rtnl/link: change add_name_filter to match_name

Since kernel commit [a3d1289126e7b][1], it is possible to set the
IFLA_IFNAME attribute in a RTM_GETLINK message, allowing to get a link
by its name without dumping the whole link list. In large setups, this
speeds up massively the library, going from "painfully slow" to "really
quick" (in my application with thousands of links, a lookup by name
went from hundreds of ms to hundreds of µs).

This is based off the equivalent function in [libnl][2].

[1]: torvalds/linux@a3d1289
[2]: https://github.com/thom311/libnl/blob/master/lib/route/link.c#L1376

rtnetlink/examples/add_address.rs

@@ -33,7 +33,7 @@ async fn add_address(link_name: &str, ip: IpNetwork, handle: Handle) -> Result<(
     let mut links = handle
         .link()
         .get()
-        .set_name_filter(link_name.to_string())
+        .match_name(link_name.to_string())
         .execute();
     if let Some(link) = links.try_next().await? {
         handle

rtnetlink/examples/add_neighbour.rs

@@ -31,7 +31,7 @@ async fn add_neighbour(link_name: &str, ip: IpAddr, handle: Handle) -> Result<()
     let mut links = handle
         .link()
         .get()
-        .set_name_filter(link_name.to_string())
+        .match_name(link_name.to_string())
         .execute();
     if let Some(link) = links.try_next().await? {
         handle

rtnetlink/examples/add_route_pref_src.rs

@@ -45,7 +45,7 @@ async fn add_route(
     let iface_idx = handle
         .link()
         .get()
-        .set_name_filter(iface)
+        .match_name(iface)
         .execute()
         .try_next()
         .await?

rtnetlink/examples/create_macvlan.rs

@@ -25,7 +25,7 @@ async fn create_macvlan(handle: Handle, veth_name: String) -> Result<(), Error>
     let mut links = handle
         .link()
         .get()
-        .set_name_filter(veth_name.clone())
+        .match_name(veth_name.clone())
         .execute();
     if let Some(link) = links.try_next().await? {
         // hard code mode: 4u32 i.e bridge mode

rtnetlink/examples/create_vxlan.rs

@@ -22,7 +22,7 @@ async fn main() -> Result<(), String> {
 }
 
 async fn create_vxlan(handle: Handle, name: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(name.clone()).execute();
+    let mut links = handle.link().get().match_name(name.clone()).execute();
     if let Some(link) = links.try_next().await? {
         handle
             .link()

rtnetlink/examples/del_link.rs

@@ -23,7 +23,7 @@ async fn main() -> Result<(), ()> {
 }
 
 async fn del_link(handle: Handle, name: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(name.clone()).execute();
+    let mut links = handle.link().get().match_name(name.clone()).execute();
     if let Some(link) = links.try_next().await? {
         handle.link().del(link.header.index).execute().await
     } else {

rtnetlink/examples/flush_addresses.rs

@@ -24,7 +24,7 @@ async fn main() -> Result<(), ()> {
 }
 
 async fn flush_addresses(handle: Handle, link: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(link.clone()).execute();
+    let mut links = handle.link().get().match_name(link.clone()).execute();
     if let Some(link) = links.try_next().await? {
         // We should have received only one message
         assert!(links.try_next().await?.is_none());

rtnetlink/examples/get_address.rs

@@ -19,7 +19,7 @@ async fn main() -> Result<(), ()> {
 }
 
 async fn dump_addresses(handle: Handle, link: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(link.clone()).execute();
+    let mut links = handle.link().get().match_name(link.clone()).execute();
     if let Some(link) = links.try_next().await? {
         let mut addresses = handle
             .address()

rtnetlink/examples/get_links.rs

@@ -70,7 +70,7 @@ async fn get_link_by_index(handle: Handle, index: u32) -> Result<(), Error> {
 }
 
 async fn get_link_by_name(handle: Handle, name: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(name.clone()).execute();
+    let mut links = handle.link().get().match_name(name.clone()).execute();
     if let Some(_) = links.try_next().await? {
         println!("found link {}", name);
         // We should only have one link with that name

rtnetlink/examples/get_links_async.rs

@@ -70,7 +70,7 @@ async fn get_link_by_index(handle: Handle, index: u32) -> Result<(), Error> {
 }
 
 async fn get_link_by_name(handle: Handle, name: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(name.clone()).execute();
+    let mut links = handle.link().get().match_name(name.clone()).execute();
     if let Some(_) = links.try_next().await? {
         println!("found link {}", name);
         // We should only have one link with that name

rtnetlink/examples/get_links_thread_builder.rs

@@ -70,7 +70,7 @@ async fn get_link_by_index(handle: Handle, index: u32) -> Result<(), Error> {
 }
 
 async fn get_link_by_name(handle: Handle, name: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(name.clone()).execute();
+    let mut links = handle.link().get().match_name(name.clone()).execute();
     if let Some(_) = links.try_next().await? {
         println!("found link {}", name);
         // We should only have one link with that name

rtnetlink/examples/property_altname.rs

@@ -106,7 +106,7 @@ async fn get_link(link_name: &str, handle: Handle) -> Result<LinkMessage, Error>
     let mut links = handle
         .link()
         .get()
-        .set_name_filter(link_name.to_string())
+        .match_name(link_name.to_string())
         .execute();
 
     match links.try_next().await? {

rtnetlink/examples/set_link_down.rs

@@ -22,7 +22,7 @@ async fn main() -> Result<(), String> {
 }
 
 async fn set_link_down(handle: Handle, name: String) -> Result<(), Error> {
-    let mut links = handle.link().get().set_name_filter(name.clone()).execute();
+    let mut links = handle.link().get().match_name(name.clone()).execute();
     if let Some(link) = links.try_next().await? {
         handle
             .link()

rtnetlink/src/link/get.rs

@@ -81,8 +81,9 @@ impl LinkGetRequest {
         self
     }
 
-    pub fn set_name_filter(mut self, name: String) -> Self {
-        self.filter_builder.name = Some(name);
+    pub fn match_name(mut self, name: String) -> Self {
+        self.dump = false;
+        self.message.nlas.push(Nla::IfName(name));
         self
     }
 }

rtnetlink/src/link/test.rs

@@ -49,10 +49,7 @@ async fn _create_wg() -> Result<LinkHandle, Error> {
 }
 
 async fn _get_wg(handle: &mut LinkHandle) -> Result<LinkMessage, Error> {
-    let mut links = handle
-        .get()
-        .set_name_filter(IFACE_NAME.to_owned())
-        .execute();
+    let mut links = handle.get().match_name(IFACE_NAME.to_owned()).execute();
     let msg = links.try_next().await?;
     msg.ok_or_else(|| Error::RequestFailed)
 }