print-arp.c - platform/external/tcpdump - Git at Google

 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
  *	The Regents of the University of California.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that: (1) source code distributions
  * retain the above copyright notice and this paragraph in its entirety, (2)
  * distributions including binary code include the above copyright notice and
  * this paragraph in its entirety in the documentation or other materials
  * provided with the distribution, and (3) all advertising materials mentioning
  * features or use of this software display the following acknowledgement:
  * ``This product includes software developed by the University of California,
  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  * the University nor the names of its contributors may be used to endorse
  * or promote products derived from this software without specific prior
  * written permission.
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */

 #define NETDISSECT_REWORKED
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <tcpdump-stdinc.h>

 #include <string.h>

 #include "interface.h"
 #include "addrtoname.h"
 #include "ether.h"
 #include "ethertype.h"
 #include "extract.h"			/* must come after interface.h */

 static const char tstr[] = "[|ARP]";

 /*
  * Address Resolution Protocol.
  *
  * See RFC 826 for protocol description.  ARP packets are variable
  * in size; the arphdr structure defines the fixed-length portion.
  * Protocol type values are the same as those for 10 Mb/s Ethernet.
  * It is followed by the variable-sized fields ar_sha, arp_spa,
  * arp_tha and arp_tpa in that order, according to the lengths
  * specified.  Field names used correspond to RFC 826.
  */
 struct  arp_pkthdr {
         u_short ar_hrd;         /* format of hardware address */
 #define ARPHRD_ETHER    1       /* ethernet hardware format */
 #define ARPHRD_IEEE802  6       /* token-ring hardware format */
 #define ARPHRD_ARCNET   7       /* arcnet hardware format */
 #define ARPHRD_FRELAY   15      /* frame relay hardware format */
 #define ARPHRD_ATM2225  19      /* ATM (RFC 2225) */
 #define ARPHRD_STRIP    23      /* Ricochet Starmode Radio hardware format */
 #define ARPHRD_IEEE1394 24      /* IEEE 1394 (FireWire) hardware format */
         u_short ar_pro;         /* format of protocol address */
         u_char  ar_hln;         /* length of hardware address */
         u_char  ar_pln;         /* length of protocol address */
         u_short ar_op;          /* one of: */
 #define ARPOP_REQUEST   1       /* request to resolve address */
 #define ARPOP_REPLY     2       /* response to previous request */
 #define ARPOP_REVREQUEST 3      /* request protocol address given hardware */
 #define ARPOP_REVREPLY  4       /* response giving protocol address */
 #define ARPOP_INVREQUEST 8      /* request to identify peer */
 #define ARPOP_INVREPLY  9       /* response identifying peer */
 #define ARPOP_NAK       10      /* NAK - only valif for ATM ARP */

 /*
  * The remaining fields are variable in size,
  * according to the sizes above.
  */
 #ifdef COMMENT_ONLY
 	u_char	ar_sha[];	/* sender hardware address */
 	u_char	ar_spa[];	/* sender protocol address */
 	u_char	ar_tha[];	/* target hardware address */
 	u_char	ar_tpa[];	/* target protocol address */
 #endif
 #define ar_sha(ap)	(((const u_char *)((ap)+1))+0)
 #define ar_spa(ap)	(((const u_char *)((ap)+1))+  (ap)->ar_hln)
 #define ar_tha(ap)	(((const u_char *)((ap)+1))+  (ap)->ar_hln+(ap)->ar_pln)
 #define ar_tpa(ap)	(((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln)
 };

