linux/net/bridge/br_device.c
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   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 */
  26netdev_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
  72out:
  73        rcu_read_unlock();
  74        return NETDEV_TX_OK;
  75}
  76
  77static 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
  89static void br_dev_set_multicast_list(struct net_device *dev)
  90{
  91}
  92
  93static 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
 105static 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
 134static 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. */
 151static 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
 168static 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
 176static 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
 189static 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
 202static 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
 215static int br_set_flags(struct net_device *netdev, u32 data)
 216{
 217        return ethtool_op_set_flags(netdev, data, ETH_FLAG_TXVLAN);
 218}
 219
 220#ifdef CONFIG_NET_POLL_CONTROLLER
 221static void br_poll_controller(struct net_device *br_dev)
 222{
 223}
 224
 225static void br_netpoll_cleanup(struct net_device *dev)
 226{
 227        struct net_bridge *br = netdev_priv(dev);
 228        struct net_bridge_port *p, *n;
 229
 230        list_for_each_entry_safe(p, n, &br->port_list, list) {
 231                br_netpoll_disable(p);
 232        }
 233}
 234
 235static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 236{
 237        struct net_bridge *br = netdev_priv(dev);
 238        struct net_bridge_port *p, *n;
 239        int err = 0;
 240
 241        list_for_each_entry_safe(p, n, &br->port_list, list) {
 242                if (!p->dev)
 243                        continue;
 244
 245                err = br_netpoll_enable(p);
 246                if (err)
 247                        goto fail;
 248        }
 249
 250out:
 251        return err;
 252
 253fail:
 254        br_netpoll_cleanup(dev);
 255        goto out;
 256}
 257
 258int br_netpoll_enable(struct net_bridge_port *p)
 259{
 260        struct netpoll *np;
 261        int err = 0;
 262
 263        np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 264        err = -ENOMEM;
 265        if (!np)
 266                goto out;
 267
 268        np->dev = p->dev;
 269
 270        err = __netpoll_setup(np);
 271        if (err) {
 272                kfree(np);
 273                goto out;
 274        }
 275
 276        p->np = np;
 277
 278out:
 279        return err;
 280}
 281
 282void br_netpoll_disable(struct net_bridge_port *p)
 283{
 284        struct netpoll *np = p->np;
 285
 286        if (!np)
 287                return;
 288
 289        p->np = NULL;
 290
 291        /* Wait for transmitting packets to finish before freeing. */
 292        synchronize_rcu_bh();
 293
 294        __netpoll_cleanup(np);
 295        kfree(np);
 296}
 297
 298#endif
 299
 300static const struct ethtool_ops br_ethtool_ops = {
 301        .get_drvinfo    = br_getinfo,
 302        .get_link       = ethtool_op_get_link,
 303        .get_tx_csum    = ethtool_op_get_tx_csum,
 304        .set_tx_csum    = br_set_tx_csum,
 305        .get_sg         = ethtool_op_get_sg,
 306        .set_sg         = br_set_sg,
 307        .get_tso        = ethtool_op_get_tso,
 308        .set_tso        = br_set_tso,
 309        .get_ufo        = ethtool_op_get_ufo,
 310        .set_ufo        = ethtool_op_set_ufo,
 311        .get_flags      = ethtool_op_get_flags,
 312        .set_flags      = br_set_flags,
 313};
 314
 315static const struct net_device_ops br_netdev_ops = {
 316        .ndo_open                = br_dev_open,
 317        .ndo_stop                = br_dev_stop,
 318        .ndo_start_xmit          = br_dev_xmit,
 319        .ndo_get_stats64         = br_get_stats64,
 320        .ndo_set_mac_address     = br_set_mac_address,
 321        .ndo_set_multicast_list  = br_dev_set_multicast_list,
 322        .ndo_change_mtu          = br_change_mtu,
 323        .ndo_do_ioctl            = br_dev_ioctl,
 324#ifdef CONFIG_NET_POLL_CONTROLLER
 325        .ndo_netpoll_setup       = br_netpoll_setup,
 326        .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 327        .ndo_poll_controller     = br_poll_controller,
 328#endif
 329};
 330
 331static void br_dev_free(struct net_device *dev)
 332{
 333        struct net_bridge *br = netdev_priv(dev);
 334
 335        free_percpu(br->stats);
 336        free_netdev(dev);
 337}
 338
 339void br_dev_setup(struct net_device *dev)
 340{
 341        random_ether_addr(dev->dev_addr);
 342        ether_setup(dev);
 343
 344        dev->netdev_ops = &br_netdev_ops;
 345        dev->destructor = br_dev_free;
 346        SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 347        dev->tx_queue_len = 0;
 348        dev->priv_flags = IFF_EBRIDGE;
 349
 350        dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 351                        NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 352                        NETIF_F_NETNS_LOCAL | NETIF_F_GSO | NETIF_F_HW_VLAN_TX;
 353}
 354