Git of dcc - dcc-suckless-config/blob - slock/slock.c

   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 <sys/types.h>
  17 #include <X11/extensions/Xrandr.h>
  18 #include <X11/extensions/Xinerama.h>
  19 #include <X11/keysym.h>
  20 #include <X11/Xlib.h>
  21 #include <X11/Xutil.h>
  22 #include <X11/XF86keysym.h>
  23
  24 #include "arg.h"
  25 #include "util.h"
  26
  27 char *argv0;
  28
  29 /* global count to prevent repeated error messages */
  30 int count_error = 0;
  31
  32 enum {
  33         INIT,
  34         INPUT,
  35         FAILED,
  36         NUMCOLS
  37 };
  38
  39 struct lock {
  40         int screen;
  41         Window root, win;
  42         Pixmap pmap;
  43         unsigned long colors[NUMCOLS];
  44 };
  45
  46 struct xrandr {
  47         int active;
  48         int evbase;
  49         int errbase;
  50 };
  51
  52 #include "config.h"
  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 void
  92 writemessage(Display *dpy, Window win, int screen)
  93 {
  94         int len, line_len, width, height, s_width, s_height, i, j, k, tab_replace, tab_size;
  95         XGCValues gr_values;
  96         XFontStruct *fontinfo;
  97         XColor color, dummy;
  98         XineramaScreenInfo *xsi;
  99         GC gc;
 100         fontinfo = XLoadQueryFont(dpy, font_name);
 101
 102         if (fontinfo == NULL) {
 103                 if (count_error == 0) {
 104                         fprintf(stderr, "slock: Unable to load font \"%s\"\n", font_name);
 105                         fprintf(stderr, "slock: Try listing fonts with 'slock -f'\n");
 106                         count_error++;
 107                 }
 108                 return;
 109         }
 110
 111         tab_size = 8 * XTextWidth(fontinfo, " ", 1);
 112
 113         XAllocNamedColor(dpy, DefaultColormap(dpy, screen),
 114                  text_color, &color, &dummy);
 115
 116         gr_values.font = fontinfo->fid;
 117         gr_values.foreground = color.pixel;
 118         gc=XCreateGC(dpy,win,GCFont+GCForeground, &gr_values);
 119
 120         /*  To prevent "Uninitialized" warnings. */
 121         xsi = NULL;
 122
 123         /*
 124          * Start formatting and drawing text
 125          */
 126
 127         len = strlen(message);
 128
 129         /* Max max line length (cut at '\n') */
 130         line_len = 0;
 131         k = 0;
 132         for (i = j = 0; i < len; i++) {
 133                 if (message[i] == '\n') {
 134                         if (i - j > line_len)
 135                                 line_len = i - j;
 136                         k++;
 137                         i++;
 138                         j = i;
 139                 }
 140         }
 141         /* If there is only one line */
 142         if (line_len == 0)
 143                 line_len = len;
 144
 145         if (XineramaIsActive(dpy)) {
 146                 xsi = XineramaQueryScreens(dpy, &i);
 147                 s_width = xsi[0].width;
 148                 s_height = xsi[0].height;
 149         } else {
 150                 s_width = DisplayWidth(dpy, screen);
 151                 s_height = DisplayHeight(dpy, screen);
 152         }
 153
 154         height = s_height*3/7 - (k*20)/3;
 155         width  = (s_width - XTextWidth(fontinfo, message, line_len))/2;
 156
 157         /* Look for '\n' and print the text between them. */
 158         for (i = j = k = 0; i <= len; i++) {
 159                 /* i == len is the special case for the last line */
 160                 if (i == len || message[i] == '\n') {
 161                         tab_replace = 0;
 162                         while (message[j] == '\t' && j < i) {
 163                                 tab_replace++;
 164                                 j++;
 165                         }
 166
 167                         XDrawString(dpy, win, gc, width + tab_size*tab_replace, height + 20*k, message + j, i - j);
 168                         while (i < len && message[i] == '\n') {
 169                                 i++;
 170                                 j = i;
 171                                 k++;
 172                         }
 173                 }
 174         }
 175
 176         /* xsi should not be NULL anyway if Xinerama is active, but to be safe */
 177         if (XineramaIsActive(dpy) && xsi != NULL)
 178                         XFree(xsi);
 179 }
 180
 181
 182
 183 static const char *
 184 gethash(void)
 185 {
 186         const char *hash;
 187         struct passwd *pw;
 188
 189         /* Check if the current user has a password entry */
 190         errno = 0;
 191         if (!(pw = getpwuid(getuid()))) {
 192                 if (errno)
 193                         die("slock: getpwuid: %s\n", strerror(errno));
 194                 else
 195                         die("slock: cannot retrieve password entry\n");
