// See the file "COPYING" in the main distribution directory for copyright.

#include "zeek/analyzer/protocol/rpc/Portmap.h"

#include "zeek/analyzer/protocol/rpc/XDR.h"

#include "zeek/analyzer/protocol/rpc/events.bif.h"

enum PortmapperProcs : uint8_t {

    PMAPPROC_NULL = 0,

    PMAPPROC_SET = 1,

    PMAPPROC_UNSET = 2,

    PMAPPROC_GETPORT = 3,

    PMAPPROC_DUMP = 4,

    PMAPPROC_CALLIT = 5,

};

namespace zeek::analyzer::rpc {

namespace detail {

bool PortmapperInterp::RPC_BuildCall(RPC_CallInfo* c, const u_char*& buf, int& n) {

    if ( c->Program() != 100000 )

        Weird("bad_RPC_program");

    switch ( c->Proc() ) {

        case PMAPPROC_NULL: break;

        case PMAPPROC_SET: {

            auto m = ExtractMapping(buf, n);

            if ( ! m )

                return false;

            c->AddVal(std::move(m));

        } break;

        case PMAPPROC_UNSET: {

            auto m = ExtractMapping(buf, n);

            if ( ! m )

                return false;

            c->AddVal(std::move(m));

        } break;

        case PMAPPROC_GETPORT: {

            auto pr = ExtractPortRequest(buf, n);

            if ( ! pr )

                return false;

            c->AddVal(std::move(pr));

        } break;

        case PMAPPROC_DUMP: break;

        case PMAPPROC_CALLIT: {

            auto call_it = ExtractCallItRequest(buf, n);

            if ( ! call_it )

                return false;

            c->AddVal(std::move(call_it));

        } break;

        default: return false;

    }

    return true;

}

bool PortmapperInterp::RPC_BuildReply(RPC_CallInfo* c, BifEnum::rpc_status status, const u_char*& buf, int& n,

                                      double start_time, double last_time, int reply_len) {

    EventHandlerPtr event;

    ValPtr reply;

    int success = (status == BifEnum::RPC_SUCCESS);

    switch ( c->Proc() ) {

        case PMAPPROC_NULL: event = success ? pm_request_null : pm_attempt_null; break;

        case PMAPPROC_SET:

            if ( success ) {

                uint32_t proc_status = extract_XDR_uint32(buf, n);

                if ( ! buf )

                    return false;

                reply = val_mgr->Bool(proc_status);

                event = pm_request_set;

            }

            else

                event = pm_attempt_set;

            break;

        case PMAPPROC_UNSET:

            if ( success ) {

                uint32_t proc_status = extract_XDR_uint32(buf, n);

                if ( ! buf )

                    return false;

                reply = val_mgr->Bool(proc_status);

                event = pm_request_unset;

            }

            else

                event = pm_attempt_unset;

            break;

        case PMAPPROC_GETPORT:

            if ( success ) {

                uint32_t port = extract_XDR_uint32(buf, n);

                if ( ! buf )

                    return false;

                RecordVal* rv = c->RequestVal()->AsRecordVal();

                auto is_tcp = rv->GetFieldAs<BoolVal>(2);

                reply = val_mgr->Port(CheckPort(port), is_tcp ? TRANSPORT_TCP : TRANSPORT_UDP);

                event = pm_request_getport;

            }

            else

                event = pm_attempt_getport;

            break;

        case PMAPPROC_DUMP:

            event = success ? pm_request_dump : pm_attempt_dump;

            if ( success ) {

                static auto pm_mappings = id::find_type<TableType>("pm_mappings");

                auto mappings = make_intrusive<TableVal>(pm_mappings);

                uint32_t nmap = 0;

                // Each call in the loop test pulls the next "opted"

                // element to see if there are more mappings.

                while ( extract_XDR_uint32(buf, n) && buf ) {

                    auto m = ExtractMapping(buf, n);

                    if ( ! m )

                        break;

                    auto index = val_mgr->Count(++nmap);

                    mappings->Assign(std::move(index), std::move(m));

                }

                if ( ! buf )

                    return false;

                reply = std::move(mappings);

                event = pm_request_dump;

