#!/usr/bin/env bash ### BEGIN INIT INFO # Provides: ipt-firewall # Required-Start: $local_fs $remote_fs $syslog $network # Required-Stop: $local_fs $remote_fs $syslog $network # Should-Start: # Should-Stop: # Default-Start: 2 3 4 5 # Default-Stop: 0 1 6 # Short-Description: IPv4 Firewall ### END INIT INFO CONFIG_DIR="/etc/ipt-firewall" CONFIG_FILE="${CONFIG_DIR}/ipt-firewall-server.conf" if [[ -z "$fail2ban_client" ]]; then fail2ban_client="$(which fail2ban-client)" fi # ------------- Load Kernel Modules ------------- # ## - Load appropriate modules. ## - if ! $host_is_vm ; then /sbin/modprobe ip_tables > /dev/null 2>&1 /sbin/modprobe iptable_nat > /dev/null 2>&1 # - Note:! # - Since Kernel 4.7 the automatic conntrack helper assignment # - is disabled by default (net.netfilter.nf_conntrack_helper = 0). # - Enable it by setting this variable in file /etc/sysctl.conf: # - # - net.netfilter.nf_conntrack_helper = 1 # - # - Reboot or type "sysctl -p" # - # - !! But this is NOT the recommend method !! # --- # - Load module for FTP Connection tracking and NAT # --- # - Once a helper is loaded, it will treat packets for a given port and all IP addresses. # - As explained before, this is not optimal and is even a security risk. A better # - solution is to load the module helper and deactivate their parsing by default. Each # - helper we need to use is then set by using a call to the CT target. # - # - Desactivate the automatic conntrack helper assignment: # - # - method 1: modprobe nf_conntrack nf_conntrack_helper=0 # - method 2: echo 0 > /proc/sys/net/netfilter/nf_conntrack_helper # - # - Note: # - ===== # - Each helper we need to use is then set by using a call to the CT target. # - Example for ftp helper on standardport: # - # - ipt -A OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp # - /sbin/modprobe nf_conntrack nf_conntrack_helper=0 > /dev/null 2>&1 #echo 0 > /proc/sys/net/netfilter/nf_conntrack_helper /sbin/modprobe nf_conntrack_ftp > /dev/null 2>&1 /sbin/modprobe nf_nat > /dev/null 2>&1 /sbin/modprobe nf_nat_ftp > /dev/null 2>&1 ## - Load modules for SIP VOIP ## - #/sbin/modprobe nf_conntrack_sip > /dev/null 2>&1 #/sbin/modprobe nf_nat_sip > /dev/null 2>&1 fi # # ------------- End: Load Kernel Modules ------------- echo echo -e "\033[37m\033[1m\tStarting firewall iptables (IpV4)..\033[m" echo ## -------------------------------------------------------------------------- ## --- All Configurations will be done in /etc/ipt-firewall/ipt-firewall.conf ## -------------------------------------------------------------------------- if [[ -f "$CONFIG_FILE" ]]; then source $CONFIG_FILE else echo echo -e "\033[31m\033[1m\tNo Configuration File found..\033[m \033[37m\033[1mExiting now!\033[m" echo exit 1 fi # ------------- # --- Activate IP Forwarding # ------------- ## - IP Forwarding deaktivieren. ## - ## - Activate if kernel_activate_forwarding ist set to true, deactivate otherwise ## - ## - Only needed, if hosts acts as a router. ## - if $kernel_activate_forwarding ; then echo 1 > /proc/sys/net/ipv4/ip_forward echononl "\tActivate Forwarding.." echo_done else echo 0 > /proc/sys/net/ipv4/ip_forward echononl "\t\033[33m\033[1mDisable Forwarding..\033[m" echo_done fi if $kernel_support_dynaddr ; then echononl "\tActivate kernel support for dynamic addresses.." if [[ -n $dynaddr_flag ]] && [[ $dynaddr_flag =~ ^-?[0-9]+$ ]]; then echo $dynaddr_flag > /proc/sys/net/ipv4/ip_dynaddr echo_done else echo_failed fi else echo 0 > /proc/sys/net/ipv4/ip_dynaddr echononl "\t\033[33m\033[1mDisable kernel support for dynamic addresses..\033[m" echo_done fi # ------------- # --- Adjust Kernel Parameters (Security/Tuning) # ------------- echononl "\tAdjust Kernel Parameters (Security/Tuning).." if ! $host_is_vm ; then ## - Reduce DoS'ing ability by reducing timeouts ## - if $kernel_reduce_timeouts ; then echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout echo 1800 > /proc/sys/net/ipv4/tcp_keepalive_time echo 1 > /proc/sys/net/ipv4/tcp_window_scaling echo 0 > /proc/sys/net/ipv4/tcp_sack fi ## - SYN COOKIES ## - if $kernel_tcp_syncookies ; then echo 1 > /proc/sys/net/ipv4/tcp_syncookies echo 2048 > /proc/sys/net/ipv4/tcp_max_syn_backlog echo 3 > /proc/sys/net/ipv4/tcp_synack_retries fi ## - Protection against ICMP bogus error responses ## - if $kernel_protect_against_icmp_bogus_messages ; then echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses fi ## - Ignore Broadcast Pings ## - if $kernel_ignore_broadcast_ping ; then echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts fi ## - Deactivate Source Routed Packets ## - if $kernel_deactivate_source_route ; then for asr in /proc/sys/net/ipv4/conf/*/accept_source_route ; do echo 0 > $asr done fi ## - Deactivate sending ICMP redirects ## - if $kernel_dont_accept_redirects ; then for rp_filter in /proc/sys/net/ipv4/conf/*/rp_filter ; do echo 1 > $rp_filter done fi ## - Logging of spoofed (source routed" and "redirect") packets ## - if $kernel_log_martians ; then echo "0" > /proc/sys/net/ipv4/conf/all/log_martians fi ## - Keine ICMP Umleitungspakete akzeptieren. ## - ## - Diese können zur Veränderung der Routing Tables verwendet ## - werden, möglicherweise mit einem böswilligen Ziel. ## - #echo "0" > /proc/sys/net/ipv4/conf/all/accept_redirects ## - NUMBER OF CONNECTIONS TO TRACK ## - #echo "65535" > /proc/sys/net/ipv4/netfilter/ip_conntrack_max echo_done # Adjust Kernel Parameters (Security/Tuning) else echo_skipped fi # ------------- Stop Fail2Ban if installed ------------- # if [ -x "$fail2ban_client" ]; then echononl "\tStopping fail2ban.." $fail2ban_client stop > /dev/null 2>&1 if [ "$?" = "0" ];then echo_done else echo_warning fi fi # # ------------- Ende: Stop Fail2Ban if installed ------------- # ------------- # --- Set default policies / Flush Rules # ------------- echo echononl "\tFlushing firewall iptable (IPv4).." # - default policies # - $ipt -P INPUT ACCEPT $ipt -P OUTPUT ACCEPT $ipt -P FORWARD ACCEPT ## - flush chains ## - $ipt -F $ipt -F INPUT $ipt -F OUTPUT $ipt -F FORWARD $ipt -F -t mangle $ipt -F -t nat $ipt -F -t raw $ipt -X $ipt -Z echo_done # Flushing firewall iptable (IPv6).. echo # ------------- # --- Prevent bridged traffic getting pushed through the host's iptables rules # ------------- echononl "\tDo not firewall bridged traffic" if $do_not_firewall_bridged_traffic ; then # - Matches if the packet is being bridged and therefore is not being routed. # - This is only useful in the FORWARD and POSTROUTING chains. # - $ipt -I FORWARD -m physdev --physdev-is-bridged -j ACCEPT # - Matches if the packet has entered through a bridge interface. # - $ipt -I FORWARD -m physdev --physdev-is-in -j ACCEPT # - Matches if the packet will leave through a bridge interface. # - $ipt -I FORWARD -m physdev --physdev-is-out -j ACCEPT echo_done else echo_skipped fi echo # ------------- # ------------ Stopping firewall if only flushing was requested (parameter flush) # ------------- case $1 in flush) echo echo -e "\t\033[37m\033[1mFlushing firewall was requested. No more rules..