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