arp获取

/*  getarp.c -- This simple program uses an IOCTL socket call to read an entry  */
/*  from the ARP cache of the local machine.  Original source unknown.  */
/*  Usage:  getarp <ip-number>   */
/*  Example:  getarp  148.85.2.1 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if_arp.h>

/*  arp_flags and at_flags field values */
#define	ATF_INUSE	0x01	/* entry in use */
#define ATF_COM		0x02	/* completed entry (enaddr valid) */
#define	ATF_PERM	0x04	/* permanent entry */
#define	ATF_PUBL	0x08	/* publish entry (respond for other host) */
#define	ATF_USETRAILERS	0x10	/* has requested trailers */
#define	ATF_PROXY	0x20	/* Do PROXY arp */

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

int s;
struct arpreq arpreq;
struct sockaddr_in *sin;
unsigned char *eap;

if (argc < 2) exit(0);

memset(&arpreq, 0, sizeof(arpreq));

sin = (struct sockaddr_in *) &arpreq.arp_pa;
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = inet_addr(argv[1]);

s = socket(AF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("socket");
exit(0);
}
strcpy(arpreq.arp_dev, "eth0");
if (ioctl(s, SIOCGARP, &arpreq) < 0) {
perror("ioctl");
exit(0);
}
printf("IP address:       %s\n", inet_ntoa(sin->sin_addr));

if (arpreq.arp_flags & ATF_COM) {
eap = (unsigned char *) &arpreq.arp_ha.sa_data[0];
printf("Ethernet address: %02X:%02X:%02X:%02X:%02X:%02X",
eap[0], eap[1], eap[2], eap[3], eap[4], eap[5]);
if (arpreq.arp_flags & ATF_PERM) printf(" PERM");
if (arpreq.arp_flags & ATF_PUBL) printf(" PUBLISHED");
if (arpreq.arp_flags & ATF_USETRAILERS) printf(" TRAILERS");
if (arpreq.arp_flags & ATF_PROXY) printf(" PROXY");
printf("\n");
} else {
printf("*** INCOMPLETE ***\n");
}
close(s);
exit(0);
}

#include <stdio.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <netdb.h>
//#include "nlist.h"
#include <net/if.h>
#include <netinet/if_ether.h>

extern int errno;

main(argc, argv)
char **argv;
{
if (argc >= 2 && strcmp(argv[1], "-a") == 0) {
#ifdef pdp11
char *kernel = "/netnix", *mem = "/dev/mem";
#else
char *kernel = "/unix", *mem = "/dev/kmem";
#endif

if (argc >= 3)
kernel = argv[2];
if (argc >= 4)
mem = argv[3];
//      dump(kernel, mem);
exit(0);
}
if (argc == 2) {
get(argv[1]);
exit(0);
}
if (argc >= 4 && strcmp(argv[1], "-s") == 0) {
printf("\n in set addr");
if (set(argc-2, &argv[2]))
exit(1);
exit(0);
}
if (argc == 3 && strcmp(argv[1], "-d") == 0) {
delete(argv[2]);
exit(0);
}
if (argc == 3 && strcmp(argv[1], "-f") == 0) {
if (file(argv[2]))
exit(1);
exit(0);
}
usage();
exit(1);
}

/*
* Process a file to set standard arp entries
*/
file(name)
char *name;
{
FILE *fp;
int i;
char line[100], arg[5][50], *args[5];
int retval;

if ((fp = fopen(name, "r")) == NULL) {
fprintf(stderr, "arp: cannot open %s\n", name);
exit(1);
}
args[0] = &arg[0][0];
args[1] = &arg[1][0];
args[2] = &arg[2][0];
args[3] = &arg[3][0];
args[4] = &arg[4][0];
retval = 0;
while(fgets(line, 100, fp) != NULL) {
i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1],
arg[2],
arg[3], arg[4]);
if (i < 2) {
fprintf(stderr, "arp: bad line: %s\n", line);
retval = 1;
continue;
}
if (set(i, args))
retval = 1;

