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

   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/keysym.h>
  19 #include <X11/Xlib.h>
  20 #include <X11/Xutil.h>
  21 #include <X11/XF86keysym.h>
  22
  23 #include "arg.h"
  24 #include "util.h"
  25
  26 char *argv0;
  27
  28 enum {
  29         INIT,
  30         INPUT,
  31         FAILED,
  32         NUMCOLS
  33 };
  34
  35 struct lock {
  36         int screen;
  37         Window root, win;
  38         Pixmap pmap;
  39         unsigned long colors[NUMCOLS];
  40 };
  41
  42 struct xrandr {
  43         int active;
  44         int evbase;
  45         int errbase;
  46 };
  47
  48 #include "config.h"
  49
  50 static void
  51 die(const char *errstr, ...)
  52 {
  53         va_list ap;
  54
  55         va_start(ap, errstr);
  56         vfprintf(stderr, errstr, ap);
  57         va_end(ap);
  58         exit(1);
  59 }
  60
  61 #ifdef __linux__
  62 #include <fcntl.h>
  63 #include <linux/oom.h>
  64
  65 static void
  66 dontkillme(void)
  67 {
  68         FILE *f;
  69         const char oomfile[] = "/proc/self/oom_score_adj";
  70
  71         if (!(f = fopen(oomfile, "w"))) {
  72                 if (errno == ENOENT)
  73                         return;
  74                 die("slock: fopen %s: %s\n", oomfile, strerror(errno));
  75         }
  76         fprintf(f, "%d", OOM_SCORE_ADJ_MIN);
  77         if (fclose(f)) {
  78                 if (errno == EACCES)
  79                         die("slock: unable to disable OOM killer. "
  80                             "Make sure to suid or sgid slock.\n");
  81                 else
  82                         die("slock: fclose %s: %s\n", oomfile, strerror(errno));
  83         }
  84 }
  85 #endif
  86
  87 static const char *
  88 gethash(void)
  89 {
  90         const char *hash;
  91         struct passwd *pw;
  92
  93         /* Check if the current user has a password entry */
  94         errno = 0;
  95         if (!(pw = getpwuid(getuid()))) {
  96                 if (errno)
  97                         die("slock: getpwuid: %s\n", strerror(errno));
  98                 else
  99                         die("slock: cannot retrieve password entry\n");
 100         }
 101         hash = pw->pw_passwd;
 102
 103 #if HAVE_SHADOW_H
 104         if (!strcmp(hash, "x")) {
 105                 struct spwd *sp;
 106                 if (!(sp = getspnam(pw->pw_name)))
 107                         die("slock: getspnam: cannot retrieve shadow entry. "
 108                             "Make sure to suid or sgid slock.\n");
 109                 hash = sp->sp_pwdp;
 110         }
 111 #else
 112         if (!strcmp(hash, "*")) {
 113 #ifdef __OpenBSD__
 114                 if (!(pw = getpwuid_shadow(getuid())))
 115                         die("slock: getpwnam_shadow: cannot retrieve shadow entry. "
 116                             "Make sure to suid or sgid slock.\n");
 117                 hash = pw->pw_passwd;
 118 #else
 119                 die("slock: getpwuid: cannot retrieve shadow entry. "
 120                     "Make sure to suid or sgid slock.\n");
 121 #endif /* __OpenBSD__ */
 122         }
 123 #endif /* HAVE_SHADOW_H */
 124
 125         return hash;
 126 }
 127
 128 static void
 129 readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 130        const char *hash)
 131 {
 132         XRRScreenChangeNotifyEvent *rre;
 133         char buf[32], passwd[256], *inputhash;
 134         int num, screen, running, failure, oldc;
 135         unsigned int len, color;
 136         KeySym ksym;
 137         XEvent ev;
 138
 139         len = 0;
 140         running = 1;
 141         failure = 0;
 142         oldc = INIT;
 143
 144         while (running && !XNextEvent(dpy, &ev)) {
 145                 if (ev.type == KeyPress) {
 146                         explicit_bzero(&buf, sizeof(buf));
 147                         num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
 148                         if (IsKeypadKey(ksym)) {
 149                                 if (ksym == XK_KP_Enter)
 150                                         ksym = XK_Return;
 151                                 else if (ksym >= XK_KP_0 && ksym <= XK_KP_9)
 152                                         ksym = (ksym - XK_KP_0) + XK_0;
 153                         }
 154                         if (IsFunctionKey(ksym) ||
 155                             IsKeypadKey(ksym) ||
 156                             IsMiscFunctionKey(ksym) ||
 157                             IsPFKey(ksym) ||
 158                             IsPrivateKeypadKey(ksym))
 159                                 continue;
 160                         switch (ksym) {
 161       case XF86XK_AudioPlay:
 162       case XF86XK_AudioStop:
 163       case XF86XK_AudioPrev:
 164       case XF86XK_AudioNext:
 165       case XF86XK_AudioRaiseVolume:
 166       case XF86XK_AudioLowerVolume:
 167       case XF86XK_AudioMute:
 168       case XF86XK_AudioMicMute:
 169       case XF86XK_MonBrightnessDown:
 170       case XF86XK_MonBrightnessUp:
 171         XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
 172         break;
 173                         case XK_Return:
 174                                 passwd[len] = '\0';
 175                                 errno = 0;
