1 files changed, 107 insertions, 92 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2f1f5d439788..060dd9922018 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -112,6 +112,27 @@ static inline u32 cstamp_delta(unsigned long cstamp)
 	return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
 }
 
+static inline s32 rfc3315_s14_backoff_init(s32 irt)
+{
+	/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
+	u64 tmp = (900000 + prandom_u32() % 200001) * (u64)irt;
+	do_div(tmp, 1000000);
+	return (s32)tmp;
+}
+
+static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
+{
+	/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
+	u64 tmp = (1900000 + prandom_u32() % 200001) * (u64)rt;
+	do_div(tmp, 1000000);
+	if ((s32)tmp > mrt) {
+		/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
+		tmp = (900000 + prandom_u32() % 200001) * (u64)mrt;
+		do_div(tmp, 1000000);
+	}
+	return (s32)tmp;
+}
+
 #ifdef CONFIG_SYSCTL
 static int addrconf_sysctl_register(struct inet6_dev *idev);
 static void addrconf_sysctl_unregister(struct inet6_dev *idev);
@@ -126,9 +147,8 @@ static inline void addrconf_sysctl_unregister(struct inet6_dev *idev)
 }
 #endif
 
-static void __ipv6_regen_rndid(struct inet6_dev *idev);
-static void __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
-static void ipv6_regen_rndid(unsigned long data);
+static void ipv6_regen_rndid(struct inet6_dev *idev);
+static void ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
 
 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
 static int ipv6_count_addresses(struct inet6_dev *idev);
@@ -187,6 +207,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
 	.dad_transmits		= 1,
 	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
 	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
+	.rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
 	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
 	.use_tempaddr		= 0,
 	.temp_valid_lft		= TEMP_VALID_LIFETIME,
@@ -232,6 +253,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
 	.dad_transmits		= 1,
 	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
 	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
+	.rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
 	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
 	.use_tempaddr		= 0,
 	.temp_valid_lft		= TEMP_VALID_LIFETIME,
@@ -386,9 +408,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 		goto err_release;
 	}
 
-	/* One reference from device.  We must do this before
-	 * we invoke __ipv6_regen_rndid().
-	 */
+	/* One reference from device. */
 	in6_dev_hold(ndev);
 
 	if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
@@ -402,17 +422,15 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 #endif
 
 	INIT_LIST_HEAD(&ndev->tempaddr_list);
-	setup_timer(&ndev->regen_timer, ipv6_regen_rndid, (unsigned long)ndev);
+	ndev->desync_factor = U32_MAX;
 	if ((dev->flags&IFF_LOOPBACK) ||
 	    dev->type == ARPHRD_TUNNEL ||
 	    dev->type == ARPHRD_TUNNEL6 ||
 	    dev->type == ARPHRD_SIT ||
 	    dev->type == ARPHRD_NONE) {
 		ndev->cnf.use_tempaddr = -1;
-	} else {
-		in6_dev_hold(ndev);
-		ipv6_regen_rndid((unsigned long) ndev);
-	}
+	} else
+		ipv6_regen_rndid(ndev);
 
 	ndev->token = in6addr_any;
 
@@ -424,7 +442,6 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 	err = addrconf_sysctl_register(ndev);
 	if (err) {
 		ipv6_mc_destroy_dev(ndev);
-		del_timer(&ndev->regen_timer);
 		snmp6_unregister_dev(ndev);
 		goto err_release;
 	}
@@ -1167,6 +1184,8 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i
 	int ret = 0;
 	u32 addr_flags;
 	unsigned long now = jiffies;
+	long max_desync_factor;
+	s32 cnf_temp_preferred_lft;
 
