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/*
* packet-pktap.c
* Routines for dissecting Apple's PKTAP header
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 2007 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/capture_dissectors.h>
#include <epan/expert.h>
#include <wsutil/pint.h>
#include "packet-eth.h"
static dissector_handle_t pcap_pktdata_handle;
void proto_register_pktap(void);
void proto_reg_handoff_pktap(void);
/*
* Apple's PKTAP header.
*/
/*
* Minimum header length.
*
* XXX - I'm assuming the header begins with a length field so that it
* can be transparently *extended*, not so that fields in the current
* header can be *omitted*.
*/
#define MIN_PKTAP_HDR_LEN 108
/*
* Record types.
*/
#define PKT_REC_NONE 0 /* nothing follows the header */
#define PKT_REC_PACKET 1 /* a packet follows the header */
/* Protocol */
static int proto_pktap = -1;
static int hf_pktap_hdrlen = -1;
static int hf_pktap_rectype = -1;
static int hf_pktap_dlt = -1;
static int hf_pktap_ifname = -1;
static int hf_pktap_flags = -1;
static int hf_pktap_pfamily = -1;
static int hf_pktap_llhdrlen = -1;
static int hf_pktap_lltrlrlen = -1;
static int hf_pktap_pid = -1;
static int hf_pktap_cmdname = -1;
static int hf_pktap_svc_class = -1;
static int hf_pktap_iftype = -1;
static int hf_pktap_ifunit = -1;
static int hf_pktap_epid = -1;
static int hf_pktap_ecmdname = -1;
static gint ett_pktap = -1;
static expert_field ei_pktap_hdrlen_too_short = EI_INIT;
static dissector_handle_t pktap_handle;
/*
* XXX - these are little-endian in the captures I've seen, but Apple
* no longer make any big-endian machines (Macs use x86, iOS machines
* use ARM and run it little-endian), so that might be by definition
* or they might be host-endian.
*
* If a big-endian PKTAP file ever shows up, and it comes from a
* big-endian machine, presumably these are host-endian, and we need
* to just fetch the fields in host byte order here but byte-swap them
* to host byte order in libwiretap.
*/
static gboolean
capture_pktap(const guchar *pd, int offset _U_, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header _U_)
{
guint32 hdrlen, rectype, dlt;
hdrlen = pletoh32(pd);
if (hdrlen < MIN_PKTAP_HDR_LEN || !BYTES_ARE_IN_FRAME(0, len, hdrlen))
return FALSE;
rectype = pletoh32(pd+4);
if (rectype != PKT_REC_PACKET)
return FALSE;
dlt = pletoh32(pd+4);
/* XXX - We should probably combine this with capture_info.c:capture_info_packet() */
switch (dlt) {
case 1: /* DLT_EN10MB */
return capture_eth(pd, hdrlen, len, cpinfo, pseudo_header);
}
return FALSE;
}
static int
dissect_pktap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *pktap_tree = NULL;
proto_item *ti = NULL;
tvbuff_t *next_tvb;
int offset = 0;
guint32 pkt_len, rectype, dlt;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PKTAP");
col_clear(pinfo->cinfo, COL_INFO);
pkt_len = tvb_get_letohl(tvb, offset);
col_add_fstr(pinfo->cinfo, COL_INFO, "PKTAP, %u byte header", pkt_len);
/* Dissect the packet */
ti = proto_tree_add_item(tree, proto_pktap, tvb, offset, pkt_len, ENC_NA);
pktap_tree = proto_item_add_subtree(ti, ett_pktap);
proto_tree_add_item(pktap_tree, hf_pktap_hdrlen, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
if (pkt_len < MIN_PKTAP_HDR_LEN) {
proto_tree_add_expert(tree, pinfo, &ei_pktap_hdrlen_too_short,
tvb, offset, 4);
return tvb_captured_length(tvb);
}
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_rectype, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
rectype = tvb_get_letohl(tvb, offset);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_dlt, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
dlt = tvb_get_letohl(tvb, offset);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_ifname, tvb, offset, 24,
ENC_ASCII|ENC_NA);
offset += 24;
