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 1.8 2024/09/02 16:15:30 christos Exp $"); 26 #endif 27 28 /* \summary: Linux Classical IP over ATM printer */ 29 30 #include <config.h> 31 32 #include <string.h> 33 34 #include "netdissect-stdinc.h" 35 36 #define ND_LONGJMP_FROM_TCHECK 37 #include "netdissect.h" 38 #include "addrtoname.h" 39 40 static const unsigned char rfcllc[] = { 41 0xaa, /* DSAP: non-ISO */ 42 0xaa, /* SSAP: non-ISO */ 43 0x03, /* Ctrl: Unnumbered Information Command PDU */ 44 0x00, /* OUI: EtherType */ 45 0x00, 46 0x00 }; 47 48 /* 49 * This is the top level routine of the printer. 'p' points 50 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp, 51 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 52 * is the number of bytes actually captured. 53 */ 54 void 55 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 56 { 57 u_int caplen = h->caplen; 58 u_int length = h->len; 59 int llc_hdrlen; 60 61 ndo->ndo_protocol = "cip"; 62 63 if (ndo->ndo_eflag) 64 /* 65 * There is no MAC-layer header, so just print the length. 66 */ 67 ND_PRINT("%u: ", length); 68 69 ND_TCHECK_LEN(p, sizeof(rfcllc)); 70 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) { 71 /* 72 * LLC header is present. Try to print it & higher layers. 73 */ 74 llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); 75 if (llc_hdrlen < 0) { 76 /* packet type not known, print raw packet */ 77 if (!ndo->ndo_suppress_default_print) 78 ND_DEFAULTPRINT(p, caplen); 79 llc_hdrlen = -llc_hdrlen; 80 } 81 } else { 82 /* 83 * LLC header is absent; treat it as just IP. 84 */ 85 llc_hdrlen = 0; 86 ip_print(ndo, p, length); 87 } 88 89 ndo->ndo_ll_hdr_len += llc_hdrlen; 90 } 91