selftests: Add IPv6 link-local address generation tests for GRE devices.

GRE devices have their special code for IPv6 link-local address
generation that has been the source of several regressions in the past.

Add selftest to check that all gre, ip6gre, gretap and ip6gretap get an
IPv6 link-link local address in accordance with the
net.ipv6.conf.<dev>.addr_gen_mode sysctl.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/2d6772af8e1da9016b2180ec3f8d9ee99f470c77.1741375285.git.gnault@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Guillaume Nault 2025-03-07 20:28:58 +01:00 committed by Paolo Abeni
parent 183185a18f
commit 6f50175cca
2 changed files with 178 additions and 0 deletions

View file

@ -31,6 +31,7 @@ TEST_PROGS += veth.sh
TEST_PROGS += ioam6.sh
TEST_PROGS += gro.sh
TEST_PROGS += gre_gso.sh
TEST_PROGS += gre_ipv6_lladdr.sh
TEST_PROGS += cmsg_so_mark.sh
TEST_PROGS += cmsg_so_priority.sh
TEST_PROGS += cmsg_time.sh cmsg_ipv6.sh

View file

@ -0,0 +1,177 @@
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
source ./lib.sh
PAUSE_ON_FAIL="no"
# The trap function handler
#
exit_cleanup_all()
{
cleanup_all_ns
exit "${EXIT_STATUS}"
}
# Add fake IPv4 and IPv6 networks on the loopback device, to be used as
# underlay by future GRE devices.
#
setup_basenet()
{
ip -netns "${NS0}" link set dev lo up
ip -netns "${NS0}" address add dev lo 192.0.2.10/24
ip -netns "${NS0}" address add dev lo 2001:db8::10/64 nodad
}
# Check if network device has an IPv6 link-local address assigned.
#
# Parameters:
#
# * $1: The network device to test
# * $2: An extra regular expression that should be matched (to verify the
# presence of extra attributes)
# * $3: The expected return code from grep (to allow checking the absence of
# a link-local address)
# * $4: The user visible name for the scenario being tested
#
check_ipv6_ll_addr()
{
local DEV="$1"
local EXTRA_MATCH="$2"
local XRET="$3"
local MSG="$4"
RET=0
set +e
ip -netns "${NS0}" -6 address show dev "${DEV}" scope link | grep "fe80::" | grep -q "${EXTRA_MATCH}"
check_err_fail "${XRET}" $? ""
log_test "${MSG}"
set -e
}
# Create a GRE device and verify that it gets an IPv6 link-local address as
# expected.
#
# Parameters:
#
# * $1: The device type (gre, ip6gre, gretap or ip6gretap)
# * $2: The local underlay IP address (can be an IPv4, an IPv6 or "any")
# * $3: The remote underlay IP address (can be an IPv4, an IPv6 or "any")
# * $4: The IPv6 interface identifier generation mode to use for the GRE
# device (eui64, none, stable-privacy or random).
#
test_gre_device()
{
local GRE_TYPE="$1"
local LOCAL_IP="$2"
local REMOTE_IP="$3"
local MODE="$4"
local ADDR_GEN_MODE
local MATCH_REGEXP
local MSG
ip link add netns "${NS0}" name gretest type "${GRE_TYPE}" local "${LOCAL_IP}" remote "${REMOTE_IP}"
case "${MODE}" in
"eui64")
ADDR_GEN_MODE=0
MATCH_REGEXP=""
MSG="${GRE_TYPE}, mode: 0 (EUI64), ${LOCAL_IP} -> ${REMOTE_IP}"
XRET=0
;;
"none")
ADDR_GEN_MODE=1
MATCH_REGEXP=""
MSG="${GRE_TYPE}, mode: 1 (none), ${LOCAL_IP} -> ${REMOTE_IP}"
XRET=1 # No link-local address should be generated
;;
"stable-privacy")
ADDR_GEN_MODE=2
MATCH_REGEXP="stable-privacy"
MSG="${GRE_TYPE}, mode: 2 (stable privacy), ${LOCAL_IP} -> ${REMOTE_IP}"
XRET=0
# Initialise stable_secret (required for stable-privacy mode)
ip netns exec "${NS0}" sysctl -qw net.ipv6.conf.gretest.stable_secret="2001:db8::abcd"
;;
"random")
ADDR_GEN_MODE=3
MATCH_REGEXP="stable-privacy"
MSG="${GRE_TYPE}, mode: 3 (random), ${LOCAL_IP} -> ${REMOTE_IP}"
XRET=0
;;
esac
# Check that IPv6 link-local address is generated when device goes up
ip netns exec "${NS0}" sysctl -qw net.ipv6.conf.gretest.addr_gen_mode="${ADDR_GEN_MODE}"
ip -netns "${NS0}" link set dev gretest up
check_ipv6_ll_addr gretest "${MATCH_REGEXP}" "${XRET}" "config: ${MSG}"
# Now disable link-local address generation
ip -netns "${NS0}" link set dev gretest down
ip netns exec "${NS0}" sysctl -qw net.ipv6.conf.gretest.addr_gen_mode=1
ip -netns "${NS0}" link set dev gretest up
# Check that link-local address generation works when re-enabled while
# the device is already up
ip netns exec "${NS0}" sysctl -qw net.ipv6.conf.gretest.addr_gen_mode="${ADDR_GEN_MODE}"
check_ipv6_ll_addr gretest "${MATCH_REGEXP}" "${XRET}" "update: ${MSG}"
ip -netns "${NS0}" link del dev gretest
}
test_gre4()
{
local GRE_TYPE
local MODE
for GRE_TYPE in "gre" "gretap"; do
printf "\n####\nTesting IPv6 link-local address generation on ${GRE_TYPE} devices\n####\n\n"
for MODE in "eui64" "none" "stable-privacy" "random"; do
test_gre_device "${GRE_TYPE}" 192.0.2.10 192.0.2.11 "${MODE}"
test_gre_device "${GRE_TYPE}" any 192.0.2.11 "${MODE}"
test_gre_device "${GRE_TYPE}" 192.0.2.10 any "${MODE}"
done
done
}
test_gre6()
{
local GRE_TYPE
local MODE
for GRE_TYPE in "ip6gre" "ip6gretap"; do
printf "\n####\nTesting IPv6 link-local address generation on ${GRE_TYPE} devices\n####\n\n"
for MODE in "eui64" "none" "stable-privacy" "random"; do
test_gre_device "${GRE_TYPE}" 2001:db8::10 2001:db8::11 "${MODE}"
test_gre_device "${GRE_TYPE}" any 2001:db8::11 "${MODE}"
test_gre_device "${GRE_TYPE}" 2001:db8::10 any "${MODE}"
done
done
}
usage()
{
echo "Usage: $0 [-p]"
exit 1
}
while getopts :p o
do
case $o in
p) PAUSE_ON_FAIL="yes";;
*) usage;;
esac
done
setup_ns NS0
set -e
trap exit_cleanup_all EXIT
setup_basenet
test_gre4
test_gre6