DNSSEC resolver, record encoding/decoding

Signed-off-by: Luca Fulchir <luca.fulchir@runesauth.com>

Cargo.toml

@@ -25,13 +25,20 @@ crate_type = [ "lib", "cdylib", "staticlib" ]
 [dependencies]
 # please keep these in alphabetical order
 
+# base85 repo has no tags, fix on a commit. v1.1.1 points to older, wrong version
+base85 = { git = "https://gitlab.com/darkwyrm/base85", rev = "d98efbfd171dd9ba48e30a5c88f94db92fc7b3c6" }
 futures = { version = "^0.3" }
+num-traits = { version = "^0.2" }
+num-derive = { version = "^0.3" }
+strum = { version = "^0.24" }
+strum_macros = { version = "^0.24" }
 thiserror = { version = "^1.0" }
 tokio = { version = "^1", features = ["full"] }
 # PERF: todo linux-only, behind "iouring" feature
 #tokio-uring = { version = "^0.4" }
 tracing = { version = "^0.1" }
-trust-dns-client = { version = "^0.22" }
+trust-dns-resolver = { version = "^0.22", features = [ "dnssec-ring" ] }
+trust-dns-client = { version = "^0.22", features = [ "dnssec" ] }
 trust-dns-proto = { version = "^0.22" }
 
 [profile.dev]

src/dnssec/mod.rs

@@ -0,0 +1,136 @@
+//! Common dnssec utils
+
+use ::std::{net::SocketAddr, vec::Vec};
+use ::tracing::error;
+use ::trust_dns_resolver::TokioAsyncResolver;
+
+pub mod record;
+pub use record::Record;
+
+/// Common errors for Dnssec setup and usage
+#[derive(::thiserror::Error, Debug)]
+pub enum Error {
+    /// Error reading or parsing /etc/resolv.conf
+    #[error("resolv.conf: {0:?}")]
+    ResolvConf(String),
+    /// Error in the resolver setup
+    #[error("resolver setup: {0:?}")]
+    Setup(String),
+    /// Errors in establishing connection or  connection drops
+    #[error("nameserver connection: {0:?}")]
+    NameserverConnection(String),
+}
+
+#[cfg(any(
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "freebsd",
+    target_os = "dragonfly",
+    target_os = "openbsd",
+    target_os = "netbsd",
+))]
+
+/// Easy Dnssec handling for Fenrir
+#[allow(missing_debug_implementations)]
+pub struct Dnssec {
+    /// real resolver
+    resolver: TokioAsyncResolver,
+}
+
+impl Dnssec {
+    /// Spawn connections to DNS via TCP
+    pub async fn new(resolvers: &Vec<SocketAddr>) -> Result<Self, Error> {
+        // use a TCP connection to the DNS.
+        // the records we need are big, will not fit in a UDP packet
+        let resolv_conf_resolvers: Vec<SocketAddr>;
+        let resolvers = if resolvers.len() > 0 {
+            resolvers
+        } else {
+            // load from system's /etc/resolv.conf
+            let resolv_conf =
+                match ::trust_dns_resolver::system_conf::read_system_conf() {
+                    Ok((resolv_conf, _)) => resolv_conf,
+                    Err(e) => return Err(Error::ResolvConf(e.to_string())),
+                };
+            resolv_conf_resolvers = resolv_conf
+                .name_servers()
+                .iter()
+                .map(|r| r.socket_addr)
+                .collect();
+
+            &resolv_conf_resolvers
+        };
+        use ::trust_dns_resolver::config::{ResolverConfig, ResolverOpts};
+        let mut opts = ResolverOpts::default();
+        opts.edns0 = true;
+        opts.validate = true;
+        opts.use_hosts_file = false;
+        opts.try_tcp_on_error = true;
+        let opts = opts; // no more mut
+
+        // default() uses google's dns: don't use
+        let mut config = ResolverConfig::new();
+
+        for resolver in resolvers.iter() {
+            use ::trust_dns_resolver::config::{NameServerConfig, Protocol};
+            config.add_name_server(NameServerConfig::new(
+                resolver.clone(),
+                Protocol::Tcp,
+            ));
+        }
+
+        let resolver = match TokioAsyncResolver::tokio(config, opts) {
+            Ok(resolver) => resolver,
+            Err(e) => return Err(Error::Setup(e.to_string())),
+        };
+
+        Ok(Self { resolver })
+    }
+    /// Get the fenrir data for a domain
+    pub async fn resolv(&self, domain: &str) -> ::std::io::Result<Record> {
+        use ::trust_dns_client::rr::Name;
+
+        let fqdn_str = "_fenrir.".to_owned() + domain;
+        ::tracing::debug!("Resolving: {}", fqdn_str);
+        let fqdn = Name::from_utf8(&fqdn_str)?;
+        let answers = self.resolver.txt_lookup(fqdn).await?;
+        const TXT_RECORD_START: &str = "v=Fenrir1 ";
+        let mut found_but_wrong: bool = false;
+        for txt_raw in answers.into_iter() {
+            let txt = ::std::format!("{}", txt_raw);
+            if !txt.starts_with(TXT_RECORD_START) {
+                ::tracing::trace!("Found NON-fenrir record: {}", txt);
+                continue;
+            }
+            ::tracing::trace!("Found fenrir record: {}", txt);
+            let base85 = txt[TXT_RECORD_START.len()..].trim();
+            let bytes = match ::base85::decode(base85) {
+                Ok(bytes) => bytes,
+                Err(e) => {
+                    ::tracing::error!("Invalid DNSSEC base85: {}", e);
+                    continue;
+                }
+            };
+            let record = match Record::decode(&bytes) {
+                Ok(record) => record,
+                Err(e) => {
+                    found_but_wrong = true;
+                    ::tracing::error!("{}: {}", fqdn_str, e);
+                    continue;
+                }
+            };
+            return Ok(record);
+        }
+        return Err(if found_but_wrong {
+            ::std::io::Error::new(
+                ::std::io::ErrorKind::InvalidData,
+                "record found but not parsable",
+            )
+        } else {
+            ::std::io::Error::new(
+                ::std::io::ErrorKind::NotFound,
+                "record not found",
+            )
+        });
+    }
+}

