wireshark/epan/dissectors/packet-sll.c

664 lines
19 KiB
C

/* packet-sll.c
* Routines for disassembly of packets from Linux "cooked mode" captures
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#define NEW_PROTO_TREE_API
#include "config.h"
#include <epan/packet.h>
#include <epan/capture_dissectors.h>
#include <epan/conversation_table.h>
#include <epan/arptypes.h>
#include <wsutil/pint.h>
#include "packet-sll.h"
#include "packet-ipx.h"
#include "packet-llc.h"
#include "packet-eth.h"
#include "packet-ppp.h"
#include "packet-gre.h"
#include "packet-arp.h"
#include <epan/addr_resolv.h>
#include <epan/etypes.h>
#include <epan/arptypes.h>
#include <epan/decode_as.h>
#include <epan/proto_data.h>
void proto_register_sll(void);
void proto_reg_handoff_sll(void);
typedef struct sll_tap_data {
address src_address;
} sll_tap_data;
/*
* A LINKTYPE_LINUX_SLL fake link-layer header.
*/
#define SLL_HEADER_SIZE 16 /* total header length */
/*
* A LINKTYPE_LINUX_SLL fake link-layer header.
*/
#define SLL2_HEADER_SIZE 20 /* total header length */
#define SLL_ADDRLEN 8 /* length of address field */
/*
* The LINUX_SLL_ values for "sll_pkttype".
*/
#define LINUX_SLL_HOST 0
#define LINUX_SLL_BROADCAST 1
#define LINUX_SLL_MULTICAST 2
#define LINUX_SLL_OTHERHOST 3
#define LINUX_SLL_OUTGOING 4
static const value_string packet_type_vals[] = {
{ LINUX_SLL_HOST, "Unicast to us" },
{ LINUX_SLL_BROADCAST, "Broadcast" },
{ LINUX_SLL_MULTICAST, "Multicast" },
{ LINUX_SLL_OTHERHOST, "Unicast to another host" },
{ LINUX_SLL_OUTGOING, "Sent by us" },
{ 0, NULL }
};
static const value_string ltype_vals[] = {
{ LINUX_SLL_P_802_3, "Raw 802.3" },
{ LINUX_SLL_P_ETHERNET, "Ethernet" },
{ LINUX_SLL_P_802_2, "802.2 LLC" },
{ LINUX_SLL_P_PPPHDLC, "PPP (HDLC)" },
{ LINUX_SLL_P_CAN, "CAN" },
{ LINUX_SLL_P_CANFD, "CAN FD" },
{ LINUX_SLL_P_IRDA_LAP, "IrDA LAP" },
{ LINUX_SLL_P_ISI, "ISI" },
{ LINUX_SLL_P_IEEE802154, "IEEE 802.15.4" },
{ 0, NULL }
};
static dissector_handle_t sll_handle;
static dissector_handle_t sll2_handle;
static dissector_handle_t ethertype_handle;
static dissector_handle_t netlink_handle;
static header_field_info *hfi_sll = NULL;
static int proto_sll;
static int sll_tap = -1;
#define SLL_HFI_INIT HFI_INIT(proto_sll)
static header_field_info hfi_sll_pkttype SLL_HFI_INIT =
{ "Packet type", "sll.pkttype", FT_UINT16, BASE_DEC,
VALS(packet_type_vals), 0x0, NULL, HFILL };
/* ARP hardware type? With Linux extensions? */
static header_field_info hfi_sll_hatype SLL_HFI_INIT =
{ "Link-layer address type", "sll.hatype", FT_UINT16, BASE_DEC,
VALS(arp_hrd_vals), 0x0, NULL, HFILL };
static header_field_info hfi_sll_halen SLL_HFI_INIT =
{ "Link-layer address length", "sll.halen", FT_UINT16, BASE_DEC,
NULL, 0x0, NULL, HFILL };
/* Source address if it's an Ethernet-type address */
static header_field_info hfi_sll_src_eth SLL_HFI_INIT =
{ "Source", "sll.src.eth", FT_ETHER, BASE_NONE,
NULL, 0x0, "Source link-layer address", HFILL };
