Add TOS and TTL information to Datagrams

This part of the refactor of mozilla#1495. This doesn't include any ECN I/O or other logic, just adds the required fields to the datagram header.
larseggert · Jan 18, 2024 · 29e650b · 29e650b
1 parent 64fb41f
commit 29e650b
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Showing 18 changed files with 215 additions and 60 deletions.
diff --git a/neqo-client/src/main.rs b/neqo-client/src/main.rs
@@ -430,7 +430,7 @@ fn process_loop(
                         break 'read;
                     }
                     if sz > 0 {
-                        let d = Datagram::new(remote, *local_addr, &buf[..sz]);
+                        let d = Datagram::new(remote, *local_addr, None, None, &buf[..sz]);
                         datagrams.push(d);
                     }
                 }
@@ -1365,7 +1365,7 @@ mod old {
                             break 'read;
                         }
                         if sz > 0 {
-                            let d = Datagram::new(remote, *local_addr, &buf[..sz]);
+                            let d = Datagram::new(remote, *local_addr, None, None, &buf[..sz]);
                             client.process_input(&d, Instant::now());
                             handler.maybe_key_update(client)?;
                         }

diff --git a/neqo-common/Cargo.toml b/neqo-common/Cargo.toml
@@ -9,6 +9,7 @@ build = "build.rs"
 
 [dependencies]
 log = { version = "0.4.0", default-features = false }
+enum-map = "~2.7.3"
 env_logger = { version = "0.10", default-features = false }
 lazy_static = "1.3.0"
 qlog = "0.11.0"

diff --git a/neqo-common/src/datagram.rs b/neqo-common/src/datagram.rs
@@ -7,20 +7,97 @@
 use std::net::SocketAddr;
 use std::ops::Deref;
 
+use enum_map::Enum;
+
 use crate::hex_with_len;
 
+// ECN (Explicit Congestion Notification) codepoints mapped to the
+// lower 2 bits of the TOS field.
+// https://www.iana.org/assignments/dscp-registry/dscp-registry.xhtml
+#[derive(Copy, Clone, PartialEq, Eq, Enum)]
+#[repr(u8)]
+pub enum IpTosEcn {
+    NotEct = 0b00, // Not-ECT (Not ECN-Capable Transport) [RFC3168]
+    Ect1 = 0b01,   // ECT(1) (ECN-Capable Transport(1))[1] [RFC8311][RFC Errata 5399][RFC9331]
+    Ect0 = 0b10,   // ECT(0) (ECN-Capable Transport(0)) [RFC3168]
+    Ce = 0b11,     // CE (Congestion Experienced) [RFC3168]
+}
+
+impl From<u8> for IpTosEcn {
+    fn from(v: u8) -> Self {
+        match v & 0b11 {
+            0b00 => IpTosEcn::NotEct,
+            0b01 => IpTosEcn::Ect1,
+            0b10 => IpTosEcn::Ect0,
+            0b11 => IpTosEcn::Ce,
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl From<IpTosEcn> for u8 {
+    fn from(val: IpTosEcn) -> Self {
+        val as u8
+    }
+}
+
+impl std::fmt::Debug for IpTosEcn {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            IpTosEcn::NotEct => f.write_str("Not-ECT"),
+            IpTosEcn::Ect1 => f.write_str("ECT(1)"),
+            IpTosEcn::Ect0 => f.write_str("ECT(0)"),
+            IpTosEcn::Ce => f.write_str("CE"),
+        }
+    }
+}
+
+// DiffServ Codepoints, mapped to the upper six bits of the TOS field.
+// https://www.iana.org/assignments/dscp-registry/dscp-registry.xhtml
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(u8)]
+pub enum IpTosDscp {
+    Cs0 = 0b0000_0000,        // [RFC2474]
+    Cs1 = 0b0010_0000,        // [RFC2474]
+    Cs2 = 0b0100_0000,        // [RFC2474]
+    Cs3 = 0b0110_0000,        // [RFC2474]
+    Cs4 = 0b1000_0000,        // [RFC2474]
+    Cs5 = 0b1010_0000,        // [RFC2474]
+    Cs6 = 0b1100_0000,        // [RFC2474]
+    Cs7 = 0b1110_0000,        // [RFC2474]
+    Af11 = 0b0010_1000,       // [RFC2597]
+    Af12 = 0b0011_0000,       // [RFC2597]
+    Af13 = 0b0011_1000,       // [RFC2597]
+    Af21 = 0b0100_1000,       // [RFC2597]
+    Af22 = 0b0101_0000,       // [RFC2597]
+    Af23 = 0b0101_1000,       // [RFC2597]
+    Af31 = 0b0110_1000,       // [RFC2597]
+    Af32 = 0b0111_0000,       // [RFC2597]
+    Af33 = 0b0111_1000,       // [RFC2597]
+    Af41 = 0b1000_1000,       // [RFC2597]
+    Af42 = 0b1001_0000,       // [RFC2597]
+    Af43 = 0b1001_1000,       // [RFC2597]
+    Ef = 0b1011_1000,         // [RFC3246]
+    VoiceAdmit = 0b1011_0000, // [RFC5865]
+    Le = 0b0000_0100,         // [RFC8622]
+}
+
 #[derive(PartialEq, Eq, Clone)]
 pub struct Datagram {
     src: SocketAddr,
     dst: SocketAddr,
+    tos: Option<u8>,
+    ttl: Option<u8>,
     d: Vec<u8>,
 }
 
