* 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)
+ * 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
skb->nf_bridge->data, header_size);
}
-/*
- * When forwarding bridge frames, we save a copy of the original
- * header before processing.
+static inline void nf_bridge_update_protocol(struct sk_buff *skb)
+{
+ if (skb->nf_bridge->mask & BRNF_8021Q)
+ skb->protocol = htons(ETH_P_8021Q);
+ else if (skb->nf_bridge->mask & BRNF_PPPoE)
+ skb->protocol = htons(ETH_P_PPP_SES);
+}
+
+/* Fill in the header for fragmented IP packets handled by
+ * the IPv4 connection tracking code.
*/
int nf_bridge_copy_header(struct sk_buff *skb)
{
int err;
- int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
+ unsigned int header_size;
+ nf_bridge_update_protocol(skb);
+ header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
err = skb_cow_head(skb, header_size);
if (err)
return err;
skb_dst_set(skb, &rt->u.dst);
skb->dev = nf_bridge->physindev;
+ nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
}
-static void __br_dnat_complain(void)
+/* Obtain the correct destination MAC address, while preserving the original
+ * source MAC address. If we already know this address, we just copy it. If we
+ * don't, we use the neighbour framework to find out. In both cases, we make
+ * sure that br_handle_frame_finish() is called afterwards.
+ */
+static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
{
- static unsigned long last_complaint;
+ struct nf_bridge_info *nf_bridge = skb->nf_bridge;
+ struct dst_entry *dst;
- if (jiffies - last_complaint >= 5 * HZ) {
- printk(KERN_WARNING "Performing cross-bridge DNAT requires IP "
- "forwarding to be enabled\n");
- last_complaint = jiffies;
+ skb->dev = bridge_parent(skb->dev);
+ if (!skb->dev)
+ goto free_skb;
+ dst = skb_dst(skb);
+ if (dst->hh) {
+ neigh_hh_bridge(dst->hh, skb);
+ skb->dev = nf_bridge->physindev;
+ return br_handle_frame_finish(skb);
+ } else if (dst->neighbour) {
+ /* the neighbour function below overwrites the complete
+ * MAC header, so we save the Ethernet source address and
+ * protocol number. */
+ skb_copy_from_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN), skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
+ /* tell br_dev_xmit to continue with forwarding */
+ nf_bridge->mask |= BRNF_BRIDGED_DNAT;
+ return dst->neighbour->output(skb);
}
+free_skb:
+ kfree_skb(skb);
+ return 0;
}
/* 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.
+ * we will need to fix up the destination Ethernet address.
*
* There are two cases to consider:
* 1. The packet was DNAT'ed to a device in the same bridge
* 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. The packet is passed
- * through the neighbour output function to build a new destination
- * MAC address, 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.
+ * Let's first consider the case that ip_route_input() succeeds:
*
+ * If the output device equals the logical bridge device the packet
+ * came in on, we can consider this bridging. The corresponding MAC
+ * address will be obtained in br_nf_pre_routing_finish_bridge.
* 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. For a redirected
* packet, ip_route_input() will give back the localhost as output device,
* which differs from the bridge device.
*
- * Let us now consider the case that ip_route_input() fails:
+ * Let's now consider the case that ip_route_input() fails:
*
* This can be because the destination address is martian, in which case
* the packet will be dropped.
- * After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input()
- * will fail, while __ip_route_output_key() will return success. The source
- * address for __ip_route_output_key() is set to zero, so __ip_route_output_key
+ * If IP forwarding is disabled, ip_route_input() will fail, while
+ * ip_route_output_key() can return success. The source
+ * address for ip_route_output_key() is set to zero, so ip_route_output_key()
* 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)
- * --Bart, 20062711 (updated) */
-static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
-{
- if (skb->pkt_type == PACKET_OTHERHOST) {
- skb->pkt_type = PACKET_HOST;
- skb->nf_bridge->mask |= BRNF_PKT_TYPE;
- }
- skb->nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
-
- skb->dev = bridge_parent(skb->dev);
- if (skb->dev) {
- struct dst_entry *dst = skb_dst(skb);
-
- nf_bridge_pull_encap_header(skb);
-
- if (dst->hh)
- return neigh_hh_output(dst->hh, skb);
- else if (dst->neighbour)
- return dst->neighbour->output(skb);
- }
- kfree_skb(skb);
- return 0;
-}
-
+ * if IP forwarding is enabled. If the output device equals the logical bridge
+ * device, we proceed as if ip_route_input() succeeded. If it differs from the
+ * logical bridge port or if ip_route_output_key() fails we drop the packet.
