In HTTP Proxy module (openvpn/transport/client/httpcli.hpp),

generalized ProxyResponseLimit and refactored out into BufferLimit

openvpn/buffer/buflimit.hpp

@@ -0,0 +1,92 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2013-2014 OpenVPN Technologies, Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    as published by the Free Software Foundation.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef OPENVPN_BUFFER_BUFLIMIT_H
+#define OPENVPN_BUFFER_BUFLIMIT_H
+
+#include <openvpn/buffer/buffer.hpp>
+
+namespace openvpn {
+
+  template <typename T>
+  class BufferLimit
+  {
+  public:
+    BufferLimit()
+    {
+      set_max(0, 0);
+      reset();
+    }
+
+    BufferLimit(const T max_lines_arg,
+		const T max_bytes_arg)
+    {
+      set_max(max_lines_arg, max_bytes_arg);
+      reset();
+    }
+
+    void set_max(const T max_lines_arg,
+		 const T max_bytes_arg)
+    {
+      max_lines = max_lines_arg;
+      max_bytes = max_bytes_arg;
+    }
+
+    void reset()
+    {
+      n_bytes = n_lines = 0;
+    }
+
+    void add(const Buffer& buf)
+    {
+      T size = (T)buf.size();
+      n_bytes += size;
+      if (max_bytes && n_bytes > max_bytes)
+	bytes_exceeded();
+      if (max_lines)
+	{
+	  const unsigned char *p = buf.c_data();
+	  while (size--)
+	    {
+	      const unsigned char c = *p++;
+	      if (c == '\n')
+		{
+		  ++n_lines;
+		  if (n_lines > max_lines)
+		    lines_exceeded();
+		}
+	    }
+	}
+    }
+
+    virtual void bytes_exceeded() = 0;
+    virtual void lines_exceeded() = 0;
+
+  protected:
+    T max_lines;
+    T max_bytes;
+    T n_bytes;
+    T n_lines;
+  };
+
+}
+
+#endif

openvpn/transport/client/httpcli.hpp

@@ -40,6 +40,7 @@
 #include <openvpn/common/number.hpp>
 #include <openvpn/common/userpass.hpp>
 #include <openvpn/buffer/bufstr.hpp>
+#include <openvpn/buffer/buflimit.hpp>
 #include <openvpn/transport/tcplink.hpp>
 #include <openvpn/transport/client/transbase.hpp>
 #include <openvpn/transport/socket_protect.hpp>
@@ -275,44 +276,17 @@ namespace openvpn {
       virtual ~Client() { stop_(); }
 
     private:
-      class ProxyResponseLimit
+      struct ProxyResponseLimit : public BufferLimit<size_t>
       {
-      public:
-	enum {
-	  MaxLines=1024,
-	  MaxBytes=65536,
-	};
+	ProxyResponseLimit() : BufferLimit(1024, 65536) {}
 
-	ProxyResponseLimit()
-	{
-	  reset();
+	virtual void bytes_exceeded() {
+	  OPENVPN_THROW_EXCEPTION("HTTP proxy response too large (> " << max_bytes << " bytes)");
 	}
 
-	void reset()
-	{
-	  n_bytes = n_lines = 0;
+	virtual void lines_exceeded() {
+	  OPENVPN_THROW_EXCEPTION("HTTP proxy response too large (> " << max_lines << " lines)");
 	}
-
-	void add(const Buffer& buf)
-	{
-	  size_t size = buf.size();
-	  if ((n_bytes += size) > MaxBytes)
-	    OPENVPN_THROW_EXCEPTION("HTTP proxy response too large (> " << MaxBytes << " bytes)");
-	  const unsigned char *p = buf.c_data();
-	  while (size--)
-	    {
-	      const unsigned char c = *p++;
-	      if (c == '\n')
-		{
-		  if (++n_lines > MaxLines)
-		    OPENVPN_THROW_EXCEPTION("HTTP proxy response too large (> " << MaxLines << " lines)");
-		}
-	    }
-	}
-
-      private:
-	size_t n_bytes;
-	size_t n_lines;
       };
 
       Client(boost::asio::io_service& io_service_arg,