 #define ARP_HDRLEN	8

 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd)
 #define HRD_LEN(ap) ((ap)->ar_hln)
 #define PROTO_LEN(ap) ((ap)->ar_pln)
 #define OP(ap)  EXTRACT_16BITS(&(ap)->ar_op)
 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro)
 #define SHA(ap) (ar_sha(ap))
 #define SPA(ap) (ar_spa(ap))
 #define THA(ap) (ar_tha(ap))
 #define TPA(ap) (ar_tpa(ap))


 static const struct tok arpop_values[] = {
     { ARPOP_REQUEST, "Request" },
     { ARPOP_REPLY, "Reply" },
     { ARPOP_REVREQUEST, "Reverse Request" },
     { ARPOP_REVREPLY, "Reverse Reply" },
     { ARPOP_INVREQUEST, "Inverse Request" },
     { ARPOP_INVREPLY, "Inverse Reply" },
     { ARPOP_NAK, "NACK Reply" },
     { 0, NULL }
 };

 static const struct tok arphrd_values[] = {
     { ARPHRD_ETHER, "Ethernet" },
     { ARPHRD_IEEE802, "TokenRing" },
     { ARPHRD_ARCNET, "ArcNet" },
     { ARPHRD_FRELAY, "FrameRelay" },
     { ARPHRD_STRIP, "Strip" },
     { ARPHRD_IEEE1394, "IEEE 1394" },
     { ARPHRD_ATM2225, "ATM" },
     { 0, NULL }
 };

 /*
  * ATM Address Resolution Protocol.
  *
  * See RFC 2225 for protocol description.  ATMARP packets are similar
  * to ARP packets, except that there are no length fields for the
  * protocol address - instead, there are type/length fields for
  * the ATM number and subaddress - and the hardware addresses consist
  * of an ATM number and an ATM subaddress.
  */
 struct  atmarp_pkthdr {
         u_short aar_hrd;        /* format of hardware address */
         u_short aar_pro;        /* format of protocol address */
         u_char  aar_shtl;       /* length of source ATM number */
         u_char  aar_sstl;       /* length of source ATM subaddress */
 #define ATMARP_IS_E164  0x40    /* bit in type/length for E.164 format */
 #define ATMARP_LEN_MASK 0x3F    /* length of {sub}address in type/length */
         u_short aar_op;         /* same as regular ARP */
         u_char  aar_spln;       /* length of source protocol address */
         u_char  aar_thtl;       /* length of target ATM number */
         u_char  aar_tstl;       /* length of target ATM subaddress */
         u_char  aar_tpln;       /* length of target protocol address */
 /*
  * The remaining fields are variable in size,
  * according to the sizes above.
  */
 #ifdef COMMENT_ONLY
 	u_char	aar_sha[];	/* source ATM number */
 	u_char	aar_ssa[];	/* source ATM subaddress */
 	u_char	aar_spa[];	/* sender protocol address */
 	u_char	aar_tha[];	/* target ATM number */
 	u_char	aar_tsa[];	/* target ATM subaddress */
 	u_char	aar_tpa[];	/* target protocol address */
 #endif

 #define ATMHRD(ap)  EXTRACT_16BITS(&(ap)->aar_hrd)
 #define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK)
 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK)
 #define ATMSPROTO_LEN(ap) ((ap)->aar_spln)
 #define ATMOP(ap)   EXTRACT_16BITS(&(ap)->aar_op)
 #define ATMPRO(ap)  EXTRACT_16BITS(&(ap)->aar_pro)
 #define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK)
 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK)
 #define ATMTPROTO_LEN(ap) ((ap)->aar_tpln)
 #define aar_sha(ap)	((const u_char *)((ap)+1))
 #define aar_ssa(ap)	(aar_sha(ap) + ATMSHRD_LEN(ap))
 #define aar_spa(ap)	(aar_ssa(ap) + ATMSSLN(ap))
 #define aar_tha(ap)	(aar_spa(ap) + ATMSPROTO_LEN(ap))
 #define aar_tsa(ap)	(aar_tha(ap) + ATMTHRD_LEN(ap))
 #define aar_tpa(ap)	(aar_tsa(ap) + ATMTSLN(ap))
 };

