From 68240908bca991b0d091c51bbb2c6d0dc403518b Mon Sep 17 00:00:00 2001
From: John Sharratt <John@TheAlien.(none)>
Date: Sat, 1 Jul 2017 10:21:14 +0200
Subject: [PATCH] Separated the TTL so that invalid sessions can be expired
 faster than valid sessions (DDOS protection and better error handling)

---
 src/ndppd.cc   |  5 +++++
 src/proxy.cc   | 12 +++++++++++-
 src/proxy.h    |  6 +++++-
 src/session.cc |  4 ++--
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/ndppd.cc b/src/ndppd.cc
index cb5450c..80dc6d4 100644
--- a/src/ndppd.cc
+++ b/src/ndppd.cc
@@ -169,6 +169,11 @@ static bool configure(ptr<conf>& cf)
             pr->ttl(30000);
         else
             pr->ttl(*x_cf);
+        
+        if (!(x_cf = pr_cf->find("deadtime")))
+            pr->deadtime(pr->ttl());
+        else
+            pr->deadtime(*x_cf);
 
         if (!(x_cf = pr_cf->find("timeout")))
             pr->timeout(500);
diff --git a/src/proxy.cc b/src/proxy.cc
index 2b6d1c9..da71c36 100644
--- a/src/proxy.cc
+++ b/src/proxy.cc
@@ -30,7 +30,7 @@ NDPPD_NS_BEGIN
 std::list<ptr<proxy> > proxy::_list;
 
 proxy::proxy() :
-    _router(true), _ttl(30000), _timeout(500), _autowire(false)
+    _router(true), _ttl(30000), _deadtime(3000), _timeout(500), _autowire(false)
 {
 }
 
@@ -197,6 +197,16 @@ void proxy::ttl(int val)
     _ttl = (val >= 0) ? val : 30000;
 }
 
+int proxy::deadtime() const
+{
+    return _deadtime;
+}
+
+void proxy::deadtime(int val)
+{
+    _deadtime = (val >= 0) ? val : 30000;
+}
+
 int proxy::timeout() const
 {
     return _timeout;
diff --git a/src/proxy.h b/src/proxy.h
index 9baf720..829321c 100644
--- a/src/proxy.h
+++ b/src/proxy.h
@@ -60,6 +60,10 @@ public:
     int ttl() const;
 
     void ttl(int val);
+    
+    int deadtime() const;
+
+    void deadtime(int val);
 
 private:
     static std::list<ptr<proxy> > _list;
@@ -76,7 +80,7 @@ private:
     
     bool _autowire;
 
-    int _ttl, _timeout;
+    int _ttl, _deadtime, _timeout;
 
     proxy();
 };
diff --git a/src/session.cc b/src/session.cc
index 85d0f75..b3c4802 100644
--- a/src/session.cc
+++ b/src/session.cc
@@ -45,7 +45,7 @@ void session::update_all(int elapsed_time)
         case session::WAITING:
             logger::debug() << "session is now invalid";
             se->_status = session::INVALID;
-            se->_ttl    = se->_pr->ttl();
+            se->_ttl    = se->_pr->deadtime();
             break;
 
         default:
@@ -81,7 +81,7 @@ ptr<session> session::create(const ptr<proxy>& pr, const address& saddr,
 
     logger::debug()
         << "session::create() pr=" << logger::format("%x", (proxy* )pr) << ", saddr=" << saddr
-        << ", daddr=" << daddr << ", taddr=" << taddr << ", autowire=" << (_autowire ? "yes" : "no") << " =" << logger::format("%x", (session* )se);
+        << ", daddr=" << daddr << ", taddr=" << taddr << ", autowire=" << (auto_wire == true ? "yes" : "no") << " =" << logger::format("%x", (session* )se);
 
     return se;
 }