Finished tracer logic and command environment data

include/environment.hpp

@@ -0,0 +1,88 @@
+#pragma once
+#include <unordered_map>
+#include <unistd.h>
+#include <memory>
+#include <sys/user.h>
+
+#include "wirekit.hpp"
+
+struct TraceContext {
+	enum class EXECUTION_MODE { STARTING, USER, KERNEL /* Currently executing a system call */ };
+
+	pid_t pid;
+	EXECUTION_MODE mode;
+	user_regs_struct regs;
+	bool regs_dirty;
+};
+
+class TraceContextCollection {
+	std::unordered_map<pid_t, std::unique_ptr<TraceContext>> m_contexts;
+	pid_t m_active;
+public:
+	TraceContextCollection(const TraceContextCollection& other) = delete;
+	TraceContextCollection(TraceContextCollection&& other);
+	TraceContextCollection& operator=(const TraceContextCollection& other) = delete;
+	TraceContextCollection& operator=(TraceContextCollection&& other);
+
+	TraceContextCollection();
+	~TraceContextCollection();
+
+	bool add_context(pid_t pid);
+	void delete_context(pid_t pid);
+	void clear();
+
+	TraceContext* context(pid_t pid);
+	const TraceContext* context(pid_t pid) const;
+
+	void context_set_active(pid_t pid);
+	void context_clear_active();
+	TraceContext* context_get_active();
+	const TraceContext* context_get_active() const;
+};
+
+class Environment {
+	struct HookPair {
+		hook_t entry = nullptr;
+		hook_t exit = nullptr;
+	};
+
+	std::unordered_map<reg_t, HookPair> m_hooks;
+	HookPair m_default_hooks;
+	TraceContextCollection m_trace_contexts;
+public:
+	Environment(const Environment& other) = delete;
+	Environment(Environment&& other) = delete;
+	Environment& operator=(const Environment& other) = delete;
+	Environment& operator=(Environment&& other) = delete;
+
+	Environment();
+	~Environment();
+
+	void register_hooks(reg_t syscall, hook_t entry, hook_t exit);
+	void register_default_hooks(hook_t entry, hook_t exit);
+
+	bool entry_hook(reg_t syscall) const;
+	bool exit_hook(reg_t syscall) const;
+	bool default_entry_hook() const;
+	bool default_exit_hook() const;
+
+	TraceContextCollection& contexts();
+	const TraceContextCollection& contexts() const;
+
+	void clear();
+};
+
+// An EnvironmentScope calls Environment::clear() when destructed
+class EnvironmentScope {
+	Environment& m_environment;
+public:
+	EnvironmentScope(const EnvironmentScope& other) = delete;
+	EnvironmentScope(EnvironmentScope&& other) = delete;
+	EnvironmentScope& operator=(const EnvironmentScope& other) = delete;
+	EnvironmentScope& operator=(EnvironmentScope&& other) = delete;
+
+	EnvironmentScope(Environment& environment);
+	~EnvironmentScope();
+};
+
+extern Environment ENV;

include/interface.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "wirekit.hpp"
+
+extern err_t(*wirekit_prepare_handle)();
+extern err_t(*wirekit_command_start_handle)(int, const char* const*);
+extern void(*wirekit_command_exit_handle)();
+extern void(*wirekit_subject_start_handle)();
+extern void(*wirekit_subject_exit_handle)();
+
+// Exposure to wirekit is achieved by adding these functions to rewire's symbol tables
+#define EXPOSED __attribute__((visibility("default")))
+
+EXPOSED err_t rewire_syscall_hook(reg_t syscall, hook_t entry, hook_t exit);
+EXPOSED err_t rewire_syscall_unhook(reg_t syscall);
+EXPOSED err_t rewire_syscall_hook_default(hook_t entry, hook_t exit);
+EXPOSED err_t rewire_syscall_unhook_default();
+EXPOSED err_t rewire_subject_id(pid_t* pid);
+EXPOSED err_t rewire_subject_get_regs(user_regs_struct* regs);
+EXPOSED err_t rewire_subject_set_regs(const user_regs_struct* regs);
+EXPOSED err_t rewire_subject_load_cstr(const char* subject_addr, char* buf, uint32_t* read, uint32_t n);

