Adding upstream version 1:9.16.44.upstream/1%9.16.44

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3965 insertions, 0 deletions

diff --git a/lib/isc/win32/socket.c b/lib/isc/win32/socket.c
new file mode 100644
index 0000000..c154175
--- /dev/null
+++ b/lib/isc/win32/socket.c
@@ -0,0 +1,3965 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0.  If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/* This code uses functions which are only available on Server 2003 and
+ * higher, and Windows XP and higher.
+ *
+ * This code is by nature multithreaded and takes advantage of various
+ * features to pass on information through the completion port for
+ * when I/O is completed.  All sends, receives, accepts, and connects are
+ * completed through the completion port.
+ *
+ * The number of Completion Port Worker threads used is the total number
+ * of CPU's + 1. This increases the likelihood that a Worker Thread is
+ * available for processing a completed request.
+ *
+ * XXXPDM 5 August, 2002
+ */
+
+#define MAKE_EXTERNAL 1
+
+#include <sys/types.h>
+
+#ifndef _WINSOCKAPI_
+#define _WINSOCKAPI_ /* Prevent inclusion of winsock.h in windows.h */
+#endif		     /* ifndef _WINSOCKAPI_ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <io.h>
+#include <process.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <isc/app.h>
+#include <isc/buffer.h>
+#include <isc/condition.h>
+#include <isc/list.h>
+#include <isc/log.h>
+#include <isc/mem.h>
+#include <isc/mutex.h>
+#include <isc/net.h>
+#include <isc/once.h>
+#include <isc/os.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/refcount.h>
+#include <isc/region.h>
+#include <isc/socket.h>
+#include <isc/stats.h>
+#include <isc/strerr.h>
+#include <isc/string.h>
+#include <isc/syslog.h>
+#include <isc/task.h>
+#include <isc/thread.h>
+#include <isc/util.h>
+#include <isc/win32os.h>
+
+/* clang-format off */
+/* U Can't Touch This */
+#include <mswsock.h>
+/* clang-format on */
+
+#ifdef HAVE_JSON_C
+#include <json_object.h>
+#endif /* HAVE_JSON_C */
+
+#ifdef HAVE_LIBXML2
+#include <libxml/xmlwriter.h>
+#define ISC_XMLCHAR (const xmlChar *)
+#endif /* HAVE_LIBXML2 */
+
+#include "errno2result.h"
+
+/*
+ * Set by the -T dscp option on the command line. If set to a value
+ * other than -1, we check to make sure DSCP values match it, and
+ * assert if not.
+ */
+LIBISC_EXTERNAL_DATA int isc_dscp_check_value = -1;
+
+/*
+ * How in the world can Microsoft exist with APIs like this?
+ * We can't actually call this directly, because it turns out
+ * no library exports this function.  Instead, we need to
+ * issue a runtime call to get the address.
+ */
+LPFN_CONNECTEX ISCConnectEx;
+LPFN_ACCEPTEX ISCAcceptEx;
+LPFN_GETACCEPTEXSOCKADDRS ISCGetAcceptExSockaddrs;
+
+/*
+ * Run expensive internal consistency checks.
+ */
+#ifdef ISC_SOCKET_CONSISTENCY_CHECKS
+#define CONSISTENT(sock) consistent(sock)
+#else /* ifdef ISC_SOCKET_CONSISTENCY_CHECKS */
+#define CONSISTENT(sock) \
+	do {             \
+	} while (0)
+#endif /* ifdef ISC_SOCKET_CONSISTENCY_CHECKS */
+static void
+consistent(isc_socket_t *sock);
+
+/*
+ * Define this macro to control the behavior of connection
+ * resets on UDP sockets.  See Microsoft KnowledgeBase Article Q263823
+ * for details.
+ * NOTE: This requires that Windows 2000 systems install Service Pack 2
+ * or later.
+ */
+#ifndef SIO_UDP_CONNRESET
+#define SIO_UDP_CONNRESET _WSAIOW(IOC_VENDOR, 12)
+#endif /* ifndef SIO_UDP_CONNRESET */
+
+/*
+ * Define what the possible "soft" errors can be.  These are non-fatal returns
+ * of various network related functions, like recv() and so on.
+ */
+#define SOFT_ERROR(e)                                                      \
+	((e) == WSAEINTR || (e) == WSAEWOULDBLOCK || (e) == EWOULDBLOCK || \
+	 (e) == EINTR || (e) == EAGAIN || (e) == 0)
+
+/*
+ * Pending errors are not really errors and should be
+ * kept separate
+ */
+#define PENDING_ERROR(e) ((e) == WSA_IO_PENDING || (e) == 0)
+
+#define DOIO_SUCCESS 0 /* i/o ok, event sent */
+#define DOIO_SOFT    1 /* i/o ok, soft error, no event sent */
+#define DOIO_HARD    2 /* i/o error, event sent */
+#define DOIO_EOF     3 /* EOF, no event sent */
+#define DOIO_PENDING 4 /* status when i/o is in process */
+#define DOIO_NEEDMORE                                          \
+	5 /* IO was processed, but we need more due to minimum \
+	   */
+
+#define DLVL(x) ISC_LOGCATEGORY_GENERAL, ISC_LOGMODULE_SOCKET, ISC_LOG_DEBUG(x)
+
+/*
+ * DLVL(90)  --  Function entry/exit and other tracing.
+ * DLVL(70)  --  Socket "correctness" -- including returning of events, etc.
+ * DLVL(60)  --  Socket data send/receive
+ * DLVL(50)  --  Event tracing, including receiving/sending completion events.
+ * DLVL(20)  --  Socket creation/destruction.
+ */
+#define TRACE_LEVEL	  90
+#define CORRECTNESS_LEVEL 70
+#define IOEVENT_LEVEL	  60
+#define EVENT_LEVEL	  50
+#define CREATION_LEVEL	  20
+
+#define TRACE	    DLVL(TRACE_LEVEL)
+#define CORRECTNESS DLVL(CORRECTNESS_LEVEL)
+#define IOEVENT	    DLVL(IOEVENT_LEVEL)
+#define EVENT	    DLVL(EVENT_LEVEL)
+#define CREATION    DLVL(CREATION_LEVEL)
+
+typedef isc_event_t intev_t;
+
+/*
+ * Socket State
+ */
+enum {
+	SOCK_INITIALIZED, /* Socket Initialized */
+	SOCK_OPEN,	  /* Socket opened but nothing yet to do */
+	SOCK_DATA,	  /* Socket sending or receiving data */
+	SOCK_LISTEN,	  /* TCP Socket listening for connects */
+	SOCK_ACCEPT,	  /* TCP socket is waiting to accept */
+	SOCK_CONNECT,	  /* TCP Socket connecting */
+	SOCK_CLOSED,	  /* Socket has been closed */
+};
+
+#define SOCKET_MAGIC	ISC_MAGIC('I', 'O', 'i', 'o')
+#define VALID_SOCKET(t) ISC_MAGIC_VALID(t, SOCKET_MAGIC)
+
+/*
+ * IPv6 control information.  If the socket is an IPv6 socket we want
+ * to collect the destination address and interface so the client can
+ * set them on outgoing packets.
+ */
+#ifndef USE_CMSG
+#define USE_CMSG 1
+#endif /* ifndef USE_CMSG */
+
+/*
+ * We really  don't want to try and use these control messages. Win32
+ * doesn't have this mechanism before XP.
+ */
+#undef USE_CMSG
+
+/*
+ * Message header for recvmsg and sendmsg calls.
+ * Used value-result for recvmsg, value only for sendmsg.
+ */
+struct msghdr {
+	SOCKADDR_STORAGE to_addr; /* UDP send/recv address */
+	int to_addr_len;	  /* length of the address */
+	WSABUF *msg_iov;	  /* scatter/gather array */
+	u_int msg_iovlen;	  /* # elements in msg_iov */
+	void *msg_control;	  /* ancillary data, see below */
+	u_int msg_controllen;	  /* ancillary data buffer len */
+	u_int msg_totallen;	  /* total length of this message */
+} msghdr;
+
+/*
+ * The size to raise the receive buffer to.
+ */
+#define RCVBUFSIZE (32 * 1024)
+
+/*
+ * The number of times a send operation is repeated if the result
+ * is WSAEINTR.
+ */
+#define NRETRIES 10
+
+struct isc_socket {
+	/* Not locked. */
+	unsigned int magic;
+	isc_socketmgr_t *manager;
+	isc_mutex_t lock;
+	isc_sockettype_t type;
+
+	/* Pointers to scatter/gather buffers */
+	WSABUF iov[ISC_SOCKET_MAXSCATTERGATHER];
+
+	/* Locked by socket lock. */
+	ISC_LINK(isc_socket_t) link;
+	isc_refcount_t references; /* EXTERNAL references */
+	SOCKET fd;		   /* file handle */
+	int pf;			   /* protocol family */
+	char name[16];
+	void *tag;
+
+	/*
+	 * Each recv() call uses this buffer.  It is a per-socket receive
+	 * buffer that allows us to decouple the system recv() from the
+	 * recv_list done events.  This means the items on the recv_list
+	 * can be removed without having to cancel pending system recv()
+	 * calls.  It also allows us to read-ahead in some cases.
+	 */
+	struct {
+		SOCKADDR_STORAGE from_addr; /* UDP send/recv address */
+		int from_addr_len;	    /* length of the address */
+		char *base;		    /* the base of the buffer */
+		char *consume_position;	    /* where to start
+					     * copying data from
+					     * next */
+		unsigned int len;	    /* the actual size of this buffer */
+		unsigned int remaining;	    /* the number of bytes
+					     * remaining */
+	} recvbuf;
+
+	ISC_LIST(isc_socketevent_t) send_list;
+	ISC_LIST(isc_socketevent_t) recv_list;
+	ISC_LIST(isc_socket_newconnev_t) accept_list;
+	ISC_LIST(isc_socket_connev_t) connect_list;
+
+	isc_sockaddr_t address; /* remote address */
+
+	unsigned int listener : 1,		    /* listener socket */
+		connected : 1, pending_connect : 1, /* connect
+						     * pending */
+		bound  : 1,			    /* bound to local addr */
+		dupped : 1;	     /* created by isc_socket_dup() */
+	unsigned int pending_iocp;   /* Should equal the counters below.
