--- /dev/null
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Handles creation and destruction of IP-in-IP or GRE tunnels over the given
+# topology. Supports both flat and hierarchical models.
+#
+# Flat Model:
+# Overlay and underlay share the same VRF.
+# SW1 uses default VRF so tunnel has no bound dev.
+# SW2 uses non-default VRF tunnel has a bound dev.
+# +-------------------------+
+# | H1 |
+# | $h1 + |
+# | 192.0.2.1/28 | |
+# +-------------------|-----+
+# |
+# +-------------------|-----+
+# | SW1 | |
+# | $ol1 + |
+# | 192.0.2.2/28 |
+# | |
+# | + g1a (gre) |
+# | loc=192.0.2.65 |
+# | rem=192.0.2.66 --. |
+# | tos=inherit | |
+# | .------------------' |
+# | | |
+# | v |
+# | + $ul1.111 (vlan) |
+# | | 192.0.2.129/28 |
+# | \ |
+# | \_______ |
+# | | |
+# |VRF default + $ul1 |
+# +------------|------------+
+# |
+# +------------|------------+
+# | SW2 + $ul2 |
+# | _______| |
+# | / |
+# | / |
+# | + $ul2.111 (vlan) |
+# | ^ 192.0.2.130/28 |
+# | | |
+# | | |
+# | '------------------. |
+# | + g2a (gre) | |
+# | loc=192.0.2.66 | |
+# | rem=192.0.2.65 --' |
+# | tos=inherit |
+# | |
+# | $ol2 + |
+# | 192.0.2.17/28 | |
+# | VRF v$ol2 | |
+# +-------------------|-----+
+# |
+# +-------------------|-----+
+# | H2 | |
+# | $h2 + |
+# | 192.0.2.18/28 |
+# +-------------------------+
+#
+# Hierarchical model:
+# The tunnel is bound to a device in a different VRF
+#
+# +---------------------------+
+# | H1 |
+# | $h1 + |
+# | 192.0.2.1/28 | |
+# +-------------------|-------+
+# |
+# +-------------------|-------+
+# | SW1 | |
+# | +-----------------|-----+ |
+# | | $ol1 + | |
+# | | 192.0.2.2/28 | |
+# | | | |
+# | | + g1a (gre) | |
+# | | rem=192.0.2.66 | |
+# | | tos=inherit | |
+# | | loc=192.0.2.65 | |
+# | | ^ | |
+# | | VRF v$ol1 | | |
+# | +-----------|-----------+ |
+# | | |
+# | +-----------|-----------+ |
+# | | VRF v$ul1 | | |
+# | | | | |
+# | | | | |
+# | | v | |
+# | | dummy1 + | |
+# | | 192.0.2.65 | |
+# | | .-------' | |
+# | | | | |
+# | | v | |
+# | | + $ul1.111 (vlan) | |
+# | | | 192.0.2.129/28 | |
+# | | \ | |
+# | | \_____ | |
+# | | | | |
+# | | + $ul1 | |
+# | +----------|------------+ |
+# +------------|--------------+
+# |
+# +------------|--------------+
+# | SW2 | |
+# | +----------|------------+ |
+# | | + $ul2 | |
+# | | _____| | |
+# | | / | |
+# | | / | |
+# | | | $ul2.111 (vlan) | |
+# | | + 192.0.2.130/28 | |
+# | | ^ | |
+# | | | | |
+# | | '-------. | |
+# | | dummy2 + | |
+# | | 192.0.2.66 | |
+# | | ^ | |
+# | | | | |
+# | | | | |
+# | | VRF v$ul2 | | |
+# | +-----------|-----------+ |
+# | | |
+# | +-----------|-----------+ |
+# | | VRF v$ol2 | | |
+# | | | | |
+# | | v | |
+# | | g2a (gre)+ | |
+# | | loc=192.0.2.66 | |
+# | | rem=192.0.2.65 | |
+# | | tos=inherit | |
+# | | | |
+# | | $ol2 + | |
+# | | 192.0.2.17/28 | | |
+# | +-----------------|-----+ |
+# +-------------------|-------+
+# |
+# +-------------------|-------+
+# | H2 | |
+# | $h2 + |
+# | 192.0.2.18/28 |
+# +---------------------------+
+source lib.sh
+
+h1_create()
+{
+ simple_if_init $h1 192.0.2.1/28 2001:db8:1::1/64
+ ip route add vrf v$h1 192.0.2.16/28 via 192.0.2.2
+}
+
+h1_destroy()
+{
+ ip route del vrf v$h1 192.0.2.16/28 via 192.0.2.2
+ simple_if_fini $h1 192.0.2.1/28
+}
+
+h2_create()
+{
+ simple_if_init $h2 192.0.2.18/28
+ ip route add vrf v$h2 192.0.2.0/28 via 192.0.2.17
+}
+
+h2_destroy()
+{
+ ip route del vrf v$h2 192.0.2.0/28 via 192.0.2.17
+ simple_if_fini $h2 192.0.2.18/28
+}
+
+sw1_flat_create()
+{
+ local type=$1; shift
+ local ol1=$1; shift
+ local ul1=$1; shift
+
+ ip link set dev $ol1 up
+ __addr_add_del $ol1 add "192.0.2.2/28"
+
+ ip link set dev $ul1 up
+ vlan_create $ul1 111 "" 192.0.2.129/28
