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 #include <sys/cdefs.h> 23 #ifndef lint 24 __RCSID("$NetBSD: print-frag6.c,v 1.9 2024/09/02 16:15:31 christos Exp $"); 25 #endif 26 27 /* \summary: IPv6 fragmentation header printer */ 28 29 #include <config.h> 30 31 #include "netdissect-stdinc.h" 32 33 #include "netdissect.h" 34 #include "extract.h" 35 36 #include "ip6.h" 37 38 int 39 frag6_print(netdissect_options *ndo, const u_char *bp, const u_char *bp2) 40 { 41 const struct ip6_frag *dp; 42 const struct ip6_hdr *ip6; 43 44 ndo->ndo_protocol = "frag6"; 45 dp = (const struct ip6_frag *)bp; 46 ip6 = (const struct ip6_hdr *)bp2; 47 48 ND_PRINT("frag ("); 49 if (ndo->ndo_vflag) 50 ND_PRINT("0x%08x:", GET_BE_U_4(dp->ip6f_ident)); 51 ND_PRINT("%u|", GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK); 52 if ((bp - bp2) + sizeof(struct ip6_frag) > 53 sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen)) 54 ND_PRINT("[length < 0] (invalid))"); 55 else 56 ND_PRINT("%zu)", 57 sizeof(struct ip6_hdr) + GET_BE_U_2(ip6->ip6_plen) - 58 (bp - bp2) - sizeof(struct ip6_frag)); 59 60 /* it is meaningless to decode non-first fragment */ 61 if ((GET_BE_U_2(dp->ip6f_offlg) & IP6F_OFF_MASK) != 0) 62 return -1; 63 else { 64 ND_PRINT(" "); 65 return sizeof(struct ip6_frag); 66 } 67 } 68