Re: [PATCH] IPv6: Privacy Extensions for Stateless Address Autoconfiguration in IPv6

["YOSHIFUJI Hideaki / 吉藤英明" <yoshfuji@linux-ipv6.org>]

In article <Pine.LNX.4.44.0210311021560.19356-100000@netcore.fi> (at Thu, 31 Oct 2002 10:24:11 +0200 (EET)), Pekka Savola <pekkas@netcore.fi> says:

> > set default to 0 (don't use it) for now is ok?
> 
> Sure, ok for me.  (I'm assuming we'll be able to change the default at 
> some point when more knowledge and experience is gained but we're talking 
> about at least a year or two here, I think).

Ok, here's revised one.

 - sync with linux-2.5.45.
 - change default value for use_tempaddr sysctl to 0 
   (don't generate and use temprary addresses by default)

Index: Documentation/networking/ip-sysctl.txt
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/Documentation/networking/ip-sysctl.txt,v
retrieving revision 1.1.1.3
retrieving revision 1.1.1.3.8.2
diff -u -r1.1.1.3 -r1.1.1.3.8.2
--- Documentation/networking/ip-sysctl.txt	30 Oct 2002 09:43:01 -0000	1.1.1.3
+++ Documentation/networking/ip-sysctl.txt	1 Nov 2002 08:29:09 -0000	1.1.1.3.8.2
@@ -611,6 +611,37 @@
 	0 to disable any limiting, otherwise the maximal rate in jiffies(1)
 	Default: 100
 
+use_tempaddr - INTEGER
+	Preference for Privacy Extensions (RFC3041).
+	  <= 0 : disable Privacy Extensions
+	  == 1 : enable Privacy Extensions, but prefer public
+	         addresses over temporary addresses.
+	  >  1 : enable Privacy Extensions and prefer temporary
+	         addresses over public addresses.
+	Default:  0 (for most devices)
+		 -1 (for point-to-point devices and loopback devices)
+
+temp_valid_lft - INTEGER
+	valid lifetime (in seconds) for temporary addresses.
+	Default: 604800 (7 days)
+
+temp_prefered_lft - INTEGER
+	Preferred lifetime (in seconds) for temorary addresses.
+	Default: 86400 (1 day)
+
+max_desync_factor - INTEGER
+	Maximum value for DESYNC_FACTOR, which is a random value
+	that ensures that clients don't synchronize with each 
+	other and generage new addresses at exactly the same time.
+	value is in seconds.
+	Default: 600
+	
+regen_max_retry - INTEGER
+	Number of attempts before give up attempting to generate
+	valid temporary addresses.
+	Default: 5
+
+
 IPv6 Update by:
 Pekka Savola <pekkas@netcore.fi>
 YOSHIFUJI Hideaki / USAGI Project <yoshfuji@linux-ipv6.org>
Index: include/linux/rtnetlink.h
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/include/linux/rtnetlink.h,v
retrieving revision 1.1.1.2
retrieving revision 1.1.1.2.8.1
diff -u -r1.1.1.2 -r1.1.1.2.8.1
--- include/linux/rtnetlink.h	30 Oct 2002 09:43:04 -0000	1.1.1.2
+++ include/linux/rtnetlink.h	1 Nov 2002 08:15:13 -0000	1.1.1.2.8.1
@@ -335,6 +335,7 @@
 /* ifa_flags */
 
 #define IFA_F_SECONDARY		0x01
+#define IFA_F_TEMPORARY		IFA_F_SECONDARY
 
 #define IFA_F_DEPRECATED	0x20
 #define IFA_F_TENTATIVE		0x40
Index: include/linux/sysctl.h
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/include/linux/sysctl.h,v
retrieving revision 1.1.1.3
retrieving revision 1.1.1.3.8.1
diff -u -r1.1.1.3 -r1.1.1.3.8.1
--- include/linux/sysctl.h	30 Oct 2002 09:43:03 -0000	1.1.1.3
+++ include/linux/sysctl.h	1 Nov 2002 08:15:13 -0000	1.1.1.3.8.1
@@ -384,7 +384,12 @@
 	NET_IPV6_DAD_TRANSMITS=7,
 	NET_IPV6_RTR_SOLICITS=8,
 	NET_IPV6_RTR_SOLICIT_INTERVAL=9,
-	NET_IPV6_RTR_SOLICIT_DELAY=10
+	NET_IPV6_RTR_SOLICIT_DELAY=10,
+	NET_IPV6_USE_TEMPADDR=11,
+	NET_IPV6_TEMP_VALID_LFT=12,
+	NET_IPV6_TEMP_PREFERED_LFT=13,
+	NET_IPV6_REGEN_MAX_RETRY=14,
+	NET_IPV6_MAX_DESYNC_FACTOR=15
 };
 