\033[m" echo exit 0;; esac # ------------- # --- Pass through Devices Interfaces (not firewalled) # ------------- if [[ ${#unprotected_if_arr[@]} -gt 0 ]]; then echononl "\tPass through Devices (not firewalled)" for _dev in ${unprotected_if_arr[@]} ; do if $log_unprotected || $log_all ; then $ipt -A INPUT -i $_dev -j LOG --log-prefix "$log_prefix Not firewalled ${_dev}: " --log-level $log_level $ipt -A OUTPUT -o $_dev -j LOG --log-prefix "$log_prefix Not firewalled ${_dev}: " --log-level $log_level $ipt -A FORWARD -i $_dev -j LOG --log-prefix "$log_prefix Not firewalled ${_dev}: " --log-level $log_level $ipt -A FORWARD -o $_dev -j LOG --log-prefix "$log_prefix Not firewalled ${_dev}: " --log-level $log_level fi $ipt -A INPUT -i $_dev -j ACCEPT $ipt -A OUTPUT -o $_dev -j ACCEPT $ipt -A FORWARD -i $_dev -j ACCEPT $ipt -A FORWARD -o $_dev -j ACCEPT done echo_done fi # ------------- # --- Block IPs / Networks / Interfaces # ------------- echononl "\tBlock IPs / Networks / Interfaces.." # --- # - Block IPs # --- for _ip in $blocked_ips ; do for _dev in ${ext_if_arr[@]} ; do if $log_blocked_ip || $log_all ; then $ipt -A INPUT -i $_dev -s $_ip -j LOG --log-prefix "$log_prefix Blocked ${_ip}: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -s $_ip -j LOG --log-prefix "$log_prefix Blocked ${_ip}: " --log-level $log_level fi fi $ipt -A INPUT -i $_dev -s $_ip -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -s $_ip -j DROP fi done done # --- # - Block Interfaces # --- for _if in ${blocked_if_arr[@]} ; do if $log_blocked_if || $log_all ; then if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_if -j LOG --log-prefix "$log_prefix Blocked IF ${_if}: " --log-level $log_level $ipt -A FORWARD -o $_if -j LOG --log-prefix "$log_prefix Blocked IF ${_if}: " --log-level $log_level fi $ipt -A INPUT -i $_if -j LOG --log-prefix "$log_prefix Blocked IF ${_if}: " --log-level $log_level $ipt -A OUTPUT -o $_if -j LOG --log-prefix "$log_prefix Blocked IF ${_if}: " --log-level $log_level fi if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_if -j DROP $ipt -A FORWARD -o $_if -j DROP fi $ipt -A INPUT -i $_if -j DROP $ipt -A OUTPUT -o $_if -j DROP done echo_done # Block IPs / Networks / Interfaces.. # --- # - Block IPs/Netwoks reading from file 'ban_ipv4.list'" # --- echononl "\tBlock IPs/Netwoks reading from file 'ban_ipv4.list' .." if [[ -f "${CONFIG_DIR}/ban_ipv4.list" ]] ; then declare -a octets declare -i index while IFS='' read -r _line || [[ -n $_line ]] ; do is_valid_ipv4=true is_valid_mask=true ipv4="" mask="" # Ignore comment lines # [[ $_line =~ ^[[:space:]]{0,}# ]] && continue # Ignore blank lines # [[ $_line =~ ^[[:space:]]*$ ]] && continue # Remove leading whitespace characters # _line="${_line#"${_line%%[![:space:]]*}"}" # Catch IPv4 Address # given_ipv4="$(echo $_line | cut -d ' ' -f1)" # Splitt Ipv4 address from possible given CIDR number # IFS='/' read -ra _addr <<< "$given_ipv4" _ipv4="${_addr[0]}" if [[ -n "${_addr[1]}" ]] ; then _mask="${_addr[1]}" test_netmask=false # Is 'mask' a valid CIDR number? If not, test agains a valid netmask # if $(test -z "${_mask##*[!0-9]*}" > /dev/null 2>&1) ; then # Its not a vaild mask number, but naybe a valit netmask. # test_netmask=true else if [[ $_mask -gt 32 ]]; then # Its not a vaild cidr number, but naybe a valit netmask. # test_netmask=true else # OK, we have a vaild cidr number between '0' and '32' # mask=$_mask fi fi # Test if given '_mask' is a valid netmask. # if $test_netmask ; then octets=( ${_mask//\./ } ) # Complete netmask if necessary # while [[ ${#octets[@]} -lt 4 ]]; do octets+=(0) done [[ ${#octets[@]} -gt 4 ]] && is_valid_mask=false index=0 for octet in ${octets[@]} ; do if [[ ${octet} =~ ^[0-9]{1,3}$ ]] ; then if [[ $octet -gt 255 ]] ; then is_valid_mask=false fi if [[ $index -gt 0 ]] ; then mask="${mask}.${octet}" else mask="${octet}" fi else is_valid_mask=false fi ((index++)) done fi adjust_mask=false else mask=32 adjust_mask=true fi # Splitt given address into their octets # octets=( ${_ipv4//\./ } ) # Complete IPv4 address if necessary # while [[ ${#octets[@]} -lt 4 ]]; do octets+=(0) # Only adjust CIDR number if not given # if $adjust_mask ; then mask="$(expr $mask - 8)" fi done # Pre-check if given IPv4 Address seems to be a valid address # [[ ${#octets[@]} -gt 4 ]] && is_valid_ipv4=false # Check if given IPv4 Address is a valid address # if $is_valid_ipv4 ; then index=0 for octet in ${octets[@]} ; do if [[ ${octet} =~ ^[0-9]{1,3}$ ]] ; then if [[ $octet -gt 255 ]] ; then is_valid_ipv4=false fi if [[ $index -gt 0 ]] ; then ipv4="${ipv4}.${octet}" else ipv4="${octet}" fi else is_valid_ipv4=false fi ((index++)) done fi if $is_valid_ipv4 && $is_valid_mask; then _ip="${ipv4}/${mask}" if containsElement "$_ip" "${ban_ipv4_arr[@]}" ; then continue fi for _dev in ${ext_if_arr[@]} ; do if $log_blocked_ip || $log_all ; then $ipt -A INPUT -i $_dev -s $_ip -j LOG --log-prefix "$log_prefix Blocked: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -s $_ip -j LOG --log-prefix "$log_prefix Blocked: " --log-level $log_level fi fi $ipt -A INPUT -i $_dev -s $_ip -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -s $_ip -j DROP fi done ban_ipv4_arr+=("$_ip") else msg="$msg '${given_ipv4}'" fi done < "${CONFIG_DIR}/ban_ipv4.list" echo_done if [[ -n "$msg" ]]; then warn "Ignored:$msg" fi else echo_skipped fi # --- # - Allow Forwarding certain private Addresses # --- if [[ ${#forward_private_ip_arr[@]} -gt 0 ]] ; then echononl "\tAllow forwarding (private) IPs / IP-Ranges.." for _ip in ${forward_private_ip_arr[@]}; do if $kernel_activate_forwarding ; then $ipt -A FORWARD -d $_ip -j ACCEPT $ipt -A FORWARD -s $_ip -j ACCEPT echo_done else echo_skipped fi done fi # ------------- # --- Protections against several attacks / unwanted packages # ------------- echo echononl "\tProtections against several attacks / unwanted packages.." # --- # - Protection against syn-flooding # --- $ipt -N syn-flood $ipt -A syn-flood -m limit --limit 1/second --limit-burst 3 -j RETURN if $log_syn_flood || $log_all ; then $ipt -A syn-flood -j LOG --log-prefix "$log_prefix SYN flood: " --log-level $log_level fi $ipt -A syn-flood -j DROP # --- # - Drop Fragments # --- # I have to say that fragments scare me more than anything. # Sending lots of non-first fragments was what allowed Jolt2 to effectively "drown" # Firewall-1. Fragments can be overlapped, and the subsequent interpretation of such # fragments