7026b1ddb6
On the output paths in particular, we have to sometimes deal with two socket contexts. First, and usually skb->sk, is the local socket that generated the frame. And second, is potentially the socket used to control a tunneling socket, such as one the encapsulates using UDP. We do not want to disassociate skb->sk when encapsulating in order to fix this, because that would break socket memory accounting. The most extreme case where this can cause huge problems is an AF_PACKET socket transmitting over a vxlan device. We hit code paths doing checks that assume they are dealing with an ipv4 socket, but are actually operating upon the AF_PACKET one. Signed-off-by: David S. Miller <davem@davemloft.net>
293 lines
6.6 KiB
C
293 lines
6.6 KiB
C
/*
|
|
* Forwarding decision
|
|
* 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/err.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/netpoll.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/if_vlan.h>
|
|
#include <linux/netfilter_bridge.h>
|
|
#include "br_private.h"
|
|
|
|
static int deliver_clone(const struct net_bridge_port *prev,
|
|
struct sk_buff *skb,
|
|
void (*__packet_hook)(const struct net_bridge_port *p,
|
|
struct sk_buff *skb));
|
|
|
|
/* Don't forward packets to originating port or forwarding disabled */
|
|
static inline int should_deliver(const struct net_bridge_port *p,
|
|
const struct sk_buff *skb)
|
|
{
|
|
return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
|
|
br_allowed_egress(p->br, nbp_get_vlan_info(p), skb) &&
|
|
p->state == BR_STATE_FORWARDING;
|
|
}
|
|
|
|
int br_dev_queue_push_xmit(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
if (!is_skb_forwardable(skb->dev, skb)) {
|
|
kfree_skb(skb);
|
|
} else {
|
|
skb_push(skb, ETH_HLEN);
|
|
br_drop_fake_rtable(skb);
|
|
dev_queue_xmit(skb);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
|
|
|
|
int br_forward_finish(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, sk, skb,
|
|
NULL, skb->dev,
|
|
br_dev_queue_push_xmit);
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(br_forward_finish);
|
|
|
|
static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
|
|
if (!skb)
|
|
return;
|
|
|
|
skb->dev = to->dev;
|
|
|
|
if (unlikely(netpoll_tx_running(to->br->dev))) {
|
|
if (!is_skb_forwardable(skb->dev, skb))
|
|
kfree_skb(skb);
|
|
else {
|
|
skb_push(skb, ETH_HLEN);
|
|
br_netpoll_send_skb(to, skb);
|
|
}
|
|
return;
|
|
}
|
|
|
|
NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, NULL, skb,
|
|
NULL, skb->dev,
|
|
br_forward_finish);
|
|
}
|
|
|
|
static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
struct net_device *indev;
|
|
|
|
if (skb_warn_if_lro(skb)) {
|
|
kfree_skb(skb);
|
|
return;
|
|
}
|
|
|
|
skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
|
|
if (!skb)
|
|
return;
|
|
|
|
indev = skb->dev;
|
|
skb->dev = to->dev;
|
|
skb_forward_csum(skb);
|
|
|
|
NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, NULL, skb,
|
|
indev, skb->dev,
|
|
br_forward_finish);
|
|
}
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
if (to && should_deliver(to, skb)) {
|
|
__br_deliver(to, skb);
|
|
return;
|
|
}
|
|
|
|
kfree_skb(skb);
|
|
}
|
|
EXPORT_SYMBOL_GPL(br_deliver);
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
|
|
{
|
|
if (should_deliver(to, skb)) {
|
|
if (skb0)
|
|
deliver_clone(to, skb, __br_forward);
|
|
else
|
|
__br_forward(to, skb);
|
|
return;
|
|
}
|
|
|
|
if (!skb0)
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
static int deliver_clone(const struct net_bridge_port *prev,
|
|
struct sk_buff *skb,
|
|
void (*__packet_hook)(const struct net_bridge_port *p,
|
|
struct sk_buff *skb))
|
|
{
|
|
