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ipv6: default route for link local address is not added while assigning a address

PATCH sohny thomas 3 participants 3 messages Jan 10, 2014

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#0 lore raw

Default route for link local address is configured automatically if NETWORKING_IPV6=yes is in ifcfg-eth*.
When the route table for the interface is flushed and a new address is added to the same device with out removing linklocal addr, default route for link local address has to added by default.

I have found the issue to be caused by this checkin

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/net/ipv6?id=62b54dd91567686a1cb118f76a72d5f4764a86dd

According to this change :
He removes adding a link local route if any other address is added , applicable across all interfaces though there's mentioned only lo interface So below patch fixes for other devices

-----

net/ipv6/addrconf.c +13 -1
index f62c72b..a8a4df9 100644
@@ -1763,6 +1763,16 @@ static int addrconf_ifid_infiniband(u8 *eui, struct net_device *dev)
        return 0;
 }
 
+static void addrconf_add_lroute(struct net_device *dev)
+{
+       struct in6_addr addr;
+
+       ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
+       addrconf_prefix_route(&addr, 64, dev, 0, 0);
+}
+
+
+
 static int __ipv6_isatap_ifid(u8 *eui, __be32 addr)
 {
        if (addr == 0)
@@ -2010,8 +2020,10 @@ static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
                return ERR_PTR(-EACCES);
 
        /* Add default multicast route */
-       if (!(dev->flags & IFF_LOOPBACK))
+       if (!(dev->flags & IFF_LOOPBACK)){
                addrconf_add_mroute(dev);
+               addrconf_add_lroute(dev);
+       }
 
        return idev;
 }
#1 lore raw
CC netdev
Quoted 5 lines · sohny thomas

Default route for link local address is configured automatically if NETWORKING_IPV6=yes is in ifcfg-eth*.
When the route table for the interface is flushed and a new address is added to the same device with out removing linklocal addr, default route for link local address has to added by default.

I would say that removing the link local route but not the link local address is a configuration problem.
If you remove a connected route but not the associated address, you will have the same problem.

Quoted 10 lines

I have found the issue to be caused by this checkin

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/net/ipv6?id=62b54dd91567686a1cb118f76a72d5f4764a86dd

According to this change :
He removes adding a link local route if any other address is added , applicable across all interfaces though there's mentioned only lo interface So below patch fixes for other devices

#2 lore raw
Quoted 10 lines · Nicolas Dichtel
CC netdev
Quoted 7 lines · sohny thomas

Default route for link local address is configured automatically if NETWORKING_IPV6=yes is in ifcfg-eth*.
When the route table for the interface is flushed and a new address is added to
the same device with out removing linklocal addr, default route for link local
address has to added by default.

Quoted 6 lines

I would say that removing the link local route but not the link local address
is a configuration problem.
If you remove a connected route but not the associated address, you will have
the same problem.

We have some user accessible routes that are essential for IPv6 stack to work at all. So I don't know if I can agree with that.

Maybe flush is a bit too aggressive?