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// Copyright 2015-2016 Benjamin Fry <benjaminfry@me.com> // // Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or // http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or // http://opensource.org/licenses/MIT>, at your option. This file may not be // copied, modified, or distributed except according to those terms. use std::collections::{HashMap, HashSet}; use std::io; use std::time::Duration; use chrono::UTC; use futures::{Async, Complete, Future, Poll, task}; use futures::IntoFuture; use futures::stream::{Peekable, Fuse as StreamFuse, Stream}; use futures::sync::mpsc::{unbounded, UnboundedReceiver, UnboundedSender}; use futures::sync::oneshot; use futures::task::park; use rand::Rng; use rand; use tokio_core::reactor::{Handle, Timeout}; use ::error::*; use ::op::{Message, MessageType, OpCode, Query, UpdateMessage}; use ::rr::{domain, DNSClass, IntoRecordSet, RData, Record, RecordType}; use ::rr::dnssec::Signer; use ::rr::rdata::NULL; const QOS_MAX_RECEIVE_MSGS: usize = 100; // max number of messages to receive from the UDP socket /// A reference to a Sender of bytes returned from the creation of a UdpClientStream or TcpClientStream pub type StreamHandle = UnboundedSender<Vec<u8>>; pub trait ClientStreamHandle { fn send(&mut self, buffer: Vec<u8>) -> io::Result<()>; } impl ClientStreamHandle for StreamHandle { fn send(&mut self, buffer: Vec<u8>) -> io::Result<()> { UnboundedSender::send(self, buffer).map_err(|_| io::Error::new(io::ErrorKind::Other, "unknown")) } } /// A DNS Client implemented over futures-rs. /// /// This Client is generic and capable of wrapping UDP, TCP, and other underlying DNS protocol /// implementations. #[must_use = "futures do nothing unless polled"] pub struct ClientFuture<S: Stream<Item=Vec<u8>, Error=io::Error>> { stream: S, reactor_handle: Handle, timeout_duration: Duration, // TODO genericize and remove this Box stream_handle: Box<ClientStreamHandle>, new_receiver: Peekable<StreamFuse<UnboundedReceiver<(Message, Complete<ClientResult<Message>>)>>>, active_requests: HashMap<u16, (Complete<ClientResult<Message>>, Timeout)>, // TODO: Maybe make a typed version of ClientFuture for Updates? signer: Option<Signer>, } impl<S: Stream<Item=Vec<u8>, Error=io::Error> + 'static> ClientFuture<S> { /// Spawns a new ClientFuture Stream. This uses a default timeout of 5 seconds for all requests. /// /// # Arguments /// /// * `stream` - A stream of bytes that can be used to send/receive DNS messages /// (see TcpClientStream or UdpClientStream) /// * `loop_handle` - A Handle to the Tokio reactor Core, this is the Core on which the /// the Stream will be spawned /// * `stream_handle` - The handle for the `stream` on which bytes can be sent/received. /// * `signer` - An optional signer for requests, needed for Updates with Sig0, otherwise not needed pub fn new(stream: Box<Future<Item=S, Error=io::Error>>, stream_handle: Box<ClientStreamHandle>, loop_handle: Handle, signer: Option<Signer>) -> BasicClientHandle { Self::with_timeout(stream, stream_handle, loop_handle, Duration::from_secs(5), signer) } /// Spawns a new ClientFuture Stream. /// /// # Arguments /// /// * `stream` - A stream of bytes that can be used to send/receive DNS messages /// (see TcpClientStream or UdpClientStream) /// * `loop_handle` - A Handle to the Tokio reactor Core, this is the Core on which the /// the Stream will be spawned /// * `timeout_duration` - All requests may fail due to lack of response, this is the time to /// wait for a response before canceling the request. /// * `stream_handle` - The handle for the `stream` on which bytes can be sent/received. /// * `signer` - An optional signer for requests, needed for Updates with Sig0, otherwise not needed pub fn with_timeout(stream: Box<Future<Item=S, Error=io::Error>>, stream_handle: Box<ClientStreamHandle>, loop_handle: Handle, timeout_duration: Duration, signer: Option<Signer>) -> BasicClientHandle { let (sender, rx) = unbounded(); let loop_handle_clone = loop_handle.clone(); loop_handle.spawn( stream.map(move |stream| { ClientFuture{ stream: stream, reactor_handle: loop_handle_clone, timeout_duration: timeout_duration, stream_handle: stream_handle, new_receiver: rx.fuse().peekable(), active_requests: HashMap::new(), signer: signer, } }).flatten() .map_err(|e| { error!