x11-init.c

在x86平台上运行不可信任代码的sandbox。

#include "u.h"
#include "lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "error.h"
#define Image IMAGE	/* kernel has its own Image */
#include <draw.h>
#include <memdraw.h>
#include <keyboard.h>
#include <cursor.h>
#include "screen.h"
#include "x11-inc.h"

#define argv0 "vxplan9"

Xprivate _x;

static int parsewinsize(char *s, Rectangle *r, int *havemin);
static void plan9cmap(void);
static XGC xgc(XDrawable, int, int);
static int setupcmap(XWindow);

static int
xerror(XDisplay *d, XErrorEvent *e)
{
	char buf[200];

	if(e->request_code == 42) /* XSetInputFocus */
		return 0;
	if(e->request_code == 18) /* XChangeProperty */
		return 0;
	/*
	 * BadDrawable happens in apps that get resized a LOT,
	 * e.g. when KDE is configured to resize continuously
	 * during a window drag.
	 */
	if(e->error_code == 9) /* BadDrawable */
		return 0;

	fprint(2, "X error: error_code=%d, request_code=%d, minor=%d disp=%p\n",
		e->error_code, e->request_code, e->minor_code, d);
	XGetErrorText(d, e->error_code, buf, sizeof buf);
	fprint(2, "%s\n", buf);
	return 0;
}

static int
xioerror(XDisplay *d)
{
	/*print("X I/O error\n"); */
	exit(0);
	/*sysfatal("X I/O error\n");*/
	abort();
	return -1;
}

Memimage*
_xattach(char *label, char *winsize)
{
	char *argv[2], *disp;
	int i, havemin, height, mask, n, width, x, xrootid, y;
	Rectangle r;
	XClassHint classhint;
	XDrawable pmid;
	XPixmapFormatValues *pfmt;
	XScreen *xscreen;
	XSetWindowAttributes attr;
	XSizeHints normalhint;
	XTextProperty name;
	XVisualInfo xvi;
	XWindow xrootwin;
	XWindowAttributes wattr;
	XWMHints hint;
	Atom atoms[2];

	/*
	if(XInitThreads() == 0){
		fprint(2, "XInitThreads failed\n");
		abort();
	}
	*/

	/*
	 * Connect to X server.
	 */
	_x.display = XOpenDisplay(NULL);
	if(_x.display == nil){
		disp = getenv("DISPLAY");
		werrstr("XOpenDisplay %s: %r", disp ? disp : ":0");
		free(disp);
		return nil;
	}
	_x.fd = ConnectionNumber(_x.display);
	XSetErrorHandler(xerror);
	XSetIOErrorHandler(xioerror);
	xrootid = DefaultScreen(_x.display);
	xrootwin = DefaultRootWindow(_x.display);

	/* 
	 * Figure out underlying screen format.
	 */
	if(XMatchVisualInfo(_x.display, xrootid, 16, TrueColor, &xvi)
	|| XMatchVisualInfo(_x.display, xrootid, 16, DirectColor, &xvi)){
		_x.vis = xvi.visual;
		_x.depth = 16;
	}
	else
	if(XMatchVisualInfo(_x.display, xrootid, 15, TrueColor, &xvi)
	|| XMatchVisualInfo(_x.display, xrootid, 15, DirectColor, &xvi)){
		_x.vis = xvi.visual;
		_x.depth = 15;
	}
	else
	if(XMatchVisualInfo(_x.display, xrootid, 24, TrueColor, &xvi)
	|| XMatchVisualInfo(_x.display, xrootid, 24, DirectColor, &xvi)){
		_x.vis = xvi.visual;
		_x.depth = 24;
	}
	else
	if(XMatchVisualInfo(_x.display, xrootid, 8, PseudoColor, &xvi)
	|| XMatchVisualInfo(_x.display, xrootid, 8, StaticColor, &xvi)){
		if(_x.depth > 8){
			werrstr("can't deal with colormapped depth %d screens",
				_x.depth);
			goto err0;
		}
		_x.vis = xvi.visual;
		_x.depth = 8;
	}
	else{
		_x.depth = DefaultDepth(_x.display, xrootid);
		if(_x.depth != 8){
			werrstr("can't understand depth %d screen", _x.depth);
			goto err0;
		}
		_x.vis = DefaultVisual(_x.display, xrootid);
	}

	if(DefaultDepth(_x.display, xrootid) == _x.depth)
		_x.usetable = 1;

