/*	The following code which has been modified and integrated 
	for use with exscan, was originally found in QueSO.
	This code has been modified and integrated with permission 
	from the author, savage (savage@apostols.org).
*/


/* These are the structures for the IP, TCP and ICMP headers */
/* $Id: tcpip.h,v 1.5 1998/09/22 20:35:43 savage Exp $ */
typedef struct
  {
    unsigned char vh;
    unsigned char stype;
    unsigned short length;
    unsigned short ident;
    unsigned short frag;
    unsigned char ttl;
    unsigned char protocol;
    unsigned short cksum;
    struct in_addr sip;
    struct in_addr dip;
  }
iprec;

typedef struct
  {
    unsigned short sport;
    unsigned short dport;
    unsigned long seqnum;
    unsigned long acknum;
    unsigned char txoff;
    unsigned char flags;
    unsigned short window;
    unsigned short cksum;
    unsigned short urgentptr;
  }
tcprec;

typedef struct
  {
    struct in_addr sip;
    struct in_addr dip;
    unsigned char zero;
    unsigned char proto;
    unsigned short tcplen;
  }
tcpsrec;

typedef struct
  {
    unsigned char type;
    unsigned char code;
    unsigned short cksum;
    unsigned long zero;
    iprec ip;
    unsigned short sport;
    unsigned short dport;
    unsigned long seq;
  }
icmprec;

/* #define's for the TCP flags */
#define YYY 0x80
#define XXX 0x40
#define URG 0x20
#define ACK 0x10
#define PSH 0x08
#define RST 0x04
#define SYN 0x02
#define FIN 0x01

/* Structure for a spoofed connection */
typedef struct
  {
    struct sockaddr_in from;
    struct sockaddr_in dest;
    unsigned short sport;
    unsigned short dport;
    unsigned long seq;
    unsigned long ack;
  }
spoofrec;

/* -------------- Prototiping --------------- */
void init_tcpip(void);
int init_pcap(char*);
unsigned short in_cksum (unsigned short *, int);  
void sendip (spoofrec *, char *, short, short *, short *, short);
unsigned short tcpcksum (spoofrec *, char *, short);
short resolve_host (char *, struct sockaddr_in *);
short gettcp (spoofrec *, tcprec *);
void sendtcp (spoofrec *, unsigned short, short); 
void sendicmp (spoofrec *, struct sockaddr_in *, unsigned short);
struct in_addr getlocalip (unsigned long dest);
char *tcpip_id(void);