("error in Client: {}", e); }) ); BasicClientHandle { message_sender: sender } } /// loop over active_requests and remove cancelled requests /// this should free up space if we already had 4096 active requests fn drop_cancelled(&mut self) { // TODO: should we have a timeout here? or always expect the caller to do this? let mut canceled = HashSet::new(); for (&id, &mut(ref mut req, ref mut timeout)) in self.active_requests.iter_mut() { if let Ok(Async::Ready(())) = req.poll_cancel() { canceled.insert(id); } // check for timeouts... match timeout.poll() { Ok(Async::Ready(_)) => { warn!("request timeout: {}", id); canceled.insert(id); }, Ok(Async::NotReady) => (), Err(e) => { error!("unexpected error from timeout: {}", e); canceled.insert(id); } } } // drop all the canceled requests for id in canceled { if let Some((req, _)) = self.active_requests.remove(&id) { // TODO, perhaps there is a different reason timeout? but there shouldn't be... // being lazy and always returning timeout in this case (if it was canceled then the // then the otherside isn't really paying attention anyway) // complete the request, it's failed... req.complete(Err(ClientErrorKind::Timeout.into())); } } } /// creates random query_id, validates against all active queries fn next_random_query_id(&self) -> Async<u16> { let mut rand = rand::thread_rng(); for _ in 0..100 { let id = rand.gen_range(0_u16, u16::max_value()); if !self.active_requests.contains_key(&id) { return Async::Ready(id) } } warn!("could not get next random query id, delaying"); park().unpark(); Async::NotReady } } impl<S: Stream<Item=Vec<u8>, Error=io::Error> + 'static> Future for ClientFuture<S> { type Item = (); type Error = ClientError; fn poll(&mut self) -> Poll<(), Self::Error> { self.drop_cancelled(); // loop over new_receiver for all outbound requests loop { // get next query_id let query_id: Option<u16> = match self.new_receiver.peek() { Ok(Async::Ready(Some(_))) => { debug!("got message from receiver"); // we have a new message to send match self.next_random_query_id() { Async::Ready(id) => Some(id), Async::NotReady => break, } }, Ok(_) => None, Err(()) => { warn!("receiver was shutdown?"); break }, }; // finally pop the reciever match self.new_receiver.poll() { Ok(Async::Ready(Some((mut message, complete)))) => { // if there was a message, and the above succesion was succesful, // register the new message, if not do not register, and set the complete to error. // getting a random query id, this mitigates potential cache poisoning. // TODO: for SIG0 we can't change the message id after signing. let query_id = query_id.expect("query_id should have been set above"); message.id(query_id); // update messages need to be signed. if let OpCode::Update = message.get_op_code() { if let Some(ref signer) = self.signer { // TODO: it's too bad this happens here... if let Err(e) = message.sign(signer, UTC::now().timestamp() as u32) { warn!("could not sign message: {}", e); complete.complete(Err(e.into())); continue // to the next message... } } } // store a Timeout for this message before sending let timeout = match Timeout::new(self.timeout_duration, &self.reactor_handle) { Ok(timeout) => timeout, Err(e) => { warn!("could not create timer: {}", e); complete.complete(Err(e.into())); continue // to the next message... } }; // send the message match message.to_vec() { Ok(buffer) => { debug!("sending message id: {}", query_id); try!(self.stream_handle.send(buffer)); // add to the map -after- the client send b/c we don't want to put it in the map if // we ended up returning from the send. self.active_requests.insert(message.get_id(), (complete, timeout)); }, Err(e) => { debug!("error message id: {} error: {}", query_id, e); // complete with the error, don't add to the map of active requests complete.complete(Err(e.into())); }, } }, Ok(_) => break, Err(()) => { warn!("receiver was shutdown?"); break }, } } // Collect all inbound requests, max 100 at a time for QoS // by having a max we will guarantee that the client can't be DOSed in this loop // TODO: make the QoS configurable let mut messages_received = 0; for i in 0..QOS_MAX_RECEIVE_MSGS { match try!(self.stream.poll()) { Async::Ready(Some(buffer)) => { messages_received = i; // deserialize or log decode_error match Message::from_vec(&buffer) { Ok(message) => { match self.active_requests.remove(&message.get_id()) { Some((complete, _)) => complete.complete(Ok(message)), None => debug!