The following patch deals with the problems you still had with the earlier one.
Changes:
1. add #if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE) everywhere
2. don't touch ip_tables.c
3. no ipt_physdev.c file yet. I'll try to make it this weekend.
As this ipt_physdev.c module is not essential I propose to already apply this patch.
Harald, should I make this module for patch-o-magic or can I post it directly to David?
The patch is also here:
http://users.pandora.be/bart.de.schuymer/ebtables/br-nf/bridge-nf-0.0.10-dev-pre3-against-2.5.44.diff
An incremental patch vs the previous one is here:
http://users.pandora.be/bart.de.schuymer/ebtables/br-nf/bridge-nf-0.0.10-dev-pre3.001-against-2.5.44.diff
cheers,
Bart
--- linux-2.5.44/include/linux/netfilter.h Sat Oct 19 06:01:54 2002
+++ linux-2.5.44-brnfpre3/include/linux/netfilter.h Thu Oct 24 18:32:34 2002
@@ -117,17 +117,23 @@
/* 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,
--- linux-2.5.44/include/linux/netfilter_ipv4.h Sat Oct 19 06:02:28 2002
+++ linux-2.5.44-brnfpre3/include/linux/netfilter_ipv4.h Thu Oct 24 18:32:34 2002
@@ -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,
--- linux-2.5.44/include/linux/netfilter_bridge.h Sat Oct 19 06:01:57 2002
+++ linux-2.5.44-brnfpre3/include/linux/netfilter_bridge.h Thu Oct 24 18:32:34 2002
@@ -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
--- linux-2.5.44/include/linux/skbuff.h Sat Oct 19 06:01:58 2002
+++ linux-2.5.44-brnfpre3/include/linux/skbuff.h Thu Oct 24 18:32:34 2002
@@ -96,6 +96,17 @@
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 @@
* @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 @@
#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 @@
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__ */
--- linux-2.5.44/net/bridge/br.c Sat Oct 19 06:01:15 2002
+++ linux-2.5.44-brnfpre3/net/bridge/br.c Thu Oct 24 18:32:34 2002
@@ -45,6 +45,10 @@
{
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 __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);
--- linux-2.5.44/net/bridge/br_forward.c Sat Oct 19 06:01:20 2002
+++ linux-2.5.44-brnfpre3/net/bridge/br_forward.c Thu Oct 24 18:32:34 2002
@@ -30,18 +30,23 @@
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 @@
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 @@
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 */
--- linux-2.5.44/net/bridge/br_input.c Sat Oct 19 06:01:18 2002
+++ linux-2.5.44-brnfpre3/net/bridge/br_input.c Thu Oct 24 18:32:34 2002
@@ -49,7 +49,7 @@
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;
--- linux-2.5.44/net/bridge/br_private.h Sat Oct 19 06:01:18 2002
+++ linux-2.5.44-brnfpre3/net/bridge/br_private.h Thu Oct 24 18:32:34 2002
@@ -144,8 +144,10 @@
/* 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 @@
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 */
@@ -176,6 +179,10 @@
unsigned long arg1,
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);
--- linux-2.5.44/net/bridge/Makefile Sat Oct 19 06:02:32 2002
+++ linux-2.5.44-brnfpre3/net/bridge/Makefile Thu Oct 24 18:32:34 2002
@@ -9,6 +9,11 @@
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
--- linux-2.5.44/net/core/netfilter.c Sat Oct 19 06:01:53 2002
+++ linux-2.5.44-brnfpre3/net/core/netfilter.c Thu Oct 24 18:32:34 2002
@@ -342,10 +342,15 @@
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 @@
{
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 @@
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 @@
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 @@
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 @@
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) {
--- linux-2.5.44/net/core/skbuff.c Sat Oct 19 06:01:17 2002
+++ linux-2.5.44-brnfpre3/net/core/skbuff.c Thu Oct 24 18:32:34 2002
@@ -248,6 +248,9 @@
#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 @@
}
#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 @@
#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 @@
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;
}
@@ -437,6 +449,10 @@
nf_conntrack_get(new->nfct);
#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
--- linux-2.5.44/net/ipv4/ip_output.c Sat Oct 19 06:02:34 2002
+++ linux-2.5.44-brnfpre3/net/ipv4/ip_output.c Thu Oct 24 18:32:34 2002
@@ -396,6 +396,10 @@
/* 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
--- linux-2.5.44/net/ipv4/netfilter/ipt_LOG.c Sat Oct 19 06:01:21 2002
+++ linux-2.5.44-brnfpre3/net/ipv4/netfilter/ipt_LOG.c Thu Oct 24 18:58:08 2002
@@ -289,6 +289,18 @@
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=");
--- /dev/null Thu Aug 24 11:00:32 2000
+++ linux-2.5.44-brnfpre3/net/bridge/br_netfilter.c Thu Oct 24 18:32:34 2002
@@ -0,0 +1,614 @@
+/*
+ * 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]);
+}
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