Use addrconf_add_dev() instead of ipv6_find_idev() in addrconf_gre_config() so that we don't just get the inet6_dev, but also install the default ff00::/8 multicast route. Before commit 3e6a0243ff00 ("gre: Fix again IPv6 link-local address generation."), the multicast route was created at the end of the function by addrconf_add_mroute(). But this code path is now only taken in one particular case (gre devices not bound to a local IP address and in EUI64 mode). For all other cases, the function exits early and addrconf_add_mroute() is not called anymore. Using addrconf_add_dev() instead of ipv6_find_idev() in addrconf_gre_config(), fixes the problem as it will create the default multicast route for all gre devices. This also brings addrconf_gre_config() a bit closer to the normal netdevice IPv6 configuration code (addrconf_dev_config()). Fixes: 3e6a0243ff00 ("gre: Fix again IPv6 link-local address generation.") Reported-by: Aiden Yang Closes: https://lore.kernel.org/netdev/CANR=AhRM7YHHXVxJ4DmrTNMeuEOY87K2mLmo9KMed1JMr20p6g@mail.gmail.com/ Reviewed-by: Gary Guo Tested-by: Gary Guo Signed-off-by: Guillaume Nault --- net/ipv6/addrconf.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index ba2ec7c870cc..870a0bd6c2ba 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3525,11 +3525,9 @@ static void addrconf_gre_config(struct net_device *dev) ASSERT_RTNL(); - idev = ipv6_find_idev(dev); - if (IS_ERR(idev)) { - pr_debug("%s: add_dev failed\n", __func__); + idev = addrconf_add_dev(dev); + if (IS_ERR(idev)) return; - } /* Generate the IPv6 link-local address using addrconf_addr_gen(), * unless we have an IPv4 GRE device not bound to an IP address and @@ -3543,9 +3541,6 @@ static void addrconf_gre_config(struct net_device *dev) } add_v4_addrs(idev); - - if (dev->flags & IFF_POINTOPOINT) - addrconf_add_mroute(dev); } #endif -- 2.39.2 The previous patch fixes a bug that prevented the creation of the default IPv6 multicast route (ff00::/8) for some GRE devices. Now let's extend the GRE IPv6 selftests to cover this case. Also, rename check_ipv6_ll_addr() to check_ipv6_device_config() and adapt comments and script output to take into account the fact that we're not limitted to link-local address generation. Signed-off-by: Guillaume Nault --- .../testing/selftests/net/gre_ipv6_lladdr.sh | 27 ++++++++++++------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/net/gre_ipv6_lladdr.sh b/tools/testing/selftests/net/gre_ipv6_lladdr.sh index 5b34f6e1f831..48eb999a3120 100755 --- a/tools/testing/selftests/net/gre_ipv6_lladdr.sh +++ b/tools/testing/selftests/net/gre_ipv6_lladdr.sh @@ -24,7 +24,10 @@ setup_basenet() ip -netns "${NS0}" address add dev lo 2001:db8::10/64 nodad } -# Check if network device has an IPv6 link-local address assigned. +# Check the IPv6 configuration of a network device. +# +# We currently check the generation of the link-local IPv6 address and the +# creation of the ff00::/8 multicast route. # # Parameters: # @@ -35,7 +38,7 @@ setup_basenet() # a link-local address) # * $4: The user visible name for the scenario being tested # -check_ipv6_ll_addr() +check_ipv6_device_config() { local DEV="$1" local EXTRA_MATCH="$2" @@ -45,7 +48,11 @@ check_ipv6_ll_addr() RET=0 set +e ip -netns "${NS0}" -6 address show dev "${DEV}" scope link | grep "fe80::" | grep -q "${EXTRA_MATCH}" - check_err_fail "${XRET}" $? "" + check_err_fail "${XRET}" $? "IPv6 link-local address generation" + + ip -netns "${NS0}" -6 route show table local type multicast ff00::/8 proto kernel | grep -q "${DEV}" + check_err_fail 0 $? "IPv6 multicast route creation" + log_test "${MSG}" set -e } @@ -102,20 +109,20 @@ test_gre_device() ;; esac - # Check that IPv6 link-local address is generated when device goes up + # Check the IPv6 device configuration when it 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: ${MSG}" + check_ipv6_device_config gretest "${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 + # Check the IPv6 device configuration when link-local address + # generation is 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: ${MSG}" + check_ipv6_device_config gretest "${MATCH_REGEXP}" "${XRET}" "update: ${MSG}" ip -netns "${NS0}" link del dev gretest } @@ -126,7 +133,7 @@ test_gre4() local MODE for GRE_TYPE in "gre" "gretap"; do - printf "\n####\nTesting IPv6 link-local address generation on ${GRE_TYPE} devices\n####\n\n" + printf "\n####\nTesting IPv6 configuration of ${GRE_TYPE} devices\n####\n\n" for MODE in "eui64" "none" "stable-privacy" "random"; do test_gre_device "${GRE_TYPE}" 192.0.2.10 192.0.2.11 "${MODE}" @@ -142,7 +149,7 @@ test_gre6() local MODE for GRE_TYPE in "ip6gre" "ip6gretap"; do - printf "\n####\nTesting IPv6 link-local address generation on ${GRE_TYPE} devices\n####\n\n" + printf "\n####\nTesting IPv6 configuration of ${GRE_TYPE} devices\n####\n\n" for MODE in "eui64" "none" "stable-privacy" "random"; do test_gre_device "${GRE_TYPE}" 2001:db8::10 2001:db8::11 "${MODE}" -- 2.39.2