src: introduce SYNPROXY matching

Add support for "synproxy" statement. For example (for TCP port 8888):

table ip x {
	chain y {
		type filter hook prerouting priority raw; policy accept;
		tcp dport 8888 tcp flags syn notrack
	}

	chain z {
		type filter hook input priority filter; policy accept;
		tcp dport 8888 ct state invalid,untracked synproxy mss 1460 wscale 7 timestamp sack-perm
		ct state invalid drop
	}
}

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/json.h b/include/json.h
index c724c299..ce57c9f7 100644
--- a/include/json.h
+++ b/include/json.h
@@ -83,6 +83,7 @@ json_t *queue_stmt_json(const struct stmt *stmt, struct output_ctx *octx);
 json_t *verdict_stmt_json(const struct stmt *stmt, struct output_ctx *octx);
 json_t *connlimit_stmt_json(const struct stmt *stmt, struct output_ctx *octx);
 json_t *tproxy_stmt_json(const struct stmt *stmt, struct output_ctx *octx);
+json_t *synproxy_stmt_json(const struct stmt *stmt, struct output_ctx *octx);
 
 int do_command_list_json(struct netlink_ctx *ctx, struct cmd *cmd);