include/wirekit.hpp

@@ -0,0 +1,33 @@
+#pragma once
+#include <sys/types.h>
+#include <sys/user.h>
+#include <cstdint>
+
+using reg_t = decltype(user_regs_struct::orig_rax);
+using hook_t = void(*)();
+using err_t = uint8_t;
+
+constexpr err_t REWIRE_SUCCESS = 0;
+constexpr err_t REWIRE_FAILURE = 1;
+constexpr err_t REWIRE_FAILURE_NOCTX = 2;
+
+extern "C" {
+
+// Exposed rewire functions - to be used by wirekit
+err_t rewire_syscall_hook(reg_t syscall, hook_t entry, hook_t exit);
+err_t rewire_syscall_unhook(reg_t syscall); // Alias for rewire_syscall_hook(syscall, nullptr, nullptr)
+err_t rewire_syscall_hook_default(hook_t entry, hook_t exit);
+err_t rewire_syscall_unhook_default(); // Alias for rewire_syscall_hook_default(nullptr, nullptr);
+err_t rewire_subject_id(pid_t* pid);
+err_t rewire_subject_get_regs(user_regs_struct* regs);
+err_t rewire_subject_set_regs(const user_regs_struct* regs);
+err_t rewire_subject_load_cstr(const char* subject_addr, char* buf, uint32_t* read, uint32_t n);
+
+// Wirekit control functions - called by rewire for setup
+err_t wirekit_prepare(); // NOCTX - Called when wirekit is loaded
+err_t wirekit_command_start(int argc, const char* const* argv); // NOCTX - Called before command is executed
+void wirekit_command_exit(); // Optional, NOCTX - Called after command finished executing
+void wirekit_subject_start(); // Optional - Called when a new thread starts working on the current command
+void wirekit_subject_exit(); // Optional - Called when a thread stops working on the current command
+
+}