src/dnssec/record.rs

@@ -0,0 +1,417 @@
+//!
+//! Structs and information to create/parse the _fenrir DNSSEC record
+//!
+//! Encoding and decoding in base85, RFC1924
+//!
+//!
+//! Basic encoding idea:
+//! * 1 byte: half-bytes
+//!   * half: num of addresses
+//!   * half: num of pubkeys
+//! [ # list of addresses
+//!   * 1 byte: bitfield
+//!     * 0..1 ipv4/ipv6
+//!     * 2..4 priority (for failover)
+//!     * 5..7 weight between priority
+//!   * 1 byte: public key id
+//!   * 2 bytes: UDP port
+//!   * X bytes: IP
+//! ]
+//! [ # list of pubkeys
+//!   * 1 byte: pubkey type
+//!   * 1 byte: pubkey id
+//!   * Y bytes: pubkey
+//! ]
+
+use ::core::num::NonZeroU16;
+use ::num_traits::FromPrimitive;
+use ::std::{net::IpAddr, vec::Vec};
+
+/*
+ * Public key data
+ */
+
+/// Public Key ID
+#[derive(Debug, Copy, Clone)]
+pub struct PublicKeyId(u8);
+
+/// Public Key Type
+#[derive(::num_derive::FromPrimitive, Debug, Copy, Clone)]
+// public enum: use non_exhaustive to force users to add a default case
+// so in the future we can expand this easily
+#[non_exhaustive]
+#[repr(u8)]
+pub enum PublicKeyType {
+    /// ed25519 asymmetric key
+    Ed25519 = 0,
+}
+
+impl PublicKeyType {
+    /// Get the size of a public key of this kind
+    pub fn key_len(&self) -> usize {
+        match &self {
+            PublicKeyType::Ed25519 => 42,
+        }
+    }
+}
+
+/// Public Key, with its type and id
+#[derive(Debug, Clone)]
+pub struct PublicKey {
+    /// public key raw data
+    raw: Vec<u8>,
+    /// type of public key
+    kind: PublicKeyType,
+    /// id of public key
+    id: PublicKeyId,
+}
+
+impl PublicKey {
+    fn raw_len(&self) -> usize {
+        let size = 2; // Public Key Type + ID
+        size + self.raw.len()
+    }
+    fn encode_into(&self, raw: &mut Vec<u8>) {
+        raw.push(self.kind as u8);
+        raw.push(self.id.0);
+        raw.extend_from_slice(&self.raw);
+    }
+    fn decode_raw(raw: &[u8]) -> Result<(Self, usize), Error> {
+        if raw.len() < 4 {
+            return Err(Error::NotEnoughData(0));
+        }
+
+        let kind = PublicKeyType::from_u8(raw[0]).unwrap();
+        let id = PublicKeyId(raw[1]);
+        if raw.len() < 2 + kind.key_len() {
+            return Err(Error::NotEnoughData(2));
+        }
+
+        let mut raw_key = Vec::with_capacity(kind.key_len());
+        raw_key.extend_from_slice(&raw[2..(2 + kind.key_len())]);
+
+        let total_length = 2 + kind.key_len();
+
+        Ok((
+            Self {
+                raw: raw_key,
+                kind,
+                id,
+            },
+            total_length,
+        ))
+    }
+}
+
+/*
+ * Address data
+ */
+
+/// Priority of each group of addresses
+#[derive(::num_derive::FromPrimitive, Debug, Copy, Clone)]
+// public enum: use non_exhaustive to force users to add a default case
+// so in the future we can expand this easily
+#[non_exhaustive]
+#[repr(u8)]
+pub enum AddressPriority {
+    /// Initially contact addresses in this priority
+    P0 = 0,
+    /// First failover
+    P1,
+    /// Second failover
+    P2,
+    /// Third failover
+    P3,
+    /// Fourth failover
+    P4,
+    /// Fifth failover
+    P5,
+    /// Sisth failover
+    P6,
+    /// Seventh failover
+    P7,
+}
+
+/// Inside of each group, weight of the address
+/// This helps in distributing the traffic to multiple authentication servers:
+/// * client sums all weights in a group
+/// * generate a random number [0..sum_of_weights]
+/// * the number indicates which server will take the connection
+/// So to equally distribute all connections you just have to use the same
+/// weight in the same group
+#[derive(::num_derive::FromPrimitive, Debug, Copy, Clone)]
+// public enum: use non_exhaustive to force users to add a default case
+// so in the future we can expand this easily
+#[non_exhaustive]
+#[repr(u8)]
+pub enum AddressWeight {
+    /// Minimum weigth: 1
+    W1 = 0,
+    /// little weigth: 2
+    W2,
+    /// little weigth: 3
+    W3,
+    /// medium weigth: 4
+    W4,
+    /// medium weigth: 5
+    W5,
+    /// heavy weigth: 6
+    W6,
+    /// heavy weigth: 7
+    W7,
+    /// Maximum weigth: 8
+    W8,
+}
+
+/// Authentication server address information:
