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// Copyright (C) 2013-2021 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include <config.h>
#include <d2srv/d2_log.h>
#include <d2srv/nc_trans.h>
#include <dns/qid_gen.h>
#include <dns/rdata.h>
#include <hooks/hooks.h>
#include <hooks/hooks_manager.h>
#include <sstream>
using namespace isc::hooks;
using namespace isc::util;
namespace {
/// Structure that holds registered hook indexes.
struct NcTransHooks {
int hooks_index_select_key_;
/// Constructor that registers hook points for the D2 server.
NcTransHooks() {
hooks_index_select_key_ = HooksManager::registerHook("select_key");
}
};
// Declare a Hooks object. As this is outside any function or method, it
// will be instantiated (and the constructor run) when the module is loaded.
// As a result, the hook indexes will be defined before any method in this
// module is called.
NcTransHooks Hooks;
}
namespace isc {
namespace d2 {
// Common transaction states
const int NameChangeTransaction::READY_ST;
const int NameChangeTransaction::SELECTING_FWD_SERVER_ST;
const int NameChangeTransaction::SELECTING_REV_SERVER_ST;
const int NameChangeTransaction::PROCESS_TRANS_OK_ST;
const int NameChangeTransaction::PROCESS_TRANS_FAILED_ST;
const int NameChangeTransaction::NCT_DERIVED_STATE_MIN;
// Common transaction events
const int NameChangeTransaction::SELECT_SERVER_EVT;
const int NameChangeTransaction::SERVER_SELECTED_EVT;
const int NameChangeTransaction::SERVER_IO_ERROR_EVT;
const int NameChangeTransaction::NO_MORE_SERVERS_EVT;
const int NameChangeTransaction::IO_COMPLETED_EVT;
const int NameChangeTransaction::UPDATE_OK_EVT;
const int NameChangeTransaction::UPDATE_FAILED_EVT;
const int NameChangeTransaction::NCT_DERIVED_EVENT_MIN;
const unsigned int NameChangeTransaction::MAX_UPDATE_TRIES_PER_SERVER;
NameChangeTransaction::
NameChangeTransaction(asiolink::IOServicePtr& io_service,
dhcp_ddns::NameChangeRequestPtr& ncr,
DdnsDomainPtr& forward_domain,
DdnsDomainPtr& reverse_domain,
D2CfgMgrPtr& cfg_mgr)
: io_service_(io_service), ncr_(ncr), forward_domain_(forward_domain),
reverse_domain_(reverse_domain), dns_client_(), dns_update_request_(),
dns_update_status_(DNSClient::OTHER), dns_update_response_(),
forward_change_completed_(false), reverse_change_completed_(false),
current_server_list_(), current_server_(), next_server_pos_(0),
update_attempts_(0), cfg_mgr_(cfg_mgr), tsig_key_() {
/// @todo if io_service is NULL we are multi-threading and should
/// instantiate our own
if (!io_service_) {
isc_throw(NameChangeTransactionError, "IOServicePtr cannot be null");
}
if (!ncr_) {
isc_throw(NameChangeTransactionError,
"NameChangeRequest cannot be null");
}
if (ncr_->isForwardChange() && !(forward_domain_)) {
isc_throw(NameChangeTransactionError,
"Forward change must have a forward domain");
}
if (ncr_->isReverseChange() && !(reverse_domain_)) {
isc_throw(NameChangeTransactionError,
"Reverse change must have a reverse domain");
}
if (!cfg_mgr_) {
isc_throw(NameChangeTransactionError,
"Configuration manager cannot be null");
}
}
NameChangeTransaction::~NameChangeTransaction(){
}
void
NameChangeTransaction::startTransaction() {
LOG_DEBUG(d2_to_dns_logger, isc::log::DBGLVL_TRACE_DETAIL,
DHCP_DDNS_STARTING_TRANSACTION)
.arg(getRequestId());
setNcrStatus(dhcp_ddns::ST_PENDING);
startModel(READY_ST);
}
void
NameChangeTransaction::operator()(DNSClient::Status status) {
// Stow the completion status and re-enter the run loop with the event
// set to indicate IO completed.
// runModel is exception safe so we are good to call it here.