            }

            else

                event = pm_attempt_dump;

            break;

        case PMAPPROC_CALLIT:

            if ( success ) {

                uint32_t port = extract_XDR_uint32(buf, n);

                int reply_n;

                const u_char* opaque_reply = extract_XDR_opaque(buf, n, reply_n);

                if ( ! opaque_reply )

                    return false;

                reply = val_mgr->Port(CheckPort(port), TRANSPORT_UDP);

                event = pm_request_callit;

            }

            else

                event = pm_attempt_callit;

            break;

        default: return false;

    }

    Event(event, c->TakeRequestVal(), status, std::move(reply));

    return true;

}

RecordValPtr PortmapperInterp::ExtractMapping(const u_char*& buf, int& len) {

    static auto pm_mapping = id::find_type<RecordType>("pm_mapping");

    auto mapping = make_intrusive<RecordVal>(pm_mapping);

    mapping->Assign(0, extract_XDR_uint32(buf, len));

    mapping->Assign(1, extract_XDR_uint32(buf, len));

    bool is_tcp = extract_XDR_uint32(buf, len) == IPPROTO_TCP;

    uint32_t port = extract_XDR_uint32(buf, len);

    mapping->Assign(2, val_mgr->Port(CheckPort(port), is_tcp ? TRANSPORT_TCP : TRANSPORT_UDP));

    if ( ! buf )

        return nullptr;

    return mapping;

}

RecordValPtr PortmapperInterp::ExtractPortRequest(const u_char*& buf, int& len) {

    static auto pm_port_request = id::find_type<RecordType>("pm_port_request");

    auto pr = make_intrusive<RecordVal>(pm_port_request);

    pr->Assign(0, extract_XDR_uint32(buf, len));

    pr->Assign(1, extract_XDR_uint32(buf, len));

    bool is_tcp = extract_XDR_uint32(buf, len) == IPPROTO_TCP;

    pr->Assign(2, is_tcp);

    (void)extract_XDR_uint32(buf, len); // consume the bogus port

    if ( ! buf )

        return nullptr;

    return pr;

}

RecordValPtr PortmapperInterp::ExtractCallItRequest(const u_char*& buf, int& len) {

    static auto pm_callit_request = id::find_type<RecordType>("pm_callit_request");

    auto c = make_intrusive<RecordVal>(pm_callit_request);

    c->Assign(0, extract_XDR_uint32(buf, len));

    c->Assign(1, extract_XDR_uint32(buf, len));

    c->Assign(2, extract_XDR_uint32(buf, len));

    int arg_n;

    (void)extract_XDR_opaque(buf, len, arg_n);

    c->Assign(3, arg_n);

    if ( ! buf )

        return nullptr;

    return c;

}

uint32_t PortmapperInterp::CheckPort(uint32_t port) {

    if ( port >= 65536 ) {

        if ( pm_bad_port ) {

            analyzer->EnqueueConnEvent(pm_bad_port, analyzer->ConnVal(), val_mgr->Count(port));

        }

        port = 0;

    }

    return port;

}

void PortmapperInterp::Event(EventHandlerPtr f, ValPtr request, BifEnum::rpc_status status, ValPtr reply) {

    if ( ! f )

        return;

    Args vl;

    vl.emplace_back(analyzer->ConnVal());

    if ( status == BifEnum::RPC_SUCCESS ) {

        if ( request )

            vl.emplace_back(std::move(request));

        if ( reply )

            vl.emplace_back(std::move(reply));

    }

    else {

        vl.emplace_back(BifType::Enum::rpc_status->GetEnumVal(status));

        if ( request )

            vl.emplace_back(std::move(request));

    }

    analyzer->EnqueueConnEvent(f, std::move(vl));

}

} // namespace detail

Portmapper_Analyzer::Portmapper_Analyzer(Connection* conn)

    : RPC_Analyzer("PORTMAPPER", conn, new detail::PortmapperInterp(this)) {

    orig_rpc = resp_rpc = nullptr;

}

void Portmapper_Analyzer::Init() {

    RPC_Analyzer::Init();

    if ( Conn()->ConnTransport() == TRANSPORT_TCP ) {

        orig_rpc = new Contents_RPC(Conn(), true, interp);

        resp_rpc = new Contents_RPC(Conn(), false, interp);

        AddSupportAnalyzer(orig_rpc);

        AddSupportAnalyzer(resp_rpc);

    }

}

} // namespace zeek::analyzer::rpc