mirror of
https://github.com/torvalds/linux.git
synced 2026-09-24 06:24:02 +02:00
e5382133c5
Add a selftest to verify that FOU-encapsulated packets addressed to a multicast destination are correctly resubmitted to the inner protocol handler (GRE) via the UDP multicast delivery path. Both IPv4 and IPv6 paths are tested. The test creates two network namespaces connected by a veth pair with a FOU/GRETAP (IPv4) and FOU/ip6gretap (IPv6) tunnel using multicast remote addresses (239.0.0.1 and ff0e::1). Ping is sent through each tunnel and received packets are counted on the receiver's tunnel interface. The veth pair is created directly inside the namespaces to avoid possible name collisions with devices in the root namespace. Static neighbor entries are configured on the sender because ARP/ND replies from the receiver cannot traverse the unidirectional multicast tunnel back to the sender. The early demux optimization (net.ipv4.ip_early_demux, which controls both IPv4 and IPv6) is disabled on the receiver to force packets through __udp4_lib_mcast_deliver() / __udp6_lib_mcast_deliver(), which is the code path being tested. Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Assisted-by: Claude:claude-opus-4-6 Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/a5b65f092d22a12b52fc536c0565b948cd8ecae3.1783372173.git.littlesmilingcloud@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
173 lines
5.1 KiB
Bash
Executable File
173 lines
5.1 KiB
Bash
Executable File
#!/bin/bash
|
|
# SPDX-License-Identifier: GPL-2.0
|
|
#
|
|
# Test that UDP encapsulation (FOU) correctly handles packet resubmit
|
|
# when packets are delivered via the multicast UDP delivery path.
|
|
#
|
|
# When a FOU-encapsulated packet arrives with a multicast destination IP,
|
|
# __udp4_lib_mcast_deliver() / __udp6_lib_mcast_deliver() must resubmit
|
|
# it to the inner protocol handler (e.g., GRE) rather than consuming it.
|
|
# This test verifies both IPv4 and IPv6 paths by creating a FOU/GRETAP
|
|
# tunnel with a multicast remote address and sending ping through it.
|
|
#
|
|
# The early demux optimization can mask this issue by routing packets via
|
|
# the unicast path (udp[6]_unicast_rcv_skb), so we disable it to force
|
|
# packets through the multicast delivery function.
|
|
|
|
source lib.sh
|
|
|
|
NSENDER=""
|
|
NRECV=""
|
|
|
|
FOU_PORT4=4797
|
|
FOU_PORT6=4798
|
|
MCAST4=239.0.0.1
|
|
MCAST6=ff0e::1
|
|
|
|
TUN4_S=192.168.99.1
|
|
TUN4_R=192.168.99.2
|
|
TUN6_S=2001:db8:99::1
|
|
TUN6_R=2001:db8:99::2
|
|
|
|
cleanup() {
|
|
cleanup_all_ns
|
|
}
|
|
|
|
trap cleanup EXIT
|
|
|
|
setup_common() {
|
|
setup_ns NSENDER NRECV
|
|
|
|
# Create veth pair directly inside namespaces to avoid name
|
|
# collisions with devices in the root namespace.
|
|
ip link add veth_s netns "$NSENDER" type veth \
|
|
peer name veth_r netns "$NRECV"
|
|
|
|
ip -n "$NSENDER" link set veth_s up
|
|
ip -n "$NRECV" link set veth_r up
|
|
|
|
# Same sysctl controls early demux for both IPv4 and IPv6.
|
|
ip netns exec "$NRECV" sysctl -wq net.ipv4.ip_early_demux=0
|
|
}
|
|
|
|
setup_ipv4() {
|
|
# IPv4 FOU (CONFIG_NET_FOU) is built in on kernels configured for
|
|
# these tests, so no module load is needed here.
|
|
ip -n "$NSENDER" addr add 10.0.0.1/24 dev veth_s
|
|
ip -n "$NRECV" addr add 10.0.0.2/24 dev veth_r
|
|
|
|
# Join multicast group on receiver
|
|
ip -n "$NRECV" addr add "$MCAST4/32" dev veth_r autojoin
|
|
|
|
ip -n "$NSENDER" route add 239.0.0.0/8 dev veth_s
|
|
ip -n "$NRECV" route add 239.0.0.0/8 dev veth_r
|
|
|
|
# Sender: GRETAP with FOU encap (no FOU listener needed on TX side)
|
|
ip -n "$NSENDER" link add eoudp4 type gretap \
|
|
remote "$MCAST4" local 10.0.0.1 \
|
|
encap fou encap-sport "$FOU_PORT4" encap-dport "$FOU_PORT4" \
|
|
key "$MCAST4"
|
|
ip -n "$NSENDER" link set eoudp4 up
|
|
ip -n "$NSENDER" addr add "$TUN4_S/24" dev eoudp4
|
|
|
|
# Receiver: FOU listener + GRETAP
|
|
ip netns exec "$NRECV" ip fou add port "$FOU_PORT4" ipproto 47
|
|
ip -n "$NRECV" link add eoudp4 type gretap \
|
|
remote "$MCAST4" local 10.0.0.2 \
|
|
encap fou encap-sport "$FOU_PORT4" encap-dport "$FOU_PORT4" \
|
|
key "$MCAST4"
