Commit 0aa30dc6 authored by Bart De Schuymer's avatar Bart De Schuymer Committed by David S. Miller

[BRIDGE]: bridge-nf, map IPv4 hooks onto bridge hooks.

parent 500ae766
......@@ -117,17 +117,23 @@ extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
/* This is gross, but inline doesn't cut it for avoiding the function
call in fast path: gcc doesn't inline (needs value tracking?). --RR */
#ifdef CONFIG_NETFILTER_DEBUG
#define NF_HOOK nf_hook_slow
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn), INT_MIN)
#define NF_HOOK_THRESH nf_hook_slow
#else
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
(list_empty(&nf_hooks[(pf)][(hook)]) \
? (okfn)(skb) \
: nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn)))
: nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn), INT_MIN))
#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
(list_empty(&nf_hooks[(pf)][(hook)]) \
? (okfn)(skb) \
: nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn), (thresh)))
#endif
int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb,
struct net_device *indev, struct net_device *outdev,
int (*okfn)(struct sk_buff *));
int (*okfn)(struct sk_buff *), int thresh);
/* Call setsockopt() */
int nf_setsockopt(struct sock *sk, int pf, int optval, char *opt,
......
......@@ -6,6 +6,7 @@
#include <linux/config.h>
#include <linux/netfilter.h>
#include <asm/atomic.h>
/* Bridge Hooks */
/* After promisc drops, checksum checks. */
......@@ -22,14 +23,39 @@
#define NF_BR_BROUTING 5
#define NF_BR_NUMHOOKS 6
#define BRNF_PKT_TYPE 0x01
#define BRNF_BRIDGED_DNAT 0x02
#define BRNF_DONT_TAKE_PARENT 0x04
enum nf_br_hook_priorities {
NF_BR_PRI_FIRST = INT_MIN,
NF_BR_PRI_FILTER_BRIDGED = -200,
NF_BR_PRI_FILTER_OTHER = 200,
NF_BR_PRI_NAT_DST_BRIDGED = -300,
NF_BR_PRI_FILTER_BRIDGED = -200,
NF_BR_PRI_BRNF = 0,
NF_BR_PRI_NAT_DST_OTHER = 100,
NF_BR_PRI_FILTER_OTHER = 200,
NF_BR_PRI_NAT_SRC = 300,
NF_BR_PRI_LAST = INT_MAX,
};
static inline
struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
{
struct nf_bridge_info **nf_bridge = &(skb->nf_bridge);
if ((*nf_bridge = kmalloc(sizeof(**nf_bridge), GFP_ATOMIC)) != NULL) {
atomic_set(&(*nf_bridge)->use, 1);
(*nf_bridge)->mask = 0;
(*nf_bridge)->physindev = (*nf_bridge)->physoutdev = NULL;
}
return *nf_bridge;
}
struct bridge_skb_cb {
union {
__u32 ipv4;
} daddr;
};
#endif
......@@ -52,8 +52,10 @@
enum nf_ip_hook_priorities {
NF_IP_PRI_FIRST = INT_MIN,
NF_IP_PRI_CONNTRACK = -200,
NF_IP_PRI_BRIDGE_SABOTAGE_FORWARD = -175,
NF_IP_PRI_MANGLE = -150,
NF_IP_PRI_NAT_DST = -100,
NF_IP_PRI_BRIDGE_SABOTAGE_LOCAL_OUT = -50,
NF_IP_PRI_FILTER = 0,
NF_IP_PRI_NAT_SRC = 100,
NF_IP_PRI_LAST = INT_MAX,
......
