X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=slock.c;h=d2f08862453615c3131332273fbd1d0187f4195c;hb=7d31ff65a0b0388f788ca6932c815ab29e5fb10f;hp=b3bee92db6621586953d821d03fed574e04ca133;hpb=0edbd2e0164a8c6cbad415e38083469041f29996;p=slock.git diff --git a/slock.c b/slock.c index b3bee92..d2f0886 100644 --- a/slock.c +++ b/slock.c @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -18,10 +19,10 @@ #include #include -#if HAVE_BSD_AUTH -#include -#include -#endif +#include "arg.h" +#include "util.h" + +char *argv0; enum { INIT, @@ -30,22 +31,20 @@ enum { NUMCOLS }; -#include "config.h" - -typedef struct { +struct lock { int screen; Window root, win; Pixmap pmap; unsigned long colors[NUMCOLS]; -} Lock; +}; -static Lock **locks; -static int nscreens; -static Bool running = True; -static Bool failure = False; -static Bool rr; -static int rrevbase; -static int rrerrbase; +struct xrandr { + int active; + int evbase; + int errbase; +}; + +#include "config.h" static void die(const char *errstr, ...) @@ -65,86 +64,85 @@ die(const char *errstr, ...) static void dontkillme(void) { - int fd; - int length; - char value[64]; - - fd = open("/proc/self/oom_score_adj", O_WRONLY); - if (fd < 0 && errno == ENOENT) - return; + FILE *f; + const char oomfile[] = "/proc/self/oom_score_adj"; - /* convert OOM_SCORE_ADJ_MIN to string for writing */ - length = snprintf(value, sizeof(value), "%d\n", OOM_SCORE_ADJ_MIN); - - /* bail on truncation */ - if (length >= sizeof(value)) - die("buffer too small\n"); - - if (fd < 0 || write(fd, value, length) != length || close(fd) != 0) - die("cannot disable the out-of-memory killer for this process\n"); + if (!(f = fopen(oomfile, "w"))) { + if (errno == ENOENT) + return; + die("slock: fopen %s: %s\n", oomfile, strerror(errno)); + } + fprintf(f, "%d", OOM_SCORE_ADJ_MIN); + if (fclose(f)) { + if (errno == EACCES) + die("slock: unable to disable OOM killer. " + "Make sure to suid or sgid slock.\n"); + else + die("slock: fclose %s: %s\n", oomfile, strerror(errno)); + } } #endif -#ifndef HAVE_BSD_AUTH -/* only run as root */ static const char * -getpw(void) +gethash(void) { - const char *rval; + const char *hash; struct passwd *pw; + /* Check if the current user has a password entry */ errno = 0; - pw = getpwuid(getuid()); - if (!pw) { + if (!(pw = getpwuid(getuid()))) { if (errno) die("slock: getpwuid: %s\n", strerror(errno)); else die("slock: cannot retrieve password entry\n"); } - rval = pw->pw_passwd; + hash = pw->pw_passwd; #if HAVE_SHADOW_H - if (rval[0] == 'x' && rval[1] == '\0') { + if (!strcmp(hash, "x")) { struct spwd *sp; - sp = getspnam(getenv("USER")); - if (!sp) - die("slock: cannot retrieve shadow entry (make sure to suid or sgid slock)\n"); - rval = sp->sp_pwdp; + if (!(sp = getspnam(pw->pw_name))) + die("slock: getspnam: cannot retrieve shadow entry. " + "Make sure to suid or sgid slock.\n"); + hash = sp->sp_pwdp; } -#endif +#else + if (!strcmp(hash, "*")) { +#ifdef __OpenBSD__ + if (!(pw = getpwuid_shadow(getuid()))) + die("slock: getpwnam_shadow: cannot retrieve shadow entry. " + "Make sure to suid or sgid slock.\n"); + hash = pw->pw_passwd; +#else + die("slock: getpwuid: cannot retrieve shadow entry. " + "Make sure to suid or sgid slock.