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 no BH (preempt_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         if (is_multicast_ether_addr(dest)) {
  52                 if (unlikely(netpoll_tx_running(dev))) {
  53                         br_flood_deliver(br, skb);
  54                         goto out;
  55                 }
  56                 if (br_multicast_rcv(br, NULL, skb))
  57                         goto out;
  58
  59                 mdst = br_mdb_get(br, skb);
  60                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  61                         br_multicast_deliver(mdst, skb);
  62                 else
  63                         br_flood_deliver(br, skb);
  64         } else if ((dst = __br_fdb_get(br, dest)) != NULL)
  65                 br_deliver(dst->dst, skb);
  66         else
  67                 br_flood_deliver(br, skb);
  68
  69 out:
  70         return NETDEV_TX_OK;
  71 }
  72
  73 static int br_dev_open(struct net_device *dev)
  74 {
  75         struct net_bridge *br = netdev_priv(dev);
  76
  77         br_features_recompute(br);
  78         netif_start_queue(dev);
  79         br_stp_enable_bridge(br);
  80         br_multicast_open(br);
  81
  82         return 0;
  83 }
  84
  85 static void br_dev_set_multicast_list(struct net_device *dev)
  86 {
  87 }
  88
  89 static int br_dev_stop(struct net_device *dev)
  90 {
  91         struct net_bridge *br = netdev_priv(dev);
  92
  93         br_stp_disable_bridge(br);
  94         br_multicast_stop(br);
  95
  96         netif_stop_queue(dev);
  97
  98         return 0;
  99 }
 100
 101 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev)
 102 {
 103         struct net_bridge *br = netdev_priv(dev);
 104         struct rtnl_link_stats64 *stats = &dev->stats64;
 105         struct br_cpu_netstats tmp, sum = { 0 };
 106         unsigned int cpu;
 107
 108         for_each_possible_cpu(cpu) {
 109                 unsigned int start;
 110                 const struct br_cpu_netstats *bstats
 111                         = per_cpu_ptr(br->stats, cpu);
 112                 do {
 113                         start = u64_stats_fetch_begin(&bstats->syncp);
 114                         memcpy(&tmp, bstats, sizeof(tmp));
 115                 } while (u64_stats_fetch_retry(&bstats->syncp, start));
 116                 sum.tx_bytes   += tmp.tx_bytes;
 117                 sum.tx_packets += tmp.tx_packets;
 118                 sum.rx_bytes   += tmp.rx_bytes;
 119                 sum.rx_packets += tmp.rx_packets;
 120         }
 121
 122         stats->tx_bytes   = sum.tx_bytes;
 123         stats->tx_packets = sum.tx_packets;
 124         stats->rx_bytes   = sum.rx_bytes;
 125         stats->rx_packets = sum.rx_packets;
 126
 127         return stats;
 128 }
 129
 130 static int br_change_mtu(struct net_device *dev, int new_mtu)
 131 {
 132         struct net_bridge *br = netdev_priv(dev);
 133         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 134                 return -EINVAL;
 135
 136         dev->mtu = new_mtu;
 137
 138 #ifdef CONFIG_BRIDGE_NETFILTER
 139         /* remember the MTU in the rtable for PMTU */
 140         br->fake_rtable.dst.metrics[RTAX_MTU - 1] = new_mtu;
 141 #endif
 142
 143         return 0;
 144 }
 145
 146 /* Allow setting mac address to any valid ethernet address. */
 147 static int br_set_mac_address(struct net_device *dev, void *p)
 148 {
 149         struct net_bridge *br = netdev_priv(dev);
 150         struct sockaddr *addr = p;
 151
 152         if (!is_valid_ether_addr(addr->sa_data))
 153                 return -EINVAL;
 154
 155         spin_lock_bh(&br->lock);
 156         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 157         br_stp_change_bridge_id(br, addr->sa_data);
 158         br->flags |= BR_SET_MAC_ADDR;
 159         spin_unlock_bh(&br->lock);
 160
 161         return 0;
 162 }
 163
 164 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 165 {
 166         strcpy(info->driver, "bridge");
 167         strcpy(info->version, BR_VERSION);
 168         strcpy(info->fw_version, "N/A");
 169         strcpy(info->bus_info, "N/A");
 170 }
 171
 172 static int br_set_sg(struct net_device *dev, u32 data)
 173 {
 174         struct net_bridge *br = netdev_priv(dev);
 175
 176         if (data)
 177                 br->feature_mask |= NETIF_F_SG;
 178         else
 179                 br->feature_mask &= ~NETIF_F_SG;
 180
 181         br_features_recompute(br);
 182         return 0;
 183 }
 184
 185 static int br_set_tso(struct net_device *dev, u32 data)
 186 {
 187         struct net_bridge *br = netdev_priv(dev);
 188
 189         if (data)
