333 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			333 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Copyright (c) 1995, 1996
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|  *	The Regents of the University of California.  All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that: (1) source code distributions
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|  * retain the above copyright notice and this paragraph in its entirety, (2)
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|  * distributions including binary code include the above copyright notice and
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|  * this paragraph in its entirety in the documentation or other materials
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|  * provided with the distribution, and (3) all advertising materials mentioning
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|  * features or use of this software display the following acknowledgement:
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|  * ``This product includes software developed by the University of California,
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|  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
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|  * the University nor the names of its contributors may be used to endorse
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|  * or promote products derived from this software without specific prior
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|  * written permission.
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|  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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|  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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|  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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|  */
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| 
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| /* \summary: Distance Vector Multicast Routing Protocol printer */
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| 
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| #ifdef HAVE_CONFIG_H
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| #include <config.h>
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| #endif
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| 
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| #include "netdissect-stdinc.h"
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| 
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| #include "netdissect.h"
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| #include "extract.h"
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| #include "addrtoname.h"
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| 
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| /*
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|  * See: RFC 1075 and draft-ietf-idmr-dvmrp-v3
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|  *
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|  * DVMRP message types and flag values shamelessly stolen from
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|  * mrouted/dvmrp.h.
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|  */
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| #define DVMRP_PROBE		1	/* for finding neighbors */
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| #define DVMRP_REPORT		2	/* for reporting some or all routes */
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| #define DVMRP_ASK_NEIGHBORS	3	/* sent by mapper, asking for a list */
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| 					/* of this router's neighbors */
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| #define DVMRP_NEIGHBORS		4	/* response to such a request */
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| #define DVMRP_ASK_NEIGHBORS2	5	/* as above, want new format reply */
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| #define DVMRP_NEIGHBORS2	6
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| #define DVMRP_PRUNE		7	/* prune message */
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| #define DVMRP_GRAFT		8	/* graft message */
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| #define DVMRP_GRAFT_ACK		9	/* graft acknowledgement */
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| static const struct tok dvmrp_msgtype_str[] = {
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| 	{ DVMRP_PROBE,          "Probe"              },
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| 	{ DVMRP_REPORT,         "Report"             },
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| 	{ DVMRP_ASK_NEIGHBORS,  "Ask-neighbors(old)" },
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| 	{ DVMRP_NEIGHBORS,      "Neighbors(old)"     },
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| 	{ DVMRP_ASK_NEIGHBORS2, "Ask-neighbors2"     },
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| 	{ DVMRP_NEIGHBORS2,     "Neighbors2"         },
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| 	{ DVMRP_PRUNE,          "Prune"              },
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| 	{ DVMRP_GRAFT,          "Graft"              },
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| 	{ DVMRP_GRAFT_ACK,      "Graft-ACK"          },
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| 	{ 0, NULL }
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| };
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| 
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| /*
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|  * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
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|  */
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| #define DVMRP_NF_TUNNEL		0x01	/* neighbors reached via tunnel */
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| #define DVMRP_NF_SRCRT		0x02	/* tunnel uses IP source routing */
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| #define DVMRP_NF_DOWN		0x10	/* kernel state of interface */
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| #define DVMRP_NF_DISABLED	0x20	/* administratively disabled */
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| #define DVMRP_NF_QUERIER	0x40	/* I am the subnet's querier */
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| 
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| static void print_probe(netdissect_options *, const u_char *, u_int);
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| static void print_report(netdissect_options *, const u_char *, u_int);
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| static void print_neighbors(netdissect_options *, const u_char *, u_int);
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| static void print_neighbors2(netdissect_options *, const u_char *, u_int, uint8_t, uint8_t);
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| 
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| void
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| dvmrp_print(netdissect_options *ndo,
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|             const u_char *bp, u_int len)
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| {
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| 	u_char type;
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| 	uint8_t major_version, minor_version;
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| 
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| 	ndo->ndo_protocol = "dvmrp";
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| 	if (len < 8) {
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| 		ND_PRINT(" [length %u < 8]", len);
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| 		goto invalid;
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| 	}
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| 
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| 	type = GET_U_1(bp + 1);
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| 
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| 	/* Skip IGMP header */
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| 	bp += 8;
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| 	len -= 8;
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| 
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| 	ND_PRINT(" %s", tok2str(dvmrp_msgtype_str, "[type %u]", type));
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| 	switch (type) {
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| 
