Initial overall to match latest updates

1 files changed, 395 insertions, 0 deletions

diff --git a/slocko/slock.c b/slocko/slock.c
new file mode 100644
index 0000000..5ae738c
--- /dev/null
+++ b/slocko/slock.c
@@ -0,0 +1,395 @@
+/* See LICENSE file for license details. */
+#define _XOPEN_SOURCE 500
+#if HAVE_SHADOW_H
+#include <shadow.h>
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <X11/extensions/Xrandr.h>
+#include <X11/keysym.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+#include "arg.h"
+#include "util.h"
+
+char *argv0;
+
+enum {
+	INIT,
+	INPUT,
+	FAILED,
+	NUMCOLS
+};
+
+struct lock {
+	int screen;
+	Window root, win;
+	Pixmap pmap;
+	unsigned long colors[NUMCOLS];
+};
+
+struct xrandr {
+	int active;
+	int evbase;
+	int errbase;
+};
+
+#include "config.h"
+
+static void
+die(const char *errstr, ...)
+{
+	va_list ap;
+
+	va_start(ap, errstr);
+	vfprintf(stderr, errstr, ap);
+	va_end(ap);
+	exit(1);
+}
+
+#ifdef __linux__
+#include <fcntl.h>
+#include <linux/oom.h>
+
+static void
+dontkillme(void)
+{
+	FILE *f;
+	const char oomfile[] = "/proc/self/oom_score_adj";
+
+	if (!(f = fopen(oomfile, "w"))) {
+		if (errno == ENOENT)
+			return;
+		die("slock: fopen %s: %s\n", oomfile, strerror(errno));
+	}
+	fprintf(f, "%d", OOM_SCORE_ADJ_MIN);
+	if (fclose(f)) {
+		if (errno == EACCES)
+			die("slock: unable to disable OOM killer. "
+			    "Make sure to suid or sgid slock.\n");
+		else
+			die("slock: fclose %s: %s\n", oomfile, strerror(errno));
+	}
+}
+#endif
+
+static const char *
+gethash(void)
+{
+	const char *hash;
+	struct passwd *pw;
+
+	/* Check if the current user has a password entry */
+	errno = 0;
+	if (!(pw = getpwuid(getuid()))) {
+		if (errno)
+			die("slock: getpwuid: %s\n", strerror(errno));
+		else
+			die("slock: cannot retrieve password entry\n");
+	}
+	hash = pw->pw_passwd;
+
+#if HAVE_SHADOW_H
+	if (!strcmp(hash, "x")) {
+		struct spwd *sp;
+		if (!(sp = getspnam(pw->pw_name)))
+			die("slock: getspnam: cannot retrieve shadow entry. "
+			    "Make sure to suid or sgid slock.\n");
+		hash = sp->sp_pwdp;
+	}
+#else
+	if (!strcmp(hash, "*")) {
+#ifdef __OpenBSD__
+		if (!(pw = getpwuid_shadow(getuid())))
+			die("slock: getpwnam_shadow: cannot retrieve shadow entry. "
+			    "Make sure to suid or sgid slock.\n");
+		hash = pw->pw_passwd;
+#else
+		die("slock: getpwuid: cannot retrieve shadow entry. "
+		    "Make sure to suid or sgid slock.\n");
+#endif /* __OpenBSD__ */
+	}
+#endif /* HAVE_SHADOW_H */
+
+	return hash;
+}
+
+static void
+readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
+       const char *hash)
+{
+	XRRScreenChangeNotifyEvent *rre;
+	char buf[32], passwd[256], *inputhash;
+	int num, screen, running, failure, oldc;
+	unsigned int len, color;
+	KeySym ksym;
+	XEvent ev;
+
+	len = 0;
+	running = 1;
+	failure = 0;
+	oldc = INIT;
+
+	while (running && !XNextEvent(dpy, &ev)) {
+		if (ev.type == KeyPress) {
+			explicit_bzero(&buf, sizeof(buf));
+			num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
+			if (IsKeypadKey(ksym)) {
+				if (ksym == XK_KP_Enter)
+					ksym = XK_Return;
+				else if (ksym >= XK_KP_0 && ksym <= XK_KP_9)
+					ksym = (ksym - XK_KP_0) + XK_0;
+			}
+			if (IsFunctionKey(ksym) ||
+			    IsKeypadKey(ksym) ||
+			    IsMiscFunctionKey(ksym) ||
+			    IsPFKey(ksym) ||
+			    IsPrivateKeypadKey(ksym))
+				continue;