+				      * Debug. */
+	unsigned int pending_recv;   /* Number of outstanding recv() calls.
+				      * */
+	unsigned int pending_send;   /* Number of outstanding send() calls.
+				      * */
+	unsigned int pending_accept; /* Number of outstanding accept()
+				      * calls. */
+	unsigned int state;	     /* Socket state. Debugging and consistency
+				      * checking.
+				      */
+	int state_lineno;	     /* line which last touched state */
+};
+
+#define _set_state(sock, _state)                 \
+	do {                                     \
+		(sock)->state = (_state);        \
+		(sock)->state_lineno = __LINE__; \
+	} while (0)
+
+/*
+ * I/O Completion ports Info structures
+ */
+
+static HANDLE hHeapHandle = NULL;
+typedef struct IoCompletionInfo {
+	OVERLAPPED overlapped;
+	isc_socketevent_t *dev;	      /* send()/recv() done event */
+	isc_socket_connev_t *cdev;    /* connect() done event */
+	isc_socket_newconnev_t *adev; /* accept() done event */
+	void *acceptbuffer;
+	DWORD received_bytes;
+	int request_type;
+	struct msghdr messagehdr;
+	void *buf;
+	unsigned int buflen;
+} IoCompletionInfo;
+
+/*
+ * Define a maximum number of I/O Completion Port worker threads
+ * to handle the load on the Completion Port. The actual number
+ * used is the number of CPU's + 1.
+ */
+#define MAX_IOCPTHREADS 20
+
+#define SOCKET_MANAGER_MAGIC ISC_MAGIC('I', 'O', 'm', 'g')
+#define VALID_MANAGER(m)     ISC_MAGIC_VALID(m, SOCKET_MANAGER_MAGIC)
+
+struct isc_socketmgr {
+	/* Not locked. */
+	unsigned int magic;
+	isc_mem_t *mctx;
+	isc_mutex_t lock;
+	isc_stats_t *stats;
+
+	/* Locked by manager lock. */
+	ISC_LIST(isc_socket_t) socklist;
+	bool bShutdown;
+	isc_condition_t shutdown_ok;
+	HANDLE hIoCompletionPort;
+	int maxIOCPThreads;
+	HANDLE hIOCPThreads[MAX_IOCPTHREADS];
+	size_t maxudp;
+
+	/*
+	 * Debugging.
+	 * Modified by InterlockedIncrement() and InterlockedDecrement()
+	 */
+	LONG totalSockets;
+	LONG iocp_total;
+};
+
+enum { SOCKET_RECV, SOCKET_SEND, SOCKET_ACCEPT, SOCKET_CONNECT };
+
+/*
+ * send() and recv() iovec counts
+ */
+#define MAXSCATTERGATHER_SEND (ISC_SOCKET_MAXSCATTERGATHER)
+#define MAXSCATTERGATHER_RECV (ISC_SOCKET_MAXSCATTERGATHER)
+
+static isc_result_t
+socket_create(isc_socketmgr_t *manager0, int pf, isc_sockettype_t type,
+	      isc_socket_t **socketp, isc_socket_t *dup_socket);
+static isc_threadresult_t WINAPI
+SocketIoThread(LPVOID ThreadContext);
+static void
+maybe_free_socket(isc_socket_t **, int);
+static void
+free_socket(isc_socket_t **, int);
+static bool
+senddone_is_active(isc_socket_t *sock, isc_socketevent_t *dev);
+static bool
+acceptdone_is_active(isc_socket_t *sock, isc_socket_newconnev_t *dev);
+static bool
+connectdone_is_active(isc_socket_t *sock, isc_socket_connev_t *dev);
+static void
+send_recvdone_event(isc_socket_t *sock, isc_socketevent_t **dev);
+static void
+send_senddone_event(isc_socket_t *sock, isc_socketevent_t **dev);
+static void
+send_acceptdone_event(isc_socket_t *sock, isc_socket_newconnev_t **adev);
+static void
+send_connectdone_event(isc_socket_t *sock, isc_socket_connev_t **cdev);
+static void
+send_recvdone_abort(isc_socket_t *sock, isc_result_t result);
+static void
+send_connectdone_abort(isc_socket_t *sock, isc_result_t result);
+static void
+queue_receive_event(isc_socket_t *sock, isc_task_t *task,
+		    isc_socketevent_t *dev);
+static void
+queue_receive_request(isc_socket_t *sock);
+
+/*
+ * This is used to dump the contents of the sock structure
+ * You should make sure that the sock is locked before
+ * dumping it. Since the code uses simple printf() statements
+ * it should only be used interactively.
+ */
+void
+sock_dump(isc_socket_t *sock) {
+	isc_socketevent_t *ldev;
+	isc_socket_newconnev_t *ndev;
+	isc_socket_connev_t *cdev;
+
+#if 0
+	isc_sockaddr_t addr;
+	char socktext[ISC_SOCKADDR_FORMATSIZE];
+	isc_result_t result;
+
+	result = isc_socket_getpeername(sock,&addr);
+	if (result == ISC_R_SUCCESS) {
+		isc_sockaddr_format(&addr,socktext,sizeof(socktext));
+		printf("Remote Socket: %s\n",socktext);
+	}
+	result = isc_socket_getsockname(sock,&addr);
+	if (result == ISC_R_SUCCESS) {
+		isc_sockaddr_format(&addr,socktext,sizeof(socktext));
+		printf("This Socket: %s\n",socktext);
+	}
+#endif /* if 0 */
+
+	printf("\n\t\tSock Dump\n");
+	printf("\t\tfd: %Iu\n", sock->fd);
+	printf("\t\treferences: %" PRIuFAST32 "\n",
+	       isc_refcount_current(&sock->references));
+	printf("\t\tpending_accept: %u\n", sock->pending_accept);
+	printf("\t\tconnecting: %u\n", sock->pending_connect);
+	printf("\t\tconnected: %u\n", sock->connected);
+	printf("\t\tbound: %u\n", sock->bound);
+	printf("\t\tpending_iocp: %u\n", sock->pending_iocp);
+	printf("\t\tsocket type: %d\n", sock->type);
+
+	printf("\n\t\tSock Recv List\n");
+	ldev = ISC_LIST_HEAD(sock->recv_list);
+	while (ldev != NULL) {
+		printf("\t\tdev: %p\n", ldev);
+		ldev = ISC_LIST_NEXT(ldev, ev_link);
+	}
+
+	printf("\n\t\tSock Send List\n");
+	ldev = ISC_LIST_HEAD(sock->send_list);
+	while (ldev != NULL) {
+		printf("\t\tdev: %p\n", ldev);
+		ldev = ISC_LIST_NEXT(ldev, ev_link);
+	}
+
+	printf("\n\t\tSock Accept List\n");
+	ndev = ISC_LIST_HEAD(sock->accept_list);
+	while (ndev != NULL) {
+		printf("\t\tdev: %p\n", ldev);
+		ndev = ISC_LIST_NEXT(ndev, ev_link);
+	}
+
+	printf("\n\t\tSock Connect List\n");
+	cdev = ISC_LIST_HEAD(sock->connect_list);
+	while (cdev != NULL) {
+		printf("\t\tdev: %p\n", cdev);
+		cdev = ISC_LIST_NEXT(cdev, ev_link);
+	}
+}
+
+static void
+socket_log(int lineno, isc_socket_t *sock, const isc_sockaddr_t *address,
+	   isc_logcategory_t *category, isc_logmodule_t *module, int level,
+	   const char *fmt, ...) ISC_FORMAT_PRINTF(10, 11);
+
+/*  This function will add an entry to the I/O completion port
+ *  that will signal the I/O thread to exit (gracefully)
+ */
+static void
+signal_iocompletionport_exit(isc_socketmgr_t *manager) {
+	int i;
+	int errval;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(VALID_MANAGER(manager));
+	for (i = 0; i < manager->maxIOCPThreads; i++) {
+		if (!PostQueuedCompletionStatus(manager->hIoCompletionPort, 0,
+						0, 0))
+		{
+			errval = GetLastError();
+			strerror_r(errval, strbuf, sizeof(strbuf));
+			FATAL_ERROR(__FILE__, __LINE__,
+				    "Can't request service thread to exit: %s",
+				    strbuf);
+		}
+	}
+}
+
+/*
+ * Create the worker threads for the I/O Completion Port
+ */
+void
+iocompletionport_createthreads(int total_threads, isc_socketmgr_t *manager) {
+	int errval;
+	char strbuf[ISC_STRERRORSIZE];
+	int i;
+
+	INSIST(total_threads > 0);
+	REQUIRE(VALID_MANAGER(manager));
+	/*
+	 * We need at least one
+	 */
+	for (i = 0; i < total_threads; i++) {
+		isc_thread_create(SocketIoThread, manager,
+				  &manager->hIOCPThreads[i]);
+	}
+}
+
+/*
+ *  Create/initialise the I/O completion port
+ */
+void
+iocompletionport_init(isc_socketmgr_t *manager) {
+	int errval;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(VALID_MANAGER(manager));
+	/*
+	 * Create a private heap to handle the socket overlapped structure
+	 * The minimum number of structures is 10, there is no maximum
+	 */
+	hHeapHandle = HeapCreate(0, 10 * sizeof(IoCompletionInfo), 0);
+	if (hHeapHandle == NULL) {
+		errval = GetLastError();
+		strerror_r(errval, strbuf, sizeof(strbuf));
+		FATAL_ERROR(__FILE__, __LINE__,
+			    "HeapCreate() failed during initialization: %s",
+			    strbuf);
+	}
+
+	/* Now Create the Completion Port */
+	manager->hIoCompletionPort = CreateIoCompletionPort(
+		INVALID_HANDLE_VALUE, NULL, 0, manager->maxIOCPThreads);
+	if (manager->hIoCompletionPort == NULL) {
+		errval = GetLastError();
+		strerror_r(errval, strbuf, sizeof(strbuf));
+		FATAL_ERROR(__FILE__, __LINE__,
+			    "CreateIoCompletionPort() failed during "
+			    "initialization: %s",
+			    strbuf);
+	}
+
+	/*
+	 * Worker threads for servicing the I/O
+	 */
+	iocompletionport_createthreads(manager->maxIOCPThreads, manager);
+}
+
+/*
+ * Associate a socket with an IO Completion Port.  This allows us to queue
+ * events for it and have our worker pool of threads process them.
