print-ether.c

来自「TCPDUMP的C语言源代码,是在数据链路层的应用」· C语言 代码 · 共 353 行

/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.105.2.1 2008-02-06 10:49:22 guy Exp $ (LBL)";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include <stdio.h>
#include <pcap.h>

#include "interface.h"
#include "addrtoname.h"
#include "ethertype.h"

#include "ether.h"

const struct tok ethertype_values[] = { 
    { ETHERTYPE_IP,		"IPv4" },
    { ETHERTYPE_MPLS,		"MPLS unicast" },
    { ETHERTYPE_MPLS_MULTI,	"MPLS multicast" },
    { ETHERTYPE_IPV6,		"IPv6" },
    { ETHERTYPE_8021Q,		"802.1Q" },
    { ETHERTYPE_VMAN,		"VMAN" },
    { ETHERTYPE_PUP,            "PUP" },
    { ETHERTYPE_ARP,            "ARP"},
    { ETHERTYPE_REVARP,         "Reverse ARP"},
    { ETHERTYPE_NS,             "NS" },
    { ETHERTYPE_SPRITE,         "Sprite" },
    { ETHERTYPE_TRAIL,          "Trail" },
    { ETHERTYPE_MOPDL,          "MOP DL" },
    { ETHERTYPE_MOPRC,          "MOP RC" },
    { ETHERTYPE_DN,             "DN" },
    { ETHERTYPE_LAT,            "LAT" },
    { ETHERTYPE_SCA,            "SCA" },
    { ETHERTYPE_LANBRIDGE,      "Lanbridge" },
    { ETHERTYPE_DECDNS,         "DEC DNS" },
    { ETHERTYPE_DECDTS,         "DEC DTS" },
    { ETHERTYPE_VEXP,           "VEXP" },
    { ETHERTYPE_VPROD,          "VPROD" },
    { ETHERTYPE_ATALK,          "Appletalk" },
    { ETHERTYPE_AARP,           "Appletalk ARP" },
    { ETHERTYPE_IPX,            "IPX" },
    { ETHERTYPE_PPP,            "PPP" },
    { ETHERTYPE_MPCP,           "MPCP" },
    { ETHERTYPE_SLOW,           "Slow Protocols" },
    { ETHERTYPE_PPPOED,         "PPPoE D" },
    { ETHERTYPE_PPPOES,         "PPPoE S" },
    { ETHERTYPE_EAPOL,          "EAPOL" },
    { ETHERTYPE_RRCP,           "RRCP" },
    { ETHERTYPE_JUMBO,          "Jumbo" },
    { ETHERTYPE_LOOPBACK,       "Loopback" },
    { ETHERTYPE_ISO,            "OSI" },
    { ETHERTYPE_GRE_ISO,        "GRE-OSI" },
    { ETHERTYPE_CFM_OLD,        "CFM (old)" },
    { ETHERTYPE_CFM,            "CFM" },
    { ETHERTYPE_LLDP,           "LLDP" },
    { 0, NULL}
};

static inline void
ether_hdr_print(register const u_char *bp, u_int length)
{
	register const struct ether_header *ep;
	ep = (const struct ether_header *)bp;

	(void)printf("%s > %s",
		     etheraddr_string(ESRC(ep)),
		     etheraddr_string(EDST(ep)));

	if (!qflag) {
	        if (ntohs(ep->ether_type) <= ETHERMTU)
		          (void)printf(", 802.3");
                else 
		          (void)printf(", ethertype %s (0x%04x)",
				       tok2str(ethertype_values,"Unknown", ntohs(ep->ether_type)),
                                       ntohs(ep->ether_type));	      
        } else {
                if (ntohs(ep->ether_type) <= ETHERMTU)
                          (void)printf(", 802.3");
                else 
                          (void)printf(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", ntohs(ep->ether_type)));  
        }

	(void)printf(", length %u: ", length);
}

void
ether_print(const u_char *p, u_int length, u_int caplen)
{
	struct ether_header *ep;
	u_short ether_type;
	u_short extracted_ether_type;

	if (caplen < ETHER_HDRLEN) {
		printf("[|ether]");
		return;
	}

	if (eflag)
		ether_hdr_print(p, length);

	length -= ETHER_HDRLEN;
	caplen -= ETHER_HDRLEN;
	ep = (struct ether_header *)p;
	p += ETHER_HDRLEN;

	ether_type = ntohs(ep->ether_type);

