step

lib/dnsbox-base/src/common_types/binary.rs

@@ -116,11 +116,11 @@ impl DnsTextData for Base64LongBlob {
 	}
 }
 
-// No length byte (or restriction), just all data to end of record. uses
-// base64 encoding for text representation, whitespace allowed, padding
-// required.
-//
-// No following field allowed, i.e. last field in the record.
+/// No length byte (or restriction), just all data to end of record. uses
+/// base64 encoding for text representation, whitespace allowed, padding
+/// required.
+///
+/// No following field allowed, i.e. last field in the record.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Base64RemainingBlob(Bytes);
 
@@ -154,11 +154,13 @@ impl DnsTextData for Base64RemainingBlob {
 	}
 }
 
+/// No length byte (or restriction), just all data to end of record. uses
+/// hex encoding for text representation, whitespace allowed.
+///
+/// No following field allowed, i.e. last field in the record.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct HexRemainingBlob(Bytes);
 
-// No length byte, just all data to end of record. uses hex encoding for
-// text representation (spaces are ignored - last field in record).
 impl DnsPacketData for HexRemainingBlob {
 	fn deserialize(data: &mut Cursor<Bytes>) -> Result<Self> {
 		Ok(HexRemainingBlob(remaining_bytes(data)))

lib/dnsbox-base/src/common_types/name/mod.rs

@@ -200,6 +200,13 @@ impl DnsPacketData for DnsName {
 #[derive(Clone)]
 pub struct DnsCompressedName(pub DnsName);
 
+impl DnsCompressedName {
+	/// Create new name representing the DNS root (".")
+	pub fn new_root() -> Self {
+		DnsCompressedName(DnsName::new_root())
+	}
+}
+
 impl Deref for DnsCompressedName {
 	type Target = DnsName;
 

lib/dnsbox-base/src/packet/mod.rs

@@ -1,12 +1,14 @@
 use byteorder::ByteOrder;
 use bytes::{Bytes, Buf, BufMut, BigEndian};
-use common_types::{Type, Class, DnsCompressedName};
+use common_types::{Type, Class, DnsCompressedName, types};
 use errors::*;
 use ser::RRData;
 use ser::packet::{DnsPacketData, DnsPacketWriteContext};
 use std::io::Cursor;
 use records::registry::deserialize_rr_data;
 
+pub mod opt;
+
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
 pub enum QueryResponse {
 	Query,
@@ -164,16 +166,40 @@ pub struct DnsPacket {
 	pub answer: Vec<Resource>,
 	pub authority: Vec<Resource>,
 	pub additional: Vec<Resource>,
+	pub opt: Option<opt::OptResult<opt::Opt>>,
 }
 
 impl DnsPacket {
-	pub fn to_bytes(&self) -> Result<Vec<u8>> {
+	/// also serializes OPT before conversion if present
+	pub fn to_bytes(&mut self) -> Result<Vec<u8>> {
+		if self.opt.is_some() {
+			// delete other OPTs, so only call it if there is a "new" OPT
+			self.serialize_opt()?;
+		}
+
 		let mut buf = Vec::new();
 		let mut ctx = DnsPacketWriteContext::new();
 		ctx.enable_compression();
 		self.serialize(&mut ctx, &mut buf)?;
 		Ok(buf)
 	}
+
+	/// overwrites existing OPT records, and serializes a new one (if
+	/// self.opt is not None)
+	pub fn serialize_opt(&mut self) -> Result<()> {
+		// delete all additional OPT records
+		self.additional.retain(|r| r.data.rr_type() != types::OPT);
+
+		match self.opt.take() {
+			Some(Err(e)) => bail!("can't serialize broken OPT: {:?}", e),
+			Some(Ok(opt)) => {
+				self.additional.push(opt.serialize()?);
+			},
+			None => (),
+		}
+
+		Ok(())
+	}
 }
 