 	write_lock_bh(&idev->lock);
 	if (ift) {
@@ -1199,23 +1218,42 @@ retry:
 	}
 	in6_ifa_hold(ifp);
 	memcpy(addr.s6_addr, ifp->addr.s6_addr, 8);
-	__ipv6_try_regen_rndid(idev, tmpaddr);
+	ipv6_try_regen_rndid(idev, tmpaddr);
 	memcpy(&addr.s6_addr[8], idev->rndid, 8);
 	age = (now - ifp->tstamp) / HZ;
+
+	regen_advance = idev->cnf.regen_max_retry *
+			idev->cnf.dad_transmits *
+			NEIGH_VAR(idev->nd_parms, RETRANS_TIME) / HZ;
+
+	/* recalculate max_desync_factor each time and update
+	 * idev->desync_factor if it's larger
+	 */
+	cnf_temp_preferred_lft = READ_ONCE(idev->cnf.temp_prefered_lft);
+	max_desync_factor = min_t(__u32,
+				  idev->cnf.max_desync_factor,
+				  cnf_temp_preferred_lft - regen_advance);
+
+	if (unlikely(idev->desync_factor > max_desync_factor)) {
+		if (max_desync_factor > 0) {
+			get_random_bytes(&idev->desync_factor,
+					 sizeof(idev->desync_factor));
+			idev->desync_factor %= max_desync_factor;
+		} else {
+			idev->desync_factor = 0;
+		}
+	}
+
 	tmp_valid_lft = min_t(__u32,
 			      ifp->valid_lft,
 			      idev->cnf.temp_valid_lft + age);
-	tmp_prefered_lft = min_t(__u32,
-				 ifp->prefered_lft,
-				 idev->cnf.temp_prefered_lft + age -
-				 idev->cnf.max_desync_factor);
+	tmp_prefered_lft = cnf_temp_preferred_lft + age -
+			    idev->desync_factor;
+	tmp_prefered_lft = min_t(__u32, ifp->prefered_lft, tmp_prefered_lft);
 	tmp_plen = ifp->prefix_len;
 	tmp_tstamp = ifp->tstamp;
 	spin_unlock_bh(&ifp->lock);
 
-	regen_advance = idev->cnf.regen_max_retry *
-			idev->cnf.dad_transmits *
-			NEIGH_VAR(idev->nd_parms, RETRANS_TIME) / HZ;
 	write_unlock_bh(&idev->lock);
 
 	/* A temporary address is created only if this calculated Preferred
@@ -2127,7 +2165,7 @@ static int ipv6_inherit_eui64(u8 *eui, struct inet6_dev *idev)
 }
 
 /* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
-static void __ipv6_regen_rndid(struct inet6_dev *idev)
+static void ipv6_regen_rndid(struct inet6_dev *idev)
 {
 regen:
 	get_random_bytes(idev->rndid, sizeof(idev->rndid));
@@ -2156,43 +2194,10 @@ regen:
 	}
 }
 
-static void ipv6_regen_rndid(unsigned long data)
-{
-	struct inet6_dev *idev = (struct inet6_dev *) data;
-	unsigned long expires;
-
-	rcu_read_lock_bh();
-	write_lock_bh(&idev->lock);
-
-	if (idev->dead)
-		goto out;
-
-	__ipv6_regen_rndid(idev);
-
-	expires = jiffies +
-		idev->cnf.temp_prefered_lft * HZ -
-		idev->cnf.regen_max_retry * idev->cnf.dad_transmits *
-		NEIGH_VAR(idev->nd_parms, RETRANS_TIME) -
-		idev->cnf.max_desync_factor * HZ;
-	if (time_before(expires, jiffies)) {
-		pr_warn("%s: too short regeneration interval; timer disabled for %s\n",
-			__func__, idev->dev->name);
-		goto out;
-	}
-
-	if (!mod_timer(&idev->regen_timer, expires))
-		in6_dev_hold(idev);
-
-out:
-	write_unlock_bh(&idev->lock);
-	rcu_read_unlock_bh();
-	in6_dev_put(idev);
-}
-
-static void  __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr)
+static void  ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr)
 {
 	if (tmpaddr && memcmp(idev->rndid, &tmpaddr->s6_addr[8], 8) == 0)
-		__ipv6_regen_rndid(idev);
+		ipv6_regen_rndid(idev);
 }
 
 /*
@@ -2333,7 +2338,7 @@ static void manage_tempaddrs(struct inet6_dev *idev,
 			max_valid = 0;
 
 		max_prefered = idev->cnf.temp_prefered_lft -
-			       idev->cnf.max_desync_factor - age;
+			       idev->desync_factor - age;
 		if (max_prefered < 0)
 			max_prefered = 0;
 