 /* /proc/sys/net/ipv6/icmp */
Index: include/net/addrconf.h
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/include/net/addrconf.h,v
retrieving revision 1.1.1.2
retrieving revision 1.1.1.2.10.1
diff -u -r1.1.1.2 -r1.1.1.2.10.1
--- include/net/addrconf.h	19 Oct 2002 05:51:09 -0000	1.1.1.2
+++ include/net/addrconf.h	1 Nov 2002 08:15:13 -0000	1.1.1.2.10.1
@@ -6,6 +6,11 @@
 #define MAX_RTR_SOLICITATIONS		3
 #define RTR_SOLICITATION_INTERVAL	(4*HZ)
 
+#define TEMP_VALID_LIFETIME		(7*86400)
+#define TEMP_PREFERRED_LIFETIME		(86400)
+#define REGEN_MAX_RETRY			(5)
+#define MAX_DESYNC_FACTOR		(600)
+
 #define ADDR_CHECK_FREQUENCY		(120*HZ)
 
 struct prefix_info {
Index: include/net/if_inet6.h
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/include/net/if_inet6.h,v
retrieving revision 1.1.1.1
retrieving revision 1.1.1.1.18.1
diff -u -r1.1.1.1 -r1.1.1.1.18.1
--- include/net/if_inet6.h	7 Oct 2002 10:22:46 -0000	1.1.1.1
+++ include/net/if_inet6.h	1 Nov 2002 08:15:13 -0000	1.1.1.1.18.1
@@ -43,6 +43,12 @@
 	struct inet6_ifaddr	*lst_next;      /* next addr in addr_lst */
 	struct inet6_ifaddr	*if_next;       /* next addr in inet6_dev */
 
+#ifdef CONFIG_IPV6_PRIVACY
+	struct inet6_ifaddr	*tmp_next;	/* next addr in tempaddr_lst */
+	struct inet6_ifaddr	*ifpub;
+	int			regen_count;
+#endif
+
 	int			dead;
 };
 
@@ -86,7 +92,13 @@
 	int		rtr_solicits;
 	int		rtr_solicit_interval;
 	int		rtr_solicit_delay;
-
+#ifdef CONFIG_IPV6_PRIVACY
+	int		use_tempaddr;
+	int		temp_valid_lft;
+	int		temp_prefered_lft;
+	int		regen_max_retry;
+	int		max_desync_factor;
+#endif
 	void		*sysctl;
 };
 
@@ -100,6 +112,13 @@
 	atomic_t		refcnt;
 	__u32			if_flags;
 	int			dead;
+
+#ifdef CONFIG_IPV6_PRIVACY
+	u8			rndid[8];
+	u8			entropy[8];
+	struct timer_list	regen_timer;
+	struct inet6_ifaddr	*tempaddr_list;
+#endif
 
 	struct neigh_parms	*nd_parms;
 	struct inet6_dev	*next;
Index: net/ipv6/Kconfig
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/net/ipv6/Kconfig,v
retrieving revision 1.1.1.1
retrieving revision 1.1.1.1.2.3
diff -u -r1.1.1.1 -r1.1.1.1.2.3
--- net/ipv6/Kconfig	31 Oct 2002 04:02:51 -0000	1.1.1.1
+++ net/ipv6/Kconfig	1 Nov 2002 08:36:47 -0000	1.1.1.1.2.3
@@ -1,5 +1,21 @@
 #
 # IPv6 configuration
 # 
+config IPV6_PRIVACY
+	bool "IPv6: Privacy Extensions (RFC 3041) support"
+	depends on IPV6
+	---help---
+	  Privacy Extensions for Stateless Address Autoconfiguration in IPv6
+	  support.  With this option, additional periodically-alter 
+	  pseudo-random global-scope unicast address(es) will assigned to
+	  your interface(s).
+	
+	  By default, kernel do not generate temporary addresses.
+	  To use temporary addresses, do
+	
+	        echo 2 >/proc/sys/net/ipv6/conf/all/use_tempaddr 
+
+	  See <file:Documentation/networking/ip-sysctl.txt> for details.
+
 source "net/ipv6/netfilter/Kconfig"
 
