implement maxudp under windows

bin/named/main.c

@@ -646,6 +646,9 @@ parse_T_opt(char *option) {
 		maxudp = 1460;
 	} else if (!strncmp(option, "maxudp=", 7)) {
 		maxudp = atoi(option + 7);
+		if (maxudp <= 0) {
+			named_main_earlyfatal("bad maxudp");
+		}
 	} else if (!strncmp(option, "mkeytimers=", 11)) {
 		p = strtok_r(option + 11, "/", &last);
 		if (p == NULL) {

lib/isc/include/isc/socket.h

@@ -1002,7 +1002,7 @@ isc_socketmgr_setreserved(isc_socketmgr_t *mgr, uint32_t);
  */
 
 void
-isc_socketmgr_maxudp(isc_socketmgr_t *mgr, int maxudp);
+isc_socketmgr_maxudp(isc_socketmgr_t *mgr, unsigned int maxudp);
 /*%<
  * Test interface. Drop UDP packet > 'maxudp'.
  */

lib/isc/unix/socket.c

@@ -386,7 +386,7 @@ struct isc__socketmgr {
 	ISC_LIST(isc__socket_t)	socklist;
 	int			reserved;	/* unlocked */
 	isc_condition_t		shutdown_ok;
-	int			maxudp;
+	size_t			maxudp;
 };
 
 struct isc__socketthread {
@@ -1592,8 +1592,11 @@ doio_recv(isc__socket_t *sock, isc_socketevent_t *dev) {
 		 * Simulate a firewall blocking UDP responses bigger than
 		 * 'maxudp' bytes.
 		 */
-		if (sock->manager->maxudp != 0 && cc > sock->manager->maxudp)
+		if (sock->manager->maxudp != 0 &&
+		    cc > (int)sock->manager->maxudp)
+		{
 			return (DOIO_SOFT);
+		}
 	}
 
 	socket_log(sock, &dev->address, IOEVENT,
@@ -1666,7 +1669,7 @@ doio_send(isc__socket_t *sock, isc_socketevent_t *dev) {
  resend:
 	if (sock->type == isc_sockettype_udp &&
 	    sock->manager->maxudp != 0 &&
-	    write_count > (size_t)sock->manager->maxudp)
+	    write_count > sock->manager->maxudp)
 		cc = write_count;
 	else
 		cc = sendmsg(sock->fd, &msghdr, 0);
@@ -3521,7 +3524,7 @@ isc_socketmgr_setreserved(isc_socketmgr_t *manager0, uint32_t reserved) {
 }
 
 void
-isc_socketmgr_maxudp(isc_socketmgr_t *manager0, int maxudp) {
+isc_socketmgr_maxudp(isc_socketmgr_t *manager0, unsigned int maxudp) {
 	isc__socketmgr_t *manager = (isc__socketmgr_t *)manager0;
 
 	REQUIRE(VALID_MANAGER(manager));

lib/isc/win32/socket.c

@@ -308,19 +308,20 @@ typedef struct IoCompletionInfo {
 
 struct isc_socketmgr {
 	/* Not locked. */
-	unsigned int			magic;
+	unsigned int		magic;
-	isc_mem_t		       *mctx;
+	isc_mem_t	       *mctx;
-	isc_mutex_t			lock;
+	isc_mutex_t		lock;
-	isc_stats_t		       *stats;
+	isc_stats_t	       *stats;
 
 	/* Locked by manager lock. */
-	ISC_LIST(isc_socket_t)		socklist;
+	ISC_LIST(isc_socket_t)	socklist;
 	bool			bShutdown;
-	isc_condition_t			shutdown_ok;
+	isc_condition_t		shutdown_ok;
-	HANDLE				hIoCompletionPort;
+	HANDLE			hIoCompletionPort;
-	int				maxIOCPThreads;
+	int			maxIOCPThreads;
-	HANDLE				hIOCPThreads[MAX_IOCPTHREADS];
+	HANDLE			hIOCPThreads[MAX_IOCPTHREADS];
-	DWORD				dwIOCPThreadIds[MAX_IOCPTHREADS];
+	DWORD			dwIOCPThreadIds[MAX_IOCPTHREADS];
+	size_t			maxudp;
 
