From 1b4d31dbd9ce1432149685eb993f9971df59bd70 Mon Sep 17 00:00:00 2001
From: Ryan Summers <ryan.summers@vertigo-designs.com>
Date: Thu, 8 Apr 2021 15:28:11 +0200
Subject: [PATCH] Updating NAL to support TCP port randomization

---
 Cargo.lock                    |  9 ++++++++-
 Cargo.toml                    |  2 +-
 src/hardware/configuration.rs | 24 ++++++++++++++++++------
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index f77e0bd..0c99862 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -437,6 +437,12 @@ dependencies = [
  "heapless 0.6.1",
 ]
 
+[[package]]
+name = "nanorand"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac1378b66f7c93a1c0f8464a19bf47df8795083842e5090f4b7305973d5a22d0"
+
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -710,10 +716,11 @@ dependencies = [
 [[package]]
 name = "smoltcp-nal"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=7572183#757218316620e074405bc38ff5502ef17a8a3499"
+source = "git+https://github.com/quartiq/smoltcp-nal.git?branch=feature/random-port#462adc56a8cc95bc1324f6d96fdbe82e85ca6d36"
 dependencies = [
  "embedded-nal",
  "heapless 0.6.1",
+ "nanorand",
  "smoltcp",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 0c4ab0d..87a0e2e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -60,7 +60,7 @@ rev = "314fa5587d"
 
 [dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
-rev = "7572183"
+branch = "feature/random-port"
 
 [patch.crates-io.minimq]
 git = "https://github.com/quartiq/minimq.git"
diff --git a/src/hardware/configuration.rs b/src/hardware/configuration.rs
index 74307dd..8a6ec0d 100644
--- a/src/hardware/configuration.rs
+++ b/src/hardware/configuration.rs
@@ -594,13 +594,25 @@ pub fn setup(
             )
         };
 
+        let random_seed = {
+            let mut rng =
+                device.RNG.constrain(ccdr.peripheral.RNG, &ccdr.clocks);
+            let mut data = [0u8; 4];
+            rng.fill(&mut data).unwrap();
+            data
+        };
+
+        let mut stack = smoltcp_nal::NetworkStack::new(
+            interface,
+            sockets,
+            &handles,
+            Some(dhcp_client),
+        );
+
+        stack.seed_random_port(&random_seed);
+
         NetworkDevices {
-            stack: smoltcp_nal::NetworkStack::new(
-                interface,
-                sockets,
-                &handles,
-                Some(dhcp_client),
-            ),
+            stack,
             phy: lan8742a,
         }
     };