SmartCookie Artifact

This repository contains the prototype source code and instructions for artifact evaluation for our USENIX Security'24 paper SMARTCOOKIE: Blocking Large-Scale SYN Floods with a Split-Proxy Defense on Programmable Data Planes.

1. Contents

The artifact consists of two major pieces: 1) source code for the switch agent and server agent of SMARTCOOKIE's split-proxy SYN-flooding defense, related benchmark code, and measurement scripts (showing availability), and 2) a hardware testbed for running and evaluating SMARTCOOKIE under key attack scenarios (showing functionality and reproducibility).

• p4src/ includes the Switch Agent program that calculates SYN cookies using HalfSipHash.
  • p4src/benchmark/ contains variants of the Switch Agent, for benchmarking max hashing rate using a different hash function (AES).
• ebpf/ includes the Server Agent programs that process cookie-verified new connection handshake and false positive packets.
  • ebpf/benchmark/ contains a XDP-based SYN cookie generator, for benchmarking max hashing rate of a server-only solution.
• experiments/ includes the relevant scripts for running key experiments.
  • experiments/measurements/ contains scripts for collecting client-side latency and server-side CPU measurements.

2. Description & Requirements

For the purposes of this artifact evaluation, our testbed consists of five servers and an Intel Tofino Wedge32X-BF programmable switch. Three machines act as attack machines. Two of the attack machines have 4-core Intel Core i5-6500 CPUs and Mellanox ConnectX-4 1x100Gbps NICs, generating attack traffic using DPDK 21.11.0 and pktgen-DPDK 21.11.0. The third attack machine has a 20-core Intel Xeon E5-2680 CPU and an Intel Xl710 2x40 Gbps NIC, generating attack traffic using DPDK 19.11.11 and pktgen-DPDK 19.12.0. Two other machines act as server and client, each with 8-core Intel Xeon D-1541 CPUs and Intel X552 2x10Gbps NICs. For simplicity of artifact evaluation, we are providing evaluators with access to our preconfigured testbed (access instructions below). Instructions for installations and dependencies are briefly included for completeness, but all installations and dependencies are already in place for the evaluation testbed. Next, we describe how to access the testbed, what hardware and software dependencies are required (these are preconfigured for the testbed), and what additional benchmarks can be run.

2.1 Security, privacy, and ethical concerns

There are no security, privacy, or ethical concerns or risks to evaluators or their machines. All experiments can be run on the authors’ testbed, which is provisioned for the planned attack rates. For testbed access, please do not share or distribute the private key (discussed further below).

2.2 Accessing the testbed

• Save the SSH private access key (shared with you directly on the submission site) to your local machine under ~/.ssh/usenixsec24ae.priv.id_rsa. Note your sudo password was also shared with you on the submission site.
• Update the permissions with chmod 600 ~/.ssh/usenixsec24ae.priv.id_rsa.
• Start the ssh-agent and load the key: eval $(ssh-agent -s) and ssh-add ~/.ssh/usenixsec24ae.priv.id_rsa.
• Put the following text into your local machine’s ~/.ssh/config, such that you can ssh into the machines by hostname using the public-facing proxy port. Your public keys are already in place.

    Host jc-gateway # Gateway server (jumphost) 
        HostName 24.229.186.134
        User usenixsec24ae
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
    Host jc5        # Client server
        HostName 10.0.0.5
        User usenixsec24ae
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
        ProxyJump jc-gateway
    Host jc6        # Server agent
        HostName 10.0.0.6
        User usenixsec24ae
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
        ProxyJump jc-gateway
    Host opti1        # Attack server 1 
        HostName 10.0.0.7             
        User usenixsec24ae
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
        ProxyJump jc-gateway
    Host opti2        # Attack server 2 
        HostName 10.0.0.8             
        User usenixsec24ae
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
        ProxyJump jc-gateway
    Host jc4        # Attack server 3 
        HostName 10.0.0.4
        User usenixsec24ae
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
        ProxyJump jc-gateway
    Host jc-tofino  # Switch agent 
        HostName 10.0.0.100
        User jsonch
        IdentityFile ~/.ssh/usenixsec24ae.priv.id_rsa
        ProxyJump jc-gateway

2.3 Hardware dependencies

The switch agent requires an Intel Tofino Wedge32X-BF programmable switch. In order to stress test the switch agent and observe the full capacity of the defense, the adversarial machines must be capable of generating at least 150 Mpps of combined adversarial traffic. This can be accomplished with either two attack machines with 20 cores and 2x100Gbps links, or with three or more machines with fewer cores.

