Merge tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block

[thirdparty/linux.git] / tools / testing / selftests / wireguard / netns.sh

#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
#
# This script tests the below topology:
#
# ┌─────────────────────┐   ┌──────────────────────────────────┐   ┌─────────────────────┐
# │   $ns1 namespace    │   │          $ns0 namespace          │   │   $ns2 namespace    │
# │                     │   │                                  │   │                     │
# │┌────────┐           │   │            ┌────────┐            │   │           ┌────────┐│
# ││  wg0   │───────────┼───┼────────────│   lo   │────────────┼───┼───────────│  wg0   ││
# │├────────┴──────────┐│   │    ┌───────┴────────┴────────┐   │   │┌──────────┴────────┤│
# ││192.168.241.1/24   ││   │    │(ns1)         (ns2)      │   │   ││192.168.241.2/24   ││
# ││fd00::1/24         ││   │    │127.0.0.1:1   127.0.0.1:2│   │   ││fd00::2/24         ││
# │└───────────────────┘│   │    │[::]:1        [::]:2     │   │   │└───────────────────┘│
# └─────────────────────┘   │    └─────────────────────────┘   │   └─────────────────────┘
#                           └──────────────────────────────────┘
#
# After the topology is prepared we run a series of TCP/UDP iperf3 tests between the
# wireguard peers in $ns1 and $ns2. Note that $ns0 is the endpoint for the wg0
# interfaces in $ns1 and $ns2. See https://www.wireguard.com/netns/ for further
# details on how this is accomplished.
set -e

exec 3>&1
export LANG=C
export WG_HIDE_KEYS=never
netns0="wg-test-$$-0"
netns1="wg-test-$$-1"
netns2="wg-test-$$-2"
pretty() { echo -e "\x1b[32m\x1b[1m[+] ${1:+NS$1: }${2}\x1b[0m" >&3; }
pp() { pretty "" "$*"; "$@"; }
maybe_exec() { if [[ $BASHPID -eq $$ ]]; then "$@"; else exec "$@"; fi; }
n0() { pretty 0 "$*"; maybe_exec ip netns exec $netns0 "$@"; }
n1() { pretty 1 "$*"; maybe_exec ip netns exec $netns1 "$@"; }
n2() { pretty 2 "$*"; maybe_exec ip netns exec $netns2 "$@"; }
ip0() { pretty 0 "ip $*"; ip -n $netns0 "$@"; }
ip1() { pretty 1 "ip $*"; ip -n $netns1 "$@"; }
ip2() { pretty 2 "ip $*"; ip -n $netns2 "$@"; }
sleep() { read -t "$1" -N 1 || true; }
waitiperf() { pretty "${1//*-}" "wait for iperf:5201 pid $2"; while [[ $(ss -N "$1" -tlpH 'sport = 5201') != *\"iperf3\",pid=$2,fd=* ]]; do sleep 0.1; done; }
waitncatudp() { pretty "${1//*-}" "wait for udp:1111 pid $2"; while [[ $(ss -N "$1" -ulpH 'sport = 1111') != *\"ncat\",pid=$2,fd=* ]]; do sleep 0.1; done; }
waitiface() { pretty "${1//*-}" "wait for $2 to come up"; ip netns exec "$1" bash -c "while [[ \$(< \"/sys/class/net/$2/operstate\") != up ]]; do read -t .1 -N 0 || true; done;"; }

cleanup() {
	set +e
	exec 2>/dev/null
	printf "$orig_message_cost" > /proc/sys/net/core/message_cost
	ip0 link del dev wg0
	ip0 link del dev wg1
	ip1 link del dev wg0
	ip1 link del dev wg1
	ip2 link del dev wg0
	ip2 link del dev wg1
	local to_kill="$(ip netns pids $netns0) $(ip netns pids $netns1) $(ip netns pids $netns2)"
	[[ -n $to_kill ]] && kill $to_kill
	pp ip netns del $netns1
	pp ip netns del $netns2
	pp ip netns del $netns0
	exit
}

orig_message_cost="$(< /proc/sys/net/core/message_cost)"
trap cleanup EXIT
printf 0 > /proc/sys/net/core/message_cost