 196         }
 197         hash = pw->pw_passwd;
 198
 199 #if HAVE_SHADOW_H
 200         if (!strcmp(hash, "x")) {
 201                 struct spwd *sp;
 202                 if (!(sp = getspnam(pw->pw_name)))
 203                         die("slock: getspnam: cannot retrieve shadow entry. "
 204                             "Make sure to suid or sgid slock.\n");
 205                 hash = sp->sp_pwdp;
 206         }
 207 #else
 208         if (!strcmp(hash, "*")) {
 209 #ifdef __OpenBSD__
 210                 if (!(pw = getpwuid_shadow(getuid())))
 211                         die("slock: getpwnam_shadow: cannot retrieve shadow entry. "
 212                             "Make sure to suid or sgid slock.\n");
 213                 hash = pw->pw_passwd;
 214 #else
 215                 die("slock: getpwuid: cannot retrieve shadow entry. "
 216                     "Make sure to suid or sgid slock.\n");
 217 #endif /* __OpenBSD__ */
 218         }
 219 #endif /* HAVE_SHADOW_H */
 220
 221         return hash;
 222 }
 223
 224 static void
 225 readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 226        const char *hash)
 227 {
 228         XRRScreenChangeNotifyEvent *rre;
 229         char buf[32], passwd[256], *inputhash;
 230         int num, screen, running, failure, oldc;
 231         unsigned int len, color;
 232         KeySym ksym;
 233         XEvent ev;
 234
 235         len = 0;
 236         running = 1;
 237         failure = 0;
 238         oldc = INIT;
 239
 240         while (running && !XNextEvent(dpy, &ev)) {
 241                 if (ev.type == KeyPress) {
 242                         explicit_bzero(&buf, sizeof(buf));
 243                         num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
 244                         if (IsKeypadKey(ksym)) {
 245                                 if (ksym == XK_KP_Enter)
 246                                         ksym = XK_Return;
 247                                 else if (ksym >= XK_KP_0 && ksym <= XK_KP_9)
 248                                         ksym = (ksym - XK_KP_0) + XK_0;
 249                         }
 250                         if (IsFunctionKey(ksym) ||
 251                             IsKeypadKey(ksym) ||
 252                             IsMiscFunctionKey(ksym) ||
 253                             IsPFKey(ksym) ||
 254                             IsPrivateKeypadKey(ksym))
 255                                 continue;
 256                         switch (ksym) {
 257       case XF86XK_AudioPlay:
 258       case XF86XK_AudioStop:
 259       case XF86XK_AudioPrev:
 260       case XF86XK_AudioNext:
 261       case XF86XK_AudioRaiseVolume:
 262       case XF86XK_AudioLowerVolume:
 263       case XF86XK_AudioMute:
 264       case XF86XK_AudioMicMute:
 265       case XF86XK_MonBrightnessDown:
 266       case XF86XK_MonBrightnessUp:
 267         XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
 268         break;
 269                         case XK_Return:
 270                                 passwd[len] = '\0';
 271                                 errno = 0;
 272                                 if (!(inputhash = crypt(passwd, hash)))
 273                                         fprintf(stderr, "slock: crypt: %s\n", strerror(errno));
 274                                 else
 275                                         running = !!strcmp(inputhash, hash);
 276                                 if (running) {
 277                                         XBell(dpy, 100);
 278                                         failure = 1;
 279                                 }
 280                                 explicit_bzero(&passwd, sizeof(passwd));
 281                                 len = 0;
 282                                 break;
 283                         case XK_Escape:
 284                                 explicit_bzero(&passwd, sizeof(passwd));
 285                                 len = 0;
 286                                 break;
 287                         case XK_BackSpace:
 288                                 if (len)
 289                                         passwd[--len] = '\0';
 290                                 break;
 291                         default:
 292                                 if (num && !iscntrl((int)buf[0]) &&
 293                                     (len + num < sizeof(passwd))) {
 294                                         memcpy(passwd + len, buf, num);
 295                                         len += num;
 296                                 }
 297                                 break;
 298                         }
 299                         color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
 300                         if (running && oldc != color) {
 301                                 for (screen = 0; screen < nscreens; screen++) {