 #define ATMSHA(ap) (aar_sha(ap))
 #define ATMSSA(ap) (aar_ssa(ap))
 #define ATMSPA(ap) (aar_spa(ap))
 #define ATMTHA(ap) (aar_tha(ap))
 #define ATMTSA(ap) (aar_tsa(ap))
 #define ATMTPA(ap) (aar_tpa(ap))

 static u_char ezero[6];

 static void
 atmarp_addr_print(netdissect_options *ndo,
 		  const u_char *ha, u_int ha_len, const u_char *srca,
     u_int srca_len)
 {
 	if (ha_len == 0)
 		ND_PRINT((ndo, "<No address>"));
 	else {
 		ND_PRINT((ndo, "%s", linkaddr_string(ndo, ha, LINKADDR_ATM, ha_len)));
 		if (srca_len != 0)
 			ND_PRINT((ndo, ",%s",
 				  linkaddr_string(ndo, srca, LINKADDR_ATM, srca_len)));
 	}
 }

 static void
 atmarp_print(netdissect_options *ndo,
 	     const u_char *bp, u_int length, u_int caplen)
 {
 	const struct atmarp_pkthdr *ap;
 	u_short pro, hrd, op;

 	ap = (const struct atmarp_pkthdr *)bp;
 	ND_TCHECK(*ap);

 	hrd = ATMHRD(ap);
 	pro = ATMPRO(ap);
 	op = ATMOP(ap);

 	if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) {
 		ND_PRINT((ndo, "%s", tstr));
 		ND_DEFAULTPRINT((const u_char *)ap, length);
 		return;
 	}

         if (!ndo->ndo_eflag) {
             ND_PRINT((ndo, "ARP, "));
         }

 	if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
 	    ATMSPROTO_LEN(ap) != 4 ||
             ATMTPROTO_LEN(ap) != 4 ||
             ndo->ndo_vflag) {
                 ND_PRINT((ndo, "%s, %s (len %u/%u)",
                           tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
                           tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
                           ATMSPROTO_LEN(ap),
                           ATMTPROTO_LEN(ap)));

                 /* don't know know about the address formats */
                 if (!ndo->ndo_vflag) {
                     goto out;
                 }
 	}

         /* print operation */
         ND_PRINT((ndo, "%s%s ",
                ndo->ndo_vflag ? ", " : "",
                tok2str(arpop_values, "Unknown (%u)", op)));

 	switch (op) {

 	case ARPOP_REQUEST:
 		ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, ATMTPA(ap))));
 		if (ATMTHRD_LEN(ap) != 0) {
 			ND_PRINT((ndo, " ("));
 			atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap),
 			    ATMTSA(ap), ATMTSLN(ap));
 			ND_PRINT((ndo, ")"));
 		}
 		ND_PRINT((ndo, "tell %s", ipaddr_string(ndo, ATMSPA(ap))));
 		break;

 	case ARPOP_REPLY:
 		ND_PRINT((ndo, "%s is-at ", ipaddr_string(ndo, ATMSPA(ap))));
 		atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
                                   ATMSSLN(ap));
 		break;

 	case ARPOP_INVREQUEST:
 		ND_PRINT((ndo, "who-is "));
 		atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap),
 		    ATMTSLN(ap));
 		ND_PRINT((ndo, " tell "));
 		atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
 		    ATMSSLN(ap));
 		break;

 	case ARPOP_INVREPLY:
 		atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
 		    ATMSSLN(ap));
 		ND_PRINT((ndo, "at %s", ipaddr_string(ndo, ATMSPA(ap))));
 		break;

 	case ARPOP_NAK:
 		ND_PRINT((ndo, "for %s", ipaddr_string(ndo, ATMSPA(ap))));
 		break;

 	default:
 		ND_DEFAULTPRINT((const u_char *)ap, caplen);
 		return;
 	}

  out:
         ND_PRINT((ndo, ", length %u", length));
         return;

 trunc:
 	ND_PRINT((ndo, "%s", tstr));
 }

 void
 arp_print(netdissect_options *ndo,
 	  const u_char *bp, u_int length, u_int caplen)
 {
 	const struct arp_pkthdr *ap;
 	u_short pro, hrd, op, linkaddr;

 	ap = (const struct arp_pkthdr *)bp;
 	ND_TCHECK(*ap);

 	hrd = HRD(ap);
 	pro = PRO(ap);
 	op = OP(ap);


