15
# Security Policy

## Supported Versions

Security advisories are published at:
https://github.com/nim-lang/security/security/advisories?state=published

Security fixes are provided in new releases and in bugfix releases.

We do not backport security fixes to older releases.

(Yet, Linux distributions might backport security fixes for their packages.)

## Reporting a Vulnerability

If you have discovered a vulnerability, please notify us about it via
security@nim-lang.org in order to set up a meeting where we can discuss the next
steps.

Please do not report vulnerabilities via GitHub issues.

/* See LICENSE file for copyright and license details. */
#include "dwm.h"
#include <errno.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/select.h>
#include <X11/cursorfont.h>
#include <X11/keysym.h>
#include <X11/Xatom.h>
#include <X11/Xproto.h>
#include <X11/Xutil.h>

/* extern */

char stext[256];
int screen, sx, sy, sw, sh, wax, way, waw, wah;
unsigned int bh, ntags;
unsigned int bpos = BARPOS;
unsigned int numlockmask = 0;
Atom wmatom[WMLast], netatom[NetLast];
Bool *seltags;
Bool selscreen = True;
Client *clients = NULL;
Client *sel = NULL;
Client *stack = NULL;
Cursor cursor[CurLast];
Display *dpy;
DC dc = {0};
Window root, barwin;

/* static */

static int (*xerrorxlib)(Display *, XErrorEvent *);
static Bool otherwm, readin;
static Bool running = True;

static void
cleanup(void) {
	close(STDIN_FILENO);
	while(stack) {
		unban(stack);
		unmanage(stack);
	}
	if(dc.font.set)
		XFreeFontSet(dpy, dc.font.set);
	else
		XFreeFont(dpy, dc.font.xfont);
	XUngrabKey(dpy, AnyKey, AnyModifier, root);
	XFreePixmap(dpy, dc.drawable);
	XFreeGC(dpy, dc.gc);
	XDestroyWindow(dpy, barwin);
	XFreeCursor(dpy, cursor[CurNormal]);
	XFreeCursor(dpy, cursor[CurResize]);
	XFreeCursor(dpy, cursor[CurMove]);
	XSetInputFocus(dpy, PointerRoot, RevertToPointerRoot, CurrentTime);
	XSync(dpy, False);
	free(seltags);
}

static unsigned long
initcolor(const char *colstr) {
	Colormap cmap = DefaultColormap(dpy, screen);
	XColor color;

	if(!XAllocNamedColor(dpy, cmap, colstr, &color, &color))
		eprint("error, cannot allocate color '%s'\n", colstr);
	return color.pixel;
}

static void
initfont(const char *fontstr) {
	char *def, **missing;
	int i, n;

	missing = NULL;
	if(dc.font.set)
		XFreeFontSet(dpy, dc.font.set);
	dc.font.set = XCreateFontSet(dpy, fontstr, &missing, &n, &def);
	if(missing) {
		while(n--)
			fprintf(stderr, "dwm: missing fontset: %s\n", missing[n]);
		XFreeStringList(missing);
	}
	if(dc.font.set) {
		XFontSetExtents *font_extents;
		XFontStruct **xfonts;
		char **font_names;
		dc.font.ascent = dc.font.descent = 0;
		font_extents = XExtentsOfFontSet(dc.font.set);
		n = XFontsOfFontSet(dc.font.set, &xfonts, &font_names);
		for(i = 0, dc.font.ascent = 0, dc.font.descent = 0; i < n; i++) {
			if(dc.font.ascent < (*xfonts)->ascent)
				dc.font.ascent = (*xfonts)->ascent;
			if(dc.font.descent < (*xfonts)->descent)
				dc.font.descent = (*xfonts)->descent;
			xfonts++;
		}
	}
	else {
		if(dc.font.xfont)
			XFreeFont(dpy, dc.font.xfont);
		dc.font.xfont = NULL;
		if(!(dc.font.xfont = XLoadQueryFont(dpy, fontstr)))
			eprint("error, cannot load font: '%s'\n", fontstr);
		dc.font.ascent = dc.font.xfont->ascent;
		dc.font.descent = dc.font.xfont->descent;
	}
	dc.font.height = dc.font.ascent + dc.font.descent;
}

static long
getstate(Window w) {
	int format, status;
	long result = -1;
	unsigned char *p = NULL;
	unsigned long n, extra;
	Atom real;

	status = XGetWindowProperty(dpy, w, wmatom[WMState], 0L, 2L, False, wmatom[WMState],
			&real, &format, &n, &extra, (unsigned char **)&p);
	if(status != Success)
		return -1;
	if(n != 0)
		result = *p;
	XFree(p);
	return result;
}

static void
scan(void) {
	unsigned int i, num;
	Window *wins, d1, d2;
	XWindowAttributes wa;