......@@ -96,6 +96,17 @@ struct nf_conntrack {
struct nf_ct_info {
struct nf_conntrack *master;
};
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
struct nf_bridge_info {
atomic_t use;
struct net_device *physindev;
struct net_device *physoutdev;
unsigned int mask;
unsigned long hh[16 / sizeof(unsigned long)];
};
#endif
#endif
struct sk_buff_head {
......@@ -166,6 +177,7 @@ struct skb_shared_info {
* @nfcache: Cache info
* @nfct: Associated connection, if any
* @nf_debug: Netfilter debugging
* @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
* @tc_index: Traffic control index
*/
......@@ -236,6 +248,9 @@ struct sk_buff {
#ifdef CONFIG_NETFILTER_DEBUG
unsigned int nf_debug;
#endif
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
struct nf_bridge_info *nf_bridge;
#endif
#endif /* CONFIG_NETFILTER */
#if defined(CONFIG_HIPPI)
union {
......@@ -1146,6 +1161,20 @@ static inline void nf_conntrack_get(struct nf_ct_info *nfct)
if (nfct)
atomic_inc(&nfct->master->use);
}
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
{
if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
kfree(nf_bridge);
}
static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
{
if (nf_bridge)
atomic_inc(&nf_bridge->use);
}
#endif
#endif
#endif /* __KERNEL__ */
......
......@@ -9,6 +9,11 @@ obj-$(CONFIG_BRIDGE) += bridge.o
bridge-objs := br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \
br_ioctl.o br_notify.o br_stp.o br_stp_bpdu.o \
br_stp_if.o br_stp_timer.o
ifeq ($(CONFIG_NETFILTER),y)
bridge-objs += br_netfilter.o
endif
obj-$(CONFIG_BRIDGE_NF_EBTABLES) += netfilter/
include $(TOPDIR)/Rules.make
......@@ -45,6 +45,10 @@ static int __init br_init(void)
{
printk(KERN_INFO "NET4: Ethernet Bridge 008 for NET4.0\n");
#ifdef CONFIG_NETFILTER
if (br_netfilter_init())
return 1;
#endif
br_handle_frame_hook = br_handle_frame;
br_ioctl_hook = br_ioctl_deviceless_stub;
#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
......@@ -63,6 +67,9 @@ static void __br_clear_ioctl_hook(void)
static void __exit br_deinit(void)
{
#ifdef CONFIG_NETFILTER
br_netfilter_fini();
#endif
unregister_netdevice_notifier(&br_device_notifier);
br_call_ioctl_atomic(__br_clear_ioctl_hook);
......
......@@ -30,18 +30,23 @@ static inline int should_deliver(struct net_bridge_port *p, struct sk_buff *skb)
return 1;
}
static int __dev_queue_push_xmit(struct sk_buff *skb)
int br_dev_queue_push_xmit(struct sk_buff *skb)
{
#ifdef CONFIG_NETFILTER
if (skb->nf_bridge)
memcpy(skb->data - 16, skb->nf_bridge->hh, 16);
#endif
skb_push(skb, ETH_HLEN);
dev_queue_xmit(skb);
return 0;
}
static int __br_forward_finish(struct sk_buff *skb)
int br_forward_finish(struct sk_buff *skb)
{
NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
__dev_queue_push_xmit);
br_dev_queue_push_xmit);
return 0;
}
......@@ -53,7 +58,7 @@ static void __br_deliver(struct net_bridge_port *to, struct sk_buff *skb)
skb->nf_debug = 0;
#endif
NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
__br_forward_finish);
br_forward_finish);
}
static void __br_forward(struct net_bridge_port *to, struct sk_buff *skb)
......@@ -64,7 +69,7 @@ static void __br_forward(struct net_bridge_port *to, struct sk_buff *skb)
skb->dev = to->dev;
NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
__br_forward_finish);
br_forward_finish);
}
/* called under bridge lock */
......
......@@ -49,7 +49,7 @@ static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
br_pass_frame_up_finish);
}
static int br_handle_frame_finish(struct sk_buff *skb)
int br_handle_frame_finish(struct sk_buff *skb)
{
struct net_bridge *br;
unsigned char *dest;
......
