version 3.02

common/count_filter.cc

@@ -0,0 +1,114 @@
+////////////////////////////////////////////////////////////////////////////////
+//                                                                            //
+// File:           count_filter.cc                                            //
+// Description:    byte counting filter for wanproxy streams                  //
+// Project:        WANProxy XTech                                             //
+// Author:         Andreu Vidal Bramfeld-Software                             //
+// Last modified:  2016-02-28                                                 //
+//                                                                            //
+////////////////////////////////////////////////////////////////////////////////
+
+#include <map>
+#include <vector>
+#include <common/buffer.h>
+#include <http/http_protocol.h>
+#include "count_filter.h"
+
+CountFilter::CountFilter (intmax_t& p, int flg) : total_count_ (p)
+{ 
+	expected_ = count_ = 0; state_ = (flg & 1); 
+}
+
+bool CountFilter::consume (Buffer& buf, int flg)
+{
+	long n = buf.length ();
+	total_count_ += n;
+	
+	if (state_ == 1 || state_ == 2)
+	{
+		header_.append (buf);
+		while (!	explore_stream (header_)) continue;
+	}
+	else if (state_ == 3 || state_ == 4)
+	{
+		count_ += n;
+		if (count_ >= expected_)
+		{
+			state_ = 1, header_.clear ();
+			if (count_ > expected_)
+			{
+				header_ = buf, header_.skip (n - (count_ - expected_));
+				while (!	explore_stream (header_)) continue;
+			}
+		}
+	}
+	
+	return produce (buf, flg | (state_ == 4 ? TO_BE_CONTINUED : 0)); 
+}
+
+void CountFilter::flush (int flg)
+{
+	state_ = 0;
+	Filter::flush (flg);
+}
+
+bool CountFilter::explore_stream (Buffer& buf)
+{
+	if (state_ == 1 && buf.length () >= 5)
+		state_ = (buf.prefix ((const uint8_t*) "HTTP/", 5) ? 2 : 0);
+	
+	if (state_ == 2)
+	{
+		unsigned pos, ext = buf.length ();
+		for (pos = 0; pos < ext - 1 && buf.find ('\n', pos, ext - pos - 1, &pos); ++pos)
+		{
+			uint8_t sfx[4] = {0, 0, 0, 0};
+			buf.copyout (sfx, pos + 1, (ext > pos + 1 ? 2 : 1));
+			if (sfx[0] == '\n' || (sfx[0] == '\r' && sfx[1] == '\n'))
+			{
+				HTTPProtocol::Message msg (HTTPProtocol::Message::Response);
+				std::map<std::string, std::vector<Buffer> >::iterator it;
+				unsigned lng = 0;
+				if (msg.decode (&buf) && msg.headers_.find ("Transfer-Encoding") == msg.headers_.end () &&
+					 (it = msg.headers_.find ("Content-Length")) != msg.headers_.end () && it->second.size () > 0)
+				{
+					Buffer val = it->second[0];
+					while (val.length () > 0)
+					{
+						uint8_t c = val.peek ();
+						val.skip (1);
+						if (c >= '0' && c <= '9')
+							lng = (lng * 10) + (c - '0');
+						else
+						{
+							lng = 0;
+							break;
+						}
+					}
+				}
+				if (lng > 0)
+				{
+					if (lng > buf.length ())
+					{
+						expected_ = lng;
+						count_ = buf.length ();
+						state_ = (lng < 1000 ? 3 : 4);  // don't wait for cookie resources
+					}
+					else
+					{
+						buf.skip (lng);
+						state_ = 1;
+						return false;
+					}
+				}
+				else
+				{
+					state_ = 0;
+				}
+				break;
+			}
+		}
+	}
+	
+	return true;
+}