// It won't exit until we hit the next IO wait or the state model ends.
setDnsUpdateStatus(status);
LOG_DEBUG(d2_to_dns_logger, isc::log::DBGLVL_TRACE_DETAIL,
DHCP_DDNS_UPDATE_RESPONSE_RECEIVED)
.arg(getRequestId())
.arg(current_server_->toText())
.arg(responseString());
runModel(IO_COMPLETED_EVT);
}
std::string
NameChangeTransaction::responseString() const {
std::ostringstream stream;
switch (getDnsUpdateStatus()) {
case DNSClient::SUCCESS:
stream << "SUCCESS, rcode: ";
if (getDnsUpdateResponse()) {
stream << getDnsUpdateResponse()->getRcode().toText();
} else {
stream << " update response is NULL";
}
break;
case DNSClient::TIMEOUT:
stream << "TIMEOUT";
break;
case DNSClient::IO_STOPPED:
stream << "IO_STOPPED";
break;
case DNSClient::INVALID_RESPONSE:
stream << "INVALID_RESPONSE";
break;
case DNSClient::OTHER:
stream << "OTHER";
break;
default:
stream << "UNKNOWN("
<< static_cast<int>(getDnsUpdateStatus()) << ")";
break;
}
return (stream.str());
}
std::string
NameChangeTransaction::transactionOutcomeString() const {
std::ostringstream stream;
stream << "Status: " << (getNcrStatus() == dhcp_ddns::ST_COMPLETED
? "Completed, " : "Failed, ")
<< "Event: " << getEventLabel(getNextEvent()) << ", ";
if (ncr_->isForwardChange()) {
stream << " Forward change:" << (getForwardChangeCompleted()
? " completed, " : " failed, ");
}
if (ncr_->isReverseChange()) {
stream << " Reverse change:" << (getReverseChangeCompleted()
? " completed, " : " failed, ");
}
stream << " request: " << ncr_->toText();
return (stream.str());
}
void
NameChangeTransaction::sendUpdate(const std::string& comment) {
try {
++update_attempts_;
// @todo add logic to add/replace TSIG key info in request if
// use_tsig_ is true. We should be able to navigate to the TSIG key
// for the current server. If not we would need to add that.
D2ParamsPtr d2_params = cfg_mgr_->getD2Params();
dns_client_->doUpdate(*io_service_, current_server_->getIpAddress(),
current_server_->getPort(), *dns_update_request_,
d2_params->getDnsServerTimeout(), tsig_key_);
// Message is on its way, so the next event should be NOP_EVT.
postNextEvent(NOP_EVT);
LOG_DEBUG(d2_to_dns_logger, isc::log::DBGLVL_TRACE_DETAIL,
DHCP_DDNS_UPDATE_REQUEST_SENT)
.arg(getRequestId())
.arg(comment)
.arg(current_server_->toText());
} catch (const std::exception& ex) {
// We were unable to initiate the send.
// It is presumed that any throw from doUpdate is due to a programmatic
// error, such as an unforeseen permutation of data, rather than an IO
// failure. IO errors should be caught by the underlying asiolink
// mechanisms and manifested as an unsuccessful IO status in the
// DNSClient callback. Any problem here most likely means the request
// is corrupt in some way and cannot be completed, therefore we will
// log it and transition it to failure.
LOG_ERROR(d2_to_dns_logger, DHCP_DDNS_TRANS_SEND_ERROR)
.arg(getRequestId())
.arg(ex.what());
transition(PROCESS_TRANS_FAILED_ST, UPDATE_FAILED_EVT);
}
}
void
NameChangeTransaction::defineEvents() {
// Call superclass impl first.
StateModel::defineEvents();
// Define NCT events.
defineEvent(SELECT_SERVER_EVT, "SELECT_SERVER_EVT");
defineEvent(SERVER_SELECTED_EVT, "SERVER_SELECTED_EVT");
defineEvent(SERVER_IO_ERROR_EVT, "SERVER_IO_ERROR_EVT");
defineEvent(NO_MORE_SERVERS_EVT, "NO_MORE_SERVERS_EVT");
defineEvent(IO_COMPLETED_EVT, "IO_COMPLETED_EVT");
defineEvent(UPDATE_OK_EVT, "UPDATE_OK_EVT");
defineEvent(UPDATE_FAILED_EVT, "UPDATE_FAILED_EVT");
}
void
NameChangeTransaction::verifyEvents() {
// Call superclass impl first.
StateModel::verifyEvents();
// Verify NCT events.
getEvent(SELECT_SERVER_EVT);
getEvent(SERVER_SELECTED_EVT);
getEvent(SERVER_IO_ERROR_EVT);
getEvent(NO_MORE_SERVERS_EVT);
getEvent(IO_COMPLETED_EVT);
getEvent(UPDATE_OK_EVT);
getEvent(UPDATE_FAILED_EVT);
}
void
NameChangeTransaction::defineStates() {
// Call superclass impl first.
StateModel::defineStates();
// This class is "abstract" in that it does not supply handlers for its
// states, derivations must do that therefore they must define them.
