net/bridge/br_device.c

   1 /*
   2  *      Device handling code
   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/kernel.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/netpoll.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/ethtool.h>
  19 #include <linux/list.h>
  20 #include <linux/netfilter_bridge.h>
  21
  22 #include <asm/uaccess.h>
  23 #include "br_private.h"
  24
  25 /* net device transmit always called with BH disabled */
  26 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  27 {
  28         struct net_bridge *br = netdev_priv(dev);
  29         const unsigned char *dest = skb->data;
  30         struct net_bridge_fdb_entry *dst;
  31         struct net_bridge_mdb_entry *mdst;
  32         struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
  33
  34 #ifdef CONFIG_BRIDGE_NETFILTER
  35         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
  36                 br_nf_pre_routing_finish_bridge_slow(skb);
  37                 return NETDEV_TX_OK;
  38         }
  39 #endif
  40
  41         u64_stats_update_begin(&brstats->syncp);
  42         brstats->tx_packets++;
  43         brstats->tx_bytes += skb->len;
  44         u64_stats_update_end(&brstats->syncp);
  45
  46         BR_INPUT_SKB_CB(skb)->brdev = dev;
  47
  48         skb_reset_mac_header(skb);
  49         skb_pull(skb, ETH_HLEN);
  50
  51         rcu_read_lock();
  52         if (is_multicast_ether_addr(dest)) {
  53                 if (unlikely(netpoll_tx_running(dev))) {
  54                         br_flood_deliver(br, skb);
  55                         goto out;
  56                 }
  57                 if (br_multicast_rcv(br, NULL, skb)) {
  58                         kfree_skb(skb);
  59                         goto out;
  60                 }
  61
  62                 mdst = br_mdb_get(br, skb);
  63                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  64                         br_multicast_deliver(mdst, skb);
  65                 else
  66                         br_flood_deliver(br, skb);
  67         } else if ((dst = __br_fdb_get(br, dest)) != NULL)
  68                 br_deliver(dst->dst, skb);
  69         else
  70                 br_flood_deliver(br, skb);
  71
  72 out:
  73         rcu_read_unlock();
  74         return NETDEV_TX_OK;
  75 }
  76
  77 static int br_dev_open(struct net_device *dev)
  78 {
  79         struct net_bridge *br = netdev_priv(dev);
  80
  81         br_features_recompute(br);
  82         netif_start_queue(dev);
  83         br_stp_enable_bridge(br);
  84         br_multicast_open(br);
  85
  86         return 0;
  87 }
  88
  89 static void br_dev_set_multicast_list(struct net_device *dev)
  90 {
  91 }
  92
  93 static int br_dev_stop(struct net_device *dev)
  94 {
  95         struct net_bridge *br = netdev_priv(dev);
  96
  97         br_stp_disable_bridge(br);
  98         br_multicast_stop(br);
  99
 100         netif_stop_queue(dev);
 101
 102         return 0;
 103 }
 104
 105 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 106                                                 struct rtnl_link_stats64 *stats)
 107 {
 108         struct net_bridge *br = netdev_priv(dev);
 109         struct br_cpu_netstats tmp, sum = { 0 };
 110         unsigned int cpu;
 111
 112         for_each_possible_cpu(cpu) {
 113                 unsigned int start;
 114                 const struct br_cpu_netstats *bstats
 115                         = per_cpu_ptr(br->stats, cpu);
 116                 do {
 117                         start = u64_stats_fetch_begin(&bstats->syncp);
 118                         memcpy(&tmp, bstats, sizeof(tmp));
 119                 } while (u64_stats_fetch_retry(&bstats->syncp, start));
 120                 sum.tx_bytes   += tmp.tx_bytes;
 121                 sum.tx_packets += tmp.tx_packets;
 122                 sum.rx_bytes   += tmp.rx_bytes;
 123                 sum.rx_packets += tmp.rx_packets;
 124         }
 125
 126         stats->tx_bytes   = sum.tx_bytes;
 127         stats->tx_packets = sum.tx_packets;
 128         stats->rx_bytes   = sum.rx_bytes;
 129         stats->rx_packets = sum.rx_packets;
 130
 131         return stats;
 132 }
 133
 134 static int br_change_mtu(struct net_device *dev, int new_mtu)
 135 {
 136         struct net_bridge *br = netdev_priv(dev);
 137         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 138                 return -EINVAL;
 139
 140         dev->mtu = new_mtu;
 141
 142 #ifdef CONFIG_BRIDGE_NETFILTER
 143         /* remember the MTU in the rtable for PMTU */
 144         br->fake_rtable.dst.metrics[RTAX_MTU - 1] = new_mtu;
 145 #endif
 146
 147         return 0;
 148 }
 149
 150 /* Allow setting mac address to any valid ethernet address. */
 151 static int br_set_mac_address(struct net_device *dev, void *p)
 152 {
 153         struct net_bridge *br = netdev_priv(dev);
 154         struct sockaddr *addr = p;
 155
 156         if (!is_valid_ether_addr(addr->sa_data))
 157                 return -EINVAL;
 158
 159         spin_lock_bh(&br->lock);
 160         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 161         br_stp_change_bridge_id(br, addr->sa_data);
 162         br->flags |= BR_SET_MAC_ADDR;
 163         spin_unlock_bh(&br->lock);
 164
 165         return 0;
 166 }
 167
 168 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 169 {
