Merge pull request containers#474 from mheon/metric

Add support for route metrics

src/network/bridge.rs

@@ -16,7 +16,7 @@ use crate::{
 };
 
 use super::{
-    constants::{NO_CONTAINER_INTERFACE_ERROR, OPTION_ISOLATE, OPTION_MTU},
+    constants::{NO_CONTAINER_INTERFACE_ERROR, OPTION_ISOLATE, OPTION_METRIC, OPTION_MTU},
     core_utils::{self, get_ipam_addresses, join_netns, parse_option, CoreUtils},
     driver::{self, DriverInfo},
     internal_types::{
@@ -41,6 +41,8 @@ struct InternalData {
     mtu: u32,
     /// if this network should be isolated from others
     isolate: bool,
+    /// Route metric for any default routes added for the network
+    metric: Option<u32>,
     // TODO: add vlan
 }
 
@@ -69,6 +71,7 @@ impl driver::NetworkDriver for Bridge<'_> {
 
         let mtu: u32 = parse_option(&self.info.network.options, OPTION_MTU, 0)?;
         let isolate: bool = parse_option(&self.info.network.options, OPTION_ISOLATE, false)?;
+        let metric: u32 = parse_option(&self.info.network.options, OPTION_METRIC, 100)?;
 
         let static_mac = match &self.info.per_network_opts.static_mac {
             Some(mac) => Some(CoreUtils::decode_address_from_hex(mac)?),
@@ -82,6 +85,7 @@ impl driver::NetworkDriver for Bridge<'_> {
             ipam,
             mtu,
             isolate,
+            metric: Some(metric),
         });
         Ok(())
     }
@@ -620,7 +624,7 @@ fn create_veth_pair(
         .wrap("set container veth up")?;
 
     if !internal {
-        core_utils::add_default_routes(netns, &data.ipam.gateway_addresses)?;
+        core_utils::add_default_routes(netns, &data.ipam.gateway_addresses, data.metric)?;
     }
 
     Ok(mac)

src/network/constants.rs

@@ -22,5 +22,9 @@ pub const DRIVER_MACVLAN: &str = "macvlan";
 pub const OPTION_ISOLATE: &str = "isolate";
 pub const OPTION_MTU: &str = "mtu";
 pub const OPTION_MODE: &str = "mode";
+pub const OPTION_METRIC: &str = "metric";
+
+// 100 is the default metric for most Linux networking tools.
+pub const DEFAULT_METRIC: u32 = 100;
 
 pub const NO_CONTAINER_INTERFACE_ERROR: &str = "no container interface name given";

src/network/core_utils.rs

@@ -309,7 +309,11 @@ fn open_netlink_socket(netns_path: &str) -> NetavarkResult<(File, RawFd)> {
     Ok((ns, ns_fd))
 }
 
-pub fn add_default_routes(sock: &mut netlink::Socket, gws: &[ipnet::IpNet]) -> NetavarkResult<()> {
+pub fn add_default_routes(
+    sock: &mut netlink::Socket,
+    gws: &[ipnet::IpNet],
+    metric: Option<u32>,
+) -> NetavarkResult<()> {
     let mut ipv4 = false;
     let mut ipv6 = false;
     for addr in gws {
@@ -323,6 +327,7 @@ pub fn add_default_routes(sock: &mut netlink::Socket, gws: &[ipnet::IpNet]) -> N
                 netlink::Route::Ipv4 {
                     dest: ipnet::Ipv4Net::new(Ipv4Addr::new(0, 0, 0, 0), 0)?,
                     gw: v4.addr(),
+                    metric,
                 }
             }
             ipnet::IpNet::V6(v6) => {
@@ -334,6 +339,7 @@ pub fn add_default_routes(sock: &mut netlink::Socket, gws: &[ipnet::IpNet]) -> N
                 netlink::Route::Ipv6 {
                     dest: ipnet::Ipv6Net::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0), 0)?,
                     gw: v6.addr(),
+                    metric,
                 }
             }
         };

src/network/macvlan.rs

@@ -12,7 +12,7 @@ use crate::{
 };
 
 use super::{
-    constants::{NO_CONTAINER_INTERFACE_ERROR, OPTION_MODE, OPTION_MTU},
+    constants::{NO_CONTAINER_INTERFACE_ERROR, OPTION_METRIC, OPTION_MODE, OPTION_MTU},
     core_utils::{self, get_ipam_addresses, parse_option, CoreUtils},
     driver::{self, DriverInfo},
     internal_types::IPAMAddresses,
@@ -31,6 +31,8 @@ struct InternalData {
     mtu: u32,
     /// macvlan mode
     macvlan_mode: u32,
+    /// Route metric for default routes added to the network
+    metric: Option<u32>,
     // TODO: add vlan
 }
 
