[Refactor] :O Machines now walk the earth!!

Old vfs_node was getting a bit big for its boots, trying to be a
filesystem, network interface and the whole damn computer all at once.

This server-side refactor introduces a 'Machine' class that rightfully
owns the VFS, network services and other machine-state sh.t.

client/src/client_network.cpp

@@ -62,7 +62,7 @@ void ClientNetwork::disconnect(void) {
     _context_thread.join();
   }
 
-  /* Should be safe to close the socket no that thread is stoped <questionmark> */
+  /* Should be safe to close the socket now that thread is stoped <questionmark> */
   if(is_connected()) {
     /* Close the socket. Causes outstanding async operations
      * in TcpConnection to compete with an error, which in return

common/src/command_processor.cpp

@@ -1,18 +1,19 @@
-#include "command_processor.h"
 #include <sol/types.hpp>
 #include <sstream>
 
+#include "command_processor.h"
 #include "vfs.h"
 #include "lua_processor.h"
-#include "vfs_manager.h"
+#include "machine_manager.h"
+#include "machine.h"
 
-CommandProcessor::CommandProcessor(vfs_node* home_vfs,
-                                   std::map<std::string, vfs_node*>& world_vfs) :
-    _world_vfs(world_vfs) {
+CommandProcessor::CommandProcessor(Machine* home_machine,
+                                   std::map<std::string, Machine*>& world_machines) :
+    _home_machine(home_machine),
+    _session_machine(home_machine),
+    _world_machines(world_machines) {
   _lua = new LuaProcessor();
-  home_vfs_root     = home_vfs;
-  session_vfs_root  = home_vfs_root;
-  _current_dir      = session_vfs_root;
+  _current_dir = _session_machine->vfs_root;
 }
 
 CommandProcessor::~CommandProcessor(void) {
@@ -41,15 +42,12 @@ std::string CommandProcessor::process_command(const std::string& command) {
     args.push_back(arg);
   }
 
-  /* Search for script in the /bin directory. */
+  /* Search for script in the /bin directory of the current session machine. */
   std::string script_filename = command_name + ".lua";
-  vfs_node* root = _current_dir;
-  while(root->parent != nullptr) {
-    root = root->parent;
-  }
+  vfs_node* root = _session_machine->vfs_root;
   if(root->children.count("bin") && root->children["bin"]->children.count(script_filename)) {
     vfs_node* script_node = root->children["bin"]->children[script_filename];
-    bool is_remote = (session_vfs_root != home_vfs_root);
+    bool is_remote = (_session_machine != _home_machine);
     sol::object result = _lua->execute(script_node->content, _current_dir, args, is_remote);
     if(result.is<std::string>()) {
       return result.as<std::string>();
@@ -101,9 +99,9 @@ std::string CommandProcessor::_handle_vfs_action(sol::table action) {
     if(_current_dir->read_only) {
       std::string remote_ip = "";
       /* Check if we are on a known remote system. */
-      if(session_vfs_root != home_vfs_root) {
-        for(auto const& [ip, root_node] : _world_vfs) {
-          if(root_node == session_vfs_root) {
+      if(!_session_machine->is_vfs_a_copy) {
+        for(auto const& [ip, machine] : _world_machines) {
+          if(machine == _session_machine) {
             remote_ip = ip;
             break;
           }
@@ -111,19 +109,29 @@ std::string CommandProcessor::_handle_vfs_action(sol::table action) {
       }
 
