src/config/network/parser.rs: parse MTU settings

src/config/network.rs

@@ -30,6 +30,8 @@ impl Interface {
             gateway_v4: None,
             cidr_v6: None,
             gateway_v6: None,
+            mtu_v4: None,
+            mtu_v6: None,
             options_v4: Vec::new(),
             options_v6: Vec::new(),
         }
@@ -107,6 +109,10 @@ impl Interface {
             }
         }
 
+        if let Some(mtu) = &self.mtu_v4 {
+            writeln!(w, "    mtu {}", mtu)?;
+        }
+
         for option in &self.options_v4 {
             writeln!(w, "    {}", option)?;
         }
@@ -124,6 +130,10 @@ impl Interface {
             }
         }
 
+        if let Some(mtu) = &self.mtu_v6 {
+            writeln!(w, "    mtu {}", mtu)?;
+        }
+
         for option in &self.options_v6 {
             writeln!(w, "    {}", option)?;
         }
@@ -148,7 +158,10 @@ impl Interface {
             writeln!(w, "auto {}", self.name)?;
         }
 
-        if self.method_v4 == self.method_v6 {
+        if self.method_v4 == self.method_v6
+            && self.mtu_v4 == self.mtu_v6
+            && self.options_v4.is_empty() == self.options_v6.is_empty()
+        {
             if let Some(method) = self.method_v4 {
                 writeln!(w, "iface {} {}", self.name, method_to_str(method))?;
                 self.write_iface_attributes_v4(w, method)?;

src/config/network/lexer.rs

@@ -21,6 +21,7 @@ pub enum Token {
     Netmask,
     Static,
     Attribute,
+    MTU,
     EOF,
 }
 
@@ -38,6 +39,7 @@ lazy_static! {
         map.insert("manual", Token::Manual);
         map.insert("netmask", Token::Netmask);
         map.insert("static", Token::Static);
+        map.insert("mtu", Token::MTU);
         map
     };
 }

src/config/network/parser.rs

@@ -121,6 +121,22 @@ impl <R: BufRead> NetworkParser<R> {
         Ok(())
     }
 
+    fn parse_iface_mtu(&mut self) -> Result<u64, Error> {
+        self.eat(Token::MTU)?;
+
+        let mtu = self.next_text()?;
+        let mtu = match u64::from_str_radix(&mtu, 10) {
+            Ok(mtu) => mtu,
+            Err(err) => {
+                bail!("unable to parse mtu value '{}' - {}", mtu, err);
+            }
+        };
+
+        self.eat(Token::Newline)?;
+
+        Ok(mtu)
+    }
+
     fn parse_to_eol(&mut self) -> Result<String, Error> {
         let mut line = String::new();
         loop {
@@ -140,7 +156,7 @@ impl <R: BufRead> NetworkParser<R> {
         Ok(())
     }
 
-    fn parse_iface_attributes(&mut self, interface: &mut Interface) -> Result<(), Error> {
+    fn parse_iface_attributes(&mut self, interface: &mut Interface, family_v4: bool, family_v6: bool) -> Result<(), Error> {
 
         loop {
             match self.peek()? {
@@ -152,6 +168,11 @@ impl <R: BufRead> NetworkParser<R> {
             match self.peek()? {
                 Token::Address => self.parse_iface_address(interface)?,
                 Token::Gateway => self.parse_iface_gateway(interface)?,
+                Token::MTU => {
+                    let mtu = self.parse_iface_mtu()?;
+                    if family_v4 { interface.mtu_v4 = Some(mtu); }
+                    if family_v6 { interface.mtu_v6 = Some(mtu); }
+                }
                 Token::Netmask => bail!("netmask is deprecated and no longer supported"),
                 _ => {
                     self.parse_iface_addon_attribute(interface)?;
@@ -200,7 +221,7 @@ impl <R: BufRead> NetworkParser<R> {
                 interface.set_method_v6(config_method)?;
             }
 
-            if has_attributes { self.parse_iface_attributes(&mut interface)?; }
+            if has_attributes { self.parse_iface_attributes(&mut interface, address_family_v4, address_family_v6)?; }
         } else {
             let mut interface = Interface::new(iface.clone());
             if address_family_v4 {
@@ -210,7 +231,7 @@ impl <R: BufRead> NetworkParser<R> {
                 interface.set_method_v6(config_method)?;
             }
 
-            if has_attributes { self.parse_iface_attributes(&mut interface)?; }
+            if has_attributes { self.parse_iface_attributes(&mut interface, address_family_v4, address_family_v6)?; }
 
             config.interfaces.insert(interface.name.clone(), interface);