proto_tree_add_item(pktap_tree, hf_pktap_flags, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_pfamily, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_llhdrlen, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_lltrlrlen, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_pid, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_cmdname, tvb, offset, 20,
ENC_UTF_8|ENC_NA);
offset += 20;
proto_tree_add_item(pktap_tree, hf_pktap_svc_class, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_iftype, tvb, offset, 2,
ENC_LITTLE_ENDIAN);
offset += 2;
proto_tree_add_item(pktap_tree, hf_pktap_ifunit, tvb, offset, 2,
ENC_LITTLE_ENDIAN);
offset += 2;
proto_tree_add_item(pktap_tree, hf_pktap_epid, tvb, offset, 4,
ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(pktap_tree, hf_pktap_ecmdname, tvb, offset, 20,
ENC_UTF_8|ENC_NA);
/*offset += 20;*/
if (rectype == PKT_REC_PACKET) {
next_tvb = tvb_new_subset_remaining(tvb, pkt_len);
call_dissector_with_data(pcap_pktdata_handle, next_tvb,
pinfo, tree, &dlt);
}
return tvb_captured_length(tvb);
}
void
proto_register_pktap(void)
{
static hf_register_info hf[] = {
{ &hf_pktap_hdrlen,
{ "Header length", "pktap.hdrlen",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_rectype,
{ "Record type", "pktap.rectype",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_dlt,
{ "DLT", "pktap.dlt",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_ifname, /* fixed length *and* null-terminated */
{ "Interface name", "pktap.ifname",
FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_flags,
{ "Flags", "pktap.flags",
FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_pfamily,
{ "Protocol family", "pktap.pfamily",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_llhdrlen,
{ "Link-layer header length", "pktap.llhdrlen",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_lltrlrlen,
{ "Link-layer trailer length", "pktap.lltrlrlen",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_pid,
{ "Process ID", "pktap.pid",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_cmdname, /* fixed length *and* null-terminated */
{ "Command name", "pktap.cmdname",
FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_svc_class,
{ "Service class", "pktap.svc_class",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_iftype,
{ "Interface type", "pktap.iftype",
FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_ifunit,
{ "Interface unit", "pktap.ifunit",
FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_epid,
{ "Effective process ID", "pktap.epid",
FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } },
{ &hf_pktap_ecmdname, /* fixed length *and* null-terminated */
{ "Effective command name", "pktap.ecmdname",
FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL } },
};
static gint *ett[] = {
&ett_pktap,
};
static ei_register_info ei[] = {
{ &ei_pktap_hdrlen_too_short,
{ "pktap.hdrlen_too_short", PI_MALFORMED, PI_ERROR,
"Header length is too short", EXPFILL }},
};
expert_module_t* expert_pktap;
proto_pktap = proto_register_protocol("PKTAP packet header", "PKTAP",
"pktap");
proto_register_field_array(proto_pktap, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_pktap = expert_register_protocol(proto_pktap);
expert_register_field_array(expert_pktap, ei, array_length(ei));
pktap_handle = register_dissector("pktap", dissect_pktap, proto_pktap);
}
void
proto_reg_handoff_pktap(void)
{
dissector_add_uint("wtap_encap", WTAP_ENCAP_PKTAP, pktap_handle);
pcap_pktdata_handle = find_dissector_add_dependency("pcap_pktdata", proto_pktap);
/* XXX - WTAP_ENCAP_USER2 to handle Mavericks' botch wherein it
uses DLT_USER2 for PKTAP; if you are using DLT_USER2 for your
own purposes, feel free to call your own capture_ routine for
WTAP_ENCAP_USER2. */
register_capture_dissector("wtap_encap", WTAP_ENCAP_PKTAP, capture_pktap, proto_pktap);
register_capture_dissector("wtap_encap", WTAP_ENCAP_USER2, capture_pktap, proto_pktap);
}
/*
* Editor modelines - http://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:
*/
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