* [PATCH net 0/2] gre: Fix regressions in IPv6 link-local address generation.
@ 2025-02-19 16:30 Guillaume Nault
2025-02-19 16:30 ` [PATCH net 1/2] gre: Fix " Guillaume Nault
2025-02-19 16:30 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
0 siblings, 2 replies; 6+ messages in thread
From: Guillaume Nault @ 2025-02-19 16:30 UTC (permalink / raw)
To: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet
Cc: netdev, Simon Horman, David Ahern, Antonio Quartulli
IPv6 link-local address generation has some special cases for GRE
devices. This has led to several regressions in the past, and some of
them are still not fixed. This series fixes the remaining problems,
like the ipv6.conf.<dev>.addr_gen_mode sysctl being ignored and the
router discovery process not being started (see details in patch 1).
To avoid any further regressions, patch 2 adds selftests covering
IPv4 and IPv6 gre/gretap devices with all combinations of currently
supported addr_gen_mode values.
Guillaume Nault (2):
gre: Fix IPv6 link-local address generation.
selftests: Add IPv6 link-local address generation tests for GRE
devices.
net/ipv6/addrconf.c | 15 +-
.../testing/selftests/net/gre_ipv6_lladdr.sh | 227 ++++++++++++++++++
2 files changed, 236 insertions(+), 6 deletions(-)
create mode 100755 tools/testing/selftests/net/gre_ipv6_lladdr.sh
--
2.39.2
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH net 1/2] gre: Fix IPv6 link-local address generation.
2025-02-19 16:30 [PATCH net 0/2] gre: Fix regressions in IPv6 link-local address generation Guillaume Nault
@ 2025-02-19 16:30 ` Guillaume Nault
2025-02-19 16:30 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
1 sibling, 0 replies; 6+ messages in thread
From: Guillaume Nault @ 2025-02-19 16:30 UTC (permalink / raw)
To: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet
Cc: netdev, Simon Horman, David Ahern, Antonio Quartulli
Use addrconf_addr_gen() to generate IPv6 link-local addresses on GRE
devices in most cases and fall back to using add_v4_addrs() only in
case the GRE configuration is incompatible with addrconf_addr_gen().
GRE used to use addrconf_addr_gen() until commit e5dd729460ca
("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL
address") restricted this use to gretap devices and created
add_v4_addrs() (borrowed from SIT) for non-Ethernet GRE ones.
The original problem came when commit 9af28511be10 ("addrconf: refuse
isatap eui64 for INADDR_ANY") made __ipv6_isatap_ifid() fail when its
addr parameter was 0. The commit says that this would create an invalid
address, however, I couldn't find any RFC saying that the generated
interface identifier would be wrong. Anyway, since plain gre devices
pass their local tunnel address to __ipv6_isatap_ifid(), that commit
broke their IPv6 link-local address generation when the local address
was unspecified.
Then commit e5dd729460ca ("ip/ip6_gre: use the same logic as SIT
interfaces when computing v6LL address") tried to fix that case by
defining add_v4_addrs() and calling it to generated the IPv6 link-local
address instead of using addrconf_addr_gen() (appart for gretap devices
which would still use the regular addrconf_addr_gen(), since they have
a MAC address).
That broke several use cases because add_v4_addrs() isn't properly
integrated into the rest of IPv6 Neighbor Discovery code. Several of
these shortcomings have been fixed over time, but add_v4_addrs()
remains broken on several aspects. In particular, it doesn't send any
Router Sollicitations, so the SLAAC process doesn't start until the
interface receives a Router Advertisement. Also, add_v4_addrs() mostly
ignores the address generation mode of the interface
(/proc/sys/net/ipv6/conf/*/addr_gen_mode), thus breaking the
IN6_ADDR_GEN_MODE_RANDOM and IN6_ADDR_GEN_MODE_STABLE_PRIVACY cases.