}
void
NameChangeTransaction::verifyStates() {
// Call superclass impl first.
StateModel::verifyStates();
// Verify NCT states. This ensures that derivations provide the handlers.
getStateInternal(READY_ST);
getStateInternal(SELECTING_FWD_SERVER_ST);
getStateInternal(SELECTING_REV_SERVER_ST);
getStateInternal(PROCESS_TRANS_OK_ST);
getStateInternal(PROCESS_TRANS_FAILED_ST);
}
void
NameChangeTransaction::onModelFailure(const std::string& explanation) {
setNcrStatus(dhcp_ddns::ST_FAILED);
LOG_ERROR(d2_to_dns_logger, DHCP_DDNS_STATE_MODEL_UNEXPECTED_ERROR)
.arg(getRequestId())
.arg(explanation);
}
void
NameChangeTransaction::retryTransition(const int fail_to_state) {
if (update_attempts_ < MAX_UPDATE_TRIES_PER_SERVER) {
// Re-enter the current state with same server selected.
transition(getCurrState(), SERVER_SELECTED_EVT);
} else {
// Transition to given fail_to_state state if we are out
// of retries.
transition(fail_to_state, SERVER_IO_ERROR_EVT);
}
}
void
NameChangeTransaction::setDnsUpdateRequest(D2UpdateMessagePtr& request) {
dns_update_request_ = request;
}
void
NameChangeTransaction::clearDnsUpdateRequest() {
dns_update_request_.reset();
}
void
NameChangeTransaction::clearUpdateAttempts() {
update_attempts_ = 0;
}
void
NameChangeTransaction::setDnsUpdateStatus(const DNSClient::Status& status) {
dns_update_status_ = status;
}
void
NameChangeTransaction::setDnsUpdateResponse(D2UpdateMessagePtr& response) {
dns_update_response_ = response;
}
void
NameChangeTransaction::clearDnsUpdateResponse() {
dns_update_response_.reset();
}
void
NameChangeTransaction::setForwardChangeCompleted(const bool value) {
forward_change_completed_ = value;
}
void
NameChangeTransaction::setReverseChangeCompleted(const bool value) {
reverse_change_completed_ = value;
}
void
NameChangeTransaction::setUpdateAttempts(const size_t value) {
update_attempts_ = value;
}
D2UpdateMessagePtr
NameChangeTransaction::prepNewRequest(DdnsDomainPtr domain) {
if (!domain) {
isc_throw(NameChangeTransactionError,
"prepNewRequest - domain cannot be null");
}
try {
// Create a "blank" update request.
D2UpdateMessagePtr request(new D2UpdateMessage(D2UpdateMessage::
OUTBOUND));
// Set the query id
request->setId(dns::QidGenerator::getInstance().generateQid());
// Construct the Zone Section.
dns::Name zone_name(domain->getName());
request->setZone(zone_name, dns::RRClass::IN());
return (request);
} catch (const std::exception& ex) {
isc_throw(NameChangeTransactionError, "Cannot create new request :"
<< ex.what());
}
}
void
NameChangeTransaction::addLeaseAddressRdata(dns::RRsetPtr& rrset) {
if (!rrset) {
isc_throw(NameChangeTransactionError,
"addLeaseAddressRdata - RRset cannot cannot be null");
}
try {
// Manufacture an RData from the lease address then add it to the RR.