Index: net/ipv6/addrconf.c
===================================================================
RCS file: /cvsroot/usagi/usagi-backport/linux25/net/ipv6/addrconf.c,v
retrieving revision 1.1.1.4
retrieving revision 1.1.1.4.8.2
diff -u -r1.1.1.4 -r1.1.1.4.8.2
--- net/ipv6/addrconf.c	30 Oct 2002 09:43:18 -0000	1.1.1.4
+++ net/ipv6/addrconf.c	1 Nov 2002 08:29:09 -0000	1.1.1.4.8.2
@@ -28,6 +28,8 @@
  *						packets.
  *	YOSHIFUJI Hideaki @USAGI	:	improved accuracy of
  *						address validation timer.
+ *	YOSHIFUJI Hideaki @USAGI	:	Privacy Extensions (RFC3041)
+ *						support.
  */
 
 #include <linux/config.h>
@@ -62,6 +64,12 @@
 #include <linux/if_tunnel.h>
 #include <linux/rtnetlink.h>
 
+#ifdef CONFIG_IPV6_PRIVACY
+#include <linux/random.h>
+#include <linux/crypto.h>
+#include <asm/scatterlist.h>
+#endif
+
 #include <asm/uaccess.h>
 
 #define IPV6_MAX_ADDRESSES 16
@@ -83,6 +91,16 @@
 int inet6_dev_count;
 int inet6_ifa_count;
 
+#ifdef CONFIG_IPV6_PRIVACY
+static int __ipv6_regen_rndid(struct inet6_dev *idev);
+static int __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr); 
+static void ipv6_regen_rndid(unsigned long data);
+
+static int desync_factor = MAX_DESYNC_FACTOR * HZ;
+#endif
+
+int ipv6_count_addresses(struct inet6_dev *idev);
+
 /*
  *	Configured unicast address hash table
  */
@@ -119,6 +137,13 @@
 	MAX_RTR_SOLICITATIONS,		/* router solicits	*/
 	RTR_SOLICITATION_INTERVAL,	/* rtr solicit interval	*/
 	MAX_RTR_SOLICITATION_DELAY,	/* rtr solicit delay	*/
+#ifdef CONFIG_IPV6_PRIVACY
+	.use_tempaddr 			= 0,
+	.temp_valid_lft			= TEMP_VALID_LIFETIME,
+	.temp_prefered_lft		= TEMP_PREFERRED_LIFETIME,
+	.regen_max_retry		= REGEN_MAX_RETRY,
+	.max_desync_factor		= MAX_DESYNC_FACTOR,
+#endif
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt =
@@ -133,6 +158,13 @@
 	MAX_RTR_SOLICITATIONS,		/* router solicits	*/
 	RTR_SOLICITATION_INTERVAL,	/* rtr solicit interval	*/
 	MAX_RTR_SOLICITATION_DELAY,	/* rtr solicit delay	*/
+#ifdef CONFIG_IPV6_PRIVACY
+	.use_tempaddr			= 0,
+	.temp_valid_lft			= TEMP_VALID_LIFETIME,
+	.temp_prefered_lft		= TEMP_PREFERRED_LIFETIME,
+	.regen_max_retry		= REGEN_MAX_RETRY,
+	.max_desync_factor		= MAX_DESYNC_FACTOR,
+#endif
 };
 
 int ipv6_addr_type(struct in6_addr *addr)
@@ -272,6 +304,24 @@
 		/* We refer to the device */
 		dev_hold(dev);
 