2.4 Software dependencies (For evaluation simplicity, all software dependencies are pre-installed and configured on the artifact testbed.)

• Switch Agent Prerequisite: please use bf-sde version 9.7.1 or newer to compile the P4 program.
• Server Agent Prerequisite: please use kernel 5.10 or newer and the latest version of the bcc toolkit. (For Ubuntu, you may run sudo apt-get install bpfcc-tools python3-bpfcc linux-headers-$(uname -r))
• Adversary Machine Prerequisite: please use DPDK 19.12.0 or newer and a matching pktgen-DPDK version.

2.5 Benchmarks

We compare the cookie hashing performance of SMARTCOOKIE’s switch-based HalfSipHash to that of AES (on the switch) and XDP (on the server). Source code and setup instructions are under /p4src/benchmark and /ebpf/benchmark/ respectively.

3. Usage and a Basic Test (Estimate: 15 human-minutes)

We next describe the setup and configuration steps to launch SMARTCOOKIE and prepare the testbed environment for evaluation. We also walk through a simple functionality test of the switch agent and server agent, with an end-to-end connection test between a client and server.

3.1 Compiling and launching the Switch Agent (Terminal 1)

• First, open a new terminal window and SSH into the switch ssh jc-tofino.
• Clone the SMARTCOOKIE artifact repo and cd SmartCookie-Artifact/p4src.
• Run the ./switchagent_compile.sh script to compile the program. This may take a few seconds, and you will see some warnings, but these can safely be ignored. Note this step only needs to be done once, unless there are changes made to the program.
• Once the compilation is complete, run ./switchagent_load.sh to load the SMARTCOOKIE-HalfSipHash.p4 program onto the switch. A successful load should output bfruntime gRPC server started as the last log line and land on the switch driver shell starting with bfshell>.
• Keep this terminal open while running experiments, and open other terminals for other operations.
• If, for any reason you need to restart the switch driver, run sudo killall bf_switchd first, then run ./switchagent_load.sh to reload the program again.
• Next, to configure the switch interfaces, copy and paste the below in the bfshell> to manually bring up ports:

    ucli
    pm
    port-add 1/1 10G NONE
    an-set 1/1 2
    port-enb 1/1
    an-set 1/1 1   
    port-add 1/3 10G NONE
    an-set 1/3 2
    port-enb 1/3
    an-set 1/3 1    
    port-add 3/0 100G RS     
    port-enb 3/0
    port-add 4/0 100G RS 
    port-enb 4/0
    port-add 5/0 40G NONE
    an-set 5/0 2
    port-enb 5/0
    an-set 5/0 1   
    port-add 6/0 40G NONE
    an-set 6/0 2
    port-enb 6/0
    an-set 6/0 1  
    show
    rate-period 1
    rate-show 
  

The last three bfshell> commands will list packet counts and throughput rates for each of the interfaces linked to the servers. This is the mapping between the servers and switch ports.

• CLIENT (10G link): Port 1/1 with DPID 129 (hex 0x81) is linked to jc5, with assigned client IP address 129.0.0.5
• SERVER (10G link): Port 1/3 with DPID 131 (hex 0x83) is linked to jc6, with assigned server IP address 131.0.0.6
• ATTACK SERVER 1 (100G link): Port 3/0 with DPID 144 (hex 0x90) is linked to opti1, with assigned IP address 144.0.0.7.
• ATTACK SERVER 2 (100G link): Port 4/0 with DPID 152 (hex 0x98) is linked to opti2, with assigned IP address 152.0.0.8.
• ATTACK SERVER 3 (two 40G links): Port 5/0 with DPID 160 (hex 0xA0) is linked to jc4 port 1, with assigned IP address 160.0.0.4, and Port 6/0 with DPID 168 (hex 0xA8) is linked to jc4 port 0, with assigned IP address 168.0.0.4.

3.2 Launching the Server Agent (Terminal 2, 3, & 4)

• Open three other terminal windows and access the server agent with ssh jc6 in each window.
• Clone the artifact repo on jc6 if you haven't already, and cd SmartCookie-Artifact/ebpf.
• Run ./configure/configure_server.sh once to configure static IP addresses and ARP entries.
• Next, use the provided python scripts in the separate terminals to compile and load the eBPF programs to the interface connected to the switch:
  • 1. sudo python3 xdp_load.py enp3s0f1 for ingress
  • 2. sudo python3 tc_load.py enp3s0f1 for egress
• You should see output that the programs have been loaded.
• Finally, run the following python script to sync timestamps between the server agent and switch agent, which is necessary for cookie checks: sudo python3 send_ts.py.

