/*
 * Copyright (c) 2017-2024 OARC, Inc.
 * Copyright (c) 2011-2017, IIS - The Internet Foundation in Sweden
 * All rights reserved.
 *
 * This file is part of PacketQ.
 *
 * PacketQ 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 3 of the License, or
 * (at your option) any later version.
 *
 * PacketQ 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 PacketQ.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "dns.h"
#include "output.h"
#include "packet_handler.h"
#include "packetq.h"
#include "tcp.h"

#include <cctype>
#include <stdio.h>
#include <stdlib.h>

namespace packetq {

char visible_char_map[256];

void fill_in_visible_char_map()
{
    for (int i = 0; i < 256; ++i) {
        visible_char_map[i] = isgraph(i) ? i : '$';
    }
}

void fill_in_visible_char_map_rfc1035()
{
    for (int i = 0; i < 256; ++i) {
        if ((i >= 'a' && i <= 'z')
            || (i >= 'A' && i <= 'Z')
            || (i >= '0' && i <= '9')
            || (i == '-' || i == '_')) {
            visible_char_map[i] = i;
        } else { // espaping needed
            visible_char_map[i] = 0;
        }
    }
}

Parse_dns::Parse_dns(bool escape_dnsnames)
{
    if (escape_dnsnames) {
        fill_in_visible_char_map_rfc1035();
    } else {
        fill_in_visible_char_map();
    }

    table_name = "dns";

    add_packet_columns();
    add_lookup_tables();
}

void Parse_dns::add_packet_columns()
{
    m_ip_helper.add_packet_columns(*this);

    add_packet_column("qname", "", Coltype::_text, COLUMN_QNAME);
    add_packet_column("aname", "", Coltype::_text, COLUMN_ANAME);
    add_packet_column("msg_id", "", Coltype::_int, COLUMN_MSG_ID);
    add_packet_column("msg_size", "", Coltype::_int, COLUMN_MSG_SIZE);
    add_packet_column("opcode", "", Coltype::_int, COLUMN_OPCODE);
    add_packet_column("rcode", "", Coltype::_int, COLUMN_RCODE);
    add_packet_column("extended_rcode", "", Coltype::_int, COLUMN_EXTENDED_RCODE);
    add_packet_column("edns_version", "", Coltype::_int, COLUMN_EDNS_VERSION);
    add_packet_column("z", "", Coltype::_int, COLUMN_Z);
    add_packet_column("udp_size", "", Coltype::_int, COLUMN_UDP_SIZE);
    add_packet_column("qd_count", "", Coltype::_int, COLUMN_QD_COUNT);
    add_packet_column("an_count", "", Coltype::_int, COLUMN_AN_COUNT);
    add_packet_column("ns_count", "", Coltype::_int, COLUMN_NS_COUNT);
    add_packet_column("ar_count", "", Coltype::_int, COLUMN_AR_COUNT);
    add_packet_column("qtype", "", Coltype::_int, COLUMN_QTYPE);
    add_packet_column("qclass", "", Coltype::_int, COLUMN_QCLASS);
    add_packet_column("qlabels", "", Coltype::_int, COLUMN_QLABELS);
    add_packet_column("atype", "", Coltype::_int, COLUMN_ATYPE);
    add_packet_column("aclass", "", Coltype::_int, COLUMN_ACLASS);
    add_packet_column("attl", "", Coltype::_int, COLUMN_ATTL);
    add_packet_column("alabels", "", Coltype::_int, COLUMN_ALABELS);
    add_packet_column("aa", "", Coltype::_bool, COLUMN_AA);
    add_packet_column("tc", "", Coltype::_bool, COLUMN_TC);
    add_packet_column("rd", "", Coltype::_bool, COLUMN_RD);
    add_packet_column("cd", "", Coltype::_bool, COLUMN_CD);
    add_packet_column("ra", "", Coltype::_bool, COLUMN_RA);
    add_packet_column("ad", "", Coltype::_bool, COLUMN_AD);
    add_packet_column("do", "", Coltype::_bool, COLUMN_DO);
    add_packet_column("edns0", "", Coltype::_bool, COLUMN_EDNS0);
    add_packet_column("qr", "", Coltype::_bool, COLUMN_QR);

