tcpdump/print-ether.c
Francois-Xavier Le Bail 7b7b84716e Ethernet: Add a bounds check
Avoid to have p (current pointer on packet data) > ndo->ndo_snapend
in isoclns_print() in some cases.

Moreover:
Add a "FIXME" comment.
2021-05-06 13:50:55 +02:00

660 lines
18 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.
*/
/* \summary: Ethernet printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "extract.h"
#include "addrtoname.h"
#include "ethertype.h"
/*
* Structure of an Ethernet header.
*/
struct ether_header {
nd_mac_addr ether_dhost;
nd_mac_addr ether_shost;
nd_uint16_t ether_length_type;
};
/*
* Length of an Ethernet header; note that some compilers may pad
* "struct ether_header" to a multiple of 4 bytes, for example, so
* "sizeof (struct ether_header)" may not give the right answer.
*/
#define ETHER_HDRLEN 14
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_8021Q9100, "802.1Q-9100" },
{ ETHERTYPE_8021QinQ, "802.1Q-QinQ" },
{ ETHERTYPE_8021Q9200, "802.1Q-9200" },
{ ETHERTYPE_MACSEC, "802.1AE MACsec" },
{ 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_TEB, "TEB" },
{ 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_MS_NLB_HB, "MS NLB heartbeat" },
{ ETHERTYPE_JUMBO, "Jumbo" },
{ ETHERTYPE_NSH, "NSH" },
{ ETHERTYPE_LOOPBACK, "Loopback" },
{ ETHERTYPE_ISO, "OSI" },
{ ETHERTYPE_GRE_ISO, "GRE-OSI" },
{ ETHERTYPE_CFM_OLD, "CFM (old)" },
{ ETHERTYPE_CFM, "CFM" },
{ ETHERTYPE_IEEE1905_1, "IEEE1905.1" },
{ ETHERTYPE_LLDP, "LLDP" },
{ ETHERTYPE_TIPC, "TIPC"},
{ ETHERTYPE_GEONET_OLD, "GeoNet (old)"},
{ ETHERTYPE_GEONET, "GeoNet"},
{ ETHERTYPE_CALM_FAST, "CALM FAST"},
{ ETHERTYPE_AOE, "AoE" },
{ ETHERTYPE_PTP, "PTP" },
{ ETHERTYPE_ARISTA, "Arista Vendor Specific Protocol" },
{ 0, NULL}
};
static void
ether_addresses_print(netdissect_options *ndo, const u_char *src,
const u_char *dst)
{
ND_PRINT("%s > %s, ",
GET_ETHERADDR_STRING(src), GET_ETHERADDR_STRING(dst));
}
static void
ether_type_print(netdissect_options *ndo, uint16_t type)
{
if (!ndo->ndo_qflag)
ND_PRINT("ethertype %s (0x%04x)",
tok2str(ethertype_values, "Unknown", type), type);
else
ND_PRINT("%s",
tok2str(ethertype_values, "Unknown Ethertype (0x%04x)", type));
}
/*
* Common code for printing Ethernet frames.
*
* It can handle Ethernet headers with extra tag information inserted
* after the destination and source addresses, as is inserted by some
* switch chips, and extra encapsulation header information before
* printing Ethernet header information (such as a LANE ID for ATM LANE).
*/
static u_int
ether_common_print(netdissect_options *ndo, const u_char *p, u_int length,
u_int caplen,
void (*print_switch_tag)(netdissect_options *ndo, const u_char *),
u_int switch_tag_len,
void (*print_encap_header)(netdissect_options *ndo, const u_char *),
const u_char *encap_header_arg)
{
const struct ether_header *ehp;
u_int orig_length;
u_int hdrlen;
u_short length_type;
int printed_length;
int llc_hdrlen;
struct lladdr_info src, dst;
if (caplen < ETHER_HDRLEN + switch_tag_len) {
nd_print_trunc(ndo);
return caplen;
}
if (length < ETHER_HDRLEN + switch_tag_len) {
nd_print_trunc(ndo);
return length;
}
if (print_encap_header != NULL)
(*print_encap_header)(ndo, encap_header_arg);
orig_length = length;
/*
* Get the source and destination addresses, skip past them,
* and print them if we're printing the link-layer header.
