consolidate ddm protocol types into a dedicated crate (#770)

The frozen DDMv2 protocol types (UpdateV2, PullResponseV2,
UnderlayUpdateV2, TunnelUpdateV2, PathVectorV2, TunnelOriginV2,
IpPrefix, Ipv4Prefix, Ipv6Prefix) were scattered across
ddm-api-types, mg-common, and ddm/src/exchange/mod.rs. Collect
them all into a single dedicated module with a module-level
comment making the freeze guarantee impossible to miss.

Add an expectorate snapshot test over the JSON schema for the two
top-level message types (UpdateV2, PullResponseV2) so that any
accidental change to the frozen wire format fails loudly.

Also remove the DDMv1 conversion helpers (UpdateV1 and its From
impls) that are no longer needed.

Author: ahl

Cargo.lock

@@ -9,6 +9,7 @@ default-members = [
     "ddm-api",
     "ddm-api-types",
     "ddm-api-types/versions",
+    "ddm-protocol",
     "dropshot-apis",
     "bfd",
     "util",
@@ -38,6 +39,7 @@ members = [
     "ddm-api",
     "ddm-api-types",
     "ddm-api-types/versions",
+    "ddm-protocol",
     "dropshot-apis",
     "bfd",
     "package",
@@ -72,6 +74,7 @@ rdb = { path = "rdb", features = ["clap"] }
 ddm-api = { path = "ddm-api" }
 ddm-api-types = { path = "ddm-api-types" }
 ddm-api-types-versions = { path = "ddm-api-types/versions" }
+ddm-protocol = { path = "ddm-protocol" }
 
 # External
 slog = { version = "2.8.2", features = ["max_level_trace", "release_max_level_debug"] }
@@ -87,7 +90,8 @@ thiserror = "2.0"
 dropshot = { version = "0.17.0", features = [ "usdt-probes" ] }
 dropshot-api-manager = "0.7.2"
 dropshot-api-manager-types = "0.7.2"
-schemars = { version = "0.8", features = [ "uuid1", "chrono" ] }
+expectorate = "1.2.0"
+schemars = { version = "0.8.22", features = [ "uuid1", "chrono" ] }
 tokio = { version = "1.49", features = ["full"] }
 serde_repr = "0.1"
 anyhow = "1.0.102"

Cargo.toml

@@ -9,3 +9,4 @@ schemars.workspace = true
 serde.workspace = true
 serde_repr.workspace = true
 uuid.workspace = true
+ddm-protocol.workspace = true

ddm-api-types/versions/Cargo.toml

@@ -2,50 +2,4 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
-use crate::v1::net::Ipv6Prefix;
-use oxnet::Ipv6Net;
-use schemars::JsonSchema;
-use serde::{Deserialize, Serialize};
-
-#[derive(
-    Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, JsonSchema,
-)]
-pub struct PathVector {
-    pub destination: Ipv6Net,
-    pub path: Vec<String>,
-}
-
-/// THIS TYPE IS FOR DDM PROTOCOL VERSION 2. IT SHALL NEVER CHANGE. THIS TYPE
-/// CAN BE REMOVED WHEN DDMV2 CLIENTS AND SERVERS NO LONGER EXIST BUT ITS
-/// DEFINITION SHALL NEVER CHANGE.
-#[derive(
-    Debug, Clone, PartialEq, Eq, Hash, Deserialize, Serialize, JsonSchema,
-)]
-pub struct PathVectorV2 {
-    pub destination: Ipv6Prefix,
-    pub path: Vec<String>,
-}
-
-impl From<PathVectorV2> for PathVector {
-    fn from(value: PathVectorV2) -> Self {
-        PathVector {
-            destination: Ipv6Net::new_unchecked(
-                value.destination.addr,
-                value.destination.len,
-            ),
-            path: value.path,
-        }
-    }
-}
-
-impl From<PathVector> for PathVectorV2 {
-    fn from(value: PathVector) -> Self {
-        PathVectorV2 {
-            destination: Ipv6Prefix {
-                addr: value.destination.addr(),
-                len: value.destination.width(),
-            },
-            path: value.path,
-        }
-    }
-}
+pub use ddm_protocol::v3::PathVector;

ddm-api-types/versions/src/initial/exchange.rs

@@ -2,42 +2,4 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
-use oxnet::IpNet;
-use schemars::JsonSchema;
-use serde::{Deserialize, Serialize};
-use std::net::{Ipv4Addr, Ipv6Addr};
-
-#[derive(
-    Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, JsonSchema,
-)]
-pub struct TunnelOrigin {
-    pub overlay_prefix: IpNet,
-    pub boundary_addr: Ipv6Addr,
-    pub vni: u32,
-    #[serde(default)]
-    pub metric: u64,
-}
-
-#[derive(
-    Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, JsonSchema,
-)]
-pub struct Ipv6Prefix {
-    pub addr: Ipv6Addr,
-    pub len: u8,
-}
-
-#[derive(
-    Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, JsonSchema,
-)]
-pub struct Ipv4Prefix {
-    pub addr: Ipv4Addr,
-    pub len: u8,
-}
-
-#[derive(
-    Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, JsonSchema,
-)]
-pub enum IpPrefix {
-    V4(Ipv4Prefix),
-    V6(Ipv6Prefix),
-}
+pub use ddm_protocol::v3::TunnelOrigin;

ddm-api-types/versions/src/initial/net.rs

@@ -20,12 +20,8 @@ pub mod db {
 
 pub mod exchange {
     pub use crate::v1::exchange::PathVector;
-    pub use crate::v1::exchange::PathVectorV2;
 }
 
 pub mod net {
-    pub use crate::v1::net::IpPrefix;
-    pub use crate::v1::net::Ipv4Prefix;
-    pub use crate::v1::net::Ipv6Prefix;
     pub use crate::v1::net::TunnelOrigin;
 }

ddm-api-types/versions/src/latest.rs

@@ -0,0 +1,13 @@
+[package]
+name = "ddm-protocol"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+oxnet.workspace = true
+schemars.workspace = true
+serde.workspace = true
+
+[dev-dependencies]
+expectorate.workspace = true
+serde_json.workspace = true