/*
* Choose an appropriate source address (RFC3484)
*/
+enum {
+ IPV6_SADDR_RULE_INIT = 0,
+ IPV6_SADDR_RULE_LOCAL,
+ IPV6_SADDR_RULE_SCOPE,
+ IPV6_SADDR_RULE_PREFERRED,
+#ifdef CONFIG_IPV6_MIP6
+ IPV6_SADDR_RULE_HOA,
+#endif
+ IPV6_SADDR_RULE_OIF,
+ IPV6_SADDR_RULE_LABEL,
+#ifdef CONFIG_IPV6_PRIVACY
+ IPV6_SADDR_RULE_PRIVACY,
+#endif
+ IPV6_SADDR_RULE_ORCHID,
+ IPV6_SADDR_RULE_PREFIX,
+ IPV6_SADDR_RULE_MAX
+};
+
struct ipv6_saddr_score {
- int addr_type;
- unsigned int attrs;
- int matchlen;
- int scope;
- unsigned int rule;
+ int rule;
+ int addr_type;
+ struct inet6_ifaddr *ifa;
+ DECLARE_BITMAP(scorebits, IPV6_SADDR_RULE_MAX);
+ int scopedist;
+ int matchlen;
};
-#define IPV6_SADDR_SCORE_LOCAL 0x0001
-#define IPV6_SADDR_SCORE_PREFERRED 0x0004
-#define IPV6_SADDR_SCORE_HOA 0x0008
-#define IPV6_SADDR_SCORE_OIF 0x0010
-#define IPV6_SADDR_SCORE_LABEL 0x0020
-#define IPV6_SADDR_SCORE_PRIVACY 0x0040
+struct ipv6_saddr_dst {
+ struct in6_addr *addr;
+ int ifindex;
+ int scope;
+ int label;
+};
static inline int ipv6_saddr_preferred(int type)
{
return 0;
}
-int ipv6_dev_get_saddr(struct net_device *daddr_dev,
+static int ipv6_get_saddr_eval(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 */
+ ret = !!(score->ifa->flags & IFA_F_HOMEADDRESS);
+ 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(&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
+ */
+ ret = (!(score->ifa->flags & IFA_F_TEMPORARY)) ^ (score->ifa->idev->cnf.use_tempaddr >= 2);
+ 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_device *dst_dev,
struct in6_addr *daddr, struct in6_addr *saddr)
{
- struct ipv6_saddr_score hiscore;
- struct inet6_ifaddr *ifa_result = NULL;
- struct net *net = daddr_dev->nd_net;
- int daddr_type = __ipv6_addr_type(daddr);
- int daddr_scope = __ipv6_addr_src_scope(daddr_type);
- int daddr_ifindex = daddr_dev ? daddr_dev->ifindex : 0;
- u32 daddr_label = ipv6_addr_label(daddr, daddr_type, daddr_ifindex);
+ struct ipv6_saddr_score scores[2],
+ *score = &scores[0], *hiscore = &scores[1];
+ struct net *net = dst_dev->nd_net;
+ struct ipv6_saddr_dst dst;
struct net_device *dev;
+ int dst_type;
+
+ dst_type = __ipv6_addr_type(daddr);
+ dst.addr = daddr;
+ dst.ifindex = dst_dev ? dst_dev->ifindex : 0;
+ dst.scope = __ipv6_addr_src_scope(dst_type);
+ dst.label = ipv6_addr_label(daddr, dst_type, dst.ifindex);
- memset(&hiscore, 0, sizeof(hiscore));
+ hiscore->rule = -1;
+ hiscore->ifa = NULL;
read_lock(&dev_base_lock);
rcu_read_lock();
for_each_netdev(net, dev) {
struct inet6_dev *idev;
- struct inet6_ifaddr *ifa;
- /* Rule 0: Candidate Source Address (section 4)
+ /* 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 site as the outgoing
* interface.)
*/
- if ((daddr_type & IPV6_ADDR_MULTICAST ||
- daddr_scope <= IPV6_ADDR_SCOPE_LINKLOCAL) &&
- daddr_dev && dev != daddr_dev)
+ if (((dst_type & IPV6_ADDR_MULTICAST) ||
+ dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL) &&
+ dst.ifindex && dev->ifindex != dst.ifindex)
continue;
idev = __in6_dev_get(dev);
continue;
read_lock_bh(&idev->lock);
- for (ifa = idev->addr_list; ifa; ifa = ifa->if_next) {
- struct ipv6_saddr_score score;
+ for (score->ifa = idev->addr_list; score->ifa; score->ifa = score->ifa->if_next) {
+ int i;
- score.addr_type = __ipv6_addr_type(&ifa->addr);
-
- /* Rule 0:
+ /*
* - Tentative Address (RFC2462 section 5.4)
* - A tentative address is not considered
* "assigned to an interface" in the traditional
* addresses, and the unspecified address MUST
* NOT be included in a candidate set.
