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                 /* The Ethernet header is not present yet, so it is
  92                  * too early to insert a VLAN tag.  Force use of an
  93                  * out-of-line tag here and let dev_hard_start_xmit()
  94                  * insert it if the slave hardware can't.
  95                  */
  96                 skb = __vlan_hwaccel_put_tag(skb, vlan_id);
  97                 if (!skb) {
  98                         pr_err("failed to insert VLAN tag\n");
  99                         return;
 100                 }
 101         }
 102
 103         ndisc_send_skb(skb, slave_dev, NULL, &mcaddr, daddr, &icmp6h);
 104 }
 105
 106 /*
 107  * Kick out an unsolicited Neighbor Advertisement for an IPv6 address on
 108  * the bonding master.  This will help the switch learn our address
 109  * if in active-backup mode.
 110  *
 111  * Caller must hold curr_slave_lock for read or better
 112  */
 113 void bond_send_unsolicited_na(struct bonding *bond)
 114 {
 115         struct slave *slave = bond->curr_active_slave;
 116         struct vlan_entry *vlan;
 117         struct inet6_dev *idev;
 118         int is_router;
 119
 120         pr_debug("%s: bond %s slave %s\n", bond->dev->name,
 121                  __func__, slave ? slave->dev->name : "NULL");
 122
 123         if (!slave || !bond->send_unsol_na ||
 124             test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 125                 return;
 126
 127         bond->send_unsol_na--;
 128
 129         idev = in6_dev_get(bond->dev);
 130         if (!idev)
 131                 return;
 132
 133         is_router = !!idev->cnf.forwarding;
 134
 135         in6_dev_put(idev);
 136
 137         if (!ipv6_addr_any(&bond->master_ipv6))
 138                 bond_na_send(slave->dev, &bond->master_ipv6, is_router, 0);
 139
 140         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
 141                 if (!ipv6_addr_any(&vlan->vlan_ipv6)) {
 142                         bond_na_send(slave->dev, &vlan->vlan_ipv6, is_router,
 143                                      vlan->vlan_id);
 144                 }
 145         }
 146 }
 147
 148 /*
 149  * bond_inet6addr_event: handle inet6addr notifier chain events.
 150  *
 151  * We keep track of device IPv6 addresses primarily to use as source
 152  * addresses in NS probes.
 153  *
 154  * We track one IPv6 for the main device (if it has one).
 155  */
 156 static int bond_inet6addr_event(struct notifier_block *this,
 157                                 unsigned long event,
 158                                 void *ptr)
 159 {
 160         struct inet6_ifaddr *ifa = ptr;
 161         struct net_device *vlan_dev, *event_dev = ifa->idev->dev;
 162         struct bonding *bond;
 163         struct vlan_entry *vlan;
 164         struct bond_net *bn = net_generic(dev_net(event_dev), bond_net_id);
 165
 166         list_for_each_entry(bond, &bn->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                         rcu_read_lock();
 187                         vlan_dev = __vlan_find_dev_deep(bond->dev,
 188                                                         vlan->vlan_id);
 189                         rcu_read_unlock();
 190                         if (vlan_dev == event_dev) {
 191                                 switch (event) {
 192                                 case NETDEV_UP:
 193                                         if (ipv6_addr_any(&vlan->vlan_ipv6))
 194                                                 ipv6_addr_copy(&vlan->vlan_ipv6,
 195                                                                &ifa->addr);
 196                                         return NOTIFY_OK;
 197                                 case NETDEV_DOWN:
 198                                         if (ipv6_addr_equal(&vlan->vlan_ipv6,
 199                                                             &ifa->addr))
 200                                                 bond_glean_dev_ipv6(vlan_dev,
 201                                                                     &vlan->vlan_ipv6);
 202                                         return NOTIFY_OK;
 203                                 default:
 204                                         return NOTIFY_DONE;
 205                                 }
 206                         }
 207                 }
 208         }
 209         return NOTIFY_DONE;
 210 }
 211
 212 static struct notifier_block bond_inet6addr_notifier = {
 213         .notifier_call = bond_inet6addr_event,
 214 };
 215
 216 void bond_register_ipv6_notifier(void)
 217 {
 218         register_inet6addr_notifier(&bond_inet6addr_notifier);
 219 }
 220
 221 void bond_unregister_ipv6_notifier(void)
 222 {
 223         unregister_inet6addr_notifier(&bond_inet6addr_notifier);
 224 }
 225