added option restartonsignal for PCAPExporterPipe

git-svn-id: file:///Users/braun/svn/vermont/branches/vermont/dtls-merge@2452 aef3b71b-58ee-0310-9ba9-8811b9f0742f

docs/config/module_configuration.txt

@@ -772,6 +772,7 @@ Output type: none
 |fiforeadercmd|  none  |A single (i.e. no shell) command, which must read PCAP files via STDIN. |
 |sigkilltimeout|  1  |Maximum additional waiting time in seconds, until a SIGKILL is sent to the reader process on module shutdown. |
 |appenddate |  false  |If set to true, the logfilename given as logfilebasename will be suffixed with the current time and date |
+|restartonsignal |  false  |If set to true, the command specified as fiforedercmd will be restarted, when a SIGUSR2 is sent to vermont |
 |linkType |  EN10MB  |Data link type of the output file. Names are DLT_ names form the pcap man page with the DLT_ removed (see `man pcap') |
 |snaplen |  PCAP_MAX_  |Snaplen for the pcap file |
 | |  CAPTURE_LENGTH  | |

src/modules/packet/PCAPExporterPipe.cpp

@@ -41,8 +41,8 @@ namespace bfs = boost::filesystem;
 
 PCAPExporterPipe::PCAPExporterPipe(const std::string& logfile)
 	: logFileName(logfile), fifoReaderCmd(""), onRestart(false),
-	appenddate(false),  fifoReaderPid(0), dummy(NULL), 
-	sigKillTimeout(1),counter(0), last_check(0)
+	appenddate(false),  restartOnSignal(false),fifoReaderPid(0), 
+	dummy(NULL), sigKillTimeout(1),counter(0), last_check(0)
 {
 }
 
@@ -65,6 +65,10 @@ void PCAPExporterPipe::setSigKillTimeout(int s)
 	sigKillTimeout = s;
 }
 
+void PCAPExporterPipe::setRestartOnSignal(bool b){
+	restartOnSignal = b;
+}
+
 int PCAPExporterPipe::execCmd(std::string& cmd)
 {
 	//char *command[] = {"tcpdump","-nr", "-" , (char*)0}; //"-w", "/tmp/pcap.dump",(char*)0};
@@ -173,6 +177,9 @@ void PCAPExporterPipe::performStart()
 
 	SignalHandler::getInstance().registerSignalHandler(SIGCHLD, this);
 	SignalHandler::getInstance().registerSignalHandler(SIGPIPE, this);
+	if(restartOnSignal)
+		SignalHandler::getInstance().registerSignalHandler(SIGUSR2, this);
+
 	dummy = pcap_open_dead(link_type, snaplen);
 	if (!dummy) {
 		THROWEXCEPTION("Could not open dummy device: %s", errbuf);
@@ -204,6 +211,8 @@ void PCAPExporterPipe::performShutdown()
 {
 	SignalHandler::getInstance().unregisterSignalHandler(SIGCHLD, this);
 	SignalHandler::getInstance().unregisterSignalHandler(SIGPIPE, this);
+	if(restartOnSignal)
+		SignalHandler::getInstance().unregisterSignalHandler(SIGUSR2, this);
 	msg(MSG_DEBUG, "Performing shutdown for PID %d", fifoReaderPid);
 	sleep(1);
 	if (dumper) {
@@ -246,7 +255,7 @@ void PCAPExporterPipe::receive(Packet* packet) {
 		 return;
 	}
 	if(fifoReaderPid == 0){
-		 msg(MSG_ERROR, "fifoReaderPid = 0...this might happen during reconfiguration");
+		 msg(MSG_VDEBUG, "fifoReaderPid = 0...this might happen during reconfiguration");
 		 return; 
 	}
 	writePCAP(packet);
@@ -282,6 +291,13 @@ void PCAPExporterPipe::handleSigChld(int sig){
 	onRestart = false;
 }
 
