1/*
  2 * Copyright(c) 2008 Hewlett-Packard Development Company, L.P.
  3 *
  4 * This program is free software; you can redistribute it and/or modify it
  5 * under the terms of the GNU General Public License as published by the
  6 * Free Software Foundation; either version 2 of the License, or
  7 * (at your option) any later version.
  8 *
  9 * This program is distributed in the hope that it will be useful, but
 10 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 11 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12 * for more details.
 13 *
 14 * You should have received a copy of the GNU General Public License along
 15 * with this program; if not, write to the Free Software Foundation, Inc.,
 16 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 17 *
 18 * The full GNU General Public License is included in this distribution in the
 19 * file called LICENSE.
 20 *
 21 */
 22
 23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 24
 25#include <linux/types.h>
 26#include <linux/if_vlan.h>
 27#include <net/ipv6.h>
 28#include <net/ndisc.h>
 29#include <net/addrconf.h>
 30#include <net/netns/generic.h>
 31#include "bonding.h"
 32
 33/*
 34 * Assign bond->master_ipv6 to the next IPv6 address in the list, or
 35 * zero it out if there are none.
 36 */
 37static void bond_glean_dev_ipv6(struct net_device *dev, struct in6_addr *addr)
 38{
 39	struct inet6_dev *idev;
 40
 41	if (!dev)
 42		return;
 43
 44	idev = in6_dev_get(dev);
 45	if (!idev)
 46		return;
 47
 48	read_lock_bh(&idev->lock);
 49	if (!list_empty(&idev->addr_list)) {
 50		struct inet6_ifaddr *ifa
 51			= list_first_entry(&idev->addr_list,
 52					   struct inet6_ifaddr, if_list);
 53		ipv6_addr_copy(addr, &ifa->addr);
 54	} else
 55		ipv6_addr_set(addr, 0, 0, 0, 0);
 56
 57	read_unlock_bh(&idev->lock);
 58
 59	in6_dev_put(idev);
 60}
 61
 62static void bond_na_send(struct net_device *slave_dev,
 63			 struct in6_addr *daddr,
 64			 int router,
 65			 unsigned short vlan_id)
 66{
 67	struct in6_addr mcaddr;
 68	struct icmp6hdr icmp6h = {
 69		.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 70	};
 71	struct sk_buff *skb;
 72
 73	icmp6h.icmp6_router = router;
 74	icmp6h.icmp6_solicited = 0;
 75	icmp6h.icmp6_override = 1;
 76
 77	addrconf_addr_solict_mult(daddr, &mcaddr);
 78
 79	pr_debug("ipv6 na on slave %s: dest %pI6, src %pI6\n",
 80		 slave_dev->name, &mcaddr, daddr);
 81
 82	skb = ndisc_build_skb(slave_dev, &mcaddr, daddr, &icmp6h, daddr,
 83			      ND_OPT_TARGET_LL_ADDR);
 84
 85	if (!skb) {
 86		pr_err("NA packet allocation failed\n");
 87		return;
 88	}
 89
 90	if (vlan_id) {
 91		/* The Ethernet header is not present yet, so it is
 92		 * too early to insert a VLAN tag.  Force use of an
 93		 * out-of-line tag here and let dev_hard_start_xmit()
 94		 * insert it if the slave hardware can't.
 95		 */
 96		skb = __vlan_hwaccel_put_tag(skb, vlan_id);
 97		if (!skb) {
 98			pr_err("failed to insert VLAN tag\n");
 99			return;
100		}
101	}
102
103	ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
104}
105
106/*
107 * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
108 * the bonding master.  This will help the switch learn our address
109 * if in active-backup mode.
110 *
111 * Caller must hold curr_slave_lock for read or better
112 */
113void bond_send_unsolicited_na(struct bonding *bond)
114{
115	struct slave *slave = bond->curr_active_slave;
116	struct vlan_entry *vlan;
117	struct inet6_dev *idev;
118	int is_router;
119
120	pr_debug("%s: bond %s slave %s\n", bond->dev->name,
121		 __func__, slave ? slave->dev->name : "NULL");
122
123	if (!slave || !bond->send_unsol_na ||
124	    test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
125		return;
126
127	bond->send_unsol_na--;
128
129	idev = in6_dev_get(bond->dev);
130	if (!idev)
131		return;
132
133	is_router = !!idev->cnf.forwarding;
134
135	in6_dev_put(idev);
136
137	if (!ipv6_addr_any(&bond->master_ipv6))
138		bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
139
140	list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
141		if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
142			bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
143				     vlan->vlan_id);
144		}
145	}
146}
147
148/*
149 * bond_inet6addr_event: handle inet6addr notifier chain events.
150 *
151 * We keep track of device IPv6 addresses primarily to use as source
152 * addresses in NS probes.
153 *
154 * We track one IPv6 for the main device (if it has one).
155 */
156static int bond_inet6addr_event(struct notifier_block *this,
157				unsigned long event,
158				void *ptr)
159{
160	struct inet6_ifaddr *ifa = ptr;
161	struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
162	struct bonding *bond;
163	struct vlan_entry *vlan;
164	struct bond_net *bn = net_generic(dev_net(event_dev), bond_net_id);
165
166	list_for_each_entry(bond, &bn->dev_list, bond_list) {
167		if (bond->dev == event_dev) {
168			switch (event) {
169			case NETDEV_UP:
170				if (ipv6_addr_any(&bond->master_ipv6))
171					ipv6_addr_copy(&bond->master_ipv6,
172						       &ifa->addr);
173				return NOTIFY_OK;
174			case NETDEV_DOWN:
175				if (ipv6_addr_equal(&bond->master_ipv6,
176						    &ifa->addr))
177					bond_glean_dev_ipv6(bond->dev,
178							    &bond->master_ipv6);
179				return NOTIFY_OK;
180			default:
181				return NOTIFY_DONE;
182			}
183		}
184
185		list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
186			rcu_read_lock();
187			vlan_dev = __vlan_find_dev_deep(bond->dev,
188							vlan->vlan_id);
189			rcu_read_unlock();
190			if (vlan_dev == event_dev) {
191				switch (event) {
192				case NETDEV_UP:
193					if (ipv6_addr_any(&vlan->vlan_ipv6))
194						ipv6_addr_copy(&vlan->vlan_ipv6,
195							       &ifa->addr);
196					return NOTIFY_OK;
197				case NETDEV_DOWN:
198					if (ipv6_addr_equal(&vlan->vlan_ipv6,
199							    &ifa->addr))
200						bond_glean_dev_ipv6(vlan_dev,
201								    &vlan->vlan_ipv6);
202					return NOTIFY_OK;
203				default:
204					return NOTIFY_DONE;
205				}
206			}
207		}
208	}
209	return NOTIFY_DONE;
210}
211
212static struct notifier_block bond_inet6addr_notifier = {
213	.notifier_call = bond_inet6addr_event,
214};
215
216void bond_register_ipv6_notifier(void)
217{
218	register_inet6addr_notifier(&bond_inet6addr_notifier);
219}
220
221void bond_unregister_ipv6_notifier(void)
222{
223	unregister_inet6addr_notifier(&bond_inet6addr_notifier);
224}
225