+/// * ip
+/// * udp port
+/// * priority
+/// * weight within priority
+#[derive(Debug, Clone, Copy)]
+pub struct Address {
+    /// Ip address of server, v4 or v6
+    pub ip: IpAddr,
+    /// udp port. None means that this address is reachable only
+    /// with Fenrir over IP
+    pub port: Option<NonZeroU16>,
+    /// Priority group of this address
+    pub priority: AddressPriority,
+    /// Weight of this address in the priority group
+    pub weight: AddressWeight,
+    /// Public key ID used by this address
+    pub public_key_id: PublicKeyId,
+}
+
+impl Address {
+    fn raw_len(&self) -> usize {
+        let size = 4; // UDP port + Priority + Weight
+        match self.ip {
+            IpAddr::V4(_) => size + 4,
+            IpAddr::V6(_) => size + 16,
+        }
+    }
+    fn encode_into(&self, raw: &mut Vec<u8>) {
+        let mut bitfield: u8 = match self.ip {
+            IpAddr::V4(_) => 0,
+            IpAddr::V6(_) => 1,
+        };
+        bitfield <<= 3;
+        bitfield |= self.priority as u8;
+        bitfield <<= 3;
+        bitfield |= self.weight as u8;
+
+        raw.push(bitfield);
+
+        raw.push(self.public_key_id.0);
+        raw.extend_from_slice(
+            &(match self.port {
+                Some(port) => port.get().to_le_bytes(),
+                None => [0, 0], // oh noez, which zero goes first?
+            }),
+        );
+
+        match self.ip {
+            IpAddr::V4(ip) => {
+                let raw_ip = ip.octets();
+                raw.extend_from_slice(&raw_ip);
+            }
+            IpAddr::V6(ip) => {
+                let raw_ip = ip.octets();
+                raw.extend_from_slice(&raw_ip);
+            }
+        };
+    }
+    fn decode_raw(raw: &[u8]) -> Result<(Self, usize), Error> {
+        if raw.len() < 8 {
+            return Err(Error::NotEnoughData(0));
+        }
+        let ip_type = raw[0] >> 6;
+        let is_ipv6: bool;
+        let total_length: usize;
+        match ip_type {
+            0 => {
+                is_ipv6 = false;
+                total_length = 8;
+            }
+            1 => {
+                total_length = 20;
+                if raw.len() < total_length {
+                    return Err(Error::NotEnoughData(1));
+                }
+                is_ipv6 = true
+            }
+            _ => return Err(Error::UnsupportedData(0)),
+        }
+        let raw_priority = (raw[0] << 2) >> 5;
+        let raw_weight = (raw[0] << 5) >> 5;
+        let priority = AddressPriority::from_u8(raw_priority).unwrap();
+        let weight = AddressWeight::from_u8(raw_weight).unwrap();
+
+        let public_key_id = PublicKeyId(raw[1]);
+
+        let raw_port = u16::from_le_bytes(raw[2..3].try_into().unwrap());
+        let port = if raw_port == 0 {
+            None
+        } else {
+            Some(NonZeroU16::new(raw_port).unwrap())
+        };
+        let ip = if is_ipv6 {
+            let raw_ip: [u8; 16] = raw[4..20].try_into().unwrap();
+            IpAddr::from(raw_ip)
+        } else {
+            let raw_ip: [u8; 4] = raw[4..8].try_into().unwrap();
+            IpAddr::from(raw_ip)
+        };
+
+        Ok((
+            Self {
+                ip,
+                port,
+                priority,
+                weight,
+                public_key_id,
+            },
+            total_length,
+        ))
+    }
+}
+
+/*
+ * Actual record puuting it all toghether
+ */
+
+/// All informations found in the DNSSEC record
+#[derive(Debug, Clone)]
+pub struct Record {
+    /// Public keys used by any authentication server
+    public_keys: Vec<PublicKey>,
+    /// List of all authentication servers' addresses.
+    /// Multiple ones can point to the same authentication server
+    addresses: Vec<Address>,
+}
+
+impl Record {
+    /// Simply encode all the record in base85
+    pub fn encode(&self) -> Result<String, Error> {
+        // check possible failure scenarios
+        if self.public_keys.len() == 0 {
+            return Err(Error::NoPublicKeyFound);
+        }
+        if self.public_keys.len() > 16 {
+            return Err(Error::Max16PublicKeys);
+        }
+        if self.addresses.len() == 0 {
