From 7de5af67e21714a8e76f4e570478011a9b21901f Mon Sep 17 00:00:00 2001
From: Dennis Kobert <dennis@kobert.dev>
Date: Wed, 26 Feb 2025 18:30:47 +0100
Subject: Implement basic ioctl abstractions

---
 src/mock.rs | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 50 insertions(+), 6 deletions(-)

(limited to 'src')

diff --git a/src/mock.rs b/src/mock.rs
index ac4fa75..4ee9ed4 100644
--- a/src/mock.rs
+++ b/src/mock.rs
@@ -1,20 +1,64 @@
+use iocuddle::*;
 use libc::rand;
 use rand::Rng;
 
 trait KernelModule {
-    fn start_trace(pid: u64) {}
-    fn stop_trace(pid: u64) {}
-    fn read_consumption(pid: u64) -> u64 {}
+    fn start_trace(&mut self, _pid: u64) {}
+    fn stop_trace(&mut self, _pid: u64) {}
+    fn read_consumption(&mut self, pid: u64) -> u64;
 }
 
 struct MockModule;
 
 impl KernelModule for MockModule {
-    fn start_trace(pid: u64) {}
+    fn start_trace(&mut self, pid: u64) {
+        println!("starting trace of {pid}");
+    }
 
-    fn stop_trace(pid: u64) {}
+    fn stop_trace(&mut self, pid: u64) {
+        println!("stopping trace of {pid}");
+    }
 
-    fn read_consumption(pid: u64) -> u64 {
+    fn read_consumption(&mut self, _pid: u64) -> u64 {
         rand::rng().random()
     }
 }
+
+#[derive(Debug)]
+struct KernelDriver {
+    file: std::fs::File,
+}
+
+impl Default for KernelDriver {
+    fn default() -> Self {
+        KernelDriver::new("/dev/rust").unwrap()
+    }
+}
+impl KernelDriver {
+    fn new(path: impl AsRef<std::path::Path>) -> Result<Self, std::io::Error> {
+        let file = std::fs::File::open(path)?;
+        Ok(Self { file })
+    }
+}
+
+const PERF_MON: Group = Group::new(b'|');
+const PREFIX: u8 = b'|';
+const START_TRACE: Ioctl<Write, &u64> = unsafe { PERF_MON.write(0x0) };
+const STOP_TRACE: Ioctl<Write, &u64> = unsafe { PERF_MON.write(0x1) };
+const READ_POWER: Ioctl<WriteRead, &u64> = unsafe { PERF_MON.write_read(0x2) };
+
+impl KernelModule for KernelDriver {
+    fn start_trace(&mut self, pid: u64) {
+        START_TRACE.ioctl(&mut self.file, &pid).unwrap();
+    }
+
+    fn stop_trace(&mut self, pid: u64) {
+        STOP_TRACE.ioctl(&mut self.file, &pid).unwrap();
+    }
+
+    fn read_consumption(&mut self, pid: u64) -> u64 {
+        let mut arg = pid;
+        READ_POWER.ioctl(&mut self.file, &mut arg).unwrap();
+        arg
+    }
+}
-- 
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