// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Device handling code
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/netpoll.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/list.h>
#include <linux/netfilter_bridge.h>
#include <linux/uaccess.h>
#include "br_private.h"
#define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
EXPORT_SYMBOL_GPL(nf_br_ops);
/* net device transmit always called with BH disabled */
netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
enum skb_drop_reason reason = pskb_may_pull_reason(skb, ETH_HLEN);
struct net_bridge_mcast_port *pmctx_null = NULL;
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_mcast *brmctx = &br->multicast_ctx;
struct net_bridge_fdb_entry *dst;
struct net_bridge_mdb_entry *mdst;
const struct nf_br_ops *nf_ops;
u8 state = BR_STATE_FORWARDING;
struct net_bridge_vlan *vlan;
const unsigned char *dest;
u16 vid = 0;
if (unlikely(reason != SKB_NOT_DROPPED_YET)) {
kfree_skb_reason(skb, reason);
return NETDEV_TX_OK;
}
memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
br_tc_skb_miss_set(skb, false);
rcu_read_lock();
nf_ops = rcu_dereference(nf_br_ops);
if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
rcu_read_unlock();
return NETDEV_TX_OK;
}
dev_sw_netstats_tx_add(dev, 1, skb->len);
br_switchdev_frame_unmark(skb);
BR_INPUT_SKB_CB(skb)->brdev = dev;
BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
skb_reset_mac_header(skb);
skb_pull(skb, ETH_HLEN);
if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid,
&state, &vlan))
goto out;
if (IS_ENABLED(CONFIG_INET) &&
(eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
br_do_proxy_suppress_arp(skb, br, vid, NULL);
} else if (IS_ENABLED(CONFIG_IPV6) &&
skb->protocol == htons(ETH_P_IPV6) &&
br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
pskb_may_pull(skb, sizeof(struct ipv6hdr) +
sizeof(struct nd_msg)) &&
ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
struct nd_msg *msg, _msg;
msg = br_is_nd_neigh_msg(skb, &_msg);
if (msg)
br_do_suppress_nd(skb, br, vid, NULL, msg);
}
dest = eth_hdr(skb)->h_dest;
if (is_broadcast_ether_addr(dest)) {
br_flood(br, skb, BR_PKT_BROADCAST, false, true, vid);
} else if (is_multicast_ether_addr(dest)) {
if (unlikely(netpoll_tx_running(dev))) {
br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
goto out;
}
if (br_multicast_rcv(&brmctx, &pmctx_null, vlan, skb, vid)) {
kfree_skb(skb);
goto out;
}
mdst = br_mdb_entry_skb_get(brmctx, skb, vid);
if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst))
br_multicast_flood(mdst, skb, brmctx, false, true);
else
br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
} else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
br_forward(dst->dst, skb, false, true);
} else {
br_flood(br, skb, BR_PKT_UNICAST, false, true, vid);
}
out:
rcu_read_unlock();
return NETDEV_TX_OK;
}
static int br_dev_init(struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
int err;
err = br_fdb_hash_init(br);
if (err)
return err;
err = br_mdb_hash_init(br);
if (err) {
br_fdb_hash_fini(br);
return err;
}
err = br_vlan_init(br);
if (err) {
br_mdb_hash_fini(br);
br_fdb_hash_fini(br);
return err;
}
err = br_multicast_init_stats(br);
if (err) {
br_vlan_flush(br);
br_mdb_hash_fini(br);
br_fdb_hash_fini(br);
return err;
}
netdev_lockdep_set_classes(dev);
return 0;
}
static void br_dev_uninit(struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
br_multicast_dev_del(br);
br_multicast_uninit_stats(br);
br_vlan_flush(br);
br_mdb_hash_fini(br);
br_fdb_hash_fini(br);
}
static int br_dev_open(struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
netdev_update_features(dev);
netif_start_queue(dev);
br_stp_enable_bridge(br);
br_multicast_open(br);
if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
br_multicast_join_snoopers(br);
return 0;
}
static void br_dev_set_multicast_list(struct net_device *dev)
{
}
static void br_dev_change_rx_flags(struct net_device *dev, int change)
