There is a simple tool for SYN flood.
Only for Linux
You can change the script to make a ack/rst/fin/etc script.
Just like :
ack = 0 # 1 is using ack flag
syn = 1 # 1 is using syn flag
git clone https://github.com/Leeon123/Simple-SYN-Flood.git
cd Simple-SYN-Flood
sudo python SYN-Flood.py