tcpdump/print-ether.c
guy e070cf232f We no longer use "packetp" for anything, so eliminate it. (If any
dissector really needs source and destination MAC addresses, we should
make global pointers to them - which would be null for packets lacking
MAC addresses, so dissectors that need them will need to do something
sensible if those pointers are null.)

Don't fake up an Ethernet header if there aren't any MAC addresses to
use when faking it up.

"bp_chaddr" in "print-bootp.c" is an array, so "bp->bp_chaddr" cannot be
null, and there's no need to test for it not being null.
2002-12-18 08:53:18 +00:00

264 lines
6.5 KiB
C

/*
* 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[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.74 2002-12-18 08:53:21 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 u_char *snapend;
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;
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);
}
void
ether_print(const u_char *p, u_int length, u_int caplen)
{
struct ether_header *ep;
u_short ether_type;
u_short extracted_ethertype;
if (caplen < ETHER_HDRLEN) {
printf("[|ether]");
return;
}
if (eflag)
ether_hdr_print(p, length);
/*
* Some printers want to check that they're not walking off the
* end of the packet.
* Rather than pass it all the way down, we set this global.
*/
snapend = p + caplen;
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?
*/
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),
&extracted_ethertype) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
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,
&extracted_ethertype) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
if (!xflag && !qflag)
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->length' is the length of the packet off the wire, and 'h->caplen'
* is the number of bytes actually captured.
*/
void
ether_if_print(u_char *user _U_, const struct pcap_pkthdr *h, const u_char *p)
{
u_int caplen = h->caplen;
u_int length = h->len;
++infodelay;
ts_print(&h->ts);
ether_print(p, length, caplen);
/*
* If "-x" was specified, print stuff past the Ethernet header,
* if there's anything to print.
*/
if (xflag && caplen > ETHER_HDRLEN)
default_print(p + ETHER_HDRLEN, caplen - ETHER_HDRLEN);
putchar('\n');
--infodelay;
if (infoprint)
info(0);
}
/*
* 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 ethertype, const u_char *p,
u_int length, u_int caplen, u_short *extracted_ethertype)
{
recurse:
*extracted_ethertype = ethertype;
switch (ethertype) {
case ETHERTYPE_IP:
ip_print(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(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:
printf("802.1Q vlan#%d P%d%s ",
ntohs(*(u_int16_t *)p) & 0xfff,
ntohs(*(u_int16_t *)p) >> 13,
(ntohs(*(u_int16_t *)p) & 0x1000) ? " CFI" : "");
ethertype = ntohs(*(u_int16_t *)(p + 2));
p += 4;
length -= 4;
caplen -= 4;
if (ethertype > ETHERMTU)
goto recurse;
*extracted_ethertype = 0;
if (llc_print(p, length, caplen, p - 18, p - 12,
extracted_ethertype) == 0) {
/* ether_type not known, print raw packet */
if (!eflag)
ether_hdr_print(p - 18, length + 4);
if (*extracted_ethertype) {
printf("(LLC %s) ",
etherproto_string(htons(*extracted_ethertype)));
}
if (!xflag && !qflag)
default_print(p - 18, caplen + 4);
}
return (1);
case ETHERTYPE_PPPOED:
case ETHERTYPE_PPPOES:
pppoe_print(p, length);
return (1);
case ETHERTYPE_PPP:
printf("ppp");
if (length) {
printf(": ");
ppp_print(p, length);
}
return (1);
case ETHERTYPE_LOOPBACK:
printf("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);
}
}