/* Source address if it's an IPv4 address */
static header_field_info hfi_sll_src_ipv4 SLL_HFI_INIT =
{ "Source", "sll.src.ipv4", FT_IPv4, BASE_NONE,
NULL, 0x0, "Source link-layer address", HFILL };
/* Source address if it's not an Ethernet-type address */
static header_field_info hfi_sll_src_other SLL_HFI_INIT =
{ "Source", "sll.src.other", FT_BYTES, BASE_NONE,
NULL, 0x0, "Source link-layer address", HFILL };
/* Unused remaining bytes */
static header_field_info hfi_sll_unused SLL_HFI_INIT =
{ "Unused", "sll.unused", FT_BYTES, BASE_NONE,
NULL, 0x0, "Unused bytes", HFILL };
/* if the protocol field is an internal Linux protocol type */
static header_field_info hfi_sll_ltype SLL_HFI_INIT =
{ "Protocol", "sll.ltype", FT_UINT16, BASE_HEX,
VALS(ltype_vals), 0x0, "Linux protocol type", HFILL };
/* if the protocol field is a GRE protocol type */
static header_field_info hfi_sll_gretype SLL_HFI_INIT =
{ "Protocol", "sll.gretype", FT_UINT16, BASE_HEX,
VALS(gre_typevals), 0x0, "GRE protocol type", HFILL };
/* registered here but handled in ethertype.c */
static header_field_info hfi_sll_etype SLL_HFI_INIT =
{ "Protocol", "sll.etype", FT_UINT16, BASE_HEX,
VALS(etype_vals), 0x0, "Ethernet protocol type", HFILL };
static header_field_info hfi_sll_trailer SLL_HFI_INIT =
{ "Trailer", "sll.trailer", FT_BYTES, BASE_NONE,
NULL, 0x0, NULL, HFILL };
/* SLL2 only */
static header_field_info hfi_sll_ifindex SLL_HFI_INIT =
{ "Interface index", "sll.ifindex", FT_UINT16, BASE_DEC,
NULL, 0x0, NULL, HFILL };
static gint ett_sll = -1;
static dissector_table_t sll_hatype_dissector_table;
static dissector_table_t sll_ltype_dissector_table;
static dissector_table_t gre_dissector_table;
static void sll_prompt(packet_info *pinfo, gchar* result)
{
g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "SLL protocol type 0x%04x as",
GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_sll, 0)));
}
static gpointer sll_value(packet_info *pinfo)
{
return p_get_proto_data(pinfo->pool, pinfo, proto_sll, 0);
}
static const char* sll_conv_get_filter_type(conv_item_t* conv, conv_filter_type_e filter)
{
if ((filter == CONV_FT_SRC_ADDRESS) && (conv->src_address.type == AT_ETHER))
return "sll.src.eth";
if ((filter == CONV_FT_ANY_ADDRESS) && (conv->src_address.type == AT_ETHER))
return "sll.src.eth";
if ((filter == CONV_FT_SRC_ADDRESS) && (conv->src_address.type == AT_IPv4))
return "sll.src.ipv4";
if ((filter == CONV_FT_ANY_ADDRESS) && (conv->src_address.type == AT_IPv4))
return "sll.src.ipv4";
return CONV_FILTER_INVALID;
}
static ct_dissector_info_t sll_ct_dissector_info = {&sll_conv_get_filter_type};
static address no_dst = {AT_NONE, 0, NULL, NULL};
static tap_packet_status
sll_conversation_packet(void *pct, packet_info *pinfo, epan_dissect_t *edt _U_, const void *vip)
{
conv_hash_t *hash = (conv_hash_t*) pct;
const sll_tap_data *tap_data = (const sll_tap_data*)vip;
