Adding upstream version 2.4.1.upstream/2.4.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 351 insertions, 0 deletions

diff --git a/src/bin/d2/simple_remove.h b/src/bin/d2/simple_remove.h
new file mode 100644
index 0000000..957cb13
--- /dev/null
+++ b/src/bin/d2/simple_remove.h
@@ -0,0 +1,351 @@
+// Copyright (C) 2020-2021 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/.
+
+#ifndef SIMPLE_REMOVE_H
+#define SIMPLE_REMOVE_H
+
+/// @file nc_remove.h This file defines the class SimpleRemoveTransaction.
+
+#include <d2srv/nc_trans.h>
+
+namespace isc {
+namespace d2 {
+
+/// @brief Thrown if the SimpleRemoveTransaction encounters a general error.
+class SimpleRemoveTransactionError : public isc::Exception {
+public:
+    SimpleRemoveTransactionError(const char* file, size_t line,
+                               const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
+/// @brief Embodies the "life-cycle" required to carry out a DDNS Remove update.
+///
+/// SimpleRemoveTransaction implements a state machine for removing a forward
+/// and/or reverse DNS mappings.  This state machine follows a basic
+/// removal scheme, that does not attempt to avoid conflicts between updating
+/// clients.  The logic may be paraphrased as follows:
+///
+/// @code
+///
+/// If the request includes a forward change:
+///     Select a forward server
+///     Send the server a request to remove client's specific forward address
+///     RR and DHCID RR.
+///     If it does not succeed
+///         abandon the update
+///
+/// If the request includes a reverse change:
+///     Select a reverse server
+///     Send a server a request to delete the matching PTR and DHCID RRs.
+///
+/// @endcode
+///
+/// This class derives from NameChangeTransaction from which it inherits
+/// states, events, and methods common to NameChangeRequest processing.
+class SimpleRemoveTransaction : public NameChangeTransaction {
+public:
+
+    //@{  Additional states needed for SimpleRemove state model.
+    /// @brief State that attempts to remove FQDN/IP and DHCID RRs for an FQDN
+    static const int REMOVING_FWD_RRS_ST = NCT_DERIVED_STATE_MIN + 2;
+
+    /// @brief State that attempts to remove reverse PTR records
+    static const int REMOVING_REV_PTRS_ST = NCT_DERIVED_STATE_MIN + 3;
+    //@}
+
+    //@{ Additional events needed for SimpleRemove state model.
+    /// @brief Event sent when replace attempt to fails with address not in use.
+    /// @todo Currently none have been identified.
+    //@}
+
+    /// @brief Constructor
+    ///
+    /// Instantiates an Remove transaction that is ready to be started.
+    ///
+    /// @param io_service IO service to be used for IO processing
+    /// @param ncr is the NameChangeRequest to fulfill
+    /// @param forward_domain is the domain to use for forward DNS updates
+    /// @param reverse_domain is the domain to use for reverse DNS updates
+    /// @param cfg_mgr pointer to the configuration manager
+    ///
+    /// @throw SimpleRemoveTransaction error if given request is not a CHG_REMOVE,
+    /// NameChangeTransaction error for base class construction errors.
+    SimpleRemoveTransaction(asiolink::IOServicePtr& io_service,
+                          dhcp_ddns::NameChangeRequestPtr& ncr,
+                          DdnsDomainPtr& forward_domain,
+                          DdnsDomainPtr& reverse_domain,
+                          D2CfgMgrPtr& cfg_mgr);
+
+    /// @brief Destructor
+    virtual ~SimpleRemoveTransaction();
+
+protected:
+    /// @brief Adds events defined by SimpleRemoveTransaction to the event set.
+    ///
+    /// Invokes NameChangeTransaction's implementation and then defines the
+    /// events unique to NCR Remove transaction processing.
+    ///
+    /// @throw StateModelError if an event definition is invalid or a duplicate.