3.3 A Quick Functionality Test (Terminal 5 & 6)

• To test a simple end-to-end connection between the jc5 client and jc6 server (protected by the intermediate switch agent and server agent), open two more terminals.
• SSH into the client with ssh jc5 and SSH once more into the server with ssh jc6.
• On the server jc6, start up a netcat server with nc -l -p 2020.
• On the client jc5, connect to the netcat server with nc 131.0.0.6 2020.
• The client will seamlessly connect to the server after verification at the switch agent, and you can send messages between the client and server, with the messages popping up on the receiving side.
• If you are curious, you can use tcpdump -evvvnX -i enp3s0f1 on both client and server to view the full packet sequence during connection setup, and map it to that of Figure 4 in the paper.
• Note that tcpdump is positioned after XDP on the ingress pipeline, and after TC on the egress pipeline (XDP-->tcpdump--> network stack on ingress, and network stack-->TC->tcpdump on egress).

4. Evaluation Workflow

There are three main experiments that showcase the key results and major claims of our work. These are described next.

4.0 Major Claims

• C1: SMARTCOOKIE defends against attacks without packet loss until high rates (up to 136 Mpps), significantly outperforming the benchmarks of other defenses, which become exhausted at attack rates starting at only ~1.3 Mpps up to ~52 Mpps. This is proven by experiment (E1), and described in Section 8.2 of the paper.
• C2: During attacks, SMARTCOOKIE protects benign clients from performance penalties and protects servers from additional CPU usage. It adds little to no latency overhead to benign connections during attacks, and any latency is comparable to the baseline latency with no ongoing attack. Additionally, it protects the server's CPU during attacks, fully keeping the CPU resources for other applications. This is proven by experiments (E2) and (E3), and shown in Section 8.3 and 8.4 of the paper.

4.1 Experiment 1 - Hashing Throughput (Estimate: 1 human-hour)

Description: Compare the hashing throughput SMARTCOOKIE-HalfSipHash (SC-HSH) can achieve without packet loss to the maximum hashing throughput of the three benchmarks:

• SMARTCOOKIE-AES (SC-AES)
• XDP-HalfSipHash (XDP-HSH)
• Kernel-SipHash (K-SH)

Use DPDK to send spoofed attack packets to the server while increasing sending rates, and observe the response packet rates untl loss is observed on the switch (for SC-AES and SC-AES) or server (for K-SH and XDP-HSH). (As noted in the paper, since our benchmarks perform one hash calculation per SYN packet, we effectively measure maximum hashing throughput.) The Tx (response) rates should exactly match Rx (received) rates for as long as SMARTCOOKIE or the benchmark is handling the attack without any packet loss. Once a defense begins to reach its capacity, the Tx rate will begin to dip below Rx rates.

Each of the defense benchmarks have slightly different setup and attack steps, which are described next. Note that the workflow for each experiment benchmark MUST BE RUN SEPARATELY, but instructions are grouped together below for some experiments, since many steps overlap.

Experiment 1A and 1B: SC-HSH and SC-AES

Initial Preparation for Experiment 1A:

• For SC-HSH, launch the switch agent in jc-tofino, as described in 3.1 above.

Initial Preparation for Experiment 1B:

• For SC-AES, launch the AES variant of the switch agent by following the workflow described in 3.1, with the exception of these different steps:
  • cd /p4src/benchmark (instead of cd /p4src).
  • Run the ./aes_switchagent_compile.sh script to compile the program (instead of ./switchagent_compile.sh). Note this step only needs to be done once, unless there are changes made to the program.
  • Once the compilation is complete, run ./aes_switchagent_load.sh to load the SMARTCOOKIE-AES.p4 program onto the switch (instead of ./switchagent_load.sh).
  • Follow the remainder of the steps in 3.1 (e.g., initializing ports).
• Then, run the controller script to load an arbitrary encryption key (this is required to set up recirculation rounds correctly): python3 SmartCookie-AES-controller/install_key.py 0x000102030405060708090a0b0c0d0e0f. The script may take a few seconds to a minute to install the key.

