From: Edip Faruk Pehlivanlı (efaruk@mng.com.tr)
Date: Mon 04 Nov 2002 - 09:46:38 EET
Çok fazla inceleme imkanım olmadı ama sanırım sisteminde ethernet kartı yok,
tanınmıyor veya network controller'da tanımlı bir bağı yok. Sadece eth0
var. Firewall loopback için değildir!. kolay gelsin linuxdaş...
----- Original Message -----
From: "orhan" <orhanefe@hotmail.com>
To: <linux-ileri@linux.org.tr>
Sent: Tuesday, October 15, 2002 7:54 PM
Subject: [linux-ileri] Re: [linux-ileri] Internet Paylaşımı
>
> aşağıdakiki BAŞLADI - BİTTİ ARasını
>
> /etc/rc.d/rc.firewall-2.4
> dosyasına yapıştır. bu dosya yoksa oluşturman gerekli
>
> ardından
>
> chmod 700 /etc/rc.d/rc.firewall-2.4
>
> komutunu verip çalıştırılabilir dosya yapman lazım
>
> daha sonra da
> /sbin/chkconfig --level=345 firewall-2.4 on
> komutu verilerek sistem açılısında çalışması sağlanır
>
> son olarak
>
> /etc/ppp/ip-up dosyasının sonuna
> /etc/rc.d/rc.firewall-2.4
> satırı eklenmeli
>
>
> selamlar
>
> ########################### BAŞLADI
> #############################################
>
> #!/bin/sh
> #
> # rc.firewall-2.4-stronger
> FWVER=0.73s
>
> # An example of a stronger IPTABLES firewall with IP Masquerade
> # support for 2.4.x kernels.
> #
> # Log:
> # 0.73s - Added comments in the output section that DHCPd is optional
> # and changed the default settings to disabled
> # 0.72s - Changed the filter from the INTNET to the INTIP to be
> # stateful; moved the command VARs to the top and made the
> # rest of the script to use them
> # 0.70s - Added a disabled examples for allowing internal DHCP
> # and external WWW access to the server
> # 0.63s - Added support for the IRC module
> # 0.62s - Initial version based upon the basic 2.4.x rc.firewall
>
>
> echo -e "\nLoading STRONGER rc.firewall - version $FWVER..\n"
>
>
> # The location of various iptables and other shell programs
> #
> # If your Linux distribution came with a copy of iptables, most
> # likely it is located in /sbin. If you manually compiled
> # iptables, the default location is in /usr/local/sbin
> #
> # ** Please use the "whereis iptables" command to figure out
> # ** where your copy is and change the path below to reflect
> # ** your setup
> #
> #IPTABLES=/sbin/iptables
> IPTABLES=/usr/local/sbin/iptables
> #
> LSMOD=/sbin/lsmod
> DEPMOD=/sbin/depmod
> INSMOD=/sbin/insmod
> GREP=/bin/grep
> AWK=/bin/awk
> SED=/bin/sed
> IFCONFIG=/sbin/ifconfig
>
>
> #Setting the EXTERNAL and INTERNAL interfaces for the network
> #
> # Each IP Masquerade network needs to have at least one
> # external and one internal network. The external network
> # is where the natting will occur and the internal network
> # should preferably be addressed with a RFC1918 private address
> # scheme.
> #
> # For this example, "eth0" is external and "eth1" is internal"
> #
> # NOTE: If this doesnt EXACTLY fit your configuration, you must
> # change the EXTIF or INTIF variables above. For example:
> #
> # EXTIF="ppp0"
> #
> # if you are a modem user.
> #
> EXTIF="ppp0"
> INTIF="eth0"
> echo " External Interface: $EXTIF"
> echo " Internal Interface: $INTIF"
> echo " ---"
>
> # Specify your Static IP address here or let the script take care of it
> # for you.
> #
> # If you prefer to use STATIC addresses in your firewalls, un-# out the
> # static example below and # out the dynamic line. If you don't care,
> # just leave this section alone.
> #
> # If you have a DYNAMIC IP address, the ruleset already takes care of
> # this for you. Please note that the different single and double quote
> # characters and the script MATTER.
> #
> #
> # DHCP users:
> # -----------
> # If you get your TCP/IP address via DHCP, **you will need ** to enable
> the
> # #ed out command below underneath the PPP section AND replace the word
> # "eth0" with the name of your EXTERNAL Internet connection (ppp0,
ippp0,
> # etc) on the lines for "ppp-ip" and "extip". You should also note that
> the
> # DHCP server can and will change IP addresses on you. To deal with
this,
> # users should configure their DHCP client to re-run the rc.firewall
> ruleset
> # everytime the DHCP lease is renewed.