 190                 br->feature_mask |= NETIF_F_TSO;
 191         else
 192                 br->feature_mask &= ~NETIF_F_TSO;
 193
 194         br_features_recompute(br);
 195         return 0;
 196 }
 197
 198 static int br_set_tx_csum(struct net_device *dev, u32 data)
 199 {
 200         struct net_bridge *br = netdev_priv(dev);
 201
 202         if (data)
 203                 br->feature_mask |= NETIF_F_NO_CSUM;
 204         else
 205                 br->feature_mask &= ~NETIF_F_ALL_CSUM;
 206
 207         br_features_recompute(br);
 208         return 0;
 209 }
 210
 211 #ifdef CONFIG_NET_POLL_CONTROLLER
 212 static void br_poll_controller(struct net_device *br_dev)
 213 {
 214 }
 215
 216 static void br_netpoll_cleanup(struct net_device *dev)
 217 {
 218         struct net_bridge *br = netdev_priv(dev);
 219         struct net_bridge_port *p, *n;
 220
 221         list_for_each_entry_safe(p, n, &br->port_list, list) {
 222                 br_netpoll_disable(p);
 223         }
 224 }
 225
 226 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 227 {
 228         struct net_bridge *br = netdev_priv(dev);
 229         struct net_bridge_port *p, *n;
 230         int err = 0;
 231
 232         list_for_each_entry_safe(p, n, &br->port_list, list) {
 233                 if (!p->dev)
 234                         continue;
 235
 236                 err = br_netpoll_enable(p);
 237                 if (err)
 238                         goto fail;
 239         }
 240
 241 out:
 242         return err;
 243
 244 fail:
 245         br_netpoll_cleanup(dev);
 246         goto out;
 247 }
 248
 249 int br_netpoll_enable(struct net_bridge_port *p)
 250 {
 251         struct netpoll *np;
 252         int err = 0;
 253
 254         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 255         err = -ENOMEM;
 256         if (!np)
 257                 goto out;
 258
 259         np->dev = p->dev;
 260
 261         err = __netpoll_setup(np);
 262         if (err) {
 263                 kfree(np);
 264                 goto out;
 265         }
 266
 267         p->np = np;
 268
 269 out:
 270         return err;
 271 }
 272
 273 void br_netpoll_disable(struct net_bridge_port *p)
 274 {
 275         struct netpoll *np = p->np;
 276
 277         if (!np)
 278                 return;
 279
 280         p->np = NULL;
 281
 282         /* Wait for transmitting packets to finish before freeing. */
 283         synchronize_rcu_bh();
 284
 285         __netpoll_cleanup(np);
 286         kfree(np);
 287 }
 288
 289 #endif
 290
 291 static const struct ethtool_ops br_ethtool_ops = {
 292         .get_drvinfo    = br_getinfo,
 293         .get_link       = ethtool_op_get_link,
 294         .get_tx_csum    = ethtool_op_get_tx_csum,
 295         .set_tx_csum    = br_set_tx_csum,
 296         .get_sg         = ethtool_op_get_sg,
 297         .set_sg         = br_set_sg,
 298         .get_tso        = ethtool_op_get_tso,
 299         .set_tso        = br_set_tso,
 300         .get_ufo        = ethtool_op_get_ufo,
 301         .set_ufo        = ethtool_op_set_ufo,
 302         .get_flags      = ethtool_op_get_flags,
 303 };
 304
 305 static const struct net_device_ops br_netdev_ops = {
 306         .ndo_open                = br_dev_open,
 307         .ndo_stop                = br_dev_stop,
 308         .ndo_start_xmit          = br_dev_xmit,
 309         .ndo_get_stats64         = br_get_stats64,
 310         .ndo_set_mac_address     = br_set_mac_address,
 311         .ndo_set_multicast_list  = br_dev_set_multicast_list,
 312         .ndo_change_mtu          = br_change_mtu,
 313         .ndo_do_ioctl            = br_dev_ioctl,
 314 #ifdef CONFIG_NET_POLL_CONTROLLER
 315         .ndo_netpoll_setup       = br_netpoll_setup,
 316         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 317         .ndo_poll_controller     = br_poll_controller,
 318 #endif
 319 };
 320
 321 static void br_dev_free(struct net_device *dev)
 322 {
 323         struct net_bridge *br = netdev_priv(dev);
 324
 325         free_percpu(br->stats);
 326         free_netdev(dev);
 327 }
 328
 329 void br_dev_setup(struct net_device *dev)
 330 {
 331         random_ether_addr(dev->dev_addr);
 332         ether_setup(dev);
 333
 334         dev->netdev_ops = &br_netdev_ops;
 335         dev->destructor = br_dev_free;
 336         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 337         dev->tx_queue_len = 0;
 338         dev->priv_flags = IFF_EBRIDGE;
 339
 340         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 341                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 342                         NETIF_F_NETNS_LOCAL | NETIF_F_GSO;
 343 }