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Diffstat (limited to 'net/bridge/br_netfilter.c')
-rw-r--r--net/bridge/br_netfilter.c319
1 files changed, 228 insertions, 91 deletions
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 0ee453fad3de..ab55e2472beb 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -37,17 +37,16 @@
#include <net/route.h>
#include <net/netfilter/br_netfilter.h>
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
#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;
@@ -112,6 +111,24 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb)
pppoe_proto(skb) == htons(PPP_IPV6) && \
brnf_filter_pppoe_tagged)
+/* largest possible L2 header, see br_nf_dev_queue_xmit() */
+#define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN)
+
+#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
+struct brnf_frag_data {
+ char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH];
+ u8 encap_size;
+ u8 size;
+};
+
+static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage);
+#endif
+
+static struct nf_bridge_info *nf_bridge_info_get(const struct sk_buff *skb)
+{
+ return skb->nf_bridge;
+}
+
static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
{
struct net_bridge_port *port;
@@ -154,6 +171,18 @@ static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
return nf_bridge;
}
+static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case __cpu_to_be16(ETH_P_8021Q):
+ return VLAN_HLEN;
+ case __cpu_to_be16(ETH_P_PPP_SES):
+ return PPPOE_SES_HLEN;
+ default:
+ return 0;
+ }
+}
+
static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
{
unsigned int len = nf_bridge_encap_header_len(skb);
@@ -178,14 +207,6 @@ static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
skb->network_header += len;
}
-static inline void nf_bridge_save_header(struct sk_buff *skb)
-{
- int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
-
- skb_copy_from_linear_data_offset(skb, -header_size,
- skb->nf_bridge->data, header_size);
-}
-
/* When handing a packet over to the IP layer
* check whether we have a skb that is in the
* expected format
@@ -239,17 +260,31 @@ drop:
return -1;
}
+static void nf_bridge_update_protocol(struct sk_buff *skb)
+{
+ switch (skb->nf_bridge->orig_proto) {
+ case BRNF_PROTO_8021Q:
+ skb->protocol = htons(ETH_P_8021Q);
+ break;
+ case BRNF_PROTO_PPPOE:
+ skb->protocol = htons(ETH_P_PPP_SES);
+ break;
+ case BRNF_PROTO_UNCHANGED:
+ break;
+ }
+}
+
/* PF_BRIDGE/PRE_ROUTING *********************************************/
/* Undo the changes made for ip6tables PREROUTING and continue the
* bridge PRE_ROUTING hook. */
-static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
+static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb)
{
- struct nf_bridge_info *nf_bridge = skb->nf_bridge;
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
struct rtable *rt;
- if (nf_bridge->mask & BRNF_PKT_TYPE) {
+ if (nf_bridge->pkt_otherhost) {
skb->pkt_type = PACKET_OTHERHOST;
- nf_bridge->mask ^= BRNF_PKT_TYPE;
+ nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
@@ -263,7 +298,8 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
skb->dev = nf_bridge->physindev;
nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb,
+ skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
@@ -274,9 +310,8 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
* 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 int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
{
- struct nf_bridge_info *nf_bridge = skb->nf_bridge;
struct neighbour *neigh;
struct dst_entry *dst;
@@ -286,12 +321,13 @@ static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
dst = skb_dst(skb);
neigh = dst_neigh_lookup_skb(dst, skb);
if (neigh) {
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
int ret;
if (neigh->hh.hh_len) {
neigh_hh_bridge(&neigh->hh, skb);
skb->dev = nf_bridge->physindev;
- ret = br_handle_frame_finish(skb);
+ ret = br_handle_frame_finish(sk, skb);
} else {
/* the neighbour function below overwrites the complete
* MAC header, so we save the Ethernet source address and
@@ -299,7 +335,7 @@ static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
*/
skb_copy_from_linear_data_offset(skb,
-(ETH_HLEN-ETH_ALEN),
- skb->nf_bridge->data,
+ nf_bridge->neigh_header,
ETH_HLEN-ETH_ALEN);
/* tell br_dev_xmit to continue with forwarding */
nf_bridge->mask |= BRNF_BRIDGED_DNAT;
@@ -314,6 +350,22 @@ free_skb:
return 0;
}
+static bool dnat_took_place(const struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || nf_ct_is_untracked(ct))
+ return false;
+
+ return test_bit(IPS_DST_NAT_BIT, &ct->status);
+#else
+ return false;
+#endif
+}
+
/* This requires some explaining. If DNAT has taken place,
* we will need to fix up the destination Ethernet address.