 176                                 if (!(inputhash = crypt(passwd, hash)))
 177                                         fprintf(stderr, "slock: crypt: %s\n", strerror(errno));
 178                                 else
 179                                         running = !!strcmp(inputhash, hash);
 180                                 if (running) {
 181                                         XBell(dpy, 100);
 182                                         failure = 1;
 183                                 }
 184                                 explicit_bzero(&passwd, sizeof(passwd));
 185                                 len = 0;
 186                                 break;
 187                         case XK_Escape:
 188                                 explicit_bzero(&passwd, sizeof(passwd));
 189                                 len = 0;
 190                                 break;
 191                         case XK_BackSpace:
 192                                 if (len)
 193                                         passwd[--len] = '\0';
 194                                 break;
 195                         default:
 196                                 if (num && !iscntrl((int)buf[0]) &&
 197                                     (len + num < sizeof(passwd))) {
 198                                         memcpy(passwd + len, buf, num);
 199                                         len += num;
 200                                 }
 201                                 break;
 202                         }
 203                         color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
 204                         if (running && oldc != color) {
 205                                 for (screen = 0; screen < nscreens; screen++) {
 206                                         XSetWindowBackground(dpy,
 207                                                              locks[screen]->win,
 208                                                              locks[screen]->colors[color]);
 209                                         XClearWindow(dpy, locks[screen]->win);
 210                                 }
 211                                 oldc = color;
 212                         }
 213                 } else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
 214                         rre = (XRRScreenChangeNotifyEvent*)&ev;
 215                         for (screen = 0; screen < nscreens; screen++) {
 216                                 if (locks[screen]->win == rre->window) {
 217                                         if (rre->rotation == RR_Rotate_90 ||
 218                                             rre->rotation == RR_Rotate_270)
 219                                                 XResizeWindow(dpy, locks[screen]->win,
 220                                                               rre->height, rre->width);
 221                                         else
 222                                                 XResizeWindow(dpy, locks[screen]->win,
 223                                                               rre->width, rre->height);
 224                                         XClearWindow(dpy, locks[screen]->win);
 225                                         break;
 226                                 }
 227                         }
 228                 } else {
 229                         for (screen = 0; screen < nscreens; screen++)
 230                                 XRaiseWindow(dpy, locks[screen]->win);
 231                 }
 232         }
 233 }
 234
 235 static struct lock *
 236 lockscreen(Display *dpy, struct xrandr *rr, int screen)
 237 {
 238         char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
 239         int i, ptgrab, kbgrab;
 240         struct lock *lock;
 241         XColor color, dummy;
 242         XSetWindowAttributes wa;
 243         Cursor invisible;
 244
 245         if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
 246                 return NULL;
 247
 248         lock->screen = screen;
 249         lock->root = RootWindow(dpy, lock->screen);
 250
 251         for (i = 0; i < NUMCOLS; i++) {
 252                 XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen),
 253                                  colorname[i], &color, &dummy);
 254                 lock->colors[i] = color.pixel;
 255         }
 256
 257         /* init */
 258         wa.override_redirect = 1;
 259         wa.background_pixel = lock->colors[INIT];
 260         lock->win = XCreateWindow(dpy, lock->root, 0, 0,
 261                                   DisplayWidth(dpy, lock->screen),
 262                                   DisplayHeight(dpy, lock->screen),
 263                                   0, DefaultDepth(dpy, lock->screen),
 264                                   CopyFromParent,
 265                                   DefaultVisual(dpy, lock->screen),
 266                                   CWOverrideRedirect | CWBackPixel, &wa);
 267         lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
 268         invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap,
 269                                         &color, &color, 0, 0);
 270         XDefineCursor(dpy, lock->win, invisible);
 271
 272         /* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */
 273         for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) {