 impl Default for DnsPacket {
@@ -185,6 +211,7 @@ impl Default for DnsPacket {
 			answer: Vec::new(),
 			authority: Vec::new(),
 			additional: Vec::new(),
+			opt: None,
 		}
 	}
 }
@@ -192,14 +219,31 @@ impl Default for DnsPacket {
 impl DnsPacketData for DnsPacket {
 	fn deserialize(data: &mut Cursor<Bytes>) -> Result<Self> {
 		let header = DnsHeader::deserialize(data)?;
-		Ok(DnsPacket {
+		let mut p = DnsPacket {
 			id: header.id,
 			flags: header.flags,
 			question:   (0..header.qdcount).map(|_| Question::deserialize(data)).collect::<Result<Vec<_>>>()?,
 			answer:     (0..header.ancount).map(|_| Resource::deserialize(data)).collect::<Result<Vec<_>>>()?,
 			authority:  (0..header.nscount).map(|_| Resource::deserialize(data)).collect::<Result<Vec<_>>>()?,
 			additional: (0..header.arcount).map(|_| Resource::deserialize(data)).collect::<Result<Vec<_>>>()?,
-		})
+			opt: None,
+		};
+
+		let mut opt_resource_ndx = None;
+
+		for (i, r) in p.additional.iter().enumerate() {
+			if r.data.rr_type() == types::OPT {
+				ensure!(opt_resource_ndx.is_none(), "multiple OPT resource records");
+				opt_resource_ndx = Some(i);
+			}
+		}
+
+		if let Some(ndx) = opt_resource_ndx {
+			let opt_rr = p.additional.remove(ndx);
+			p.opt = Some(opt::Opt::deserialize(&opt_rr)?);
+		}
+
+		Ok(p)
 	}
 
 	fn serialize(&self, context: &mut DnsPacketWriteContext, packet: &mut Vec<u8>) -> Result<()> {

