[IPV6] ADDRCONF: Optimistic Duplicate Address Detection (RFC 4429) Support.

[deliverable/linux.git] / net / ipv6 / ndisc.c

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 121f31c283f8f823a0a26e747124839f542449ff..b79b00042310a86038b969642b56902d2e1b542b 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -319,6 +319,8 @@ int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int d
        return -EINVAL;
 }
 
+EXPORT_SYMBOL(ndisc_mc_map);
+
 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
 {
        const u32 *p32 = pkey;
@@ -447,6 +449,8 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
        ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
        if (ifp) {
                src_addr = solicited_addr;
+               if (ifp->flags & IFA_F_OPTIMISTIC)
+                       override = 0;
                in6_ifa_put(ifp);
        } else {
                if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
@@ -542,7 +546,8 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
        int send_llinfo;
 
        if (saddr == NULL) {
-               if (ipv6_get_lladdr(dev, &addr_buf))
+               if (ipv6_get_lladdr(dev, &addr_buf,
+                                  (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
                        return;
                saddr = &addr_buf;
        }
@@ -622,9 +627,33 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
        struct sk_buff *skb;
        struct icmp6hdr *hdr;
        __u8 * opt;
+       struct inet6_ifaddr *ifp;
+       int send_sllao = dev->addr_len;
        int len;
        int err;
 
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+       /*
+        * According to section 2.2 of RFC 4429, we must not
+        * send router solicitations with a sllao from
+        * optimistic addresses, but we may send the solicitation
+        * if we don't include the sllao.  So here we check
+        * if our address is optimistic, and if so, we
+        * supress the inclusion of the sllao.
+        */
+       if (send_sllao) {
+               ifp = ipv6_get_ifaddr(saddr, dev, 1);
+               if (ifp) {
+                       if (ifp->flags & IFA_F_OPTIMISTIC)  {
+                               send_sllao=0;
+                               in6_ifa_put(ifp);
+                       }
+               } else {
+                       send_sllao = 0;
+               }
+       }
+#endif
        ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
                        dev->ifindex);
 
@@ -637,7 +666,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
                return;
 
        len = sizeof(struct icmp6hdr);
-       if (dev->addr_len)
+       if (send_sllao)
                len += ndisc_opt_addr_space(dev);
 
        skb = sock_alloc_send_skb(sk,
@@ -664,7 +693,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
 
        opt = (u8*) (hdr + 1);
 
-       if (dev->addr_len)
+       if (send_sllao)
                ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
                                       dev->addr_len, dev->type);
 
@@ -796,28 +825,39 @@ static void ndisc_recv_ns(struct sk_buff *skb)
        inc = ipv6_addr_is_multicast(daddr);
 
        if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
-               if (ifp->flags & IFA_F_TENTATIVE) {
-                       /* Address is tentative. If the source
-                          is unspecified address, it is someone
-                          does DAD, otherwise we ignore solicitations
-                          until DAD timer expires.
-                        */
-                       if (!dad)
+
+               if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
+                       if (dad) {
+                               if (dev->type == ARPHRD_IEEE802_TR) {
+                                       unsigned char *sadr = skb->mac.raw;
+                                       if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
+                                           sadr[9] == dev->dev_addr[1] &&
+                                           sadr[10] == dev->dev_addr[2] &&
+                                           sadr[11] == dev->dev_addr[3] &&
+                                           sadr[12] == dev->dev_addr[4] &&
+                                           sadr[13] == dev->dev_addr[5]) {
+                                               /* looped-back to us */
+                                               goto out;
+                                       }
+                               }
+
+                               /*
+                                * We are colliding with another node
+                                * who is doing DAD
+                                * so fail our DAD process
+                                */
+                               addrconf_dad_failure(ifp);
                                goto out;
-                       if (dev->type == ARPHRD_IEEE802_TR) {
-                               unsigned char *sadr = skb->mac.raw;
-                               if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
-                                   sadr[9] == dev->dev_addr[1] &&
-                                   sadr[10] == dev->dev_addr[2] &&
-                                   sadr[11] == dev->dev_addr[3] &&
-                                   sadr[12] == dev->dev_addr[4] &&
-                                   sadr[13] == dev->dev_addr[5]) {
-                                       /* looped-back to us */
+                       } else {
+                               /*
+                                * This is not a dad solicitation.
+                                * If we are an optimistic node,
+                                * we should respond.
+                                * Otherwise, we should ignore it.
+                                */
+                               if (!(ifp->flags & IFA_F_OPTIMISTIC))
                                        goto out;
-                               }
                        }
-                       addrconf_dad_failure(ifp);
-                       return;
                }
 
                idev = ifp->idev;
@@ -1406,7 +1446,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
 
        dev = skb->dev;
 
-       if (ipv6_get_lladdr(dev, &saddr_buf)) {
+       if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
                ND_PRINTK2(KERN_WARNING
                           "ICMPv6 Redirect: no link-local address on %s\n",
                           dev->name);