 170         strcpy(info->driver, "bridge");
 171         strcpy(info->version, BR_VERSION);
 172         strcpy(info->fw_version, "N/A");
 173         strcpy(info->bus_info, "N/A");
 174 }
 175
 176 static int br_set_sg(struct net_device *dev, u32 data)
 177 {
 178         struct net_bridge *br = netdev_priv(dev);
 179
 180         if (data)
 181                 br->feature_mask |= NETIF_F_SG;
 182         else
 183                 br->feature_mask &= ~NETIF_F_SG;
 184
 185         br_features_recompute(br);
 186         return 0;
 187 }
 188
 189 static int br_set_tso(struct net_device *dev, u32 data)
 190 {
 191         struct net_bridge *br = netdev_priv(dev);
 192
 193         if (data)
 194                 br->feature_mask |= NETIF_F_TSO;
 195         else
 196                 br->feature_mask &= ~NETIF_F_TSO;
 197
 198         br_features_recompute(br);
 199         return 0;
 200 }
 201
 202 static int br_set_tx_csum(struct net_device *dev, u32 data)
 203 {
 204         struct net_bridge *br = netdev_priv(dev);
 205
 206         if (data)
 207                 br->feature_mask |= NETIF_F_NO_CSUM;
 208         else
 209                 br->feature_mask &= ~NETIF_F_ALL_CSUM;
 210
 211         br_features_recompute(br);
 212         return 0;
 213 }
 214
 215 #ifdef CONFIG_NET_POLL_CONTROLLER
 216 static void br_poll_controller(struct net_device *br_dev)
 217 {
 218 }
 219
 220 static void br_netpoll_cleanup(struct net_device *dev)
 221 {
 222         struct net_bridge *br = netdev_priv(dev);
 223         struct net_bridge_port *p, *n;
 224
 225         list_for_each_entry_safe(p, n, &br->port_list, list) {
 226                 br_netpoll_disable(p);
 227         }
 228 }
 229
 230 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 231 {
 232         struct net_bridge *br = netdev_priv(dev);
 233         struct net_bridge_port *p, *n;
 234         int err = 0;
 235
 236         list_for_each_entry_safe(p, n, &br->port_list, list) {
 237                 if (!p->dev)
 238                         continue;
 239
 240                 err = br_netpoll_enable(p);
 241                 if (err)
 242                         goto fail;
 243         }
 244
 245 out:
 246         return err;
 247
 248 fail:
 249         br_netpoll_cleanup(dev);
 250         goto out;
 251 }
 252
 253 int br_netpoll_enable(struct net_bridge_port *p)
 254 {
 255         struct netpoll *np;
 256         int err = 0;
 257
 258         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 259         err = -ENOMEM;
 260         if (!np)
 261                 goto out;
 262
 263         np->dev = p->dev;
 264
 265         err = __netpoll_setup(np);
 266         if (err) {
 267                 kfree(np);
 268                 goto out;
 269         }
 270
 271         p->np = np;
 272
 273 out:
 274         return err;
 275 }
 276
 277 void br_netpoll_disable(struct net_bridge_port *p)
 278 {
 279         struct netpoll *np = p->np;
 280
 281         if (!np)
 282                 return;
 283
 284         p->np = NULL;
 285
 286         /* Wait for transmitting packets to finish before freeing. */
 287         synchronize_rcu_bh();
 288
 289         __netpoll_cleanup(np);
 290         kfree(np);
 291 }
 292
 293 #endif
 294
 295 static const struct ethtool_ops br_ethtool_ops = {
 296         .get_drvinfo    = br_getinfo,
 297         .get_link       = ethtool_op_get_link,
 298         .get_tx_csum    = ethtool_op_get_tx_csum,
 299         .set_tx_csum    = br_set_tx_csum,
 300         .get_sg         = ethtool_op_get_sg,
 301         .set_sg         = br_set_sg,
 302         .get_tso        = ethtool_op_get_tso,
 303         .set_tso        = br_set_tso,
 304         .get_ufo        = ethtool_op_get_ufo,
 305         .set_ufo        = ethtool_op_set_ufo,
 306         .get_flags      = ethtool_op_get_flags,
 307 };
 308
 309 static const struct net_device_ops br_netdev_ops = {
 310         .ndo_open                = br_dev_open,
 311         .ndo_stop                = br_dev_stop,
 312         .ndo_start_xmit          = br_dev_xmit,
 313         .ndo_get_stats64         = br_get_stats64,
 314         .ndo_set_mac_address     = br_set_mac_address,
 315         .ndo_set_multicast_list  = br_dev_set_multicast_list,
 316         .ndo_change_mtu          = br_change_mtu,
 317         .ndo_do_ioctl            = br_dev_ioctl,
 318 #ifdef CONFIG_NET_POLL_CONTROLLER
 319         .ndo_netpoll_setup       = br_netpoll_setup,
 320         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 321         .ndo_poll_controller     = br_poll_controller,
 322 #endif
 323 };
 324
 325 static void br_dev_free(struct net_device *dev)
 326 {
 327         struct net_bridge *br = netdev_priv(dev);
 328
 329         free_percpu(br->stats);
 330         free_netdev(dev);
 331 }
 332
 333 void br_dev_setup(struct net_device *dev)
 334 {
 335         random_ether_addr(dev->dev_addr);
 336         ether_setup(dev);
 337
 338         dev->netdev_ops = &br_netdev_ops;
 339         dev->destructor = br_dev_free;
 340         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 341         dev->tx_queue_len = 0;
 342         dev->priv_flags = IFF_EBRIDGE;
 343
 344         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 345                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 346                         NETIF_F_NETNS_LOCAL | NETIF_F_GSO;
 347 }