dns::rdata::ConstRdataPtr rdata;
if (ncr_->isV4()) {
rdata.reset(new dns::rdata::in::A(ncr_->getIpAddress()));
} else {
rdata.reset(new dns::rdata::in::AAAA(ncr_->getIpAddress()));
}
rrset->addRdata(rdata);
} catch (const std::exception& ex) {
isc_throw(NameChangeTransactionError, "Cannot add address rdata: "
<< ex.what());
}
}
void
NameChangeTransaction::addDhcidRdata(dns::RRsetPtr& rrset) {
if (!rrset) {
isc_throw(NameChangeTransactionError,
"addDhcidRdata - RRset cannot cannot be null");
}
try {
const std::vector<uint8_t>& ncr_dhcid = ncr_->getDhcid().getBytes();
util::InputBuffer buffer(ncr_dhcid.data(), ncr_dhcid.size());
dns::rdata::ConstRdataPtr rdata (new dns::rdata::in::
DHCID(buffer, ncr_dhcid.size()));
rrset->addRdata(rdata);
} catch (const std::exception& ex) {
isc_throw(NameChangeTransactionError, "Cannot add DCHID rdata: "
<< ex.what());
}
}
void
NameChangeTransaction::addPtrRdata(dns::RRsetPtr& rrset) {
if (!rrset) {
isc_throw(NameChangeTransactionError,
"addPtrRdata - RRset cannot cannot be null");
}
try {
dns::rdata::ConstRdataPtr rdata(new dns::rdata::generic::
PTR(getNcr()->getFqdn()));
rrset->addRdata(rdata);
} catch (const std::exception& ex) {
isc_throw(NameChangeTransactionError, "Cannot add PTR rdata: "
<< ex.what());
}
}
const dhcp_ddns::NameChangeRequestPtr&
NameChangeTransaction::getNcr() const {
return (ncr_);
}
const TransactionKey&
NameChangeTransaction::getTransactionKey() const {
return (ncr_->getDhcid());
}
std::string
NameChangeTransaction::getRequestId() const {
return (ncr_->getRequestId());
}
dhcp_ddns::NameChangeStatus
NameChangeTransaction::getNcrStatus() const {
return (ncr_->getStatus());
}
DdnsDomainPtr&
NameChangeTransaction::getForwardDomain() {
return (forward_domain_);
}
DdnsDomainPtr&
NameChangeTransaction::getReverseDomain() {
return (reverse_domain_);
}
void
NameChangeTransaction::initServerSelection(const DdnsDomainPtr& domain) {
if (!domain) {
isc_throw(NameChangeTransactionError,
"initServerSelection called with an empty domain");
}
current_server_list_ = domain->getServers();
next_server_pos_ = 0;
current_server_.reset();
}
bool
NameChangeTransaction::selectNextServer() {
for (;;) {
if ((current_server_list_) &&
(next_server_pos_ < current_server_list_->size())) {
current_server_ = (*current_server_list_)[next_server_pos_];
// Toss out any previous response.
dns_update_response_.reset();
// Set the tsig_key to that of the current server.
if (!selectTSIGKey()) {
++next_server_pos_;
continue;
}
// @todo Protocol is set on DNSClient constructor. We need
// to propagate a configuration value downward, probably starting
// at global, then domain, finishing by server.
// Once that is supported we need to add it here.
dns_client_.reset(new DNSClient(dns_update_response_, this,
DNSClient::UDP));
++next_server_pos_;
return (true);
}
return (false);
}
}
bool
NameChangeTransaction::selectTSIGKey() {
TSIGKeyInfoPtr tsig_key_info = current_server_->getTSIGKeyInfo();
if (tsig_key_info) {
tsig_key_ = tsig_key_info->getTSIGKey();
} else {
tsig_key_.reset();
}
// This hook point allows hooks libraries to overwrite the TSIG key.
if (HooksManager::calloutsPresent(Hooks.hooks_index_select_key_)) {
CalloutHandlePtr callout_handle = HooksManager::createCalloutHandle();
callout_handle->setArgument("current_server", current_server_);
callout_handle->setArgument("tsig_key", tsig_key_);
HooksManager::callCallouts(Hooks.hooks_index_select_key_,
*callout_handle);
// This server is skipped because the status is not NEXT_STEP_CONTINUE.
if (callout_handle->getStatus() != CalloutHandle::NEXT_STEP_CONTINUE) {
return (false);
}
// Reread the TSIG key.
callout_handle->getArgument("tsig_key", tsig_key_);
}
return (true);
}
const DNSClientPtr&
NameChangeTransaction::getDNSClient() const {
return (dns_client_);
}
const DnsServerInfoPtr&
NameChangeTransaction::getCurrentServer() const {
return (current_server_);
}
void
NameChangeTransaction::setNcrStatus(const dhcp_ddns::NameChangeStatus& status) {
return (ncr_->setStatus(status));
}
const D2UpdateMessagePtr&
NameChangeTransaction::getDnsUpdateRequest() const {
return (dns_update_request_);
}
DNSClient::Status
NameChangeTransaction::getDnsUpdateStatus() const {
return (dns_update_status_);
}
const D2UpdateMessagePtr&
NameChangeTransaction::getDnsUpdateResponse() const {
return (dns_update_response_);
}
bool
NameChangeTransaction::getForwardChangeCompleted() const {
return (forward_change_completed_);
}
bool
NameChangeTransaction::getReverseChangeCompleted() const {
return (reverse_change_completed_);
}
size_t
NameChangeTransaction::getUpdateAttempts() const {
return (update_attempts_);
}
const dns::RRType&
NameChangeTransaction::getAddressRRType() const {
return (ncr_->isV4() ? dns::RRType::A() : dns::RRType::AAAA());
}
} // namespace isc::d2
} // namespace isc
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