4359881338
If user has configured a MAC address that is not one of the existing ports of the bridge, then we need to add a special entry in the forwarding table. This forwarding table entry has no outgoing port so it has to be treated a little differently. The special entry is reported by the netlink interface with ifindex of bridge, but ignored by the old interface since there is no usable way to put it in the ABI. Reported-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
271 lines
6.1 KiB
C
271 lines
6.1 KiB
C
/*
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* Forwarding decision
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* Linux ethernet bridge
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*
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* Authors:
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* Lennert Buytenhek <buytenh@gnu.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/netpoll.h>
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#include <linux/skbuff.h>
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#include <linux/if_vlan.h>
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#include <linux/netfilter_bridge.h>
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#include "br_private.h"
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static int deliver_clone(const struct net_bridge_port *prev,
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struct sk_buff *skb,
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void (*__packet_hook)(const struct net_bridge_port *p,
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struct sk_buff *skb));
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/* Don't forward packets to originating port or forwarding diasabled */
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static inline int should_deliver(const struct net_bridge_port *p,
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const struct sk_buff *skb)
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{
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return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
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p->state == BR_STATE_FORWARDING);
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}
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static inline unsigned packet_length(const struct sk_buff *skb)
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{
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return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
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}
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int br_dev_queue_push_xmit(struct sk_buff *skb)
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{
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/* ip_fragment doesn't copy the MAC header */
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if (nf_bridge_maybe_copy_header(skb) ||
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(packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))) {
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kfree_skb(skb);
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} else {
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skb_push(skb, ETH_HLEN);
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dev_queue_xmit(skb);
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}
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return 0;
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}
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int br_forward_finish(struct sk_buff *skb)
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{
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return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
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br_dev_queue_push_xmit);
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}
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static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
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{
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skb->dev = to->dev;
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if (unlikely(netpoll_tx_running(to->dev))) {
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if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
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kfree_skb(skb);
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else {
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skb_push(skb, ETH_HLEN);
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br_netpoll_send_skb(to, skb);
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}
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return;
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}
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NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
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br_forward_finish);
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}
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static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
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{
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struct net_device *indev;
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if (skb_warn_if_lro(skb)) {
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kfree_skb(skb);
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return;
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}
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indev = skb->dev;
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skb->dev = to->dev;
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skb_forward_csum(skb);
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NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
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br_forward_finish);
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}
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/* called with rcu_read_lock */
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void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
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{
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if (to && should_deliver(to, skb)) {
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__br_deliver(to, skb);
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return;
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}
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kfree_skb(skb);
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}
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/* called with rcu_read_lock */
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void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
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{
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if (should_deliver(to, skb)) {
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if (skb0)
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deliver_clone(to, skb, __br_forward);
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else
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__br_forward(to, skb);
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return;
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}
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if (!skb0)
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kfree_skb(skb);
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}
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static int deliver_clone(const struct net_bridge_port *prev,
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struct sk_buff *skb,
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void (*__packet_hook)(const struct net_bridge_port *p,
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struct sk_buff *skb))
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{
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struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
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skb = skb_clone(skb, GFP_ATOMIC);
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if (!skb) {
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dev->stats.tx_dropped++;
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return -ENOMEM;
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}
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__packet_hook(prev, skb);
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return 0;
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}
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static struct net_bridge_port *maybe_deliver(
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struct net_bridge_port *prev, struct net_bridge_port *p,
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struct sk_buff *skb,
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void (*__packet_hook)(const struct net_bridge_port *p,
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struct sk_buff *skb))
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{
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int err;
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if (!should_deliver(p, skb))
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return prev;
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if (!prev)
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goto out;
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err = deliver_clone(prev, skb, __packet_hook);
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if (err)
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return ERR_PTR(err);
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out:
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return p;
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}
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/* called under bridge lock */
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static void br_flood(struct net_bridge *br, struct sk_buff *skb,
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struct sk_buff *skb0,
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void (*__packet_hook)(const struct net_bridge_port *p,
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struct sk_buff *skb))
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{
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struct net_bridge_port *p;
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struct net_bridge_port *prev;
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prev = NULL;
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list_for_each_entry_rcu(p, &br->port_list, list) {
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prev = maybe_deliver(prev, p, skb, __packet_hook);
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if (IS_ERR(prev))
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goto out;
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}
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if (!prev)
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goto out;
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if (skb0)
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deliver_clone(prev, skb, __packet_hook);
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else
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__packet_hook(prev, skb);
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return;
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out:
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if (!skb0)
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kfree_skb(skb);
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}
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/* called with rcu_read_lock */
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void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb)
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{
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br_flood(br, skb, NULL, __br_deliver);
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}
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/* called under bridge lock */
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void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
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struct sk_buff *skb2)
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{
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br_flood(br, skb, skb2, __br_forward);
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}
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#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
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/* called with rcu_read_lock */
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static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
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struct sk_buff *skb, struct sk_buff *skb0,
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void (*__packet_hook)(
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const struct net_bridge_port *p,
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struct sk_buff *skb))
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{
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struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
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struct net_bridge *br = netdev_priv(dev);
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struct net_bridge_port *prev = NULL;
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struct net_bridge_port_group *p;
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struct hlist_node *rp;
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rp = rcu_dereference(hlist_first_rcu(&br->router_list));
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p = mdst ? rcu_dereference(mdst->ports) : NULL;
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while (p || rp) {
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struct net_bridge_port *port, *lport, *rport;
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lport = p ? p->port : NULL;
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rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
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NULL;
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port = (unsigned long)lport > (unsigned long)rport ?
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lport : rport;
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prev = maybe_deliver(prev, port, skb, __packet_hook);
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if (IS_ERR(prev))
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goto out;
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if ((unsigned long)lport >= (unsigned long)port)
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p = rcu_dereference(p->next);
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if ((unsigned long)rport >= (unsigned long)port)
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rp = rcu_dereference(hlist_next_rcu(rp));
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}
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if (!prev)
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goto out;
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if (skb0)
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deliver_clone(prev, skb, __packet_hook);
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else
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__packet_hook(prev, skb);
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return;
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out:
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if (!skb0)
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kfree_skb(skb);
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}
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/* called with rcu_read_lock */
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void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
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struct sk_buff *skb)
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{
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br_multicast_flood(mdst, skb, NULL, __br_deliver);
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}
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/* called with rcu_read_lock */
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void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
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struct sk_buff *skb, struct sk_buff *skb2)
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{
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br_multicast_flood(mdst, skb, skb2, __br_forward);
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}
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#endif
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