@@ -2995,7 +3000,7 @@ static void init_loopback(struct net_device *dev)
 				 * lo device down, release this obsolete dst and
 				 * reallocate a new router for ifa.
 				 */
-				if (sp_ifa->rt->dst.obsolete > 0) {
+				if (!atomic_read(&sp_ifa->rt->rt6i_ref)) {
 					ip6_rt_put(sp_ifa->rt);
 					sp_ifa->rt = NULL;
 				} else {
@@ -3571,9 +3576,6 @@ restart:
 	if (!how)
 		idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY);
 
-	if (how && del_timer(&idev->regen_timer))
-		in6_dev_put(idev);
-
 	/* Step 3: clear tempaddr list */
 	while (!list_empty(&idev->tempaddr_list)) {
 		ifa = list_first_entry(&idev->tempaddr_list,
@@ -3687,7 +3689,7 @@ static void addrconf_rs_timer(unsigned long data)
 	if (idev->if_flags & IF_RA_RCVD)
 		goto out;
 
-	if (idev->rs_probes++ < idev->cnf.rtr_solicits) {
+	if (idev->rs_probes++ < idev->cnf.rtr_solicits || idev->cnf.rtr_solicits < 0) {
 		write_unlock(&idev->lock);
 		if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
 			ndisc_send_rs(dev, &lladdr,
@@ -3696,11 +3698,13 @@ static void addrconf_rs_timer(unsigned long data)
 			goto put;
 
 		write_lock(&idev->lock);
+		idev->rs_interval = rfc3315_s14_backoff_update(
+			idev->rs_interval, idev->cnf.rtr_solicit_max_interval);
 		/* The wait after the last probe can be shorter */
 		addrconf_mod_rs_timer(idev, (idev->rs_probes ==
 					     idev->cnf.rtr_solicits) ?
 				      idev->cnf.rtr_solicit_delay :
-				      idev->cnf.rtr_solicit_interval);
+				      idev->rs_interval);
 	} else {
 		/*
 		 * Note: we do not support deprecated "all on-link"
@@ -3949,7 +3953,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
 	send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp);
 	send_rs = send_mld &&
 		  ipv6_accept_ra(ifp->idev) &&
-		  ifp->idev->cnf.rtr_solicits > 0 &&
+		  ifp->idev->cnf.rtr_solicits != 0 &&
 		  (dev->flags&IFF_LOOPBACK) == 0;
 	read_unlock_bh(&ifp->idev->lock);
 
@@ -3971,10 +3975,11 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
 
 		write_lock_bh(&ifp->idev->lock);
 		spin_lock(&ifp->lock);
+		ifp->idev->rs_interval = rfc3315_s14_backoff_init(
+			ifp->idev->cnf.rtr_solicit_interval);
 		ifp->idev->rs_probes = 1;
 		ifp->idev->if_flags |= IF_RS_SENT;
-		addrconf_mod_rs_timer(ifp->idev,
-				      ifp->idev->cnf.rtr_solicit_interval);
+		addrconf_mod_rs_timer(ifp->idev, ifp->idev->rs_interval);
 		spin_unlock(&ifp->lock);
 		write_unlock_bh(&ifp->idev->lock);
 	}
@@ -4891,6 +4896,8 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
 	array[DEVCONF_RTR_SOLICITS] = cnf->rtr_solicits;
 	array[DEVCONF_RTR_SOLICIT_INTERVAL] =
 		jiffies_to_msecs(cnf->rtr_solicit_interval);
+	array[DEVCONF_RTR_SOLICIT_MAX_INTERVAL] =
+		jiffies_to_msecs(cnf->rtr_solicit_max_interval);
 	array[DEVCONF_RTR_SOLICIT_DELAY] =
 		jiffies_to_msecs(cnf->rtr_solicit_delay);
 	array[DEVCONF_FORCE_MLD_VERSION] = cnf->force_mld_version;
@@ -4961,18 +4968,18 @@ static inline size_t inet6_if_nlmsg_size(void)
 }
 
 static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
-				      int items, int bytes)
+					int bytes)
 {
 	int i;
-	int pad = bytes - sizeof(u64) * items;
+	int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
 	BUG_ON(pad < 0);
 
