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/*
* netsniff-ng - the packet sniffing beast
* Copyright 2009, 2010 Daniel Borkmann.
* Subject to the GPL, version 2.
*/
#include <stdint.h>
#include <arpa/inet.h>
#include <netinet/in.h> /* for ntohs() */
#include <linux/if_ether.h>
#include "proto.h"
#include "protos.h"
#include "lookup.h"
#include "pkt_buff.h"
#include "built_in.h"
struct arphdr {
uint16_t ar_hrd; /* format of hardware address */
uint16_t ar_pro; /* format of protocol address */
uint8_t ar_hln; /* length of hardware address */
uint8_t ar_pln; /* length of protocol address */
uint16_t ar_op; /* ARP opcode (command) */
uint8_t ar_sha[6]; /* sender hardware address */
uint8_t ar_sip[4]; /* sender IP address */
uint8_t ar_tha[6]; /* target hardware address */
uint8_t ar_tip[4]; /* target IP address */
} __packed;
#define ARPHRD_ETHER 1
#define ARPHRD_IEEE802 6
#define ARPHRD_ARCNET 7
#define ARPHRD_ATM 16
#define ARPHRD_ATM2 19
#define ARPHRD_SERIAL 20
#define ARPHRD_ATM3 21
#define ARPHRD_IEEE1394 24
#define ARPOP_REQUEST 1 /* ARP request */
#define ARPOP_REPLY 2 /* ARP reply */
#define ARPOP_RREQUEST 3 /* RARP request */
#define ARPOP_RREPLY 4 /* RARP reply */
#define ARPOP_InREQUEST 8 /* InARP request */
#define ARPOP_InREPLY 9 /* InARP reply */
#define ARPOP_NAK 10 /* (ATM)ARP NAK */
enum addr_direct {
ADDR_SENDER,
ADDR_TARGET,
};
static void arp_print_addrs(struct arphdr *arp, enum addr_direct addr_dir)
{
char *dir = addr_dir == ADDR_SENDER ? "Sender" : "Target";
bool has_eth;
bool has_ip4;
has_eth = ntohs(arp->ar_hrd) == ARPHRD_ETHER;
has_ip4 = ntohs(arp->ar_pro) == ETH_P_IP;
if (has_eth) {
uint8_t *mac;
mac = addr_dir == ADDR_SENDER ? &arp->ar_sha[0] : &arp->ar_tha[0];
tprintf(", %s MAC (%.2x:%.2x:%.2x:%.2x:%.2x:%.2x)",
dir, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}
if (has_ip4) {
char ip_str[INET_ADDRSTRLEN];
uint32_t ip;
if (addr_dir == ADDR_SENDER)
ip = *(uint32_t *)&arp->ar_sip[0];
else
ip = *(uint32_t *)&arp->ar_tip[0];
inet_ntop(AF_INET, &ip, ip_str, sizeof(ip_str));
tprintf(", %s IP (%s)", dir, ip_str);
}
}
static void arp(struct pkt_buff *pkt)
{
char *hrd;
const char *pro;
char *opcode;
struct arphdr *arp = (struct arphdr *) pkt_pull(pkt, sizeof(*arp));
if (arp == NULL)
return;
switch (ntohs(arp->ar_hrd)) {
case ARPHRD_ETHER:
hrd = "Ethernet";
break;
case ARPHRD_IEEE802:
hrd = "IEEE 802";
break;
case ARPHRD_ARCNET:
hrd = "ARCNET";
break;
case ARPHRD_ATM:
case ARPHRD_ATM2:
case ARPHRD_ATM3:
hrd = "ATM";
break;
case ARPHRD_SERIAL:
hrd = "Serial Line";
break;
case ARPHRD_IEEE1394:
hrd = "IEEE 1394.1995";
break;
default:
hrd = "Unknown";
break;
}
pro = lookup_ether_type(ntohs(arp->ar_pro));
if (pro == NULL)
pro = "Unknown";
switch (ntohs(arp->ar_op)) {
case ARPOP_REQUEST:
opcode = "ARP request";
break;
case ARPOP_REPLY:
opcode = "ARP reply";
break;
case ARPOP_RREQUEST:
opcode = "RARP request";
break;
case ARPOP_RREPLY:
opcode = "RARP reply";
break;
case ARPOP_InREQUEST:
opcode = "InARP request";
break;
case ARPOP_InREPLY:
opcode = "InARP reply";
break;
case ARPOP_NAK:
opcode = "(ATM) ARP NAK";
break;
default:
opcode = "Unknown";
break;
};
tprintf(" [ ARP ");
tprintf("Format HA (%u => %s), ", ntohs(arp->ar_hrd), hrd);
tprintf("Format Proto (0x%.4x => %s), ", ntohs(arp->ar_pro), pro);
tprintf("HA Len (%u), ", arp->ar_hln);
tprintf("Proto Len (%u), ", arp->ar_pln);
tprintf("Opcode (%u => %s)", ntohs(arp->ar_op), opcode);
arp_print_addrs(arp, ADDR_SENDER);
arp_print_addrs(arp, ADDR_TARGET);
tprintf(" ]\n");
}
static void arp_less(struct pkt_buff *pkt)
{
char *opcode = NULL;
struct arphdr *arp = (struct arphdr *) pkt_pull(pkt, sizeof(*arp));
if (arp == NULL)
return;
switch (ntohs(arp->ar_op)) {
case ARPOP_REQUEST:
opcode = "ARP request";
break;
case ARPOP_REPLY:
opcode = "ARP reply";
break;
case ARPOP_RREQUEST:
opcode = "RARP request";
break;
case ARPOP_RREPLY:
opcode = "RARP reply";
break;
case ARPOP_InREQUEST:
opcode = "InARP request";
break;
case ARPOP_InREPLY:
opcode = "InARP reply";
break;
case ARPOP_NAK:
opcode = "(ATM) ARP NAK";
break;
default:
opcode = "Unknown";
break;
};
tprintf(" Op %s", opcode);
}
struct protocol arp_ops = {
.key = 0x0806,
.print_full = arp,
.print_less = arp_less,
};
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