+ */
+void
+iocompletionport_update(isc_socket_t *sock) {
+	HANDLE hiocp;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	hiocp = CreateIoCompletionPort((HANDLE)sock->fd,
+				       sock->manager->hIoCompletionPort,
+				       (ULONG_PTR)sock, 0);
+
+	if (hiocp == NULL) {
+		DWORD errval = GetLastError();
+		strerror_r(errval, strbuf, sizeof(strbuf));
+		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
+			      ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
+			      "iocompletionport_update: failed to open io "
+			      "completion port: %s",
+			      strbuf);
+
+		/* XXXMLG temporary hack to make failures detected.
+		 * This function should return errors to the caller, not
+		 * exit here.
+		 */
+		FATAL_ERROR(__FILE__, __LINE__,
+			    "CreateIoCompletionPort() failed during "
+			    "initialization: %s",
+			    strbuf);
+	}
+
+	InterlockedIncrement(&sock->manager->iocp_total);
+}
+
+/*
+ * Routine to cleanup and then close the socket.
+ * Only close the socket here if it is NOT associated
+ * with an event, otherwise the WSAWaitForMultipleEvents
+ * may fail due to the fact that the Wait should not
+ * be running while closing an event or a socket.
+ * The socket is locked before calling this function
+ */
+void
+socket_close(isc_socket_t *sock) {
+	REQUIRE(sock != NULL);
+
+	if (sock->fd != INVALID_SOCKET) {
+		closesocket(sock->fd);
+		sock->fd = INVALID_SOCKET;
+		_set_state(sock, SOCK_CLOSED);
+		InterlockedDecrement(&sock->manager->totalSockets);
+	}
+}
+
+static isc_once_t initialise_once = ISC_ONCE_INIT;
+static bool initialised = false;
+
+static void
+initialise(void) {
+	WORD wVersionRequested;
+	WSADATA wsaData;
+	int err;
+	SOCKET sock;
+	GUID GUIDConnectEx = WSAID_CONNECTEX;
+	GUID GUIDAcceptEx = WSAID_ACCEPTEX;
+	GUID GUIDGetAcceptExSockaddrs = WSAID_GETACCEPTEXSOCKADDRS;
+	DWORD dwBytes;
+
+	/* Need Winsock 2.2 or better */
+	wVersionRequested = MAKEWORD(2, 2);
+
+	err = WSAStartup(wVersionRequested, &wsaData);
+	if (err != 0) {
+		char strbuf[ISC_STRERRORSIZE];
+		strerror_r(err, strbuf, sizeof(strbuf));
+		FATAL_ERROR(__FILE__, __LINE__, "WSAStartup() failed: %s",
+			    strbuf);
+	}
+	/*
+	 * The following APIs do not exist as functions in a library, but
+	 * we must ask winsock for them.  They are "extensions" -- but why
+	 * they cannot be actual functions is beyond me.  So, ask winsock
+	 * for the pointers to the functions we need.
+	 */
+	sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+	INSIST(sock != INVALID_SOCKET);
+	err = WSAIoctl(sock, SIO_GET_EXTENSION_FUNCTION_POINTER, &GUIDConnectEx,
+		       sizeof(GUIDConnectEx), &ISCConnectEx,
+		       sizeof(ISCConnectEx), &dwBytes, NULL, NULL);
+	INSIST(err == 0);
+
+	err = WSAIoctl(sock, SIO_GET_EXTENSION_FUNCTION_POINTER, &GUIDAcceptEx,
+		       sizeof(GUIDAcceptEx), &ISCAcceptEx, sizeof(ISCAcceptEx),
+		       &dwBytes, NULL, NULL);
+	INSIST(err == 0);
+
+	err = WSAIoctl(sock, SIO_GET_EXTENSION_FUNCTION_POINTER,
+		       &GUIDGetAcceptExSockaddrs,
+		       sizeof(GUIDGetAcceptExSockaddrs),
+		       &ISCGetAcceptExSockaddrs,
+		       sizeof(ISCGetAcceptExSockaddrs), &dwBytes, NULL, NULL);
+	INSIST(err == 0);
+
+	closesocket(sock);
+
+	initialised = true;
+}
+
+/*
+ * Initialize socket services
+ */
+void
+InitSockets(void) {
+	RUNTIME_CHECK(isc_once_do(&initialise_once, initialise) ==
+		      ISC_R_SUCCESS);
+	if (!initialised) {
+		exit(1);
+	}
+}
+
+int
+internal_sendmsg(isc_socket_t *sock, IoCompletionInfo *lpo,
+		 struct msghdr *messagehdr, int flags, int *Error) {
+	int Result;
+	DWORD BytesSent;
+	DWORD Flags = flags;
+	int total_sent;
+
+	*Error = 0;
+	Result = WSASendTo(sock->fd, messagehdr->msg_iov,
+			   messagehdr->msg_iovlen, &BytesSent, Flags,
+			   (SOCKADDR *)&messagehdr->to_addr,
+			   messagehdr->to_addr_len, (LPWSAOVERLAPPED)lpo, NULL);
+
+	total_sent = (int)BytesSent;
+
+	/* Check for errors.*/
+	if (Result == SOCKET_ERROR) {
+		*Error = WSAGetLastError();
+
+		switch (*Error) {
+		case WSA_IO_INCOMPLETE:
+		case WSA_WAIT_IO_COMPLETION:
+		case WSA_IO_PENDING:
+		case NO_ERROR: /* Strange, but okay */
+			sock->pending_iocp++;
+			sock->pending_send++;
+			break;
+
+		default:
+			return (-1);
+			break;
+		}
+	} else {
+		sock->pending_iocp++;
+		sock->pending_send++;
+	}
+
+	if (lpo != NULL) {
+		return (0);
+	} else {
+		return (total_sent);
+	}
+}
+
+static void
+queue_receive_request(isc_socket_t *sock) {
+	DWORD Flags = 0;
+	DWORD NumBytes = 0;
+	int Result;
+	int Error;
+	int need_retry;
+	WSABUF iov[1];
+	IoCompletionInfo *lpo = NULL;
+	isc_result_t isc_result;
+
+retry:
+	need_retry = false;
+
+	/*
+	 * If we already have a receive pending, do nothing.
+	 */
+	if (sock->pending_recv > 0) {
+		if (lpo != NULL) {
+			HeapFree(hHeapHandle, 0, lpo);
+		}
+		return;
+	}
+
+	/*
+	 * If no one is waiting, do nothing.
+	 */
+	if (ISC_LIST_EMPTY(sock->recv_list)) {
+		if (lpo != NULL) {
+			HeapFree(hHeapHandle, 0, lpo);
+		}
+		return;
+	}
+
+	INSIST(sock->recvbuf.remaining == 0);
+	INSIST(sock->fd != INVALID_SOCKET);
+
+	iov[0].len = sock->recvbuf.len;
+	iov[0].buf = sock->recvbuf.base;
+
+	if (lpo == NULL) {
+		lpo = (IoCompletionInfo *)HeapAlloc(hHeapHandle,
+						    HEAP_ZERO_MEMORY,
+						    sizeof(IoCompletionInfo));
+		RUNTIME_CHECK(lpo != NULL);
+	} else {
+		ZeroMemory(lpo, sizeof(IoCompletionInfo));
+	}
+	lpo->request_type = SOCKET_RECV;
+
+	sock->recvbuf.from_addr_len = sizeof(sock->recvbuf.from_addr);
+
+	Error = 0;
+	Result = WSARecvFrom((SOCKET)sock->fd, iov, 1, &NumBytes, &Flags,
+			     (SOCKADDR *)&sock->recvbuf.from_addr,
+			     &sock->recvbuf.from_addr_len, (LPWSAOVERLAPPED)lpo,
+			     NULL);
+
+	/* Check for errors. */
+	if (Result == SOCKET_ERROR) {
+		Error = WSAGetLastError();
+
+		switch (Error) {
+		case WSA_IO_PENDING:
+			sock->pending_iocp++;
+			sock->pending_recv++;
+			break;
+
+		/* direct error: no completion event */
+		case ERROR_HOST_UNREACHABLE:
+		case WSAENETRESET:
+		case WSAECONNRESET:
+			if (!sock->connected) {
+				/* soft error */
+				need_retry = true;
+				break;
+			}
+			FALLTHROUGH;
+
+		default:
+			isc_result = isc__errno2result(Error);
+			if (isc_result == ISC_R_UNEXPECTED) {
+				UNEXPECTED_ERROR(__FILE__, __LINE__,
+						 "WSARecvFrom: Windows error "
+						 "code: %d, isc result %d",
+						 Error, isc_result);
+			}
+			send_recvdone_abort(sock, isc_result);
+			HeapFree(hHeapHandle, 0, lpo);
+			lpo = NULL;
+			break;
+		}
+	} else {
+		/*
+		 * The recv() finished immediately, but we will still get
+		 * a completion event.  Rather than duplicate code, let
+		 * that thread handle sending the data along its way.