*
@@ -352,11 +404,11 @@ free_skb:
* 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)
+static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct iphdr *iph = ip_hdr(skb);
- struct nf_bridge_info *nf_bridge = skb->nf_bridge;
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
struct rtable *rt;
int err;
int frag_max_size;
@@ -364,9 +416,9 @@ static int br_nf_pre_routing_finish(struct sk_buff *skb)
frag_max_size = IPCB(skb)->frag_max_size;
BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size;
- if (nf_bridge->mask & BRNF_PKT_TYPE) {
+ if (nf_bridge->pkt_otherhost) {
skb->pkt_type = PACKET_OTHERHOST;
- nf_bridge->mask ^= BRNF_PKT_TYPE;
+ nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
if (dnat_took_place(skb)) {
@@ -405,7 +457,7 @@ bridged_dnat:
nf_bridge_push_encap_header(skb);
NF_HOOK_THRESH(NFPROTO_BRIDGE,
NF_BR_PRE_ROUTING,
- skb, skb->dev, NULL,
+ sk, skb, skb->dev, NULL,
br_nf_pre_routing_finish_bridge,
1);
return 0;
@@ -425,7 +477,8 @@ bridged_dnat:
skb->dev = nf_bridge->physindev;
nf_bridge_update_protocol(skb);
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb,
+ skb->dev, NULL,
br_handle_frame_finish, 1);
return 0;
@@ -448,20 +501,21 @@ static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct
/* Some common code for IPv4/IPv6 */
static struct net_device *setup_pre_routing(struct sk_buff *skb)
{
- struct nf_bridge_info *nf_bridge = skb->nf_bridge;
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
- nf_bridge->mask |= BRNF_PKT_TYPE;
+ nf_bridge->pkt_otherhost = true;
}
nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
nf_bridge->physindev = skb->dev;
skb->dev = brnf_get_logical_dev(skb, skb->dev);
+
if (skb->protocol == htons(ETH_P_8021Q))
- nf_bridge->mask |= BRNF_8021Q;
+ nf_bridge->orig_proto = BRNF_PROTO_8021Q;
else if (skb->protocol == htons(ETH_P_PPP_SES))
- nf_bridge->mask |= BRNF_PPPoE;
+ nf_bridge->orig_proto = BRNF_PROTO_PPPOE;
/* Must drop socket now because of tproxy. */
skb_orphan(skb);
@@ -527,9 +581,7 @@ bad:
* to ip6tables, which doesn't support NAT, so things are fairly simple. */
static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
const struct ipv6hdr *hdr;
u32 pkt_len;
@@ -563,7 +615,8 @@ static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
return NF_DROP;
skb->protocol = htons(ETH_P_IPV6);
- NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->sk, skb,
+ skb->dev, NULL,
br_nf_pre_routing_finish_ipv6);
return NF_STOLEN;
@@ -577,9 +630,7 @@ static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
* address to be able to detect DNAT afterwards. */
static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
struct net_bridge_port *p;
struct net_bridge *br;
@@ -588,7 +639,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
if (unlikely(!pskb_may_pull(skb, len)))
return NF_DROP;
- p = br_port_get_rcu(in);
+ p = br_port_get_rcu(state->in);
if (p == NULL)
return NF_DROP;
br = p->br;
@@ -598,7 +649,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
return NF_ACCEPT;
nf_bridge_pull_encap_header_rcsum(skb);
- return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn);
+ return br_nf_pre_routing_ipv6(ops, skb, state);
}
if (!brnf_call_iptables && !br->nf_call_iptables)
@@ -617,10 +668,11 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
return NF_DROP;
if (!setup_pre_routing(skb))
return NF_DROP;
- store_orig_dstaddr(skb);
+
skb->protocol = htons(ETH_P_IP);
- NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
+ NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->sk, skb,
+ skb->dev, NULL,
br_nf_pre_routing_finish);
return NF_STOLEN;
@@ -636,25 +688,30 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
* prevent this from happening. */
static unsigned int br_nf_local_in(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
br_drop_fake_rtable(skb);
return NF_ACCEPT;
}
/* PF_BRIDGE/FORWARD *************************************************/
-static int br_nf_forward_finish(struct sk_buff *skb)
+static int br_nf_forward_finish(struct sock *sk, struct sk_buff *skb)
