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      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 #ifdef HAVE_CONFIG_H
     27 #include "config.h"
     28 #endif
     29 
     30 #include <netdissect-stdinc.h>
     31 
     32 #include <string.h>
     33 
     34 #include "netdissect.h"
     35 #include "addrtoname.h"
     36 
     37 #include "ether.h"
     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 	struct lladdr_info src, dst;
     97 	int llc_hdrlen;
     98 
     99 	if (caplen < IPFC_HDRLEN) {
    100 		ND_PRINT((ndo, "[|ipfc]"));
    101 		return (caplen);
    102 	}
    103 	/*
    104 	 * Get the network addresses into a canonical form
    105 	 */
    106 	extract_ipfc_addrs(ipfcp, (char *)ESRC(&ehdr), (char *)EDST(&ehdr));
    107 
    108 	if (ndo->ndo_eflag)
    109 		ipfc_hdr_print(ndo, ipfcp, length, ESRC(&ehdr), EDST(&ehdr));
    110 
    111 	src.addr = ESRC(&ehdr);
    112 	src.addr_string = etheraddr_string;
    113 	dst.addr = EDST(&ehdr);
    114 	dst.addr_string = etheraddr_string;
    115 
    116 	/* Skip over Network_Header */
    117 	length -= IPFC_HDRLEN;
    118 	p += IPFC_HDRLEN;
    119 	caplen -= IPFC_HDRLEN;
    120 
    121 	/* Try to print the LLC-layer header & higher layers */
    122 	llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
    123 	if (llc_hdrlen < 0) {
    124 		/*
    125 		 * Some kinds of LLC packet we cannot
    126 		 * handle intelligently
    127 		 */
    128 		if (!ndo->ndo_suppress_default_print)
    129 			ND_DEFAULTPRINT(p, caplen);
    130 		llc_hdrlen = -llc_hdrlen;
    131 	}
    132 	return (IPFC_HDRLEN + llc_hdrlen);
    133 }
    134 
    135 /*
    136  * This is the top level routine of the printer.  'p' points
    137  * to the Network_Header of the packet, 'h->ts' is the timestamp,
    138  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
    139  * is the number of bytes actually captured.
    140  */
    141 u_int
    142 ipfc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p)
    143 {
    144 	return (ipfc_print(ndo, p, h->len, h->caplen));
    145 }
    146