Ubuntu的默认防火墙管理工具是ufw，它是一个通过Python实现的工具，最终也是转换为iptables命令实现防火墙规则过滤的。
但有一点比较令人讨厌的是，ufw默认启用了非常多的规则，且配置文件非常不便于配置。
而对于习惯于直接通过iptables指令来设置防火墙规则的管理员，RHEL的iptables脚本管理方式就非常的干净利落。
但是直接将RHEL上的iptables脚本拿到Ubuntu下，是无法正常运行的，需要做很多的修改。
以下是相关步骤：
1.创建配置文件iptables-conf
$ sudo mkdir /etc/sysconfig
$ sudo vim /etc/sysconfig/iptables-config
# Load additional iptables modules (nat helpers) # Default: -none- # Space separated list of nat helpers (e.g. 'ip_nat_ftp ip_nat_irc'), which # are loaded after the firewall rules are applied. Options for the helpers are # stored in /etc/modprobe.conf. IPTABLES_MODULES="" # Unload modules on restart and stop # Value: yes|no, default: yes # This option has to be 'yes' to get to a sane state for a firewall # restart or stop. Only set to 'no' if there are problems unloading netfilter # modules. IPTABLES_MODULES_UNLOAD="yes" # Save current firewall rules on stop. # Value: yes|no, default: no # Saves all firewall rules to /etc/sysconfig/iptables if firewall gets stopped # (e.g. on system shutdown). IPTABLES_SAVE_ON_STOP="no" # Save current firewall rules on restart. # Value: yes|no, default: no # Saves all firewall rules to /etc/sysconfig/iptables if firewall gets # restarted. IPTABLES_SAVE_ON_RESTART="no" # Save (and restore) rule and chain counter. # Value: yes|no, default: no # Save counters for rules and chains to /etc/sysconfig/iptables if # 'service iptables save' is called or on stop or restart if SAVE_ON_STOP or # SAVE_ON_RESTART is enabled. IPTABLES_SAVE_COUNTER="no" # Numeric status output # Value: yes|no, default: yes # Print IP addresses and port numbers in numeric format in the status output. IPTABLES_STATUS_NUMERIC="yes" # Verbose status output # Value: yes|no, default: yes # Print info about the number of packets and bytes plus the "input-" and # "outputdevice" in the status output. IPTABLES_STATUS_VERBOSE="no" # Status output with numbered lines # Value: yes|no, default: yes # Print a counter/number for every rule in the status output. IPTABLES_STATUS_LINENUMBERS="yes"
2.创建规则命令文件iptables（以我的Blog为例）
$ sudo vim /etc/sysconfig/iptables
*filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [4336605:3237430358] :OUTPUT ACCEPT [19418758:35598823868] -A INPUT -i lo -j ACCEPT -A INPUT -s 10.10.10.0/255.255.255.0 -j ACCEPT -A INPUT -p gre -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 47 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 1723 -j ACCEPT -A INPUT -p udp -m state --state NEW -m udp --dport 1194 -j ACCEPT -A INPUT -p icmp -m icmp --icmp-type any -j ACCEPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p udp -m udp --dport 53 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 443 -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 -j REJECT --reject-with icmp-host-prohibited COMMIT
3.创建经过修改过后得以成功执行的管理服务脚本：
$ sudo touch /etc/init.d/iptables
$ sudo chmod +x /etc/init.d/iptables
$ sudo vim /etc/init.d/iptables
#!/bin/bash
#
# iptables Start iptables firewall
#
# chkconfig: 2345 08 92
# description: Starts, stops and saves iptables firewall
#
# config: /etc/sysconfig/iptables
# config: /etc/sysconfig/iptables-config
# Source function library.
. /lib/lsb/init-functions
IPTABLES=iptables
IPTABLES_DATA=/etc/sysconfig/$IPTABLES
IPTABLES_CONFIG=/etc/sysconfig/${IPTABLES}-config
IPV=${IPTABLES%tables} # ip for ipv4 | ip6 for ipv6
PROC_IPTABLES_NAMES=/proc/net/${IPV}_tables_names
VAR_SUBSYS_IPTABLES=/var/lock/subsys/$IPTABLES
if [ ! -x /sbin/$IPTABLES ]; then
log_failure_msg $"/sbin/$IPTABLES does not exist."
exit 0
fi
if lsmod 2>/dev/null | grep -q ipchains ; then
log_failure_msg $"ipchains and $IPTABLES can not be used together."