\n"); +#endif /* __OpenBSD__ */ + } +#endif /* HAVE_SHADOW_H */ - /* drop privileges */ - if (geteuid() == 0 && - ((getegid() != pw->pw_gid && setgid(pw->pw_gid) < 0) || setuid(pw->pw_uid) < 0)) - die("slock: cannot drop privileges\n"); - return rval; + return hash; } -#endif static void -#ifdef HAVE_BSD_AUTH -readpw(Display *dpy) -#else -readpw(Display *dpy, const char *pws) -#endif +readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens, + const char *hash) { - char buf[32], passwd[256]; - int num, screen; + XRRScreenChangeNotifyEvent *rre; + char buf[32], passwd[256], *inputhash; + int num, screen, running, failure, oldc; unsigned int len, color; KeySym ksym; XEvent ev; - static int oldc = INIT; len = 0; - running = True; + running = 1; + failure = 0; + oldc = INIT; - /* As "slock" stands for "Simple X display locker", the DPMS settings - * had been removed and you can set it with "xset" or some other - * utility. This way the user can easily set a customized DPMS - * timeout. */ while (running && !XNextEvent(dpy, &ev)) { if (ev.type == KeyPress) { - buf[0] = 0; + explicit_bzero(&buf, sizeof(buf)); num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0); if (IsKeypadKey(ksym)) { if (ksym == XK_KP_Enter) @@ -160,45 +158,51 @@ readpw(Display *dpy, const char *pws) continue; switch (ksym) { case XK_Return: - passwd[len] = 0; -#ifdef HAVE_BSD_AUTH - running = !auth_userokay(getlogin(), NULL, "auth-xlock", passwd); -#else - running = !!strcmp(crypt(passwd, pws), pws); -#endif + passwd[len] = '\0'; + errno = 0; + if (!(inputhash = crypt(passwd, hash))) + fprintf(stderr, "slock: crypt: %s\n", strerror(errno)); + else + running = !!strcmp(inputhash, hash); if (running) { XBell(dpy, 100); - failure = True; + failure = 1; } + explicit_bzero(&passwd, sizeof(passwd)); len = 0; break; case XK_Escape: + explicit_bzero(&passwd, sizeof(passwd)); len = 0; break; case XK_BackSpace: if (len) - --len; + passwd[len--] = '\0'; break; default: - if (num && !iscntrl((int) buf[0]) && (len + num < sizeof(passwd))) { + if (num && !iscntrl((int)buf[0]) && + (len + num < sizeof(passwd))) { memcpy(passwd + len, buf, num); len += num; } break; } - color = len ? INPUT : (failure || failonclear ? FAILED : INIT); - if (oldc != color) { + color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT); + if (running && oldc != color) { for (screen = 0; screen < nscreens; screen++) { - XSetWindowBackground(dpy, locks[screen]->win, locks[screen]->colors[color]); + XSetWindowBackground(dpy, + locks[screen]->win, + locks[screen]->colors[color]); XClearWindow(dpy, locks[screen]->win); } oldc = color; } - } else if (rr && ev.type == rrevbase + RRScreenChangeNotify) { - XRRScreenChangeNotifyEvent *rre = (XRRScreenChangeNotifyEvent*)&ev; + } else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) { + rre = (XRRScreenChangeNotifyEvent*)&ev; for (screen = 0; screen < nscreens; screen++) { if (locks[screen]->win == rre->window) { - XResizeWindow(dpy, locks[screen]->win, rre->width, rre->height); + XResizeWindow(dpy, locks[screen]->win, + rre->width, rre->height); XClearWindow(dpy, locks[screen]->win); } } @@ -207,151 +211,177 @@ readpw(Display *dpy, const char *pws) } } -static void -unlockscreen(Display *dpy, Lock *lock) -{ - if(dpy == NULL || lock == NULL) - return; - - XUngrabPointer(dpy, CurrentTime); - XFreeColors(dpy, DefaultColormap(dpy, lock->screen), lock->colors, NUMCOLS, 0); - XFreePixmap(dpy, lock->pmap); - XDestroyWindow(dpy, lock->win); - - free(lock); -} - -static Lock * -lockscreen(Display *dpy, int screen) +static struct lock * +lockscreen(Display *dpy, struct xrandr *rr, int