         /* if its ATM then call the ATM ARP printer
            for Frame-relay ARP most of the fields
            are similar to Ethernet so overload the Ethernet Printer
            and set the linkaddr type for linkaddr_string(ndo, ) accordingly */

         switch(hrd) {
         case ARPHRD_ATM2225:
             atmarp_print(ndo, bp, length, caplen);
             return;
         case ARPHRD_FRELAY:
             linkaddr = LINKADDR_FRELAY;
             break;
         default:
             linkaddr = LINKADDR_ETHER;
             break;
 	}

 	if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) {
 		ND_PRINT((ndo, "%s", tstr));
 		ND_DEFAULTPRINT((const u_char *)ap, length);
 		return;
 	}

         if (!ndo->ndo_eflag) {
             ND_PRINT((ndo, "ARP, "));
         }

         /* print hardware type/len and proto type/len */
         if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
 	    PROTO_LEN(ap) != 4 ||
             HRD_LEN(ap) == 0 ||
             ndo->ndo_vflag) {
             ND_PRINT((ndo, "%s (len %u), %s (len %u)",
                       tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
                       HRD_LEN(ap),
                       tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
                       PROTO_LEN(ap)));

             /* don't know know about the address formats */
             if (!ndo->ndo_vflag) {
                 goto out;
             }
 	}

         /* print operation */
         ND_PRINT((ndo, "%s%s ",
                ndo->ndo_vflag ? ", " : "",
                tok2str(arpop_values, "Unknown (%u)", op)));

 	switch (op) {

 	case ARPOP_REQUEST:
 		ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, TPA(ap))));
 		if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0)
 			ND_PRINT((ndo, " (%s)",
 				  linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap))));
 		ND_PRINT((ndo, " tell %s", ipaddr_string(ndo, SPA(ap))));
 		break;

 	case ARPOP_REPLY:
 		ND_PRINT((ndo, "%s is-at %s",
                           ipaddr_string(ndo, SPA(ap)),
                           linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
 		break;

 	case ARPOP_REVREQUEST:
 		ND_PRINT((ndo, "who-is %s tell %s",
 			  linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
 			  linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
 		break;

 	case ARPOP_REVREPLY:
 		ND_PRINT((ndo, "%s at %s",
 			  linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
 			  ipaddr_string(ndo, TPA(ap))));
 		break;

 	case ARPOP_INVREQUEST:
 		ND_PRINT((ndo, "who-is %s tell %s",
 			  linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
 			  linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
 		break;

 	case ARPOP_INVREPLY:
 		ND_PRINT((ndo,"%s at %s",
 			  linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)),
 			  ipaddr_string(ndo, SPA(ap))));
 		break;

 	default:
 		ND_DEFAULTPRINT((const u_char *)ap, caplen);
 		return;
 	}

  out:
         ND_PRINT((ndo, ", length %u", length));

 	return;
 trunc:
 	ND_PRINT((ndo, "%s", tstr));
 }

 /*
  * Local Variables:
  * c-style: bsd
  * End:
  */
	/*
	* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
	* The Regents of the University of California. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that: (1) source code distributions
	* retain the above copyright notice and this paragraph in its entirety, (2)
	* distributions including binary code include the above copyright notice and
	* this paragraph in its entirety in the documentation or other materials
	* provided with the distribution, and (3) all advertising materials mentioning
	* features or use of this software display the following acknowledgement:
	* ``This product includes software developed by the University of California,
	* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
	* the University nor the names of its contributors may be used to endorse
	* or promote products derived from this software without specific prior
	* written permission.
	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	*/

	#define NETDISSECT_REWORKED
	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <tcpdump-stdinc.h>

	#include <string.h>

	#include "interface.h"
	#include "addrtoname.h"
	#include "ether.h"
	#include "ethertype.h"
	#include "extract.h" /* must come after interface.h */

	static const char tstr[] = "[\|ARP]";