+            return Err(Error::NoAddressFound);
+        }
+        if self.addresses.len() > 16 {
+            return Err(Error::Max16Addresses);
+        }
+        // everything else is all good
+
+        let total_size: usize = 1
+            + self.addresses.iter().map(|a| a.raw_len()).sum::<usize>()
+            + self.public_keys.iter().map(|a| a.raw_len()).sum::<usize>();
+
+        let mut raw = Vec::with_capacity(total_size);
+
+        // amount of data. addresses, then pubkeys. 4 bits each
+        let len_combined: u8 = self.addresses.len() as u8;
+        let len_combined = len_combined << 4;
+        let len_combined = len_combined | self.public_keys.len() as u8;
+
+        raw.push(len_combined);
+
+        for address in self.addresses.iter() {
+            address.encode_into(&mut raw);
+        }
+        for public_key in self.public_keys.iter() {
+            public_key.encode_into(&mut raw);
+        }
+
+        Ok(::base85::encode(&raw))
+    }
+    /// Decode from base85 to the actual object
+    pub fn decode(raw: &[u8]) -> Result<Self, Error> {
+        // bare minimum for 1 address and key
+        const MIN_RAW_LENGTH: usize = 1 + 8 + 8;
+        if raw.len() <= MIN_RAW_LENGTH {
+            return Err(Error::NotEnoughData(0));
+        }
+        let mut num_addresses = (raw[0] >> 4) as usize;
+        let mut num_public_keys = (raw[0] & 0x0F) as usize;
+        let mut bytes_parsed = 1;
+
+        let mut result = Self {
+            addresses: Vec::with_capacity(num_addresses),
+            public_keys: Vec::with_capacity(num_public_keys),
+        };
+
+        while num_addresses > 0 {
+            let (address, bytes) =
+                match Address::decode_raw(&raw[bytes_parsed..]) {
+                    Ok(address) => address,
+                    Err(Error::UnsupportedData(b)) => {
+                        return Err(Error::UnsupportedData(bytes_parsed + b))
+                    }
+                    Err(Error::NotEnoughData(b)) => {
+                        return Err(Error::NotEnoughData(bytes_parsed + b))
+                    }
+                    Err(e) => return Err(e),
+                };
+            bytes_parsed = bytes_parsed + bytes;
+            result.addresses.push(address);
+            num_addresses = num_addresses - 1;
+        }
+        while num_public_keys > 0 {
+            let (public_key, bytes) =
+                match PublicKey::decode_raw(&raw[bytes_parsed..]) {
+                    Ok(public_key) => public_key,
+                    Err(Error::UnsupportedData(b)) => {
+                        return Err(Error::UnsupportedData(bytes_parsed + b))
+                    }
+                    Err(Error::NotEnoughData(b)) => {
+                        return Err(Error::NotEnoughData(bytes_parsed + b))
+                    }
+                    Err(e) => return Err(e),
+                };
+            bytes_parsed = bytes_parsed + bytes;
+            result.public_keys.push(public_key);
+            num_public_keys = num_public_keys - 1;
+        }
+        if bytes_parsed != raw.len() {
+            Err(Error::UnknownData(bytes_parsed))
+        } else {
+            Ok(result)
+        }
+    }
+}
+
+/// Possible errors in encoding or decoding the DNSSEC record
+#[derive(::thiserror::Error, Debug)]
+pub enum Error {
+    /// General IO error
+    #[error("IO error: {0:?}")]
+    IO(#[from] ::std::io::Error),
+    /// We need at least one address
+    #[error("no addresses found")]
+    NoAddressFound,
+    /// Too many addresses (max 16)
+    #[error("can't encode more than 16 addresses")]
+    Max16Addresses,
+    /// We need at least one public key
+    #[error("no public keys found")]
+    NoPublicKeyFound,
+    /// Maximum 16 public keys supported
+    #[error("can't encode more than 16 public keys")]
+    Max16PublicKeys,
+    /// Not enough data to decode something meaningful
+    #[error("not enough data. Parsed {0} bytes")]
+    NotEnoughData(usize),
+    /// Unsupported Data: can't parse
+    #[error("Unsupported data. Parsed {0} bytes")]
+    UnsupportedData(usize),
+    /// Unknown data at the end
+    #[error("Unknown data after {0} bytes")]
+    UnknownData(usize),
+}