	/*
	 * _x.depth is only the number of significant pixel bits,
	 * not the total number of pixel bits.  We need to walk the
	 * display list to find how many actual bits are used
	 * per pixel.
	 */
	_x.chan = 0;
	pfmt = XListPixmapFormats(_x.display, &n);
	for(i=0; i<n; i++){
		if(pfmt[i].depth == _x.depth){
			switch(pfmt[i].bits_per_pixel){
			case 1:	/* untested */
				_x.chan = GREY1;
				break;
			case 2:	/* untested */
				_x.chan = GREY2;
				break;
			case 4:	/* untested */
				_x.chan = GREY4;
				break;
			case 8:
				_x.chan = CMAP8;
				break;
			case 15:
				_x.chan = RGB15;
				break;
			case 16: /* how to tell RGB15? */
				_x.chan = RGB16;
				break;
			case 24: /* untested (impossible?) */
				_x.chan = RGB24;
				break;
			case 32:
				_x.chan = XRGB32;
				break;
			}
		}
	}
	if(_x.chan == 0){
		werrstr("could not determine screen pixel format");
		goto err0;
	}

	/*
	 * Set up color map if necessary.
	 */
	xscreen = DefaultScreenOfDisplay(_x.display);
	_x.cmap = DefaultColormapOfScreen(xscreen);
	if(_x.vis->class != StaticColor){
		plan9cmap();
		setupcmap(xrootwin);
	}

	/*
	 * We get to choose the initial rectangle size.
	 * This is arbitrary.  In theory we should read the
	 * command line and allow the traditional X options.
	 */
	mask = 0;
	x = 0;
	y = 0;
	if(winsize && winsize[0]){
		if(parsewinsize(winsize, &r, &havemin) < 0)
			panic("bad window size: %r");
	}else{
		/*
		 * Parse the various X resources.  Thanks to Peter Canning.
		 */
		char *screen_resources, *display_resources, *geom, 
			*geomrestype, *home, *file;
		XrmDatabase database;
		XrmValue geomres;

		database = XrmGetDatabase(_x.display);
		screen_resources = XScreenResourceString(xscreen);
		if(screen_resources != nil){
			XrmCombineDatabase(XrmGetStringDatabase(screen_resources), &database, False);
			XFree(screen_resources);
		}

		display_resources = XResourceManagerString(_x.display);
		if(display_resources == nil){
			home = getenv("HOME");
			if(home!=nil && (file=smprint("%s/.Xdefaults", home)) != nil){
				XrmCombineFileDatabase(file, &database, False);
				free(file);
			}
		}else
			XrmCombineDatabase(XrmGetStringDatabase(display_resources), &database, False);

		geom = smprint("%s.geometry", label);
		if(geom && XrmGetResource(database, geom, nil, &geomrestype, &geomres))
			mask = XParseGeometry(geomres.addr, &x, &y, (uint*)&width, (uint*)&height);
		free(geom);

		if((mask & WidthValue) && (mask & HeightValue)){
			r = Rect(0, 0, width, height);
		}else{
			r = Rect(0, 0, WidthOfScreen(xscreen)*3/4,
					HeightOfScreen(xscreen)*3/4);
			if(Dx(r) > Dy(r)*3/2)
				r.max.x = r.min.x + Dy(r)*3/2;
			if(Dy(r) > Dx(r)*3/2)
				r.max.y = r.min.y + Dx(r)*3/2;
		}
		if(mask & XNegative){
			x += WidthOfScreen(xscreen);
		}
		if(mask & YNegative){
			y += HeightOfScreen(xscreen);
		}
		havemin = 0;
	}
	screenrect = Rect(0, 0, WidthOfScreen(xscreen), HeightOfScreen(xscreen));
	mouserect = Rect(0, 0, Dx(r), Dy(r));

	memset(&attr, 0, sizeof attr);
	attr.colormap = _x.cmap;
	attr.background_pixel = ~0;
	attr.border_pixel = 0;
	_x.drawable = XCreateWindow(
		_x.display,	/* display */
		xrootwin,	/* parent */
		x,		/* x */
		y,		/* y */
		Dx(r),		/* width */
	 	Dy(r),		/* height */
		0,		/* border width */
		_x.depth,	/* depth */
		InputOutput,	/* class */
		_x.vis,		/* visual */
				/* valuemask */
		CWBackPixel|CWBorderPixel|CWColormap,
		&attr		/* attributes (the above aren't?!) */
	);

