/* file-pcap.c
 * Routines for PCAP File Format
 * https://wiki.wireshark.org/Development/LibpcapFileFormat
 *
 * Copyright 2015, Michal Labedzki for Tieto Corporation
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 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/prefs.h>
#include <epan/expert.h>
#include <epan/exceptions.h>
#include <epan/show_exception.h>
#include <epan/wmem/wmem.h>

#include <wiretap/wtap.h>
#include <wiretap/pcap-encap.h>

static int proto_pcap = -1;

static dissector_handle_t pcap_handle;
dissector_handle_t pcap_pseudoheader_handle;

static int hf_pcap_header = -1;
static int hf_pcap_header_magic_number = -1;
static int hf_pcap_header_version_major = -1;
static int hf_pcap_header_version_minor = -1;
static int hf_pcap_header_this_zone = -1;
static int hf_pcap_header_sigfigs = -1;
static int hf_pcap_header_snapshot_length = -1;
static int hf_pcap_header_link_type = -1;
static int hf_pcap_packet = -1;
static int hf_pcap_packet_timestamp = -1;
static int hf_pcap_packet_timestamp_sec = -1;
static int hf_pcap_packet_timestamp_usec = -1;
static int hf_pcap_packet_included_length = -1;
static int hf_pcap_packet_origin_length = -1;
static int hf_pcap_packet_data = -1;
static int hf_pcap_packet_data_pseudoheader = -1;
static int hf_pcap_packet_data_pseudoheader_bluetooth_direction = -1;
static int hf_pcap_packet_data_data = -1;

static expert_field ei_unknown_encoding = EI_INIT;

static gint ett_pcap = -1;
static gint ett_pcap_header = -1;
static gint ett_pcap_packet = -1;
static gint ett_pcap_packet_data = -1;
static gint ett_pcap_pseudoheader = -1;
static gint ett_pcap_timestamp = -1;

static dissector_table_t wtap_encap_table;

static gboolean pref_dissect_next_layer = FALSE;

static const value_string magic_number_vals[] = {
    { 0xA1B2C3D4,  "Little-endian" },
    { 0xD4C3B2A1,  "Big-endian" },
    { 0, NULL }
};

static const value_string link_type_vals[] = {
    { 0,    "NULL" },
    { 1,    "ETHERNET" },
    { 3,    "AX25" },
    { 6,    "IEEE802_5" },
    { 7,    "ARCNET_BSD" },
    { 8,    "SLIP" },
    { 9,    "PPP" },
    { 10,   "FDDI" },
    { 50,   "PPP_HDLC" },
    { 51,   "PPP_ETHER" },
    { 100,  "ATM_RFC1483" },
    { 101,  "RAW" },
    { 104,  "C_HDLC" },
    { 105,  "IEEE802_11" },
    { 107,  "FRELAY" },
    { 108,  "LOOP" },
    { 113,  "LINUX_SLL" },
    { 114,  "LTALK" },
    { 117,  "PFLOG" },
    { 119,  "IEEE802_11_PRISM" },
    { 122,  "IP_OVER_FC" },
    { 123,  "SUNATM" },
    { 127,  "IEEE802_11_RADIOTAP" },
    { 129,  "ARCNET_LINUX" },
    { 138,  "APPLE_IP_OVER_IEEE1394" },
    { 139,  "MTP2_WITH_PHDR" },
    { 140,  "MTP2" },
    { 141,  "MTP3" },
    { 142,  "SCCP" },
    { 143,  "DOCSIS" },
    { 144,  "LINUX_IRDA" },
    { 147,  "USER_0" },
    { 148,  "USER_1" },
    { 149,  "USER_2" },
    { 150,  "USER_3" },
    { 151,  "USER_4" },
    { 152,  "USER_5" },
    { 153,  "USER_6" },
    { 154,  "USER_7" },
    { 155,  "USER_8" },
    { 156,  "USER_9" },
    { 157,  "USER_10" },
    { 158,  "USER_11" },
    { 159,  "USER_12" },
    { 160,  "USER_13" },
    { 161,  "USER_14" },
    { 162,  "USER_15" },
    { 163,  "IEEE802_11_AVS" },
    { 165,  "BACNET_MS_TP" },
    { 166,  "PPP_PPPD" },
    { 169,  "GPRS_LLC" },
    { 177,  "LINUX_LAPD" },
    { 187,  "BLUETOOTH_HCI_H4" },
    { 189,  "USB_LINUX" },
    { 192,  "PPI" },
    { 195,  "IEEE802_15_4" },
    { 196,  "SITA" },
    { 197,  "ERF" },
    { 201,  "BLUETOOTH_HCI_H4_WITH_PHDR" },
    { 202,  "AX25_KISS" },
    { 203,  "LAPD" },
    { 204,  "PPP_WITH_DIR" },
    { 205,  "C_HDLC_WITH_DIR" },
    { 206,  "FRELAY_WITH_DIR" },
    { 209,  "IPMB_LINUX" },
    { 215,  "IEEE802_15_4_NONASK_PHY" },
    { 220,  "USB_LINUX_MMAPPED" },
    { 224,  "FC_2" },
    { 225,  "FC_2_WITH_FRAME_DELIMS" },
    { 226,  "IPNET" },
    { 227,  "CAN_SOCKETCAN" },
    { 228,  "IPV4" },
    { 229,  "IPV6" },
    { 230,  "IEEE802_15_4_NOFCS" },
    { 231,  "DBUS" },
    { 235,  "DVB_CI" },
    { 236,  "MUX27010" },
    { 237,  "STANAG_5066_D_PDU" },
    { 239,  "NFLOG" },
    { 240,  "NETANALYZER" },
    { 241,  "NETANALYZER_TRANSPARENT" },
    { 242,  "IPOIB" },
    { 243,  "MPEG_2_TS" },
    { 244,  "NG40" },
    { 245,  "NFC_LLCP" },
    { 247,  "INFINIBAND" },
    { 248,  "SCTP" },
    { 249,  "USBPCAP" },
    { 250,  "RTAC_SERIAL" },
    { 251,  "BLUETOOTH_LE_LL" },
    { 253,  "NETLINK" },
    { 254,  "BLUETOOTH_LINUX_MONITOR" },
    { 255,  "BLUETOOTH_BREDR_BB" },
    { 256,  "BLUETOOTH_LE_LL_WITH_PHDR" },
    { 257,  "PROFIBUS_DL" },
    { 258,  "PKTAP" },
    { 259,  "EPON" },
    { 260,  "IPMI_HPM_2" },
    { 261,  "ZWAVE_R1_R2" },
    { 262,  "ZWAVE_R3" },
    { 263,  "WATTSTOPPER_DLM" },
    { 0, NULL }
};