+#ifdef CONFIG_IPV6_PRIVACY
+		get_random_bytes(ndev->rndid, sizeof(ndev->rndid));
+		get_random_bytes(ndev->entropy, sizeof(ndev->entropy));
+		init_timer(&ndev->regen_timer);
+		ndev->regen_timer.function = ipv6_regen_rndid;
+		ndev->regen_timer.data = (unsigned long) ndev;
+		if ((dev->flags&IFF_LOOPBACK) ||
+		    dev->type == ARPHRD_TUNNEL ||
+		    dev->type == ARPHRD_SIT) {
+			printk(KERN_INFO
+				"Disabled Privacy Extensions on device %p(%s)\n",
+				dev, dev->name);
+			ndev->cnf.use_tempaddr = -1;
+		} else {
+			__ipv6_regen_rndid(ndev);
+		}
+#endif
+
 		write_lock_bh(&addrconf_lock);
 		dev->ip6_ptr = ndev;
 		/* One reference from device */
@@ -396,6 +446,18 @@
 	/* Add to inet6_dev unicast addr list. */
 	ifa->if_next = idev->addr_list;
 	idev->addr_list = ifa;
+
+#ifdef CONFIG_IPV6_PRIVACY
+	ifa->regen_count = 0;
+	if (ifa->flags&IFA_F_TEMPORARY) {
+		ifa->tmp_next = idev->tempaddr_list;
+		idev->tempaddr_list = ifa;
+		in6_ifa_hold(ifa);
+	} else {
+		ifa->tmp_next = NULL;
+	}
+#endif
+
 	in6_ifa_hold(ifa);
 	write_unlock_bh(&idev->lock);
 	read_unlock(&addrconf_lock);
@@ -417,6 +479,15 @@
 
 	ifp->dead = 1;
 
+#ifdef CONFIG_IPV6_PRIVACY
+	spin_lock_bh(&ifp->lock);
+	if (ifp->ifpub) {
+		__in6_ifa_put(ifp->ifpub);
+		ifp->ifpub = NULL;
+	}
+	spin_unlock_bh(&ifp->lock);
+#endif
+
 	write_lock_bh(&addrconf_hash_lock);
 	for (ifap = &inet6_addr_lst[hash]; (ifa=*ifap) != NULL;
 	     ifap = &ifa->lst_next) {
@@ -430,6 +501,24 @@
 	write_unlock_bh(&addrconf_hash_lock);
 
 	write_lock_bh(&idev->lock);
+#ifdef CONFIG_IPV6_PRIVACY
+	if (ifp->flags&IFA_F_TEMPORARY) {
+		for (ifap = &idev->tempaddr_list; (ifa=*ifap) != NULL;
+		     ifap = &ifa->tmp_next) {
+			if (ifa == ifp) {
+				*ifap = ifa->tmp_next;
+				if (ifp->ifpub) {
+					__in6_ifa_put(ifp->ifpub);
+					ifp->ifpub = NULL;
+				}
+				__in6_ifa_put(ifp);
+				ifa->tmp_next = NULL;
+				break;
+			}
+		}
+	}
+#endif
+
 	for (ifap = &idev->addr_list; (ifa=*ifap) != NULL;
 	     ifap = &ifa->if_next) {
 		if (ifa == ifp) {
@@ -450,6 +539,96 @@
 	in6_ifa_put(ifp);
 }
 