is very OS-dependent (see this paper for details). # I am not going to trust any fragments. # Log fragments just to see if we get any, and deny them too for _dev in ${ext_if_arr[@]} ; do if $log_fragments || $log_all ; then $ipt -A INPUT -i $_dev -f -j LOG --log-prefix "$log_prefix IPTABLES FRAGMENTS: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -f -j LOG --log-prefix "$log_prefix IPTABLES FRAGMENTS: " --log-level $log_level fi fi $ipt -A INPUT -i $_dev -f -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -f -j DROP fi done # --- # - drop new packages without syn flag # --- if $log_new_not_sync || $log_all ; then $ipt -A INPUT -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "$log_prefix New but not SYN: " --log-level $log_level $ipt -A OUTPUT -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "$log_prefix New but not SYN: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "$log_prefix New but not SYN: " --log-level $log_level fi fi $ipt -A INPUT -p tcp ! --syn -m state --state NEW -j DROP $ipt -A OUTPUT -p tcp ! --syn -m state --state NEW -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -p tcp ! --syn -m state --state NEW -j DROP fi # --- # - drop invalid packages # --- if $log_invalid_state || $log_all ; then $ipt -A INPUT -m state --state INVALID -j LOG --log-prefix "$log_prefix Invalid state: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -m state --state INVALID -j LOG --log-prefix "$log_prefix Invalid state: " --log-level $log_level fi fi $ipt -A INPUT -m state --state INVALID -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -m state --state INVALID -j DROP fi # --- # - ungewöhnliche Flags verwerfen # --- for _dev in ${ext_if_arr[@]} ; do if $log_invalid_flags || $log_all ; then $ipt -A INPUT -i $_dev -p tcp --tcp-flags ALL ACK,RST,SYN,FIN -j LOG --log-prefix "$log_prefix Invalid flags: " --log-level $log_level $ipt -A INPUT -i $_dev -p tcp --tcp-flags SYN,FIN SYN,FIN -j LOG --log-prefix "$log_prefix Invalid flags: " --log-level $log_level $ipt -A INPUT -i $_dev -p tcp --tcp-flags SYN,RST SYN,RST -j LOG --log-prefix "$log_prefix Invalid flags: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -p tcp --tcp-flags ALL ACK,RST,SYN,FIN -j LOG --log-prefix "$log_prefix Invalid flags: " --log-level $log_level $ipt -A FORWARD -i $_dev -p tcp --tcp-flags SYN,FIN SYN,FIN -j LOG --log-prefix "$log_prefix Invalid flags: " --log-level $log_level $ipt -A FORWARD -i $_dev -p tcp --tcp-flags SYN,RST SYN,RST -j LOG --log-prefix "$log_prefix Invalid flags: " --log-level $log_level fi fi $ipt -A INPUT -i $_dev -p tcp --tcp-flags ALL ACK,RST,SYN,FIN -j DROP $ipt -A INPUT -i $_dev -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP $ipt -A INPUT -i $_dev -p tcp --tcp-flags SYN,RST SYN,RST -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -p tcp --tcp-flags ALL ACK,RST,SYN,FIN -j DROP $ipt -A FORWARD -i $_dev -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP $ipt -A FORWARD -i $_dev -p tcp --tcp-flags SYN,RST SYN,RST -j DROP fi done # --- # - Refuse private addresses on extern interfaces # --- # Refuse spoofed packets pretending to be from your IP address. if $log_spoofed || $log_all ; then # input for _ip in ${ext_ip_arr[@]} ; do $ipt -A INPUT -s $_ip -d $_ip -j LOG --log-prefix "$log_prefix Spoofed (own ip): " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -s $_ip -d $_ip -j LOG --log-prefix "$log_prefix Spoofed (own ip): " --log-level $log_level fi done fi for _ip in ${ext_ip_arr[@]} ; do $ipt -A INPUT -s $_ip -d $_ip -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -s $_ip -d $_ip -j DROP fi done # Refuse packets claiming to be from a # Class A private network # Class B private network # Class C private network # loopback interface # Class D multicast address # Class E reserved IP address # broadcast address for _dev in ${ext_if_arr[@]} ; do if $log_spoofed || $log_all ; then $ipt -A INPUT -i $_dev -s $priv_class_a -j LOG --log-prefix "$log_prefix Class A private net: " --log-level $log_level $ipt -A INPUT -i $_dev -s $priv_class_b -j LOG --log-prefix "$log_prefix Class B private net: " --log-level $log_level $ipt -A INPUT -i $_dev -s $priv_class_c -j LOG --log-prefix "$log_prefix Class C private net: " --log-level $log_level $ipt -A INPUT -i $_dev -s $loopback -j LOG --log-prefix "$log_prefix From Loopback: " --log-level $log_level $ipt -A INPUT -i $_dev -s $class_d_multicast -j LOG --log-prefix "$log_prefix Class D Multicast: " --log-level $log_level $ipt -A INPUT -i $_dev -s $class_e_reserved -j LOG --log-prefix "$log_prefix Class E reserved: " --log-level $log_level #$ipt -A INPUT -i $_dev -d $broadcast_addr -j LOG --log-prefix "$log_prefix Broadcast Address: " --log-level $log_level # if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -s $priv_class_a -j LOG --log-prefix "$log_prefix Class A private net: " --log-level $log_level $ipt -A FORWARD -i $_dev -s $priv_class_b -j LOG --log-prefix "$log_prefix Class B private net: " --log-level $log_level $ipt -A FORWARD -i $_dev -s $priv_class_c -j LOG --log-prefix "$log_prefix Class C private net: " --log-level $log_level $ipt -A FORWARD -i $_dev -s $loopback -j LOG --log-prefix "$log_prefix From Loopback: " --log-level $log_level $ipt -A FORWARD -i $_dev -s $class_d_multicast -j LOG --log-prefix "$log_prefix Class D Multicast: " --log-level $log_level $ipt -A FORWARD -i $_dev -s $class_e_reserved -j LOG --log-prefix "$log_prefix Class E reserved: " --log-level $log_level #$ipt -A FORWARD -i $_dev -d $broadcast_addr -j LOG --log-prefix "$log_prefix Broadcast Address: " --log-level $log_level fi fi # Refuse packets claiming to be from a Class A private network. $ipt -A INPUT -i $_dev -s $priv_class_a -j DROP # Refuse packets claiming to be from a Class B private network. $ipt -A INPUT -i $_dev -s $priv_class_b -j DROP # Retfuse packets claiming to be from a Class C private network. $ipt -A INPUT -i $_dev -s $priv_class_c -j DROP # Refuse packets claiming to be from loopback interface. $ipt -A INPUT -i $_dev -s $loopback -j DROP # Refuse Class D multicast addresses. Multicast is illegal as a source address. $ipt -A INPUT -i $_dev -s $class_d_multicast -j DROP # Refuse Class E reserved IP addresses. $ipt -A INPUT -i $_dev -s $class_e_reserved -j DROP # Refuse broadcast address packets. #$ipt -A INPUT -i $_dev -d $broadcast_addr -j DROP if $kernel_activate_forwarding ; then # Refuse packets claiming to be from a Class A private network. $ipt -A FORWARD -i $_dev -s $priv_class_a -j DROP # Refuse packets claiming to be from a Class B private network. $ipt -A FORWARD -i $_dev -s $priv_class_b -j DROP # Refuse packets claiming to be from a Class C private network. $ipt -A FORWARD -i $_dev -s $priv_class_c -j DROP # Refuse