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 #include <linux/types.h>
  24 #include <linux/if_vlan.h>
  25 #include <net/ipv6.h>
  26 #include <net/ndisc.h>
  27 #include <net/addrconf.h>
  28 #include "bonding.h"
  29
  30 /*
  31  * Assign bond->master_ipv6 to the next IPv6 address in the list, or
  32  * zero it out if there are none.
  33  */
  34 static void bond_glean_dev_ipv6(struct net_device *dev, struct in6_addr *addr)
  35 {
  36         struct inet6_dev *idev;
  37         struct inet6_ifaddr *ifa;
  38
  39         if (!dev)
  40                 return;
  41
  42         idev = in6_dev_get(dev);
  43         if (!idev)
  44                 return;
  45
  46         read_lock_bh(&idev->lock);
  47         ifa = idev->addr_list;
  48         if (ifa)
  49                 ipv6_addr_copy(addr, &ifa->addr);
  50         else
  51                 ipv6_addr_set(addr, 0, 0, 0, 0);
  52
  53         read_unlock_bh(&idev->lock);
  54
  55         in6_dev_put(idev);
  56 }
  57
  58 static void bond_na_send(struct net_device *slave_dev,
  59                          struct in6_addr *daddr,
  60                          int router,
  61                          unsigned short vlan_id)
  62 {
  63         struct in6_addr mcaddr;
  64         struct icmp6hdr icmp6h = {
  65                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
  66         };
  67         struct sk_buff *skb;
  68
  69         icmp6h.icmp6_router = router;
  70         icmp6h.icmp6_solicited = 0;
  71         icmp6h.icmp6_override = 1;
  72
  73         addrconf_addr_solict_mult(daddr, &mcaddr);
  74
  75         pr_debug("ipv6 na on slave %s: dest %pI6, src %pI6\n",
  76                slave_dev->name, &mcaddr, daddr);
  77
  78         skb = ndisc_build_skb(slave_dev, &mcaddr, daddr, &icmp6h, daddr,
  79                               ND_OPT_TARGET_LL_ADDR);
  80
  81         if (!skb) {
  82                 pr_err(DRV_NAME ": NA packet allocation failed\n");
  83                 return;
  84         }
  85
  86         if (vlan_id) {
  87                 skb = vlan_put_tag(skb, vlan_id);
  88                 if (!skb) {
  89                         pr_err(DRV_NAME ": failed to insert VLAN tag\n");
  90                         return;
  91                 }
  92         }
  93
  94         ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
  95 }
  96
  97 /*
  98  * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
  99  * the bonding master.  This will help the switch learn our address
 100  * if in active-backup mode.
 101  *
 102  * Caller must hold curr_slave_lock for read or better
 103  */
 104 void bond_send_unsolicited_na(struct bonding *bond)
 105 {
 106         struct slave *slave = bond->curr_active_slave;
 107         struct vlan_entry *vlan;
 108         struct inet6_dev *idev;
 109         int is_router;
 110
 111         pr_debug("bond_send_unsol_na: bond %s slave %s\n", bond->dev->name,
 112                                 slave ? slave->dev->name : "NULL");
 113
 114         if (!slave || !bond->send_unsol_na ||
 115             test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 116                 return;
 117
 118         bond->send_unsol_na--;
 119
 120         idev = in6_dev_get(bond->dev);
 121         if (!idev)
 122                 return;
 123
 124         is_router = !!idev->cnf.forwarding;
 125
 126         in6_dev_put(idev);
 127
 128         if (!ipv6_addr_any(&bond->master_ipv6))
 129                 bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
 130
 131         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 132                 if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
 133                         bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
 134                                      vlan->vlan_id);
 135                 }
 136         }
 137 }
 138
 139 /*
 140  * bond_inet6addr_event: handle inet6addr notifier chain events.
 141  *
 142  * We keep track of device IPv6 addresses primarily to use as source
 143  * addresses in NS probes.
 144  *
 145  * We track one IPv6 for the main device (if it has one).
 146  */
 147 static int bond_inet6addr_event(struct notifier_block *this,
 148                                 unsigned long event,
 149                                 void *ptr)
 150 {
 151         struct inet6_ifaddr *ifa = ptr;
 152         struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
 153         struct bonding *bond;
 154         struct vlan_entry *vlan;
 155
 156         if (dev_net(event_dev) != &init_net)
 157                 return NOTIFY_DONE;
 158
 159         list_for_each_entry(bond, &bond_dev_list, bond_list) {
 160                 if (bond->dev == event_dev) {
 161                         switch (event) {
 162                         case NETDEV_UP:
 163                                 if (ipv6_addr_any(&bond->master_ipv6))
 164                                         ipv6_addr_copy(&bond->master_ipv6,
 165                                                        &ifa->addr);
 166                                 return NOTIFY_OK;
 167                         case NETDEV_DOWN:
 168                                 if (ipv6_addr_equal(&bond->master_ipv6,
 169                                                     &ifa->addr))
 170                                         bond_glean_dev_ipv6(bond->dev,
 171                                                             &bond->master_ipv6);
 172                                 return NOTIFY_OK;
 173                         default:
 174                                 return NOTIFY_DONE;
 175                         }
 176                 }
 177
 178                 list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 179                         vlan_dev = vlan_group_get_device(bond->vlgrp,
 180                                                          vlan->vlan_id);
 181                         if (vlan_dev == event_dev) {
 182                                 switch (event) {
 183                                 case NETDEV_UP:
 184                                         if (ipv6_addr_any(&vlan->vlan_ipv6))
 185                                                 ipv6_addr_copy(&vlan->vlan_ipv6,
 186                                                                &ifa->addr);
 187                                         return NOTIFY_OK;
 188                                 case NETDEV_DOWN:
 189                                         if (ipv6_addr_equal(&vlan->vlan_ipv6,
 190                                                             &ifa->addr))
 191                                                 bond_glean_dev_ipv6(vlan_dev,
 192                                                                     &vlan->vlan_ipv6);
 193                                         return NOTIFY_OK;
 194                                 default:
 195                                         return NOTIFY_DONE;
 196                                 }
 197                         }
 198                 }
 199         }
 200         return NOTIFY_DONE;
 201 }
 202
 203 static struct notifier_block bond_inet6addr_notifier = {
 204         .notifier_call = bond_inet6addr_event,
 205 };
 206
 207 void bond_register_ipv6_notifier(void)
 208 {
 209         register_inet6addr_notifier(&bond_inet6addr_notifier);
 210 }
 211
 212 void bond_unregister_ipv6_notifier(void)
 213 {
 214         unregister_inet6addr_notifier(&bond_inet6addr_notifier);
 215 }
 216