int main(int argc, char* argv[]) {
if (argc != 2) {
cout << "Usage: " << argv[0] << " <interface>" << endl;
return 1;
}
try {
// Construct the sniffer configuration object
SnifferConfiguration config;
// Only capture TCP traffic sent from/to port 80
config.set_filter("tcp port 80");
// Construct the sniffer we'll use
Sniffer sniffer(argv[1], config);
cout << "Starting capture on interface " << argv[1] << endl;
// Now construct the stream follower
StreamFollower follower;
// We just need to specify the callback to be executed when a new
// stream is captured. In this stream, you should define which callbacks
// will be executed whenever new data is sent on that stream
// (see on_new_connection)
follower.new_stream_callback(&on_new_connection);
// Now start capturing. Every time there's a new packet, call
// follower.process_packet
sniffer.sniff_loop([&](Packet& packet) {
follower.process_packet(packet);
return true;
});
}
catch (exception& ex) {
cerr << "Error: " << ex.what() << endl;
return 1;
}
}
TEST_F(FlowTest, StreamFollower_FINClosesStream) {
using std::placeholders::_1;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
for (size_t i = 0; i < packets.size(); ++i) {
follower.process_packet(packets[i]);
}
Stream stream = follower.find_stream(IPv4Address("1.2.3.4"), 22,
IPv4Address("4.3.2.1"), 25);
IP server_packet = IP("1.2.3.4", "4.3.2.1") / TCP(22, 25);
server_packet.rfind_pdu<TCP>().flags(TCP::FIN | TCP::ACK);
stream.process_packet(server_packet);
EXPECT_EQ(Flow::FIN_SENT, stream.server_flow().state());
EXPECT_FALSE(stream.is_finished());
IP client_packet = IP("4.3.2.1", "1.2.3.4") / TCP(25, 22);
client_packet.rfind_pdu<TCP>().flags(TCP::FIN | TCP::ACK);
stream.process_packet(client_packet);
EXPECT_EQ(Flow::FIN_SENT, stream.client_flow().state());
EXPECT_TRUE(stream.is_finished());
}
TEST_F(FlowTest, StreamFollower_FollowStream) {
using std::placeholders::_1;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
ordering_info_type chunks = split_payload(payload, 5);
vector<EthernetII> chunk_packets = chunks_to_packets(30 /*initial_seq*/, chunks, payload);
set_endpoints(chunk_packets, "1.2.3.4", 22, "4.3.2.1", 25);
packets.insert(packets.end(), chunk_packets.begin(), chunk_packets.end());
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
for (size_t i = 0; i < packets.size(); ++i) {
follower.process_packet(packets[i]);
}
EXPECT_EQ(chunk_packets.size(), stream_client_payload_chunks.size());
EXPECT_EQ(payload, merge_chunks(stream_client_payload_chunks));
}
TEST_F(FlowTest, StreamFollower_CleanupWorks) {
using std::placeholders::_1;
bool timed_out = false;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
follower.stream_termination_callback([&](Stream&, StreamFollower::TerminationReason reason) {
timed_out = (reason == StreamFollower::TIMEOUT);
});
packets[2].rfind_pdu<IP>().src_addr("6.6.6.6");
auto base_time = duration_cast<Stream::timestamp_type>(system_clock::now().time_since_epoch());
Packet packet1(packets[0], base_time);
Packet packet2(packets[1], base_time + seconds(50));
Packet packet3(packets[2], base_time + minutes(10));
follower.process_packet(packet1);
Stream& stream = follower.find_stream(IPv4Address("1.2.3.4"), 22,
IPv4Address("4.3.2.1"), 25);
EXPECT_EQ(base_time, stream.create_time());
follower.process_packet(packet2);
follower.process_packet(packet3);
// At this point, it should be cleaned up
EXPECT_THROW(
follower.find_stream(IPv4Address("1.2.3.4"), 22, IPv4Address("4.3.2.1"), 25),
stream_not_found
);
EXPECT_TRUE(timed_out);
}
TEST_F(FlowTest, AckNumbersAreCorrect) {
using std::placeholders::_1;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
