diff --git a/lib/isc/include/isc/socket.h b/lib/isc/include/isc/socket.h
index 56c66396ce..50ba2c42a4 100644
--- a/lib/isc/include/isc/socket.h
+++ b/lib/isc/include/isc/socket.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.h,v 1.53 2001/02/12 21:43:17 bwelling Exp $ */
+/* $Id: socket.h,v 1.54 2001/03/06 01:23:02 bwelling Exp $ */
 
 #ifndef ISC_SOCKET_H
 #define ISC_SOCKET_H 1
@@ -167,6 +167,7 @@ typedef enum {
  * Flags for isc_socket_send() and isc_socket_recv() calls.
  */
 #define ISC_SOCKFLAG_IMMEDIATE	0x00000001	/* send event only if needed */
+#define ISC_SOCKFLAG_NORETRY	0x00000002	/* drop failed UDP sends */
 
 /***
  *** Socket and Socket Manager Functions
@@ -569,12 +570,20 @@ isc_socket_sendto2(isc_socket_t *sock, isc_region_t *region,
  *	expected to be initialized.
  *
  *	For isc_socket_sendto2():
- *	The only defined value for 'flags' is ISC_SOCKFLAG_IMMEDIATE.  If
- *	set and the operation completes, the return value will be
- *	ISC_R_SUCCESS and the event will be filled in and not sent.  If the
- *	operation does not complete, the return value will be
- *	ISC_R_INPROGRESS and the event will be sent when the operation
- *	completes.
+ *	The only defined values for 'flags' are ISC_SOCKFLAG_IMMEDIATE
+ *	and ISC_SOCKFLAG_NORETRY.
+ *
+ *	If ISC_SOCKFLAG_IMMEDIATE is set and the operation completes, the
+ *	return value will be ISC_R_SUCCESS and the event will be filled
+ *	in and not sent.  If the operation does not complete, the return
+ *	value will be ISC_R_INPROGRESS and the event will be sent when
+ *	the operation completes.
+ *
+ *	ISC_SOCKFLAG_NORETRY can only be set for UDP sockets.  If set
+ *	and the send operation fails due to a transient error, the send
+ *	will not be retried and the error will be indicated in the event.
+ *	Using this option along with ISC_SOCKFLAG_IMMEDIATE allows the caller
+ *	to specify a region that is allocated on the stack.
  *
  * Requires:
  *
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index 05e28b4ed3..f58e0676b4 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.c,v 1.193 2001/02/24 23:51:09 gson Exp $ */
+/* $Id: socket.c,v 1.194 2001/03/06 01:23:03 bwelling Exp $ */
 
 #include <config.h>
 
@@ -151,6 +151,11 @@ typedef isc_event_t intev_t;
 
 #endif /* USE_CMSG */
 
+/*
+ * The number of times a send operation is repeated if the result is EINTR.
+ */
+#define NRETRIES 10
+
 struct isc_socket {
 	/* Not locked. */
 	unsigned int		magic;
@@ -1002,15 +1007,20 @@ doio_send(isc_socket_t *sock, isc_socketevent_t *dev) {
 #else
 	char *cmsg = NULL;
 #endif
+	int attempts = 0;
 
 	build_msghdr_send(sock, dev, &msghdr, cmsg, iov, &write_count);
 
+ resend:
 	cc = sendmsg(sock->fd, &msghdr, 0);
 
 	/*
 	 * Check for error or block condition.
 	 */
 	if (cc < 0) {
+		if (errno == EINTR && ++attempts < NRETRIES)
+			goto resend;
+
 		if (SOFT_ERROR(errno))
 			return (DOIO_SOFT);
 
@@ -2476,33 +2486,36 @@ socket_send(isc_socket_t *sock, isc_socketevent_t *dev, isc_task_t *task,
 	case DOIO_SOFT:
 		/*
 		 * We couldn't send all or part of the request right now, so
-		 * queue it.
+		 * queue it unless ISC_SOCKFLAG_NORETRY is set.
 		 */
-		isc_task_attach(task, &ntask);
-		dev->attributes |= ISC_SOCKEVENTATTR_ATTACHED;
+		if ((flags & ISC_SOCKFLAG_NORETRY) == 0) {
+			isc_task_attach(task, &ntask);
+			dev->attributes |= ISC_SOCKEVENTATTR_ATTACHED;
 
-		if (!have_lock) {
-			LOCK(&sock->lock);
-			have_lock = ISC_TRUE;
+			if (!have_lock) {
+				LOCK(&sock->lock);
+				have_lock = ISC_TRUE;
+			}
+
+			/*
+			 * Enqueue the request.  If the socket was previously
+			 * not being watched, poke the watcher to start
+			 * paying attention to it.
+			 */
+			if (ISC_LIST_EMPTY(sock->send_list))
+				select_poke(sock->manager, sock->fd,
+					    SELECT_POKE_WRITE);
+			ISC_LIST_ENQUEUE(sock->send_list, dev, ev_link);
+
+			socket_log(sock, NULL, EVENT, NULL, 0, 0,
+				   "socket_send: event %p -> task %p",
+				   dev, ntask);
+
+			if ((flags & ISC_SOCKFLAG_IMMEDIATE) != 0)
+				result = ISC_R_INPROGRESS;
+			break;
 		}
 
-		/*
-		 * Enqueue the request.  If the socket was previously not being
-		 * watched, poke the watcher to start paying attention to it.
-		 */
-		if (ISC_LIST_EMPTY(sock->send_list))
-			select_poke(sock->manager, sock->fd,
-				    SELECT_POKE_WRITE);
-		ISC_LIST_ENQUEUE(sock->send_list, dev, ev_link);
-
-		socket_log(sock, NULL, EVENT, NULL, 0, 0,
-			   "socket_send: event %p -> task %p",
-			   dev, ntask);
-
-		if ((flags & ISC_SOCKFLAG_IMMEDIATE) != 0)
-			result = ISC_R_INPROGRESS;
-		break;
-
 	case DOIO_HARD:
 	case DOIO_SUCCESS:
 		if ((flags & ISC_SOCKFLAG_IMMEDIATE) == 0)
@@ -2609,6 +2622,9 @@ isc_socket_sendto2(isc_socket_t *sock, isc_region_t *region,
 		   isc_sockaddr_t *address, struct in6_pktinfo *pktinfo,
 		   isc_socketevent_t *event, unsigned int flags)
 {
+	REQUIRE((flags & ~(ISC_SOCKFLAG_IMMEDIATE|ISC_SOCKFLAG_NORETRY)) == 0);
+	if ((flags & ISC_SOCKFLAG_NORETRY) != 0)
+		REQUIRE(sock->type == isc_sockettype_udp);
 	event->ev_sender = sock;
 	event->result = ISC_R_UNEXPECTED;
 	ISC_LIST_INIT(event->bufferlist);