+    virtual void defineEvents();
+
+    /// @brief Validates the contents of the set of events.
+    ///
+    /// Invokes NameChangeTransaction's implementation and then verifies the
+    /// Remove transaction's events. This tests that the needed events are in
+    /// the event dictionary.
+    ///
+    /// @throw StateModelError if an event value is undefined.
+    virtual void verifyEvents();
+
+    /// @brief Adds states defined by SimpleRemoveTransaction to the state set.
+    ///
+    /// Invokes NameChangeTransaction's implementation and then defines the
+    /// states unique to NCR Remove transaction processing.
+    ///
+    /// @throw StateModelError if an state definition is invalid or a duplicate.
+    virtual void defineStates();
+
+    /// @brief Validates the contents of the set of states.
+    ///
+    /// Invokes NameChangeTransaction's implementation and then verifies the
+    /// Remove transaction's states.  This tests that the needed states are in
+    /// the state dictionary.
+    ///
+    /// @throw StateModelError if an event value is undefined.
+    virtual void verifyStates();
+
+    /// @brief State handler for READY_ST.
+    ///
+    /// Entered from:
+    /// - INIT_ST with next event of START_EVT
+    ///
+    /// The READY_ST is the state the model transitions into when the inherited
+    /// method, startTransaction() is invoked.  This handler, therefore, is the
+    /// entry point into the state model execution.  Its primary task is to
+    /// determine whether to start with a forward DNS change or a reverse DNS
+    /// change.
+    ///
+    /// Transitions to:
+    /// - SELECTING_FWD_SERVER_ST with next event of SERVER_SELECT_ST if request
+    /// includes a forward change.
+    ///
+    /// - SELECTING_REV_SERVER_ST with next event of SERVER_SELECT_ST if request
+    /// includes only a reverse change.
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not
+    /// START_EVT.
+    void readyHandler();
+
+    /// @brief State handler for SELECTING_FWD_SERVER_ST.
+    ///
+    /// Entered from:
+    /// - READY_ST with next event of SELECT_SERVER_EVT
+    /// - REMOVING_FWD_RRS_ST with next event of SERVER_IO_ERROR_EVT
+    ///
+    /// Selects the server to be used from the forward domain for the forward
+    /// DNS update.  If next event is SELECT_SERVER_EVT the handler initializes
+    /// the forward domain's server selection mechanism and then attempts to
+    /// select the next server. If next event is SERVER_IO_ERROR_EVT then the
+    /// handler simply attempts to select the next server.
+    ///
+    /// Transitions to:
+    /// - REMOVING_FWD_RRS_ST with next event of SERVER_SELECTED upon
+    /// successful server selection
+    ///
+    /// - PROCESS_TRANS_FAILED with next event of NO_MORE_SERVERS_EVT upon
+    /// failure to select a server
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not
+    /// SELECT_SERVER_EVT or SERVER_IO_ERROR_EVT.
+    void selectingFwdServerHandler();
+
+    /// @brief State handler for SELECTING_REV_SERVER_ST.
+    ///
+    /// Entered from:
+    /// - READY_ST with next event of SELECT_SERVER_EVT
+    /// - REMOVING_FWD_RRS_ST with next event of SELECT_SERVER_EVT
+    /// - REMOVING_REV_PTRS_ST with next event of SERVER_IO_ERROR_EVT
+    ///
+    /// Selects the server to be used from the reverse domain for the reverse
+    /// DNS update.  If next event is SELECT_SERVER_EVT the handler initializes
+    /// the reverse domain's server selection mechanism and then attempts to
+    /// select the next server. If next event is SERVER_IO_ERROR_EVT then the
+    /// handler simply attempts to select the next server.
+    ///
+    /// Transitions to:
+    /// - REMOVING_REV_PTRS_ST with next event of SERVER_SELECTED upon
+    /// successful server selection
+    ///
+    /// - PROCESS_TRANS_FAILED with next event of NO_MORE_SERVERS_EVT upon
+    /// failure to select a server
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not
+    /// SELECT_SERVER_EVT or SERVER_IO_ERROR_EVT.
