From: Florian Westphal <fw@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/linux/netfilter_bridge.h | 31 -------------------------------
net/bridge/br_forward.c | 4 +---
net/bridge/br_netfilter.c | 29 ++++++++++++++++++++++++++++-
3 files changed, 29 insertions(+), 35 deletions(-)
diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h
index c755e49..332ef8a 100644
--- a/include/linux/netfilter_bridge.h
+++ b/include/linux/netfilter_bridge.h
@@ -44,36 +44,6 @@ static inline void nf_bridge_update_protocol(struct sk_buff *skb)
skb->protocol = htons(ETH_P_PPP_SES);
}
-/* Fill in the header for fragmented IP packets handled by
- * the IPv4 connection tracking code.
- *
- * Only used in br_forward.c
- */
-static inline int 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 err;
-
- 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 0;
-}
-
-static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
-{
- if (skb->nf_bridge &&
- skb->nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT))
- return nf_bridge_copy_header(skb);
- return 0;
-}
-
static inline unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
{
if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
@@ -119,7 +89,6 @@ static inline void br_drop_fake_rtable(struct sk_buff *skb)
}
#else
-#define nf_bridge_maybe_copy_header(skb) (0)
#define nf_bridge_pad(skb) (0)
#define br_drop_fake_rtable(skb) do { } while (0)
#endif /* CONFIG_BRIDGE_NETFILTER */
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 @@ static inline int should_deliver(const struct net_bridge_port *p,
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 @@ static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops,
}
#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 @@ static int br_nf_dev_queue_xmit(struct sk_buff *skb)
/* 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);
--
1.7.10.4
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