network: inter-container networking support

network/src/autonet.rs

@@ -0,0 +1,181 @@
+use anyhow::{anyhow, Result};
+use smoltcp::wire::{EthernetAddress, Ipv4Cidr, Ipv6Cidr};
+use std::{collections::HashMap, str::FromStr};
+use uuid::Uuid;
+use xenstore::client::{XsdClient, XsdInterface, XsdTransaction};
+
+pub struct AutoNetworkCollector {
+    client: XsdClient,
+    known: HashMap<Uuid, NetworkMetadata>,
+}
+
+#[derive(Debug, Clone)]
+pub struct NetworkSide {
+    pub ipv4: Ipv4Cidr,
+    pub ipv6: Ipv6Cidr,
+    pub mac: EthernetAddress,
+}
+
+#[derive(Debug, Clone)]
+pub struct NetworkMetadata {
+    pub domid: u32,
+    pub uuid: Uuid,
+    pub guest: NetworkSide,
+    pub gateway: NetworkSide,
+}
+
+impl NetworkMetadata {
+    pub fn interface(&self) -> String {
+        format!("vif{}.20", self.domid)
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct AutoNetworkChangeset {
+    pub added: Vec<NetworkMetadata>,
+    pub removed: Vec<NetworkMetadata>,
+}
+
+impl AutoNetworkCollector {
+    pub fn new() -> Result<AutoNetworkCollector> {
+        Ok(AutoNetworkCollector {
+            client: XsdClient::open()?,
+            known: HashMap::new(),
+        })
+    }
+
+    pub fn read(&mut self) -> Result<Vec<NetworkMetadata>> {
+        let mut networks = Vec::new();
+        let mut tx = self.client.transaction()?;
+        for domid_string in tx.list_any("/local/domain")? {
+            let Ok(domid) = domid_string.parse::<u32>() else {
+                continue;
+            };
+
+            let dom_path = format!("/local/domain/{}", domid_string);
+            let Some(uuid_string) = tx.read_string_optional(&format!("{}/hypha/uuid", dom_path))?
+            else {
+                continue;
+            };
+
+            let Ok(uuid) = uuid_string.parse::<Uuid>() else {
+                continue;
+            };
+
+            let Ok(guest) =
+                AutoNetworkCollector::read_network_side(uuid, &mut tx, &dom_path, "guest")
+            else {
+                continue;
+            };
+
+            let Ok(gateway) =
+                AutoNetworkCollector::read_network_side(uuid, &mut tx, &dom_path, "gateway")
+            else {
+                continue;
+            };
+
+            networks.push(NetworkMetadata {
+                domid,
+                uuid,
+                guest,
+                gateway,
+            });
+        }
+        tx.commit()?;
+        Ok(networks)
+    }
+
+    fn read_network_side(
+        uuid: Uuid,
+        tx: &mut XsdTransaction<'_>,
+        dom_path: &str,
+        side: &str,
+    ) -> Result<NetworkSide> {
+        let side_path = format!("{}/hypha/network/{}", dom_path, side);
+        let Some(ipv4) = tx.read_string_optional(&format!("{}/ipv4", side_path))? else {
+            return Err(anyhow!(
+                "hypha domain {} is missing {} ipv4 network entry",
+                uuid,
+                side
+            ));
+        };
+
+        let Some(ipv6) = tx.read_string_optional(&format!("{}/ipv6", side_path))? else {
+            return Err(anyhow!(
+                "hypha domain {} is missing {} ipv6 network entry",
+                uuid,
+                side
+            ));
+        };
+
+        let Some(mac) = tx.read_string_optional(&format!("{}/mac", side_path))? else {
+            return Err(anyhow!(
+                "hypha domain {} is missing {} mac address entry",
+                uuid,
+                side
+            ));
+        };
+
+        let Ok(ipv4) = Ipv4Cidr::from_str(&ipv4) else {
+            return Err(anyhow!(
+                "hypha domain {} has invalid {} ipv4 network cidr entry: {}",
+                uuid,
+                side,
+                ipv4
+            ));
+        };
+
+        let Ok(ipv6) = Ipv6Cidr::from_str(&ipv6) else {
+            return Err(anyhow!(
+                "hypha domain {} has invalid {} ipv6 network cidr entry: {}",
+                uuid,
+                side,
+                ipv6
+            ));
+        };
+
+        let Ok(mac) = EthernetAddress::from_str(&mac) else {
+            return Err(anyhow!(
+                "hypha domain {} has invalid {} mac address entry: {}",
+                uuid,
+                side,
+                mac
+            ));
+        };
+
+        Ok(NetworkSide { ipv4, ipv6, mac })
+    }
+
+    pub fn read_changes(&mut self) -> Result<AutoNetworkChangeset> {
+        let mut seen: Vec<Uuid> = Vec::new();
+        let mut added: Vec<NetworkMetadata> = Vec::new();
+        let mut removed: Vec<NetworkMetadata> = Vec::new();
+
+        for network in self.read()? {
+            seen.push(network.uuid);
+            if self.known.contains_key(&network.uuid) {
+                continue;
+            }
+            let _ = self.known.insert(network.uuid, network.clone());
+            added.push(network);
+        }
+
+        let mut gone: Vec<Uuid> = Vec::new();
+        for uuid in self.known.keys() {
+            if seen.contains(uuid) {
+                continue;
+            }
+            gone.push(*uuid);
+        }
+
+        for uuid in &gone {
+            let Some(network) = self.known.remove(uuid) else {
+                continue;
+            };
+
+            removed.push(network);
+        }
+
+        Ok(AutoNetworkChangeset { added, removed })
+    }
+}