static const value_string pseudoheader_bluetooth_direction_vals[] = {
    { 0,  "Sent" },
    { 1,  "Recv" },
    { 0, NULL }
};


void proto_register_file_pcap(void);
void proto_reg_handoff_file_pcap(void);

static int
dissect_pcap_pseudoheader(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    gint         offset = 0;
    guint32     *link_type;
    guint32      length = 0;
    tvbuff_t    *next_tvb;
    proto_item  *pseudoheader_item;
    proto_tree  *pseudoheader_tree = NULL;
    proto_item  *packet_item;
    proto_tree  *packet_tree;

    DISSECTOR_ASSERT(data);

    link_type = (guint32 *) data;
    pinfo->phdr->pkt_encap = wtap_pcap_encap_to_wtap_encap(*link_type);

    switch (*link_type) {
    case 139:
/* TODO no description for pseudoheader at http://www.tcpdump.org/linktypes.html */
        break;
    case 196:
        length = 5;
        break;
    case 197:
/* TODO no description for pseudoheader at http://www.tcpdump.org/linktypes.html */
        break;
    case 201:
        length = 4;
        break;
    case 204:
        length = 1;
        break;
    case 205:
        length = 1;
        break;
    case 206:
        length = 1;
        break;
    case 209:
        length = 6;
        break;
    case 226:
        length = 24;
        break;
    case 227:
/* TODO no description for pseudoheader at http://www.tcpdump.org/linktypes.html */
        break;
    case 240:
    case 241:
        length = 4;
        break;
    case 244:
        length = 20;
        break;
    case 245:
        length = 20;
        break;
    }

    if (length > 0) {
        pseudoheader_item = proto_tree_add_item(tree, hf_pcap_packet_data_pseudoheader, tvb, offset, length, ENC_NA);
        pseudoheader_tree = proto_item_add_subtree(pseudoheader_item, ett_pcap_pseudoheader);
    }

    switch (*link_type) {
    case 201:
        proto_tree_add_item(pseudoheader_tree, hf_pcap_packet_data_pseudoheader_bluetooth_direction, tvb, offset, 4, ENC_BIG_ENDIAN);
        if (tvb_get_guint32(tvb, offset, ENC_BIG_ENDIAN) == 0)
            pinfo->p2p_dir = P2P_DIR_SENT;
        else if (tvb_get_guint32(tvb, offset, ENC_BIG_ENDIAN) == 1)
            pinfo->p2p_dir = P2P_DIR_RECV;
        else
            pinfo->p2p_dir = P2P_DIR_UNKNOWN;
        offset += 4;
        break;
    default:
        offset += length;
    }

    next_tvb = tvb_new_subset_remaining(tvb, offset);

