linux/include/linux/netfilter/nf_conntrack_ftp.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NF_CONNTRACK_FTP_H
#define _NF_CONNTRACK_FTP_H

#include <linux/netfilter.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <uapi/linux/netfilter/nf_conntrack_ftp.h>
#include <uapi/linux/netfilter/nf_conntrack_tuple_common.h>

#define FTP_PORT	21

#define NF_CT_FTP_SEQ_PICKUP	(1 << 0)

#define NUM_SEQ_TO_REMEMBER 2
/* This structure exists only once per master */
struct nf_ct_ftp_master {
	/* Valid seq positions for cmd matching after newline */
	u_int32_t seq_aft_nl[IP_CT_DIR_MAX][NUM_SEQ_TO_REMEMBER];
	/* 0 means seq_match_aft_nl not set */
	u_int16_t seq_aft_nl_num[IP_CT_DIR_MAX];
	/* pickup sequence tracking, useful for conntrackd */
	u_int16_t flags[IP_CT_DIR_MAX];
};

/* For NAT to hook in when we find a packet which describes what other
 * connection we should expect. */
extern unsigned int (*nf_nat_ftp_hook)(struct sk_buff *skb,
				       enum ip_conntrack_info ctinfo,
				       enum nf_ct_ftp_type type,
				       unsigned int protoff,
				       unsigned int matchoff,
				       unsigned int matchlen,
				       struct nf_conntrack_expect *exp);
#endif /* _NF_CONNTRACK_FTP_H */