www.pudn.com > Source_program.rar > ARPSCAN.C

#define VERSION "0.05" 
 
#include  
#include  
#include  
#include  
#include  
#include  
 
#include "ether.h" 
#include "netutil.h" 
#include "net.h" 
#include "ip.h" 
 
#define CFGFILE     "tcplean.cfg"   /* Default config filename */ 
#define CFGEXT      ".cfg"          /* Default config extension */ 
#define MAXNETCFG   40              /* Max length of a net config string */ 
 
#define SCANCOUNT   20              /* Default number of addresses to scan */ 
#define DELTIME     100             /* Delay between transmissions (msec) */ 
 
GENFRAME genframe;                  /* Frame for network Tx/Rx */ 
char cfgfile[MAXPATH+5]=CFGFILE;    /* Config filename */ 
char netcfg[MAXNETCFG+1]="??";      /* Network config string */ 
extern BYTE bcast[MACLEN];          /* Broadcast Ethernet addr */ 
extern BYTE myeth[MACLEN];          /* My Ethernet address */ 
NODE  locnode;                      /* My Ethernet and IP addresses */ 
NODE remnode;                       /* Remote Ethernet and IP addresses */ 
int scancount=SCANCOUNT;            /* Number of addresses to scan */ 
int breakflag;                      /* Flag to indicate ctrl-break pressed */ 
 
extern int netdebug;                /* Debug flag - net packet display */ 
 
/* Function pointer: upcall from TCP/IP stack */ 
extern NODE *(*get_locnode_n)(int n);           /* Get local node */ 
 
/* Prototypes */ 
WORD read_netconfig(char *fname, NODE *np); 
NODE *locnode_n(int n); 
void disp_usage(void); 
void break_handler(int sig); 
 
int main(int argc, char *argv[]) 
{ 
    int args=0, err=0; 
    LWORD remip=0, mstimer; 
    WORD rxlen, txlen, dtype; 
    GENFRAME *gfp; 
    ARPKT *arp; 
    char *p, temps[18]; 
 
    printf("ARPSCAN v" VERSION "\n"); 
    signal(SIGINT, break_handler);              /* Trap ctrl-C */ 
    while (argc > ++args)                       /* Process command-line args */ 
    { 
        if (argv[args][0]=='-') 
        { 
            switch (toupper(argv[args][1])) 
            { 
            case 'C':                           /* -C: config filename */ 
                strncpy(cfgfile, argv[++args], MAXPATH); 
                if ((p=strrchr(cfgfile, '.'))==0 || !isalpha(*(p+1))) 
                    strcat(cfgfile, CFGEXT); 
                break; 
            case 'N':                           /* -N: num of nodes to scan */ 
                scancount = atoi(argv[++args]); 
                break; 
            case 'V':                           /* -V: verbose packet display */ 
                netdebug = 1; 
                break; 
            default: 
                err = 1; 
            } 
        } 
        else if isdigit(argv[args][0])          /* Starting IP address */ 
            remip = atoip(argv[args]); 
    } 
    if (err)                                    /* Prompt user if error */ 
        disp_usage(); 
    else if (!(dtype=read_netconfig(cfgfile, &locnode))) 
        printf("Invalid configuration '%s'\n", cfgfile); 
    else 
    { 
        remnode.dtype = genframe.g.dtype = dtype;   /* Set frame driver type */ 
        gfp = &genframe;                            /* Get pointer to frame */ 
        printf("Press ESC or ctrl-C to exit\n"); 
        printf("IP %s", ipstr(locnode.ip, temps)); 
        if (dtype & DTYPE_ETHER) 
            printf(" Ethernet %s (local)\n\n", ethstr(locnode.mac, temps)); 
        mstimeout(&mstimer, 0);                 /* Refresh timer */ 
        while (!breakflag) 
        {                                       /* If scanning & timeout.. */ 
            if (remip && mstimeout(&mstimer, DELTIME)) 
            { 
                if (!scancount--)               /* ..stop looping if done */ 
                    break; 
                remnode.ip = remip++;           /* Broadcast next IP adr */ 
                memcpy(remnode.mac, bcast, MACLEN); 
                txlen = make_arp(gfp, &locnode, &remnode, ARPREQ); 
                put_frame(gfp, txlen); 
            } 
            poll_net(gfp->g.dtype);             /* Keep network alive */ 
            if ((rxlen=get_frame(gfp)) > 0)     /* Check for incoming pkts */ 
            { 
                if (is_arp(gfp, rxlen)) 
                {                               /* ARP response? */ 
                    arp = getframe_datap(gfp); 
                    if (arp->op==ARPRESP && arp->sip==remnode.ip) 
                    { 
                        printf("IP %s ", ipstr(remnode.ip, temps)); 
                        printf("Ethernet %s\n", ethstr(arp->smac, temps)); 
                    } 
                    if (arp->op==ARPREQ && arp->dip==locnode.ip) 
                    {                           /* ARP request? */ 
                        remnode.ip = arp->sip;  /* Make ARP response */ 
                        memcpy(remnode.mac, arp->smac, MACLEN); 
                        txlen = make_arp(gfp, &locnode, &remnode, ARPRESP); 
                        put_frame(gfp, txlen); 
                    } 
                } 
            } 
            if (kbhit())                        /* If user hit a key.. */ 
                breakflag = getch()==0x1b;      /* ..check for ESC */ 
        } 
        close_net(dtype);                       /* Shut down net driver */ 
    } 
    return(0); 
} 
 
/* Read network config file to get IP address 
** Return driver type, 0 if error */ 
WORD read_netconfig(char *fname, NODE *np) 
{ 
    char temps[31]; 
    WORD dtype=0; 
 
    if (read_cfgstr(fname, "net", netcfg, MAXNETCFG)) 
    {                                               /* Get IP address */ 
        if (!read_cfgstr(fname, "ip", temps, 30) || (np->ip=atoip(temps))==0) 
            printf("No IP address\n"); 
        else if (!(dtype = open_net(netcfg)))       /* Open net driver */ 
            printf("Can't open net driver '%s'\n", netcfg); 
        else                                        /* Save ether address */ 
            memcpy(np->mac, ether_addr(dtype), MACLEN); 
    } 
    return(dtype); 
} 
 
/* Return ptr to local node 'n' (n=0 for first), return 0 if doesn't exist 
** Used by IP functions to get my netmask & gateway addresses */ 
NODE *locnode_n(int n) 
{ 
    return(n==0 ? &locnode : 0); 
} 
 
/* Display usage help */ 
void disp_usage(void) 
{ 
    printf("Usage:    ARPSCAN [options] [start_IP_addr]\n"); 
    printf("          If IP address is omitted, acts as server\n"); 
    printf("Options:  -c name     Config filename (default %s)\n", cfgfile); 
    printf("          -n count    Scan count (default %u)\n", SCANCOUNT); 
    printf("Example:  ARPSCAN -c test.cfg 10.1.1.1\n"); 
} 
 
/* Ctrl-break handler: set flag and return */ 
void break_handler(int sig) 
{ 
    breakflag = sig; 
} 
 
/* EOF */