 274                 if (ptgrab != GrabSuccess) {
 275                         ptgrab = XGrabPointer(dpy, lock->root, False,
 276                                               ButtonPressMask | ButtonReleaseMask |
 277                                               PointerMotionMask, GrabModeAsync,
 278                                               GrabModeAsync, None, invisible, CurrentTime);
 279                 }
 280                 if (kbgrab != GrabSuccess) {
 281                         kbgrab = XGrabKeyboard(dpy, lock->root, True,
 282                                                GrabModeAsync, GrabModeAsync, CurrentTime);
 283                 }
 284
 285                 /* input is grabbed: we can lock the screen */
 286                 if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
 287                         XMapRaised(dpy, lock->win);
 288                         if (rr->active)
 289                                 XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
 290
 291                         XSelectInput(dpy, lock->root, SubstructureNotifyMask);
 292                         return lock;
 293                 }
 294
 295                 /* retry on AlreadyGrabbed but fail on other errors */
 296                 if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) ||
 297                     (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess))
 298                         break;
 299
 300                 usleep(100000);
 301         }
 302
 303         /* we couldn't grab all input: fail out */
 304         if (ptgrab != GrabSuccess)
 305                 fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n",
 306                         screen);
 307         if (kbgrab != GrabSuccess)
 308                 fprintf(stderr, "slock: unable to grab keyboard for screen %d\n",
 309                         screen);
 310         return NULL;
 311 }
 312
 313 static void
 314 usage(void)
 315 {
 316         die("usage: slock [-v] [cmd [arg ...]]\n");
 317 }
 318
 319 int
 320 main(int argc, char **argv) {
 321         struct xrandr rr;
 322         struct lock **locks;
 323         struct passwd *pwd;
 324         struct group *grp;
 325         uid_t duid;
 326         gid_t dgid;
 327         const char *hash;
 328         Display *dpy;
 329         int s, nlocks, nscreens;
 330
 331         ARGBEGIN {
 332         case 'v':
 333                 fprintf(stderr, "slock-"VERSION"\n");
 334                 return 0;
 335         default:
 336                 usage();
 337         } ARGEND
 338
 339         /* validate drop-user and -group */
 340         errno = 0;
 341         if (!(pwd = getpwnam(user)))
 342                 die("slock: getpwnam %s: %s\n", user,
 343                     errno ? strerror(errno) : "user entry not found");
 344         duid = pwd->pw_uid;
 345         errno = 0;
 346         if (!(grp = getgrnam(group)))
 347                 die("slock: getgrnam %s: %s\n", group,
 348                     errno ? strerror(errno) : "group entry not found");
 349         dgid = grp->gr_gid;
 350
 351 #ifdef __linux__
 352         dontkillme();
 353 #endif
 354
 355         hash = gethash();
 356         errno = 0;
 357         if (!crypt("", hash))
 358                 die("slock: crypt: %s\n", strerror(errno));
 359
 360         if (!(dpy = XOpenDisplay(NULL)))
 361                 die("slock: cannot open display\n");
 362
 363         /* drop privileges */
 364         if (setgroups(0, NULL) < 0)
 365                 die("slock: setgroups: %s\n", strerror(errno));
 366         if (setgid(dgid) < 0)
 367                 die("slock: setgid: %s\n", strerror(errno));
 368         if (setuid(duid) < 0)
 369                 die("slock: setuid: %s\n", strerror(errno));
 370
 371         /* check for Xrandr support */
 372         rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase);
 373
 374         /* get number of screens in display "dpy" and blank them */
 375         nscreens = ScreenCount(dpy);
 376         if (!(locks = calloc(nscreens, sizeof(struct lock *))))
 377                 die("slock: out of memory\n");
 378         for (nlocks = 0, s = 0; s < nscreens; s++) {
 379                 if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
 380                         nlocks++;
 381                 else
 382                         break;
 383         }
 384         XSync(dpy, 0);
 385
 386         /* did we manage to lock everything? */
 387         if (nlocks != nscreens)
 388                 return 1;
 389
 390         /* run post-lock command */
 391         if (argc > 0) {
 392                 switch (fork()) {
 393                 case -1:
 394                         die("slock: fork failed: %s\n", strerror(errno));
 395                 case 0:
 396                         if (close(ConnectionNumber(dpy)) < 0)
 397                                 die("slock: close: %s\n", strerror(errno));
 398                         execvp(argv[0], argv);
 399                         fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno));
 400                         _exit(1);
 401                 }
 402         }
 403
 404         /* everything is now blank. Wait for the correct password */
 405         readpw(dpy, &rr, locks, nscreens, hash);
 406
 407         return 0;
 408 }