ip netns del $netns0 2>/dev/null || true
ip netns del $netns1 2>/dev/null || true
ip netns del $netns2 2>/dev/null || true
pp ip netns add $netns0
pp ip netns add $netns1
pp ip netns add $netns2
ip0 link set up dev lo

ip0 link add dev wg0 type wireguard
ip0 link set wg0 netns $netns1
ip0 link add dev wg0 type wireguard
ip0 link set wg0 netns $netns2
key1="$(pp wg genkey)"
key2="$(pp wg genkey)"
key3="$(pp wg genkey)"
key4="$(pp wg genkey)"
pub1="$(pp wg pubkey <<<"$key1")"
pub2="$(pp wg pubkey <<<"$key2")"
pub3="$(pp wg pubkey <<<"$key3")"
pub4="$(pp wg pubkey <<<"$key4")"
psk="$(pp wg genpsk)"
[[ -n $key1 && -n $key2 && -n $psk ]]

configure_peers() {
	ip1 addr add 192.168.241.1/24 dev wg0
	ip1 addr add fd00::1/112 dev wg0

	ip2 addr add 192.168.241.2/24 dev wg0
	ip2 addr add fd00::2/112 dev wg0

	n1 wg set wg0 \
		private-key <(echo "$key1") \
		listen-port 1 \
		peer "$pub2" \
			preshared-key <(echo "$psk") \
			allowed-ips 192.168.241.2/32,fd00::2/128
	n2 wg set wg0 \
		private-key <(echo "$key2") \
		listen-port 2 \
		peer "$pub1" \
			preshared-key <(echo "$psk") \
			allowed-ips 192.168.241.1/32,fd00::1/128

	ip1 link set up dev wg0
	ip2 link set up dev wg0
}
configure_peers

tests() {
	# Ping over IPv4
	n2 ping -c 10 -f -W 1 192.168.241.1
	n1 ping -c 10 -f -W 1 192.168.241.2

	# Ping over IPv6
	n2 ping6 -c 10 -f -W 1 fd00::1
	n1 ping6 -c 10 -f -W 1 fd00::2

	# TCP over IPv4
	n2 iperf3 -s -1 -B 192.168.241.2 &
	waitiperf $netns2 $!
	n1 iperf3 -Z -t 3 -c 192.168.241.2

	# TCP over IPv6
	n1 iperf3 -s -1 -B fd00::1 &
	waitiperf $netns1 $!
	n2 iperf3 -Z -t 3 -c fd00::1

	# UDP over IPv4
	n1 iperf3 -s -1 -B 192.168.241.1 &
	waitiperf $netns1 $!
	n2 iperf3 -Z -t 3 -b 0 -u -c 192.168.241.1

	# UDP over IPv6
	n2 iperf3 -s -1 -B fd00::2 &
	waitiperf $netns2 $!
	n1 iperf3 -Z -t 3 -b 0 -u -c fd00::2
}

[[ $(ip1 link show dev wg0) =~ mtu\ ([0-9]+) ]] && orig_mtu="${BASH_REMATCH[1]}"
big_mtu=$(( 34816 - 1500 + $orig_mtu ))

# Test using IPv4 as outer transport
n1 wg set wg0 peer "$pub2" endpoint 127.0.0.1:2
n2 wg set wg0 peer "$pub1" endpoint 127.0.0.1:1
# Before calling tests, we first make sure that the stats counters and timestamper are working
n2 ping -c 10 -f -W 1 192.168.241.1
{ read _; read _; read _; read rx_bytes _; read _; read tx_bytes _; } < <(ip2 -stats link show dev wg0)
(( rx_bytes == 1372 && (tx_bytes == 1428 || tx_bytes == 1460) ))
{ read _; read _; read _; read rx_bytes _; read _; read tx_bytes _; } < <(ip1 -stats link show dev wg0)
(( tx_bytes == 1372 && (rx_bytes == 1428 || rx_bytes == 1460) ))
read _ rx_bytes tx_bytes < <(n2 wg show wg0 transfer)
(( rx_bytes == 1372 && (tx_bytes == 1428 || tx_bytes == 1460) ))
read _ rx_bytes tx_bytes < <(n1 wg show wg0 transfer)
(( tx_bytes == 1372 && (rx_bytes == 1428 || rx_bytes == 1460) ))
read _ timestamp < <(n1 wg show wg0 latest-handshakes)
(( timestamp != 0 ))