*/
- if ((ifa->flags & IFA_F_TENTATIVE) &&
- (!(ifa->flags & IFA_F_OPTIMISTIC)))
+ if ((score->ifa->flags & IFA_F_TENTATIVE) &&
+ (!(score->ifa->flags & IFA_F_OPTIMISTIC)))
continue;
- if (unlikely(score.addr_type == IPV6_ADDR_ANY ||
- score.addr_type & IPV6_ADDR_MULTICAST)) {
+
+ score->addr_type = __ipv6_addr_type(&score->ifa->addr);
+
+ if (unlikely(score->addr_type == IPV6_ADDR_ANY ||
+ score->addr_type & IPV6_ADDR_MULTICAST)) {
LIMIT_NETDEBUG(KERN_DEBUG
"ADDRCONF: unspecified / multicast address "
"assigned as unicast address on %s",
continue;
}
- score.attrs = 0;
- score.matchlen = 0;
- score.scope = 0;
- score.rule = 0;
-
- if (ifa_result == NULL) {
- /* record it if the first available entry */
- goto record_it;
- }
-
- /* Rule 1: Prefer same address */
- if (hiscore.rule < 1) {
- if (ipv6_addr_equal(&ifa_result->addr, daddr))
- hiscore.attrs |= IPV6_SADDR_SCORE_LOCAL;
- hiscore.rule++;
- }
- if (ipv6_addr_equal(&ifa->addr, daddr)) {
- score.attrs |= IPV6_SADDR_SCORE_LOCAL;
- if (!(hiscore.attrs & IPV6_SADDR_SCORE_LOCAL)) {
- score.rule = 1;
- goto record_it;
- }
- } else {
- if (hiscore.attrs & IPV6_SADDR_SCORE_LOCAL)
- 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(hiscore, &dst, i);
+ miniscore = ipv6_get_saddr_eval(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) {
+ struct ipv6_saddr_score *tmp;
- /* Rule 2: Prefer appropriate scope */
- if (hiscore.rule < 2) {
- hiscore.scope = __ipv6_addr_src_scope(hiscore.addr_type);
- hiscore.rule++;
- }
- score.scope = __ipv6_addr_src_scope(score.addr_type);
- if (hiscore.scope < score.scope) {
- if (hiscore.scope < daddr_scope) {
- score.rule = 2;
- goto record_it;
- } else
- continue;
- } else if (score.scope < hiscore.scope) {
- if (score.scope < daddr_scope)
- break; /* addresses sorted by scope */
- else {
- score.rule = 2;
- goto record_it;
- }
- }
+ if (hiscore->ifa)
+ in6_ifa_put(hiscore->ifa);
- /* Rule 3: Avoid deprecated and optimistic addresses */
- if (hiscore.rule < 3) {
- if (ipv6_saddr_preferred(hiscore.addr_type) ||
- (((ifa_result->flags &
- (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC)) == 0)))
- hiscore.attrs |= IPV6_SADDR_SCORE_PREFERRED;
- hiscore.rule++;
- }
- if (ipv6_saddr_preferred(score.addr_type) ||
- (((ifa->flags &
- (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC)) == 0))) {
- score.attrs |= IPV6_SADDR_SCORE_PREFERRED;
- if (!(hiscore.attrs & IPV6_SADDR_SCORE_PREFERRED)) {
- score.rule = 3;
- goto record_it;
- }
- } else {
- if (hiscore.attrs & IPV6_SADDR_SCORE_PREFERRED)
- continue;
- }
+ in6_ifa_hold(score->ifa);
- /* Rule 4: Prefer home address */
-#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
- if (hiscore.rule < 4) {
- if (ifa_result->flags & IFA_F_HOMEADDRESS)
- hiscore.attrs |= IPV6_SADDR_SCORE_HOA;
- hiscore.rule++;
- }
- if (ifa->flags & IFA_F_HOMEADDRESS) {
- score.attrs |= IPV6_SADDR_SCORE_HOA;
- if (!(ifa_result->flags & IFA_F_HOMEADDRESS)) {
- score.rule = 4;
