[PATCH net] ipv6/addrconf: allow adding multicast addr if IFA_F_MCAUTOJOIN is set

[Hangbin Liu]

The ip address autojoin is not working for IPv6 as ipv6_add_addr()
will return -EADDRNOTAVAIL when adding a multicast address.

Reported-by: Jianlin Shi <ji...@redhat.com>
Fixes: 93a714d6b53d ("multicast: Extend ip address command to enable multicast 
group join/leave on")
Signed-off-by: Hangbin Liu <liuhang...@gmail.com>
---
 net/ipv6/addrconf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index dc73888c7859..ced995f3fec4 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1045,7 +1045,8 @@ ipv6_add_addr(struct inet6_dev *idev, struct ifa6_config 
*cfg,
        int err = 0;
 
        if (addr_type == IPV6_ADDR_ANY ||
-           addr_type & IPV6_ADDR_MULTICAST ||
+           (addr_type & IPV6_ADDR_MULTICAST &&
+            !(cfg->ifa_flags & IFA_F_MCAUTOJOIN)) ||
            (!(idev->dev->flags & IFF_LOOPBACK) &&
             !netif_is_l3_master(idev->dev) &&
             addr_type & IPV6_ADDR_LOOPBACK))
-- 
2.19.2