From 2b06925cab3c06917a5757b9df7b351ffe9f3e84 Mon Sep 17 00:00:00 2001
From: Maximilian Hils <mhils@google.com>
Date: Sun, 27 Oct 2024 14:38:36 +0100
Subject: [PATCH] fix tun mode

---
 CHANGELOG.md              |  1 +
 src/messages.rs           | 13 ++++++++++++-
 src/packet_sources/tun.rs |  2 ++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8baae17..276dfb83 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## Unreleased: mitmproxy_rs next
 
+- Assign a local IP address to our `tun` interface for Linux compatibility.
 
 ## 27 October 2024: mitmproxy_rs 0.10.0
 
diff --git a/src/messages.rs b/src/messages.rs
index ae8dcba3..f38d03b5 100755
--- a/src/messages.rs
+++ b/src/messages.rs
@@ -1,4 +1,5 @@
 use std::fmt;
+use std::fmt::Formatter;
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
 
 use anyhow::{anyhow, Result};
@@ -112,12 +113,22 @@ impl TransportCommand {
 }
 
 /// Generic IPv4/IPv6 packet type that wraps smoltcp's IPv4 and IPv6 packet buffers
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub enum SmolPacket {
     V4(Ipv4Packet<Vec<u8>>),
     V6(Ipv6Packet<Vec<u8>>),
 }
 
+impl fmt::Debug for SmolPacket {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        f.debug_struct("SmolPacket")
+            .field("src_ip", &self.src_ip())
+            .field("dst_ip", &self.dst_ip())
+            .field("transport_protocol", &self.transport_protocol())
+            .finish()
+    }
+}
+
 impl From<Ipv4Packet<Vec<u8>>> for SmolPacket {
     fn from(packet: Ipv4Packet<Vec<u8>>) -> Self {
         SmolPacket::V4(packet)
diff --git a/src/packet_sources/tun.rs b/src/packet_sources/tun.rs
index 010f61fe..4b47fa48 100644
--- a/src/packet_sources/tun.rs
+++ b/src/packet_sources/tun.rs
@@ -29,6 +29,8 @@ impl PacketSourceConf for TunConf {
     ) -> Result<(Self::Task, Self::Data)> {
         let mut config = tun2::Configuration::default();
         config.mtu(MAX_PACKET_SIZE as u16);
+        // Setting a local address is required on Linux.
+        config.address("169.254.0.1");
         config.up();
         if let Some(tun_name) = self.tun_name {
             config.tun_name(&tun_name);