slock.c (11835B)
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 24 #include "arg.h" 25 #include "util.h" 26 27 char *argv0; 28 29 enum { 30 INIT, 31 INPUT, 32 FAILED, 33 NUMCOLS 34 }; 35 36 struct lock { 37 int screen; 38 Window root, win; 39 Pixmap pmap; 40 Pixmap bgmap; 41 unsigned long colors[NUMCOLS]; 42 }; 43 44 struct xrandr { 45 int active; 46 int evbase; 47 int errbase; 48 }; 49 50 #include "config.h" 51 52 Imlib_Image image; 53 54 static void 55 die(const char *errstr, ...) 56 { 57 va_list ap; 58 59 va_start(ap, errstr); 60 vfprintf(stderr, errstr, ap); 61 va_end(ap); 62 exit(1); 63 } 64 65 #ifdef __linux__ 66 #include <fcntl.h> 67 #include <linux/oom.h> 68 69 static void 70 dontkillme(void) 71 { 72 FILE *f; 73 const char oomfile[] = "/proc/self/oom_score_adj"; 74 75 if (!(f = fopen(oomfile, "w"))) { 76 if (errno == ENOENT) 77 return; 78 die("slock: fopen %s: %s\n", oomfile, strerror(errno)); 79 } 80 fprintf(f, "%d", OOM_SCORE_ADJ_MIN); 81 if (fclose(f)) { 82 if (errno == EACCES) 83 die("slock: unable to disable OOM killer. " 84 "Make sure to suid or sgid slock.\n"); 85 else 86 die("slock: fclose %s: %s\n", oomfile, strerror(errno)); 87 } 88 } 89 #endif 90 91 static const char * 92 gethash(void) 93 { 94 const char *hash; 95 struct passwd *pw; 96 97 /* Check if the current user has a password entry */ 98 errno = 0; 99 if (!(pw = getpwuid(getuid()))) { 100 if (errno) 101 die("slock: getpwuid: %s\n", strerror(errno)); 102 else 103 die("slock: cannot retrieve password entry\n"); 104 } 105 hash = pw->pw_passwd; 106 107 #if HAVE_SHADOW_H 108 if (!strcmp(hash, "x")) { 109 struct spwd *sp; 110 if (!(sp = getspnam(pw->pw_name))) 111 die("slock: getspnam: cannot retrieve shadow entry. " 112 "Make sure to suid or sgid slock.\n"); 113 hash = sp->sp_pwdp; 114 } 115 #else 116 if (!strcmp(hash, "*")) { 117 #ifdef __OpenBSD__ 118 if (!(pw = getpwuid_shadow(getuid()))) 119 die("slock: getpwnam_shadow: cannot retrieve shadow entry. " 120 "Make sure to suid or sgid slock.\n"); 121 hash = pw->pw_passwd; 122 #else 123 die("slock: getpwuid: cannot retrieve shadow entry. " 124 "Make sure to suid or sgid slock.\n"); 125 #endif /* __OpenBSD__ */ 126 } 127 #endif /* HAVE_SHADOW_H */ 128 129 return hash; 130 } 131 132 static void 133 readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens, 134 const char *hash) 135 { 136 XRRScreenChangeNotifyEvent *rre; 137 char buf[32], passwd[256], *inputhash; 138 int num, screen, running, failure, oldc; 139 unsigned int len, color; 140 KeySym ksym; 141 XEvent ev; 142 143 len = 0; 144 running = 1; 145 failure = 0; 146 oldc = INIT; 147 148 while (running && !XNextEvent(dpy, &ev)) { 149 if (ev.type == KeyPress) { 150 explicit_bzero(&buf, sizeof(buf)); 151 num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0); 152 if (IsKeypadKey(ksym)) { 153 if (ksym == XK_KP_Enter) 154 ksym = XK_Return; 155 else if (ksym >= XK_KP_0 && ksym <= XK_KP_9) 156 ksym = (ksym - XK_KP_0) + XK_0; 157 } 158 if (IsFunctionKey(ksym) || 159 IsKeypadKey(ksym) || 160 IsMiscFunctionKey(ksym) || 161 IsPFKey(ksym) || 162 IsPrivateKeypadKey(ksym)) 163 continue; 164 switch (ksym) { 165 case XK_Return: 166 passwd[len] = '\0'; 167 errno = 0; 168 if (!(inputhash = crypt(passwd, hash))) 169 fprintf(stderr, "slock: crypt: %s\n", strerror(errno)); 170 else 171 running = !!strcmp(inputhash, hash); 172 if (running) { 173 XBell(dpy, 100); 174 failure = 1; 175 } 176 explicit_bzero(&passwd, sizeof(passwd)); 177 len = 0; 178 break; 179 case XK_Escape: 180 explicit_bzero(&passwd, sizeof(passwd)); 181 len = 0; 182 break; 183 case XK_BackSpace: 184 if (len) 185 passwd[--len] = '\0'; 186 break; 187 default: 188 if (num && !iscntrl((int)buf[0]) && 189 (len + num < sizeof(passwd))) { 190 memcpy(passwd + len, buf, num); 191 len += num; 192 } else if (buf[0] == '\025') { /* ctrl-u clears input */ 193 explicit_bzero(&passwd, sizeof(passwd)); 194 len = 0; 195 } 196 break; 