	/*
	 * Is it (gag) an 802.3 encapsulation?
	 */
	if (ether_type <= ETHERMTU) {
		/* Try to print the LLC-layer header & higher layers */
		if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
		    &extracted_ether_type) == 0) {
			/* ether_type not known, print raw packet */
			if (!eflag)
				ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);

			if (!suppress_default_print)
				default_print(p, caplen);
		}
	} else if (ether_encap_print(ether_type, p, length, caplen,
	    &extracted_ether_type) == 0) {
		/* ether_type not known, print raw packet */
		if (!eflag)
			ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);

		if (!suppress_default_print)
			default_print(p, caplen);
	} 
}

/*
 * This is the top level routine of the printer.  'p' points
 * to the ether header of the packet, 'h->ts' is the timestamp,
 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 * is the number of bytes actually captured.
 */
u_int
ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
{
	ether_print(p, h->len, h->caplen);

	return (ETHER_HDRLEN);
}

/*
 * Prints the packet encapsulated in an Ethernet data segment
 * (or an equivalent encapsulation), given the Ethernet type code.
 *
 * Returns non-zero if it can do so, zero if the ethertype is unknown.
 *
 * The Ethernet type code is passed through a pointer; if it was
 * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
 * the 802.1Q payload, for the benefit of lower layers that might
 * want to know what it is.
 */

int
ether_encap_print(u_short ether_type, const u_char *p,
    u_int length, u_int caplen, u_short *extracted_ether_type)
{
 recurse:
	*extracted_ether_type = ether_type;

	switch (ether_type) {

	case ETHERTYPE_IP:
	        ip_print(gndo, p, length);
		return (1);

#ifdef INET6
	case ETHERTYPE_IPV6:
		ip6_print(p, length);
		return (1);
#endif /*INET6*/

	case ETHERTYPE_ARP:
	case ETHERTYPE_REVARP:
  	        arp_print(gndo, p, length, caplen);
		return (1);

	case ETHERTYPE_DN:
		decnet_print(p, length, caplen);
		return (1);

	case ETHERTYPE_ATALK:
		if (vflag)
			fputs("et1 ", stdout);
		atalk_print(p, length);
		return (1);

	case ETHERTYPE_AARP:
		aarp_print(p, length);
		return (1);

	case ETHERTYPE_IPX:
		printf("(NOV-ETHII) ");
		ipx_print(p, length);
		return (1);

	case ETHERTYPE_8021Q:
	        if (eflag)
		    printf("vlan %u, p %u%s, ",
			   ntohs(*(u_int16_t *)p) & 0xfff,
			   ntohs(*(u_int16_t *)p) >> 13,
			   (ntohs(*(u_int16_t *)p) & 0x1000) ? ", CFI" : "");

		ether_type = ntohs(*(u_int16_t *)(p + 2));
		p += 4;
		length -= 4;
		caplen -= 4;

		if (ether_type > ETHERMTU) {
		        if (eflag)
			        printf("ethertype %s, ",
				       tok2str(ethertype_values,"0x%04x", ether_type));
			goto recurse;
		}

		*extracted_ether_type = 0;

		if (llc_print(p, length, caplen, p - 18, p - 12,
		    extracted_ether_type) == 0) {
                        ether_hdr_print(p - 18, length + 4);

                        if (!suppress_default_print) {
                                default_print(p - 18, caplen + 4);
                        }
		}


		return (1);

        case ETHERTYPE_JUMBO:
                ether_type = ntohs(*(u_int16_t *)(p));
                p += 2;
                length -= 2;      
                caplen -= 2;

                if (ether_type > ETHERMTU) {
                    if (eflag)
                        printf("ethertype %s, ",
                               tok2str(ethertype_values,"0x%04x", ether_type));
                    goto recurse;
                }

                *extracted_ether_type = 0;

                if (llc_print(p, length, caplen, p - 16, p - 10,
                              extracted_ether_type) == 0) {
                    ether_hdr_print(p - 16, length + 2);

                    if (!suppress_default_print) {
                            default_print(p - 16, caplen + 2);
                    }
                }

                return (1);

        case ETHERTYPE_ISO:
                isoclns_print(p+1, length-1, length-1);
                return(1);

	case ETHERTYPE_PPPOED:
	case ETHERTYPE_PPPOES:
		pppoe_print(p, length);
		return (1);

	case ETHERTYPE_EAPOL:
	        eap_print(gndo, p, length);
		return (1);

	case ETHERTYPE_RRCP:
	        rrcp_print(gndo, p - 14 , length + 14);
		return (1);

	case ETHERTYPE_PPP:
		if (length) {
			printf(": ");
			ppp_print(p, length);
		}
		return (1);

	case ETHERTYPE_MPCP:
	        mpcp_print(p, length);
		return (1);

	case ETHERTYPE_SLOW:
	        slow_print(p, length);
		return (1);

	case ETHERTYPE_CFM:
	case ETHERTYPE_CFM_OLD:
	        cfm_print(p, length);
		return (1);

	case ETHERTYPE_LLDP:
	        lldp_print(p, length);
		return (1);

        case ETHERTYPE_LOOPBACK:
                return (1);

	case ETHERTYPE_MPLS:
	case ETHERTYPE_MPLS_MULTI:
		mpls_print(p, length);
		return (1);

	case ETHERTYPE_LAT:
	case ETHERTYPE_SCA:
	case ETHERTYPE_MOPRC:
	case ETHERTYPE_MOPDL:
		/* default_print for now */
	default:
		return (0);
	}
}


/*
 * Local Variables:
 * c-style: whitesmith
 * c-basic-offset: 8
 * End:
 */