+    void selectingRevServerHandler();
+
+    /// @brief State handler for REMOVING_FWD_RRS_ST.
+    ///
+    /// Entered from:
+    /// - SELECTING_FWD_SERVER_ST with next event SEVER_SELECTED_EVT
+    ///
+    /// Attempts to delete any remaining RRs associated with the given FQDN
+    /// such as the DHCID RR.  If this is first invocation of the handler after
+    /// transitioning into this state, any previous update request context is
+    /// deleted and the handler builds the forward remove request. It then
+    /// schedules an asynchronous send via sendUpdate(),
+    /// and returns.  Note that sendUpdate will post NOP_EVT as the next event.
+    ///
+    /// Posting the NOP_EVT will cause runModel() to suspend execution of
+    /// the state model thus affecting a "wait" for the update IO to complete.
+    /// Update completion occurs via the DNSClient callback operator() method
+    /// inherited from NameChangeTransaction.  When invoked this callback will
+    /// post a next event of IO_COMPLETED_EVT and then invoke runModel which
+    /// resumes execution of the state model.
+    ///
+    /// When the handler is invoked with a next event of IO_COMPLETED_EVT,
+    /// the DNS update status is checked and acted upon accordingly:
+    ///
+    /// Transitions to:
+    /// - SELECTING_REV_SERVER_ST with a next event of SELECT_SERVER_EVT upon
+    /// successful completion and the request includes a reverse DNS update.
+    ///
+    /// - PROCESS_TRANS_OK_ST with next event of UPDATE_OK_EVT upon successful
+    /// completion and the request does not include a reverse DNS update.
+    ///
+    /// - PROCESS_TRANS_FAILED_ST with a next event of UPDATE_FAILED_EVT if the
+    /// DNS server rejected the update for any other reason or the IO completed
+    /// with an unrecognized status.
+    ///
+    /// - RE-ENTER this state with a next event of SERVER_SELECTED_EVT if
+    /// there was an IO error communicating with the server and the number of
+    /// per server retries has not been exhausted.
+    ///
+    /// - PROCESS_TRANS_FAILED_ST with a next event of SERVER_IO_ERROR_EVT if
+    /// there we have reached maximum number of retries without success on the
+    /// current server.
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not:
+    /// UPDATE_OK_EVT or IO_COMPLETE_EVT
+    void removingFwdRRsHandler();
+
+    /// @brief State handler for REMOVING_REV_PTRS_ST.
+    ///
+    /// Entered from:
+    /// - SELECTING_REV_SERVER_ST with a next event of SERVER_SELECTED_EVT
+    ///
+    /// Attempts to delete a reverse DNS entry for a given FQDN. If this is
+    /// first invocation of the handler after transitioning into this state,
+    /// any previous update request context is deleted.  If next event is
+    /// SERVER_SELECTED_EVT, the handler builds the reverse remove request,
+    /// schedules an asynchronous send via sendUpdate(), and then returns.
+    /// Note that sendUpdate will post NOP_EVT as next event.
+    ///
+    /// Posting the NOP_EVT will cause runModel() to suspend execution of
+    /// the state model thus affecting a "wait" for the update IO to complete.
+    /// Update completion occurs via the DNSClient callback operator() method
+    /// inherited from NameChangeTransaction.  When invoked this callback will
+    /// post a next event of IO_COMPLETED_EVT and then invoke runModel which
+    /// resumes execution of the state model.
+    ///
+    /// When the handler is invoked with a next event of IO_COMPLETED_EVT,
+    /// the DNS update status is checked and acted upon accordingly:
+    ///
+    /// Transitions to:
+    /// - PROCESS_TRANS_OK_ST with a next event of UPDATE_OK_EVT upon
+    /// successful completion.
