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-rwxr-xr-xslockf/slock.c395
1 files changed, 395 insertions, 0 deletions
diff --git a/slockf/slock.c b/slockf/slock.c
new file mode 100755
index 0000000..5ae738c
--- /dev/null
+++ b/slockf/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;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-11-14 22:07:15 +0000