Commit 336d3262 authored by Harvey Harrison's avatar Harvey Harrison Committed by David S. Miller
Browse files

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



Signed-off-by: default avatarHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4e54064e

include/net/sctp/checksum.h

+14 −9
Original line number Diff line number Diff line
@@ -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;

}

net/ipv4/netfilter/nf_nat_proto_sctp.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

}

net/sctp/input.c

+2 −2
Original line number Diff line number Diff line
@@ -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),

net/sctp/output.c

+2 −2
Original line number Diff line number Diff line
@@ -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