From 900c5f53e08aacb9e391ba9de400e82ee528afe3 Mon Sep 17 00:00:00 2001
From: Chris Tallon <chris@telescope.org>
Date: Mon, 7 Jan 2013 17:30:39 +0000
Subject: [PATCH] New VOMP discovery protocol

---
 mvpserver.c        | 20 ++++++++++++---
 mvpserver.h        |  1 +
 udpreplier.c       | 63 ++++++++++++++++++++++++++++++++++++++--------
 udpreplier.h       |  5 ++--
 vompclientrrproc.c | 15 +++++++----
 vompclientrrproc.h |  2 ++
 6 files changed, 85 insertions(+), 21 deletions(-)

diff --git a/mvpserver.c b/mvpserver.c
index 9a2eabf..8ae63b8 100644
--- a/mvpserver.c
+++ b/mvpserver.c
@@ -29,6 +29,7 @@ MVPServer::MVPServer()
 {
   // MH in case anbody has a better position :-)
   pthread_mutex_init(&threadClientMutex, NULL);
+  tcpServerPort = 0;
 }
 
 MVPServer::~MVPServer()
@@ -91,6 +92,12 @@ int MVPServer::run(char* tconfigDir)
     dsyslog("VOMP: Logging disabled");
   }
 
+  // Get UDP port number for discovery service
+
+  int fail = 1;
+  int udpport = config.getValueLong("General", "UDP port", &fail);
+  if (fail) udpport = 51051;  
+  
   // Work out a name for this server
 
   char* serverName;
@@ -100,13 +107,18 @@ int MVPServer::run(char* tconfigDir)
   if (!serverName) // If not, get the hostname
   {
     serverName = new char[1024];
-    if (gethostname(serverName, 1024)) // if not, just use "-"
+    if (gethostname(serverName, 1024)) // if not, set default
     {
-      strcpy(serverName, "-");
+      strcpy(serverName, "VOMP Server");
     }
   }
 
-  int udpSuccess = udpr.run(serverName);
+  // Get VOMP server TCP port to give to UDP replier to put in packets
+  fail = 1;
+  tcpServerPort = config.getValueLong("General", "TCP port", &fail);
+  if (fail) tcpServerPort = 3024;
+  
+  int udpSuccess = udpr.run(udpport, serverName, tcpServerPort);
 
   delete[] serverName;
 
@@ -232,7 +244,7 @@ void MVPServer::threadMethod()
 
   struct sockaddr_in address;
   address.sin_family = AF_INET;
-  address.sin_port = htons(3024);
+  address.sin_port = htons(tcpServerPort);
   address.sin_addr.s_addr = INADDR_ANY;
   socklen_t length = sizeof(address);
 
diff --git a/mvpserver.h b/mvpserver.h
index 07ca1c9..80cc211 100644
--- a/mvpserver.h
+++ b/mvpserver.h
@@ -54,6 +54,7 @@ class MVPServer : public Thread
     MVPRelay mvprelay;
     int listeningSocket;
     char* configDir;
+    USHORT tcpServerPort;
 };
 
 #endif
diff --git a/udpreplier.c b/udpreplier.c
index 0b43e17..a98a1e2 100644
--- a/udpreplier.c
+++ b/udpreplier.c
@@ -18,11 +18,14 @@
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
 
+#include "vompclientrrproc.h"
+
 #include "udpreplier.h"
 
 UDPReplier::UDPReplier()
 {
-  serverName = NULL;
+  message = NULL;
+  messageLen = 0;
 }
 
 UDPReplier::~UDPReplier()
@@ -34,19 +37,59 @@ int UDPReplier::shutdown()
 {
   if (threadIsActive()) threadCancel();
 
-  if (serverName) delete[] serverName;
-  serverName = NULL;
+  if (message) delete[] message;
+  message = NULL;
   return 1;
 }
 
-int UDPReplier::run(char* tserverName)
+int UDPReplier::run(USHORT port, char* serverName, USHORT serverPort)
 {
   if (threadIsActive()) return 1;
 
