The Tcpdump Group git mirrors - tcpdump/blob - print-ipfc.c

   1 /*
   2  * Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <tcpdump-stdinc.h>
  27
  28 #include <string.h>
  29
  30 #include "netdissect.h"
  31 #include "addrtoname.h"
  32
  33 #include "ether.h"
  34
  35 /*
  36  * RFC 2625 IP-over-Fibre Channel.
  37  */
  38
  39 struct ipfc_header {
  40         u_char  ipfc_dhost[8];
  41         u_char  ipfc_shost[8];
  42 };
  43
  44 #define IPFC_HDRLEN 16
  45
  46 /* Extract src, dst addresses */
  47 static inline void
  48 extract_ipfc_addrs(const struct ipfc_header *ipfcp, char *ipfcsrc,
  49     char *ipfcdst)
  50 {
  51         /*
  52          * We assume that, as per RFC 2625, the lower 48 bits of the
  53          * source and destination addresses are MAC addresses.
  54          */
  55         memcpy(ipfcdst, (const char *)&ipfcp->ipfc_dhost[2], 6);
  56         memcpy(ipfcsrc, (const char *)&ipfcp->ipfc_shost[2], 6);
  57 }
  58
  59 /*
  60  * Print the Network_Header
  61  */
  62 static inline void
  63 ipfc_hdr_print(netdissect_options *ndo,
  64            register const struct ipfc_header *ipfcp _U_,
  65            register u_int length, register const u_char *ipfcsrc,
  66            register const u_char *ipfcdst)
  67 {
  68         const char *srcname, *dstname;
  69
  70         srcname = etheraddr_string(ndo, ipfcsrc);
  71         dstname = etheraddr_string(ndo, ipfcdst);
  72
  73         /*
  74          * XXX - should we show the upper 16 bits of the addresses?
  75          * Do so only if "vflag" is set?
  76          * Section 3.3 "FC Port and Node Network Addresses" says that
  77          *
  78          *    In this specification, both the Source and Destination
  79          *    4-bit NAA identifiers SHALL be set to binary '0001'
  80          *    indicating that an IEEE 48-bit MAC address is contained
  81          *    in the lower 48 bits of the network address fields. The
  82          *    high order 12 bits in the network address fields SHALL
  83          *    be set to 0x0000.
  84          *
  85          * so, for captures following this specification, the upper 16
  86          * bits should be 0x1000, followed by a MAC address.
  87          */
  88         ND_PRINT((ndo, "%s > %s, length %u: ", srcname, dstname, length));
  89 }
  90
  91 static u_int
  92 ipfc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen)
  93 {
  94         const struct ipfc_header *ipfcp = (const struct ipfc_header *)p;
  95         struct ether_header ehdr;
  96         int llc_hdrlen;
  97
  98         if (caplen < IPFC_HDRLEN) {
  99                 ND_PRINT((ndo, "[|ipfc]"));
 100                 return (caplen);
 101         }
 102         /*
 103          * Get the network addresses into a canonical form
 104          */
 105         extract_ipfc_addrs(ipfcp, (char *)ESRC(&ehdr), (char *)EDST(&ehdr));
 106
 107         if (ndo->ndo_eflag)
 108                 ipfc_hdr_print(ndo, ipfcp, length, ESRC(&ehdr), EDST(&ehdr));
 109
 110         /* Skip over Network_Header */
 111         length -= IPFC_HDRLEN;
 112         p += IPFC_HDRLEN;
 113         caplen -= IPFC_HDRLEN;
 114
 115         /* Try to print the LLC-layer header & higher layers */
 116         llc_hdrlen = llc_print(ndo, p, length, caplen, ESRC(&ehdr), EDST(&ehdr));
 117         if (llc_hdrlen < 0) {
 118                 /*
 119                  * Some kinds of LLC packet we cannot
 120                  * handle intelligently
 121                  */
 122                 if (!ndo->ndo_suppress_default_print)
 123                         ND_DEFAULTPRINT(p, caplen);
 124                 llc_hdrlen = -llc_hdrlen;
 125         }
 126         return (IPFC_HDRLEN + llc_hdrlen);
 127 }
 128
 129 /*
 130  * This is the top level routine of the printer.  'p' points
 131  * to the Network_Header of the packet, 'h->ts' is the timestamp,
 132  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 133  * is the number of bytes actually captured.
 134  */
 135 u_int
 136 ipfc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p)
 137 {
 138         return (ipfc_print(ndo, p, h->len, h->caplen));
 139 }