*/
ehp = (const struct ether_header *)p;
src.addr = ehp->ether_shost;
src.addr_string = etheraddr_string;
dst.addr = ehp->ether_dhost;
dst.addr_string = etheraddr_string;
length -= 2*MAC_ADDR_LEN;
caplen -= 2*MAC_ADDR_LEN;
p += 2*MAC_ADDR_LEN;
hdrlen = 2*MAC_ADDR_LEN;
if (ndo->ndo_eflag)
ether_addresses_print(ndo, src.addr, dst.addr);
/*
* Print the switch tag, if we have one, and skip past it.
*/
if (print_switch_tag != NULL)
(*print_switch_tag)(ndo, p);
length -= switch_tag_len;
caplen -= switch_tag_len;
p += switch_tag_len;
hdrlen += switch_tag_len;
/*
* Get the length/type field, skip past it, and print it
* if we're printing the link-layer header.
*/
recurse:
length_type = GET_BE_U_2(p);
length -= 2;
caplen -= 2;
p += 2;
hdrlen += 2;
/*
* Process 802.1AE MACsec headers.
*/
printed_length = 0;
if (length_type == ETHERTYPE_MACSEC) {
/*
* MACsec, aka IEEE 802.1AE-2006
* Print the header, and try to print the payload if it's not encrypted
*/
if (ndo->ndo_eflag) {
ether_type_print(ndo, length_type);
ND_PRINT(", length %u: ", orig_length);
printed_length = 1;
}
int ret = macsec_print(ndo, &p, &length, &caplen, &hdrlen,
&src, &dst);
if (ret == 0) {
/* Payload is encrypted; print it as raw data. */
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
return hdrlen;
} else if (ret > 0) {
/* Problem printing the header; just quit. */
return ret;
} else {
/*
* Keep processing type/length fields.
*/
length_type = GET_BE_U_2(p);
length -= 2;
caplen -= 2;
p += 2;
hdrlen += 2;
}
}
/*
* Process VLAN tag types.
*/
while (length_type == ETHERTYPE_8021Q ||
length_type == ETHERTYPE_8021Q9100 ||
length_type == ETHERTYPE_8021Q9200 ||
length_type == ETHERTYPE_8021QinQ) {
/*
* It has a VLAN tag.
* Print VLAN information, and then go back and process
* the enclosed type field.
*/
if (caplen < 4) {
ndo->ndo_protocol = "vlan";
nd_print_trunc(ndo);
return hdrlen + caplen;
}
if (length < 4) {
ndo->ndo_protocol = "vlan";
nd_print_trunc(ndo);
return hdrlen + length;
}
if (ndo->ndo_eflag) {
uint16_t tag = GET_BE_U_2(p);
ether_type_print(ndo, length_type);
if (!printed_length) {
ND_PRINT(", length %u: ", orig_length);
printed_length = 1;
} else
ND_PRINT(", ");
ND_PRINT("%s, ", ieee8021q_tci_string(tag));
}
length_type = GET_BE_U_2(p + 2);
p += 4;
length -= 4;
caplen -= 4;
hdrlen += 4;
}
/*
* We now have the final length/type field.
*/
if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
/*
* It's a length field, containing the length of the
* remaining payload; use it as such, as long as
* it's not too large (bigger than the actual payload).
*/
if (length_type < length) {
length = length_type;
if (caplen > length)
caplen = length;
}
/*
* Cut off the snapshot length to the end of the
* payload.
*/
nd_push_snapend(ndo, p + length);
if (ndo->ndo_eflag) {
ND_PRINT("802.3");
if (!printed_length)
ND_PRINT(", length %u: ", length);
}
/*
* An LLC header follows the length. Print that and
* higher layers.
*/
llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
if (llc_hdrlen < 0) {
/* packet type not known, print raw packet */
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
llc_hdrlen = -llc_hdrlen;
}
hdrlen += llc_hdrlen;
nd_pop_packet_info(ndo);
} else if (length_type == ETHERTYPE_JUMBO) {
/*
* It's a type field, with the type for Alteon jumbo frames.
* See
*
* https://tools.ietf.org/html/draft-ietf-isis-ext-eth-01
*
* which indicates that, following the type field,
* there's an LLC header and payload.