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| 	case DVMRP_PROBE:
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| 		if (ndo->ndo_vflag) {
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| 			print_probe(ndo, bp, len);
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| 		}
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| 		break;
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| 
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| 	case DVMRP_REPORT:
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| 		if (ndo->ndo_vflag > 1) {
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| 			print_report(ndo, bp, len);
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| 		}
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| 		break;
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| 
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| 	case DVMRP_NEIGHBORS:
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| 		print_neighbors(ndo, bp, len);
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| 		break;
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| 
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| 	case DVMRP_NEIGHBORS2:
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| 		/*
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| 		 * extract version from IGMP group address field
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| 		 */
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| 		bp -= 4;
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| 		major_version = GET_U_1(bp + 3);
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| 		minor_version = GET_U_1(bp + 2);
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| 		bp += 4;
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| 		print_neighbors2(ndo, bp, len, major_version, minor_version);
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| 		break;
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| 
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| 	case DVMRP_PRUNE:
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| 		ND_PRINT(" src %s grp %s", GET_IPADDR_STRING(bp), GET_IPADDR_STRING(bp + 4));
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| 		ND_PRINT(" timer ");
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| 		unsigned_relts_print(ndo, GET_BE_U_4(bp + 8));
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| 		break;
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| 
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| 	case DVMRP_GRAFT:
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| 		ND_PRINT(" src %s grp %s", GET_IPADDR_STRING(bp), GET_IPADDR_STRING(bp + 4));
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| 		break;
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| 
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| 	case DVMRP_GRAFT_ACK:
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| 		ND_PRINT(" src %s grp %s", GET_IPADDR_STRING(bp), GET_IPADDR_STRING(bp + 4));
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| 		break;
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| 	}
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| 	return;
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| 
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| invalid:
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| 	nd_print_invalid(ndo);
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| }
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| 
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| static void
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| print_report(netdissect_options *ndo,
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|              const u_char *bp,
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|              u_int len)
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| {
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| 	uint32_t mask, origin;
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| 	u_int metric, done;
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| 	u_int i, width;
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| 
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| 	while (len > 0) {
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| 		if (len < 3) {
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| 			ND_PRINT(" [length %u < 3]", len);
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| 			goto invalid;
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| 		}
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| 		mask = (uint32_t)0xff << 24 | GET_U_1(bp) << 16 |
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| 			GET_U_1(bp + 1) << 8 | GET_U_1(bp + 2);
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| 		width = 1;
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| 		if (GET_U_1(bp))
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| 			width = 2;
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| 		if (GET_U_1(bp + 1))
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| 			width = 3;
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| 		if (GET_U_1(bp + 2))
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| 			width = 4;
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| 
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| 		ND_PRINT("\n\tMask %s", intoa(htonl(mask)));
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| 		bp += 3;
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| 		len -= 3;
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| 		do {
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| 			if (len < width + 1) {
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| 				ND_PRINT("\n\t  [Truncated Report]");
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| 				goto invalid;
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| 			}
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| 			origin = 0;
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| 			for (i = 0; i < width; ++i) {
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| 				origin = origin << 8 | GET_U_1(bp);
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| 				bp++;
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| 			}
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| 			for ( ; i < 4; ++i)
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| 				origin <<= 8;
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| 
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| 			metric = GET_U_1(bp);
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| 			bp++;
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| 			done = metric & 0x80;
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| 			metric &= 0x7f;
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| 			ND_PRINT("\n\t  %s metric %u", intoa(htonl(origin)),
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| 				metric);
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| 			len -= width + 1;
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| 		} while (!done);
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| 	}
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| 	return;
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| 
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| invalid:
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| 	nd_print_invalid(ndo);
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| }
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| 
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| static void
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| print_probe(netdissect_options *ndo,
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|             const u_char *bp,
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|             u_int len)
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| {
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| 	if (len < 4) {
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| 		ND_PRINT(" [full length %u < 4]", len);
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| 		goto invalid;
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| 	}
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| 	ND_PRINT(ndo->ndo_vflag > 1 ? "\n\t" : " ");
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| 	ND_PRINT("genid %u", GET_BE_U_4(bp));
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| 	if (ndo->ndo_vflag < 2)
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| 		return;
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| 
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| 	bp += 4;