screen) { char curs[] = {0, 0, 0, 0, 0, 0, 0, 0}; - unsigned int len; - int i; - Lock *lock; + int i, ptgrab, kbgrab; + struct lock *lock; XColor color, dummy; XSetWindowAttributes wa; Cursor invisible; - if (dpy == NULL || screen < 0) - return NULL; - - lock = malloc(sizeof(Lock)); - if (lock == NULL) + if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock)))) return NULL; lock->screen = screen; - lock->root = RootWindow(dpy, lock->screen); for (i = 0; i < NUMCOLS; i++) { - XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen), colorname[i], &color, &dummy); + XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen), + colorname[i], &color, &dummy); lock->colors[i] = color.pixel; } /* init */ wa.override_redirect = 1; wa.background_pixel = lock->colors[INIT]; - lock->win = XCreateWindow(dpy, lock->root, 0, 0, DisplayWidth(dpy, lock->screen), DisplayHeight(dpy, lock->screen), - 0, DefaultDepth(dpy, lock->screen), CopyFromParent, - DefaultVisual(dpy, lock->screen), CWOverrideRedirect | CWBackPixel, &wa); + lock->win = XCreateWindow(dpy, lock->root, 0, 0, + DisplayWidth(dpy, lock->screen), + DisplayHeight(dpy, lock->screen), + 0, DefaultDepth(dpy, lock->screen), + CopyFromParent, + DefaultVisual(dpy, lock->screen), + CWOverrideRedirect | CWBackPixel, &wa); lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8); - invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap, &color, &color, 0, 0); + invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap, + &color, &color, 0, 0); XDefineCursor(dpy, lock->win, invisible); - XMapRaised(dpy, lock->win); - if (rr) - XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask); - for (len = 1000; len; len--) { - if (XGrabPointer(dpy, lock->root, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask, - GrabModeAsync, GrabModeAsync, None, invisible, CurrentTime) == GrabSuccess) - break; - usleep(1000); - } - if (running && (len > 0)) { - for (len = 1000; len; len--) { - if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess) - break; - usleep(1000); + + /* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */ + for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) { + if (ptgrab != GrabSuccess) { + ptgrab = XGrabPointer(dpy, lock->root, False, + ButtonPressMask | ButtonReleaseMask | + PointerMotionMask, GrabModeAsync, + GrabModeAsync, None, invisible, CurrentTime); + } + if (kbgrab != GrabSuccess) { + kbgrab = XGrabKeyboard(dpy, lock->root, True, + GrabModeAsync, GrabModeAsync, CurrentTime); } - } - running &= (len > 0); - if (!running) { - unlockscreen(dpy, lock); - lock = NULL; - } - else { - XSelectInput(dpy, lock->root, SubstructureNotifyMask); + /* input is grabbed: we can lock the screen */ + if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) { + XMapRaised(dpy, lock->win); + if (rr->active) + XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask); + + XSelectInput(dpy, lock->root, SubstructureNotifyMask); + return lock; + } + + /* retry on AlreadyGrabbed but fail on other errors */ + if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) || + (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess)) + break; + + usleep(100000); } - return lock; + /* we couldn't grab all input: fail out */ + if (ptgrab != GrabSuccess) + fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", + screen); + if (kbgrab != GrabSuccess) + fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", + screen); + return NULL; } static void usage(void) { - fprintf(stderr, "usage: slock [-v]\n"); - exit(1); + die("usage: slock [-v] [cmd [arg ...]]