/
catalog.rs
618 lines (565 loc) · 22.3 KB
/
catalog.rs
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/*
* Copyright (C) 2015 Benjamin Fry <benjaminfry@me.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// TODO, I've implemented this as a separate entity from the cache, but I wonder if the cache
// should be the only "front-end" for lookups, where if that misses, then we go to the catalog
// then, if requested, do a recursive lookup... i.e. the catalog would only point to files.
use std::borrow::Borrow;
use std::collections::HashMap;
use std::future::Future;
use std::io;
use std::pin::Pin;
use log::{debug, error, info, trace, warn};
use crate::authority::{
AuthLookup, MessageRequest, MessageResponse, MessageResponseBuilder, ZoneType,
};
use crate::authority::{
AuthorityObject, BoxedLookupFuture, EmptyLookup, LookupError, LookupObject,
};
use crate::client::op::{Edns, Header, LowerQuery, MessageType, OpCode, ResponseCode};
use crate::client::rr::dnssec::{Algorithm, SupportedAlgorithms};
use crate::client::rr::rdata::opt::{EdnsCode, EdnsOption};
use crate::client::rr::{LowerName, RecordType};
use crate::server::{Request, RequestHandler, ResponseHandler};
/// Set of authorities, zones, available to this server.
#[derive(Default)]
pub struct Catalog {
authorities: HashMap<LowerName, Box<dyn AuthorityObject>>,
}
fn send_response<R: ResponseHandler>(
response_edns: Option<Edns>,
mut response: MessageResponse,
mut response_handle: R,
) -> io::Result<()> {
if let Some(mut resp_edns) = response_edns {
// set edns DAU and DHU
// send along the algorithms which are supported by this authority
let mut algorithms = SupportedAlgorithms::new();
algorithms.set(Algorithm::RSASHA256);
algorithms.set(Algorithm::ECDSAP256SHA256);
algorithms.set(Algorithm::ECDSAP384SHA384);
algorithms.set(Algorithm::ED25519);
let dau = EdnsOption::DAU(algorithms);
let dhu = EdnsOption::DHU(algorithms);
resp_edns.options_mut().insert(dau);
resp_edns.options_mut().insert(dhu);
response.set_edns(resp_edns);
}
response_handle.send_response(response)
}
impl RequestHandler for Catalog {
type ResponseFuture = Pin<Box<dyn Future<Output = ()> + Send>>;
/// Determines what needs to happen given the type of request, i.e. Query or Update.
///
/// # Arguments
///
/// * `request` - the requested action to perform.
/// * `response_handle` - sink for the response message to be sent
fn handle_request<R: ResponseHandler>(
&self,
request: Request,
mut response_handle: R,
) -> Self::ResponseFuture {
let request_message = request.message;
trace!("request: {:?}", request_message);
let response_edns: Option<Edns>;
// check if it's edns
if let Some(req_edns) = request_message.edns() {
let mut response = MessageResponseBuilder::new(Some(request_message.raw_queries()));
let mut response_header = Header::default();
response_header.set_id(request_message.id());
let mut resp_edns: Edns = Edns::new();
// check our version against the request
// TODO: what version are we?
let our_version = 0;
resp_edns.set_dnssec_ok(true);
resp_edns.set_max_payload(req_edns.max_payload().max(512));
resp_edns.set_version(our_version);
if req_edns.version() > our_version {
warn!(
"request edns version greater than {}: {}",
our_version,
req_edns.version()
);
response_header.set_response_code(ResponseCode::BADVERS);
response.edns(resp_edns);
// TODO: should ResponseHandle consume self?
let result =
response_handle.send_response(response.build_no_records(response_header));
if let Err(e) = result {
error!("request error: {}", e);
}
return Box::pin(async {});
}
response_edns = Some(resp_edns);
} else {
response_edns = None;
}
let result = match request_message.message_type() {
// TODO think about threading query lookups for multiple lookups, this could be a huge improvement
// especially for recursive lookups
MessageType::Query => match request_message.op_code() {
OpCode::Query => {
debug!("query received: {}", request_message.id());
return Box::pin(self.lookup(request_message, response_edns, response_handle));
}
OpCode::Update => {
debug!("update received: {}", request_message.id());
// TODO: this should be a future
self.update(&request_message, response_edns, response_handle)
}
c => {
warn!("unimplemented op_code: {:?}", c);
let response = MessageResponseBuilder::new(Some(request_message.raw_queries()));
response_handle.send_response(response.error_msg(
request_message.id(),
request_message.op_code(),
ResponseCode::NotImp,
))
}
},
MessageType::Response => {
warn!(
"got a response as a request from id: {}",
request_message.id()
);
let response = MessageResponseBuilder::new(Some(request_message.raw_queries()));
response_handle.send_response(response.error_msg(
request_message.id(),
request_message.op_code(),
ResponseCode::FormErr,
))
}
};
if let Err(e) = result {
error!("request failed: {}", e);
}
Box::pin(async {})
}
}
impl Catalog {
/// Constructs a new Catalog
pub fn new() -> Self {
Catalog {
authorities: HashMap::new(),
}
}
/// Insert or update a zone authority
///
/// # Arguments
///
/// * `name` - zone name, e.g. example.com.
