netlink: add del_{addr,route} calls

It is not required for netavark since we just delete links on teardown but the dhcp proxy might need to remove addresses and/or routes when it gets a new lease. Unfortunately the del_route unit test doe snot seem to work since it requires "real" working routes which we cannot create in a custom netns. Signed-off-by: Paul Holzinger <[email protected]>
containers · Oct 13, 2022 · 59be422 · 59be422
1 parent a2458d6
commit 59be422
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Showing 2 changed files with 121 additions and 5 deletions.
diff --git a/src/network/netlink.rs b/src/network/netlink.rs
@@ -12,7 +12,7 @@ use netlink_packet_route::{
     nlas::link::{Info, InfoData, InfoKind, Nla},
     AddressMessage, LinkMessage, NetlinkHeader, NetlinkMessage, NetlinkPayload, RouteMessage,
     RtnlMessage, AF_INET, AF_INET6, IFF_UP, NLM_F_ACK, NLM_F_CREATE, NLM_F_DUMP, NLM_F_EXCL,
-    NLM_F_REQUEST, RTN_UNICAST, RTPROT_STATIC, RT_SCOPE_UNIVERSE, RT_TABLE_MAIN,
+    NLM_F_REQUEST, RTN_UNICAST, RTPROT_STATIC, RTPROT_UNSPEC, RT_SCOPE_UNIVERSE, RT_TABLE_MAIN,
 };
 use netlink_sys::{protocols::NETLINK_ROUTE, SocketAddr};
 
@@ -118,7 +118,7 @@ impl Socket {
         Ok(())
     }
 
-    pub fn add_addr(&mut self, link_id: u32, addr: &ipnet::IpNet) -> NetavarkResult<()> {
+    fn create_addr_msg(link_id: u32, addr: &ipnet::IpNet) -> AddressMessage {
         let mut msg = AddressMessage::default();
         msg.header.index = link_id;
 
@@ -139,6 +139,11 @@ impl Socket {
         msg.header.prefix_len = addr.prefix_len();
         msg.nlas
             .push(netlink_packet_route::address::Nla::Local(addr_vec));
+        msg
+    }
+
+    pub fn add_addr(&mut self, link_id: u32, addr: &ipnet::IpNet) -> NetavarkResult<()> {
+        let msg = Self::create_addr_msg(link_id, addr);
         let result = self.make_netlink_request(
             RtnlMessage::NewAddress(msg),
             NLM_F_ACK | NLM_F_EXCL | NLM_F_CREATE,
@@ -150,7 +155,17 @@ impl Socket {
         Ok(())
     }
 
-    pub fn add_route(&mut self, route: &Route) -> NetavarkResult<()> {
+    pub fn del_addr(&mut self, link_id: u32, addr: &ipnet::IpNet) -> NetavarkResult<()> {
+        let msg = Self::create_addr_msg(link_id, addr);
+        let result = self.make_netlink_request(RtnlMessage::DelAddress(msg), NLM_F_ACK)?;
+        if !result.is_empty() {
+            return Err(NetavarkError::msg_str("unexpected netlink result"));
+        }
+
+        Ok(())
+    }
+
+    fn create_route_msg(route: &Route) -> RouteMessage {
         let mut msg = RouteMessage::default();
 
         msg.header.table = RT_TABLE_MAIN;
@@ -182,6 +197,11 @@ impl Socket {
             .push(netlink_packet_route::route::Nla::Destination(dest_vec));
         msg.nlas
             .push(netlink_packet_route::route::Nla::Gateway(gateway_vec));
+        msg
+    }
+
+    pub fn add_route(&mut self, route: &Route) -> NetavarkResult<()> {
+        let msg = Self::create_route_msg(route);
 
         let result =
             self.make_netlink_request(RtnlMessage::NewRoute(msg), NLM_F_ACK | NLM_F_CREATE)?;
@@ -192,11 +212,22 @@ impl Socket {
         Ok(())
     }
 
+    pub fn del_route(&mut self, route: &Route) -> NetavarkResult<()> {
+        let msg = Self::create_route_msg(route);
+
+        let result = self.make_netlink_request(RtnlMessage::DelRoute(msg), NLM_F_ACK)?;
+        if !result.is_empty() {
+            return Err(NetavarkError::msg_str("unexpected netlink result"));
+        }
+
+        Ok(())
+    }
+
     pub fn dump_routes(&mut self) -> NetavarkResult<Vec<RouteMessage>> {
         let mut msg = RouteMessage::default();
 
         msg.header.table = RT_TABLE_MAIN;
-        msg.header.protocol = RTPROT_STATIC;
+        msg.header.protocol = RTPROT_UNSPEC;
         msg.header.scope = RT_SCOPE_UNIVERSE;
         msg.header.kind = RTN_UNICAST;
 
