testing: Add scenarios to test ICMP forwarding

2026-02-12 16:21:37 +01:00
parent 22e502b286
commit a7c03a415e
26 changed files with 692 additions and 0 deletions
@@ -0,0 +1,18 @@
+A connection between the gateways <b>moon</b> and <b>sun</b> is set up, which
+connects <b>alice</b> and <b>moon</b> with a small subnet behind gateway <b>sun</b>.
+A second tunnel is created between client <b>venus</b> and gateway <b>moon</b>,
+which connects <b>venus</b> with another small subnet behind, in this case,
+non-IPsec gateway <b>sun</b>.
+The authentication is based on <b>X.509 certificates</b>.
+<p/>
+In order to test ICMP error forwarding, which <b>venus</b>, <b>moon</b> and
+<b>sun</b> all enabled, <b>alice</b> and <b>moon</b> ping unreachable IPs behind
+IPsec gateway <b>sun</b> and behind host <b>bob</b>, respectively. The
+corresponding ICMP Destination Unreachable messages, with source IP addresses
+outside the IPsec tunnel traffic selectors are expected to be forwarded
+by <b>sun</b> and <b>moon</b>.
+<p/>
+Similar tests are run from <b>venus</b>, in which case the non-IPsec router
+<b>sun</b> generates ICMP Time Exceeded (TTL expired) and Fragmentation Needed
+(MTU exceeded) messages with a source IP outside of the traffic selectors.
+These messages should again get forwarded by <b>moon</b>.
@@ -0,0 +1,18 @@
+moon::swanctl --list-sas --raw 2> /dev/null::gw-gw.*version=2 state=ESTABLISHED local-host=192.168.0.1 local-port=500 local-id=moon.strongswan.org remote-host=192.168.0.2 remote-port=500 remote-id=sun.strongswan.org initiator=yes.*encr-alg=AES_CBC encr-keysize=128 integ-alg=HMAC_SHA2_256_128 prf-alg=PRF_HMAC_SHA2_256 dh-group=CURVE_25519.*child-sas.*net-net.*state=INSTALLED mode=TUNNEL.*ESP.*encr-alg=AES_GCM_16 encr-keysize=128.*local-ts=\[10.1.0.0/16] remote-ts=\[10.2.0.16/28]::YES
+sun:: swanctl --list-sas --raw 2> /dev/null::gw-gw.*version=2 state=ESTABLISHED local-host=192.168.0.2 local-port=500 local-id=sun.strongswan.org remote-host=192.168.0.1 remote-port=500 remote-id=moon.strongswan.org.*encr-alg=AES_CBC encr-keysize=128 integ-alg=HMAC_SHA2_256_128 prf-alg=PRF_HMAC_SHA2_256 dh-group=CURVE_25519.*child-sas.*net-net.*state=INSTALLED mode=TUNNEL.*ESP.*encr-alg=AES_GCM_16 encr-keysize=128.*local-ts=\[10.2.0.16/28] remote-ts=\[10.1.0.0/16]::YES
+moon::swanctl --list-sas --raw 2> /dev/null::venus.*version=2 state=ESTABLISHED local-host=10.1.0.1 local-port=500 local-id=moon.strongswan.org remote-host=10.1.0.20 remote-port=500 remote-id=venus.strongswan.org.*encr-alg=AES_CBC encr-keysize=128 integ-alg=HMAC_SHA2_256_128 prf-alg=PRF_HMAC_SHA2_256 dh-group=CURVE_25519.*child-sas.*net-net.*state=INSTALLED mode=TUNNEL.*ESP.*encr-alg=AES_GCM_16 encr-keysize=128.*local-ts=\[10.2.0.8/30] remote-ts=\[10.1.0.20/32]::YES
+venus::swanctl --list-sas --raw 2> /dev/null::rw.*version=2 state=ESTABLISHED local-host=10.1.0.20 local-port=500 local-id=venus.strongswan.org remote-host=10.1.0.1 remote-port=500 remote-id=moon.strongswan.org initiator=yes.*encr-alg=AES_CBC encr-keysize=128 integ-alg=HMAC_SHA2_256_128 prf-alg=PRF_HMAC_SHA2_256 dh-group=CURVE_25519.*child-sas.*rw.*state=INSTALLED mode=TUNNEL.*ESP.*encr-alg=AES_GCM_16 encr-keysize=128.*local-ts=\[10.1.0.20/32] remote-ts=\[10.2.0.8/30]::YES
