Add cleanup() to do free(locks) + XCloseDisplay()

[slock.git] / slock.c

diff --git a/slock.c b/slock.c
index fa7ec84..4980325 100644 (file)
--- a/slock.c
+++ b/slock.c
@@ -23,6 +23,11 @@
 #include <bsd_auth.h>
 #endif
 
 #include <bsd_auth.h>
 #endif
 

+#include "arg.h"
+#include "util.h"
+
+char *argv0;
+

 enum {
        INIT,
        INPUT,
 enum {
        INIT,
        INPUT,


@@ -65,23 +70,23 @@ die(const char *errstr, ...)
 static void
 dontkillme(void)
 {
 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;
-
-       /* 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");
+       FILE *f;
+       const char oomfile[] = "/proc/self/oom_score_adj";

 
 

-       if (fd < 0 || write(fd, value, length) != length || close(fd) != 0)
-               die("cannot disable the out-of-memory killer for this process (make sure to suid or sgid slock)\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. "
+                           "suid or sgid set?\n");
+               else
+                       die("slock: fclose %s: %s\n", oomfile,
+                           strerror(errno));
+       }

 }
 #endif
 
 }
 #endif
 


@@ -96,9 +101,9 @@ getpw(void)
        errno = 0;
        if (!(pw = getpwuid(getuid()))) {
                if (errno)
        errno = 0;
        if (!(pw = getpwuid(getuid()))) {
                if (errno)

-                       die("slock: getpwuid: %s\n", strerror(errno));
+                       die("getpwuid: %s\n", strerror(errno));

                else
                else

-                       die("slock: cannot retrieve password entry\n");
+                       die("cannot retrieve password entry\n");

        }
        rval = pw->pw_passwd;
 
        }
        rval = pw->pw_passwd;
 


@@ -106,7 +111,7 @@ getpw(void)
        if (rval[0] == 'x' && rval[1] == '\0') {
                struct spwd *sp;
                if (!(sp = getspnam(getenv("USER"))))
        if (rval[0] == 'x' && rval[1] == '\0') {
                struct spwd *sp;
                if (!(sp = getspnam(getenv("USER"))))

-                       die("slock: cannot retrieve shadow entry (make sure to suid or sgid slock)\n");
+                       die("cannot retrieve shadow entry (make sure to suid or sgid slock)\n");

                rval = sp->sp_pwdp;
        }
 #endif
                rval = sp->sp_pwdp;
        }
 #endif


@@ -114,7 +119,7 @@ getpw(void)
        /* drop privileges */
        if (geteuid() == 0 &&
            ((getegid() != pw->pw_gid && setgid(pw->pw_gid) < 0) || setuid(pw->pw_uid) < 0))
        /* 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");
+               die("cannot drop privileges\n");

        return rval;
 }
 #endif
        return rval;
 }
 #endif


@@ -126,7 +131,7 @@ readpw(Display *dpy)
 readpw(Display *dpy, const char *pws)
 #endif
 {
 readpw(Display *dpy, const char *pws)
 #endif
 {

-       char buf[32], passwd[256];
+       char buf[32], passwd[256], *encrypted;

        int num, screen;
        unsigned int len, color;
        KeySym ksym;
        int num, screen;
        unsigned int len, color;
        KeySym ksym;


@@ -142,7 +147,7 @@ readpw(Display *dpy, const char *pws)
         * timeout. */
        while (running && !XNextEvent(dpy, &ev)) {
                if (ev.type == KeyPress) {
         * 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)
                        num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
                        if (IsKeypadKey(ksym)) {
                                if (ksym == XK_KP_Enter)


@@ -160,22 +165,28 @@ readpw(Display *dpy, const char *pws)
                        case XK_Return:
                                passwd[len] = 0;
 #ifdef HAVE_BSD_AUTH
                        case XK_Return:
                                passwd[len] = 0;
 #ifdef HAVE_BSD_AUTH

