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 /* \summary: Linux Classical IP over ATM printer */ 24 25 #include <config.h> 26 27 #include <string.h> 28 29 #include "netdissect-stdinc.h" 30 31 #define ND_LONGJMP_FROM_TCHECK 32 #include "netdissect.h" 33 #include "addrtoname.h" 34 35 static const unsigned char rfcllc[] = { 36 0xaa, /* DSAP: non-ISO */ 37 0xaa, /* SSAP: non-ISO */ 38 0x03, /* Ctrl: Unnumbered Information Command PDU */ 39 0x00, /* OUI: EtherType */ 40 0x00, 41 0x00 }; 42 43 /* 44 * This is the top level routine of the printer. 'p' points 45 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp, 46 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 47 * is the number of bytes actually captured. 48 */ 49 void 50 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 51 { 52 u_int caplen = h->caplen; 53 u_int length = h->len; 54 int llc_hdrlen; 55 56 ndo->ndo_protocol = "cip"; 57 58 if (ndo->ndo_eflag) 59 /* 60 * There is no MAC-layer header, so just print the length. 61 */ 62 ND_PRINT("%u: ", length); 63 64 ND_TCHECK_LEN(p, sizeof(rfcllc)); 65 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) { 66 /* 67 * LLC header is present. Try to print it & higher layers. 68 */ 69 llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); 70 if (llc_hdrlen < 0) { 71 /* packet type not known, print raw packet */ 72 if (!ndo->ndo_suppress_default_print) 73 ND_DEFAULTPRINT(p, caplen); 74 llc_hdrlen = -llc_hdrlen; 75 } 76 } else { 77 /* 78 * LLC header is absent; treat it as just IP. 79 */ 80 llc_hdrlen = 0; 81 ip_print(ndo, p, length); 82 } 83 84 ndo->ndo_ll_hdr_len += llc_hdrlen; 85 } 86