 302                                         XSetWindowBackground(dpy,
 303                                                              locks[screen]->win,
 304                                                              locks[screen]->colors[color]);
 305                                         XClearWindow(dpy, locks[screen]->win);
 306                                         writemessage(dpy, locks[screen]->win, screen);
 307                                 }
 308                                 oldc = color;
 309                         }
 310                 } else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
 311                         rre = (XRRScreenChangeNotifyEvent*)&ev;
 312                         for (screen = 0; screen < nscreens; screen++) {
 313                                 if (locks[screen]->win == rre->window) {
 314                                         if (rre->rotation == RR_Rotate_90 ||
 315                                             rre->rotation == RR_Rotate_270)
 316                                                 XResizeWindow(dpy, locks[screen]->win,
 317                                                               rre->height, rre->width);
 318                                         else
 319                                                 XResizeWindow(dpy, locks[screen]->win,
 320                                                               rre->width, rre->height);
 321                                         XClearWindow(dpy, locks[screen]->win);
 322                                         break;
 323                                 }
 324                         }
 325                 } else {
 326                         for (screen = 0; screen < nscreens; screen++)
 327                                 XRaiseWindow(dpy, locks[screen]->win);
 328                 }
 329         }
 330 }
 331
 332 static struct lock *
 333 lockscreen(Display *dpy, struct xrandr *rr, int screen)
 334 {
 335         char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
 336         int i, ptgrab, kbgrab;
 337         struct lock *lock;
 338         XColor color, dummy;
 339         XSetWindowAttributes wa;
 340         Cursor invisible;
 341
 342         if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
 343                 return NULL;
 344
 345         lock->screen = screen;
 346         lock->root = RootWindow(dpy, lock->screen);
 347
 348         for (i = 0; i < NUMCOLS; i++) {
 349                 XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen),
 350                                  colorname[i], &color, &dummy);
 351                 lock->colors[i] = color.pixel;
 352         }
 353
 354         /* init */
 355         wa.override_redirect = 1;
 356         wa.background_pixel = lock->colors[INIT];
 357         lock->win = XCreateWindow(dpy, lock->root, 0, 0,
 358                                   DisplayWidth(dpy, lock->screen),
 359                                   DisplayHeight(dpy, lock->screen),
 360                                   0, DefaultDepth(dpy, lock->screen),
 361                                   CopyFromParent,
 362                                   DefaultVisual(dpy, lock->screen),
 363                                   CWOverrideRedirect | CWBackPixel, &wa);
 364         lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
 365         invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap,
 366                                         &color, &color, 0, 0);
 367         XDefineCursor(dpy, lock->win, invisible);
 368
 369         /* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */
 370         for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) {
 371                 if (ptgrab != GrabSuccess) {
 372                         ptgrab = XGrabPointer(dpy, lock->root, False,
 373                                               ButtonPressMask | ButtonReleaseMask |
 374                                               PointerMotionMask, GrabModeAsync,
 375                                               GrabModeAsync, None, invisible, CurrentTime);
 376                 }
 377                 if (kbgrab != GrabSuccess) {
 378                         kbgrab = XGrabKeyboard(dpy, lock->root, True,
 379                                                GrabModeAsync, GrabModeAsync, CurrentTime);
 380                 }
 381
 382                 /* input is grabbed: we can lock the screen */
 383                 if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
 384                         XMapRaised(dpy, lock->win);
 385                         if (rr->active)
 386                                 XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
 387
 388                         XSelectInput(dpy, lock->root, SubstructureNotifyMask);
 389                         return lock;
 390                 }