add_conversation_table_data(hash, &tap_data->src_address, &no_dst, 0, 0, 1, pinfo->fd->pkt_len, &pinfo->rel_ts, &pinfo->abs_ts, &sll_ct_dissector_info, ENDPOINT_NONE);
return TAP_PACKET_REDRAW;
}
static const char* sll_host_get_filter_type(hostlist_talker_t* host, conv_filter_type_e filter)
{
if ((filter == CONV_FT_SRC_ADDRESS) && (host->myaddress.type == AT_ETHER))
return "sll.src.eth";
if ((filter == CONV_FT_ANY_ADDRESS) && (host->myaddress.type == AT_ETHER))
return "sll.src.eth";
if ((filter == CONV_FT_SRC_ADDRESS) && (host->myaddress.type == AT_IPv4))
return "sll.src.ipv4";
if ((filter == CONV_FT_ANY_ADDRESS) && (host->myaddress.type == AT_IPv4))
return "sll.src.ipv4";
return CONV_FILTER_INVALID;
}
static hostlist_dissector_info_t sll_host_dissector_info = {&sll_host_get_filter_type};
static tap_packet_status
sll_hostlist_packet(void *pit, packet_info *pinfo, epan_dissect_t *edt _U_, const void *vip)
{
conv_hash_t *hash = (conv_hash_t*) pit;
const sll_tap_data *tap_data = (const sll_tap_data*)vip;
add_hostlist_table_data(hash, &tap_data->src_address, 0, TRUE, 1, pinfo->fd->pkt_len, &sll_host_dissector_info, ENDPOINT_NONE);
return TAP_PACKET_REDRAW;
}
static gboolean
capture_sll(const guchar *pd, int offset _U_, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header _U_)
{
guint16 hatype;
guint16 protocol;
if (!BYTES_ARE_IN_FRAME(0, len, SLL_HEADER_SIZE))
return FALSE;
protocol = pntoh16(&pd[14]);
if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
/*
* "proto" is *not* a length field, it's a Linux internal
* protocol type.
*/
hatype = pntoh16(&pd[2]);
if (try_capture_dissector("sll.hatype", hatype, pd,
SLL_HEADER_SIZE, len, cpinfo, pseudo_header))
return TRUE;
return try_capture_dissector("sll.ltype", protocol, pd, SLL_HEADER_SIZE, len, cpinfo, pseudo_header);
} else {
return try_capture_dissector("ethertype", protocol, pd, SLL_HEADER_SIZE, len, cpinfo, pseudo_header);
}
return FALSE;
}
static gboolean
capture_sll2(const guchar *pd, int offset _U_, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header _U_)
{
guint16 hatype;
guint16 protocol;
if (!BYTES_ARE_IN_FRAME(0, len, SLL2_HEADER_SIZE))
return FALSE;
protocol = pntoh16(&pd[0]);
if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
/*
* "proto" is *not* a length field, it's a Linux internal
* protocol type.
*/
hatype = pntoh16(&pd[8]);
if (try_capture_dissector("sll.hatype", hatype, pd,
SLL2_HEADER_SIZE, len, cpinfo, pseudo_header))
return TRUE;
return try_capture_dissector("sll.ltype", protocol, pd, SLL2_HEADER_SIZE, len, cpinfo, pseudo_header);
} else {
return try_capture_dissector("ethertype", protocol, pd, SLL2_HEADER_SIZE, len, cpinfo, pseudo_header);
}
return FALSE;
}
static void
add_ll_address(proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb,
int halen_offset, int halen_len, sll_tap_data *tap_data)
{
guint32 ha_len;
int ha_offset = halen_offset + halen_len;
/*
* XXX - check the link-layer address type value?
* For now, we just assume ha_len 4 is IPv4 and ha_len 6
* is Ethernet.