{
if (change & IFF_PROMISC)
br_manage_promisc(netdev_priv(dev));
}
static int br_dev_stop(struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
br_stp_disable_bridge(br);
br_multicast_stop(br);
if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
br_multicast_leave_snoopers(br);
netif_stop_queue(dev);
return 0;
}
static int br_change_mtu(struct net_device *dev, int new_mtu)
{
struct net_bridge *br = netdev_priv(dev);
WRITE_ONCE(dev->mtu, new_mtu);
/* this flag will be cleared if the MTU was automatically adjusted */
br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
/* remember the MTU in the rtable for PMTU */
dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
#endif
return 0;
}
/* Allow setting mac address to any valid ethernet address. */
static int br_set_mac_address(struct net_device *dev, void *p)
{
struct net_bridge *br = netdev_priv(dev);
struct sockaddr *addr = p;
if (!is_valid_ether_addr(addr->sa_data))
return -EADDRNOTAVAIL;
/* dev_set_mac_addr() can be called by a master device on bridge's
* NETDEV_UNREGISTER, but since it's being destroyed do nothing
*/
if (dev->reg_state != NETREG_REGISTERED)
return -EBUSY;
spin_lock_bh(&br->lock);
if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
/* Mac address will be changed in br_stp_change_bridge_id(). */
br_stp_change_bridge_id(br, addr->sa_data);
}
spin_unlock_bh(&br->lock);
return 0;
}
static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
strscpy(info->driver, "bridge", sizeof(info->driver));
strscpy(info->version, BR_VERSION, sizeof(info->version));
strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
strscpy(info->bus_info, "N/A", sizeof(info->bus_info));
}
static int br_get_link_ksettings(struct net_device *dev,
struct ethtool_link_ksettings *cmd)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *p;
cmd->base.duplex = DUPLEX_UNKNOWN;
cmd->base.port = PORT_OTHER;
cmd->base.speed = SPEED_UNKNOWN;
list_for_each_entry(p, &br->port_list, list) {
struct ethtool_link_ksettings ecmd;
struct net_device *pdev = p->dev;
if (!netif_running(pdev) || !netif_oper_up(pdev))
continue;
if (__ethtool_get_link_ksettings(pdev, &ecmd))
continue;
if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
continue;
if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
cmd->base.speed < ecmd.base.speed)
cmd->base.speed = ecmd.base.speed;
}
return 0;
}
static netdev_features_t br_fix_features(struct net_device *dev,
netdev_features_t features)
{
struct net_bridge *br = netdev_priv(dev);
return br_features_recompute(br, features);
}
#ifdef CONFIG_NET_POLL_CONTROLLER
static void br_poll_controller(struct net_device *br_dev)
{
}
static void br_netpoll_cleanup(struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *p;
list_for_each_entry(p, &br->port_list, list)
br_netpoll_disable(p);
}
static int __br_netpoll_enable(struct net_bridge_port *p)
{
struct netpoll *np;
int err;
np = kzalloc(sizeof(*p->np), GFP_KERNEL);
if (!np)
return -ENOMEM;
err = __netpoll_setup(np, p->dev);
if (err) {
kfree(np);
return err;
}
p->np = np;
return err;
}
int br_netpoll_enable(struct net_bridge_port *p)
{
if (!p->br->dev->npinfo)
return 0;
return __br_netpoll_enable(p);
}
static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
{
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_port *p;
int err = 0;
list_for_each_entry(p, &br->port_list, list) {
if (!p->dev)
continue;
err = __br_netpoll_enable(p);
if (err)
goto fail;
}
out:
return err;
fail:
br_netpoll_cleanup(dev);
goto out;
}
void br_netpoll_disable(struct net_bridge_port *p)
{
struct netpoll *np = p->np;
if (!np)
return;
p->np = NULL;
__netpoll_free(np);
}
#endif
static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
struct netlink_ext_ack *extack)
{
struct net_bridge *br = netdev_priv(dev);
return br_add_if(br, slave_dev, extack);
}
static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
{
struct net_bridge *br = netdev_priv(dev);