|
|
ip -n "$NRECV" link set eoudp4 up
|
|
ip -n "$NRECV" addr add "$TUN4_R/24" dev eoudp4
|
|
|
|
# Static neigh on sender: ARP replies cannot traverse the
|
|
# unidirectional multicast tunnel.
|
|
local recv_mac
|
|
recv_mac=$(ip -n "$NRECV" link show eoudp4 | awk '/ether/{print $2}')
|
|
ip -n "$NSENDER" neigh add "$TUN4_R" lladdr "$recv_mac" dev eoudp4
|
|
}
|
|
|
|
setup_ipv6() {
|
|
# Skip cleanly if IPv6 or the fou6 module is not available.
|
|
[ -e /proc/sys/net/ipv6 ] || return "$ksft_skip"
|
|
modprobe -q fou6 || return "$ksft_skip"
|
|
|
|
ip -n "$NSENDER" addr add 2001:db8::1/64 dev veth_s nodad
|
|
ip -n "$NRECV" addr add 2001:db8::2/64 dev veth_r nodad
|
|
|
|
# Join multicast group on receiver
|
|
ip -n "$NRECV" addr add "$MCAST6/128" dev veth_r autojoin
|
|
|
|
ip -n "$NSENDER" -6 route add ff00::/8 dev veth_s
|
|
ip -n "$NRECV" -6 route add ff00::/8 dev veth_r
|
|
|
|
# Sender: ip6gretap with FOU encap
|
|
ip -n "$NSENDER" link add eoudp6 type ip6gretap \
|
|
remote "$MCAST6" local 2001:db8::1 \
|
|
encap fou encap-sport "$FOU_PORT6" encap-dport "$FOU_PORT6" \
|
|
key 42
|
|
ip -n "$NSENDER" link set eoudp6 up
|
|
ip -n "$NSENDER" addr add "$TUN6_S/64" dev eoudp6 nodad
|
|
|
|
# Receiver: FOU listener (IPv6) + ip6gretap
|
|
ip netns exec "$NRECV" ip fou add port "$FOU_PORT6" ipproto 47 -6
|
|
ip -n "$NRECV" link add eoudp6 type ip6gretap \
|
|
remote "$MCAST6" local 2001:db8::2 \
|
|
encap fou encap-sport "$FOU_PORT6" encap-dport "$FOU_PORT6" \
|
|
key 42
|
|
ip -n "$NRECV" link set eoudp6 up
|
|
ip -n "$NRECV" addr add "$TUN6_R/64" dev eoudp6 nodad
|
|
|
|
# Static neigh on sender: neighbor discovery cannot traverse the
|
|
# unidirectional multicast tunnel.
|
|
local recv_mac
|
|
recv_mac=$(ip -n "$NRECV" link show eoudp6 | awk '/ether/{print $2}')
|
|
ip -n "$NSENDER" neigh add "$TUN6_R" lladdr "$recv_mac" dev eoudp6
|
|
}
|
|
|
|
get_rx_packets() {
|
|
local dev="$1"
|
|
|
|
ip -n "$NRECV" -s link show "$dev" | awk '/RX:/{getline; print $2}'
|
|
}
|
|
|
|
run_ping_test() {
|
|
local family="$1"
|
|
local dev="$2"
|
|
local dst="$3"
|
|
local name="$4"
|
|
local count=100
|
|
local rx_before rx_after rx_delta
|
|
|
|
# Warmup: let any initial broadcast/ND traffic settle
|
|
ip netns exec "$NSENDER" ping "$family" -c 1 -W 1 "$dst" \
|
|
>/dev/null 2>&1
|
|
sleep 1
|
|
|
|
rx_before=$(get_rx_packets "$dev")
|
|
ip netns exec "$NSENDER" ping "$family" -i 0.01 -c $count -W 1 "$dst" \
|
|
>/dev/null 2>&1
|
|
sleep 1
|
|
rx_after=$(get_rx_packets "$dev")
|
|
|
|
rx_delta=$((rx_after - rx_before))
|
|
|
|
if [ "$rx_delta" -ge "$count" ]; then
|
|
RET=$ksft_pass
|
|
else
|
|
RET=$ksft_fail
|
|
fi
|
|
log_test "$name (received $rx_delta/$count)"
|
|
}
|
|
|
|
setup_common
|
|
setup_ipv4
|
|
run_ping_test -4 eoudp4 "$TUN4_R" "FOU/GRETAP IPv4 multicast encap resubmit"
|
|
|
|
if setup_ipv6; then
|
|
run_ping_test -6 eoudp6 "$TUN6_R" "FOU/ip6gretap IPv6 multicast encap resubmit"
|
|
else
|
|
log_test_skip "FOU/ip6gretap IPv6 multicast encap resubmit"
|
|
fi
|
|
|
|
exit "$EXIT_STATUS"
|