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
  23 #include "br_private.h"
  24
  25 /*
  26  * Handle changes in state of network devices enslaved to a bridge.
  27  *
  28  * Note: don't care about up/down if bridge itself is down, because
  29  *     port state is checked when bridge is brought up.
  30  */
  31 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
  32 {
  33         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
  34         struct net_bridge_port *p;
  35         struct net_bridge *br;
  36         bool changed_addr;
  37         int err;
  38
  39         /* register of bridge completed, add sysfs entries */
  40         if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
  41                 br_sysfs_addbr(dev);
  42                 return NOTIFY_DONE;
  43         }
  44
  45         /* not a port of a bridge */
  46         p = br_port_get_rtnl(dev);
  47         if (!p)
  48                 return NOTIFY_DONE;
  49
  50         br = p->br;
  51
  52         switch (event) {
  53         case NETDEV_CHANGEMTU:
  54                 dev_set_mtu(br->dev, br_min_mtu(br));
  55                 break;
  56
  57         case NETDEV_CHANGEADDR:
  58                 spin_lock_bh(&br->lock);
  59                 br_fdb_changeaddr(p, dev->dev_addr);
  60                 changed_addr = br_stp_recalculate_bridge_id(br);
  61                 spin_unlock_bh(&br->lock);
  62
  63                 if (changed_addr)
  64                         call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
  65
  66                 break;
  67
  68         case NETDEV_CHANGE:
  69                 br_port_carrier_check(p);
  70                 break;
  71
  72         case NETDEV_FEAT_CHANGE:
  73                 netdev_update_features(br->dev);
  74                 break;
  75
  76         case NETDEV_DOWN:
  77                 spin_lock_bh(&br->lock);
  78                 if (br->dev->flags & IFF_UP)
  79                         br_stp_disable_port(p);
  80                 spin_unlock_bh(&br->lock);
  81                 break;
  82
  83         case NETDEV_UP:
  84                 if (netif_running(br->dev) && netif_oper_up(dev)) {
  85                         spin_lock_bh(&br->lock);
  86                         br_stp_enable_port(p);
  87                         spin_unlock_bh(&br->lock);
  88                 }
  89                 break;
  90
  91         case NETDEV_UNREGISTER:
  92                 br_del_if(br, dev);
  93                 break;
  94
  95         case NETDEV_CHANGENAME:
  96                 err = br_sysfs_renameif(p);
  97                 if (err)
  98                         return notifier_from_errno(err);
  99                 break;
 100
 101         case NETDEV_PRE_TYPE_CHANGE:
 102                 /* Forbid underlaying device to change its type. */
 103                 return NOTIFY_BAD;
 104
 105         case NETDEV_RESEND_IGMP:
 106                 /* Propagate to master device */
 107                 call_netdevice_notifiers(event, br->dev);
 108                 break;
 109         }
 110
 111         /* Events that may cause spanning tree to refresh */
 112         if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 113             event == NETDEV_CHANGE || event == NETDEV_DOWN)
 114                 br_ifinfo_notify(RTM_NEWLINK, p);
 115
 116         return NOTIFY_DONE;
 117 }
 118
 119 static struct notifier_block br_device_notifier = {
 120         .notifier_call = br_device_event
 121 };
 122
 123 static void __net_exit br_net_exit(struct net *net)
 124 {
 125         struct net_device *dev;
 126         LIST_HEAD(list);
 127
 128         rtnl_lock();
 129         for_each_netdev(net, dev)
 130                 if (dev->priv_flags & IFF_EBRIDGE)
 131                         br_dev_delete(dev, &list);
 132
 133         unregister_netdevice_many(&list);
 134         rtnl_unlock();
 135
 136 }
 137
 138 static struct pernet_operations br_net_ops = {
 139         .exit   = br_net_exit,
 140 };
 141
 142 static const struct stp_proto br_stp_proto = {
 143         .rcv    = br_stp_rcv,
 144 };
 145
 146 static int __init br_init(void)
 147 {
 148         int err;
 149
 150         err = stp_proto_register(&br_stp_proto);
 151         if (err < 0) {
 152                 pr_err("bridge: can't register sap for STP\n");
 153                 return err;
 154         }
 155
 156         err = br_fdb_init();
 157         if (err)
 158                 goto err_out;
 159
 160         err = register_pernet_subsys(&br_net_ops);
 161         if (err)
 162                 goto err_out1;
 163
 164         err = br_nf_core_init();
 165         if (err)
 166                 goto err_out2;
 167
 168         err = register_netdevice_notifier(&br_device_notifier);
 169         if (err)
 170                 goto err_out3;
 171
 172         err = br_netlink_init();
 173         if (err)
 174                 goto err_out4;
 175
 176         brioctl_set(br_ioctl_deviceless_stub);
 177
 178 #if IS_ENABLED(CONFIG_ATM_LANE)
 179         br_fdb_test_addr_hook = br_fdb_test_addr;
 180 #endif
 181
 182         pr_info("bridge: automatic filtering via arp/ip/ip6tables has been "
 183                 "deprecated. Update your scripts to load br_netfilter if you "
 184                 "need this.\n");
 185
 186         return 0;
 187
 188 err_out4:
 189         unregister_netdevice_notifier(&br_device_notifier);
 190 err_out3:
 191         br_nf_core_fini();
 192 err_out2:
 193         unregister_pernet_subsys(&br_net_ops);
 194 err_out1:
 195         br_fdb_fini();
 196 err_out:
 197         stp_proto_unregister(&br_stp_proto);
 198         return err;
 199 }
 200
 201 static void __exit br_deinit(void)
 202 {
 203         stp_proto_unregister(&br_stp_proto);
 204         br_netlink_fini();
 205         unregister_netdevice_notifier(&br_device_notifier);
 206         brioctl_set(NULL);
 207         unregister_pernet_subsys(&br_net_ops);
 208
 209         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 210
 211         br_nf_core_fini();
 212 #if IS_ENABLED(CONFIG_ATM_LANE)
 213         br_fdb_test_addr_hook = NULL;
 214 #endif
 215         br_fdb_fini();
 216 }
 217
 218 module_init(br_init)
 219 module_exit(br_deinit)
 220 MODULE_LICENSE("GPL");
 221 MODULE_VERSION(BR_VERSION);
 222 MODULE_ALIAS_RTNL_LINK("bridge");