/*
* Handle firewalling
* Linux ethernet bridge
*
* Authors:
* Lennert Buytenhek <buytenh@gnu.org>
* Bart De Schuymer <bart.de.schuymer@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/ip.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/if_ether.h>
#include <linux/netfilter_bridge.h>
#include <linux/netfilter_ipv4.h>
#include <linux/in_route.h>
#include <net/ip.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
#include "br_private.h"
#define skb_origaddr(skb) (((struct bridge_skb_cb *) \
(skb->cb))->daddr.ipv4)
#define store_orig_dstaddr(skb) (skb_origaddr(skb) = (skb)->nh.iph->daddr)
#define dnat_took_place(skb) (skb_origaddr(skb) != (skb)->nh.iph->daddr)
#define clear_cb(skb) (memset(&skb_origaddr(skb), 0, \
sizeof(struct bridge_skb_cb)))
#define has_bridge_parent(device) ((device)->br_port != NULL)
#define bridge_parent(device) (&((device)->br_port->br->dev))
/* We need these fake structures to make netfilter happy --
* lots of places assume that skb->dst != NULL, which isn't
* all that unreasonable.
*
* 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 struct net_device __fake_net_device = {
hard_header_len: ETH_HLEN
};
static struct rtable __fake_rtable = {
u: {
dst: {
__refcnt: ATOMIC_INIT(1),
dev: &__fake_net_device,
pmtu: 1500
}
},
rt_flags: 0
};
/* PF_BRIDGE/PRE_ROUTING *********************************************/
static void __br_dnat_complain(void)
{
static unsigned long last_complaint = 0;
if (jiffies - last_complaint >= 5 * HZ) {
printk(KERN_WARNING "Performing cross-bridge DNAT requires IP "
"forwarding to be enabled\n");
last_complaint = jiffies;
}
}
/* This requires some explaining. If DNAT has taken place,
* we will need to fix up the destination Ethernet address,
* and this is a tricky process.
*
* There are two cases to consider:
* 1. The packet was DNAT'ed to a device in the same bridge
* port group as it was received on. We can still bridge
* the packet.
* 2. The packet was DNAT'ed to a different device, either
* a non-bridged device or another bridge port group.
* The packet will need to be routed.
*
* The correct way of distinguishing between these two cases is to
* call ip_route_input() and to look at skb->dst->dev, which is
* changed to the destination device if ip_route_input() succeeds.
*
* Let us first consider the case that ip_route_input() succeeds:
*
* If skb->dst->dev equals the logical bridge device the packet
* came in on, we can consider this bridging. We then call
* skb->dst->output() which will make the packet enter br_nf_local_out()
* not much later. In that function it is assured that the iptables
* FORWARD chain is traversed for the packet.
*
* Otherwise, the packet is considered to be routed and we just
* change the destination MAC address so that the packet will
* later be passed up to the IP stack to be routed.
*
* Let us now consider the case that ip_route_input() fails:
*
* After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input()
* will fail, while ip_route_output() will return success. The source
* address for ip_route_output() is set to zero, so ip_route_output()
* thinks we're handling a locally generated packet and won't care
* if IP forwarding is allowed. We send a warning message to the users's
* log telling her to put IP forwarding on.
*
* ip_route_input() will also fail if there is no route available.
* In that case we just drop the packet.
*
* --Lennert, 20020411
* --Bart, 20020416 (updated)
* --Bart, 20021007 (updated)
*/
static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
{
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug |= (1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_FORWARD);
#endif
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
skb->nf_bridge->mask |= BRNF_PKT_TYPE;
}
skb->dev = bridge_parent(skb->dev);
skb->dst->output(skb);
return 0;
}
static int br_nf_pre_routing_finish(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct iphdr *iph = skb->nh.iph;
struct nf_bridge_info *nf_bridge = skb->nf_bridge;
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug ^= (1 << NF_BR_PRE_ROUTING);
#endif
if (nf_bridge->mask & BRNF_PKT_TYPE) {
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->mask ^= BRNF_PKT_TYPE;
}
if (dnat_took_place(skb)) {
if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
dev)) {
struct rtable *rt;
if (!ip_route_output(&rt, iph->daddr, 0, iph->tos, 0)) {
/* Bridged-and-DNAT'ed traffic doesn't
* require ip_forwarding.