       if(!remote_ip.empty()) {
-        /* CoW for a remote system. */
+        /* This machine is using a shared VFS. Copy it! ;) */
         fprintf(stderr, "CoW: Write attempt on read-only remote system '%s'."
                 "Creating persistant copy.\n", remote_ip.c_str());
         std::string original_path = get_full_path(_current_dir);
-        vfs_node* new_root = copy_vfs_node(session_vfs_root, nullptr);
-        make_vfs_writable(new_root);
-        _world_vfs[remote_ip] = new_root;
-        session_vfs_root = new_root;
-        _current_dir = find_node_by_path(session_vfs_root, original_path);
-        if(!_current_dir) { _current_dir = session_vfs_root; } /* Just in case. */
+        /* Copy the sh.t out of the VFS. */
+        vfs_node* new_vfs_root = copy_vfs_node(_session_machine->vfs_root, nullptr);
+        make_vfs_writable(new_vfs_root);
+
+        /* Create the new machine that will hold the copied VFS. */
+        auto* new_machine = new Machine(_session_machine->id, _session_machine->hostname);
+        new_machine->vfs_root = new_vfs_root;
+        new_machine->services = _session_machine->services;
+        new_machine->is_vfs_a_copy = true; /* Mark as copy. */
+
+        /* Update the world map and the current session. */
+        _world_machines[remote_ip] = new_machine;
+        _session_machine = new_machine;
+
+        /* Update _current_dir to point to the equivalent dir in the new VFS. */
+        _current_dir = find_node_by_path(_session_machine->vfs_root, original_path);
+        if(!_current_dir) { _current_dir = _session_machine->vfs_root; }
       } else {
-        /* If not a known remote system, i.e, player's own /bin, deny. */
-        return "Permission denied: Filesystem is read-only.";
+        return "Permission denied: Filesystem is read-only and not part of the world.";
       }
     }
   }
@@ -163,9 +171,9 @@ std::string CommandProcessor::_handle_vfs_action(sol::table action) {
     return ""; /* Success. */
   } else if(action_name == "ssh") {
     std::string target_ip = action["target"].get_or<std::string>("");
-    if(_world_vfs.count(target_ip)) {
-      session_vfs_root = _world_vfs[target_ip];
-      _current_dir = session_vfs_root;
+    if(_world_machines.count(target_ip)) {
+      _session_machine = _world_machines[target_ip];
+      _current_dir = _session_machine->vfs_root;
       return "Connected to " + target_ip;
     }
     return "ssh: Could not resolve hostname " + target_ip + ": Name or service not known";
@@ -187,26 +195,26 @@ std::string CommandProcessor::_handle_vfs_action(sol::table action) {
     }
       return ""; /* Success. */
   } else if(action_name == "disconnect") {
-    session_vfs_root = home_vfs_root;
-    _current_dir = home_vfs_root;
+    _session_machine = _home_machine;
+    _current_dir = _home_machine->vfs_root;
     return "Connection closed.";
   } else if(action_name == "close_terminal") {
     return "__CLOSE_CONNECTION__";
   } else if(action_name == "scan") {
     std::string target_ip = action["target"].get_or<std::string>("");
-    if(!_world_vfs.count(target_ip)) {
+    if(!_world_machines.count(target_ip)) {
       return std::string("nmap: Could not resolve host: ") + target_ip;
     }
 
-    vfs_node* target_root = _world_vfs[target_ip];
-    if(target_root->services.empty()) {
+    Machine* target_machine = _world_machines[target_ip];
+    if(target_machine->services.empty()) {
       return std::string("No open ports for ") + target_ip;
     }
 
     std::stringstream ss;
     ss<<"Host: "<<target_ip<<"\n";
     ss<<"PORT\tSTATE\tSERVICE\n";
-    for(auto const& [port, service_name] : target_root->services) {
+    for(auto const& [port, service_name] : target_machine->services) {
       ss<<port<<"/tcp\t"<<"open\t"<<service_name<<"\n";
     }
     return ss.str();

common/src/command_processor.h

@@ -4,11 +4,12 @@
 #include <string>
 #include <map>
 
+#include "machine.h"
 #include "vfs.h"
 
 class CommandProcessor {
 public:
-  CommandProcessor(vfs_node* home_vfs, std::map<std::string, vfs_node*>& world_vfs);
+  CommandProcessor(Machine* home_machine, std::map<std::string, Machine*>& world_machines);
   ~CommandProcessor(void);
 
   std::string process_command(const std::string& command);
@@ -16,9 +17,9 @@ public:
 
 private:
   std::string _handle_vfs_action(sol::table action);
-  vfs_node* home_vfs_root;
-  vfs_node* session_vfs_root;
+  Machine* _home_machine;
+  Machine* _session_machine;
   vfs_node* _current_dir;
-  std::map<std::string, vfs_node*>& _world_vfs;
+  std::map<std::string, Machine*>& _world_machines;
   LuaProcessor* _lua;
 };

common/src/machine.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <string>
+#include <map>
+#include <cstdint>
+
+#include "vfs.h"
+
+
+class Machine {
+public:
+  Machine(uint32_t id, std::string hostname) :
+      id(id),
+      hostname(std::move(hostname)),
+      vfs_root(nullptr),
+      is_vfs_a_copy(false) {}
+
+  /* TODO: Implement recursive deletion of vfs_root. */
+  ~Machine(void); /* Clean up VFS tree. */
+
+  uint32_t id;
+  std::string hostname;
+  vfs_node* vfs_root;
+  std::map<int, std::string> services;
+  bool is_vfs_a_copy; /* Flag for CoW mechanism. */
+
+  /* TODO: We'll add hardware and sh.t here. */
+};

common/src/machine_manager.cpp

@@ -1,8 +1,10 @@
 #include <filesystem>
 #include <fstream>
 #include <sstream>
+#include <utility>
 