+#ifdef CONFIG_IPV6_PRIVACY
+static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *ift)
+{
+	struct inet6_dev *idev;
+	struct in6_addr addr, *tmpaddr;
+	unsigned long tmp_prefered_lft, tmp_valid_lft;
+	int tmp_plen;
+	int ret = 0;
+
+	if (ift) {
+		spin_lock_bh(&ift->lock);
+		memcpy(&addr.s6_addr[8], &ift->addr.s6_addr[8], 8);
+		spin_unlock_bh(&ift->lock);
+		tmpaddr = &addr;
+	} else {
+		tmpaddr = NULL;
+	}
+retry:
+	spin_lock_bh(&ifp->lock);
+	in6_ifa_hold(ifp);
+	idev = ifp->idev;
+	in6_dev_hold(idev);
+	memcpy(addr.s6_addr, ifp->addr.s6_addr, 8);
+	write_lock(&idev->lock);
+	if (idev->cnf.use_tempaddr <= 0) {
+		write_unlock(&idev->lock);
+		spin_unlock_bh(&ifp->lock);
+		printk(KERN_INFO
+			"ipv6_create_tempaddr(): use_tempaddr is disabled.\n");
+		in6_dev_put(idev);
+		in6_ifa_put(ifp);
+		ret = -1;
+		goto out;
+	}
+	if (ifp->regen_count++ >= idev->cnf.regen_max_retry) {
+		idev->cnf.use_tempaddr = -1;	/*XXX*/
+		write_unlock(&idev->lock);
+		spin_unlock_bh(&ifp->lock);
+		printk(KERN_WARNING
+			"ipv6_create_tempaddr(): regeneration time exceeded. disabled temporary address support.\n");
+		in6_dev_put(idev);
+		in6_ifa_put(ifp);
+		ret = -1;
+		goto out;
+	}
+	if (__ipv6_try_regen_rndid(idev, tmpaddr) < 0) {
+		write_unlock(&idev->lock);
+		spin_unlock_bh(&ifp->lock);
+		printk(KERN_WARNING
+			"ipv6_create_tempaddr(): regeneration of randomized interface id failed.\n");
+		in6_dev_put(idev);
+		in6_ifa_put(ifp);
+		ret = -1;
+		goto out;
+	}
+	memcpy(&addr.s6_addr[8], idev->rndid, 8);
+	tmp_valid_lft = min_t(__u32,
+			      ifp->valid_lft,
+			      idev->cnf.temp_valid_lft);
+	tmp_prefered_lft = min_t(__u32, 
+				 ifp->prefered_lft, 
+				 idev->cnf.temp_prefered_lft - desync_factor / HZ);
+	tmp_plen = ifp->prefix_len;
+	write_unlock(&idev->lock);
+	spin_unlock_bh(&ifp->lock);
+	ift = ipv6_count_addresses(idev) < IPV6_MAX_ADDRESSES ?
+		ipv6_add_addr(idev, &addr, tmp_plen,
+			      ipv6_addr_type(&addr)&IPV6_ADDR_SCOPE_MASK, IFA_F_TEMPORARY) : 0;
+	if (!ift) {
+		in6_dev_put(idev);
+		in6_ifa_put(ifp);
+		printk(KERN_INFO
+			"ipv6_create_tempaddr(): retry temporary address regeneration.\n");
+		tmpaddr = &addr;
+		goto retry;
+	}
+	spin_lock_bh(&ift->lock);
+	ift->ifpub = ifp;
+	ift->valid_lft = tmp_valid_lft;
+	ift->prefered_lft = tmp_prefered_lft;
+	ift->tstamp = ifp->tstamp;
+	spin_unlock_bh(&ift->lock);
+	addrconf_dad_start(ift);
+	in6_ifa_put(ift);
+	in6_dev_put(idev);
+out:
+	return ret;
+}
+#endif
+
 /*
  *	Choose an apropriate source address
  *	should do:
@@ -458,6 +637,22 @@
  *		an address of the attached interface 
  *	iii)	don't use deprecated addresses
  */
+static int inline ipv6_saddr_pref(const struct inet6_ifaddr *ifp, u8 invpref)
+{
+	int pref;
+	pref = ifp->flags&IFA_F_DEPRECATED ? 0 : 2;
+#ifdef CONFIG_IPV6_PRIVACY
+	pref |= (ifp->flags^invpref)&IFA_F_TEMPORARY ? 0 : 1;
+#endif
+	return pref;
+}
+
+#ifdef CONFIG_IPV6_PRIVACY
+#define IPV6_GET_SADDR_MAXSCORE(score)	((score) == 3)
+#else
+#define IPV6_GET_SADDR_MAXSCORE(score)	(score)
+#endif
+
 int ipv6_get_saddr(struct dst_entry *dst,
 		   struct in6_addr *daddr, struct in6_addr *saddr)
 {
@@ -468,6 +663,7 @@
 	struct inet6_dev *idev;
 	struct rt6_info *rt;
 	int err;
+	int hiscore = -1, score;
 
