ipv6: Do not iterate over all interfaces when finding source address on specific...
authorYOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji@miraclelinux.com>
Fri, 10 Jul 2015 07:58:31 +0000 (16:58 +0900)
committerDavid S. Miller <davem@davemloft.net>
Sat, 11 Jul 2015 06:19:25 +0000 (23:19 -0700)
If outgoing interface is specified and the candidate address is
restricted to the outgoing interface, it is enough to iterate
over that given interface only.

Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Acked-by: Erik Kline <ek@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv6/addrconf.c

index 21c2c818df3b8379226555268ef526c08553d00d..4ab74d56f65a13f53e93a494b21987a043df53a9 100644 (file)
@@ -1358,15 +1358,94 @@ out:
        return ret;
 }
 
+static void __ipv6_dev_get_saddr(struct net *net,
+                                struct ipv6_saddr_dst *dst,
+                                unsigned int prefs,
+                                const struct in6_addr *saddr,
+                                struct inet6_dev *idev,
+                                struct ipv6_saddr_score *scores)
+{
+       struct ipv6_saddr_score *score = &scores[0], *hiscore = &scores[1];
+
+       read_lock_bh(&idev->lock);
+       list_for_each_entry(score->ifa, &idev->addr_list, if_list) {
+               int i;
+
+               /*
+                * - Tentative Address (RFC2462 section 5.4)
+                *  - A tentative address is not considered
+                *    "assigned to an interface" in the traditional
+                *    sense, unless it is also flagged as optimistic.
+                * - Candidate Source Address (section 4)
+                *  - In any case, anycast addresses, multicast
+                *    addresses, and the unspecified address MUST
+                *    NOT be included in a candidate set.
+                */
+               if ((score->ifa->flags & IFA_F_TENTATIVE) &&
+                   (!(score->ifa->flags & IFA_F_OPTIMISTIC)))
+                       continue;
+
+               score->addr_type = __ipv6_addr_type(&score->ifa->addr);
+
+               if (unlikely(score->addr_type == IPV6_ADDR_ANY ||
+                            score->addr_type & IPV6_ADDR_MULTICAST)) {
+                       net_dbg_ratelimited("ADDRCONF: unspecified / multicast address assigned as unicast address on %s",
+                                           idev->dev->name);
+                       continue;
+               }
+
+               score->rule = -1;
+               bitmap_zero(score->scorebits, IPV6_SADDR_RULE_MAX);
+
+               for (i = 0; i < IPV6_SADDR_RULE_MAX; i++) {
+                       int minihiscore, miniscore;
+
+                       minihiscore = ipv6_get_saddr_eval(net, hiscore, dst, i);
+                       miniscore = ipv6_get_saddr_eval(net, score, dst, i);
+
+                       if (minihiscore > miniscore) {
+                               if (i == IPV6_SADDR_RULE_SCOPE &&
+                                   score->scopedist > 0) {
+                                       /*
+                                        * special case:
+                                        * each remaining entry
+                                        * has too small (not enough)
+                                        * scope, because ifa entries
+                                        * are sorted by their scope
+                                        * values.
+                                        */
+                                       goto out;
+                               }
+                               break;
+                       } else if (minihiscore < miniscore) {
+                               if (hiscore->ifa)
+                                       in6_ifa_put(hiscore->ifa);
+
+                               in6_ifa_hold(score->ifa);
+
+                               swap(hiscore, score);
+
+                               /* restore our iterator */
+                               score->ifa = hiscore->ifa;
+
+                               break;
+                       }
+               }
+       }
+out:
+       read_unlock_bh(&idev->lock);
+}
+
 int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
                       const struct in6_addr *daddr, unsigned int prefs,
                       struct in6_addr *saddr)
 {
-       struct ipv6_saddr_score scores[2],
-                               *score = &scores[0], *hiscore = &scores[1];
+       struct ipv6_saddr_score scores[2], *hiscore = &scores[1];
        struct ipv6_saddr_dst dst;
+       struct inet6_dev *idev;
        struct net_device *dev;
        int dst_type;
+       bool use_oif_addr = false;
 
        dst_type = __ipv6_addr_type(daddr);
        dst.addr = daddr;
@@ -1380,97 +1459,35 @@ int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
 
        rcu_read_lock();
 
