Sharing the message queue between instances of ip:127.0.0.1/*. (#20)

The initial version of the IP loopback had one message queue for each
connection. This doesn't make sense, we need to share the message
queue across all connections.

schemes/ipd/src/main.rs

@@ -58,8 +58,7 @@ fn test() {
     println!("* Test that we can read a simple packet from the same connection.");
     let bytes = "TEST".as_bytes();
     let mut scheme = IpScheme::new();
-    let a = scheme.open("ip:127.0.0.1/11").unwrap();
-    let b = scheme.open("ip:127.0.0.1/11").unwrap();
+    let a = scheme.open(&"ip:127.0.0.1/11".as_bytes(), 0, 0, 0).unwrap();
     let num_bytes_written = scheme.write(a, bytes).unwrap();
     assert_eq!(num_bytes_written, bytes.len());
 
@@ -70,12 +69,41 @@ fn test() {
     let bytes_read = &buf[0..num_bytes_read];
     assert_eq!(bytes, bytes_read);
 
-    println!("* Test that we cannot read the same packet from a different connection.");
+
+
+    println!("* Test that the loopback is now empty.");
+    let num_bytes_read = scheme.read(a, &mut buf).unwrap();
+    assert_eq!(num_bytes_read, 0);
+
+
+
+    println!("* Test that we can read the same packet from a different connection.");
+    let num_bytes_written = scheme.write(a, bytes).unwrap();
+    assert_eq!(num_bytes_written, bytes.len());
+
+    let b = scheme.open("ip:127.0.0.1/11".as_bytes(), 0, 0, 0).unwrap();
+
+    let num_bytes_read = scheme.read(b, &mut buf).unwrap();
+    assert_eq!(num_bytes_read, num_bytes_written);
+
+    let bytes_read = &buf[0..num_bytes_read];
+    assert_eq!(bytes, bytes_read);
+
+
+
+    println!("* Test that the loopback is now empty for both connections.");
+
+    let num_bytes_read = scheme.read(a, &mut buf).unwrap();
+    assert_eq!(num_bytes_read, 0);
+
     let num_bytes_read = scheme.read(b, &mut buf).unwrap();
     assert_eq!(num_bytes_read, 0);
 
+
+
+
     println!("* Push a number of packets, check that we get them in the right order.");
-    let mut payloads : Vec<String> = 0..100.map(|i| format!("TEST {}", i)).collect();
+    let mut payloads : Vec<String> = (0..100).map(|i| format!("TEST {}", i)).collect();
     for payload in &payloads {
         let bytes = payload.into_bytes();
         let num_bytes_written = scheme.write(a, &bytes).unwrap();

schemes/ipd/src/resource.rs

@@ -1,5 +1,8 @@
+use std::cell::RefCell;
 use std::{cmp, mem};
 use std::collections::VecDeque;
+use std::rc::Rc;
+use std::sync::Mutex;
 
 use netutils::{n16, Ipv4Addr, Checksum, Ipv4Header, Ipv4};
 use resource_scheme::Resource;
@@ -43,11 +46,13 @@ pub enum Connection {
         init_data: Vec<u8>,
     },
     Loopback {
-        /// FIFO queue of packets written to the connection and waiting to be read.
+        /// FIFO queue of packets written to the loopback and waiting to be read.
         ///
         /// The data stored contains the exact data that has been added by the client
         /// calling `write()`, without adding any headers.
-        packets: VecDeque<Vec<u8>>
+        ///
+        /// This buffer is shared between all loopback connections.
+        packets: Rc<RefCell<VecDeque<Vec<u8>>>>
     }
 }
 
@@ -63,9 +68,7 @@ impl Resource for IpResource {
     fn dup(&self) -> Result<Box<Self>> {
         use self::Connection::*;
         let connection = match self.connection {
-            Loopback { ref packets } => Loopback {
-                packets: packets.clone()
-            },
+            Loopback { ref packets }=> Loopback { packets: packets.clone() },
             Device { link, ref init_data } => {
                 let link = try!(syscall::dup(link));
                 let init_data = init_data.clone();
@@ -122,8 +125,8 @@ impl Resource for IpResource {
     fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
         use self::Connection::*;
         match self.connection {
-            Loopback { ref mut packets } => {
-                match packets.pop_front() {
+            Loopback { ref packets }=> {
+                match packets.borrow_mut().pop_front() {
                     None => Ok(0),
                     Some(data) => {
                         for (b, d) in buf.iter_mut().zip(data.iter()) {
@@ -176,7 +179,7 @@ impl Resource for IpResource {
 
         let ip_data = Vec::from(buf);
         match self.connection {
-            Loopback { ref mut packets } => {
+            Loopback { ref packets } => {
                 // Make sure that we're not going to store data that can't be read.
                 let buf =
                     if buf.len() > MAX_PACKET_LENGTH {
@@ -184,7 +187,7 @@ impl Resource for IpResource {
                     } else {
                         buf
                     };
-                packets.push_back(buf.to_vec());
+                packets.borrow_mut().push_back(buf.to_vec());
                 return Ok(buf.len())
             }
             Device { link, .. } => {

schemes/ipd/src/scheme.rs

@@ -1,6 +1,7 @@
 use std::cell::RefCell;
 use std::collections::VecDeque;
 use std::rand;
+use std::rc::Rc;
 use std::{str, u16};
 
 use netutils::{getcfg, n16, MacAddr, Ipv4Addr, ArpHeader, Arp, Ipv4};
@@ -23,12 +24,21 @@ pub struct ArpEntry {
 /// A IP scheme
 pub struct IpScheme {
     pub arp: RefCell<Vec<ArpEntry>>,
+
+    /// FIFO queue of packets written to the loopback and waiting to be read.
+    ///
+    /// The data stored contains the exact data that has been added by the client
+    /// calling `write()`, without adding any headers.
+    ///
+    /// This buffer is shared between all loopback connections.
+    pub loopback_fifo: Rc<RefCell<VecDeque<Vec<u8>>>>,
 }
 
 impl IpScheme {
     pub fn new() -> IpScheme {
         IpScheme {
-            arp: RefCell::new(Vec::new())
+            arp: RefCell::new(Vec::new()),
+            loopback_fifo: Rc::new(RefCell::new(VecDeque::new())),
         }
     }
 }
@@ -55,7 +65,7 @@ impl ResourceScheme<IpResource> for IpScheme {
                             if peer_addr.equals(LOCALHOST) {
                                 return Ok(Box::new(IpResource {
                                     connection: Connection::Loopback {
-                                        packets: VecDeque::new()
+                                        packets: self.loopback_fifo.clone()
                                     },
                                     host_addr: ip_addr,
                                     peer_addr: peer_addr,