	wins = NULL;
	if(XQueryTree(dpy, root, &d1, &d2, &wins, &num)) {
		for(i = 0; i < num; i++) {
			if(!XGetWindowAttributes(dpy, wins[i], &wa)
			|| wa.override_redirect || XGetTransientForHint(dpy, wins[i], &d1))
				continue;
			if(wa.map_state == IsViewable || getstate(wins[i]) == IconicState)
				manage(wins[i], &wa);
		}
		for(i = 0; i < num; i++) { /* now the transients */
			if(!XGetWindowAttributes(dpy, wins[i], &wa))
				continue;
			if(XGetTransientForHint(dpy, wins[i], &d1)
			&& (wa.map_state == IsViewable || getstate(wins[i]) == IconicState))
				manage(wins[i], &wa);
		}
	}
	if(wins)
		XFree(wins);
}

static void
setup(void) {
	int i, j;
	unsigned int mask;
	Window w;
	XModifierKeymap *modmap;
	XSetWindowAttributes wa;

	/* init atoms */
	wmatom[WMProtocols] = XInternAtom(dpy, "WM_PROTOCOLS", False);
	wmatom[WMDelete] = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
	wmatom[WMName] = XInternAtom(dpy, "WM_NAME", False);
	wmatom[WMState] = XInternAtom(dpy, "WM_STATE", False);
	netatom[NetSupported] = XInternAtom(dpy, "_NET_SUPPORTED", False);
	netatom[NetWMName] = XInternAtom(dpy, "_NET_WM_NAME", False);
	XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
			PropModeReplace, (unsigned char *) netatom, NetLast);
	/* init cursors */
	cursor[CurNormal] = XCreateFontCursor(dpy, XC_left_ptr);
	cursor[CurResize] = XCreateFontCursor(dpy, XC_sizing);
	cursor[CurMove] = XCreateFontCursor(dpy, XC_fleur);
	/* init modifier map */
	modmap = XGetModifierMapping(dpy);
	for (i = 0; i < 8; i++)
		for (j = 0; j < modmap->max_keypermod; j++) {
			if(modmap->modifiermap[i * modmap->max_keypermod + j]
					== XKeysymToKeycode(dpy, XK_Num_Lock))
				numlockmask = (1 << i);
		}
	XFreeModifiermap(modmap);
	/* select for events */
	wa.event_mask = SubstructureRedirectMask | SubstructureNotifyMask
		| EnterWindowMask | LeaveWindowMask | StructureNotifyMask;
	wa.cursor = cursor[CurNormal];
	XChangeWindowAttributes(dpy, root, CWEventMask | CWCursor, &wa);
	XSelectInput(dpy, root, wa.event_mask);
	grabkeys();
	compileregs();
	for(ntags = 0; tags[ntags]; ntags++);
	seltags = emallocz(sizeof(Bool) * ntags);
	seltags[0] = True;
	/* style */
	dc.norm[ColBorder] = initcolor(NORMBORDERCOLOR);
	dc.norm[ColBG] = initcolor(NORMBGCOLOR);
	dc.norm[ColFG] = initcolor(NORMFGCOLOR);
	dc.sel[ColBorder] = initcolor(SELBORDERCOLOR);
	dc.sel[ColBG] = initcolor(SELBGCOLOR);
	dc.sel[ColFG] = initcolor(SELFGCOLOR);
	initfont(FONT);
	/* geometry */
	sx = sy = 0;
	sw = DisplayWidth(dpy, screen);
	sh = DisplayHeight(dpy, screen);
	initlayouts();
	/* bar */
	dc.h = bh = dc.font.height + 2;
	wa.override_redirect = 1;
	wa.background_pixmap = ParentRelative;
	wa.event_mask = ButtonPressMask | ExposureMask;
	barwin = XCreateWindow(dpy, root, sx, sy, sw, bh, 0,
			DefaultDepth(dpy, screen), CopyFromParent, DefaultVisual(dpy, screen),
			CWOverrideRedirect | CWBackPixmap | CWEventMask, &wa);
	XDefineCursor(dpy, barwin, cursor[CurNormal]);
	updatebarpos();
	XMapRaised(dpy, barwin);
	strcpy(stext, "dwm-"VERSION);
	/* pixmap for everything */
	dc.drawable = XCreatePixmap(dpy, root, sw, bh, DefaultDepth(dpy, screen));
	dc.gc = XCreateGC(dpy, root, 0, 0);
	XSetLineAttributes(dpy, dc.gc, 1, LineSolid, CapButt, JoinMiter);
	if(!dc.font.set)
		XSetFont(dpy, dc.gc, dc.font.xfont->fid);
	/* multihead support */
	selscreen = XQueryPointer(dpy, root, &w, &w, &i, &i, &i, &i, &mask);
}

