// IP packet structures...
// -----------------------
// Note: All of this is hard coded little endian!


typedef long n_long;
typedef short n_short;
typedef long n_time;


struct ip
  {
    unsigned int ip_hl:4;               /* header length */
    unsigned int ip_v:4;                /* version */
    u_char ip_tos;                    /* type of service */
    u_short ip_len;                     /* total length */
    u_short ip_id;                      /* identification */
    u_short ip_off;                     /* fragment offset field */
#define IP_RF 0x8000                    /* reserved fragment flag */
#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 */
    struct in_addr ip_src, ip_dst;      /* source and dest address */
  };

#define    MAX_IPOPTLEN            40

/*
 *	IEEE 802.3 Ethernet magic constants.  The frame sizes omit the preamble
 *	and FCS/CRC (frame check sequence). 
 */

#define ETH_ALEN	6		/* Octets in one ethernet addr	 */
#define ETH_HLEN	14		/* Total octets in header.	 */
#define ETH_ZLEN	60		/* Min. octets in frame sans FCS */
#define ETH_DATA_LEN	1500		/* Max. octets in payload	 */
#define ETH_FRAME_LEN	1514		/* Max. octets in frame sans FCS */

/*
 *	These are the defined Ethernet Protocol ID's.
 */

#define ETH_P_LOOP	0x0060		/* Ethernet Loopback packet	*/
#define ETH_P_ECHO	0x0200		/* Ethernet Echo packet		*/
#define ETH_P_PUP	0x0400		/* Xerox PUP packet		*/
#define ETH_P_IP	0x0800		/* Internet Protocol packet	*/
#define ETH_P_X25	0x0805		/* CCITT X.25			*/
#define ETH_P_ARP	0x0806		/* Address Resolution packet	*/
#define	ETH_P_BPQ	0x08FF		/* G8BPQ AX.25 Ethernet Packet	[ NOT AN OFFICIALLY REGISTERED ID ] */
#define ETH_P_DEC       0x6000          /* DEC Assigned proto           */
#define ETH_P_DNA_DL    0x6001          /* DEC DNA Dump/Load            */
#define ETH_P_DNA_RC    0x6002          /* DEC DNA Remote Console       */
#define ETH_P_DNA_RT    0x6003          /* DEC DNA Routing              */
#define ETH_P_LAT       0x6004          /* DEC LAT                      */
#define ETH_P_DIAG      0x6005          /* DEC Diagnostics              */
#define ETH_P_CUST      0x6006          /* DEC Customer use             */
#define ETH_P_SCA       0x6007          /* DEC Systems Comms Arch       */
#define ETH_P_RARP      0x8035		/* Reverse Addr Res packet	*/
#define ETH_P_ATALK	0x809B		/* Appletalk DDP		*/
#define ETH_P_AARP	0x80F3		/* Appletalk AARP		*/
#define ETH_P_IPX	0x8137		/* IPX over DIX			*/
#define ETH_P_IPV6	0x86DD		/* IPv6 over bluebook		*/

/*
 *	Non DIX types. Won't clash for 1500 types.
 */
 
#define ETH_P_802_3	0x0001		/* Dummy type for 802.3 frames  */
#define ETH_P_AX25	0x0002		/* Dummy protocol id for AX.25  */
#define ETH_P_ALL	0x0003		/* Every packet (be careful!!!) */
#define ETH_P_802_2	0x0004		/* 802.2 frames 		*/
#define ETH_P_SNAP	0x0005		/* Internal only		*/
#define ETH_P_DDCMP     0x0006          /* DEC DDCMP: Internal only     */
#define ETH_P_WAN_PPP   0x0007          /* Dummy type for WAN PPP frames*/
#define ETH_P_PPP_MP    0x0008          /* Dummy type for PPP MP frames */
#define ETH_P_LOCALTALK 0x0009		/* Localtalk pseudo type 	*/
#define ETH_P_PPPTALK	0x0010		/* Dummy type for Atalk over PPP*/
#define ETH_P_TR_802_2	0x0011		/* 802.2 frames 		*/

struct etherproto {
	char *s;
	u_short p;
};
extern struct etherproto etherproto_db[];

// Ethernet Header
struct ether_header 
{
	unsigned char	h_dest[ETH_ALEN];	/* destination eth addr	*/
	unsigned char	h_source[ETH_ALEN];	/* source ether addr	*/
	unsigned short	h_proto;		/* packet type ID field	*/
};

// ARP/RARP
///////////////////////////////////////////////////////////////////////
static u_char bcastaddr[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