*/
/* Try to print the LLC-layer header & higher layers */
llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
if (llc_hdrlen < 0) {
/* packet type not known, print raw packet */
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
llc_hdrlen = -llc_hdrlen;
}
hdrlen += llc_hdrlen;
} else if (length_type == ETHERTYPE_ARISTA) {
if (caplen < 2) {
ND_PRINT("[|arista]");
return hdrlen + caplen;
}
if (length < 2) {
ND_PRINT("[|arista]");
return hdrlen + length;
}
ether_type_print(ndo, length_type);
ND_PRINT(", length %u: ", orig_length);
int bytesConsumed = arista_ethertype_print(ndo, p, length);
if (bytesConsumed > 0) {
p += bytesConsumed;
length -= bytesConsumed;
caplen -= bytesConsumed;
hdrlen += bytesConsumed;
goto recurse;
} else {
/* subtype/version not known, print raw packet */
if (!ndo->ndo_eflag && length_type > MAX_ETHERNET_LENGTH_VAL) {
ether_addresses_print(ndo, src.addr, dst.addr);
ether_type_print(ndo, length_type);
ND_PRINT(", length %u: ", orig_length);
}
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
}
} else {
/*
* It's a type field with some other value.
*/
if (ndo->ndo_eflag) {
ether_type_print(ndo, length_type);
if (!printed_length)
ND_PRINT(", length %u: ", orig_length);
else
ND_PRINT(", ");
}
if (ethertype_print(ndo, length_type, p, length, caplen, &src, &dst) == 0) {
/* type not known, print raw packet */
if (!ndo->ndo_eflag) {
/*
* We didn't print the full link-layer
* header, as -e wasn't specified, so
* print only the source and destination
* MAC addresses and the final Ethernet
* type.
*/
ether_addresses_print(ndo, src.addr, dst.addr);
ether_type_print(ndo, length_type);
ND_PRINT(", length %u: ", orig_length);
}
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
}
}
return hdrlen;
}
/*
* Print an Ethernet frame while specyfing a non-standard Ethernet header
* length.
* This might be encapsulated within another frame; we might be passed
* a pointer to a function that can print header information for that
* frame's protocol, and an argument to pass to that function.
*
* FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
*/
u_int
ether_switch_tag_print(netdissect_options *ndo, const u_char *p, u_int length,
u_int caplen,
void (*print_switch_tag)(netdissect_options *, const u_char *),
u_int switch_tag_len)
{
return ether_common_print(ndo, p, length, caplen, print_switch_tag,
switch_tag_len, NULL, NULL);
}
/*
* Print an Ethernet frame.
* This might be encapsulated within another frame; we might be passed
* a pointer to a function that can print header information for that
* frame's protocol, and an argument to pass to that function.
*
* FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
*/
u_int
ether_print(netdissect_options *ndo,
const u_char *p, u_int length, u_int caplen,
void (*print_encap_header)(netdissect_options *ndo, const u_char *),
const u_char *encap_header_arg)
{
ndo->ndo_protocol = "ether";
return ether_common_print(ndo, p, length, caplen, NULL, 0,
print_encap_header, encap_header_arg);
}
/*
* This is the top level routine of the printer. 'p' points
* to the ether header of the packet, 'h->len' is the length
* of the packet off the wire, and 'h->caplen' is the number
* of bytes actually captured.
*/
void
ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
const u_char *p)
{
ndo->ndo_protocol = "ether";
ndo->ndo_ll_hdr_len +=
ether_print(ndo, p, h->len, h->caplen, NULL, NULL);
}
/*
* This is the top level routine of the printer. 'p' points
* to the ether header of the packet, 'h->len' is the length
* of the packet off the wire, and 'h->caplen' is the number
* of bytes actually captured.
*
* This is for DLT_NETANALYZER, which has a 4-byte pseudo-header
* before the Ethernet header.
*/
void
netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
const u_char *p)
{
/*
* Fail if we don't have enough data for the Hilscher pseudo-header.
*/
ndo->ndo_protocol = "netanalyzer";
ND_TCHECK_LEN(p, 4);
/* Skip the pseudo-header. */
ndo->ndo_ll_hdr_len += 4;
ndo->ndo_ll_hdr_len +=
ether_print(ndo, p + 4, h->len - 4, h->caplen - 4, NULL, NULL);
}
/*
* This is the top level routine of the printer. 'p' points
* to the ether header of the packet, 'h->len' is the length
* of the packet off the wire, and 'h->caplen' is the number
* of bytes actually captured.
*
* This is for DLT_NETANALYZER_TRANSPARENT, which has a 4-byte
* pseudo-header, a 7-byte Ethernet preamble, and a 1-byte Ethernet SOF
* before the Ethernet header.
