/* $Id: tcpedit.h 1505 2006-07-17 02:56:37Z aturner $ */

/*
 * Copyright (c) 2001-2006 Aaron Turner.
 * 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 names of the copyright owners 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 ``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 AUTHORS OR COPYRIGHT HOLDERS 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.
 */

#include "defines.h"
#include "dlt.h"
#include "../common.h"

#ifndef _TCPEDIT_H_
#define _TCPEDIT_H_

#define L2DATALEN 255           /* Max size of the L2 data file */
    
struct l2_s {
    int enabled; /* are we rewritting the L2 header ? */
    int len;  /* user data length */
    u_char data1[L2DATALEN];
    u_char data2[L2DATALEN];

    /* 
     * we need to store the *new* linktype which we will then use to 
     * select the correct union slice.  set to LINKTYPE_USER to 
     * use the user specified data (data1[] & data2[])
     * other valid options are LINKTYPE_VLAN and LINKTYPE_ETHER for
     * 802.1q and standard ethernet frames respectively.
     */
    int dlt;
#define DLT_USER           DLT_USER0
#define DLT_VLAN           DLT_USER1
    
    u_int16_t vlan_tag;
    u_int8_t vlan_pri;
    u_int8_t vlan_cfi;
};

typedef struct l2_s l2_t;

#define TCPEDIT_ERRSTR_LEN 1024
struct tcpedit_runtime_s {
    COUNTER packetnum;
    COUNTER total_bytes;
    COUNTER pkts_edited;
    pcap_t *pcap1;
    pcap_t *pcap2;
    libnet_t *lnet;
    char errstr[TCPEDIT_ERRSTR_LEN];
#ifdef FORCE_ALIGN
    u_char *ipbuff = NULL;            /* IP header and above buffer */
#endif
};

typedef struct tcpedit_runtime_s tcpedit_runtime_t;

/*
 * portmap data struct
 */
struct tcpedit_portmap_s {
    long from;
    long to;
    struct tcpedit_portmap_s *next;
};
typedef struct tcpedit_portmap_s tcpedit_portmap_t;

/*
 * all the arguments that the packet editing library supports
 */
struct tcpedit_s {
    int validated;  /* have we run tcpedit_validate()? */
    
    /* runtime variables, don't mess with these */
    tcpedit_runtime_t runtime;

    /* we use the mask to say which are valid values */
    char mac_mask;  
#define TCPEDIT_MAC_MASK_SMAC1 0x1
#define TCPEDIT_MAC_MASK_SMAC2 0x2
#define TCPEDIT_MAC_MASK_DMAC1 0x4
#define TCPEDIT_MAC_MASK_DMAC2 0x8

    /* rewrite traffic bi-directionally */
    char bidir;
#define TCPEDIT_BIDIR_OFF 0x0
#define TCPEDIT_BIDIR_ON  0x1

    /* 802.1q VLAN tag stuff */
    char vlan;
#define TCPEDIT_VLAN_OFF 0x0
#define TCPEDIT_VLAN_DEL 0x1 /* strip 802.1q and rewrite as standard 
                              * 802.3 Ethernet */
#define TCPEDIT_VLAN_ADD 0x2 /* add/replace 802.1q vlan tag */

    /* pad or truncate packets */
    char fixlen;
#define TCPEDIT_FIXLEN_OFF   0x0
#define TCPEDIT_FIXLEN_PAD   0x1
#define TCPEDIT_FIXLEN_TRUNC 0x2
#define TCPEDIT_FIXLEN_DEL   0x3

    /* rewrite ip? */
    char rewrite_ip;
#define TCPEDIT_REWRITE_IP_OFF 0x0
#define TCPEDIT_REWRITE_IP_ON  0x1
    
    /* fix IP/TCP/UDP checksums */
    char fixcsum;
#define TCPEDIT_FIXCSUM_OFF 0x0
#define TCPEDIT_FIXCSUM_ON  0x1

    /* remove ethernet FCS */
    char efcs;
#define TCPEDIT_EFCS_OFF 0x0
#define TCPEDIT_EFCS_ON  0x1

    char padding1; /* keep things 4 byte aligned */

    /* values to rewrite src/dst MAC addresses */
    tcpr_macaddr_t intf1_dmac;
    tcpr_macaddr_t intf1_smac;
    tcpr_macaddr_t intf2_dmac;
    tcpr_macaddr_t intf2_smac;

    /* other L2 editing options */
    u_int16_t l2proto;
    u_int16_t l2_mem_align; /* keep things 4 byte aligned */

    /* rewrite L2 data in full */
    l2_t l2;

    /* rewrite end-point IP addresses between cidrmap1 & cidrmap2 */
    tcpr_cidrmap_t *cidrmap1;       /* tcpprep cache data */
    tcpr_cidrmap_t *cidrmap2;
    
    /* pseudo-randomize IP addresses using a seed */
    int seed;
    
    /* rewrite tcp/udp ports */
    tcpedit_portmap_t *portmap;
    
    int mtu;                /* Deal with different MTU's */
    int maxpacket;          /* L2 header + MTU */
};

typedef struct tcpedit_s tcpedit_t;

int tcpedit_init(tcpedit_t *tcpedit, pcap_t *pcap1, pcap_t *pcap2);
char *tcpedit_geterr(tcpedit_t *tcpedit);
void tcpedit_seterr(tcpedit_t *tcpedit, const char *fmt, ...);
int tcpedit_validate(tcpedit_t *tcpedit, int srcdlt, int dstdlt);

int tcpedit_packet(tcpedit_t *tcpedit, struct pcap_pkthdr **pkthdr, 
        u_char **pktdata, int direction);

int tcpedit_close(tcpedit_t *tcpedit);

COUNTER tcpedit_get_total_bytes(tcpedit_t *tcpedit);
COUNTER tcpedit_get_pkts_edited(tcpedit_t *tcpedit);

#endif