-  serverName = new char[strlen(tserverName)+1];
-  strcpy(serverName, tserverName);
-
-  if (!ds.init(3024))
+  /*
+  VOMP Discovery Protocol V1
+
+  Client transmits: "VDP-0001\0<6-byte MAC>" on ports 51051-51055
+
+  Server responds:
+
+  Field 1 p0: 9 bytes "VDP-0002\0"
+  
+  Field 2 p9, 1 byte:
+
+  0 = no IP specified
+  4 = first 4 bytes of field 2 are IPv4 address of server
+  6 = field 2 16 bytes are IPv6 address of server
+
+  Field 3, p10, 16 bytes:
+  As described above. If field 1 is 0, this should be all zeros. If this is an IPv4 address, remaining bytes should be zeros.
+
+  Field 4 p26, 2 bytes:
+  Port number of server
+
+  Field 5 p28, 4 bytes:
+  VOMP protocol version (defined in vdr.cc)
+  
+  Field 6 p32, variable length
+  String of server name, null terminated
+  */
+  
+  messageLen = strlen(serverName) + 33;
+  message = new char[messageLen];
+  memset(message, 0, messageLen);
+  // by zeroing the packet, this sets no ip address return information
+  
+  strcpy(message, "VDP-0002");
+  
+  USHORT temp = htons(serverPort);
+  memcpy(&message[26], &temp, 2);
+  
+  ULONG temp2 = htonl(VompClientRRProc::getProtocolVersion());
+  memcpy(&message[28], &temp2, 4);
+  
+  strcpy(&message[32], serverName);
+
+  if (!ds.init(port))
   {
     shutdown();
     return 0;
@@ -70,10 +113,10 @@ void UDPReplier::threadMethod()
     retval = ds.waitforMessage(0);
     if (retval == 1) continue;
 
-    if (!strcmp(ds.getData(), "VOMP"))
+    if (!strncmp(ds.getData(), "VDP-0001", 8))
     {
       Log::getInstance()->log("UDPReplier", Log::DEBUG, "UDP request from %s", ds.getFromIPA());
-      ds.send(ds.getFromIPA(), 3024, serverName, strlen(serverName));
+      ds.send(ds.getFromIPA(), ds.getFromPort(), message, messageLen);
     }
   }
 }
diff --git a/udpreplier.h b/udpreplier.h
index a287189..9383d84 100644
--- a/udpreplier.h
+++ b/udpreplier.h
@@ -34,14 +34,15 @@ class UDPReplier : public Thread
     UDPReplier();
     virtual ~UDPReplier();
 
-    int run(char* tserverName);
+    int run(USHORT udpPort, char* serverName, USHORT serverPort);
     int shutdown();
 
   private:
     void threadMethod();
 
     DatagramSocket ds;
-    char* serverName;
+    char* message;
+    int messageLen;
 };
 
 #endif
diff --git a/vompclientrrproc.c b/vompclientrrproc.c
index ae670cf..c313ce8 100644
--- a/vompclientrrproc.c
+++ b/vompclientrrproc.c
@@ -42,14 +42,19 @@
 
 bool ResumeIDLock;
 
-#define VOMP_PROTOCOLL_VERSION 0x00000100
+ULONG VompClientRRProc::VOMP_PROTOCOL_VERSION = 0x00000100;
 // format is aabbccdd
-// cc is release protocol version, increase with every release, that changes protocoll
+// cc is release protocol version, increase with every release, that changes protocol
 // dd is development protocol version, set to zero at every release, 
-// increase for every protocoll change in git
-// bb not equal zero should indicate a non loggytronic protocoll
+// increase for every protocol change in git
+// bb not equal zero should indicate a non loggytronic protocol
 // aa is reserved for future use
 
+ULONG VompClientRRProc::getProtocolVersion()
+{
+  return VOMP_PROTOCOL_VERSION;
+}
+
 VompClientRRProc::VompClientRRProc(VompClient& x)
  : x(x)
 {
@@ -309,7 +314,7 @@ int VompClientRRProc::processLogin()
 
   resp->addULONG(timeNow);
   resp->addLONG(timeOffset);
-  resp->addULONG(VOMP_PROTOCOLL_VERSION);
+  resp->addULONG(VOMP_PROTOCOL_VERSION);
   resp->finalise();
   x.tcp.sendPacket(resp->getPtr(), resp->getLen());
   log->log("RRProc", Log::DEBUG, "written login reply len %lu", resp->getLen());
diff --git a/vompclientrrproc.h b/vompclientrrproc.h
index 535766c..8e7bc7b 100644
--- a/vompclientrrproc.h
+++ b/vompclientrrproc.h
@@ -52,6 +52,7 @@ class VompClientRRProc : public Thread
   public:
     VompClientRRProc(VompClient& x);
     ~VompClientRRProc();
+    static ULONG getProtocolVersion();
     
     bool init();
     bool recvRequest(RequestPacket*);
@@ -99,6 +100,7 @@ class VompClientRRProc : public Thread
     RequestPacket* req;
     RequestPacketQueue req_queue;
     ResponsePacket* resp;
+    static ULONG VOMP_PROTOCOL_VERSION;
     
     Log* log;
 };
-- 
2.39.5