From 4feb8f7f37d19d536efb59ba3ec0f6a29fcb1e53 Mon Sep 17 00:00:00 2001
From: fanyang <fanyang89@outlook.com>
Date: Fri, 15 May 2026 13:04:37 +0800
Subject: [PATCH 1/3] chore: update kcp to 2.0.0

---
 kcp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kcp b/kcp
index f4f3a89..32da082 160000
--- a/kcp
+++ b/kcp
@@ -1 +1 @@
-Subproject commit f4f3a89cc632647dabdcb146932d2afd5591e62e
+Subproject commit 32da082e529a26730aea3eb19922f80634ee6dea

From e83b61adcdadd548d6a62e6b5cb9edeabb6f4a50 Mon Sep 17 00:00:00 2001
From: fanyang <fanyang89@outlook.com>
Date: Fri, 15 May 2026 13:23:49 +0800
Subject: [PATCH 2/3] feat: expose kcp congestion control API

---
 src/ffi_safe.rs | 41 +++++++++++++++++++++++++++++++++++++++++
 src/lib.rs      |  2 +-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/src/ffi_safe.rs b/src/ffi_safe.rs
index a927bea..3cb4af1 100644
--- a/src/ffi_safe.rs
+++ b/src/ffi_safe.rs
@@ -110,6 +110,35 @@ impl Kcp {
         self.output_cb = Some(output_cb);
     }
 
+    /// Installs a KCP 2.0 congestion control implementation.
+    ///
+    /// # Safety
+    ///
+    /// KCP stores the provided operations pointer and calls it from C. The caller must ensure the
+    /// `IKCPOPS` value outlives every `Kcp` using it, and that its callbacks preserve KCP's aliasing
+    /// and thread-safety requirements.
+    pub unsafe fn set_congestion_control(
+        &mut self,
+        ops: Option<&'static IKCPOPS>,
+    ) -> Result<(), Error> {
+        let ops = ops.map_or(std::ptr::null(), |ops| ops as *const IKCPOPS);
+        let ret = unsafe { ikcp_setcc(self.kcp, ops) };
+        if ret < 0 {
+            Err(anyhow::anyhow!("setcc failed, return: {}", ret).into())
+        } else {
+            Ok(())
+        }
+    }
+
+    pub fn reset_congestion_control(&mut self) -> Result<(), Error> {
+        let ret = unsafe { ikcp_setcc(self.kcp, std::ptr::null()) };
+        if ret < 0 {
+            Err(anyhow::anyhow!("reset setcc failed, return: {}", ret).into())
+        } else {
+            Ok(())
+        }
+    }
+
     pub fn handle_input(&mut self, data: &[u8]) -> Result<(), Error> {
         let ret = unsafe { ikcp_input(self.kcp, data.as_ptr() as *const _, data.len() as _) };
         if ret < 0 {
@@ -220,3 +249,15 @@ impl Drop for Kcp {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn reset_congestion_control_uses_builtin_algorithm() {
+        let mut kcp = Kcp::new(KcpConfig::new(1)).unwrap();
+
+        kcp.reset_congestion_control().unwrap();
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 6cb89fb..9fc4e31 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-mod ffi;
+pub mod ffi;
 mod state;
 
 pub mod endpoint;

From 8d995dbf73149df326e690c269d9ca6fb99cc3b3 Mon Sep 17 00:00:00 2001
From: fanyang <fanyang89@outlook.com>
Date: Fri, 15 May 2026 13:33:29 +0800
Subject: [PATCH 3/3] With cmake4

---
 .github/workflows/rust.yml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 5e3a263..51676af 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -129,6 +129,11 @@ jobs:
       - name: Test
         run: cargo test --target ${{ matrix.target }} --verbose ${{ matrix.profile == 'release' && '--release' || '' }}
 
+      - name: Install CMake 4
+        uses: step-security/get-cmake@v4
+        with:
+          cmakeVersion: "^4.0.0"
+
       - name: Build KCP native test
         run: |
           cmake -S kcp -B kcp/build -DBUILD_TESTING=ON