	/*
	 * Label and other properties required by ICCCCM.
	 */
	memset(&name, 0, sizeof name);
	if(label == nil)
		label = "pjw-face-here";
	name.value = (uchar*)label;
	name.encoding = XA_STRING;
	name.format = 8;
	name.nitems = strlen((char*)name.value);

	memset(&normalhint, 0, sizeof normalhint);
	normalhint.flags = PSize|PMaxSize;
	if(winsize && winsize[0]){
		normalhint.flags &= ~PSize;
		normalhint.flags |= USSize;
		normalhint.width = Dx(r);
		normalhint.height = Dy(r);
	}else{
		if((mask & WidthValue) && (mask & HeightValue)){
			normalhint.flags &= ~PSize;
			normalhint.flags |= USSize;
			normalhint.width = width;
			normalhint.height = height;
		}
		if((mask & WidthValue) && (mask & HeightValue)){
			normalhint.flags |= USPosition;
			normalhint.x = x;
			normalhint.y = y;
		}
	}

	normalhint.max_width = WidthOfScreen(xscreen);
	normalhint.max_height = HeightOfScreen(xscreen);

	memset(&hint, 0, sizeof hint);
	hint.flags = InputHint|StateHint;
	hint.input = 1;
	hint.initial_state = NormalState;

	memset(&classhint, 0, sizeof classhint);
	classhint.res_name = label;
	classhint.res_class = label;

	argv[0] = label;
	argv[1] = nil;

	XSetWMProperties(
		_x.display,	/* display */
		_x.drawable,	/* window */
		&name,		/* XA_WM_NAME property */
		&name,		/* XA_WM_ICON_NAME property */
		argv,		/* XA_WM_COMMAND */
		1,		/* argc */
		&normalhint,	/* XA_WM_NORMAL_HINTS */
		&hint,		/* XA_WM_HINTS */
		&classhint	/* XA_WM_CLASSHINTS */
	);
	XFlush(_x.display);

	if(havemin){
		XWindowChanges ch;

		memset(&ch, 0, sizeof ch);
		ch.x = r.min.x;
		ch.y = r.min.y;
		XConfigureWindow(_x.display, _x.drawable, CWX|CWY, &ch);
		/*
		 * Must pretend origin is 0,0 for X.
		 */
		r = Rect(0,0,Dx(r),Dy(r));
	}

	_x.kmcon = XOpenDisplay(NULL);
	if(_x.kmcon == nil)
		panic("XOpenDisplay kmcon");

	_x.snarfcon = XOpenDisplay(NULL);
	if(_x.snarfcon == nil)
		panic("XOpenDisplay snarfcon");

	/*
	 * Look up clipboard atom.
	 */
	_x.clipboard = XInternAtom(_x.display, "CLIPBOARD", False);
	_x.utf8string = XInternAtom(_x.display, "UTF8_STRING", False);
	_x.targets = XInternAtom(_x.display, "TARGETS", False);
	_x.text = XInternAtom(_x.display, "TEXT", False);
	_x.compoundtext = XInternAtom(_x.display, "COMPOUND_TEXT", False);
	_x.takefocus = XInternAtom(_x.display, "WM_TAKE_FOCUS", False);
	_x.losefocus = XInternAtom(_x.display, "_9WM_LOSE_FOCUS", False);
	_x.wmprotos = XInternAtom(_x.display, "WM_PROTOCOLS", False);
	_x.wmstate = XInternAtom(_x.display, "_NET_WM_STATE", False);
	_x.wmfullscreen = XInternAtom(_x.display, "_NET_WM_STATE_FULLSCREEN", False);

	atoms[0] = _x.takefocus;
	atoms[1] = _x.losefocus;
	XChangeProperty(_x.display, _x.drawable, _x.wmprotos, XA_ATOM, 32,
		PropModeReplace, (uchar*)atoms, 2);

	/*
	 * Put the window on the screen, check to see what size we actually got.
	 */
	XMapWindow(_x.display, _x.drawable);
	XSync(_x.display, False);

	if(!XGetWindowAttributes(_x.display, _x.drawable, &wattr))
		fprint(2, "XGetWindowAttributes failed\n");
	else if(wattr.width && wattr.height){
		if(wattr.width != Dx(r) || wattr.height != Dy(r)){
			r.max.x = r.min.x + wattr.width;
			r.max.y = r.min.y + wattr.height;
		}
	}else
		fprint(2, "XGetWindowAttributes: bad attrs\n");

	/*
	 * Allocate our local backing store.
	 */
	_x.screenr = r;
	_x.screenpm = XCreatePixmap(_x.display, _x.drawable, Dx(r), Dy(r), _x.depth);
	_x.nextscreenpm = _x.screenpm;
	_x.screenimage = _xallocmemimage(r, _x.chan, _x.screenpm);

	/*
	 * Figure out physical window location.
	 */
	int rx, ry;
	XWindow w;
	if(XTranslateCoordinates(_x.display, _x.drawable,
			DefaultRootWindow(_x.display), 0, 0, &rx, &ry, &w))
		r = Rect(rx, ry, Dx(r), Dy(r));
	windowrect = r;

	/*
	 * Allocate some useful graphics contexts for the future.
	 */
	_x.gcfill	= xgc(_x.screenpm, FillSolid, -1);