leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

net: qualcomm: rmnet: drop some unary NOTs

Browse Source 
We compare a payload checksum with a pseudo checksum value for
equality in rmnet_map_ipv4_dl_csum_trailer().  Both of those values
are computed with a unary NOT (~) operation.  The result of the
comparison is the same if we omit that NOT for both values.

Remove these operations in rmnet_map_ipv6_dl_csum_trailer() also.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alex Elder 2021-06-12 09:37:35 -05:00 committed by David S. Miller
parent be754f6435
commit 411a795e14
1 changed files with 7 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
View File

@ -87,11 +87,11 @@ 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 = ~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,
ip4h->protocol, 0);
pseudo_csum = csum_tcpudp_magic(ip4h->saddr, ip4h->daddr,
ntohs(ip4h->tot_len) - ip4h->ihl * 4,
ip4h->protocol, 0);
/* The cast is required to ensure only the low 16 bits are examined */
if (ip_payload_csum != (__sum16)~pseudo_csum) {
@ -132,13 +132,13 @@ 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(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) :
ntohs(ip6h->payload_len);
pseudo_csum = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
length, ip6h->nexthdr, 0);
pseudo_csum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
length, ip6h->nexthdr, 0);
/* It's sufficient to compare the IP payload checksum with the
* negated pseudo checksum to determine whether the packet