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 BONDING_DEBUG 1
  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 "bonding.h"
  31
  32 /*
  33  * Assign bond->master_ipv6 to the next IPv6 address in the list, or
  34  * zero it out if there are none.
  35  */
  36 static void bond_glean_dev_ipv6(struct net_device *dev, struct in6_addr *addr)
  37 {
  38         struct inet6_dev *idev;
  39         struct inet6_ifaddr *ifa;
  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         ifa = idev->addr_list;
  50         if (ifa)
  51                 ipv6_addr_copy(addr, &ifa->addr);
  52         else
  53                 ipv6_addr_set(addr, 0, 0, 0, 0);
  54
  55         read_unlock_bh(&idev->lock);
  56
  57         in6_dev_put(idev);
  58 }
  59
  60 static void bond_na_send(struct net_device *slave_dev,
  61                          struct in6_addr *daddr,
  62                          int router,
  63                          unsigned short vlan_id)
  64 {
  65         struct in6_addr mcaddr;
  66         struct icmp6hdr icmp6h = {
  67                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
  68         };
  69         struct sk_buff *skb;
  70
  71         icmp6h.icmp6_router = router;
  72         icmp6h.icmp6_solicited = 0;
  73         icmp6h.icmp6_override = 1;
  74
  75         addrconf_addr_solict_mult(daddr, &mcaddr);
  76
  77         dprintk("ipv6 na on slave %s: dest %pI6, src %pI6\n",
  78                slave->name, &mcaddr, daddr);
  79
  80         skb = ndisc_build_skb(slave_dev, &mcaddr, daddr, &icmp6h, daddr,
  81                               ND_OPT_TARGET_LL_ADDR);
  82
  83         if (!skb) {
  84                 printk(KERN_ERR DRV_NAME ": NA packet allocation failed\n");
  85                 return;
  86         }
  87
  88         if (vlan_id) {
  89                 skb = vlan_put_tag(skb, vlan_id);
  90                 if (!skb) {
  91                         printk(KERN_ERR DRV_NAME ": failed to insert VLAN tag\n");
  92                         return;
  93                 }
  94         }
  95
  96         ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
  97 }
  98
  99 /*
 100  * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
 101  * the bonding master.  This will help the switch learn our address
 102  * if in active-backup mode.
 103  *
 104  * Caller must hold curr_slave_lock for read or better
 105  */
 106 void bond_send_unsolicited_na(struct bonding *bond)
 107 {
 108         struct slave *slave = bond->curr_active_slave;
 109         struct vlan_entry *vlan;
 110         struct inet6_dev *idev;
 111         int is_router;
 112
 113         dprintk("bond_send_unsol_na: bond %s slave %s\n", bond->dev->name,
 114                                 slave ? slave->dev->name : "NULL");
 115
 116         if (!slave || !bond->send_unsol_na ||
 117             test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 118                 return;
 119
 120         bond->send_unsol_na--;
 121
 122         idev = in6_dev_get(bond->dev);
 123         if (!idev)
 124                 return;
 125
 126         is_router = !!idev->cnf.forwarding;
 127
 128         in6_dev_put(idev);
 129
 130         if (!ipv6_addr_any(&bond->master_ipv6))
 131                 bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
 132
 133         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 134                 if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
 135                         bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
 136                                      vlan->vlan_id);
 137                 }
 138         }
 139 }
 140
 141 /*
 142  * bond_inet6addr_event: handle inet6addr notifier chain events.
 143  *
 144  * We keep track of device IPv6 addresses primarily to use as source
 145  * addresses in NS probes.
 146  *
 147  * We track one IPv6 for the main device (if it has one).
 148  */
 149 static int bond_inet6addr_event(struct notifier_block *this,
 150                                 unsigned long event,
 151                                 void *ptr)
 152 {
 153         struct inet6_ifaddr *ifa = ptr;
 154         struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
 155         struct bonding *bond;
 156         struct vlan_entry *vlan;
 157
 158         if (dev_net(event_dev) != &init_net)
 159                 return NOTIFY_DONE;
 160
 161         list_for_each_entry(bond, &bond_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                         vlan_dev = vlan_group_get_device(bond->vlgrp,
 182                                                          vlan->vlan_id);
 183                         if (vlan_dev == event_dev) {
 184                                 switch (event) {
 185                                 case NETDEV_UP:
 186                                         if (ipv6_addr_any(&vlan->vlan_ipv6))
 187                                                 ipv6_addr_copy(&vlan->vlan_ipv6,
 188                                                                &ifa->addr);
 189                                         return NOTIFY_OK;
 190                                 case NETDEV_DOWN:
 191                                         if (ipv6_addr_equal(&vlan->vlan_ipv6,
 192                                                             &ifa->addr))
 193                                                 bond_glean_dev_ipv6(vlan_dev,
 194                                                                     &vlan->vlan_ipv6);
 195                                         return NOTIFY_OK;
 196                                 default:
 197                                         return NOTIFY_DONE;
 198                                 }
 199                         }
 200                 }
 201         }
 202         return NOTIFY_DONE;
 203 }
 204
 205 static struct notifier_block bond_inet6addr_notifier = {
 206         .notifier_call = bond_inet6addr_event,
 207 };
 208
 209 void bond_register_ipv6_notifier(void)
 210 {
 211         register_inet6addr_notifier(&bond_inet6addr_notifier);
 212 }
 213
 214 void bond_unregister_ipv6_notifier(void)
 215 {
 216         unregister_inet6addr_notifier(&bond_inet6addr_notifier);
 217 }
 218