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 /* called with RTNL or RCU */
 125 static int br_switchdev_event(struct notifier_block *unused,
 126                               unsigned long event, void *ptr)
 127 {
 128         struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
 129         struct net_bridge_port *p;
 130         struct net_bridge *br;
 131         struct switchdev_notifier_fdb_info *fdb_info;
 132         int err = NOTIFY_DONE;
 133
 134         p = br_port_get_rtnl_rcu(dev);
 135         if (!p)
 136                 goto out;
 137
 138         br = p->br;
 139
 140         switch (event) {
 141         case SWITCHDEV_FDB_ADD_TO_BRIDGE:
 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                 }
 149                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 150                                      fdb_info->vid);
 151                 break;
 152         case SWITCHDEV_FDB_DEL_TO_BRIDGE:
 153                 fdb_info = ptr;
 154                 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
 155                                                 fdb_info->vid);
 156                 if (err)
 157                         err = notifier_from_errno(err);
 158                 break;
 159         case SWITCHDEV_FDB_OFFLOADED:
 160                 fdb_info = ptr;
 161                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 162                                      fdb_info->vid);
 163                 break;
 164         }
 165
 166 out:
 167         return err;
 168 }
 169
 170 static struct notifier_block br_switchdev_notifier = {
 171         .notifier_call = br_switchdev_event,
 172 };
 173
 174 static void __net_exit br_net_exit(struct net *net)
 175 {
 176         struct net_device *dev;
 177         LIST_HEAD(list);
 178
 179         rtnl_lock();
 180         for_each_netdev(net, dev)
 181                 if (dev->priv_flags & IFF_EBRIDGE)
 182                         br_dev_delete(dev, &list);
 183
 184         unregister_netdevice_many(&list);
 185         rtnl_unlock();
 186
 187 }
 188
 189 static struct pernet_operations br_net_ops = {
 190         .exit   = br_net_exit,
 191 };
 192
 193 static const struct stp_proto br_stp_proto = {
 194         .rcv    = br_stp_rcv,
 195 };
 196
 197 static int __init br_init(void)
 198 {
 199         int err;
 200
 201         BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
 202
 203         err = stp_proto_register(&br_stp_proto);
 204         if (err < 0) {
 205                 pr_err("bridge: can't register sap for STP\n");
 206                 return err;
 207         }
 208
 209         err = br_fdb_init();
 210         if (err)
 211                 goto err_out;
 212
 213         err = register_pernet_subsys(&br_net_ops);
 214         if (err)
 215                 goto err_out1;
 216
 217         err = br_nf_core_init();
 218         if (err)
 219                 goto err_out2;
 220
 221         err = register_netdevice_notifier(&br_device_notifier);
 222         if (err)
 223                 goto err_out3;
 224
 225         err = register_switchdev_notifier(&br_switchdev_notifier);
 226         if (err)
 227                 goto err_out4;
 228
 229         err = br_netlink_init();
 230         if (err)
 231                 goto err_out5;
 232
 233         brioctl_set(br_ioctl_deviceless_stub);
 234
 235 #if IS_ENABLED(CONFIG_ATM_LANE)
 236         br_fdb_test_addr_hook = br_fdb_test_addr;
 237 #endif
 238
 239 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
 240         pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
 241                 "by default. Update your scripts to load br_netfilter if you "
 242                 "need this.\n");
 243 #endif
 244
 245         return 0;
 246
 247 err_out5:
 248         unregister_switchdev_notifier(&br_switchdev_notifier);
 249 err_out4:
 250         unregister_netdevice_notifier(&br_device_notifier);
 251 err_out3:
 252         br_nf_core_fini();
 253 err_out2:
 254         unregister_pernet_subsys(&br_net_ops);
 255 err_out1:
 256         br_fdb_fini();
 257 err_out:
 258         stp_proto_unregister(&br_stp_proto);
 259         return err;
 260 }
 261
 262 static void __exit br_deinit(void)
 263 {
 264         stp_proto_unregister(&br_stp_proto);
 265         br_netlink_fini();
 266         unregister_switchdev_notifier(&br_switchdev_notifier);
 267         unregister_netdevice_notifier(&br_device_notifier);
 268         brioctl_set(NULL);
 269         unregister_pernet_subsys(&br_net_ops);
 270
 271         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 272
 273         br_nf_core_fini();
 274 #if IS_ENABLED(CONFIG_ATM_LANE)
 275         br_fdb_test_addr_hook = NULL;
 276 #endif
 277         br_fdb_fini();
 278 }
 279
 280 module_init(br_init)
 281 module_exit(br_deinit)
 282 MODULE_LICENSE("GPL");
 283 MODULE_VERSION(BR_VERSION);
 284 MODULE_ALIAS_RTNL_LINK("bridge");