+static int ipv6_get_saddr_eval(struct net *net,
+ struct ipv6_saddr_score *score,
+ struct ipv6_saddr_dst *dst,
+ int i)
+{
+ int ret;
+
+ if (i <= score->rule) {
+ switch (i) {
+ case IPV6_SADDR_RULE_SCOPE:
+ ret = score->scopedist;
+ break;
+ case IPV6_SADDR_RULE_PREFIX:
+ ret = score->matchlen;
+ break;
+ default:
+ ret = !!test_bit(i, score->scorebits);
+ }
+ goto out;
+ }
+
+ switch (i) {
+ case IPV6_SADDR_RULE_INIT:
+ /* Rule 0: remember if hiscore is not ready yet */
+ ret = !!score->ifa;
+ break;
+ case IPV6_SADDR_RULE_LOCAL:
+ /* Rule 1: Prefer same address */
+ ret = ipv6_addr_equal(&score->ifa->addr, dst->addr);
+ break;
+ case IPV6_SADDR_RULE_SCOPE:
+ /* Rule 2: Prefer appropriate scope
+ *
+ * ret
+ * ^
+ * -1 | d 15
+ * ---+--+-+---> scope
+ * |
+ * | d is scope of the destination.
+ * B-d | \
+ * | \ <- smaller scope is better if
+ * B-15 | \ if scope is enough for destinaion.
+ * | ret = B - scope (-1 <= scope >= d <= 15).
+ * d-C-1 | /
+ * |/ <- greater is better
+ * -C / if scope is not enough for destination.
+ * /| ret = scope - C (-1 <= d < scope <= 15).
+ *
+ * d - C - 1 < B -15 (for all -1 <= d <= 15).
+ * C > d + 14 - B >= 15 + 14 - B = 29 - B.
+ * Assume B = 0 and we get C > 29.
+ */
+ ret = __ipv6_addr_src_scope(score->addr_type);
+ if (ret >= dst->scope)
+ ret = -ret;
+ else
+ ret -= 128; /* 30 is enough */
+ score->scopedist = ret;
+ break;
+ case IPV6_SADDR_RULE_PREFERRED:
+ /* Rule 3: Avoid deprecated and optimistic addresses */
+ ret = ipv6_saddr_preferred(score->addr_type) ||
+ !(score->ifa->flags & (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC));
+ break;
+#ifdef CONFIG_IPV6_MIP6
+ case IPV6_SADDR_RULE_HOA:
+ {
+ /* Rule 4: Prefer home address */
+ int prefhome = !(dst->prefs & IPV6_PREFER_SRC_COA);
+ ret = !(score->ifa->flags & IFA_F_HOMEADDRESS) ^ prefhome;
+ break;
+ }
+#endif
+ case IPV6_SADDR_RULE_OIF:
+ /* Rule 5: Prefer outgoing interface */
+ ret = (!dst->ifindex ||
+ dst->ifindex == score->ifa->idev->dev->ifindex);
+ break;
+ case IPV6_SADDR_RULE_LABEL:
+ /* Rule 6: Prefer matching label */
+ ret = ipv6_addr_label(net,
+ &score->ifa->addr, score->addr_type,
+ score->ifa->idev->dev->ifindex) == dst->label;
+ break;
+#ifdef CONFIG_IPV6_PRIVACY
+ case IPV6_SADDR_RULE_PRIVACY:
+ {
+ /* Rule 7: Prefer public address
+ * Note: prefer temprary address if use_tempaddr >= 2
+ */
+ int preftmp = dst->prefs & (IPV6_PREFER_SRC_PUBLIC|IPV6_PREFER_SRC_TMP) ?
+ !!(dst->prefs & IPV6_PREFER_SRC_TMP) :
+ score->ifa->idev->cnf.use_tempaddr >= 2;
+ ret = (!(score->ifa->flags & IFA_F_TEMPORARY)) ^ preftmp;
+ break;
+ }
+#endif
+ case IPV6_SADDR_RULE_ORCHID:
+ /* Rule 8-: Prefer ORCHID vs ORCHID or
+ * non-ORCHID vs non-ORCHID
+ */
+ ret = !(ipv6_addr_orchid(&score->ifa->addr) ^
+ ipv6_addr_orchid(dst->addr));
+ break;
+ case IPV6_SADDR_RULE_PREFIX:
+ /* Rule 8: Use longest matching prefix */
+ score->matchlen = ret = ipv6_addr_diff(&score->ifa->addr,
+ dst->addr);
+ break;
+ default:
+ ret = 0;
+ }
+
+ if (ret)
+ __set_bit(i, score->scorebits);
+ score->rule = i;
+out:
+ return ret;
+}
+
+int ipv6_dev_get_saddr(struct net *net, struct net_device *dst_dev,
+ const struct in6_addr *daddr, unsigned int prefs,
+ struct in6_addr *saddr)