exit 0
fi
# Old or new modutils
/sbin/modprobe --version 2>&1 | grep -q module-init-tools \
&& NEW_MODUTILS=1 \
|| NEW_MODUTILS=0
# Default firewall configuration:
IPTABLES_MODULES=""
IPTABLES_MODULES_UNLOAD="yes"
IPTABLES_SAVE_ON_STOP="no"
IPTABLES_SAVE_ON_RESTART="no"
IPTABLES_SAVE_COUNTER="no"
IPTABLES_STATUS_NUMERIC="yes"
# Load firewall configuration.
[ -f "$IPTABLES_CONFIG" ] && . "$IPTABLES_CONFIG"
rmmod_r() {
# Unload module with all referring modules.
# At first all referring modules will be unloaded, then the module itself.
local mod=$1
local ret=0
local ref=
# Get referring modules.
# New modutils have another output format.
[ $NEW_MODUTILS = 1 ] \
&& ref=`lsmod | awk "/^${mod}/ { print \\\$4; }" | tr ',' ' '` \
|| ref=`lsmod | grep ^${mod} | cut -d "[" -s -f 2 | cut -d "]" -s -f 1`
# recursive call for all referring modules
for i in $ref; do
rmmod_r $i
let ret+=$?;
done
# Unload module.
# The extra test is for 2.6: The module might have autocleaned,
# after all referring modules are unloaded.
if grep -q "^${mod}" /proc/modules ; then
modprobe -r $mod > /dev/null 2>&1
let ret+=$?;
fi
return $ret
}
flush_n_delete() {
# Flush firewall rules and delete chains.
[ -e "$PROC_IPTABLES_NAMES" ] || return 1
# Check if firewall is configured (has tables)
tables=`cat $PROC_IPTABLES_NAMES 2>/dev/null`
[ -z "$tables" ] && return 1
log_daemon_msg $"Flushing firewall rules: "
ret=0
# For all tables
for i in $tables; do
# Flush firewall rules.
$IPTABLES -t $i -F;
let ret+=$?;
# Delete firewall chains.
$IPTABLES -t $i -X;
let ret+=$?;
# Set counter to zero.
$IPTABLES -t $i -Z;
let ret+=$?;
done
[ $ret -eq 0 ] && log_end_msg 0 || log_end_msg 1
echo
return $ret
}
set_policy() {
# Set policy for configured tables.
policy=$1
# Check if iptable module is loaded
[ ! -e "$PROC_IPTABLES_NAMES" ] && return 1
# Check if firewall is configured (has tables)
tables=`cat $PROC_IPTABLES_NAMES 2>/dev/null`
[ -z "$tables" ] && return 1
log_daemon_msg $"Setting chains to policy $policy: "
ret=0
for i in $tables; do
log_daemon_msg "$i "
case "$i" in
raw)
$IPTABLES -t raw -P PREROUTING $policy \
&& $IPTABLES -t raw -P OUTPUT $policy \
|| let ret+=1
;;
filter)
$IPTABLES -t filter -P INPUT $policy \
&& $IPTABLES -t filter -P OUTPUT $policy \
&& $IPTABLES -t filter -P FORWARD $policy \
|| let ret+=1
;;
nat)
$IPTABLES -t nat -P PREROUTING $policy \
&& $IPTABLES -t nat -P POSTROUTING $policy \
&& $IPTABLES -t nat -P OUTPUT $policy \
|| let ret+=1
;;
mangle)
$IPTABLES -t mangle -P PREROUTING $policy \
&& $IPTABLES -t mangle -P POSTROUTING $policy \
&& $IPTABLES -t mangle -P INPUT $policy \
&& $IPTABLES -t mangle -P OUTPUT $policy \
&& $IPTABLES -t mangle -P FORWARD $policy \
|| let ret+=1
;;
*)
let ret+=1
;;
esac
done
[ $ret -eq 0 ] && log_end_msg 0 || log_end_msg 1
echo
return $ret
}
start() {
# Do not start if there is no config file.
[ -f "$IPTABLES_DATA" ] || return 1
log_daemon_msg $"Applying $IPTABLES firewall rules: "
OPT=
[ "x$IPTABLES_SAVE_COUNTER" = "xyes" ] && OPT="-c"
$IPTABLES-restore $OPT $IPTABLES_DATA
if [ $? -eq 0 ]; then
log_end_msg 0; echo
else
log_end_msg 1; echo; return 1
fi
# Load additional modules (helpers)
if [ -n "$IPTABLES_MODULES" ]; then
log_daemon_msg $"Loading additional $IPTABLES modules: "
ret=0
for mod in $IPTABLES_MODULES; do
log_daemon_msg "$mod "
modprobe $mod > /dev/null 2>&1
let ret+=$?;
