Support changing host veth name

src/network/bridge.rs

@@ -20,8 +20,8 @@ use crate::{
 use super::{
     constants::{
         ISOLATE_OPTION_FALSE, ISOLATE_OPTION_STRICT, ISOLATE_OPTION_TRUE,
-        NO_CONTAINER_INTERFACE_ERROR, OPTION_ISOLATE, OPTION_METRIC, OPTION_MTU,
-        OPTION_NO_DEFAULT_ROUTE, OPTION_VRF,
+        NO_CONTAINER_INTERFACE_ERROR, OPTION_HOST_INTERFACE_NAME, OPTION_ISOLATE, OPTION_METRIC,
+        OPTION_MTU, OPTION_NO_DEFAULT_ROUTE, OPTION_VRF,
     },
     core_utils::{self, get_ipam_addresses, join_netns, parse_option, CoreUtils},
     driver::{self, DriverInfo},
@@ -38,6 +38,8 @@ const NO_BRIDGE_NAME_ERROR: &str = "no bridge interface name given";
 struct InternalData {
     /// interface name of the veth pair inside the container netns
     container_interface_name: String,
+    /// interace name of the veth pair in the host netns
+    host_interface_name: String,
     /// interface name of the bridge for on the host
     bridge_interface_name: String,
     /// static mac address
@@ -86,6 +88,11 @@ impl driver::NetworkDriver for Bridge<'_> {
         let no_default_route: bool =
             parse_option(&self.info.network.options, OPTION_NO_DEFAULT_ROUTE)?.unwrap_or(false);
         let vrf: Option<String> = parse_option(&self.info.network.options, OPTION_VRF)?;
+        let host_interface_name = parse_option(
+            &self.info.per_network_opts.options,
+            OPTION_HOST_INTERFACE_NAME,
+        )?
+        .unwrap_or_else(|| "".to_string());
 
         let static_mac = match &self.info.per_network_opts.static_mac {
             Some(mac) => Some(CoreUtils::decode_address_from_hex(mac)?),
@@ -95,6 +102,7 @@ impl driver::NetworkDriver for Bridge<'_> {
         self.data = Some(InternalData {
             bridge_interface_name: bridge_name,
             container_interface_name: self.info.per_network_opts.interface_name.clone(),
+            host_interface_name,
             mac_address: static_mac,
             ipam,
             mtu,
@@ -647,17 +655,25 @@ fn create_veth_pair<'fd>(
     let mut peer = LinkMessage::default();
     netlink::parse_create_link_options(&mut peer, peer_opts);
 
-    let mut host_veth = netlink::CreateLinkOptions::new(String::from(""), InfoKind::Veth);
+    let mut host_veth =
+        netlink::CreateLinkOptions::new(data.host_interface_name.clone(), InfoKind::Veth);
     host_veth.mtu = data.mtu;
     host_veth.primary_index = primary_index;
     host_veth.info_data = Some(InfoData::Veth(InfoVeth::Peer(peer)));
 
     host.create_link(host_veth).map_err(|err| match err {
         NetavarkError::Netlink(ref e) if -e.raw_code() == libc::EEXIST => NetavarkError::wrap(
-            format!(
-                "create veth pair: interface {} already exists on container namespace",
-                data.container_interface_name
-            ),
+            if data.host_interface_name.is_empty() {
+                format!(
+                    "create veth pair: interface {} already exists on container namespace",
+                    data.container_interface_name
+                )
+            } else {
+                format!(
+                    "create veth pair: interface {} already exists on container namespace or {} exists on host namespace",
+                    data.container_interface_name, data.host_interface_name,
+                )
+            },
             err,
         ),
         _ => NetavarkError::wrap("create veth pair", err),

src/network/constants.rs

@@ -22,6 +22,7 @@ pub const OPTION_METRIC: &str = "metric";
 pub const OPTION_NO_DEFAULT_ROUTE: &str = "no_default_route";
 pub const OPTION_BCLIM: &str = "bclim";
 pub const OPTION_VRF: &str = "vrf";
+pub const OPTION_HOST_INTERFACE_NAME: &str = "host_interface_name";
 