src/lib.rs

@@ -13,29 +13,36 @@
 //!
 //! libFenrir is the official rust library implementing the Fenrir protocol
 
-use ::std::{io::Result, net::SocketAddr, result, sync::Arc};
+use ::std::{net::SocketAddr, sync::Arc};
-use ::tokio::{net::UdpSocket, runtime, task::JoinHandle};
+use ::tokio::{net::UdpSocket, task::JoinHandle};
-use trust_dns_client::client::{
-    AsyncClient as DnssecClient, ClientHandle as DnssecHandle,
-};
 
 mod config;
 pub use config::Config;
+pub mod dnssec;
+
+/// Main fenrir library errors
+#[derive(::thiserror::Error, Debug)]
+pub enum Error {
+    /// General I/O error
+    #[error("IO: {0:?}")]
+    IO(#[from] ::std::io::Error),
+    /// Dnssec errors
+    #[error("Dnssec: {0:?}")]
+    Dnssec(#[from] dnssec::Error),
+    /// The library was not initialized (run .start())
+    #[error("not initialized")]
+    NotInitialized,
+}
 
 /// Instance of a fenrir endpoint
 #[allow(missing_copy_implementations, missing_debug_implementations)]
 pub struct Fenrir {
     /// library Configuration
     cfg: Config,
-    /// internal runtime
-    rt: ::tokio::runtime::Runtime,
     /// listening udp sockets
-    sockets: Vec<(Arc<UdpSocket>, JoinHandle<Result<()>>)>,
+    sockets: Vec<(Arc<UdpSocket>, JoinHandle<::std::io::Result<()>>)>,
-    /// DNSSEC resolvers. multiple for failover
+    /// DNSSEC resolver, with failovers
-    resolvers: Vec<(
+    dnssec: Option<dnssec::Dnssec>,
-        DnssecClient,
-        JoinHandle<result::Result<(), ::trust_dns_proto::error::ProtoError>>,
-    )>,
     /// Broadcast channel to tell workers to stop working
     stop_working: ::tokio::sync::broadcast::Sender<bool>,
 }
@@ -50,86 +57,56 @@ impl Drop for Fenrir {
 