Attack Preparation for both Experiment 1A and 1B:

• In three additional terminals, SSH into the attack machines: ssh opti1, ssh opti2, and ssh jc4. DPDK and pktgen-DPDK are already configured for you.
• For each attack terminal, cd /home/shared/pktgen-dpdk and launch pktgen with sudo -E tools/run.py testbed.
• If the server has been rebooted recently, reconfigure the huge pages: cd /home/shared/dpdk/usertools and run ./dpdk-setup.sh.
  • On opti1 and opti2, we have non-NUMA systems, so choose the option to setup hugepage mappings for non-NUMA systems [5]. Meanwhile, for jc4, choose the option for NUMA systems [52].
  • Enter 8192 pages per node.
  • Exit the script and return to the above steps to launch pktgen.

Attack Execution for both Experiment 1A and 1B:

• From within the Pktgen:/> console of each of the attack machines, launch the SYN flood against the jc6 server, using the following commands (which set the SYN flag 0x02 with a random mask, and spoof source IPs).
• On attack server opti1, copy-paste the following comands:

  set 0 type ipv4
  set 0 count 0
  set 0 burst 10000
  set 0 rate 1
  enable 0 random 
  set 0 rnd 0 46 ........00000010................
  set 0 proto tcp
  set 0 size 40 
  set 0 src mac 00:00:00:00:00:90
  set 0 dst mac 00:00:00:00:00:83 
  set 0 src ip 144.0.0.7/32 
  set 0 dst ip 131.0.0.6
  set 0 dport 8090 
  start 0
  

• On attack server opti2, copy-paste the following comands:

  set 0 type ipv4
  set 0 count 0
  set 0 burst 10000
  set 0 rate 1
  enable 0 random 
  set 0 rnd 0 46 ........00000010................
  set 0 proto tcp
  set 0 size 40 
  set 0 src mac 00:00:00:00:00:98
  set 0 dst mac 00:00:00:00:00:83 
  set 0 src ip 152.0.0.8/32 
  set 0 dst ip 131.0.0.6
  set 0 dport 8090 
  start 0
  

• On attack server jc4, copy-paste the following comands:

  set 0 type ipv4
  set 0 count 0
  set 0 burst 10000
  set 0 rate 1
  enable 0 random 
  set 0 rnd 0 46 ........00000010................
  set 0 proto tcp
  set 0 size 40 
  set 0 src mac 00:00:00:00:00:A8
  set 0 dst mac 00:00:00:00:00:83
  set 0 src ip 168.0.0.4/32 
  set 0 dst ip 131.0.0.6
  set 0 dport 8090 
  
  set 1 type ipv4
  set 1 count 0
  set 1 burst 10000
  set 1 rate 1
  enable 1 random 
  set 1 rnd 0 46 ........00000010................
  set 1 proto tcp
  set 1 size 40 
  set 1 src mac 00:00:00:00:00:A0
  set 1 dst mac 00:00:00:00:00:83
  set 1 src ip 160.0.0.4/32 
  set 1 dst ip 131.0.0.6
  set 1 dport 8090 
  
  start 0
  start 1   
  

• The commands start 0 and start 1 begin the attack, and you should see pktgen's continuous Rx/Tx rates in the Pktgen:/> consoles. (Note: If the console displays ever get messy, page main will reset the display.)
• In the switch agent's bf-sde.pm> console, the command rate-show will also show Rx/Tx rates of the attack on the switch (ports 3/0, 4/0, 5/0, and 6/0).

Results for both Experiment 1A and 1B:

• To observe the maximum attack rate that SC-HSH and SC-AES can handle before any packet loss, you can play around with increasing the sending attack rate with commands set 0 rate X and set 1 rate X, with a maximum X of 100. As long as the Rx/Tx rates observed with rate-show in the switch agent match each other, the switch agent is successfully defending against the SYN flood attack packets without any packet loss.
• SC-HSH can accomplish this up until rates of ~136 Mpps, while SC-AES can only achieve ~52 Mpps.
• To verify these maximum rates directly, use the following attack rates:
  • Turn off attack traffic from both opti1 and opti2 with stop 0.
  • Max out the sending rates on both ports on jc4 with set 0 rate 100 and set 1 rate 100. Using rate-show in the switch console, you should see the combined Tx (response) rate from both ports matches the combined Rx (received) rate at ~37.8 Mpps.
  • For SC-AES: Turn on the attack from opti1 with set 0 rate 1 and start 0. Refresh the switch counters (rate-show), and confirm the Rx/Tx rates still match (it should be ~39 Mpps). Try inching the attack rate up on opti1 with set 0 rate 5, and observe that at ~45 Mpps total attack rates the loss on the switch remains 0 (or very close to it). Increase the attack rate to ~52 Mpps with set 0 rate 10 on opti1, and observe some now-consistent loss on the Tx rate of the switch (although it should still be a relatively low loss rate). Finally, increase the attack rate to ~59 Mpps with set 0 rate 15 on opti1, and observe that the Tx rate on the switch has now dropped consistently and significantly below the Rx rate (the Tx should be about ~53 Mpps), showing that SC-AES has reached its maximum defense capacity. To see this effect magnified, increase the attack rate to 80 Mpps with set 0 rate 100 on opti1, and observe that the response rate drops to ~41 Mpps, compared to the ~80 Mpps attack rate. At this point, the defense is effectively dropping 50% of the traffic it receives without being able to process it.
  • For SC-HSH: Directly max out the sending rate from opti1 with set 0 rate 100 (with jc4 attack continuing as well). You should see that even under an ~80 Mpps attack, the SMARTCOOKIE-HalfSipHash switch agent defends against the attack without any packet loss (the Tx rate closely matching the Rx rate on the switch). Max out the sending rate from opti2 with set 0 rate 100 as well, to get to a total attack rate of ~113 Mpps. You should see that the switch agent continues to maintain the defense without packet loss. SC-HSH can achieve this performance up to ~135 Mpps, but unfortunately due to the hardware limitations in our artifact testbed (which is separately operated from the testbed hardware we used in our original experiments), we can only demonstrate attack rates up to ~113 Mpps.

Experiment 1C and 1D: XDP-HSH and K-SH

Initial Preparation for both Experiment 1C and 1D:

• For XDP-HSH and K-SH, there is no defense running on the switch. Instead, we need to launch a supporting wire program (synflood_assist.p4) on the switch, which ensures attack traffic from DPDK are properly formed SYN packets before they are forwarded onto the server (where the XDP and kernel defenses operate). Follow the workflow described in 3.1, with the exception of these different steps:
  • cd /p4src/benchmark (instead of cd /p4src).
  • Run the ./switch_assist_compile.sh script to compile the program (instead of ./switchagent_compile.sh). Note this step only needs to be done once, unless there are changes made to the program.
  • Once the compilation is complete, run ./switch_assist_load.sh to load the synflood_assist.p4 program onto the switch (instead of ./switchagent_load.sh).
  • Follow the remainder of the steps in 3.1 (e.g., initializing ports).
• For just XDP-HSH, we also need to bring up benchmark defense code on the server:
  • SSH into the server with ssh jc6 and cd SmartCookie-Artifact/ebpf/benchmark.
  • Run sudo python3 xdp_cookie_load.py enp3s0f1 3 to launch the XDP cookie defense. (The final argument specifies the IFINDEX which is associated with the interface, and can be found with ip a.)
• For both XDP-HSH and K-SH, launch an http server on the jc6 server that will be ready to accept connection requests from incoming SYN packets:
  • SSH into the server with ssh jc6 and cd SmartCookie-Artifact/experiments.
  • Run go run http_server.go, which will launch an HTTP server that listens for connections on port 8090.
• Finally, for both XDP-HSH and K-SH, load measurement scripts on the jc6 server that will track its Rx and Tx rates:
  • Open two new terminals. In each terminal, SSH into the server with ssh jc6 and cd SmartCookie-Artifact/experiments/measurements.
    • 1. ./rx_pps.sh to capture a continous Rx packet count
    • 2. ./tx_pps.sh to capture a continous Tx packet count

Attack Preparation for both Experiment 1C and 1D:

• In one additional terminal, SSH into JUST the opti1 attack machine: ssh opti1 (we only need one attack machine for these benchmarks, as they are easily overwhelmed by lower attack rates). DPDK and pktgen-DPDK are already configured for you.
• In the opti1 terminal, cd /home/shared/pktgen-dpdk and launch pktgen with sudo -E tools/run.py testbed.