("unexpected request_id: {}", message.get_id()), } }, // TODO: return src address for diagnostics Err(e) => debug!("error decoding message: {}", e), } }, Async::Ready(None) | Async::NotReady => break, } } // Clean shutdown happens when all pending requests are done and the // incoming channel has been closed (e.g. you'll never receive another // request). try! will early return the error... let done = if let Async::Ready(None) = try!(self.new_receiver.peek()) { true } else { false }; if self.active_requests.is_empty() && done { return Ok(().into()); // we are done } // If still active, then if the qos (for _ in 0..100 loop) limit // was hit then "yield". This'll make sure that the future is // woken up immediately on the next turn of the event loop. if messages_received == QOS_MAX_RECEIVE_MSGS { task::park().unpark(); } // Finally, return not ready to keep the 'driver task' alive. return Ok(Async::NotReady) } } /// Root ClientHandle implementaton returned by ClientFuture /// /// This can be used directly to perform queries. See `trust_dns::client::SecureClientHandle` for /// a DNSSEc chain validator. #[derive(Clone)] #[must_use = "queries can only be sent through a ClientHandle"] pub struct BasicClientHandle { message_sender: UnboundedSender<(Message, Complete<ClientResult<Message>>)>, } impl ClientHandle for BasicClientHandle { fn send(&mut self, message: Message) -> Box<Future<Item=Message, Error=ClientError>> { let (complete, receiver) = oneshot::channel(); let message_sender: &mut _ = &mut self.message_sender; let receiver = match message_sender.send((message, complete)) { Ok(()) => receiver, Err(e) => { let (complete, receiver) = oneshot::channel(); complete.complete(Err(e.into())); receiver } }; // conver the oneshot into a Box of a Future message and error. Box::new(receiver.map_err(|c| ClientError::from(c)).map(|result| result.into_future()).flatten()) } } /// A trait for implementing high level functions of DNS. #[must_use = "queries can only be sent through a ClientHandle"] pub trait ClientHandle: Clone { /// Send a message via the channel in the client /// /// # Arguments /// /// * `message` - the fully constructed Message to send, note that most implementations of /// will most likely be required to rewrite the QueryId, do no rely on that as /// being stable. fn send(&mut self, message: Message) -> Box<Future<Item=Message, Error=ClientError>>; /// A *classic* DNS query /// /// *Note* As of now, this will not recurse on PTR or CNAME record responses, that is up to /// the caller. /// /// # Arguments /// /// * `name` - the label to lookup /// * `query_class` - most likely this should always be DNSClass::IN /// * `query_type` - record type to lookup fn query(&mut self, name: domain::Name, query_class: DNSClass, query_type: RecordType) -> Box<Future<Item=Message, Error=ClientError>> { debug!("querying: {} {:?}", name, query_type); // build the message let mut message: Message = Message::new(); let id: u16 = rand::random(); // TODO make recursion a parameter message.id(id).message_type(MessageType::Query).op_code(OpCode::Query).recursion_desired(true); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } // add the query let mut query: Query = Query::new(); query.name(name.clone()).query_class(query_class).query_type(query_type); message.add_query(query); self.send(message) } /// Sends a NOTIFY message to the remote system /// /// [RFC 1996](https://tools.ietf.org/html/rfc1996), DNS NOTIFY, August 1996 /// /// /// ```text /// 1. Rationale and Scope /// /// 1.1. Slow propagation of new and changed data in a DNS zone can be /// due to a zone's relatively long refresh times. Longer refresh times /// are beneficial in that they reduce load on the master servers, but /// that benefit comes at the cost of long intervals of incoherence among /// authority servers whenever the zone is updated. /// /// 1.2. The DNS NOTIFY transaction allows master servers to inform slave /// servers when the zone has changed -- an interrupt as opposed to poll /// model -- which it is hoped will reduce propagation delay while not /// unduly increasing the masters' load. This specification only allows /// slaves to be notified of SOA RR changes, but the architechture of /// NOTIFY is intended to be extensible to other RR types. /// /// 1.3. This document intentionally gives more