/*
 *	This structure defines an ethernet arp header.
 */

struct arphdr
{
	unsigned short	ar_hrd;		/* format of hardware address	*/
	unsigned short	ar_pro;		/* format of protocol address	*/
	unsigned char	ar_hln;		/* length of hardware address	*/
	unsigned char	ar_pln;		/* length of protocol address	*/
	unsigned short	ar_op;		/* ARP opcode (command)		*/
};

#define ARPD_UPDATE	0x01
#define ARPD_LOOKUP	0x02
#define ARPD_FLUSH	0x03

/*#define ARPHRD_ETHER	0x01

#define ARPOP_REQUEST	0x01
#define ARPOP_REPLY		0x02
#define ARPOP_REVREQUEST	0x03
#define ARPOP_REVREPLY		0x04
*/
/*
 * Ethernet Address Resolution Protocol.
 *
 * See RFC 826 for protocol description.  Structure below is adapted
 * to resolving internet addresses.  Field names used correspond to
 * RFC 826.
 */
struct	ether_arp {
	struct	arphdr ea_hdr;	/* fixed-size header */
	u_char	arp_sha[ETH_ALEN];	/* sender hardware address */
	u_char	arp_spa[4];	/* sender protocol address */
	u_char	arp_tha[ETH_ALEN];	/* target hardware address */
	u_char	arp_tpa[4];	/* target protocol address */
};
#define	arp_hrd	ea_hdr.ar_hrd
#define	arp_pro	ea_hdr.ar_pro
#define	arp_hln	ea_hdr.ar_hln
#define	arp_pln	ea_hdr.ar_pln
#define	arp_op	ea_hdr.ar_op

// IP Header in Little Endian
//////////////////////////////
struct iphdr {
	u_char	ip_hl:4,		/* header length */
			ip_v:4;			/* version */
	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 */
	u_char	ip_ttl;			/* time to live */
	u_char	ip_p;			/* protocol */
	u_short	ip_sum;			/* checksum */
	struct	in_addr ip_src,ip_dst;	/* source and dest address */
};

#define	IP_MAXPACKET	65535		/* maximum packet size */

// 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 */


// Time stamp option structure.
struct	ip_timestamp {
	u_char	ipt_code;		/* IPOPT_TS */
	u_char	ipt_len;		/* size of structure (variable) */
	u_char	ipt_ptr;		/* index of current entry */
	u_char	ipt_flg:4,		/* flags, see below */
		ipt_oflw:4;			/* overflow counter */
	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;
};

/* flag bits for ipt_flg */
#define	IPOPT_TS_TSONLY		0		/* timestamps only */
#define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
#define	IPOPT_TS_PRESPEC	2		/* 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

// ICMP Header
////////////////////////////////////////////////////////////////////////
struct icmphdr {
	u_char	icmp_type;		/* type of message, see below */
	u_char	icmp_code;		/* type sub code */
	u_short	icmp_cksum;		/* ones complement cksum of struct */
	union {
		u_char ih_pptr;			/* ICMP_PARAMPROB */
		struct in_addr ih_gwaddr;	/* ICMP_REDIRECT */
		struct ih_idseq {
			n_short	icd_id;
			n_short	icd_seq;
		} ih_idseq;
		int ih_void;
	} icmp_hun;
#define	icmp_pptr	icmp_hun.ih_pptr
#define	icmp_gwaddr	icmp_hun.ih_gwaddr
#define	icmp_id		icmp_hun.ih_idseq.icd_id
#define	icmp_seq	icmp_hun.ih_idseq.icd_seq
#define	icmp_void	icmp_hun.ih_void
	union {
		struct id_ts {
			n_time its_otime;
			n_time its_rtime;
			n_time its_ttime;
		} id_ts;
		struct id_ip  {
			struct iphdr idi_ip;
			/* options and then 64 bits of data */
		} id_ip;
		u_long	id_mask;
		char	id_data[1];
	} icmp_dun;
#define	icmp_otime	icmp_dun.id_ts.its_otime
#define	icmp_rtime	icmp_dun.id_ts.its_rtime
#define	icmp_ttime	icmp_dun.id_ts.its_ttime
#define	icmp_ip		icmp_dun.id_ip.idi_ip
#define	icmp_mask	icmp_dun.id_mask
#define	icmp_data	icmp_dun.id_data
};

