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 <pwd.h>
   9 #include <stdarg.h>
  10 #include <stdlib.h>
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <sys/types.h>
  15 #include <X11/keysym.h>
  16 #include <X11/Xlib.h>
  17 #include <X11/Xutil.h>
  18 #include <X11/extensions/dpms.h>
  19
  20 #if HAVE_BSD_AUTH
  21 #include <login_cap.h>
  22 #include <bsd_auth.h>
  23 #endif
  24
  25 void
  26 eprint(const char *errstr, ...) {
  27         va_list ap;
  28
  29         va_start(ap, errstr);
  30         vfprintf(stderr, errstr, ap);
  31         va_end(ap);
  32         exit(EXIT_FAILURE);
  33 }
  34
  35 #ifndef HAVE_BSD_AUTH
  36 const char *
  37 get_password() { /* only run as root */
  38         const char *rval;
  39         struct passwd *pw;
  40
  41         if(geteuid() != 0)
  42                 eprint("slock: cannot retrieve password entry (make sure to suid slock)\n");
  43         pw = getpwuid(getuid());
  44         endpwent();
  45         rval =  pw->pw_passwd;
  46
  47 #if HAVE_SHADOW_H
  48         {
  49                 struct spwd *sp;
  50                 sp = getspnam(getenv("USER"));
  51                 endspent();
  52                 rval = sp->sp_pwdp;
  53         }
  54 #endif
  55
  56         /* drop privileges */
  57         if(setgid(pw->pw_gid) < 0 || setuid(pw->pw_uid) < 0)
  58                 eprint("slock: cannot drop privileges\n");
  59         return rval;
  60 }
  61 #endif
  62
  63 int
  64 main(int argc, char **argv) {
  65         char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
  66         char buf[32], passwd[256];
  67         int num, screen;
  68
  69 #ifndef HAVE_BSD_AUTH
  70         const char *pws;
  71 #endif
  72         unsigned int len;
  73         Bool running = True;
  74         Cursor invisible;
  75         Display *dpy;
  76         KeySym ksym;
  77         Pixmap pmap;
  78         Window root, w;
  79         XColor black, dummy;
  80         XEvent ev;
  81         XSetWindowAttributes wa;
  82
  83         if((argc == 2) && !strcmp("-v", argv[1]))
  84                 eprint("slock-"VERSION", © 2006-2008 Anselm R Garbe\n");
  85         else if(argc != 1)
  86                 eprint("usage: slock [-v]\n");
  87
  88 #ifndef HAVE_BSD_AUTH
  89         pws = get_password();
  90 #endif
  91
  92         if(!(dpy = XOpenDisplay(0)))
  93                 eprint("slock: cannot open display\n");
  94         screen = DefaultScreen(dpy);
  95         root = RootWindow(dpy, screen);
  96
  97         /* init */
  98         wa.override_redirect = 1;
  99         wa.background_pixel = BlackPixel(dpy, screen);
 100         w = XCreateWindow(dpy, root, 0, 0, DisplayWidth(dpy, screen), DisplayHeight(dpy, screen),
 101                         0, DefaultDepth(dpy, screen), CopyFromParent,
 102                         DefaultVisual(dpy, screen), CWOverrideRedirect | CWBackPixel, &wa);
 103         XAllocNamedColor(dpy, DefaultColormap(dpy, screen), "black", &black, &dummy);
 104         pmap = XCreateBitmapFromData(dpy, w, curs, 8, 8);
 105         invisible = XCreatePixmapCursor(dpy, pmap, pmap, &black, &black, 0, 0);
 106         XDefineCursor(dpy, w, invisible);
 107         XMapRaised(dpy, w);
 108         for(len = 1000; len; len--) {
 109                 if(XGrabPointer(dpy, root, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
 110                         GrabModeAsync, GrabModeAsync, None, invisible, CurrentTime) == GrabSuccess)
 111                         break;
 112                 usleep(1000);
 113         }
 114         if((running = running && (len > 0))) {
 115                 for(len = 1000; len; len--) {
 116                         if(XGrabKeyboard(dpy, root, True, GrabModeAsync, GrabModeAsync, CurrentTime)
 117                                 == GrabSuccess)
 118                                 break;
 119                         usleep(1000);
 120                 }
 121                 running = (len > 0);
 122         }
 123         len = 0;
 124         XSync(dpy, False);
 125
 126         /* main event loop */
 127         while(running && !XNextEvent(dpy, &ev)) {
 128                 if(len == 0 && DPMSCapable(dpy)) {
 129                         DPMSEnabled(dpy);
 130                         DPMSForceLevel(dpy, DPMSModeOff);
 131                 }
 132                 if(ev.type == KeyPress) {
 133                         buf[0] = 0;
 134                         num = XLookupString(&ev.xkey, buf, sizeof buf, &ksym, 0);
 135                         if(IsKeypadKey(ksym))
 136                                 if(ksym == XK_KP_Enter)
 137                                         ksym = XK_Return;
 138                                 else if(ksym >= XK_KP_0 && ksym <= XK_KP_9)
 139                                         ksym = (ksym - XK_KP_0) + XK_0;
 140                         if(IsFunctionKey(ksym) || IsKeypadKey(ksym)
 141                                         || IsMiscFunctionKey(ksym) || IsPFKey(ksym)
 142                                         || IsPrivateKeypadKey(ksym))
 143                                 continue;
 144                         switch(ksym) {
 145                         case XK_Return:
 146                                 passwd[len] = 0;
 147
 148 #ifdef HAVE_BSD_AUTH
 149                                 running = !auth_userokay(getlogin(), NULL, "auth-xlock", passwd);
 150 #else
 151                                 running = strcmp(crypt(passwd, pws), pws);
 152 #endif
 153
 154                                 if (running != 0)
 155                                         XBell(dpy, 100);
 156                                 len = 0;
 157                                 break;
 158                         case XK_Escape:
 159                                 len = 0;
 160                                 break;
 161                         case XK_BackSpace:
 162                                 if(len)
 163                                         --len;
 164                                 break;
 165                         default:
 166                                 if(num && !iscntrl((int) buf[0]) && (len + num < sizeof passwd)) {
 167                                         memcpy(passwd + len, buf, num);
 168                                         len += num;
 169                                 }
 170                                 break;
 171                         }
 172                 }
 173         }
 174         XUngrabPointer(dpy, CurrentTime);
 175         XFreePixmap(dpy, pmap);
 176         XDestroyWindow(dpy, w);
 177         XCloseDisplay(dpy);
 178         return 0;
 179 }