 391
 392                 /* retry on AlreadyGrabbed but fail on other errors */
 393                 if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) ||
 394                     (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess))
 395                         break;
 396
 397                 usleep(100000);
 398         }
 399
 400         /* we couldn't grab all input: fail out */
 401         if (ptgrab != GrabSuccess)
 402                 fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n",
 403                         screen);
 404         if (kbgrab != GrabSuccess)
 405                 fprintf(stderr, "slock: unable to grab keyboard for screen %d\n",
 406                         screen);
 407         return NULL;
 408 }
 409
 410 static void
 411 usage(void)
 412 {
 413         die("usage: slock [-v] [-f] [-m message] [cmd [arg ...]]\n");
 414 }
 415
 416 int
 417 main(int argc, char **argv) {
 418         struct xrandr rr;
 419         struct lock **locks;
 420         struct passwd *pwd;
 421         struct group *grp;
 422         uid_t duid;
 423         gid_t dgid;
 424         const char *hash;
 425         Display *dpy;
 426         int i, s, nlocks, nscreens;
 427         int count_fonts;
 428         char **font_names;
 429
 430         ARGBEGIN {
 431         case 'v':
 432                 fprintf(stderr, "slock-"VERSION"\n");
 433                 return 0;
 434         case 'm':
 435                 message = EARGF(usage());
 436                 break;
 437         case 'f':
 438                 if (!(dpy = XOpenDisplay(NULL)))
 439                         die("slock: cannot open display\n");
 440                 font_names = XListFonts(dpy, "*", 10000 /* list 10000 fonts*/, &count_fonts);
 441                 for (i=0; i<count_fonts; i++) {
 442                         fprintf(stderr, "%s\n", *(font_names+i));
 443                 }
 444                 return 0;
 445         default:
 446                 usage();
 447         } ARGEND
 448
 449         /* validate drop-user and -group */
 450         errno = 0;
 451         if (!(pwd = getpwnam(user)))
 452                 die("slock: getpwnam %s: %s\n", user,
 453                     errno ? strerror(errno) : "user entry not found");
 454         duid = pwd->pw_uid;
 455         errno = 0;
 456         if (!(grp = getgrnam(group)))
 457                 die("slock: getgrnam %s: %s\n", group,
 458                     errno ? strerror(errno) : "group entry not found");
 459         dgid = grp->gr_gid;
 460
 461 #ifdef __linux__
 462         dontkillme();
 463 #endif
 464
 465         hash = gethash();
 466         errno = 0;
 467         if (!crypt("", hash))
 468                 die("slock: crypt: %s\n", strerror(errno));
 469
 470         if (!(dpy = XOpenDisplay(NULL)))
 471                 die("slock: cannot open display\n");
 472
 473         /* drop privileges */
 474         if (setgroups(0, NULL) < 0)
 475                 die("slock: setgroups: %s\n", strerror(errno));
 476         if (setgid(dgid) < 0)
 477                 die("slock: setgid: %s\n", strerror(errno));
 478         if (setuid(duid) < 0)
 479                 die("slock: setuid: %s\n", strerror(errno));
 480
 481         /* check for Xrandr support */
 482         rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase);
 483
 484         /* get number of screens in display "dpy" and blank them */
 485         nscreens = ScreenCount(dpy);
 486         if (!(locks = calloc(nscreens, sizeof(struct lock *))))
 487                 die("slock: out of memory\n");
 488         for (nlocks = 0, s = 0; s < nscreens; s++) {
 489                 if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL) {
 490                         writemessage(dpy, locks[s]->win, s);
 491                         nlocks++;
 492                 } else {
 493                         break;
 494                 }
 495         }
 496         XSync(dpy, 0);
 497
 498         /* did we manage to lock everything? */
 499         if (nlocks != nscreens)
 500                 return 1;
 501
 502         /* run post-lock command */
 503         if (argc > 0) {
 504                 switch (fork()) {
 505                 case -1:
 506                         die("slock: fork failed: %s\n", strerror(errno));
 507                 case 0:
 508                         if (close(ConnectionNumber(dpy)) < 0)
 509                                 die("slock: close: %s\n", strerror(errno));
 510                         execvp(argv[0], argv);
 511                         fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno));
 512                         _exit(1);
 513                 }
 514         }
 515
 516         /* everything is now blank. Wait for the correct password */
 517         readpw(dpy, &rr, locks, nscreens, hash);
 518
 519         return 0;
 520 }