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 #define NETDISSECT_REWORKED 24 #ifdef HAVE_CONFIG_H 25 #include "config.h" 26 #endif 27 28 #include <string.h> 29 30 #include <tcpdump-stdinc.h> 31 32 #include "interface.h" 33 #include "addrtoname.h" 34 35 #define RFC1483LLC_LEN 8 36 37 static const unsigned char rfcllc[] = { 38 0xaa, /* DSAP: non-ISO */ 39 0xaa, /* SSAP: non-ISO */ 40 0x03, /* Ctrl: Unnumbered Information Command PDU */ 41 0x00, /* OUI: EtherType */ 42 0x00, 43 0x00 }; 44 45 static inline void 46 cip_print(netdissect_options *ndo, int length) 47 { 48 /* 49 * There is no MAC-layer header, so just print the length. 50 */ 51 ND_PRINT((ndo, "%d: ", length)); 52 } 53 54 /* 55 * This is the top level routine of the printer. 'p' points 56 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp, 57 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 58 * is the number of bytes actually captured. 59 */ 60 u_int 61 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 62 { 63 u_int caplen = h->caplen; 64 u_int length = h->len; 65 u_short extracted_ethertype; 66 67 if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) { 68 ND_PRINT((ndo, "[|cip]")); 69 return (0); 70 } 71 72 if (ndo->ndo_eflag) 73 cip_print(ndo, length); 74 75 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) { 76 /* 77 * LLC header is present. Try to print it & higher layers. 78 */ 79 if (llc_print(ndo, p, length, caplen, NULL, NULL, 80 &extracted_ethertype) == 0) { 81 /* ether_type not known, print raw packet */ 82 if (!ndo->ndo_eflag) 83 cip_print(ndo, length); 84 if (extracted_ethertype) { 85 ND_PRINT((ndo, "(LLC %s) ", 86 etherproto_string(htons(extracted_ethertype)))); 87 } 88 if (!ndo->ndo_suppress_default_print) 89 ND_DEFAULTPRINT(p, caplen); 90 } 91 } else { 92 /* 93 * LLC header is absent; treat it as just IP. 94 */ 95 ip_print(ndo, p, length); 96 } 97 98 return (0); 99 } 100 101 102 /* 103 * Local Variables: 104 * c-style: whitesmith 105 * c-basic-offset: 8 106 * End: 107 */ 108