197 } 198 color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT); 199 if (running && oldc != color) { 200 for (screen = 0; screen < nscreens; screen++) { 201 if(locks[screen]->bgmap) 202 XSetWindowBackgroundPixmap(dpy, locks[screen]->win, locks[screen]->bgmap); 203 else 204 XSetWindowBackground(dpy, locks[screen]->win, locks[screen]->colors[0]); 205 XClearWindow(dpy, locks[screen]->win); 206 } 207 oldc = color; 208 } 209 } else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) { 210 rre = (XRRScreenChangeNotifyEvent*)&ev; 211 for (screen = 0; screen < nscreens; screen++) { 212 if (locks[screen]->win == rre->window) { 213 if (rre->rotation == RR_Rotate_90 || 214 rre->rotation == RR_Rotate_270) 215 XResizeWindow(dpy, locks[screen]->win, 216 rre->height, rre->width); 217 else 218 XResizeWindow(dpy, locks[screen]->win, 219 rre->width, rre->height); 220 XClearWindow(dpy, locks[screen]->win); 221 break; 222 } 223 } 224 } else { 225 for (screen = 0; screen < nscreens; screen++) 226 XRaiseWindow(dpy, locks[screen]->win); 227 } 228 } 229 } 230 231 static struct lock * 232 lockscreen(Display *dpy, struct xrandr *rr, int screen) 233 { 234 char curs[] = {0, 0, 0, 0, 0, 0, 0, 0}; 235 int i, ptgrab, kbgrab; 236 struct lock *lock; 237 XColor color, dummy; 238 XSetWindowAttributes wa; 239 Cursor invisible; 240 241 if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock)))) 242 return NULL; 243 244 lock->screen = screen; 245 lock->root = RootWindow(dpy, lock->screen); 246 247 if(image) 248 { 249 lock->bgmap = XCreatePixmap(dpy, lock->root, DisplayWidth(dpy, lock->screen), DisplayHeight(dpy, lock->screen), DefaultDepth(dpy, lock->screen)); 250 imlib_context_set_image(image); 251 imlib_context_set_display(dpy); 252 imlib_context_set_visual(DefaultVisual(dpy, lock->screen)); 253 imlib_context_set_colormap(DefaultColormap(dpy, lock->screen)); 254 imlib_context_set_drawable(lock->bgmap); 255 imlib_render_image_on_drawable(0, 0); 256 imlib_free_image(); 257 } 258 for (i = 0; i < NUMCOLS; i++) { 259 XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen), 260 colorname[i], &color, &dummy); 261 lock->colors[i] = color.pixel; 262 } 263 264 /* init */ 265 wa.override_redirect = 1; 266 wa.background_pixel = lock->colors[INIT]; 267 lock->win = XCreateWindow(dpy, lock->root, 0, 0, 268 DisplayWidth(dpy, lock->screen), 269 DisplayHeight(dpy, lock->screen), 270 0, DefaultDepth(dpy, lock->screen), 271 CopyFromParent, 272 DefaultVisual(dpy, lock->screen), 273 CWOverrideRedirect | CWBackPixel, &wa); 274 if(lock->bgmap) 275 XSetWindowBackgroundPixmap(dpy, lock->win, lock->bgmap); 276 lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8); 277 invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap, 278 &color, &color, 0, 0); 279 XDefineCursor(dpy, lock->win, invisible); 280 281 /* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */ 282 for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) { 283 if (ptgrab != GrabSuccess) { 284 ptgrab = XGrabPointer(dpy, lock->root, False, 285 ButtonPressMask | ButtonReleaseMask | 286 PointerMotionMask, GrabModeAsync, 287 GrabModeAsync, None, invisible, CurrentTime); 288 } 289 if (kbgrab != GrabSuccess) { 290 kbgrab = XGrabKeyboard(dpy, lock->root, True, 291 GrabModeAsync, GrabModeAsync, CurrentTime); 292 } 293 294 /* input is grabbed: we can lock the screen */ 295 if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) { 296 XMapRaised(dpy, lock->win); 297 if (rr->active) 298 XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask); 299 300 XSelectInput(dpy, lock->root, SubstructureNotifyMask); 301 return lock; 302 } 303 304 /* retry on AlreadyGrabbed but fail on other errors */ 305 if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) || 306 (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess)) 307 break; 308 309 usleep(100000); 310 } 311 312 /* we couldn't grab all input: fail out */ 313 if (ptgrab != GrabSuccess) 314 fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", 315 screen); 316 if (kbgrab != GrabSuccess) 317 fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", 318 screen); 319 return NULL; 320 } 321 322 static void 323 usage(void) 324 { 325 die("usage: slock [-v] [cmd [arg ...]]