-#include "vfs_manager.h"
+#include "machine_manager.h"
+#include "machine.h"
 #include "vfs.h"
 
 /* Create a new node. */
@@ -33,14 +35,14 @@ vfs_node* copy_vfs_node(vfs_node* original, vfs_node* new_parent) {
   return new_copy;
 }
 
-VFSManager::VFSManager(void) {
+MachineManager::MachineManager(void) {
   /* Create template VFS that holds shared, read-only directories. */
-  _vfs_root = new_node("/", DIR_NODE, nullptr);
-  vfs_node* bin = new_node("bin", DIR_NODE, _vfs_root);
-  _vfs_root->children["bin"] = bin;
+  _vfs_template_root = new_node("/", DIR_NODE, nullptr);
+  vfs_node* bin = new_node("bin", DIR_NODE, _vfs_template_root);
+  _vfs_template_root->children["bin"] = bin;
 
-  _vfs_root->read_only  = true;
-  bin->read_only        = true;
+  _vfs_template_root->read_only  = true;
+  bin->read_only                 = true;
 
   /* Load all scripts from assets/scripts/bin into the VFS. */
   const std::string path = "assets/scripts/bin";
@@ -58,12 +60,15 @@ VFSManager::VFSManager(void) {
   }
 }
 
-VFSManager::~VFSManager(void) {
+MachineManager::~MachineManager(void) {
   /* TODO: Implement recursive deletion of all created VFS nodes.*/
   //delete _vfs_root;
 }
 
-vfs_node* VFSManager::create_vfs(const std::string& system_type) {
+Machine* MachineManager::create_machine(uint32_t id, const std::string& hostname,
+                                         const std::string& system_type) {
+  auto* new_machine = new Machine(id, hostname);
+
   vfs_node* root = new_node("/", DIR_NODE, nullptr);
 
   /* Create directories for this specific VFS. */
@@ -75,10 +80,13 @@ vfs_node* VFSManager::create_vfs(const std::string& system_type) {
   user->children["readme.txt"] = readme;
 
   /* Link to the shared directories from the template. */
-  root->children["bin"] = copy_vfs_node(_vfs_root->children["bin"], root);
+  root->children["bin"] = copy_vfs_node(_vfs_template_root->children["bin"], root);
+
+  /* Assign the VFS to the new machine. */
+  new_machine->vfs_root = root;
 
   /* Default services. All machines have SSH currently. */
-  root->services[22] = "SSH v1.2";
+  new_machine->services[22] = "SSH v1.2";
 
   if(system_type == "npc") {
     vfs_node* npc_file = new_node("npc_system.txt", FILE_NODE, root);
@@ -87,5 +95,5 @@ vfs_node* VFSManager::create_vfs(const std::string& system_type) {
 
   }
 
-  return root;
+  return new_machine;
 }

common/src/machine_manager.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <string>
+
+#include "machine.h"
+#include "vfs.h"
+
+/* Recursive copy function for our Copy-on-Write behaviour. */
+vfs_node* copy_vfs_node(vfs_node* original, vfs_node* new_parent);
+
+class MachineManager {
+public:
+  MachineManager(void);
+  ~MachineManager(void); /* TODO: Implement recursive VFS deletion. */
+
+  Machine* create_machine(uint32_t id, const std::string& hostname,
+                          const std::string& system_type);
+private:
+  vfs_node* _vfs_template_root;
+};
+

common/src/vfs.h

@@ -24,9 +24,6 @@ struct vfs_node {
   /* Directories. */
   vfs_child_map children;
   vfs_node* parent;
-
-  /* Services (for root nodes). */
-  std::map<int, std::string> services;
 };
 
 std::string get_full_path(vfs_node* node);

common/src/vfs_manager.h

@@ -1,19 +0,0 @@
-#pragma once
-
-#include <string>
-
-#include "vfs.h"
-
-/* Recursive copy function for our Copy-on-Write behaviour. */
-vfs_node* copy_vfs_node(vfs_node* original, vfs_node* new_parent);
-
-class VFSManager {
-public:
-  VFSManager(void);
-  ~VFSManager(void); /* TODO: Implement recursive VFS deletion. */
-
-  vfs_node* create_vfs(const std::string& system_type);
-private:
-  vfs_node* _vfs_root;
-};
-

server/src/network_manager.cpp

@@ -1,6 +1,7 @@
 #include <cstdio>
 #include <exception>
 #include <functional>
+#include <memory>
 
