slock.c (12339B)
1 /* See LICENSE file for license details. */ 2 #define _XOPEN_SOURCE 500 3 #if HAVE_SHADOW_H 4 #include <shadow.h> 5 #endif 6 7 #include <ctype.h> 8 #include <errno.h> 9 #include <grp.h> 10 #include <pwd.h> 11 #include <stdarg.h> 12 #include <stdlib.h> 13 #include <stdio.h> 14 #include <string.h> 15 #include <unistd.h> 16 #include <spawn.h> 17 #include <sys/types.h> 18 #include <X11/extensions/Xrandr.h> 19 #include <X11/keysym.h> 20 #include <X11/Xlib.h> 21 #include <X11/Xutil.h> 22 #include <Imlib2.h> 23 #include <X11/xpm.h> 24 25 #include "arg.h" 26 #include "util.h" 27 28 char *argv0; 29 30 enum { 31 INIT, 32 INPUT, 33 FAILED, 34 NUMCOLS 35 }; 36 37 struct lock { 38 int screen; 39 Window root, win; 40 Pixmap pmap; 41 Pixmap bgmap; 42 unsigned long colors[NUMCOLS]; 43 }; 44 45 struct xrandr { 46 int active; 47 int evbase; 48 int errbase; 49 }; 50 51 #include "config.h" 52 53 Imlib_Image image; 54 55 static void 56 die(const char *errstr, ...) 57 { 58 va_list ap; 59 60 va_start(ap, errstr); 61 vfprintf(stderr, errstr, ap); 62 va_end(ap); 63 exit(1); 64 } 65 66 #ifdef __linux__ 67 #include <fcntl.h> 68 #include <linux/oom.h> 69 70 static void 71 dontkillme(void) 72 { 73 FILE *f; 74 const char oomfile[] = "/proc/self/oom_score_adj"; 75 76 if (!(f = fopen(oomfile, "w"))) { 77 if (errno == ENOENT) 78 return; 79 die("slock: fopen %s: %s\n", oomfile, strerror(errno)); 80 } 81 fprintf(f, "%d", OOM_SCORE_ADJ_MIN); 82 if (fclose(f)) { 83 if (errno == EACCES) 84 die("slock: unable to disable OOM killer. " 85 "Make sure to suid or sgid slock.\n"); 86 else 87 die("slock: fclose %s: %s\n", oomfile, strerror(errno)); 88 } 89 } 90 #endif 91 92 static const char * 93 gethash(void) 94 { 95 const char *hash; 96 struct passwd *pw; 97 98 /* Check if the current user has a password entry */ 99 errno = 0; 100 if (!(pw = getpwuid(getuid()))) { 101 if (errno) 102 die("slock: getpwuid: %s\n", strerror(errno)); 103 else 104 die("slock: cannot retrieve password entry\n"); 105 } 106 hash = pw->pw_passwd; 107 108 #if HAVE_SHADOW_H 109 if (!strcmp(hash, "x")) { 110 struct spwd *sp; 111 if (!(sp = getspnam(pw->pw_name))) 112 die("slock: getspnam: cannot retrieve shadow entry. " 113 "Make sure to suid or sgid slock.\n"); 114 hash = sp->sp_pwdp; 115 } 116 #else 117 if (!strcmp(hash, "*")) { 118 #ifdef __OpenBSD__ 119 if (!(pw = getpwuid_shadow(getuid()))) 120 die("slock: getpwnam_shadow: cannot retrieve shadow entry. " 121 "Make sure to suid or sgid slock.\n"); 122 hash = pw->pw_passwd; 123 #else 124 die("slock: getpwuid: cannot retrieve shadow entry. " 125 "Make sure to suid or sgid slock.\n"); 126 #endif /* __OpenBSD__ */ 127 } 128 #endif /* HAVE_SHADOW_H */ 129 130 return hash; 131 } 132 133 static void 134 showimage(Display *dpy, Window win) 135 { 136 XImage *ximage; 137 138 if (!XpmReadFileToImage (dpy, imgpath, &ximage, NULL, NULL)) { 139 XSelectInput(dpy, win, ButtonPressMask|ExposureMask); 140 XMapWindow(dpy, win); 141 142 XPutImage(dpy, win, DefaultGC(dpy, 0), ximage, 0, 0, imgoffsetx, imgoffsety, imgwidth, imgheight); 143 } 144 } 145 146 static void 147 readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens, 148 const char *hash) 149 { 150 XRRScreenChangeNotifyEvent *rre; 151 char buf[32], passwd[256], *inputhash; 152 int num, screen, running, failure, oldc; 153 unsigned int len, color; 154 KeySym ksym; 155 XEvent ev; 156 157 memset(passwd, 0, sizeof(passwd)); 158 159 len = 0; 160 running = 1; 161 failure = 0; 162 oldc = INIT; 163 164 while (running && !XNextEvent(dpy, &ev)) { 165 if (ev.type == KeyPress) { 166 explicit_bzero(&buf, sizeof(buf)); 167 num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0); 168 if (IsKeypadKey(ksym)) { 169 if (ksym == XK_KP_Enter) 170 ksym = XK_Return; 171 else if (ksym >= XK_KP_0 && ksym <= XK_KP_9) 172 ksym = (ksym - XK_KP_0) + XK_0; 173 } 174 if (IsFunctionKey(ksym) || 175 IsKeypadKey(ksym) || 176 IsMiscFunctionKey(ksym) || 177 IsPFKey(ksym) || 178 IsPrivateKeypadKey(ksym)) 179 continue; 180 if ((&ev.xkey)->state & ControlMask) { 181 if (ksym == XK_BackSpace) { 182 explicit_bzero(&passwd, sizeof(passwd)); 183 len = 0; 184 } 185 } 186 switch (ksym) { 187 case XK_Return: 188 passwd[len] = '\0'; 189 errno = 0; 190 if (!(inputhash = crypt(passwd, hash))) 191 fprintf(stderr, "slock: crypt: %s\n", strerror(errno)); 192 else 193 running = !!strcmp(inputhash, hash); 194 if (running) { 195 if (xbell == 1) 196 XBell(dpy, 100); 197 failure = 1; 198 } 199 explicit_bzero(&passwd, sizeof(passwd)); 200 len = 0; 201 break; 202 case XK_Escape: 203 explicit_bzero(&passwd, sizeof(passwd)); 204 len = 0; 205 break; 206 case XK_BackSpace: 207 if (len) 208 passwd[--len] = '\0'; 209 break; 210 default: 211 if (num && !iscntrl((int)buf[0]) && 212 (len + num < sizeof(passwd))) { 213 memcpy(passwd + len, buf, num); 214 len += num; 215 } else if (buf[0] == '\025') { /* ctrl-u clears input */ 216 explicit_bzero(&passwd, sizeof(passwd)); 217 len = 0; 218 } 219 break; 220 } 221 222 color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT); 223 if (running && oldc != color) { 224 for (screen = 0; screen < nscreens; screen++) { 225 if (locks[screen]->bgmap) 226 XSetWindowBackgroundPixmap(dpy, locks[screen]->win, locks[screen]->bgmap); 227 else 228 XSetWindowBackground(dpy, locks[screen]->win, locks[screen]->colors[0]); 229 XClearWindow(dpy, locks[screen]->win); 230 231 if (strlen(passwd) > 0) { 232 showimage(dpy, locks[screen]->win); 233 } 234 235 } 236 oldc = color; 237 } 238 } else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) { 239 rre = (XRRScreenChangeNotifyEvent*)&ev; 240 for (screen = 0; screen < nscreens; screen++) { 241 if (locks[screen]->win == rre->window) { 242 if (rre->rotation == RR_Rotate_90 || 243 rre->rotation == RR_Rotate_270) 244 XResizeWindow(dpy, locks[screen]->win, 245 rre->height, rre->width); 246 else 247 XResizeWindow(dpy, locks[screen]->win, 248 rre->width, rre->height); 249 XClearWindow(dpy, locks[screen]->win); 250 break; 251 } 252 } 253 } else { 254 for (screen = 0; screen < nscreens; screen++) 255 XRaiseWindow(dpy, locks[screen]->win); 256 } 257 } 258 } 259 260 static struct lock * 261 lockscreen(Display *dpy, struct xrandr *rr, int screen) 262 { 263 char curs[] = {0, 0, 0, 0, 0, 0, 0, 0}; 264 int i, ptgrab, kbgrab; 265 struct lock *lock; 266 XColor color, dummy; 267 XSetWindowAttributes wa; 268 Cursor invisible; 269 270 if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock)))) 271 return NULL; 272 273 lock->screen = screen; 274 lock->root = RootWindow(dpy, lock->screen); 275 276 if(image) 277 { 278 lock->bgmap = XCreatePixmap(dpy, lock->root, DisplayWidth(dpy, lock->screen), DisplayHeight(dpy, lock->screen), DefaultDepth(dpy, lock->screen)); 279 imlib_context_set_display(dpy); 280 imlib_context_set_visual(DefaultVisual(dpy, lock->screen)); 281 imlib_context_set_colormap(DefaultColormap(dpy, lock->screen)); 282 imlib_context_set_drawable(lock->bgmap); 283 imlib_render_image_on_drawable(0, 0); 284 imlib_free_image(); 285 } 286 287 for (i = 0; i < NUMCOLS; i++) { 288 XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen), 289 colorname[i], &color, &dummy); 290 lock->colors[i] = color.pixel; 291 } 292 293 /* init */ 294 wa.override_redirect = 1; 295 wa.background_pixel = lock->colors[INIT]; 296 lock->win = XCreateWindow(dpy, lock->root, 0, 0, 297 DisplayWidth(dpy, lock->screen), 298 DisplayHeight(dpy, lock->screen), 299 0, DefaultDepth(dpy, lock->screen), 300 CopyFromParent, 301 DefaultVisual(dpy, lock->screen), 302 CWOverrideRedirect | CWBackPixel, &wa); 303 if(lock->bgmap) 304 XSetWindowBackgroundPixmap(dpy, lock->win, lock->bgmap); 305 lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8); 306 invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap, 307 &color, &color, 0, 0); 308 XDefineCursor(dpy, lock->win, invisible); 309 310 /* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */ 311 for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) { 312 if (ptgrab != GrabSuccess) { 313 ptgrab = XGrabPointer(dpy, lock->root, False, 314 ButtonPressMask | ButtonReleaseMask | 315 PointerMotionMask, GrabModeAsync, 316 GrabModeAsync, None, invisible, CurrentTime); 317 } 318 if (kbgrab != GrabSuccess) { 319 kbgrab = XGrabKeyboard(dpy, lock->root, True, 320 GrabModeAsync, GrabModeAsync, CurrentTime); 321 } 322 323 /* input is grabbed: we can lock the screen */ 324 if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) { 325 XMapRaised(dpy, lock->win); 326 if (rr->active) 327 XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask); 328 329 XSelectInput(dpy, lock->root, SubstructureNotifyMask); 330 return lock; 331 } 332 333 /* retry on AlreadyGrabbed but fail on other errors */ 334 if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) || 335 (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess)) 336 break; 337 338 usleep(100000); 339 } 340 341 /* we couldn't grab all input: fail out */ 342 if (ptgrab != GrabSuccess) 343 fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", 344 screen); 345 if (kbgrab != GrabSuccess) 346 fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", 347 screen); 348 return NULL; 349 } 350 351 static void 352 usage(void) 353 { 354 die("usage: slock [-v] [cmd [arg ...]]