Commit be754f64 authored by Alex Elder's avatar Alex Elder Committed by David S. Miller
Browse files

net: qualcomm: rmnet: trailer value is a checksum 



The csum_value field in the rmnet_map_dl_csum_trailer structure is a
"real" Internet checksum.  It is a 16 bit value, in big endian format,
which represents an inverted ones' complement sum over pairs of bytes.

Make that clear by changing its type to __sum16.

This makes a typecast in rmnet_map_ipv4_dl_csum_trailer() and
another in rmnet_map_ipv6_dl_csum_trailer() unnecessary.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 698aa6c4

drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

+2 −3
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ rmnet_map_ipv4_dl_csum_trailer(struct sk_buff *skb, 
	 * header checksum value; it is already accounted for in the

	 * checksum value found in the trailer.

	 */

	ip_payload_csum = (__force __sum16)~csum_trailer->csum_value;

	ip_payload_csum = ~csum_trailer->csum_value;



	pseudo_csum = ~csum_tcpudp_magic(ip4h->saddr, ip4h->daddr,

					 ntohs(ip4h->tot_len) - ip4h->ihl * 4,
@@ -132,8 +132,7 @@ 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(csum_trailer->csum_value, ip_header_csum);



	length = (ip6h->nexthdr == IPPROTO_UDP) ?

		 ntohs(((struct udphdr *)txporthdr)->len) :

include/linux/if_rmnet.h

+1 −1
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ struct rmnet_map_dl_csum_trailer { 
	u8 flags;			/* MAP_CSUM_DL_VALID_FLAG */

	__be16 csum_start_offset;

	__be16 csum_length;

	__be16 csum_value;

	__sum16 csum_value;

} __aligned(1);



/* rmnet_map_dl_csum_trailer flags field: