/*
* Handle firewalling
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
* Bart De Schuymer <bdschuym@pandora.be>
*
* 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.
*
* Lennert dedicates this file to Kerstin Wurdinger.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/ip.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/if_pppox.h>
#include <linux/ppp_defs.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter_arp.h>
#include <linux/in_route.h>
#include <linux/inetdevice.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/route.h>
#include <asm/uaccess.h>
#include "br_private.h"
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
#define skb_origaddr(skb) (((struct bridge_skb_cb *) \
(skb->nf_bridge->data))->daddr.ipv4)
#define store_orig_dstaddr(skb) (skb_origaddr(skb) = ip_hdr(skb)->daddr)
#define dnat_took_place(skb) (skb_origaddr(skb) != ip_hdr(skb)->daddr)
#ifdef CONFIG_SYSCTL
static struct ctl_table_header *brnf_sysctl_header;
static int brnf_call_iptables __read_mostly = 1;
static int brnf_call_ip6tables __read_mostly = 1;
static int brnf_call_arptables __read_mostly = 1;
static int brnf_filter_vlan_tagged __read_mostly = 0;
static int brnf_filter_pppoe_tagged __read_mostly = 0;
#else
#define brnf_call_iptables 1
#define brnf_call_ip6tables 1
#define brnf_call_arptables 1
#define brnf_filter_vlan_tagged 0
#define brnf_filter_pppoe_tagged 0
#endif
#define IS_IP(skb) \
(!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IP))
#define IS_IPV6(skb) \
(!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6))
#define IS_ARP(skb) \
(!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_ARP))
static inline __be16 vlan_proto(const struct sk_buff *skb)
{
if (vlan_tx_tag_present(skb))
return skb->protocol;
else if (skb->protocol == htons(ETH_P_8021Q))
return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
else
return 0;
}
#define IS_VLAN_IP(skb) \
(vlan_proto(skb) == htons(ETH_P_IP) && \
brnf_filter_vlan_tagged)
#define IS_VLAN_IPV6(skb) \
(vlan_proto(skb) == htons(ETH_P_IPV6) && \
brnf_filter_vlan_tagged)
#define IS_VLAN_ARP(skb) \
(vlan_proto(skb) == htons(ETH_P_ARP) && \
brnf_filter_vlan_tagged)
static inline __be16 pppoe_proto(const struct sk_buff *skb)
{
return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
sizeof(struct pppoe_hdr)));
}
#define IS_PPPOE_IP(skb) \
(skb->protocol == htons(ETH_P_PPP_SES) && \
pppoe_proto(skb) == htons(PPP_IP) && \
brnf_filter_pppoe_tagged)
#define IS_PPPOE_IPV6(skb) \
(skb->protocol == htons(ETH_P_PPP_SES) && \
pppoe_proto(skb) == htons(PPP_IPV6) && \
brnf_filter_pppoe_tagged)
static void fake_update_pmtu(struct dst_entry *dst, u32 mtu)
{
}
static u32 *fake_cow_metrics(struct dst_entry *dst, unsigned long old)
{
return NULL;
}
static struct neighbour *fake_neigh_lookup(const struct dst_entry *dst, const void *daddr)
{
return NULL;
}
static unsigned int fake_mtu(const struct dst_entry *dst)
{
return dst->dev->mtu;
}
static struct dst_ops fake_dst_ops = {
.family = AF_INET,
.protocol = cpu_to_be16(ETH_P_IP),
.update_pmtu = fake_update_pmtu,
.cow_metrics = fake_cow_metrics,
.neigh_lookup = fake_neigh_lookup,
.mtu = fake_mtu,
};
/*
* Initialize bogus route table used to keep netfilter happy.
* Currently, we fill in the PMTU entry because netfilter
* refragmentation needs it, and the rt_flags entry because
* ipt_REJECT needs it. Future netfilter modules might
* require us to fill additional fields.
*/
static const u32 br_dst_default_metrics[RTAX_MAX] = {
[RTAX_MTU - 1] = 1500,
};
void br_netfilter_rtable_init(struct net_bridge *br)
{
struct rtable *rt = &br->fake_rtable;
atomic_set(&rt->dst.__refcnt, 1);
rt->dst.dev = br->dev;
rt->dst.path = &rt->dst;
dst_init_metrics(&rt->dst, br_dst_default_metrics, true);
rt->dst.flags = DST_NOXFRM | DST_NOPEER;
rt->dst.ops = &fake_dst_ops;
}
static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
{
struct net_bridge_port *port;
port = br_port_get_rcu(dev);
return port ? &port->br->fake_rtable : NULL;
}
static inline struct net_device *bridge_parent(const struct net_device *dev