/* See LICENSE file for license details. */ #define _XOPEN_SOURCE 500 #if HAVE_SHADOW_H #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 #include 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; CARD16 standby, suspend, off; 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; /* DPMS magic to disable the monitor */ if (!DPMSCapable(dpy)) die("slock: DPMSCapable failed\n"); if (!DPMSEnable(dpy)) die("slock: DPMSEnable failed\n"); if (!DPMSGetTimeouts(dpy, &standby, &suspend, &off)) die("slock: DPMSGetTimeouts failed\n"); if (!standby || !suspend || !off) die("slock: at least one DPMS variable is zero\n"); if (!DPMSSetTimeouts(dpy, monitortime, monitortime, monitortime)) die("slock: DPMSSetTimeouts failed\n"); XSync(dpy, 0); /* 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); /* reset DPMS values to inital ones */ DPMSSetTimeouts(dpy, standby, suspend, off); XSync(dpy, 0); return 0; }