> #
> # NOTE #1: Some DHCP clients like the original "pump" (the newer
> # versions have been fixed) did NOT have the ability to run
> # scripts after a lease-renew. Because of this, you need to
> # replace it with something like "dhcpcd" or "dhclient".
> #
> # NOTE #2: The syntax for "dhcpcd" has changed in recent versions.
> #
> # Older versions used syntax like:
> # dhcpcd -c /etc/rc.d/rc.firewall eth0
> #
> # Newer versions execute a file called
> /etc/dhcpc/dhcpcd-eth0.exe
> #
> # NOTE #3: For Pump users, put the following line in /etc/pump.conf:
> #
> # script /etc/rc.d/rc.firewall
> #
> # PPP users:
> # ----------
> # If you aren't already aware, the /etc/ppp/ip-up script is always run
> when
> # a PPP connection comes up. Because of this, we can make the ruleset
go
> and
> # get the new PPP IP address and update the strong firewall ruleset.
> #
> # If the /etc/ppp/ip-up file already exists, you should edit it and add
a
> line
> # containing "/etc/rc.d/rc.firewall" near the end of the file.
> #
> # If you don't already have a /etc/ppp/ip-up sccript, you need to create
> the
> # following link to run the /etc/rc.d/rc.firewall script.
> #
> # ln -s /etc/rc.d/rc.firewall /etc/ppp/ip-up
> #
> # * You then want to enable the #ed out shell command below *
> #
> #
> # Determine the external IP automatically:
> # ----------------------------------------
> #
> EXTIP="`$IFCONFIG $EXTIF | $GREP 'inet addr' | $AWK '{print $2}' | \
> $SED -e 's/.*://'`"
>
> # For users who wish to use STATIC IP addresses:
> #
> # # out the EXTIP line above and un-# out the EXTIP line below
> #
> #EXTIP="your.static.PPP.address"
> echo " External IP: $EXTIP"
> echo " ---"
>
>
> # Assign the internal TCP/IP network and IP address
> INTNET="192.168.1.0/24"
> INTIP="192.168.1.1/24"
> echo " Internal Network: $INTNET"
> echo " Internal IP: $INTIP"
> echo " ---"
>
>
>
>
> # Setting a few other local variables
> #
> UNIVERSE="0.0.0.0/0"
>
> #======================================================================
> #== No editing beyond this line is required for initial MASQ testing ==
>
> # Need to verify that all modules have all required dependencies
> #
> echo " - Verifying that all kernel modules are ok"
> $DEPMOD -a
>
> echo -en " Loading kernel modules: "
>
> # With the new IPTABLES code, the core MASQ functionality is now either
> # modular or compiled into the kernel. This HOWTO shows ALL IPTABLES
> # options as MODULES. If your kernel is compiled correctly, there is
> # NO need to load the kernel modules manually.
> #
> # NOTE: The following items are listed ONLY for informational reasons.
> # There is no reason to manual load these modules unless your
> # kernel is either mis-configured or you intentionally disabled
> # the kernel module autoloader.
> #
>
> # Upon the commands of starting up IP Masq on the server, the
> # following kernel modules will be automatically loaded:
> #
> # NOTE: Only load the IP MASQ modules you need. All current IP MASQ
> # modules are shown below but are commented out from loading.
> # ===============================================================
>
> #Load the main body of the IPTABLES module - "ip_tables"
> # - Loaded automatically when the "iptables" command is invoked
> #
> # - Loaded manually to clean up kernel auto-loading timing issues
> #
> echo -en "ip_tables, "
> #
> #Verify the module isn't loaded. If it is, skip it
> #
> if [ -z "` $LSMOD | $GREP ip_tables | $AWK {'print $1'} `" ]; then
> $INSMOD ip_tables
> fi
>
>
> #Load the IPTABLES filtering module - "iptable_filter"
> #
> # - Loaded automatically when filter policies are activated
>
>
> #Load the stateful connection tracking framework - "ip_conntrack"
> #
> # The conntrack module in itself does nothing without other specific
> # conntrack modules being loaded afterwards such as the "ip_conntrack_ftp"
> # module
> #
> # - This module is loaded automatically when MASQ functionality is
> # enabled
> #
> # - Loaded manually to clean up kernel auto-loading timing issues
> #
> echo -en "ip_conntrack, "
> #
> #Verify the module isn't loaded. If it is, skip it
> #
> if [ -z "` $LSMOD | $GREP ip_conntrack | $AWK {'print $1'} `" ]; then
> $INSMOD ip_conntrack
> fi
>
>
> #Load the FTP tracking mechanism for full FTP tracking
> #
> # Enabled by default -- insert a "#" on the next line to deactivate
> #
> echo -e "ip_conntrack_ftp, "
> #
> #Verify the module isn't loaded. If it is, skip it
> #
> if [ -z "` $LSMOD | $GREP ip_conntrack_ftp | $AWK {'print $1'} `" ]; then
> $INSMOD ip_conntrack_ftp
> fi
>
>
> #Load the IRC tracking mechanism for full IRC tracking
> #
> # Enabled by default -- insert a "#" on the next line to deactivate
> #
> echo -en " ip_conntrack_irc, "
> #
> #Verify the module isn't loaded. If it is, skip it
> #
> if [ -z "` $LSMOD | $GREP ip_conntrack_irc | $AWK {'print $1'} `" ]; then
> $INSMOD ip_conntrack_irc
> fi
>
>
> #Load the general IPTABLES NAT code - "iptable_nat"
> # - Loaded automatically when MASQ functionality is turned on
> #
> # - Loaded manually to clean up kernel auto-loading timing issues
> #
> echo -en "iptable_nat, "
> #
> #Verify the module isn't loaded. If it is, skip it
> #
> if [ -z "` $LSMOD | $GREP iptable_nat | $AWK {'print $1'} `" ]; then
> $INSMOD iptable_nat
> fi
>
>
> #Loads the FTP NAT functionality into the core IPTABLES code
> # Required to support non-PASV FTP.
