1 files changed, 62 insertions, 0 deletions
diff --git a/src/common/util.c b/src/common/util.c
index 27cc9df878..1359776b21 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -964,6 +964,68 @@ string_is_key_value(int severity, const char *string)
   return 1;
 }
 
+/** Return true if <b>string</b> represents a valid IPv4 adddress in
+ * 'a.b.c.d' form.
+ */
+int
+string_is_valid_ipv4_address(const char *string)
+{
+  struct in_addr addr;
+
+  return (tor_inet_pton(AF_INET,string,&addr) == 1);
+}
+
+/** Return true if <b>string</b> represents a valid IPv6 address in
+ * a form that inet_pton() can parse.
+ */
+int
+string_is_valid_ipv6_address(const char *string)
+{
+  struct in6_addr addr;
+
+  return (tor_inet_pton(AF_INET6,string,&addr) == 1);
+}
+
+/** Return true iff <b>string</b> matches a pattern of DNS names
+ * that we allow Tor clients to connect to.
+ */
+int
+string_is_valid_hostname(const char *string)
+{
+  int result = 1;
+  smartlist_t *components;
+
+  components = smartlist_new();
+
+  smartlist_split_string(components,string,".",0,0);
+
+  SMARTLIST_FOREACH_BEGIN(components, char *, c) {
+    if (c[0] == '-') {
+      result = 0;
+      break;
+    }
+
+    do {
+      if ((*c >= 'a' && *c <= 'z') ||
+          (*c >= 'A' && *c <= 'Z') ||
+          (*c >= '0' && *c <= '9') ||
+          (*c == '-'))
+        c++;
+      else
+        result = 0;
+    } while (result && *c);
+
+  } SMARTLIST_FOREACH_END(c);
+
+  SMARTLIST_FOREACH_BEGIN(components, char *, c) {
+    tor_free(c);
+  } SMARTLIST_FOREACH_END(c);
+
+  smartlist_free(components);
+
+  return result;
+}
+
 /** Return true iff the DIGEST256_LEN bytes in digest are all zero. */
 int
 tor_digest256_is_zero(const char *digest)