}
fclose(fp);
return (retval);
}

/*
* Set an individual arp entry
*/
set(argc, argv)
char **argv;
{
struct arpreq ar;
struct hostent *hp;
struct sockaddr_in *sin;
u_char *ea;
int s;
char *host = argv[0], *eaddr = argv[1];

printf("\nargv[0]=%s",argv[0]);
printf("\nargv[1]=%s",argv[1]);

argc -= 2;
argv += 2;
bzero((caddr_t)&ar, sizeof ar);
sin = (struct sockaddr_in *)&ar.arp_pa;
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = inet_addr(host);
if (sin->sin_addr.s_addr == -1) {
hp = gethostbyname(host);
if (hp == NULL) {
fprintf(stderr, "arp: %s: unknown host\n",
host);
return (1);
}
bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
sizeof sin->sin_addr);
}
ea = (u_char *)ar.arp_ha.sa_data;
if (ether_aton(eaddr, ea))
return (1);
ar.arp_flags = ATF_PERM;
while (argc-- > 0) {
if (strncmp(argv[0], "temp", 4) == 0)
ar.arp_flags &= ~ATF_PERM;
if (strncmp(argv[0], "pub", 3) == 0)
ar.arp_flags |= ATF_PUBL;
if (strncmp(argv[0], "trail", 5) == 0)
ar.arp_flags |= ATF_USETRAILERS;
argv++;
}

s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("arp: socket");
exit(1);
}
if (ioctl(s, SIOCSARP, (caddr_t)&ar) < 0) {
perror(host);
exit(1);
}
close(s);
return (0);
}

/*
* Display an individual arp entry
*/
get(host)
char *host;
{
struct arpreq ar;
struct hostent *hp;
struct sockaddr_in *sin;
u_char *ea;
int s;

bzero((caddr_t)&ar, sizeof ar);
ar.arp_pa.sa_family = AF_INET;
sin = (struct sockaddr_in *)&ar.arp_pa;
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = inet_addr(host);
if (sin->sin_addr.s_addr == -1) {
hp = gethostbyname(host);
if (hp == NULL) {
fprintf(stderr, "arp: %s: unknown host\n",
host);
exit(1);
}
bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
sizeof sin->sin_addr);
}
s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("arp: socket");
exit(1);
}
if (ioctl(s, SIOCGARP, (caddr_t)&ar) < 0) {
if (errno == ENXIO)
printf("%s (%s) -- no entry\n",
host, inet_ntoa(sin->sin_addr));
else
perror("SIOCGARP");
exit(1);
}
close(s);
ea = (u_char *)ar.arp_ha.sa_data;
printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr));
if (ar.arp_flags & ATF_COM)
ether_print(ea);
else
printf("(incomplete)");
if (ar.arp_flags & ATF_PERM) printf(" permanent");
if (ar.arp_flags & ATF_PUBL) printf(" published");
if (ar.arp_flags & ATF_USETRAILERS) printf(" trailers");
printf("\n");
}

/*
* Delete an arp entry
*/
delete(host)
char *host;
{
struct arpreq ar;
struct hostent *hp;
struct sockaddr_in *sin;
int s;
bzero((caddr_t)&ar, sizeof ar);
ar.arp_pa.sa_family = AF_INET;
sin = (struct sockaddr_in *)&ar.arp_pa;
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = inet_addr(host);
if (sin->sin_addr.s_addr == -1) {
hp = gethostbyname(host);
if (hp == NULL) {
fprintf(stderr, "arp: %s: unknown host\n",
host);
exit(1);
}
bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
sizeof sin->sin_addr);
}
s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("arp: socket");
exit(1);
}
if (ioctl(s, SIOCDARP, (caddr_t)&ar) < 0) {
if (errno == ENXIO)
printf("%s (%s) -- no entry\n",
host, inet_ntoa(sin->sin_addr));
else
perror("SIOCDARP");
exit(1);
}
close(s);
printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));
}

ether_print(cp)
u_char *cp;
{
printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4],
cp[5]);
}

ether_aton(a, n)
char *a;
u_char *n;
{
int i, o[6];

i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2],
&o[3], &o[4], &o[5]);
if (i != 6) {
fprintf(stderr, "arp: invalid Ethernet address '%s'\n",
a);
return (1);
}
for (i=0; i<6; i++)
n = o;
return (0);
}

usage()
{
printf("Usage: arp hostname\n");
printf("       arp -a [/vmunix] [/dev/kmem]\n");
printf("       arp -d hostname\n");
printf("       arp -s hostname ether_addr [temp] [pub]
[trail]\n");
printf("       arp -f filename\n");
}