+
+ tunnel_create g1a $type 192.0.2.65 192.0.2.66 tos inherit "$@"
+ ip link set dev g1a up
+ __addr_add_del g1a add "192.0.2.65/32"
+
+ ip route add 192.0.2.66/32 via 192.0.2.130
+
+ ip route add 192.0.2.16/28 nexthop dev g1a
+}
+
+sw1_flat_destroy()
+{
+ local ol1=$1; shift
+ local ul1=$1; shift
+
+ ip route del 192.0.2.16/28
+
+ ip route del 192.0.2.66/32 via 192.0.2.130
+ __simple_if_fini g1a 192.0.2.65/32
+ tunnel_destroy g1a
+
+ vlan_destroy $ul1 111
+ __simple_if_fini $ul1
+ __simple_if_fini $ol1 192.0.2.2/28
+}
+
+sw2_flat_create()
+{
+ local type=$1; shift
+ local ol2=$1; shift
+ local ul2=$1; shift
+
+ simple_if_init $ol2 192.0.2.17/28
+ __simple_if_init $ul2 v$ol2
+ vlan_create $ul2 111 v$ol2 192.0.2.130/28
+
+ tunnel_create g2a $type 192.0.2.66 192.0.2.65 tos inherit dev v$ol2 \
+ "$@"
+ __simple_if_init g2a v$ol2 192.0.2.66/32
+
+ ip route add vrf v$ol2 192.0.2.65/32 via 192.0.2.129
+ ip route add vrf v$ol2 192.0.2.0/28 nexthop dev g2a
+}
+
+sw2_flat_destroy()
+{
+ local ol2=$1; shift
+ local ul2=$1; shift
+
+ ip route del vrf v$ol2 192.0.2.0/28
+
+ ip route del vrf v$ol2 192.0.2.65/32 via 192.0.2.129
+ __simple_if_fini g2a 192.0.2.66/32
+ tunnel_destroy g2a
+
+ vlan_destroy $ul2 111
+ __simple_if_fini $ul2
+ simple_if_fini $ol2 192.0.2.17/28
+}
+
+sw1_hierarchical_create()
+{
+ local type=$1; shift
+ local ol1=$1; shift
+ local ul1=$1; shift
+
+ simple_if_init $ol1 192.0.2.2/28
+ simple_if_init $ul1
+ ip link add name dummy1 type dummy
+ __simple_if_init dummy1 v$ul1 192.0.2.65/32
+
+ vlan_create $ul1 111 v$ul1 192.0.2.129/28
+ tunnel_create g1a $type 192.0.2.65 192.0.2.66 tos inherit dev dummy1 \
+ "$@"
+ ip link set dev g1a master v$ol1
+
+ ip route add vrf v$ul1 192.0.2.66/32 via 192.0.2.130
+ ip route add vrf v$ol1 192.0.2.16/28 nexthop dev g1a
+}
+
+sw1_hierarchical_destroy()
+{
+ local ol1=$1; shift
+ local ul1=$1; shift
+
+ ip route del vrf v$ol1 192.0.2.16/28
+ ip route del vrf v$ul1 192.0.2.66/32
+
+ tunnel_destroy g1a
+ vlan_destroy $ul1 111
+
+ __simple_if_fini dummy1 192.0.2.65/32
+ ip link del dev dummy1
+
+ simple_if_fini $ul1
+ simple_if_fini $ol1 192.0.2.2/28
+}
+
+sw2_hierarchical_create()
+{
+ local type=$1; shift
+ local ol2=$1; shift
+ local ul2=$1; shift
+
+ simple_if_init $ol2 192.0.2.17/28
+ simple_if_init $ul2
+
+ ip link add name dummy2 type dummy
+ __simple_if_init dummy2 v$ul2 192.0.2.66/32
+
+ vlan_create $ul2 111 v$ul2 192.0.2.130/28
+ tunnel_create g2a $type 192.0.2.66 192.0.2.65 tos inherit dev dummy2 \
+ "$@"
+ ip link set dev g2a master v$ol2
+
+ ip route add vrf v$ul2 192.0.2.65/32 via 192.0.2.129
+ ip route add vrf v$ol2 192.0.2.0/28 nexthop dev g2a
+}
+
+sw2_hierarchical_destroy()
+{
+ local ol2=$1; shift
+ local ul2=$1; shift
+
+ ip route del vrf v$ol2 192.0.2.0/28
+ ip route del vrf v$ul2 192.0.2.65/32
+
+ tunnel_destroy g2a
+ vlan_destroy $ul2 111
+
+ __simple_if_fini dummy2 192.0.2.66/32
+ ip link del dev dummy2
+
+ simple_if_fini $ul2
+ simple_if_fini $ol2 192.0.2.17/28
+}
+
+topo_mtu_change()
+{
+ local mtu=$1
+
+ ip link set mtu $mtu dev $h1
+ ip link set mtu $mtu dev $ol1
+ ip link set mtu $mtu dev g1a
+ ip link set mtu $mtu dev $ul1
+ ip link set mtu $mtu dev $ul1.111
+ ip link set mtu $mtu dev $h2
+ ip link set mtu $mtu dev $ol2
+ ip link set mtu $mtu dev g2a
+ ip link set mtu $mtu dev $ul2
+ ip link set mtu $mtu dev $ul2.111
+}
+
+test_mtu_change()
+{
+ local encap=$1; shift
+
+ RET=0
+
+ ping_do $h1 192.0.2.18 "-s 1800 -w 3"
+ check_fail $? "ping $encap should not pass with size 1800"
+
+ RET=0
+
+ topo_mtu_change 2000
+ ping_do $h1 192.0.2.18 "-s 1800 -w 3"
+ check_err $?
+ log_test "ping $encap packet size 1800 after MTU change"
+}