 	/*
 	 * Debugging.
@@ -1133,12 +1134,23 @@ fill_recv(isc_socket_t *sock, isc_socketevent_t *dev) {
 			sock->recvbuf.from_addr_len);
 		if (isc_sockaddr_getport(&dev->address) == 0) {
 			if (isc_log_wouldlog(isc_lctx, IOEVENT_LEVEL)) {
-				socket_log(__LINE__, sock, &dev->address, IOEVENT,
+				socket_log(__LINE__, sock, &dev->address,
+					   IOEVENT,
 					   "dropping source port zero packet");
 			}
 			sock->recvbuf.remaining = 0;
 			return;
 		}
+		/*
+		 * Simulate a firewall blocking UDP responses bigger than
+		 * 'maxudp' bytes.
+		 */
+		if (sock->manager->maxudp != 0 &&
+		    sock->recvbuf.remaining > sock->manager->maxudp)
+		{
+			sock->recvbuf.remaining = 0;
+			return;
+		}
 	} else if (sock->type == isc_sockettype_tcp) {
 		dev->address = sock->address;
 	}
@@ -1247,6 +1259,18 @@ startio_send(isc_socket_t *sock, isc_socketevent_t *dev, int *nbytes,
 	int status;
 	struct msghdr *mh;
 
+	/*
+	 * Simulate a firewall blocking UDP responses bigger than
+	 * 'maxudp' bytes.
+	 */
+	if (sock->type == isc_sockettype_udp &&
+	    sock->manager->maxudp != 0 &&
+	    dev->region.length - dev->n > sock->manager->maxudp)
+	{
+		*nbytes = dev->region.length - dev->n;
+		return (DOIO_SUCCESS);
+	}
+
 	lpo = (IoCompletionInfo *)HeapAlloc(hHeapHandle,
 					    HEAP_ZERO_MEMORY,
 					    sizeof(IoCompletionInfo));
@@ -2100,9 +2124,11 @@ internal_recv(isc_socket_t *sock, int nbytes)
 		   "internal_recv: %d bytes received", nbytes);
 
 	/*
-	 * If we got here, the I/O operation succeeded.  However, we might still have removed this
+	 * If we got here, the I/O operation succeeded.  However, we might
-	 * event from our notification list (or never placed it on it due to immediate completion.)
+	 * still have removed this event from our notification list (or never
-	 * Handle the reference counting here, and handle the cancellation event just after.
+	 * placed it on it due to immediate completion.)
+	 * Handle the reference counting here, and handle the cancellation
+	 * event just after.
 	 */
 	INSIST(sock->pending_iocp > 0);
 	sock->pending_iocp--;
@@ -2110,13 +2136,15 @@ internal_recv(isc_socket_t *sock, int nbytes)
 	sock->pending_recv--;
 
 	/*
-	 * The only way we could have gotten here is that our I/O has successfully completed.
+	 * The only way we could have gotten here is that our I/O has
-	 * Update our pointers, and move on.  The only odd case here is that we might not
+	 * successfully completed. Update our pointers, and move on.
-	 * have received enough data on a TCP stream to satisfy the minimum requirements.  If
+	 *  The only odd case here is that we might not have received
-	 * this is the case, we will re-issue the recv() call for what we need.
+	 * enough data on a TCP stream to satisfy the minimum requirements.
+	 * If this is the case, we will re-issue the recv() call for what
+	 * we need.
 	 *
-	 * We do check for a recv() of 0 bytes on a TCP stream.  This means the remote end
+	 * We do check for a recv() of 0 bytes on a TCP stream.  This
-	 * has closed.
+	 * means the remote end has closed.
 	 */
 	if (nbytes == 0 && sock->type == isc_sockettype_tcp) {
 		send_recvdone_abort(sock, ISC_R_EOF);
@@ -2508,6 +2536,7 @@ isc_socketmgr_create2(isc_mem_t *mctx, isc_socketmgr_t **managerp,
 	manager->bShutdown = false;
 	manager->totalSockets = 0;
 	manager->iocp_total = 0;
+	manager->maxudp = 0;
 
 	*managerp = manager;
 
@@ -3870,9 +3899,10 @@ isc_socketmgr_createinctx(isc_mem_t *mctx, isc_socketmgr_t **managerp)
 	return (result);
 }
 
-/* Not implemented for win32 */
 void
-isc_socketmgr_maxudp(isc_socketmgr_t *manager, int maxudp) {
+isc_socketmgr_maxudp(isc_socketmgr_t *manager, unsigned int maxudp) {
-	UNUSED(manager);
+
-	UNUSED(maxudp);
+	REQUIRE(VALID_MANAGER(manager));
+
+	manager->maxudp = maxudp;
 }