/* 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

#endif