/// * `authority` - the zone data
pub fn upsert(&mut self, name: LowerName, authority: Box<dyn AuthorityObject>) {
self.authorities.insert(name, authority);
}
/// Remove a zone from the catalog
pub fn remove(&mut self, name: &LowerName) -> Option<Box<dyn AuthorityObject>> {
self.authorities.remove(name)
}
/// Update the zone given the Update request.
///
/// [RFC 2136](https://tools.ietf.org/html/rfc2136), DNS Update, April 1997
///
/// ```text
/// 3.1 - Process Zone Section
///
/// 3.1.1. The Zone Section is checked to see that there is exactly one
/// RR therein and that the RR's ZTYPE is SOA, else signal FORMERR to the
/// requestor. Next, the ZNAME and ZCLASS are checked to see if the zone
/// so named is one of this server's authority zones, else signal NOTAUTH
/// to the requestor. If the server is a zone Secondary, the request will be
/// forwarded toward the Primary Zone Server.
///
/// 3.1.2 - Pseudocode For Zone Section Processing
///
/// if (zcount != 1 || ztype != SOA)
/// return (FORMERR)
/// if (zone_type(zname, zclass) == SECONDARY)
/// return forward()
/// if (zone_type(zname, zclass) == PRIMARY)
/// return update()
/// return (NOTAUTH)
///
/// Sections 3.2 through 3.8 describe the primary's behaviour,
/// whereas Section 6 describes a forwarder's behaviour.
///
/// 3.8 - Response
///
/// At the end of UPDATE processing, a response code will be known. A
/// response message is generated by copying the ID and Opcode fields
/// from the request, and either copying the ZOCOUNT, PRCOUNT, UPCOUNT,
/// and ADCOUNT fields and associated sections, or placing zeros (0) in
/// the these "count" fields and not including any part of the original
/// update. The QR bit is set to one (1), and the response is sent back
/// to the requestor. If the requestor used UDP, then the response will
/// be sent to the requestor's source UDP port. If the requestor used
/// TCP, then the response will be sent back on the requestor's open TCP
/// connection.
/// ```
///
/// The "request" should be an update formatted message.
/// The response will be in the alternate, all 0's format described in RFC 2136 section 3.8
/// as this is more efficient.
///
/// # Arguments
///
/// * `request` - an update message
/// * `response_handle` - sink for the response message to be sent
pub fn update<R: ResponseHandler + 'static>(
&self,
update: &MessageRequest,
response_edns: Option<Edns>,
response_handle: R,
) -> io::Result<()> {
let zones: &[LowerQuery] = update.queries();
// 2.3 - Zone Section
//
// All records to be updated must be in the same zone, and
// therefore the Zone Section is allowed to contain exactly one record.
// The ZNAME is the zone name, the ZTYPE must be SOA, and the ZCLASS is
// the zone's class.