+		 */
+		sock->pending_iocp++;
+		sock->pending_recv++;
+	}
+
+	socket_log(__LINE__, sock, NULL, IOEVENT,
+		   "queue_io_request: fd %d result %d error %d", sock->fd,
+		   Result, Error);
+
+	CONSISTENT(sock);
+
+	if (need_retry) {
+		goto retry;
+	}
+}
+
+static void
+manager_log(isc_socketmgr_t *sockmgr, isc_logcategory_t *category,
+	    isc_logmodule_t *module, int level, const char *fmt, ...) {
+	char msgbuf[2048];
+	va_list ap;
+
+	if (!isc_log_wouldlog(isc_lctx, level)) {
+		return;
+	}
+
+	va_start(ap, fmt);
+	vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
+	va_end(ap);
+
+	isc_log_write(isc_lctx, category, module, level, "sockmgr %p: %s",
+		      sockmgr, msgbuf);
+}
+
+static void
+socket_log(int lineno, isc_socket_t *sock, const isc_sockaddr_t *address,
+	   isc_logcategory_t *category, isc_logmodule_t *module, int level,
+	   const char *fmt, ...) {
+	char msgbuf[2048];
+	char peerbuf[256];
+	va_list ap;
+
+	if (!isc_log_wouldlog(isc_lctx, level)) {
+		return;
+	}
+
+	va_start(ap, fmt);
+	vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
+	va_end(ap);
+
+	if (address == NULL) {
+		isc_log_write(isc_lctx, category, module, level,
+			      "socket %p line %d: %s", sock, lineno, msgbuf);
+	} else {
+		isc_sockaddr_format(address, peerbuf, sizeof(peerbuf));
+		isc_log_write(isc_lctx, category, module, level,
+			      "socket %p line %d %s: %s", sock, lineno, peerbuf,
+			      msgbuf);
+	}
+}
+
+/*
+ * Make an fd SOCKET non-blocking.
+ */
+static isc_result_t
+make_nonblock(SOCKET fd) {
+	int ret;
+	unsigned long flags = 1;
+	char strbuf[ISC_STRERRORSIZE];
+
+	/* Set the socket to non-blocking */
+	ret = ioctlsocket(fd, FIONBIO, &flags);
+
+	if (ret == -1) {
+		strerror_r(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "ioctlsocket(%d, FIOBIO, %d): %s", fd, flags,
+				 strbuf);
+
+		return (ISC_R_UNEXPECTED);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Windows 2000 systems incorrectly cause UDP sockets using WSARecvFrom
+ * to not work correctly, returning a WSACONNRESET error when a WSASendTo
+ * fails with an "ICMP port unreachable" response and preventing the
+ * socket from using the WSARecvFrom in subsequent operations.
+ * The function below fixes this, but requires that Windows 2000
+ * Service Pack 2 or later be installed on the system.  NT 4.0
+ * systems are not affected by this and work correctly.
+ * See Microsoft Knowledge Base Article Q263823 for details of this.
+ */
+isc_result_t
+connection_reset_fix(SOCKET fd) {
+	DWORD dwBytesReturned = 0;
+	BOOL bNewBehavior = FALSE;
+	DWORD status;
+
+	if (isc_win32os_versioncheck(5, 0, 0, 0) < 0) {
+		return (ISC_R_SUCCESS); /*  NT 4.0 has no problem */
+	}
+	/* disable bad behavior using IOCTL: SIO_UDP_CONNRESET */
+	status = WSAIoctl(fd, SIO_UDP_CONNRESET, &bNewBehavior,
+			  sizeof(bNewBehavior), NULL, 0, &dwBytesReturned, NULL,
+			  NULL);
+	if (status != SOCKET_ERROR) {
+		return (ISC_R_SUCCESS);
+	} else {
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "WSAIoctl(SIO_UDP_CONNRESET, oldBehaviour) "
+				 "failed");
+		return (ISC_R_UNEXPECTED);
+	}
+}
+
+/*
+ * Construct an iov array and attach it to the msghdr passed in.  This is
+ * the SEND constructor, which will use the used region of the buffer
+ * (if using a buffer list) or will use the internal region (if a single
+ * buffer I/O is requested).
+ *
+ * Nothing can be NULL, and the done event must list at least one buffer
+ * on the buffer linked list for this function to be meaningful.
+ */
+static void
+build_msghdr_send(isc_socket_t *sock, isc_socketevent_t *dev,
+		  struct msghdr *msg, char *cmsg, WSABUF *iov,
+		  IoCompletionInfo *lpo) {
+	unsigned int iovcount;
+	size_t write_count;
+
+	memset(msg, 0, sizeof(*msg));
+
+	memmove(&msg->to_addr, &dev->address.type, dev->address.length);
+	msg->to_addr_len = dev->address.length;
+
+	write_count = 0;
+	iovcount = 0;
+
+	/*
+	 * Single buffer I/O?  Skip what we've done so far in this region.
+	 */
+	write_count = dev->region.length - dev->n;
+	lpo->buf = HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY, write_count);
+	RUNTIME_CHECK(lpo->buf != NULL);
+
+	socket_log(__LINE__, sock, NULL, TRACE, "alloc_buffer %p %d", lpo->buf,
+		   write_count);
+
+	memmove(lpo->buf, (dev->region.base + dev->n), write_count);
+	lpo->buflen = (unsigned int)write_count;
+	iov[0].buf = lpo->buf;
+	iov[0].len = (u_long)write_count;
+	iovcount = 1;
+
+	msg->msg_iov = iov;
+	msg->msg_iovlen = iovcount;
+	msg->msg_totallen = (u_int)write_count;
+}
+
+static void
+set_dev_address(const isc_sockaddr_t *address, isc_socket_t *sock,
+		isc_socketevent_t *dev) {
+	if (sock->type == isc_sockettype_udp) {
+		if (address != NULL) {
+			dev->address = *address;
+		} else {
+			dev->address = sock->address;
+		}
+	} else if (sock->type == isc_sockettype_tcp) {
+		INSIST(address == NULL);
+		dev->address = sock->address;
+	}
+}
+
+static void
+destroy_socketevent(isc_event_t *event) {
+	isc_socketevent_t *ev = (isc_socketevent_t *)event;
+
+	(ev->destroy)(event);
+}
+
+static isc_socketevent_t *
+allocate_socketevent(isc_mem_t *mctx, isc_socket_t *sock,
+		     isc_eventtype_t eventtype, isc_taskaction_t action,
+		     void *arg) {
+	isc_socketevent_t *ev;
+
+	ev = (isc_socketevent_t *)isc_event_allocate(mctx, sock, eventtype,
+						     action, arg, sizeof(*ev));
+
+	ev->result = ISC_R_IOERROR; /* XXXMLG temporary change to detect failure
+				     */
+				    /* to set */
+	ISC_LINK_INIT(ev, ev_link);
+	ev->region.base = NULL;
+	ev->n = 0;
+	ev->offset = 0;
+	ev->attributes = 0;
+	ev->destroy = ev->ev_destroy;
+	ev->ev_destroy = destroy_socketevent;
+	ev->dscp = 0;
+
+	return (ev);
+}
+
+#if defined(ISC_SOCKET_DEBUG)
+static void
+dump_msg(struct msghdr *msg, isc_socket_t *sock) {
+	unsigned int i;
+
+	printf("MSGHDR %p, Socket #: %Iu\n", msg, sock->fd);
+	printf("\tname %p, namelen %d\n", msg->msg_name, msg->msg_namelen);
+	printf("\tiov %p, iovlen %d\n", msg->msg_iov, msg->msg_iovlen);
+	for (i = 0; i < (unsigned int)msg->msg_iovlen; i++) {
+		printf("\t\t%u\tbase %p, len %u\n", i, msg->msg_iov[i].buf,
+		       msg->msg_iov[i].len);
+	}
+}
+#endif /* if defined(ISC_SOCKET_DEBUG) */
+
+/*
+ * map the error code
+ */
+int
+map_socket_error(isc_socket_t *sock, int windows_errno, int *isc_errno,
+		 char *errorstring, size_t bufsize) {
+	int doreturn;
+	switch (windows_errno) {
+	case WSAECONNREFUSED:
+		*isc_errno = ISC_R_CONNREFUSED;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case WSAENETUNREACH:
+	case ERROR_NETWORK_UNREACHABLE:
+		*isc_errno = ISC_R_NETUNREACH;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case ERROR_PORT_UNREACHABLE:
+	case ERROR_HOST_UNREACHABLE:
+	case WSAEHOSTUNREACH:
+		*isc_errno = ISC_R_HOSTUNREACH;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case WSAENETDOWN:
+		*isc_errno = ISC_R_NETDOWN;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case WSAEHOSTDOWN:
+		*isc_errno = ISC_R_HOSTDOWN;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case WSAEACCES:
+		*isc_errno = ISC_R_NOPERM;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case WSAECONNRESET:
+	case WSAENETRESET:
+	case WSAECONNABORTED:
+	case WSAEDISCON:
+		*isc_errno = ISC_R_CONNECTIONRESET;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case WSAENOTCONN:
+		*isc_errno = ISC_R_NOTCONNECTED;
+		if (sock->connected) {
+			doreturn = DOIO_HARD;
+		} else {
+			doreturn = DOIO_SOFT;
+		}
+		break;
+	case ERROR_OPERATION_ABORTED:
+	case ERROR_CONNECTION_ABORTED:
+	case ERROR_REQUEST_ABORTED:
+		*isc_errno = ISC_R_CONNECTIONRESET;
+		doreturn = DOIO_HARD;
+		break;
+	case WSAENOBUFS:
+		*isc_errno = ISC_R_NORESOURCES;
+		doreturn = DOIO_HARD;
+		break;
+	case WSAEAFNOSUPPORT:
+		*isc_errno = ISC_R_FAMILYNOSUPPORT;
+		doreturn = DOIO_HARD;
+		break;
+	case WSAEADDRNOTAVAIL:
+		*isc_errno = ISC_R_ADDRNOTAVAIL;
+		doreturn = DOIO_HARD;
+		break;
+	case WSAEDESTADDRREQ:
+		*isc_errno = ISC_R_BADADDRESSFORM;
+		doreturn = DOIO_HARD;
+		break;
+	case ERROR_NETNAME_DELETED:
+		*isc_errno = ISC_R_NETDOWN;
+		doreturn = DOIO_HARD;
+		break;
+	default:
+		*isc_errno = ISC_R_IOERROR;
+		doreturn = DOIO_HARD;
+		break;
+	}
+	if (doreturn == DOIO_HARD) {
+		strerror_r(windows_errno, errorstring, bufsize);
+	}
+	return (doreturn);
+}
+
+static void
+fill_recv(isc_socket_t *sock, isc_socketevent_t *dev) {
+	int copylen;
+
+	INSIST(dev->n < dev->minimum);
+	INSIST(sock->recvbuf.remaining > 0);
+	INSIST(sock->pending_recv == 0);
+
+	if (sock->type == isc_sockettype_udp) {
+		dev->address.length = sock->recvbuf.from_addr_len;
+		memmove(&dev->address.type, &sock->recvbuf.from_addr,
+			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,
+					   "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;
+	}
+
+	copylen = min(dev->region.length - dev->n, sock->recvbuf.remaining);
+	memmove(dev->region.base + dev->n, sock->recvbuf.consume_position,
+		copylen);
+	sock->recvbuf.consume_position += copylen;
+	sock->recvbuf.remaining -= copylen;
+	dev->n += copylen;
+
+	/*
+	 * UDP receives are all-consuming.  That is, if we have 4k worth of
+	 * data in our receive buffer, and the caller only gave us
+	 * 1k of space, we will toss the remaining 3k of data.  TCP
+	 * will keep the extra data around and use it for later requests.