+# the kernel currently sets the source incorrectly to the non-existent IP
+# allow both in case it gets fixed
+alice::ping -c 1 -W 4 10.2.0.25::From \(PH_IP_SUN\|10.2.0.25\) icmp_seq=1 Destination Host Unreachable::YES
+moon::ping -c 1 -W 4 10.2.0.17::From PH_IP_BOB icmp_seq=1 Destination Host Unreachable::YES
+# test other types of ICMPs with venus
+venus::ping -c 1 PH_IP_BOB::64 bytes from PH_IP_BOB: icmp_.eq=1::YES
+venus::ping -t 2 -c 1 PH_IP_BOB::From PH_IP_SUN.*Time to live exceeded::YES
+venus::ping -M do -s 1320 -c 1 PH_IP_BOB::From PH_IP_SUN.*Frag needed and DF set (mtu = 1280)::YES
+sun::tcpdump::IP moon.strongswan.org > sun.strongswan.org: ESP::2
+sun::tcpdump::IP sun.strongswan.org > moon.strongswan.org: ESP::2
+sun::tcpdump::IP sun.strongswan.org > alice.strongswan.org: ICMP host 10.2.0.25 unreachable::NO
+sun::tcpdump::IP bob.strongswan.org > moon1.strongswan.org: ICMP host 10.2.0.17 unreachable::NO
+venus::tcpdump::IP venus.strongswan.org > moon1.strongswan.org: ESP::3
+venus::tcpdump::IP moon1.strongswan.org > venus.strongswan.org: ESP::3
@@ -0,0 +1,48 @@
+*filter
+
+# default policy is DROP
+-P INPUT DROP
+-P OUTPUT DROP
+-P FORWARD DROP
+
+# allow esp
+-A INPUT  -i eth0 -p 50 -j ACCEPT
+-A OUTPUT -o eth0 -p 50 -j ACCEPT
+
+# allow IKE
+-A INPUT  -i eth0 -p udp --sport 500 --dport 500 -j ACCEPT
+-A OUTPUT -o eth0 -p udp --dport 500 --sport 500 -j ACCEPT
+
+# allow MobIKE
+-A INPUT  -i eth0 -p udp --sport 4500 --dport 4500 -j ACCEPT
+-A OUTPUT -o eth0 -p udp --dport 4500 --sport 4500 -j ACCEPT
+
+# allow ssh
+-A INPUT  -p tcp --dport 22 -j ACCEPT
+-A OUTPUT -p tcp --sport 22 -j ACCEPT
+
+# allow crl fetch from winnetou
+-A INPUT  -i eth0 -p tcp --sport 80 -s 192.168.0.150 -j ACCEPT
+-A OUTPUT -o eth0 -p tcp --dport 80 -d 192.168.0.150 -j ACCEPT
+
+# allow decrypted ICMPs from any source IP (updown script is too specific)
+-A INPUT -p icmp --icmp-type destination-unreachable -m policy --dir in -j ACCEPT
+-A FORWARD -p icmp --icmp-type destination-unreachable -m policy --dir in -j ACCEPT
+
+# allow venus to connect and fetch crls
+-A INPUT -i eth1 -p udp --sport 500 --dport 500 -j ACCEPT
+-A OUTPUT -o eth1 -p udp --dport 500 --sport 500 -j ACCEPT
+-A INPUT -i eth1 -p 50 -j ACCEPT
+-A OUTPUT -o eth1 -p 50 -j ACCEPT
+-A FORWARD -i eth0 -o eth1 -p tcp --sport 80 -s 192.168.0.150 -j ACCEPT
+-A FORWARD -o eth0 -i eth1 -p tcp --dport 80 -d 192.168.0.150 -j ACCEPT
+
+# forward specific errors to venus
+-A FORWARD -d 10.1.0.20/32 -p icmp --icmp-type time-exceeded -j ACCEPT
+-A FORWARD -d 10.1.0.20/32 -p icmp --icmp-type fragmentation-needed -j ACCEPT
+
+# log dropped packets
+-A INPUT  -j LOG --log-prefix " IN: "
+-A OUTPUT -j LOG --log-prefix " OUT: "
+
+COMMIT
@@ -0,0 +1,9 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+swanctl {
+  load = pem pkcs1 pubkey openssl random
+}
+
+charon-systemd {
+  load = random nonce openssl pem pkcs1 revocation curl kernel-netlink socket-default updown vici
+}
@@ -0,0 +1,48 @@
+connections {
+
+   gw-gw {
+      local_addrs  = PH_IP_MOON
+      remote_addrs = PH_IP_SUN
+
+      local {
+         auth = pubkey
