diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 6b6bd42d6134a3bfccb36f0bad4447c8c35ab3ff..07f9ccd28654b6590edb63b97b0aa42b1d4748cf 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2805,6 +2805,23 @@ static inline void skb_postpull_rcsum(struct sk_buff *skb, unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); +static inline void skb_postpush_rcsum(struct sk_buff *skb, + const void *start, unsigned int len) +{ + /* For performing the reverse operation to skb_postpull_rcsum(), + * we can instead of ... + * + * skb->csum = csum_add(skb->csum, csum_partial(start, len, 0)); + * + * ... just use this equivalent version here to save a few + * instructions. Feeding csum of 0 in csum_partial() and later + * on adding skb->csum is equivalent to feed skb->csum in the + * first place. + */ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_partial(start, len, skb->csum); +} + /** * pskb_trim_rcsum - trim received skb and update checksum * @skb: buffer to trim diff --git a/net/core/filter.c b/net/core/filter.c index 35e6fed287093b7f81eabf1b159a1efd542b6a29..0db92b5e2cbfb49364196586c88dbec7aa741523 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1368,8 +1368,9 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) /* skb_store_bits cannot return -EFAULT here */ skb_store_bits(skb, offset, ptr, len); - if (BPF_RECOMPUTE_CSUM(flags) && skb->ip_summed == CHECKSUM_COMPLETE) - skb->csum = csum_add(skb->csum, csum_partial(ptr, len, 0)); + if (BPF_RECOMPUTE_CSUM(flags)) + skb_postpush_rcsum(skb, ptr, len); + return 0; } @@ -1525,8 +1526,12 @@ static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5) if (unlikely(!skb2)) return -ENOMEM; - if (BPF_IS_REDIRECT_INGRESS(flags)) + if (BPF_IS_REDIRECT_INGRESS(flags)) { + if (skb_at_tc_ingress(skb2)) + skb_postpush_rcsum(skb2, skb_mac_header(skb2), + skb2->mac_len); return dev_forward_skb(dev, skb2); + } skb2->dev = dev; skb_sender_cpu_clear(skb2); @@ -1569,8 +1574,12 @@ int skb_do_redirect(struct sk_buff *skb) return -EINVAL; } - if (BPF_IS_REDIRECT_INGRESS(ri->flags)) + if (BPF_IS_REDIRECT_INGRESS(ri->flags)) { + if (skb_at_tc_ingress(skb)) + skb_postpush_rcsum(skb, skb_mac_header(skb), + skb->mac_len); return dev_forward_skb(dev, skb); + } skb->dev = dev; skb_sender_cpu_clear(skb);