Fix IPv6 address text representation

Translated longest consquent 16-Bit 0 Fields to ::.

4 files changed, 81 insertions, 3 deletions

diff --git a/src/main/java/com/lumaserv/bgp/protocol/IPAddress.java b/src/main/java/com/lumaserv/bgp/protocol/IPAddress.java
new file mode 100644
index 0000000..025e392
--- /dev/null
+++ b/src/main/java/com/lumaserv/bgp/protocol/IPAddress.java
@@ -0,0 +1,76 @@
+package com.lumaserv.bgp.protocol;
+
+import java.net.InetAddress;
+import java.net.Inet6Address;
+
+public class IPAddress {
+
+    static int toInt(byte[] array, int pos) {
+        return (((int)array[pos] & 0xff) << 8) + ((int)array[pos + 1] & 0xff);
+    }
+
+    public static String toString(InetAddress address) {
+        byte[] raw = address.getAddress();
+
+        if (!(raw.length == 16 && address instanceof Inet6Address))
+            return address.getHostAddress();
+
+        int maxPos = -1;
+        int maxCount = 0;
+        int pos = -1;
+        int count = 0;
+
+        for (int i=0; i < 8; i++) {
+            int value = toInt(raw, i * 2);
+            if (value == 0) {
+                if (pos < 0) {
+                    pos = i;
+                    count = 0;
+                }
+                count++;
+            } else {
+                if (count > maxCount) {
+                    maxPos = pos;
+                    maxCount = count;
+                }
+                pos = -1;
+                count = 0;
+            }
+        }
+
+        if (count > maxCount) {
+            maxPos = pos;
+            maxCount = count;
+        }
+
+        if (maxCount < 2) {
+            maxPos = -1;
+            maxCount = 0;
+        }
+
+        StringBuffer buf = new StringBuffer(8 * (4+1));
+
+        pos = -1;
+        count = 0;
+        for (int i=0; i < 8; i++) {
+            if (count > 0) {
+                count--;
+                if (count == 0) {
+                    if (i == 7)
+                        buf.append("::");
+                    else
+                        buf.append(":");
+                }
+            } else if (i == maxPos) {
+                count = maxCount - 1;
+                pos = maxPos;
+            } else {
+                if (i > 0)
+                    buf.append(":");
+                int value = toInt(raw, i * 2);
+                buf.append(Integer.toString(value, 16));
+            }
+        }
+        return buf.toString();
+    }
+}
diff --git a/src/main/java/com/lumaserv/bgp/protocol/IPPrefix.java b/src/main/java/com/lumaserv/bgp/protocol/IPPrefix.java
index f68677c..5d38cf6 100644
--- a/src/main/java/com/lumaserv/bgp/protocol/IPPrefix.java
+++ b/src/main/java/com/lumaserv/bgp/protocol/IPPrefix.java
@@ -17,7 +17,7 @@ public class IPPrefix {
 
     public String toString() {
         try {
-            return InetAddress.getByAddress(address).getHostAddress() + "/" + length;
+            return IPAddress.toString(InetAddress.getByAddress(address)) + "/" + length;
         } catch (UnknownHostException e) {
             e.printStackTrace();
             return null;
diff --git a/src/main/java/com/lumaserv/bgp/protocol/attribute/MPReachableNLRIAttribute.java b/src/main/java/com/lumaserv/bgp/protocol/attribute/MPReachableNLRIAttribute.java
index 0cb2e49..392b2de 100644
--- a/src/main/java/com/lumaserv/bgp/protocol/attribute/MPReachableNLRIAttribute.java
+++ b/src/main/java/com/lumaserv/bgp/protocol/attribute/MPReachableNLRIAttribute.java
@@ -10,6 +10,7 @@ import lombok.Getter;
 import lombok.Setter;
 
 import com.lumaserv.bgp.protocol.AFI;
+import com.lumaserv.bgp.protocol.IPAddress;
 import com.lumaserv.bgp.protocol.IPPrefix;
 import com.lumaserv.bgp.protocol.SAFI;
 
@@ -60,6 +61,6 @@ public class MPReachableNLRIAttribute implements PathAttribute {
     }
 
     public String toString() {
-        return "{AFI:" + afi + " SAFI:" + safi + " NextHop:" + nextHop.getHostAddress() + " NLRIs:" + nlriPrefixes + "}";
+        return "{AFI:" + afi + " SAFI:" + safi + " NextHop:" + IPAddress.toString(nextHop) + " NLRIs:" + nlriPrefixes + "}";
     }
 }
diff --git a/src/main/java/com/lumaserv/bgp/protocol/attribute/TunnelEncapsAttribute.java b/src/main/java/com/lumaserv/bgp/protocol/attribute/TunnelEncapsAttribute.java
index 747b923..0cfd9bc 100644
--- a/src/main/java/com/lumaserv/bgp/protocol/attribute/TunnelEncapsAttribute.java
+++ b/src/main/java/com/lumaserv/bgp/protocol/attribute/TunnelEncapsAttribute.java
@@ -1,6 +1,7 @@
 package com.lumaserv.bgp.protocol.attribute;
 
 import com.lumaserv.bgp.protocol.AFI;
+import com.lumaserv.bgp.protocol.IPAddress;
 
 import lombok.AllArgsConstructor;
 import lombok.Getter;
@@ -291,7 +292,7 @@ public class TunnelEncapsAttribute implements PathAttribute {
 
         @Override
         public String toString() {
-            return "IP:" + address.getHostAddress();
+            return "IP:" + IPAddress.toString(address);
         }
     }