slock.c - slock - [fork] simple X display locker utility
HTML git clone https://git.drkhsh.at/slock.git
DIR Log
DIR Files
DIR Refs
DIR README
DIR LICENSE
---
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 }