lib/dnsbox-base/src/packet/opt.rs

@@ -0,0 +1,285 @@
+use byteorder::ByteOrder;
+use bytes::{Bytes, Buf, BufMut, BigEndian};
+use common_types::{DnsCompressedName, Class, types};
+use errors::*;
+use packet::Resource;
+use records::UnknownRecord;
+use ser::packet::{DnsPacketData, DnsPacketWriteContext, get_blob, remaining_bytes};
+use std::io::{Cursor, Read};
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub enum OptError {
+	UnknownVersion,
+	InvalidData,
+}
+
+/// parsing OPT can fail without having to throw away the packet
+/// completely; just fail in some way
+///
+/// TODO: define some useful error...
+pub type OptResult<T> = ::std::result::Result<T, OptError>;
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub struct OptFlag(pub u16);
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub struct OptFlags(pub u16);
+
+impl ::std::ops::BitOr<OptFlag> for OptFlags {
+	type Output = bool;
+
+	fn bitor(self, rhs: OptFlag) -> Self::Output {
+		0 != self.0 & rhs.0
+	}
+}
+
+impl ::std::ops::BitOr<OptFlags> for OptFlag {
+	type Output = bool;
+
+	fn bitor(self, rhs: OptFlags) -> Self::Output {
+		0 != self.0 & rhs.0
+	}
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum DnsOption {
+	/// DNS Name Server Identifier (0x0003)
+	NSID(Bytes),
+	// DAU (0x0005)
+	// DHU (0x0006)
+	// N3U (0x0007)
+	// edns-client-subnet (0x0008)
+	ClientSubnet {
+		source_prefix_length: u8,
+		scope_prefix_length: u8,
+		addr: IpAddr,
+	},
+	// EDNS EXPIRE (0x0009)
+	// COOKIE (0x000a)
+	// edns-tcp-keepalive (0x000b)
+	// Padding (0x000c)
+	// CHAIN (0x000d)
+	// edns-key-tag (0x000e)
+	// DeviceID (26946 = 0x6942)
+	Unknown {
+		code: u16,
+		data: Bytes,
+	}
+}
+
+impl DnsOption {
+	fn parse_client_subnet(data: &mut Cursor<Bytes>) -> Result<Self> {
+		let addr_family = u16::deserialize(data)?;
+		let source_prefix_length = u8::deserialize(data)?;
+		let scope_prefix_length = u8::deserialize(data)?;
+		let addr_prefix_len = ((source_prefix_length + 7) / 8) as usize;
+		ensure!(scope_prefix_length <= source_prefix_length, "scope prefix {} > source prefix {}", scope_prefix_length, source_prefix_length);
+		let addr = match addr_family {
+			1 => {
+				ensure!(source_prefix_length <= 32, "invalid prefix for IPv4");
+				let mut o = [0u8; 4];
+				data.read_exact(&mut o[0..addr_prefix_len])?;
+				if 0 != source_prefix_length % 8 {
+					let mask = 0xff >> (source_prefix_length % 8);
+					ensure!(0 == o[addr_prefix_len - 1] & mask, "non-zero padding");
+				}
+				IpAddr::V4(Ipv4Addr::from(o))
+			},
+			2 => {
+				ensure!(source_prefix_length <= 128, "invalid prefix for IPv6");
+				let mut o = [0u8; 16];
+				data.read_exact(&mut o[0..addr_prefix_len])?;
+				if 0 != source_prefix_length % 8 {
+					let mask = 0xff >> (source_prefix_length % 8);
+					ensure!(0 == o[addr_prefix_len - 1] & mask, "non-zero padding");
+				}
+				IpAddr::V6(Ipv6Addr::from(o))
+			},
+			_ => {
+				bail!("unknown address family {}", addr_family);
+			},
+		};
+		Ok(DnsOption::ClientSubnet{
+			source_prefix_length,
+			scope_prefix_length,
+			addr,
+		})
+	}
+
+	fn parse_opt(code: u16, opt_data: Bytes) -> Result<Self> {
+		let mut data = Cursor::new(opt_data);
+
+		let result = (|| Ok(match code {
+			0x0003 => DnsOption::NSID(remaining_bytes(&mut data)),
+			0x0008 => DnsOption::parse_client_subnet(&mut data)?,
+			_ => bail!("unknown option {}", code),
+		}))()?;
+
+		ensure!(!data.has_remaining(), "option data remaining: {} bytes", data.remaining());
+
+		Ok(result)
+	}
+
+	fn write_opt_data(&self, _context: &mut DnsPacketWriteContext, packet: &mut Vec<u8>) -> Result<()> {
+		match *self {
+			DnsOption::NSID(ref id) => {
+				packet.reserve(id.len());
+				packet.put_slice(id);
+			},
+			DnsOption::ClientSubnet{source_prefix_length, scope_prefix_length, ref addr} => {