tests
ip1 link set wg0 mtu $big_mtu
ip2 link set wg0 mtu $big_mtu
tests

ip1 link set wg0 mtu $orig_mtu
ip2 link set wg0 mtu $orig_mtu

# Test using IPv6 as outer transport
n1 wg set wg0 peer "$pub2" endpoint [::1]:2
n2 wg set wg0 peer "$pub1" endpoint [::1]:1
tests
ip1 link set wg0 mtu $big_mtu
ip2 link set wg0 mtu $big_mtu
tests

# Test that route MTUs work with the padding
ip1 link set wg0 mtu 1300
ip2 link set wg0 mtu 1300
n1 wg set wg0 peer "$pub2" endpoint 127.0.0.1:2
n2 wg set wg0 peer "$pub1" endpoint 127.0.0.1:1
n0 iptables -A INPUT -m length --length 1360 -j DROP
n1 ip route add 192.168.241.2/32 dev wg0 mtu 1299
n2 ip route add 192.168.241.1/32 dev wg0 mtu 1299
n2 ping -c 1 -W 1 -s 1269 192.168.241.1
n2 ip route delete 192.168.241.1/32 dev wg0 mtu 1299
n1 ip route delete 192.168.241.2/32 dev wg0 mtu 1299
n0 iptables -F INPUT

ip1 link set wg0 mtu $orig_mtu
ip2 link set wg0 mtu $orig_mtu

# Test using IPv4 that roaming works
ip0 -4 addr del 127.0.0.1/8 dev lo
ip0 -4 addr add 127.212.121.99/8 dev lo
n1 wg set wg0 listen-port 9999
n1 wg set wg0 peer "$pub2" endpoint 127.0.0.1:2
n1 ping6 -W 1 -c 1 fd00::2
[[ $(n2 wg show wg0 endpoints) == "$pub1	127.212.121.99:9999" ]]

# Test using IPv6 that roaming works
n1 wg set wg0 listen-port 9998
n1 wg set wg0 peer "$pub2" endpoint [::1]:2
n1 ping -W 1 -c 1 192.168.241.2
[[ $(n2 wg show wg0 endpoints) == "$pub1	[::1]:9998" ]]

# Test that crypto-RP filter works
n1 wg set wg0 peer "$pub2" allowed-ips 192.168.241.0/24
exec 4< <(n1 ncat -l -u -p 1111)
ncat_pid=$!
waitncatudp $netns1 $ncat_pid
n2 ncat -u 192.168.241.1 1111 <<<"X"
read -r -N 1 -t 1 out <&4 && [[ $out == "X" ]]
kill $ncat_pid
more_specific_key="$(pp wg genkey | pp wg pubkey)"
n1 wg set wg0 peer "$more_specific_key" allowed-ips 192.168.241.2/32
n2 wg set wg0 listen-port 9997
exec 4< <(n1 ncat -l -u -p 1111)
ncat_pid=$!
waitncatudp $netns1 $ncat_pid
n2 ncat -u 192.168.241.1 1111 <<<"X"
! read -r -N 1 -t 1 out <&4 || false
kill $ncat_pid
n1 wg set wg0 peer "$more_specific_key" remove
[[ $(n1 wg show wg0 endpoints) == "$pub2	[::1]:9997" ]]

# Test that we can change private keys keys and immediately handshake
n1 wg set wg0 private-key <(echo "$key1") peer "$pub2" preshared-key <(echo "$psk") allowed-ips 192.168.241.2/32 endpoint 127.0.0.1:2
n2 wg set wg0 private-key <(echo "$key2") listen-port 2 peer "$pub1" preshared-key <(echo "$psk") allowed-ips 192.168.241.1/32
n1 ping -W 1 -c 1 192.168.241.2
n1 wg set wg0 private-key <(echo "$key3")
n2 wg set wg0 peer "$pub3" preshared-key <(echo "$psk") allowed-ips 192.168.241.1/32 peer "$pub1" remove
n1 ping -W 1 -c 1 192.168.241.2
n2 wg set wg0 peer "$pub3" remove

