---

yaml
---
r: 103210
b: refs/heads/master
c: 1b34be7
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 778d80be52699596bf70e0eb0761cf5e1e46088d
+refs/heads/master: 1b34be74cbf18f5d58cc85c7c4afcd9f7d74accd

trunk/Documentation/networking/ip-sysctl.txt

@@ -1029,6 +1029,13 @@ disable_ipv6 - BOOLEAN
 	Disable IPv6 operation.
 	Default: FALSE (enable IPv6 operation)
 
+accept_dad - INTEGER
+	Whether to accept DAD (Duplicate Address Detection).
+	0: Disable DAD
+	1: Enable DAD (default)
+	2: Enable DAD, and disable IPv6 operation if MAC-based duplicate
+	   link-local address has been found.
+
 icmp/*:
 ratelimit - INTEGER
 	Limit the maximal rates for sending ICMPv6 packets.

trunk/include/linux/ipv6.h

@@ -164,6 +164,7 @@ struct ipv6_devconf {
 	__s32		mc_forwarding;
 #endif
 	__s32		disable_ipv6;
+	__s32		accept_dad;
 	void		*sysctl;
 };
 
@@ -196,6 +197,7 @@ enum {
 	DEVCONF_ACCEPT_SOURCE_ROUTE,
 	DEVCONF_MC_FORWARDING,
 	DEVCONF_DISABLE_IPV6,
+	DEVCONF_ACCEPT_DAD,
 	DEVCONF_MAX
 };
 

trunk/net/ipv6/addrconf.c

@@ -119,6 +119,7 @@ static void ipv6_regen_rndid(unsigned long data);
 static int desync_factor = MAX_DESYNC_FACTOR * HZ;
 #endif
 
+static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
 static int ipv6_count_addresses(struct inet6_dev *idev);
 
 /*
@@ -184,6 +185,7 @@ struct ipv6_devconf ipv6_devconf __read_mostly = {
 	.proxy_ndp		= 0,
 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
 	.disable_ipv6		= 0,
+	.accept_dad		= 1,
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -217,6 +219,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
 	.proxy_ndp		= 0,
 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
 	.disable_ipv6		= 0,
+	.accept_dad		= 1,
 };
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@@ -380,6 +383,9 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 	 */
 	in6_dev_hold(ndev);
 
+	if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
+		ndev->cnf.accept_dad = -1;
+
 #if defined(CONFIG_IPV6_SIT) || defined(CONFIG_IPV6_SIT_MODULE)
 	if (dev->type == ARPHRD_SIT && (dev->priv_flags & IFF_ISATAP)) {
 		printk(KERN_INFO
@@ -1421,6 +1427,20 @@ static void addrconf_dad_stop(struct inet6_ifaddr *ifp)
 
 void addrconf_dad_failure(struct inet6_ifaddr *ifp)
 {
+	struct inet6_dev *idev = ifp->idev;
+	if (idev->cnf.accept_dad > 1 && !idev->cnf.disable_ipv6) {
+		struct in6_addr addr;
+
+		addr.s6_addr32[0] = htonl(0xfe800000);
+		addr.s6_addr32[1] = 0;
+
+		if (!ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) &&
+		    ipv6_addr_equal(&ifp->addr, &addr)) {
+			/* DAD failed for link-local based on MAC address */
+			idev->cnf.disable_ipv6 = 1;
+		}
+	}
+
 	if (net_ratelimit())
 		printk(KERN_INFO "%s: duplicate address detected!\n", ifp->idev->dev->name);
 	addrconf_dad_stop(ifp);
@@ -2753,6 +2773,7 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
 	spin_lock_bh(&ifp->lock);
 
 	if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
+	    idev->cnf.accept_dad < 1 ||
 	    !(ifp->flags&IFA_F_TENTATIVE) ||
 	    ifp->flags & IFA_F_NODAD) {
 		ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC);
@@ -2800,6 +2821,11 @@ static void addrconf_dad_timer(unsigned long data)
 		read_unlock_bh(&idev->lock);
 		goto out;
 	}
+	if (idev->cnf.accept_dad > 1 && idev->cnf.disable_ipv6) {
+		read_unlock_bh(&idev->lock);
+		addrconf_dad_failure(ifp);
+		return;
+	}
 	spin_lock_bh(&ifp->lock);
 	if (ifp->probes == 0) {
 		/*
@@ -3660,6 +3686,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
 	array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;
 #endif
 	array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
+	array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;
 }
 
 static inline size_t inet6_if_nlmsg_size(void)
@@ -4226,6 +4253,14 @@ static struct addrconf_sysctl_table
 			.mode		=	0644,
 			.proc_handler	=	&proc_dointvec,
 		},
+		{
+			.ctl_name	=	CTL_UNNUMBERED,
+			.procname	=	"accept_dad",
+			.data		=	&ipv6_devconf.accept_dad,
+			.maxlen		=	sizeof(int),
+			.mode		=	0644,
+			.proc_handler	=	&proc_dointvec,
+		},
 		{
 			.ctl_name	=	0,	/* sentinel */
 		}