*/
if (((struct dst_entry *)rt)->dev == dev) {
skb->dst = (struct dst_entry *)rt;
goto bridged_dnat;
}
__br_dnat_complain();
dst_release((struct dst_entry *)rt);
}
kfree_skb(skb);
return 0;
} else {
if (skb->dst->dev == dev) {
bridged_dnat:
/* Tell br_nf_local_out this is a
* bridged frame
*/
nf_bridge->mask |= BRNF_BRIDGED_DNAT;
skb->dev = nf_bridge->physindev;
clear_cb(skb);
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING,
skb, skb->dev, NULL,
br_nf_pre_routing_finish_bridge,
1);
return 0;
}
memcpy(skb->mac.ethernet->h_dest, dev->dev_addr,
ETH_ALEN);
}
} else {
skb->dst = (struct dst_entry *)&__fake_rtable;
dst_hold(skb->dst);
}
clear_cb(skb);
skb->dev = nf_bridge->physindev;
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
}
/* Replicate the checks that IPv4 does on packet reception.
* Set skb->dev to the bridge device (i.e. parent of the
* receiving device) to make netfilter happy, the REDIRECT
* target in particular. Save the original destination IP
* address to be able to detect DNAT afterwards.
*/
static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct iphdr *iph;
__u32 len;
struct sk_buff *skb;
struct nf_bridge_info *nf_bridge;
if ((*pskb)->protocol != __constant_htons(ETH_P_IP))
return NF_ACCEPT;
if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL)
goto out;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto inhdr_error;
iph = skb->nh.iph;
if (iph->ihl < 5 || iph->version != 4)
goto inhdr_error;
if (!pskb_may_pull(skb, 4*iph->ihl))
goto inhdr_error;
iph = skb->nh.iph;
if (ip_fast_csum((__u8 *)iph, iph->ihl) != 0)
goto inhdr_error;
len = ntohs(iph->tot_len);
if (skb->len < len || len < 4*iph->ihl)
goto inhdr_error;
if (skb->len > len) {
__pskb_trim(skb, len);
if (skb->ip_summed == CHECKSUM_HW)
skb->ip_summed = CHECKSUM_NONE;
}
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug ^= (1 << NF_IP_PRE_ROUTING);
#endif
if ((nf_bridge = nf_bridge_alloc(skb)) == NULL)
return NF_DROP;
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
nf_bridge->mask |= BRNF_PKT_TYPE;
}
nf_bridge->physindev = skb->dev;
skb->dev = bridge_parent(skb->dev);
store_orig_dstaddr(skb);
NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
br_nf_pre_routing_finish);
return NF_STOLEN;
inhdr_error:
// IP_INC_STATS_BH(IpInHdrErrors);
out:
return NF_DROP;
}
/* PF_BRIDGE/LOCAL_IN ************************************************/
/* The packet is locally destined, which requires a real
* dst_entry, so detach the fake one. On the way up, the
* packet would pass through PRE_ROUTING again (which already
* took place when the packet entered the bridge), but we
* register an IPv4 PRE_ROUTING 'sabotage' hook that will
* prevent this from happening.
*/
static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *pskb;
if (skb->protocol != __constant_htons(ETH_P_IP))
return NF_ACCEPT;
if (skb->dst == (struct dst_entry *)&__fake_rtable) {
dst_release(skb->dst);
skb->dst = NULL;
}
return NF_ACCEPT;
}
/* PF_BRIDGE/FORWARD *************************************************/
static int br_nf_forward_finish(struct sk_buff *skb)
{
struct nf_bridge_info *nf_bridge = skb->nf_bridge;
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug ^= (1 << NF_BR_FORWARD);
#endif
if (nf_bridge->mask & BRNF_PKT_TYPE) {
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->mask ^= BRNF_PKT_TYPE;
}
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, nf_bridge->physindev,
skb->dev, br_forward_finish, 1);
return 0;
}
/* This is the 'purely bridged' case. We pass the packet to
* netfilter with indev and outdev set to the bridge device,
* but we are still able to filter on the 'real' indev/outdev
* because another bit of the bridge-nf patch overloads the
* '-i' and '-o' iptables interface checks to take
* skb->phys{in,out}dev into account as well (so both the real
* device and the bridge device will match).
