Added exception handling for virtual socket add/del functions

include/libzt.h

@@ -105,9 +105,19 @@ struct zts_ifreq {
 // For LWIP configuration see: include/lwipopts.h
 
 #if defined(STACK_LWIP)
+/*
+  Specifies the polling interval and the callback function that should
+  be called to poll the application. The interval is specified in
+  number of TCP coarse grained timer shots, which typically occurs
+  twice a second. An interval of 10 means that the application would
+  be polled every 5 seconds. */
 #define LWIP_APPLICATION_POLL_FREQ         2
-#define LWIP_TCP_TIMER_INTERVAL            50
+
-#define LWIP_STATUS_TMR_INTERVAL           500 // How often we check VirtualSocket statuses (in ms)
+#define LWIP_TCP_TIMER_INTERVAL            25
+
+// How often we check VirtualSocket statuses (in ms)
+#define LWIP_STATUS_TMR_INTERVAL           500 
+
 // #define LWIP_CHKSUM <your_checksum_routine>, See: RFC1071 for inspiration
 #endif
 
@@ -591,26 +601,26 @@ ZeroTier::VirtualSocket *get_virtual_socket(int fd);
 /*
  * Removes a VirtualSocket
  */
-void del_virtual_socket(int fd);
+int del_virtual_socket(int fd);
 
 /*
  * Adds a virtualSocket
  */
-void add_unassigned_virtual_socket(int fd, ZeroTier::VirtualSocket *vs);
+int add_unassigned_virtual_socket(int fd, ZeroTier::VirtualSocket *vs);
 /*
  * Removes unassigned VirtualSocket
  */
-void del_unassigned_virtual_socket(int fd);
+int del_unassigned_virtual_socket(int fd);
 
 /*
  * Adds an assigned VirtualSocket
  */
-void add_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd);
+int add_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd);
 
 /*
  * Removes an assigned VirtualSocket
  */
-void del_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd);
+int del_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd);
 
 /*
  * Gets a pair of associated virtual objects (VirtualSocket bound to a VirtualTap)

src/libzt.cpp

@@ -140,7 +140,16 @@ void zts_simple_start(const char *path, const char *nwid)
 	while(!zts_running()) {
 		nanosleep((const struct timespec[]){{0, (ZT_API_CHECK_INTERVAL * 1000000)}}, NULL);
 	}
+	while(1) {
+		try {
 			zts_join(nwid);
+			break;
+		}
+		catch( ... ) {
+			DEBUG_ERROR("there was a problem joining the virtual network");
+			handle_general_failure();
+		}
+	}
 	while(!zts_has_address(nwid)) {
 		nanosleep((const struct timespec[]){{0, (ZT_API_CHECK_INTERVAL * 1000000)}}, NULL);
 	}
@@ -2153,9 +2162,11 @@ ZeroTier::VirtualSocket *get_virtual_socket(int fd)
 	return vs;
 }
 
-void del_virtual_socket(int fd)
+int del_virtual_socket(int fd)
 {
+	int err = 0;
 	ZeroTier::_multiplexer_lock.lock();
+	try {
 		std::map<int, ZeroTier::VirtualSocket*>::iterator un_iter = ZeroTier::unmap.find(fd);
 		if(un_iter != ZeroTier::unmap.end()) {
 			ZeroTier::unmap.erase(un_iter);
@@ -2164,12 +2175,21 @@ void del_virtual_socket(int fd)
 		if(fd_iter != ZeroTier::fdmap.end()) {
 			ZeroTier::fdmap.erase(fd_iter);
 		}
+	}
+	catch( ... ) {
+		DEBUG_ERROR("unable to remove virtual socket");
+		handle_general_failure();
+		err = -1;
+	}
 	ZeroTier::_multiplexer_lock.unlock();
+	return err;
 }
 
-void add_unassigned_virtual_socket(int fd, ZeroTier::VirtualSocket *vs)
+int add_unassigned_virtual_socket(int fd, ZeroTier::VirtualSocket *vs)
 {
+	int err = 0;
 	ZeroTier::_multiplexer_lock.lock();
+	try {
 		std::map<int, ZeroTier::VirtualSocket*>::iterator un_iter = ZeroTier::unmap.find(fd);
 		if(un_iter == ZeroTier::unmap.end()) {
 			ZeroTier::unmap[fd] = vs;
@@ -2178,22 +2198,40 @@ void add_unassigned_virtual_socket(int fd, ZeroTier::VirtualSocket *vs)
 			DEBUG_ERROR("fd=%d already contained in <fd:vs> map", fd);
 			handle_general_failure();
 		}
+	}
+	catch( ... ) {
+		DEBUG_ERROR("unable to add virtual socket");
+		handle_general_failure();
+		err = -1;
+	}
 	ZeroTier::_multiplexer_lock.unlock();
+	return err;
 }
 
-void del_unassigned_virtual_socket(int fd)
+int del_unassigned_virtual_socket(int fd)
 {
+	int err = 0;
 	ZeroTier::_multiplexer_lock.lock();
+	try {
 		std::map<int, ZeroTier::VirtualSocket*>::iterator un_iter = ZeroTier::unmap.find(fd);
 		if(un_iter != ZeroTier::unmap.end()) {
 			ZeroTier::unmap.erase(un_iter);
 		}
+	}
+	catch( ... ) {
+		DEBUG_ERROR("unable to remove virtual socket");
+		handle_general_failure();
+		err = -1;
+	}
 	ZeroTier::_multiplexer_lock.unlock();
+	return err;
 }
 
-void add_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd)
+int add_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd)
 {
+	int err = 0;
 	ZeroTier::_multiplexer_lock.lock();
+	try {
 		std::map<int, std::pair<ZeroTier::VirtualSocket*,ZeroTier::VirtualTap*>*>::iterator fd_iter = ZeroTier::fdmap.find(fd);
 		if(fd_iter == ZeroTier::fdmap.end()) {
 			ZeroTier::fdmap[fd] = new std::pair<ZeroTier::VirtualSocket*,ZeroTier::VirtualTap*>(vs, tap);
@@ -2202,17 +2240,33 @@ void add_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSoc
 			DEBUG_ERROR("fd=%d already contained in <fd,<vs,vt>> map", fd);
 			handle_general_failure();
 		}
+	}
+	catch( ... ) {
+		DEBUG_ERROR("unable to add virtual socket");
+		handle_general_failure();
+		err = -1;
+	}
 	ZeroTier::_multiplexer_lock.unlock();
+	return err;
 }
 
-void del_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd)
+int del_assigned_virtual_socket(ZeroTier::VirtualTap *tap, ZeroTier::VirtualSocket *vs, int fd)
 {
+	int err = 0;
 	ZeroTier::_multiplexer_lock.lock();
+	try {
 		std::map<int, std::pair<ZeroTier::VirtualSocket*,ZeroTier::VirtualTap*>*>::iterator fd_iter = ZeroTier::fdmap.find(fd);
 		if(fd_iter != ZeroTier::fdmap.end()) {
 			ZeroTier::fdmap.erase(fd_iter);
 		}
+	}
+	catch( ... ) {
+		DEBUG_ERROR("unable to remove virtual socket");
+		handle_general_failure();
+		err = -1;
+	}
 	ZeroTier::_multiplexer_lock.unlock();
+	return err;
 }
 
 std::pair<ZeroTier::VirtualSocket*, ZeroTier::VirtualTap*> *get_assigned_virtual_pair(int fd)