From: bert hubert <bert.hubert@netherlabs.nl>
Date: Wed, 1 Apr 2015 11:28:43 +0000 (+0200)
Subject: first step in taking TCP/IP seriously: we actually apply policy now
X-Git-Tag: dnsdist-1.0.0-alpha1~248^2~88^2~19^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6ce2da14384c5d10fb2b77c4339222c1c0037f62;p=thirdparty%2Fpdns.git

first step in taking TCP/IP seriously: we actually apply policy now
---

diff --git a/pdns/dnsdist-tcp.cc b/pdns/dnsdist-tcp.cc
index b7b59a1893..22f1628bb4 100644
--- a/pdns/dnsdist-tcp.cc
+++ b/pdns/dnsdist-tcp.cc
@@ -43,43 +43,15 @@ using std::atomic;
    Let's start naively.
 */
 
-int getTCPDownstream(policy_t policy, string pool, DownstreamState** ds, const ComboAddress& remote, const DNSName& qname, uint16_t qtype, dnsheader* dh)
+static int setupTCPDownstream(const ComboAddress& remote)
 {  
-  {
-    std::lock_guard<std::mutex> lock(g_luamutex);
-    *ds = policy(getDownstreamCandidates(g_dstates.getCopy(), pool), remote, qname, qtype, dh).get(); 
-  }
   
-  vinfolog("TCP connecting to downstream %s", (*ds)->remote.toStringWithPort());
-  int sock = SSocket((*ds)->remote.sin4.sin_family, SOCK_STREAM, 0);
-  SConnect(sock, (*ds)->remote);
+  vinfolog("TCP connecting to downstream %s", remote.toStringWithPort());
+  int sock = SSocket(remote.sin4.sin_family, SOCK_STREAM, 0);
+  SConnect(sock, remote);
   return sock;
 }
 
-bool getMsgLen(int fd, uint16_t* len)
-try
-{
-  uint16_t raw;
-  int ret = readn2(fd, &raw, 2);
-  if(ret != 2)
-    return false;
-  *len = ntohs(raw);
-  return true;
-}
-catch(...) {
-   return false;
-}
-
-bool putMsgLen(int fd, uint16_t len)
-try
-{
-  uint16_t raw = htons(len);
-  int ret = writen2(fd, &raw, 2);
-  return ret==2;
-}
-catch(...) {
-  return false;
-}
 
 struct ConnectionInfo
 {
@@ -107,27 +79,24 @@ void TCPClientCollection::addTCPClientThread()
 
 TCPClientCollection g_tcpclientthreads;
 
-
-
 void* tcpClientThread(int pipefd)
 {
   /* we get launched with a pipe on which we receive file descriptors from clients that we own
      from that point on */
-  int dsock = -1;
-  DownstreamState *ds=0;
-  
+  auto localPolicy = g_policy.getLocal();
+  map<ComboAddress,int> sockets;
   for(;;) {
     ConnectionInfo* citmp, ci;
 
     readn2(pipefd, &citmp, sizeof(citmp));
     --g_tcpclientthreads.d_queued;
     ci=*citmp;
-    delete citmp;
-    
+    delete citmp;    
+
     uint16_t qlen, rlen;
-    string pool; // empty for now
+    string pool; // empty for now, we actually should do ACL, rulactions, the works here! XXX
+    shared_ptr<DownstreamState> ds;
     try {
-      auto localPolicy = g_policy.getLocal();
       for(;;) {      
         if(!getMsgLen(ci.fd, &qlen))
           break;
@@ -137,12 +106,18 @@ void* tcpClientThread(int pipefd)
 	uint16_t qtype;
 	DNSName qname(query, qlen, 12, false, &qtype);
 	struct dnsheader* dh =(dnsheader*)query;
-	if(dsock == -1) {
-	  dsock = getTCPDownstream(localPolicy->policy, pool, &ds, ci.remote, qname, qtype, dh);
+
+	{
+	  std::lock_guard<std::mutex> lock(g_luamutex);
+	  ds = localPolicy->policy(getDownstreamCandidates(g_dstates.getCopy(), pool), ci.remote, qname, qtype, dh);
 	}
-	else {
-	  vinfolog("Reusing existing TCP connection to %s", ds->remote.toStringWithPort());
+	int dsock;
+	if(sockets.count(ds->remote) == 0) {
+	  dsock=sockets[ds->remote]=setupTCPDownstream(ds->remote);
 	}
+	else
+	  dsock=sockets[ds->remote];
+
         ds->queries++;
         ds->outstanding++;
 
@@ -153,7 +128,7 @@ void* tcpClientThread(int pipefd)
         if(!putMsgLen(dsock, qlen)) {
 	  vinfolog("Downstream connection to %s died on us, getting a new one!", ds->remote.toStringWithPort());
           close(dsock);
-          dsock=getTCPDownstream(localPolicy->policy, pool, &ds, ci.remote, qname, qtype, dh);
+          sockets[ds->remote]=dsock=setupTCPDownstream(ds->remote);
           goto retry;
         }
       
@@ -162,7 +137,7 @@ void* tcpClientThread(int pipefd)
         if(!getMsgLen(dsock, &rlen)) {
 	  vinfolog("Downstream connection to %s died on us phase 2, getting a new one!", ds->remote.toStringWithPort());
           close(dsock);
-          dsock=getTCPDownstream(localPolicy->policy, pool, &ds, ci.remote, qname, qtype, dh);
+          sockets[ds->remote]=dsock=setupTCPDownstream(ds->remote);
           goto retry;
         }
 
@@ -178,7 +153,8 @@ void* tcpClientThread(int pipefd)
     vinfolog("Closing client connection with %s", ci.remote.toStringWithPort());
     close(ci.fd); 
     ci.fd=-1;
-    --ds->outstanding;
+    if(ds)
+      --ds->outstanding;
   }
   return 0;
 }
@@ -211,3 +187,29 @@ void* tcpAcceptorThread(void* p)
 
   return 0;
 }
+
+
+bool getMsgLen(int fd, uint16_t* len)
+try
+{
+  uint16_t raw;
+  int ret = readn2(fd, &raw, 2);
+  if(ret != 2)
+    return false;
+  *len = ntohs(raw);
+  return true;
+}
+catch(...) {
+   return false;
+}
+
+bool putMsgLen(int fd, uint16_t len)
+try
+{
+  uint16_t raw = htons(len);
+  int ret = writen2(fd, &raw, 2);
+  return ret==2;
+}
+catch(...) {
+  return false;
+}
diff --git a/pdns/dnsdist.cc b/pdns/dnsdist.cc
index b0b179f7ab..e7fe21082c 100644
--- a/pdns/dnsdist.cc
+++ b/pdns/dnsdist.cc
@@ -160,12 +160,9 @@ DownstreamState::DownstreamState(const ComboAddress& remote_)
   infolog("Added downstream server %s", remote.toStringWithPort());
 }
 
-
-
 std::mutex g_luamutex;
 LuaContext g_lua;
 
-
 GlobalStateHolder<ServerPolicy> g_policy;
 
 shared_ptr<DownstreamState> firstAvailable(const NumberedServerVector& servers, const ComboAddress& remote, const DNSName& qname, uint16_t qtype, dnsheader* dh)