#!/bin/sh


function BBR_Install {
    ## This part of the script is modified from https://github.com/KozakaiAya/TCP_BBR
    apt-get -qqy install dkms
    apt-get -qqy install linux-headers-$(uname -r)
    wget https://raw.githubusercontent.com/jerry048/Seedbox-Components/main/BBR/5.10.0/tcp_bbrx.c
    kernel_ver=5.10.0
    algo=bbrx
    bbr_file=tcp_$algo
    bbr_src=$bbr_file.c
    bbr_obj=$bbr_file.o

    mkdir -p $HOME/.bbr/src
    cd $HOME/.bbr/src

    mv $HOME/$bbr_src $HOME/.bbr/src/$bbr_src

    # Create Makefile
    cat > ./Makefile << EOF
obj-m:=$bbr_obj

default:
	make -C /lib/modules/\$(shell uname -r)/build M=\$(PWD)/src modules

clean:
	-rm modules.order
	-rm Module.symvers
	-rm .[!.]* ..?*
	-rm $bbr_file.mod
	-rm $bbr_file.mod.c
	-rm *.o
	-rm *.cmd
EOF

    # Create dkms.conf
    cd ..
    cat > ./dkms.conf << EOF
MAKE="'make' -C src/"
CLEAN="make -C src/ clean"
BUILT_MODULE_NAME=$bbr_file
BUILT_MODULE_LOCATION=src/
DEST_MODULE_LOCATION=/updates/net/ipv4
PACKAGE_NAME=$algo
PACKAGE_VERSION=$kernel_ver
REMAKE_INITRD=yes
EOF

    # Start dkms install
    cp -R . /usr/src/$algo-$kernel_ver

    dkms add -m $algo -v $kernel_ver
    if [ ! $? -eq 0 ]; then
        dkms remove -m $algo/$kernel_ver --all
        exit 1
    fi

    dkms build -m $algo -v $kernel_ver
    if [ ! $? -eq 0 ]; then
        dkms remove -m $algo/$kernel_ver --all
        exit 1
    fi

    dkms install -m $algo -v $kernel_ver
    if [ ! $? -eq 0 ]; then
        dkms remove -m $algo/$kernel_ver --all
        exit 1
    fi

    # Test loading module
    modprobe $bbr_file
    if [ ! $? -eq 0 ]; then
        exit 1
    fi

    # Auto-load kernel module at system startup
    echo $bbr_file | sudo tee -a /etc/modules
    sed -i '/net.ipv4.tcp_congestion_control/d' /etc/sysctl.conf
    echo "net.ipv4.tcp_congestion_control = $algo" >> /etc/sysctl.conf
    sysctl -p > /dev/null

    cd $HOME
    rm -r $HOME/.bbr
}

## Installing BBR
cd $HOME
BBR_Install

## Clear
systemctl disable bbrinstall.service
rm /etc/systemd/system/bbrinstall.service
rm BBR.sh