 	rt = (struct rt6_info *) dst;
 	if (rt)
@@ -497,17 +693,27 @@
 			read_lock_bh(&idev->lock);
 			for (ifp=idev->addr_list; ifp; ifp=ifp->if_next) {
 				if (ifp->scope == scope) {
-					if (!(ifp->flags & (IFA_F_DEPRECATED|IFA_F_TENTATIVE))) {
-						in6_ifa_hold(ifp);
+					if (ifp->flags&IFA_F_TENTATIVE)
+						continue;
+#ifdef CONFIG_IPV6_PRIVACY
+					score = ipv6_saddr_pref(ifp, idev->cnf.use_tempaddr > 1 ? IFA_F_TEMPORARY : 0);
+#else
+					score = ipv6_saddr_pref(ifp, 0);
+#endif
+					if (score <= hiscore)
+						continue;
+
+					if (match)
+						in6_ifa_put(match);
+					match = ifp;
+					hiscore = score;
+					in6_ifa_hold(ifp);
+
+					if (IPV6_GET_SADDR_MAXSCORE(score)) {
 						read_unlock_bh(&idev->lock);
 						read_unlock(&addrconf_lock);
 						goto out;
 					}
-
-					if (!match && !(ifp->flags & IFA_F_TENTATIVE)) {
-						match = ifp;
-						in6_ifa_hold(ifp);
-					}
 				}
 			}
 			read_unlock_bh(&idev->lock);
@@ -530,16 +736,26 @@
 			read_lock_bh(&idev->lock);
 			for (ifp=idev->addr_list; ifp; ifp=ifp->if_next) {
 				if (ifp->scope == scope) {
-					if (!(ifp->flags&(IFA_F_DEPRECATED|IFA_F_TENTATIVE))) {
-						in6_ifa_hold(ifp);
+					if (ifp->flags&IFA_F_TENTATIVE)
+						continue;
+#ifdef CONFIG_IPV6_PRIVACY
+					score = ipv6_saddr_pref(ifp, idev->cnf.use_tempaddr > 1 ? IFA_F_TEMPORARY : 0);
+#else
+					score = ipv6_saddr_pref(ifp, 0);
+#endif
+					if (score <= hiscore)
+						continue;
+
+					if (match)
+						in6_ifa_put(match);
+					match = ifp;
+					hiscore = score;
+					in6_ifa_hold(ifp);
+
+					if (IPV6_GET_SADDR_MAXSCORE(score)) {
 						read_unlock_bh(&idev->lock);
 						goto out_unlock_base;
 					}
-
-					if (!match && !(ifp->flags&IFA_F_TENTATIVE)) {
-						match = ifp;
-						in6_ifa_hold(ifp);
-					}
 				}
 			}
 			read_unlock_bh(&idev->lock);
@@ -551,19 +767,12 @@
 	read_unlock(&dev_base_lock);
 
 out:
-	if (ifp == NULL) {
-		ifp = match;
-		match = NULL;
-	}
-
 	err = -EADDRNOTAVAIL;
-	if (ifp) {
-		ipv6_addr_copy(saddr, &ifp->addr);
+	if (match) {
+		ipv6_addr_copy(saddr, &match->addr);
 		err = 0;
-		in6_ifa_put(ifp);
-	}
-	if (match)
 		in6_ifa_put(match);
+	}
 
 	return err;
 }
@@ -653,6 +862,21 @@
 		ifp->flags |= IFA_F_TENTATIVE;
 		spin_unlock_bh(&ifp->lock);
 		in6_ifa_put(ifp);
+#ifdef CONFIG_IPV6_PRIVACY
+	} else if (ifp->flags&IFA_F_TEMPORARY) {
+		struct inet6_ifaddr *ifpub;
+		spin_lock_bh(&ifp->lock);
+		ifpub = ifp->ifpub;
+		if (ifpub) {
+			in6_ifa_hold(ifpub);
+			spin_unlock_bh(&ifp->lock);
+			ipv6_create_tempaddr(ifpub, ifp);
+			in6_ifa_put(ifpub);
+		} else {
+			spin_unlock_bh(&ifp->lock);
+		}
+		ipv6_del_addr(ifp);
+#endif
 	} else
 		ipv6_del_addr(ifp);
 }
@@ -718,6 +942,108 @@
 	return err;
 }
 