{
- struct nf_bridge_info *nf_bridge = skb->nf_bridge;
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
struct net_device *in;
if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) {
+ int frag_max_size;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ frag_max_size = IPCB(skb)->frag_max_size;
+ BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size;
+ }
+
in = nf_bridge->physindev;
- if (nf_bridge->mask & BRNF_PKT_TYPE) {
+ if (nf_bridge->pkt_otherhost) {
skb->pkt_type = PACKET_OTHERHOST;
- nf_bridge->mask ^= BRNF_PKT_TYPE;
+ nf_bridge->pkt_otherhost = false;
}
nf_bridge_update_protocol(skb);
} else {
@@ -662,8 +719,8 @@ static int br_nf_forward_finish(struct sk_buff *skb)
}
nf_bridge_push_encap_header(skb);
- NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in,
- skb->dev, br_forward_finish, 1);
+ NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, sk, skb,
+ in, skb->dev, br_forward_finish, 1);
return 0;
}
@@ -675,9 +732,7 @@ static int br_nf_forward_finish(struct sk_buff *skb)
* bridge ports. */
static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
struct nf_bridge_info *nf_bridge;
struct net_device *parent;
@@ -691,7 +746,11 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
if (!nf_bridge_unshare(skb))
return NF_DROP;
- parent = bridge_parent(out);
+ nf_bridge = nf_bridge_info_get(skb);
+ if (!nf_bridge)
+ return NF_DROP;
+
+ parent = bridge_parent(state->out);
if (!parent)
return NF_DROP;
@@ -704,40 +763,42 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
nf_bridge_pull_encap_header(skb);
- nf_bridge = skb->nf_bridge;
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
- nf_bridge->mask |= BRNF_PKT_TYPE;
+ nf_bridge->pkt_otherhost = true;
}
- if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb))
- return NF_DROP;
+ if (pf == NFPROTO_IPV4) {
+ int frag_max = BR_INPUT_SKB_CB(skb)->frag_max_size;
+
+ if (br_parse_ip_options(skb))
+ return NF_DROP;
+
+ IPCB(skb)->frag_max_size = frag_max;
+ }
- /* The physdev module checks on this */
- nf_bridge->mask |= BRNF_BRIDGED;
nf_bridge->physoutdev = skb->dev;
if (pf == NFPROTO_IPV4)
skb->protocol = htons(ETH_P_IP);
else
skb->protocol = htons(ETH_P_IPV6);
- NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent,
- br_nf_forward_finish);
+ NF_HOOK(pf, NF_INET_FORWARD, NULL, skb,
+ brnf_get_logical_dev(skb, state->in),
+ parent, br_nf_forward_finish);
return NF_STOLEN;
}
static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
struct net_bridge_port *p;
struct net_bridge *br;
struct net_device **d = (struct net_device **)(skb->cb);
- p = br_port_get_rcu(out);
+ p = br_port_get_rcu(state->out);
if (p == NULL)
return NF_ACCEPT;
br = p->br;
@@ -756,55 +817,93 @@ static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops,
nf_bridge_push_encap_header(skb);
return NF_ACCEPT;
}
- *d = (struct net_device *)in;
- NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in,
- (struct net_device *)out, br_nf_forward_finish);
+ *d = state->in;
+ NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, state->sk, skb,
+ state->in, state->out, br_nf_forward_finish);
return NF_STOLEN;
}
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
-static int br_nf_dev_queue_xmit(struct sk_buff *skb)
+static int br_nf_push_frag_xmit(struct sock *sk, struct sk_buff *skb)
+{
+ struct brnf_frag_data *data;
+ int err;
+
+ data = this_cpu_ptr(&brnf_frag_data_storage);
+ err = skb_cow_head(skb, data->size);
+
+ if (err) {
+ kfree_skb(skb);
+ return 0;
+ }
+
+ skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size);
+ __skb_push(skb, data->encap_size);
+
+ return br_dev_queue_push_xmit(sk, skb);
+}
+
+static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
{
int ret;
int frag_max_size;
+ unsigned int mtu_reserved;
+
+ if (skb_is_gso(skb) || skb->protocol != htons(ETH_P_IP))
+ return br_dev_queue_push_xmit(sk, skb);
+ mtu_reserved = nf_bridge_mtu_reduction(skb);
/* This is wrong! We should preserve the original fragment
* boundaries by preserving frag_list rather than refragmenting.
