Add support for tc matchall filter

This adds a new method `matchall` to the TrafficFilterNewRequest struct,
equivalent to commands like `tc filter ... matchall`. The matchall
filter will match every packet and apply defined actions (etc) to it.

Author: Erich Heine

src/traffic_control/add_filter.rs

@@ -108,6 +108,32 @@ impl TrafficFilterNewRequest {
         self
     }
 
+    /// The matchall filter matches every packet and applies actions, etc
+    /// Equivalent to `tc filter ... matchall`
+    pub fn matchall(
+        mut self,
+        data: Vec<tc::matchall::Nla>,
+    ) -> Result<Self, Error> {
+        if self
+            .message
+            .nlas
+            .iter()
+            .any(|nla| matches!(nla, tc::Nla::Kind(_)))
+        {
+            return Err(Error::InvalidNla(
+                "message kind has already been set.".to_string(),
+            ));
+        }
+
+        self.message
+            .nlas
+            .push(tc::Nla::Kind(tc::matchall::KIND.to_string()));
+        self.message.nlas.push(tc::Nla::Options(
+            data.into_iter().map(tc::TcOpt::Matchall).collect(),
+        ));
+        Ok(self)
+    }
+
     /// The 32bit filter allows to match arbitrary bitfields in the packet.
     /// Equivalent to `tc filter ... u32`.
     pub fn u32(mut self, data: Vec<tc::u32::Nla>) -> Result<Self, Error> {