packet.c

Linux 上的socket嗅探器

/*
 *
 * Copyright (C) 2003 Xiangbin Lee <[e-mail]> <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation.
 */

#include "packet.h"

#include <string.h>
#include <stdlib.h>

/* static password inche */
unsigned short pppcrctab[256] = {
    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
    0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
    0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,

    0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
    0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
    0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,

    0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
    0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
    0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,

    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
    0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
    0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,

    0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
    0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
    0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,

    0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
    0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
    0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,

    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
    0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
    0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,

    0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
    0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
    0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};


/*-------------------------------------------------------------
**  function name : TransPass
**  function describ: TransPass buffer acording the key randid
**  function interface :
       param:
           lpbuf  : char*, point to packet buffer
           buflen:  int, the length of packet buffer
           randid:  unsigned short, point to packet buffer
       return:
            NULL
-------------------------------------------------------------*/
void TransPass(unsigned char *lpbuf, int buflen, unsigned short randid)
{
    int freei;
    unsigned char *sbox=(unsigned char *)pppcrctab;
    for(freei=0;freei<buflen;freei++)
    {
        lpbuf[freei]^=(sbox[(randid+freei)%512]);

        if(freei%2)
            lpbuf[freei]^=(pppcrctab[randid%256]/256);
        else
            lpbuf[freei]^=(pppcrctab[randid%256]%256);

        randid=pppcrctab[randid%256];
    }
}


/*-------------------------------------------------------------
**  function name : TransPacket
**  function describ: Translate packet to frame
**  function interface :
       param:
           dest  : char*, point to object frame
           source: char*, point to packet buffer
           scrlen:  int , the length of packet buffer
       return:
           the length of frame, this length must LE 1280
-------------------------------------------------------------*/
int TransPacket(unsigned char *dest, unsigned char *source, int scrlen)
{
    int bytetype=2, len=scrlen, retlen=0, ifpass=0;
    unsigned short randid=0;
    unsigned char byte=0;
    unsigned char *lpdest = dest;

    randid=(rand()&0xFFFF);
    TransPass(source,scrlen,randid);

    while(len>0)
    {
        if(ifpass>1)
        {
            byte = *source++;
            len--;
        }
        else if(ifpass==0)
        {
            byte=(unsigned char)(randid/256);
            ifpass++;
        }
        else if(ifpass==1)
        {
            byte=(unsigned char)(randid%256);
            ifpass++;
        }

        if(byte<0x10)
        {
            if(bytetype == 2)
            {
                *lpdest++=0xF1;
                retlen++;
            }
            else if(bytetype == 3)
            {
                *lpdest++=0xF4;
                *lpdest++=0xF1;
                retlen+=2;
            }

            *lpdest++=(byte+0x10);
            bytetype=1;
        }
        else if(byte>=0xF0)
        {
            if(bytetype == 1)
            {
                *lpdest++=0xF2;
                *lpdest++=0xF3;
                retlen+=2;
            }
            else if(bytetype == 2)
            {
                *lpdest++=0xF3;
                retlen++;
            }

            *lpdest++=(byte-0x10);
            bytetype=3;
        }
        else
        {
            if(bytetype == 1)
            {
                *lpdest++=0xF2;
                retlen++;
            }
            else if(bytetype == 3)
            {
                *lpdest++=0xF4;
                retlen++;
            }

            *lpdest++=(byte);
            bytetype=2;
        }

        retlen++;
    };

    if(bytetype == 1)
    {
        *lpdest++=0xF2;
        retlen++;
    }
    else if(bytetype == 3)
    {
        *lpdest++=0xF4;
        retlen++;
    }

    (*lpdest++)=0;
    return retlen;
}


/*-------------------------------------------------------------
**  function name : ExTransPacket
**  function describ: ExTransPacket frame to packet
**  function interface :
       param:
           dest  : char*, point to object packet buffer
           source: char*, point to source frame
           scrlen:  int , the length of frame
       return:
           the length of packet buffer, this length must LE 571
-------------------------------------------------------------*/
int ExTransPacket(unsigned char *dest, unsigned char *source, int scrlen)
{
    int bytetype=2, len=scrlen, retlen=0, ifpass=0;
    unsigned short randid=0;
    unsigned char *lpdest = dest ;
    unsigned char byte=0;

    while(len>0)
    {
        byte = *source++;
        len--;

        if(byte == 0xF1)
            bytetype=1;
        else if(byte == 0xF3)
            bytetype=3;
        else if(byte == 0xF2||byte == 0xF4)
            bytetype=2;
        else
        {
            if(bytetype == 1)
                byte=(byte-0x10);
            else if(bytetype == 3)
                byte=(byte+0x10);

            if(ifpass>1)
            {
                (*lpdest++)=byte;
                retlen++;
            }
            else if(ifpass==0)
            {
                randid=byte*256;
                ifpass++;
            }
            else if(ifpass==1)
            {
                randid+=byte;
                ifpass++;
            }
        }
    };
    (*lpdest++)=0;

