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sctp: remove unnecessary byteshifting, calculate directly in big-endian 

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harvey Harrison 2008-07-18 23:07:09 -07:00 committed by David S. Miller
parent 4e54064e0a
commit 336d3262df
4 changed files with 20 additions and 15 deletions
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23
include/net/sctp/checksum.h
View File

@ -46,9 +46,14 @@
#include <net/sctp/sctp.h>
#include <linux/crc32c.h>
static inline __u32 sctp_start_cksum(__u8 *buffer, __u16 length)
static inline __be32 sctp_crc32c(__be32 crc, u8 *buffer, u16 length)
{
__u32 crc = ~(__u32) 0;
return (__force __be32)crc32c((__force u32)crc, buffer, length);
}
static inline __be32 sctp_start_cksum(__u8 *buffer, __u16 length)
{
__be32 crc = ~cpu_to_be32(0);
__u8 zero[sizeof(__u32)] = {0};
/* Optimize this routine to be SCTP specific, knowing how
@ -56,23 +61,23 @@ static inline __u32 sctp_start_cksum(__u8 *buffer, __u16 length)
*/
/* Calculate CRC up to the checksum. */
crc = crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32));
crc = sctp_crc32c(crc, buffer, sizeof(struct sctphdr) - sizeof(__u32));
/* Skip checksum field of the header. */
crc = crc32c(crc, zero, sizeof(__u32));
crc = sctp_crc32c(crc, zero, sizeof(__u32));
/* Calculate the rest of the CRC. */
crc = crc32c(crc, &buffer[sizeof(struct sctphdr)],
crc = sctp_crc32c(crc, &buffer[sizeof(struct sctphdr)],
length - sizeof(struct sctphdr));
return crc;
}
static inline __u32 sctp_update_cksum(__u8 *buffer, __u16 length, __u32 crc32)
static inline __be32 sctp_update_cksum(__u8 *buffer, __u16 length, __be32 crc32)
{
return crc32c(crc32, buffer, length);
return sctp_crc32c(crc32, buffer, length);
}
static inline __u32 sctp_end_cksum(__u32 crc32)
static inline __be32 sctp_end_cksum(__be32 crc32)
{
return ntohl(~crc32);
return ~crc32;
}

4
net/ipv4/netfilter/nf_nat_proto_sctp.c
View File

@ -36,7 +36,7 @@ sctp_manip_pkt(struct sk_buff *skb,
sctp_sctphdr_t *hdr;
unsigned int hdroff = iphdroff + iph->ihl*4;
__be32 oldip, newip;
u32 crc32;
__be32 crc32;
if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
return false;
@ -61,7 +61,7 @@ sctp_manip_pkt(struct sk_buff *skb,
crc32 = sctp_update_cksum((u8 *)skb->data, skb_headlen(skb),
crc32);
crc32 = sctp_end_cksum(crc32);
hdr->checksum = htonl(crc32);
hdr->checksum = crc32;
return true;
}

4
net/sctp/input.c
View File

@ -83,8 +83,8 @@ static inline int sctp_rcv_checksum(struct sk_buff *skb)
{
struct sk_buff *list = skb_shinfo(skb)->frag_list;
struct sctphdr *sh = sctp_hdr(skb);
__u32 cmp = ntohl(sh->checksum);
__u32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
__be32 cmp = sh->checksum;
__be32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
for (; list; list = list->next)
val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),

4
net/sctp/output.c
View File

@ -365,7 +365,7 @@ int sctp_packet_transmit(struct sctp_packet *packet)
struct sctp_transport *tp = packet->transport;
struct sctp_association *asoc = tp->asoc;
struct sctphdr *sh;
__u32 crc32 = 0;
__be32 crc32 = __constant_cpu_to_be32(0);
struct sk_buff *nskb;
struct sctp_chunk *chunk, *tmp;
struct sock *sk;
@ -538,7 +538,7 @@ int sctp_packet_transmit(struct sctp_packet *packet)
/* 3) Put the resultant value into the checksum field in the
* common header, and leave the rest of the bits unchanged.
*/
sh->checksum = htonl(crc32);
sh->checksum = crc32;
/* IP layer ECN support
* From RFC 2481