\n"); 326 } 327 328 int 329 main(int argc, char **argv) { 330 struct xrandr rr; 331 struct lock **locks; 332 struct passwd *pwd; 333 struct group *grp; 334 uid_t duid; 335 gid_t dgid; 336 const char *hash; 337 Display *dpy; 338 int s, nlocks, nscreens; 339 340 ARGBEGIN { 341 case 'v': 342 puts("slock-"VERSION); 343 return 0; 344 default: 345 usage(); 346 } ARGEND 347 348 /* validate drop-user and -group */ 349 errno = 0; 350 if (!(pwd = getpwnam(user))) 351 die("slock: getpwnam %s: %s\n", user, 352 errno ? strerror(errno) : "user entry not found"); 353 duid = pwd->pw_uid; 354 errno = 0; 355 if (!(grp = getgrnam(group))) 356 die("slock: getgrnam %s: %s\n", group, 357 errno ? strerror(errno) : "group entry not found"); 358 dgid = grp->gr_gid; 359 360 #ifdef __linux__ 361 dontkillme(); 362 #endif 363 364 hash = gethash(); 365 errno = 0; 366 if (!crypt("", hash)) 367 die("slock: crypt: %s\n", strerror(errno)); 368 369 if (!(dpy = XOpenDisplay(NULL))) 370 die("slock: cannot open display\n"); 371 372 /* drop privileges */ 373 if (setgroups(0, NULL) < 0) 374 die("slock: setgroups: %s\n", strerror(errno)); 375 if (setgid(dgid) < 0) 376 die("slock: setgid: %s\n", strerror(errno)); 377 if (setuid(duid) < 0) 378 die("slock: setuid: %s\n", strerror(errno)); 379 380 /*Create screenshot Image*/ 381 Screen *scr = ScreenOfDisplay(dpy, DefaultScreen(dpy)); 382 image = imlib_create_image(scr->width,scr->height); 383 imlib_context_set_image(image); 384 imlib_context_set_display(dpy); 385 imlib_context_set_visual(DefaultVisual(dpy,0)); 386 imlib_context_set_drawable(RootWindow(dpy,XScreenNumberOfScreen(scr))); 387 imlib_copy_drawable_to_image(0,0,0,scr->width,scr->height,0,0,1); 388 389 #ifdef BLUR 390 391 /*Blur function*/ 392 imlib_image_blur(blurRadius); 393 #endif // BLUR 394 395 #ifdef PIXELATION 396 /*Pixelation*/ 397 int width = scr->width; 398 int height = scr->height; 399 400 for(int y = 0; y < height; y += pixelSize) 401 { 402 for(int x = 0; x < width; x += pixelSize) 403 { 404 int red = 0; 405 int green = 0; 406 int blue = 0; 407 408 Imlib_Color pixel; 409 Imlib_Color* pp; 410 pp = &pixel; 411 for(int j = 0; j < pixelSize && j < height; j++) 412 { 413 for(int i = 0; i < pixelSize && i < width; i++) 414 { 415 imlib_image_query_pixel(x+i,y+j,pp); 416 red += pixel.red; 417 green += pixel.green; 418 blue += pixel.blue; 419 } 420 } 421 red /= (pixelSize*pixelSize); 422 green /= (pixelSize*pixelSize); 423 blue /= (pixelSize*pixelSize); 424 imlib_context_set_color(red,green,blue,pixel.alpha); 425 imlib_image_fill_rectangle(x,y,pixelSize,pixelSize); 426 red = 0; 427 green = 0; 428 blue = 0; 429 } 430 } 431 432 433 #endif 434 /* check for Xrandr support */ 435 rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase); 436 437 /* get number of screens in display "dpy" and blank them */ 438 nscreens = ScreenCount(dpy); 439 if (!(locks = calloc(nscreens, sizeof(struct lock *)))) 440 die("slock: out of memory\n"); 441 for (nlocks = 0, s = 0; s < nscreens; s++) { 442 if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL) 443 nlocks++; 444 else 445 break; 446 } 447 XSync(dpy, 0); 448 449 /* did we manage to lock everything? */ 450 if (nlocks != nscreens) 451 return 1; 452 453 /* run post-lock command */ 454 if (argc > 0) { 455 pid_t pid; 456 extern char **environ; 457 int err = posix_spawnp(&pid, argv[0], NULL, NULL, argv, environ); 458 if (err) { 459 die("slock: failed to execute post-lock command: %s: %s\n", 460 argv[0], strerror(err)); 461 } 462 } 463 464 /* everything is now blank. Wait for the correct password */ 465 readpw(dpy, &rr, locks, nscreens, hash); 466 467 return 0; 468 }