    add_packet_column("edns0_ecs", "", Coltype::_bool, COLUMN_EDNS0_ECS);
    add_packet_column("edns0_ecs_family", "", Coltype::_int, COLUMN_EDNS0_ECS_FAMILY);
    add_packet_column("edns0_ecs_source", "", Coltype::_int, COLUMN_EDNS0_ECS_SOURCE);
    add_packet_column("edns0_ecs_scope", "", Coltype::_int, COLUMN_EDNS0_ECS_SCOPE);
    add_packet_column("edns0_ecs_address", "", Coltype::_text, COLUMN_EDNS0_ECS_ADDRESS);
}

void Parse_dns::add_lookup_tables()
{
    g_db.add_lut("qtype", 1, "A");
    g_db.add_lut("qtype", 2, "NS");
    g_db.add_lut("qtype", 3, "MD");
    g_db.add_lut("qtype", 4, "MF");
    g_db.add_lut("qtype", 5, "CNAME");
    g_db.add_lut("qtype", 6, "SOA");
    g_db.add_lut("qtype", 7, "MB");
    g_db.add_lut("qtype", 8, "MG");
    g_db.add_lut("qtype", 9, "MR");
    g_db.add_lut("qtype", 10, "NULL");
    g_db.add_lut("qtype", 11, "WKS");
    g_db.add_lut("qtype", 12, "PTR");
    g_db.add_lut("qtype", 13, "HINFO");
    g_db.add_lut("qtype", 14, "MINFO");
    g_db.add_lut("qtype", 15, "MX");
    g_db.add_lut("qtype", 16, "TXT");
    g_db.add_lut("qtype", 17, "RP");
    g_db.add_lut("qtype", 18, "AFSDB");
    g_db.add_lut("qtype", 19, "X25");
    g_db.add_lut("qtype", 20, "ISDN");
    g_db.add_lut("qtype", 21, "RT");
    g_db.add_lut("qtype", 22, "NSAP");
    g_db.add_lut("qtype", 23, "NSAP-PTR");
    g_db.add_lut("qtype", 24, "SIG");
    g_db.add_lut("qtype", 25, "KEY");
    g_db.add_lut("qtype", 26, "PX");
    g_db.add_lut("qtype", 27, "GPOS");
    g_db.add_lut("qtype", 28, "AAAA");
    g_db.add_lut("qtype", 29, "LOC");
    g_db.add_lut("qtype", 30, "NXT");
    g_db.add_lut("qtype", 31, "EID");
    g_db.add_lut("qtype", 32, "NIMLOC");
    g_db.add_lut("qtype", 33, "SRV");
    g_db.add_lut("qtype", 34, "ATMA");
    g_db.add_lut("qtype", 35, "NAPTR");
    g_db.add_lut("qtype", 36, "KX");
    g_db.add_lut("qtype", 37, "CERT");
    g_db.add_lut("qtype", 38, "A6");
    g_db.add_lut("qtype", 39, "DNAME");
    g_db.add_lut("qtype", 40, "SINK");
    g_db.add_lut("qtype", 41, "OPT");
    g_db.add_lut("qtype", 42, "APL");
    g_db.add_lut("qtype", 43, "DS");
    g_db.add_lut("qtype", 44, "SSHFP");
    g_db.add_lut("qtype", 45, "IPSECKEY");
    g_db.add_lut("qtype", 46, "RRSIG");
    g_db.add_lut("qtype", 47, "NSEC");
    g_db.add_lut("qtype", 48, "DNSKEY");
    g_db.add_lut("qtype", 49, "DHCID");
    g_db.add_lut("qtype", 50, "NSEC3");
    g_db.add_lut("qtype", 51, "NSEC3PARAM");
    g_db.add_lut("qtype", 52, "TLSA");
    g_db.add_lut("qtype", 53, "SMIMEA");
    g_db.add_lut("qtype", 55, "HIP");
    g_db.add_lut("qtype", 56, "NINFO");
    g_db.add_lut("qtype", 57, "RKEY");
    g_db.add_lut("qtype", 58, "TALINK");
    g_db.add_lut("qtype", 59, "CDS");
    g_db.add_lut("qtype", 60, "CDNSKEY");
    g_db.add_lut("qtype", 61, "OPENPGPKEY");
    g_db.add_lut("qtype", 62, "CSYNC");
    g_db.add_lut("qtype", 63, "ZONEMD");
    g_db.add_lut("qtype", 64, "SVCB");
    g_db.add_lut("qtype", 65, "HTTPS");
    g_db.add_lut("qtype", 99, "SPF");
    g_db.add_lut("qtype", 100, "UINFO");
    g_db.add_lut("qtype", 101, "UID");
    g_db.add_lut("qtype", 102, "GID");
    g_db.add_lut("qtype", 103, "UNSPEC");
    g_db.add_lut("qtype", 104, "NID");
    g_db.add_lut("qtype", 105, "L32");
    g_db.add_lut("qtype", 106, "L64");
    g_db.add_lut("qtype", 107, "LP");
    g_db.add_lut("qtype", 108, "EUI48");
    g_db.add_lut("qtype", 109, "EUI64");
    g_db.add_lut("qtype", 249, "TKEY");
    g_db.add_lut("qtype", 250, "TSIG");
    g_db.add_lut("qtype", 251, "IXFR");
    g_db.add_lut("qtype", 252, "AXFR");
    g_db.add_lut("qtype", 253, "MAILB");
    g_db.add_lut("qtype", 254, "MAILA");
    g_db.add_lut("qtype", 255, "*");
    g_db.add_lut("qtype", 256, "URI");
    g_db.add_lut("qtype", 257, "CAA");
    g_db.add_lut("qtype", 258, "AVC");
    g_db.add_lut("qtype", 259, "DOA");
    g_db.add_lut("qtype", 260, "AMTRELAY");
    g_db.add_lut("qtype", 32768, "TA");
    g_db.add_lut("qtype", 32769, "DLV");