Attack Execution for both Experiment 1C and 1D:

• From within the Pktgen:/> console, launch the attack against the jc6 server, using the following commands (NOTE: we are generating spoofed UDP packets here, which the synflood_assist.p4 program on the switch converts to properly formed SYN packets before sending to the server, as generating properly formed SYN packets was less convenient to do directly using pktgen).
• On attack server opti1, copy-paste the following comands:

	set 0 type ipv4
	set 0 count 0
	set 0 burst 10000
	set 0 rate 0.01
	enable 0 range 
	range 0 proto udp
	range 0 size 64 64 64 0 
	range 0 src mac 00:00:00:00:00:90 00:00:00:00:00:90 00:00:00:00:00:90 00:00:00:00:00:00
	range 0 dst mac 00:00:00:00:00:83 00:00:00:00:00:83 00:00:00:00:00:83 00:00:00:00:00:00
	range 0 src ip 144.0.0.7 144.0.0.7 144.0.255.255 0.0.0.1
	range 0 dst ip 131.0.0.6 131.0.0.6 131.0.0.6 0.0.0.0 
	range 0 dst port 8090 8090 8090 0
	start 0

• The commands start 0 and start 1 begin the attack, and you should see pktgen's continuous Rx/Tx rates in the Pktgen:/> consoles. (Note: If the console displays ever get messy, page main will reset the display. Also, page main displays the sending counters, but does not reflect the configurations from the commands above. Go to page range to see these.)
• In the switch's bf-sde.pm> console, the command rate-show will also show Rx/Tx rates of the attack on the switch (port 3/0 for opti1). Look at Tx rates on 1/3 to see the packets sent to the jc6 server, and compare this to the Rx rates on 1/3, which shows the packets received back from the server (the server's response rate).

Results for both Experiment 1C and 1D:

• To observe the maximum attack rate that XDP-HSH and K-SH can handle before any packet loss, you can play around with increasing the sending attack rate with commands set 0 rate X with a maximum X of 100. As long as the Rx/Tx rates observed with rate-show for port 1/3 in the switch match each other, and the rx_pps.sh and tx_pps.sh measurement script outputs on the server also generally match each other, the benchmark is defending against the SYN flood attack packets without packet loss.
• XDP-HSH can only accomplish this until around ~7.3 Mpps, while K-SH can only reach ~1.3 Mpps before the server's CPUs are exhausted.
  • To verify these maximum rates directly, use the following attack rates:
    • Turn on the attack from just opti1 with set 0 rate 0.5 and start 0. Using rate-show in the switch console, you should see the Tx (send) rate on port 1/3 match the Rx (received) rate at ~0.74 Mpps. The measurement scripts on the server should also show a similar count of Rx and Tx packets.
    • For XDP-HSH: Increase the attack from opti1 with set 0 rate 3. Refresh the switch counters (rate-show), and confirm the Rx/Tx rates still match (it should be ~4.45 Mpps). Try inching the attack rate up with set 0 rate 4.5, and observe that at ~6.6 Mpps attack rates we are beginning to see some loss in the server's response (Rx counters on port 1/3 on the switch). Increase the attack rate to ~7.3 Mpps with set 0 rate 5 on opti1, and observe some now-consistent loss on the Rx rate of port 1/3 on the switch. Finally, increase the attack rate to ~14.7 Mpps with set 0 rate 10 on opti1, and observe that the Rx rate on 1/3 of the switch has now dropped consistently and significantly below the Tx rate, showing that XDP-HSH has reached its maximum defense capacity.
    • For K-SH: Slowly increase the attack from opti1 with set 0 rate 0.75. Refresh the switch counters (rate-show), and confirm the Rx/Tx rates still match (it should be ~1.11 Mpps). Try inching the attack rate up with set 0 rate 0.9, and observe that at ~1.3 Mpps attack rates we are beginning to see some loss in the server's response (Rx counters on port 1/3 on the switch). Increase the attack rate to ~2.2 Mpps with set 0 rate 1.5 on opti1, and observe some now-consistent loss on the Rx rate of port 1/3 on the switch. Finally, increase the attack rate to ~14.7 Mpps with set 0 rate 10 on opti1, and observe that the Rx rate on 1/3 of the switch has now dropped consistently and significantly below the Tx rate, showing that K-SH has reached its maximum defense capacity.

4.2 Experiment 2 - Latency Overhead (Estimate: 1 human-hour)

Description: Measure the end-to-end setup latency for benign client connections during an attack, to show that SMARTCOOKIE adds little to no latency overhead compared to the baseline without any attack.

