+
+/* make sure the hostname is not "localhost" */
+bool is_localhost(const char *hostname) {
+ assert(hostname);
+
+ /* This tries to identify local host and domain names
+ * described in RFC6761 plus the redhatism of .localdomain */
+
+ return streq(hostname, "localhost") ||
+ streq(hostname, "localhost.") ||
+ streq(hostname, "localdomain.") ||
+ streq(hostname, "localdomain") ||
+ 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;
+}
+
+int is_symlink(const char *path) {
+ struct stat info;
+
+ if (lstat(path, &info) < 0)
+ return -errno;
+
+ if (S_ISLNK(info.st_mode))
+ return 1;
+
+ return 0;
+}
+
+int unquote_first_word(const char **p, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ size_t allocated = 0, sz = 0;
+
+ enum {
+ START,
+ VALUE,
+ VALUE_ESCAPE,
+ SINGLE_QUOTE,
+ SINGLE_QUOTE_ESCAPE,
+ DOUBLE_QUOTE,
+ DOUBLE_QUOTE_ESCAPE,
+ SPACE,
+ } state = START;
+
+ assert(p);
+ assert(*p);
+ assert(ret);
+
+ /* Parses the first word of a string, and returns it in
+ * *ret. Removes all quotes in the process. When parsing fails
+ * (because of an uneven number of quotes or similar), leaves
+ * the pointer *p at the first invalid character. */
+
+ for (;;) {
+ char c = **p;
+
+ switch (state) {
+
+ case START:
+ if (c == 0)
+ goto finish;
+ else if (strchr(WHITESPACE, c))
+ break;
+
+ state = VALUE;
+ /* fallthrough */
+
+ case VALUE:
+ if (c == 0)
+ goto finish;
+ else if (c == '\'')
+ state = SINGLE_QUOTE;
+ else if (c == '\\')
+ state = VALUE_ESCAPE;
+ else if (c == '\"')
+ state = DOUBLE_QUOTE;
+ else if (strchr(WHITESPACE, c))
+ state = SPACE;
+ else {
+ if (!GREEDY_REALLOC(s, allocated, sz+2))
+ return -ENOMEM;
+
+ s[sz++] = c;
+ }
+
+ break;
+
+ case VALUE_ESCAPE:
+ if (c == 0)
+ return -EINVAL;
+
+ if (!GREEDY_REALLOC(s, allocated, sz+2))
+ return -ENOMEM;
+
+ s[sz++] = c;
+ state = VALUE;
+
+ break;
+
+ case SINGLE_QUOTE:
+ if (c == 0)
+ return -EINVAL;
+ else if (c == '\'')
+ state = VALUE;
+ else if (c == '\\')
+ state = SINGLE_QUOTE_ESCAPE;
+ else {
+ if (!GREEDY_REALLOC(s, allocated, sz+2))
+ return -ENOMEM;
+
+ s[sz++] = c;
+ }
+
+ break;
+
+ case SINGLE_QUOTE_ESCAPE:
+ if (c == 0)
+ return -EINVAL;
+
+ if (!GREEDY_REALLOC(s, allocated, sz+2))
+ return -ENOMEM;
+
+ s[sz++] = c;
+ state = SINGLE_QUOTE;
+ break;
+
+ case DOUBLE_QUOTE:
+ if (c == 0)
+ return -EINVAL;
+ else if (c == '\"')
+ state = VALUE;
+ else if (c == '\\')
+ state = DOUBLE_QUOTE_ESCAPE;
+ else {
+ if (!GREEDY_REALLOC(s, allocated, sz+2))
+ return -ENOMEM;
+
+ s[sz++] = c;
+ }
+
+ break;
+
+ case DOUBLE_QUOTE_ESCAPE:
+ if (c == 0)
+ return -EINVAL;
+
+ if (!GREEDY_REALLOC(s, allocated, sz+2))
+ return -ENOMEM;
+
+ s[sz++] = c;
+ state = DOUBLE_QUOTE;
+ break;
+
+ case SPACE:
+ if (c == 0)
+ goto finish;
+ if (!strchr(WHITESPACE, c))
+ goto finish;
+
+ break;
+ }
+
+ (*p) ++;
+ }
+
+finish:
+ if (!s) {
+ *ret = NULL;
+ return 0;
+ }
+
+ s[sz] = 0;
+ *ret = s;
+ s = NULL;
+
+ return 1;
+}
+
+int unquote_many_words(const char **p, ...) {
+ va_list ap;
+ char **l;
+ int n = 0, i, c, r;
+
+ /* Parses a number of words from a string, stripping any
+ * quotes if necessary. */
+
+ assert(p);
+
+ /* Count how many words are expected */
+ va_start(ap, p);
+ for (;;) {
+ if (!va_arg(ap, char **))
+ break;
+ n++;
+ }
+ va_end(ap);
+
+ if (n <= 0)
+ return 0;
+
+ /* Read all words into a temporary array */
+ l = newa0(char*, n);
+ for (c = 0; c < n; c++) {
+
+ r = unquote_first_word(p, &l[c]);
+ if (r < 0) {
+ int j;
+
+ for (j = 0; j < c; j++)
+ free(l[j]);
+
+ return r;
+ }
+
+ if (r == 0)
+ break;
+ }
+
+ /* If we managed to parse all words, return them in the passed
+ * in parameters */
+ va_start(ap, p);
+ for (i = 0; i < n; i++) {
+ char **v;
+
+ v = va_arg(ap, char **);
+ assert(v);
+
+ *v = l[i];
+ }
+ va_end(ap);
+
+ return c;
+}
+
+int free_and_strdup(char **p, const char *s) {
+ char *t;
+
+ assert(p);
+
+ /* Replaces a string pointer with an strdup()ed new string,
+ * possibly freeing the old one. */
+
+ if (s) {
+ t = strdup(s);
+ if (!t)
+ return -ENOMEM;
+ } else
+ t = NULL;
+
+ free(*p);
+ *p = t;
+
+ return 0;
+}