Redo networking (#22)

* Rewriting network functions

* Add buffer to dup
Fix non-blocking handling by triggering once on enabling events to read to EOF

* Modifications for UDP API

* Implement TCP client side

* Add active close

* Add DMAR parser

* Implement basic TCP listening. Need to improve the state machine

* Reduce debugging

* Fixes for close procedure

* Updates to fix path processing in libstd

crates/event/src/lib.rs

@@ -38,13 +38,43 @@ impl<R> EventQueue<R> {
         Ok(())
     }
 
+    /// Remove a file from the event queue, returning its callback if found
+    pub fn remove(&mut self, fd: RawFd) -> Result<Option<Box<FnMut(usize) -> Result<Option<R>>>>> {
+        if let Some(callback) = self.callbacks.remove(&fd) {
+            syscall::fevent(fd, 0).map_err(|x| Error::from_sys(x))?;
+
+            Ok(Some(callback))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Send an event to a descriptor callback
+    pub fn trigger(&mut self, fd: RawFd, count: usize) -> Result<Option<R>> {
+        if let Some(callback) = self.callbacks.get_mut(&fd) {
+            callback(count)
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Send an event to all descriptor callbacks, useful for cleaning out buffers after init
+    pub fn trigger_all(&mut self, count: usize) -> Result<Vec<R>> {
+        let mut rets = Vec::new();
+        for (_fd, callback) in self.callbacks.iter_mut() {
+            if let Some(ret) = callback(count)? {
+                rets.push(ret);
+            }
+        }
+        Ok(rets)
+    }
+
     /// Process the event queue until a callback returns Some(R)
     pub fn run(&mut self) -> Result<R> {
         loop {
             let mut event = syscall::Event::default();
-            self.file.read(&mut event)?;
-            if let Some(callback) = self.callbacks.get_mut(&event.id) {
-                if let Some(ret) = callback(event.data)? {
+            if self.file.read(&mut event)? > 0 {
+                if let Some(ret) = self.trigger(event.id, event.data)? {
                     return Ok(ret);
                 }
             }