/* SPDX-License-Identifier: BSD-3-Clause */
/*
 * Copyright (c) 1982, 1986, 1993
 *  The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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.
 *
 *  @(#)ip.h    8.1 (Berkeley) 6/10/93
 * ip.h,v 1.3 1994/08/21 05:27:30 paul Exp
 */

#ifndef IP_H
#define IP_H

#ifndef BX_LITTLE_ENDIAN
# undef NTOHL
# undef NTOHS
# undef HTONL
# undef HTONS
# define NTOHL(d)
# define NTOHS(d)
# define HTONL(d)
# define HTONS(d)
#else
# ifndef NTOHL
#  define NTOHL(d) ((d) = ntohl((d)))
# endif
# ifndef NTOHS
#  define NTOHS(d) ((d) = ntohs((uint16_t)(d)))
# endif
# ifndef HTONL
#  define HTONL(d) ((d) = htonl((d)))
# endif
# ifndef HTONS
#  define HTONS(d) ((d) = htons((uint16_t)(d)))
# endif
#endif

typedef uint32_t n_long;                 /* long as received from the net */

/*
 * Definitions for internet protocol version 4.
 * Per RFC 791, September 1981.
 */
#define IPVERSION   4

/*
 * Structure of an internet header, naked of options.
 */
SLIRP_PACKED_BEGIN
struct ip {
#ifndef BX_LITTLE_ENDIAN
    uint8_t ip_v:4,         /* version */
        ip_hl:4;        /* header length */
#else
    uint8_t ip_hl:4,        /* header length */
        ip_v:4;         /* version */
#endif
    uint8_t     ip_tos;         /* type of service */
    uint16_t    ip_len;         /* total length */
    uint16_t    ip_id;          /* identification */
    uint16_t    ip_off;         /* fragment offset field */
#define IP_DF 0x4000            /* don't fragment flag */
#define IP_MF 0x2000            /* more fragments flag */
#define IP_OFFMASK 0x1fff       /* mask for fragmenting bits */
    uint8_t ip_ttl;         /* time to live */
    uint8_t ip_p;           /* protocol */
    uint16_t    ip_sum;         /* checksum */
    struct  in_addr ip_src,ip_dst;  /* source and dest address */
} SLIRP_PACKED_END;

#define IP_MAXPACKET    65535       /* maximum packet size */

/*
 * Definitions for IP type of service (ip_tos)
 */
#define IPTOS_LOWDELAY      0x10
#define IPTOS_THROUGHPUT    0x08
#define IPTOS_RELIABILITY   0x04

/*
 * Definitions for options.
 */
#define IPOPT_COPIED(o)     ((o)&0x80)
#define IPOPT_CLASS(o)      ((o)&0x60)
#define IPOPT_NUMBER(o)     ((o)&0x1f)

#define IPOPT_CONTROL       0x00
#define IPOPT_RESERVED1     0x20
#define IPOPT_DEBMEAS       0x40
#define IPOPT_RESERVED2     0x60

#define IPOPT_EOL       0       /* end of option list */
#define IPOPT_NOP       1       /* no operation */

#define IPOPT_RR        7       /* record packet route */
#define IPOPT_TS        68      /* timestamp */
#define IPOPT_SECURITY      130     /* provide s,c,h,tcc */
#define IPOPT_LSRR      131     /* loose source route */
#define IPOPT_SATID     136     /* satnet id */
#define IPOPT_SSRR      137     /* strict source route */

/*
 * Offsets to fields in options other than EOL and NOP.
 */
#define IPOPT_OPTVAL        0       /* option ID */
#define IPOPT_OLEN      1       /* option length */
#define IPOPT_OFFSET        2       /* offset within option */
#define IPOPT_MINOFF        4       /* min value of above */

/*
 * Time stamp option structure.
 */
SLIRP_PACKED_BEGIN
struct  ip_timestamp {
    uint8_t ipt_code;       /* IPOPT_TS */
    uint8_t ipt_len;        /* size of structure (variable) */
    uint8_t ipt_ptr;        /* index of current entry */
#ifndef BX_LITTLE_ENDIAN
    uint8_t ipt_oflw:4,     /* overflow counter */
        ipt_flg:4;      /* flags, see below */
#else
    uint8_t ipt_flg:4,      /* flags, see below */
        ipt_oflw:4;     /* overflow counter */
#endif
    union ipt_timestamp {
        n_long  ipt_time[1];
        struct  ipt_ta {
            struct in_addr ipt_addr;
            n_long ipt_time;
        } ipt_ta[1];
    } ipt_timestamp;
} SLIRP_PACKED_END;

/* flag bits for ipt_flg */
#define IPOPT_TS_TSONLY     0       /* timestamps only */
#define IPOPT_TS_TSANDADDR  1       /* timestamps and addresses */
#define IPOPT_TS_PRESPEC    3       /* specified modules only */

/* bits for security (not byte swapped) */
#define IPOPT_SECUR_UNCLASS 0x0000
#define IPOPT_SECUR_CONFID  0xf135
#define IPOPT_SECUR_EFTO    0x789a
#define IPOPT_SECUR_MMMM    0xbc4d
#define IPOPT_SECUR_RESTR   0xaf13
#define IPOPT_SECUR_SECRET  0xd788
#define IPOPT_SECUR_TOPSECRET   0x6bc5

/*
 * Internet implementation parameters.
 */
#define MAXTTL      255     /* maximum time to live (seconds) */
#define IPDEFTTL    64      /* default ttl, from RFC 1340 */
#define IPFRAGTTL   60      /* time to live for frags, slowhz */
#define IPTTLDEC    1       /* subtracted when forwarding */

#define IP_MSS      576     /* default maximum segment size */

#if SIZEOF_INT_P == 4
SLIRP_PACKED_BEGIN
struct mbuf_ptr {
    struct mbuf *mptr;
    uint32_t dummy;
} SLIRP_PACKED_END;
#else
SLIRP_PACKED_BEGIN
struct mbuf_ptr {
    struct mbuf *mptr;
} SLIRP_PACKED_END;
#endif
struct qlink {
    void *next, *prev;
};

/*
 * Overlay for ip header used by other protocols (tcp, udp).
 */
SLIRP_PACKED_BEGIN
struct ipovly {
    struct mbuf_ptr ih_mbuf;    /* backpointer to mbuf */
    uint8_t ih_x1;          /* (unused) */
    uint8_t ih_pr;          /* protocol */
    uint16_t    ih_len;         /* protocol length */
    struct  in_addr ih_src;     /* source internet address */
    struct  in_addr ih_dst;     /* destination internet address */
} SLIRP_PACKED_END;

/*
 * Ip reassembly queue structure.  Each fragment
 * being reassembled is attached to one of these structures.
 * They are timed out after ipq_ttl drops to 0, and may also
 * be reclaimed if memory becomes tight.
 */
struct ipq {
    struct qlink ip_link;               /* to other reass headers */
    uint8_t ipq_ttl;        /* time for reass q to live */
    uint8_t ipq_p;          /* protocol of this fragment */
    uint16_t    ipq_id;         /* sequence id for reassembly */
    struct  in_addr ipq_src,ipq_dst;
};

struct  ipas {
    struct qlink link;
    union {
        struct ipq ipq;
        struct ip ipf_ip;
    };
};

#define ipf_off      ipf_ip.ip_off
#define ipf_tos      ipf_ip.ip_tos
#define ipf_len      ipf_ip.ip_len

#endif
