Refactor dontkillme()

[slock.git] / slock.c

diff --git a/slock.c b/slock.c
index 847b328..9ec2f71 100644 (file)
--- a/slock.c
+++ b/slock.c
@@ -65,19 +65,27 @@ die(const char *errstr, ...)
 
 #ifdef __linux__
 #include <fcntl.h>
+#include <linux/oom.h>
 
 static void
 dontkillme(void)
 {
-       int fd;
+       FILE *f;
+       const char oomfile[] = "/proc/self/oom_score_adj";
 
-       fd = open("/proc/self/oom_score_adj", O_WRONLY);
-       if (fd < 0 && errno == ENOENT) {
-               return;
+       if (!(f = fopen(oomfile, "w"))) {
+               if (errno == ENOENT)
+                       return;
+               die("slock: fopen %s: %s\n", oomfile, strerror(errno));
        }
-       if (fd < 0 || write(fd, "-1000\n", (sizeof("-1000\n") - 1)) !=
-           (sizeof("-1000\n") - 1) || close(fd) != 0) {
-               die("can't tame the oom-killer. is suid or sgid set?\n");
+       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
@@ -123,7 +131,7 @@ readpw(Display *dpy)
 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;
@@ -159,7 +167,11 @@ readpw(Display *dpy, const char *pws)
 #ifdef HAVE_BSD_AUTH
                                running = !auth_userokay(getlogin(), NULL, "auth-slock", passwd);
 #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);
@@ -278,7 +290,7 @@ lockscreen(Display *dpy, int screen)
 static void
 usage(void)
 {
-       die("usage: slock [-v | cmd [arg ...]]\n");
+       die("usage: slock [-v] [cmd [arg ...]]\n");
 }
 
 int
@@ -312,6 +324,8 @@ main(int argc, char **argv) {
 
 #ifndef HAVE_BSD_AUTH
        pws = getpw();
+       if (strlen(pws) < 2)
+               die("slock: failed to get user password hash.\n");
 #endif
 
        if (!(dpy = XOpenDisplay(NULL)))