/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
#ifndef _MPTCP_H
#define _MPTCP_H

#include <netinet/in.h>        /* for sockaddr_in and sockaddr_in6    */
#include <sys/socket.h>        /* for struct sockaddr            */

#include <linux/const.h>
#include <linux/types.h>
#include <linux/in.h>        /* for sockaddr_in            */
#include <linux/in6.h>        /* for sockaddr_in6            */
#include <linux/socket.h>    /* for sockaddr_storage and sa_family    */

#define MPTCP_SUBFLOW_FLAG_MCAP_REM        _BITUL(0)
#define MPTCP_SUBFLOW_FLAG_MCAP_LOC        _BITUL(1)
#define MPTCP_SUBFLOW_FLAG_JOIN_REM        _BITUL(2)
#define MPTCP_SUBFLOW_FLAG_JOIN_LOC        _BITUL(3)
#define MPTCP_SUBFLOW_FLAG_BKUP_REM        _BITUL(4)
#define MPTCP_SUBFLOW_FLAG_BKUP_LOC        _BITUL(5)
#define MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED    _BITUL(6)
#define MPTCP_SUBFLOW_FLAG_CONNECTED        _BITUL(7)
#define MPTCP_SUBFLOW_FLAG_MAPVALID        _BITUL(8)

enum {
    MPTCP_SUBFLOW_ATTR_UNSPEC,
    MPTCP_SUBFLOW_ATTR_TOKEN_REM,
    MPTCP_SUBFLOW_ATTR_TOKEN_LOC,
    MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
    MPTCP_SUBFLOW_ATTR_MAP_SEQ,
    MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
    MPTCP_SUBFLOW_ATTR_SSN_OFFSET,
    MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
    MPTCP_SUBFLOW_ATTR_FLAGS,
    MPTCP_SUBFLOW_ATTR_ID_REM,
    MPTCP_SUBFLOW_ATTR_ID_LOC,
    MPTCP_SUBFLOW_ATTR_PAD,
    __MPTCP_SUBFLOW_ATTR_MAX
};

#define MPTCP_SUBFLOW_ATTR_MAX (__MPTCP_SUBFLOW_ATTR_MAX - 1)

/* netlink interface */
#define MPTCP_PM_NAME        "mptcp_pm"
#define MPTCP_PM_CMD_GRP_NAME    "mptcp_pm_cmds"
#define MPTCP_PM_EV_GRP_NAME    "mptcp_pm_events"
#define MPTCP_PM_VER        0x1

/*
 * ATTR types defined for MPTCP
 */
enum {
    MPTCP_PM_ATTR_UNSPEC,

    MPTCP_PM_ATTR_ADDR,                /* nested address */
    MPTCP_PM_ATTR_RCV_ADD_ADDRS,            /* u32 */
    MPTCP_PM_ATTR_SUBFLOWS,                /* u32 */
    MPTCP_PM_ATTR_TOKEN,                /* u32 */
    MPTCP_PM_ATTR_LOC_ID,                /* u8 */
    MPTCP_PM_ATTR_ADDR_REMOTE,            /* nested address */

    __MPTCP_PM_ATTR_MAX
};

#define MPTCP_PM_ATTR_MAX (__MPTCP_PM_ATTR_MAX - 1)

enum {
    MPTCP_PM_ADDR_ATTR_UNSPEC,

    MPTCP_PM_ADDR_ATTR_FAMILY,            /* u16 */
    MPTCP_PM_ADDR_ATTR_ID,                /* u8 */
    MPTCP_PM_ADDR_ATTR_ADDR4,            /* struct in_addr */
    MPTCP_PM_ADDR_ATTR_ADDR6,            /* struct in6_addr */
    MPTCP_PM_ADDR_ATTR_PORT,            /* u16 */
    MPTCP_PM_ADDR_ATTR_FLAGS,            /* u32 */
    MPTCP_PM_ADDR_ATTR_IF_IDX,            /* s32 */

    __MPTCP_PM_ADDR_ATTR_MAX
};

#define MPTCP_PM_ADDR_ATTR_MAX (__MPTCP_PM_ADDR_ATTR_MAX - 1)

#define MPTCP_PM_EV_FLAG_DENY_JOIN_ID0        _BITUL(0)

