bonding: fix bond_inet6addr_event()
[linux-2.6.git] / drivers / net / bonding / bond_ipv6.c
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  */
37 static 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
62 static 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                 skb = vlan_put_tag(skb, vlan_id);
92                 if (!skb) {
93                         pr_err("failed to insert VLAN tag\n");
94                         return;
95                 }
96         }
97
98         ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
99 }
100
101 /*
102  * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
103  * the bonding master.  This will help the switch learn our address
104  * if in active-backup mode.
105  *
106  * Caller must hold curr_slave_lock for read or better
107  */
108 void bond_send_unsolicited_na(struct bonding *bond)
109 {
110         struct slave *slave = bond->curr_active_slave;
111         struct vlan_entry *vlan;
112         struct inet6_dev *idev;
113         int is_router;
114
115         pr_debug("%s: bond %s slave %s\n", bond->dev->name,
116                  __func__, slave ? slave->dev->name : "NULL");
117
118         if (!slave || !bond->send_unsol_na ||
119             test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
120                 return;
121
122         bond->send_unsol_na--;
123
124         idev = in6_dev_get(bond->dev);
125         if (!idev)
126                 return;
127
128         is_router = !!idev->cnf.forwarding;
129
130         in6_dev_put(idev);
131
132         if (!ipv6_addr_any(&bond->master_ipv6))
133                 bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
134
135         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
136                 if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
137                         bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
138                                      vlan->vlan_id);
139                 }
140         }
141 }
142
143 /*
144  * bond_inet6addr_event: handle inet6addr notifier chain events.
145  *
146  * We keep track of device IPv6 addresses primarily to use as source
147  * addresses in NS probes.
148  *
149  * We track one IPv6 for the main device (if it has one).
150  */
151 static int bond_inet6addr_event(struct notifier_block *this,
152                                 unsigned long event,
153                                 void *ptr)
154 {
155         struct inet6_ifaddr *ifa = ptr;
156         struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
157         struct bonding *bond;
158         struct vlan_entry *vlan;
159         struct bond_net *bn = net_generic(dev_net(event_dev), bond_net_id);
160
161         list_for_each_entry(bond, &bn->dev_list, bond_list) {
162                 if (bond->dev == event_dev) {
163                         switch (event) {
164                         case NETDEV_UP:
165                                 if (ipv6_addr_any(&bond->master_ipv6))
166                                         ipv6_addr_copy(&bond->master_ipv6,
167                                                        &ifa->addr);
168                                 return NOTIFY_OK;
169                         case NETDEV_DOWN:
170                                 if (ipv6_addr_equal(&bond->master_ipv6,
171                                                     &ifa->addr))
172                                         bond_glean_dev_ipv6(bond->dev,
173                                                             &bond->master_ipv6);
174                                 return NOTIFY_OK;
175                         default:
176                                 return NOTIFY_DONE;
177                         }
178                 }
179
180                 list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
181                         if (!bond->vlgrp)
182                                 continue;
183                         vlan_dev = vlan_group_get_device(bond->vlgrp,
184                                                          vlan->vlan_id);
185                         if (vlan_dev == event_dev) {
186                                 switch (event) {
187                                 case NETDEV_UP:
188                                         if (ipv6_addr_any(&vlan->vlan_ipv6))
189                                                 ipv6_addr_copy(&vlan->vlan_ipv6,
190                                                                &ifa->addr);
191                                         return NOTIFY_OK;
192                                 case NETDEV_DOWN:
193                                         if (ipv6_addr_equal(&vlan->vlan_ipv6,
194                                                             &ifa->addr))
195                                                 bond_glean_dev_ipv6(vlan_dev,
196                                                                     &vlan->vlan_ipv6);
197                                         return NOTIFY_OK;
198                                 default:
199                                         return NOTIFY_DONE;
200                                 }
201                         }
202                 }
203         }
204         return NOTIFY_DONE;
205 }
206
207 static struct notifier_block bond_inet6addr_notifier = {
208         .notifier_call = bond_inet6addr_event,
209 };
210
211 void bond_register_ipv6_notifier(void)
212 {
213         register_inet6addr_notifier(&bond_inet6addr_notifier);
214 }
215
216 void bond_unregister_ipv6_notifier(void)
217 {
218         unregister_inet6addr_notifier(&bond_inet6addr_notifier);
219 }
220