はじめに
2つのルーティングテーブルを持つようにルーターにVPNを設定しようとしています。すべてのフィルタリングがiptablesで行われ、iprouteが特定のfwmark、つまり一般的なルールにのみ作用するようにしたいと思います。
特定のサブネットをVPNトンネルにルーティングする の改善です。
この完全なプロジェクトの現在の作業構成を見つけることができます
それが機能し、私が現在それを使用している間のそのソリューションの主な問題は、iptablesとipルールの両方でフィルタリングする必要があるため、あまり柔軟性がありません。
1のマークが付いたパケットは、直接ppp0から出て、2のマークが付いたパケットはtun0を通過するという考え方です。
概要
ネットワーク図
まず、両方のルーティングテーブルを追加しました。
gateway:~# cat /etc/iproute2/rt_tables
1 ISP
2 VPN
ルーティングスクリプト
Ppp0が起動時に起動したときに追加されるルール。物事を一般的に保つためにpppdフックを使用していることに注意してください https://ppp.samba.org/pppd.html#sect1
gateway:~# cat /etc/ppp/ip-up
#!/bin/sh
#
# This script is run by pppd when there's a successful ppp connection.
#
# Flush out any old routes when ppp0 goes down
/sbin/ip route flush table ISP
# Add a route for this subnet to the ISP table
/sbin/ip route add 192.168.1.0/24 dev eth0 table ISP prio 1
# Add a route from the ISP table
/sbin/ip rule add from ${IPLOCAL} table ISP prio 1
# Set default route to ppp0
/sbin/ip route add table ISP default via ${IPLOCAL} prio 1
VPNが起動したときに追加されるルール。 OpenVPNには環境変数もあります: https://openvpn.net/index.php/open-source/documentation/manuals/65-openvpn-20x-manpage.html#lbAS
# cat /etc/openvpn/route-up-fwmark.sh
#!/bin/sh
#
# This script is run by OpenVPN when there's a successful VPN connection.
#
# Flush out any old routes when ppp0 goes down
/sbin/ip route flush table VPN
# Add a route for this subnet to the VPN table
/sbin/ip route add 192.168.2.0/24 dev eth0 table VPN prio 2
# Add a route from the VPN table
/sbin/ip rule add from ${route_vpn_gateway} table VPN prio 2
# Set default route to tun0
/sbin/ip route add default via ${route_vpn_gateway} dev ${dev} table VPN prio 2
ルーティングテーブル
メイン:
gateway:~# ip route sh table main
default dev ppp0 scope link metric 300
172.16.32.0/20 dev tun0 proto kernel scope link src 172.16.39.64
192.168.0.0/30 dev eth1 proto kernel scope link src 192.168.0.2
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.1
192.168.2.0/24 dev eth0 proto kernel scope link src 192.168.2.1
${IPREMOTE} dev ppp0 proto kernel scope link src ${IPLOCAL}
ISP:
gateway:~# ip route sh table ISP
default via ${IPLOCAL} dev ppp0
192.168.1.0/24 dev eth0 scope link
VPN:
gateway:~# ip route sh table VPN
default via 172.16.32.1 dev tun0
192.168.2.0/24 dev eth0 scope link
IPルール
/ etc/network/interfacesで、これをインターフェースの1つの下に追加しました。
post-up /etc/network/fwmark_2_0_subnet_rules
を含む:
gateway:~# cat /etc/network/fwmark_2_0_subnet_rules
#!/bin/sh
/sbin/ip rule add fwmark 1 table ISP prio 1
/sbin/ip rule add fwmark 2 table VPN prio 2
最後に、上記のすべてのIPルール:
gateway:~# ip rule
0: from all lookup local
1: from all fwmark 0x1 lookup ISP
1: from <PPP IP ADDRESS> lookup ISP
2: from all fwmark 0x2 lookup VPN
2: from 172.16.32.1 lookup VPN
32766: from all lookup main
32767: from all lookup default
IPTablesルール
#########################################################################
# Advanced routing rule set
# Uses 192.168.1.0 via ISP
# 192.168.2.0 via VPN
#
# Packets to/from 192.168.1.0/24 are marked with 0x1 and routed to ISP
# Packets to/from 192.168.2.0/24 are marked with 0x2 and routed to VPN
#
# http://nerdboys.com/2006/05/05/conning-the-mark-multiwan-connections-using-iptables-mark-connmark-and-iproute2/
# http://nerdboys.com/2006/05/08/multiwan-connections-addendum/
#########################################################################
# Set up the mangle table
*mangle
