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// Copyright (C) 2015-2022 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 <util/buffer.h>
#include <dhcp/iface_mgr.h>
#include <dhcp/pkt4.h>
#include <dhcp/pkt4o6.h>
#include <dhcp/pkt6.h>
#include <dhcpsrv/callout_handle_store.h>
#include <dhcpsrv/cfgmgr.h>
#include <dhcp4/ctrl_dhcp4_srv.h>
#include <dhcp4/dhcp4to6_ipc.h>
#include <dhcp4/dhcp4_log.h>
#include <hooks/callout_handle.h>
#include <hooks/hooks_log.h>
#include <hooks/hooks_manager.h>
using namespace std;
using namespace isc::dhcp;
using namespace isc::hooks;
namespace isc {
namespace dhcp {
Dhcp4to6Ipc::Dhcp4to6Ipc() : Dhcp4o6IpcBase() {}
Dhcp4to6Ipc& Dhcp4to6Ipc::instance() {
static Dhcp4to6Ipc dhcp4to6_ipc;
return (dhcp4to6_ipc);
}
void Dhcp4to6Ipc::open() {
uint16_t port = CfgMgr::instance().getStagingCfg()->getDhcp4o6Port();
if (port == 0) {
Dhcp4o6IpcBase::close();
return;
}
if (port > 65534) {
isc_throw(OutOfRange, "DHCP4o6 port " << port);
}
int old_fd = socket_fd_;
socket_fd_ = Dhcp4o6IpcBase::open(port, ENDPOINT_TYPE_V4);
if ((old_fd == -1) && (socket_fd_ != old_fd)) {
IfaceMgr::instance().addExternalSocket(socket_fd_,
Dhcp4to6Ipc::handler);
}
}
void Dhcp4to6Ipc::handler(int /* fd */) {
Dhcp4to6Ipc& ipc = Dhcp4to6Ipc::instance();
Pkt6Ptr pkt;
try {
LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_DHCP4O6_RECEIVING);
// Receive message from the IPC socket.
pkt = ipc.receive();
// from Dhcpv4Srv::run_one() after receivePacket()
if (pkt) {
LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC, DHCP4_DHCP4O6_PACKET_RECEIVED)
.arg(static_cast<int>(pkt->getType()))
.arg(pkt->getRemoteAddr().toText())
.arg(pkt->getRemotePort())
.arg(pkt->getIface());
}
} catch (const std::exception& e) {
LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_DHCP4O6_RECEIVE_FAIL)
.arg(e.what());
}
if (!pkt) {
return;
}
// Each message must contain option holding DHCPv4 message.
OptionCollection msgs = pkt->getOptions(D6O_DHCPV4_MSG);
if (msgs.empty()) {
LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_DHCP4O6_BAD_PACKET)
.arg("DHCPv4 message option not present");
return;
} else if (msgs.size() > 1) {
LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_DHCP4O6_BAD_PACKET)
.arg("more than one DHCPv4 message option");
return;
}
// Get the DHCPv4 message.
OptionPtr msg = msgs.begin()->second;
if (!msg) {
LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL, DHCP4_DHCP4O6_BAD_PACKET)
.arg("null DHCPv4 message option");
return;
}
// Extract the DHCPv4 packet with DHCPv6 packet attached
Pkt4Ptr query(new Pkt4o6(msg->getData(), pkt));
// From Dhcpv4Srv::run_one() processing and after
Pkt4Ptr rsp;
ControlledDhcpv4Srv::getInstance()->processPacket(query, rsp, false);
if (!rsp) {
return;
}
try {
// Now all fields and options are constructed into output wire buffer.
// Option objects modification does not make sense anymore. Hooks
// can only manipulate wire buffer at this stage.
// Let's execute all callouts registered for buffer4_send
if (HooksManager::calloutsPresent(Dhcpv4Srv::getHookIndexBuffer4Send())) {
CalloutHandlePtr callout_handle = getCalloutHandle(query);
// Delete previously set arguments
callout_handle->deleteAllArguments();
// Use the RAII wrapper to make sure that the callout handle state is
// reset when this object goes out of scope. All hook points must do
// it to prevent possible circular dependency between the callout
// handle and its arguments.
ScopedCalloutHandleState callout_handle_state(callout_handle);
// Enable copying options from the packet within hook library.
ScopedEnableOptionsCopy<Pkt4> response4_options_copy(rsp);
// Pass incoming packet as argument
callout_handle->setArgument("response4", rsp);
// Call callouts
HooksManager::callCallouts(Dhcpv4Srv::getHookIndexBuffer4Send(),
*callout_handle);
// Callouts decided to skip the next processing step. The next
// processing step would be to parse the packet, so skip at this
// stage means drop.
if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) ||
(callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP)) {
LOG_DEBUG(hooks_logger, DBG_DHCP4_HOOKS,
DHCP4_HOOK_BUFFER_SEND_SKIP)
.arg(rsp->getLabel());
return;
}
callout_handle->getArgument("response4", rsp);
}
Pkt4o6Ptr rsp6 = boost::dynamic_pointer_cast<Pkt4o6>(rsp);
// Should not happen
if (!rsp6) {
isc_throw(Unexpected, "Dhcp4o6 packet cast fail");
}
LOG_DEBUG(packet4_logger, DBG_DHCP4_BASIC, DHCP4_DHCP4O6_PACKET_SEND)
.arg(rsp6->getLabel())
.arg(rsp6->getName())
.arg(static_cast<int>(rsp6->getType()))
.arg(rsp6->getRemoteAddr())
.arg(rsp6->getRemotePort())
.arg(rsp6->getIface())
.arg(rsp->getLabel())
.arg(rsp->getName())
.arg(static_cast<int>(rsp->getType()));
LOG_DEBUG(packet4_logger, DBG_DHCP4_DETAIL_DATA,
DHCP4_DHCP4O6_RESPONSE_DATA)
.arg(rsp6->getLabel())
.arg(rsp6->getName())
.arg(static_cast<int>(rsp6->getType()))
.arg(rsp6->toText());
ipc.send(rsp6->getPkt6());
// Update statistics accordingly for sent packet.
Dhcpv4Srv::processStatsSent(rsp);
} catch (const std::exception& e) {
LOG_ERROR(packet4_logger, DHCP4_DHCP4O6_PACKET_SEND_FAIL)
.arg(rsp->getLabel())
.arg(e.what());
}
}
} // namespace dhcp
} // namespace isc
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