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 1.5 2017/01/24 23:29:13 christos Exp $"); 26 #endif 27 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 #include <string.h> 33 34 #include <netdissect-stdinc.h> 35 36 #include "netdissect.h" 37 #include "addrtoname.h" 38 39 #define RFC1483LLC_LEN 8 40 41 static const unsigned char rfcllc[] = { 42 0xaa, /* DSAP: non-ISO */ 43 0xaa, /* SSAP: non-ISO */ 44 0x03, /* Ctrl: Unnumbered Information Command PDU */ 45 0x00, /* OUI: EtherType */ 46 0x00, 47 0x00 }; 48 49 static inline void 50 cip_print(netdissect_options *ndo, int length) 51 { 52 /* 53 * There is no MAC-layer header, so just print the length. 54 */ 55 ND_PRINT((ndo, "%d: ", length)); 56 } 57 58 /* 59 * This is the top level routine of the printer. 'p' points 60 * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp, 61 * 'h->len' is the length of the packet off the wire, and 'h->caplen' 62 * is the number of bytes actually captured. 63 */ 64 u_int 65 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) 66 { 67 u_int caplen = h->caplen; 68 u_int length = h->len; 69 int llc_hdrlen; 70 71 if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) { 72 ND_PRINT((ndo, "[|cip]")); 73 return (0); 74 } 75 76 if (ndo->ndo_eflag) 77 cip_print(ndo, length); 78 79 if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) { 80 /* 81 * LLC header is present. Try to print it & higher layers. 82 */ 83 llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL); 84 if (llc_hdrlen < 0) { 85 /* packet type not known, print raw packet */ 86 if (!ndo->ndo_suppress_default_print) 87 ND_DEFAULTPRINT(p, caplen); 88 llc_hdrlen = -llc_hdrlen; 89 } 90 } else { 91 /* 92 * LLC header is absent; treat it as just IP. 93 */ 94 llc_hdrlen = 0; 95 ip_print(ndo, p, length); 96 } 97 98 return (llc_hdrlen); 99 } 100 101 102 /* 103 * Local Variables: 104 * c-style: whitesmith 105 * c-basic-offset: 8 106 * End: 107 */ 108