diff options
Diffstat (limited to '')
| -rw-r--r-- | src/bin/d2/simple_add.h | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/src/bin/d2/simple_add.h b/src/bin/d2/simple_add.h new file mode 100644 index 0000000..bf617a5 --- /dev/null +++ b/src/bin/d2/simple_add.h @@ -0,0 +1,355 @@ +// 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_ADD_H +#define SIMPLE_ADD_H + +/// @file nc_add.h This file defines the class SimpleAddTransaction. + +#include <d2srv/nc_trans.h> +#include <dns/rdata.h> + +namespace isc { +namespace d2 { + +/// @brief Thrown if the SimpleAddTransaction encounters a general error. +class SimpleAddTransactionError : public isc::Exception { +public: + SimpleAddTransactionError(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 Add update. +/// +/// SimpleAddTransaction implements a state machine for adding (or replacing) a +/// forward and/or reverse DNS mapping. This state machine follows a basic +/// remove and replace 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 delete and then add forward entry +/// +/// If the request includes a reverse change: +/// Select a reverse server +/// Send a server a request to delete and then add reverse entry +/// +/// @endcode +/// +/// This class derives from NameChangeTransaction from which it inherits +/// states, events, and methods common to NameChangeRequest processing. +class SimpleAddTransaction : public NameChangeTransaction { +public: + + //@{ Additional states needed for SimpleAdd state model. + /// @brief State that attempts to add forward address records. + static const int REPLACING_FWD_ADDRS_ST = NCT_DERIVED_STATE_MIN + 1; + + /// @brief State that attempts to replace reverse PTR records + static const int REPLACING_REV_PTRS_ST = NCT_DERIVED_STATE_MIN + 3; + //@} + + //@{ Additional events needed for SimpleAdd state model. + /// @brief Event sent when an add attempt fails with address in use. + static const int FQDN_IN_USE_EVT = NCT_DERIVED_EVENT_MIN + 1; + + /// @brief Event sent when replace attempt to fails with address not in use. + static const int FQDN_NOT_IN_USE_EVT = NCT_DERIVED_EVENT_MIN + 2; + //@} + + /// @brief Constructor + /// + /// Instantiates an Add 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 SimpleAddTransaction error if given request is not a CHG_ADD, + /// NameChangeTransaction error for base class construction errors. + SimpleAddTransaction(asiolink::IOServicePtr& io_service, + dhcp_ddns::NameChangeRequestPtr& ncr, + DdnsDomainPtr& forward_domain, + DdnsDomainPtr& reverse_domain, + D2CfgMgrPtr& cfg_mgr); + + /// @brief Destructor + virtual ~SimpleAddTransaction(); + +protected: + /// @brief Adds events defined by SimpleAddTransaction to the event set. + /// + /// Invokes NameChangeTransaction's implementation and then defines the + /// events unique to NCR Add 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 + /// Add transaction's. 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 SimpleAddTransaction to the state set. + /// + /// Invokes NameChangeTransaction's implementation and then defines the + /// states unique to NCR Add 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 + /// Add 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.h 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 SimpleAddTransactionError 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 + /// - REPLACING_FWD_ADDRS_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: + /// - REPLACING_FWD_ADDRS_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 SimpleAddTransactionError 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 + /// - REPLACING_FWD_ADDRS_ST with next event of SELECT_SERVER_EVT + /// - REPLACING_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: + /// - REPLACING_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 SimpleAddTransactionError if upon entry next event is not + /// SELECT_SERVER_EVT or SERVER_IO_ERROR_EVT. + void selectingRevServerHandler(); + + /// @brief State handler for REPLACING_FWD_ADDRS_ST. + /// + /// Entered from: + /// - SELECTING_FWD_SERVER with next event of SERVER_SELECTED_EVT + /// + /// Attempts to replace a forward 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 forward add request, + /// schedules an asynchronous send via sendUpdate(), and 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: + /// - SELECTING_REV_SERVER_ST with next event of SELECT_SERVER_EVT upon + /// successful addition and the request includes a reverse DNS update. + /// + /// - PROCESS_TRANS_OK_ST with next event of UPDATE_OK_EVT upon successful + /// addition and no reverse DNS update is required. + /// + /// - PROCESS_TRANS_FAILED_ST with 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 states with next event of SERVER_SELECTED_EVT_EVT if + /// there was an IO error communicating with the server and the number of + /// per server retries has not been exhausted. + /// + /// - SELECTING_FWD_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 SimpleAddTransactionError if upon entry next event is not + /// SERVER_SELECTED_EVT or IO_COMPLETE_EVT. + void replacingFwdAddrsHandler(); + + /// @brief State handler for REPLACING_REV_PTRS_ST. + /// + /// Entered from: + /// - SELECTING_REV_SERVER_ST with a next event of SERVER_SELECTED_EVT + /// + /// Attempts to delete and then add 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 replacement + /// add request, schedules an asynchronous send via sendUpdate(), and + /// 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 replacement. + /// + /// - 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 SimpleAddTransactionError if upon entry next event is not: + /// SERVER_SELECTED_EVT or IO_COMPLETED_EVT + void replacingRevPtrsHandler(); + + /// @brief State handler for PROCESS_TRANS_OK_ST. + /// + /// Entered from: + /// - REPLACING_FWD_ADDRS_ST with a next event of UPDATE_OK_EVT + /// - REPLACING_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 SimpleAddTransactionError if upon entry next event is not: + /// UPDATE_OK_EVT + void processAddOkHandler(); + + /// @brief State handler for PROCESS_TRANS_FAILED_ST. + /// + /// Entered from: + /// - SELECTING_FWD_SERVER_ST with a next event of NO_MORE_SERVERS + /// - REPLACING_FWD_ADDRS_ST with a next event of UPDATE_FAILED_EVT + /// - SELECTING_REV_SERVER_ST with a next event of NO_MORE_SERVERS + /// - REPLACING_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 SimpleAddTransactionError if upon entry next event is not: + /// UPDATE_FAILED_EVT + void processAddFailedHandler(); + + /// @brief Builds a DNS request to add/replace a forward DNS entry for an + /// FQDN + /// + /// Constructs a DNS update request, based upon the NCR, for adding a + /// forward DNS mapping. Once constructed, the request is stored as + /// the transaction's DNS update request. + /// + /// Prerequisite RRsets: + /// - There are no prerequisites. + /// + /// Updates RRsets: + /// -# A delete of any existing PTR RRs for the lease address + /// -# A delete of any existing DHCID RRs for the lease address + /// -# An FQDN/IP RR addition (type A for IPv4, AAAA for IPv6) + /// -# An FQDN/DHCID RR addition (type DHCID) + /// + /// @throw This method does not throw but underlying methods may. + void buildReplaceFwdAddressRequest(); + + /// @brief Builds a DNS request to replace a reverse DNS entry for an FQDN + /// + /// Constructs a DNS update request, based upon the NCR, for replacing a + /// reverse DNS mapping. Once constructed, the request is stored as + /// the transaction's DNS update request. + /// + /// Prerequisite RRsets: + /// - There are no prerequisites. + /// + /// Updates RRsets: + /// -# A delete of any existing PTR RRs for the lease address + /// -# A delete of any existing DHCID RRs for the lease address + /// -# A PTR RR addition for the lease address and FQDN + /// -# A DHCID RR addition for the lease address and lease client DHCID + /// + /// @throw This method does not throw but underlying methods may. + void buildReplaceRevPtrsRequest(); +}; + +/// @brief Defines a pointer to a SimpleAddTransaction. +typedef boost::shared_ptr<SimpleAddTransaction> SimpleAddTransactionPtr; + +} // namespace isc::d2 +} // namespace isc +#endif |