done
[ $ret -eq 0 ] && log_end_msg 0 || log_end_msg 1
echo
fi
touch $VAR_SUBSYS_IPTABLES
return $ret
}
stop() {
# Do not stop if iptables module is not loaded.
[ -e "$PROC_IPTABLES_NAMES" ] || return 1
flush_n_delete
set_policy ACCEPT
if [ "x$IPTABLES_MODULES_UNLOAD" = "xyes" ]; then
log_daemon_msg $"Unloading $IPTABLES modules: "
ret=0
rmmod_r ${IPV}_tables
let ret+=$?;
rmmod_r ${IPV}_conntrack
let ret+=$?;
[ $ret -eq 0 ] && log_end_msg 0 || log_end_msg 1
echo
fi
rm -f $VAR_SUBSYS_IPTABLES
return $ret
}
save() {
# Check if iptable module is loaded
[ ! -e "$PROC_IPTABLES_NAMES" ] && return 1
# Check if firewall is configured (has tables)
tables=`cat $PROC_IPTABLES_NAMES 2>/dev/null`
[ -z "$tables" ] && return 1
log_daemon_msg $"Saving firewall rules to $IPTABLES_DATA: "
OPT=
[ "x$IPTABLES_SAVE_COUNTER" = "xyes" ] && OPT="-c"
ret=0
TMP_FILE=`/bin/mktemp -q /tmp/$IPTABLES.XXXXXX` \
&& chmod 600 "$TMP_FILE" \
&& $IPTABLES-save $OPT > $TMP_FILE 2>/dev/null \
&& size=`stat -c '%s' $TMP_FILE` && [ $size -gt 0 ] \
|| ret=1
if [ $ret -eq 0 ]; then
if [ -e $IPTABLES_DATA ]; then
cp -f $IPTABLES_DATA $IPTABLES_DATA.save \
&& chmod 600 $IPTABLES_DATA.save \
|| ret=1
fi
if [ $ret -eq 0 ]; then
cp -f $TMP_FILE $IPTABLES_DATA \
&& chmod 600 $IPTABLES_DATA \
|| ret=1
fi
fi
[ $ret -eq 0 ] && log_end_msg 0 || log_end_msg 1
echo
rm -f $TMP_FILE
return $ret
}
status() {
tables=`cat $PROC_IPTABLES_NAMES 2>/dev/null`
# Do not print status if lockfile is missing and iptables modules are not
# loaded.
# Check if iptable module is loaded
if [ ! -f "$VAR_SUBSYS_IPTABLES" -a -z "$tables" ]; then
log_daemon_msg $"Firewall is stopped."
return 1
fi
# Check if firewall is configured (has tables)
if [ ! -e "$PROC_IPTABLES_NAMES" ]; then
log_daemon_msg $"Firewall is not configured. "
return 1
fi
if [ -z "$tables" ]; then
log_daemon_msg $"Firewall is not configured. "
return 1
fi
NUM=
[ "x$IPTABLES_STATUS_NUMERIC" = "xyes" ] && NUM="-n"
VERBOSE=
[ "x$IPTABLES_STATUS_VERBOSE" = "xyes" ] && VERBOSE="--verbose"
COUNT=
[ "x$IPTABLES_STATUS_LINENUMBERS" = "xyes" ] && COUNT="--line-numbers"
for table in $tables; do
log_daemon_msg $"Table: $table"
$IPTABLES -t $table --list $NUM $VERBOSE $COUNT && echo
done
return 0
}
restart() {
[ "x$IPTABLES_SAVE_ON_RESTART" = "xyes" ] && save
stop
start
}
case "$1" in
start)
stop
start
RETVAL=$?
;;
stop)
[ "x$IPTABLES_SAVE_ON_STOP" = "xyes" ] && save
stop
RETVAL=$?
;;
restart)
restart
RETVAL=$?
;;
condrestart)
[ -e "$VAR_SUBSYS_IPTABLES" ] && restart
RETVAL=$?
;;
status)
status
RETVAL=$?
;;
panic)
flush_n_delete
set_policy DROP
RETVAL=$?
;;
save)
save
RETVAL=$?
;;
*)
log_action_msg $"Usage: $0 {start|stop|restart|condrestart|status|panic|save}"
exit 1
;;
esac
exit $RETVAL