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
|
|
|
|
skb = skb_clone(skb, GFP_ATOMIC);
|
|
if (!skb) {
|
|
dev->stats.tx_dropped++;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
__packet_hook(prev, skb);
|
|
return 0;
|
|
}
|
|
|
|
static struct net_bridge_port *maybe_deliver(
|
|
struct net_bridge_port *prev, struct net_bridge_port *p,
|
|
struct sk_buff *skb,
|
|
void (*__packet_hook)(const struct net_bridge_port *p,
|
|
struct sk_buff *skb))
|
|
{
|
|
int err;
|
|
|
|
if (!should_deliver(p, skb))
|
|
return prev;
|
|
|
|
if (!prev)
|
|
goto out;
|
|
|
|
err = deliver_clone(prev, skb, __packet_hook);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
|
|
out:
|
|
return p;
|
|
}
|
|
|
|
/* called under bridge lock */
|
|
static void br_flood(struct net_bridge *br, struct sk_buff *skb,
|
|
struct sk_buff *skb0,
|
|
void (*__packet_hook)(const struct net_bridge_port *p,
|
|
struct sk_buff *skb),
|
|
bool unicast)
|
|
{
|
|
struct net_bridge_port *p;
|
|
struct net_bridge_port *prev;
|
|
|
|
prev = NULL;
|
|
|
|
list_for_each_entry_rcu(p, &br->port_list, list) {
|
|
/* Do not flood unicast traffic to ports that turn it off */
|
|
if (unicast && !(p->flags & BR_FLOOD))
|
|
continue;
|
|
|
|
/* Do not flood to ports that enable proxy ARP */
|
|
if (p->flags & BR_PROXYARP)
|
|
continue;
|
|
if ((p->flags & BR_PROXYARP_WIFI) &&
|
|
BR_INPUT_SKB_CB(skb)->proxyarp_replied)
|
|
continue;
|
|
|
|
prev = maybe_deliver(prev, p, skb, __packet_hook);
|
|
if (IS_ERR(prev))
|
|
goto out;
|
|
}
|
|
|
|
if (!prev)
|
|
goto out;
|
|
|
|
if (skb0)
|
|
deliver_clone(prev, skb, __packet_hook);
|
|
else
|
|
__packet_hook(prev, skb);
|
|
return;
|
|
|
|
out:
|
|
if (!skb0)
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
|
|
{
|
|
br_flood(br, skb, NULL, __br_deliver, unicast);
|
|
}
|
|
|
|
/* called under bridge lock */
|
|
void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
|
|
struct sk_buff *skb2, bool unicast)
|
|
{
|
|
br_flood(br, skb, skb2, __br_forward, unicast);
|
|
}
|
|
|
|
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
|
|
/* called with rcu_read_lock */
|
|
static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
|
|
struct sk_buff *skb, struct sk_buff *skb0,
|
|
void (*__packet_hook)(
|
|
const struct net_bridge_port *p,
|
|
struct sk_buff *skb))
|
|
{
|
|
struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
|
|
struct net_bridge *br = netdev_priv(dev);
|
|
struct net_bridge_port *prev = NULL;
|
|
struct net_bridge_port_group *p;
|
|
struct hlist_node *rp;
|
|
|
|
rp = rcu_dereference(hlist_first_rcu(&br->router_list));
|
|
p = mdst ? rcu_dereference(mdst->ports) : NULL;
|
|
while (p || rp) {
|
|
struct net_bridge_port *port, *lport, *rport;
|
|
|
|
lport = p ? p->port : NULL;
|
|
rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
|
|
NULL;
|
|
|
|
port = (unsigned long)lport > (unsigned long)rport ?
|
|
lport : rport;
|
|
|
|
prev = maybe_deliver(prev, port, skb, __packet_hook);
|
|
if (IS_ERR(prev))
|
|
goto out;
|
|
|
|
if ((unsigned long)lport >= (unsigned long)port)
|
|
p = rcu_dereference(p->next);
|
|
if ((unsigned long)rport >= (unsigned long)port)
|
|
rp = rcu_dereference(hlist_next_rcu(rp));
|
|
}
|
|
|
|
if (!prev)
|
|
goto out;
|
|
|
|
if (skb0)
|
|
deliver_clone(prev, skb, __packet_hook);
|
|
else
|
|
__packet_hook(prev, skb);
|
|
return;
|
|
|
|
out:
|
|
if (!skb0)
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
|
|
struct sk_buff *skb)
|
|
{
|
|
br_multicast_flood(mdst, skb, NULL, __br_deliver);
|
|
}
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
|
|
struct sk_buff *skb, struct sk_buff *skb2)
|
|
{
|
|
br_multicast_flood(mdst, skb, skb2, __br_forward);
|
|
}
|
|
#endif
|