#define MPTCP_PM_ADDR_FLAG_SIGNAL            (1 << 0)
#define MPTCP_PM_ADDR_FLAG_SUBFLOW            (1 << 1)
#define MPTCP_PM_ADDR_FLAG_BACKUP            (1 << 2)
#define MPTCP_PM_ADDR_FLAG_FULLMESH            (1 << 3)
#define MPTCP_PM_ADDR_FLAG_IMPLICIT            (1 << 4)

enum {
    MPTCP_PM_CMD_UNSPEC,

    MPTCP_PM_CMD_ADD_ADDR,
    MPTCP_PM_CMD_DEL_ADDR,
    MPTCP_PM_CMD_GET_ADDR,
    MPTCP_PM_CMD_FLUSH_ADDRS,
    MPTCP_PM_CMD_SET_LIMITS,
    MPTCP_PM_CMD_GET_LIMITS,
    MPTCP_PM_CMD_SET_FLAGS,
    MPTCP_PM_CMD_ANNOUNCE,
    MPTCP_PM_CMD_REMOVE,
    MPTCP_PM_CMD_SUBFLOW_CREATE,
    MPTCP_PM_CMD_SUBFLOW_DESTROY,

    __MPTCP_PM_CMD_AFTER_LAST
};

#define MPTCP_INFO_FLAG_FALLBACK        _BITUL(0)
#define MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED    _BITUL(1)

struct mptcp_info {
    __u8    mptcpi_subflows;
    __u8    mptcpi_add_addr_signal;
    __u8    mptcpi_add_addr_accepted;
    __u8    mptcpi_subflows_max;
    __u8    mptcpi_add_addr_signal_max;
    __u8    mptcpi_add_addr_accepted_max;
    __u32    mptcpi_flags;
    __u32    mptcpi_token;
    __u64    mptcpi_write_seq;
    __u64    mptcpi_snd_una;
    __u64    mptcpi_rcv_nxt;
    __u8    mptcpi_local_addr_used;
    __u8    mptcpi_local_addr_max;
    __u8    mptcpi_csum_enabled;
    __u32    mptcpi_retransmits;
    __u64    mptcpi_bytes_retrans;
    __u64    mptcpi_bytes_sent;
    __u64    mptcpi_bytes_received;
    __u64    mptcpi_bytes_acked;
};

/*
 * MPTCP_EVENT_CREATED: token, family, saddr4 | saddr6, daddr4 | daddr6,
 *                      sport, dport, server-side, [flags]
 * A new MPTCP connection has been created. It is the good time to allocate
 * memory and send ADD_ADDR if needed. Depending on the traffic-patterns
 * it can take a long time until the MPTCP_EVENT_ESTABLISHED is sent.
 *
 * MPTCP_EVENT_ESTABLISHED: token, family, saddr4 | saddr6, daddr4 | daddr6,
 *                sport, dport, server-side, [flags]
 * A MPTCP connection is established (can start new subflows).
 *
 * MPTCP_EVENT_CLOSED: token
 * A MPTCP connection has stopped.
 *
 * MPTCP_EVENT_ANNOUNCED: token, rem_id, family, daddr4 | daddr6 [, dport]
 * A new address has been announced by the peer.
 *
 * MPTCP_EVENT_REMOVED: token, rem_id
 * An address has been lost by the peer.
 *
 * MPTCP_EVENT_SUB_ESTABLISHED: token, family, loc_id, rem_id,
 *                              saddr4 | saddr6, daddr4 | daddr6, sport,
 *                              dport, backup, if_idx [, error]
 * A new subflow has been established. 'error' should not be set.
 *
 * MPTCP_EVENT_SUB_CLOSED: token, family, loc_id, rem_id, saddr4 | saddr6,
 *                         daddr4 | daddr6, sport, dport, backup, if_idx
 *                         [, error]
 * A subflow has been closed. An error (copy of sk_err) could be set if an
 * error has been detected for this subflow.
 *
 * MPTCP_EVENT_SUB_PRIORITY: token, family, loc_id, rem_id, saddr4 | saddr6,
 *                           daddr4 | daddr6, sport, dport, backup, if_idx
 *                           [, error]
 * The priority of a subflow has changed. 'error' should not be set.
 *
 * MPTCP_EVENT_LISTENER_CREATED: family, sport, saddr4 | saddr6
 * A new PM listener is created.
 *
 * MPTCP_EVENT_LISTENER_CLOSED: family, sport, saddr4 | saddr6
 * A PM listener is closed.
 */
enum mptcp_event_type {
    MPTCP_EVENT_UNSPEC = 0,
    MPTCP_EVENT_CREATED = 1,
    MPTCP_EVENT_ESTABLISHED = 2,
    MPTCP_EVENT_CLOSED = 3,

