freebsd-dev/contrib/tcpdump/print-ether.c
Garrett Wollman 0bfc6e6706 This is a hack. Decode IEEE 802.1Q VLAN tagging so that we can decode
tagged traffic according to the encapsulated protocol.  It needs in
addition modifications to the filter generator which would deal with
checking the ethertype and vlan header as required.
1997-12-08 21:42:35 +00:00

208 lines
5.4 KiB
C

/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996
* 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[] =
"@(#) $Header: print-ether.c,v 1.43 96/09/26 23:36:43 leres Exp $ (LBL)";
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#if __STDC__
struct mbuf;
struct rtentry;
#endif
#include <net/if.h>
#include <netinet/in.h>
#include <net/ethernet.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <stdio.h>
#include <pcap.h>
#include "interface.h"
#include "addrtoname.h"
#include "ethertype.h"
const u_char *packetp;
const u_char *snapend;
static inline void
ether_print(register const u_char *bp, u_int length)
{
register const struct ether_header *ep;
ep = (const struct ether_header *)bp;
if (qflag)
(void)printf("%s %s %d: ",
etheraddr_string(ESRC(ep)),
etheraddr_string(EDST(ep)),
length);
else
(void)printf("%s %s %s %d: ",
etheraddr_string(ESRC(ep)),
etheraddr_string(EDST(ep)),
etherproto_string(ep->ether_type),
length);
}
/*
* This is the top level routine of the printer. 'p' is the points
* to the ether header of the packet, 'tvp' is the timestamp,
* 'length' is the length of the packet off the wire, and 'caplen'
* is the number of bytes actually captured.
*/
void
ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
u_int caplen = h->caplen;
u_int length = h->len;
struct ether_header *ep;
u_short ether_type;
extern u_short extracted_ethertype;
ts_print(&h->ts);
if (caplen < sizeof(struct ether_header)) {
printf("[|ether]");
goto out;
}
if (eflag)
ether_print(p, length);
/*
* Some printers want to get back at the ethernet addresses,
* and/or check that they're not walking off the end of the packet.
* Rather than pass them all the way down, we set these globals.
*/
packetp = p;
snapend = p + caplen;
length -= sizeof(struct ether_header);
caplen -= sizeof(struct ether_header);
ep = (struct ether_header *)p;
p += sizeof(struct ether_header);
ether_type = ntohs(ep->ether_type);
/*
* Is it (gag) an 802.3 encapsulation?
*/
extracted_ethertype = 0;
if (ether_type <= ETHERMTU) {
/* Try to print the LLC-layer header & higher layers */
if (llc_print(p, length, caplen, ESRC(ep), EDST(ep)) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
ether_print((u_char *)ep, length);
if (extracted_ethertype) {
printf("(LLC %s) ",
etherproto_string(htons(extracted_ethertype)));
}
if (!xflag && !qflag)
default_print(p, caplen);
}
} else if (ether_encap_print(ether_type, p, length, caplen) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
ether_print((u_char *)ep, length + sizeof(*ep));
if (!xflag && !qflag)
default_print(p, caplen);
}
if (xflag)
default_print(p, caplen);
out:
putchar('\n');
}
/*
* 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.
*
* Stuffs the ether type into a global for the benefit of lower layers
* that might want to know what it is.
*/
u_short extracted_ethertype;
int
ether_encap_print(u_short ethertype, const u_char *p,
u_int length, u_int caplen)
{
if (ethertype == 0x8100) { /* IEEE 802.1Q vlan tagging encapsulation */
printf ("[vlan %d] ", ntohs(*(u_short *)p) & 0x17ff);
ethertype = ntohs(((u_short *)p)[1]);
p += 4;
length -= 4;
caplen -= 4;
}
extracted_ethertype = ethertype;
switch (ethertype) {
case ETHERTYPE_IP:
ip_print(p, length);
return (1);
case ETHERTYPE_ARP:
case ETHERTYPE_REVARP:
arp_print(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:
ipx_print(p, length);
return (1);
case ETHERTYPE_LAT:
case ETHERTYPE_SCA:
case ETHERTYPE_MOPRC:
case ETHERTYPE_MOPDL:
/* default_print for now */
default:
return (0);
}
}