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
# If packet MARK is 2, then it means there is already a connection mark and the original packet came in on VPN
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT
# Else MARK packet as 2
#-A PREROUTING -i tun0 -j MARK --set-xmark 0x2/0xffffffff
-A PREROUTING -i tun0 -m conntrack --ctstate NEW -m mark --mark 0x0 -j MARK --set-xmark 0x2/0xffffffff
# If packet MARK is 1, then it means there is already a connection mark and the original packet came in on ISP
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT
# Else MARK packet as 1
#-A PREROUTING -i ppp0 -j MARK --set-xmark 0x1/0xffffffff
-A PREROUTING -i ppp0 -m conntrack --ctstate NEW -m mark --mark 0x0 -j MARK --set-xmark 0x1/0xffffffff
# Save MARK to CONNMARK
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT
# Set up the filter table
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
# Create rule chain per input interface for forwarding packets
:FWD_ETH0 - [0:0]
:FWD_ETH1 - [0:0]
:FWD_PPP0 - [0:0]
:FWD_TUN0 - [0:0]
# Create rule chain per input interface for input packets (for Host itself)
:IN_ETH0 - [0:0]
:IN_ETH1 - [0:0]
:IN_PPP0 - [0:0]
:IN_TUN0 - [0:0]
# Pass input packet to corresponded rule chain
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -j IN_ETH0
-A INPUT -i eth1 -j IN_ETH1
-A INPUT -i ppp0 -j IN_PPP0
-A INPUT -i tun0 -j IN_TUN0
# TCP flag checks - block invalid flags
-A INPUT -m conntrack --ctstate INVALID -j DROP
# Log packets that are dropped in INPUT chain (useful for debugging)
-A INPUT -j LOG --log-prefix "iptables/filter/INPUT end"
# Pass forwarded packet to corresponded rule chain
-A FORWARD -i eth0 -j FWD_ETH0
-A FORWARD -i eth1 -j FWD_ETH1
-A FORWARD -i ppp0 -j FWD_PPP0
-A FORWARD -i tun0 -j FWD_TUN0
# Log packets that are dropped in FORWARD chain (useful for debugging)
-A FORWARD -j LOG --log-prefix "iptables/filter/FORWARD end"
# Forward traffic to LAN
-A FWD_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Forward traffic to VPN
-A FWD_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Forward SSH packets from network to modem
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.1.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A FWD_ETH1 -s 192.168.0.0/30 -d 192.168.2.0/24 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Forward traffic to ppp0 WAN port
-A FWD_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# Forward ICMP from VPN, (breaks traceroute through VPN if you don't have this)
-A FWD_TUN0 -d 192.168.2.0/24 -p icmp -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# Forward traffic to tun0 VPN port
-A FWD_TUN0 -d 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# SSH to Router
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# DNS to Router
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 53 -m conntrack --ctstate NEW -j ACCEPT
# FreeRadius Client
-A IN_ETH0 -s 192.168.1.0/24 -p tcp -m tcp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 1812 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Ubiquiti UAP Device Discovery Broadcast
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 10001 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# NTP
-A IN_ETH0 -s 192.168.1.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -p udp -m udp --dport 123 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Accept traffic to router on both subnets