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| 	len -= 4;
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| 	while (len > 0) {
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| 		if (len < 4) {
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| 			ND_PRINT("[remaining length %u < 4]", len);
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| 			goto invalid;
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| 		}
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| 		ND_PRINT("\n\tneighbor %s", GET_IPADDR_STRING(bp));
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| 		bp += 4; len -= 4;
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| 	}
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| 	return;
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| 
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| invalid:
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| 	nd_print_invalid(ndo);
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| }
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| 
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| static void
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| print_neighbors(netdissect_options *ndo,
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|                 const u_char *bp,
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|                 u_int len)
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| {
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| 	const u_char *laddr;
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| 	u_char metric;
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| 	u_char thresh;
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| 	int ncount;
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| 
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| 	while (len > 0) {
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| 		if (len < 7) {
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| 			ND_PRINT(" [length %u < 7]", len);
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| 			goto invalid;
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| 		}
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| 		laddr = bp;
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| 		bp += 4;
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| 		metric = GET_U_1(bp);
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| 		bp++;
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| 		thresh = GET_U_1(bp);
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| 		bp++;
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| 		ncount = GET_U_1(bp);
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| 		bp++;
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| 		len -= 7;
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| 		while (--ncount >= 0) {
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| 			if (len < 4) {
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| 				ND_PRINT(" [length %u < 4]", len);
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| 				goto invalid;
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| 			}
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| 			ND_PRINT(" [%s ->", GET_IPADDR_STRING(laddr));
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| 			ND_PRINT(" %s, (%u/%u)]",
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| 				   GET_IPADDR_STRING(bp), metric, thresh);
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| 			bp += 4;
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| 			len -= 4;
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| 		}
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| 	}
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| 	return;
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| 
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| invalid:
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| 	nd_print_invalid(ndo);
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| }
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| 
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| static void
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| print_neighbors2(netdissect_options *ndo,
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|                  const u_char *bp,
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|                  u_int len, uint8_t major_version,
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|                  uint8_t minor_version)
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| {
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| 	const u_char *laddr;
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| 	u_char metric, thresh, flags;
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| 	int ncount;
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| 
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| 	ND_PRINT(" (v %u.%u):", major_version, minor_version);
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| 
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| 	while (len > 0) {
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| 		if (len < 8) {
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| 			ND_PRINT(" [length %u < 8]", len);
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| 			goto invalid;
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| 		}
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| 		laddr = bp;
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| 		bp += 4;
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| 		metric = GET_U_1(bp);
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| 		bp++;
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| 		thresh = GET_U_1(bp);
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| 		bp++;
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| 		flags = GET_U_1(bp);
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| 		bp++;
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| 		ncount = GET_U_1(bp);
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| 		bp++;
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| 		len -= 8;
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| 		while (--ncount >= 0 && len > 0) {
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| 			if (len < 4) {
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| 				ND_PRINT(" [length %u < 4]", len);
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| 				goto invalid;
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| 			}
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| 			ND_PRINT(" [%s -> ", GET_IPADDR_STRING(laddr));
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| 			ND_PRINT("%s (%u/%u", GET_IPADDR_STRING(bp),
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| 				     metric, thresh);
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| 			if (flags & DVMRP_NF_TUNNEL)
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| 				ND_PRINT("/tunnel");
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| 			if (flags & DVMRP_NF_SRCRT)
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| 				ND_PRINT("/srcrt");
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| 			if (flags & DVMRP_NF_QUERIER)
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| 				ND_PRINT("/querier");
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| 			if (flags & DVMRP_NF_DISABLED)
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| 				ND_PRINT("/disabled");
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| 			if (flags & DVMRP_NF_DOWN)
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| 				ND_PRINT("/down");
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| 			ND_PRINT(")]");
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| 			bp += 4;
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| 			len -= 4;
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| 		}
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| 		if (ncount != -1) {
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| 			ND_PRINT(" [invalid ncount]");
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| 			goto invalid;
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| 		}
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| 	}
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| 	return;
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| 
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| invalid:
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| 	nd_print_invalid(ndo);
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| }
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