 #include "network_manager.h"
 
@@ -9,19 +10,20 @@
 #include "asio/ip/tcp.hpp"
 #include "command_processor.h"
 #include "player.h"
+#include "machine.h"
 #include "net/tcp_connection.h"
 #include "vfs.h"
 
 NetworkManager::NetworkManager(void) : _acceptor(_io_context) {
-  /* VFS setup. */
-  _world_vfs["8.8.8.8"]   = _vfs_manager.create_vfs("npc");
-  _world_vfs["10.0.2.15"] = _vfs_manager.create_vfs("npc");
+  /* World setup. */
+  _world_machines["8.8.8.8"]   = _machine_manager.create_machine(1000, "dns.google", "npc");
+  _world_machines["10.0.2.15"] = _machine_manager.create_machine(1001, "corp.internal", "npc");
 
   /* Specific npc services. */
-  _world_vfs["8.8.8.8"]->services[80] = "HTTPD v2.4";
-  _world_vfs["10.0.2.15"]->services[21] = "FTPd v3.0";
+  _world_machines["8.8.8.8"]->services[80] = "HTTPD v2.4";
+  _world_machines["10.0.2.15"]->services[21] = "FTPd v3.0";
 
-  fprintf(stderr, "Created world with %zu networks\n", _world_vfs.size());
+  fprintf(stderr, "Created world with %zu networks\n", _world_machines.size());
 }
 
 NetworkManager::~NetworkManager(void) { stop(); }
@@ -64,7 +66,9 @@ void NetworkManager::start_accept(void) {
 
         /* Create a new player for this connection. */
         uint32_t player_id = _next_player_id++;
-        auto new_player = std::make_unique<Player>(player_id, _vfs_manager, _world_vfs);
+        Machine* player_machine = _machine_manager.create_machine(player_id, "player.home",
+                                                                  "player");
+        auto new_player = std::make_unique<Player>(player_id, player_machine, _world_machines);
         Player* new_player_ptr = new_player.get();
         _players[player_id] = std::move(new_player);
         new_connection->set_id(player_id);

server/src/network_manager.h

@@ -10,7 +10,7 @@
 #include "asio/io_context.hpp"
 #include "net/tcp_connection.h"
 #include "player.h"
-#include "vfs_manager.h"
+#include "machine_manager.h"
 
 class NetworkManager {
 public:
@@ -34,6 +34,6 @@ private:
   std::unordered_map<uint32_t, std::unique_ptr<Player>> _players;
   uint32_t _next_player_id = 1;
 
-  std::map<std::string, vfs_node*> _world_vfs; /* For NPC's. */
-  VFSManager _vfs_manager;
+  std::map<std::string, Machine*> _world_machines; /* For NPC's. */
+  MachineManager _machine_manager;
 };

server/src/player.cpp

@@ -1,17 +1,15 @@
 #include "player.h"
 #include "command_processor.h"
+#include "machine.h"
 
-Player::Player(uint32_t new_id, VFSManager& vfs_manager,
-               std::map<std::string, vfs_node*>& world_vfs) :
+Player::Player(uint32_t new_id, Machine* home_machine,
+               std::map<std::string, Machine*>& world_machines) :
     id(new_id) {
-  vfs_node* player_vfs = vfs_manager.create_vfs("player");
-  cmd_processor = new CommandProcessor(player_vfs, world_vfs);
+  cmd_processor = new CommandProcessor(home_machine, world_machines);
 }
 
 Player::~Player(void) {
   if(cmd_processor) {
     delete cmd_processor;
   }
-
-  /* TODO: The VFSManager should handle deleting the player_vfs_root. */
 }

server/src/player.h

@@ -1,16 +1,15 @@
 #pragma once
 
 #include <cstdint>
+#include <map>
+#include <string>
 
 #include "command_processor.h"
-#include "vfs.h"
-#include "vfs_manager.h"
-
-class CommandProcessor;
+#include "machine.h"
 
 class Player {
 public:
-  Player(uint32_t id, VFSManager& vfs_manager, std::map<std::string, vfs_node*>& world_vfs);
+  Player(uint32_t id, Machine* home_machine, std::map<std::string, Machine*>& world_machines);
   ~Player(void);
 
   uint32_t id;