPHelper.isLocalhost("0:0:0:0:0:0:0:1"));
+    assertTrue(IPHelper.isLocalhost("ip6-localhost"));
+
+    assertFalse(IPHelper.isLocalhost("dummy.com"));
+    assertFalse(IPHelper.isLocalhost("192.168.0.1"));
+  }
+
+  @Test
+  void lookupLocalhost() {
+    assertArrayEquals(new byte[] {127, 0, 0, 1}, IPHelper.lookupLocalhost("localhost"));
+    assertArrayEquals(new byte[] {127, 0, 0, 42}, IPHelper.lookupLocalhost("127.0.0.42"));
+
+    byte[] ipv6 = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
+    assertArrayEquals(ipv6, IPHelper.lookupLocalhost("::1"));
+    assertArrayEquals(ipv6, IPHelper.lookupLocalhost("0:0:0:0:0:0:0:1"));
+    assertArrayEquals(ipv6, IPHelper.lookupLocalhost("ip6-localhost"));
+
+    assertNull(IPHelper.lookupLocalhost("dummy.com"));
+    assertNull(IPHelper.lookupLocalhost("192.168.0.1"));
+  }
+
+  @Test
+  void toByteArray() {
+    assertArrayEquals(new byte[] {127, 0, 0, 1}, IPHelper.toByteArray("localhost"));
+    assertArrayEquals(new byte[] {127, 0, 0, 1}, IPHelper.toByteArray("127.0.0.1"));
+    assertArrayEquals(new byte[] {127, 0, 0, 42}, IPHelper.toByteArray("127.0.0.42"));
+
+    byte[] ipv6 = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
+    assertArrayEquals(ipv6, IPHelper.toByteArray("::1"));
+    assertArrayEquals(ipv6, IPHelper.toByteArray("[::1]"));
+    assertArrayEquals(ipv6, IPHelper.toByteArray("0:0:0:0:0:0:0:1"));
+    assertArrayEquals(ipv6, IPHelper.toByteArray("[0:0:0:0:0:0:0:1]"));
+    assertArrayEquals(ipv6, IPHelper.toByteArray("ip6-localhost"));
+
+    assertNull(IPHelper.toByteArray("dummy.com"));
+    assertArrayEquals(new byte[] {1, 2, 3, 4}, IPHelper.toByteArray("1.2.3.4"));
+    assertArrayEquals(new byte[] {192 - 256, 168 - 256, 0, 1}, IPHelper.toByteArray("192.168.0.1"));
+
+    assertNull(IPHelper.toByteArray("[::1"));
+    assertNull(IPHelper.toByteArray("::1]"));
+
+    assertNull(IPHelper.toByteArray("127.0.0.1x"));
+    assertNull(IPHelper.toByteArray("[::1x]"));
+  }
+
+  @Test
+  void toInetAddress() throws UnknownHostException {
+    assertArrayEquals(new byte[] {127, 0, 0, 1}, IPHelper.toInetAddress("localhost").getAddress());
+    assertArrayEquals(
+        new byte[] {127, 0, 0, 42}, IPHelper.toInetAddress("127.0.0.42").getAddress());
+
+    byte[] ipv6 = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
+    assertArrayEquals(ipv6, IPHelper.toInetAddress("::1").getAddress());
+  }
+}
diff --git a/src/test/java/org/scion/jpan/testutil/ExamplePacket.java b/src/test/java/org/scion/jpan/testutil/ExamplePacket.java
@@ -102,4 +102,13 @@ public class ExamplePacket {
     86, -46, 89, 0, 31, -112, -83, -100, 0, 19, 68, -82, 72, 101, 108, 108,
     111, 32, 115, 99, 105, 111, 110,
   };
+
+  /** A real world long path from 64-2:0:9 to 71-2:0:48. */
+  public static final byte[] PATH_RAW_UP_CORE_DOWN = {
+    0, 0, 32, -62, 0, 0, 33, 38, 102, 84, -122, 69, 0, 0, -103, -70, 102, 84, -122, -64, 1, 0, -11,
+    54, 102, 84, -122, -64, 0, 63, 0, 1, 0, 0, 117, -46, 17, -106, -11, -104, 0, 63, 0, 0, 0, 5, -2,
+    -52, -56, 123, -91, 72, 0, 63, 0, 30, 0, 0, 77, -86, 93, 42, -83, -82, 0, 63, 0, 7, 0, 5, 21,
+    107, -89, 61, 117, 32, 0, 63, 0, 0, 0, 3, 83, -69, 122, -45, 58, -111, 0, 63, 0, 0, 0, 6, -46,
+    -42, 67, 69, 117, 2, 0, 63, 0, 1, 0, 0, 85, -55, 20, 110, -37, 90
+  };
 }