4.2.1 Preparation for Experiment 2

• Bring up the SMARTCOOKIE switch agent and server agent as described 3.1 and 3.2 of this README. * Start up an HTTP server on port 8090 on the jc6 server with go run experiments/http_server.go.
• In one additional terminal, SSH into the opti1 attack machine: ssh opti1 (we only need one attack machine for these benchmarks, as they are easily overwhelmed by lower attack rates). DPDK and pktgen-DPDK are already configured for you.
  • In the opti1 terminal, cd /home/shared/pktgen-dpdk and launch pktgen with sudo -E tools/run.py testbed.

4.2.2 Execution for Experiment 2

• From within the Pktgen:/> console of opti1, launch the SYN flood against the jc6 server, using the following commands (which set the SYN flag 0x02 with a random mask, and spoof source IPs):

	set 0 type ipv4
	set 0 count 0
	set 0 burst 10000
	set 0 rate 1
	enable 0 random 
	set 0 rnd 0 46 ........00000010................
	set 0 proto tcp
	set 0 size 40 
	set 0 src mac 00:00:00:00:00:90
	set 0 dst mac 00:00:00:00:00:83 
	set 0 src ip 144.0.0.7/32 
	set 0 dst ip 131.0.0.6
	set 0 dport 8090 
	start 0

4.2.3 Results for Experiment 2

• On the jc5 client machine, measure the connection latency across multiple clients by running the script ./experiments/measurements/collect_latency.sh <attack\_rps> <local\_port>, specifying the current attack rate and desired local source port. The latency collection script will print out connection latency.
• As describd in 4.1, play with different attack rates (using set 0 rate X on opti1), and verify with the latency measurement script what the end-to-end connection latencies are under different attacks. Figure 6 in the paper presents results up until attack rates of ~35 Mpps, and you should see that the latency remains effectively the same throughout (note that this will be the case for SMARTCOOKIE up until ~135 Mpps).
• Finally, you can turn off the attack and verify what the average end-to-end connection latency is for the baseline without the attack, and compare it to the latency during an attack, which should be relatively close.

4.3 Experiment 3 - Server CPU Usage (Estimate: 1 human-hour)

Description: Measure the CPU usage on the server during an attack, to show that SMARTCOOKIE fully protects server CPU usage during attacks.

4.3.1 Preparation for Experiment 3

The preparation for E3 is identical to that of E2 (4.2.2).

4.3.2 Execution for Experiment 3

The execution for E3 is identical to that of E2 (4.2.2).

4.3.3 Results for Experiment 3

• The simplest way to verify and visualize the CPU usage is with htop on the jc6 server machine. You can keep a terminal open to continually track CPU usage during the experiment.
• The more robust way of measuring the CPU usage is to run the script ./experiments/measurements/collect_cpu_instr.sh <attack_rps>, while specifying the current attack rate and where the collected data should be stored.
• As describd in 4.1, play with different attack rates (using set 0 rate X on opti1), and verify with htop and the CPU measurement script what the usage rates are under different attacks. Figure 7 in the paper presents results up until attack rates of ~35 Mpps, and you should see that the CPU usage remains almost non-existent throughout (note that this will be the case for SMARTCOOKIE up until ~135 Mpps).
• Finally, you can turn off the attack and verify what the CPU usage is for the baseline without the attack, and it should directly match the CPU usage during an attack (effectively none), demonstrating that SMARTCOOKIE fully protects the server from CPU usage during attacks.

Citing

If you find this implementation or our paper useful, please consider citing:

@inproceedings{yoo2024smartcookie,
    title={SMARTCOOKIE: Blocking Large-Scale SYN Floods with a Split-Proxy Defense on Programmable Data Planes},
    author={Yoo, Sophia and Chen, Xiaoqi and Rexford, Jennifer},
    booktitle={33rd USENIX Security Symposium (USENIX Security 24)},
    year={2024},
    publisher={USENIX Association}
}

License

Copyright 2023 Sophia Yoo & Xiaoqi Chen, Princeton University.

The project's source code are released here under the GNU Affero General Public License v3. In particular,

• You are entitled to redistribute the program or its modified version, however you must also make available the full source code and a copy of the license to the recipient. Any modified version or derivative work must also be licensed under the same licensing terms.
• You also must make available a copy of the modified program's source code available, under the same licensing terms, to all users interacting with the modified program remotely through a computer network.

(TL;DR: you should also open-source your derivative work's source code under AGPLv3.)