-                               running = !auth_userokay(getlogin(), NULL, "auth-xlock", passwd);
+                               running = !auth_userokay(getlogin(), NULL, "auth-slock", passwd);

 #else
 #else

-                               running = !!strcmp(crypt(passwd, pws), pws);
+                               errno = 0;
+                               if (!(encrypted = crypt(passwd, pws)))
+                                       fprintf(stderr, "slock: crypt: %s\n", strerror(errno));
+                               else
+                                       running = !!strcmp(encrypted, pws);

 #endif
                                if (running) {
                                        XBell(dpy, 100);
                                        failure = True;
                                }
 #endif
                                if (running) {
                                        XBell(dpy, 100);
                                        failure = True;
                                }

+                               explicit_bzero(&passwd, sizeof(passwd));

                                len = 0;
                                break;
                        case XK_Escape:
                                len = 0;
                                break;
                        case XK_Escape:

+                               explicit_bzero(&passwd, sizeof(passwd));

                                len = 0;
                                break;
                        case XK_BackSpace:
                                if (len)
                                len = 0;
                                break;
                        case XK_BackSpace:
                                if (len)

-                                       --len;
+                                       passwd[len--] = 0;

                                break;
                        default:
                                if (num && !iscntrl((int)buf[0]) && (len + num < sizeof(passwd))) {
                                break;
                        default:
                                if (num && !iscntrl((int)buf[0]) && (len + num < sizeof(passwd))) {


@@ -219,11 +230,17 @@ unlockscreen(Display *dpy, Lock *lock)
        free(lock);
 }
 
        free(lock);
 }
 

+static void
+cleanup(Display *dpy)
+{
+       free(locks);
+       XCloseDisplay(dpy);
+}
+

 static Lock *
 lockscreen(Display *dpy, int screen)
 {
        char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
 static Lock *
 lockscreen(Display *dpy, int screen)
 {
        char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};

-       unsigned int len;

        int i;
        Lock *lock;
        XColor color, dummy;
        int i;
        Lock *lock;
        XColor color, dummy;


@@ -250,41 +267,37 @@ lockscreen(Display *dpy, int screen)
        lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
        invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap, &color, &color, 0, 0);
        XDefineCursor(dpy, lock->win, invisible);
        lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
        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);

 
        /* Try to grab mouse pointer *and* keyboard, else fail the lock */
 
        /* Try to grab mouse pointer *and* keyboard, else fail the lock */

-       for (len = 1000; len; len--) {
-               if (XGrabPointer(dpy, lock->root, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
-                   GrabModeAsync, GrabModeAsync, None, invisible, CurrentTime) == GrabSuccess)
-                       break;
-               usleep(1000);
-       }
-       if (!len) {
+       if (XGrabPointer(dpy, lock->root, False, ButtonPressMask |
+           ButtonReleaseMask | PointerMotionMask, GrabModeAsync, GrabModeAsync,
+           None, invisible, CurrentTime) != GrabSuccess) {

                fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", screen);
                fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", screen);

-       } else {
-               for (len = 1000; len; len--) {
-                       if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess) {
-                               /* everything fine, we grabbed both inputs */
-                               XSelectInput(dpy, lock->root, SubstructureNotifyMask);
-                               return lock;
-                       }
-                       usleep(1000);
-               }
+               running = 0;
+               unlockscreen(dpy, lock);
+               return NULL;
+       }
+
+       if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync,
+           CurrentTime) != GrabSuccess) {

                fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", screen);
                fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", screen);

+               running = 0;
+               unlockscreen(dpy, lock);
+               return NULL;

        }
        }

-       /* grabbing one of the inputs failed */
-       running = 0;
-       unlockscreen(dpy, lock);
-       return NULL;
+
+       XMapRaised(dpy, lock->win);
+       if (rr)
+               XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
+
+       XSelectInput(dpy, lock->root, SubstructureNotifyMask);
+       return lock;