src/environment.cpp

@@ -0,0 +1,182 @@
+#include "environment.hpp"
+
+#include <cstring>
+
+Environment ENV;
+
+// Trace context collection
+
+TraceContextCollection::TraceContextCollection(TraceContextCollection&& other) {
+	m_contexts = std::move(other.m_contexts);
+	m_active = other.m_active;
+	other.context_clear_active();
+}
+
+TraceContextCollection& TraceContextCollection::operator=(TraceContextCollection&& other) {
+	if (this == &other)
+		return *this;
+
+	m_contexts = std::move(other.m_contexts);
+	m_active = other.m_active;
+	other.context_clear_active();
+	return *this;
+}
+
+TraceContextCollection::TraceContextCollection() {}
+
+TraceContextCollection::~TraceContextCollection() {}
+
+bool TraceContextCollection::add_context(pid_t pid) {
+	if (m_contexts.contains(pid))
+		return false;
+
+	std::unique_ptr<TraceContext> new_context = std::make_unique<TraceContext>();
+	if (!new_context)
+		return false;
+
+	new_context->pid = pid;
+	new_context->mode = TraceContext::EXECUTION_MODE::STARTING;
+	std::memset(&new_context->regs, 0, sizeof(new_context->regs));
+	new_context->regs_dirty = false;
+
+	m_contexts.emplace(pid, std::move(new_context));
+	return true;
+}
+
+void TraceContextCollection::delete_context(pid_t pid) {
+	if (m_contexts.contains(pid))
+		m_contexts.erase(pid);
+	if (m_active == pid)
+		context_clear_active();
+}
+
+void TraceContextCollection::clear() {
+	m_contexts.clear();
+	context_clear_active();
+}
+
+TraceContext* TraceContextCollection::context(pid_t pid) {
+	if (!m_contexts.contains(pid))
+		return nullptr;
+
+	return m_contexts.at(pid).get();
+}
+
+const TraceContext* TraceContextCollection::context(pid_t pid) const {
+	if (!m_contexts.contains(pid))
+		return nullptr;
+
+	return m_contexts.at(pid).get();
+}
+
+void TraceContextCollection::context_set_active(pid_t pid) {
+	if (m_contexts.contains(pid))
+		m_active = pid;
+	else
+		context_clear_active();
+}
+
+void TraceContextCollection::context_clear_active() {
+	m_active = -1;
+}
+
+TraceContext* TraceContextCollection::context_get_active() {
+	return context(m_active);
+}
+
+const TraceContext* TraceContextCollection::context_get_active() const {
+	return context(m_active);
+}
+
+// Environment
+
+Environment::Environment() {
+	clear();
+}
+
+Environment::~Environment() {}
+
+void Environment::register_hooks(reg_t syscall, hook_t entry, hook_t exit) {
+	if (!entry && !exit) {
+		if (m_hooks.contains(syscall))
+			m_hooks.erase(syscall);
+
+		return;
+	}
+
+	if (!m_hooks.contains(syscall))
+		m_hooks.emplace(syscall, HookPair{});
+
+	HookPair& hooks = m_hooks.at(syscall);
+	hooks.entry = entry;
+	hooks.exit = exit;
+}
+
+void Environment::register_default_hooks(hook_t entry, hook_t exit) {
+	m_default_hooks.entry = entry;
+	m_default_hooks.exit = exit;
+}
+
+bool Environment::entry_hook(reg_t syscall) const {
+	if (!m_hooks.contains(syscall))
+		return false;
+
+	const HookPair& hooks = m_hooks.at(syscall);
+	if (!hooks.entry)
+		return false;
+
+	hooks.entry();
+	return true;
+}
+
+bool Environment::exit_hook(reg_t syscall) const {
+	if (!m_hooks.contains(syscall))
+		return false;
+
+	const HookPair& hooks = m_hooks.at(syscall);
+	if (!hooks.exit)
+		return false;
+
+	hooks.exit();
+	return true;
+}
+
+bool Environment::default_entry_hook() const {
+	if (!m_default_hooks.entry)
+		return false;
+
+	m_default_hooks.entry();
+	return true;
+}
+
+bool Environment::default_exit_hook() const {
+	if (!m_default_hooks.exit)
+		return false;
+
+	m_default_hooks.exit();
+	return true;
+}
+
+TraceContextCollection& Environment::contexts() {
+	return m_trace_contexts;
+}
+
+const TraceContextCollection& Environment::contexts() const {
+	return m_trace_contexts;
+}
+
+void Environment::clear() {
+	m_hooks.clear();
+	m_default_hooks.entry = nullptr;
+	m_default_hooks.exit = nullptr;
+	m_trace_contexts.clear();
+}
+
+// EnvironmentScope to clear Environment on scope exit
+
+EnvironmentScope::EnvironmentScope(Environment& environment) : m_environment{ environment } {}
+
+EnvironmentScope::~EnvironmentScope() {
+	m_environment.clear();
+}
+

src/interface.cpp

@@ -0,0 +1,88 @@
+#include "interface.hpp"
+#include "environment.hpp"
+
+#include <cstring>
+#include <sys/ptrace.h>
+#include <errno.h>
+
+err_t(*wirekit_prepare_handle)() = nullptr;
+err_t(*wirekit_command_start_handle)(int, const char* const*) = nullptr;
+void(*wirekit_command_exit_handle)() = nullptr;
+void(*wirekit_subject_start_handle)() = nullptr;
+void(*wirekit_subject_exit_handle)() = nullptr;
+
+err_t rewire_syscall_hook(reg_t syscall, hook_t entry, hook_t exit) {
+	ENV.register_hooks(syscall, entry, exit);
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_syscall_unhook(reg_t syscall) {
+	rewire_syscall_hook(syscall, nullptr, nullptr);
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_syscall_hook_default(hook_t entry, hook_t exit) {
+	ENV.register_default_hooks(entry, exit);
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_syscall_unhook_default() {
+	rewire_syscall_hook_default(nullptr, nullptr);
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_subject_id(pid_t* pid) {
+	const TraceContext* ctx = ENV.contexts().context_get_active();
+	if (!ctx)
+		return REWIRE_FAILURE_NOCTX;
+
+	*pid = ctx->pid;
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_subject_get_regs(user_regs_struct* regs) {
+	const TraceContext* ctx = ENV.contexts().context_get_active();
+	if (!ctx)
+		return REWIRE_FAILURE_NOCTX;
+
+	std::memcpy(regs, &ctx->regs, sizeof(ctx->regs));
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_subject_set_regs(const user_regs_struct* regs) {
+	TraceContext* ctx = ENV.contexts().context_get_active();
+	if (!ctx)
+		return REWIRE_FAILURE_NOCTX;
+
+	std::memcpy(&ctx->regs, regs, sizeof(ctx->regs));
+	ctx->regs_dirty = true;
+	return REWIRE_SUCCESS;
+}
+
+err_t rewire_subject_load_cstr(const char* subject_addr, char* buf, uint32_t* read, uint32_t n) {
+	const TraceContext* ctx = ENV.contexts().context_get_active();
+	if (!ctx)
+		return REWIRE_FAILURE_NOCTX;
+
+	*read = 0;
+	while (*read < n) {
+		errno = 0;
+		long word = ptrace(PTRACE_PEEKDATA, ctx->pid, (char*)subject_addr, NULL); // TODO
+		if (errno == -1l && errno != 0) // errno differentiates successful -1 word from error
+			return REWIRE_FAILURE;
+
+		for (unsigned i = 0; i < sizeof(long) && *read < n; i++) {
+			char c = *(reinterpret_cast<char*>(&word) + i); // Unlike bit operations, this is independent of endianness
+			*(buf++) = c;
+			(*read)++;
+
+			if (c == 0)
+				return REWIRE_SUCCESS; // Encountered terminating null byte
+		}
+
+		subject_addr += sizeof(long);
+	}
+
+	return REWIRE_SUCCESS;
+}
+

