tcpdump/print-bcm-li.c
Denis Ovsienko 9ec0a1a346 Broadcom LI: Modernize packet parsing style.
Enable ND_LONGJMP_FROM_TCHECK. Add and use a standard invalid section.
Test bounds if not decoding the packet fully. Lose a variable, fixup
indentation and simplify some code.
2020-10-16 16:09:47 +01:00

131 lines
3.6 KiB
C

/*
* Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
* 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.
*/
/* \summary: Broadcom LI Printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#define BCM_LI_SHIM_LEN 4
static const struct tok bcm_li_direction_values[] = {
{ 1, "unused" },
{ 2, "egress" },
{ 3, "ingress" },
{ 0, NULL}
};
#define BCM_LI_PKT_TYPE_UNDECIDED 4
#define BCM_LI_PKT_TYPE_IPV4 5
#define BCM_LI_PKT_TYPE_IPV6 6
#define BCM_LI_PKT_TYPE_ETHERNET 7
static const struct tok bcm_li_pkt_type_values[] = {
{ BCM_LI_PKT_TYPE_UNDECIDED, "undecided" },
{ BCM_LI_PKT_TYPE_IPV4, "ipv4" },
{ BCM_LI_PKT_TYPE_IPV6, "ipv6" },
{ BCM_LI_PKT_TYPE_ETHERNET, "ethernet" },
{ 0, NULL}
};
static const struct tok bcm_li_pkt_subtype_values[] = {
{ 1, "single VLAN tag" },
{ 2, "double VLAN tag" },
{ 3, "untagged" },
{ 0, NULL}
};
void
bcm_li_print(netdissect_options *ndo,
const u_char *bp, u_int length)
{
u_int shim, direction, pkt_type, pkt_subtype, li_id;
ndo->ndo_protocol = "bcm_li";
if (length < BCM_LI_SHIM_LEN) {
ND_PRINT(" (length %u < %u)", length, BCM_LI_SHIM_LEN);
goto invalid;
}
shim = GET_BE_U_4(bp);
direction = (shim >> 29) & 0x7;
pkt_type = (shim >> 25) & 0xf;
pkt_subtype = (shim >> 22) & 0x7;
li_id = shim & 0x3fffff;
length -= BCM_LI_SHIM_LEN;
bp += BCM_LI_SHIM_LEN;
ND_PRINT("%sBCM-LI-SHIM: direction %s, pkt-type %s, pkt-subtype %s, li-id %u%s",
ndo->ndo_vflag ? "\n " : "",
tok2str(bcm_li_direction_values, "unknown", direction),
tok2str(bcm_li_pkt_type_values, "unknown", pkt_type),
tok2str(bcm_li_pkt_subtype_values, "unknown", pkt_subtype),
li_id,
ndo->ndo_vflag ? "\n ": "");
if (!ndo->ndo_vflag) {
ND_TCHECK_LEN(bp, length);
return;
}
switch (pkt_type) {
case BCM_LI_PKT_TYPE_ETHERNET:
ether_print(ndo, bp, length, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
break;
case BCM_LI_PKT_TYPE_IPV4:
ip_print(ndo, bp, length);
break;
case BCM_LI_PKT_TYPE_IPV6:
ip6_print(ndo, bp, length);
break;
case BCM_LI_PKT_TYPE_UNDECIDED:
/*
* Guess IP version from first nibble.
*/
if ((GET_U_1(bp) >> 4) == 4) {
ip_print(ndo, bp, length);
} else if ((GET_U_1(bp) >> 4) == 6) {
ip6_print(ndo, bp, length);
} else {
ND_PRINT("unknown payload");
}
break;
default:
goto invalid;
}
return;
invalid:
nd_print_invalid(ndo);
}