From: Thomas Winter <Thomas.Winter@xxxxxxxxxxxxxxxxxxx>
[ Upstream commit 30e2291f61f93f7132c060190f8360df52644ec1 ]
We recently found that our non-point-to-point tunnels were not
generating any IPv6 link local address and instead generating an
IPv6 compat address, breaking IPv6 communication on the tunnel.
Previously, addrconf_gre_config always would call addrconf_addr_gen
and generate a EUI64 link local address for the tunnel.
Then commit e5dd729460ca changed the code path so that add_v4_addrs
is called but this only generates a compat IPv6 address for
non-point-to-point tunnels.
I assume the compat address is specifically for SIT tunnels so
have kept that only for SIT - GRE tunnels now always generate link
local addresses.
Fixes: e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address")
Signed-off-by: Thomas Winter <Thomas.Winter@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv6/addrconf.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index eaecaf2ffe00..e6c7edcf6834 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3127,17 +3127,17 @@ static void add_v4_addrs(struct inet6_dev *idev)
offset = sizeof(struct in6_addr) - 4;
memcpy(&addr.s6_addr32[3], idev->dev->dev_addr + offset, 4);
- if (idev->dev->flags&IFF_POINTOPOINT) {
+ if (!(idev->dev->flags & IFF_POINTOPOINT) && idev->dev->type == ARPHRD_SIT) {
+ scope = IPV6_ADDR_COMPATv4;
+ plen = 96;
+ pflags |= RTF_NONEXTHOP;
+ } else {
if (idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_NONE)
return;
addr.s6_addr32[0] = htonl(0xfe800000);
scope = IFA_LINK;
plen = 64;
- } else {
- scope = IPV6_ADDR_COMPATv4;
- plen = 96;
- pflags |= RTF_NONEXTHOP;
}
if (addr.s6_addr32[3]) {
--
2.39.0