*/
proto_tree_add_item_ret_uint(tree, &hfi_sll_halen, tvb, halen_offset, halen_len, ENC_BIG_ENDIAN, &ha_len);
switch (ha_len) {
case 4:
set_address_tvb(&pinfo->dl_src, AT_IPv4, 4, tvb, ha_offset);
copy_address_shallow(&pinfo->src, &pinfo->dl_src);
copy_address_wmem(wmem_file_scope(), &tap_data->src_address, &pinfo->src);
proto_tree_add_item(tree, &hfi_sll_src_ipv4, tvb, ha_offset, 4, ENC_BIG_ENDIAN);
break;
case 6:
set_address_tvb(&pinfo->dl_src, AT_ETHER, 6, tvb, ha_offset);
copy_address_shallow(&pinfo->src, &pinfo->dl_src);
copy_address_wmem(wmem_file_scope(), &tap_data->src_address, &pinfo->src);
proto_tree_add_item(tree, &hfi_sll_src_eth, tvb, ha_offset, 6, ENC_NA);
break;
case 0:
break;
default:
proto_tree_add_item(tree, &hfi_sll_src_other, tvb,
ha_offset, ha_len > 8 ? 8 : ha_len, ENC_NA);
break;
}
/* Not all bytes of SLL_ADDRLEN have been used. Add remaining as unused */
if (ha_len < SLL_ADDRLEN)
proto_tree_add_item(tree, &hfi_sll_unused, tvb, ha_offset + ha_len,
SLL_ADDRLEN - ha_len, ENC_BIG_ENDIAN);
}
static guint16
add_protocol_type(proto_tree *fh_tree, tvbuff_t *tvb, int protocol_offset,
int hatype)
{
guint16 protocol;
protocol = tvb_get_ntohs(tvb, protocol_offset);
if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
/*
* "proto" is *not* a length field, it's a Linux internal
* protocol type.
* We therefore cannot say how much of the packet will
* be trailer data.
* XXX - do the same thing we do for packets with Ethertypes?
*/
proto_tree_add_uint(fh_tree, &hfi_sll_ltype, tvb,
protocol_offset, 2, protocol);
} else {
switch (hatype) {
case ARPHRD_IPGRE:
/*
* XXX - the link-layer header appears to consist
* of an IPv4 header followed by a bunch of stuff
* that includes the GRE flags and version, but
* cooked captures strip the link-layer header,
* so we can't provide the flags and version to
* the dissector.
*/
proto_tree_add_uint(fh_tree, &hfi_sll_gretype, tvb,
protocol_offset, 2, protocol);
break;
default:
proto_tree_add_uint(fh_tree, &hfi_sll_etype, tvb,
protocol_offset, 2, protocol);
break;
}
}
return protocol;
}
static void
dissect_payload(proto_tree *tree, packet_info *pinfo, proto_tree *fh_tree,
tvbuff_t *tvb, int header_size, int hatype, guint16 protocol)
{
tvbuff_t *next_tvb;
ethertype_data_t ethertype_data;
next_tvb = tvb_new_subset_remaining(tvb, header_size);
if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
/*
* "proto" is *not* a length field, it's a Linux internal
* protocol type.
* We therefore cannot say how much of the packet will
* be trailer data.
* XXX - do the same thing we do for packets with Ethertypes?
*/
if (!dissector_try_uint(sll_hatype_dissector_table, hatype,
next_tvb, pinfo, tree)) {
p_add_proto_data(pinfo->pool, pinfo, proto_sll, 0, GUINT_TO_POINTER((guint)protocol));
if (!dissector_try_uint(sll_ltype_dissector_table,
protocol, next_tvb, pinfo, tree)) {
call_data_dissector(next_tvb, pinfo, tree);
}
}
} else {
switch (hatype) {
case ARPHRD_IPGRE:
/*
* XXX - the link-layer header appears to consist
* of an IPv4 header followed by a bunch of stuff
* that includes the GRE flags and version, but
* cooked captures strip the link-layer header,
* so we can't provide the flags and version to
* the dissector.
