libcrafter Examples

A collection of example programs demonstrating the usage of libcrafter, a high-level C++ library for crafting and decoding network packets.

libcrafter is designed to make packet manipulation easy, allowing developers to forge and decode packets from the application layer down to the link layer. It supports IPv4, IPv6, TCP, UDP, ICMP, ARP, DNS, DHCP, and many other protocols.

Building

Using CMake (recommended)

cmake .
make

Executables will be placed in the bin/ directory.

Manual compilation (single example)

g++ main.cpp -o example -lcrafter -lpcap -lpthread -lresolv

Running

Most examples require root privileges to send/receive raw packets:

sudo ./bin/ExampleName

Note: Before running, check the interface name (commonly wlan0, eth0, or enp0s3) and IP address ranges in the source code. Modify them according to your network configuration.

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Examples Overview

Basic Examples

Example	Description
HelloWorld	Simplest example. Creates a raw layer with "Hello World!" and writes it to the network interface.
PayloadHelloWorld	Demonstrates RawLayer manipulation, payload concatenation, and the / operator for combining layers.
BasicSend	Constructs a TCP packet with Ethernet, IP, and TCP headers, sends it, and shows field auto-completion.

ICMP / Ping

Example	Description
Ping	Forges an ICMP echo-request (ping) and sends it to a destination.
BasicPingPong	Sends a ping and waits for a reply using SendRecv().
NetworkPing	Performs a ping scan on a /24 network using multi-threaded SendRecv().
Ping6	IPv6 ping example using ICMPv6.
PingIPv4IPv6	IP-version-independent ping using IPLayer and ICMPLayer abstractions.
SnifferNetworkPing	Network ping scan using a sniffer to capture replies instead of SendRecv().
TimeExceeded	Creates an ICMP Time Exceeded message with MPLS extensions.

ARP

Example	Description
ARPPing	ARP scan on a local network using SendRecv() to discover live hosts.
ARPPingL2Socket	Efficient ARP scan using raw L2 sockets and a sniffer.
SnifferARPPing	ARP scan using Send() with a spawned sniffer for replies.
SimpleARPPoison	Basic ARP spoofing between two hosts (man-in-the-middle).
SnifferARPPoison	ARP poisoning combined with HTTP traffic sniffing.
SpawnARPPoison	Uses ARPSpoofingReply() helper function for background ARP poisoning.

DNS

Example	Description
DNSQuery	Forges a DNS query and sends it to a DNS server, prints the response.
DNSSpoof	DNS spoofing attack combined with ARP poisoning.

TCP

Example	Description
SimpleTCP	User-level TCP connection establishment using TCPConnection class.
TCPOptions	Demonstrates TCP options: MSS, Window Scale, Timestamp.
TCPTraceroute	TCP-based traceroute using SYN packets with varying TTL.
SimpleHijackConnection	TCP session hijacking demonstration.
SimpleSpoofConnection	Spoofed TCP connection from a victim's IP address.

UDP

Example	Description
UDPTraceroute	UDP-based traceroute using varying TTL values.

DHCP

Example	Description
DHCPRequest	Sends DHCP Discovery and Request messages, parses server responses.

IPv6

Example	Description
ExampleIPv6	Basic IPv6 packet construction and transmission.
CombineIPv4IPv6	IP-version-independent code using IPLayer abstraction.
IPv6RoutingHeader	Creates IPv6 packets with Segment Routing and Mobile Routing headers.

IP Options

Example	Description
IPOptions	ICMP ping with IP Traceroute option.
IPOptionRecordRoute	Uses LSRR (Loose Source Record Route) and RR (Record Route) IP options.

Packet Capture / PCAP

Example	Description
SimpleSniffer	Basic packet sniffer capturing TCP port 22 traffic.
FileSniffer	Captures HTTP traffic and saves payloads to a file.
ReadPcap	Reads packets from a pcap file and prints them.
DumpPcap	Creates packets and dumps them to pcap files, then reads them back.

Advanced / Miscellaneous

Example	Description
FilterSendRecv	Uses custom tcpdump filter expressions with SendRecv().
UserSockets	Demonstrates using user-created raw sockets with libcrafter.
NULLHeader	Reads pcap files with NULL/Loopback link layer (requires Boost).
SACKOption	TCP SACK (Selective Acknowledgment) option parsing and creation (requires Boost).
ExtendedDataOffset	TCP Extended Data Offset (EDO) option examples.

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Code Patterns

Creating and Sending a Packet

#include <crafter.h>
using namespace Crafter;

// Create layers
IP ip; 
ip.SetSourceIP("192.168.1.100");
ip.SetDestinationIP("192.168.1.1");

ICMP icmp;
icmp.SetType(ICMP::EchoRequest);

// Combine layers using / operator
Packet packet = ip / icmp;

// Send the packet
packet.Send("eth0");

Send and Receive

Packet* reply = packet.SendRecv("eth0", 2.0);  // 2 second timeout
if (reply) {
    reply->Print();
    delete reply;
}

Sniffing Packets

void handler(Packet* pkt, void* user) {
    pkt->Print();
}

Sniffer sniff("tcp port 80", "eth0", handler);
sniff.Capture(10);  // Capture 10 packets

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Important Notes

1. Interface Names: Default examples use wlan0. Change to your interface (e.g., eth0, enp0s3).

2. IP Addresses: Network ranges like 192.168.0.* are hardcoded. Adjust for your network.

3. Root Privileges: Raw socket operations require root access.

4. Security Warning: Some examples (ARP poisoning, DNS spoofing, connection hijacking) are for educational purposes only. Use responsibly and only on networks you own or have permission to test.

5. iptables: Some examples modify iptables rules. They attempt cleanup on exit, but verify your firewall rules after running.

License

These examples are provided for educational purposes to demonstrate libcrafter usage.