![Nikolay Aleksandrov](/assets/img/avatar_default.png)
This patch adds support for a new port flag - BR_ISOLATED. If it is set then isolated ports cannot communicate between each other, but they can still communicate with non-isolated ports. The same can be achieved via ACLs but they can't scale with large number of ports and also the complexity of the rules grows. This feature can be used to achieve isolated vlan functionality (similar to pvlan) as well, though currently it will be port-wide (for all vlans on the port). The new test in should_deliver uses data that is already cache hot and the new boolean is used to avoid an additional source port test in should_deliver. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
320 lines
7.3 KiB
C
320 lines
7.3 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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/* Don't forward packets to originating port or forwarding disabled */
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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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struct net_bridge_vlan_group *vg;
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vg = nbp_vlan_group_rcu(p);
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return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
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br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING &&
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nbp_switchdev_allowed_egress(p, skb) &&
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!br_skb_isolated(p, skb);
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}
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int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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if (!is_skb_forwardable(skb->dev, skb))
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goto drop;
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skb_push(skb, ETH_HLEN);
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br_drop_fake_rtable(skb);
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if (skb->ip_summed == CHECKSUM_PARTIAL &&
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(skb->protocol == htons(ETH_P_8021Q) ||
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skb->protocol == htons(ETH_P_8021AD))) {
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int depth;
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if (!__vlan_get_protocol(skb, skb->protocol, &depth))
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goto drop;
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skb_set_network_header(skb, depth);
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}
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dev_queue_xmit(skb);
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return 0;
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drop:
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kfree_skb(skb);
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return 0;
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}
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EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
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int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
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net, sk, skb, NULL, skb->dev,
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br_dev_queue_push_xmit);
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}
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EXPORT_SYMBOL_GPL(br_forward_finish);
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static void __br_forward(const struct net_bridge_port *to,
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struct sk_buff *skb, bool local_orig)
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{
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struct net_bridge_vlan_group *vg;
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struct net_device *indev;
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struct net *net;
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int br_hook;
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vg = nbp_vlan_group_rcu(to);
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skb = br_handle_vlan(to->br, to, vg, skb);
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if (!skb)
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return;
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indev = skb->dev;
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skb->dev = to->dev;
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if (!local_orig) {
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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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br_hook = NF_BR_FORWARD;
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skb_forward_csum(skb);
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net = dev_net(indev);
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} else {
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if (unlikely(netpoll_tx_running(to->br->dev))) {
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if (!is_skb_forwardable(skb->dev, 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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br_hook = NF_BR_LOCAL_OUT;
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net = dev_net(skb->dev);
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indev = NULL;
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}
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NF_HOOK(NFPROTO_BRIDGE, br_hook,
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net, NULL, skb, indev, skb->dev,
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br_forward_finish);
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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, bool local_orig)
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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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__br_forward(prev, skb, local_orig);
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return 0;
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}
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/**
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* br_forward - forward a packet to a specific port
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* @to: destination port
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* @skb: packet being forwarded
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* @local_rcv: packet will be received locally after forwarding
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* @local_orig: packet is locally originated
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*
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* Should be called with rcu_read_lock.
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*/
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void br_forward(const struct net_bridge_port *to,
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struct sk_buff *skb, bool local_rcv, bool local_orig)
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{
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if (to && should_deliver(to, skb)) {
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if (local_rcv)
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deliver_clone(to, skb, local_orig);
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else
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__br_forward(to, skb, local_orig);
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return;
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}
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if (!local_rcv)
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kfree_skb(skb);
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}
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EXPORT_SYMBOL_GPL(br_forward);
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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, bool local_orig)
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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, local_orig);
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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 rcu_read_lock */
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void br_flood(struct net_bridge *br, struct sk_buff *skb,
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enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
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{
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u8 igmp_type = br_multicast_igmp_type(skb);
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struct net_bridge_port *prev = NULL;
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struct net_bridge_port *p;
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list_for_each_entry_rcu(p, &br->port_list, list) {
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/* Do not flood unicast traffic to ports that turn it off, nor
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* other traffic if flood off, except for traffic we originate
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*/
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switch (pkt_type) {
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case BR_PKT_UNICAST:
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if (!(p->flags & BR_FLOOD))
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continue;
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break;
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case BR_PKT_MULTICAST:
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if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
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continue;
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break;
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case BR_PKT_BROADCAST:
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if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
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continue;
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break;
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}
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/* Do not flood to ports that enable proxy ARP */
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if (p->flags & BR_PROXYARP)
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continue;
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if ((p->flags & (BR_PROXYARP_WIFI | BR_NEIGH_SUPPRESS)) &&
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BR_INPUT_SKB_CB(skb)->proxyarp_replied)
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continue;
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prev = maybe_deliver(prev, p, skb, local_orig);
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if (IS_ERR(prev))
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goto out;
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if (prev == p)
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br_multicast_count(p->br, p, skb, igmp_type,
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BR_MCAST_DIR_TX);
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}
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if (!prev)
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goto out;
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if (local_rcv)
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deliver_clone(prev, skb, local_orig);
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else
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__br_forward(prev, skb, local_orig);
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return;
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out:
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if (!local_rcv)
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kfree_skb(skb);
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}
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#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
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static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
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const unsigned char *addr, bool local_orig)
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{
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struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
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const unsigned char *src = eth_hdr(skb)->h_source;
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if (!should_deliver(p, skb))
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return;
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/* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
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if (skb->dev == p->dev && ether_addr_equal(src, addr))
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return;
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skb = skb_copy(skb, GFP_ATOMIC);
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if (!skb) {
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dev->stats.tx_dropped++;
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return;
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}
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if (!is_broadcast_ether_addr(addr))
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memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
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__br_forward(p, skb, local_orig);
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}
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/* called with rcu_read_lock */
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void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
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struct sk_buff *skb,
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bool local_rcv, bool local_orig)
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{
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struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
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u8 igmp_type = br_multicast_igmp_type(skb);
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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 = hlist_entry_safe(rp, struct net_bridge_port, rlist);
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if ((unsigned long)lport > (unsigned long)rport) {
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port = lport;
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if (port->flags & BR_MULTICAST_TO_UNICAST) {
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maybe_deliver_addr(lport, skb, p->eth_addr,
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local_orig);
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goto delivered;
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}
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} else {
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port = rport;
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}
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prev = maybe_deliver(prev, port, skb, local_orig);
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delivered:
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if (IS_ERR(prev))
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goto out;
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if (prev == port)
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br_multicast_count(port->br, port, skb, igmp_type,
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BR_MCAST_DIR_TX);
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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 (local_rcv)
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deliver_clone(prev, skb, local_orig);
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else
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__br_forward(prev, skb, local_orig);
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return;
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out:
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if (!local_rcv)
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kfree_skb(skb);
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}
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#endif
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