+			switch (ksym) {
+			case XK_Return:
+				passwd[len] = '\0';
+				errno = 0;
+				if (!(inputhash = crypt(passwd, hash)))
+					fprintf(stderr, "slock: crypt: %s\n", strerror(errno));
+				else
+					running = !!strcmp(inputhash, hash);
+				if (running) {
+					XBell(dpy, 100);
+					failure = 1;
+				}
+				explicit_bzero(&passwd, sizeof(passwd));
+				len = 0;
+				break;
+			case XK_Escape:
+				explicit_bzero(&passwd, sizeof(passwd));
+				len = 0;
+				break;
+			case XK_BackSpace:
+				if (len)
+					passwd[--len] = '\0';
+				break;
+			default:
+				if (num && !iscntrl((int)buf[0]) &&
+				    (len + num < sizeof(passwd))) {
+					memcpy(passwd + len, buf, num);
+					len += num;
+				}
+				break;
+			}
+			color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
+			if (running && oldc != color) {
+				for (screen = 0; screen < nscreens; screen++) {
+					XSetWindowBackground(dpy,
+					                     locks[screen]->win,
+					                     locks[screen]->colors[color]);
+					XClearWindow(dpy, locks[screen]->win);
+				}
+				oldc = color;
+			}
+		} else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
+			rre = (XRRScreenChangeNotifyEvent*)&ev;
+			for (screen = 0; screen < nscreens; screen++) {
+				if (locks[screen]->win == rre->window) {
+					if (rre->rotation == RR_Rotate_90 ||
+					    rre->rotation == RR_Rotate_270)
+						XResizeWindow(dpy, locks[screen]->win,
+						              rre->height, rre->width);
+					else
+						XResizeWindow(dpy, locks[screen]->win,
+						              rre->width, rre->height);
+					XClearWindow(dpy, locks[screen]->win);
+					break;
+				}
+			}
+		} else {
+			for (screen = 0; screen < nscreens; screen++)
+				XRaiseWindow(dpy, locks[screen]->win);
+		}
+	}
+}
+
+static struct lock *
+lockscreen(Display *dpy, struct xrandr *rr, int screen)
+{
+	char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
+	int i, ptgrab, kbgrab;
+	struct lock *lock;
+	XColor color, dummy;
+	XSetWindowAttributes wa;
+	Cursor invisible;
+
+	if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
+		return NULL;
+
+	lock->screen = screen;
+	lock->root = RootWindow(dpy, lock->screen);
+
+	for (i = 0; i < NUMCOLS; i++) {
+		XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen),
+		                 colorname[i], &color, &dummy);
+		lock->colors[i] = color.pixel;
+	}
+
+	/* init */
+	wa.override_redirect = 1;
+	wa.background_pixel = lock->colors[INIT];
+	lock->win = XCreateWindow(dpy, lock->root, 0, 0,
+	                          DisplayWidth(dpy, lock->screen),
+	                          DisplayHeight(dpy, lock->screen),
+	                          0, DefaultDepth(dpy, lock->screen),
+	                          CopyFromParent,
+	                          DefaultVisual(dpy, lock->screen),
+	                          CWOverrideRedirect | CWBackPixel, &wa);
+	lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
+	invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap,
+	                                &color, &color, 0, 0);
+	XDefineCursor(dpy, lock->win, invisible);
+
+	/* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */
+	for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) {
+		if (ptgrab != GrabSuccess) {
+			ptgrab = XGrabPointer(dpy, lock->root, False,
+			                      ButtonPressMask | ButtonReleaseMask |