\n"); 355 } 356 357 int 358 main(int argc, char **argv) { 359 struct xrandr rr; 360 struct lock **locks; 361 struct passwd *pwd; 362 struct group *grp; 363 uid_t duid; 364 gid_t dgid; 365 const char *hash; 366 Display *dpy; 367 int s, nlocks, nscreens; 368 369 ARGBEGIN { 370 case 'v': 371 puts("slock-"VERSION); 372 return 0; 373 default: 374 usage(); 375 } ARGEND 376 377 /* validate drop-user and -group */ 378 errno = 0; 379 if (!(pwd = getpwnam(user))) 380 die("slock: getpwnam %s: %s\n", user, 381 errno ? strerror(errno) : "user entry not found"); 382 duid = pwd->pw_uid; 383 errno = 0; 384 if (!(grp = getgrnam(group))) 385 die("slock: getgrnam %s: %s\n", group, 386 errno ? strerror(errno) : "group entry not found"); 387 dgid = grp->gr_gid; 388 389 #ifdef __linux__ 390 dontkillme(); 391 #endif 392 393 hash = gethash(); 394 errno = 0; 395 if (!crypt("", hash)) 396 die("slock: crypt: %s\n", strerror(errno)); 397 398 if (!(dpy = XOpenDisplay(NULL))) 399 die("slock: cannot open display\n"); 400 401 /* drop privileges */ 402 if (setgroups(0, NULL) < 0) 403 die("slock: setgroups: %s\n", strerror(errno)); 404 if (setgid(dgid) < 0) 405 die("slock: setgid: %s\n", strerror(errno)); 406 if (setuid(duid) < 0) 407 die("slock: setuid: %s\n", strerror(errno)); 408 409 /* Load picture */ 410 Imlib_Image buffer = imlib_load_image(background_image); 411 imlib_context_set_image(buffer); 412 int background_image_width = imlib_image_get_width(); 413 int background_image_height = imlib_image_get_height(); 414 415 /* Create an image to be rendered */ 416 Screen *scr = ScreenOfDisplay(dpy, DefaultScreen(dpy)); 417 image = imlib_create_image(scr->width, scr->height); 418 imlib_context_set_image(image); 419 420 /* Fill the image for every X monitor */ 421 XRRMonitorInfo *monitors; 422 int number_of_monitors; 423 monitors = XRRGetMonitors(dpy, RootWindow(dpy, XScreenNumberOfScreen(scr)), True, &number_of_monitors); 424 425 int i; 426 for (i = 0; i < number_of_monitors; i++) { 427 imlib_blend_image_onto_image(buffer, 0, 0, 0, background_image_width, background_image_height, monitors[i].x, monitors[i].y, monitors[i].width, monitors[i].height); 428 } 429 430 /* Clean up */ 431 imlib_context_set_image(buffer); 432 imlib_free_image(); 433 imlib_context_set_image(image); 434 435 /* check for Xrandr support */ 436 rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase); 437 438 /* get number of screens in display "dpy" and blank them */ 439 nscreens = ScreenCount(dpy); 440 if (!(locks = calloc(nscreens, sizeof(struct lock *)))) 441 die("slock: out of memory\n"); 442 for (nlocks = 0, s = 0; s < nscreens; s++) { 443 if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL) 444 nlocks++; 445 else 446 break; 447 } 448 XSync(dpy, 0); 449 450 /* did we manage to lock everything? */ 451 if (nlocks != nscreens) 452 return 1; 453 454 /* run post-lock command */ 455 if (argc > 0) { 456 pid_t pid; 457 extern char **environ; 458 int err = posix_spawnp(&pid, argv[0], NULL, NULL, argv, environ); 459 if (err) { 460 die("slock: failed to execute post-lock command: %s: %s\n", 461 argv[0], strerror(err)); 462 } 463 } 464 465 /* everything is now blank. Wait for the correct password */ 466 readpw(dpy, &rr, locks, nscreens, hash); 467 468 return 0; 469 }