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Date: Thu, 12 Mar 2015 18:05:21 +0100
From: Florian Westphal <fw@...len.de>
To: netfilter-devel@...r.kernel.org
Cc: netdev@...r.kernel.org, Florian Westphal <fw@...len.de>
Subject: [PATCH v2 nf-next 2/6] netfilter: bridge: don't use nf_bridge_info to store mac header
Currently br_netfilter maintains an extra state, nf_bridge_info,
which is attached to skb via skb->nf_bridge pointer. Amongst
other things we use skb->nf_bridge->data to store the original
mac header for every processed skb.
This is required for ip refragmentation when using conntrack
on top of bridge, because ip_fragment doesn't copy it from original skb.
However there is no need anymore to do this unconditionally.
Move this to the one place where its needed -- when br_netfilter calls
ip_fragment().
Also switch to percpu storage for this, there is no need to use
skb->nf_bridge->data.
After this change, only one user of skb->nf_bridge->data is left.
It will be removed by followup patch.
Signed-off-by: Florian Westphal <fw@...len.de>
---
include/linux/netfilter_bridge.h | 12 --------
net/bridge/br_netfilter.c | 66 +++++++++++++++++++++++++---------------
2 files changed, 42 insertions(+), 36 deletions(-)
diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h
index fbbd5de..b131613 100644
--- a/include/linux/netfilter_bridge.h
+++ b/include/linux/netfilter_bridge.h
@@ -23,18 +23,6 @@ enum nf_br_hook_priorities {
#define BRNF_8021Q 0x10
#define BRNF_PPPoE 0x20
-static inline 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;
- }
-}
-
int br_handle_frame_finish(struct sk_buff *skb);
static inline void br_drop_fake_rtable(struct sk_buff *skb)
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 550ee19..669b4fa 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -111,6 +111,27 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb)
pppoe_proto(skb) == htons(PPP_IPV6) && \
brnf_filter_pppoe_tagged)
+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:
+ break;
+ }
+ return 0;
+}
+
+/* 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)
+static DEFINE_PER_CPU(__u8 [NF_BRIDGE_MAX_MAC_HEADER_LENGTH],
+ brnf_mac_header_storage);
+#endif
+
static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
{
struct net_bridge_port *port;
@@ -177,14 +198,6 @@ 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
@@ -785,30 +798,28 @@ 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)
+static int br_nf_push_frag_xmit(struct sk_buff *skb)
{
- int err;
unsigned int header_size;
+ unsigned int encap_size;
+ char *mac;
+ int err;
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;
-}
+ encap_size = nf_bridge_encap_header_len(skb);
+ header_size = ETH_HLEN + encap_size;
-static int br_nf_push_frag_xmit(struct sk_buff *skb)
-{
- if (!nf_bridge_copy_header(skb)) {
+ err = skb_cow_head(skb, header_size);
+ if (err) {
kfree_skb(skb);
return 0;
}
+ mac = this_cpu_ptr(brnf_mac_header_storage);
+ skb_copy_to_linear_data_offset(skb, -header_size, mac, header_size);
+ __skb_push(skb, encap_size);
+
return br_dev_queue_push_xmit(skb);
}
@@ -834,7 +845,8 @@ static int br_nf_dev_queue_xmit(struct sk_buff *skb)
* boundaries by preserving frag_list rather than refragmenting.
*/
if (skb->len + mtu_reserved > mtu) {
- unsigned int llrs;
+ unsigned int llrs, header_size;
+ char *mac;
frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
if (br_parse_ip_options(skb))
@@ -847,6 +859,13 @@ static int br_nf_dev_queue_xmit(struct sk_buff *skb)
*/
llrs = nf_bridge_encap_header_len(skb);
+ mac = this_cpu_ptr(brnf_mac_header_storage);
+
+ header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
+
+ skb_copy_from_linear_data_offset(skb, -header_size, mac,
+ header_size);
+
mtu -= mtu_reserved;
ret = ip_fragment(skb, mtu, llrs, br_nf_push_frag_xmit);
} else
@@ -898,7 +917,6 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
}
nf_bridge_pull_encap_header(skb);
- nf_bridge_save_header(skb);
if (pf == NFPROTO_IPV4)
skb->protocol = htons(ETH_P_IP);
else
--
2.0.5
--
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