+			                      PointerMotionMask, GrabModeAsync,
+			                      GrabModeAsync, None, invisible, CurrentTime);
+		}
+		if (kbgrab != GrabSuccess) {
+			kbgrab = XGrabKeyboard(dpy, lock->root, True,
+			                       GrabModeAsync, GrabModeAsync, CurrentTime);
+		}
+
+		/* input is grabbed: we can lock the screen */
+		if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
+			XMapRaised(dpy, lock->win);
+			if (rr->active)
+				XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
+
+			XSelectInput(dpy, lock->root, SubstructureNotifyMask);
+			return lock;
+		}
+
+		/* retry on AlreadyGrabbed but fail on other errors */
+		if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) ||
+		    (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess))
+			break;
+
+		usleep(100000);
+	}
+
+	/* we couldn't grab all input: fail out */
+	if (ptgrab != GrabSuccess)
+		fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n",
+		        screen);
+	if (kbgrab != GrabSuccess)
+		fprintf(stderr, "slock: unable to grab keyboard for screen %d\n",
+		        screen);
+	return NULL;
+}
+
+static void
+usage(void)
+{
+	die("usage: slock [-v] [cmd [arg ...]]\n");
+}
+
+int
+main(int argc, char **argv) {
+	struct xrandr rr;
+	struct lock **locks;
+	struct passwd *pwd;
+	struct group *grp;
+	uid_t duid;
+	gid_t dgid;
+	const char *hash;
+	Display *dpy;
+	int s, nlocks, nscreens;
+
+	ARGBEGIN {
+	case 'v':
+		fprintf(stderr, "slock-"VERSION"\n");
+		return 0;
+	default:
+		usage();
+	} ARGEND
+
+	/* validate drop-user and -group */
+	errno = 0;
+	if (!(pwd = getpwnam(user)))
+		die("slock: getpwnam %s: %s\n", user,
+		    errno ? strerror(errno) : "user entry not found");
+	duid = pwd->pw_uid;
+	errno = 0;
+	if (!(grp = getgrnam(group)))
+		die("slock: getgrnam %s: %s\n", group,
+		    errno ? strerror(errno) : "group entry not found");
+	dgid = grp->gr_gid;
+
+#ifdef __linux__
+	dontkillme();
+#endif
+
+	hash = gethash();
+	errno = 0;
+	if (!crypt("", hash))
+		die("slock: crypt: %s\n", strerror(errno));
+
+	if (!(dpy = XOpenDisplay(NULL)))
+		die("slock: cannot open display\n");
+
+	/* drop privileges */
+	if (setgroups(0, NULL) < 0)
+		die("slock: setgroups: %s\n", strerror(errno));
+	if (setgid(dgid) < 0)
+		die("slock: setgid: %s\n", strerror(errno));
+	if (setuid(duid) < 0)
+		die("slock: setuid: %s\n", strerror(errno));
+
+	/* check for Xrandr support */
+	rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase);
+
+	/* get number of screens in display "dpy" and blank them */
+	nscreens = ScreenCount(dpy);
+	if (!(locks = calloc(nscreens, sizeof(struct lock *))))
+		die("slock: out of memory\n");
+	for (nlocks = 0, s = 0; s < nscreens; s++) {
+		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
+			nlocks++;
+		else
+			break;
+	}
+	XSync(dpy, 0);
+
+	/* did we manage to lock everything? */
+	if (nlocks != nscreens)
+		return 1;
+
+	/* run post-lock command */
+	if (argc > 0) {
+		switch (fork()) {
+		case -1:
+			die("slock: fork failed: %s\n", strerror(errno));
+		case 0:
+			if (close(ConnectionNumber(dpy)) < 0)
+				die("slock: close: %s\n", strerror(errno));
+			execvp(argv[0], argv);
+			fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno));
+			_exit(1);
+		}
+	}
+
+	/* everything is now blank. Wait for the correct password */
+	readpw(dpy, &rr, locks, nscreens, hash);
+
+	return 0;
+}