+void PCAPExporterPipe::handleSigUsr2(int sig){
+	if (! restartOnSignal) return;
+	int pid = fifoReaderPid;
+	fifoReaderPid = 0;
+	kill_all(pid);
+	handleSigChld(sig);
+}
 void PCAPExporterPipe::kill_pid(int pid)
 {
 	int i = sigKillTimeout;

src/modules/packet/PCAPExporterPipe.h

@@ -40,9 +40,11 @@ public:
 	~PCAPExporterPipe();
     void setPipeReaderCmd(const std::string& cmd);
     void setSigKillTimeout(int s);
-	virtual void handleSigChld(int i);
-	virtual void handleSigPipe(int sig);
+	void setRestartOnSignal(bool b);
 	void setAppendDate(bool b);
+	virtual void handleSigChld(int sig);
+	virtual void handleSigPipe(int sig);
+	virtual void handleSigUsr2(int sig);
 	bool isRunning(int pid);
     int execCmd(std::string& cmd);
     void kill_all(int ppid);
@@ -64,6 +66,7 @@ private:
 	std::string logFileName;
 	std::string fifoReaderCmd;
 	bool appenddate;
+	bool restartOnSignal;
     int fifoReaderPid;
 	pcap_t* dummy;
     int sigKillTimeout;

src/modules/packet/PCAPExporterPipeCfg.cpp

@@ -28,7 +28,7 @@
 PCAPExporterPipeCfg::PCAPExporterPipeCfg(XMLElement* elem) 
 	: CfgHelper<PCAPExporterPipe, PCAPExporterPipeCfg>(elem, "pcapExporterPipe"), 
         link_type(DLT_EN10MB), snaplen(PCAP_MAX_CAPTURE_LENGTH), sigkilltimeout(1),
-        logFileName(""), fifoReaderCmd(""), appenddate(false)
+        logFileName(""), fifoReaderCmd(""), appenddate(false), restart(false)
 { 
 	if (!elem) return;
 
@@ -49,12 +49,14 @@ PCAPExporterPipeCfg::PCAPExporterPipeCfg(XMLElement* elem)
 			}
 		} else if (e->matches("snaplen")) {
 			snaplen = getInt("snaplen", PCAP_MAX_CAPTURE_LENGTH, e);
-		} else if (e->matches("sigkilltimeout")){
+		} else if (e->matches("sigkilltimeout")) {
             sigkilltimeout = getInt("sigkilltimeout", 1, e);
-        } else if(e->matches("fiforeadercmd")){
+        } else if(e->matches("fiforeadercmd")) {
             fifoReaderCmd = e->getFirstText();
-        }else if(e->matches("appenddate")){
+        } else if (e->matches("appenddate")) {
 			appenddate = getBool("appenddate", false, e);
+		} else if(e->matches("restartonsignal")) {
+			restart = getBool("restartonsignal", false, e);
 		}
 	}
 } 
@@ -78,6 +80,7 @@ PCAPExporterPipe* PCAPExporterPipeCfg::createInstance()
     instance->setSigKillTimeout(sigkilltimeout);
     instance->setPipeReaderCmd(fifoReaderCmd);
 	instance->setAppendDate(appenddate);
+	instance->setRestartOnSignal(restart);
 	return instance;
 }
 
@@ -88,7 +91,8 @@ bool PCAPExporterPipeCfg::deriveFrom(PCAPExporterPipeCfg* old)
         snaplen != old->snaplen ||
         fifoReaderCmd != old->fifoReaderCmd || 
         sigkilltimeout != old->sigkilltimeout ||
-		appenddate != old->appenddate
+		appenddate != old->appenddate ||
+		restart != old->restart
         ) return false;
 	return true; // FIXME: implement
 }

src/modules/packet/PCAPExporterPipeCfg.h

@@ -49,6 +49,7 @@ private:
 	int snaplen;
     int sigkilltimeout;
 	bool appenddate;
+	bool restart;
 	std::string logFileName;
     std::string fifoReaderCmd;
 };