# Test that we can route wg through wg
ip1 addr flush dev wg0
ip2 addr flush dev wg0
ip1 addr add fd00::5:1/112 dev wg0
ip2 addr add fd00::5:2/112 dev wg0
n1 wg set wg0 private-key <(echo "$key1") peer "$pub2" preshared-key <(echo "$psk") allowed-ips fd00::5:2/128 endpoint 127.0.0.1:2
n2 wg set wg0 private-key <(echo "$key2") listen-port 2 peer "$pub1" preshared-key <(echo "$psk") allowed-ips fd00::5:1/128 endpoint 127.212.121.99:9998
ip1 link add wg1 type wireguard
ip2 link add wg1 type wireguard
ip1 addr add 192.168.241.1/24 dev wg1
ip1 addr add fd00::1/112 dev wg1
ip2 addr add 192.168.241.2/24 dev wg1
ip2 addr add fd00::2/112 dev wg1
ip1 link set mtu 1340 up dev wg1
ip2 link set mtu 1340 up dev wg1
n1 wg set wg1 listen-port 5 private-key <(echo "$key3") peer "$pub4" allowed-ips 192.168.241.2/32,fd00::2/128 endpoint [fd00::5:2]:5
n2 wg set wg1 listen-port 5 private-key <(echo "$key4") peer "$pub3" allowed-ips 192.168.241.1/32,fd00::1/128 endpoint [fd00::5:1]:5
tests
# Try to set up a routing loop between the two namespaces
ip1 link set netns $netns0 dev wg1
ip0 addr add 192.168.241.1/24 dev wg1
ip0 link set up dev wg1
n0 ping -W 1 -c 1 192.168.241.2
n1 wg set wg0 peer "$pub2" endpoint 192.168.241.2:7
ip2 link del wg0
ip2 link del wg1
! n0 ping -W 1 -c 10 -f 192.168.241.2 || false # Should not crash kernel

ip0 link del wg1
ip1 link del wg0

# Test using NAT. We now change the topology to this:
# ┌────────────────────────────────────────┐    ┌────────────────────────────────────────────────┐     ┌────────────────────────────────────────┐
# │             $ns1 namespace             │    │                 $ns0 namespace                 │     │             $ns2 namespace             │
# │                                        │    │                                                │     │                                        │
# │  ┌─────┐             ┌─────┐           │    │    ┌──────┐              ┌──────┐              │     │  ┌─────┐            ┌─────┐            │
# │  │ wg0 │─────────────│vethc│───────────┼────┼────│vethrc│              │vethrs│──────────────┼─────┼──│veths│────────────│ wg0 │            │
# │  ├─────┴──────────┐  ├─────┴──────────┐│    │    ├──────┴─────────┐    ├──────┴────────────┐ │     │  ├─────┴──────────┐ ├─────┴──────────┐ │
# │  │192.168.241.1/24│  │192.168.1.100/24││    │    │192.168.1.1/24  │    │10.0.0.1/24        │ │     │  │10.0.0.100/24   │ │192.168.241.2/24│ │
# │  │fd00::1/24      │  │                ││    │    │                │    │SNAT:192.168.1.0/24│ │     │  │                │ │fd00::2/24      │ │
# │  └────────────────┘  └────────────────┘│    │    └────────────────┘    └───────────────────┘ │     │  └────────────────┘ └────────────────┘ │
# └────────────────────────────────────────┘    └────────────────────────────────────────────────┘     └────────────────────────────────────────┘

ip1 link add dev wg0 type wireguard
ip2 link add dev wg0 type wireguard
configure_peers

ip0 link add vethrc type veth peer name vethc
ip0 link add vethrs type veth peer name veths
ip0 link set vethc netns $netns1
ip0 link set veths netns $netns2
ip0 link set vethrc up
ip0 link set vethrs up
ip0 addr add 192.168.1.1/24 dev vethrc
ip0 addr add 10.0.0.1/24 dev vethrs
ip1 addr add 192.168.1.100/24 dev vethc
ip1 link set vethc up
ip1 route add default via 192.168.1.1
ip2 addr add 10.0.0.100/24 dev veths
ip2 link set veths up
waitiface $netns0 vethrc
waitiface $netns0 vethrs
waitiface $netns1 vethc
waitiface $netns2 veths