-A IN_ETH0 -s 192.168.1.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
-A IN_ETH0 -s 192.168.2.0/24 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Prevent leakages from 192.168.2.0/24 hosts when VPN goes down for some reason
-A IN_ETH0 -s 192.168.2.0/24 -o ppp0 -j REJECT --reject-with icmp-port-unreachable
# SSH To Modem from Router
-A IN_ETH1 -s 192.168.0.0/30 -d 192.168.0.0/30 -p tcp -m tcp --sport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
# Accept incoming tracked PPP0 connections
-A IN_PPP0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# Incoming ICMP from VPN, (breaks traceroute through VPN if you don't have this)
-A IN_TUN0 -d 192.168.2.0/24 -p icmp -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# Accept incoming tracked connections from 192.168.2.0/24 to VPN
-A IN_TUN0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
COMMIT
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
# Bittorrent forwarded to Linux Workstation through VPN
-A PREROUTING -i tun0 -p tcp -m tcp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
-A PREROUTING -i tun0 -p udp -m udp --dport 6881:6889 -j DNAT --to-destination 192.168.2.20
# Allows for network hosts to access the internet via VPN tunnel
-A POSTROUTING -s 192.168.2.0/24 -o tun0 -j MASQUERADE
# Allows for network hosts to access the internet via WAN port
-A POSTROUTING -s 192.168.1.0/24 -o ppp0 -j MASQUERADE
COMMIT
問題はマングルテーブルにあると思います。一部のパケットがマークされているようです。
gateway:~# iptables -L --line-numbers -n -v -t mangle
Chain PREROUTING (policy ACCEPT 1577 packets, 139K bytes)
num pkts bytes target prot opt in out source destination
1 1577 139K CONNMARK all -- * * 0.0.0.0/0 0.0.0.0/0 CONNMARK restore
2 0 0 ACCEPT all -- * * 192.168.2.0/24 0.0.0.0/0 mark match 0x2
3 0 0 MARK all -- tun0 * 0.0.0.0/0 0.0.0.0/0 ctstate NEW mark match 0x0 MARK set 0x2
4 0 0 ACCEPT all -- * * 192.168.1.0/24 0.0.0.0/0 mark match 0x1
5 112 6720 MARK all -- ppp0 * 0.0.0.0/0 0.0.0.0/0 ctstate NEW mark match 0x0 MARK set 0x1
6 1577 139K CONNMARK all -- * * 0.0.0.0/0 0.0.0.0/0 CONNMARK save
Chain INPUT (policy ACCEPT 758 packets, 68909 bytes)
num pkts bytes target prot opt in out source destination
Chain FORWARD (policy ACCEPT 819 packets, 69715 bytes)
num pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 620 packets, 99208 bytes)
num pkts bytes target prot opt in out source destination
Chain POSTROUTING (policy ACCEPT 1380 packets, 166K bytes)
num pkts bytes target prot opt in out source destination
その他の改善は歓迎します。AlpineLinuxwikiの記事を変更して更新する予定です。
私はついにこれに対する解決策を見つけました。
まず、前の質問と同様に、編集して/ etc/iproute2/rt_tablesに追加します
1 ISP
2 VPN
次に、/ etc/network/interfacesに追加します
auto eth0:2
iface eth0:2 inet static
address 192.168.2.1
netmask 255.255.255.0
post-up /etc/network/fwmark_rules
ここにファイル/ etc/network/fwmark_rulesを作成し、fwmarkルールを作成します。
#!/bin/sh
# Normal packets to go direct out WAN
/sbin/ip rule add fwmark 1 table ISP prio 100
# Put packets destined into VPN when VPN is up
/sbin/ip rule add fwmark 2 table VPN prio 200
# Prevent packets from being routed out when VPN is down.
# This prevents packets from falling back to the main table
# that has a priority of 32766
/sbin/ip rule add prohibit fwmark 2 prio 300
禁止行は、優先度が32766未満であるため、VPNがダウンした場合に、テーブルVPN内のものがメインにフォールバックするのを防ぎます。禁止およびその他の特別なルールについては、 4.9。ルーティングポリシーデータベース(RPDB) で読むことができます。 ==
