+
+int fflush_and_check(FILE *f) {
+ assert(f);
+
+ errno = 0;
+ fflush(f);
+
+ if (ferror(f))
+ return errno ? -errno : -EIO;
+
+ return 0;
+}
+
+char *tempfn_xxxxxx(const char *p) {
+ const char *fn;
+ char *t;
+ size_t k;
+
+ assert(p);
+
+ t = new(char, strlen(p) + 1 + 6 + 1);
+ if (!t)
+ return NULL;
+
+ fn = basename(p);
+ k = fn - p;
+
+ strcpy(stpcpy(stpcpy(mempcpy(t, p, k), "."), fn), "XXXXXX");
+
+ return t;
+}
+
+char *tempfn_random(const char *p) {
+ const char *fn;
+ char *t, *x;
+ uint64_t u;
+ size_t k;
+ unsigned i;
+
+ assert(p);
+
+ t = new(char, strlen(p) + 1 + 16 + 1);
+ if (!t)
+ return NULL;
+
+ fn = basename(p);
+ k = fn - p;
+
+ x = stpcpy(stpcpy(mempcpy(t, p, k), "."), fn);
+
+ u = random_u64();
+ for (i = 0; i < 16; i++) {
+ *(x++) = hexchar(u & 0xF);
+ u >>= 4;
+ }
+
+ *x = 0;
+
+ return t;
+}
+
+/* make sure the hostname is not "localhost" */
+bool is_localhost(const char *hostname) {
+ assert(hostname);
+
+ /* This tries to identify local hostnames described in RFC6761
+ * plus the redhatism of .localdomain */
+
+ return streq(hostname, "localhost") ||
+ streq(hostname, "localhost.") ||
+ endswith(hostname, ".localhost") ||
+ endswith(hostname, ".localhost.") ||
+ endswith(hostname, ".localdomain") ||
+ endswith(hostname, ".localdomain.");
+}
+
+int take_password_lock(const char *root) {
+
+ struct flock flock = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_SET,
+ .l_start = 0,
+ .l_len = 0,
+ };
+
+ const char *path;
+ int fd, r;
+
+ /* This is roughly the same as lckpwdf(), but not as awful. We
+ * don't want to use alarm() and signals, hence we implement
+ * our own trivial version of this.
+ *
+ * Note that shadow-utils also takes per-database locks in
+ * addition to lckpwdf(). However, we don't given that they
+ * are redundant as they they invoke lckpwdf() first and keep
+ * it during everything they do. The per-database locks are
+ * awfully racy, and thus we just won't do them. */
+
+ if (root)
+ path = strappenda(root, "/etc/.pwd.lock");
+ else
+ path = "/etc/.pwd.lock";
+
+ fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600);
+ if (fd < 0)
+ return -errno;
+
+ r = fcntl(fd, F_SETLKW, &flock);
+ if (r < 0) {
+ safe_close(fd);
+ return -errno;
+ }
+
+ return fd;
+}