+#ifdef CONFIG_IPV6_PRIVACY
+/* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
+static int __ipv6_regen_rndid(struct inet6_dev *idev)
+{
+	struct net_device *dev;
+	u8 eui64[8];
+	u8 digest[16];
+	struct crypto_tfm *tfm;
+	struct scatterlist sg[2];
+
+	sg[0].page = virt_to_page(idev->entropy);
+	sg[0].offset = ((long) idev->entropy & ~PAGE_MASK);
+	sg[0].length = 8;
+	sg[1].page = virt_to_page(eui64);
+	sg[1].offset = ((long) eui64 & ~PAGE_MASK);
+	sg[1].length = 8;
+
+	if (!del_timer(&idev->regen_timer))
+		in6_dev_hold(idev);
+
+	dev = idev->dev;
+
+	if (ipv6_generate_eui64(eui64, dev)) {
+		printk(KERN_INFO
+			"__ipv6_regen_rndid(idev=%p): cannot get EUI64 identifier; use random bytes.\n",
+			idev);
+		get_random_bytes(eui64, sizeof(eui64));
+	}
+regen:
+	tfm = crypto_alloc_tfm("md5", 0);
+	if (tfm == NULL) {
+		if (net_ratelimit())
+			printk(KERN_WARNING
+				"failed to load transform for md5\n");
+		in6_dev_put(idev);
+		return -1;
+	}
+	crypto_digest_init(tfm);
+	crypto_digest_update(tfm, sg, 2);
+	crypto_digest_final(tfm, digest);
+	crypto_free_tfm(tfm);
+
+	memcpy(idev->rndid, &digest[0], 8);
+	idev->rndid[0] &= ~0x02;
+	memcpy(idev->entropy, &digest[8], 8);
+
+	/*
+	 * <draft-ietf-ipngwg-temp-addresses-v2-00.txt>:
+	 * check if generated address is not inappropriate
+	 *
+	 *  - Reserved subnet anycast (RFC 2526)
+	 *	11111101 11....11 1xxxxxxx
+	 *  - ISATAP (draft-ietf-ngtrans-isatap-01.txt) 4.3
+	 *	00-00-5E-FE-xx-xx-xx-xx
+	 *  - value 0
+	 *  - XXX: already assigned to an address on the device
+	 */
+	if (idev->rndid[0] == 0xfd && 
+	    (idev->rndid[1]&idev->rndid[2]&idev->rndid[3]&idev->rndid[4]&idev->rndid[5]&idev->rndid[6]) &&
+	    (idev->rndid[7]&0x80))
+		goto regen;
+	if ((idev->rndid[0]|idev->rndid[1]) == 0) {
+		if (idev->rndid[2] == 0x5e && idev->rndid[3] == 0xfe)
+			goto regen;
+		if ((idev->rndid[2]|idev->rndid[3]|idev->rndid[4]|idev->rndid[5]|idev->rndid[6]|idev->rndid[7]) == 0x00)
+			goto regen;
+	}
+	
+	if (time_before(idev->regen_timer.expires, jiffies)) {
+		idev->regen_timer.expires = 0;
+		printk(KERN_WARNING
+			"__ipv6_regen_rndid(): too short regeneration interval; timer diabled for %s.\n",
+			idev->dev->name);
+		in6_dev_put(idev);
+		return -1;
+	}
+
+	add_timer(&idev->regen_timer);
+	return 0;
+}
+
+static void ipv6_regen_rndid(unsigned long data)
+{
+	struct inet6_dev *idev = (struct inet6_dev *) data;
+
+	read_lock_bh(&addrconf_lock);
+	write_lock_bh(&idev->lock);
+	if (!idev->dead)
+		__ipv6_regen_rndid(idev);
+	write_unlock_bh(&idev->lock);
+	read_unlock_bh(&addrconf_lock);
+}
+
+static int __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr) {
+	int ret = 0;
+
+	if (tmpaddr && memcmp(idev->rndid, &tmpaddr->s6_addr[8], 8) == 0)
+		ret = __ipv6_regen_rndid(idev);
+	return ret;
+}
+#endif
+
 /*
  *	Add prefix route.
  */
@@ -889,6 +1215,7 @@
 		struct inet6_ifaddr * ifp;
 		struct in6_addr addr;
 		int plen;
+		int create = 0;
 
 		plen = pinfo->prefix_len >> 3;
 
@@ -924,6 +1251,7 @@
 				return;
 			}
 
+			create = 1;
 			addrconf_dad_start(ifp);
 		}
 
@@ -934,6 +1262,9 @@
 
 		if (ifp) {
 			int flags;
+#ifdef CONFIG_IPV6_PRIVACY
+			struct inet6_ifaddr *ift;
+#endif
 
