#!/bin/bash
flagFile="/root/centos6-init.executed"
precheck(){
if [[ "$(whoami)" != "root" ]]; then
echo "please run this script as root ." >&2
exit 1
fi
if [ -f "$flagFile" ]; then
echo "this script had been executed, please do not execute again!!" >&2
exit 1
fi
echo -e "\033[31m WARNING! THIS SCRIPT WILL \033[0m\n"
echo -e "\033[31m *1 update the system; \033[0m\n"
echo -e "\033[31m *2 setup security permissions; \033[0m\n"
echo -e "\033[31m *3 stop irrelevant services; \033[0m\n"
echo -e "\033[31m *4 reconfig kernel parameters; \033[0m\n"
echo -e "\033[31m *5 setup timezone and sync time periodically; \033[0m\n"
echo -e "\033[31m *6 setup tcp_wrapper and netfilter firewall; \033[0m\n"
echo -e "\033[31m *7 setup vsftpd; \033[0m\n"
sleep 5
}
yum_update(){
yum -y update
echo "40 3 * * * root yum -y update && yum clean packages" >> /etc/crontab
}
permission_config(){
}
selinux(){
sed -i 's/SELINUX=disabled/SELINUX=enforcing/g' /etc/sysconfig/selinux
setenforce 1
}
stop_services(){
for server in `chkconfig --list |grep 3:on|awk '{print $1}'`
do
chkconfig --level 3 $server off
done
for server in crond network rsyslog sshd iptables
do
chkconfig --level 3 $server on
done
}
limits_config(){
cat >> /etc/security/limits.conf <<EOF
* soft nproc 65535
* hard nproc 65535
* soft nofile 65535
* hard nofile 65535
EOF
echo "ulimit -SH 65535" >> /etc/rc.local
}
sysctl_config(){
sed -i 's/net.ipv4.tcp_syncookies.*$/net.ipv4.tcp_syncookies = 1/g' /etc/sysctl.conf
sed -i 's/net.ipv4.ip_forward.*$/net.ipv4.ip_forward = 1/g' /etc/sysctl.conf
cat >> /etc/sysctl.conf <<EOF
net.ipv4.tcp_max_syn_backlog = 65536
net.core.netdev_max_backlog = 32768
net.core.somaxconn = 32768
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.ip_local_port_range = 1024 65535
EOF
sysctl -p
}
sshd_config(){
if [ ! -f "/root/.ssh/id_rsa.pub" ]; then
ssh-keygen -t rsa -P '' -f /root/.ssh/id_rsa
cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys
chmod 600 /root/.ssh/authorized_keys
fi
sed -i '/^#UseDNS/s/#UseDNS no/UseDNS yes/g' /etc/ssh/sshd_config
sed -i 's/#PermitEmptyPasswords yes/PermitEmptyPasswords no/g' /etc/ssh/sshd_config
sed -i 's/PasswordAuthentication yes/PasswordAuthentication no/g' /etc/ssh/sshd_config
/etc/init.d/sshd restart
}
time_config(){
echo "TZ='Asia/Shanghai'; export TZ" >> /etc/profile
if [! -f "/usr/sbin/ntpdate"]; then
yum -y install ntpdate
fi
/usr/sbin/ntpdate pool.ntp.org
echo "30 3 * * * root (/usr/sbin/ntpdate pool.ntp.org && /sbin/hwclock -w) &> /dev/null" >> /etc/crontab
/sbin/service crond restart
}
iptables(){
cat > /etc/sysconfig/iptables << EOF
*filter
:INPUT DROP [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:syn-flood - [0:0]
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A INPUT -p icmp -m limit --limit 100/sec --limit-burst 100 -j ACCEPT
-A INPUT -p icmp -m limit --limit 1/s --limit-burst 10 -j ACCEPT
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -j syn-flood
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A syn-flood -p tcp -m limit --limit 3/sec --limit-burst 6 -j RETURN
-A syn-flood -j REJECT --reject-with icmp-port-unreachable
COMMIT
EOF
/sbin/service iptables restart
source /etc/profile
}
other(){
sed -i 's/^id:.*$/id:3:initdefault:/' /etc/inittab
/sbin/init q
sed -i '4a auth required pam_tally2.so deny=5 unlock_time=180' /etc/pam.d/system-auth
}
vsftpd_setup(){
yum -y install vsftpd
mv /etc/vsftpd/vsftpd.conf /etc/vsftpd/vsftpd.conf.bak
touch /etc/vsftpd/chroot_list
setsebool -P ftp_home_dir=1
cat >> /etc/vsftpd/vsftpd.conf <<EOF
local_enable=YES
write_enable=YES
local_umask=022
chroot_local_user=YES
chroot_list_enable=YES
chroot_list_file=/etc/vsftpd/chroot_list
local_max_rate=10000000
anonymous_enable=YES
no_anon_password=YES
anon_max_rate=1000000
data_connection_timeout=60
idle_session_timeout=600
max_clients=50
max_per_ip=5
use_localtime=YES
dirmessage_enable=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_std_format=YES
listen=YES
pam_service_name=vsftpd
tcp_wrappers=YES
dual_log_enable=YES
pasv_min_port=65400
pasv_max_port=65410
EOF
chkconfig --level 3 vsftpd on
service vsftpd restart
}
main(){
precheck
printf "\033[32m================%40s================\033[0m\n" "updating the system "
yum_update
printf "\033[32m================%40s================\033[0m\n" "re-config permission "
permission_config
printf "\033[32m================%40s================\033[0m\n" "enabling selinux "
selinux
printf "\033[32m================%40s================\033[0m\n" "stopping irrelevant services "
stop_services
printf "\033[32m================%40s================\033[0m\n" "/etc/security/limits.config "
limits_config
printf "\033[32m================%40s================\033[0m\n" "/etc/sysctl.conf "
sysctl_config
printf "\033[32m================%40s================\033[0m\n" "sshd re-configuring "
sshd_config
printf "\033[32m================%40s================\033[0m\n" "configuring time "
time_config
printf "\033[32m================%40s================\033[0m\n" "configuring firewall "
printf "\033[32m================%40s================\033[0m\n" "someother stuff "
other
printf "\033[32m================%40s================\033[0m\n" "done! rebooting "
touch "$flagFile"
sleep 5
reboot
}
main
