-static bool hostname_valid_char(char c) {
- return
- (c >= 'a' && c <= 'z') ||
- (c >= 'A' && c <= 'Z') ||
- (c >= '0' && c <= '9') ||
- c == '-' ||
- c == '_' ||
- c == '.';
-}
-
-bool hostname_is_valid(const char *s) {
- const char *p;
- bool dot;
-
- if (isempty(s))
- return false;
-
- /* Doesn't accept empty hostnames, hostnames with trailing or
- * leading dots, and hostnames with multiple dots in a
- * sequence. Also ensures that the length stays below
- * HOST_NAME_MAX. */
-
- for (p = s, dot = true; *p; p++) {
- if (*p == '.') {
- if (dot)
- return false;
-
- dot = true;
- } else {
- if (!hostname_valid_char(*p))
- return false;
-
- dot = false;
- }
- }
-
- if (dot)
- return false;
-
- if (p-s > HOST_NAME_MAX)
- return false;
-
- return true;
-}
-
-char* hostname_cleanup(char *s, bool lowercase) {
- char *p, *d;
- bool dot;
-
- for (p = s, d = s, dot = true; *p; p++) {
- if (*p == '.') {
- if (dot)
- continue;
-
- *(d++) = '.';
- dot = true;
- } else if (hostname_valid_char(*p)) {
- *(d++) = lowercase ? tolower(*p) : *p;
- dot = false;
- }
-
- }
-
- if (dot && d > s)
- d[-1] = 0;
- else
- *d = 0;
-
- strshorten(s, HOST_NAME_MAX);
-
- return s;
-}
-