definition to the roles /// of "Master," "Slave" and "Stealth" servers, their enumeration in NS /// RRs, and the SOA MNAME field. In that sense, this document can be /// considered an addendum to [RFC1035]. /// /// ``` /// /// The below section describes how the Notify message should be constructed. The function /// implmentation accepts a Record, but the actual data of the record should be ignored by the /// server, i.e. the server should make a request subsequent to receiving this Notification for /// the authority record, but could be used to decide to request an update or not: /// /// ```text /// 3.7. A NOTIFY request has QDCOUNT>0, ANCOUNT>=0, AUCOUNT>=0, /// ADCOUNT>=0. If ANCOUNT>0, then the answer section represents an /// unsecure hint at the new RRset for this <QNAME,QCLASS,QTYPE>. A /// slave receiving such a hint is free to treat equivilence of this /// answer section with its local data as a "no further work needs to be /// done" indication. If ANCOUNT=0, or ANCOUNT>0 and the answer section /// differs from the slave's local data, then the slave should query its /// known masters to retrieve the new data. /// ``` /// /// Client's should be ready to handle, or be aware of, a server response of NOTIMP: /// /// ```text /// 3.12. If a NOTIFY request is received by a slave who does not /// implement the NOTIFY opcode, it will respond with a NOTIMP /// (unimplemented feature error) message. A master server who receives /// such a NOTIMP should consider the NOTIFY transaction complete for /// that slave. /// ``` /// /// # Arguments /// /// * `name` - the label which is being notified /// * `query_class` - most likely this should always be DNSClass::IN /// * `query_type` - record type which has been updated /// * `rrset` - the new version of the record(s) being notified fn notify<R>(&mut self, name: domain::Name, query_class: DNSClass, query_type: RecordType, rrset: Option<R>) -> Box<Future<Item=Message, Error=ClientError>> where R: IntoRecordSet { debug!("notifying: {} {:?}", name, query_type); // build the message let mut message: Message = Message::new(); let id: u16 = rand::random(); message.id(id) // 3.3. NOTIFY is similar to QUERY in that it has a request message with // the header QR flag "clear" and a response message with QR "set". The // response message contains no useful information, but its reception by // the master is an indication that the slave has received the NOTIFY // and that the master can remove the slave from any retry queue for // this NOTIFY event. .message_type(MessageType::Query) .op_code(OpCode::Notify); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } // add the query let mut query: Query = Query::new(); query.name(name.clone()).query_class(query_class).query_type(query_type); message.add_query(query); // add the notify message, see https://tools.ietf.org/html/rfc1996, section 3.7 if let Some(rrset) = rrset { message.add_answers(rrset.into_record_set()); } self.send(message) } /// Sends a record to create on the server, this will fail if the record exists (atomicity /// depends on the server) /// /// [RFC 2136](https://tools.ietf.org/html/rfc2136), DNS Update, April 1997 /// /// ```text /// 2.4.3 - RRset Does Not Exist /// /// No RRs with a specified NAME and TYPE (in the zone and class denoted /// by the Zone Section) can exist. /// /// For this prerequisite, a requestor adds to the section a single RR /// whose NAME and TYPE are equal to that of the RRset whose nonexistence /// is required. The RDLENGTH of this record is zero (0), and RDATA /// field is therefore empty. CLASS must be specified as NONE in order /// to distinguish this condition from a valid RR whose RDLENGTH is /// naturally zero (0) (for example, the NULL RR). TTL must be specified /// as zero (0). /// /// 2.5.1 - Add To An RRset /// /// RRs are added to the Update Section whose NAME, TYPE, TTL, RDLENGTH /// and RDATA are those being added, and CLASS is the same as the zone /// class. Any duplicate RRs will be silently ignored by the primary /// master. /// ``` /// /// # Arguments /// /// * `rrset` - the record(s) to create /// * `zone_origin` - the zone name to update, i.e. SOA name /// /// The update must go to a zone authority (i.e. the server used in the ClientConnection) fn create<R>(&mut self, rrset: R, zone_origin: domain::Name) -> Box<Future<Item=Message, Error=ClientError>> where R: IntoRecordSet { // TODO: assert non-empty rrset? let rrset = rrset.into_record_set(); assert!