From a2bfe6bf09a5f38df2bd0b1734f5fdee76f9366f Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 5 Aug 2016 00:11:11 +0200 Subject: [PATCH] bpf: also call skb_postpush_rcsum on xmit occasions Follow-up to commit f8ffad69c9f8 ("bpf: add skb_postpush_rcsum and fix dev_forward_skb occasions") to fix an issue for dev_queue_xmit() redirect locations which need CHECKSUM_COMPLETE fixups on ingress. For the same reasons as described in f8ffad69c9f8 already, we of course also need this here, since dev_queue_xmit() on a veth device will let us end up in the dev_forward_skb() helper again to cross namespaces. Latter then calls into skb_postpull_rcsum() to pull out L2 header, so that netif_rx_internal() sees CHECKSUM_COMPLETE as it is expected. That is, CHECKSUM_COMPLETE on ingress covering L2 _payload_, not L2 headers. Also here we have to address bpf_redirect() and bpf_clone_redirect(). Fixes: 3896d655f4d4 ("bpf: introduce bpf_clone_redirect() helper") Fixes: 27b29f63058d ("bpf: add bpf_redirect() helper") Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- net/core/filter.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 5708999f8a79..c46244f83a8f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1365,6 +1365,12 @@ static inline int bpf_try_make_writable(struct sk_buff *skb, return err; } +static inline void bpf_push_mac_rcsum(struct sk_buff *skb) +{ + if (skb_at_tc_ingress(skb)) + skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len); +} + static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) { struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp); @@ -1607,9 +1613,6 @@ static const struct bpf_func_proto bpf_csum_diff_proto = { static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb) { - if (skb_at_tc_ingress(skb)) - skb_postpush_rcsum(skb, skb_mac_header(skb), skb->mac_len); - return dev_forward_skb(dev, skb); } @@ -1648,6 +1651,8 @@ static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) if (unlikely(!skb)) return -ENOMEM; + bpf_push_mac_rcsum(skb); + return flags & BPF_F_INGRESS ? __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb); } @@ -1693,6 +1698,8 @@ int skb_do_redirect(struct sk_buff *skb) return -EINVAL; } + bpf_push_mac_rcsum(skb); + return ri->flags & BPF_F_INGRESS ? __bpf_rx_skb(dev, skb) : __bpf_tx_skb(dev, skb); } -- 2.39.2