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         netif_carrier_off(dev);
  82
  83         br_features_recompute(br);
  84         netif_start_queue(dev);
  85         br_stp_enable_bridge(br);
  86         br_multicast_open(br);
  87
  88         return 0;
  89 }
  90
  91 static void br_dev_set_multicast_list(struct net_device *dev)
  92 {
  93 }
  94
  95 static int br_dev_stop(struct net_device *dev)
  96 {
  97         struct net_bridge *br = netdev_priv(dev);
  98
  99         netif_carrier_off(dev);
 100
 101         br_stp_disable_bridge(br);
 102         br_multicast_stop(br);
 103
 104         netif_stop_queue(dev);
 105
 106         return 0;
 107 }
 108
 109 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 110                                                 struct rtnl_link_stats64 *stats)
 111 {
 112         struct net_bridge *br = netdev_priv(dev);
 113         struct br_cpu_netstats tmp, sum = { 0 };
 114         unsigned int cpu;
 115
 116         for_each_possible_cpu(cpu) {
 117                 unsigned int start;
 118                 const struct br_cpu_netstats *bstats
 119                         = per_cpu_ptr(br->stats, cpu);
 120                 do {
 121                         start = u64_stats_fetch_begin(&bstats->syncp);
 122                         memcpy(&tmp, bstats, sizeof(tmp));
 123                 } while (u64_stats_fetch_retry(&bstats->syncp, start));
 124                 sum.tx_bytes   += tmp.tx_bytes;
 125                 sum.tx_packets += tmp.tx_packets;
 126                 sum.rx_bytes   += tmp.rx_bytes;
 127                 sum.rx_packets += tmp.rx_packets;
 128         }
 129
 130         stats->tx_bytes   = sum.tx_bytes;
 131         stats->tx_packets = sum.tx_packets;
 132         stats->rx_bytes   = sum.rx_bytes;
 133         stats->rx_packets = sum.rx_packets;
 134
 135         return stats;
 136 }
 137
 138 static int br_change_mtu(struct net_device *dev, int new_mtu)
 139 {
 140         struct net_bridge *br = netdev_priv(dev);
 141         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 142                 return -EINVAL;
 143
 144         dev->mtu = new_mtu;
 145
 146 #ifdef CONFIG_BRIDGE_NETFILTER
 147         /* remember the MTU in the rtable for PMTU */
 148         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 149 #endif
 150
 151         return 0;
 152 }
 153
 154 /* Allow setting mac address to any valid ethernet address. */
 155 static int br_set_mac_address(struct net_device *dev, void *p)
 156 {
 157         struct net_bridge *br = netdev_priv(dev);
 158         struct sockaddr *addr = p;
 159
 160         if (!is_valid_ether_addr(addr->sa_data))
 161                 return -EINVAL;
 162
 163         spin_lock_bh(&br->lock);
 164         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 165         br_stp_change_bridge_id(br, addr->sa_data);
 166         br->flags |= BR_SET_MAC_ADDR;
 167         spin_unlock_bh(&br->lock);
 168
 169         return 0;
 170 }
 171
 172 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 173 {
 174         strcpy(info->driver, "bridge");
 175         strcpy(info->version, BR_VERSION);
 176         strcpy(info->fw_version, "N/A");
 177         strcpy(info->bus_info, "N/A");
 178 }
 179
 180 static int br_set_sg(struct net_device *dev, u32 data)
 181 {
 182         struct net_bridge *br = netdev_priv(dev);
 183
 184         if (data)
 185                 br->feature_mask |= NETIF_F_SG;
 186         else
 187                 br->feature_mask &= ~NETIF_F_SG;
 188
 189         br_features_recompute(br);
 190         return 0;
 191 }
 192
 193 static int br_set_tso(struct net_device *dev, u32 data)
 194 {
 195         struct net_bridge *br = netdev_priv(dev);
 196
 197         if (data)
 198                 br->feature_mask |= NETIF_F_TSO;
 199         else
 200                 br->feature_mask &= ~NETIF_F_TSO;
 201
 202         br_features_recompute(br);
 203         return 0;
 204 }
 205
 206 static int br_set_tx_csum(struct net_device *dev, u32 data)
 207 {
 208         struct net_bridge *br = netdev_priv(dev);
 209
 210         if (data)
 211                 br->feature_mask |= NETIF_F_NO_CSUM;
 212         else
 213                 br->feature_mask &= ~NETIF_F_ALL_CSUM;
 214
 215         br_features_recompute(br);
 216         return 0;
 217 }
 218
 219 static int br_set_flags(struct net_device *netdev, u32 data)
 220 {
 221         return ethtool_op_set_flags(netdev, data, ETH_FLAG_TXVLAN);
 222 }
 223
 224 #ifdef CONFIG_NET_POLL_CONTROLLER
 225 static void br_poll_controller(struct net_device *br_dev)