Fix the situation by using add_v4_addrs() only in the specific scenario
where normal method would fail. That is, for interfaces that have all
of the following characteristics:
* transport IP packets directly, not Ethernet (that is, not gretap),
* run over IPv4,
* tunnel endpoint is INADDR_ANY (that is, 0),
* device address generation mode is EUI64.
In all other cases, revert back to the regular addrconf_addr_gen().
Also, remove the special case for ip6gre interfaces in add_v4_addrs(),
since ip6gre devices now always use addrconf_addr_gen() instead.
Fixes: e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
net/ipv6/addrconf.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index ac8cc1076536..8b6258819dad 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3209,16 +3209,13 @@ static void add_v4_addrs(struct inet6_dev *idev)
struct in6_addr addr;
struct net_device *dev;
struct net *net = dev_net(idev->dev);
- int scope, plen, offset = 0;
+ int scope, plen;
u32 pflags = 0;
ASSERT_RTNL();
memset(&addr, 0, sizeof(struct in6_addr));
- /* in case of IP6GRE the dev_addr is an IPv6 and therefore we use only the last 4 bytes */
- if (idev->dev->addr_len == sizeof(struct in6_addr))
- offset = sizeof(struct in6_addr) - 4;
- memcpy(&addr.s6_addr32[3], idev->dev->dev_addr + offset, 4);
+ memcpy(&addr.s6_addr32[3], idev->dev->dev_addr, 4);
if (!(idev->dev->flags & IFF_POINTOPOINT) && idev->dev->type == ARPHRD_SIT) {
scope = IPV6_ADDR_COMPATv4;
@@ -3529,7 +3526,13 @@ static void addrconf_gre_config(struct net_device *dev)
return;
}
- if (dev->type == ARPHRD_ETHER) {
+ /* Generate the IPv6 link-local address using addrconf_addr_gen(),
+ * unless we have an IPv4 GRE device not bound to an IP address and
+ * which is in EUI64 mode (as __ipv6_isatap_ifid() would fail in this
+ * case). Such devices fall back to add_v4_addrs() instead.
+ */
+ if (!(dev->type == ARPHRD_IPGRE && *(__be32 *)dev->dev_addr == 0 &&
+ idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)) {
addrconf_addr_gen(idev, true);
return;
}
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices.
2025-02-19 16:30 [PATCH net 0/2] gre: Fix regressions in IPv6 link-local address generation Guillaume Nault
2025-02-19 16:30 ` [PATCH net 1/2] gre: Fix " Guillaume Nault
@ 2025-02-19 16:30 ` Guillaume Nault
2025-02-19 17:44 ` Guillaume Nault
1 sibling, 1 reply; 6+ messages in thread
From: Guillaume Nault @ 2025-02-19 16:30 UTC (permalink / raw)
To: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet
Cc: netdev, Simon Horman, David Ahern, Antonio Quartulli
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>
---
.../testing/selftests/net/gre_ipv6_lladdr.sh | 227 ++++++++++++++++++
1 file changed, 227 insertions(+)
create mode 100755 tools/testing/selftests/net/gre_ipv6_lladdr.sh
diff --git a/tools/testing/selftests/net/gre_ipv6_lladdr.sh b/tools/testing/selftests/net/gre_ipv6_lladdr.sh
new file mode 100755
index 000000000000..85e40b6df55e
--- /dev/null
+++ b/tools/testing/selftests/net/gre_ipv6_lladdr.sh
@@ -0,0 +1,227 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+ERR=4 # Return 4 by default, which is the SKIP code for kselftest
+PAUSE_ON_FAIL="no"
+
+readonly NS0=$(mktemp -u ns0-XXXXXXXX)
+
+# Exit the script after having removed the network namespaces it created
+#
+# Parameters:
+#
+# * The list of network namespaces to delete before exiting.