-       for_each_netdev_rcu(net, dev) {
-               struct inet6_dev *idev;
-
-               /* Candidate Source Address (section 4)
-                *  - multicast and link-local destination address,
-                *    the set of candidate source address MUST only
-                *    include addresses assigned to interfaces
-                *    belonging to the same link as the outgoing
-                *    interface.
-                * (- For site-local destination addresses, the
-                *    set of candidate source addresses MUST only
-                *    include addresses assigned to interfaces
-                *    belonging to the same site as the outgoing
-                *    interface.)
-                */
-               if (((dst_type & IPV6_ADDR_MULTICAST) ||
-                    dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL) &&
-                   dst.ifindex && dev->ifindex != dst.ifindex)
-                       continue;
-
-               idev = __in6_dev_get(dev);
-               if (!idev)
-                       continue;
-
-               read_lock_bh(&idev->lock);
-               list_for_each_entry(score->ifa, &idev->addr_list, if_list) {
-                       int i;
-
-                       /*
-                        * - Tentative Address (RFC2462 section 5.4)
-                        *  - A tentative address is not considered
-                        *    "assigned to an interface" in the traditional
-                        *    sense, unless it is also flagged as optimistic.
-                        * - Candidate Source Address (section 4)
-                        *  - In any case, anycast addresses, multicast
-                        *    addresses, and the unspecified address MUST
-                        *    NOT be included in a candidate set.
-                        */
-                       if ((score->ifa->flags & IFA_F_TENTATIVE) &&
-                           (!(score->ifa->flags & IFA_F_OPTIMISTIC)))
-                               continue;
-
-                       score->addr_type = __ipv6_addr_type(&score->ifa->addr);
+       /* Candidate Source Address (section 4)
+        *  - multicast and link-local destination address,
+        *    the set of candidate source address MUST only
+        *    include addresses assigned to interfaces
+        *    belonging to the same link as the outgoing
+        *    interface.
+        * (- For site-local destination addresses, the
+        *    set of candidate source addresses MUST only
+        *    include addresses assigned to interfaces
+        *    belonging to the same site as the outgoing
+        *    interface.)
+        */
+       if (dst_dev) {
+               if ((dst_type & IPV6_ADDR_MULTICAST) ||
+                   dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL) {
+                       idev = __in6_dev_get(dst_dev);
+                       use_oif_addr = true;
+               }
+       }
 
-                       if (unlikely(score->addr_type == IPV6_ADDR_ANY ||
-                                    score->addr_type & IPV6_ADDR_MULTICAST)) {
-                               net_dbg_ratelimited("ADDRCONF: unspecified / multicast address assigned as unicast address on %s",
-                                                   dev->name);
+       if (use_oif_addr) {
+               __ipv6_dev_get_saddr(net, &dst, prefs, saddr, idev, scores);
+       } else {
+               for_each_netdev_rcu(net, dev) {
+                       idev = __in6_dev_get(dev);
+                       if (!idev)
                                continue;
-                       }
-
-                       score->rule = -1;
-                       bitmap_zero(score->scorebits, IPV6_SADDR_RULE_MAX);
-
-                       for (i = 0; i < IPV6_SADDR_RULE_MAX; i++) {
-                               int minihiscore, miniscore;
-
-                               minihiscore = ipv6_get_saddr_eval(net, hiscore, &dst, i);
-                               miniscore = ipv6_get_saddr_eval(net, score, &dst, i);
-
-                               if (minihiscore > miniscore) {
-                                       if (i == IPV6_SADDR_RULE_SCOPE &&
-                                           score->scopedist > 0) {
-                                               /*
-                                                * special case:
-                                                * each remaining entry
-                                                * has too small (not enough)
-                                                * scope, because ifa entries
-                                                * are sorted by their scope
-                                                * values.
-                                                */
-                                               goto try_nextdev;
-                                       }
-                                       break;
-                               } else if (minihiscore < miniscore) {
-                                       if (hiscore->ifa)
-                                               in6_ifa_put(hiscore->ifa);
-
-                                       in6_ifa_hold(score->ifa);
-
-                                       swap(hiscore, score);
-
-                                       /* restore our iterator */
-                                       score->ifa = hiscore->ifa;
-
-                                       break;
-                               }
-                       }
+                       __ipv6_dev_get_saddr(net, &dst, prefs, saddr, idev, scores);
                }
-try_nextdev:
-               read_unlock_bh(&idev->lock);
        }
        rcu_read_unlock();