    g_db.add_lut("rcode", 0, "NoError");
    g_db.add_lut("rcode", 1, "FormErr");
    g_db.add_lut("rcode", 2, "ServFail");
    g_db.add_lut("rcode", 3, "NXDomain");
    g_db.add_lut("rcode", 4, "NotImp");
    g_db.add_lut("rcode", 5, "Refused");
    g_db.add_lut("rcode", 6, "YXDomain");
    g_db.add_lut("rcode", 7, "YXRRSet");
    g_db.add_lut("rcode", 8, "NXRRSet");
    g_db.add_lut("rcode", 9, "NotAuth");
    g_db.add_lut("rcode", 10, "NotZone");
    g_db.add_lut("rcode", 16, "BADVERS");
    g_db.add_lut("rcode", 16, "BADSIG");
    g_db.add_lut("rcode", 17, "BADKEY");
    g_db.add_lut("rcode", 18, "BADTIME");
    g_db.add_lut("rcode", 19, "BADMODE");
    g_db.add_lut("rcode", 20, "BADNAME");
    g_db.add_lut("rcode", 21, "BADALG");
    g_db.add_lut("rcode", 22, "BADTRUNC");
}

void Parse_dns::on_table_created(Table* table, const std::vector<int>& columns)
{
    m_ip_helper.on_table_created(table, columns);

