tcp: add skb-less helpers to retrieve SYN cookie
This patch allows generation of a SYN cookie before an SKB has been
allocated, as is the case at XDP.
Signed-off-by: Petar Penkov <ppenkov@google.com>
Reviewed-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e5cf514..fb7e153 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -415,6 +415,16 @@ void tcp_parse_options(const struct net *net, const struct sk_buff *skb,
const u8 *tcp_parse_md5sig_option(const struct tcphdr *th);
/*
+ * BPF SKB-less helpers
+ */
+u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph,
+ struct tcphdr *th, u32 *cookie);
+u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
+ struct tcphdr *th, u32 *cookie);
+u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops,
+ const struct tcp_request_sock_ops *af_ops,
+ struct sock *sk, struct tcphdr *th);
+/*
* TCP v4 functions exported for the inet6 API
*/