+				let addr_prefix_len = ((source_prefix_length + 7) / 8) as usize;
+				packet.reserve(4 + addr_prefix_len);
+				packet.put_u16::<BigEndian>(match *addr {
+					IpAddr::V4(_) => 1,
+					IpAddr::V6(_) => 2,
+				});
+				packet.put_u8(source_prefix_length);
+				packet.put_u8(scope_prefix_length);
+
+				match *addr {
+					IpAddr::V4(ref addr) => {
+						let o = addr.octets();
+						packet.put_slice(&o[..addr_prefix_len]);
+					},
+					IpAddr::V6(ref addr) => {
+						let o = addr.octets();
+						packet.put_slice(&o[..addr_prefix_len]);
+					},
+				}
+			},
+			DnsOption::Unknown{ref data, ..} => {
+				packet.reserve(data.len());
+				packet.put_slice(data);
+			},
+		}
+		Ok(())
+	}
+}
+
+impl DnsPacketData for DnsOption {
+	fn deserialize(data: &mut Cursor<Bytes>) -> Result<Self> {
+		let code = u16::deserialize(data)?;
+		let opt_len = u16::deserialize(data)? as usize;
+
+		let opt_data = get_blob(data, opt_len)?;
+
+		DnsOption::parse_opt(code, opt_data.clone()).or_else(|_| {
+			Ok(DnsOption::Unknown{
+				code: code,
+				data: opt_data,
+			})
+		})
+	}
+
+	fn serialize(&self, context: &mut DnsPacketWriteContext, packet: &mut Vec<u8>) -> Result<()> {
+		let code: u16 = match *self {
+			DnsOption::NSID(_) => 0x0003,
+			DnsOption::ClientSubnet{..} => 0x0008,
+			DnsOption::Unknown{code, ..} => code,
+		};
+		code.serialize(context, packet)?;
+
+		let opt_len_pos = packet.len();
+		packet.reserve(2);
+		packet.put_u16::<BigEndian>(0); // stub
+
+		let opt_start = packet.len();
+		self.write_opt_data(context, packet)?;
+		let opt_end = packet.len();
+		let opt_len = opt_end - opt_start;
+
+		ensure!(opt_len < 0x1_0000, "OPTION DATA too big");
+
+		// now patch length
+		BigEndian::write_u16(&mut packet[opt_len_pos..][..2], opt_len as u16);
+
+		Ok(())
+	}
+}
+
+pub const DNSSEC_OK: OptFlag = OptFlag(0x8000);
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct Opt {
+	// "CLASS"
+	pub udp_payload_size: u16,
+	// "TTL"
+	pub extended_rcode_high: u8,
+	pub version: u8,
+	pub flags: OptFlags,
+
+	// RDATA
+	pub options: Vec<DnsOption>,
+}
+
+impl Opt {
+	fn deserialize_options(ur: &UnknownRecord) -> Result<Vec<DnsOption>> {
+		let mut data = Cursor::new(ur.raw().clone());
+		let mut options = Vec::new();
+		while data.has_remaining() {
+			options.push(DnsOption::deserialize(&mut data)?);
+		}
+
+		Ok(options)
+	}
+
+	pub fn deserialize(r: &Resource) -> Result<OptResult<Self>> {
+		let udp_payload_size = r.class.0;
+		let extended_rcode_high = (r.ttl >> 24) as u8;
+		let version = (r.ttl >> 16) as u8;
+		let flags = OptFlags(r.ttl as u16);
+
+		if version > 0 { return Ok(Err(OptError::UnknownVersion)); }
+
+		let ur = match r.data.as_any().downcast_ref::<UnknownRecord>() {
+			Some(ur) => ur,
+			None => bail!("need to parse OPT from UnknownRecord"),
+		};
+
+		let options = match Opt::deserialize_options(ur) {
+			Ok(options) => options,
+			Err(_) => return Ok(Err(OptError::InvalidData)),
+		};
+
+		Ok(Ok(Opt {
+			udp_payload_size,
+			extended_rcode_high,
+			version,
+			flags,
+			options,
+		}))
+	}
+
+	pub fn serialize(&self) -> Result<Resource> {
+		let mut data = Vec::new();
+		let mut ctx = DnsPacketWriteContext::new();
+
+		for o in &self.options {
+			o.serialize(&mut ctx, &mut data)?;
+		}
+		let ur = UnknownRecord::new(types::OPT, data.into());
+
+		let ttl = ((self.extended_rcode_high as u32) << 24)
+			| ((self.version as u32) << 16)
+			| self.flags.0 as u32;
+		Ok(Resource{
+			name: DnsCompressedName::new_root(),
+			class: Class(self.udp_payload_size),
+			ttl: ttl,
+			data: Box::new(ur) as _,
+		})
+	}
+}
+
+impl Default for Opt {
+	fn default() -> Self {
+		Opt {
+			udp_payload_size: 500,
+			extended_rcode_high: 0,
+			version: 0,
+			flags: OptFlags(0),
+			options: Vec::new(),
+		}
+	}
+}

