link: add Display + FromStr impls for bridge enums

cathay4t · cathay4t · commit 0032b0d6156c · 2026-06-02T20:40:27.000+08:00
Add Display and FromStr implementations for bridge-related enums
to eliminate manual parsing/formatting in downstream crates:

  BridgeStpState        Display: "no"/"kernel_stp"/"user_stp"
                        FromStr: accepts name and numeric ("0"/"1"/"2")
  BridgeMulticastRouterType  Display: "disabled"/"auto"/"permanent"/"temp"
                             FromStr: accepts name and numeric
  BridgePortState       Display: "disabled"/"listening"/"learning"/
                                 "forwarding"/"blocking"
                        FromStr: accepts string names
  BridgeFlag            Display: "master"/"self"
                        FromStr: accepts string names
  BridgeMode            Display: "veb"/"vepa"
                        FromStr: accepts string names
  VlanProtocol          FromStr: case-insensitive "802.1q"/"802.1ad"
                        (Display already existed)

Other(d) variants produce raw numeric values matching iproute2 output.

Signed-off-by: Gris Ge &lt;cnfourt@gmail.com&gt;
diff --git a/src/link/af_spec/bridge.rs b/src/link/af_spec/bridge.rs
@@ -222,6 +222,31 @@ impl From<BridgeFlag> for u16 {
     }
 }
 
+impl std::fmt::Display for BridgeFlag {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Controller => f.write_str("master"),
+            Self::LowerDev => f.write_str("self"),
+            Self::Other(d) => write!(f, "{d}"),
+        }
+    }
+}
+
+impl std::str::FromStr for BridgeFlag {
+    type Err = DecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "master" => Ok(Self::Controller),
+            "self" => Ok(Self::LowerDev),
+            _ => s
+                .parse::<u16>()
+                .map(Self::from)
+                .map_err(|_| DecodeError::from(format!("unknown bridge flag: {s}"))),
+        }
+    }
+}
+
 impl BridgeFlag {
     pub const LENGTH: usize = 2;
 }
@@ -259,6 +284,31 @@ impl From<BridgeMode> for u16 {
     }
 }
 
+impl std::fmt::Display for BridgeMode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Veb => f.write_str("veb"),
+            Self::Vepa => f.write_str("vepa"),
+            Self::Other(d) => write!(f, "{d}"),
+        }
+    }
+}
+
+impl std::str::FromStr for BridgeMode {
+    type Err = DecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "veb" => Ok(Self::Veb),
+            "vepa" => Ok(Self::Vepa),
+            _ => s
+                .parse::<u16>()
+                .map(Self::from)
+                .map_err(|_| DecodeError::from(format!("unknown bridge mode: {s}"))),
+        }
+    }
+}
+
 impl BridgeMode {
     pub const LENGTH: usize = 2;
 }
diff --git a/src/link/link_info/bridge.rs b/src/link/link_info/bridge.rs
@@ -743,6 +743,33 @@ impl From<BridgeStpState> for u32 {
     }
 }
 
+impl std::fmt::Display for BridgeStpState {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Disabled => f.write_str("no"),
+            Self::KernelStp => f.write_str("kernel_stp"),
+            Self::UserStp => f.write_str("user_stp"),
+            Self::Other(d) => write!(f, "{d}"),
+        }
+    }
+}
+
+impl std::str::FromStr for BridgeStpState {
+    type Err = DecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "no" => Ok(Self::Disabled),
+            "kernel_stp" => Ok(Self::KernelStp),
+            "user_stp" => Ok(Self::UserStp),
+            _ => s
+                .parse::<u32>()
+                .map(Self::from)
+                .map_err(|_| DecodeError::from(format!("unknown bridge STP state: {s}"))),
+        }
+    }
+}
+
 const MDB_RTR_TYPE_DISABLED: u8 = 0;
 const MDB_RTR_TYPE_TEMP_QUERY: u8 = 1;
 const MDB_RTR_TYPE_PERM: u8 = 2;
@@ -787,3 +814,36 @@ impl From<BridgeMulticastRouterType> for u8 {
         }
     }
 }
+
+impl std::fmt::Display for BridgeMulticastRouterType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Disabled => f.write_str("disabled"),
+            Self::TempQuery => f.write_str("auto"),
+            Self::Permanent => f.write_str("permanent"),
+            Self::Temp => f.write_str("temp"),
+            Self::Other(d) => write!(f, "{d}"),
+        }
+    }
+}
+
+impl std::str::FromStr for BridgeMulticastRouterType {
+    type Err = DecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "disabled" => Ok(Self::Disabled),
+            "auto" | "temp_query" => Ok(Self::TempQuery),
+            "permanent" => Ok(Self::Permanent),
+            "temp" => Ok(Self::Temp),
+            _ => s
+                .parse::<u8>()
+                .map(Self::from)
+                .map_err(|_| {
+                    DecodeError::from(format!(
+                        "unknown bridge multicast router type: {s}"
+                    ))
+                }),
+        }
+    }
+}
diff --git a/src/link/link_info/bridge_port.rs b/src/link/link_info/bridge_port.rs
@@ -564,3 +564,34 @@ impl From<BridgePortState> for u8 {
         }
     }
 }
+
+impl std::fmt::Display for BridgePortState {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Disabled => f.write_str("disabled"),
+            Self::Listening => f.write_str("listening"),
+            Self::Learning => f.write_str("learning"),
+            Self::Forwarding => f.write_str("forwarding"),
+            Self::Blocking => f.write_str("blocking"),
+            Self::Other(d) => write!(f, "{d}"),
+        }
+    }
+}
+
+impl std::str::FromStr for BridgePortState {
+    type Err = DecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "disabled" => Ok(Self::Disabled),
+            "listening" => Ok(Self::Listening),
+            "learning" => Ok(Self::Learning),
+            "forwarding" => Ok(Self::Forwarding),
+            "blocking" => Ok(Self::Blocking),
+            _ => s
+                .parse::<u8>()
+                .map(Self::from)
+                .map_err(|_| DecodeError::from(format!("unknown bridge port state: {s}"))),
+        }
+    }
+}
diff --git a/src/link/tests/bridge.rs b/src/link/tests/bridge.rs
@@ -1231,3 +1231,147 @@ fn test_bridge_netns_immutable() {
 