+#
+exit_cleanup()
+{
+ for ns in "$@"; do
+ ip netns delete "${ns}" 2>/dev/null || true
+ done
+
+ if [ "${ERR}" -eq 4 ]; then
+ echo "Error: Setting up the testing environment failed." >&2
+ fi
+
+ exit "${ERR}"
+}
+
+# Create the network namespaces used by the script (NS0)
+#
+create_namespaces()
+{
+ ip netns add "${NS0}" || exit_cleanup
+}
+
+# The trap function handler
+#
+exit_cleanup_all()
+{
+ exit_cleanup "${NS0}"
+}
+
+# Add fake IPv4 and IPv6 networks on the loopback device, to be used as
+# underlay by future GRE devices.
+#
+setup_basenet()
+{
+ ip -netns "${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 abscence 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="$4"
+ local RET
+
+ printf "%-75s " "${MSG}"
+
+ set +e
+ ip -netns "${NS0}" -6 address show dev "${DEV}" scope link | grep "fe80::" | grep -q "${EXTRA_MATCH}"
+ RET=$?
+ set -e
+
+ if [ "${RET}" -eq "${XRET}" ]; then
+ printf "[ OK ]\n"
+ else
+ ERR=1
+ printf "[FAIL]\n"
+ if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+ printf "\nHit enter to continue, 'q' to quit\n"
+ read -r a
+ if [ "$a" = "q" ]; then
+ exit 1
+ fi
+ fi
+ fi
+}
+
+
+# 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 $o in
+ p) PAUSE_ON_FAIL="yes";;
+ *) usage;;
+ esac
+done
+
+# Create namespaces before setting up the exit trap.
+# Otherwise, exit_cleanup_all() could delete namespaces that were not created
+# by this script.
+create_namespaces
+
+set -e
+trap exit_cleanup_all EXIT
+
+setup_basenet
+
+test_gre4
+test_gre6
+
+if [ "${ERR}" -eq 1 ]; then
+ echo "Some tests failed." >&2
+else
+ ERR=0
+fi
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices.
2025-02-19 16:30 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
@ 2025-02-19 17:44 ` Guillaume Nault
0 siblings, 0 replies; 6+ messages in thread
From: Guillaume Nault @ 2025-02-19 17:44 UTC (permalink / raw)
To: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet
Cc: netdev, Simon Horman, David Ahern, Antonio Quartulli
On Wed, Feb 19, 2025 at 05:30:15PM +0100, Guillaume Nault wrote:
> 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.
Forgot the Makefile update.
Will resubmit tomorrow.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH net 0/2] gre: Reapply IPv6 link-local address generation fix.
@ 2025-05-02 22:57 Guillaume Nault
2025-05-02 22:57 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
0 siblings, 1 reply; 6+ messages in thread
From: Guillaume Nault @ 2025-05-02 22:57 UTC (permalink / raw)
To: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet
Cc: netdev, Simon Horman, David Ahern, Antonio Quartulli,
Ido Schimmel, Stanislav Fomichev, Petr Machata
Reintroduce the IPv6 link-local address generation fix for GRE and its
kernel selftest. These patches were introduced by merge commit
b3fc5927de4b ("Merge branch
'gre-fix-regressions-in-ipv6-link-local-address-generation'") but have
been reverted by commit 8417db0be5bb ("Merge branch
'gre-revert-ipv6-link-local-address-fix'"), because it uncovered
another bug in multipath routing. Now that this bug has been
investigated and fixed, we can apply the GRE link-local address fix
and its kernel selftest again.
For convenience, here's the original cover letter:
IPv6 link-local address generation has some special cases for GRE
devices. This has led to several regressions in the past, and some of
them are still not fixed. This series fixes the remaining problems,
like the ipv6.conf.<dev>.addr_gen_mode sysctl being ignored and the
router discovery process not being started (see details in patch 1).
To avoid any further regressions, patch 2 adds selftests covering
IPv4 and IPv6 gre/gretap devices with all combinations of currently
supported addr_gen_mode values.
