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