ipv6/addrconf: allow adding multicast addr if IFA_F_MCAUTOJOIN is set
In commit
93a714d6b53d ("multicast: Extend ip address command to enable
multicast group join/leave on") we added a new flag IFA_F_MCAUTOJOIN
to make user able to add multicast address on ethernet interface.
This works for IPv4, but not for IPv6. See the inet6_addr_add code.
static int inet6_addr_add()
{
...
if (cfg->ifa_flags & IFA_F_MCAUTOJOIN) {
ipv6_mc_config(net->ipv6.mc_autojoin_sk, true...)
}
ifp = ipv6_add_addr(idev, cfg, true, extack); <- always fail with maddr
if (!IS_ERR(ifp)) {
...
} else if (cfg->ifa_flags & IFA_F_MCAUTOJOIN) {
ipv6_mc_config(net->ipv6.mc_autojoin_sk, false...)
}
}
But in ipv6_add_addr() it will check the address type and reject multicast
address directly. So this feature is never worked for IPv6.
We should not remove the multicast address check totally in ipv6_add_addr(),
but could accept multicast address only when IFA_F_MCAUTOJOIN flag supplied.
v2: update commit description
Fixes: 93a714d6b53d ("multicast: Extend ip address command to enable multicast group join/leave on")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>