net: ipv6: Make address flushing on ifdown optional (f1705ec1) · Commits · 戴 / test

Documentation/networking/ip-sysctl.txt

+9 −0

Original line number	Diff line number	Diff line
		@@ -1563,6 +1563,15 @@ temp_prefered_lft - INTEGER
		Preferred lifetime (in seconds) for temporary addresses.
		Default: 86400 (1 day)

		keep_addr_on_down - INTEGER
		Keep all IPv6 addresses on an interface down event. If set static
		global addresses with no expiration time are not flushed.
		>0 : enabled
		0 : system default
		<0 : disabled

		Default: 0 (addresses are removed)

		max_desync_factor - INTEGER
		Maximum value for DESYNC_FACTOR, which is a random value
		that ensures that clients don't synchronize with each

include/linux/ipv6.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -62,6 +62,7 @@ struct ipv6_devconf {
		struct in6_addr secret;
		} stable_secret;
		__s32 use_oif_addrs_only;
		__s32 keep_addr_on_down;
		void *sysctl;
		};

include/uapi/linux/ipv6.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -176,6 +176,7 @@ enum {
		DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN,
		DEVCONF_DROP_UNICAST_IN_L2_MULTICAST,
		DEVCONF_DROP_UNSOLICITED_NA,
		DEVCONF_KEEP_ADDR_ON_DOWN,
		DEVCONF_MAX
		};

net/ipv6/addrconf.c

+121 −15

Original line number	Diff line number	Diff line
		@@ -216,6 +216,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
		},
		.use_oif_addrs_only = 0,
		.ignore_routes_with_linkdown = 0,
		.keep_addr_on_down = 0,
		};

		static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
		@@ -260,6 +261,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
		},
		.use_oif_addrs_only = 0,
		.ignore_routes_with_linkdown = 0,
		.keep_addr_on_down = 0,
		};

		/* Check if a valid qdisc is available */
		@@ -3168,6 +3170,55 @@ static void addrconf_gre_config(struct net_device *dev)
		}
		#endif

		static int fixup_permanent_addr(struct inet6_dev *idev,
		struct inet6_ifaddr *ifp)
		{
		if (!ifp->rt) {
		struct rt6_info *rt;

		rt = addrconf_dst_alloc(idev, &ifp->addr, false);
		if (unlikely(IS_ERR(rt)))
		return PTR_ERR(rt);

		ifp->rt = rt;
		}

		if (!(ifp->flags & IFA_F_NOPREFIXROUTE)) {
		addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
		idev->dev, 0, 0);
		}

		addrconf_dad_start(ifp);

		return 0;
		}

		static void addrconf_permanent_addr(struct net_device *dev)
		{
		struct inet6_ifaddr ifp, tmp;
		struct inet6_dev *idev;

		idev = __in6_dev_get(dev);
		if (!idev)
		return;

		write_lock_bh(&idev->lock);

		list_for_each_entry_safe(ifp, tmp, &idev->addr_list, if_list) {
		if ((ifp->flags & IFA_F_PERMANENT) &&
		fixup_permanent_addr(idev, ifp) < 0) {
		write_unlock_bh(&idev->lock);
		ipv6_del_addr(ifp);
		write_lock_bh(&idev->lock);

		net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n",
		idev->dev->name, &ifp->addr);
		}
		}

		write_unlock_bh(&idev->lock);
		}

		static int addrconf_notify(struct notifier_block *this, unsigned long event,
		void *ptr)
		{
		@@ -3253,6 +3304,9 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event,
		run_pending = 1;
		}

		/* restore routes for permanent addresses */
		addrconf_permanent_addr(dev);

		switch (dev->type) {
		#if IS_ENABLED(CONFIG_IPV6_SIT)
		case ARPHRD_SIT:
		@@ -3356,7 +3410,10 @@ static int addrconf_ifdown(struct net_device *dev, int how)
		{
		struct net *net = dev_net(dev);
		struct inet6_dev *idev;
		struct inet6_ifaddr *ifa;
		struct inet6_ifaddr ifa, tmp;
		struct list_head del_list;
		int _keep_addr;
		bool keep_addr;
		int state, i;

		ASSERT_RTNL();
		@@ -3383,6 +3440,16 @@ static int addrconf_ifdown(struct net_device *dev, int how)

		}

		/* aggregate the system setting and interface setting */
		_keep_addr = net->ipv6.devconf_all->keep_addr_on_down;
		if (!_keep_addr)
		_keep_addr = idev->cnf.keep_addr_on_down;