n0 bash -c 'printf 1 > /proc/sys/net/ipv4/ip_forward'
n0 bash -c 'printf 2 > /proc/sys/net/netfilter/nf_conntrack_udp_timeout'
n0 bash -c 'printf 2 > /proc/sys/net/netfilter/nf_conntrack_udp_timeout_stream'
n0 iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -d 10.0.0.0/24 -j SNAT --to 10.0.0.1

n1 wg set wg0 peer "$pub2" endpoint 10.0.0.100:2 persistent-keepalive 1
n1 ping -W 1 -c 1 192.168.241.2
n2 ping -W 1 -c 1 192.168.241.1
[[ $(n2 wg show wg0 endpoints) == "$pub1	10.0.0.1:1" ]]
# Demonstrate n2 can still send packets to n1, since persistent-keepalive will prevent connection tracking entry from expiring (to see entries: `n0 conntrack -L`).
pp sleep 3
n2 ping -W 1 -c 1 192.168.241.1
n1 wg set wg0 peer "$pub2" persistent-keepalive 0

# Test that onion routing works, even when it loops
n1 wg set wg0 peer "$pub3" allowed-ips 192.168.242.2/32 endpoint 192.168.241.2:5
ip1 addr add 192.168.242.1/24 dev wg0
ip2 link add wg1 type wireguard
ip2 addr add 192.168.242.2/24 dev wg1
n2 wg set wg1 private-key <(echo "$key3") listen-port 5 peer "$pub1" allowed-ips 192.168.242.1/32
ip2 link set wg1 up
n1 ping -W 1 -c 1 192.168.242.2
ip2 link del wg1
n1 wg set wg0 peer "$pub3" endpoint 192.168.242.2:5
! n1 ping -W 1 -c 1 192.168.242.2 || false # Should not crash kernel
n1 wg set wg0 peer "$pub3" remove
ip1 addr del 192.168.242.1/24 dev wg0

# Do a wg-quick(8)-style policy routing for the default route, making sure vethc has a v6 address to tease out bugs.
ip1 -6 addr add fc00::9/96 dev vethc
ip1 -6 route add default via fc00::1
ip2 -4 addr add 192.168.99.7/32 dev wg0
ip2 -6 addr add abab::1111/128 dev wg0
n1 wg set wg0 fwmark 51820 peer "$pub2" allowed-ips 192.168.99.7,abab::1111
ip1 -6 route add default dev wg0 table 51820
ip1 -6 rule add not fwmark 51820 table 51820
ip1 -6 rule add table main suppress_prefixlength 0
ip1 -4 route add default dev wg0 table 51820
ip1 -4 rule add not fwmark 51820 table 51820
ip1 -4 rule add table main suppress_prefixlength 0
# Flood the pings instead of sending just one, to trigger routing table reference counting bugs.
n1 ping -W 1 -c 100 -f 192.168.99.7
n1 ping -W 1 -c 100 -f abab::1111

# Have ns2 NAT into wg0 packets from ns0, but return an icmp error along the right route.
n2 iptables -t nat -A POSTROUTING -s 10.0.0.0/24 -d 192.168.241.0/24 -j SNAT --to 192.168.241.2
n0 iptables -t filter -A INPUT \! -s 10.0.0.0/24 -i vethrs -j DROP # Manual rpfilter just to be explicit.
n2 bash -c 'printf 1 > /proc/sys/net/ipv4/ip_forward'
ip0 -4 route add 192.168.241.1 via 10.0.0.100
n2 wg set wg0 peer "$pub1" remove
[[ $(! n0 ping -W 1 -c 1 192.168.241.1 || false) == *"From 10.0.0.100 icmp_seq=1 Destination Host Unreachable"* ]]

n0 iptables -t nat -F
n0 iptables -t filter -F
n2 iptables -t nat -F
ip0 link del vethrc
ip0 link del vethrs
ip1 link del wg0
ip2 link del wg0