    packet_item = proto_tree_add_item(tree, hf_pcap_packet_data_data, tvb, offset, tvb_reported_length(next_tvb), ENC_NA);
    packet_tree = proto_item_add_subtree(packet_item, ett_pcap_packet_data);

    offset = dissector_try_uint_new(wtap_encap_table, pinfo->phdr->pkt_encap, next_tvb, pinfo, packet_tree, TRUE, NULL);

    return offset;
}

static int
dissect_pcap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    static const guint8 pcap_magic[]           = { 0xA1, 0xB2, 0xC3, 0xD4 };
    static const guint8 pcap_swapped_magic[]   = { 0xD4, 0xC3, 0xB2, 0xA1 };
    volatile gint    offset = 0;
    proto_tree      *main_tree;
    proto_item      *main_item;
    proto_tree      *header_tree;
    proto_item      *header_item;
    proto_tree      *packet_tree;
    proto_item      *packet_item;
    proto_tree      *timestamp_tree;
    proto_item      *timestamp_item;
    proto_tree      *packet_data_tree;
    proto_item      *packet_data_item;
    volatile guint32 encoding;
    guint32          origin_length;
    guint32          length;
    guint32          link_type;
    volatile guint32 frame_number = 1;
    nstime_t         timestamp;

    if (tvb_memeql(tvb, 0, pcap_magic, sizeof(pcap_magic)) &&
            tvb_memeql(tvb, 0, pcap_swapped_magic, sizeof(pcap_swapped_magic)))
        return 0;

    main_item = proto_tree_add_item(tree, proto_pcap, tvb, offset, -1, ENC_NA);
    main_tree = proto_item_add_subtree(main_item, ett_pcap);

    header_item = proto_tree_add_item(main_tree, hf_pcap_header    , tvb, offset, 24, ENC_NA);
    header_tree = proto_item_add_subtree(header_item, ett_pcap_header);

    proto_tree_add_item(header_tree, hf_pcap_header_magic_number, tvb, offset, 4, ENC_HOST_ENDIAN);
    encoding = tvb_get_guint32(tvb, offset, ENC_HOST_ENDIAN);
    if (encoding == 0xA1B2C3D4) {
        encoding = ENC_LITTLE_ENDIAN;
    } else if (encoding == 0xD4C3B2A1) {
        encoding = ENC_BIG_ENDIAN;
    } else {
        expert_add_info(pinfo, main_item, &ei_unknown_encoding);
        return offset;
    }
    offset += 4;

    proto_tree_add_item(header_tree, hf_pcap_header_version_major, tvb, offset, 2, encoding);
    offset += 2;

    proto_tree_add_item(header_tree, hf_pcap_header_version_minor, tvb, offset, 2, encoding);
    offset += 2;

    proto_tree_add_item(header_tree, hf_pcap_header_this_zone, tvb, offset, 4, encoding);
    offset += 4;

    proto_tree_add_item(header_tree, hf_pcap_header_sigfigs, tvb, offset, 4, encoding);
    offset += 4;

    proto_tree_add_item(header_tree, hf_pcap_header_snapshot_length, tvb, offset, 4, encoding);
    offset += 4;

    proto_tree_add_item(header_tree, hf_pcap_header_link_type, tvb, offset, 4, encoding);
    link_type = tvb_get_guint32(tvb, offset, encoding);
    offset += 4;

    while (offset < (gint) tvb_reported_length(tvb)) {
        packet_item = proto_tree_add_item(main_tree, hf_pcap_packet, tvb, offset, 4 * 4, ENC_NA);
        packet_tree = proto_item_add_subtree(packet_item, ett_pcap_packet);
        proto_item_append_text(packet_item, " %u", frame_number);

        timestamp.secs = tvb_get_guint32(tvb, offset, encoding);
        timestamp.nsecs = tvb_get_guint32(tvb, offset + 4, encoding) * 1000;

        timestamp_item = proto_tree_add_time(packet_tree, hf_pcap_packet_timestamp, tvb, offset, 8, &timestamp);
        timestamp_tree = proto_item_add_subtree(timestamp_item, ett_pcap_timestamp);

        proto_tree_add_item(timestamp_tree, hf_pcap_packet_timestamp_sec, tvb, offset, 4, encoding);
        offset += 4;

        proto_tree_add_item(timestamp_tree, hf_pcap_packet_timestamp_usec, tvb, offset, 4, encoding);
        offset += 4;

        proto_tree_add_item_ret_uint(packet_tree, hf_pcap_packet_included_length, tvb, offset, 4, encoding, &length);
        offset += 4;

        proto_tree_add_item_ret_uint(packet_tree, hf_pcap_packet_origin_length, tvb, offset, 4, encoding, &origin_length);
        offset += 4;

