From 8bd63cf1a426e69bf4f611b08978f721e46c194f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 5 Mar 2015 00:52:33 +0100 Subject: [PATCH] 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 Signed-off-by: Pablo Neira Ayuso --- 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 c755e4971fa3..332ef8ab37e9 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 f96933a823e3..32541d4f72e8 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 0ee453fad3de..e5479112c4a3 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);