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-rw-r--r--include/linux/netfilter.h17
-rw-r--r--include/linux/netfilter_ipv4.h2
-rw-r--r--include/linux/netfilter_ipv6.h3
-rw-r--r--net/ipv4/netfilter.c33
-rw-r--r--net/ipv6/netfilter.c34
5 files changed, 89 insertions, 0 deletions
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 6ee168c..b31a9bc 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -285,6 +285,8 @@ extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
struct nf_afinfo {
unsigned short family;
+ unsigned int (*checksum)(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol);
void (*saveroute)(const struct sk_buff *skb,
struct nf_info *info);
int (*reroute)(struct sk_buff **skb,
@@ -298,6 +300,21 @@ static inline struct nf_afinfo *nf_get_afinfo(unsigned short family)
return rcu_dereference(nf_afinfo[family]);
}
+static inline unsigned int
+nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
+ u_int8_t protocol, unsigned short family)
+{
+ struct nf_afinfo *afinfo;
+ unsigned int csum = 0;
+
+ rcu_read_lock();
+ afinfo = nf_get_afinfo(family);
+ if (afinfo)
+ csum = afinfo->checksum(skb, hook, dataoff, protocol);
+ rcu_read_unlock();
+ return csum;
+}
+
extern int nf_register_afinfo(struct nf_afinfo *afinfo);
extern void nf_unregister_afinfo(struct nf_afinfo *afinfo);
diff --git a/include/linux/netfilter_ipv4.h b/include/linux/netfilter_ipv4.h
index 43c09d7..85301c5 100644
--- a/include/linux/netfilter_ipv4.h
+++ b/include/linux/netfilter_ipv4.h
@@ -80,6 +80,8 @@ enum nf_ip_hook_priorities {
#ifdef __KERNEL__
extern int ip_route_me_harder(struct sk_buff **pskb);
extern int ip_xfrm_me_harder(struct sk_buff **pskb);
+extern unsigned int nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol);
#endif /*__KERNEL__*/
#endif /*__LINUX_IP_NETFILTER_H*/
diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h
index 14f2bd0..52a7b9e 100644
--- a/include/linux/netfilter_ipv6.h
+++ b/include/linux/netfilter_ipv6.h
@@ -73,6 +73,9 @@ enum nf_ip6_hook_priorities {
};
#ifdef CONFIG_NETFILTER
+extern unsigned int nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol);
+
extern int ipv6_netfilter_init(void);
extern void ipv6_netfilter_fini(void);
#else /* CONFIG_NETFILTER */
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index b25339c..6a9e34b 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -161,8 +161,41 @@ static int nf_ip_reroute(struct sk_buff **pskb, const struct nf_info *info)
return 0;
}
+unsigned int nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol)
+{
+ struct iphdr *iph = skb->nh.iph;
+ unsigned int csum = 0;
+
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
+ if (hook != NF_IP_PRE_ROUTING && hook != NF_IP_LOCAL_IN)
+ break;
+ if ((protocol == 0 && !(u16)csum_fold(skb->csum)) ||
+ !csum_tcpudp_magic(iph->saddr, iph->daddr,
+ skb->len - dataoff, protocol,
+ skb->csum)) {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ break;
+ }
+ /* fall through */
+ case CHECKSUM_NONE:
+ if (protocol == 0)
+ skb->csum = 0;
+ else
+ skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
+ skb->len - dataoff,
+ protocol, 0);
+ csum = __skb_checksum_complete(skb);
+ }
+ return csum;
+}
+
+EXPORT_SYMBOL(nf_ip_checksum);
+
static struct nf_afinfo nf_ip_afinfo = {
.family = AF_INET,
+ .checksum = nf_ip_checksum,
.saveroute = nf_ip_saveroute,
.reroute = nf_ip_reroute,
.route_key_size = sizeof(struct ip_rt_info),
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index f514a01..3e9ecfa 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -79,8 +79,42 @@ static int nf_ip6_reroute(struct sk_buff **pskb, const struct nf_info *info)
return 0;
}
+unsigned int nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, u_int8_t protocol)
+{
+ struct ipv6hdr *ip6h = skb->nh.ipv6h;
+ unsigned int csum = 0;
+
+ switch (skb->ip_summed) {
+ case CHECKSUM_HW:
+ if (hook != NF_IP6_PRE_ROUTING && hook != NF_IP6_LOCAL_IN)
+ break;
+ if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ skb->len - dataoff, protocol,
+ csum_sub(skb->csum,
+ skb_checksum(skb, 0,
+ dataoff, 0)))) {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ break;
+ }
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ skb->len - dataoff,
+ protocol,
+ csum_sub(0,
+ skb_checksum(skb, 0,
+ dataoff, 0)));
+ csum = __skb_checksum_complete(skb);
+ }
+ return csum;
+}
+
+EXPORT_SYMBOL(nf_ip6_checksum);
+
static struct nf_afinfo nf_ip6_afinfo = {
.family = AF_INET6,
+ .checksum = nf_ip6_checksum,
.saveroute = nf_ip6_saveroute,
.reroute = nf_ip6_reroute,
.route_key_size = sizeof(struct ip6_rt_info),
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