let ztype = zones
.first()
.map(LowerQuery::query_type)
.unwrap_or(RecordType::Unknown(0));
let result = if zones.len() != 1 || ztype != RecordType::SOA {
warn!(
"invalid update request zones must be 1 and not SOA records, zones: {} ztype: {}",
zones.len(),
ztype
);
Err(ResponseCode::FormErr)
} else {
zones
.first()
.map(LowerQuery::name)
.and_then(|name| self.find(name).map(|a| a.box_clone()))
.ok_or(ResponseCode::Refused)
};
let response_code = match result {
Ok(authority) => {
// Ask for Master/Slave terms to be replaced
#[allow(deprecated)]
match authority.zone_type() {
ZoneType::Slave | ZoneType::Master => {
warn!("Consider replacing the usage of master/slave with primary/secondary, see Juneteenth.");
}
_ => (),
}
#[allow(deprecated)]
match authority.zone_type() {
ZoneType::Secondary | ZoneType::Slave => {
error!("secondary forwarding for update not yet implemented");
ResponseCode::NotImp
}
ZoneType::Primary | ZoneType::Master => {
let update_result = authority.update(update);
match update_result {
// successful update
Ok(..) => ResponseCode::NoError,
Err(response_code) => response_code,
}
}
_ => ResponseCode::NotAuth,
}
}
Err(response_code) => response_code,
};
let response = MessageResponseBuilder::new(None);
let mut response_header = Header::default();
response_header.set_id(update.id());
response_header.set_op_code(OpCode::Update);
response_header.set_message_type(MessageType::Response);
response_header.set_response_code(response_code);
send_response(
response_edns,
response.build_no_records(response_header),
response_handle,
)
}
/// Checks whether the `Catalog` contains DNS records for `name`
///
/// Use this when you know the exact `LowerName` that was used when
/// adding an authority and you don't care about the authority it
/// contains. For public domain names, `LowerName` is usually the
/// top level domain name like `example.com.`.
///
/// If you do not know the exact domain name to use or you actually
/// want to use the authority it contains, use `find` instead.
pub fn contains(&self, name: &LowerName) -> bool {
self.authorities.contains_key(name)
}
/// Given the requested query, lookup and return any matching results.
///
/// # Arguments
///
/// * `request` - the query message.
/// * `response_handle` - sink for the response message to be sent
pub fn lookup<R: ResponseHandler>(
&self,
request: MessageRequest,
response_edns: Option<Edns>,
response_handle: R,
) -> impl Future<Output = ()> + 'static {
let queries_and_authorities = request
.queries()
.iter()
.enumerate()
.filter_map(|(i, q)| {
self.find(q.name())
.map(|authority| (i, authority.box_clone()))
})
.collect::<Vec<_>>();
if queries_and_authorities.is_empty() {
let response = MessageResponseBuilder::new(Some(request.raw_queries()));
send_response(
response_edns
.as_ref()
.map(|arc| Borrow::<Edns>::borrow(arc).clone()),
response.error_msg(request.id(), request.op_code(), ResponseCode::NXDomain),
response_handle.clone(),
)
.map_err(|e| error!("failed to send response: {}", e))
.ok();
}
lookup(
queries_and_authorities,
request,
response_edns,
response_handle,
)
}
/// Recursively searches the catalog for a matching authority
pub fn find(&self, name: &LowerName) -> Option<&(dyn AuthorityObject + 'static)> {
debug!("searching authorities for: {}", name);
self.authorities
.get(name)
.map(|authority| &**authority)
.or_else(|| {
if !name.is_root() {
let name = name.base_name();
self.find(&name)
} else {
None
}
})
}
}
async fn lookup<R: ResponseHandler + Unpin>(
queries_and_authorities: Vec<(usize, Box<dyn AuthorityObject>)>,
request: MessageRequest,
response_edns: Option<Edns>,
response_handle: R,
) {
// TODO: the spec is very unclear on what to do with multiple queries
// we will search for each, in the future, maybe make this threaded to respond even faster.