     expected.emit(&mut buf);
 }
+
+#[test]
+fn test_bridge_flag_display() {
+    assert_eq!("master", BridgeFlag::Controller.to_string());
+    assert_eq!("self", BridgeFlag::LowerDev.to_string());
+    assert_eq!("255", BridgeFlag::Other(255).to_string());
+}
+
+#[test]
+fn test_bridge_flag_from_str() {
+    use std::str::FromStr;
+    assert_eq!(BridgeFlag::Controller, "master".parse().unwrap());
+    assert_eq!(BridgeFlag::LowerDev, "self".parse().unwrap());
+    assert_eq!(BridgeFlag::from(1), "1".parse().unwrap());
+    assert_eq!(BridgeFlag::from(2), "2".parse().unwrap());
+    assert_eq!(BridgeFlag::Other(99), "99".parse().unwrap());
+    assert!(BridgeFlag::from_str("bogus").is_err());
+}
+
+#[test]
+fn test_bridge_mode_display() {
+    assert_eq!("veb", BridgeMode::Veb.to_string());
+    assert_eq!("vepa", BridgeMode::Vepa.to_string());
+    assert_eq!("255", BridgeMode::Other(255).to_string());
+}
+
+#[test]
+fn test_bridge_mode_from_str() {
+    use std::str::FromStr;
+    assert_eq!(BridgeMode::Veb, "veb".parse().unwrap());
+    assert_eq!(BridgeMode::Vepa, "vepa".parse().unwrap());
+    assert_eq!(BridgeMode::from(0), "0".parse().unwrap());
+    assert_eq!(BridgeMode::from(1), "1".parse().unwrap());
+    assert_eq!(BridgeMode::Other(99), "99".parse().unwrap());
+    assert!(BridgeMode::from_str("bogus").is_err());
+}
+
+#[test]
+fn test_bridge_stp_state_display() {
+    assert_eq!("no", BridgeStpState::Disabled.to_string());
+    assert_eq!("kernel_stp", BridgeStpState::KernelStp.to_string());
+    assert_eq!("user_stp", BridgeStpState::UserStp.to_string());
+    assert_eq!("255", BridgeStpState::Other(255).to_string());
+}
+
+#[test]
+fn test_bridge_stp_state_from_str() {
+    use std::str::FromStr;
+    assert_eq!(BridgeStpState::Disabled, "no".parse().unwrap());
+    assert_eq!(BridgeStpState::KernelStp, "kernel_stp".parse().unwrap());
+    assert_eq!(BridgeStpState::UserStp, "user_stp".parse().unwrap());
+    assert_eq!(BridgeStpState::Disabled, "0".parse().unwrap());
+    assert_eq!(BridgeStpState::KernelStp, "1".parse().unwrap());
+    assert_eq!(BridgeStpState::UserStp, "2".parse().unwrap());
+    assert_eq!(BridgeStpState::Other(99), "99".parse().unwrap());
+    assert!(BridgeStpState::from_str("bogus").is_err());
+}
+
+#[test]
+fn test_bridge_multicast_router_type_display() {
+    assert_eq!("disabled", BridgeMulticastRouterType::Disabled.to_string());
+    assert_eq!("auto", BridgeMulticastRouterType::TempQuery.to_string());
+    assert_eq!("permanent", BridgeMulticastRouterType::Permanent.to_string());
+    assert_eq!("temp", BridgeMulticastRouterType::Temp.to_string());
+    assert_eq!("255", BridgeMulticastRouterType::Other(255).to_string());
+}
+
+#[test]
+fn test_bridge_multicast_router_type_from_str() {
+    use std::str::FromStr;
+    assert_eq!(
+        BridgeMulticastRouterType::Disabled,
+        "disabled".parse().unwrap()
+    );
+    assert_eq!(
+        BridgeMulticastRouterType::TempQuery,
+        "auto".parse().unwrap()
+    );
+    assert_eq!(
+        BridgeMulticastRouterType::TempQuery,
+        "temp_query".parse().unwrap()
+    );
+    assert_eq!(
+        BridgeMulticastRouterType::Permanent,
+        "permanent".parse().unwrap()
+    );
+    assert_eq!(
+        BridgeMulticastRouterType::Temp,