> #
> # Enabled by default -- insert a "#" on the next line to deactivate
> #
> echo -e "ip_nat_ftp"
> #
> #Verify the module isn't loaded. If it is, skip it
> #
> if [ -z "` $LSMOD | $GREP ip_nat_ftp | $AWK {'print $1'} `" ]; then
> $INSMOD ip_nat_ftp
> fi
>
> echo " ---"
>
> # Just to be complete, here is a list of the remaining kernel modules
> # and their function. Please note that several modules should be only
> # loaded by the correct master kernel module for proper operation.
> # --------------------------------------------------------------------
> #
> # ipt_mark - this target marks a given packet for future action.
> # This automatically loads the ipt_MARK module
> #
> # ipt_tcpmss - this target allows to manipulate the TCP MSS
> # option for braindead remote firewalls.
> # This automatically loads the ipt_TCPMSS module
> #
> # ipt_limit - this target allows for packets to be limited to
> # to many hits per sec/min/hr
> #
> # ipt_multiport - this match allows for targets within a range
> # of port numbers vs. listing each port individually
> #
> # ipt_state - this match allows to catch packets with various
> # IP and TCP flags set/unset
> #
> # ipt_unclean - this match allows to catch packets that have invalid
> # IP/TCP flags set
> #
> # iptable_filter - this module allows for packets to be DROPped,
> # REJECTed, or LOGged. This module automatically
> # loads the following modules:
> #
> # ipt_LOG - this target allows for packets to be
> # logged
> #
> # ipt_REJECT - this target DROPs the packet and
returns
> # a configurable ICMP packet back to the
> # sender.
> #
> # iptable_mangle - this target allows for packets to be manipulated
> # for things like the TCPMSS option, etc.
>
>
> #CRITICAL: Enable IP forwarding since it is disabled by default since
> #
> # Redhat Users: you may try changing the options in
> # /etc/sysconfig/network from:
> #
> # FORWARD_IPV4=false
> # to
> # FORWARD_IPV4=true
> #
> echo " Enabling forwarding.."
> echo "1" > /proc/sys/net/ipv4/ip_forward
>
>
> # Dynamic IP users:
> #
> # If you get your IP address dynamically from SLIP, PPP, or DHCP,
> # enable the following option. This enables dynamic-address hacking
> # which makes the life with Diald and similar programs much easier.
> #
> echo " Enabling DynamicAddr.."
> echo "1" > /proc/sys/net/ipv4/ip_dynaddr
>
> echo " ---"
>
>
############################################################################
> #
> #
> # Enable Stronger IP forwarding and Masquerading
> #
> # NOTE: In IPTABLES speak, IP Masquerading is a form of SourceNAT or
SNAT.
> #
> # NOTE #2: The following is an example for an internal LAN address in
the
> # 192.168.1.x network with a 255.255.255.0 or a "24" bit subnet
> # mask connecting to the Internet on external interface "eth0".
> # This example will MASQ internal traffic out to the Internet
> # but not allow non-initiated traffic into your internal
network.
> #
> #
> # ** Please change the above network numbers, subnet mask, and
your
> # *** Internet connection interface name to match your setup
> #
>
> #Clearing any previous configuration
> #
> # Unless specified, the defaults for INPUT, OUTPUT, and FORWARD to DROP.
> #
> # You CANNOT change this to REJECT as it isn't a vaild setting for a
> # policy. If you want REJECT, you must explictly REJECT at the end
> # of a giving INPUT, OUTPUT, or FORWARD chain
> #
> echo " Clearing any existing rules and setting default policy to DROP.."