    TransPass(dest,retlen,randid);
    return retlen;
}


int AchbufToPktbuf(unsigned char *dest, unsigned char *frame, int framelen)
{
    int retlen=0;
    /*--------------- check frame length --------------*/
    if(framelen<4)
        return 0;
    /*-------  packet and frame must not be null  -----*/
    if(dest == NULL||frame == NULL)
        return 0 ;
    /*------------ check frame head and tail ----------*/
    if(frame[0]!=EXTRANS_FP_HEAD||frame[framelen-1]!=EXTRANS_FP_TAIL)
        return 0;
    /*------- Transmisstion frame into packet buffer --*/
    retlen= ExTransPacket(dest, frame+1, framelen-2);
    /*------- check packet buffer length --------------*/
    return retlen ;
}

int PktbufToAchbuf(unsigned char *dest, unsigned char *buf, int buflen)
{
    int retlen=0;
    /*-------  packet and frame must not be null  -----*/
    if(dest == NULL||buf == NULL)return 0 ;
    /*------- Transmisstion packet buffer into frame --*/
    *dest++=EXTRANS_FP_HEAD;
    retlen=TransPacket(dest, buf, buflen);
    dest+=retlen;
    *dest++=EXTRANS_FP_TAIL;
    retlen+=2;
    return retlen ;
}



int ClipAche_Reset(CLIP_ACHE *lpache)
{
    if(lpache==NULL)
        return 0;

    memset(lpache->TRANSACHE,0,MAXRECLEN*3*5);        /* more than 5 packet for protocal */
    memset(lpache->CHIPACHE,0,CHIPBUFLENGTH*30);        /* more than 30 chip packet for receive */

    ResetAchStatus(&(lpache->PKTAche),    lpache->TRANSACHE,MAXRECLEN*3*5,EXTRANS_FP_HEAD,EXTRANS_FP_TAIL,0xFF);
    SetAcheMode(&(lpache->PKTAche),        ACHE_AS_QUEUE,ACHERW_TRANS,ACHERW_NOTRANS);
    ResetAchStatus(&(lpache->CHIPAche),    lpache->CHIPACHE,CHIPBUFLENGTH*30,EXTRANS_CP_HEAD,EXTRANS_CP_TAIL,0xFF);
    SetAcheMode(&(lpache->CHIPAche),    ACHE_AS_QUEUE,ACHERW_TRANS,ACHERW_NOTRANS);
    ResetAchStatus(&(lpache->SendAche),    lpache->SENDACHE,CHIPBUFLENGTH*30,EXTRANS_CP_HEAD,EXTRANS_CP_TAIL,0xFF);
    SetAcheMode(&(lpache->SendAche),    ACHE_AS_QUEUE,ACHERW_TRANS,ACHERW_NOTRANS);

    return 1;
}


int ClipAche_WriteClip(CLIP_ACHE *lpache, unsigned char *lpbuf, unsigned long chiplen)
{
    int ret=0;
    if(lpache==NULL)
        return 0;
    if(chiplen>0)
    {
        ret=WriterAche(&(lpache->CHIPAche), lpbuf,chiplen);
    }
    return ret;
}

int ClipAche_ClipToPacketPro(CLIP_ACHE *lpache)
{

    unsigned char chipbuf[CHIPBUFLENGTH+8];
    int chiplen=0;

    if(lpache==NULL)
        return 0;
    /*       read chip buffer and add this data to packet buf   */
    chiplen= ReaderAche(&(lpache->CHIPAche), chipbuf);
    if(chiplen>0)
    {
        WriterAche(&(lpache->PKTAche), chipbuf,chiplen);
    }

    return chiplen;
}


int ClipAche_ReadPacket(CLIP_ACHE *lpache, unsigned char *lpbuf)
{
    unsigned char transbuf[MAXRECLEN*3+8];
    int translen=0,recvlen=0;
    if(lpache==NULL)
        return 0;

    translen=ReaderAche(&(lpache->PKTAche), transbuf);
    if(translen>0)
    {
        recvlen=ExTransPacket((unsigned char *)lpbuf, transbuf, translen);
    }
    return recvlen;
}


int ClipAche_SendPacket(CLIP_ACHE *lpache, unsigned char *dest, int sendlen)
{
    unsigned char *s_chipbuf=0;
    unsigned char s_transbuf[MAXRECLEN*3+8];
    int s_chiplen=0,s_translen=0;
    int freei,chipn=0;

    s_transbuf[0]=EXTRANS_FP_HEAD&0xFF;
    s_translen=TransPacket(
        (unsigned char *)(s_transbuf+1),
        (unsigned char *)(dest),
        sendlen);

    if(s_translen>0)
    {
        s_transbuf[1+s_translen]=EXTRANS_FP_TAIL&0xFF;
        s_translen+=2;
        /*    flit the packet to chip buf   */
        chipn=s_translen/(CHIPBUFLENGTH-2)+(int)(s_translen%(CHIPBUFLENGTH-2)>0);
        for(freei=0;freei<chipn;freei++)
        {
            if(s_translen%(CHIPBUFLENGTH-2)==0)
                s_chiplen=(CHIPBUFLENGTH-2);
            else if(freei>=chipn-1)
                s_chiplen=s_translen%(CHIPBUFLENGTH-2);
            else
                s_chiplen=(CHIPBUFLENGTH-2);

            s_chipbuf=(unsigned char *)(s_transbuf+freei*(CHIPBUFLENGTH-2));

            WriterAche(&(lpache->SendAche), s_chipbuf,s_chiplen);

        }/*    for(freei=0;freei<chipn;freei++)*/
    }/*    if(s_translen>0)*/

    return chipn*2+s_translen;
}

int ClipAche_ClipSendPro(CLIP_ACHE *lpache, int sd_int)
{
    int s_chiplen, res, ret=0;
    unsigned char s_chipbuf[CHIPBUFLENGTH+8];

    while((s_chiplen=ReaderAche(&(lpache->SendAche),s_chipbuf))>0)
    {
        res=write(sd_int,(char*)(s_chipbuf),s_chiplen);
        if (res<0)
        {
            return -1;
        }
        ret+=s_chiplen;
    }

    return s_chiplen;
}