/*
 * Lower bounds on packet lengths for various types.
 * For the error advice packets must first insure that the
 * packet is large enought to contain the returned ip header.
 * Only then can we do the check to see if 64 bits of packet
 * data have been returned, since we need to check the returned
 * ip header length.
 */
#define	ICMP_MINLEN	8				/* abs minimum */
#define	ICMP_TSLEN	(8 + 3 * sizeof (n_time))	/* timestamp */
#define	ICMP_MASKLEN	12				/* address mask */
#define	ICMP_ADVLENMIN	(8 + sizeof (struct ip) + 8)	/* min */
#define	ICMP_ADVLEN(p)	(8 + ((p)->icmp_ip.ip_hl << 2) + 8)
	/* N.B.: must separately check that ip_hl >= 5 */

/*
 * Definition of type and code field values.
 */
#define	ICMP_ECHOREPLY		0		/* echo reply */

/* UNREACH codes */
#define ICMP_UNREACH					3       /* dest unreachable, codes: */ 
#define ICMP_UNREACH_NET                0       /* bad net */
#define ICMP_UNREACH_HOST               1       /* bad host */
#define ICMP_UNREACH_PROTOCOL           2       /* bad protocol */
#define ICMP_UNREACH_PORT               3       /* bad port */
#define ICMP_UNREACH_NEEDFRAG           4       /* IP_DF caused drop */
#define ICMP_UNREACH_SRCFAIL            5       /* src route failed */
#define ICMP_UNREACH_NET_UNKNOWN        6       /* unknown net */
#define ICMP_UNREACH_HOST_UNKNOWN       7       /* unknown host */
#define ICMP_UNREACH_ISOLATED           8       /* src host isolated */
#define ICMP_UNREACH_NET_PROHIB         9       /* net denied */
#define ICMP_UNREACH_HOST_PROHIB        10      /* host denied */
#define ICMP_UNREACH_TOSNET             11      /* bad tos for net */
#define ICMP_UNREACH_TOSHOST            12      /* bad tos for host */
#define ICMP_UNREACH_FILTER_PROHIB      13      /* admin prohib */
#define ICMP_UNREACH_HOST_PRECEDENCE    14      /* host prec vio. */
#define ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* prec cutoff */
   

#define	ICMP_SOURCEQUENCH				4		/* packet lost, slow down */
#define ICMP_ROUTERADVERT				9       /* router advertisement */
#define ICMP_ROUTERSOLICIT				10      /* router solicitation */    
#define	ICMP_REDIRECT					5		/* shorter route, codes: */
#define	ICMP_REDIRECT_NET				0		/* for network */
#define	ICMP_REDIRECT_HOST				1		/* for host */
#define	ICMP_REDIRECT_TOSNET			2		/* for tos and net */
#define	ICMP_REDIRECT_TOSHOST			3		/* for tos and host */
#define	ICMP_ECHO						8		/* echo service */
#define	ICMP_TIMXCEED					11		/* time exceeded, code: */
#define	ICMP_TIMXCEED_INTRANS			0		/* ttl==0 in transit */
#define	ICMP_TIMXCEED_REASS				1		/* ttl==0 in reass */
#define	ICMP_PARAMPROB					12		/* ip header bad */
#define	ICMP_TSTAMP						13		/* timestamp request */
#define	ICMP_TSTAMPREPLY				14		/* timestamp reply */
#define	ICMP_IREQ						15		/* information request */
#define	ICMP_IREQREPLY					16		/* information reply */
#define	ICMP_MASKREQ					17		/* address mask request */
#define	ICMP_MASKREPLY					18		/* address mask reply */

#define	ICMP_MAXTYPE		18

#define	ICMP_INFOTYPE(type) \
	((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
	(type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
	(type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
	(type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)

/*** ICMP types ********************************************************/
#define ICMP_TYPE_0     "Echo reply"
#define ICMP_TYPE_3     "Destination unreachable"
#define ICMP_TYPE_4     "Source quench"
#define ICMP_TYPE_5     "Redirect"
#define ICMP_TYPE_8     "Echo"
#define ICMP_TYPE_11    "Time exceeded"
#define ICMP_TYPE_12    "Parameter problem"
#define ICMP_TYPE_13    "Timestamp"
#define ICMP_TYPE_14    "Timestamp reply"
#define ICMP_TYPE_15    "Information request"
#define ICMP_TYPE_16    "Information reply"
#define ICMP_TYPE_17    "Address mask request"
#define ICMP_TYPE_18    "Adress mask reply"

/* pulled token stuff from tcpdump */
struct tok {
	int v;			/* value */
	char *s;		/* string */
};

// TCP
/////////////////////////////////////////////////////////////////////////
typedef	u_long	tcp_seq;