posix: Fix TCP posix hanging when data and FIN is recv right after eachother resulting in os block not getting time

Co-authored-by: Martin Nordsletten <mnordsletten@gmail.com>

Author: AndreasAakesson

api/net/tcp/connection_states.hpp

@@ -352,11 +352,15 @@ class Connection::LastAck : public State {
   */
   virtual Result handle(Connection&, Packet_view& in) override;
 
-  inline virtual std::string to_string() const override {
+  std::string to_string() const override {
     return "LAST-ACK";
   };
 
-  inline virtual bool is_closing() const override {
+  bool is_closing() const override {
+    return true;
+  }
+
+  bool is_closed() const override {
     return true;
   }
 

src/posix/tcp_fd.cpp

@@ -311,8 +311,10 @@ ssize_t TCP_FD_Conn::recv(void* dest, size_t len, int)
     bytes = buffer->size();
   });
 
-  // BLOCK HERE
-  while (!done || !conn->is_readable()) {
+  // BLOCK HERE:
+  // 1. if we havent read the data we asked for
+  // 2. or we aren't readable but not closed (not 100% sure here hehe..)
+  while (!done || (!conn->is_readable() and !conn->is_closed())) {
     OS::block();
   }
   // restore

test/posix/integration/tcp/test.py

@@ -50,6 +50,7 @@ def TCP_connect():
   sock.connect((HOST, PORT))
   MESSAGE = "POSIX is for hipsters"
   sock.send(MESSAGE)
+  sock.close()
 
 def TCP_recv(trigger_line):
   server.listen(1)