| Message ID | 20210612143736.3498712-3-elder@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | net: qualcomm: rmnet: MAPv4 download checksum cleanup, part 2 | expand |
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c index 3e6feef0fd252..1b170e9189d8a 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c @@ -140,8 +140,8 @@ rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb, * checksum computed over the pseudo header. */ ip_header_csum = (__force __be16)ip_fast_csum(ip6h, sizeof(*ip6h) / 4); - ip6_payload_csum = csum16_sub((__force __sum16)~csum_trailer->csum_value, - ~ip_header_csum); + ip6_payload_csum = ~csum16_sub((__force __sum16)csum_trailer->csum_value, + ip_header_csum); length = (ip6h->nexthdr == IPPROTO_UDP) ? ntohs(((struct udphdr *)txporthdr)->len) :
With the ones' complement arithmetic, the sum of two negated values is equal to the negation of the sum of the two original values [1]. Rearrange the calculation ip6_payload_sum using this property. [1] https://tools.ietf.org/html/rfc1071 Signed-off-by: Alex Elder <elder@linaro.org> --- drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.27.0