From 28d4703338eb2764babbdeffedc311355902c319 Mon Sep 17 00:00:00 2001
From: Finn Behrens <me@kloenk.de>
Date: Thu, 22 Apr 2021 22:42:54 +0200
Subject: [PATCH] WIP: drivers/net/dummy_rs

Signed-off-by: Finn Behrens <me@kloenk.de>
---
 drivers/net/Kconfig     |  16 ++++++
 drivers/net/Makefile    |   1 +
 drivers/net/dummy_rs.rs | 112 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+)
 create mode 100644 drivers/net/dummy_rs.rs

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index bcd31f458d1acd..3e7fc2c55a7ab4 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -72,6 +72,22 @@ config DUMMY
 	  To compile this driver as a module, choose M here: the module
 	  will be called dummy.
 
+config DUMMY_RS
+	tristate "Dummy net driver support"
+    depends on HAS_RUST
+	help
+	  This is essentially a bit-bucket device (i.e. traffic you send to
+	  this device is consigned into oblivion) with a configurable IP
+	  address. It is most commonly used in order to make your currently
+	  inactive SLIP address seem like a real address for local programs.
+	  If you use SLIP or PPP, you might want to say Y here. It won't
+	  enlarge your kernel. What a deal. Read about it in the Network
+	  Administrator's Guide, available from
+	  <http://www.tldp.org/docs.html#guide>.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called dummy_rs.
+
 config WIREGUARD
 	tristate "WireGuard secure network tunnel"
 	depends on NET && INET
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index f4990ff32fa4cc..8c2f8e10e49617 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_BONDING) += bonding/
 obj-$(CONFIG_IPVLAN) += ipvlan/
 obj-$(CONFIG_IPVTAP) += ipvlan/
 obj-$(CONFIG_DUMMY) += dummy.o
+obj-$(CONFIG_DUMMY_RS) += dummy_rs.o
 obj-$(CONFIG_WIREGUARD) += wireguard/
 obj-$(CONFIG_EQUALIZER) += eql.o
 obj-$(CONFIG_IFB) += ifb.o
diff --git a/drivers/net/dummy_rs.rs b/drivers/net/dummy_rs.rs
new file mode 100644
index 00000000000000..eb40d1adfb5d22
--- /dev/null
+++ b/drivers/net/dummy_rs.rs
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust dummy network driver
+
+#![no_std]
+#![feature(allocator_api, global_asm)]
+
+use kernel::prelude::*;
+use kernel::net::prelude::*;
+use kernel::net::device;
+
+module! {
+    type: RustNetDummy,
+    name: b"dummy_rs",
+    author: b"Rust for Linux Contributors",
+    description: b"Rust dummy network driver",
+    license: b"GPL v2",
+    params: {
+        numdummies: usize {
+            default: 0,
+            permissions: 0o644,
+            description: b"Number of dummy_rs pseudo devices",
+        },
+    },
+}
+
+fn setup(dev: &mut NetDevice<DummyRsDev>) {
+    dev.ether_setup();
+
+    // Fill in device structure with ethernet-generic values.
+    dev.add_flag(device::Iff::NOARP);
+    dev.remove_flag(device::Iff::MULTICAST);
+
+    dev.add_private_flag(device::IffPriv::LIVE_ADDR_CHANGE);
+    dev.add_private_flag(device::IffPriv::IFF_NO_QUEUE);
+
+    dev.add_feature(device::Feature::NETIF_F_SG);
+    dev.add_feature(device::Feature::NETIF_F_FRAGLIST_BIT);
+    dev.add_feature(device::Feature::NETIF_F_GSO_SOFTWARE);
+}
+
+rtnl_link_ops! {
+    kind: b"dummy_rs",
+    type: DummyRsDev,
+    setup: setup,
+    maxtype: 20,
+}
+
+struct RustNetDummy {
+    dev: NetDevice<DummyRsDev>,
+}
+
+
+impl KernelModule for RustNetDummy {
+    fn init() -> KernelResult<Self> {
+        {
+            let lock =THIS_MODULE.kernel_param_lock();
+            pr_info!("Rust Network Dummy with {} pseudo devices\n", numdummies.read(&lock));
+        }
+
+        let dev = NetDevice::new(DummyRsDev, kernel::cstr!("dummyrs%d"), kernel::net::device::NetNameAssingType::Enum, 1, 1)?;
+
+        if let Err(e) = dev.register() {
+            pr_warn!("could not register: {}", e.to_kernel_errno());
+        }
+
+        Ok(RustNetDummy {
+            dev,
+        })
+    }
+}
+
+impl Drop for RustNetDummy {
+    fn drop(&mut self) {
+        pr_info!("remove rust net dummy");
+        // TODO
+    }
+}
+
+
+struct DummyRsDev;
+
+impl NetDeviceOps<Self> for DummyRsDev {
+    kernel::declare_net_device_ops!();
+
+    fn init(dev: &NetDevice<Self>) -> KernelResult<()> {
+        Ok(())
+    }
+
+    fn uninit(dev: &NetDevice<Self>) {
+
+    }
+}
+
+impl NetDeviceAdapter for DummyRsDev {
+    type Inner = Self;
+
+    type Ops = Self;
+
+    type EthOps = Self;
+
+    fn setup(dev: &mut NetDevice<Self>) {
+        pr_info!("called netdev_setup");
+        //dev.rtnl_link_ops = unsafe { &dummy_rs_rtnl_link_ops as *const kernel::bindings::rtnl_link_ops as *mut _ };
+        dev.set_rtnl_ops( unsafe { &dummy_rs_rtnl_link_ops });
+
+    }
+}
+
+impl EthToolOps<Self> for DummyRsDev {
+    kernel::declare_eth_tool_ops!();
+}