Implement SDCH Dictionary domain matching as per RFC 2965

net/base/url_util.cc

Index: net/base/url_util.cc
diff --git a/net/base/url_util.cc b/net/base/url_util.cc
index 879c746c9b3fea7584840034f6c29680f57915c0..e6add8473bb874c6dadb359011b13fe1ddd2b79d 100644
--- a/net/base/url_util.cc
+++ b/net/base/url_util.cc
@@ -438,4 +438,37 @@ bool IsLocalHostname(base::StringPiece host, bool* is_local6) {
          IsNormalizedLocalhostTLD(normalized_host);
 }
 
+bool IsDomainMatch(const std::string& domain, const std::string& host) {
+  // Can domain match in two ways; as a domain cookie (where the cookie
+  // domain begins with ".") or as a host cookie (where it doesn't).
+
+  // Some consumers of the CookieMonster expect to set cookies on
+  // URLs like http://.strange.url.  To retrieve cookies in this instance,
+  // we allow matching as a host cookie even when the domain_ starts with
+  // a period.
+  if (host == domain)
+    return true;
+
+  // Domain cookie must have an initial ".".  To match, it must be
+  // equal to url's host with initial period removed, or a suffix of
+  // it.
+
+  // Arguably this should only apply to "http" or "https" cookies, but
+  // extension cookie tests currently use the funtionality, and if we
+  // ever decide to implement that it should be done by preventing
+  // such cookies from being set.
+  if (domain.empty() || domain[0] != '.')
+    return false;
+
+  // The host with a "." prefixed.
+  if (domain.compare(1, std::string::npos, host) == 0)
+    return true;
+
+  // A pure suffix of the host (ok since we know the domain already
+  // starts with a ".")
+  return (host.length() > domain.length() &&
+          host.compare(host.length() - domain.length(), domain.length(),
+                       domain) == 0);
+}
+
 }  // namespace net