bridge: move mac header copying into br_netfilter
The mac header only has to be copied back into the skb for
fragments generated by ip_fragment(), which only happens
for bridge forwarded packets with nf-call-iptables=1 && active nf_defrag.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index f96933a..32541d4 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -37,9 +37,7 @@
int br_dev_queue_push_xmit(struct sk_buff *skb)
{
- /* ip_fragment doesn't copy the MAC header */
- if (nf_bridge_maybe_copy_header(skb) ||
- !is_skb_forwardable(skb->dev, skb)) {
+ if (!is_skb_forwardable(skb->dev, skb)) {
kfree_skb(skb);
} else {
skb_push(skb, ETH_HLEN);
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 0ee453f..e547911 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -764,6 +764,33 @@
}
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
+static bool nf_bridge_copy_header(struct sk_buff *skb)
+{
+ int err;
+ 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 false;
+
+ skb_copy_to_linear_data_offset(skb, -header_size,
+ skb->nf_bridge->data, header_size);
+ __skb_push(skb, nf_bridge_encap_header_len(skb));
+ return true;
+}
+
+static int br_nf_push_frag_xmit(struct sk_buff *skb)
+{
+ if (!nf_bridge_copy_header(skb)) {
+ kfree_skb(skb);
+ return 0;
+ }
+
+ return br_dev_queue_push_xmit(skb);
+}
+
static int br_nf_dev_queue_xmit(struct sk_buff *skb)
{
int ret;
@@ -780,7 +807,7 @@
/* Drop invalid packet */
return NF_DROP;
IPCB(skb)->frag_max_size = frag_max_size;
- ret = ip_fragment(skb, br_dev_queue_push_xmit);
+ ret = ip_fragment(skb, br_nf_push_frag_xmit);
} else
ret = br_dev_queue_push_xmit(skb);