return br_del_if(br, slave_dev);
}
static int br_fill_forward_path(struct net_device_path_ctx *ctx,
struct net_device_path *path)
{
struct net_bridge_fdb_entry *f;
struct net_bridge_port *dst;
struct net_bridge *br;
if (netif_is_bridge_port(ctx->dev))
return -1;
br = netdev_priv(ctx->dev);
br_vlan_fill_forward_path_pvid(br, ctx, path);
f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
if (!f)
return -1;
dst = READ_ONCE(f->dst);
if (!dst)
return -1;
if (br_vlan_fill_forward_path_mode(br, dst, path))
return -1;
path->type = DEV_PATH_BRIDGE;
path->dev = dst->br->dev;
ctx->dev = dst->dev;
switch (path->bridge.vlan_mode) {
case DEV_PATH_BR_VLAN_TAG:
if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
return -ENOSPC;
ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
ctx->num_vlans++;
break;
case DEV_PATH_BR_VLAN_UNTAG_HW:
case DEV_PATH_BR_VLAN_UNTAG:
ctx->num_vlans--;
break;
case DEV_PATH_BR_VLAN_KEEP:
break;
}
return 0;
}
static const struct ethtool_ops br_ethtool_ops = {
.get_drvinfo = br_getinfo,
.get_link = ethtool_op_get_link,
.get_link_ksettings = br_get_link_ksettings,
};
static const struct net_device_ops br_netdev_ops = {
.ndo_open = br_dev_open,
.ndo_stop = br_dev_stop,
.ndo_init = br_dev_init,
.ndo_uninit = br_dev_uninit,
.ndo_start_xmit = br_dev_xmit,
.ndo_get_stats64 = dev_get_tstats64,
.ndo_set_mac_address = br_set_mac_address,
.ndo_set_rx_mode = br_dev_set_multicast_list,
.ndo_change_rx_flags = br_dev_change_rx_flags,
.ndo_change_mtu = br_change_mtu,
.ndo_siocdevprivate = br_dev_siocdevprivate,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_netpoll_setup = br_netpoll_setup,
.ndo_netpoll_cleanup = br_netpoll_cleanup,
.ndo_poll_controller = br_poll_controller,
#endif
.ndo_add_slave = br_add_slave,
.ndo_del_slave = br_del_slave,
.ndo_fix_features = br_fix_features,
.ndo_fdb_add = br_fdb_add,
.ndo_fdb_del = br_fdb_delete,
.ndo_fdb_del_bulk = br_fdb_delete_bulk,
.ndo_fdb_dump = br_fdb_dump,
.ndo_fdb_get = br_fdb_get,
.ndo_mdb_add = br_mdb_add,
.ndo_mdb_del = br_mdb_del,
.ndo_mdb_del_bulk = br_mdb_del_bulk,
.ndo_mdb_dump = br_mdb_dump,
.ndo_mdb_get = br_mdb_get,
.ndo_bridge_getlink = br_getlink,
.ndo_bridge_setlink = br_setlink,
.ndo_bridge_dellink = br_dellink,
.ndo_features_check = passthru_features_check,
.ndo_fill_forward_path = br_fill_forward_path,
};
static const struct device_type br_type = {
.name = "bridge",
};
void br_dev_setup(struct net_device *dev)
{
struct net_bridge *br = netdev_priv(dev);
eth_hw_addr_random(dev);
ether_setup(dev);
dev->netdev_ops = &br_netdev_ops;
dev->needs_free_netdev = true;
dev->ethtool_ops = &br_ethtool_ops;
SET_NETDEV_DEVTYPE(dev, &br_type);
dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
dev->lltx = true;
dev->netns_local = true;
dev->features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX;
dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX;
dev->vlan_features = COMMON_FEATURES;
dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
br->dev = dev;
spin_lock_init(&br->lock);
INIT_LIST_HEAD(&br->port_list);
INIT_HLIST_HEAD(&br->fdb_list);
INIT_HLIST_HEAD(&br->frame_type_list);
#if IS_ENABLED(CONFIG_BRIDGE_MRP)
INIT_HLIST_HEAD(&br->mrp_list);
#endif
#if IS_ENABLED(CONFIG_BRIDGE_CFM)
INIT_HLIST_HEAD(&br->mep_list);
#endif
spin_lock_init(&br->hash_lock);
br->bridge_id.prio[0] = 0x80;
br->bridge_id.prio[1] = 0x00;
ether_addr_copy(br->group_addr, eth_stp_addr);
br->stp_enabled = BR_NO_STP;
br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
br->designated_root = br->bridge_id;
br->bridge_max_age = br->max_age = 20 * HZ;
br->bridge_hello_time = br->hello_time = 2 * HZ;
br->bridge_forward_delay = br->forward_delay = 15 * HZ;
br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
dev->max_mtu = ETH_MAX_MTU;
br_netfilter_rtable_init(br);
br_stp_timer_init(br);
br_multicast_init(br);
INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
}
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