 impl Datagram {
-    pub fn new<V: Into<Vec<u8>>>(src: SocketAddr, dst: SocketAddr, d: V) -> Self {
+    pub fn new<V: Into<Vec<u8>>>(src: SocketAddr, dst: SocketAddr, tos: Option<u8>, ttl: Option<u8>, d: V) -> Self {
         Self {
             src,
             dst,
+            tos,
+            ttl,
             d: d.into(),
         }
     }
@@ -34,7 +111,16 @@ impl Datagram {
     pub fn destination(&self) -> SocketAddr {
         self.dst
     }
-}
+
+    #[must_use]
+    pub fn tos(&self) -> Option<u8> {
+        self.tos
+    }
+
+    #[must_use]
+    pub fn ttl(&self) -> Option<u8> {
+        self.ttl
+    }}
 
 impl Deref for Datagram {
     type Target = Vec<u8>;
@@ -48,7 +134,9 @@ impl std::fmt::Debug for Datagram {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         write!(
             f,
-            "Datagram {:?}->{:?}: {}",
+            "Datagram TOS {:?} TTL {:?} {:?}->{:?}: {}",
+            self.tos,
+            self.ttl,
             self.src,
             self.dst,
             hex_with_len(&self.d)

diff --git a/neqo-common/src/lib.rs b/neqo-common/src/lib.rs
@@ -18,7 +18,7 @@ pub mod qlog;
 pub mod timer;
 
 pub use self::codec::{Decoder, Encoder};
-pub use self::datagram::Datagram;
+pub use self::datagram::{IpTosDscp, IpTosEcn, Datagram};
 pub use self::header::Header;
 pub use self::incrdecoder::{
     IncrementalDecoderBuffer, IncrementalDecoderIgnore, IncrementalDecoderUint,

diff --git a/neqo-interop/src/main.rs b/neqo-interop/src/main.rs
@@ -148,7 +148,7 @@ fn process_loop(
             continue;
         }
         if sz > 0 {
-            let received = Datagram::new(nctx.remote_addr, nctx.local_addr, &buf[..sz]);
+            let received = Datagram::new(nctx.remote_addr, nctx.local_addr, None, None, &buf[..sz]);
             client.process_input(&received, Instant::now());
         }
     }
@@ -309,7 +309,7 @@ fn process_loop_h3(
             continue;
         }
         if sz > 0 {
-            let received = Datagram::new(nctx.remote_addr, nctx.local_addr, &buf[..sz]);
+            let received = Datagram::new(nctx.remote_addr, nctx.local_addr, None, None, &buf[..sz]);
             handler.h3.process_input(&received, Instant::now());
         }
     }
@@ -682,7 +682,13 @@ impl Handler for VnHandler {
     fn rewrite_out(&mut self, d: &Datagram) -> Option<Datagram> {
         let mut payload = d[..].to_vec();
         payload[1] = 0x1a;
-        Some(Datagram::new(d.source(), d.destination(), payload))
+        Some(Datagram::new(
+            d.source(),
+            d.destination(),
+            d.tos(),
+            d.ttl(),
+            payload,
+        ))
     }
 }
 

diff --git a/neqo-server/src/main.rs b/neqo-server/src/main.rs
@@ -606,7 +606,7 @@ fn read_dgram(
         eprintln!("zero length datagram received?");
         Ok(None)
     } else {
-        Ok(Some(Datagram::new(remote_addr, *local_address, &buf[..sz])))
+        Ok(Some(Datagram::new(remote_addr, *local_address, None, None, &buf[..sz])))
     }
 }
 

diff --git a/neqo-transport/src/connection/mod.rs b/neqo-transport/src/connection/mod.rs
@@ -1149,7 +1149,7 @@ impl Connection {
     /// part that we don't have keys for.
     fn save_datagram(&mut self, cspace: CryptoSpace, d: &Datagram, remaining: usize, now: Instant) {
         let d = if remaining < d.len() {
-            Datagram::new(d.source(), d.destination(), &d[d.len() - remaining..])
+            Datagram::new(d.source(), d.destination(), d.tos(), d.ttl(), &d[d.len() - remaining..])
         } else {
             d.clone()
         };

diff --git a/neqo-transport/src/connection/tests/close.rs b/neqo-transport/src/connection/tests/close.rs
@@ -9,9 +9,8 @@ use super::{connect, connect_force_idle, default_client, default_server, send_so
 use crate::tparams::{self, TransportParameter};
 use crate::{AppError, ConnectionError, Error, ERROR_APPLICATION_CLOSE};
 
