1 /* 2 * Marko Kiiskila carnil@cs.tut.fi 3 * 4 * Tampere University of Technology - Telecommunications Laboratory 5 * 6 * Permission to use, copy, modify and distribute this 7 * software and its documentation is hereby granted, 8 * provided that both the copyright notice and this 9 * permission notice appear in all copies of the software, 10 * derivative works or modified versions, and any portions 11 * thereof, that both notices appear in supporting 12 * documentation, and that the use of this software is 13 * acknowledged in any publications resulting from using 14 * the software. 15 * 16 * TUT ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 17 * CONDITION AND DISCLAIMS ANY LIABILITY OF ANY KIND FOR 18 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS 19 * SOFTWARE. 20 * 21 */ 22 23 #include <sys/cdefs.h> 24 #ifndef lint 25 __RCSID("$NetBSD: print-cip.c,v 1.7 2023/08/17 20:19:40 christos Exp $"); 26 #endif 27 28 /* \summary: Linux Classical IP over ATM printer */ 29 30 #ifdef HAVE_CONFIG_H 31 #include <config.h> 32 #endif 33 34 #include <string.h> 35 36 #include "netdissect-stdinc.h" 37 38 #define ND_LONGJMP_FROM_TCHECK 39 #include "netdissect.h" 40 #include "addrtoname.h" 41 42 static const unsigned char rfcllc[] = { 43 0xaa, /* DSAP: non-ISO */ 44 0xaa, /* SSAP: non-ISO */ 45 0x03, /* Ctrl: Unnumbered Information Command PDU */ 46 0x00, /* OUI: EtherType */ 47 0x00, 48 0x00 }; 49 50 /* 51 * This is the top level routine of the printer. 'p' points 52 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp, 53 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 54 * is the number of bytes actually captured. 55 */ 56 void 57 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 58 { 59 u_int caplen = h->caplen; 60 u_int length = h->len; 61 int llc_hdrlen; 62 63 ndo->ndo_protocol = "cip"; 64 65 if (ndo->ndo_eflag) 66 /* 67 * There is no MAC-layer header, so just print the length. 68 */ 69 ND_PRINT("%u: ", length); 70 71 ND_TCHECK_LEN(p, sizeof(rfcllc)); 72 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) { 73 /* 74 * LLC header is present. Try to print it & higher layers. 75 */ 76 llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); 77 if (llc_hdrlen < 0) { 78 /* packet type not known, print raw packet */ 79 if (!ndo->ndo_suppress_default_print) 80 ND_DEFAULTPRINT(p, caplen); 81 llc_hdrlen = -llc_hdrlen; 82 } 83 } else { 84 /* 85 * LLC header is absent; treat it as just IP. 86 */ 87 llc_hdrlen = 0; 88 ip_print(ndo, p, length); 89 } 90 91 ndo->ndo_ll_hdr_len += llc_hdrlen; 92 } 93