src/proto_arp.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2009, 2010 Daniel Borkmann.
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #ifndef PROTO_ARP_H
   9 #define PROTO_ARP_H
  10
  11 #include <stdint.h>
  12 #include <stdint.h>
  13 #include <netinet/in.h>    /* for ntohs() */
  14
  15 #include "proto_struct.h"
  16 #include "dissector_eth.h"
  17 #include "pkt_buff.h"
  18 #include "built_in.h"
  19
  20 struct arphdr {
  21         uint16_t ar_hrd;   /* format of hardware address */
  22         uint16_t ar_pro;   /* format of protocol address */
  23         uint8_t ar_hln;    /* length of hardware address */
  24         uint8_t ar_pln;    /* length of protocol address */
  25         uint16_t ar_op;    /* ARP opcode (command)       */
  26         uint8_t ar_sha[6]; /* sender hardware address    */
  27         uint8_t ar_sip[4]; /* sender IP address          */
  28         uint8_t ar_tha[6]; /* target hardware address    */
  29         uint8_t ar_tip[4]; /* target IP address          */
  30 } __packed;
  31
  32 #define ARPOP_REQUEST   1  /* ARP request                */
  33 #define ARPOP_REPLY     2  /* ARP reply                  */
  34 #define ARPOP_RREQUEST  3  /* RARP request               */
  35 #define ARPOP_RREPLY    4  /* RARP reply                 */
  36 #define ARPOP_InREQUEST 8  /* InARP request              */
  37 #define ARPOP_InREPLY   9  /* InARP reply                */
  38 #define ARPOP_NAK       10 /* (ATM)ARP NAK               */
  39
  40 static inline void arp(struct pkt_buff *pkt)
  41 {
  42         char *opcode = NULL;
  43         struct arphdr *arp = (struct arphdr *) pkt_pull(pkt, sizeof(*arp));
  44
  45         if (arp == NULL)
  46                 return;
  47
  48         switch (ntohs(arp->ar_op)) {
  49         case ARPOP_REQUEST:
  50                 opcode = "ARP request";
  51                 break;
  52         case ARPOP_REPLY:
  53                 opcode = "ARP reply";
  54                 break;
  55         case ARPOP_RREQUEST:
  56                 opcode = "RARP request";
  57                 break;
  58         case ARPOP_RREPLY:
  59                 opcode = "RARP reply";
  60                 break;
  61         case ARPOP_InREQUEST:
  62                 opcode = "InARP request";
  63                 break;
  64         case ARPOP_InREPLY:
  65                 opcode = "InARP reply";
  66                 break;
  67         case ARPOP_NAK:
  68                 opcode = "(ATM) ARP NAK";
  69                 break;
  70         default:
  71                 opcode = "Unknown";
  72                 break;
  73         };
  74
  75         tprintf(" [ ARP ");
  76         tprintf("Format HA (%u), ", ntohs(arp->ar_hrd));
  77         tprintf("Format Proto (%u), ", ntohs(arp->ar_pro));
  78         tprintf("HA Len (%u), ", ntohs(arp->ar_hln));
  79         tprintf("Proto Len (%u), ", ntohs(arp->ar_pln));
  80         tprintf("Opcode (%u => %s)", ntohs(arp->ar_op), opcode);
  81         tprintf(" ]\n");
  82 }
  83
  84 static inline void arp_less(struct pkt_buff *pkt)
  85 {
  86         char *opcode = NULL;
  87         struct arphdr *arp = (struct arphdr *) pkt_pull(pkt, sizeof(*arp));
  88
  89         if (arp == NULL)
  90                 return;
  91
  92         switch (ntohs(arp->ar_op)) {
  93         case ARPOP_REQUEST:
  94                 opcode = "ARP request";
  95                 break;
  96         case ARPOP_REPLY:
  97                 opcode = "ARP reply";
  98                 break;
  99         case ARPOP_RREQUEST:
 100                 opcode = "RARP request";
 101                 break;
 102         case ARPOP_RREPLY:
 103                 opcode = "RARP reply";
 104                 break;
 105         case ARPOP_InREQUEST:
 106                 opcode = "InARP request";
 107                 break;
 108         case ARPOP_InREPLY:
 109                 opcode = "InARP reply";
 110                 break;
 111         case ARPOP_NAK:
 112                 opcode = "(ATM) ARP NAK";
 113                 break;
 114         default:
 115                 opcode = "Unknown";
 116                 break;
 117         };
 118
 119         tprintf(" Op %s", opcode);
 120 }
 121
 122 struct protocol arp_ops = {
 123         .key = 0x0806,
 124         .print_full = arp,
 125         .print_less = arp_less,
 126 };
 127
 128 #endif /* PROTO_ARP_H */