*/
static unsigned int br_nf_forward(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *pskb;
struct nf_bridge_info *nf_bridge;
if (skb->protocol != __constant_htons(ETH_P_IP))
return NF_ACCEPT;
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug ^= (1 << NF_BR_FORWARD);
#endif
nf_bridge = skb->nf_bridge;
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
nf_bridge->mask |= BRNF_PKT_TYPE;
}
nf_bridge->physoutdev = skb->dev;
NF_HOOK(PF_INET, NF_IP_FORWARD, skb, bridge_parent(nf_bridge->physindev),
bridge_parent(skb->dev), br_nf_forward_finish);
return NF_STOLEN;
}
/* PF_BRIDGE/LOCAL_OUT ***********************************************/
static int br_nf_local_out_finish(struct sk_buff *skb)
{
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug &= ~(1 << NF_BR_LOCAL_OUT);
#endif
NF_HOOK_THRESH(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
br_forward_finish, NF_BR_PRI_FIRST + 1);
return 0;
}
/* This function sees both locally originated IP packets and forwarded
* IP packets (in both cases the destination device is a bridge
* device). It also sees bridged-and-DNAT'ed packets.
* For the sake of interface transparency (i.e. properly
* overloading the '-o' option), we steal packets destined to
* a bridge device away from the PF_INET/FORWARD and PF_INET/OUTPUT hook
* functions, and give them back later, when we have determined the real
* output device. This is done in here.
*
* If (nf_bridge->mask & BRNF_BRIDGED_DNAT) then the packet is bridged
* and we fake the PF_BRIDGE/FORWARD hook. The function br_nf_forward()
* will then fake the PF_INET/FORWARD hook. br_nf_local_out() has priority
* NF_BR_PRI_FIRST, so no relevant PF_BRIDGE/INPUT functions have been nor
* will be executed.
* Otherwise, if nf_bridge->physindev is NULL, the bridge-nf code never touched
* this packet before, and so the packet was locally originated. We fake
* the PF_INET/LOCAL_OUT hook.
* Finally, if nf_bridge->physindev isn't NULL, then the packet was IP routed,
* so we fake the PF_INET/FORWARD hook. ipv4_sabotage_out() makes sure
* even routed packets that didn't arrive on a bridge interface have their
* nf_bridge->physindev set.
*/
static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*_okfn)(struct sk_buff *))
{
int (*okfn)(struct sk_buff *skb);
struct net_device *realindev;
struct sk_buff *skb = *pskb;
struct nf_bridge_info *nf_bridge;
if (skb->protocol != __constant_htons(ETH_P_IP))
return NF_ACCEPT;
/* Sometimes we get packets with NULL ->dst here (for example,
* running a dhcp client daemon triggers this).
*/
if (skb->dst == NULL)
return NF_ACCEPT;
nf_bridge = skb->nf_bridge;
nf_bridge->physoutdev = skb->dev;
realindev = nf_bridge->physindev;
/* Bridged, take PF_BRIDGE/FORWARD.
* (see big note in front of br_nf_pre_routing_finish)
*/
if (nf_bridge->mask & BRNF_BRIDGED_DNAT) {
okfn = br_forward_finish;
if (nf_bridge->mask & BRNF_PKT_TYPE) {
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->mask ^= BRNF_PKT_TYPE;
}
NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, realindev,
skb->dev, okfn);
} else {
okfn = br_nf_local_out_finish;
/* IP forwarded traffic has a physindev, locally
* generated traffic hasn't.
