/* packet-nflog.c

 * Copyright 2011,2012 Jakub Zawadzki <darkjames-ws@darkjames.pl>

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

#include "config.h"

#include <epan/etypes.h>

#include <epan/packet.h>

#include <wiretap/wtap.h>

#include <wsutil/ws_roundup.h>

#include "packet-arp.h"

#include "packet-netlink.h"

void proto_register_nflog(void);

void proto_reg_handoff_nflog(void);

/* nfulnl_attr_type enum from <linux/netfilter/nfnetlink_log.h> */

enum ws_nfulnl_attr_type {

    WS_NFULA_UNSPEC,

    WS_NFULA_PACKET_HDR,

    WS_NFULA_MARK,               /* __u32 nfmark */

    WS_NFULA_TIMESTAMP,          /* nfulnl_msg_packet_timestamp */

    WS_NFULA_IFINDEX_INDEV,      /* __u32 ifindex */

    WS_NFULA_IFINDEX_OUTDEV,     /* __u32 ifindex */

    WS_NFULA_IFINDEX_PHYSINDEV,  /* __u32 ifindex */

    WS_NFULA_IFINDEX_PHYSOUTDEV, /* __u32 ifindex */

    WS_NFULA_HWADDR,             /* nfulnl_msg_packet_hw */

    WS_NFULA_PAYLOAD,            /* opaque data payload */

    WS_NFULA_PREFIX,             /* string prefix */

    WS_NFULA_UID,                /* user id of socket */

    WS_NFULA_SEQ,                /* instance-local sequence number */

    WS_NFULA_SEQ_GLOBAL,         /* global sequence number */

    WS_NFULA_GID,                /* group id of socket */

    WS_NFULA_HWTYPE,             /* hardware type */

    WS_NFULA_HWHEADER,           /* hardware header */

    WS_NFULA_HWLEN,              /* hardware header length */

    WS_NFULA_CT,                 /* nfnetlink_conntrack.h */

    WS_NFULA_CT_INFO,            /* enum ip_conntrack_info */

};

static const value_string nflog_tlv_vals[] = {

    { WS_NFULA_UNSPEC,             "NFULA_UNSPEC" },

    { WS_NFULA_PACKET_HDR,         "NFULA_PACKET_HDR" },

    { WS_NFULA_MARK,               "NFULA_MARK" },

    { WS_NFULA_TIMESTAMP,          "NFULA_TIMESTAMP" },

    { WS_NFULA_IFINDEX_INDEV,      "NFULA_IFINDEX_INDEV" },

    { WS_NFULA_IFINDEX_OUTDEV,     "NFULA_IFINDEX_OUTDEV" },

    { WS_NFULA_IFINDEX_PHYSINDEV,  "NFULA_IFINDEX_PHYSINDEV" },

    { WS_NFULA_IFINDEX_PHYSOUTDEV, "NFULA_IFINDEX_PHYSOUTDEV" },

    { WS_NFULA_HWADDR,             "NFULA_HWADDR" },

    { WS_NFULA_PAYLOAD,            "NFULA_PAYLOAD" },

    { WS_NFULA_PREFIX,             "NFULA_PREFIX" },

    { WS_NFULA_UID,                "NFULA_UID" },

    { WS_NFULA_SEQ,                "NFULA_SEQ" },

    { WS_NFULA_SEQ_GLOBAL,         "NFULA_SEQ_GLOBAL" },

    { WS_NFULA_GID,                "NFULA_GID" },

    { WS_NFULA_HWTYPE,             "NFULA_HWTYPE" },

    { WS_NFULA_HWHEADER,           "NFULA_HWHEADER" },

    { WS_NFULA_HWLEN,              "NFULA_HWLEN" },

    { WS_NFULA_CT,                 "NFULA_CT" },

    { WS_NFULA_CT_INFO,            "NFULA_CT_INFO" },

    { 0, NULL }

};

static int proto_nflog;

static int hf_nflog_tlv_ct;

static int hf_nflog_tlv_ct_info;

static int hf_nflog_family;

static int hf_nflog_resid;

static int hf_nflog_tlv;

static int hf_nflog_tlv_gid;

static int hf_nflog_tlv_hook;

