/*      $NetBSD: etherfun.h,v 1.5 2011/02/02 17:53:41 chuck Exp $       */

/*
 * Copyright (c) 1995 Charles D. Cranor and Seth Widoff
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */
/* etherfun.h */

/* constants */
/* ether header */
#define ETYPE_RARP 0x8035  /* ethertype is RARP */
#define ETYPE_IP   0x800   /* ethertype is IP   */

/* rev arp */
#define PTYPE_IP 0x800     /* Protocol type is IP      */
#define OPCODE_RARP 3      /* Optype is REVARP request */
#define OPCODE_REPLY 4     /* Optype is REVARP reply   */

/* ip header */
#define  IPP_UDP 17        /* IP Protocol is UDP       */
#define  IP_VERSION 4      /* IP version number        */
#define  IP_HLEN 5         /* IP header length is a fixed 50 bytes */
#define N 1536

/* tftp header */
#define FTPOP_ACKN 4      /* Opcode is acknowledge     */
#define FTPOP_ERR 5       /* Opcode is Error           */
#define FTP_PORT 69       /* Standard TFTP port number */
#define MSG "\0\1xxxxxxxx.147\0octet\0" /* implicit NULL */

/* data structures */

struct  ether_header {
        u_char  ether_dhost[6];
        u_char  ether_shost[6];
        u_short ether_type;
};

struct  ether_arp {
        u_short ar_hrd;         /* format of hardware address */
        u_short ar_pro;         /* format of protocol address */
        u_char  ar_hln;         /* length of hardware address */
        u_char  ar_pln;         /* length of protocol address */
        u_short ar_op;
        u_char  arp_sha[6];     /* sender hardware address */
        u_char  arp_spa[4];     /* sender protocol address */
        u_char  arp_tha[6];     /* target hardware address */
        u_char  arp_tpa[4];     /* target protocol address */
};

struct ip {
        u_char  ip_v:4,                 /* version */
                ip_hl:4;                /* header length */
        u_char  ip_tos;                 /* type of service */
        short   ip_len;                 /* total length */
        u_short ip_id;                  /* identification */
        short   ip_off;                 /* fragment offset field */
#define IP_DF 0x4000                    /* dont fragment flag */
#define IP_MF 0x2000                    /* more fragments flag */
#define IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
        u_char  ip_ttl;                 /* time to live */
        u_char  ip_p;                   /* protocol */
        u_short ip_sum;                 /* checksum */
        u_char  ip_src[4];
        u_char  ip_dst[4];              /* source and dest address */
};

struct udp {
        u_short uh_sport;
        u_short uh_dport;
        short uh_ulen;
        u_short uh_sum;
};

struct tftph {
        u_short op_code;
        u_short block;
};

struct tftphr {
        struct tftph info;
        char data[1];
};

/* globals */
int last_ack;
u_char buf[N];
struct ether_header *eh = (struct ether_header *)buf;
struct ether_arp *rarp = 
    (struct ether_arp *)(buf + sizeof(struct ether_header));
struct ip *iph = (struct ip *)(buf + sizeof(struct ether_header));
struct udp *udph = (struct udp *)(buf + sizeof(struct ether_header) + 
    sizeof(struct ip));
u_char *tftp_r = buf + sizeof(struct ether_header) + sizeof(struct ip) + 
    sizeof(struct udp);
struct tftph *tftp_a = (struct tftph *)(buf + sizeof(struct ether_header) + 
    sizeof(struct ip) + sizeof(struct udp));
struct tftphr *tftp = (struct tftphr *)(buf + sizeof(struct ether_header) + 
    sizeof(struct ip) + sizeof(struct udp));