+         certs = moonCert.pem
+         id = moon.strongswan.org
+      }
+      remote {
+         auth = pubkey
+         id = sun.strongswan.org
+      }
+      children {
+         net-net {
+            local_ts  = 10.1.0.0/16
+            remote_ts = 10.2.0.0/16
+            icmp = yes
+
+            updown = /usr/local/libexec/ipsec/_updown iptables
+            hostaccess = yes
+            esp_proposals = aes128gcm128-x25519
+         }
+      }
+      version = 2
+      mobike = no
+      proposals = aes128-sha256-x25519
+   }
+
+   venus : connections.gw-gw {
+      local_addrs = PH_IP_MOON1
+      remote_addrs = PH_IP_VENUS
+
+      remote {
+         id = venus.strongswan.org
+      }
+      children {
+         net-net {
+            # only include bob
+            local_ts = 10.2.0.8/30
+            remote_ts = dynamic
+            hostaccess = no
+         }
+      }
+   }
+}
@@ -0,0 +1,42 @@
+*filter
+
+# default policy is DROP
+-P INPUT DROP
+-P OUTPUT DROP
+-P FORWARD DROP
+
+# allow esp
+-A INPUT  -i eth0 -p 50 -j ACCEPT
+-A OUTPUT -o eth0 -p 50 -j ACCEPT
+
+# allow IKE
+-A INPUT  -i eth0 -p udp --sport 500 --dport 500 -j ACCEPT
+-A OUTPUT -o eth0 -p udp --dport 500 --sport 500 -j ACCEPT
+
+# allow MobIKE
+-A INPUT  -i eth0 -p udp --sport 4500 --dport 4500 -j ACCEPT
+-A OUTPUT -o eth0 -p udp --dport 4500 --sport 4500 -j ACCEPT
+
+# allow ssh
+-A INPUT  -p tcp --dport 22 -j ACCEPT
+-A OUTPUT -p tcp --sport 22 -j ACCEPT
+
+# allow crl fetch from winnetou
+-A INPUT  -i eth0 -p tcp --sport 80 -s 192.168.0.150 -j ACCEPT
+-A OUTPUT -o eth0 -p tcp --dport 80 -d 192.168.0.150 -j ACCEPT
+
+# explicitly allow ICMP responses we don't actually want to see as they should get encrypted
+-A OUTPUT -p icmp --icmp-type destination-unreachable -j ACCEPT
+-A FORWARD -p icmp --icmp-type destination-unreachable -j ACCEPT
+
+# allow only specific ICMPs from/to venus for this scenario
+-A FORWARD -s 10.1.0.20/32 -p icmp --icmp-type echo-request -j ACCEPT
+-A FORWARD -d 10.1.0.20/32 -p icmp --icmp-type echo-reply -j ACCEPT
+-A OUTPUT -d 10.1.0.20/32 -p icmp --icmp-type time-exceeded -j ACCEPT
+-A OUTPUT -d 10.1.0.20/32 -p icmp --icmp-type fragmentation-needed -j ACCEPT
+
+# log dropped packets
+-A INPUT  -j LOG --log-prefix " IN: "
+-A OUTPUT -j LOG --log-prefix " OUT: "
+
+COMMIT
@@ -0,0 +1,9 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+swanctl {
+  load = pem pkcs1 pubkey openssl random
+}
+
+charon-systemd {
+  load = random nonce openssl pem pkcs1 revocation curl kernel-netlink socket-default updown vici
+}
@@ -0,0 +1,31 @@
+connections {
+
+   gw-gw {
+      local_addrs  = PH_IP_SUN
+      remote_addrs = PH_IP_MOON
+
+      local {
+         auth = pubkey
+         certs = sunCert.pem
+         id = sun.strongswan.org
+      }
+      remote {
+         auth = pubkey
+         id = moon.strongswan.org
+      }
+      children {
+         net-net {
+            # exclude sun's and bob's IPs
+            local_ts  = 10.2.0.16/28
+            remote_ts = 10.1.0.0/16
+            icmp = yes
+
+            updown = /usr/local/libexec/ipsec/_updown iptables
+            esp_proposals = aes128gcm128-x25519
