Wrote IPX configuration tool, not completely finished

Makefile

@@ -15,12 +15,13 @@
 # Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 CFLAGS := -Wall
+CXXFLAGS := -Wall
 
 IPXWRAPPER_DEPS := src/ipxwrapper.o src/winsock.o src/ipxwrapper_stubs.o src/ipxwrapper.def
 WSOCK32_DEPS := src/stubdll.o src/wsock32_stubs.o src/wsock32.def
 MSWSOCK_DEPS := src/stubdll.o src/mswsock_stubs.o src/mswsock.def
 
-all: ipxwrapper.dll wsock32.dll mswsock.dll
+all: ipxwrapper.dll wsock32.dll mswsock.dll ipxconfig.exe
 
 clean:
 	rm -f src/*.o
@@ -61,3 +62,6 @@ src/mswsock_stubs.o: src/mswsock_stubs.s
 
 src/mswsock_stubs.s: src/mswsock_stubs.txt
 	perl mkstubs.pl src/mswsock_stubs.txt src/mswsock_stubs.s mswsock.dll
+
+ipxconfig.exe: src/ipxconfig.cpp
+	$(CXX) $(CXXFLAGS) -D_WIN32_IE=0x0400 -mwindows -o ipxconfig.exe src/ipxconfig.cpp -liphlpapi

src/ipxconfig.cpp

@@ -0,0 +1,627 @@
+/* ipxwrapper - Configuration tool
+ * Copyright (C) 2011 Daniel Collins <solemnwarning@solemnwarning.net>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#include <windows.h>
+#include <windowsx.h>
+#include <commctrl.h>
+#include <iphlpapi.h>
+#include <iostream>
+#include <assert.h>
+#include <string>
+#include <vector>
+
+#define ID_NIC_LIST 1
+#define ID_NIC_ENABLE 2
+#define ID_NIC_PRIMARY 3
+#define ID_SAVE 4
+#define ID_NIC_NET 5
+#define ID_NIC_NODE 6
+
+#define ID_DIALOG_TXT 1
+#define ID_DIALOG_OK 2
+#define ID_DIALOG_CANCEL 3
+
+struct iface {
+	/* C style strings used so they can be passed directly to the listview */
+	char name[MAX_ADAPTER_DESCRIPTION_LENGTH+4];
+	char hwaddr[18];
+	
+	char ipx_net[12];
+	char ipx_node[18];
+	
+	bool enabled;
+	bool primary;
+};
+
+struct reg_value {
+	unsigned char ipx_net[4];
+	unsigned char ipx_node[6];
+	unsigned char enabled;
+	unsigned char primary;
+} __attribute__((__packed__));
+
+typedef std::vector<iface> iface_list;
+
+static void addr_input_dialog(const char *desc, char *dest, int size);
+static void get_nics();
+static void set_primary(unsigned int id);
+static void save_nics();
+static void saddr_to_bin(unsigned char *bin, const char *str);
+static void baddr_to_str(char *str, const unsigned char *bin, int size);
+static void init_windows();
+static void update_nic_conf();
+static HWND create_child(HWND parent, int x, int y, int w, int h, LPCTSTR class_name, LPCTSTR title, DWORD style = 0, DWORD ex_style = 0, unsigned int id = 0);
+static void add_list_column(HWND hwnd, int id, char *text, int width);
+static int get_text_width(HWND hwnd, const char *txt);
+static int get_text_height(HWND hwnd);
+
+static iface_list nics;
+static HKEY regkey = NULL;
+
+typedef LRESULT CALLBACK (*wproc_fptr)(HWND,UINT,WPARAM,LPARAM);
+static wproc_fptr groupbox_wproc = NULL;
+
+static struct {
+	HWND main;
+	HWND nic_list;
+	
+	HWND nic_conf;
+	HWND nic_net;
+	HWND nic_node;
+	HWND nic_enabled;
+	HWND nic_primary;
+	
+	HWND save_btn;
+} windows;
+
+/* Callback for the main window */
+static LRESULT CALLBACK main_wproc(HWND window, UINT msg, WPARAM wp, LPARAM lp) {
+	switch(msg) {
+		case WM_CLOSE:
+			DestroyWindow(window);
+			break;
+			
+		case WM_DESTROY:
+			PostQuitMessage(0);
+			break;
+		
+		case WM_NOTIFY:
+			NMHDR *nhdr = (NMHDR*)lp;
+			
+			if(nhdr->idFrom == ID_NIC_LIST) {
+				if(nhdr->code == LVN_GETDISPINFO) {
+					NMLVDISPINFO *di = (NMLVDISPINFOA*)lp;
+					
+					char *values[] = {
+						nics[di->item.iItem].name,
+						nics[di->item.iItem].ipx_net,
+						nics[di->item.iItem].ipx_node,
+						(char*)(nics[di->item.iItem].enabled ? "Yes" : "No"),
+						(char*)(nics[di->item.iItem].primary ? "Yes" : "No")
+					};
+					
+					di->item.pszText = values[di->item.iSubItem];
+					di->item.cchTextMax = strlen(di->item.pszText);
+				}else if(nhdr->code == LVN_ITEMCHANGED) {
+					NMLISTVIEW *lv = (NMLISTVIEW*)lp;
+					
+					if(lv->uNewState & LVIS_FOCUSED) {
+						update_nic_conf();
+					}
+				}
+			}
+			
+			break;
+			
+		case WM_COMMAND:
+			if(HIWORD(wp) == BN_CLICKED) {
+				int selected_nic = ListView_GetNextItem(windows.nic_list, (LPARAM)-1, LVNI_FOCUSED);
+				
+				switch(LOWORD(wp)) {
+					case ID_NIC_ENABLE:
+						nics[selected_nic].enabled = Button_GetCheck(windows.nic_enabled) == BST_CHECKED;
+						update_nic_conf();
+						
+						ListView_Update(windows.nic_list, selected_nic);
+						
+						break;
+					
+					case ID_NIC_PRIMARY:
+						if(Button_GetCheck(windows.nic_primary) == BST_CHECKED) {
+							set_primary(selected_nic);
+						}else{
+							nics[selected_nic].primary = false;
+						}
+						
+						for(unsigned int i = 0; i < nics.size(); i++) {
+							ListView_Update(windows.nic_list, i);
+						}
+						
+						break;
+					
+					case ID_NIC_NET:
+						addr_input_dialog("Network number", nics[selected_nic].ipx_net, 4);
+						break;
+					
+					case ID_NIC_NODE:
+						addr_input_dialog("Node number", nics[selected_nic].ipx_node, 6);
+						break;
+					
+					case ID_SAVE:
+						save_nics();
+						break;
+					
+					default:
+						break;
+				}
+			}
+			
+			break;
+		
+		case WM_SIZE:
+			int width = LOWORD(lp), height = HIWORD(lp);
+			
+			RECT rect;
+			
+			assert(GetWindowRect(windows.nic_conf, &rect));
+			int conf_h = rect.bottom - rect.top;
+			
+			assert(GetWindowRect(windows.save_btn, &rect));
+			int save_h = rect.bottom - rect.top;
+			int save_w = rect.right - rect.left;
+			
+			MoveWindow(windows.nic_list, 0, 0, width, height-conf_h, TRUE);
+			MoveWindow(windows.nic_conf, 0, height-conf_h, width-save_w-1, conf_h, TRUE);
+			MoveWindow(windows.save_btn, width-save_w, height-save_h, save_w, save_h, TRUE);
+		
+			break;
+		
+		default:
+			return DefWindowProc(window, msg, wp, lp);
+	}
+	
+	return 0;
+}
+
+/* Callback for the NIC config groupbox */
+static LRESULT CALLBACK conf_group_wproc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {
+	if(msg == WM_COMMAND) {
+		PostMessage(windows.main, msg, wp, lp);
+		return 0;
+	}
+	
+	return groupbox_wproc(hwnd, msg, wp, lp);
+}
+
+struct addr_dialog_vars {
+	const char *desc;
+	
+	char *dest;
+	int size;
+};
+
+/* Callback for address entry dialog */
+static LRESULT CALLBACK addr_dialog_wproc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) {
+	static addr_dialog_vars *vars = NULL;
+	
+	switch(msg) {
+		case WM_CREATE:
+			CREATESTRUCT *cs = (CREATESTRUCT*)lp;
+			vars = (addr_dialog_vars*)cs->lpCreateParams;
+			
+			HWND edit = create_child(hwnd, 0, 0, 0, 0, "EDIT", vars->dest, WS_TABSTOP, WS_EX_CLIENTEDGE, ID_DIALOG_TXT);
+			HWND ok = create_child(hwnd, 0, 0, 0, 0, "BUTTON", "OK", BS_PUSHBUTTON | WS_TABSTOP, 0, ID_DIALOG_OK);
+			HWND cancel = create_child(hwnd, 0, 0, 0, 0, "BUTTON", "Cancel", BS_PUSHBUTTON | WS_TABSTOP, 0, ID_DIALOG_CANCEL);
+			
+			int edge = GetSystemMetrics(SM_CYEDGE);
+			int height = get_text_height(edit) + 2*edge;
+			
+			int edit_w = get_text_width(edit, "FF:FF:FF:FF:FF:FF") + 2*edge;
+			int btn_w = (int)(get_text_width(cancel, "Cancel") * 1.5) + 2*edge;
+			
+			MoveWindow(edit, 5, 5, edit_w, height, TRUE);
+			MoveWindow(ok, edit_w+10, 5, btn_w, height, TRUE);
+			MoveWindow(cancel, edit_w+btn_w+15, 5, btn_w, height, TRUE);
+			
+			RECT crect, brect;
+			assert(GetClientRect(hwnd, &crect));
+			assert(GetWindowRect(hwnd, &brect));
+			
+			int win_w = ((brect.right - brect.left) - crect.right) + edit_w + 2*btn_w + 20;
+			int win_h = ((brect.bottom - brect.top) - crect.bottom) + height + 10;
+			
+			assert(GetWindowRect(windows.main, &brect));
+			
+			int win_x = brect.left + (brect.right - brect.left) / 2 - win_w / 2;
+			int win_y = brect.top + (brect.bottom - brect.top) / 2 - win_h / 2;
+			
+			MoveWindow(hwnd, win_x, win_y, win_w, win_h, TRUE);
+			
+			EnableWindow(windows.main, FALSE);
+			
+			ShowWindow(hwnd, SW_SHOW);
+			UpdateWindow(hwnd);
+			
+			break;
+		
+		case WM_CLOSE:
+			delete vars;
+			
+			EnableWindow(windows.main, TRUE);
+			SetFocus(windows.main);
+			
+			DestroyWindow(hwnd);
+			
+			break;
+		
+		case WM_COMMAND:
+			if(HIWORD(wp) == BN_CLICKED) {
+				int btn = LOWORD(wp);
+				
+				if(btn == ID_DIALOG_OK) {
+					char text[256];
+					GetWindowText(GetDlgItem(hwnd, ID_DIALOG_TXT), text, sizeof(text));
+					
+					bool success = false;
+					
+					if(vars->size == 4) {
+						int buf[4];
+						
+						if(sscanf(text, "%02X:%02X:%02X:%02X", &buf[0], &buf[1], &buf[2], &buf[3]) == 4) {
+							unsigned char uc[] = {buf[0], buf[1], buf[2], buf[3]};
+							
+							baddr_to_str(vars->dest, uc, 4);
+							success = true;
+						}
+					}else{
+						int buf[6];
+						
+						if(sscanf(text, "%02X:%02X:%02X:%02X:%02X:%02X", &buf[0], &buf[1], &buf[2], &buf[3], &buf[4], &buf[5]) == 6) {
+							unsigned char uc[] = {buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]};
+							
+							baddr_to_str(vars->dest, uc, 6);
+							success = true;
+						}
+					}
+					
+					if(success) {
+						int nic = ListView_GetNextItem(windows.nic_list, (LPARAM)-1, LVNI_FOCUSED);
+						
+						ListView_Update(windows.nic_list, nic);
+						PostMessage(hwnd, WM_CLOSE, 0, 0);
+					}else{
+						std::string m = std::string("Invalid ") + vars->desc;
+						MessageBox(hwnd, m.c_str(), NULL, MB_OK | MB_ICONEXCLAMATION);
+					}
+				}else if(btn == ID_DIALOG_CANCEL) {
+					PostMessage(hwnd, WM_CLOSE, 0, 0);
+				}
+			}
+		
+		default:
+			return DefWindowProc(hwnd, msg, wp, lp);
+	};
+	
+	return 0;
+}
+
+static void addr_input_dialog(const char *desc, char *dest, int size) {
+	addr_dialog_vars *v = new addr_dialog_vars;
+	
+	v->desc = desc;
+	v->dest = dest;
+	v->size = size;
+	
+	assert(CreateWindow(
+		"ipxconfig_dialog",
+		desc,
+		WS_DLGFRAME,
+		CW_USEDEFAULT, CW_USEDEFAULT,
+		CW_USEDEFAULT, CW_USEDEFAULT,
+		windows.main,
+		NULL,
+		NULL,
+		v
+	));
+}
+
+int main() {
+	assert(RegCreateKeyEx(
+		HKEY_CURRENT_USER,
+		"Software\\IPXWrapper",
+		0,
+		NULL,
+		0,
+		KEY_QUERY_VALUE | KEY_SET_VALUE,
+		NULL,
+		&regkey,
+		NULL
+	) == ERROR_SUCCESS);
+	
+	get_nics();
+	
+	init_windows();
+	
+	MSG msg;
+	BOOL mret;
+	
+	while((mret = GetMessage(&msg, NULL, 0, 0))) {
+		assert(mret != -1);
+		
+		TranslateMessage(&msg);
+		DispatchMessage(&msg);
+	}
+	
+	RegCloseKey(regkey);
+	
+	return msg.wParam;
+}
+
+static void get_nics() {
+	IP_ADAPTER_INFO tbuf;
+	ULONG bufsize = sizeof(IP_ADAPTER_INFO);
+	
+	int rval = GetAdaptersInfo(&tbuf, &bufsize);
+	if(rval != ERROR_SUCCESS && rval != ERROR_BUFFER_OVERFLOW) {
+		assert(0);
+	}
+	
+	IP_ADAPTER_INFO *buf = new IP_ADAPTER_INFO[bufsize / sizeof(tbuf)];
+	
+	rval = GetAdaptersInfo(buf, &bufsize);
+	if(rval != ERROR_SUCCESS) {
+		assert(0);
+	}
+	
+	for(IP_ADAPTER_INFO *ptr = buf; ptr; ptr = ptr->Next) {
+		if(ptr->AddressLength != 6) {
+			continue;
+		}
+		
+		iface new_if;
+		
+		strcpy(new_if.name, ptr->Description);
+		
+		baddr_to_str(new_if.hwaddr, ptr->Address, 6);
+		
+		strcpy(new_if.ipx_net, "00:00:00:01");
+		strcpy(new_if.ipx_node, new_if.hwaddr);
+		
+		new_if.enabled = true;
+		new_if.primary = false;
+		
+		reg_value rval;
+		DWORD rsize = sizeof(rval);
+		bool primary = false;
+		
+		if(RegQueryValueEx(regkey, new_if.hwaddr, NULL, NULL, (BYTE*)&rval, &rsize) == ERROR_SUCCESS && rsize == sizeof(rval)) {
+			baddr_to_str(new_if.ipx_net, rval.ipx_net, 4);
+			baddr_to_str(new_if.ipx_node, rval.ipx_node, 6);
+			
+			new_if.enabled = rval.enabled;
+			primary = rval.primary;
+		}
+		
+		nics.push_back(new_if);
+		
+		if(primary) {
+			set_primary(nics.size()-1);
+		}
+	}
+	
+	delete buf;
+}
+
+static void set_primary(unsigned int id) {
+	for(unsigned int i = 0; i < nics.size(); i++) {
+		nics[i].primary = i == id ? true : false;
+	}
+}
+
+static void save_nics() {
+	for(iface_list::iterator i = nics.begin(); i != nics.end(); i++) {
+		reg_value rval;
+		
+		saddr_to_bin(rval.ipx_net, i->ipx_net);
+		saddr_to_bin(rval.ipx_node, i->ipx_node);
+		rval.enabled = i->enabled;
+		rval.primary = i->primary;
+		
+		assert(RegSetValueEx(regkey, i->hwaddr, 0, REG_BINARY, (BYTE*)&rval, sizeof(rval)) == ERROR_SUCCESS);
+	}
+}
+
+/* Convert string format address to binary
+ * NO SANITY CHECKS, ENSURE INPUT DATA IS VALID AND BUFFER SIZE SUFFICIENT
+*/
+static void saddr_to_bin(unsigned char *bin, const char *str) {
+	unsigned int i = 0;
+	
+	while(*str) {
+		bin[i++] = strtoul(str, NULL, 16);
+		str += strcspn(str, ":");
+		str += strspn(str, ":");
+	}
+}
+
+/* Convert binary format address to string
+ * Same warnings as above
+*/
+static void baddr_to_str(char *str, const unsigned char *bin, int size) {
+	for(int i = 0; i < size; i++) {
+		sprintf(str+(i*3), "%02X", bin[i]);
+		
+		if(i+1 < size) {
+			strcat(str, ":");
+		}
+	}
+}
+
+static void init_windows() {
+	WNDCLASS wclass;
+	
+	memset(&wclass, 0, sizeof(wclass));
+	wclass.style = 0;
+	wclass.lpfnWndProc = &main_wproc;
+	wclass.hInstance = GetModuleHandle(NULL);
+	wclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+	wclass.hbrBackground = (HBRUSH)(COLOR_BTNFACE+1);
+	wclass.lpszMenuName  = NULL;
+	wclass.lpszClassName = "ipxconfig_class";
+	
+	assert(RegisterClass(&wclass));
+	
+	wclass.lpfnWndProc = &addr_dialog_wproc;
+	wclass.lpszClassName = "ipxconfig_dialog";
+	
+	assert(RegisterClass(&wclass));
+	
+	windows.main = CreateWindow(
+		"ipxconfig_class",
+		"IPXWrapper configuration",
+		WS_TILEDWINDOW,
+		CW_USEDEFAULT, CW_USEDEFAULT,
+		800, 500,
+		NULL,
+		NULL,
+		NULL,
+		NULL
+	);
+	
+	assert(windows.main);
+	
+	windows.nic_list = create_child(windows.main, 0, 0, 0, 0, WC_LISTVIEW, NULL, LVS_SINGLESEL | LVS_REPORT | WS_TABSTOP, WS_EX_CLIENTEDGE, ID_NIC_LIST);
+	
+	ListView_SetExtendedListViewStyle(windows.nic_list, LVS_EX_FULLROWSELECT);
+	
+	add_list_column(windows.nic_list, 0, "Name", 200);
+	add_list_column(windows.nic_list, 1, "IPX Network Number", 120);
+	add_list_column(windows.nic_list, 2, "IPX Node Number", 150);
+	add_list_column(windows.nic_list, 3, "Enabled", 60);
+	add_list_column(windows.nic_list, 4, "Primary", 60);
+	
+	windows.nic_conf = create_child(windows.main, 0, 0, 0, 0, "BUTTON", "Interface settings", BS_GROUPBOX);
+	
+	int window_edge = GetSystemMetrics(SM_CYEDGE);
+	int text_h = get_text_height(windows.nic_conf);
+	int row_h = window_edge*2 + text_h;
+	
+	int btn_w = get_text_width(windows.nic_conf, "Set IPX network number...") + 2*window_edge;
+	int cbox_w = get_text_width(windows.nic_conf, "Make primary interface");
+	
+	MoveWindow(windows.nic_conf, 0, 0, 0, text_h + 2*row_h + 15, TRUE);
+	
+	windows.nic_net = create_child(windows.nic_conf, 10, text_h, btn_w, row_h, "BUTTON", "Set IPX network number...", WS_TABSTOP | BS_PUSHBUTTON, 0, ID_NIC_NET);
+	windows.nic_node = create_child(windows.nic_conf, 10, text_h+row_h+5, btn_w, row_h, "BUTTON", "Set IPX node number...", WS_TABSTOP | BS_PUSHBUTTON, 0, ID_NIC_NODE);
+	
+	windows.nic_enabled = create_child(windows.nic_conf, 20+btn_w, text_h, cbox_w, row_h, "BUTTON", "Enable interface", BS_AUTOCHECKBOX | WS_TABSTOP, 0, ID_NIC_ENABLE);
+	windows.nic_primary = create_child(windows.nic_conf, 20+btn_w, text_h+row_h+5, cbox_w, row_h, "BUTTON", "Make primary interface", BS_AUTOCHECKBOX | WS_TABSTOP, 0, ID_NIC_PRIMARY);
+	
+	update_nic_conf();
+	
+	windows.save_btn = create_child(windows.main, 0, 0, 75, row_h, "BUTTON", "Save", BS_PUSHBUTTON | WS_TABSTOP, 0, ID_SAVE);
+	
+	LVITEM lvi;
+	
+	lvi.mask = LVIF_TEXT | LVIF_STATE;
+	lvi.iItem = 0;
+	lvi.iSubItem = 0;
+	lvi.state = 0;
+	lvi.stateMask = 0;
+	lvi.pszText = LPSTR_TEXTCALLBACK;
+	
+	for(iface_list::iterator i = nics.begin(); i != nics.end(); i++) {
+		ListView_InsertItem(windows.nic_list, &lvi);
+		lvi.iItem++;
+	}
+	
+	ShowWindow(windows.main, SW_SHOW);
+	UpdateWindow(windows.main);
+	
+	groupbox_wproc = (wproc_fptr)SetWindowLongPtr(windows.nic_conf, GWLP_WNDPROC, (LONG)&conf_group_wproc);
+}
+
+static void update_nic_conf() {
+	int selected_nic = ListView_GetNextItem(windows.nic_list, (LPARAM)-1, LVNI_FOCUSED);
+	bool enabled = selected_nic >= 0 ? nics[selected_nic].enabled : false;
+	
+	EnableWindow(windows.nic_net, enabled ? TRUE : FALSE);
+	EnableWindow(windows.nic_node, enabled ? TRUE : FALSE);
+	EnableWindow(windows.nic_enabled, selected_nic >= 0 ? TRUE : FALSE);
+	EnableWindow(windows.nic_primary, enabled ? TRUE : FALSE);
+	
+	if(selected_nic >= 0) {
+		Button_SetCheck(windows.nic_enabled, nics[selected_nic].enabled ? BST_CHECKED : BST_UNCHECKED);
+		Button_SetCheck(windows.nic_primary, nics[selected_nic].primary ? BST_CHECKED : BST_UNCHECKED);
+	}
+}
+
+static HWND create_child(HWND parent, int x, int y, int w, int h, LPCTSTR class_name, LPCTSTR title, DWORD style, DWORD ex_style, unsigned int id) {
+	static unsigned int idnum = 100;
+	
+	HWND hwnd = CreateWindowEx(
+		ex_style,
+		class_name,
+		title,
+		WS_CHILD | WS_VISIBLE | style,
+		x, y, w, h,
+		parent,
+		(HMENU)(id ? id : idnum++),
+		NULL,
+		NULL
+	);
+	
+	assert(hwnd);
+	
+	SendMessage(hwnd, WM_SETFONT, (WPARAM)GetStockObject(DEFAULT_GUI_FONT), TRUE);
+	
+	return hwnd;
+}
+
+static void add_list_column(HWND hwnd, int id, char *text, int width) {
+	LVCOLUMN lvc;
+	lvc.mask = LVCF_FMT | LVCF_WIDTH | LVCF_TEXT;
+	lvc.fmt = LVCFMT_LEFT;
+	lvc.cx = width;
+	lvc.pszText = text;
+	
+	ListView_InsertColumn(hwnd, id, &lvc);
+}
+
+static int get_text_width(HWND hwnd, const char *txt) {
+	HDC dc = GetDC(hwnd);
+	assert(dc);
+	
+	SIZE size;
+	assert(GetTextExtentPoint32(dc, txt, strlen(txt), &size));
+	
+	ReleaseDC(hwnd, dc);
+	
+	return size.cx;
+}
+
+static int get_text_height(HWND hwnd) {
+	HDC dc = GetDC(hwnd);
+	assert(dc);
+	
+	TEXTMETRIC tm;
+	assert(GetTextMetrics(dc, &tm));
+	
+	ReleaseDC(hwnd, dc);
+	
+	return tm.tmHeight;
+}