# Test that saddr routing is sticky but not too sticky, changing to this topology:
# ┌────────────────────────────────────────┐    ┌────────────────────────────────────────┐
# │             $ns1 namespace             │    │             $ns2 namespace             │
# │                                        │    │                                        │
# │  ┌─────┐             ┌─────┐           │    │  ┌─────┐            ┌─────┐            │
# │  │ wg0 │─────────────│veth1│───────────┼────┼──│veth2│────────────│ wg0 │            │
# │  ├─────┴──────────┐  ├─────┴──────────┐│    │  ├─────┴──────────┐ ├─────┴──────────┐ │
# │  │192.168.241.1/24│  │10.0.0.1/24     ││    │  │10.0.0.2/24     │ │192.168.241.2/24│ │
# │  │fd00::1/24      │  │fd00:aa::1/96   ││    │  │fd00:aa::2/96   │ │fd00::2/24      │ │
# │  └────────────────┘  └────────────────┘│    │  └────────────────┘ └────────────────┘ │
# └────────────────────────────────────────┘    └────────────────────────────────────────┘

ip1 link add dev wg0 type wireguard
ip2 link add dev wg0 type wireguard
configure_peers
ip1 link add veth1 type veth peer name veth2
ip1 link set veth2 netns $netns2
n1 bash -c 'printf 0 > /proc/sys/net/ipv6/conf/all/accept_dad'
n2 bash -c 'printf 0 > /proc/sys/net/ipv6/conf/all/accept_dad'
n1 bash -c 'printf 0 > /proc/sys/net/ipv6/conf/veth1/accept_dad'
n2 bash -c 'printf 0 > /proc/sys/net/ipv6/conf/veth2/accept_dad'
n1 bash -c 'printf 1 > /proc/sys/net/ipv4/conf/veth1/promote_secondaries'

# First we check that we aren't overly sticky and can fall over to new IPs when old ones are removed
ip1 addr add 10.0.0.1/24 dev veth1
ip1 addr add fd00:aa::1/96 dev veth1
ip2 addr add 10.0.0.2/24 dev veth2
ip2 addr add fd00:aa::2/96 dev veth2
ip1 link set veth1 up
ip2 link set veth2 up
waitiface $netns1 veth1
waitiface $netns2 veth2
n1 wg set wg0 peer "$pub2" endpoint 10.0.0.2:2
n1 ping -W 1 -c 1 192.168.241.2
ip1 addr add 10.0.0.10/24 dev veth1
ip1 addr del 10.0.0.1/24 dev veth1
n1 ping -W 1 -c 1 192.168.241.2
n1 wg set wg0 peer "$pub2" endpoint [fd00:aa::2]:2
n1 ping -W 1 -c 1 192.168.241.2
ip1 addr add fd00:aa::10/96 dev veth1
ip1 addr del fd00:aa::1/96 dev veth1
n1 ping -W 1 -c 1 192.168.241.2

# Now we show that we can successfully do reply to sender routing
ip1 link set veth1 down
ip2 link set veth2 down
ip1 addr flush dev veth1
ip2 addr flush dev veth2
ip1 addr add 10.0.0.1/24 dev veth1
ip1 addr add 10.0.0.2/24 dev veth1
ip1 addr add fd00:aa::1/96 dev veth1
ip1 addr add fd00:aa::2/96 dev veth1
ip2 addr add 10.0.0.3/24 dev veth2
ip2 addr add fd00:aa::3/96 dev veth2
ip1 link set veth1 up
ip2 link set veth2 up
waitiface $netns1 veth1
waitiface $netns2 veth2
n2 wg set wg0 peer "$pub1" endpoint 10.0.0.1:1
n2 ping -W 1 -c 1 192.168.241.1
[[ $(n2 wg show wg0 endpoints) == "$pub1	10.0.0.1:1" ]]
n2 wg set wg0 peer "$pub1" endpoint [fd00:aa::1]:1
n2 ping -W 1 -c 1 192.168.241.1
[[ $(n2 wg show wg0 endpoints) == "$pub1	[fd00:aa::1]:1" ]]
n2 wg set wg0 peer "$pub1" endpoint 10.0.0.2:1
n2 ping -W 1 -c 1 192.168.241.1
[[ $(n2 wg show wg0 endpoints) == "$pub1	10.0.0.2:1" ]]
n2 wg set wg0 peer "$pub1" endpoint [fd00:aa::2]:1
n2 ping -W 1 -c 1 192.168.241.1
[[ $(n2 wg show wg0 endpoints) == "$pub1	[fd00:aa::2]:1" ]]

