[IPV6] ADDRCONF: Allow non-DAD'able addresses.

IFA_F_NODAD flag, similar to IN6_IFF_NODAD in BSDs, is introduced
to skip DAD.

This flag should be set to Mobile IPv6 Home Address(es) on Mobile
Node because DAD would fail if we should perform DAD; our Home Agent
protects our Home Address(es).

Signed-off-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/if_addr.h b/include/linux/if_addr.h
index e159045..ca24b9d 100644 (file)
--- a/include/linux/if_addr.h
+++ b/include/linux/if_addr.h
@@ -38,6 +38,7 @@ enum
 #define IFA_F_SECONDARY                0x01
 #define IFA_F_TEMPORARY                IFA_F_SECONDARY
 
+#define        IFA_F_NODAD             0x02
 #define IFA_F_DEPRECATED       0x20
 #define IFA_F_TENTATIVE                0x40
 #define IFA_F_PERMANENT                0x80

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c09ebb7..adb583a 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1873,12 +1873,11 @@ err_exit:
  *     Manual configuration of address on an interface
  */
 static int inet6_addr_add(int ifindex, struct in6_addr *pfx, int plen,
-                         __u32 prefered_lft, __u32 valid_lft)
+                         __u8 ifa_flags, __u32 prefered_lft, __u32 valid_lft)
 {
        struct inet6_ifaddr *ifp;
        struct inet6_dev *idev;
        struct net_device *dev;
-       __u8 ifa_flags = 0;
        int scope;
 
        ASSERT_RTNL();
@@ -1971,7 +1970,7 @@ int addrconf_add_ifaddr(void __user *arg)
 
        rtnl_lock();
        err = inet6_addr_add(ireq.ifr6_ifindex, &ireq.ifr6_addr, ireq.ifr6_prefixlen,
-                            INFINITY_LIFE_TIME, INFINITY_LIFE_TIME);
+                            IFA_F_PERMANENT, INFINITY_LIFE_TIME, INFINITY_LIFE_TIME);
        rtnl_unlock();
        return err;
 }
@@ -2514,7 +2513,8 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
        spin_lock_bh(&ifp->lock);
 
        if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
-           !(ifp->flags&IFA_F_TENTATIVE)) {
+           !(ifp->flags&IFA_F_TENTATIVE) ||
+           ifp->flags & IFA_F_NODAD) {
                ifp->flags &= ~IFA_F_TENTATIVE;
                spin_unlock_bh(&ifp->lock);
                read_unlock_bh(&idev->lock);
@@ -2912,28 +2912,25 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
        return inet6_addr_del(ifm->ifa_index, pfx, ifm->ifa_prefixlen);
 }
 
-static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 prefered_lft,
-                            u32 valid_lft)
+static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
+                            u32 prefered_lft, u32 valid_lft)
 {
-       int ifa_flags = 0;
-
        if (!valid_lft || (prefered_lft > valid_lft))
                return -EINVAL;
 
        if (valid_lft == INFINITY_LIFE_TIME)
-               ifa_flags = IFA_F_PERMANENT;
+               ifa_flags |= IFA_F_PERMANENT;
        else if (valid_lft >= 0x7FFFFFFF/HZ)
                valid_lft = 0x7FFFFFFF/HZ;
 
        if (prefered_lft == 0)
-               ifa_flags = IFA_F_DEPRECATED;
+               ifa_flags |= IFA_F_DEPRECATED;
        else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&
                 (prefered_lft != INFINITY_LIFE_TIME))
                prefered_lft = 0x7FFFFFFF/HZ;
 
        spin_lock_bh(&ifp->lock);
-       ifp->flags = (ifp->flags & ~(IFA_F_DEPRECATED|IFA_F_PERMANENT)) | ifa_flags;
-
+       ifp->flags = (ifp->flags & ~(IFA_F_DEPRECATED | IFA_F_PERMANENT | IFA_F_NODAD)) | ifa_flags;
        ifp->tstamp = jiffies;
        ifp->valid_lft = valid_lft;
        ifp->prefered_lft = prefered_lft;
@@ -2955,7 +2952,8 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
        struct in6_addr *pfx;
        struct inet6_ifaddr *ifa;
        struct net_device *dev;
-       u32 valid_lft, preferred_lft;
+       u32 valid_lft = INFINITY_LIFE_TIME, preferred_lft = INFINITY_LIFE_TIME;
+       u8 ifa_flags;
        int err;
 
        err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
@@ -2982,6 +2980,9 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
        if (dev == NULL)
                return -ENODEV;
 
+       /* We ignore other flags so far. */
+       ifa_flags = ifm->ifa_flags & IFA_F_NODAD;
+
        ifa = ipv6_get_ifaddr(pfx, dev, 1);
        if (ifa == NULL) {
                /*
@@ -2989,14 +2990,14 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                 * userspace alreay relies on not having to provide this.
                 */
                return inet6_addr_add(ifm->ifa_index, pfx, ifm->ifa_prefixlen,
-                                     preferred_lft, valid_lft);
+                                     ifa_flags, preferred_lft, valid_lft);
        }
 
        if (nlh->nlmsg_flags & NLM_F_EXCL ||
            !(nlh->nlmsg_flags & NLM_F_REPLACE))
                err = -EEXIST;
        else
-               err = inet6_addr_modify(ifa, preferred_lft, valid_lft);
+               err = inet6_addr_modify(ifa, ifa_flags, preferred_lft, valid_lft);
 
        in6_ifa_put(ifa);