src/main.cpp

@@ -1,9 +1,20 @@
 #include <iostream>
 #include <filesystem>
+#include <vector>
+#include <sstream>
+#include <unistd.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <errno.h>
 
 #include "cli.hpp"
 #include "dl.hpp"
 #include "install.hpp"
+#include "interface.hpp"
+#include "environment.hpp"
+
+#define FORCEQUIT { std::cout << "Forcefully quitting!" << std::endl; while (true) exit(1); }
 
 int launch_help(int argc, char** argv) {
 	std::cout << "Use rewire via one of the following commands:" << std::endl;
@@ -95,6 +106,200 @@ int launch_list(int argc, char** argv) {
 	return 0;
 }
 
+pid_t dispatch_tracee(int argc, const char* const* argv) {
+	pid_t child = fork();
+
+	if (child != 0)
+		return child; // Either -1 on error or child pid
+
+	ptrace(PTRACE_TRACEME, 0, 0, 0);
+	execvp(argv[0], (char* const*)argv); // Removing const here is in child process
+	// Note -> Tracee stops with SIGTRAP immediately after execvp!
+
+	// Child should never return from execvp
+	while (true) exit(1);
+}
+
+class KillWrapper {
+	pid_t m_pid;
+public:
+	KillWrapper(const KillWrapper& other) = delete;
+	KillWrapper(KillWrapper&& other) = delete;
+	KillWrapper& operator=(const KillWrapper& other) = delete;
+	KillWrapper& operator=(KillWrapper&& other) = delete;
+
+	KillWrapper(pid_t pid) : m_pid{ pid } {}
+
+	~KillWrapper() {
+		if (m_pid != -1)
+			kill(m_pid, SIGKILL);
+	}
+
+	void release() {
+		m_pid = -1;
+	}
+};
+
+void run_command(int argc, const char* const* argv) {
+	EnvironmentScope es { ENV }; // Make sure environment is cleared after each command
+
+	// Notify wirekit about command start
+	if (wirekit_command_start_handle(argc, argv) != REWIRE_SUCCESS) {
+		std::cout << "Wirekit prohibited command execution!" << std::endl;
+		return;
+	}
+
+	// Dispatch main command process
+	pid_t main_pid = dispatch_tracee(argc, argv);
+	if (main_pid == -1) {
+		std::cout << "Failed to start command main process!" << std::endl;
+		return;
+	}
+
+	KillWrapper kw { main_pid }; // Make sure it gets whiped until in main trace loop
+
+	int exec_status;
+	if (waitpid(main_pid, &exec_status, 0) != main_pid || !WIFSTOPPED(exec_status) || WSTOPSIG(exec_status) != SIGTRAP) {
+		std::cout << "Execvp failed to run the command!" << std::endl;
+		return;
+	}
+
+	/*
+	PTRACE_O_EXITKILL -> Kill tracees when tracer exits
+	PTRACE_O_TRACESYSGOOD -> SIGTRAP signals caused by system call entry/exit stops have 0x80 bit set
+	PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK, PTRACE_O_TRACECLONE -> Automatically trace new children (inherit options and mode)
+	*/
+	if (ptrace(PTRACE_SETOPTIONS, main_pid, PTRACE_O_EXITKILL, PTRACE_O_TRACESYSGOOD,
+			PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK, PTRACE_O_TRACECLONE) != 0) {
+		std::cout << "Tracer failed to set trace options of command main process!" << std::endl;
+		return;
+	}
+
+	// Let first thread actually start running (until syscall entry)
+	if (ptrace(PTRACE_SYSCALL, main_pid, 0, 0) != 0) {
+		std::cout << "Failed to start command main process execution!" << std::endl;
+		return;
+	}
+
+	// Inform wirekit about first thread and initialize its trace context
+	ENV.contexts().add_context(main_pid);
+	ENV.contexts().context(main_pid)->mode = TraceContext::EXECUTION_MODE::USER;
+
+	ENV.contexts().context_set_active(main_pid);
+
+	if (wirekit_subject_start_handle)
+		wirekit_subject_start_handle();
+
+	ENV.contexts().context_clear_active();
+
+	// Start tracer loop
+	kw.release();
+
+	int status;
+	pid_t pid;
+
+	while ((pid = waitpid(-1, &status, __WALL)) != -1 || errno != ECHILD /* No (grand)children left */) {
+		if (pid == -1) {
+			std::cout << "Tracer interrupted by signal (errno=" << errno << ")!" << std::endl;
+			FORCEQUIT;
+		}
+
+		/*
+		New processes and threads inherit PTRACE_SYSCALL execution mode from parent and thus end up
+		here when they perform their first syscall. Start logging context at this point.
+		*/
+		if (!ENV.contexts().context(pid)) {
+			ENV.contexts().add_context(pid);
+			ENV.contexts().context(pid)->mode = TraceContext::EXECUTION_MODE::USER;
+
+			ENV.contexts().context_set_active(pid);
+
+			if (wirekit_subject_start_handle)
+				wirekit_subject_start_handle();
+
+			ENV.contexts().context_clear_active();
+		}
+
+		// Activate context (definitely exists now)
+		ENV.contexts().context_set_active(pid);
+
+		if (WIFEXITED(status)) {
+			// A child exited -> notify wirekit and stop tracing it
+			if (wirekit_subject_exit_handle)
+				wirekit_subject_exit_handle();
+
+			ENV.contexts().delete_context(pid);
+		} else if (WIFSTOPPED(status)) {
+			int sig = WSTOPSIG(status);
+
+			if (sig == SIGTRAP) {
+				int event = (unsigned)status >> 16;
+
+				if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK || event == PTRACE_EVENT_CLONE) {
+					; // New thread but nothing to do -> tracer attaches on first syscall
+				} else {
+					std::cout << "Received non-syscall SIGTRAP without thread creation event!" << std::endl;
+					FORCEQUIT;
+				}
+			} else if (sig == (SIGTRAP | 0x80) /* 0x80 thanks to PTRACE_O_TRACESYSGOOD */) {
+				// Tracee was trapped on either syscall entry or exit
+				TraceContext* ctx = ENV.contexts().context_get_active();
+
+				if (ptrace(PTRACE_GETREGS, pid, 0, &ctx->regs) != 0) {
+					std::cout << "Failed to read tracee registers!" << std::endl;
+					FORCEQUIT;
+				}
+
+				ctx->regs_dirty = false;
+
+				reg_t syscall = ctx->regs.orig_rax;
+
+				if (ctx->mode == TraceContext::EXECUTION_MODE::USER)
+					ENV.entry_hook(syscall) || ENV.default_entry_hook(); // Short-circuit guaranteed by C++ standard ;)
+				else if (ctx->mode == TraceContext::EXECUTION_MODE::KERNEL)
+					ENV.exit_hook(syscall) || ENV.default_exit_hook();
+
+				if (ctx->regs_dirty) {
+					if (ptrace(PTRACE_SETREGS, pid, NULL, &ctx->regs) != 0) {
+						std::cout << "Failed to write tracee registers!" << std::endl;
+						FORCEQUIT;
+					}
+				}
+
+				ctx->regs_dirty = false;
+
+				auto progress_mode = [](TraceContext::EXECUTION_MODE m) {
+					switch (m) {
+						case TraceContext::EXECUTION_MODE::STARTING:
+							return TraceContext::EXECUTION_MODE::USER;
+						case TraceContext::EXECUTION_MODE::USER:
+							return TraceContext::EXECUTION_MODE::KERNEL;
+						case TraceContext::EXECUTION_MODE::KERNEL:
+							return TraceContext::EXECUTION_MODE::USER;
+					}
+
+					return TraceContext::EXECUTION_MODE::STARTING;
+				};
+
+				ctx->mode = progress_mode(ctx->mode);
+			}
+
+			// Let tracee continue until next system call event (entry or exit)
+			if (ptrace(PTRACE_SYSCALL, pid, 0, 0) != 0) {
+				std::cout << "Failed to continue command execution after SIGTRAP!" << std::endl;
+				FORCEQUIT;
+			}
+		} // else { Weird signal is happening, should be irrelevant to wirekit though! }
+
+		// Deactivate current context
+		ENV.contexts().context_clear_active();
+	}
+
+	// Notify wirekit that command has finished executing (no threads are left)
+	if (wirekit_command_exit_handle)
+		wirekit_command_exit_handle();
+}
+
 int launch_run(int argc, char** argv) {
 	if (argc < 2) {
 		std::cout << "Invalid usage, try \"rewire help\" for more information!" << std::endl;
@@ -119,16 +324,64 @@ int launch_run(int argc, char** argv) {
 		return 1;
 	}
 