 			spin_lock(&ifp->lock);
 			ifp->valid_lft = valid_lft;
@@ -946,6 +1277,42 @@
 			if (!(flags&IFA_F_TENTATIVE))
 				ipv6_ifa_notify((flags&IFA_F_DEPRECATED) ?
 						0 : RTM_NEWADDR, ifp);
+
+#ifdef CONFIG_IPV6_PRIVACY
+			read_lock_bh(&in6_dev->lock);
+			/* update all temporary addresses in the list */
+			for (ift=in6_dev->tempaddr_list; ift; ift=ift->tmp_next) {
+				/*
+				 * When adjusting the lifetimes of an existing
+				 * temporary address, only lower the lifetimes.
+				 * Implementations must not increase the
+				 * lifetimes of an existing temporary address
+				 * when processing a Prefix Information Option.
+				 */
+				spin_lock(&ift->lock);
+				flags = ift->flags;
+				if (ift->valid_lft > valid_lft &&
+				    ift->valid_lft - valid_lft > (jiffies - ift->tstamp) / HZ)
+					ift->valid_lft = valid_lft + (jiffies - ift->tstamp) / HZ;
+				if (ift->prefered_lft > prefered_lft &&
+				    ift->prefered_lft - prefered_lft > (jiffies - ift->tstamp) / HZ)
+					ift->prefered_lft = prefered_lft + (jiffies - ift->tstamp) / HZ;
+				spin_unlock(&ift->lock);
+				if (!(flags&IFA_F_TENTATIVE))
+					ipv6_ifa_notify(0, ift);
+			}
+
+			if (create && in6_dev->cnf.use_tempaddr > 0) {
+				/*
+				 * When a new public address is created as described in [ADDRCONF],
+				 * also create a new temporary address.
+				 */
+				read_unlock_bh(&in6_dev->lock); 
+				ipv6_create_tempaddr(ifp, NULL);
+			} else {
+				read_unlock_bh(&in6_dev->lock);
+			}
+#endif
 			in6_ifa_put(ifp);
 			addrconf_verify(0);
 		}
@@ -1910,7 +2277,7 @@
 static struct addrconf_sysctl_table
 {
 	struct ctl_table_header *sysctl_header;
-	ctl_table addrconf_vars[11];
+	ctl_table addrconf_vars[16];
 	ctl_table addrconf_dev[2];
 	ctl_table addrconf_conf_dir[2];
 	ctl_table addrconf_proto_dir[2];
@@ -1957,6 +2324,28 @@
          &ipv6_devconf.rtr_solicit_delay, sizeof(int), 0644, NULL,
          &proc_dointvec_jiffies},
 
+#ifdef CONFIG_IPV6_PRIVACY
+	{NET_IPV6_USE_TEMPADDR, "use_tempaddr",
+	 &ipv6_devconf.use_tempaddr, sizeof(int), 0644, NULL,
+	 &proc_dointvec},
+
+	{NET_IPV6_TEMP_VALID_LFT, "temp_valid_lft",
+	 &ipv6_devconf.temp_valid_lft, sizeof(int), 0644, NULL,
+	 &proc_dointvec},
+
+	{NET_IPV6_TEMP_PREFERED_LFT, "temp_prefered_lft",
+	 &ipv6_devconf.temp_prefered_lft, sizeof(int), 0644, NULL,
+	 &proc_dointvec},
+
+	{NET_IPV6_REGEN_MAX_RETRY, "regen_max_retry",
+	 &ipv6_devconf.regen_max_retry, sizeof(int), 0644, NULL,
+	 &proc_dointvec},
+
+	{NET_IPV6_MAX_DESYNC_FACTOR, "max_desync_factor",
+	 &ipv6_devconf.max_desync_factor, sizeof(int), 0644, NULL,
+	 &proc_dointvec},
+#endif
+
 	{0}},
 
 	{{NET_PROTO_CONF_ALL, "all", NULL, 0, 0555, addrconf_sysctl.addrconf_vars},{0}},
@@ -1975,7 +2364,7 @@
 	if (t == NULL)
 		return;
 	memcpy(t, &addrconf_sysctl, sizeof(*t));
-	for (i=0; i<sizeof(t->addrconf_vars)/sizeof(t->addrconf_vars[0])-1; i++) {
+	for (i=0; t->addrconf_vars[i].data; i++) {
 		t->addrconf_vars[i].data += (char*)p - (char*)&ipv6_devconf;
 		t->addrconf_vars[i].de = NULL;
 	}


-- 
Hideaki YOSHIFUJI @ USAGI Project <yoshfuji@linux-ipv6.org>
GPG FP: 9022 65EB 1ECF 3AD1 0BDF  80D8 4807 F894 E062 0EEA