-use neqo_common::Datagram;
 use std::time::Duration;
-use test_fixture::{self, addr, now};
+use test_fixture::{self, datagram, now};
 
 fn assert_draining(c: &Connection, expected: &Error) {
     assert!(c.state().closed());
@@ -201,6 +200,6 @@ fn stateless_reset_client() {
         .unwrap();
     connect_force_idle(&mut client, &mut server);
 
-    client.process_input(&Datagram::new(addr(), addr(), vec![77; 21]), now());
+    client.process_input(&datagram(vec![77; 21]), now());
     assert_draining(&client, &Error::StatelessReset);
 }
diff --git a/neqo-transport/src/connection/tests/handshake.rs b/neqo-transport/src/connection/tests/handshake.rs
@@ -30,7 +30,7 @@ use std::mem;
 use std::net::{IpAddr, Ipv6Addr, SocketAddr};
 use std::rc::Rc;
 use std::time::Duration;
-use test_fixture::{self, addr, assertions, fixture_init, now, split_datagram};
+use test_fixture::{self, addr, assertions, datagram, fixture_init, now, split_datagram};
 
 const ECH_CONFIG_ID: u8 = 7;
 const ECH_PUBLIC_NAME: &str = "public.example";
@@ -615,7 +615,7 @@ fn corrupted_initial() {
         .find(|(_, &v)| v != 0)
         .unwrap();
     corrupted[idx] ^= 0x76;
-    let dgram = Datagram::new(d.source(), d.destination(), corrupted);
+    let dgram = Datagram::new(d.source(), d.destination(), d.tos(), d.ttl(), corrupted);
     server.process_input(&dgram, now());
     // The server should have received two packets,
     // the first should be dropped, the second saved.
@@ -711,7 +711,7 @@ fn extra_initial_invalid_cid() {
     let mut copy = hs.to_vec();
     assert_ne!(copy[5], 0); // The DCID should be non-zero length.
     copy[6] ^= 0xc4;
-    let dgram_copy = Datagram::new(hs.destination(), hs.source(), copy);
+    let dgram_copy = Datagram::new(hs.destination(), hs.source(), hs.tos(), hs.ttl(), copy);
     let nothing = client.process(Some(&dgram_copy), now).dgram();
     assert!(nothing.is_none());
 }
@@ -814,7 +814,7 @@ fn garbage_initial() {
     let mut corrupted = Vec::from(&initial[..initial.len() - 1]);
     corrupted.push(initial[initial.len() - 1] ^ 0xb7);
     corrupted.extend_from_slice(rest.as_ref().map_or(&[], |r| &r[..]));
-    let garbage = Datagram::new(addr(), addr(), corrupted);
+    let garbage = datagram(corrupted);
     assert_eq!(Output::None, server.process(Some(&garbage), now()));
 }
 
@@ -832,6 +832,8 @@ fn drop_initial_packet_from_wrong_address() {
     let dgram = Datagram::new(
         SocketAddr::new(IpAddr::V6(Ipv6Addr::new(0xfe80, 0, 0, 0, 0, 0, 0, 2)), 443),
         p.destination(),
+        p.tos(),
+        p.ttl(),
         &p[..],
     );
 
@@ -858,6 +860,8 @@ fn drop_handshake_packet_from_wrong_address() {
     let dgram = Datagram::new(
         SocketAddr::new(IpAddr::V6(Ipv6Addr::new(0xfe80, 0, 0, 0, 0, 0, 0, 2)), 443),
         p.destination(),
+        p.tos(),
+        p.ttl(),
         &p[..],
     );
 

diff --git a/neqo-transport/src/connection/tests/migration.rs b/neqo-transport/src/connection/tests/migration.rs
@@ -52,7 +52,7 @@ fn loopback() -> SocketAddr {
 }
 
 fn change_path(d: &Datagram, a: SocketAddr) -> Datagram {
-    Datagram::new(a, a, &d[..])
+    Datagram::new(a, a, d.tos(), d.ttl(), &d[..])
 }
 
 fn new_port(a: SocketAddr) -> SocketAddr {
@@ -61,7 +61,7 @@ fn new_port(a: SocketAddr) -> SocketAddr {
 }
 
 fn change_source_port(d: &Datagram) -> Datagram {
-    Datagram::new(new_port(d.source()), d.destination(), &d[..])
+    Datagram::new(new_port(d.source()), d.destination(), d.tos(), d.ttl(), &d[..])
 }
 
 /// As these tests use a new path, that path often has a non-zero RTT.