+        "temp".parse().unwrap()
+    );
+    assert_eq!(BridgeMulticastRouterType::from(0), "0".parse().unwrap());
+    assert_eq!(BridgeMulticastRouterType::from(1), "1".parse().unwrap());
+    assert_eq!(BridgeMulticastRouterType::from(2), "2".parse().unwrap());
+    assert_eq!(BridgeMulticastRouterType::from(3), "3".parse().unwrap());
+    assert_eq!(
+        BridgeMulticastRouterType::Other(99),
+        "99".parse().unwrap()
+    );
+    assert!(BridgeMulticastRouterType::from_str("bogus").is_err());
+}
+
+#[test]
+fn test_bridge_port_state_display() {
+    assert_eq!("disabled", BridgePortState::Disabled.to_string());
+    assert_eq!("listening", BridgePortState::Listening.to_string());
+    assert_eq!("learning", BridgePortState::Learning.to_string());
+    assert_eq!("forwarding", BridgePortState::Forwarding.to_string());
+    assert_eq!("blocking", BridgePortState::Blocking.to_string());
+    assert_eq!("255", BridgePortState::Other(255).to_string());
+}
+
+#[test]
+fn test_bridge_port_state_from_str() {
+    use std::str::FromStr;
+    assert_eq!(BridgePortState::Disabled, "disabled".parse().unwrap());
+    assert_eq!(BridgePortState::Listening, "listening".parse().unwrap());
+    assert_eq!(BridgePortState::Learning, "learning".parse().unwrap());
+    assert_eq!(BridgePortState::Forwarding, "forwarding".parse().unwrap());
+    assert_eq!(BridgePortState::Blocking, "blocking".parse().unwrap());
+    assert_eq!(BridgePortState::from(0), "0".parse().unwrap());
+    assert_eq!(BridgePortState::from(1), "1".parse().unwrap());
+    assert_eq!(BridgePortState::from(2), "2".parse().unwrap());
+    assert_eq!(BridgePortState::from(3), "3".parse().unwrap());
+    assert_eq!(BridgePortState::from(4), "4".parse().unwrap());
+    assert_eq!(BridgePortState::Other(99), "99".parse().unwrap());
+    assert!(BridgePortState::from_str("bogus").is_err());
+}
+
+#[test]
+fn test_vlan_protocol_display() {
+    assert_eq!("802.1q", VlanProtocol::Ieee8021Q.to_string());
+    assert_eq!("802.1ad", VlanProtocol::Ieee8021Ad.to_string());
+}
+
+#[test]
+fn test_vlan_protocol_from_str() {
+    use std::str::FromStr;
+    assert_eq!(VlanProtocol::Ieee8021Q, "802.1q".parse().unwrap());
+    assert_eq!(VlanProtocol::Ieee8021Ad, "802.1ad".parse().unwrap());
+    assert_eq!(VlanProtocol::Ieee8021Q, "802.1Q".parse().unwrap());
+    assert_eq!(VlanProtocol::Ieee8021Ad, "802.1AD".parse().unwrap());
+    assert!(VlanProtocol::from_str("bogus").is_err());
+    assert!(VlanProtocol::from_str("802.1Qq").is_err());
+}
diff --git a/src/link/vlan_protocol.rs b/src/link/vlan_protocol.rs
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MIT
 
+use netlink_packet_core::DecodeError;
+
 const ETH_P_8021Q: u16 = 0x8100;
 const ETH_P_8021AD: u16 = 0x88A8;
 
@@ -51,3 +53,19 @@ impl std::fmt::Display for VlanProtocol {
         )
     }
 }
+
+impl std::str::FromStr for VlanProtocol {
+    type Err = DecodeError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s.eq_ignore_ascii_case("802.1q") {
+            Ok(Self::Ieee8021Q)
+        } else if s.eq_ignore_ascii_case("802.1ad") {
+            Ok(Self::Ieee8021Ad)
+        } else {
+            Err(DecodeError::from(format!(
+                "unknown VLAN protocol: {s}"
+            )))
+        }
+    }
+}
