/*      $OpenBSD: mpls.h,v 1.47 2025/03/02 21:28:32 bluhm Exp $ */

/*
 * Copyright (C) 1999, 2000 and 2001 AYAME Project, WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULARPURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, ORCONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE.
 */

#ifndef _NETMPLS_MPLS_H_
#define _NETMPLS_MPLS_H_

/*
 * Structure of a SHIM header.
 */
#define MPLS_LABEL_MAX          ((1 << 20) - 1)

struct shim_hdr {
        u_int32_t shim_label;   /* 20 bit label, 4 bit exp & BoS, 8 bit TTL */
};

#define MPLS_HDRLEN     sizeof(struct shim_hdr)

/*
 * By byte-swapping the constants, we avoid ever having to byte-swap IP
 * addresses inside the kernel.  Unfortunately, user-level programs rely
 * on these macros not doing byte-swapping.
 */

#ifdef _KERNEL
#define __MADDR(x)     ((u_int32_t)htonl((u_int32_t)(x)))
#else
#define __MADDR(x)     ((u_int32_t)(x))
#endif

#define MPLS_LABEL_MASK         __MADDR(0xfffff000U)
#define MPLS_LABEL_OFFSET       12
#define MPLS_EXP_MASK           __MADDR(0x00000e00U)
#define MPLS_EXP_OFFSET         9
#define MPLS_BOS_MASK           __MADDR(0x00000100U)
#define MPLS_BOS_OFFSET         8
#define MPLS_TTL_MASK           __MADDR(0x000000ffU)

#define CW_ZERO_MASK            __MADDR(0xf0000000U)
#define CW_FRAG_MASK            __MADDR(0x00300000U)

#define MPLS_BOS_ISSET(l)       (((l) & MPLS_BOS_MASK) == MPLS_BOS_MASK)

/* Reserved label values (RFC3032) */
#define MPLS_LABEL_IPV4NULL     0               /* IPv4 Explicit NULL Label */
#define MPLS_LABEL_RTALERT      1               /* Router Alert Label       */
#define MPLS_LABEL_IPV6NULL     2               /* IPv6 Explicit NULL Label */
#define MPLS_LABEL_IMPLNULL     3               /* Implicit NULL Label      */
/*      MPLS_LABEL_RESERVED     4-15 */         /* Values 4-15 are reserved */
#define MPLS_LABEL_RESERVED_MAX 15

/*
 * Socket address
 */

struct sockaddr_mpls {
        u_int8_t        smpls_len;              /* length */
        u_int8_t        smpls_family;           /* AF_MPLS */
        u_int16_t       smpls_pad0;
        u_int32_t       smpls_label;            /* MPLS label */
        u_int32_t       smpls_pad1[2];
};

struct rt_mpls {
        u_int32_t       mpls_label;
        u_int8_t        mpls_operation;
        u_int8_t        mpls_exp;
};

#define MPLS_OP_LOCAL           0x0
#define MPLS_OP_POP             0x1
#define MPLS_OP_PUSH            0x2
#define MPLS_OP_SWAP            0x4

#define MPLS_INKERNEL_LOOP_MAX  16

#define satosmpls(sa)           ((struct sockaddr_mpls *)(sa))
#define smplstosa(smpls)        ((struct sockaddr *)(smpls))

/*
 * Names for MPLS sysctl objects
 */
#define MPLSCTL_ENABLE                  1
#define MPLSCTL_DEFTTL                  2
#define MPLSCTL_MAPTTL_IP               5
#define MPLSCTL_MAPTTL_IP6              6
#define MPLSCTL_MAXID                   7       

#define MPLSCTL_NAMES { \
        { NULL, 0 }, \
        { NULL, 0 }, \
        { "ttl", CTLTYPE_INT }, \
        { "ifq", CTLTYPE_NODE },\
        { NULL, 0 }, \
        { "mapttl_ip", CTLTYPE_INT }, \
        { "mapttl_ip6", CTLTYPE_INT } \
}

#define IMR_TYPE_NONE                   0
#define IMR_TYPE_ETHERNET               1
#define IMR_TYPE_ETHERNET_TAGGED        2

#define IMR_FLAG_CONTROLWORD            0x1

struct ifmpwreq {
        uint32_t        imr_flags;
        uint32_t        imr_type; /* pseudowire type */
        struct          shim_hdr imr_lshim; /* local label */
        struct          shim_hdr imr_rshim; /* remote label */
        struct          sockaddr_storage imr_nexthop;
};

#endif

#ifdef _KERNEL

#define MPLS_LABEL2SHIM(_l)     (htonl((_l) << MPLS_LABEL_OFFSET))
#define MPLS_SHIM2LABEL(_s)     (ntohl((_s)) >> MPLS_LABEL_OFFSET)

extern int              mpls_defttl;
extern int              mpls_mapttl_ip;
extern int              mpls_mapttl_ip6;


struct mbuf     *mpls_shim_pop(struct mbuf *);
struct mbuf     *mpls_shim_swap(struct mbuf *, struct rt_mpls *);
struct mbuf     *mpls_shim_push(struct mbuf *, struct rt_mpls *);

struct mbuf     *mpls_ip_adjttl(struct mbuf *, u_int8_t);
#ifdef INET6
struct mbuf     *mpls_ip6_adjttl(struct mbuf *, u_int8_t);
#endif

int              mpls_output(struct ifnet *, struct mbuf *, struct sockaddr *,
                    struct rtentry *);
void             mpls_input(struct ifnet *, struct mbuf *, struct netstack *);

#endif /* _KERNEL */