*/
void
netanalyzer_transparent_if_print(netdissect_options *ndo,
const struct pcap_pkthdr *h,
const u_char *p)
{
/*
* Fail if we don't have enough data for the Hilscher pseudo-header,
* preamble, and SOF.
*/
ndo->ndo_protocol = "netanalyzer_transparent";
ND_TCHECK_LEN(p, 12);
/* Skip the pseudo-header, preamble, and SOF. */
ndo->ndo_ll_hdr_len += 12;
ndo->ndo_ll_hdr_len +=
ether_print(ndo, p + 12, h->len - 12, h->caplen - 12, NULL, NULL);
}
/*
* Prints the packet payload, given an Ethernet type code for the payload's
* protocol.
*
* Returns non-zero if it can do so, zero if the ethertype is unknown.
*/
int
ethertype_print(netdissect_options *ndo,
u_short ether_type, const u_char *p,
u_int length, u_int caplen,
const struct lladdr_info *src, const struct lladdr_info *dst)
{
switch (ether_type) {
case ETHERTYPE_IP:
ip_print(ndo, p, length);
return (1);
case ETHERTYPE_IPV6:
ip6_print(ndo, p, length);
return (1);
case ETHERTYPE_ARP:
case ETHERTYPE_REVARP:
arp_print(ndo, p, length, caplen);
return (1);
case ETHERTYPE_DN:
decnet_print(ndo, p, length, caplen);
return (1);
case ETHERTYPE_ATALK:
if (ndo->ndo_vflag)
ND_PRINT("et1 ");
atalk_print(ndo, p, length);
return (1);
case ETHERTYPE_AARP:
aarp_print(ndo, p, length);
return (1);
case ETHERTYPE_IPX:
ND_PRINT("(NOV-ETHII) ");
ipx_print(ndo, p, length);
return (1);
case ETHERTYPE_ISO:
if (length == 0 || caplen == 0) {
ndo->ndo_protocol = "isoclns";
nd_print_trunc(ndo);
return (1);
}
/* At least one byte is required */
/* FIXME: Reference for this byte? */
ND_TCHECK_LEN(p, 1);
isoclns_print(ndo, p + 1, length - 1);
return(1);
case ETHERTYPE_PPPOED:
case ETHERTYPE_PPPOES:
case ETHERTYPE_PPPOED2:
case ETHERTYPE_PPPOES2:
pppoe_print(ndo, p, length);
return (1);
case ETHERTYPE_EAPOL:
eapol_print(ndo, p);
return (1);
case ETHERTYPE_RRCP:
rrcp_print(ndo, p, length, src, dst);
return (1);
case ETHERTYPE_PPP:
if (length) {
ND_PRINT(": ");
ppp_print(ndo, p, length);
}
return (1);
case ETHERTYPE_MPCP:
mpcp_print(ndo, p, length);
return (1);
case ETHERTYPE_SLOW:
slow_print(ndo, p, length);
return (1);
case ETHERTYPE_CFM:
case ETHERTYPE_CFM_OLD:
cfm_print(ndo, p, length);
return (1);
case ETHERTYPE_LLDP:
lldp_print(ndo, p, length);
return (1);
case ETHERTYPE_NSH:
nsh_print(ndo, p, length);
return (1);
case ETHERTYPE_LOOPBACK:
loopback_print(ndo, p, length);
return (1);
case ETHERTYPE_MPLS:
case ETHERTYPE_MPLS_MULTI:
mpls_print(ndo, p, length);
return (1);
case ETHERTYPE_TIPC:
tipc_print(ndo, p, length, caplen);
return (1);
case ETHERTYPE_MS_NLB_HB:
msnlb_print(ndo, p);
return (1);
case ETHERTYPE_GEONET_OLD:
case ETHERTYPE_GEONET:
geonet_print(ndo, p, length, src);
return (1);
case ETHERTYPE_CALM_FAST:
calm_fast_print(ndo, p, length, src);
return (1);
case ETHERTYPE_AOE:
aoe_print(ndo, p, length);
return (1);
case ETHERTYPE_PTP:
ptp_print(ndo, p, length);
return (1);
case ETHERTYPE_LAT:
case ETHERTYPE_SCA:
case ETHERTYPE_MOPRC:
case ETHERTYPE_MOPDL:
case ETHERTYPE_IEEE1905_1:
/* default_print for now */
default:
return (0);
}
}