lib/dnsbox-base/src/records/powerdns_tests.rs

@@ -4,13 +4,14 @@ use bytes::Bytes;
 use common_types::{DnsName, DnsCompressedName, Class, Type, types, classes};
 use errors::*;
 use packet::*;
-use records::{UnknownRecord, registry};
+use packet::opt::{Opt, DnsOption};
+use records::{UnknownRecord, registry, A};
 use ser::{RRData, RRDataText, text};
 use ser::packet::{DnsPacketData, deserialize_with};
 use std::io::Cursor;
 
 fn fake_packet(rrtype: Type, raw: &[u8]) -> Bytes {
-	let p = DnsPacket{
+	let mut p = DnsPacket{
 		question: vec![
 			Question {
 				qname: ".".parse().unwrap(),
@@ -55,7 +56,7 @@ fn get_first_answer_rdata(packet: Bytes) -> Result<Bytes> {
 }
 
 fn serialized_answer(rrdata: Box<RRData>) -> Result<Bytes> {
-	let p = DnsPacket{
+	let mut p = DnsPacket{
 		question: vec![
 			Question {
 				qname: ".".parse().unwrap(),
@@ -841,3 +842,57 @@ fn test_invalid_data_checks() {
 	check_invalid_zone(types::CNAME, "123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.123456789012345678901234567890123456789012345678901234567890123.12345678901234567890123456789012345678901234567890123456789012.");
 	check_invalid_zone(types::SOA, "ns.rec.test hostmaster.test.rec 20130512010 3600 3600 604800 120"); // too long serial
 }
+
+#[test]
+fn test_opt_record_in() {
+	let p = deserialize_with(
+		Bytes::from_static(b"\xf0\x01\x01\x00\x00\x01\x00\x01\x00\x00\x00\x01\x03www\x08powerdns\x03com\x00\x00\x01\x00\x01\x03www\x08powerdns\x03com\x00\x00\x01\x00\x01\x00\x00\x00\x10\x00\x04\x7f\x00\x00\x01\x00\x00\x29\x05\x00\x00\x00\x00\x00\x00\x0c\x00\x03\x00\x08powerdns"),
+		DnsPacket::deserialize
+	).unwrap();
+
+	let opt = p.opt.unwrap().unwrap();
+
+	assert_eq!(opt.udp_payload_size, 1280);
+	assert_eq!(opt.options, vec![
+		DnsOption::NSID(Bytes::from_static(b"powerdns")),
+	]);
+}
+
+#[test]
+fn test_opt_record_out() {
+	let mut p = DnsPacket{
+		id: 0xf001,
+		flags: DnsHeaderFlags {
+			recursion_desired: true,
+			.. Default::default()
+		},
+		question: vec![
+			Question {
+				qname: "www.powerdns.com.".parse().unwrap(),
+				qtype: types::A,
+				qclass: classes::IN,
+			}
+		],
+		answer: vec![
+			Resource {
+				name: "www.powerdns.com.".parse().unwrap(),
+				class: classes::IN,
+				ttl: 16,
+				data: Box::new(A { addr: "127.0.0.1".parse().unwrap() }),
+			}
+		],
+		opt: Some(Ok(Opt {
+			udp_payload_size: 1280,
+			options: vec![
+				DnsOption::NSID(Bytes::from_static(b"powerdns")),
+			],
+			.. Default::default()
+		})),
+		.. Default::default()
+	};
+
+	assert_eq!(
+		&p.to_bytes().unwrap() as &[u8],
+		b"\xf0\x01\x01\x00\x00\x01\x00\x01\x00\x00\x00\x01\x03www\x08powerdns\x03com\x00\x00\x01\x00\x01\xc0\x0c\x00\x01\x00\x01\x00\x00\x00\x10\x00\x04\x7f\x00\x00\x01\x00\x00\x29\x05\x00\x00\x00\x00\x00\x00\x0c\x00\x03\x00\x08powerdns" as &[u8]
+	);
+}

lib/dnsbox-base/src/records/structs.rs

@@ -10,7 +10,7 @@ use std::net::{Ipv4Addr, Ipv6Addr};
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug, DnsPacketData, DnsTextData, RRData)]
 #[RRClass(IN)]
 pub struct A {
-	addr: Ipv4Addr,
+	pub addr: Ipv4Addr,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug, DnsPacketData, DnsTextData, RRData)]

lib/dnsbox-base/src/records/tests.rs

@@ -48,6 +48,13 @@ where
 	let d2: T = rrdata_parse(txt).context("couldn't parse text record")?;
 	ensure!(d1 == d2, "decoded data not equal: {:?} != {:?}", d1, d2);
 