*/
if (realindev != NULL) {
if (((nf_bridge->mask & BRNF_DONT_TAKE_PARENT) == 0) &&
has_bridge_parent(realindev))
realindev = bridge_parent(realindev);
NF_HOOK_THRESH(PF_INET, NF_IP_FORWARD, skb, realindev,
bridge_parent(skb->dev), okfn,
NF_IP_PRI_BRIDGE_SABOTAGE_FORWARD + 1);
} else {
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug ^= (1 << NF_IP_LOCAL_OUT);
#endif
NF_HOOK_THRESH(PF_INET, NF_IP_LOCAL_OUT, skb, realindev,
bridge_parent(skb->dev), okfn,
NF_IP_PRI_BRIDGE_SABOTAGE_LOCAL_OUT + 1);
}
}
return NF_STOLEN;
}
/* PF_BRIDGE/POST_ROUTING ********************************************/
static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct sk_buff *skb = *pskb;
struct nf_bridge_info *nf_bridge = (*pskb)->nf_bridge;
/* Be very paranoid. */
if (skb->mac.raw < skb->head || skb->mac.raw + ETH_HLEN > skb->data) {
printk(KERN_CRIT "br_netfilter: Argh!! br_nf_post_routing: "
"bad mac.raw pointer.");
if (skb->dev != NULL) {
printk("[%s]", skb->dev->name);
if (has_bridge_parent(skb->dev))
printk("[%s]", bridge_parent(skb->dev)->name);
}
printk("\n");
return NF_ACCEPT;
}
if (skb->protocol != __constant_htons(ETH_P_IP))
return NF_ACCEPT;
/* Sometimes we get packets with NULL ->dst here (for example,
* running a dhcp client daemon triggers this).
*/
if (skb->dst == NULL)
return NF_ACCEPT;
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug ^= (1 << NF_IP_POST_ROUTING);
#endif
/* We assume any code from br_dev_queue_push_xmit onwards doesn't care
* about the value of skb->pkt_type.
*/
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
nf_bridge->mask |= BRNF_PKT_TYPE;
}
memcpy(nf_bridge->hh, skb->data - 16, 16);
NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL,
bridge_parent(skb->dev), br_dev_queue_push_xmit);
return NF_STOLEN;
}
/* IPv4/SABOTAGE *****************************************************/
/* Don't hand locally destined packets to PF_INET/PRE_ROUTING
* for the second time.
*/
static unsigned int ipv4_sabotage_in(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
if (in->hard_start_xmit == br_dev_xmit &&
okfn != br_nf_pre_routing_finish) {
okfn(*pskb);
return NF_STOLEN;
}
return NF_ACCEPT;
}
/* Postpone execution of PF_INET/FORWARD, PF_INET/LOCAL_OUT
* and PF_INET/POST_ROUTING until we have done the forwarding
* decision in the bridge code and have determined skb->physoutdev.
*/
static unsigned int ipv4_sabotage_out(unsigned int hook, struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
if (out->hard_start_xmit == br_dev_xmit &&
okfn != br_nf_forward_finish &&
okfn != br_nf_local_out_finish &&
okfn != br_dev_queue_push_xmit) {
struct sk_buff *skb = *pskb;
struct nf_bridge_info *nf_bridge;
if (!skb->nf_bridge && !nf_bridge_alloc(skb))
return NF_DROP;
nf_bridge = skb->nf_bridge;
/* This frame will arrive on PF_BRIDGE/LOCAL_OUT and we
* will need the indev then. For a brouter, the real indev
* can be a bridge port, so we make sure br_nf_local_out()
* doesn't use the bridge parent of the indev by using
* the BRNF_DONT_TAKE_PARENT mask.
*/
if (hook == NF_IP_FORWARD && nf_bridge->physindev == NULL) {
nf_bridge->mask &= BRNF_DONT_TAKE_PARENT;
nf_bridge->physindev = (struct net_device *)in;
}
okfn(skb);
return NF_STOLEN;
}
return NF_ACCEPT;
}
/* For br_nf_local_out we need (prio = NF_BR_PRI_FIRST), to insure that innocent
* PF_BRIDGE/NF_BR_LOCAL_OUT functions don't get bridged traffic as input.
* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
* ip_refrag() can return NF_STOLEN.
*/
static struct nf_hook_ops br_nf_ops[] = {
{ { NULL, NULL }, br_nf_pre_routing, PF_BRIDGE, NF_BR_PRE_ROUTING, NF_BR_PRI_BRNF },
{ { NULL, NULL }, br_nf_local_in, PF_BRIDGE, NF_BR_LOCAL_IN, NF_BR_PRI_BRNF },
{ { NULL, NULL }, br_nf_forward, PF_BRIDGE, NF_BR_FORWARD, NF_BR_PRI_BRNF },
{ { NULL, NULL }, br_nf_local_out, PF_BRIDGE, NF_BR_LOCAL_OUT, NF_BR_PRI_FIRST },
{ { NULL, NULL }, br_nf_post_routing, PF_BRIDGE, NF_BR_POST_ROUTING, NF_BR_PRI_LAST },
{ { NULL, NULL }, ipv4_sabotage_in, PF_INET, NF_IP_PRE_ROUTING, NF_IP_PRI_FIRST },
{ { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_FORWARD, NF_IP_PRI_BRIDGE_SABOTAGE_FORWARD },
{ { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_LOCAL_OUT, NF_IP_PRI_BRIDGE_SABOTAGE_LOCAL_OUT },
{ { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_POST_ROUTING, NF_IP_PRI_FIRST }
};
#define NUMHOOKS (sizeof(br_nf_ops)/sizeof(br_nf_ops[0]))
int br_netfilter_init(void)
{
int i;
for (i = 0; i < NUMHOOKS; i++) {
int ret;
if ((ret = nf_register_hook(&br_nf_ops[i])) >= 0)
continue;
while (i--)
nf_unregister_hook(&br_nf_ops[i]);
return ret;
}
printk(KERN_NOTICE "Bridge firewalling registered\n");
return 0;
}
void br_netfilter_fini(void)
{
int i;
for (i = NUMHOOKS - 1; i >= 0; i--)
nf_unregister_hook(&br_nf_ops[i]);
}
......@@ -144,8 +144,10 @@ extern void br_fdb_insert(struct net_bridge *br,
/* br_forward.c */
extern void br_deliver(struct net_bridge_port *to,
struct sk_buff *skb);
extern int br_dev_queue_push_xmit(struct sk_buff *skb);
extern void br_forward(struct net_bridge_port *to,
struct sk_buff *skb);
extern int br_forward_finish(struct sk_buff *skb);
extern void br_flood_deliver(struct net_bridge *br,
struct sk_buff *skb,
int clone);
......@@ -166,6 +168,7 @@ extern void br_get_port_ifindices(struct net_bridge *br,
int *ifindices);
/* br_input.c */
extern int br_handle_frame_finish(struct sk_buff *skb);
extern int br_handle_frame(struct sk_buff *skb);
/* br_ioctl.c */
......@@ -177,6 +180,10 @@ extern int br_ioctl(struct net_bridge *br,
unsigned long arg2);
extern int br_ioctl_deviceless_stub(unsigned long arg);
/* br_netfilter.c */
extern int br_netfilter_init(void);
extern void br_netfilter_fini(void);
/* br_stp.c */
extern int br_is_root_bridge(struct net_bridge *br);
extern struct net_bridge_port *br_get_port(struct net_bridge *br,
......
......@@ -342,10 +342,15 @@ static unsigned int nf_iterate(struct list_head *head,
const struct net_device *indev,
const struct net_device *outdev,
struct list_head **i,
int (*okfn)(struct sk_buff *))
int (*okfn)(struct sk_buff *),
int hook_thresh)
{
for (*i = (*i)->next; *i != head; *i = (*i)->next) {
struct nf_hook_ops *elem = (struct nf_hook_ops *)*i;
if (hook_thresh > elem->priority)
continue;
switch (elem->hook(hook, skb, indev, outdev, okfn)) {
case NF_QUEUE:
return NF_QUEUE;
......@@ -413,6 +418,10 @@ static void nf_queue(struct sk_buff *skb,
{
int status;
struct nf_info *info;
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
struct net_device *physindev = NULL;
struct net_device *physoutdev = NULL;
#endif
if (!queue_handler[pf].outfn) {
kfree_skb(skb);
......@@ -435,11 +444,24 @@ static void nf_queue(struct sk_buff *skb,
if (indev) dev_hold(indev);
if (outdev) dev_hold(outdev);
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
if (skb->nf_bridge) {
physindev = skb->nf_bridge->physindev;
if (physindev) dev_hold(physindev);
physoutdev = skb->nf_bridge->physoutdev;
if (physoutdev) dev_hold(physoutdev);
}
#endif
status = queue_handler[pf].outfn(skb, info, queue_handler[pf].data);
if (status < 0) {
/* James M doesn't say fuck enough. */
