[IPV6]: order addresses by scope

If IPv6 addresses are ordered by scope, then ipv6_dev_get_saddr() can
break-out of the device addr_list for() loop when the candidate source
address scope is less than the destination address scope.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 3 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c250d0af10d7..9d9a3c6056fa 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -508,6 +508,25 @@ void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp)
         kfree(ifp);
 }
 
+static void
+ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
+{
+        struct inet6_ifaddr *ifa, **ifap;
+
+        /*
+         * Each device address list is sorted in order of scope -
+         * global before linklocal.
+         */
+        for (ifap = &idev->addr_list; (ifa = *ifap) != NULL;
+             ifap = &ifa->if_next) {
+                if (ifp->scope > ifa->scope)
+                        break;
+        }
+
+        ifp->if_next = *ifap;
+        *ifap = ifp;
+}
+
 /* On success it returns ifp with increased reference count */
 
 static struct inet6_ifaddr *
@@ -573,8 +592,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
 
         write_lock(&idev->lock);
         /* Add to inet6_dev unicast addr list. */
-        ifa->if_next = idev->addr_list;
-        idev->addr_list = ifa;
+        ipv6_link_dev_addr(idev, ifa);
 
 #ifdef CONFIG_IPV6_PRIVACY
         if (ifa->flags&IFA_F_TEMPORARY) {
@@ -987,7 +1005,7 @@ int ipv6_dev_get_saddr(struct net_device *daddr_dev,
                                         continue;
                         } else if (score.scope < hiscore.scope) {
                                 if (score.scope < daddr_scope)
-                                        continue;
+                                        break; /* addresses sorted by scope */
                                 else {
                                         score.rule = 2;
                                         goto record_it;