# What happens if the inbound destination address belongs to a different interface as the default route?
ip1 link add dummy0 type dummy
ip1 addr add 10.50.0.1/24 dev dummy0
ip1 link set dummy0 up
ip2 route add 10.50.0.0/24 dev veth2
n2 wg set wg0 peer "$pub1" endpoint 10.50.0.1:1
n2 ping -W 1 -c 1 192.168.241.1
[[ $(n2 wg show wg0 endpoints) == "$pub1	10.50.0.1:1" ]]

ip1 link del dummy0
ip1 addr flush dev veth1
ip2 addr flush dev veth2
ip1 route flush dev veth1
ip2 route flush dev veth2

# Now we see what happens if another interface route takes precedence over an ongoing one
ip1 link add veth3 type veth peer name veth4
ip1 link set veth4 netns $netns2
ip1 addr add 10.0.0.1/24 dev veth1
ip2 addr add 10.0.0.2/24 dev veth2
ip1 addr add 10.0.0.3/24 dev veth3
ip1 link set veth1 up
ip2 link set veth2 up
ip1 link set veth3 up
ip2 link set veth4 up
waitiface $netns1 veth1
waitiface $netns2 veth2
waitiface $netns1 veth3
waitiface $netns2 veth4
ip1 route flush dev veth1
ip1 route flush dev veth3
ip1 route add 10.0.0.0/24 dev veth1 src 10.0.0.1 metric 2
n1 wg set wg0 peer "$pub2" endpoint 10.0.0.2:2
n1 ping -W 1 -c 1 192.168.241.2
[[ $(n2 wg show wg0 endpoints) == "$pub1	10.0.0.1:1" ]]
ip1 route add 10.0.0.0/24 dev veth3 src 10.0.0.3 metric 1
n1 bash -c 'printf 0 > /proc/sys/net/ipv4/conf/veth1/rp_filter'
n2 bash -c 'printf 0 > /proc/sys/net/ipv4/conf/veth4/rp_filter'
n1 bash -c 'printf 0 > /proc/sys/net/ipv4/conf/all/rp_filter'
n2 bash -c 'printf 0 > /proc/sys/net/ipv4/conf/all/rp_filter'
n1 ping -W 1 -c 1 192.168.241.2
[[ $(n2 wg show wg0 endpoints) == "$pub1	10.0.0.3:1" ]]

ip1 link del veth1
ip1 link del veth3
ip1 link del wg0
ip2 link del wg0

# We test that Netlink/IPC is working properly by doing things that usually cause split responses
ip0 link add dev wg0 type wireguard
config=( "[Interface]" "PrivateKey=$(wg genkey)" "[Peer]" "PublicKey=$(wg genkey)" )
for a in {1..255}; do
	for b in {0..255}; do
		config+=( "AllowedIPs=$a.$b.0.0/16,$a::$b/128" )
	done
done
n0 wg setconf wg0 <(printf '%s\n' "${config[@]}")
i=0
for ip in $(n0 wg show wg0 allowed-ips); do
	((++i))
done
((i == 255*256*2+1))
ip0 link del wg0
ip0 link add dev wg0 type wireguard
config=( "[Interface]" "PrivateKey=$(wg genkey)" )
for a in {1..40}; do
	config+=( "[Peer]" "PublicKey=$(wg genkey)" )
	for b in {1..52}; do
		config+=( "AllowedIPs=$a.$b.0.0/16" )
	done
done
n0 wg setconf wg0 <(printf '%s\n' "${config[@]}")
i=0
while read -r line; do
	j=0
	for ip in $line; do
		((++j))
	done
	((j == 53))
	((++i))
done < <(n0 wg show wg0 allowed-ips)
((i == 40))
ip0 link del wg0
ip0 link add wg0 type wireguard
config=( )
for i in {1..29}; do
	config+=( "[Peer]" "PublicKey=$(wg genkey)" )
done
config+=( "[Peer]" "PublicKey=$(wg genkey)" "AllowedIPs=255.2.3.4/32,abcd::255/128" )
n0 wg setconf wg0 <(printf '%s\n' "${config[@]}")
n0 wg showconf wg0 > /dev/null
ip0 link del wg0