// Server's ACK number is 9898
packets[1].rfind_pdu<TCP>().ack_seq(9898);
// Client's ACK number is 1717
packets[2].rfind_pdu<TCP>().ack_seq(1717);
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
for (size_t i = 0; i < packets.size(); ++i) {
follower.process_packet(packets[i]);
}
Stream& stream = follower.find_stream(IPv4Address("1.2.3.4"), 22,
IPv4Address("4.3.2.1"), 25);
EXPECT_EQ(1717U, stream.client_flow().ack_tracker().ack_number());
EXPECT_EQ(9898U, stream.server_flow().ack_tracker().ack_number());
}
TEST_F(FlowTest, StreamFollower_ThreeWayHandshake) {
using std::placeholders::_1;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
packets[0].src_addr("00:01:02:03:04:05");
packets[0].dst_addr("05:04:03:02:01:00");
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
Stream::timestamp_type ts(10000);
Stream::timestamp_type create_time = ts;
for (size_t i = 0; i < packets.size(); ++i) {
if (i != 0) {
ts += milliseconds(100);
}
Packet packet(packets[i], duration_cast<microseconds>(ts));
follower.process_packet(packet);
}
Stream& stream = follower.find_stream(IPv4Address("1.2.3.4"), 22,
IPv4Address("4.3.2.1"), 25);
EXPECT_EQ(Flow::ESTABLISHED, stream.client_flow().state());
EXPECT_EQ(Flow::SYN_SENT, stream.server_flow().state());
EXPECT_EQ(30U, stream.client_flow().sequence_number());
EXPECT_EQ(60U, stream.server_flow().sequence_number());
EXPECT_EQ(IPv4Address("4.3.2.1"), stream.client_flow().dst_addr_v4());
EXPECT_EQ(25, stream.client_flow().dport());
EXPECT_EQ(IPv4Address("1.2.3.4"), stream.server_flow().dst_addr_v4());
EXPECT_EQ(22, stream.server_flow().dport());
EXPECT_EQ(IPv4Address("1.2.3.4"), stream.client_addr_v4());
EXPECT_EQ(IPv4Address("4.3.2.1"), stream.server_addr_v4());
EXPECT_EQ(HWAddress<6>("00:01:02:03:04:05"), stream.client_hw_addr());
EXPECT_EQ(HWAddress<6>("05:04:03:02:01:00"), stream.server_hw_addr());
EXPECT_EQ(22, stream.client_port());
EXPECT_EQ(25, stream.server_port());
EXPECT_EQ(create_time, stream.create_time());
EXPECT_EQ(ts, stream.last_seen());
IP server_packet = IP("1.2.3.4", "4.3.2.1") / TCP(22, 25);
server_packet.rfind_pdu<TCP>().flags(TCP::ACK);
follower.process_packet(server_packet);
EXPECT_EQ(Flow::ESTABLISHED, stream.server_flow().state());
EXPECT_EQ(61U, stream.server_flow().sequence_number());
}
TEST_F(FlowTest, StreamFollower_StreamIsRemovedWhenFinished) {
using std::placeholders::_1;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
for (size_t i = 0; i < packets.size(); ++i) {
follower.process_packet(packets[i]);
}
IP server_packet = IP("1.2.3.4", "4.3.2.1") / TCP(22, 25);
server_packet.rfind_pdu<TCP>().flags(TCP::RST);
follower.process_packet(server_packet);
// We shouldn't be able to find it
EXPECT_THROW(
follower.find_stream(IPv4Address("1.2.3.4"), 22, IPv4Address("4.3.2.1"), 25),
stream_not_found
);
}
TEST_F(FlowTest, StreamFollower_TCPOptions) {
using std::placeholders::_1;
vector<EthernetII> packets = three_way_handshake(29, 60, "1.2.3.4", 22, "4.3.2.1", 25);
// Client's mss is 1220
packets[0].rfind_pdu<TCP>().mss(1220);
// Server's mss is 1460
packets[1].rfind_pdu<TCP>().mss(1460);
// Server supports SACK
packets[1].rfind_pdu<TCP>().sack_permitted();
StreamFollower follower;
follower.new_stream_callback(bind(&FlowTest::on_new_stream, this, _1));
for (size_t i = 0; i < packets.size(); ++i) {
follower.process_packet(packets[i]);
}
Stream& stream = follower.find_stream(IPv4Address("1.2.3.4"), 22,
IPv4Address("4.3.2.1"), 25);
EXPECT_EQ(1220, stream.client_flow().mss());
EXPECT_EQ(1460, stream.server_flow().mss());
EXPECT_FALSE(stream.client_flow().sack_permitted());
EXPECT_TRUE(stream.server_flow().sack_permitted());
}