Guillaume Nault (2):
gre: Fix again IPv6 link-local address generation.
selftests: Add IPv6 link-local address generation tests for GRE
devices.
net/ipv6/addrconf.c | 15 +-
tools/testing/selftests/net/Makefile | 1 +
.../testing/selftests/net/gre_ipv6_lladdr.sh | 177 ++++++++++++++++++
3 files changed, 187 insertions(+), 6 deletions(-)
create mode 100755 tools/testing/selftests/net/gre_ipv6_lladdr.sh
--
2.39.2
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices.
2025-05-02 22:57 [PATCH net 0/2] gre: Reapply IPv6 link-local address generation fix Guillaume Nault
@ 2025-05-02 22:57 ` Guillaume Nault
2025-05-05 7:38 ` Ido Schimmel
0 siblings, 1 reply; 6+ messages in thread
From: Guillaume Nault @ 2025-05-02 22:57 UTC (permalink / raw)
To: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet
Cc: netdev, Simon Horman, David Ahern, Antonio Quartulli,
Ido Schimmel, Stanislav Fomichev, Petr Machata
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.
Note:
This patch was originally applied as commit 6f50175ccad4 ("selftests:
Add IPv6 link-local address generation tests for GRE devices.").
However, it was then reverted by commit 355d940f4d5a ("Revert "selftests:
Add IPv6 link-local address generation tests for GRE devices."")
because the commit it depended on was going to be reverted. Now that
the situation is resolved, we can add this selftest again (no changes
since original patch, appart from context update in
tools/testing/selftests/net/Makefile).
Signed-off-by: Guillaume Nault <gnault@redhat.com>
---
tools/testing/selftests/net/Makefile | 1 +
.../testing/selftests/net/gre_ipv6_lladdr.sh | 177 ++++++++++++++++++
2 files changed, 178 insertions(+)
create mode 100755 tools/testing/selftests/net/gre_ipv6_lladdr.sh
diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 124078b56fa4..70a38f485d4d 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -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 += test_so_rcv.sh
diff --git a/tools/testing/selftests/net/gre_ipv6_lladdr.sh b/tools/testing/selftests/net/gre_ipv6_lladdr.sh
new file mode 100755
index 000000000000..5b34f6e1f831
--- /dev/null
+++ b/tools/testing/selftests/net/gre_ipv6_lladdr.sh
@@ -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
--
2.39.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices.
2025-05-02 22:57 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
@ 2025-05-05 7:38 ` Ido Schimmel
0 siblings, 0 replies; 6+ messages in thread
From: Ido Schimmel @ 2025-05-05 7:38 UTC (permalink / raw)
To: Guillaume Nault
Cc: David Miller, Jakub Kicinski, Paolo Abeni, Eric Dumazet, netdev,
Simon Horman, David Ahern, Antonio Quartulli, Stanislav Fomichev,
Petr Machata
On Sat, May 03, 2025 at 12:57:59AM +0200, Guillaume Nault wrote:
> 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.
>
> Note:
> This patch was originally applied as commit 6f50175ccad4 ("selftests:
> Add IPv6 link-local address generation tests for GRE devices.").
> However, it was then reverted by commit 355d940f4d5a ("Revert "selftests:
> Add IPv6 link-local address generation tests for GRE devices."")
> because the commit it depended on was going to be reverted. Now that
> the situation is resolved, we can add this selftest again (no changes
> since original patch, appart from context update in
> tools/testing/selftests/net/Makefile).
> Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-05-05 7:38 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-02-19 16:30 [PATCH net 0/2] gre: Fix regressions in IPv6 link-local address generation Guillaume Nault
2025-02-19 16:30 ` [PATCH net 1/2] gre: Fix " Guillaume Nault
2025-02-19 16:30 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
2025-02-19 17:44 ` Guillaume Nault
-- strict thread matches above, loose matches on Subject: below --
2025-05-02 22:57 [PATCH net 0/2] gre: Reapply IPv6 link-local address generation fix Guillaume Nault
2025-05-02 22:57 ` [PATCH net 2/2] selftests: Add IPv6 link-local address generation tests for GRE devices Guillaume Nault
2025-05-05 7:38 ` Ido Schimmel
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