packets claiming to be from loopback interface. $ipt -A FORWARD -i $_dev -s $loopback -j DROP # Refuse Class D multicast addresses. Multicast is illegal as a source address. $ipt -A FORWARD -i $_dev -s $class_d_multicast -j DROP # Refuse Class E reserved IP addresses. $ipt -A FORWARD -i $_dev -s $class_e_reserved -j DROP # Refuse broadcast address packets. #$ipt -A FORWARD -i $_dev -d $broadcast_addr -j DROP fi done # --- # - Refuse packets claiming to be to the loopback interface. # --- # Refusing packets claiming to be to the loopback interface protects against # source quench, whereby a machine can be told to slow itself down by an icmp source # quench to the loopback. for _dev in ${ext_if_arr[@]} ; do if $log_to_lo || $log_all ; then $ipt -A INPUT -i $_dev -d $loopback -j LOG --log-prefix "$log_prefix To Loopback: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -d $loopback -j LOG --log-prefix "$log_prefix To Loopback: " --log-level $log_level fi fi $ipt -A INPUT -i $_dev -d $loopback -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -d $loopback -j DROP fi done # --- # - Don't allow spoofing from that server # --- for _dev in ${ext_if_arr[@]} ; do if $log_spoofed_out || $log_all ; then $ipt -A OUTPUT -o $_dev -s $priv_class_a -j LOG --log-prefix "$log_prefix out Class A: " --log-level $log_level $ipt -A OUTPUT -o $_dev -s $priv_class_b -j LOG --log-prefix "$log_prefix out Class B: " --log-level $log_level $ipt -A OUTPUT -o $_dev -s $priv_class_c -j LOG --log-prefix "$log_prefix out Class C: " --log-level $log_level $ipt -A OUTPUT -o $_dev -s $loopback -j LOG --log-prefix "$log_prefix out Loopback: " --log-level $log_level if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -s $priv_class_a -j LOG --log-prefix "$log_prefix out Class A: " --log-level $log_level $ipt -A FORWARD -o $_dev -s $priv_class_b -j LOG --log-prefix "$log_prefix out Class B: " --log-level $log_level $ipt -A FORWARD -o $_dev -s $priv_class_c -j LOG --log-prefix "$log_prefix out Class C: " --log-level $log_level $ipt -A FORWARD -o $_dev -s $loopback -j LOG --log-prefix "$log_prefix out Loopback: " --log-level $log_level fi fi $ipt -A OUTPUT -o $_dev -s $priv_class_a -j DROP $ipt -A OUTPUT -o $_dev -s $priv_class_b -j DROP $ipt -A OUTPUT -o $_dev -s $priv_class_c -j DROP $ipt -A OUTPUT -o $_dev -s $loopback -j DROP if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -s $priv_class_a -j DROP $ipt -A FORWARD -o $_dev -s $priv_class_b -j DROP $ipt -A FORWARD -o $_dev -s $priv_class_c -j DROP $ipt -A FORWARD -o $_dev -s $loopback -j DROP fi done echo_done # ------------- # ------------- Stopping firewall here if requested (parameter stop) # ------------- case $1 in sto*) #echononl "Stopping firewall iptable (IPv4).." echo echo -e "\t\033[37m\033[1mStop was requested. No more rules..\033[m" echo exit 0;; esac echo # ------------- # --- Traffic Counter (used by munin) # ------------- echononl "\tCreate Traffic Counter (used by munin)" if $create_traffic_counter ; then for _ip in ${ext_ip_arr[@]} ; do $ipt -A INPUT -d $_ip $ipt -A INPUT -s $_ip if $kernel_activate_forwarding ; then $ipt -A FORWARD -d $_ip $ipt -A FORWARD -s $_ip fi done echo_done else echo_skipped fi # ------------- # --- iPerf # ------------- # iPerf is a tool for active measurements of the maximum achievable bandwidth on IP networks. # It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, # SCTP with IPv4 and IPv6). For each test it reports the bandwidth, loss, and other parameters. echononl "\tCreate \"iPerf\" rules.." if $create_iperf_rules ; then $ipt -A INPUT -p tcp --dport 5001 -j ACCEPT $ipt -A INPUT -p tcp --sport 5001 -j ACCEPT # $ipt -A OUTPUT -p tcp --dport 5001 -j ACCEPT $ipt -A OUTPUT -p tcp --sport 5001 -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -p tcp --dport 5001 -j ACCEPT $ipt -A FORWARD -p tcp --sport 5001 -j ACCEPT fi echo_done else echo_skipped fi # ------------- # --- Generally prohibited # ------------- echononl "\tGenerally prohibited traffic.." for _dev in ${ext_if_arr[@]} ; do if $log_prohibited || $log_all ; then for _port in ${block_tcp_port_arr[@]} ; do $ipt -A INPUT -p tcp -i $_dev --dport $_port -j LOG --log-prefix "$log_prefix gen. prohibited: " --log-level $log_level done for _port in ${block_udp_port_arr[@]} ; do $ipt -A INPUT -p udp -i $_dev --dport $_port -j LOG --log-prefix "$log_prefix gen. prohibited: " --log-level $log_level done if $kernel_activate_forwarding ; then for _port in ${block_tcp_port_arr[@]} ; do $ipt -A FORWARD -p tcp -i $_dev --dport $_port -j LOG --log-prefix "$log_prefix gen. prohibited: " --log-level $log_level done for _port in ${block_udp_port_arr[@]} ; do $ipt -A FORWARD -p udp -i $_dev --dport $_port -j LOG --log-prefix "$log_prefix gen. prohibited: " --log-level $log_level done fi fi for _port in ${block_tcp_port_arr[@]} ; do $ipt -A INPUT -p tcp -i $_dev --dport $_port -j DROP done for _port in ${block_udp_port_arr[@]} ; do $ipt -A INPUT -p udp -i $_dev --dport $_port -j DROP done if $kernel_activate_forwarding ; then for _port in ${block_tcp_port_arr[@]} ; do $ipt -A FORWARD -p tcp -i $_dev --dport $_port -j DROP done for _port in ${block_udp_port_arr[@]} ; do $ipt -A FORWARD -p udp -i $_dev --dport $_port -j DROP done fi done echo_done echo # ------------- # --- Traffic generally allowed # ------------- echononl "\tLoopback device generally allowed.." # --- # - Loopback device # --- $ipt -A INPUT -i lo -j ACCEPT $ipt -A OUTPUT -o lo -j ACCEPT echo_done # --- # - Already established connections # --- echononl "\tAccept already established connections.." $ipt -A INPUT -p ALL -m state --state ESTABLISHED,RELATED -j ACCEPT $ipt -A OUTPUT -p ALL -m state --state ESTABLISHED,RELATED -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -p ALL -m state --state ESTABLISHED,RELATED -j ACCEPT fi echo_done # --- # - Permit all traffic through VPN lines # --- echononl "\tPermit all traffic through VPN lines.." for _vpn_if in ${vpn_if_arr[@]} ; do $ipt -A INPUT -i $_vpn_if -m state --state NEW -j ACCEPT $ipt -A OUTPUT -o $_vpn_if -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_vpn_if -m state --state NEW -j ACCEPT $ipt -A FORWARD -o $_vpn_if -m state --state NEW -j ACCEPT fi done echo_done echo # ------------- # ---- Restrict local Servive to given (extern) IP-Address/Network # ------------- echononl "\tRestrict local Service to given (extern) IP-Address/Network" if [[ ${#restrict_local_service_to_net_arr[@]} -gt 0 ]] ; then _deny_service_arr=() for _val in "${restrict_local_service_to_net_arr[@]}" ; do IFS=':' read -a _val_arr <<< "${_val}" for _dev in ${ext_if_arr[@]} ; do $ipt -A INPUT -i $_dev -p ${_val_arr[3]} -s ${_val_arr[0]} -d ${_val_arr[1]} --dport ${_val_arr[2]} -m state --state NEW -j ACCEPT if ! containsElement "${_dev}:${_val_arr[1]}:${_val_arr[2]}:${_val_arr[3]}" "${_deny_service_arr[@]}" ; then _deny_service_arr+=("${_dev}:${_val_arr[1]}:${_val_arr[2]}:${_val_arr[3]}") fi done done for _val in "${_deny_service_arr[@]}" ; do IFS=':' read -a _val_arr <<< "${_val}" $ipt -A INPUT -i ${_val_arr[0]} -p ${_val_arr[3]} -d ${_val_arr[1]} --dport ${_val_arr[2]} -j DROP done echo_done else echo_skipped fi # ------------- # ---- Restrict local Network to given extern IP-Address/Network # ------------- echononl "\tRestrict local Address/Network to given extern Address/Network" if [[ ${#restrict_local_net_to_net_arr[@]} -gt 0 ]] ; then _deny_net_arr=() for _val in "${restrict_local_net_to_net_arr[@]}" ; do IFS=':' read -a _val_arr <<< "${_val}" for _dev in ${ext_if_arr[@]} ; do $ipt -A INPUT -i $_dev -s ${_val_arr[0]} -d ${_val_arr[1]} -m state --state NEW -j ACCEPT if ! containsElement "${_dev}:${_val_arr[1]}" "${_deny_net_arr[@]}" ; then _deny_net_arr+=("${_dev}:${_val_arr[1]}") fi done done for _val in "${_deny_net_arr[@]}" ; do IFS=':' read -a _val_arr <<< "${_val}" $ipt -A INPUT -i ${_val_arr[0]} -d ${_val_arr[1]} -j DROP done echo_done else echo_skipped fi # ------------- # --- Services # ------------- echo echo -e "\t\033[37m\033[1mAdd Rules for Services..\033[m" # ------------- # ---- Allow extern Service # ------------- echononl "\t\tAllow extern Service" if [[ ${#allow_ext_service_arr[@]} -gt 0 ]] ; then for _dev in "${ext_if_arr[@]}" ; do for _val in "${allow_ext_service_arr[@]}" ; do IFS=':' read -a _val_arr <<< "${_val}" $ipt -A OUTPUT -o $_dev -p ${_val_arr[2]} -d ${_val_arr[0]} --dport ${_val_arr[1]} -m state --state NEW -j ACCEPT done done echo_done else echo_skipped fi # ------------- # ---- Allow extern IP-Address/Network # ------------- echononl "\t\tAllow extern IP-Address/Network" if [[ ${#allow_ext_net_arr[@]} -gt 0 ]] ; then for _dev in "${ext_if_arr[@]}" ; do for _net in "${allow_ext_net_arr[@]}" ; do $ipt -A OUTPUT -o $_dev -p all -d $_net -m state --state NEW -j ACCEPT done done echo_done else echo_skipped fi echo # ------------- # ---- Allow (non-standard) local Services # ------------- echononl "\t\tAllow (non-standard) local Services" if [[ ${#allow_local_service_arr[@]} -gt 0 ]] ; then for _dev in "${ext_if_arr[@]}" ; do for _val in "${allow_local_service_arr[@]}" ; do IFS=':' read -a _val_arr <<< "${_val}" $ipt -A INPUT -i $_dev -p ${_val_arr[1]} --dport ${_val_arr[0]} -m state --state NEW -j ACCEPT done done echo_done else echo_skipped fi echo # --- # - DHCP # --- echononl "\t\tDHCP" if [[ ${#dhcp_if_arr[@]} -gt 0 ]] ; then for _dev in ${dhcp_if_arr[@]} ; do # - in $ipt -A INPUT -p udp -i $_dev -s 0/0 --sport 68 -d 255.255.255.255 --dport 67 -j ACCEPT # - out $ipt -A OUTPUT -p udp -o $_dev --sport 67 -d 0/0 --dport 68 -j ACCEPT done echo_done else echo_skipped fi # --- # - DNS out only # --- echononl "\t\tDNS out only" # - Nameservers on the INET must be reachable for the local recursiv nameserver # - but also for all others # - for _dev in ${ext_if_arr[@]} ; do # - out from local and virtual mashine(s) $ipt -A OUTPUT -o $_dev -p udp --dport 53 -m state --state NEW -j ACCEPT $ipt -A OUTPUT -o $_dev -p tcp --dport 53 -m state --state NEW -j ACCEPT # - Only useful (needed) if kernel forwarding is activated (kernel_activate_forwarding=true) if $kernel_activate_forwarding ; then # - forward from virtual mashine(s) $ipt -A FORWARD -o $_dev -p udp --dport 53 -m state --state NEW -j ACCEPT $ipt -A FORWARD -o $_dev -p tcp --dport 53 -m state --state NEW -j ACCEPT fi done echo_done # --- # - DNS Service # --- echononl "\t\tDNS Service" if [[ ${#dns_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_dns_server_ip_arr[@]} -gt 0 ]] ; then if [[ ${#dns_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${dns_server_ips[@]} ; do # dns requests # # Note: # If the total size of the DNS record is larger than 512 bytes, # it will be sent over TCP, not UDP. # $ipt -A INPUT -p udp -d $_ip --dport 53 -m state --state NEW -j ACCEPT $ipt -A INPUT -p tcp -d $_ip --dport 53 -m state --state NEW -j ACCEPT # Zonetransfer $ipt -A OUTPUT -p tcp -s $_ip --dport 53 -m state --state NEW -j ACCEPT done fi if [[ ${#forward_dns_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_dns_server_ip_arr[@]} ; do # dns requests # # Note: # If the total size of the DNS record is larger than 512 bytes, # it will be sent over TCP, not UDP. # $ipt -A FORWARD -p udp -d $_ip --dport 53 -m state --state NEW -j ACCEPT $ipt -A FORWARD -p tcp -d $_ip --dport 53 -m state --state NEW -j ACCEPT # Zonetransfer $ipt -A FORWARD -p tcp -s $_ip --dport 53 -m state --state NEW -j ACCEPT done fi echo_done else echo_skipped fi # --- # - SSH out only # --- echononl "\t\tSSH out only" # ausgehende Anfragen for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 22 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 22 -m state --state NEW -j ACCEPT fi done for _dev in ${local_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 22 -m state --state NEW -j ACCEPT done echo_done # --- # - SSH Service # --- echononl "\t\tSSH Service" if [[ ${#ssh_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_ssh_server_ip_arr[@]} -gt 0 ]] ; then if [[ ${#ssh_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${ssh_server_ip_arr[@]} ; do for _port in ${ssh_port_arr[@]} ; do $ipt -A INPUT -p tcp -d $_ip --dport $_port -m state --state NEW -j ACCEPT done done fi if [[ ${#forward_ssh_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_ssh_server_ip_arr[@]} ; do for _port in ${ssh_port_arr[@]} ; do $ipt -A FORWARD -p tcp -d $_ip --dport $_port -m state --state NEW -j ACCEPT done done fi echo_done else echo_skipped fi # --- # - VPN # --- echononl "\t\tVPN Service only out" if [[ ${#vpn_port_arr[@]} -gt 0 ]] ; then for _dev in ${ext_if_arr[@]} ; do for _port in ${vpn_port_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p udp --dport $_port -m state --state NEW -j ACCEPT done done echo_done else echo_skipped fi echononl "\t\tVPN Services.." if [[ ${#vpn_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_vpn_server_ip_arr[@]} -gt 0 ]] ; then if [[ ${#vpn_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${vpn_server_ip_arr[@]} ; do for _port in ${vpn_port_arr[@]} ; do $ipt -A INPUT -p udp -d $_ip --dport $_port -m state --state NEW -j ACCEPT done done fi if [[ ${#forward_vpn_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_vpn_server_ip_arr[@]} ; do for _port in ${vpn_port_arr[@]} ; do $ipt -A FORWARD -p udp -d $_ip --dport $_port -m state --state NEW -j ACCEPT done done fi echo_done else echo_skipped fi # --- # - Rsync Out # --- echononl "\t\tRsync (only OUT)" if [[ ${#rsync_out_ip_arr[@]} -gt 0 ]] || [[ ${#forward_rsync_out_ip_arr[@]} -gt 0 ]] ; then