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: Classical-IP over ATM printer */ 24 25 #ifdef HAVE_CONFIG_H 26 #include "config.h" 27 #endif 28 29 #include <string.h> 30 31 #include <netdissect-stdinc.h> 32 33 #include "netdissect.h" 34 #include "addrtoname.h" 35 36 static const unsigned char rfcllc[] = { 37 0xaa, /* DSAP: non-ISO */ 38 0xaa, /* SSAP: non-ISO */ 39 0x03, /* Ctrl: Unnumbered Information Command PDU */ 40 0x00, /* OUI: EtherType */ 41 0x00, 42 0x00 }; 43 44 static inline void 45 cip_print(netdissect_options *ndo, u_int length) 46 { 47 /* 48 * There is no MAC-layer header, so just print the length. 49 */ 50 ND_PRINT((ndo, "%u: ", length)); 51 } 52 53 /* 54 * This is the top level routine of the printer. 'p' points 55 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp, 56 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 57 * is the number of bytes actually captured. 58 */ 59 u_int 60 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 61 { 62 u_int caplen = h->caplen; 63 u_int length = h->len; 64 size_t cmplen; 65 int llc_hdrlen; 66 67 cmplen = sizeof(rfcllc); 68 if (cmplen > caplen) 69 cmplen = caplen; 70 if (cmplen > length) 71 cmplen = length; 72 73 if (ndo->ndo_eflag) 74 cip_print(ndo, length); 75 76 if (cmplen == 0) { 77 ND_PRINT((ndo, "[|cip]")); 78 return 0; 79 } 80 if (memcmp(rfcllc, p, cmplen) == 0) { 81 /* 82 * LLC header is present. Try to print it & higher layers. 83 */ 84 llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); 85 if (llc_hdrlen < 0) { 86 /* packet type not known, print raw packet */ 87 if (!ndo->ndo_suppress_default_print) 88 ND_DEFAULTPRINT(p, caplen); 89 llc_hdrlen = -llc_hdrlen; 90 } 91 } else { 92 /* 93 * LLC header is absent; treat it as just IP. 94 */ 95 llc_hdrlen = 0; 96 ip_print(ndo, p, length); 97 } 98 99 return (llc_hdrlen); 100 } 101 102 103 /* 104 * Local Variables: 105 * c-style: whitesmith 106 * c-basic-offset: 8 107 * End: 108 */ 109