@@ -61,6 +63,7 @@ impl driver::NetworkDriver for MacVlan<'_> {
         let mut ipam = get_ipam_addresses(self.info.per_network_opts, self.info.network)?;
 
         let mtu = parse_option(&self.info.network.options, OPTION_MTU, 0)?;
+        let metric = parse_option(&self.info.network.options, OPTION_METRIC, 100)?;
 
         let static_mac = match &self.info.per_network_opts.static_mac {
             Some(mac) => Some(CoreUtils::decode_address_from_hex(mac)?),
@@ -83,6 +86,7 @@ impl driver::NetworkDriver for MacVlan<'_> {
             ipam,
             macvlan_mode,
             mtu,
+            metric: Some(metric),
         });
         Ok(())
     }
@@ -226,7 +230,7 @@ fn setup(
         .set_up(netlink::LinkID::ID(dev.header.index))
         .wrap("set macvlan up")?;
 
-    core_utils::add_default_routes(netns, &data.ipam.gateway_addresses)?;
+    core_utils::add_default_routes(netns, &data.ipam.gateway_addresses, data.metric)?;
 
     for nla in dev.nlas.into_iter() {
         if let Nla::Address(ref addr) = nla {

src/network/netlink.rs

@@ -5,9 +5,10 @@ use std::{
 
 use crate::{
     error::{ErrorWrap, NetavarkError, NetavarkResult},
+    network::constants,
     wrap,
 };
-use log::trace;
+use log::{info, trace};
 use netlink_packet_route::{
     nlas::link::{Info, InfoData, InfoKind, Nla},
     AddressMessage, LinkMessage, NetlinkHeader, NetlinkMessage, NetlinkPayload, RouteMessage,
@@ -41,17 +42,33 @@ pub enum LinkID {
 }
 
 pub enum Route {
-    Ipv4 { dest: ipnet::Ipv4Net, gw: Ipv4Addr },
-    Ipv6 { dest: ipnet::Ipv6Net, gw: Ipv6Addr },
+    Ipv4 {
+        dest: ipnet::Ipv4Net,
+        gw: Ipv4Addr,
+        metric: Option<u32>,
+    },
+    Ipv6 {
+        dest: ipnet::Ipv6Net,
+        gw: Ipv6Addr,
+        metric: Option<u32>,
+    },
 }
 
 impl std::fmt::Display for Route {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let (dest, gw) = match self {
-            Route::Ipv4 { dest, gw } => (dest.to_string(), gw.to_string()),
-            Route::Ipv6 { dest, gw } => (dest.to_string(), gw.to_string()),
+        let (dest, gw, metric) = match self {
+            Route::Ipv4 { dest, gw, metric } => (
+                dest.to_string(),
+                gw.to_string(),
+                metric.unwrap_or(constants::DEFAULT_METRIC),
+            ),
+            Route::Ipv6 { dest, gw, metric } => (
+                dest.to_string(),
+                gw.to_string(),
+                metric.unwrap_or(constants::DEFAULT_METRIC),
+            ),
         };
-        write!(f, "(dest: {} ,gw: {})", dest, gw)
+        write!(f, "(dest: {} ,gw: {}, metric {})", dest, gw, metric)
     }
 }
 
@@ -220,21 +237,25 @@ impl Socket {
         msg.header.scope = RT_SCOPE_UNIVERSE;
         msg.header.kind = RTN_UNICAST;
 
