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         struct inet6_ifaddr *ifa;
  41
  42         if (!dev)
  43                 return;
  44
  45         idev = in6_dev_get(dev);
  46         if (!idev)
  47                 return;
  48
  49         read_lock_bh(&idev->lock);
  50         ifa = idev->addr_list;
  51         if (ifa)
  52                 ipv6_addr_copy(addr, &ifa->addr);
  53         else
  54                 ipv6_addr_set(addr, 0, 0, 0, 0);
  55
  56         read_unlock_bh(&idev->lock);
  57
  58         in6_dev_put(idev);
  59 }
  60
  61 static void bond_na_send(struct net_device *slave_dev,
  62                          struct in6_addr *daddr,
  63                          int router,
  64                          unsigned short vlan_id)
  65 {
  66         struct in6_addr mcaddr;
  67         struct icmp6hdr icmp6h = {
  68                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
  69         };
  70         struct sk_buff *skb;
  71
  72         icmp6h.icmp6_router = router;
  73         icmp6h.icmp6_solicited = 0;
  74         icmp6h.icmp6_override = 1;
  75
  76         addrconf_addr_solict_mult(daddr, &mcaddr);
  77
  78         pr_debug("ipv6 na on slave %s: dest %pI6, src %pI6\n",
  79                  slave_dev->name, &mcaddr, daddr);
  80
  81         skb = ndisc_build_skb(slave_dev, &mcaddr, daddr, &icmp6h, daddr,
  82                               ND_OPT_TARGET_LL_ADDR);
  83
  84         if (!skb) {
  85                 pr_err("NA packet allocation failed\n");
  86                 return;
  87         }
  88
  89         if (vlan_id) {
  90                 skb = vlan_put_tag(skb, vlan_id);
  91                 if (!skb) {
  92                         pr_err("failed to insert VLAN tag\n");
  93                         return;
  94                 }
  95         }
  96
  97         ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
  98 }
  99
 100 /*
 101  * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
 102  * the bonding master.  This will help the switch learn our address
 103  * if in active-backup mode.
 104  *
 105  * Caller must hold curr_slave_lock for read or better
 106  */
 107 void bond_send_unsolicited_na(struct bonding *bond)
 108 {
 109         struct slave *slave = bond->curr_active_slave;
 110         struct vlan_entry *vlan;
 111         struct inet6_dev *idev;
 112         int is_router;
 113
 114         pr_debug("%s: bond %s slave %s\n", bond->dev->name,
 115                  __func__, slave ? slave->dev->name : "NULL");
 116
 117         if (!slave || !bond->send_unsol_na ||
 118             test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 119                 return;
 120
 121         bond->send_unsol_na--;
 122
 123         idev = in6_dev_get(bond->dev);
 124         if (!idev)
 125                 return;
 126
 127         is_router = !!idev->cnf.forwarding;
 128
 129         in6_dev_put(idev);
 130
 131         if (!ipv6_addr_any(&bond->master_ipv6))
 132                 bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
 133
 134         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 135                 if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
 136                         bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
 137                                      vlan->vlan_id);
 138                 }
 139         }
 140 }
 141
 142 /*
 143  * bond_inet6addr_event: handle inet6addr notifier chain events.
 144  *
 145  * We keep track of device IPv6 addresses primarily to use as source
 146  * addresses in NS probes.
 147  *
 148  * We track one IPv6 for the main device (if it has one).
 149  */
 150 static int bond_inet6addr_event(struct notifier_block *this,
 151                                 unsigned long event,
 152                                 void *ptr)
 153 {
 154         struct inet6_ifaddr *ifa = ptr;
 155         struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
 156         struct bonding *bond;
 157         struct vlan_entry *vlan;
 158         struct bond_net *bn = net_generic(dev_net(event_dev), bond_net_id);
 159
 160         list_for_each_entry(bond, &bn->dev_list, bond_list) {
 161                 if (bond->dev == event_dev) {
 162                         switch (event) {
 163                         case NETDEV_UP:
 164                                 if (ipv6_addr_any(&bond->master_ipv6))
 165                                         ipv6_addr_copy(&bond->master_ipv6,
 166                                                        &ifa->addr);
 167                                 return NOTIFY_OK;
 168                         case NETDEV_DOWN:
 169                                 if (ipv6_addr_equal(&bond->master_ipv6,
 170                                                     &ifa->addr))
 171                                         bond_glean_dev_ipv6(bond->dev,
 172                                                             &bond->master_ipv6);
 173                                 return NOTIFY_OK;
 174                         default:
 175                                 return NOTIFY_DONE;
 176                         }
 177                 }
 178
 179                 list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 180                         vlan_dev = vlan_group_get_device(bond->vlgrp,
 181                                                          vlan->vlan_id);
 182                         if (vlan_dev == event_dev) {
 183                                 switch (event) {
 184                                 case NETDEV_UP:
 185                                         if (ipv6_addr_any(&vlan->vlan_ipv6))
 186                                                 ipv6_addr_copy(&vlan->vlan_ipv6,
 187                                                                &ifa->addr);
 188                                         return NOTIFY_OK;
 189                                 case NETDEV_DOWN:
 190                                         if (ipv6_addr_equal(&vlan->vlan_ipv6,
 191                                                             &ifa->addr))
 192                                                 bond_glean_dev_ipv6(vlan_dev,
 193                                                                     &vlan->vlan_ipv6);
 194                                         return NOTIFY_OK;
 195                                 default:
 196                                         return NOTIFY_DONE;
 197                                 }
 198                         }
 199                 }
 200         }
 201         return NOTIFY_DONE;
 202 }
 203
 204 static struct notifier_block bond_inet6addr_notifier = {
 205         .notifier_call = bond_inet6addr_event,
 206 };
 207
 208 void bond_register_ipv6_notifier(void)
 209 {
 210         register_inet6addr_notifier(&bond_inet6addr_notifier);
 211 }
 212
 213 void bond_unregister_ipv6_notifier(void)
 214 {
 215         unregister_inet6addr_notifier(&bond_inet6addr_notifier);
 216 }
 217