Commit abc5d1ff authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

net: Add inet_proto_csum_replace_by_diff utility function 



This function updates a checksum field value and skb->csum based on
a value which is the difference between the old and new checksum.

Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4b048d6d

include/net/checksum.h

+2 −0
Original line number Diff line number Diff line
@@ -144,6 +144,8 @@ void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, 
void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,

			       const __be32 *from, const __be32 *to,

			       bool pseudohdr);

void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,

				     __wsum diff, bool pseudohdr);



static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb,

					    __be16 from, __be16 to,

net/core/utils.c

+13 −0
Original line number Diff line number Diff line
@@ -336,6 +336,19 @@ void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb, 
}

EXPORT_SYMBOL(inet_proto_csum_replace16);



void inet_proto_csum_replace_by_diff(__sum16 *sum, struct sk_buff *skb,

				     __wsum diff, bool pseudohdr)

{

	if (skb->ip_summed != CHECKSUM_PARTIAL) {

		*sum = csum_fold(csum_add(diff, ~csum_unfold(*sum)));

		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)

			skb->csum = ~csum_add(diff, ~skb->csum);

	} else if (pseudohdr) {

		*sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));

	}

}

EXPORT_SYMBOL(inet_proto_csum_replace_by_diff);



struct __net_random_once_work {

	struct work_struct work;

	struct static_key *key;