(zone_origin.zone_of(rrset.get_name())); // for updates, the query section is used for the zone let mut zone: Query = Query::new(); zone.name(zone_origin).query_class(rrset.get_dns_class()).query_type(RecordType::SOA); // build the message let mut message: Message = Message::new(); message.id(rand::random()).message_type(MessageType::Query).op_code(OpCode::Update).recursion_desired(false); message.add_zone(zone); let mut prerequisite = Record::with(rrset.get_name().clone(), rrset.get_record_type(), 0); prerequisite.dns_class(DNSClass::NONE); message.add_pre_requisite(prerequisite); message.add_updates(rrset); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } self.send(message) } /// Appends a record to an existing rrset, optionally require the rrset to exis (atomicity /// depends on the server) /// /// [RFC 2136](https://tools.ietf.org/html/rfc2136), DNS Update, April 1997 /// /// ```text /// 2.4.1 - RRset Exists (Value Independent) /// /// At least one RR with a specified NAME and TYPE (in the zone and class /// specified in the Zone Section) must exist. /// /// For this prerequisite, a requestor adds to the section a single RR /// whose NAME and TYPE are equal to that of the zone RRset whose /// existence is required. RDLENGTH is zero and RDATA is therefore /// empty. CLASS must be specified as ANY to differentiate this /// condition from that of an actual RR whose RDLENGTH is naturally zero /// (0) (e.g., NULL). TTL is specified as zero (0). /// /// 2.5.1 - Add To An RRset /// /// RRs are added to the Update Section whose NAME, TYPE, TTL, RDLENGTH /// and RDATA are those being added, and CLASS is the same as the zone /// class. Any duplicate RRs will be silently ignored by the primary /// master. /// ``` /// /// # Arguments /// /// * `rrset` - the record(s) to append to an RRSet /// * `zone_origin` - the zone name to update, i.e. SOA name /// * `must_exist` - if true, the request will fail if the record does not exist /// /// The update must go to a zone authority (i.e. the server used in the ClientConnection). If /// the rrset does not exist and must_exist is false, then the RRSet will be created. fn append<R>(&mut self, rrset: R, zone_origin: domain::Name, must_exist: bool) -> Box<Future<Item=Message, Error=ClientError>> where R: IntoRecordSet { let rrset = rrset.into_record_set(); assert!(zone_origin.zone_of(rrset.get_name())); // for updates, the query section is used for the zone let mut zone: Query = Query::new(); zone.name(zone_origin).query_class(rrset.get_dns_class()).query_type(RecordType::SOA); // build the message let mut message: Message = Message::new(); message.id(rand::random()).message_type(MessageType::Query).op_code(OpCode::Update).recursion_desired(false); message.add_zone(zone); if must_exist { let mut prerequisite = Record::with(rrset.get_name().clone(), rrset.get_record_type(), 0); prerequisite.dns_class(DNSClass::ANY); message.add_pre_requisite(prerequisite); } message.add_updates(rrset); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } self.send(message) } /// Compares and if it matches, swaps it for the new value (atomicity depends on the server) /// /// ```text /// 2.4.2 - RRset Exists (Value Dependent) /// /// A set of RRs with a specified NAME and TYPE exists and has the same /// members with the same RDATAs as the RRset specified here in this /// section. While RRset ordering is undefined and therefore not /// significant to this comparison, the sets be identical in their /// extent. /// /// For this prerequisite, a requestor adds to the section an entire /// RRset whose preexistence is required. NAME and TYPE are that of the /// RRset being denoted. CLASS is that of the zone. TTL must be /// specified as zero (0) and is ignored when comparing RRsets for /// identity. /// /// 2.5.4 - Delete An RR From An RRset /// /// RRs to be deleted are added to the Update Section. The NAME, TYPE, /// RDLENGTH and RDATA must match the RR being deleted. TTL must be /// specified as zero (0) and will otherwise be ignored by the primary /// master. CLASS must be specified as NONE to distinguish this from an /// RR addition. If no such RRs exist, then this Update RR will be /// silently ignored by the primary master. /// /// 2.5.1 - Add To An RRset /// /// RRs are added to