+	 */
+	if (sock->type == isc_sockettype_udp) {
+		sock->recvbuf.remaining = 0;
+	}
+}
+
+/*
+ * Copy out as much data from the internal buffer to done events.
+ * As each done event is filled, send it along its way.
+ */
+static void
+completeio_recv(isc_socket_t *sock) {
+	isc_socketevent_t *dev;
+
+	/*
+	 * If we are in the process of filling our buffer, we cannot
+	 * touch it yet, so don't.
+	 */
+	if (sock->pending_recv > 0) {
+		return;
+	}
+
+	while (sock->recvbuf.remaining > 0 && !ISC_LIST_EMPTY(sock->recv_list))
+	{
+		dev = ISC_LIST_HEAD(sock->recv_list);
+
+		/*
+		 * See if we have sufficient data in our receive buffer
+		 * to handle this.  If we do, copy out the data.
+		 */
+		fill_recv(sock, dev);
+
+		/*
+		 * Did we satisfy it?
+		 */
+		if (dev->n >= dev->minimum) {
+			dev->result = ISC_R_SUCCESS;
+			send_recvdone_event(sock, &dev);
+		}
+	}
+}
+
+/*
+ * Returns:
+ *	DOIO_SUCCESS	The operation succeeded.  dev->result contains
+ *			ISC_R_SUCCESS.
+ *
+ *	DOIO_HARD	A hard or unexpected I/O error was encountered.
+ *			dev->result contains the appropriate error.
+ *
+ *	DOIO_SOFT	A soft I/O error was encountered.  No senddone
+ *			event was sent.  The operation should be retried.
+ *
+ *	No other return values are possible.
+ */
+static int
+completeio_send(isc_socket_t *sock, isc_socketevent_t *dev,
+		struct msghdr *messagehdr, int cc, int send_errno) {
+	char strbuf[ISC_STRERRORSIZE];
+
+	if (send_errno != 0) {
+		if (SOFT_ERROR(send_errno)) {
+			return (DOIO_SOFT);
+		}
+
+		return (map_socket_error(sock, send_errno, &dev->result, strbuf,
+					 sizeof(strbuf)));
+	}
+
+	/*
+	 * If we write less than we expected, update counters, poke.
+	 */
+	dev->n += cc;
+	if (cc != messagehdr->msg_totallen) {
+		return (DOIO_SOFT);
+	}
+
+	/*
+	 * Exactly what we wanted to write.  We're done with this
+	 * entry.  Post its completion event.
+	 */
+	dev->result = ISC_R_SUCCESS;
+	return (DOIO_SUCCESS);
+}
+
+static int
+startio_send(isc_socket_t *sock, isc_socketevent_t *dev, int *nbytes,
+	     int *send_errno) {
+	char *cmsg = NULL;
+	char strbuf[ISC_STRERRORSIZE];
+	IoCompletionInfo *lpo;
+	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));
+	RUNTIME_CHECK(lpo != NULL);
+	lpo->request_type = SOCKET_SEND;
+	lpo->dev = dev;
+	mh = &lpo->messagehdr;
+	memset(mh, 0, sizeof(struct msghdr));
+
+	build_msghdr_send(sock, dev, mh, cmsg, sock->iov, lpo);
+
+	*nbytes = internal_sendmsg(sock, lpo, mh, 0, send_errno);
+
+	if (*nbytes <= 0) {
+		/*
+		 * I/O has been initiated
+		 * completion will be through the completion port
+		 */
+		if (PENDING_ERROR(*send_errno)) {
+			status = DOIO_PENDING;
+			goto done;
+		}
+
+		if (SOFT_ERROR(*send_errno)) {
+			status = DOIO_SOFT;
+			goto done;
+		}
+
+		/*
+		 * If we got this far then something is wrong
+		 */
+		if (isc_log_wouldlog(isc_lctx, IOEVENT_LEVEL)) {
+			strerror_r(*send_errno, strbuf, sizeof(strbuf));
+			socket_log(__LINE__, sock, NULL, IOEVENT,
+				   "startio_send: internal_sendmsg(%d) %d "
+				   "bytes, err %d/%s",
+				   sock->fd, *nbytes, *send_errno, strbuf);
+		}
+		status = DOIO_HARD;
+		goto done;
+	}
+	dev->result = ISC_R_SUCCESS;
+	status = DOIO_SOFT;
+done:
+	_set_state(sock, SOCK_DATA);
+	return (status);
+}
+
+static void
+use_min_mtu(isc_socket_t *sock) {
+#ifdef IPV6_USE_MIN_MTU
+	/* use minimum MTU */
+	if (sock->pf == AF_INET6) {
+		int on = 1;
+		(void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_USE_MIN_MTU,
+				 (void *)&on, sizeof(on));
+	}
+#else  /* ifdef IPV6_USE_MIN_MTU */
+	UNUSED(sock);
+#endif /* ifdef IPV6_USE_MIN_MTU */
+}
+
+static isc_result_t
+allocate_socket(isc_socketmgr_t *manager, isc_sockettype_t type,
+		isc_socket_t **socketp) {
+	isc_socket_t *sock;
+
+	sock = isc_mem_get(manager->mctx, sizeof(*sock));
+
+	sock->magic = 0;
+	isc_refcount_init(&sock->references, 0);
+
+	sock->manager = manager;
+	sock->type = type;
+	sock->fd = INVALID_SOCKET;
+
+	ISC_LINK_INIT(sock, link);
+
+	/*
+	 * Set up list of readers and writers to be initially empty.
+	 */
+	ISC_LIST_INIT(sock->recv_list);
+	ISC_LIST_INIT(sock->send_list);
+	ISC_LIST_INIT(sock->accept_list);
+	ISC_LIST_INIT(sock->connect_list);
+	sock->pending_accept = 0;
+	sock->pending_recv = 0;
+	sock->pending_send = 0;
+	sock->pending_iocp = 0;
+	sock->listener = 0;
+	sock->connected = 0;
+	sock->pending_connect = 0;
+	sock->bound = 0;
+	sock->dupped = 0;
+	memset(sock->name, 0, sizeof(sock->name)); /* zero the name field */
+	_set_state(sock, SOCK_INITIALIZED);
+
+	sock->recvbuf.len = 65536;
+	sock->recvbuf.consume_position = sock->recvbuf.base;
+	sock->recvbuf.remaining = 0;
+	sock->recvbuf.base = isc_mem_get(manager->mctx,
+					 sock->recvbuf.len); /* max buffer */
+							     /* size */
+
+	/*
+	 * Initialize the lock.
+	 */
+	isc_mutex_init(&sock->lock);
+
+	socket_log(__LINE__, sock, NULL, EVENT, "allocated");
+
+	sock->magic = SOCKET_MAGIC;
+	*socketp = sock;
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Verify that the socket state is consistent.
+ */
+static void
+consistent(isc_socket_t *sock) {
+	isc_socketevent_t *dev;
+	isc_socket_newconnev_t *nev;
+	unsigned int count;
+	char *crash_reason;
+	bool crash = false;
+
+	REQUIRE(sock->pending_iocp == sock->pending_recv + sock->pending_send +
+					      sock->pending_accept +
+					      sock->pending_connect);
+
+	dev = ISC_LIST_HEAD(sock->send_list);
+	count = 0;
+	while (dev != NULL) {
+		count++;
+		dev = ISC_LIST_NEXT(dev, ev_link);
+	}
+	if (count > sock->pending_send) {
+		crash = true;
+		crash_reason = "send_list > sock->pending_send";
+	}
+
+	nev = ISC_LIST_HEAD(sock->accept_list);
+	count = 0;
+	while (nev != NULL) {
+		count++;
+		nev = ISC_LIST_NEXT(nev, ev_link);
+	}
+	if (count > sock->pending_accept) {
+		crash = true;
+		crash_reason = "accept_list > sock->pending_accept";
+	}
+
+	if (crash) {
+		socket_log(__LINE__, sock, NULL, CREATION,
+			   "SOCKET INCONSISTENT: %s", crash_reason);
+		sock_dump(sock);
+		INSIST(!crash);
+	}
+}
+
+/*
+ * Maybe free the socket.
