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

#include <linux/netdevice.h>
#include <linux/types.h>
#include <net/rtnetlink.h>

/* General GTP protocol related definitions. */

#define GTP0_PORT       3386
#define GTP1U_PORT      2152

/* GTP messages types */
#define GTP_ECHO_REQ    1       /* Echo Request */
#define GTP_ECHO_RSP    2       /* Echo Response */
#define GTP_TPDU        255

#define GTPIE_RECOVERY  14

struct gtp0_header {    /* According to GSM TS 09.60. */
        __u8    flags;
        __u8    type;
        __be16  length;
        __be16  seq;
        __be16  flow;
        __u8    number;
        __u8    spare[3];
        __be64  tid;
} __attribute__ ((packed));

struct gtp1_header {    /* According to 3GPP TS 29.060. */
        __u8    flags;
        __u8    type;
        __be16  length;
        __be32  tid;
} __attribute__ ((packed));

struct gtp1_header_long {       /* According to 3GPP TS 29.060. */
        __u8    flags;
        __u8    type;
        __be16  length;
        __be32  tid;
        __be16  seq;
        __u8    npdu;
        __u8    next;
} __packed;

/* GTP Information Element */
struct gtp_ie {
        __u8    tag;
        __u8    val;
} __packed;

struct gtp0_packet {
        struct gtp0_header gtp0_h;
        struct gtp_ie ie;
} __packed;

struct gtp1u_packet {
        struct gtp1_header_long gtp1u_h;
        struct gtp_ie ie;
} __packed;

struct gtp_pdu_session_info {   /* According to 3GPP TS 38.415. */
        u8      pdu_type;
        u8      qfi;
};

static inline bool netif_is_gtp(const struct net_device *dev)
{
        return dev->rtnl_link_ops &&
                !strcmp(dev->rtnl_link_ops->kind, "gtp");
}

#define GTP1_F_NPDU     0x01
#define GTP1_F_SEQ      0x02
#define GTP1_F_EXTHDR   0x04
#define GTP1_F_MASK     0x07

struct gtp_ext_hdr {
        __u8    len;
        __u8    data[];
};

#endif