🛰️ NS-3 OLSR Blackhole & Link Spoofing Attack Implementation

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📌 Project Overview

This repository contains a specialized implementation of the Optimized Link State Routing (OLSR) protocol for the NS-3 Network Simulator. It is designed for Network Layer Security research within Mobile Ad-hoc Networks (MANETs).

Modified by Oded Ofek (2025), this version introduces a sophisticated Blackhole Attack and Link Spoofing capabilities directly into the core protocol logic. By manipulating both the Control Plane and the Data Plane, a malicious node can effectively position itself as a central routing hub and silently discard network traffic.

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🏴‍☠️ Attack Mechanisms

The implementation utilizes four distinct techniques to compromise the network topology and disrupt data delivery:

1. Willingness Manipulation (Control Plane)

In standard OLSR, nodes select Multi-Point Relays (MPRs) based on their advertised willingness to forward traffic.

• Modification: When the IsMalicious attribute is enabled, the node overrides its default willingness.
• Implementation: The node sets its Willingness field to WILL_ALWAYS (value 7) in all outgoing HELLO messages.
• Impact: According to RFC 3626, neighbors are forced to prioritize this node as an MPR, ensuring the attacker is included in nearly all routing paths.

2. Topology Poisoning via ANSN (Control Plane)

The Advertised Neighbor Sequence Number (ANSN) is used by nodes to verify the freshness of topology information.

• Modification: The attacker artificially manipulates the sequence number arithmetic.
• Implementation: In the SendTc function, the attacker increments the ANSN by a large offset (+200) before broadcasting updates.
• Impact: Neighboring nodes perceive the attacker's topology information as significantly newer than legitimate updates, causing valid routing table entries to be overwritten by the malicious path.

3. Link Spoofing (Control Plane)

• Modification: The node advertises symmetric links with non-existent (phantom) neighbors.
• Implementation: The node generates HELLO messages containing fake IP addresses (starting from 200.0.0.1 / 0xC8000001) with a SYM_LINK / SYM_NEIGH status.
• Impact: This artificially inflates the node's degree of connectivity. Pathfinding algorithms like Dijkstra will perceive the attacker as the most efficient "short-cut" for traffic, attracting flows from across the network.

4. Silent Packet Drop / Blackhole (Data Plane)

• Modification: Interception and destruction of transit traffic.
• Implementation: Within the RouteInput function, if the node is malicious, it intercepts unicast packets destined for other nodes.
• Impact: The protocol returns true (signaling successful processing) but intentionally fails to invoke the UnicastForwardCallback. Packets are dropped from memory without generating ICMP error messages, making the attack difficult to detect through standard diagnostic tools.

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📂 Repository Structure

The source files are organized to mirror the standard NS-3 module tree for seamless integration:

File	Description
olsr-routing-protocol.h	Defines the m_isMalicious flag and m_spoofedLinksCount attribute.
olsr-routing-protocol.cc	Implements the attack logic in SendHello, SendTc, and RouteInput.
README.md	Comprehensive documentation of the implementation.

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🛠️ Installation & Integration

Prerequisites

• A working installation of NS-3 (v3.35 or higher recommended).
• Basic knowledge of compiling NS-3 using the ./ns3 build system.

Step-by-Step Setup

1. Backup your original OLSR files located in src/olsr/model/.
2. Copy the modified olsr-routing-protocol.h and olsr-routing-protocol.cc from this repository into src/olsr/model/.
3. Rebuild the simulator:

   ./ns3 build

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🚀 Simulation Usage

You can dynamically enable or disable the attack behavior in your NS-3 simulation scripts using the attribute system:

Ptr<Node> node = nodes.Get(5);
Ptr<olsr::RoutingProtocol> protocol = node->GetObject<olsr::RoutingProtocol>();

protocol->SetAttribute("IsMalicious", BooleanValue(true));
protocol->SetAttribute("SpoofedLinksCount", UintegerValue(15));

🔧 Configurable Attributes

IsMalicious Boolean flag to toggle Blackhole behavior, ANSN poisoning, and Willingness manipulation.

SpoofedLinksCount Number of fake symmetric neighbors advertised in HELLO messages.

⚠️ Research Disclaimer

This implementation is intended strictly for academic and research purposes, such as evaluating protocol vulnerabilities or testing Intrusion Detection Systems (IDS). Unauthorized use of these techniques in real-world environments is prohibited...