diff options
| -rw-r--r-- | include/linux/skbuff.h | 52 | ||||
| -rw-r--r-- | net/core/filter.c | 4 |
2 files changed, 35 insertions, 21 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 6f0b3e0adc73..0f665cb26b50 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2847,6 +2847,18 @@ static inline int skb_linearize_cow(struct sk_buff *skb) __skb_linearize(skb) : 0; } +static __always_inline void +__skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, + unsigned int off) +{ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_block_sub(skb->csum, + csum_partial(start, len, 0), off); + else if (skb->ip_summed == CHECKSUM_PARTIAL && + skb_checksum_start_offset(skb) < 0) + skb->ip_summed = CHECKSUM_NONE; +} + /** * skb_postpull_rcsum - update checksum for received skb after pull * @skb: buffer to update @@ -2857,36 +2869,38 @@ static inline int skb_linearize_cow(struct sk_buff *skb) * update the CHECKSUM_COMPLETE checksum, or set ip_summed to * CHECKSUM_NONE so that it can be recomputed from scratch. */ - static inline void skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len) { - if (skb->ip_summed == CHECKSUM_COMPLETE) - skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); - else if (skb->ip_summed == CHECKSUM_PARTIAL && - skb_checksum_start_offset(skb) < 0) - skb->ip_summed = CHECKSUM_NONE; + __skb_postpull_rcsum(skb, start, len, 0); } -unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); +static __always_inline void +__skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len, + unsigned int off) +{ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_block_add(skb->csum, + csum_partial(start, len, 0), off); +} +/** + * skb_postpush_rcsum - update checksum for received skb after push + * @skb: buffer to update + * @start: start of data after push + * @len: length of data pushed + * + * After doing a push on a received packet, you need to call this to + * update the CHECKSUM_COMPLETE checksum. + */ 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); + __skb_postpush_rcsum(skb, start, len, 0); } +unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); + /** * skb_push_rcsum - push skb and update receive checksum * @skb: buffer to update diff --git a/net/core/filter.c b/net/core/filter.c index c46244f83a8f..5ecd5c9836c3 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1401,7 +1401,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) return -EFAULT; if (flags & BPF_F_RECOMPUTE_CSUM) - skb_postpull_rcsum(skb, ptr, len); + __skb_postpull_rcsum(skb, ptr, len, offset); memcpy(ptr, from, len); @@ -1410,7 +1410,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags) skb_store_bits(skb, offset, ptr, len); if (flags & BPF_F_RECOMPUTE_CSUM) - skb_postpush_rcsum(skb, ptr, len); + __skb_postpush_rcsum(skb, ptr, len, offset); if (flags & BPF_F_INVALIDATE_HASH) skb_clear_hash(skb); |