the Update Section whose NAME, TYPE, TTL, RDLENGTH /// and RDATA are those being added, and CLASS is the same as the zone /// class. Any duplicate RRs will be silently ignored by the primary /// master. /// ``` /// /// # Arguements /// /// * `current` - the current rrset which must exist for the swap to complete /// * `new` - the new rrset with which to replace the current rrset /// * `zone_origin` - the zone name to update, i.e. SOA name /// /// The update must go to a zone authority (i.e. the server used in the ClientConnection). fn compare_and_swap<C,N>(&mut self, current: C, new: N, zone_origin: domain::Name) -> Box<Future<Item=Message, Error=ClientError>> where C: IntoRecordSet, N: IntoRecordSet { let current = current.into_record_set(); let new = new.into_record_set(); assert!(zone_origin.zone_of(current.get_name())); assert!(zone_origin.zone_of(new.get_name())); // for updates, the query section is used for the zone let mut zone: Query = Query::new(); zone.name(zone_origin).query_class(new.get_dns_class()).query_type(RecordType::SOA); // build the message let mut message: Message = Message::new(); message.id(rand::random()).message_type(MessageType::Query).op_code(OpCode::Update).recursion_desired(false); message.add_zone(zone); // make sure the record is what is expected let mut prerequisite = current.clone(); prerequisite.set_ttl(0); message.add_pre_requisites(prerequisite); // add the delete for the old record let mut delete = current; // the class must be none for delete delete.set_dns_class(DNSClass::NONE); // the TTL should be 0 delete.set_ttl(0); message.add_updates(delete); // insert the new record... message.add_updates(new); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } self.send(message) } /// Deletes a record (by rdata) from an rrset, optionally require the rrset to exist. /// /// [RFC 2136](https://tools.ietf.org/html/rfc2136), DNS Update, April 1997 /// /// ```text /// 2.4.1 - RRset Exists (Value Independent) /// /// At least one RR with a specified NAME and TYPE (in the zone and class /// specified in the Zone Section) must exist. /// /// For this prerequisite, a requestor adds to the section a single RR /// whose NAME and TYPE are equal to that of the zone RRset whose /// existence is required. RDLENGTH is zero and RDATA is therefore /// empty. CLASS must be specified as ANY to differentiate this /// condition from that of an actual RR whose RDLENGTH is naturally zero /// (0) (e.g., NULL). TTL is specified as zero (0). /// /// 2.5.4 - Delete An RR From An RRset /// /// RRs to be deleted are added to the Update Section. The NAME, TYPE, /// RDLENGTH and RDATA must match the RR being deleted. TTL must be /// specified as zero (0) and will otherwise be ignored by the primary /// master. CLASS must be specified as NONE to distinguish this from an /// RR addition. If no such RRs exist, then this Update RR will be /// silently ignored by the primary master. /// ``` /// /// # Arguments /// /// * `rrset` - the record(s) to delete from a RRSet, the name, type and rdata must match the /// record to delete /// * `zone_origin` - the zone name to update, i.e. SOA name /// * `signer` - the signer, with private key, to use to sign the request /// /// The update must go to a zone authority (i.e. the server used in the ClientConnection). If /// the rrset does not exist and must_exist is false, then the RRSet will be deleted. fn delete_by_rdata<R>(&mut self, rrset: R, zone_origin: domain::Name) -> Box<Future<Item=Message, Error=ClientError>> where R: IntoRecordSet { let mut rrset = rrset.into_record_set(); assert!(zone_origin.zone_of(rrset.get_name())); // for updates, the query section is used for the zone let mut zone: Query = Query::new(); zone.name(zone_origin).query_class(rrset.get_dns_class()).query_type(RecordType::SOA); // build the message let mut message: Message = Message::new(); message.id(rand::random()).message_type(MessageType::Query).op_code(OpCode::Update).recursion_desired(false); message.add_zone(zone); // the class must be none for delete rrset.set_dns_class(DNSClass::NONE); // the TTL shoudl be 0 rrset.set_ttl(0); message.add_updates(rrset); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } self.send(message) } /// Deletes an entire rrset, optionally require the rrset to exist. /// /// [RFC 2136](https://tools.ietf.org/html/rfc2136), DNS Update, April 1997 /// /// ```text /// 2.4.1 - RRset Exists (Value Independent) /// /// At least one RR with a specified NAME and TYPE (in the zone and class /// specified in the Zone Section) must exist. /// /// For this prerequisite, a requestor adds to the section a single RR /// whose NAME and TYPE are equal to that of the zone RRset whose /// existence is required. RDLENGTH is zero and RDATA is therefore /// empty. CLASS must be specified as ANY to differentiate this /// condition from that of an actual RR whose RDLENGTH is naturally zero /// (0) (e.g., NULL). TTL is specified as zero (0). /// /// 2.5.2 - Delete An RRset /// /// One RR is added to the Update Section whose NAME and TYPE are those /// of the RRset to be deleted. TTL must be specified as zero (0) and is /// otherwise not used by the primary master. CLASS must be specified as /// ANY. RDLENGTH must be zero (0) and RDATA must therefore be empty. /// If no such RRset exists, then this Update RR will be silently ignored /// by the primary master. /// ``` /// /// # Arguments /// /// * `record` - The name, class and record_type will be used to match and delete the RecordSet /// * `zone_origin` - the zone name to update, i.e. SOA name /// * `signer` - the signer, with private key, to use to sign the request /// /// The update must go to a zone authority (i.e. the server used in the ClientConnection). If /// the rrset does not exist and must_exist is false, then the RRSet will be deleted. fn delete_rrset(&mut self, mut record: Record, zone_origin: domain::Name) -> Box<Future<Item=Message, Error=ClientError>> { assert!(zone_origin.zone_of(record.get_name())); // for updates, the query section is used for the zone let mut zone: Query = Query::new(); zone.name(zone_origin).query_class(record.get_dns_class()).query_type(RecordType::SOA); // build the message let mut message: Message = Message::new(); message.id(rand::random()).message_type(MessageType::Query).op_code(OpCode::Update).recursion_desired(false); message.add_zone(zone); // the class must be none for an rrset delete record.dns_class(DNSClass::ANY); // the TTL shoudl be 0 record.ttl(0); // the rdata must be null to delete all rrsets record.rdata(RData::NULL(NULL::new())); message.add_update(record); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } self.send(message) } /// Deletes all records at the specified name /// /// [RFC 2136](https://tools.ietf.org/html/rfc2136), DNS Update, April 1997 /// /// ```text /// 2.5.3 - Delete All RRsets From A Name /// /// One RR is added to the Update Section whose NAME is that of the name /// to be cleansed of RRsets. TYPE must be specified as ANY. TTL must /// be specified as zero (0) and is otherwise not used by the primary /// master. CLASS must be specified as ANY. RDLENGTH must be zero (0) /// and RDATA must therefore be empty. If no such RRsets exist, then /// this Update RR will be silently ignored by the primary master. /// ``` /// /// # Arguments /// /// * `name_of_records` - the name of all the record sets to delete /// * `zone_origin` - the zone name to update, i.e. SOA name /// * `dns_class` - the class of the SOA /// * `signer` - the signer, with private key, to use to sign the request /// /// The update must go to a zone authority (i.e. the server used in the ClientConnection). This /// operation attempts to delete all resource record sets the the specified name reguardless of /// the record type. fn delete_all(&mut self, name_of_records: domain::Name, zone_origin: domain::Name, dns_class: DNSClass) -> Box<Future<Item=Message, Error=ClientError>> { assert!(zone_origin.zone_of(&name_of_records)); // for updates, the query section is used for the zone let mut zone: Query = Query::new(); zone.name(zone_origin).query_class(dns_class).query_type(RecordType::SOA); // build the message let mut message: Message = Message::new(); message.id(rand::random()).message_type(MessageType::Query).op_code(OpCode::Update).recursion_desired(false); message.add_zone(zone); // the TTL shoudl be 0 // the rdata must be null to delete all rrsets // the record type must be any let mut record = Record::with(name_of_records, RecordType::ANY, 0); // the class must be none for an rrset delete record.dns_class(DNSClass::ANY); message.add_update(record); // Extended dns { let edns = message.get_edns_mut(); edns.set_max_payload(1500); edns.set_version(0); } self.send(message) } }