        packet_data_item = proto_tree_add_item(packet_tree, hf_pcap_packet_data, tvb, offset, length, ENC_NA);
        packet_data_tree = proto_item_add_subtree(packet_data_item, ett_pcap_packet_data);

        pinfo->fd->num = frame_number;
        pinfo->fd->abs_ts = timestamp;

        if (pref_dissect_next_layer) {
            TRY {
                call_dissector_with_data(pcap_pseudoheader_handle, tvb_new_subset(tvb, offset, length, origin_length), pinfo, packet_data_tree, &link_type);
            }
            CATCH_BOUNDS_ERRORS {
                show_exception(tvb, pinfo, packet_data_tree, EXCEPT_CODE, GET_MESSAGE);
            }
            ENDTRY;
        }
        offset += length;

        proto_item_set_len(packet_item, 4 * 4 + length);
        frame_number += 1;
    }

    return offset;
}

static gboolean
dissect_pcap_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    return dissect_pcap(tvb, pinfo, tree, NULL) > 0;
}

void
proto_register_file_pcap(void)
{
    module_t         *module;
    expert_module_t  *expert_module;

    static hf_register_info hf[] = {
        { &hf_pcap_header,
            { "Header",                                    "pcap.header",
            FT_NONE, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_magic_number,
            { "Magic Bytes",                               "pcap.header.magic_bytes",
            FT_UINT32, BASE_HEX, VALS(magic_number_vals), 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_version_major,
            { "Version Major",                             "pcap.header.version.major",
            FT_UINT16, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_version_minor,
            { "Version Minor",                             "pcap.header.version.minor",
            FT_UINT16, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_this_zone,
            { "This Zone",                                 "pcap.header.this_zone",
            FT_INT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_sigfigs,
            { "Sigfigs",                                   "pcap.header.sigfigs",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_snapshot_length,
            { "Snapshot Length",                           "pcap.header.snapshot_length",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_header_link_type,
            { "Link Type",                                 "pcap.header.link_type",
            FT_UINT32, BASE_DEC_HEX, VALS(link_type_vals), 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet,
            { "Packet",                                    "pcap.packet",
            FT_NONE, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_timestamp,
            { "Timestamp",                             "pcap.packet.timestamp",
            FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_timestamp_sec,
            { "Timestamp sec",                             "pcap.packet.timestamp.sec",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_timestamp_usec,
            { "Timestamp usec",                            "pcap.packet.timestamp.usec",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_included_length,
            { "Included Length",                           "pcap.packet.included_length",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_origin_length,
            { "Origin Length",                             "pcap.packet.origin_length",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_data,
            { "Data",                                      "pcap.packet.data",
            FT_NONE, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_data_pseudoheader,
            { "Pseudoheader",                              "pcap.packet.data.pseudoheader",
            FT_NONE, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_data_pseudoheader_bluetooth_direction,
            { "Direction",                                 "pcap.packet.data.pseudoheader.bluetooth.direction",
            FT_UINT32, BASE_HEX, VALS(pseudoheader_bluetooth_direction_vals), 0x00,
            NULL, HFILL }
        },
        { &hf_pcap_packet_data_data,
            { "Data",                                      "pcap.packet.data.data",
            FT_NONE, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },
    };

    static ei_register_info ei[] = {
        { &ei_unknown_encoding,      { "pcap.unknown_encoding",      PI_PROTOCOL, PI_ERROR, "Unknown Encoding", EXPFILL }}
    };

    static gint *ett[] = {
        &ett_pcap,
        &ett_pcap_header,
        &ett_pcap_packet,
        &ett_pcap_packet_data,
        &ett_pcap_pseudoheader,
        &ett_pcap_timestamp
    };

    proto_pcap = proto_register_protocol("PCAP File Format", "File-PCAP", "file-pcap");
    proto_register_field_array(proto_pcap, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));

    pcap_handle = new_register_dissector("file-pcap", dissect_pcap, proto_pcap);
    pcap_pseudoheader_handle = new_create_dissector_handle(dissect_pcap_pseudoheader, proto_pcap);

    module = prefs_register_protocol(proto_pcap, NULL);
    prefs_register_static_text_preference(module, "version",
            "PCAP version: >=2.4",
            "Version of file-format supported by this dissector.");

    prefs_register_bool_preference(module, "dissect_next_layer",
            "Dissect next layer",
            "Dissect next layer",
            &pref_dissect_next_layer);

    expert_module = expert_register_protocol(proto_pcap);
    expert_register_field_array(expert_module, ei, array_length(ei));
}

void
proto_reg_handoff_file_pcap(void)
{
    heur_dissector_add("wtap_file", dissect_pcap_heur, "PCAP File", "pcap_wtap", proto_pcap, HEURISTIC_ENABLE);
    wtap_encap_table = find_dissector_table("wtap_encap");
}

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */