[NETFILTER]: Add partial checksum validation helper
Move the UDP-Lite conntrack checksum validation to a generic helper
similar to nf_checksum() and make it fall back to nf_checksum()
in case the full packet is to be checksummed and hardware checksums
are available. This is to be used by DCCP conntrack, which also
needs to verify partial checksums.
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 66bc520..e4c6659 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -234,6 +234,11 @@
unsigned short family;
__sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, u_int8_t protocol);
+ __sum16 (*checksum_partial)(struct sk_buff *skb,
+ unsigned int hook,
+ unsigned int dataoff,
+ unsigned int len,
+ u_int8_t protocol);
int (*route)(struct dst_entry **dst, struct flowi *fl);
void (*saveroute)(const struct sk_buff *skb,
struct nf_queue_entry *entry);
@@ -263,6 +268,23 @@
return csum;
}
+static inline __sum16
+nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, unsigned int len,
+ u_int8_t protocol, unsigned short family)
+{
+ const struct nf_afinfo *afinfo;
+ __sum16 csum = 0;
+
+ rcu_read_lock();
+ afinfo = nf_get_afinfo(family);
+ if (afinfo)
+ csum = afinfo->checksum_partial(skb, hook, dataoff, len,
+ protocol);
+ rcu_read_unlock();
+ return csum;
+}
+
extern int nf_register_afinfo(const struct nf_afinfo *afinfo);
extern void nf_unregister_afinfo(const struct nf_afinfo *afinfo);