/*
 * Startup Error handler to check if another window manager
 * is already running.
 */
static int
xerrorstart(Display *dsply, XErrorEvent *ee) {
	otherwm = True;
	return -1;
}

/* extern */

Bool
gettextprop(Window w, Atom atom, char *text, unsigned int size) {
	char **list = NULL;
	int n;
	XTextProperty name;

	if(!text || size == 0)
		return False;
	text[0] = '\0';
	XGetTextProperty(dpy, w, &name, atom);
	if(!name.nitems)
		return False;
	if(name.encoding == XA_STRING)
		strncpy(text, (char *)name.value, size - 1);
	else {
		if(XmbTextPropertyToTextList(dpy, &name, &list, &n) >= Success
		&& n > 0 && *list)
		{
			strncpy(text, *list, size - 1);
			XFreeStringList(list);
		}
	}
	text[size - 1] = '\0';
	XFree(name.value);
	return True;
}

void
quit(const char *arg) {
	readin = running = False;
}

/* There's no way to check accesses to destroyed windows, thus those cases are
 * ignored (especially on UnmapNotify's).  Other types of errors call Xlibs
 * default error handler, which may call exit.
 */
int
xerror(Display *dpy, XErrorEvent *ee) {
	if(ee->error_code == BadWindow
	|| (ee->request_code == X_SetInputFocus && ee->error_code == BadMatch)
	|| (ee->request_code == X_PolyText8 && ee->error_code == BadDrawable)
	|| (ee->request_code == X_PolyFillRectangle && ee->error_code == BadDrawable)
	|| (ee->request_code == X_PolySegment && ee->error_code == BadDrawable)
	|| (ee->request_code == X_ConfigureWindow && ee->error_code == BadMatch)
	|| (ee->request_code == X_GrabKey && ee->error_code == BadAccess)
	|| (ee->request_code == X_CopyArea && ee->error_code == BadDrawable))
		return 0;
	fprintf(stderr, "dwm: fatal error: request code=%d, error code=%d\n",
		ee->request_code, ee->error_code);
	return xerrorxlib(dpy, ee); /* may call exit */
}

int
main(int argc, char *argv[]) {
	char *p;
	int r, xfd;
	fd_set rd;
	XEvent ev;

	if(argc == 2 && !strcmp("-v", argv[1]))
		eprint("dwm-"VERSION", © 2006-2007 A. R. Garbe, S. van Dijk, J. Salmi, P. Hruby, S. Nagy\n");
	else if(argc != 1)
		eprint("usage: dwm [-v]\n");
	setlocale(LC_CTYPE, "");
	if(!(dpy = XOpenDisplay(0)))
		eprint("dwm: cannot open display\n");
	xfd = ConnectionNumber(dpy);
	screen = DefaultScreen(dpy);
	root = RootWindow(dpy, screen);
	otherwm = False;
	XSetErrorHandler(xerrorstart);
	/* this causes an error if some other window manager is running */
	XSelectInput(dpy, root, SubstructureRedirectMask);
	XSync(dpy, False);
	if(otherwm)
		eprint("dwm: another window manager is already running\n");

	XSync(dpy, False);
	XSetErrorHandler(NULL);
	xerrorxlib = XSetErrorHandler(xerror);
	XSync(dpy, False);
	setup();
	drawstatus();
	scan();

	/* main event loop, also reads status text from stdin */
	XSync(dpy, False);
	readin = True;
	while(running) {
		FD_ZERO(&rd);
		if(readin)
			FD_SET(STDIN_FILENO, &rd);
		FD_SET(xfd, &rd);
		if(select(xfd + 1, &rd, NULL, NULL, NULL) == -1) {
			if(errno == EINTR)
				continue;
			eprint("select failed\n");
		}
		if(FD_ISSET(STDIN_FILENO, &rd)) {
			switch(r = read(STDIN_FILENO, stext, sizeof stext - 1)) {
			case -1:
				strncpy(stext, strerror(errno), sizeof stext - 1);
				stext[sizeof stext - 1] = '\0';
				readin = False;
				break;
			case 0:
				strncpy(stext, "EOF", 4);
				readin = False;
				break;
			default:
				for(stext[r] = '\0', p = stext + strlen(stext) - 1; p >= stext && *p == '\n'; *p-- = '\0');
				for(; p >= stext && *p != '\n'; --p);
				if(p > stext)
					strncpy(stext, p + 1, sizeof stext);
			}
			drawstatus();
		}
		while(XPending(dpy)) {
			XNextEvent(dpy, &ev);
			if(handler[ev.type])
				(handler[ev.type])(&ev); /* call handler */
		}
	}
	cleanup();
	XCloseDisplay(dpy);
	return 0;
}