 impl Fenrir {
     /// Create a new Fenrir endpoint
-    pub fn new(config: &Config) -> Result<Self> {
+    pub fn new(config: &Config) -> Result<Self, Error> {
-        let mut builder = runtime::Builder::new_multi_thread();
-        if let Some(threads) = config.threads {
-            builder.worker_threads(threads.get());
-        }
-        let rt = match builder.thread_name("libFenrir").build() {
-            Ok(rt) => rt,
-            Err(e) => {
-                ::tracing::error!("Can't initialize: {}", e);
-                return Err(e);
-            }
-        };
-        // start listening
         let listen_num = config.listen.len();
-        let resolvers_num = config.resolvers.len();
         let (sender, _) = ::tokio::sync::broadcast::channel(1);
         let endpoint = Fenrir {
             cfg: config.clone(),
-            rt: rt,
             sockets: Vec::with_capacity(listen_num),
-            resolvers: Vec::with_capacity(resolvers_num),
+            dnssec: None,
             stop_working: sender,
         };
         Ok(endpoint)
     }
     /// Start all workers, listeners
-    pub async fn start(&mut self) -> Result<()> {
+    pub async fn start(&mut self) -> Result<(), Error> {
         if let Err(e) = self.add_sockets().await {
             self.stop().await;
-            return Err(e);
+            return Err(e.into());
-        }
-        if let Err(e) = self.setup_dnssec().await {
-            self.stop().await;
-            return Err(e);
         }
+        self.dnssec = Some(dnssec::Dnssec::new(&self.cfg.resolvers).await?);
         Ok(())
     }
     /// Stop all workers, listeners
     /// asyncronous version for Drop
     fn stop_sync(&mut self) {
-        let mut toempty_resolv = Vec::new();
         let mut toempty_socket = Vec::new();
-        ::std::mem::swap(&mut self.resolvers, &mut toempty_resolv);
         ::std::mem::swap(&mut self.sockets, &mut toempty_socket);
-        self.rt
+        let task = ::tokio::task::spawn(Self::real_stop(toempty_socket));
-            .block_on(Self::real_stop(toempty_socket, toempty_resolv));
+        let _ = futures::executor::block_on(task);
+        self.dnssec = None;
     }
     /// Stop all workers, listeners
     pub async fn stop(&mut self) {
-        // TODO
         let _ = self.stop_working.send(true);
-        let mut toempty_resolv = Vec::new();
         let mut toempty_socket = Vec::new();
-        ::std::mem::swap(&mut self.resolvers, &mut toempty_resolv);
         ::std::mem::swap(&mut self.sockets, &mut toempty_socket);
-        Self::real_stop(toempty_socket, toempty_resolv).await;
+        Self::real_stop(toempty_socket).await;
+        self.dnssec = None;
     }
     /// actually do the work of stopping resolvers and listeners
     async fn real_stop(
-        sockets: Vec<(Arc<UdpSocket>, JoinHandle<Result<()>>)>,
+        sockets: Vec<(Arc<UdpSocket>, JoinHandle<::std::io::Result<()>>)>,
-        resolvers: Vec<(
-            DnssecClient,
-            JoinHandle<
-                result::Result<(), ::trust_dns_proto::error::ProtoError>,
-            >,
-        )>,
     ) {
-        for r in resolvers.into_iter() {
-            let _ = r.1.await;
-        }
         for s in sockets.into_iter() {
             let _ = s.1.await;
         }
     }
     /// Add all UDP sockets found in config
     /// and start listening for packets
-    async fn add_sockets(&mut self) -> Result<()> {
+    async fn add_sockets(&mut self) -> ::std::io::Result<()> {
         let sockets = self.cfg.listen.iter().map(|s_addr| async {
-            //let socket = self.rt.block_on(bind_udp(s_addr.clone()))?;
