netfilter: nf_reject_ipv6: split nf_send_reset6() in smaller functions

That can be reused by the reject bridge expression to build the reject
packet. The new functions are:

* nf_reject_ip6_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_ip6hdr_put(): to build the IPv6 header.
* nf_reject_ip6_tcphdr_put(): to build the TCP header.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/net/netfilter/ipv6/nf_reject.h b/include/net/netfilter/ipv6/nf_reject.h
index 48e18810a9be..23216d48abf9 100644
--- a/include/net/netfilter/ipv6/nf_reject.h
+++ b/include/net/netfilter/ipv6/nf_reject.h
@@ -15,4 +15,14 @@ nf_send_unreach6(struct net *net, struct sk_buff *skb_in, unsigned char code,
 
 void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook);
 
+const struct tcphdr *nf_reject_ip6_tcphdr_get(struct sk_buff *oldskb,
+                                              struct tcphdr *otcph,
+                                              unsigned int *otcplen, int hook);
+struct ipv6hdr *nf_reject_ip6hdr_put(struct sk_buff *nskb,
+                                     const struct sk_buff *oldskb,
+                                     __be16 protocol, int hoplimit);
+void nf_reject_ip6_tcphdr_put(struct sk_buff *nskb,
+                              const struct sk_buff *oldskb,
+                              const struct tcphdr *oth, unsigned int otcplen);
+
 #endif /* _IPV6_NF_REJECT_H */