> $IPTABLES -P INPUT DROP
> $IPTABLES -F INPUT
> $IPTABLES -P OUTPUT DROP
> $IPTABLES -F OUTPUT
> $IPTABLES -P FORWARD DROP
> $IPTABLES -F FORWARD
> $IPTABLES -F -t nat
>
> #Not needed and it will only load the unneeded kernel module
> #$IPTABLES -F -t mangle
> #
> # Flush the user chain.. if it exists
> if [ -n "`$IPTABLES -L | $GREP drop-and-log-it`" ]; then
> $IPTABLES -F drop-and-log-it
> fi
> #
> # Delete all User-specified chains
> $IPTABLES -X
> #
> # Reset all IPTABLES counters
> $IPTABLES -Z
>
>
> #Configuring specific CHAINS for later use in the ruleset
> #
> # NOTE: Some users prefer to have their firewall silently
> # "DROP" packets while others prefer to use "REJECT"
> # to send ICMP error messages back to the remote
> # machine. The default is "REJECT" but feel free to
> # change this below.
> #
> # NOTE: Without the --log-level set to "info", every single
> # firewall hit will goto ALL vtys. This is a very big
> # pain.
> #
> echo " Creating a DROP chain.."
> $IPTABLES -N drop-and-log-it
> $IPTABLES -A drop-and-log-it -j LOG --log-level info
> $IPTABLES -A drop-and-log-it -j DROP
>
> echo -e "\n - Loading INPUT rulesets"
>
>
> #######################################################################
> # INPUT: Incoming traffic from various interfaces. All rulesets are
> # already flushed and set to a default policy of DROP.
> #
>
> # loopback interfaces are valid.
> #
> $IPTABLES -A INPUT -i lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT
>
>
> # local interface, local machines, going anywhere is valid
> #
> $IPTABLES -A INPUT -i $INTIF -s $INTNET -d $UNIVERSE -j ACCEPT
>
>
> # remote interface, claiming to be local machines, IP spoofing, get lost
> #
> $IPTABLES -A INPUT -i $EXTIF -s $INTNET -d $UNIVERSE -j drop-and-log-it
>
>
> # external interface, from any source, for ICMP traffic is valid
> #
> # If you would like your machine to "ping" from the Internet,
> # enable this next line
> #
> #$IPTABLES -A INPUT -i $EXTIF -p ICMP -s $UNIVERSE -d $EXTIP -j ACCEPT
>
>
> # remote interface, any source, going to permanent PPP address is valid
> #
> #$IPTABLES -A INPUT -i $EXTIF -s $UNIVERSE -d $EXTIP -j ACCEPT
>
>
> # Allow any related traffic coming back to the MASQ server in
> #
> $IPTABLES -A INPUT -i $EXTIF -s $UNIVERSE -d $EXTIP -m state --state \
> ESTABLISHED,RELATED -j ACCEPT
>
>
> # ----- Begin OPTIONAL Section -----
> #
>
> # DHCPd - Enable the following lines if you run an INTERNAL DHCPd server
> #
> #$IPTABLES -A INPUT -i $INTIF -p tcp --sport 68 --dport 67 -j ACCEPT
> #$IPTABLES -A INPUT -i $INTIF -p udp --sport 68 --dport 67 -j ACCEPT
>
> # HTTPd - Enable the following lines if you run an EXTERNAL WWW server
> #
> #echo -e " - Allowing EXTERNAL access to the WWW server"
> #$IPTABLES -A INPUT -i $EXTIF -m state --state NEW,ESTABLISHED,RELATED \
> #-p tcp -s $UNIVERSE -d $EXTIP --dport 80 -j ACCEPT
>
> #
> # ----- End OPTIONAL Section -----
>
>
>
> # Catch all rule, all other incoming is denied and logged.
> #
> $IPTABLES -A INPUT -s $UNIVERSE -d $UNIVERSE -j drop-and-log-it
>
>
> echo -e " - Loading OUTPUT rulesets"
>
> #######################################################################
> # OUTPUT: Outgoing traffic from various interfaces. All rulesets are
> # already flushed and set to a default policy of DROP.
> #
>
> # loopback interface is valid.
> #
> $IPTABLES -A OUTPUT -o lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT
>
>
> # local interfaces, any source going to local net is valid
> #
> $IPTABLES -A OUTPUT -o $INTIF -s $EXTIP -d $INTNET -j ACCEPT
>
>
> # local interface, any source going to local net is valid
> #
> $IPTABLES -A OUTPUT -o $INTIF -s $INTIP -d $INTNET -j ACCEPT
>
>
> # outgoing to loca
>
>
> ################################# BİTİİ
> ##############################################
>
>
>
>
>