static int hf_nflog_tlv_hw_type;

static int hf_nflog_tlv_hwheader_len;

static int hf_nflog_tlv_hwprotocol;

static int hf_nflog_tlv_ifindex_indev;

static int hf_nflog_tlv_ifindex_outdev;

static int hf_nflog_tlv_ifindex_physindev;

static int hf_nflog_tlv_ifindex_physoutdev;

static int hf_nflog_tlv_length;

static int hf_nflog_tlv_prefix;

static int hf_nflog_tlv_timestamp;

static int hf_nflog_tlv_type;

static int hf_nflog_tlv_uid;

static int hf_nflog_tlv_unknown;

static int hf_nflog_version;

static int ett_nflog;

static int ett_nflog_tlv;

static dissector_handle_t ip_handle;

static dissector_handle_t ip6_handle;

static dissector_handle_t eth_handle;

static dissector_table_t ethertype_table;

static dissector_handle_t nflog_handle;

static bool eth_ip_layout_inside = true;

static int

dissect_nflog(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)

{

    const int start_tlv_offset = 4;

    proto_tree *nflog_tree = NULL;

    proto_item *ti;

    unsigned offset = 0;

    struct {

        proto_tree *parent;

        tvbuff_t   *buffer;

    } payload = {NULL, NULL}, hwheader = {NULL, NULL};

    int pf;

    uint16_t hw_protocol = 0;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "NFLOG");

    col_clear(pinfo->cinfo, COL_INFO);

    pf = tvb_get_uint8(tvb, 0);

    /* Header */

    if (proto_field_is_referenced(tree, proto_nflog)) {

        ti = proto_tree_add_item(tree, proto_nflog, tvb, 0, -1, ENC_NA);

        nflog_tree = proto_item_add_subtree(ti, ett_nflog);

        proto_tree_add_item(nflog_tree, hf_nflog_family, tvb, offset, 1, ENC_NA);

        offset += 1;

        proto_tree_add_item(nflog_tree, hf_nflog_version, tvb, offset, 1, ENC_NA);

        offset += 1;

        proto_tree_add_item(nflog_tree, hf_nflog_resid, tvb, offset, 2, ENC_BIG_ENDIAN);

        /*offset += 2;*/

    }

    offset = start_tlv_offset;

    /* TLVs */

    while (tvb_reported_length_remaining(tvb, offset) >= 4) {

        uint16_t tlv_len = tvb_get_h_uint16(tvb, offset + 0);

        uint16_t tlv_type;

        uint16_t value_len;

        proto_tree *tlv_tree;

        /* malformed */

        if (tlv_len < 4)

            return offset;

        value_len = tlv_len - 4;

        tlv_type = (tvb_get_h_uint16(tvb, offset + 2) & 0x7fff);

        bool handled = false;

        ti = proto_tree_add_bytes_format(nflog_tree, hf_nflog_tlv,

                         tvb, offset, tlv_len, NULL,

                         "TLV Type: %s (%u), Length: %u",

                         val_to_str_const(tlv_type, nflog_tlv_vals, "Unknown"),

                         tlv_type, tlv_len);

        tlv_tree = proto_item_add_subtree(ti, ett_nflog_tlv);

        proto_tree_add_item(tlv_tree, hf_nflog_tlv_length, tvb, offset + 0, 2, ENC_HOST_ENDIAN);

        proto_tree_add_item(tlv_tree, hf_nflog_tlv_type, tvb, offset + 2, 2, ENC_HOST_ENDIAN);

        switch (tlv_type) {

            case WS_NFULA_PACKET_HDR:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_hwprotocol,

                                tvb, offset + 4, 2, ENC_BIG_ENDIAN);

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_hook,

                                tvb, offset + 6, 1, ENC_NA);

                    hw_protocol = tvb_get_ntohs(tvb, offset + 4);

                    handled = true;

                }

                break;

            case WS_NFULA_IFINDEX_INDEV:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_ifindex_indev, tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_IFINDEX_OUTDEV:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_ifindex_outdev, tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_IFINDEX_PHYSINDEV:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_ifindex_physindev, tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_IFINDEX_PHYSOUTDEV:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_ifindex_physoutdev, tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_PAYLOAD:

                payload.buffer = tvb_new_subset_length(tvb, offset + 4, value_len);

                payload.parent = tlv_tree;

                handled = true;

                break;

            case WS_NFULA_PREFIX:

                if (value_len >= 1) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_prefix,

                                tvb, offset + 4, value_len, ENC_ASCII);

                    handled = true;

                }

                break;

            case WS_NFULA_UID:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_uid,

                                tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_GID:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_gid,

                                tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_TIMESTAMP:

                if (value_len == 16) {

                    /*

                     * 64-bit seconds and 64-bit microseconds.