+ */
static int br_nf_pre_routing_finish(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
skb_dst_set(skb, (struct dst_entry *)rt);
goto bridged_dnat;
}
- /* we are sure that forwarding is disabled, so printing
- * this message is no problem. Note that the packet could
- * still have a martian destination address, in which case
- * the packet could be dropped even if forwarding were enabled */
- __br_dnat_complain();
dst_release((struct dst_entry *)rt);
}
free_skb:
} else {
if (skb_dst(skb)->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;
+ nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING,
+ NF_HOOK_THRESH(NFPROTO_BRIDGE,
+ NF_BR_PRE_ROUTING,
skb, skb->dev, NULL,
br_nf_pre_routing_finish_bridge,
1);
}
skb->dev = nf_bridge->physindev;
+ nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
nf_bridge->physindev = skb->dev;
skb->dev = bridge_parent(skb->dev);
+ if (skb->protocol == htons(ETH_P_8021Q))
+ nf_bridge->mask |= BRNF_8021Q;
+ else if (skb->protocol == htons(ETH_P_PPP_SES))
+ nf_bridge->mask |= BRNF_PPPoE;
return skb->dev;
}
if (!setup_pre_routing(skb))
return NF_DROP;
- NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
+ skb->protocol = htons(ETH_P_IPV6);
+ NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
br_nf_pre_routing_finish_ipv6);
return NF_STOLEN;
if (!setup_pre_routing(skb))
return NF_DROP;
store_orig_dstaddr(skb);
+ skb->protocol = htons(ETH_P_IP);
- NF_HOOK(PF_INET, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
br_nf_pre_routing_finish);
return NF_STOLEN;
} else {
in = *((struct net_device **)(skb->cb));
}
+ nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, in,
+
+ NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in,
skb->dev, br_forward_finish, 1);
return 0;
}
/* The physdev module checks on this */
nf_bridge->mask |= BRNF_BRIDGED;
nf_bridge->physoutdev = skb->dev;
+ if (pf == PF_INET)
+ skb->protocol = htons(ETH_P_IP);
+ else
+ skb->protocol = htons(ETH_P_IPV6);
NF_HOOK(pf, NF_INET_FORWARD, skb, bridge_parent(in), parent,
br_nf_forward_finish);
return NF_STOLEN;
}
-/* PF_BRIDGE/LOCAL_OUT ***********************************************
- *
- * 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.
- *
- * 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.
- */
-static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
-{
- struct net_device *realindev;
- struct nf_bridge_info *nf_bridge;
-
- if (!skb->nf_bridge)
- return NF_ACCEPT;
-
- /* Need exclusive nf_bridge_info since we might have multiple
- * different physoutdevs. */
- if (!nf_bridge_unshare(skb))
- return NF_DROP;
-
- nf_bridge = skb->nf_bridge;
- if (!(nf_bridge->mask & BRNF_BRIDGED_DNAT))
- return NF_ACCEPT;
-
- /* Bridged, take PF_BRIDGE/FORWARD.
- * (see big note in front of br_nf_pre_routing_finish) */
- nf_bridge->physoutdev = skb->dev;
- realindev = nf_bridge->physindev;
-
- if (nf_bridge->mask & BRNF_PKT_TYPE) {
- skb->pkt_type = PACKET_OTHERHOST;
- nf_bridge->mask ^= BRNF_PKT_TYPE;
- }
- nf_bridge_push_encap_header(skb);
-
- NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, realindev, skb->dev,
- br_forward_finish);
- return NF_STOLEN;
-}
-
#if defined(CONFIG_NF_CONNTRACK_IPV4) || defined(CONFIG_NF_CONNTRACK_IPV4_MODULE)
static int br_nf_dev_queue_xmit(struct sk_buff *skb)
{
- if (skb->nfct != NULL &&
- (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb)) &&
+ if (skb->nfct != NULL && skb->protocol == htons(ETH_P_IP) &&
skb->len > skb->dev->mtu &&
!skb_is_gso(skb))
return ip_fragment(skb, br_dev_queue_push_xmit);
struct net_device *realoutdev = bridge_parent(skb->dev);
u_int8_t pf;
-#ifdef CONFIG_NETFILTER_DEBUG
- /* Be very paranoid. This probably won't happen anymore, but let's
- * keep the check just to be sure... */
- if (skb_mac_header(skb) < skb->head ||
- skb_mac_header(skb) + ETH_HLEN > skb->data) {
- printk(KERN_CRIT "br_netfilter: Argh!! br_nf_post_routing: "
- "bad mac.raw pointer.\n");
- goto print_error;
- }
-#endif
-
- if (!nf_bridge)
- return NF_ACCEPT;
-
- if (!(nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT)))
+ if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
return NF_ACCEPT;
if (!realoutdev)
else
return NF_ACCEPT;
-#ifdef CONFIG_NETFILTER_DEBUG
- if (skb_dst(skb) == NULL) {
- printk(KERN_INFO "br_netfilter post_routing: skb->dst == NULL\n");
- goto print_error;
- }
-#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) {
nf_bridge_pull_encap_header(skb);
nf_bridge_save_header(skb);
+ if (pf == PF_INET)
+ skb->protocol = htons(ETH_P_IP);
+ else
+ skb->protocol = htons(ETH_P_IPV6);
NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev,
br_nf_dev_queue_xmit);
return NF_STOLEN;
-
-#ifdef CONFIG_NETFILTER_DEBUG
-print_error:
- if (skb->dev != NULL) {
- printk("[%s]", skb->dev->name);
- if (realoutdev)
- printk("[%s]", realoutdev->name);
- }
- printk(" head:%p, raw:%p, data:%p\n", skb->head, skb_mac_header(skb),
- skb->data);
- dump_stack();
- return NF_ACCEPT;
-#endif
}
/* IP/SABOTAGE *****************************************************/
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. */
+/* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
+ * br_dev_queue_push_xmit is called afterwards */
static struct nf_hook_ops br_nf_ops[] __read_mostly = {
{
.hook = br_nf_pre_routing,
.hooknum = NF_BR_FORWARD,
.priority = NF_BR_PRI_BRNF,
},
- {
- .hook = br_nf_local_out,
- .owner = THIS_MODULE,
- .pf = PF_BRIDGE,
- .hooknum = NF_BR_LOCAL_OUT,
- .priority = NF_BR_PRI_FIRST,
- },
{
.hook = br_nf_post_routing,
.owner = THIS_MODULE,
git.openpandora.org / pandora-kernel.git / blobdiff