*/
dissector_try_uint(gre_dissector_table, protocol,
next_tvb, pinfo, tree);
break;
default:
ethertype_data.etype = protocol;
ethertype_data.payload_offset = header_size;
ethertype_data.fh_tree = fh_tree;
ethertype_data.trailer_id = hfi_sll_trailer.id;
ethertype_data.fcs_len = 0;
call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, &ethertype_data);
break;
}
}
}
static int
dissect_sll_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int encap)
{
guint16 pkttype;
guint16 protocol;
guint16 hatype;
int header_size;
int version;
proto_item *ti;
proto_tree *fh_tree;
sll_tap_data* tap_data;
switch (encap) {
case WTAP_ENCAP_SLL:
pkttype = tvb_get_ntohs(tvb, 0);
header_size = SLL_HEADER_SIZE;
version = 1;
break;
case WTAP_ENCAP_SLL2:
pkttype = tvb_get_ntohs(tvb, 10);
header_size = SLL2_HEADER_SIZE;
version = 2;
break;
default:
DISSECTOR_ASSERT_NOT_REACHED();
}
/*
* Set "pinfo->p2p_dir" if the packet wasn't received
* promiscuously.
*/
switch (pkttype) {
case LINUX_SLL_HOST:
case LINUX_SLL_BROADCAST:
case LINUX_SLL_MULTICAST:
pinfo->p2p_dir = P2P_DIR_RECV;
break;
case LINUX_SLL_OUTGOING:
pinfo->p2p_dir = P2P_DIR_SENT;
break;
}
switch (encap) {
case WTAP_ENCAP_SLL:
hatype = tvb_get_ntohs(tvb, 2);
break;
case WTAP_ENCAP_SLL2:
hatype = tvb_get_ntohs(tvb, 8);
break;
default:
DISSECTOR_ASSERT_NOT_REACHED();
}
/*
* XXX - special purpose hack. Netlink packets have a hardware
* address type of ARPHRD_NETLINK, but the protocol type value
* indicates the Netlink message type; we just hand the netlink
* dissector our *entire* packet.
*
* That's different from link-layer types such as 802.11+radiotap,
* where the payload follows the complete SLL header, and the
* protocol field in the SLL header is irrelevant; for those,
* we have the sll.hatype dissector table.
*/
if (hatype == ARPHRD_NETLINK) {
return call_dissector(netlink_handle, tvb, pinfo, tree);
}
col_set_str(pinfo->cinfo, COL_PROTOCOL, "SLL");
col_clear(pinfo->cinfo, COL_INFO);
col_add_str(pinfo->cinfo, COL_INFO,
val_to_str(pkttype, packet_type_vals, "Unknown (%u)"));
ti = proto_tree_add_protocol_format(tree, hfi_sll->id, tvb, 0,
header_size, "Linux cooked capture v%d", version);
fh_tree = proto_item_add_subtree(ti, ett_sll);
tap_data = wmem_new0(wmem_file_scope(), sll_tap_data);
switch (encap) {
case WTAP_ENCAP_SLL:
proto_tree_add_item(fh_tree, &hfi_sll_pkttype, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_uint(fh_tree, &hfi_sll_hatype, tvb, 2, 2, hatype);
add_ll_address(fh_tree, pinfo, tvb, 4, 2, tap_data);
protocol = add_protocol_type(fh_tree, tvb, 14, hatype);
dissect_payload(tree, pinfo, fh_tree, tvb, SLL_HEADER_SIZE, hatype, protocol);
break;
case WTAP_ENCAP_SLL2:
protocol = add_protocol_type(fh_tree, tvb, 0, hatype);
proto_tree_add_item(fh_tree, &hfi_sll_ifindex, tvb, 4, 4, ENC_BIG_ENDIAN);
proto_tree_add_uint(fh_tree, &hfi_sll_hatype, tvb, 8, 2, hatype);
proto_tree_add_item(fh_tree, &hfi_sll_pkttype, tvb, 10, 1, ENC_BIG_ENDIAN);
add_ll_address(fh_tree, pinfo, tvb, 11, 1, tap_data);
dissect_payload(tree, pinfo, fh_tree, tvb, SLL2_HEADER_SIZE, hatype, protocol);
break;
default:
DISSECTOR_ASSERT_NOT_REACHED();
}
tap_queue_packet(sll_tap, pinfo, tap_data);