+         }
+      }
+      version = 2
+      mobike = no
+      proposals = aes128-sha256-x25519
+   }
+}
@@ -0,0 +1,9 @@
+# /etc/strongswan.conf - strongSwan configuration file
+
+swanctl {
+  load = pem pkcs1 pubkey openssl random
+}
+
+charon-systemd {
+  load = random nonce openssl pem pkcs1 revocation curl kernel-netlink socket-default updown vici
+}
@@ -0,0 +1,29 @@
+connections {
+
+   rw {
+      remote_addrs = PH_IP_MOON1
+
+      local {
+         auth = pubkey
+         certs = venusCert.pem
+         id = venus.strongswan.org
+      }
+      remote {
+         auth = pubkey
+         id = moon.strongswan.org
+      }
+      children {
+         rw {
+            remote_ts = 10.2.0.0/16
+            icmp = yes
+
+            updown = /usr/local/libexec/ipsec/_updown iptables
+            hostaccess = yes
+            esp_proposals = aes128gcm128-x25519
+         }
+      }
+      version = 2
+      mobike = no
+      proposals = aes128-sha256-x25519
+   }
+}
@@ -0,0 +1,13 @@
+moon::swanctl --terminate --ike gw-gw 2> /dev/null
+moon::swanctl --terminate --ike venus 2> /dev/null
+venus::systemctl stop strongswan
+moon::systemctl stop strongswan
+sun::systemctl stop strongswan
+venus::iptables-restore < /etc/iptables.flush
+moon::iptables-restore < /etc/iptables.flush
+sun::iptables-restore < /etc/iptables.flush
+sun::ip route del 10.2.0.16/30 via PH_IP_BOB
+moon::ip route del 10.2.0.8/30 via PH_IP_SUN
+sun::ip route del PH_IP_VENUS/32 via PH_IP_MOON
+sun::ip route del 10.2.0.8/30 dev eth1 src PH_IP_SUN1
+winnetou::ip route del 10.1.0.0/16 via PH_IP_MOON
@@ -0,0 +1,21 @@
+venus::iptables-restore < /etc/iptables.rules
+moon::iptables-restore < /etc/iptables.rules
+sun::iptables-restore < /etc/iptables.rules
+venus::systemctl start --no-block strongswan
+moon::systemctl start --no-block strongswan
+sun::systemctl start --no-block strongswan
+# add a route for part of the private subnet via bob
+sun::ip route add 10.2.0.16/30 via PH_IP_BOB
+# setup routes to test with venus
+winnetou::ip route add 10.1.0.0/16 via PH_IP_MOON
+moon::ip route add 10.2.0.8/30 via PH_IP_SUN
+sun::ip route add PH_IP_VENUS/32 via PH_IP_MOON
+# force a lower MTU for traffic to bob
+sun::ip route add 10.2.0.8/30 dev eth1 src PH_IP_SUN1 mtu 1280
+# allow decrypted ICMPs from any source IP (rules for sun and moon are in iptables.rules)
+venus::iptables -A INPUT -p icmp -m policy --dir in -j ACCEPT
+venus::expect-connection rw
+moon::expect-connection gw-gw
+sun::expect-connection gw-gw
+moon::swanctl --initiate --child net-net 2> /dev/null
+venus::swanctl --initiate --child rw 2> /dev/null
@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This configuration file provides information on the
+# guest instances used for this test
+
+# All guest instances that are required for this test
+#
+VIRTHOSTS="alice venus moon winnetou sun bob"
+
+# Corresponding block diagram
+#
+DIAGRAM="a-v-m-w-s-b.png"
+
+# Guest instances on which tcpdump is to be started
+#
+TCPDUMPHOSTS="venus sun"
+
+# Guest instances on which IPsec is started
+# Used for IPsec logging purposes
+#
+IPSECHOSTS="venus moon sun"
+
+# charon controlled by swanctl
+#
+SWANCTL=1