\n"); } int main(int argc, char **argv) { -#ifndef HAVE_BSD_AUTH - const char *pws; -#endif + struct xrandr rr; + struct lock **locks; + struct passwd *pwd; + struct group *grp; + uid_t duid; + gid_t dgid; + const char *hash; Display *dpy; - int screen; + int s, nlocks, nscreens; - if ((argc == 2) && !strcmp("-v", argv[1])) - die("slock-%s, © 2006-2015 slock engineers\n", VERSION); - else if (argc != 1) + ARGBEGIN { + case 'v': + fprintf(stderr, "slock-"VERSION"\n"); + return 0; + default: usage(); + } ARGEND + + /* validate drop-user and -group */ + errno = 0; + if (!(pwd = getpwnam(user))) + die("slock: getpwnam %s: %s\n", user, + errno ? strerror(errno) : "user entry not found"); + duid = pwd->pw_uid; + errno = 0; + if (!(grp = getgrnam(group))) + die("slock: getgrnam %s: %s\n", group, + errno ? strerror(errno) : "group entry not found"); + dgid = grp->gr_gid; #ifdef __linux__ dontkillme(); #endif - if (!getpwuid(getuid())) - die("slock: no passwd entry for you\n"); - -#ifndef HAVE_BSD_AUTH - pws = getpw(); -#endif + hash = gethash(); + errno = 0; + if (!crypt("", hash)) + die("slock: crypt: %s\n", strerror(errno)); - if (!(dpy = XOpenDisplay(0))) + if (!(dpy = XOpenDisplay(NULL))) die("slock: cannot open display\n"); - rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase); - /* Get the number of screens in display "dpy" and blank them all. */ + + /* drop privileges */ + if (setgroups(0, NULL) < 0) + die("slock: setgroups: %s\n", strerror(errno)); + if (setgid(dgid) < 0) + die("slock: setgid: %s\n", strerror(errno)); + if (setuid(duid) < 0) + die("slock: setuid: %s\n", strerror(errno)); + + /* check for Xrandr support */ + rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase); + + /* get number of screens in display "dpy" and blank them */ nscreens = ScreenCount(dpy); - locks = malloc(sizeof(Lock *) * nscreens); - if (locks == NULL) - die("slock: malloc: %s\n", strerror(errno)); - int nlocks = 0; - for (screen = 0; screen < nscreens; screen++) { - if ( (locks[screen] = lockscreen(dpy, screen)) != NULL) + if (!(locks = calloc(nscreens, sizeof(struct lock *)))) + die("slock: out of memory\n"); + for (nlocks = 0, s = 0; s < nscreens; s++) { + if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL) nlocks++; + else + break; } - XSync(dpy, False); + XSync(dpy, 0); - /* Did we actually manage to lock something? */ - if (nlocks == 0) { /* nothing to protect */ - free(locks); - XCloseDisplay(dpy); + /* did we manage to lock everything? */ + if (nlocks != nscreens) return 1; - } - - /* Everything is now blank. Now wait for the correct password. */ -#ifdef HAVE_BSD_AUTH - readpw(dpy); -#else - readpw(dpy, pws); -#endif - /* Password ok, unlock everything and quit. */ - for (screen = 0; screen < nscreens; screen++) - unlockscreen(dpy, locks[screen]); + /* run post-lock command */ + if (argc > 0) { + switch (fork()) { + case -1: + die("slock: fork failed: %s\n", strerror(errno)); + case 0: + if (close(ConnectionNumber(dpy)) < 0) + die("slock: close: %s\n", strerror(errno)); + execvp(argv[0], argv); + fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno)); + _exit(1); + } + } - free(locks); - XCloseDisplay(dpy); + /* everything is now blank. Wait for the correct password */ + readpw(dpy, &rr, locks, nscreens, hash); return 0; }