+    ///
+    /// - PROCESS_TRANS_FAILED_ST with a next event of UPDATE_FAILED_EVT If the
+    /// DNS server rejected the update for any reason or the IO completed
+    /// with an unrecognized status.
+    ///
+    /// - RE-ENTER this state with a next event of SERVER_SELECTED_EVT if
+    /// there was an IO error communicating with the server and the number of
+    /// per server retries has not been exhausted.
+    ///
+    /// - SELECTING_REV_SERVER_ST with next event of SERVER_IO_ERROR_EVT if
+    /// there was an IO error communicating with the server and the number of
+    /// per server retries has been exhausted.
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not:
+    /// SERVER_SELECTED_EVT or IO_COMPLETED_EVT
+    void removingRevPtrsHandler();
+
+    /// @brief State handler for PROCESS_TRANS_OK_ST.
+    ///
+    /// Entered from:
+    /// - REMOVING_FWD_RRS_ST with a next event of UPDATE_OK_EVT
+    /// - REMOVING_REV_PTRS_ST with a next event of UPDATE_OK_EVT
+    ///
+    /// Sets the transaction action status to indicate success and ends
+    /// model execution.
+    ///
+    /// Transitions to:
+    /// - END_ST with a next event of END_EVT.
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not:
+    /// UPDATE_OK_EVT
+    void processRemoveOkHandler();
+
+    /// @brief State handler for PROCESS_TRANS_FAILED_ST.
+    ///
+    /// Entered from:
+    /// - SELECTING_FWD_SERVER_ST with a next event of NO_MORE_SERVERS
+    /// - REMOVING_FWD_RRS_ST with a next event of UPDATE_FAILED_EVT
+    /// - REMOVING_FWD_RRS_ST with a next event of SERVER_IO_ERROR_EVT
+    /// - SELECTING_REV_SERVER_ST with a next event of NO_MORE_SERVERS
+    /// - REMOVING_REV_PTRS_ST with a next event of UPDATE_FAILED_EVT
+    ///
+    /// Sets the transaction status to indicate failure and ends
+    /// model execution.
+    ///
+    /// Transitions to:
+    /// - END_ST with a next event of FAIL_EVT.
+    ///
+    /// @throw SimpleRemoveTransactionError if upon entry next event is not:
+    /// UPDATE_FAILED_EVT
+    void processRemoveFailedHandler();
+
+    /// @brief Builds a DNS request to remove all forward DNS RRs for a FQDN.
+    ///
+    /// Constructs a DNS update request, based upon the NCR, to remove the
+    /// forward DNS (A or AAAA) RR and DHCID RR. Once constructed, the request
+    /// is stored as the transaction's DNS update request.
+    ///
+    /// Prerequisite RRsets:
+    /// - None
+    ///
+    /// Updates RRsets:
+    /// -# A delete of FQDN/IP RR for the FQDN
+    /// -# A delete of DHCID RR for the FQDN
+    ///
+    /// @throw This method does not throw but underlying methods may.
+    void buildRemoveFwdRRsRequest();
+
+    /// @brief Builds a DNS request to remove a reverse DNS entry for a FQDN
+    ///
+    /// Constructs a DNS update request, based upon the NCR, for removing a
+    /// reverse DNS mapping.  Once constructed, the request is stored as
+    /// the transaction's DNS update request.
+    ///
+    /// Prerequisite RRsets:
+    /// - None
+    ///
+    /// Updates RRsets:
+    /// -# A delete of PTR RR for the IP
+    /// -# A delete of DHCID RR for the IP
+    ///
+    /// @throw This method does not throw but underlying methods may.
+    void buildRemoveRevPtrsRequest();
+};
+
+/// @brief Defines a pointer to a SimpleRemoveTransaction.
+typedef boost::shared_ptr<SimpleRemoveTransaction> SimpleRemoveTransactionPtr;
+
+
+} // namespace isc::d2
+} // namespace isc
+#endif