- goto record_it;
- }
- } else {
- if (hiscore.attrs & IPV6_SADDR_SCORE_HOA)
- continue;
- }
-#else
- if (hiscore.rule < 4)
- hiscore.rule++;
-#endif
+ tmp = hiscore;
+ hiscore = score;
+ score = tmp;
- /* Rule 5: Prefer outgoing interface */
- if (hiscore.rule < 5) {
- if (daddr_dev == NULL ||
- daddr_dev == ifa_result->idev->dev)
- hiscore.attrs |= IPV6_SADDR_SCORE_OIF;
- hiscore.rule++;
- }
- if (daddr_dev == NULL ||
- daddr_dev == ifa->idev->dev) {
- score.attrs |= IPV6_SADDR_SCORE_OIF;
- if (!(hiscore.attrs & IPV6_SADDR_SCORE_OIF)) {
- score.rule = 5;
- goto record_it;
- }
- } else {
- if (hiscore.attrs & IPV6_SADDR_SCORE_OIF)
- continue;
- }
-
- /* Rule 6: Prefer matching label */
- if (hiscore.rule < 6) {
- if (ipv6_addr_label(&ifa_result->addr,
- hiscore.addr_type,
- ifa_result->idev->dev->ifindex) == daddr_label)
- hiscore.attrs |= IPV6_SADDR_SCORE_LABEL;
- hiscore.rule++;
- }
- if (ipv6_addr_label(&ifa->addr,
- score.addr_type,
- ifa->idev->dev->ifindex) == daddr_label) {
- score.attrs |= IPV6_SADDR_SCORE_LABEL;
- if (!(hiscore.attrs & IPV6_SADDR_SCORE_LABEL)) {
- score.rule = 6;
- goto record_it;
- }
- } else {
- if (hiscore.attrs & IPV6_SADDR_SCORE_LABEL)
- continue;
- }
+ /* restore our iterator */
+ score->ifa = hiscore->ifa;
-#ifdef CONFIG_IPV6_PRIVACY
- /* Rule 7: Prefer public address
- * Note: prefer temprary address if use_tempaddr >= 2
- */
- if (hiscore.rule < 7) {
- if ((!(ifa_result->flags & IFA_F_TEMPORARY)) ^
- (ifa_result->idev->cnf.use_tempaddr >= 2))
- hiscore.attrs |= IPV6_SADDR_SCORE_PRIVACY;
- hiscore.rule++;
- }
- if ((!(ifa->flags & IFA_F_TEMPORARY)) ^
- (ifa->idev->cnf.use_tempaddr >= 2)) {
- score.attrs |= IPV6_SADDR_SCORE_PRIVACY;
- if (!(hiscore.attrs & IPV6_SADDR_SCORE_PRIVACY)) {
- score.rule = 7;
- goto record_it;
+ break;
}
- } else {
- if (hiscore.attrs & IPV6_SADDR_SCORE_PRIVACY)
- continue;
- }
-#else
- if (hiscore.rule < 7)
- hiscore.rule++;
-#endif
-
- /* Skip rule 8 for orchid -> non-orchid address pairs. */
- if (ipv6_addr_orchid(&ifa->addr) && !ipv6_addr_orchid(daddr))
- continue;
-
- /* Rule 8: Use longest matching prefix */
- if (hiscore.rule < 8) {
- hiscore.matchlen = ipv6_addr_diff(&ifa_result->addr, daddr);
- hiscore.rule++;
- }
- score.matchlen = ipv6_addr_diff(&ifa->addr, daddr);
- if (score.matchlen > hiscore.matchlen) {
- score.rule = 8;
- goto record_it;
}
-#if 0
- else if (score.matchlen < hiscore.matchlen)
- continue;
-#endif
-
- /* Final Rule: choose first available one */
- continue;
-record_it:
- if (ifa_result)
- in6_ifa_put(ifa_result);
- in6_ifa_hold(ifa);
- ifa_result = ifa;
- hiscore = score;
}
+try_nextdev:
read_unlock_bh(&idev->lock);
}
rcu_read_unlock();
read_unlock(&dev_base_lock);
- if (!ifa_result)
+ if (!hiscore->ifa)
return -EADDRNOTAVAIL;
- ipv6_addr_copy(saddr, &ifa_result->addr);
- in6_ifa_put(ifa_result);
+ ipv6_addr_copy(saddr, &hiscore->ifa->addr);
+ in6_ifa_put(hiscore->ifa);
return 0;
}
projects / linux-2.6 / commitdiff