From: Thomas Winter Thomas.Winter@alliedtelesis.co.nz
[ 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@alliedtelesis.co.nz Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 cc1c94bc5b0e..6ba34f51c411 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3129,17 +3129,17 @@ 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]) {