	/*
	* Address Resolution Protocol.
	*
	* See RFC 826 for protocol description. ARP packets are variable
	* in size; the arphdr structure defines the fixed-length portion.
	* Protocol type values are the same as those for 10 Mb/s Ethernet.
	* It is followed by the variable-sized fields ar_sha, arp_spa,
	* arp_tha and arp_tpa in that order, according to the lengths
	* specified. Field names used correspond to RFC 826.
	*/
	struct arp_pkthdr {
	u_short ar_hrd; /* format of hardware address */
	#define ARPHRD_ETHER 1 /* ethernet hardware format */
	#define ARPHRD_IEEE802 6 /* token-ring hardware format */
	#define ARPHRD_ARCNET 7 /* arcnet hardware format */
	#define ARPHRD_FRELAY 15 /* frame relay hardware format */
	#define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */
	#define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */
	#define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */
	u_short ar_pro; /* format of protocol address */
	u_char ar_hln; /* length of hardware address */
	u_char ar_pln; /* length of protocol address */
	u_short ar_op; /* one of: */
	#define ARPOP_REQUEST 1 /* request to resolve address */
	#define ARPOP_REPLY 2 /* response to previous request */
	#define ARPOP_REVREQUEST 3 /* request protocol address given hardware */
	#define ARPOP_REVREPLY 4 /* response giving protocol address */
	#define ARPOP_INVREQUEST 8 /* request to identify peer */
	#define ARPOP_INVREPLY 9 /* response identifying peer */
	#define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */

	/*
	* The remaining fields are variable in size,
	* according to the sizes above.
	*/
	#ifdef COMMENT_ONLY
	u_char ar_sha[]; /* sender hardware address */
	u_char ar_spa[]; /* sender protocol address */
	u_char ar_tha[]; /* target hardware address */
	u_char ar_tpa[]; /* target protocol address */
	#endif
	#define ar_sha(ap) (((const u_char *)((ap)+1))+0)
	#define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln)
	#define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln)
	#define ar_tpa(ap) (((const u_char )((ap)+1))+2(ap)->ar_hln+(ap)->ar_pln)
	};

	#define ARP_HDRLEN 8

	#define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd)
	#define HRD_LEN(ap) ((ap)->ar_hln)
	#define PROTO_LEN(ap) ((ap)->ar_pln)
	#define OP(ap) EXTRACT_16BITS(&(ap)->ar_op)
	#define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro)
	#define SHA(ap) (ar_sha(ap))
	#define SPA(ap) (ar_spa(ap))
	#define THA(ap) (ar_tha(ap))
	#define TPA(ap) (ar_tpa(ap))


	static const struct tok arpop_values[] = {
	{ ARPOP_REQUEST, "Request" },
	{ ARPOP_REPLY, "Reply" },
	{ ARPOP_REVREQUEST, "Reverse Request" },
	{ ARPOP_REVREPLY, "Reverse Reply" },
	{ ARPOP_INVREQUEST, "Inverse Request" },
	{ ARPOP_INVREPLY, "Inverse Reply" },
	{ ARPOP_NAK, "NACK Reply" },
	{ 0, NULL }
	};

	static const struct tok arphrd_values[] = {
	{ ARPHRD_ETHER, "Ethernet" },
	{ ARPHRD_IEEE802, "TokenRing" },
	{ ARPHRD_ARCNET, "ArcNet" },
	{ ARPHRD_FRELAY, "FrameRelay" },
	{ ARPHRD_STRIP, "Strip" },
	{ ARPHRD_IEEE1394, "IEEE 1394" },
	{ ARPHRD_ATM2225, "ATM" },
	{ 0, NULL }
	};

	/*
	* ATM Address Resolution Protocol.
	*
	* See RFC 2225 for protocol description. ATMARP packets are similar
	* to ARP packets, except that there are no length fields for the
	* protocol address - instead, there are type/length fields for
	* the ATM number and subaddress - and the hardware addresses consist
	* of an ATM number and an ATM subaddress.
	*/
	struct atmarp_pkthdr {
	u_short aar_hrd; /* format of hardware address */
	u_short aar_pro; /* format of protocol address */
	u_char aar_shtl; /* length of source ATM number */
	u_char aar_sstl; /* length of source ATM subaddress */
	#define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */
	#define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */
	u_short aar_op; /* same as regular ARP */
	u_char aar_spln; /* length of source protocol address */
	u_char aar_thtl; /* length of target ATM number */
	u_char aar_tstl; /* length of target ATM subaddress */
	u_char aar_tpln; /* length of target protocol address */
	/*
	* The remaining fields are variable in size,
	* according to the sizes above.
	*/
	#ifdef COMMENT_ONLY
	u_char aar_sha[]; /* source ATM number */
	u_char aar_ssa[]; /* source ATM subaddress */
	u_char aar_spa[]; /* sender protocol address */
	u_char aar_tha[]; /* target ATM number */
	u_char aar_tsa[]; /* target ATM subaddress */
	u_char aar_tpa[]; /* target protocol address */
	#endif

