/*

This program sends out one ARP packet with source/target IP

and Ethernet hardware addresses suuplied by the user. It

compiles and works on Linux and will probably work on any

Unix that has SOCK_PACKET. [email]volobuev@t1.chem.umn.edu[/email]

*/

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#define ETH_HW_ADDR_LEN 6

#define IP_ADDR_LEN 4

#define ARP_FRAME_TYPE 0x0806

#define ETHER_HW_TYPE 1

#define IP_PROTO_TYPE 0x0800

#define OP_ARP_REQUEST 2

#define OP_ARP_QUEST 1

#define DEFAULT_DEVICE "eth0"

char usage[] = {"send_arp: sends out custom ARP packet. yuri volobuev

usage: send_arp src_ip_addr src_hw_addr targ_ip_addr tar_hw_addr number"};

struct arp_packet

{

u_char targ_hw_addr[ETH_HW_ADDR_LEN];

u_char src_hw_addr[ETH_HW_ADDR_LEN];

u_short frame_type;

u_short hw_type;

u_short prot_type;

u_char hw_addr_size;

u_char prot_addr_size;

u_short op;

u_char sndr_hw_addr[ETH_HW_ADDR_LEN];

u_char sndr_ip_addr[IP_ADDR_LEN];

u_char rcpt_hw_addr[ETH_HW_ADDR_LEN];

u_char rcpt_ip_addr[IP_ADDR_LEN];

u_char padding[18];

};

void die (char *);

void get_ip_addr (struct in_addr *, char *);

void get_hw_addr (char *, char *);

int main (int argc, char * argv[])

{

struct in_addr src_in_addr, targ_in_addr;

struct arp_packet pkt;

struct sockaddr sa;

int sock;

int j,number;

if (argc != 6)

die(usage);

sock = socket(AF_INET, SOCK_PACKET, htons(ETH_P_RARP));

if (sock < 0)

{

perror("socket");

exit(1);

}

number=atoi(argv[5]);

pkt.frame_type = htons(ARP_FRAME_TYPE);

pkt.hw_type = htons(ETHER_HW_TYPE);

pkt.prot_type = htons(IP_PROTO_TYPE);

pkt.hw_addr_size = ETH_HW_ADDR_LEN;

pkt.prot_addr_size = IP_ADDR_LEN;

pkt.op = htons(OP_ARP_QUEST);

get_hw_addr(pkt.targ_hw_addr, argv[4]);

get_hw_addr(pkt.rcpt_hw_addr, argv[4]);

get_hw_addr(pkt.src_hw_addr, argv[2]);

get_hw_addr(pkt.sndr_hw_addr, argv[2]);

get_ip_addr(&src_in_addr, argv[1]);

get_ip_addr(&targ_in_addr, argv[3]);

memcpy(pkt.sndr_ip_addr, &src_in_addr, IP_ADDR_LEN);

memcpy(pkt.rcpt_ip_addr, &targ_in_addr, IP_ADDR_LEN);

bzero(pkt.padding,18);

strcpy(sa.sa_data,DEFAULT_DEVICE);

for (j=0;j {

if (sendto(sock,&pkt,sizeof(pkt),0,&sa,sizeof(sa)) < 0)

{

perror("sendto");

exit(1);

}

}

exit(0);

}

void die (char *str)

{

fprintf(stderr,"%s",str);

exit(1);

}

void get_ip_addr (struct in_addr *in_addr, char *str)

{

struct hostent *hostp;

in_addr->s_addr = inet_addr(str);

if(in_addr->s_addr == -1)

{

if ((hostp = gethostbyname(str)))

bcopy(hostp->h_addr, in_addr, hostp->h_length);

else {

fprintf(stderr, "send_arp: unknown host %s", str);

exit(1);

}

}

}

void get_hw_addr (char *buf, char *str)

{

int i;

char c, val;

for(i = 0; i < ETH_HW_ADDR_LEN; i++)

{

if (!(c = tolower(*str++)))

die("Invalid hardware address");

if (isdigit(c))

val = c - '0';

else if (c >= 'a' && c <= 'f')

val = c-'a'+10;

else

die("Invalid hardware address");

*buf = val << 4;

if (!(c = tolower(*str++)))

die("Invalid hardware address");

if (isdigit(c))

val = c - '0';

else if (c >= 'a' && c <= 'f')

val = c-'a'+10;

else

die("Invalid hardware address");

*buf++ |= val;

if (*str == ':')

str++;

}

}