From 0daf4349406074fc03e4889ba5e97e6fb5311bab Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sun, 2 Jul 2017 02:13:25 +0200 Subject: bpf, net: add skb_mac_header_len helper Add a small skb_mac_header_len() helper similarly as the skb_network_header_len() we have and replace open coded places in BPF's bpf_skb_change_proto() helper. Will also be used in upcoming work. Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/linux/skbuff.h | 5 +++++ net/core/filter.c | 4 ++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d0b9f3846eab..3d3ceaac13b1 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2206,6 +2206,11 @@ static inline int skb_mac_offset(const struct sk_buff *skb) return skb_mac_header(skb) - skb->data; } +static inline u32 skb_mac_header_len(const struct sk_buff *skb) +{ + return skb->network_header - skb->mac_header; +} + static inline int skb_mac_header_was_set(const struct sk_buff *skb) { return skb->mac_header != (typeof(skb->mac_header))~0U; diff --git a/net/core/filter.c b/net/core/filter.c index e5c280aa5de6..68d8cd865c4a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2012,7 +2012,7 @@ static int bpf_skb_net_hdr_pop(struct sk_buff *skb, u32 off, u32 len) static int bpf_skb_proto_4_to_6(struct sk_buff *skb) { const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr); - u32 off = skb->network_header - skb->mac_header; + u32 off = skb_mac_header_len(skb); int ret; ret = skb_cow(skb, len_diff); @@ -2048,7 +2048,7 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb) static int bpf_skb_proto_6_to_4(struct sk_buff *skb) { const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr); - u32 off = skb->network_header - skb->mac_header; + u32 off = skb_mac_header_len(skb); int ret; ret = skb_unclone(skb, GFP_ATOMIC); -- cgit v1.2.3