Implement MPReachableNLRIAttribute.build()

1 files changed, 24 insertions, 2 deletions

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 a02f5c2..1c0a475 100644
--- a/src/main/java/com/lumaserv/bgp/protocol/attribute/MPReachableNLRIAttribute.java
+++ b/src/main/java/com/lumaserv/bgp/protocol/attribute/MPReachableNLRIAttribute.java
@@ -7,6 +7,7 @@ import java.util.ArrayList;
 import java.util.Collection;
 
 import lombok.Getter;
+import lombok.NoArgsConstructor;
 import lombok.Setter;
 
 import com.lumaserv.bgp.protocol.AFI;
@@ -15,6 +16,7 @@ import com.lumaserv.bgp.protocol.IPPrefix;
 import com.lumaserv.bgp.protocol.SAFI;
 
 @Getter
+@NoArgsConstructor
 @Setter
 public class MPReachableNLRIAttribute implements PathAttribute {
 
@@ -60,8 +62,28 @@ public class MPReachableNLRIAttribute implements PathAttribute {
     }
 
     public byte[] build() {
-        // FIXME
-        return null;
+        int nhLen = nextHop.getAddress().length;
+        int len = 4 + nhLen + 1;
+        for (IPPrefix prefix : nlriPrefixes) {
+            len += 1 + (int)Math.ceil(prefix.getLength() / 8d);
+        }
+        byte[] data = new byte[len];
+        data[0] = (byte)((afi.getValue() >> 8) & 0xff);
+        data[1] = (byte)(afi.getValue() & 0xff);
+        data[2] = (byte)safi.getValue();
+        data[3] = (byte)nhLen;
+        System.arraycopy(nextHop.getAddress(), 0, data, 4, nhLen);
+        int offset = 4 + nhLen;
+        data[offset] = 0;
+        offset++;
+        for (IPPrefix prefix : nlriPrefixes) {
+            data[offset] = (byte)prefix.getLength();
+            offset++;
+            int addressLen = (int)Math.ceil(prefix.getLength() / 8d);
+            System.arraycopy(prefix.getAddress(), 0, data, offset, addressLen);
+            offset += addressLen;
+        }
+        return data;
     }
 
     public String toString() {