if [[ ${#rsync_out_ip_arr[@]} -gt 0 ]] ; then for _port in ${rsync_port_arr[@]} ; do for _ip in ${rsync_out_ip_arr[@]} ; do $ipt -A OUTPUT -p tcp -s $_ip --dport $_port -m state --state NEW -j ACCEPT done done fi if [[ ${#forward_rsync_out_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _port in ${rsync_port_arr[@]} ; do for _ip in ${forward_rsync_out_ip_arr[@]} ; do $ipt -A FORWARD -p tcp -s $_ip --dport $_port -m state --state NEW -j ACCEPT done done fi echo_done else echo_skipped fi # --- # - Telnet # --- echononl "\t\tTelnet (only OUT)" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 23 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 23 -m state --state NEW -j ACCEPT fi done echo_done # --- # - MySQL # --- echononl "\t\tMySQL (only OUT)" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 3306 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 3306 -m state --state NEW -j ACCEPT fi done echo_done # --- # - Munin remote service # --- echononl "\t\tMunin remote service" if [ "X$munin_remote_ip" != "X" ]; then for _dev in ${ext_if_arr[@]} ; do $ipt -A INPUT -i $_dev -p tcp --syn -s $munin_remote_ip --dport $munin_local_port -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -i $_dev -p tcp --syn -s $munin_remote_ip --dport $munin_local_port -m state --state NEW -j ACCEPT fi done echo_done else echo_skipped fi # --- # - Munin local service # --- echononl "\t\tMunin local service" if [[ ${#munin_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_munin_server_ip_arr[@]} -gt 0 ]] ; then if [[ ${#munin_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${munin_server_ip_arr[@]} ; do $ipt -A OUTPUT -p tcp --syn -s $_ip --dport $munin_remote_port -m state --state NEW -j ACCEPT done fi if [[ ${#forward_munin_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_munin_server_ip_arr[@]} ; do $ipt -A FORWARD -p tcp --syn -s $_ip --dport $munin_remote_port -m state --state NEW -j ACCEPT done fi echo_done else echo_skipped fi # --- # - Mail (SMTP OUT) # --- echononl "\t\tMail (SMTP OUT)" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 25 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 25 -m state --state NEW -j ACCEPT fi done echo_done # --- # - Mail SMTP Server (Port 25) including Spam Control # --- echononl "\t\tMail SMTP Server (Port 25) including Spam Control" if [[ ${#smtpd_ips_arr[@]} -gt 0 ]] || [[ ${#forward_smtpd_ip_arr[@]} -gt 0 ]] ; then if [[ ${#smtpd_ips_arr[@]} > 0 ]] ; then for _ip in ${smtpd_ips_arr[@]} ; do $ipt -A INPUT -p tcp -d $_ip --dport 25 -m state --state NEW -j ACCEPT # # Razor2 (TCP Port 2703) $ipt -A OUTPUT -p tcp -s $_ip --dport 2703 -m state --state NEW -j ACCEPT # DEPRECATED: TCP Port 7 (echo) $ipt -A OUTPUT -p tcp -s $_ip --dport 7 -m state --state NEW -j ACCEPT # # Pyzor (UDP Port 24441 or TCP Port 24441 or both ?) $ipt -A OUTPUT -p udp -s $_ip --dport 24441 -m state --state NEW -j ACCEPT $ipt -A OUTPUT -p tcp -s $_ip --dport 24441 -m state --state NEW -j ACCEPT # # - DCC (port udp:6277) $ipt -A OUTPUT -s $_ip -p udp -m udp --dport 6277 -m state --state NEW -j ACCEPT # if DCC Server is running (port tcp:6277) $ipt -A INPUT -p tcp -d $_ip --dport 6277 -j ACCEPT $ipt -A OUTPUT -p tcp -s $_ip --dport 6277 -j ACCEPT done fi if [[ ${#forward_smtpd_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_smtpd_ip_arr[@]} ; do $ipt -A FORWARD -p tcp -d $_ip --dport 25 -m state --state NEW -j ACCEPT # # Razor2 (TCP Port 2703) $ipt -A FORWARD -p tcp -s $_ip --dport 2703 -m state --state NEW -j ACCEPT # DEPRECATED: TCP Port 7 (echo) $ipt -A FORWARD -p tcp -s $_ip --dport 7 -m state --state NEW -j ACCEPT # # Pyzor (UDP Port 24441 or TCP Port 24441 or both ?) $ipt -A FORWARD -p udp -s $_ip --dport 24441 -m state --state NEW -j ACCEPT $ipt -A FORWARD -p tcp -s $_ip --dport 24441 -m state --state NEW -j ACCEPT # # DCC (port udp:6277) $ipt -A FORWARD -s $_ip -p udp -m udp --dport 6277 -m state --state NEW -j ACCEPT # if DCC Server is running (port tcp:6277) $ipt -A FORWARD -p tcp -d $_ip --dport 6277 -j ACCEPT $ipt -A FORWARD -p tcp -s $_ip --dport 6277 -j ACCEPT done fi echo_done else echo_skipped fi # --- # - Mailservice (Submission/SMTPS/POP/IMAP Server) # --- echononl "\t\tMailservice (Submission/SMTPS/POP/IMAP Server)" if [[ ${#mail_server_ips_arr[@]} -gt 0 ]] || [[ ${#forward_mail_server_ip_arr[@]} -gt 0 ]] ; then if [[ ${#mail_server_ips_arr[@]} -gt 0 ]] ; then for _ip in ${mail_server_ips_arr[@]} ; do # mail ports # $ipt -A INPUT -p tcp -d $_ip -m multiport --dports $mail_user_ports -m state --state NEW -j ACCEPT done fi # if [[ ${#mail_server_ips_arr[@]} -gt 0 ]] if [[ ${#forward_mail_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_mail_server_ip_arr[@]} ; do # mail ports # $ipt -A FORWARD -p tcp -d $_ip -m multiport --dports $mail_user_ports -m state --state NEW -j ACCEPT done fi # if [[ ${#forward_mail_server_ip_arr[@]} -gt 0 ]] ; then echo_done else echo_skipped fi # --- # - Mail Client (Submission/SMTPS/POPS/IMAPS) out only # --- echononl "\t\tMail Client (Submission/SMTPS/POPS/IMAPS) out only" if [[ ${#mail_client_ips_arr[@]} -gt 0 ]] || [[ ${#forward_mail_client_ip_arr[@]} -gt 0 ]] ; then if [[ ${#mail_client_ips_arr[@]} -gt 0 ]] ; then for _ip in ${mail_client_ips_arr[@]} ; do # mail ports # $ipt -A OUTPUT -p tcp -s $_ip -m multiport --dports $mail_user_ports -m state --state NEW -j ACCEPT done fi # if [[ ${#mail_client_ips_arr[@]} -gt 0 ]] if [[ ${#forward_mail_client_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_mail_client_ip_arr[@]} ; do # mail ports # $ipt -A FORWARD -p tcp -s $_ip -m multiport --dports $mail_user_ports -m state --state NEW -j ACCEPT done fi # if [[ ${#forward_mail_client_ip_arr[@]} -gt 0 ]] ; then echo_done else echo_skipped fi # --- # - HTTP(S) OUT # --- echononl "\t\tHTTP(S) out only" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp -m multiport --dports $http_ports -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp -m multiport --dports $http_ports -m state --state NEW -j ACCEPT fi done echo_done # --- # - HTTP(S) (local) Webserver # --- echononl "\t\tHTTP(S) (local) Webserver" if [[ ${#http_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_http_server_ip_arr[@]} -gt 0 ]] ; then if [[ ${#http_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${http_server_ip_arr[@]} ; do $ipt -A INPUT -p tcp -d $_ip -m multiport --dports $http_ports -m state --state NEW -j ACCEPT done if [[ ${#forward_http_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_http_server_ip_arr[@]} ; do $ipt -A FORWARD -p tcp -d $_ip -m multiport --dports $http_ports -m state --state NEW -j ACCEPT done fi fi echo_done else echo_skipped fi # --- # - FTP out only" # --- echononl "\t\tFTP out only (using CT target)" # - (Re)define helper # - $ipt -A OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp # - Used for different ftpdata recent lists 'ftpdata_out_$j' # - declare -i j=1 for _dev in ${ext_if_arr[@]} ; do # - (1) # - # - Open FTP connection and add the destination ip (--rdest) to ftpdata recent list 'ftpdata_out_$j'. # - $ipt -A OUTPUT -o $_dev -p tcp --dport 21 -m state --state NEW \ -m recent --name ftpdata_out_$j --rdest --set -j ACCEPT # - (2) # - - Accept packets if the destination ip-address (--rdest) is in the 'ftpdata_$j' list (--update) # - and the destination ip-address was seen within the last 1800 seconds (--seconds 1800). # - # - - If matched, the "last seen" timestamp of the destination address will be updated (--update). # - # - - Entries in the ftpdata list not seen in the last 1800 will be removed (--reap). # - $ipt -A OUTPUT -o $_dev -p tcp -m state --state NEW --dport 1024: \ -m recent --name ftpdata_out_$j --rdest --update --seconds 1800 --reap -j ACCEPT ((i++)) # - Accept (helper ftp) related connections # - $ipt -A OUTPUT -m conntrack --ctstate RELATED -m helper --helper ftp -o $_dev -p tcp --dport 1024: -j ACCEPT done echo_done #echononl "\t\tFTP out only" # #for _dev in ${ext_if_arr[@]} ; do # # (Datenkanal aktiv) # $ipt -A INPUT -i $_dev -p tcp --sport 20 -m state --state NEW -j ACCEPT # # (Datenkanal passiv) # $ipt -A OUTPUT -o $_dev -p tcp --sport $unprivports --dport $unprivports -m state --state NEW -j ACCEPT # # (Kontrollverbindung) # $ipt -A OUTPUT -o $_dev -p tcp --dport 21 -m state --state NEW -j ACCEPT # if $kernel_activate_forwarding ; then # # (Datenkanal aktiv) # $ipt -A FORWARD -i $_dev -p tcp --sport 20 -m state --state NEW -j ACCEPT # # (Datenkanal passiv) # $ipt -A FORWARD -o $_dev -p tcp --sport $unprivports --dport $unprivports -m state --state NEW -j ACCEPT # # (Kontrollverbindung) # $ipt -A FORWARD -o $_dev -p tcp --dport 21 -m state --state NEW -j ACCEPT # fi #done # #echo_done # --- # - FTP Server" # --- echononl "\t\tFTP Server (using CT target)" if [[ ${#ftp_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_ftp_server_ip_arr[@]} -gt 0 ]] ; then # - Used for different ftpdata recent lists 'ftpdata_$i' declare -i i=1 # - (Re)define helper # - # - !! Note: !! # - for both, local FTP server (ftp_server_ip_arr) # - and forward to FTP server (forward_ftp_server_ip_arr) # - $ipt -A PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp if [[ ${#ftp_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${ftp_server_ip_arr[@]} ; do # ===== # - # - ip_conntrack_ftp cannot see the TLS-encrypted traffic # - ====================================================== # - # - Workaround: # - (1) add source ip to a 'recent list' named 'ftpdata_$i! if ftp control connections appear # - (2) accept packets of the formaly created recent list 'ftpdata_$i! # - # ===== # - (1) # - # - Accept initial FTP connection and add the source ip to ftpdata recent list 'ftpdata_$i'. # - $ipt -A INPUT -p tcp -m state --state NEW -d $_ip --dport 21 -m recent --name ftpdata_$i --set -j ACCEPT # - (2) # - - Accept packets if the source ip-address is in the 'ftpdata_$i' list (--update) and the # - source ip-address was seen within the last 1800 seconds (--seconds 1800). # - # - - If matched, the "last seen" timestamp of the source address will be updated (--update). # - # - - Entries in the ftpdata list not seen in the last 1800 will be removed (--reap). # - $ipt -A INPUT -p tcp -m state --state NEW --sport 1024: -d $_ip --dport $ftp_passive_port_range \ -m recent --name ftpdata_$i --update --seconds 1800 --reap -j ACCEPT # - Accept (helper ftp) related connections # - $ipt -A INPUT -m conntrack --ctstate RELATED -m helper --helper ftp -d $_ip -p tcp --dport 1024: -j ACCEPT ((i++)) done fi if [[ ${#forward_ftp_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _ip in ${forward_ftp_server_ip_arr[@]} ; do # ===== # - # - ip_conntrack_ftp cannot see the TLS-encrypted traffic # - ====================================================== # - # - Workaround: # - (1) add source ip to a 'recent list' named 'ftpdata_$i! if ftp control connections appear # - (2) accept packets of the formaly created recent list 'ftpdata_$i! # - # ===== # - (1) # - # - Accept initial FTP connection and add the source ip to ftpdata recent list 'ftpdata_$i'. # - $ipt -A FORWARD -p tcp -m state --state NEW -d $_ip --dport 21 -m recent --name ftpdata_$i --set -j ACCEPT # - (2) # - - Accept packets if the source ip-address is in the 'ftpdata_$i' list (--update) and the # - source ip-address was seen within the last 1800 seconds (--seconds 1800). # - # - - If matched, the "last seen" timestamp of the source address will be updated (--update). # - # - - Entries in the ftpdata list not seen in the last 1800 will be removed (--reap). # - $ipt -A FORWARD -p tcp -m state --state NEW --sport 1024: -d $_ip --dport $ftp_passive_port_range \ -m recent --name ftpdata_$i --update --seconds 1800 --reap -j ACCEPT $ipt -A FORWARD -p tcp -m state --state NEW --dport 1024: -s $_ip --sport $ftp_passive_port_range \ -m recent --name ftpdata_$i --update --seconds 1800 --reap -j ACCEPT # - Accept (helper ftp) related connections # - $ipt -A FORWARD -m conntrack --ctstate RELATED -m helper --helper ftp -d $_ip -p tcp --dport 1024: -j ACCEPT $ipt -A FORWARD -m conntrack --ctstate RELATED -m helper --helper ftp -s $_ip -p tcp --sport 1024: -j ACCEPT ((i++)) done fi echo_done else echo_skipped fi #echononl "\t\tFTP Server" # #if [[ ${#ftp_server_ip_arr[@]} -gt 0 ]] || [[ ${#forward_ftp_server_ip_arr[@]} -gt 0 ]] ; then # if [[ ${#ftp_server_ip_arr[@]} -gt 0 ]] ; then # for _ip in ${ftp_server_ip_arr[@]} ; do # # (Datenkanal aktiv) # $ipt -A OUTPUT -p tcp -s $_ip --sport 20 -m state --state NEW -j ACCEPT # # Datenkanal (passiver modus) # $ipt -A INPUT -p tcp -d $_ip --dport $unprivports --sport $unprivports -m state --state NEW -j ACCEPT # # - Kontrollverbindung # $ipt -A INPUT -p tcp -d $_ip --dport 21 --sport $unprivports -m state --state NEW -j ACCEPT # done # fi # # if [[ ${#forward_ftp_server_ip_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then # for _ip in ${forward_ftp_server_ip_arr[@]} ; do # # (Datenkanal aktiv) # $ipt -A FORWARD -p tcp -s $_ip --sport 20 -m state --state NEW -j ACCEPT # # Datenkanal (passiver modus) # $ipt -A FORWARD -p tcp -d $_ip --dport $unprivports --sport $unprivports -m state --state NEW -j ACCEPT # # - Kontrollverbindung # $ipt -A FORWARD -p tcp -d $_ip --dport 21 --sport $unprivports -m state --state NEW -j ACCEPT # done # fi # # echo_done #else # echo_skipped #fi # --- # - Mumble Service # --- echononl "\t\tMumble Service" if [[ ${#mumble_server_ip_arr[@]} -gt 0 ]] || $local_mumble_service ; then if [[ ${#mumble_server_ip_arr[@]} -gt 0 ]] ; then for _ip