-	/*
-	TODO
-	environment.hpp/cpp
-	class Environment -> kit handles, hooks, trace contexts
-	class CommandScope -> hooks and trace contexts can only be added while scope holds environment, all cleared on scope exit
-	class TraceContext -> execution data on individual tracee threads
-	class TraceContextCollection -> management of all trace contexts and selection of active context
-	*/
+	// Collect wirekit control function handles
+	if (!(wirekit_prepare_handle = (err_t(*)())wirekit.resolve("wirekit_prepare"))) {
+		std::cout << "Wirekit is missing \"wirekit_prepare\" implementation!" << std::endl;
+		return 1;
+	}
 
-	// TODO -> Execute single command (argc > 2) or shell
+	if (!(wirekit_command_start_handle = (err_t(*)(int, const char* const*))wirekit.resolve("wirekit_command_start"))) {
+		std::cout << "Wirekit is missing \"wirekit_command_start\" implementation!" << std::endl;
+		return 1;
+	}
+
+	wirekit_command_exit_handle = (void(*)())wirekit.resolve("wirekit_command_exit");
+	wirekit_subject_start_handle = (void(*)())wirekit.resolve("wirekit_subject_start");
+	wirekit_subject_exit_handle = (void(*)())wirekit.resolve("wirekit_subject_exit");
+
+	// Prepare wirekit
+	err_t prepare_err;
+	if ((prepare_err = wirekit_prepare_handle()) != REWIRE_SUCCESS) {
+		std::cout << "Wirekit preparation failed (wirekit_prepare returned " << prepare_err << ")!" << std::endl;
+		return 1;
+	}
+
+	// Execute commands in rewired syscall environment
+	if (argc > 2) {
+		run_command(argc - 2, (const char**)(argv + 2)); // Execute a single command
+	} else {
+		// Shell mode
+		while (true) {
+			std::cout << "> ";
+
+			std::string command;
+			std::getline(std::cin, command);
+
+			// Split command at whitespaces
+			std::stringstream command_stream { command };
+			std::vector<std::string> command_split; // No need to reserve, presumably not many elements
+
+			std::string part;
+			while (command_stream >> std::quoted(part))
+				command_split.emplace_back(std::move(part));
+
+			if (command_split.empty())
+				continue;
+
+			if (command_split[0] == "exit")
+				break;
+
+			// Compile argv (cstr pointer array)
+			std::vector<const char*> command_split_cstr;
+			command_split_cstr.resize(command_split.size() + 1, nullptr); // +1 for nullptr termination
+
+			for (std::size_t i = 0; i < command_split.size(); i++)
+				command_split_cstr[i] = command_split[i].c_str();
+
+			// Execute command
+			run_command((int)command_split_cstr.size() - 1, command_split_cstr.data());
+		}
+	}
 
 	return 0;
 }