/ etc/ppp/ip-upを追加します。これは、PPP接続がオンラインになったときのIPルールを配置する場所です。
#!/bin/sh
#
# This script is run by pppd when there's a successful ppp connection.
#
# Flush out any old rules that might be there
/sbin/ip route flush table ISP
# Add route to table from subnets on LAN
/sbin/ip route add 192.168.1.0/24 dev eth0 table ISP prio 100
/sbin/ip route add 192.168.2.0/24 dev eth0 table ISP prio 200
# Add route from IP given by ISP to the table
/sbin/ip rule add from ${IPLOCAL} table ISP prio 100
# Add a default route
/sbin/ip route add table ISP default via ${IPLOCAL} prio 100
必ず/ etc/ppp/ip-downを追加してください。ここで、インターフェイスがダウンしたときにルールを削除して、重複が発生しないようにします。 pppd man file --Scripts で特別なフック値について読むことができます
#!/bin/sh
#
# This script is run by pppd after the connection has ended.
#
# Delete the rules when we take the interface down
/sbin/ip rule del from ${IPLOCAL} table ISP prio 100
次に、OpenVPNのルーティングスクリプトを作成する必要があります。したがって、編集/ etc/openvpn/route-up-fwmark.shOpenVPNにも特別な環境変数があります OpenVPN-環境変数)
#!/bin/sh
#
# This script is run by OpenVPN when there's a successful VPN connection.
#
# Flush out any old rules that might be there
/sbin/ip route flush table VPN
# Add route to table from 192.168.2.0/24 subnet on LAN
/sbin/ip route add 192.168.2.0/24 dev eth0 table VPN prio 200
# Add route from VPN interface IP to the VPN table
/sbin/ip rule add from ${ifconfig_local} table VPN prio 200
# Add a default route
/sbin/ip route add default via ${ifconfig_local} dev ${dev} table VPN prio 200
そして、インターフェースがシャットダウンする直前にルールを削除するには/ etc/openvpn/route-pre-down-fwmark.sh
#!/bin/sh
#
# This script is run by OpenVPN after the connection has ended
#
# Delete the rules when we take the interface down
/sbin/ip rule del from ${ifconfig_local} table VPN prio 200
最後に、マングルテーブルは次のようになります。
*mangle
# Set default policies for table
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
# Restore CONNMARK to the MARK (If one doesn't exist then no mark is set)
-A PREROUTING -j CONNMARK --restore-mark --nfmask 0xffffffff --ctmask 0xffffffff
# If packet MARK is 2, then it means there is already a connection mark and the original packet came in on VPN
-A PREROUTING -s 192.168.2.0/24 -m mark --mark 0x2 -j ACCEPT
# Check exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) are 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -m mark --mark 0x1 -j ACCEPT
# Check packets coming from 192.168.2.0/24 are 0x2
-A PREROUTING -s 192.168.2.0/24 -j MARK --set-xmark 0x2/0xffffffff
# If packet MARK is 1, then it means there is already a connection mark and the original packet came in on ISP
-A PREROUTING -s 192.168.1.0/24 -m mark --mark 0x1 -j ACCEPT
# Check packets coming from 192.168.1.0/24 are 0x1
-A PREROUTING -s 192.168.1.0/24 -j MARK --set-xmark 0x1/0xffffffff
# Mark exception (this is a server which when accessed on a 192.168.2.0/24 address will go out the ISP table) as 0x1
#-A PREROUTING -s 192.168.2.0/24 -d <IP_OF_EXCEPTED_SERVER>/32 -j MARK --set-xmark 0x1/0xffffffff
# Save MARK to CONNMARK (remember iproute can't see CONNMARKs)
-A PREROUTING -j CONNMARK --save-mark --nfmask 0xffffffff --ctmask 0xffffffff
COMMIT
また、/ etc/openvpn/openvpn.confを編集して追加することもできます
# Prevents default gateway from being set on the default routing table
route-noexec
# Allows route-up script to be executed
script-security 2
# Calls custom Shell script after connection to add necessary routes
route-up /etc/openvpn/route-up-fwmark.sh
route-pre-down /etc/openvpn/route-pre-down-fwmark.sh