 }
 
 static void
 usage(void)
 {
 }
 
 static void
 usage(void)
 {

-       fprintf(stderr, "usage: slock [-v|POST_LOCK_CMD]\n");
-       exit(1);
+       die("usage: slock [-v] [cmd [arg ...]]\n");

 }
 
 int
 }
 
 int


@@ -293,66 +306,88 @@ main(int argc, char **argv) {
        const char *pws;
 #endif
        Display *dpy;
        const char *pws;
 #endif
        Display *dpy;

-       int screen;
-
-       if ((argc == 2) && !strcmp("-v", argv[1]))
-               die("slock-%s, © 2006-2015 slock engineers\n", VERSION);
+       int s, nlocks;

 
 

-       if ((argc == 2) && !strcmp("-h", argv[1]))
+       ARGBEGIN {
+       case 'v':
+               fprintf(stderr, "slock-"VERSION"\n");
+               return 0;
+       default:

                usage();
                usage();

+       } ARGEND

 
 #ifdef __linux__
        dontkillme();
 #endif
 
 
 #ifdef __linux__
        dontkillme();
 #endif
 

-       if (!getpwuid(getuid()))
-               die("slock: no passwd entry for you\n");
+       /* Check if the current user has a password entry */
+       errno = 0;
+       if (!getpwuid(getuid())) {
+               if (errno == 0)
+                       die("slock: no password entry for current user\n");
+               else
+                       die("slock: getpwuid: %s\n", strerror(errno));
+       }

 
 #ifndef HAVE_BSD_AUTH
        pws = getpw();
 
 #ifndef HAVE_BSD_AUTH
        pws = getpw();

+       if (strlen(pws) < 2)
+               die("slock: failed to get user password hash.\n");

 #endif
 
 #endif
 

-       if (!(dpy = XOpenDisplay(0)))
+       if (!(dpy = XOpenDisplay(NULL)))

                die("slock: cannot open display\n");
                die("slock: cannot open display\n");

+
+       /* check for Xrandr support */

        rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
        rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);

-       /* Get the number of screens in display "dpy" and blank them all. */
+
+       /* get number of screens in display "dpy" and blank them */

        nscreens = ScreenCount(dpy);
        nscreens = ScreenCount(dpy);

-       if (!(locks = malloc(sizeof(Lock*) * nscreens)))
-               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 = malloc(sizeof(Lock *) * nscreens))) {
+               XCloseDisplay(dpy);
+               die("slock: out of memory\n");
+       }
+       for (nlocks = 0, s = 0; s < nscreens; s++) {
+               if ((locks[s] = lockscreen(dpy, s)) != NULL)

                        nlocks++;
        }
                        nlocks++;
        }

-       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 actually manage to lock anything? */
+       if (nlocks == 0) {
+               /* nothing to protect */
+               cleanup(dpy);

                return 1;
        }
 
                return 1;
        }
 

-       if (argc >= 2 && fork() == 0) {
-               if (dpy)
-                       close(ConnectionNumber(dpy));
-               execvp(argv[1], argv+1);
-               die("slock: execvp %s failed: %s\n", argv[1], strerror(errno));
+       /* run post-lock command */
+       if (argc > 0) {
+               switch (fork()) {
+               case -1:
+                       cleanup(dpy);
+                       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);
+               }

        }
 
        }
 

-       /* Everything is now blank. Now wait for the correct password. */
+       /* everything is now blank. Wait for the correct password */

 #ifdef HAVE_BSD_AUTH
        readpw(dpy);
 #else
        readpw(dpy, pws);
 #endif
 
 #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]);
+       /* password ok, unlock everything and quit */
+       for (s = 0; s < nscreens; s++)
+               unlockscreen(dpy, locks[s]);

 
 

-       free(locks);
-       XCloseDisplay(dpy);
+       cleanup(dpy);

 
        return 0;
 }
 
        return 0;
 }