1 files changed, 162 insertions, 0 deletions
diff --git a/src/lib/dhcpsrv/tracking_lease_mgr.cc b/src/lib/dhcpsrv/tracking_lease_mgr.cc
new file mode 100644
index 0000000..35c8192
--- /dev/null
+++ b/src/lib/dhcpsrv/tracking_lease_mgr.cc
@@ -0,0 +1,162 @@
+// Copyright (C) 2023 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 <exceptions/exceptions.h>
+#include <dhcpsrv/dhcpsrv_log.h>
+#include <dhcpsrv/tracking_lease_mgr.h>
+#include <util/multi_threading_mgr.h>
+#include <boost/tuple/tuple.hpp>
+
+using namespace isc::asiolink;
+using namespace isc::util;
+
+namespace isc {
+namespace dhcp {
+
+TrackingLeaseMgr::TrackingLeaseMgr()
+    : LeaseMgr(), callbacks_(new TrackingLeaseMgr::CallbackContainer()) {
+}
+
+bool
+TrackingLeaseMgr::tryLock(const LeasePtr& lease) {
+    // Try inserting a lease. If such a lease already exists in the set, return false.
+    auto result = locked_leases_.insert(lease->addr_);
+    return (result.second);
+}
+
+void
+TrackingLeaseMgr::unlock(const LeasePtr& lease) {
+    // Remove the locked lease from the set.
+    locked_leases_.erase(lease->addr_);
+}
+
+bool
+TrackingLeaseMgr::isLocked(const LeasePtr& lease) {
+    return (locked_leases_.find(lease->addr_) != locked_leases_.end());
+}
+
+void
+TrackingLeaseMgr::trackAddLease(const LeasePtr& lease) {
+    runCallbacks(TRACK_ADD_LEASE, lease);
+}
+
+void
+TrackingLeaseMgr::trackUpdateLease(const LeasePtr& lease) {
+    runCallbacks(TRACK_UPDATE_LEASE, lease);
+}
+
+void
+TrackingLeaseMgr::trackDeleteLease(const LeasePtr& lease) {
+    runCallbacks(TRACK_DELETE_LEASE, lease);
+}
+
+void
+TrackingLeaseMgr::registerCallback(TrackingLeaseMgr::CallbackType type,
+                                   std::string owner,
+                                   SubnetID subnet_id,
+                                   Lease::Type lease_type,
+                                   TrackingLeaseMgr::CallbackFn callback_fn) {
+    // The first index filters the callbacks by type and subnet_id.
+    auto& idx = callbacks_->get<0>();
+    auto range = idx.equal_range(boost::make_tuple(type, subnet_id, lease_type));
+    if (range.first != range.second) {
+        // Make sure that the callback for this owner does not exist.
+        if (std::find_if(range.first, range.second,
+                         [&owner] (const Callback& cb) -> bool {
+                             return (cb.owner == owner);
+                         }) != range.second) {
+            isc_throw(InvalidOperation, "the callback owned by the " << owner
+                      << ", for subnet ID " << subnet_id
+                      << ", and lease type " << Lease::typeToText(lease_type)
+                      << " has already been registered in the lease manager");
+        }
+    }
+    TrackingLeaseMgr::Callback callback{type, owner, subnet_id, lease_type, callback_fn};
+    callbacks_->insert(callback);
+}
+
+void
+TrackingLeaseMgr::registerCallback(TrackingLeaseMgr::CallbackType type,
+                                   std::string owner,
+                                   Lease::Type lease_type,
+                                   TrackingLeaseMgr::CallbackFn callback_fn) {
+    registerCallback(type, owner, SUBNET_ID_GLOBAL, lease_type, callback_fn);
+}
+
+void
+TrackingLeaseMgr::unregisterCallbacks(SubnetID subnet_id, Lease::Type lease_type) {
+    // The second index filters the callbacks by the subnet identifier and
+    // the lease type.
+    auto& idx = callbacks_->get<1>();
+    auto range = idx.equal_range(boost::make_tuple(subnet_id, lease_type));
+    if (range.first != range.second) {
+        idx.erase(range.first, range.second);
+    }
+}
+
+void
+TrackingLeaseMgr::unregisterAllCallbacks() {
+    callbacks_->clear();
+}
+
+bool
+TrackingLeaseMgr::hasCallbacks() const {
+    return (!callbacks_->empty());
+}
+
+std::string
+TrackingLeaseMgr::callbackTypeToString(CallbackType type) {
+    switch (type) {
+    case TrackingLeaseMgr::TRACK_ADD_LEASE:
+        return ("add_lease");
+    case TrackingLeaseMgr::TRACK_UPDATE_LEASE:
+        return ("update_lease");
+    case TrackingLeaseMgr::TRACK_DELETE_LEASE:
+        return ("delete_lease");
+    default:
+        return ("unknown");
+    }
+}
+
+void
+TrackingLeaseMgr::runCallbacks(TrackingLeaseMgr::CallbackType type,
+                               const LeasePtr& lease) {
+    runCallbacksForSubnetID(type, SUBNET_ID_GLOBAL, lease);
+    runCallbacksForSubnetID(type, lease->subnet_id_, lease);
+}
+
+void
+TrackingLeaseMgr::runCallbacksForSubnetID(CallbackType type, SubnetID subnet_id,
+                                          const LeasePtr& lease) {
+    // The first index filters by callback type and subnet_id.
+    auto& idx = callbacks_->get<0>();
+    auto cbs = idx.equal_range(boost::make_tuple(type, subnet_id, lease->getType()));
+    if (cbs.first == cbs.second) {
+        return;
+    }
+    for (auto it = cbs.first; it != cbs.second; ++it) {
+        auto cb = *it;
+        try {
+            cb.fn(lease);
+        } catch (const std::exception& ex) {
+            LOG_WARN(dhcpsrv_logger, DHCPSRV_LEASE_MGR_CALLBACK_EXCEPTION)
+                .arg(callbackTypeToString(type))
+                .arg(subnet_id)
+                .arg(lease->addr_.toText())
+                .arg(ex.what());
+        } catch (...) {
+            LOG_WARN(dhcpsrv_logger, DHCPSRV_LEASE_MGR_CALLBACK_UNKNOWN_EXCEPTION)
+                .arg(callbackTypeToString(type))
+                .arg(subnet_id)
+                .arg(lease->addr_.toText());
+        }
+    }
+}
+
+} // end of namespace isc::dhcp
+} // end of namespace isc