 226 {
 227 }
 228
 229 static void br_netpoll_cleanup(struct net_device *dev)
 230 {
 231         struct net_bridge *br = netdev_priv(dev);
 232         struct net_bridge_port *p, *n;
 233
 234         list_for_each_entry_safe(p, n, &br->port_list, list) {
 235                 br_netpoll_disable(p);
 236         }
 237 }
 238
 239 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 240 {
 241         struct net_bridge *br = netdev_priv(dev);
 242         struct net_bridge_port *p, *n;
 243         int err = 0;
 244
 245         list_for_each_entry_safe(p, n, &br->port_list, list) {
 246                 if (!p->dev)
 247                         continue;
 248
 249                 err = br_netpoll_enable(p);
 250                 if (err)
 251                         goto fail;
 252         }
 253
 254 out:
 255         return err;
 256
 257 fail:
 258         br_netpoll_cleanup(dev);
 259         goto out;
 260 }
 261
 262 int br_netpoll_enable(struct net_bridge_port *p)
 263 {
 264         struct netpoll *np;
 265         int err = 0;
 266
 267         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 268         err = -ENOMEM;
 269         if (!np)
 270                 goto out;
 271
 272         np->dev = p->dev;
 273
 274         err = __netpoll_setup(np);
 275         if (err) {
 276                 kfree(np);
 277                 goto out;
 278         }
 279
 280         p->np = np;
 281
 282 out:
 283         return err;
 284 }
 285
 286 void br_netpoll_disable(struct net_bridge_port *p)
 287 {
 288         struct netpoll *np = p->np;
 289
 290         if (!np)
 291                 return;
 292
 293         p->np = NULL;
 294
 295         /* Wait for transmitting packets to finish before freeing. */
 296         synchronize_rcu_bh();
 297
 298         __netpoll_cleanup(np);
 299         kfree(np);
 300 }
 301
 302 #endif
 303
 304 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 305
 306 {
 307         struct net_bridge *br = netdev_priv(dev);
 308
 309         return br_add_if(br, slave_dev);
 310 }
 311
 312 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 313 {
 314         struct net_bridge *br = netdev_priv(dev);
 315
 316         return br_del_if(br, slave_dev);
 317 }
 318
 319 static const struct ethtool_ops br_ethtool_ops = {
 320         .get_drvinfo    = br_getinfo,
 321         .get_link       = ethtool_op_get_link,
 322         .get_tx_csum    = ethtool_op_get_tx_csum,
 323         .set_tx_csum    = br_set_tx_csum,
 324         .get_sg         = ethtool_op_get_sg,
 325         .set_sg         = br_set_sg,
 326         .get_tso        = ethtool_op_get_tso,
 327         .set_tso        = br_set_tso,
 328         .get_ufo        = ethtool_op_get_ufo,
 329         .set_ufo        = ethtool_op_set_ufo,
 330         .get_flags      = ethtool_op_get_flags,
 331         .set_flags      = br_set_flags,
 332 };
 333
 334 static const struct net_device_ops br_netdev_ops = {
 335         .ndo_open                = br_dev_open,
 336         .ndo_stop                = br_dev_stop,
 337         .ndo_start_xmit          = br_dev_xmit,
 338         .ndo_get_stats64         = br_get_stats64,
 339         .ndo_set_mac_address     = br_set_mac_address,
 340         .ndo_set_multicast_list  = br_dev_set_multicast_list,
 341         .ndo_change_mtu          = br_change_mtu,
 342         .ndo_do_ioctl            = br_dev_ioctl,
 343 #ifdef CONFIG_NET_POLL_CONTROLLER
 344         .ndo_netpoll_setup       = br_netpoll_setup,
 345         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 346         .ndo_poll_controller     = br_poll_controller,
 347 #endif
 348         .ndo_add_slave           = br_add_slave,
 349         .ndo_del_slave           = br_del_slave,
 350 };
 351
 352 static void br_dev_free(struct net_device *dev)
 353 {
 354         struct net_bridge *br = netdev_priv(dev);
 355
 356         free_percpu(br->stats);
 357         free_netdev(dev);
 358 }
 359
 360 void br_dev_setup(struct net_device *dev)
 361 {
 362         random_ether_addr(dev->dev_addr);
 363         ether_setup(dev);
 364
 365         dev->netdev_ops = &br_netdev_ops;
 366         dev->destructor = br_dev_free;
 367         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 368         dev->tx_queue_len = 0;
 369         dev->priv_flags = IFF_EBRIDGE;
 370
 371         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 372                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 373                         NETIF_F_NETNS_LOCAL | NETIF_F_GSO | NETIF_F_HW_VLAN_TX;
 374 }