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         /* The Ethernet header is built in ndisc_send_skb(), not
  70          * ndisc_build_skb(), so we cannot insert a VLAN tag.  Only an
  71          * out-of-line tag inserted by the hardware will work.
  72          */
  73         if (vlan_id && !(slave_dev->features & NETIF_F_HW_VLAN_TX))
  74                 return;
  75
  76         icmp6h.icmp6_router = router;
  77         icmp6h.icmp6_solicited = 0;
  78         icmp6h.icmp6_override = 1;
  79
  80         addrconf_addr_solict_mult(daddr, &mcaddr);
  81
  82         pr_debug("ipv6 na on slave %s: dest %pI6, src %pI6\n",
  83                slave_dev->name, &mcaddr, daddr);
  84
  85         skb = ndisc_build_skb(slave_dev, &mcaddr, daddr, &icmp6h, daddr,
  86                               ND_OPT_TARGET_LL_ADDR);
  87
  88         if (!skb) {
  89                 pr_err(DRV_NAME ": NA packet allocation failed\n");
  90                 return;
  91         }
  92
  93         if (vlan_id) {
  94                 skb = __vlan_hwaccel_put_tag(skb, vlan_id);
  95                 if (!skb) {
  96                         pr_err(DRV_NAME ": failed to insert VLAN tag\n");
  97                         return;
  98                 }
  99         }
 100
 101         ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
 102 }
 103
 104 /*
 105  * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
 106  * the bonding master.  This will help the switch learn our address
 107  * if in active-backup mode.
 108  *
 109  * Caller must hold curr_slave_lock for read or better
 110  */
 111 void bond_send_unsolicited_na(struct bonding *bond)
 112 {
 113         struct slave *slave = bond->curr_active_slave;
 114         struct vlan_entry *vlan;
 115         struct inet6_dev *idev;
 116         int is_router;
 117
 118         pr_debug("bond_send_unsol_na: bond %s slave %s\n", bond->dev->name,
 119                                 slave ? slave->dev->name : "NULL");
 120
 121         if (!slave || !bond->send_unsol_na ||
 122             test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 123                 return;
 124
 125         bond->send_unsol_na--;
 126
 127         idev = in6_dev_get(bond->dev);
 128         if (!idev)
 129                 return;
 130
 131         is_router = !!idev->cnf.forwarding;
 132
 133         in6_dev_put(idev);
 134
 135         if (!ipv6_addr_any(&bond->master_ipv6))
 136                 bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
 137
 138         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 139                 if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
 140                         bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
 141                                      vlan->vlan_id);
 142                 }
 143         }
 144 }
 145
 146 /*
 147  * bond_inet6addr_event: handle inet6addr notifier chain events.
 148  *
 149  * We keep track of device IPv6 addresses primarily to use as source
 150  * addresses in NS probes.
 151  *
 152  * We track one IPv6 for the main device (if it has one).
 153  */
 154 static int bond_inet6addr_event(struct notifier_block *this,
 155                                 unsigned long event,
 156                                 void *ptr)
 157 {
 158         struct inet6_ifaddr *ifa = ptr;
 159         struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
 160         struct bonding *bond;
 161         struct vlan_entry *vlan;
 162
 163         if (dev_net(event_dev) != &init_net)
 164                 return NOTIFY_DONE;
 165
 166         list_for_each_entry(bond, &bond_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                         vlan_dev = vlan_group_get_device(bond->vlgrp,
 187                                                          vlan->vlan_id);
 188                         if (vlan_dev == event_dev) {
 189                                 switch (event) {
 190                                 case NETDEV_UP:
 191                                         if (ipv6_addr_any(&vlan->vlan_ipv6))
 192                                                 ipv6_addr_copy(&vlan->vlan_ipv6,
 193                                                                &ifa->addr);
 194                                         return NOTIFY_OK;
 195                                 case NETDEV_DOWN:
 196                                         if (ipv6_addr_equal(&vlan->vlan_ipv6,
 197                                                             &ifa->addr))
 198                                                 bond_glean_dev_ipv6(vlan_dev,
 199                                                                     &vlan->vlan_ipv6);
 200                                         return NOTIFY_OK;
 201                                 default:
 202                                         return NOTIFY_DONE;
 203                                 }
 204                         }
 205                 }
 206         }
 207         return NOTIFY_DONE;
 208 }
 209
 210 static struct notifier_block bond_inet6addr_notifier = {
 211         .notifier_call = bond_inet6addr_event,
 212 };
 213
 214 void bond_register_ipv6_notifier(void)
 215 {
 216         register_inet6addr_notifier(&bond_inet6addr_notifier);
 217 }
 218
 219 void bond_unregister_ipv6_notifier(void)
 220 {
 221         unregister_inet6addr_notifier(&bond_inet6addr_notifier);
 222 }
 223