	#define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd)
	#define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK)
	#define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK)
	#define ATMSPROTO_LEN(ap) ((ap)->aar_spln)
	#define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op)
	#define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro)
	#define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK)
	#define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK)
	#define ATMTPROTO_LEN(ap) ((ap)->aar_tpln)
	#define aar_sha(ap) ((const u_char *)((ap)+1))
	#define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap))
	#define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap))
	#define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap))
	#define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap))
	#define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap))
	};

	#define ATMSHA(ap) (aar_sha(ap))
	#define ATMSSA(ap) (aar_ssa(ap))
	#define ATMSPA(ap) (aar_spa(ap))
	#define ATMTHA(ap) (aar_tha(ap))
	#define ATMTSA(ap) (aar_tsa(ap))
	#define ATMTPA(ap) (aar_tpa(ap))

	static u_char ezero[6];

	static void
	atmarp_addr_print(netdissect_options *ndo,
	const u_char ha, u_int ha_len, const u_char srca,
	u_int srca_len)
	{
	if (ha_len == 0)
	ND_PRINT((ndo, "<No address>"));
	else {
	ND_PRINT((ndo, "%s", linkaddr_string(ndo, ha, LINKADDR_ATM, ha_len)));
	if (srca_len != 0)
	ND_PRINT((ndo, ",%s",
	linkaddr_string(ndo, srca, LINKADDR_ATM, srca_len)));
	}
	}

	static void
	atmarp_print(netdissect_options *ndo,
	const u_char *bp, u_int length, u_int caplen)
	{
	const struct atmarp_pkthdr *ap;
	u_short pro, hrd, op;

	ap = (const struct atmarp_pkthdr *)bp;
	ND_TCHECK(*ap);

	hrd = ATMHRD(ap);
	pro = ATMPRO(ap);
	op = ATMOP(ap);

	if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) {
	ND_PRINT((ndo, "%s", tstr));
	ND_DEFAULTPRINT((const u_char *)ap, length);
	return;
	}

	if (!ndo->ndo_eflag) {
	ND_PRINT((ndo, "ARP, "));
	}

	if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) \|\|
	ATMSPROTO_LEN(ap) != 4 \|\|
	ATMTPROTO_LEN(ap) != 4 \|\|
	ndo->ndo_vflag) {
	ND_PRINT((ndo, "%s, %s (len %u/%u)",
	tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
	tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
	ATMSPROTO_LEN(ap),
	ATMTPROTO_LEN(ap)));

	/* don't know know about the address formats */
	if (!ndo->ndo_vflag) {
	goto out;
	}
	}

	/* print operation */
	ND_PRINT((ndo, "%s%s ",
	ndo->ndo_vflag ? ", " : "",
	tok2str(arpop_values, "Unknown (%u)", op)));

	switch (op) {

	case ARPOP_REQUEST:
	ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, ATMTPA(ap))));
	if (ATMTHRD_LEN(ap) != 0) {
	ND_PRINT((ndo, " ("));
	atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap),
	ATMTSA(ap), ATMTSLN(ap));
	ND_PRINT((ndo, ")"));
	}
	ND_PRINT((ndo, "tell %s", ipaddr_string(ndo, ATMSPA(ap))));
	break;

	case ARPOP_REPLY:
	ND_PRINT((ndo, "%s is-at ", ipaddr_string(ndo, ATMSPA(ap))));
	atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
	ATMSSLN(ap));
	break;

	case ARPOP_INVREQUEST:
	ND_PRINT((ndo, "who-is "));
	atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap),
	ATMTSLN(ap));
	ND_PRINT((ndo, " tell "));
	atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
	ATMSSLN(ap));
	break;