+ *
+ * This function will verify that the socket is no longer in use in any way,
+ * either internally or externally.  This is the only place where this
+ * check is to be made; if some bit of code believes that IT is done with
+ * the socket (e.g., some reference counter reaches zero), it should call
+ * this function.
+ *
+ * When calling this function, the socket must be locked, and the manager
+ * must be unlocked.
+ *
+ * When this function returns, *socketp will be NULL.  No tricks to try
+ * to hold on to this pointer are allowed.
+ */
+static void
+maybe_free_socket(isc_socket_t **socketp, int lineno) {
+	isc_socket_t *sock = *socketp;
+	*socketp = NULL;
+
+	INSIST(VALID_SOCKET(sock));
+	CONSISTENT(sock);
+
+	if (sock->pending_iocp > 0 || sock->pending_recv > 0 ||
+	    sock->pending_send > 0 || sock->pending_accept > 0 ||
+	    isc_refcount_current(&sock->references) > 0 ||
+	    sock->pending_connect == 1 || !ISC_LIST_EMPTY(sock->recv_list) ||
+	    !ISC_LIST_EMPTY(sock->send_list) ||
+	    !ISC_LIST_EMPTY(sock->accept_list) ||
+	    !ISC_LIST_EMPTY(sock->connect_list) || sock->fd != INVALID_SOCKET)
+	{
+		UNLOCK(&sock->lock);
+		return;
+	}
+	UNLOCK(&sock->lock);
+
+	free_socket(&sock, lineno);
+}
+
+void
+free_socket(isc_socket_t **sockp, int lineno) {
+	isc_socketmgr_t *manager;
+	isc_socket_t *sock = *sockp;
+	*sockp = NULL;
+
+	/*
+	 * Seems we can free the socket after all.
+	 */
+	manager = sock->manager;
+	socket_log(__LINE__, sock, NULL, CREATION,
+		   "freeing socket line %d fd %d lock %p semaphore %p", lineno,
+		   sock->fd, &sock->lock, sock->lock.LockSemaphore);
+
+	sock->magic = 0;
+	isc_mutex_destroy(&sock->lock);
+
+	if (sock->recvbuf.base != NULL) {
+		isc_mem_put(manager->mctx, sock->recvbuf.base,
+			    sock->recvbuf.len);
+	}
+
+	LOCK(&manager->lock);
+	if (ISC_LINK_LINKED(sock, link)) {
+		ISC_LIST_UNLINK(manager->socklist, sock, link);
+	}
+	isc_mem_put(manager->mctx, sock, sizeof(*sock));
+
+	if (ISC_LIST_EMPTY(manager->socklist)) {
+		SIGNAL(&manager->shutdown_ok);
+	}
+	UNLOCK(&manager->lock);
+}
+
+/*
+ * Create a new 'type' socket managed by 'manager'.  Events
+ * will be posted to 'task' and when dispatched 'action' will be
+ * called with 'arg' as the arg value.  The new socket is returned
+ * in 'socketp'.
+ */
+static isc_result_t
+socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
+	      isc_socket_t **socketp, isc_socket_t *dup_socket) {
+	isc_socket_t *sock = NULL;
+	isc_result_t result;
+#if defined(USE_CMSG)
+	int on = 1;
+#endif /* if defined(USE_CMSG) */
+#if defined(SO_RCVBUF)
+	socklen_t optlen;
+	int size;
+#endif /* if defined(SO_RCVBUF) */
+	int socket_errno;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(socketp != NULL && *socketp == NULL);
+
+#ifndef SOCK_RAW
+	if (type == isc_sockettype_raw) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+#endif /* ifndef SOCK_RAW */
+
+	result = allocate_socket(manager, type, &sock);
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	sock->pf = pf;
+	switch (type) {
+	case isc_sockettype_udp:
+		sock->fd = socket(pf, SOCK_DGRAM, IPPROTO_UDP);
+		if (sock->fd != INVALID_SOCKET) {
+			result = connection_reset_fix(sock->fd);
+			if (result != ISC_R_SUCCESS) {
+				socket_log(__LINE__, sock, NULL, EVENT,
+					   "closed %d %d %" PRIuFAST32 " "
+					   "con_reset_fix_failed",
+					   sock->pending_recv,
+					   sock->pending_send,
+					   isc_refcount_current(
+						   &sock->references));
+				closesocket(sock->fd);
+				_set_state(sock, SOCK_CLOSED);
+				sock->fd = INVALID_SOCKET;
+				free_socket(&sock, __LINE__);
+				return (result);
+			}
+		}
+		break;
+	case isc_sockettype_tcp:
+		sock->fd = socket(pf, SOCK_STREAM, IPPROTO_TCP);
+		break;
+#ifdef SOCK_RAW
+	case isc_sockettype_raw:
+		sock->fd = socket(pf, SOCK_RAW, 0);
+#ifdef PF_ROUTE
+		if (pf == PF_ROUTE) {
+			sock->bound = 1;
+		}
+#endif /* ifdef PF_ROUTE */
+		break;
+#endif /* ifdef SOCK_RAW */
+	}
+
+	if (sock->fd == INVALID_SOCKET) {
+		socket_errno = WSAGetLastError();
+		free_socket(&sock, __LINE__);
+
+		switch (socket_errno) {
+		case WSAEMFILE:
+		case WSAENOBUFS:
+			return (ISC_R_NORESOURCES);
+
+		case WSAEPROTONOSUPPORT:
+		case WSAEPFNOSUPPORT:
+		case WSAEAFNOSUPPORT:
+			return (ISC_R_FAMILYNOSUPPORT);
+
+		default:
+			strerror_r(socket_errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "socket() failed: %s", strbuf);
+			return (ISC_R_UNEXPECTED);
+		}
+	}
+
+	result = make_nonblock(sock->fd);
+	if (result != ISC_R_SUCCESS) {
+		socket_log(__LINE__, sock, NULL, EVENT,
+			   "closed %d %d %" PRIuFAST32 " make_nonblock_failed",
+			   sock->pending_recv, sock->pending_send,
+			   isc_refcount_current(&sock->references));
+		closesocket(sock->fd);
+		sock->fd = INVALID_SOCKET;
+		free_socket(&sock, __LINE__);
+		return (result);
+	}
+
+	/*
+	 * Use minimum mtu if possible.
+	 */
+	use_min_mtu(sock);
+
+#if defined(USE_CMSG) || defined(SO_RCVBUF)
+	if (type == isc_sockettype_udp) {
+#if defined(USE_CMSG)
+#ifdef IPV6_RECVPKTINFO
+		/* 2292bis */
+		if ((pf == AF_INET6) &&
+		    (setsockopt(sock->fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
+				(char *)&on, sizeof(on)) < 0))
+		{
+			strerror_r(WSAGetLastError(), strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "setsockopt(%d, IPV6_RECVPKTINFO) "
+					 "failed: %s",
+					 sock->fd, strbuf);
+		}
+#else  /* ifdef IPV6_RECVPKTINFO */
+		/* 2292 */
+		if ((pf == AF_INET6) &&
+		    (setsockopt(sock->fd, IPPROTO_IPV6, IPV6_PKTINFO,
+				(char *)&on, sizeof(on)) < 0))
+		{
+			strerror_r(WSAGetLastError(), strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "setsockopt(%d, IPV6_PKTINFO) %s: %s",
+					 sock->fd, strbuf);
+		}
+#endif /* IPV6_RECVPKTINFO */
+#endif /* defined(USE_CMSG) */
+
+#if defined(SO_RCVBUF)
+		optlen = sizeof(size);
+		if (getsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF, (char *)&size,
+			       &optlen) >= 0 &&
+		    size < RCVBUFSIZE)
+		{
+			size = RCVBUFSIZE;
+			(void)setsockopt(sock->fd, SOL_SOCKET, SO_RCVBUF,
+					 (char *)&size, sizeof(size));
+		}
+#endif /* if defined(SO_RCVBUF) */
+	}
+#endif /* defined(USE_CMSG) || defined(SO_RCVBUF) */
+
+	_set_state(sock, SOCK_OPEN);
+	isc_refcount_init(&sock->references, 1);
+	*socketp = sock;
+
+	iocompletionport_update(sock);
+
+	if (dup_socket) {
+#ifndef ISC_ALLOW_MAPPED
+		isc_socket_ipv6only(sock, true);
+#endif /* ifndef ISC_ALLOW_MAPPED */
+
+		if (dup_socket->bound) {
+			isc_sockaddr_t local;
+
+			result = isc_socket_getsockname(dup_socket, &local);
+			if (result != ISC_R_SUCCESS) {
+				isc_socket_close(sock);
+				return (result);
+			}
+			result = isc_socket_bind(sock, &local,
+						 ISC_SOCKET_REUSEADDRESS);
+			if (result != ISC_R_SUCCESS) {
+				isc_socket_close(sock);
+				return (result);
+			}
+		}
+		sock->dupped = 1;
+	}
+
+	/*
+	 * Note we don't have to lock the socket like we normally would because
+	 * there are no external references to it yet.
+	 */
+	LOCK(&manager->lock);
+	ISC_LIST_APPEND(manager->socklist, sock, link);
+	InterlockedIncrement(&manager->totalSockets);
+	UNLOCK(&manager->lock);
+
+	socket_log(__LINE__, sock, NULL, CREATION, "created %u type %u",
+		   sock->fd, type);
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
+		  isc_socket_t **socketp) {
+	return (socket_create(manager, pf, type, socketp, NULL));
+}
+
+isc_result_t
+isc_socket_dup(isc_socket_t *sock, isc_socket_t **socketp) {
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(socketp != NULL && *socketp == NULL);
+
+	return (socket_create(sock->manager, sock->pf, sock->type, socketp,
+			      sock));
+}
+
+isc_result_t
+isc_socket_open(isc_socket_t *sock) {
+	REQUIRE(VALID_SOCKET(sock));
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+/*
+ * Attach to a socket.  Caller must explicitly detach when it is done.
