Introducing helper function to validate IPv4 address strings.

2 files changed, 18 insertions, 2 deletions

diff --git a/src/common/util.c b/src/common/util.c
index 606b9e1ea0..ba9d78afac 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -957,8 +957,19 @@ string_is_key_value(int severity, const char *string)
   return 1;
 }
 
-/** Return true iff <b>string</b> is valid DNS name, as defined in
- * RFC 1035 Section 2.3.1.
+/** 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 sockaddr_in sockaddr;
+
+   return (tor_inet_pton(AF_INET,string,&sockaddr) == 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)
@@ -988,6 +999,10 @@ string_is_valid_hostname(const char *string)
 
    } SMARTLIST_FOREACH_END(c);
 
+   SMARTLIST_FOREACH_BEGIN(components, char *, c) {
+     tor_free(c);
+   } SMARTLIST_FOREACH_END(c);
+
    smartlist_free(components);
 
    return result;
diff --git a/src/common/util.h b/src/common/util.h
index 2634adc62b..dcb54f0aea 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -228,6 +228,7 @@ const char *find_str_at_start_of_line(const char *haystack,
 int string_is_C_identifier(const char *string);
 int string_is_key_value(int severity, const char *string);
 int string_is_valid_hostname(const char *string);
+int string_is_valid_ipv4_address(const char *string);
 
 int tor_mem_is_zero(const char *mem, size_t len);
 int tor_digest_is_zero(const char *digest);