in ${mumble_server_ip_arr[@]} ; do $ipt -A INPUT -p tcp -d $_ip -m multiport --dports $mumble_ports -m state --state NEW -j ACCEPT $ipt -A INPUT -p udp -d $_ip -m multiport --dports $mumble_ports -m state --state NEW -j ACCEPT done fi if [[ ${#forward_mumble_server_ip_arr[@]} ]] && $kernel_activate_forwarding ; then for _ip in ${forward_mumble_server_ip_arr[@]} ; do $ipt -A FORWARD -p tcp -d $_ip -m multiport --dports $mumble_ports -m state --state NEW -j ACCEPT $ipt -A FORWARD -p udp -d $_ip -m multiport --dports $mumble_ports -m state --state NEW -j ACCEPT done fi echo_done else echo_skipped fi # --- # - Timeserver (Port 37 NOT NTP!)" # --- echononl "\t\tTimeserver (Port 37 NOT NTP!) out only" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 37 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 37 -m state --state NEW -j ACCEPT fi done echo_done # --- # - NTP out only" # --- echononl "\t\tNTP out only" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 123 -m state --state NEW -j ACCEPT $ipt -A OUTPUT -o $_dev -p udp --dport 123 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 123 -m state --state NEW -j ACCEPT $ipt -A FORWARD -o $_dev -p udp --dport 123 -m state --state NEW -j ACCEPT fi done echo_done # --- # - Whois out only # --- echononl "\t\tWhois out only" for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport 43 -m state --state NEW -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p tcp --dport 43 -m state --state NEW -j ACCEPT fi done echo_done echo # --- # - Special TCP Ports OUT # --- echononl "\t\tSpecial TCP Ports OUT" if [[ ${#tcp_out_port_arr[@]} -gt 0 ]] || [[ ${#forward_tcp_out_port_arr[@]} -gt 0 ]] ; then if [[ ${#forward_tcp_out_port_arr[@]} -gt 0 ]] ; then for _dev in ${ext_if_arr[@]} ; do for _port in ${tcp_out_port_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p tcp --dport $_port -m state --state NEW -j ACCEPT done done fi if [[ ${#forward_tcp_out_port_arr[@]} -gt 0 ]] && $kernel_activate_forwarding ; then for _dev in ${ext_if_arr[@]} ; do for _port in ${tcp_out_port_arr[@]} ; do $ipt -A FORWARD -o $_dev -p tcp --dport $_port -m state --state NEW -j ACCEPT done done fi echo_done else echo_skipped fi # --- # - Special UDP Ports OUT # --- echononl "\t\tSpecial UDP Ports OUT" if [[ ${#udp_out_port_arr[@]} -gt 0 ]] || [[ ${#forward_udp_out_port_arr[@]} -gt 0 ]] ; then if [[ ${#udp_out_port_arr[@]} -gt 0 ]] ; then for _dev in ${ext_if_arr[@]} ; do for _port in ${udp_out_port_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p udp --dport $_port -m state --state NEW -j ACCEPT done done fi if [[ ${#forward_udp_out_port_arr[@]} -gt 0 ]] ; then for _dev in ${ext_if_arr[@]} ; do for _port in ${forward_udp_out_port_arr[@]} ; do $ipt -A FORWARD -o $_dev -p udp --dport $_port -m state --state NEW -j ACCEPT done done fi echo_done else echo_skipped fi echo # --- # - UNIX Traceroute # --- echononl "\t\tUNIX Traceroute" # versendet udp packete im gegensatz zu tracert von windows # der icmp-echo-request pakete versendet # einige implementierungen von traceroute (linux) erm�lichens # die option -I und versenden dann ebenfalls icmp-echo-request pakete for _dev in ${ext_if_arr[@]} ; do $ipt -A OUTPUT -o $_dev -p udp -m state --state NEW --dport 33434:33530 -j ACCEPT $ipt -A INPUT -i $_dev -p udp -m state --state NEW --dport 33434:33530 -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -o $_dev -p udp -m state --state NEW --dport 33434:33530 -j ACCEPT $ipt -A FORWARD -i $_dev -p udp -m state --state NEW --dport 33434:33530 -j ACCEPT fi done echo_done # --- # - Ping # --- echononl "\t\tPing" $ipt -A INPUT -p icmp -j ACCEPT $ipt -A OUTPUT -p icmp -j ACCEPT if $kernel_activate_forwarding ; then $ipt -A FORWARD -p icmp -j ACCEPT fi #for _dev in ${ext_if_arr[@]} ; do # $ipt -A INPUT -i $_dev -p icmp -j ACCEPT # $ipt -A OUTPUT -o $_dev -p icmp -j ACCEPT # if $kernel_activate_forwarding ; then # $ipt -A FORWARD -i $_dev -p icmp -j ACCEPT # $ipt -A FORWARD -o $_dev -p icmp -j ACCEPT # fi #done #for _dev in ${local_if_arr[@]} ; do # $ipt -A INPUT -i $_dev -p icmp -j ACCEPT # $ipt -A OUTPUT -o $_dev -p icmp -j ACCEPT # if $kernel_activate_forwarding ; then # $ipt -A FORWARD -i $_dev -p icmp -j ACCEPT # $ipt -A FORWARD -o $_dev -p icmp -j ACCEPT # fi #done echo_done # --- # - log all rejected traffic # --- echo echononl "\tLogging all rejected traffic" if $log_rejected || $log_all ; then #$ipt -A OUTPUT -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level #$ipt -A INPUT -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level #$ipt -A FORWARD -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level $ipt -A OUTPUT -m limit --limit-burst 5 -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level $ipt -A INPUT -m limit --limit-burst 5 -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level if $kernel_activate_forwarding ; then #$ipt -A FORWARD -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level $ipt -A FORWARD -m limit --limit-burst 5 -j LOG --log-prefix "$log_prefix Rejected: " --log-level $log_level fi echo_done else echo_skipped fi # --- # - Drop all other # --- echo echononl "\tDrop all other on all interfaces" $ipt -A INPUT -j DROP $ipt -A OUTPUT -j DROP $ipt -A FORWARD -j DROP echo_done # ------------- # ------------- Start Fail2Ban if installed # ------------- if [ -x "$fail2ban_client" ]; then echo echononl "\tStarting fail2ban.." $fail2ban_client start > /dev/null 2>&1 if [ "$?" = "0" ];then echo_done elif [ "$?" = "255" ]; then echo_skipped else echo_failed fi fi echo exit 0 # ------------ Portforwarding ------------- # # - # - !! NOTICE: # - you need also portforwarding enabled at the kernel # - echo 1 >/proc/sys/net/ipv4/ip_forward # # # ---------------------------------------------- # : --> ::80 # ---------------------------------------------- # #$ipt -A FORWARD [-i ] -p tcp --dport -d -j ACCEPT #$ipt -A FORWARD [-o ] -p tcp --sport -s -j ACCEPT # #$ipt -t nat -A PREROUTING [-i ] -p tcp --dport [-d ] -j DNAT --to-destination : #$ipt -t nat -A POSTROUTING -d -j MASQUERADE # # # ----------------------------------------------- # www-alt.oopen.de --> www-neu.oopen.de # # 46.4.129.3:80 --> 83.223.86.130:80 # 46.4.129.3:443 --> 83.223.86.130:443 # ----------------------------------------------- # #$ipt -A FORWARD -p tcp -m multiport --dports 80,443 -d 83.223.86.130 -j ACCEPT #$ipt -A FORWARD -p tcp -m multiport --sports 80,443 -s 83.223.86.130 -j ACCEPT # #$ipt -t nat -A PREROUTING -p tcp --dport 80 -d 46.4.129.3 -j DNAT --to-destination 83.223.86.130:80 #$ipt -t nat -A PREROUTING -p tcp --dport 443 -d 46.4.129.3 -j DNAT --to-destination 83.223.86.130:443 #$ipt -t nat -A POSTROUTING -d 83.223.86.130 -j MASQUERADE # # - # ---------- Ende Portforwarding ---------- #