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net/sctp: Refactor SCTP skb checksum computation

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This patch consolidates the SCTP checksum calculation code from various
places to a single new function, sctp_compute_cksum(skb, offset).

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Joe Stringer 2013-07-25 10:52:05 +09:00 committed by David S. Miller
parent e7428e95a0
commit 024ec3deac
4 changed files with 20 additions and 36 deletions
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15
include/net/sctp/checksum.h
View file

@ -85,4 +85,19 @@ static inline __le32 sctp_end_cksum(__u32 crc32)
return cpu_to_le32(~crc32); return cpu_to_le32(~crc32);
} }
/* Calculate the CRC32C checksum of an SCTP packet. */
static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
unsigned int offset)
{
const struct sk_buff *iter;
__u32 crc32 = sctp_start_cksum(skb->data + offset,
skb_headlen(skb) - offset);
skb_walk_frags(skb, iter)
crc32 = sctp_update_cksum((__u8 *) iter->data,
skb_headlen(iter), crc32);
return sctp_end_cksum(crc32);
}
#endif /* __sctp_checksum_h__ */ #endif /* __sctp_checksum_h__ */

23
net/netfilter/ipvs/ip_vs_proto_sctp.c
View file

@ -66,15 +66,7 @@ sctp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
static void sctp_nat_csum(struct sk_buff *skb, sctp_sctphdr_t *sctph, static void sctp_nat_csum(struct sk_buff *skb, sctp_sctphdr_t *sctph,
unsigned int sctphoff) unsigned int sctphoff)
{ {
__u32 crc32; sctph->checksum = sctp_compute_cksum(skb, sctphoff);
struct sk_buff *iter;
crc32 = sctp_start_cksum((__u8 *)sctph, skb_headlen(skb) - sctphoff);
skb_walk_frags(skb, iter)
crc32 = sctp_update_cksum((u8 *) iter->data,
skb_headlen(iter), crc32);
sctph->checksum = sctp_end_cksum(crc32);
skb->ip_summed = CHECKSUM_UNNECESSARY; skb->ip_summed = CHECKSUM_UNNECESSARY;
} }
@ -151,10 +143,7 @@ sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
{ {
unsigned int sctphoff; unsigned int sctphoff;
struct sctphdr *sh, _sctph; struct sctphdr *sh, _sctph;
struct sk_buff *iter; __le32 cmp, val;
__le32 cmp;
__le32 val;
__u32 tmp;
#ifdef CONFIG_IP_VS_IPV6 #ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6) if (af == AF_INET6)
@ -168,13 +157,7 @@ sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
return 0; return 0;
cmp = sh->checksum; cmp = sh->checksum;
val = sctp_compute_cksum(skb, sctphoff);
tmp = sctp_start_cksum((__u8 *) sh, skb_headlen(skb));
skb_walk_frags(skb, iter)
tmp = sctp_update_cksum((__u8 *) iter->data,
skb_headlen(iter), tmp);
val = sctp_end_cksum(tmp);
if (val != cmp) { if (val != cmp) {
/* CRC failure, dump it. */ /* CRC failure, dump it. */

8
net/netfilter/nf_nat_proto_sctp.c
View file

@ -34,9 +34,7 @@ sctp_manip_pkt(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple, const struct nf_conntrack_tuple *tuple,
enum nf_nat_manip_type maniptype) enum nf_nat_manip_type maniptype)
{ {
struct sk_buff *frag;
sctp_sctphdr_t *hdr; sctp_sctphdr_t *hdr;
__u32 crc32;
if (!skb_make_writable(skb, hdroff + sizeof(*hdr))) if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
return false; return false;
@ -51,11 +49,7 @@ sctp_manip_pkt(struct sk_buff *skb,
hdr->dest = tuple->dst.u.sctp.port; hdr->dest = tuple->dst.u.sctp.port;
} }
crc32 = sctp_start_cksum((u8 *)hdr, skb_headlen(skb) - hdroff); hdr->checksum = sctp_compute_cksum(skb, hdroff);
skb_walk_frags(skb, frag)
crc32 = sctp_update_cksum((u8 *)frag->data, skb_headlen(frag),
crc32);
hdr->checksum = sctp_end_cksum(crc32);
return true; return true;
} }

10
net/sctp/input.c
View file

@ -87,15 +87,7 @@ static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb)
{ {
struct sctphdr *sh = sctp_hdr(skb); struct sctphdr *sh = sctp_hdr(skb);
__le32 cmp = sh->checksum; __le32 cmp = sh->checksum;
struct sk_buff *list; __le32 val = sctp_compute_cksum(skb, 0);
__le32 val;
__u32 tmp = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
skb_walk_frags(skb, list)
tmp = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
tmp);
val = sctp_end_cksum(tmp);
if (val != cmp) { if (val != cmp) {
/* CRC failure, dump it. */ /* CRC failure, dump it. */