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 /* \summary: IP over Fibre Channel printer */
  23
  24 /* specification: RFC 2625 */
  25
  26 #include <config.h>
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include <string.h>
  31
  32 #define ND_LONGJMP_FROM_TCHECK
  33 #include "netdissect.h"
  34 #include "addrtoname.h"
  35
  36
  37 struct ipfc_header {
  38         nd_byte ipfc_dhost[2+MAC48_LEN];
  39         nd_byte ipfc_shost[2+MAC48_LEN];
  40 };
  41
  42 #define IPFC_HDRLEN 16
  43
  44 /* Extract src, dst addresses */
  45 static void
  46 extract_ipfc_addrs(const struct ipfc_header *ipfcp, char *ipfcsrc,
  47                    char *ipfcdst)
  48 {
  49         /*
  50          * We assume that, as per RFC 2625, the lower 48 bits of the
  51          * source and destination addresses are MAC addresses.
  52          */
  53         memcpy(ipfcdst, (const char *)&ipfcp->ipfc_dhost[2], MAC48_LEN);
  54         memcpy(ipfcsrc, (const char *)&ipfcp->ipfc_shost[2], MAC48_LEN);
  55 }
  56
  57 /*
  58  * Print the Network_Header
  59  */
  60 static void
  61 ipfc_hdr_print(netdissect_options *ndo,
  62                const struct ipfc_header *ipfcp _U_, u_int length,
  63                const u_char *ipfcsrc, const u_char *ipfcdst)
  64 {
  65         const char *srcname, *dstname;
  66
  67         srcname = mac48_string(ndo, ipfcsrc);
  68         dstname = mac48_string(ndo, ipfcdst);
  69
  70         /*
  71          * XXX - should we show the upper 16 bits of the addresses?
  72          * Do so only if "vflag" is set?
  73          * Section 3.3 "FC Port and Node Network Addresses" says that
  74          *
  75          *    In this specification, both the Source and Destination
  76          *    4-bit NAA identifiers SHALL be set to binary '0001'
  77          *    indicating that an IEEE 48-bit MAC address is contained
  78          *    in the lower 48 bits of the network address fields. The
  79          *    high order 12 bits in the network address fields SHALL
  80          *    be set to 0x0000.
  81          *
  82          * so, for captures following this specification, the upper 16
  83          * bits should be 0x1000, followed by a MAC address.
  84          */
  85         ND_PRINT("%s > %s, length %u: ", srcname, dstname, length);
  86 }
  87
  88 static u_int
  89 ipfc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen)
  90 {
  91         const struct ipfc_header *ipfcp = (const struct ipfc_header *)p;
  92         nd_mac48 srcmac, dstmac;
  93         struct lladdr_info src, dst;
  94         int llc_hdrlen;
  95
  96         ndo->ndo_protocol = "ipfc";
  97         ND_TCHECK_LEN(p, IPFC_HDRLEN);
  98         /*
  99          * Get the network addresses into a canonical form
 100          */
 101         extract_ipfc_addrs(ipfcp, (char *)srcmac, (char *)dstmac);
 102
 103         if (ndo->ndo_eflag)
 104                 ipfc_hdr_print(ndo, ipfcp, length, srcmac, dstmac);
 105
 106         src.addr = srcmac;
 107         src.addr_string = mac48_string;
 108         dst.addr = dstmac;
 109         dst.addr_string = mac48_string;
 110
 111         /* Skip over Network_Header */
 112         length -= IPFC_HDRLEN;
 113         p += IPFC_HDRLEN;
 114         caplen -= IPFC_HDRLEN;
 115
 116         /* Try to print the LLC-layer header & higher layers */
 117         llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
 118         if (llc_hdrlen < 0) {
 119                 /*
 120                  * Some kinds of LLC packet we cannot
 121                  * handle intelligently
 122                  */
 123                 if (!ndo->ndo_suppress_default_print)
 124                         ND_DEFAULTPRINT(p, caplen);
 125                 llc_hdrlen = -llc_hdrlen;
 126         }
 127         return (IPFC_HDRLEN + llc_hdrlen);
 128 }
 129
 130 /*
 131  * This is the top level routine of the printer.  'p' points
 132  * to the Network_Header of the packet, 'h->ts' is the timestamp,
 133  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 134  * is the number of bytes actually captured.
 135  */
 136 void
 137 ipfc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
 138 {
 139         ndo->ndo_protocol = "ipfc";
 140         ndo->ndo_ll_hdr_len += ipfc_print(ndo, p, h->len, h->caplen);
 141 }