/*      $NetBSD: if_gre.h,v 1.50 2021/12/03 13:27:39 andvar Exp $ */

/*
* Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Heiko W.Rupp <[email protected]>
*
* This code is derived from software contributed to The NetBSD Foundation
* by David Young <[email protected]>
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL 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.
*
* This material is based upon work partially supported by NSF
* under Contract No. NSF CNS-0626584.
*/

#ifndef _NET_IF_GRE_H_
#define _NET_IF_GRE_H_

#include <sys/ioccom.h>
#include <sys/evcnt.h>
#include <sys/queue.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/malloc.h>
#include <sys/mallocvar.h>

#ifdef _KERNEL

#include <sys/pcq.h>

struct gre_soparm {
       struct socket           *sp_so;
       struct sockaddr_storage sp_src; /* source of gre packets */
       struct sockaddr_storage sp_dst; /* destination of gre packets */
       int             sp_type;        /* encapsulating socket type */
       int             sp_proto;       /* encapsulating protocol */
       bool            sp_bysock;      /* encapsulation configured by passing
                                        * socket, not by SIOCSLIFPHYADDR
                                        */
};

enum gre_state {
         GRE_S_IDLE = 0
       , GRE_S_IOCTL
       , GRE_S_DIE
};

struct gre_bufq {
       pcq_t           *bq_q;
       volatile int    bq_drops;
};

enum gre_msg {
         GRE_M_NONE = 0
       , GRE_M_SETFP
       , GRE_M_DELFP
       , GRE_M_STOP
       , GRE_M_OK
       , GRE_M_ERR
};

struct gre_softc {
       struct ifnet            sc_if;
       kmutex_t                sc_mtx;
       kcondvar_t              sc_condvar;
       kcondvar_t              sc_fp_condvar;
       struct gre_bufq         sc_snd;
       struct gre_soparm       sc_soparm;
       volatile enum gre_state sc_state;
       volatile int            sc_waiters;
       volatile int            sc_fp_waiters;
       void                    *sc_si;

       struct evcnt            sc_recv_ev;
       struct evcnt            sc_send_ev;

       struct evcnt            sc_block_ev;
       struct evcnt            sc_error_ev;
       struct evcnt            sc_pullup_ev;
       struct evcnt            sc_unsupp_ev;
       struct evcnt            sc_oflow_ev;
       file_t  * volatile      sc_fp;
       volatile enum gre_msg   sc_msg;
       int                     sc_fd;
};

struct gre_h {
       uint16_t flags;         /* GRE flags */
       uint16_t ptype;         /* protocol type of payload typically
                                * ethernet protocol type
                                */
/*
*  from here on: fields are optional, presence indicated by flags
*
       u_int_16 checksum       checksum (one-complements of GRE header
                               and payload
                               Present if (ck_pres | rt_pres == 1).
                               Valid if (ck_pres == 1).
       u_int_16 offset         offset from start of routing field to
                               first octet of active SRE (see below).
                               Present if (ck_pres | rt_pres == 1).
                               Valid if (rt_pres == 1).
       u_int_32 key            inserted by encapsulator e.g. for
                               authentication
                               Present if (key_pres ==1 ).
       u_int_32 seq_num        Sequence number to allow for packet order
                               Present if (seq_pres ==1 ).
       struct gre_sre[] routing Routing fields (see below)
                               Present if (rt_pres == 1)
*/
};
#define GRE_CP          0x8000  /* Checksum Present */
#define GRE_RP          0x4000  /* Routing Present */
#define GRE_KP          0x2000  /* Key Present */
#define GRE_SP          0x1000  /* Sequence Present */
#define GRE_SS          0x0800  /* Strict Source Route */

/*
* gre_sre defines a Source route Entry. These are needed if packets
* should be routed over more than one tunnel hop by hop
*/
struct gre_sre {
       uint16_t sre_family;    /* address family */
       u_char  sre_offset;     /* offset to first octet of active entry */
       u_char  sre_length;     /* number of octets in the SRE.
                                  sre_lengthl==0 -> last entry. */
       u_char  *sre_rtinfo;    /* the routing information */
};

#define GRE_TTL 30
extern int ip_gre_ttl;
#endif /* _KERNEL */

/*
* ioctls needed to manipulate the interface
*/

#define GRESADDRS        _IOW('i', 101, struct ifreq)
#define GRESADDRD        _IOW('i', 102, struct ifreq)
#define GREGADDRS       _IOWR('i', 103, struct ifreq)
#define GREGADDRD       _IOWR('i', 104, struct ifreq)
#define GRESPROTO        _IOW('i', 105, struct ifreq)
#define GREGPROTO       _IOWR('i', 106, struct ifreq)
#define GRESSOCK         _IOW('i', 107, struct ifreq)
#define GREDSOCK         _IOW('i', 108, struct ifreq)

#endif /* !_NET_IF_GRE_H_ */