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      1 /*
      2  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that: (1) source code distributions
      7  * retain the above copyright notice and this paragraph in its entirety, (2)
      8  * distributions including binary code include the above copyright notice and
      9  * this paragraph in its entirety in the documentation or other materials
     10  * provided with the distribution, and (3) all advertising materials mentioning
     11  * features or use of this software display the following acknowledgement:
     12  * ``This product includes software developed by the University of California,
     13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
     14  * the University nor the names of its contributors may be used to endorse
     15  * or promote products derived from this software without specific prior
     16  * written permission.
     17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
     18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
     19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
     20  */
     21 
     22 /* \summary: IPv6 fragmentation header printer */
     23 
     24 #ifdef HAVE_CONFIG_H
     25 #include "config.h"
     26 #endif
     27 
     28 #include <netdissect-stdinc.h>
     29 
     30 #include "netdissect.h"
     31 #include "extract.h"
     32 
     33 #include "ip6.h"
     34 
     35 int
     36 frag6_print(netdissect_options *ndo, register const u_char *bp, register const u_char *bp2)
     37 {
     38 	register const struct ip6_frag *dp;
     39 	register const struct ip6_hdr *ip6;
     40 
     41 	dp = (const struct ip6_frag *)bp;
     42 	ip6 = (const struct ip6_hdr *)bp2;
     43 
     44 	ND_TCHECK(*dp);
     45 
     46 	if (ndo->ndo_vflag) {
     47 		ND_PRINT((ndo, "frag (0x%08x:%d|%ld)",
     48 		       EXTRACT_32BITS(&dp->ip6f_ident),
     49 		       EXTRACT_16BITS(&dp->ip6f_offlg) & IP6F_OFF_MASK,
     50 		       sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen) -
     51 			       (long)(bp - bp2) - sizeof(struct ip6_frag)));
     52 	} else {
     53 		ND_PRINT((ndo, "frag (%d|%ld)",
     54 		       EXTRACT_16BITS(&dp->ip6f_offlg) & IP6F_OFF_MASK,
     55 		       sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen) -
     56 			       (long)(bp - bp2) - sizeof(struct ip6_frag)));
     57 	}
     58 
     59 	/* it is meaningless to decode non-first fragment */
     60 	if ((EXTRACT_16BITS(&dp->ip6f_offlg) & IP6F_OFF_MASK) != 0)
     61 		return -1;
     62 	else
     63 	{
     64 		ND_PRINT((ndo, " "));
     65 		return sizeof(struct ip6_frag);
     66 	}
     67 trunc:
     68 	ND_PRINT((ndo, "[|frag]"));
     69 	return -1;
     70 }
     71