return tvb_captured_length(tvb);
}
static int
dissect_sll_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
return dissect_sll_common(tvb, pinfo, tree, WTAP_ENCAP_SLL);
}
static int
dissect_sll_v2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
return dissect_sll_common(tvb, pinfo, tree, WTAP_ENCAP_SLL2);
}
void
proto_register_sll(void)
{
#ifndef HAVE_HFI_SECTION_INIT
static header_field_info *hfi[] = {
&hfi_sll_pkttype,
/* ARP hardware type? With Linux extensions? */
&hfi_sll_hatype,
&hfi_sll_halen,
&hfi_sll_src_eth,
&hfi_sll_src_ipv4,
&hfi_sll_src_other,
&hfi_sll_unused,
&hfi_sll_ltype,
&hfi_sll_gretype,
&hfi_sll_etype,
&hfi_sll_trailer,
&hfi_sll_ifindex,
};
#endif
static gint *ett[] = {
&ett_sll
};
/* Decode As handling */
static build_valid_func sll_da_build_value[1] = {sll_value};
static decode_as_value_t sll_da_values = {sll_prompt, 1, sll_da_build_value};
static decode_as_t sll_da = {"sll.ltype", "sll.ltype", 1, 0, &sll_da_values, NULL, NULL,
decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL};
proto_sll = proto_register_protocol("Linux cooked-mode capture",
"SLL", "sll" );
hfi_sll = proto_registrar_get_nth(proto_sll);
proto_register_fields(proto_sll, hfi, array_length(hfi));
proto_register_subtree_array(ett, array_length(ett));
sll_handle = create_dissector_handle(dissect_sll_v1, proto_sll);
sll2_handle = create_dissector_handle(dissect_sll_v2, proto_sll);
sll_tap = register_tap("sll");
/*
* Sigh.
*
* For some packets, the link-layer header *isn't* been stripped
* off in a cooked capture; the hardware address type is the
* device ARPTYPE, so, for those packets, we should call the
* dissector for that value.
*
* We define a "sll.hatype" dissector table; we try dissecting
* with that first, and then try the protocol type if nothing
* is found in sll.hatype.
*/
sll_hatype_dissector_table = register_dissector_table (
"sll.hatype",
"Linux SLL ARPHRD_ type",
proto_sll, FT_UINT16,
BASE_DEC
);
register_capture_dissector_table("sll.hatype", "Linux SLL ARPHRD_ type");
sll_ltype_dissector_table = register_dissector_table (
"sll.ltype",
"Linux SLL protocol type",
proto_sll, FT_UINT16,
BASE_HEX
);
register_capture_dissector_table("sll.ltype", "Linux SLL protocol");
register_conversation_table(proto_sll, TRUE, sll_conversation_packet, sll_hostlist_packet);
register_decode_as(&sll_da);
}
void
proto_reg_handoff_sll(void)
{
capture_dissector_handle_t sll_cap_handle;
capture_dissector_handle_t sll2_cap_handle;
/*
* Get handles for the IPX and LLC dissectors.
*/
gre_dissector_table = find_dissector_table("gre.proto");
ethertype_handle = find_dissector_add_dependency("ethertype", proto_sll);
netlink_handle = find_dissector_add_dependency("netlink", proto_sll);
dissector_add_uint("wtap_encap", WTAP_ENCAP_SLL, sll_handle);
dissector_add_uint("wtap_encap", WTAP_ENCAP_SLL2, sll2_handle);
sll_cap_handle = create_capture_dissector_handle(capture_sll, proto_sll);
capture_dissector_add_uint("wtap_encap", WTAP_ENCAP_SLL, sll_cap_handle);
sll2_cap_handle = create_capture_dissector_handle(capture_sll2, proto_sll);
capture_dissector_add_uint("wtap_encap", WTAP_ENCAP_SLL2, sll2_cap_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/