Commit 1d142804 authored Dec 21, 2005 by Kristian Slavov Committed by David S. Miller Dec 21, 2005

[IPV6]: Fix address deletion



If you add more than one IPv6 address belonging to the same prefix and 
delete the address that was last added, routing table entry for that 
prefix is also deleted.
Tested on 2.6.14.4

To reproduce:
ip addr add 3ffe::1/64 dev eth0
ip addr add 3ffe::2/64 dev eth0
/* wait DAD */
sleep 1
ip addr del 3ffe::2/64 dev eth0
ip -6 route

(route to 3ffe::/64 should be gone)

In ipv6_del_addr(), if ifa == ifp, we set ifa->if_next to NULL, and later 
assign ifap = &ifa->if_next, effectively terminating the for-loop.
This prevents us from checking if there are other addresses using the same 
prefix that are valid, and thus resulting in deletion of the prefix.
This applies only if the first entry in idev->addr_list is the address to 
be deleted.

Signed-off-by: Kristian Slavov <kristian.slavov@nomadiclab.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 7eb1b3d3

net/ipv6/addrconf.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -634,8 +634,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
		}
		#endif

		for (ifap = &idev->addr_list; (ifa=*ifap) != NULL;
		ifap = &ifa->if_next) {
		for (ifap = &idev->addr_list; (ifa=*ifap) != NULL;) {
		if (ifa == ifp) {
		*ifap = ifa->if_next;
		__in6_ifa_put(ifp);
		@@ -643,6 +642,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
		if (!(ifp->flags & IFA_F_PERMANENT) \|\| onlink > 0)
		break;
		deleted = 1;
		continue;
		} else if (ifp->flags & IFA_F_PERMANENT) {
		if (ipv6_prefix_equal(&ifa->addr, &ifp->addr,
		ifp->prefix_len)) {
		@@ -666,6 +666,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
		}
		}
		}
		ifap = &ifa->if_next;
		}
		write_unlock_bh(&idev->lock);

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