@@ -305,7 +336,6 @@ impl Socket {
 
             loop {
                 let bytes = &self.buffer[offset..];
-
                 let rx_packet: NetlinkMessage<RtnlMessage> = NetlinkMessage::deserialize(bytes)
                     .map_err(|e| {
                         NetavarkError::Message(format!(

diff --git a/src/test/netlink.rs b/src/test/netlink.rs
@@ -66,4 +66,90 @@ mod tests {
 
         assert!(out.contains(net), "addr does not exists");
     }
+
+    #[test]
+    fn test_del_addr() {
+        test_setup!();
+        let mut sock = Socket::new().expect("Socket::new()");
+
+        let out = run_command!("ip", "link", "add", "test1", "type", "dummy");
+        eprintln!("{}", String::from_utf8(out.stderr).unwrap());
+        assert!(out.status.success(), "failed to add link via ip");
+
+        let net = "10.0.0.2/24";
+
+        let out = run_command!("ip", "addr", "add", net, "dev", "test1");
+        eprintln!("{}", String::from_utf8(out.stderr).unwrap());
+        assert!(out.status.success(), "failed to add addr via ip");
+
+        let link = sock
+            .get_link(LinkID::Name("test1".into()))
+            .expect("get_link failed");
+
+        sock.del_addr(link.header.index, &net.parse().unwrap())
+            .expect("del_addr failed");
+
+        let out = run_command!("ip", "addr", "show", "test1");
+        let stdout = String::from_utf8(out.stdout).unwrap();
+        eprintln!("{}", stdout);
+        assert!(out.status.success(), "failed to show addr via ip");
+
+        assert!(!stdout.contains(net), "addr does exist");
+    }
+
+    /// This test fails because we do not have actual functioning routes in the test netns
+    /// For some reason the kernel expects us to set different options to make it work but
+    /// I do not want to expose them just for a test.
+    /// With these option you could get it to work but it will not work in the actual use case
+    ///         msg.header.protocol = RTPROT_UNSPEC;
+    ///         msg.header.scope = RT_SCOPE_NOWHERE;
+    ///         msg.header.kind = RTN_UNSPEC;
+    #[test]
+    #[ignore]
+    fn test_del_route() {
+        test_setup!();
+        let mut sock = Socket::new().expect("Socket::new()");
+
+        let out = run_command!("ip", "link", "add", "test1", "type", "dummy");
+        eprintln!("{}", String::from_utf8(out.stderr).unwrap());
+        assert!(out.status.success(), "failed to add link via ip");
+
+        let net = "10.0.0.2/24";
+
+        let out = run_command!("ip", "addr", "add", net, "dev", "test1");
+        eprintln!("{}", String::from_utf8(out.stderr).unwrap());
+        assert!(out.status.success(), "failed to add addr via ip");
+
+        // route requires that the link is up!
+        let out = run_command!("ip", "link", "set", "dev", "test1", "up");
+        eprintln!("{}", String::from_utf8(out.stderr).unwrap());
+        assert!(out.status.success(), "failed to set test1 up via ip");
+
+        let net = "10.0.1.0/24";
+        let gw = "10.0.0.2";
+
+        let out = run_command!("ip", "route", "add", net, "via", gw);
+        eprintln!("{}", String::from_utf8(out.stderr).unwrap());
+        assert!(out.status.success(), "failed to add route via ip");
+
+        let out = run_command!("ip", "route", "show");
+        let stdout = String::from_utf8(out.stdout).unwrap();
+        eprintln!("{}", stdout);
+        assert!(out.status.success(), "failed to show addr via ip");
+
+        assert!(stdout.contains(net), "route should exist");
+
+        sock.del_route(&Route::Ipv4 {
+            dest: net.parse().unwrap(),
+            gw: gw.parse().unwrap(),
+        })
+        .expect("del_route failed");
+
+        let out = run_command!("ip", "route", "show");
+        let stdout = String::from_utf8(out.stdout).unwrap();
+        eprintln!("{}", stdout);
+        assert!(out.status.success(), "failed to show addr via ip");
+
+        assert!(!stdout.contains(net), "route should not exist");
+    }
 }