allowedips=( )
for i in {1..197}; do
        allowedips+=( abcd::$i )
done
saved_ifs="$IFS"
IFS=,
allowedips="${allowedips[*]}"
IFS="$saved_ifs"
ip0 link add wg0 type wireguard
n0 wg set wg0 peer "$pub1"
n0 wg set wg0 peer "$pub2" allowed-ips "$allowedips"
{
	read -r pub allowedips
	[[ $pub == "$pub1" && $allowedips == "(none)" ]]
	read -r pub allowedips
	[[ $pub == "$pub2" ]]
	i=0
	for _ in $allowedips; do
		((++i))
	done
	((i == 197))
} < <(n0 wg show wg0 allowed-ips)
ip0 link del wg0

! n0 wg show doesnotexist || false

ip0 link add wg0 type wireguard
n0 wg set wg0 private-key <(echo "$key1") peer "$pub2" preshared-key <(echo "$psk")
[[ $(n0 wg show wg0 private-key) == "$key1" ]]
[[ $(n0 wg show wg0 preshared-keys) == "$pub2	$psk" ]]
n0 wg set wg0 private-key /dev/null peer "$pub2" preshared-key /dev/null
[[ $(n0 wg show wg0 private-key) == "(none)" ]]
[[ $(n0 wg show wg0 preshared-keys) == "$pub2	(none)" ]]
n0 wg set wg0 peer "$pub2"
n0 wg set wg0 private-key <(echo "$key2")
[[ $(n0 wg show wg0 public-key) == "$pub2" ]]
[[ -z $(n0 wg show wg0 peers) ]]
n0 wg set wg0 peer "$pub2"
[[ -z $(n0 wg show wg0 peers) ]]
n0 wg set wg0 private-key <(echo "$key1")
n0 wg set wg0 peer "$pub2"
[[ $(n0 wg show wg0 peers) == "$pub2" ]]
n0 wg set wg0 private-key <(echo "/${key1:1}")
[[ $(n0 wg show wg0 private-key) == "+${key1:1}" ]]
n0 wg set wg0 peer "$pub2" allowed-ips 0.0.0.0/0,10.0.0.0/8,100.0.0.0/10,172.16.0.0/12,192.168.0.0/16
n0 wg set wg0 peer "$pub2" allowed-ips 0.0.0.0/0
n0 wg set wg0 peer "$pub2" allowed-ips ::/0,1700::/111,5000::/4,e000::/37,9000::/75
n0 wg set wg0 peer "$pub2" allowed-ips ::/0
n0 wg set wg0 peer "$pub2" remove
for low_order_point in AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= 4Ot6fDtBuK4WVuP68Z/EatoJjeucMrH9hmIFFl9JuAA= X5yVvKNQjCSx0LFVnIPvWwREXMRYHI6G2CJO3dCfEVc= 7P///////////////////////////////////////38= 7f///////////////////////////////////////38= 7v///////////////////////////////////////38=; do
	n0 wg set wg0 peer "$low_order_point" persistent-keepalive 1 endpoint 127.0.0.1:1111
done
[[ -n $(n0 wg show wg0 peers) ]]
exec 4< <(n0 ncat -l -u -p 1111)
ncat_pid=$!
waitncatudp $netns0 $ncat_pid
ip0 link set wg0 up
! read -r -n 1 -t 2 <&4 || false
kill $ncat_pid
ip0 link del wg0

declare -A objects
while read -t 0.1 -r line 2>/dev/null || [[ $? -ne 142 ]]; do
	[[ $line =~ .*(wg[0-9]+:\ [A-Z][a-z]+\ [0-9]+)\ .*(created|destroyed).* ]] || continue
	objects["${BASH_REMATCH[1]}"]+="${BASH_REMATCH[2]}"
done < /dev/kmsg
alldeleted=1
for object in "${!objects[@]}"; do
	if [[ ${objects["$object"]} != *createddestroyed ]]; then
		echo "Error: $object: merely ${objects["$object"]}" >&3
		alldeleted=0
	fi
done
[[ $alldeleted -eq 1 ]]
pretty "" "Objects that were created were also destroyed."