		/* combine the user config with event to determine if permanent
		* addresses are to be removed from address hash table
		*/
		keep_addr = !(how \|\| _keep_addr <= 0);

		/* Step 2: clear hash table */
		for (i = 0; i < IN6_ADDR_HSIZE; i++) {
		struct hlist_head *h = &inet6_addr_lst[i];
		@@ -3391,11 +3458,17 @@ static int addrconf_ifdown(struct net_device *dev, int how)
		restart:
		hlist_for_each_entry_rcu(ifa, h, addr_lst) {
		if (ifa->idev == idev) {
		hlist_del_init_rcu(&ifa->addr_lst);
		addrconf_del_dad_work(ifa);
		/* combined flag + permanent flag decide if
		* address is retained on a down event
		*/
		if (!keep_addr \|\|
		!(ifa->flags & IFA_F_PERMANENT)) {
		hlist_del_init_rcu(&ifa->addr_lst);
		goto restart;
		}
		}
		}
		spin_unlock_bh(&addrconf_hash_lock);
		}

		@@ -3427,31 +3500,53 @@ restart:
		write_lock_bh(&idev->lock);
		}

		while (!list_empty(&idev->addr_list)) {
		ifa = list_first_entry(&idev->addr_list,
		struct inet6_ifaddr, if_list);
		addrconf_del_dad_work(ifa);
		/* re-combine the user config with event to determine if permanent
		* addresses are to be removed from the interface list
		*/
		keep_addr = (!how && _keep_addr > 0);

		list_del(&ifa->if_list);
		INIT_LIST_HEAD(&del_list);
		list_for_each_entry_safe(ifa, tmp, &idev->addr_list, if_list) {
		addrconf_del_dad_work(ifa);

		write_unlock_bh(&idev->lock);

		spin_lock_bh(&ifa->lock);

		if (keep_addr && (ifa->flags & IFA_F_PERMANENT)) {
		/* set state to skip the notifier below */
		state = INET6_IFADDR_STATE_DEAD;
		ifa->state = 0;
		if (!(ifa->flags & IFA_F_NODAD))
		ifa->flags \|= IFA_F_TENTATIVE;
		} else {
		state = ifa->state;
		ifa->state = INET6_IFADDR_STATE_DEAD;

		list_del(&ifa->if_list);
		list_add(&ifa->if_list, &del_list);
		}

		spin_unlock_bh(&ifa->lock);

		if (state != INET6_IFADDR_STATE_DEAD) {
		__ipv6_ifa_notify(RTM_DELADDR, ifa);
		inet6addr_notifier_call_chain(NETDEV_DOWN, ifa);
		}
		in6_ifa_put(ifa);

		write_lock_bh(&idev->lock);
		}

		write_unlock_bh(&idev->lock);

		/* now clean up addresses to be removed */
		while (!list_empty(&del_list)) {
		ifa = list_first_entry(&del_list,
		struct inet6_ifaddr, if_list);
		list_del(&ifa->if_list);

		in6_ifa_put(ifa);
		}

		/* Step 5: Discard anycast and multicast list */
		if (how) {
		ipv6_ac_destroy_dev(idev);
		@@ -4716,6 +4811,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
		array[DEVCONF_USE_OIF_ADDRS_ONLY] = cnf->use_oif_addrs_only;
		array[DEVCONF_DROP_UNICAST_IN_L2_MULTICAST] = cnf->drop_unicast_in_l2_multicast;
		array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na;
		array[DEVCONF_KEEP_ADDR_ON_DOWN] = cnf->keep_addr_on_down;
		}

		static inline size_t inet6_ifla6_size(void)
		@@ -5197,10 +5293,12 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
		if (rt)
		ip6_del_rt(rt);
		}
		if (ifp->rt) {
		dst_hold(&ifp->rt->dst);

		ip6_del_rt(ifp->rt);

		ifp->rt = NULL;
		}
		rt_genid_bump_ipv6(net);
		break;
		}
		@@ -5803,6 +5901,14 @@ static struct addrconf_sysctl_table
		.mode = 0644,
		.proc_handler = proc_dointvec,
		},
		{
		.procname = "keep_addr_on_down",
		.data = &ipv6_devconf.keep_addr_on_down,
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = proc_dointvec,

		},
		{
		/* sentinel */
		}

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