if (indev) dev_put(indev);
if (outdev) dev_put(outdev);
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
if (physindev) dev_put(physindev);
if (physoutdev) dev_put(physoutdev);
#endif
kfree(info);
kfree_skb(skb);
return;
......@@ -449,7 +471,8 @@ static void nf_queue(struct sk_buff *skb,
int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb,
struct net_device *indev,
struct net_device *outdev,
int (*okfn)(struct sk_buff *))
int (*okfn)(struct sk_buff *),
int hook_thresh)
{
struct list_head *elem;
unsigned int verdict;
......@@ -481,7 +504,7 @@ int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb,
elem = &nf_hooks[pf][hook];
verdict = nf_iterate(&nf_hooks[pf][hook], &skb, hook, indev,
outdev, &elem, okfn);
outdev, &elem, okfn, hook_thresh);
if (verdict == NF_QUEUE) {
NFDEBUG("nf_hook: Verdict = QUEUE.\n");
nf_queue(skb, elem, pf, hook, indev, outdev, okfn);
......@@ -530,7 +553,7 @@ void nf_reinject(struct sk_buff *skb, struct nf_info *info,
verdict = nf_iterate(&nf_hooks[info->pf][info->hook],
&skb, info->hook,
info->indev, info->outdev, &elem,
info->okfn);
info->okfn, INT_MIN);
}
switch (verdict) {
......
......@@ -248,6 +248,9 @@ static inline void skb_headerinit(void *p, kmem_cache_t *cache,
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug = 0;
#endif
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
skb->nf_bridge = NULL;
#endif
#endif
#ifdef CONFIG_NET_SCHED
skb->tc_index = 0;
......@@ -327,6 +330,9 @@ void __kfree_skb(struct sk_buff *skb)
}
#ifdef CONFIG_NETFILTER
nf_conntrack_put(skb->nfct);
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
nf_bridge_put(skb->nf_bridge);
#endif
#endif
skb_headerinit(skb, NULL, 0); /* clean state */
kfree_skbmem(skb);
......@@ -392,6 +398,9 @@ struct sk_buff *skb_clone(struct sk_buff *skb, int gfp_mask)
#ifdef CONFIG_NETFILTER_DEBUG
C(nf_debug);
#endif
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
C(nf_bridge);
#endif
#endif /*CONFIG_NETFILTER*/
#if defined(CONFIG_HIPPI)
C(private);
......@@ -404,6 +413,9 @@ struct sk_buff *skb_clone(struct sk_buff *skb, int gfp_mask)
skb->cloned = 1;
#ifdef CONFIG_NETFILTER
nf_conntrack_get(skb->nfct);
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
nf_bridge_get(skb->nf_bridge);
#endif
#endif
return n;
}
......@@ -438,6 +450,10 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
#ifdef CONFIG_NETFILTER_DEBUG
new->nf_debug = old->nf_debug;
#endif
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
new->nf_bridge = old->nf_bridge;
nf_bridge_get(new->nf_bridge);
#endif
#endif
#ifdef CONFIG_NET_SCHED
new->tc_index = old->tc_index;
......
......@@ -402,6 +402,10 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
/* Connection association is same as pre-frag packet */
to->nfct = from->nfct;
nf_conntrack_get(to->nfct);
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
to->nf_bridge = from->nf_bridge;
nf_bridge_get(to->nf_bridge);
#endif
#ifdef CONFIG_NETFILTER_DEBUG
to->nf_debug = from->nf_debug;
#endif
......
......@@ -289,6 +289,18 @@ ipt_log_target(struct sk_buff **pskb,
loginfo->prefix,
in ? in->name : "",
out ? out->name : "");
#if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
if ((*pskb)->nf_bridge) {
struct net_device *physindev = (*pskb)->nf_bridge->physindev;
struct net_device *physoutdev = (*pskb)->nf_bridge->physoutdev;
if (physindev && in != physindev)
printk("PHYSIN=%s ", physindev->name);
if (physoutdev && out != physoutdev)
printk("PHYSOUT=%s ", physoutdev->name);
}
#endif
if (in && !out) {
/* MAC logging for input chain only. */
printk("MAC=");
......
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