+            let socket = ::tokio::spawn(bind_udp(s_addr.clone())).await??;
-            let socket = self.rt.spawn(bind_udp(s_addr.clone())).await??;
             Ok(Arc::new(socket))
         });
         let sockets = ::futures::future::join_all(sockets).await;
@@ -138,7 +115,7 @@ impl Fenrir {
                 Ok(s) => {
                     let stop_working = self.stop_working.subscribe();
                     let join =
-                        self.rt.spawn(listen_udp(stop_working, s.clone()));
+                        ::tokio::spawn(listen_udp(stop_working, s.clone()));
                     self.sockets.push((s, join));
                 }
                 Err(e) => {
@@ -148,65 +125,17 @@ impl Fenrir {
         }
         Ok(())
     }
-    /// Add and initialize the DNSSEC resolvers to the endpoint
+    /// Get the raw TXT record of a Fenrir domain
-    async fn setup_dnssec(&mut self) -> Result<()> {
+    pub async fn resolv(&self, domain: &str) -> Result<dnssec::Record, Error> {
-        // use a TCP connection to the DNS.
+        match &self.dnssec {
-        // the records we need are big, will not fit in a UDP packet
+            Some(dnssec) => Ok(dnssec.resolv(domain).await?),
-        use tokio::net::TcpStream;
+            None => Err(Error::NotInitialized),
-        use trust_dns_client::{
-            client::AsyncClient, proto::iocompat::AsyncIoTokioAsStd,
-            tcp::TcpClientStream,
-        };
-
-        for resolver in self.cfg.resolvers.iter() {
-            let (stream, sender) = TcpClientStream::<
-                AsyncIoTokioAsStd<TcpStream>,
-            >::new(resolver.clone());
-            let client_tostart = AsyncClient::new(stream, sender, None);
-            // await the connection to be established
-            let (client, bg) = client_tostart.await?;
-
-            let handle = self.rt.spawn(bg);
-            self.resolvers.push((client, handle));
         }
-        Ok(())
-    }
-    /// get the fenrir data for a domain
-    pub async fn resolv(&mut self, domain: &str) -> Result<String> {
-        use std::str::FromStr;
-        use trust_dns_client::rr::{DNSClass, Name, RData, RecordType};
-
-        let fullname = "_fenrir".to_owned() + domain;
-        for client in self.resolvers.iter_mut() {
-            let query = client.0.query(
-                Name::from_str(&fullname).unwrap(),
-                DNSClass::IN,
-                RecordType::TXT,
-            );
-
-            // wait for its response
-            let response = query.await?;
-
-            // validate it's what we expected
-            match response.answers()[0].data() {
-                Some(RData::TXT(text)) => return Ok(text.to_string()),
-                _ => {
-                    return Err(::std::io::Error::new(
-                        ::std::io::ErrorKind::NotFound,
-                        "No TXT record found",
-                    ))
-                }
-            }
-        }
-        Err(::std::io::Error::new(
-            ::std::io::ErrorKind::NotConnected,
-            "No DNS server usable",
-        ))
     }
 }
 
 /// Add an async udp listener
-async fn bind_udp(sock: SocketAddr) -> Result<UdpSocket> {
+async fn bind_udp(sock: SocketAddr) -> ::std::io::Result<UdpSocket> {
     let socket = UdpSocket::bind(sock).await?;
     // PERF: SO_REUSEADDR/REUSEPORT
     Ok(socket)
@@ -216,7 +145,7 @@ async fn bind_udp(sock: SocketAddr) -> Result<UdpSocket> {
 async fn listen_udp(
     mut stop_working: ::tokio::sync::broadcast::Receiver<bool>,
     socket: Arc<UdpSocket>,
-) -> Result<()> {
+) -> ::std::io::Result<()> {
     // jumbo frames are 9K max
     let mut buffer: [u8; 9000] = [0; 9000];
     loop {