    MPTCP_EVENT_ANNOUNCED = 6,
    MPTCP_EVENT_REMOVED = 7,

    MPTCP_EVENT_SUB_ESTABLISHED = 10,
    MPTCP_EVENT_SUB_CLOSED = 11,

    MPTCP_EVENT_SUB_PRIORITY = 13,

    MPTCP_EVENT_LISTENER_CREATED = 15,
    MPTCP_EVENT_LISTENER_CLOSED = 16,
};

enum mptcp_event_attr {
    MPTCP_ATTR_UNSPEC = 0,

    MPTCP_ATTR_TOKEN,    /* u32 */
    MPTCP_ATTR_FAMILY,    /* u16 */
    MPTCP_ATTR_LOC_ID,    /* u8 */
    MPTCP_ATTR_REM_ID,    /* u8 */
    MPTCP_ATTR_SADDR4,    /* be32 */
    MPTCP_ATTR_SADDR6,    /* struct in6_addr */
    MPTCP_ATTR_DADDR4,    /* be32 */
    MPTCP_ATTR_DADDR6,    /* struct in6_addr */
    MPTCP_ATTR_SPORT,    /* be16 */
    MPTCP_ATTR_DPORT,    /* be16 */
    MPTCP_ATTR_BACKUP,    /* u8 */
    MPTCP_ATTR_ERROR,    /* u8 */
    MPTCP_ATTR_FLAGS,    /* u16 */
    MPTCP_ATTR_TIMEOUT,    /* u32 */
    MPTCP_ATTR_IF_IDX,    /* s32 */
    MPTCP_ATTR_RESET_REASON,/* u32 */
    MPTCP_ATTR_RESET_FLAGS, /* u32 */
    MPTCP_ATTR_SERVER_SIDE,    /* u8 */

    __MPTCP_ATTR_AFTER_LAST
};

#define MPTCP_ATTR_MAX (__MPTCP_ATTR_AFTER_LAST - 1)

/* MPTCP Reset reason codes, rfc8684 */
#define MPTCP_RST_EUNSPEC    0
#define MPTCP_RST_EMPTCP    1
#define MPTCP_RST_ERESOURCE    2
#define MPTCP_RST_EPROHIBIT    3
#define MPTCP_RST_EWQ2BIG    4
#define MPTCP_RST_EBADPERF    5
#define MPTCP_RST_EMIDDLEBOX    6

struct mptcp_subflow_data {
    __u32        size_subflow_data;        /* size of this structure in userspace */
    __u32        num_subflows;            /* must be 0, set by kernel */
    __u32        size_kernel;            /* must be 0, set by kernel */
    __u32        size_user;            /* size of one element in data[] */
} __attribute__((aligned(8)));

struct mptcp_subflow_addrs {
    union {
        __kernel_sa_family_t sa_family;
        struct sockaddr sa_local;
        struct sockaddr_in sin_local;
        struct sockaddr_in6 sin6_local;
        struct __kernel_sockaddr_storage ss_local;
    };
    union {
        struct sockaddr sa_remote;
        struct sockaddr_in sin_remote;
        struct sockaddr_in6 sin6_remote;
        struct __kernel_sockaddr_storage ss_remote;
    };
};

struct mptcp_subflow_info {
    __u32                id;
    struct mptcp_subflow_addrs    addrs;
};

struct mptcp_full_info {
    __u32        size_tcpinfo_kernel;    /* must be 0, set by kernel */
    __u32        size_tcpinfo_user;
    __u32        size_sfinfo_kernel;    /* must be 0, set by kernel */
    __u32        size_sfinfo_user;
    __u32        num_subflows;        /* must be 0, set by kernel (real subflow count) */
    __u32        size_arrays_user;    /* max subflows that userspace is interested in;
                         * the buffers at subflow_info/tcp_info
                         * are respectively at least:
                         *  size_arrays * size_sfinfo_user
                         *  size_arrays * size_tcpinfo_user
                         * bytes wide
                         */
    __aligned_u64        subflow_info;
    __aligned_u64        tcp_info;
    struct mptcp_info    mptcp_info;
};

/* MPTCP socket options */
#define MPTCP_INFO        1
#define MPTCP_TCPINFO        2
#define MPTCP_SUBFLOW_ADDRS    3
#define MPTCP_FULL_INFO        4

#endif /* _MPTCP_H */