 	/* Use put_unaligned() because stats may not be aligned for u64. */
-	put_unaligned(items, &stats[0]);
-	for (i = 1; i < items; i++)
+	put_unaligned(ICMP6_MIB_MAX, &stats[0]);
+	for (i = 1; i < ICMP6_MIB_MAX; i++)
 		put_unaligned(atomic_long_read(&mib[i]), &stats[i]);
 
-	memset(&stats[items], 0, pad);
+	memset(&stats[ICMP6_MIB_MAX], 0, pad);
 }
 
 static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -5005,7 +5012,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
 				     offsetof(struct ipstats_mib, syncp));
 		break;
 	case IFLA_INET6_ICMP6STATS:
-		__snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, ICMP6_MIB_MAX, bytes);
+		__snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, bytes);
 		break;
 	}
 }
@@ -5099,7 +5106,7 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
 		return -EINVAL;
 	if (!ipv6_accept_ra(idev))
 		return -EINVAL;
-	if (idev->cnf.rtr_solicits <= 0)
+	if (idev->cnf.rtr_solicits == 0)
 		return -EINVAL;
 
 	write_lock_bh(&idev->lock);
@@ -5128,8 +5135,10 @@ update_lft:
 
 	if (update_rs) {
 		idev->if_flags |= IF_RS_SENT;
+		idev->rs_interval = rfc3315_s14_backoff_init(
+			idev->cnf.rtr_solicit_interval);
 		idev->rs_probes = 1;
-		addrconf_mod_rs_timer(idev, idev->cnf.rtr_solicit_interval);
+		addrconf_mod_rs_timer(idev, idev->rs_interval);
 	}
 
 	/* Well, that's kinda nasty ... */
@@ -5467,20 +5476,6 @@ int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
 }
 
 static
-int addrconf_sysctl_hop_limit(struct ctl_table *ctl, int write,
-                              void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct ctl_table lctl;
-	int min_hl = 1, max_hl = 255;
-
-	lctl = *ctl;
-	lctl.extra1 = &min_hl;
-	lctl.extra2 = &max_hl;
-
-	return proc_dointvec_minmax(&lctl, write, buffer, lenp, ppos);
-}
-
-static
 int addrconf_sysctl_mtu(struct ctl_table *ctl, int write,
 			void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -5713,6 +5708,10 @@ int addrconf_sysctl_ignore_routes_with_linkdown(struct ctl_table *ctl,
 	return ret;
 }
 
+static int minus_one = -1;
+static const int one = 1;
+static const int two_five_five = 255;
+
 static const struct ctl_table addrconf_sysctl[] = {
 	{
 		.procname	= "forwarding",
@@ -5726,7 +5725,9 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.data		= &ipv6_devconf.hop_limit,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= addrconf_sysctl_hop_limit,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&one,
+		.extra2		= (void *)&two_five_five,
 	},
 	{
 		.procname	= "mtu",
@@ -5768,7 +5769,8 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.data		= &ipv6_devconf.rtr_solicits,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &minus_one,
 	},
 	{
 		.procname	= "router_solicitation_interval",
@@ -5778,6 +5780,13 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.proc_handler	= proc_dointvec_jiffies,
 	},
 	{
+		.procname	= "router_solicitation_max_interval",
+		.data		= &ipv6_devconf.rtr_solicit_max_interval,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{
 		.procname	= "router_solicitation_delay",
 		.data		= &ipv6_devconf.rtr_solicit_delay,
 		.maxlen		= sizeof(int),
@@ -6044,8 +6053,14 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 
 	for (i = 0; table[i].data; i++) {
 		table[i].data += (char *)p - (char *)&ipv6_devconf;
-		table[i].extra1 = idev; /* embedded; no ref */
-		table[i].extra2 = net;
+		/* If one of these is already set, then it is not safe to
+		 * overwrite either of them: this makes proc_dointvec_minmax
+		 * usable.
+		 */
+		if (!table[i].extra1 && !table[i].extra2) {
+			table[i].extra1 = idev; /* embedded; no ref */
+			table[i].extra2 = net;
+		}
 	}
 
 	snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);