*/
- if (skb->protocol == htons(ETH_P_IP) &&
- skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu &&
- !skb_is_gso(skb)) {
+ if (skb->len + mtu_reserved > skb->dev->mtu) {
+ struct brnf_frag_data *data;
+
frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
if (br_parse_ip_options(skb))
/* Drop invalid packet */
return NF_DROP;
IPCB(skb)->frag_max_size = frag_max_size;
- ret = ip_fragment(skb, br_dev_queue_push_xmit);
- } else
- ret = br_dev_queue_push_xmit(skb);
+
+ nf_bridge_update_protocol(skb);
+
+ data = this_cpu_ptr(&brnf_frag_data_storage);
+ data->encap_size = nf_bridge_encap_header_len(skb);
+ data->size = ETH_HLEN + data->encap_size;
+
+ skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
+ data->size);
+
+ ret = ip_fragment(sk, skb, br_nf_push_frag_xmit);
+ } else {
+ ret = br_dev_queue_push_xmit(sk, skb);
+ }
return ret;
}
#else
-static int br_nf_dev_queue_xmit(struct sk_buff *skb)
+static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
{
- return br_dev_queue_push_xmit(skb);
+ return br_dev_queue_push_xmit(sk, skb);
}
#endif
/* PF_BRIDGE/POST_ROUTING ********************************************/
static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
- struct nf_bridge_info *nf_bridge = skb->nf_bridge;
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
struct net_device *realoutdev = bridge_parent(skb->dev);
u_int8_t pf;
- if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
+ /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in
+ * on a bridge, but was delivered locally and is now being routed:
+ *
+ * POST_ROUTING was already invoked from the ip stack.
+ */
+ if (!nf_bridge || !nf_bridge->physoutdev)
return NF_ACCEPT;
if (!realoutdev)
@@ -821,17 +920,17 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
* about the value of skb->pkt_type. */
if (skb->pkt_type == PACKET_OTHERHOST) {
skb->pkt_type = PACKET_HOST;
- nf_bridge->mask |= BRNF_PKT_TYPE;
+ nf_bridge->pkt_otherhost = true;
}
nf_bridge_pull_encap_header(skb);
- nf_bridge_save_header(skb);
if (pf == NFPROTO_IPV4)
skb->protocol = htons(ETH_P_IP);
else
skb->protocol = htons(ETH_P_IPV6);
- NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev,
+ NF_HOOK(pf, NF_INET_POST_ROUTING, state->sk, skb,
+ NULL, realoutdev,
br_nf_dev_queue_xmit);
return NF_STOLEN;
@@ -842,9 +941,7 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
* for the second time. */
static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops,
struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- int (*okfn)(struct sk_buff *))
+ const struct nf_hook_state *state)
{
if (skb->nf_bridge &&
!(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
@@ -854,6 +951,44 @@ static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops,
return NF_ACCEPT;
}
+/* This is called when br_netfilter has called into iptables/netfilter,
+ * and DNAT has taken place on a bridge-forwarded packet.
+ *
+ * neigh->output has created a new MAC header, with local br0 MAC
+ * as saddr.
+ *
+ * This restores the original MAC saddr of the bridged packet
+ * before invoking bridge forward logic to transmit the packet.
+ */
+static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
+{
+ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
+
+ skb_pull(skb, ETH_HLEN);
+ nf_bridge->mask &= ~BRNF_BRIDGED_DNAT;
+
+ BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN));
+
+ skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN),
+ nf_bridge->neigh_header,
+ ETH_HLEN - ETH_ALEN);
+ skb->dev = nf_bridge->physindev;
+ br_handle_frame_finish(NULL, skb);
+}
+
+static int br_nf_dev_xmit(struct sk_buff *skb)
+{
+ if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
+ br_nf_pre_routing_finish_bridge_slow(skb);
+ return 1;
+ }
+ return 0;
+}
+
+static const struct nf_br_ops br_ops = {
+ .br_dev_xmit_hook = br_nf_dev_xmit,
+};
+
void br_netfilter_enable(void)
{
}
@@ -991,12 +1126,14 @@ static int __init br_netfilter_init(void)
return -ENOMEM;
}
#endif
+ RCU_INIT_POINTER(nf_br_ops, &br_ops);
printk(KERN_NOTICE "Bridge firewalling registered\n");
return 0;
}
static void __exit br_netfilter_fini(void)
{
+ RCU_INIT_POINTER(nf_br_ops, NULL);
nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
#ifdef CONFIG_SYSCTL
unregister_net_sysctl_table(brnf_sysctl_header);
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 20:32:58 +0000