/*
* Handle firewalling
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
* Bart De Schuymer (maintainer) <bdschuym@pandora.be>
*
* Changes:
* Apr 29 2003: physdev module support (bdschuym)
* Jun 19 2003: let arptables see bridged ARP traffic (bdschuym)
* Oct 06 2003: filter encapsulated IP/ARP VLAN traffic on untagged bridge
* (bdschuym)
* Sep 01 2004: add IPv6 filtering (bdschuym)
*
* 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/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_filter_vlan_tagged 0
#define brnf_filter_pppoe_tagged 0
#endif
static inline __be16 vlan_proto(const struct sk_buff *skb)
{
return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
}
#define IS_VLAN_IP(skb) \
(skb->protocol == htons(ETH_P_8021Q) && \
vlan_proto(skb) == htons(ETH_P_IP) && \
brnf_filter_vlan_tagged)
#define IS_VLAN_IPV6(skb) \
(skb->protocol == htons(ETH_P_8021Q) && \
vlan_proto(skb) == htons(ETH_P_IPV6) &&\
brnf_filter_vlan_tagged)
#define IS_VLAN_ARP(skb) \
(skb->protocol == htons(ETH_P_8021Q) && \
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 struct dst_ops fake_dst_ops = {
.family = AF_INET,
.protocol = cpu_to_be16(ETH_P_IP),
.update_pmtu = fake_update_pmtu,
.entries = ATOMIC_INIT(0),
};
/*
* 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.
*/
void br_netfilter_rtable_init(struct net_bridge *br)
{
struct rtable *rt = &br->fake_rtable;
atomic_set(&rt->u.dst.__refcnt, 1);
rt->u.dst.dev = br->dev;
rt->u.dst.path = &rt->u.dst;
rt->u.dst.metrics[RTAX_MTU - 1] = 1500;
rt->u.dst.flags = DST_NOXFRM;
rt->u.dst.ops = &fake_dst_ops;
}
static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
{
struct net_bridge_port *port = rcu_dereference(dev->br_port);
return port ? &port->br->fake_rtable : NULL;
}
static inline struct net_device *bridge_parent(const struct net_device *dev)
{
struct net_bridge_port *port = rcu_dereference(dev->br_port);
return port ? port->br->dev : NULL;
}
static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
{
skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
if (likely(skb->nf_bridge))
atomic_set(&(skb->nf_bridge->use), 1);
return skb->nf_bridge;
}
static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
{
struct nf_bridge_info *nf_bridge = skb->nf_bridge;
if (atomic_read(&nf_bridge->use) > 1) {
struct nf_bridge_info *tmp = nf_bridge_alloc(skb);
if (tmp) {
memcpy