kernel/net/bridge/br.c

   1 /*
   2  *      Generic parts
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/init.h>
  19 #include <linux/llc.h>
  20 #include <net/llc.h>
  21 #include <net/stp.h>
  22 #include <net/switchdev.h>
  23
  24 #include "br_private.h"
  25
  26 /*
  27  * Handle changes in state of network devices enslaved to a bridge.
  28  *
  29  * Note: don't care about up/down if bridge itself is down, because
  30  *     port state is checked when bridge is brought up.
  31  */
  32 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
  33 {
  34         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
  35         struct net_bridge_port *p;
  36         struct net_bridge *br;
  37         bool changed_addr;
  38         int err;
  39
  40         /* register of bridge completed, add sysfs entries */
  41         if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
  42                 br_sysfs_addbr(dev);
  43                 return NOTIFY_DONE;
  44         }
  45
  46         /* not a port of a bridge */
  47         p = br_port_get_rtnl(dev);
  48         if (!p)
  49                 return NOTIFY_DONE;
  50
  51         br = p->br;
  52
  53         switch (event) {
  54         case NETDEV_CHANGEMTU:
  55                 dev_set_mtu(br->dev, br_min_mtu(br));
  56                 break;
  57
  58         case NETDEV_CHANGEADDR:
  59                 spin_lock_bh(&br->lock);
  60                 br_fdb_changeaddr(p, dev->dev_addr);
  61                 changed_addr = br_stp_recalculate_bridge_id(br);
  62                 spin_unlock_bh(&br->lock);
  63
  64                 if (changed_addr)
  65                         call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
  66
  67                 break;
  68
  69         case NETDEV_CHANGE:
  70                 br_port_carrier_check(p);
  71                 break;
  72
  73         case NETDEV_FEAT_CHANGE:
  74                 netdev_update_features(br->dev);
  75                 break;
  76
  77         case NETDEV_DOWN:
  78                 spin_lock_bh(&br->lock);
  79                 if (br->dev->flags & IFF_UP)
  80                         br_stp_disable_port(p);
  81                 spin_unlock_bh(&br->lock);
  82                 break;
  83
  84         case NETDEV_UP:
  85                 if (netif_running(br->dev) && netif_oper_up(dev)) {
  86                         spin_lock_bh(&br->lock);
  87                         br_stp_enable_port(p);
  88                         spin_unlock_bh(&br->lock);
  89                 }
  90                 break;
  91
  92         case NETDEV_UNREGISTER:
  93                 br_del_if(br, dev);
  94                 break;
  95
  96         case NETDEV_CHANGENAME:
  97                 err = br_sysfs_renameif(p);
  98                 if (err)
  99                         return notifier_from_errno(err);
 100                 break;
 101
 102         case NETDEV_PRE_TYPE_CHANGE:
 103                 /* Forbid underlaying device to change its type. */
 104                 return NOTIFY_BAD;
 105
 106         case NETDEV_RESEND_IGMP:
 107                 /* Propagate to master device */
 108                 call_netdevice_notifiers(event, br->dev);
 109                 break;
 110         }
 111
 112         /* Events that may cause spanning tree to refresh */
 113         if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 114             event == NETDEV_CHANGE || event == NETDEV_DOWN)
 115                 br_ifinfo_notify(RTM_NEWLINK, p);
 116
 117         return NOTIFY_DONE;
 118 }
 119
 120 static struct notifier_block br_device_notifier = {
 121         .notifier_call = br_device_event
 122 };
 123
 124 static int br_netdev_switch_event(struct notifier_block *unused,
 125                                   unsigned long event, void *ptr)
 126 {
 127         struct net_device *dev = netdev_switch_notifier_info_to_dev(ptr);
 128         struct net_bridge_port *p;
 129         struct net_bridge *br;
 130         struct netdev_switch_notifier_fdb_info *fdb_info;
 131         int err = NOTIFY_DONE;
 132
 133         rtnl_lock();
 134         p = br_port_get_rtnl(dev);
 135         if (!p)
 136                 goto out;
