linux_dsm_epyc7002/net/bridge/br_input.c
Vlad Yasevich 867a59436f bridge: Add a flag to control unicast packet flood.
Add a flag to control flood of unicast traffic.  By default, flood is
on and the bridge will flood unicast traffic if it doesn't know
the destination.  When the flag is turned off, unicast traffic
without an FDB will not be forwarded to the specified port.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-11 02:04:32 -07:00

243 lines
5.8 KiB
C

/*
* Handle incoming frames
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netfilter_bridge.h>
#include <linux/export.h>
#include <linux/rculist.h>
#include "br_private.h"
/* Hook for brouter */
br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
EXPORT_SYMBOL(br_should_route_hook);
static int br_pass_frame_up(struct sk_buff *skb)
{
struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
struct net_bridge *br = netdev_priv(brdev);
struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
u64_stats_update_begin(&brstats->syncp);
brstats->rx_packets++;
brstats->rx_bytes += skb->len;
u64_stats_update_end(&brstats->syncp);
/* Bridge is just like any other port. Make sure the
* packet is allowed except in promisc modue when someone
* may be running packet capture.
*/
if (!(brdev->flags & IFF_PROMISC) &&
!br_allowed_egress(br, br_get_vlan_info(br), skb)) {
kfree_skb(skb);
return NET_RX_DROP;
}
skb = br_handle_vlan(br, br_get_vlan_info(br), skb);
if (!skb)
return NET_RX_DROP;
indev = skb->dev;
skb->dev = brdev;
return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
netif_receive_skb);
}
/* note: already called with rcu_read_lock */
int br_handle_frame_finish(struct sk_buff *skb)
{
const unsigned char *dest = eth_hdr(skb)->h_dest;
struct net_bridge_port *p = br_port_get_rcu(skb->dev);
struct net_bridge *br;
struct net_bridge_fdb_entry *dst;
struct net_bridge_mdb_entry *mdst;
struct sk_buff *skb2;
bool unicast = true;
u16 vid = 0;
if (!p || p->state == BR_STATE_DISABLED)
goto drop;
if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb, &vid))
goto drop;
/* insert into forwarding database after filtering to avoid spoofing */
br = p->br;
if (p->flags & BR_LEARNING)
br_fdb_update(br, p, eth_hdr(skb)->h_source, vid);
if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
br_multicast_rcv(br, p, skb))
goto drop;
if (p->state == BR_STATE_LEARNING)
goto drop;
BR_INPUT_SKB_CB(skb)->brdev = br->dev;
/* The packet skb2 goes to the local host (NULL to skip). */
skb2 = NULL;
if (br->dev->flags & IFF_PROMISC)
skb2 = skb;
dst = NULL;
if (is_broadcast_ether_addr(dest)) {
skb2 = skb;
unicast = false;
} else if (is_multicast_ether_addr(dest)) {
mdst = br_mdb_get(br, skb, vid);
if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) {
if ((mdst && mdst->mglist) ||
br_multicast_is_router(br))
skb2 = skb;
br_multicast_forward(mdst, skb, skb2);
skb = NULL;
if (!skb2)
goto out;
} else
skb2 = skb;
unicast = false;
br->dev->stats.multicast++;
} else if ((dst = __br_fdb_get(br, dest, vid)) &&
dst->is_local) {
skb2 = skb;
/* Do not forward the packet since it's local. */
skb = NULL;
}
if (skb) {
if (dst) {
dst->used = jiffies;
br_forward(dst->dst, skb, skb2);
} else
br_flood_forward(br, skb, skb2, unicast);
}
if (skb2)
return br_pass_frame_up(skb2);
out:
return 0;
drop:
kfree_skb(skb);
goto out;
}
/* note: already called with rcu_read_lock */
static int br_handle_local_finish(struct sk_buff *skb)
{
struct net_bridge_port *p = br_port_get_rcu(skb->dev);
u16 vid = 0;
br_vlan_get_tag(skb, &vid);
if (p->flags & BR_LEARNING)
br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid);
return 0; /* process further */
}
/*
* Return NULL if skb is handled
* note: already called with rcu_read_lock
*/
rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
{
struct net_bridge_port *p;
struct sk_buff *skb = *pskb;
const unsigned char *dest = eth_hdr(skb)->h_dest;
br_should_route_hook_t *rhook;
if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
return RX_HANDLER_PASS;
if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
goto drop;
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
return RX_HANDLER_CONSUMED;
p = br_port_get_rcu(skb->dev);
if (unlikely(is_link_local_ether_addr(dest))) {
/*
* See IEEE 802.1D Table 7-10 Reserved addresses
*
* Assignment Value
* Bridge Group Address 01-80-C2-00-00-00
* (MAC Control) 802.3 01-80-C2-00-00-01
* (Link Aggregation) 802.3 01-80-C2-00-00-02
* 802.1X PAE address 01-80-C2-00-00-03
*
* 802.1AB LLDP 01-80-C2-00-00-0E
*
* Others reserved for future standardization
*/
switch (dest[5]) {
case 0x00: /* Bridge Group Address */
/* If STP is turned off,
then must forward to keep loop detection */
if (p->br->stp_enabled == BR_NO_STP)
goto forward;
break;
case 0x01: /* IEEE MAC (Pause) */
goto drop;
default:
/* Allow selective forwarding for most other protocols */
if (p->br->group_fwd_mask & (1u << dest[5]))
goto forward;
}
/* Deliver packet to local host only */
if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
NULL, br_handle_local_finish)) {
return RX_HANDLER_CONSUMED; /* consumed by filter */
} else {
*pskb = skb;
return RX_HANDLER_PASS; /* continue processing */
}
}
forward:
switch (p->state) {
case BR_STATE_FORWARDING:
rhook = rcu_dereference(br_should_route_hook);
if (rhook) {
if ((*rhook)(skb)) {
*pskb = skb;
return RX_HANDLER_PASS;
}
dest = eth_hdr(skb)->h_dest;
}
/* fall through */
case BR_STATE_LEARNING:
if (ether_addr_equal(p->br->dev->dev_addr, dest))
skb->pkt_type = PACKET_HOST;
NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish);
break;
default:
drop:
kfree_skb(skb);
}
return RX_HANDLER_CONSUMED;
}