/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * Management Component Transport Protocol (MCTP)
 *
 * Copyright (c) 2021 Code Construct
 * Copyright (c) 2021 Google
 */

#ifndef __UAPI_MCTP_H
#define __UAPI_MCTP_H

#include <linux/types.h>
#include <linux/socket.h>
#include <linux/netdevice.h>

typedef __u8                    mctp_eid_t;

struct mctp_addr {
        mctp_eid_t              s_addr;
};

struct sockaddr_mctp {
        __kernel_sa_family_t    smctp_family;
        __u16                   __smctp_pad0;
        unsigned int            smctp_network;
        struct mctp_addr        smctp_addr;
        __u8                    smctp_type;
        __u8                    smctp_tag;
        __u8                    __smctp_pad1;
};

struct sockaddr_mctp_ext {
        struct sockaddr_mctp    smctp_base;
        int                     smctp_ifindex;
        __u8                    smctp_halen;
        __u8                    __smctp_pad0[3];
        __u8                    smctp_haddr[MAX_ADDR_LEN];
};

/* A "fully qualified" MCTP address, which includes the system-local network ID,
 * required to uniquely resolve a routable EID.
 */
struct mctp_fq_addr {
        unsigned int    net;
        mctp_eid_t      eid;
};

#define MCTP_NET_ANY            0x0

#define MCTP_ADDR_NULL          0x00
#define MCTP_ADDR_ANY           0xff

#define MCTP_TAG_MASK           0x07
#define MCTP_TAG_OWNER          0x08
#define MCTP_TAG_PREALLOC       0x10

#define MCTP_OPT_ADDR_EXT       1

#define SIOCMCTPALLOCTAG        (SIOCPROTOPRIVATE + 0)
#define SIOCMCTPDROPTAG         (SIOCPROTOPRIVATE + 1)
#define SIOCMCTPALLOCTAG2       (SIOCPROTOPRIVATE + 2)
#define SIOCMCTPDROPTAG2        (SIOCPROTOPRIVATE + 3)

/* Deprecated: use mctp_ioc_tag_ctl2 / TAG2 ioctls instead, which defines the
 * MCTP network ID as part of the allocated tag. Using this assumes the default
 * net ID for allocated tags, which may not give correct behaviour on system
 * with multiple networks configured.
 */
struct mctp_ioc_tag_ctl {
        mctp_eid_t      peer_addr;

        /* For SIOCMCTPALLOCTAG: must be passed as zero, kernel will
         * populate with the allocated tag value. Returned tag value will
         * always have TO and PREALLOC set.
         *
         * For SIOCMCTPDROPTAG: userspace provides tag value to drop, from
         * a prior SIOCMCTPALLOCTAG call (and so must have TO and PREALLOC set).
         */
        __u8            tag;
        __u16           flags;
};

struct mctp_ioc_tag_ctl2 {
        /* Peer details: network ID, peer EID, local EID. All set by the
         * caller.
         *
         * Local EID must be MCTP_ADDR_NULL or MCTP_ADDR_ANY in current
         * kernels.
         */
        unsigned int    net;
        mctp_eid_t      peer_addr;
        mctp_eid_t      local_addr;

        /* Set by caller, but no flags defined currently. Must be 0 */
        __u16           flags;

        /* For SIOCMCTPALLOCTAG2: must be passed as zero, kernel will
         * populate with the allocated tag value. Returned tag value will
         * always have TO and PREALLOC set.
         *
         * For SIOCMCTPDROPTAG2: userspace provides tag value to drop, from
         * a prior SIOCMCTPALLOCTAG2 call (and so must have TO and PREALLOC set).
         */
        __u8            tag;

};

#endif /* __UAPI_MCTP_H */