-        let (dest_vec, dest_prefix, gateway_vec) = match route {
-            Route::Ipv4 { dest, gw } => {
+        info!("Adding route {}", route);
+
+        let (dest_vec, dest_prefix, gateway_vec, final_metric) = match route {
+            Route::Ipv4 { dest, gw, metric } => {
                 msg.header.address_family = AF_INET as u8;
                 (
                     dest.addr().octets().to_vec(),
                     dest.prefix_len(),
                     gw.octets().to_vec(),
+                    metric.unwrap_or(constants::DEFAULT_METRIC),
                 )
             }
-            Route::Ipv6 { dest, gw } => {
+            Route::Ipv6 { dest, gw, metric } => {
                 msg.header.address_family = AF_INET6 as u8;
                 (
                     dest.addr().octets().to_vec(),
                     dest.prefix_len(),
                     gw.octets().to_vec(),
+                    metric.unwrap_or(constants::DEFAULT_METRIC),
                 )
             }
         };
@@ -244,6 +265,8 @@ impl Socket {
             .push(netlink_packet_route::route::Nla::Destination(dest_vec));
         msg.nlas
             .push(netlink_packet_route::route::Nla::Gateway(gateway_vec));
+        msg.nlas
+            .push(netlink_packet_route::route::Nla::Priority(final_metric));
         msg
     }
 

src/test/netlink.rs

@@ -142,6 +142,7 @@ mod tests {
         sock.del_route(&Route::Ipv4 {
             dest: net.parse().unwrap(),
             gw: gw.parse().unwrap(),
+            metric: None,
         })
         .expect("del_route failed");
 

test/100-bridge-iptables.bats

@@ -666,3 +666,31 @@ EOF
     expected_rc=1 run_netavark --file ${TESTSDIR}/testfiles/ipv6-bridge.json setup $(get_container_netns_path)
     assert '{"error":"add ip addr to bridge: failed to add ipv6 address, is ipv6 enabled in the kernel?: Netlink error: Permission denied (os error 13)"}' "error message"
 }
+
+@test "$fw_driver - route metric from config" {
+    run_netavark --file ${TESTSDIR}/testfiles/metric.json setup $(get_container_netns_path)
+
+    run_in_container_netns ip -j route list match 0.0.0.0
+    default_route="$output"
+    assert_json "$default_route" '.[0].dst' == "default" "Default route was selected"
+    assert_json "$default_route" '.[0].metric' == "200" "Route metric set from config"
+
+    run_in_container_netns ip -j -6 route list match ::0
+    default_route_v6="$output"
+    assert_json "$default_route_v6" '.[0].dst' == "default" "Default route was selected"
+    assert_json "$default_route_v6" '.[0].metric' == "200" "v6 route metric matches v4"
+}
+
+@test "$fw_drive - default route metric" {
+    run_netavark --file ${TESTSDIR}/testfiles/dualstack-bridge.json setup $(get_container_netns_path)
+
+    run_in_container_netns ip -j route list match 0.0.0.0
+    default_route="$output"
+    assert_json "$default_route" '.[0].dst' == "default" "Default route was selected"
+    assert_json "$default_route" '.[0].metric' == "100" "Default metric was chosen"
+
+    run_in_container_netns ip -j -6 route list match ::0
+    default_route_v6="$output"
+    assert_json "$default_route_v6" '.[0].dst' == "default" "Default route was selected"
+    assert_json "$default_route_v6" '.[0].metric' == "100" "v6 route metric matches v4"
+}

test/testfiles/metric.json

@@ -0,0 +1,37 @@
+{
+    "container_id": "bc14fe7cd3633e7be338522002bb0c3ccb18150da7a6c733735ffdf8ff7e85d1",
+    "container_name": "metrictest",
+    "networks": {
+        "metric": {
+            "interface_name": "eth1",
+            "static_ips": [
+                "10.89.0.2",
+                "fde0::2"
+            ]
+        }
+    },
+    "network_info": {
+        "metric": {
+            "dns_enabled": false,
+            "driver": "bridge",
+            "id": "7ba44a9a709f8093621eae1a1db2ccafc2471bae19cdf9dd2ea7cf3773b9211c",
+            "internal": false,
+            "ipv6_enabled": true,
+            "name": "metric",
+            "network_interface": "metric",
+            "subnets": [
+                {
+                    "gateway": "10.89.0.1",
+                    "subnet": "10.89.0.0/24"
+                },
+                {
+                    "subnet": "fde0::/64",
+                    "gateway": "fde0::1"
+               }
+            ],
+            "options": {
+                "metric": "200"
+             }
+        }
+    }
+}