    acc_msg_id         = table->get_accessor<int_column>("msg_id");
    acc_msg_size       = table->get_accessor<int_column>("msg_size");
    acc_opcode         = table->get_accessor<int_column>("opcode");
    acc_rcode          = table->get_accessor<int_column>("rcode");
    acc_extended_rcode = table->get_accessor<int_column>("extended_rcode");
    acc_edns_version   = table->get_accessor<int_column>("edns_version");
    acc_z              = table->get_accessor<int_column>("z");
    acc_udp_size       = table->get_accessor<int_column>("udp_size");
    acc_qd_count       = table->get_accessor<int_column>("qd_count");
    acc_an_count       = table->get_accessor<int_column>("an_count");
    acc_ns_count       = table->get_accessor<int_column>("ns_count");
    acc_ar_count       = table->get_accessor<int_column>("ar_count");
    acc_qtype          = table->get_accessor<int_column>("qtype");
    acc_qclass         = table->get_accessor<int_column>("qclass");
    acc_qlabels        = table->get_accessor<int_column>("qlabels");
    acc_atype          = table->get_accessor<int_column>("atype");
    acc_aclass         = table->get_accessor<int_column>("aclass");
    acc_attl           = table->get_accessor<int_column>("attl");
    acc_alabels        = table->get_accessor<int_column>("alabels");

    acc_qr    = table->get_accessor<bool_column>("qr");
    acc_aa    = table->get_accessor<bool_column>("aa");
    acc_tc    = table->get_accessor<bool_column>("tc");
    acc_rd    = table->get_accessor<bool_column>("rd");
    acc_cd    = table->get_accessor<bool_column>("cd");
    acc_ra    = table->get_accessor<bool_column>("ra");
    acc_ad    = table->get_accessor<bool_column>("ad");
    acc_do    = table->get_accessor<bool_column>("do");
    acc_edns0 = table->get_accessor<bool_column>("edns0");

    acc_qname = table->get_accessor<text_column>("qname");
    acc_aname = table->get_accessor<text_column>("aname");

    acc_edns0_ecs         = table->get_accessor<bool_column>("edns0_ecs");
    acc_edns0_ecs_family  = table->get_accessor<int_column>("edns0_ecs_family");
    acc_edns0_ecs_source  = table->get_accessor<int_column>("edns0_ecs_source");
    acc_edns0_ecs_scope   = table->get_accessor<int_column>("edns0_ecs_scope");
    acc_edns0_ecs_address = table->get_accessor<text_column>("edns0_ecs_address");
}

Packet::ParseResult Parse_dns::parse(Packet& packet, const std::vector<int>& columns, Row& destination_row, bool sample)
{
    if (not(packet.m_len >= 12 && (packet.m_ip_header.proto == IPPROTO_UDP || packet.m_ip_header.proto == IPPROTO_TCP)))
        return Packet::ERROR;

    if (!sample)
        return Packet::NOT_SAMPLED;

    unsigned char* ddata   = packet.m_data;
    int            dlength = packet.m_len;

    if (packet.m_ip_header.proto == IPPROTO_TCP) {
        int dns_size = (int(ddata[0]) << 8) | ddata[1];
        ddata += 2;
        dlength -= 2;
        if (dns_size != dlength)
            return Packet::ERROR;
    }

    DNSMessage message(ddata, dlength, packet.m_ip_header);

    DNSMessage::Header& header    = message.m_header;
    IP_header&          ip_header = message.m_ip_header;

    if (message.m_error != 0)
        return Packet::ERROR;

    if (!header.qr and header.qdcount == 0)
        return Packet::ERROR;

    Row* r = &destination_row;

    m_ip_helper.assign(r, &ip_header, columns);

    for (auto i = columns.begin(), end = columns.end(); i != end; ++i) {
        switch (*i) {
        case COLUMN_MSG_ID:
            acc_msg_id.value(r) = header.id;
            break;

        case COLUMN_MSG_SIZE:
            acc_msg_size.value(r) = message.m_length;
            break;

        case COLUMN_QR:
            acc_qr.value(r) = header.qr;
            break;

        case COLUMN_AA:
            acc_aa.value(r) = header.aa;
            break;

        case COLUMN_TC:
            acc_tc.value(r) = header.tc;
            break;

        case COLUMN_RD:
            acc_rd.value(r) = header.rd;
            break;

        case COLUMN_CD:
            acc_cd.value(r) = header.cd;
            break;

        case COLUMN_RA:
            acc_ra.value(r) = header.ra;
            break;