+ */
+void
+isc_socket_attach(isc_socket_t *sock, isc_socket_t **socketp) {
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(socketp != NULL && *socketp == NULL);
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+	UNLOCK(&sock->lock);
+
+	isc_refcount_increment0(&sock->references);
+
+	*socketp = sock;
+}
+
+/*
+ * Dereference a socket.  If this is the last reference to it, clean things
+ * up by destroying the socket.
+ */
+void
+isc_socket_detach(isc_socket_t **socketp) {
+	isc_socket_t *sock;
+	uint32_t references;
+
+	REQUIRE(socketp != NULL);
+	sock = *socketp;
+	*socketp = NULL;
+	REQUIRE(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	references = isc_refcount_decrement(&sock->references);
+
+	socket_log(__LINE__, sock, NULL, EVENT,
+		   "detach_socket %d %d %" PRIuFAST32, sock->pending_recv,
+		   sock->pending_send, isc_refcount_current(&sock->references));
+
+	if (references == 1 && sock->fd != INVALID_SOCKET) {
+		closesocket(sock->fd);
+		sock->fd = INVALID_SOCKET;
+		_set_state(sock, SOCK_CLOSED);
+	}
+
+	maybe_free_socket(&sock, __LINE__); /* Also unlocks the socket lock */
+}
+
+isc_result_t
+isc_socket_close(isc_socket_t *sock) {
+	REQUIRE(VALID_SOCKET(sock));
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+/*
+ * Dequeue an item off the given socket's read queue, set the result code
+ * in the done event to the one provided, and send it to the task it was
+ * destined for.
+ *
+ * If the event to be sent is on a list, remove it before sending.  If
+ * asked to, send and detach from the task as well.
+ *
+ * Caller must have the socket locked if the event is attached to the socket.
+ */
+static void
+send_recvdone_event(isc_socket_t *sock, isc_socketevent_t **dev) {
+	isc_task_t *task;
+
+	task = (*dev)->ev_sender;
+	(*dev)->ev_sender = sock;
+
+	if (ISC_LINK_LINKED(*dev, ev_link)) {
+		ISC_LIST_DEQUEUE(sock->recv_list, *dev, ev_link);
+	}
+
+	if (((*dev)->attributes & ISC_SOCKEVENTATTR_ATTACHED) != 0) {
+		isc_task_sendanddetach(&task, (isc_event_t **)dev);
+	} else {
+		isc_task_send(task, (isc_event_t **)dev);
+	}
+
+	CONSISTENT(sock);
+}
+
+/*
+ * See comments for send_recvdone_event() above.
+ */
+static void
+send_senddone_event(isc_socket_t *sock, isc_socketevent_t **dev) {
+	isc_task_t *task;
+
+	INSIST(dev != NULL && *dev != NULL);
+
+	task = (*dev)->ev_sender;
+	(*dev)->ev_sender = sock;
+
+	if (ISC_LINK_LINKED(*dev, ev_link)) {
+		ISC_LIST_DEQUEUE(sock->send_list, *dev, ev_link);
+	}
+
+	if (((*dev)->attributes & ISC_SOCKEVENTATTR_ATTACHED) != 0) {
+		isc_task_sendanddetach(&task, (isc_event_t **)dev);
+	} else {
+		isc_task_send(task, (isc_event_t **)dev);
+	}
+
+	CONSISTENT(sock);
+}
+
+/*
+ * See comments for send_recvdone_event() above.
+ */
+static void
+send_acceptdone_event(isc_socket_t *sock, isc_socket_newconnev_t **adev) {
+	isc_task_t *task;
+
+	INSIST(adev != NULL && *adev != NULL);
+
+	task = (*adev)->ev_sender;
+	(*adev)->ev_sender = sock;
+
+	if (ISC_LINK_LINKED(*adev, ev_link)) {
+		ISC_LIST_DEQUEUE(sock->accept_list, *adev, ev_link);
+	}
+
+	isc_task_sendanddetach(&task, (isc_event_t **)adev);
+
+	CONSISTENT(sock);
+}
+
+/*
+ * See comments for send_recvdone_event() above.
+ */
+static void
+send_connectdone_event(isc_socket_t *sock, isc_socket_connev_t **cdev) {
+	isc_task_t *task;
+
+	INSIST(cdev != NULL && *cdev != NULL);
+
+	task = (*cdev)->ev_sender;
+	(*cdev)->ev_sender = sock;
+
+	if (ISC_LINK_LINKED(*cdev, ev_link)) {
+		ISC_LIST_DEQUEUE(sock->connect_list, *cdev, ev_link);
+	}
+
+	isc_task_sendanddetach(&task, (isc_event_t **)cdev);
+
+	CONSISTENT(sock);
+}
+
+/*
+ * On entry to this function, the event delivered is the internal
+ * readable event, and the first item on the accept_list should be
+ * the done event we want to send.  If the list is empty, this is a no-op,
+ * so just close the new connection, unlock, and return.
+ *
+ * Note the socket is locked before entering here
+ */
+static void
+internal_accept(isc_socket_t *sock, IoCompletionInfo *lpo, int accept_errno) {
+	isc_socket_newconnev_t *adev;
+	isc_result_t result = ISC_R_SUCCESS;
+	isc_socket_t *nsock;
+	struct sockaddr *localaddr;
+	int localaddr_len = sizeof(*localaddr);
+	struct sockaddr *remoteaddr;
+	int remoteaddr_len = sizeof(*remoteaddr);
+
+	INSIST(VALID_SOCKET(sock));
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	socket_log(__LINE__, sock, NULL, TRACE, "internal_accept called");
+
+	INSIST(sock->listener);
+
+	INSIST(sock->pending_iocp > 0);
+	sock->pending_iocp--;
+	INSIST(sock->pending_accept > 0);
+	sock->pending_accept--;
+
+	adev = lpo->adev;
+
+	/*
+	 * If the event is no longer in the list we can just return.
+	 */
+	if (!acceptdone_is_active(sock, adev)) {
+		goto done;
+	}
+
+	nsock = adev->newsocket;
+
+	/*
+	 * Pull off the done event.
+	 */
+	ISC_LIST_UNLINK(sock->accept_list, adev, ev_link);
+
+	/*
+	 * Extract the addresses from the socket, copy them into the structure,
+	 * and return the new socket.
+	 */
+	ISCGetAcceptExSockaddrs(
+		lpo->acceptbuffer, 0, sizeof(SOCKADDR_STORAGE) + 16,
+		sizeof(SOCKADDR_STORAGE) + 16, (LPSOCKADDR *)&localaddr,
+		&localaddr_len, (LPSOCKADDR *)&remoteaddr, &remoteaddr_len);
+	memmove(&adev->address.type, remoteaddr, remoteaddr_len);
+	adev->address.length = remoteaddr_len;
+	nsock->address = adev->address;
+	nsock->pf = adev->address.type.sa.sa_family;
+
+	socket_log(__LINE__, nsock, &nsock->address, TRACE,
+		   "internal_accept parent %p", sock);
+
+	result = make_nonblock(adev->newsocket->fd);
+	INSIST(result == ISC_R_SUCCESS);
+
+	/*
+	 * Use minimum mtu if possible.
+	 */
+	use_min_mtu(adev->newsocket);
+
+	INSIST(setsockopt(nsock->fd, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT,
+			  (char *)&sock->fd, sizeof(sock->fd)) == 0);
+
+	/*
+	 * Hook it up into the manager.
+	 */
+	nsock->bound = 1;
+	nsock->connected = 1;
+	_set_state(nsock, SOCK_OPEN);
+
+	LOCK(&nsock->manager->lock);
+	ISC_LIST_APPEND(nsock->manager->socklist, nsock, link);
+	InterlockedIncrement(&nsock->manager->totalSockets);
+	UNLOCK(&nsock->manager->lock);
+
+	socket_log(__LINE__, sock, &nsock->address, CREATION,
+		   "accepted_connection new_socket %p fd %d", nsock, nsock->fd);
+
+	adev->result = result;
+	send_acceptdone_event(sock, &adev);
+
+done:
+	CONSISTENT(sock);
+	UNLOCK(&sock->lock);
+
+	HeapFree(hHeapHandle, 0, lpo->acceptbuffer);
+	lpo->acceptbuffer = NULL;
+}
+
+/*
+ * Called when a socket with a pending connect() finishes.
+ * Note that the socket is locked before entering.
+ */
+static void
+internal_connect(isc_socket_t *sock, IoCompletionInfo *lpo, int connect_errno) {
+	isc_socket_connev_t *cdev;
+	isc_result_t result;
+	char strbuf[ISC_STRERRORSIZE];
+
+	INSIST(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+
+	INSIST(sock->pending_iocp > 0);
+	sock->pending_iocp--;
+	INSIST(sock->pending_connect == 1);
+	sock->pending_connect = 0;
+
+	/*
+	 * If the event is no longer in the list we can just close and return.
+	 */
+	cdev = lpo->cdev;
+	if (!connectdone_is_active(sock, cdev)) {
+		sock->pending_connect = 0;
+		if (sock->fd != INVALID_SOCKET) {
+			closesocket(sock->fd);
+			sock->fd = INVALID_SOCKET;
+			_set_state(sock, SOCK_CLOSED);
+		}
+		CONSISTENT(sock);
+		UNLOCK(&sock->lock);
+		return;
+	}
+
+	/*
+	 * Check possible Windows network event error status here.
+	 */
+	if (connect_errno != 0) {
+		/*
+		 * If the error is SOFT, just try again on this
+		 * fd and pretend nothing strange happened.
+		 */
+		if (SOFT_ERROR(connect_errno) ||
+		    connect_errno == WSAEINPROGRESS)
+		{
+			sock->pending_connect = 1;
+			CONSISTENT(sock);
+			UNLOCK(&sock->lock);
+			return;
+		}
+
+		/*
+		 * Translate other errors into ISC_R_* flavors.