 /// 100 is the default metric for most Linux networking tools.
 pub const DEFAULT_METRIC: u32 = 100;

src/network/types.rs

@@ -112,6 +112,10 @@ pub struct PerNetworkOptions {
     /// MAC address for the container interface.
     #[serde(rename = "static_mac")]
     pub static_mac: Option<String>,
+
+    /// Driver-specific options for this container.
+    #[serde(rename = "options")]
+    pub options: Option<HashMap<String, String>>,
 }
 
 /// PortMapping is one or more ports that will be mapped into the container.

test/610-bridge-vethname.bats

@@ -0,0 +1,30 @@
+#!/usr/bin/env bats   -*- bats -*-
+#
+# bridge driver tests with static veth names
+#
+
+load helpers
+
+@test bridge - valid veth name {
+    run_netavark --file ${TESTSDIR}/testfiles/bridge-vethname.json setup $(get_container_netns_path)
+
+    run_in_host_netns ip -j --details link show my-veth
+    link_info="$output"
+    assert_json "$link_info" '.[].flags[] | select(.=="UP")' == "UP" "Host veth is up"
+    assert_json "$link_info" ".[].linkinfo.info_kind" == "veth" "The veth interface is actually a veth"
+    assert_json "$link_info" ".[].master" "==" "podman0" "veth is part of the correct bridge"
+
+    run_netavark --file ${TESTSDIR}/testfiles/bridge-vethname.json teardown $(get_container_netns_path)
+
+    # check if the interface gets removed
+    expected_rc=1 run_in_host_netns ip -j --details link show my-veth
+    assert "$output" "==" 'Device "my-veth" does not exist.'
+}
+
+@test bridge - existing veth name {
+    expected_rc=1 run_netavark --file ${TESTSDIR}/testfiles/bridge-vethname-exists.json setup $(get_container_netns_path)
+    assert_json ".error" "create veth pair: interface eth0 already exists on container namespace or podman0 exists on host namespace: Netlink error: File exists (os error 17)"
+
+    expected_rc=1 run_in_host_netns ip -j --details link show my-veth
+    assert "$output" "==" 'Device "my-veth" does not exist.'
+}

test/testfiles/bridge-vethname-exists.json

@@ -0,0 +1,32 @@
+{
+    "container_id": "6ce776ea58b5",
+    "container_name": "testcontainer",
+    "networks": {
+        "podman": {
+            "interface_name": "eth0",
+            "static_ips": [
+                "10.88.0.2"
+            ],
+            "options": {
+                "host_interface_name": "podman0"
+            }
+        }
+    },
+    "network_info": {
+        "podman": {
+            "dns_enabled": false,
+            "driver": "bridge",
+            "id": "53ce4390f2adb1681eb1a90ec8b48c49c015e0a8d336c197637e7f65e365fa9e",
+            "internal": false,
+            "ipv6_enabled": false,
+            "name": "podman",
+            "network_interface": "podman0",
+            "subnets": [
+                {
+                    "gateway": "10.88.0.1",
+                    "subnet": "10.88.0.0/16"
+                }
+            ]
+        }
+    }
+}

test/testfiles/bridge-vethname.json

@@ -0,0 +1,32 @@
+{
+    "container_id": "6ce776ea58b5",
+    "container_name": "testcontainer",
+    "networks": {
+        "podman": {
+            "interface_name": "eth0",
+            "static_ips": [
+                "10.88.0.2"
+            ],
+            "options": {
+                "host_interface_name": "my-veth"
+            }
+        }
+    },
+    "network_info": {
+        "podman": {
+            "dns_enabled": false,
+            "driver": "bridge",
+            "id": "53ce4390f2adb1681eb1a90ec8b48c49c015e0a8d336c197637e7f65e365fa9e",
+            "internal": false,
+            "ipv6_enabled": false,
+            "name": "podman",
+            "network_interface": "podman0",
+            "subnets": [
+                {
+                    "gateway": "10.88.0.1",
+                    "subnet": "10.88.0.0/16"
+                }
+            ]
+        }
+    }
+}