	case ARPOP_INVREPLY:
	atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap),
	ATMSSLN(ap));
	ND_PRINT((ndo, "at %s", ipaddr_string(ndo, ATMSPA(ap))));
	break;

	case ARPOP_NAK:
	ND_PRINT((ndo, "for %s", ipaddr_string(ndo, ATMSPA(ap))));
	break;

	default:
	ND_DEFAULTPRINT((const u_char *)ap, caplen);
	return;
	}

	out:
	ND_PRINT((ndo, ", length %u", length));
	return;

	trunc:
	ND_PRINT((ndo, "%s", tstr));
	}

	void
	arp_print(netdissect_options *ndo,
	const u_char *bp, u_int length, u_int caplen)
	{
	const struct arp_pkthdr *ap;
	u_short pro, hrd, op, linkaddr;

	ap = (const struct arp_pkthdr *)bp;
	ND_TCHECK(*ap);

	hrd = HRD(ap);
	pro = PRO(ap);
	op = OP(ap);


	/* if its ATM then call the ATM ARP printer
	for Frame-relay ARP most of the fields
	are similar to Ethernet so overload the Ethernet Printer
	and set the linkaddr type for linkaddr_string(ndo, ) accordingly */

	switch(hrd) {
	case ARPHRD_ATM2225:
	atmarp_print(ndo, bp, length, caplen);
	return;
	case ARPHRD_FRELAY:
	linkaddr = LINKADDR_FRELAY;
	break;
	default:
	linkaddr = LINKADDR_ETHER;
	break;
	}

	if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) {
	ND_PRINT((ndo, "%s", tstr));
	ND_DEFAULTPRINT((const u_char *)ap, length);
	return;
	}

	if (!ndo->ndo_eflag) {
	ND_PRINT((ndo, "ARP, "));
	}

	/* print hardware type/len and proto type/len */
	if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) \|\|
	PROTO_LEN(ap) != 4 \|\|
	HRD_LEN(ap) == 0 \|\|
	ndo->ndo_vflag) {
	ND_PRINT((ndo, "%s (len %u), %s (len %u)",
	tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
	HRD_LEN(ap),
	tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
	PROTO_LEN(ap)));

	/* don't know know about the address formats */
	if (!ndo->ndo_vflag) {
	goto out;
	}
	}

	/* print operation */
	ND_PRINT((ndo, "%s%s ",
	ndo->ndo_vflag ? ", " : "",
	tok2str(arpop_values, "Unknown (%u)", op)));

	switch (op) {

	case ARPOP_REQUEST:
	ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, TPA(ap))));
	if (memcmp((const char )ezero, (const char )THA(ap), HRD_LEN(ap)) != 0)
	ND_PRINT((ndo, " (%s)",
	linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap))));
	ND_PRINT((ndo, " tell %s", ipaddr_string(ndo, SPA(ap))));
	break;

	case ARPOP_REPLY:
	ND_PRINT((ndo, "%s is-at %s",
	ipaddr_string(ndo, SPA(ap)),
	linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
	break;

	case ARPOP_REVREQUEST:
	ND_PRINT((ndo, "who-is %s tell %s",
	linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
	linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
	break;

	case ARPOP_REVREPLY:
	ND_PRINT((ndo, "%s at %s",
	linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
	ipaddr_string(ndo, TPA(ap))));
	break;

	case ARPOP_INVREQUEST:
	ND_PRINT((ndo, "who-is %s tell %s",
	linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
	linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
	break;

	case ARPOP_INVREPLY:
	ND_PRINT((ndo,"%s at %s",
	linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)),
	ipaddr_string(ndo, SPA(ap))));
	break;

	default:
	ND_DEFAULTPRINT((const u_char *)ap, caplen);
	return;
	}

	out:
	ND_PRINT((ndo, ", length %u", length));

	return;
	trunc:
	ND_PRINT((ndo, "%s", tstr));
	}

	/*
	* Local Variables:
	* c-style: bsd
	* End:
	*/