                     *

                     * XXX - add an "expert info" warning if the

                     * microseconds are >= 10^6?

                     */

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_timestamp,

                                tvb, offset + 4, value_len,

                                ENC_TIME_SECS_USECS|ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_HWTYPE:

                if (value_len == 2) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_hw_type,

                                tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_HWHEADER:

                hwheader.buffer = tvb_new_subset_length(tvb, offset + 4, value_len);

                hwheader.parent = tlv_tree;

                handled = true;

                break;

            case WS_NFULA_HWLEN:

                if (value_len == 2 || value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_hwheader_len,

                                tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

            case WS_NFULA_CT:

                if (value_len > 0) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_ct,

                                tvb, offset + 4, value_len, ENC_ASCII);

                    handled = true;

                }

                break;

            case WS_NFULA_CT_INFO:

                if (value_len == 4) {

                    proto_tree_add_item(tlv_tree, hf_nflog_tlv_ct_info,

                                tvb, offset + 4, value_len, ENC_BIG_ENDIAN);

                    handled = true;

                }

                break;

        }

        if (!handled)

                proto_tree_add_item(tlv_tree, hf_nflog_tlv_unknown,

                                    tvb, offset + 4, value_len, ENC_NA);

        offset += WS_ROUNDUP_4(tlv_len); /* next TLV aligned to 4B */

    }

    if (hwheader.buffer && eth_handle) {

        proto_tree *parent = eth_ip_layout_inside ? hwheader.parent : tree;

        // for others it is not guaranteed to be full, just for avoiding errors

        if (hw_protocol == ETHERTYPE_IP) {

            call_dissector(eth_handle, hwheader.buffer, pinfo, parent);

        } else {

            call_data_dissector(hwheader.buffer, pinfo, parent);

        }

    }

    if (payload.buffer) {

        proto_tree *parent = eth_ip_layout_inside ? payload.parent : tree;

               if (hw_protocol) {

            if (!dissector_try_uint(ethertype_table, hw_protocol, payload.buffer, pinfo, parent))

                call_data_dissector(payload.buffer, pinfo, parent);

        } else {

            switch (pf) {

                /* Note: NFPROTO_INET is not supposed to appear here, it is mapped

                 * to NFPROTO_IPV4 or NFPROTO_IPV6 */

                case WS_NFPROTO_IPV4:

                    call_dissector(ip_handle, payload.buffer, pinfo, parent);

                    break;

                case WS_NFPROTO_IPV6:

                    call_dissector(ip6_handle, payload.buffer, pinfo, parent);

                    break;

                default:

                    call_data_dissector(payload.buffer, pinfo, parent);

                    break;

            }

        }

    }

    return tvb_captured_length(tvb);

}

void

proto_register_nflog(void)

{

    static hf_register_info hf[] = {

        { &hf_nflog_family,

            { "Family", "nflog.family",

              FT_UINT8, BASE_DEC, VALS(nfproto_family_vals), 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_version,

            { "Version", "nflog.version",

              FT_UINT8, BASE_DEC, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_resid,

            { "Resource id", "nflog.res_id",

              FT_UINT16, BASE_DEC, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv,

            { "TLV", "nflog.tlv",

              FT_BYTES, BASE_NONE, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_length,

            { "Length", "nflog.tlv_length",

              FT_UINT16, BASE_DEC, NULL, 0x00,

              "TLV Length", HFILL }

        },

        { &hf_nflog_tlv_type,

            { "Type", "nflog.tlv_type",

              FT_UINT16, BASE_DEC, VALS(nflog_tlv_vals), 0x7fff,

              "TLV Type", HFILL }

        },

        { &hf_nflog_tlv_hwprotocol,

            { "HW protocol", "nflog.protocol",

              FT_UINT16, BASE_HEX, VALS(etype_vals), 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_hw_type,

            { "HW Type", "nflog.hwtype",

              FT_UINT16, BASE_DEC, VALS(arp_hrd_vals), 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_hwheader_len,

            { "Hardware header length", "nflog.hwhdr_len",

              FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }

        },

        { &hf_nflog_tlv_hook,

            { "Netfilter hook", "nflog.hook",

              FT_UINT8, BASE_DEC, VALS(netfilter_hooks_vals), 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_ifindex_indev,

            { "IFINDEX_INDEV", "nflog.ifindex_indev",

              FT_UINT32, BASE_DEC, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_ifindex_outdev,

            { "IFINDEX_OUTDEV", "nflog.ifindex_outdev",

              FT_UINT32, BASE_DEC, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_ifindex_physindev,

            { "IFINDEX_PHYSINDEV", "nflog.ifindex_physindev",

              FT_UINT32, BASE_DEC, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_ifindex_physoutdev,

            { "IFINDEX_PHYSOUTDEV", "nflog.ifindex_physoutdev",

              FT_UINT32, BASE_DEC, NULL, 0x00,

              NULL, HFILL }

        },

        { &hf_nflog_tlv_prefix,

            { "Prefix", "nflog.prefix",

              FT_STRINGZ, BASE_NONE, NULL, 0x00,

              "TLV Prefix Value", HFILL }

        },

        { &hf_nflog_tlv_uid,

            { "UID", "nflog.uid",

              FT_INT32, BASE_DEC, NULL, 0x00,

              "TLV UID Value", HFILL }

        },

        { &hf_nflog_tlv_gid,

            { "GID", "nflog.gid",

              FT_INT32, BASE_DEC, NULL, 0x00,

              "TLV GID Value", HFILL }

        },

        { &hf_nflog_tlv_timestamp,

            { "Timestamp", "nflog.timestamp",

              FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00,

              "TLV Timestamp Value", HFILL }

        },

        { &hf_nflog_tlv_ct_info,

            { "CT INFO", "nflog.ctinfo",

              FT_INT32, BASE_DEC, VALS(nfq_ctinfo_vals), 0x00,

              "TLV CT INFO", HFILL }

        },

        { &hf_nflog_tlv_ct,

            { "CT", "nflog.ct",

              FT_STRINGZ, BASE_NONE, NULL, 0x00,

              "TLV CT", HFILL }

        },

        { &hf_nflog_tlv_unknown,

            { "Value", "nflog.tlv_value",

              FT_BYTES, BASE_NONE, NULL, 0x00,

              "TLV Value", HFILL }

        },

    };

    static int *ett[] = {

        &ett_nflog,

        &ett_nflog_tlv

    };

    module_t *nflog_module;

    proto_nflog = proto_register_protocol("Linux Netfilter NFLOG", "NFLOG", "nflog");

    nflog_handle = register_dissector("nflog", dissect_nflog, proto_nflog);

    proto_register_field_array(proto_nflog, hf, array_length(hf));

    proto_register_subtree_array(ett, array_length(ett));

    // user preferences

    nflog_module = prefs_register_protocol(proto_nflog, NULL);

    prefs_register_bool_preference(nflog_module, "eth_ip_layout_inside",

        "Place ip and eth inside",

        "Place ip and eth sections inside appropriate TLV's "

        "(payload and hw header respectively). If false, then place on top level",

        &eth_ip_layout_inside);

}

void

proto_reg_handoff_nflog(void)

{

    ip_handle  = find_dissector_add_dependency("ip", proto_nflog);

    ip6_handle = find_dissector_add_dependency("ipv6", proto_nflog);

    eth_handle = find_dissector_add_dependency("eth_header", proto_nflog);

    dissector_add_uint("wtap_encap", WTAP_ENCAP_NFLOG, nflog_handle);

    ethertype_table = find_dissector_table("ethertype");

}

/*

 * Editor modelines

 *

 * Local Variables:

 * c-basic-offset: 4

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

 * ex: set shiftwidth=4 tabstop=8 expandtab:

 * :indentSize=4:tabSize=8:noTabs=true:

 */