        case COLUMN_AD:
            acc_ad.value(r) = header.ad;
            break;

        case COLUMN_OPCODE:
            acc_opcode.value(r) = header.opcode;
            break;

        case COLUMN_RCODE:
            acc_rcode.value(r) = header.rcode;
            break;

        case COLUMN_QD_COUNT:
            acc_qd_count.value(r) = header.qdcount;
            break;

        case COLUMN_AN_COUNT:
            acc_an_count.value(r) = header.ancount;
            break;

        case COLUMN_NS_COUNT:
            acc_ns_count.value(r) = header.nscount;
            break;

        case COLUMN_AR_COUNT:
            acc_ar_count.value(r) = header.arcount;
            break;

        case COLUMN_QTYPE:
            acc_qtype.value(r) = message.m_questions[0].qtype;
            break;

        case COLUMN_QCLASS:
            acc_qclass.value(r) = message.m_questions[0].qclass;
            break;

        case COLUMN_QLABELS:
            acc_qlabels.value(r) = message.m_questions[0].qname.labels;
            break;

        case COLUMN_QNAME:
            acc_qname.value(r) = RefCountString::construct(message.m_questions[0].qname.fqdn);
            break;

        case COLUMN_EDNS0:
            acc_edns0.value(r) = message.m_edns0 ? 1 : 0;
            break;

        case COLUMN_DO:
            acc_do.value(r) = message.m_edns0 ? message.m_do : 0;
            break;

        case COLUMN_EXTENDED_RCODE:
            acc_extended_rcode.value(r) = message.m_edns0 ? message.m_extended_rcode : 0;
            break;

        case COLUMN_EDNS_VERSION:
            acc_edns_version.value(r) = message.m_edns0 ? message.m_edns_version : 0;
            break;

        case COLUMN_Z:
            acc_z.value(r) = message.m_edns0 ? message.m_z : 0;
            break;

        case COLUMN_UDP_SIZE:
            acc_udp_size.value(r) = message.m_edns0 ? message.m_udp_size : 0;
            break;

        case COLUMN_ANAME:
            acc_aname.value(r) = header.ancount ? RefCountString::construct(message.m_answer[0].name.fqdn) : RefCountString::construct("");
            break;

        case COLUMN_ATYPE:
            acc_atype.value(r) = header.ancount ? message.m_answer[0].type : 0;
            break;

        case COLUMN_ACLASS:
            acc_aclass.value(r) = header.ancount ? message.m_answer[0].rr_class : 0;
            break;

        case COLUMN_ATTL:
            acc_attl.value(r) = header.ancount ? message.m_answer[0].ttl : 0;
            break;

        case COLUMN_ALABELS:
            acc_alabels.value(r) = header.ancount ? message.m_answer[0].name.labels : 0;
            break;

        case COLUMN_EDNS0_ECS:
            acc_edns0_ecs.value(r) = message.m_edns0_ecs ? 1 : 0;
            break;

        case COLUMN_EDNS0_ECS_FAMILY:
            acc_edns0_ecs_family.value(r) = message.m_edns0_ecs_family;
            break;

        case COLUMN_EDNS0_ECS_SOURCE:
            acc_edns0_ecs_source.value(r) = message.m_edns0_ecs_source;
            break;

        case COLUMN_EDNS0_ECS_SCOPE:
            acc_edns0_ecs_scope.value(r) = message.m_edns0_ecs_scope;
            break;

        case COLUMN_EDNS0_ECS_ADDRESS:
            if (message.m_edns0_ecs_addr_set && message.m_edns0_ecs_family == 1)
                acc_edns0_ecs_address.value(r) = v4_addr2str(message.m_edns0_ecs_addr);
            else if (message.m_edns0_ecs_addr_set && message.m_edns0_ecs_family == 2)
                acc_edns0_ecs_address.value(r) = v6_addr2str(message.m_edns0_ecs_addr);
            else
                acc_edns0_ecs_address.value(r) = RefCountString::construct("");
            break;
        }
    }

    return Packet::OK;
}

} // namespace packetq