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/*
* Copyright (c) 2017, Matias Fontanini
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <iostream>
#include <iomanip>
#include <vector>
#include <set>
#include <string>
#include <cstdlib>
#include <pthread.h>
#include <unistd.h>
#include <tins/ip.h>
#include <tins/tcp.h>
#include <tins/ip_address.h>
#include <tins/ethernetII.h>
#include <tins/network_interface.h>
#include <tins/sniffer.h>
#include <tins/utils.h>
#include <tins/packet_sender.h>
using std::cout;
using std::endl;
using std::vector;
using std::pair;
using std::setw;
using std::string;
using std::set;
using std::runtime_error;
using namespace Tins;
typedef pair<Sniffer*, string> sniffer_data;
class Scanner {
public:
Scanner(const NetworkInterface& interface,
const IPv4Address& address,
const vector<string>& ports);
void run();
private:
void send_syns(const NetworkInterface& iface, IPv4Address dest_ip);
bool callback(PDU& pdu);
static void* thread_proc(void* param);
void launch_sniffer();
NetworkInterface iface;
IPv4Address host_to_scan;
set<uint16_t> ports_to_scan;
Sniffer sniffer;
};
Scanner::Scanner(const NetworkInterface& interface,
const IPv4Address& address,
const vector<string>& ports)
: iface(interface), host_to_scan(address), sniffer(interface.name()) {
sniffer.set_filter(
"tcp and ip src " + address.to_string() + " and tcp[tcpflags] & (tcp-rst|tcp-syn) != 0"
);
for (size_t i = 0; i < ports.size(); ++i) {
ports_to_scan.insert(atoi(ports[i].c_str()));
}
}
void* Scanner::thread_proc(void* param) {
Scanner* data = (Scanner*)param;
data->launch_sniffer();
return 0;
}
void Scanner::launch_sniffer() {
sniffer.sniff_loop(make_sniffer_handler(this, &Scanner::callback));
}
/* Our scan handler. This will receive SYNs and RSTs and inform us
* the scanned port's status.
*/
bool Scanner::callback(PDU& pdu) {
// Find the layers we want.
const IP& ip = pdu.rfind_pdu<IP>();
const TCP& tcp = pdu.rfind_pdu<TCP>();
// Check if the host that we're scanning sent this packet and
// the source port is one of those that we scanned.
if(ip.src_addr() == host_to_scan && ports_to_scan.count(tcp.sport()) == 1) {
// Ok, it's a TCP PDU. Is RST flag on? Then port is closed.
if(tcp.get_flag(TCP::RST)) {
// This indicates we should stop sniffing.
if(tcp.get_flag(TCP::SYN))
return false;
cout << "Port: " << setw(5) << tcp.sport() << " closed\n";
}
// Is SYN flag on? Then port is open!
else if(tcp.has_flags(TCP::SYN | TCP::ACK)) {
cout << "Port: " << setw(5) << tcp.sport() << " open\n";
}
}
return true;
}
void Scanner::run() {
pthread_t thread;
// Launch our sniff thread.
pthread_create(&thread, 0, &Scanner::thread_proc, this);
// Start sending SYNs to port.
send_syns(iface, host_to_scan);
// Wait for our sniffer.
void* dummy;
pthread_join(thread, &dummy);
}
// Send syns to the given ip address, using the destination ports provided.
void Scanner::send_syns(const NetworkInterface& iface, IPv4Address dest_ip) {
// Retrieve the addresses.
NetworkInterface::Info info = iface.addresses();
PacketSender sender;
// Allocate the IP PDU
IP ip = IP(dest_ip, info.ip_addr) / TCP();
// Get the reference to the TCP PDU
TCP& tcp = ip.rfind_pdu<TCP>();
// Set the SYN flag on.
tcp.set_flag(TCP::SYN, 1);
// Just some random port.
tcp.sport(1337);
cout << "Sending SYNs..." << endl;
for (set<uint16_t>::const_iterator it = ports_to_scan.begin(); it != ports_to_scan.end(); ++it) {
// Set the new port and send the packet!
tcp.dport(*it);
sender.send(ip);
}
// Wait 1 second.
sleep(1);
/* Special packet to indicate that we're done. This will be sniffed
* by our function, which will in turn return false.
*/
tcp.set_flag(TCP::RST, 1);
tcp.sport(*ports_to_scan.begin());
// Pretend we're the scanned host...
ip.src_addr(dest_ip);
// We use an ethernet pdu, otherwise the kernel will drop it.
EthernetII eth = EthernetII(info.hw_addr, info.hw_addr) / ip;
sender.send(eth, iface);
}
void scan(int argc, char* argv[]) {
IPv4Address ip(argv[1]);
// Resolve the interface which will be our gateway
NetworkInterface iface(ip);
cout << "Sniffing on interface: " << iface.name() << endl;
// Consume arguments
argv += 2;
argc -= 2;
Scanner scanner(iface, ip, vector<string>(argv, argv + (argc)));
scanner.run();
}
int main(int argc, char* argv[]) {
if (argc < 3) {
cout << "Usage: " <<* argv << " <IPADDR> <port1> [port2] [port3]" << endl;
return 1;
}
try {
scan(argc, argv);
}
catch(runtime_error& ex) {
cout << "Error - " << ex.what() << endl;
}
}
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