// the current impl will return on the first query result
for (query_idx, authority) in queries_and_authorities {
let query = &request.queries()[query_idx];
info!(
"request: {} found authority: {}",
request.id(),
authority.origin()
);
let (response_header, sections) =
build_response(&*authority, request.id(), query, request.edns()).await;
let response = MessageResponseBuilder::new(Some(request.raw_queries())).build(
response_header,
sections.answers.iter(),
sections.ns.iter(),
sections.soa.iter(),
sections.additionals.iter(),
);
let result = send_response(response_edns.clone(), response, response_handle.clone());
if let Err(e) = result {
error!("error sending response: {}", e);
}
}
}
async fn build_response(
authority: &dyn AuthorityObject,
request_id: u16,
query: &LowerQuery,
edns: Option<&Edns>,
) -> (Header, LookupSections) {
let (is_dnssec, supported_algorithms) =
edns.map_or((false, SupportedAlgorithms::new()), |edns| {
let supported_algorithms =
if let Some(&EdnsOption::DAU(algs)) = edns.option(EdnsCode::DAU) {
algs
} else {
debug!("no DAU in request, used default SupportAlgorithms");
Default::default()
};
(edns.dnssec_ok(), supported_algorithms)
});
// log algorithms being requested
if is_dnssec {
info!(
"request: {} supported_algs: {}",
request_id, supported_algorithms
);
}
let mut response_header = Header::new();
response_header.set_id(request_id);
response_header.set_op_code(OpCode::Query);
response_header.set_message_type(MessageType::Response);
response_header.set_authoritative(authority.zone_type().is_authoritative());
debug!("performing {} on {}", query, authority.origin());
let future = authority.search(query, is_dnssec, supported_algorithms);
#[allow(deprecated)]
let sections = match authority.zone_type() {
ZoneType::Primary | ZoneType::Secondary | ZoneType::Master | ZoneType::Slave => {
send_authoritative_response(
future,
authority,
&mut response_header,
is_dnssec,
supported_algorithms,
request_id,
&query,
)
.await
}
ZoneType::Forward | ZoneType::Hint => {
send_forwarded_response(future, &mut response_header).await
}
};
(response_header, sections)
}
async fn send_authoritative_response(
future: BoxedLookupFuture,
authority: &dyn AuthorityObject,
response_header: &mut Header,
is_dnssec: bool,
supported_algorithms: SupportedAlgorithms,
request_id: u16,
query: &LowerQuery,
) -> LookupSections {
// In this state we await the records, on success we transition to getting
// NS records, which indicate an authoritative response.
//
// On Errors, the transition depends on the type of error.
let answers = match future.await {
Ok(records) => {
response_header.set_response_code(ResponseCode::NoError);
response_header.set_authoritative(true);
Some(records)
}
// This request was refused
// TODO: there are probably other error cases that should just drop through (FormErr, ServFail)
Err(LookupError::ResponseCode(ResponseCode::Refused)) => {
response_header.set_response_code(ResponseCode::Refused);
return LookupSections {
answers: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
ns: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
soa: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
additionals: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
};
}
Err(e) => {
if e.is_nx_domain() {
response_header.set_response_code(ResponseCode::NXDomain);
} else if e.is_name_exists() {
response_header.set_response_code(ResponseCode::NoError);
};
None
}
};
let (ns, soa) = if answers.is_some() {
// This was a successful authoritative lookup:
// get the NS records
match authority.ns(is_dnssec, supported_algorithms).await {
Ok(ns) => (Some(ns), None),
Err(e) => {
warn!("ns_lookup errored: {}", e);
(None, None)
}
}
} else {
let nsecs = if is_dnssec {
// in the dnssec case, nsec records should exist, we return NoError + NoData + NSec...
debug!("request: {} non-existent adding nsecs", request_id);
// run the nsec lookup future, and then transition to get soa
let future = authority.get_nsec_records(query.name(), true, supported_algorithms);
match future.await {
// run the soa lookup
Ok(nsecs) => Some(nsecs),
Err(e) => {
warn!("failed to lookup nsecs: {}", e);
None
}
}
} else {
None
};
match authority.soa_secure(is_dnssec, supported_algorithms).await {
Ok(soa) => (nsecs, Some(soa)),
Err(e) => {
warn!("failed to lookup soa: {}", e);
(nsecs, None)
}
}
};
// everything is done, return results.
let (answers, additionals) = match answers {
Some(mut answers) => match answers.take_additionals() {
Some(additionals) => (answers, additionals),
None => (
answers,
Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
),
},
None => (
Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
),
};
LookupSections {
answers,
ns: ns.unwrap_or_else(|| Box::new(AuthLookup::default()) as Box<dyn LookupObject>),
soa: soa.unwrap_or_else(|| Box::new(AuthLookup::default()) as Box<dyn LookupObject>),
additionals,
}
}
async fn send_forwarded_response(
future: BoxedLookupFuture,
response_header: &mut Header,
) -> LookupSections {
let answers = match future.await {
Ok(rsp) => rsp,
Err(e) => {
if e.is_nx_domain() {
response_header.set_response_code(ResponseCode::NXDomain);
}
error!("error resolving: {}", e);
Box::new(EmptyLookup)
}
};
response_header.set_authoritative(false);
LookupSections {
answers,
ns: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
soa: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
additionals: Box::new(AuthLookup::default()) as Box<dyn LookupObject>,
}
}
struct LookupSections {
answers: Box<dyn LookupObject>,
ns: Box<dyn LookupObject>,
soa: Box<dyn LookupObject>,
additionals: Box<dyn LookupObject>,
}