+	let d1_text = d1.text().unwrap();
+	let d2_text = d2.text().unwrap();
+	let canon_text = (T::NAME.to_owned(), canon.into());
+
+	ensure!(d1_text == canon_text, "re-formatted binary record not equal to canonical representation: {:?} != {:?}", d1_text, canon_text);
+	ensure!(d2_text == canon_text, "re-formatted text record not equal to canonical representation: {:?} != {:?}", d2_text, canon_text);
+
 	Ok(())
 }
 
@@ -66,10 +73,10 @@ where
 	T: StaticRRData + fmt::Debug + PartialEq
 {
 	// at least one "segment" (which could be empty)
-	check2::<T>(r#" "" "#, b"", r#" "" "#).unwrap_err();
-	check2::<T>(r#""#, b"\x00", r#" "" "#).unwrap_err();
+	check2::<T>(r#" "" "#, b"", r#""""#).unwrap_err();
+	check2::<T>(r#""#, b"\x00", r#""""#).unwrap_err();
 	// one empty segment
-	check2::<T>(r#" "" "#, b"\x00", r#" "" "#).unwrap();
+	check2::<T>(r#" "" "#, b"\x00", r#""""#).unwrap();
 	// one segment
 	check::<T>(r#" "foo" "#, b"\x03foo").unwrap();
 	// two segments

lib/dnsbox-base/src/records/unknown.rs

@@ -24,6 +24,10 @@ impl UnknownRecord {
 		}
 	}
 
+	pub fn raw(&self) -> &Bytes {
+		&self.raw
+	}
+
 	pub fn deserialize(rr_type: Type, data: &mut ::std::io::Cursor<Bytes>) -> Result<Self> {
 		Ok(UnknownRecord::new(rr_type, remaining_bytes(data)))
 	}
@@ -89,4 +93,8 @@ impl RRData for UnknownRecord {
 	fn clone_box(&self) -> Box<RRData> {
 		Box::new(self.clone()) as _
 	}
+
+	fn as_any(&self) -> &::std::any::Any {
+		self as _
+	}
 }

lib/dnsbox-base/src/ser/rrdata.rs

@@ -1,12 +1,13 @@
 use bytes::Bytes;
 use common_types::{Class, Type, classes};
 use errors::*;
+use records::UnknownRecord;
 use ser::packet::{DnsPacketData, DnsPacketWriteContext};
 use ser::text::{DnsTextData, DnsTextFormatter, DnsTextContext};
+use std::any::Any;
 use std::borrow::Cow;
 use std::fmt;
 use std::io::Cursor;
-use records::UnknownRecord;
 
 pub trait RRDataPacket {
 	fn deserialize_rr_data(ttl: u32, rr_class: Class, rr_type: Type, data: &mut Cursor<Bytes>) -> Result<Self>
@@ -93,8 +94,10 @@ impl<T: DnsTextData + StaticRRData> RRDataText for T {
 	}
 }
 
-pub trait RRData: RRDataPacket + RRDataText + fmt::Debug {
+pub trait RRData: RRDataPacket + RRDataText + fmt::Debug + 'static {
 	fn clone_box(&self) -> Box<RRData>;
+
+	fn as_any(&self) -> &Any;
 }
 
 impl Clone for Box<RRData> {

lib/dnsbox-derive/src/rrdata.rs

@@ -76,6 +76,10 @@ pub fn build(ast: &syn::DeriveInput) -> quote::Tokens {
 			fn clone_box(&self) -> Box<::dnsbox_base::ser::RRData> {
 				Box::new(self.clone() as #name) as _
 			}
+
+			fn as_any(&self) -> &::std::any::Any {
+				self as _
+			}
 		}
 
 		impl ::dnsbox_base::ser::StaticRRData for #name {