 137
 138         br = p->br;
 139
 140         switch (event) {
 141         case NETDEV_SWITCH_FDB_ADD:
 142                 fdb_info = ptr;
 143                 err = br_fdb_external_learn_add(br, p, fdb_info->addr,
 144                                                 fdb_info->vid);
 145                 if (err)
 146                         err = notifier_from_errno(err);
 147                 break;
 148         case NETDEV_SWITCH_FDB_DEL:
 149                 fdb_info = ptr;
 150                 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
 151                                                 fdb_info->vid);
 152                 if (err)
 153                         err = notifier_from_errno(err);
 154                 break;
 155         }
 156
 157 out:
 158         rtnl_unlock();
 159         return err;
 160 }
 161
 162 static struct notifier_block br_netdev_switch_notifier = {
 163         .notifier_call = br_netdev_switch_event,
 164 };
 165
 166 static void __net_exit br_net_exit(struct net *net)
 167 {
 168         struct net_device *dev;
 169         LIST_HEAD(list);
 170
 171         rtnl_lock();
 172         for_each_netdev(net, dev)
 173                 if (dev->priv_flags & IFF_EBRIDGE)
 174                         br_dev_delete(dev, &list);
 175
 176         unregister_netdevice_many(&list);
 177         rtnl_unlock();
 178
 179 }
 180
 181 static struct pernet_operations br_net_ops = {
 182         .exit   = br_net_exit,
 183 };
 184
 185 static const struct stp_proto br_stp_proto = {
 186         .rcv    = br_stp_rcv,
 187 };
 188
 189 static int __init br_init(void)
 190 {
 191         int err;
 192
 193         BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
 194
 195         err = stp_proto_register(&br_stp_proto);
 196         if (err < 0) {
 197                 pr_err("bridge: can't register sap for STP\n");
 198                 return err;
 199         }
 200
 201         err = br_fdb_init();
 202         if (err)
 203                 goto err_out;
 204
 205         err = register_pernet_subsys(&br_net_ops);
 206         if (err)
 207                 goto err_out1;
 208
 209         err = br_nf_core_init();
 210         if (err)
 211                 goto err_out2;
 212
 213         err = register_netdevice_notifier(&br_device_notifier);
 214         if (err)
 215                 goto err_out3;
 216
 217         err = register_netdev_switch_notifier(&br_netdev_switch_notifier);
 218         if (err)
 219                 goto err_out4;
 220
 221         err = br_netlink_init();
 222         if (err)
 223                 goto err_out5;
 224
 225         brioctl_set(br_ioctl_deviceless_stub);
 226
 227 #if IS_ENABLED(CONFIG_ATM_LANE)
 228         br_fdb_test_addr_hook = br_fdb_test_addr;
 229 #endif
 230
 231         pr_info("bridge: automatic filtering via arp/ip/ip6tables has been "
 232                 "deprecated. Update your scripts to load br_netfilter if you "
 233                 "need this.\n");
 234
 235         return 0;
 236
 237 err_out5:
 238         unregister_netdev_switch_notifier(&br_netdev_switch_notifier);
 239 err_out4:
 240         unregister_netdevice_notifier(&br_device_notifier);
 241 err_out3:
 242         br_nf_core_fini();
 243 err_out2:
 244         unregister_pernet_subsys(&br_net_ops);
 245 err_out1:
 246         br_fdb_fini();
 247 err_out:
 248         stp_proto_unregister(&br_stp_proto);
 249         return err;
 250 }
 251
 252 static void __exit br_deinit(void)
 253 {
 254         stp_proto_unregister(&br_stp_proto);
 255         br_netlink_fini();
 256         unregister_netdev_switch_notifier(&br_netdev_switch_notifier);
 257         unregister_netdevice_notifier(&br_device_notifier);
 258         brioctl_set(NULL);
 259         unregister_pernet_subsys(&br_net_ops);
 260
 261         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 262
 263         br_nf_core_fini();
 264 #if IS_ENABLED(CONFIG_ATM_LANE)
 265         br_fdb_test_addr_hook = NULL;
 266 #endif
 267         br_fdb_fini();
 268 }
 269
 270 module_init(br_init)
 271 module_exit(br_deinit)
 272 MODULE_LICENSE("GPL");
 273 MODULE_VERSION(BR_VERSION);
 274 MODULE_ALIAS_RTNL_LINK("bridge");