Set SO_REUSEADDR on local DNS resolver socket

This fixes an issue where bind() fails due to other sockets

Co-authored-by: Joakim Hulthe <joakim.hulthe@mullvad.net>

3 files changed, 51 insertions, 1 deletions

diff --git a/talpid-macos/Cargo.toml b/talpid-macos/Cargo.toml
index 7b910f5e6d..0b4caa4258 100644
--- a/talpid-macos/Cargo.toml
+++ b/talpid-macos/Cargo.toml
@@ -11,5 +11,7 @@ rust-version.workspace = true
 workspace = true
 
 [target.'cfg(target_os="macos")'.dependencies]
+anyhow.workspace = true
+log.workspace = true
 libc = "0.2.172"
-log = { workspace = true }
+tokio = { workspace = true, features = ["process"] }
diff --git a/talpid-macos/src/lib.rs b/talpid-macos/src/lib.rs
index 5a282660d3..1dad718685 100644
--- a/talpid-macos/src/lib.rs
+++ b/talpid-macos/src/lib.rs
@@ -9,3 +9,6 @@ pub mod process;
 /// OS bindings generated by 'generate_bindings.rs'
 #[allow(non_camel_case_types)]
 mod bindings;
+
+/// Networking utilities
+pub mod net;
diff --git a/talpid-macos/src/net.rs b/talpid-macos/src/net.rs
new file mode 100644
index 0000000000..5eff2f6878
--- /dev/null
+++ b/talpid-macos/src/net.rs
@@ -0,0 +1,45 @@
+use anyhow::{anyhow, bail, Context};
+use std::net::IpAddr;
+use tokio::process::Command;
+
+/// Adds an alias to a network interface.
+pub async fn add_alias(interface: &str, addr: IpAddr) -> anyhow::Result<()> {
+    let context = || anyhow!("Failed to add interface {interface} alias {addr}");
+    let output = Command::new("ifconfig")
+        .args([interface, "alias", &format!("{addr}"), "up"])
+        .output()
+        .await
+        .context("Failed to spawn ifconfig")
+        .with_context(context)?;
+
+    if !output.status.success() {
+        bail!(
+            "{}: Non-zero exit code from ifconfig: {}",
+            context(),
+            output.status
+        );
+    }
+
+    Ok(())
+}
+
+/// Removes an alias from a network interface.
+pub async fn remove_alias(interface: &str, addr: IpAddr) -> anyhow::Result<()> {
+    let context = || anyhow!("Failed to remove interface {interface} alias {addr}");
+    let output = Command::new("ifconfig")
+        .args([interface, "delete", &format!("{addr}")])
+        .output()
+        .await
+        .context("Failed to spawn ifconfig")
+        .with_context(context)?;
+
+    if !output.status.success() {
+        bail!(
+            "{}: Non-zero exit code from ifconfig: {}",
+            context(),
+            output.status
+        );
+    }
+
+    Ok(())
+}