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243 | // Copyright (C) 2023-2024 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Kea Hooks Basic
// Commercial End User License Agreement v2.0. See COPYING file in the premium/
// directory.
#include <config.h>
#include <asiolink/io_service_mgr.h>
#include <database/audit_entry.h>
#include <dhcpsrv/cfgmgr.h>
#include <ping_check_log.h><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
#include <ping_check_mgr.h><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
#include <hooks/hooks.h>
#include <process/daemon.h>
#include <string><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
namespace isc {
namespace ping_check {
/// @brief PingCheckMgr singleton
PingCheckMgrPtr mgr;
} // end of namespace ping_check
} // end of namespace isc
using namespace isc;
using namespace isc::asiolink;
using namespace isc::log;
using namespace isc::data;
using namespace isc::db;
using namespace isc::dhcp;
using namespace isc::ping_check;
using namespace isc::hooks;
using namespace isc::process;
using namespace std;
// Functions accessed by the hooks framework use C linkage to avoid the name
// mangling that accompanies use of the C++ compiler as well as to avoid
// issues related to namespaces.
extern "C" {
/// @brief dhcp4_srv_configured implementation.
///
/// @param handle callout handle.
int dhcp4_srv_configured(CalloutHandle& handle) {
try {
SrvConfigPtr server_config;
handle.getArgument("server_config", server_config);
mgr->updateSubnetConfig(server_config);
NetworkStatePtr network_state;
handle.getArgument("network_state", network_state);
// Schedule a start of the services. This ensures we begin after
// the dust has settled and Kea MT mode has been firmly established.
mgr->startService(network_state);
IOServiceMgr::instance().registerIOService(mgr->getIOService());
} catch (const std::exception& ex) {
LOG_ERROR(ping_check_logger, PING_CHECK_DHCP4_SRV_CONFIGURED_FAILED)
.arg(ex.what());
handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
ostringstream os;
os << "Error: " << ex.what();
string error(os.str());
handle.setArgument("error", error);
return (1);
}
return (0);
}
/// @brief cb4_updated callout implementation.
///
/// If it detects that any subnets were altered by the update it
/// replaces the subnet cache contents. If any of the subnets
/// fail to parse, the error is logged and the function returns
/// a non-zero value.
///
/// @param handle CalloutHandle.
///
/// @return 0 upon success, 1 otherwise
int cb4_updated(CalloutHandle& handle) {<--- Parameter 'handle' can be declared as reference to const
AuditEntryCollectionPtr audit_entries;
handle.getArgument("audit_entries", audit_entries);
auto const& object_type_idx = audit_entries->get<AuditEntryObjectTypeTag>();
auto range = object_type_idx.equal_range("dhcp4_subnet");
if (std::distance(range.first, range.second)) {
try {
// Server config has been committed, so use the current configuration.
mgr->updateSubnetConfig(CfgMgr::instance().getCurrentCfg());
} catch (const std::exception& ex) {
LOG_ERROR(ping_check_logger, PING_CHECK_CB4_UPDATE_FAILED)
.arg(ex.what());
return (1);
}
}
return (0);
}
/// @brief lease4_offer callout implementation.
///
/// @param handle callout handle.
int lease4_offer(CalloutHandle& handle) {
CalloutHandle::CalloutNextStep status = handle.getStatus();<--- Shadowed declaration
if (status == CalloutHandle::NEXT_STEP_DROP ||
status == CalloutHandle::NEXT_STEP_SKIP) {
return (0);
}
Pkt4Ptr query4;
Lease4Ptr lease4;
ParkingLotHandlePtr parking_lot;<--- Shadowed declaration
try {
// Get all arguments available for the leases4_committed hook point.
// If any of these arguments is not available this is a programmatic
// error. An exception will be thrown which will be caught by the
// caller and logged.
handle.getArgument("query4", query4);
Lease4CollectionPtr leases4;
handle.getArgument("leases4", leases4);
uint32_t offer_lifetime;
handle.getArgument("offer_lifetime", offer_lifetime);
Lease4Ptr old_lease;
handle.getArgument("old_lease", old_lease);
if (query4->getType() != DHCPDISCOVER) {
isc_throw(InvalidOperation, "query4 is not a DHCPDISCOVER");
}
if (!leases4) {
isc_throw(InvalidOperation, "leases4 is null");
}
if (!leases4->empty()) {
lease4 = (*leases4)[0];
}
if (!lease4) {
isc_throw(InvalidOperation, "leases4 is empty, no lease to check");
}
// Fetch the parking lot. If it's empty the server is not employing
// parking, which is fine.
// Create a reference to the parked packet. This signals that we have a
// stake in unparking it.
ParkingLotHandlePtr parking_lot = handle.getParkingLotHandlePtr();<--- Shadow variable
if (parking_lot) {
parking_lot->reference(query4);
}
// Get configuration based on the lease's subnet.
auto const& config = mgr->getScopedConfig(lease4);
// Call shouldPing() to determine if we should ping check or not.
// - status == PARK - ping check it
// - status == CONTINUE - check not needed, release DHCPOFFER to client
// - status == DROP - duplicate check, drop the duplicate DHCPOFFER
auto status = mgr->shouldPing(lease4, query4, old_lease, config);<--- Shadow variable
handle.setStatus(status);
if (status == CalloutHandle::NEXT_STEP_PARK) {
mgr->startPing(lease4, query4, parking_lot, config);
} else {
// Dereference the parked packet. This releases our stake in it.
if (parking_lot) {
parking_lot->dereference(query4);
}
}
} catch (const std::exception& ex) {
LOG_ERROR(ping_check_logger, PING_CHECK_LEASE4_OFFER_FAILED)
.arg(query4 ? query4->getLabel() : "<no query>")
.arg(lease4 ? lease4->addr_.toText() : "<no lease>")
.arg(ex.what());
// Make sure we dereference.
if (parking_lot) {
parking_lot->dereference(query4);
}
return (1);
}
return (0);
}
/// @brief This function is called when the library is loaded.
///
/// @param handle library handle
/// @return 0 when initialization is successful, 1 otherwise
int load(LibraryHandle& handle) {
try {
// Make the hook library only loadable by kea-dhcp4.
const string& proc_name = Daemon::getProcName();
if (proc_name != "kea-dhcp4") {
isc_throw(isc::Unexpected, "Bad process name: " << proc_name
<< ", expected kea-dhcp4");
}
// Instantiate the manager singleton.
mgr.reset(new PingCheckMgr());
// Configure the manager using the hook library's parameters.
ConstElementPtr json = handle.getParameters();
mgr->configure(json);
} catch (const exception& ex) {
LOG_ERROR(ping_check_logger, PING_CHECK_LOAD_ERROR)
.arg(ex.what());
return (1);
}
LOG_INFO(ping_check_logger, PING_CHECK_LOAD_OK);
return (0);
}
/// @brief This function is called when the library is unloaded.
///
/// @return always 0.
int unload() {
if (mgr) {
IOServiceMgr::instance().unregisterIOService(mgr->getIOService());
if (mgr->getIOService()) {
mgr->getIOService()->stopAndPoll();
}
}
mgr.reset();
LOG_INFO(ping_check_logger, PING_CHECK_UNLOAD);
return (0);
}
/// @brief This function is called to retrieve the multi-threading compatibility.
///
/// @return 1 which means compatible with multi-threading.
int multi_threading_compatible() {
return (1);
}
} // end extern "C"
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