+		 */
+		switch (connect_errno) {
+#define ERROR_MATCH(a, b)   \
+	case a:             \
+		result = b; \
+		break;
+			ERROR_MATCH(WSAEACCES, ISC_R_NOPERM);
+			ERROR_MATCH(WSAEADDRNOTAVAIL, ISC_R_ADDRNOTAVAIL);
+			ERROR_MATCH(WSAEAFNOSUPPORT, ISC_R_ADDRNOTAVAIL);
+			ERROR_MATCH(WSAECONNREFUSED, ISC_R_CONNREFUSED);
+			ERROR_MATCH(WSAEHOSTUNREACH, ISC_R_HOSTUNREACH);
+			ERROR_MATCH(WSAEHOSTDOWN, ISC_R_HOSTDOWN);
+			ERROR_MATCH(WSAENETUNREACH, ISC_R_NETUNREACH);
+			ERROR_MATCH(WSAENETDOWN, ISC_R_NETDOWN);
+			ERROR_MATCH(WSAENOBUFS, ISC_R_NORESOURCES);
+			ERROR_MATCH(WSAECONNRESET, ISC_R_CONNECTIONRESET);
+			ERROR_MATCH(WSAECONNABORTED, ISC_R_CONNECTIONRESET);
+			ERROR_MATCH(WSAETIMEDOUT, ISC_R_TIMEDOUT);
+#undef ERROR_MATCH
+		default:
+			result = ISC_R_UNEXPECTED;
+			strerror_r(connect_errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__,
+					 "internal_connect: connect() %s",
+					 strbuf);
+		}
+	} else {
+		INSIST(setsockopt(sock->fd, SOL_SOCKET,
+				  SO_UPDATE_CONNECT_CONTEXT, NULL, 0) == 0);
+		result = ISC_R_SUCCESS;
+		sock->connected = 1;
+		socket_log(__LINE__, sock, &sock->address, IOEVENT,
+			   "internal_connect: success");
+	}
+
+	do {
+		cdev->result = result;
+		send_connectdone_event(sock, &cdev);
+		cdev = ISC_LIST_HEAD(sock->connect_list);
+	} while (cdev != NULL);
+
+	UNLOCK(&sock->lock);
+}
+
+/*
+ * Loop through the socket, returning ISC_R_EOF for each done event pending.
+ */
+static void
+send_recvdone_abort(isc_socket_t *sock, isc_result_t result) {
+	isc_socketevent_t *dev;
+
+	while (!ISC_LIST_EMPTY(sock->recv_list)) {
+		dev = ISC_LIST_HEAD(sock->recv_list);
+		dev->result = result;
+		send_recvdone_event(sock, &dev);
+	}
+}
+
+/*
+ * Loop through the socket, returning result for each done event pending.
+ */
+static void
+send_connectdone_abort(isc_socket_t *sock, isc_result_t result) {
+	isc_socket_connev_t *dev;
+
+	while (!ISC_LIST_EMPTY(sock->connect_list)) {
+		dev = ISC_LIST_HEAD(sock->connect_list);
+		dev->result = result;
+		send_connectdone_event(sock, &dev);
+	}
+}
+
+/*
+ * Take the data we received in our private buffer, and if any recv() calls on
+ * our list are satisfied, send the corresponding done event.
+ *
+ * If we need more data (there are still items on the recv_list after we consume
+ * all our data) then arrange for another system recv() call to fill our
+ * buffers.
+ */
+static void
+internal_recv(isc_socket_t *sock, int nbytes) {
+	INSIST(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	socket_log(__LINE__, sock, NULL, IOEVENT,
+		   "internal_recv: %d bytes received", nbytes);
+
+	/*
+	 * If we got here, the I/O operation succeeded.  However, we might
+	 * still have removed this event from our notification list (or never
+	 * 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--;
+	INSIST(sock->pending_recv > 0);
+	sock->pending_recv--;
+
+	/*
+	 * The only way we could have gotten here is that our I/O has
+	 * successfully completed. Update our pointers, and move on.
+	 *  The only odd case here is that we might not have received
+	 * 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 has closed.
+	 */
+	if (nbytes == 0 && sock->type == isc_sockettype_tcp) {
+		send_recvdone_abort(sock, ISC_R_EOF);
+		maybe_free_socket(&sock, __LINE__);
+		return;
+	}
+	sock->recvbuf.remaining = nbytes;
+	sock->recvbuf.consume_position = sock->recvbuf.base;
+	completeio_recv(sock);
+
+	/*
+	 * If there are more receivers waiting for data, queue another receive
+	 * here.
+	 */
+	queue_receive_request(sock);
+
+	/*
+	 * Unlock and/or destroy if we are the last thing this socket has left
+	 * to do.
+	 */
+	maybe_free_socket(&sock, __LINE__);
+}
+
+static void
+internal_send(isc_socket_t *sock, isc_socketevent_t *dev,
+	      struct msghdr *messagehdr, int nbytes, int send_errno,
+	      IoCompletionInfo *lpo) {
+	/*
+	 * Find out what socket this is and lock it.
+	 */
+	INSIST(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	socket_log(__LINE__, sock, NULL, IOEVENT,
+		   "internal_send: task got socket event %p", dev);
+
+	if (lpo->buf != NULL) {
+		socket_log(__LINE__, sock, NULL, TRACE, "free_buffer %p",
+			   lpo->buf);
+
+		HeapFree(hHeapHandle, 0, lpo->buf);
+		lpo->buf = NULL;
+		lpo->buflen = 0;
+	}
+
+	INSIST(sock->pending_iocp > 0);
+	sock->pending_iocp--;
+	INSIST(sock->pending_send > 0);
+	sock->pending_send--;
+
+	/* If the event is no longer in the list we can just return */
+	if (!senddone_is_active(sock, dev)) {
+		goto done;
+	}
+
+	/*
+	 * Set the error code and send things on its way.
+	 */
+	switch (completeio_send(sock, dev, messagehdr, nbytes, send_errno)) {
+	case DOIO_SOFT:
+		break;
+	case DOIO_HARD:
+	case DOIO_SUCCESS:
+		send_senddone_event(sock, &dev);
+		break;
+	}
+
+done:
+	maybe_free_socket(&sock, __LINE__);
+}
+
+/*
+ * These return if the done event passed in is on the list.
+ * Using these ensures we will not double-send an event.
+ */
+static bool
+senddone_is_active(isc_socket_t *sock, isc_socketevent_t *dev) {
+	isc_socketevent_t *ldev;
+
+	ldev = ISC_LIST_HEAD(sock->send_list);
+	while (ldev != NULL && ldev != dev) {
+		ldev = ISC_LIST_NEXT(ldev, ev_link);
+	}
+
+	return (ldev == NULL ? false : true);
+}
+
+static bool
+acceptdone_is_active(isc_socket_t *sock, isc_socket_newconnev_t *dev) {
+	isc_socket_newconnev_t *ldev;
+
+	ldev = ISC_LIST_HEAD(sock->accept_list);
+	while (ldev != NULL && ldev != dev) {
+		ldev = ISC_LIST_NEXT(ldev, ev_link);
+	}
+
+	return (ldev == NULL ? false : true);
+}
+
+static bool
+connectdone_is_active(isc_socket_t *sock, isc_socket_connev_t *dev) {
+	isc_socket_connev_t *cdev;
+
+	cdev = ISC_LIST_HEAD(sock->connect_list);
+	while (cdev != NULL && cdev != dev) {
+		cdev = ISC_LIST_NEXT(cdev, ev_link);
+	}
+
+	return (cdev == NULL ? false : true);
+}
+
+/* */
+/* The Windows network stack seems to have two very distinct paths depending */
+/* on what is installed.  Specifically, if something is looking at network */
+/* connections (like an anti-virus or anti-malware application, such as */
+/* McAfee products) Windows may return additional error conditions which */
+/* were not previously returned. */
+/* */
+/* One specific one is when a TCP SYN scan is used.  In this situation, */
+/* Windows responds with the SYN-ACK, but the scanner never responds with */
+/* the 3rd packet, the ACK.  Windows considers this a partially open connection.
+ */
+/* Most Unix networking stacks, and Windows without McAfee installed, will */
+/* not return this to the caller.  However, with this product installed, */
+/* Windows returns this as a failed status on the Accept() call.  Here, we */
+/* will just re-issue the ISCAcceptEx() call as if nothing had happened. */
+/* */
+/* This code should only be called when the listening socket has received */
+/* such an error.  Additionally, the "parent" socket must be locked. */
+/* Additionally, the lpo argument is re-used here, and must not be freed */
+/* by the caller. */
+/* */
+static isc_result_t
+restart_accept(isc_socket_t *parent, IoCompletionInfo *lpo) {
+	isc_socket_t *nsock = lpo->adev->newsocket;
+	SOCKET new_fd;
+
+	/*
+	 * AcceptEx() requires we pass in a socket.  Note that we carefully
+	 * do not close the previous socket in case of an error message returned
+	 * by our new socket() call.  If we return an error here, our caller
+	 * will clean up.
+	 */
+	new_fd = socket(parent->pf, SOCK_STREAM, IPPROTO_TCP);
+	if (nsock->fd == INVALID_SOCKET) {
+		return (ISC_R_FAILURE); /* parent will ask windows for error */
+					/* message */
+	}
+	closesocket(nsock->fd);
+	nsock->fd = new_fd;
+
+	memset(&lpo->overlapped, 0, sizeof(lpo->overlapped));
+
+	ISCAcceptEx(parent->fd, nsock->fd,	   /* Accepted Socket */
+		    lpo->acceptbuffer,		   /* Buffer for initial Recv */
+		    0,				   /* Length of Buffer */
+		    sizeof(SOCKADDR_STORAGE) + 16, /* Local address length + 16
+						    */
+		    sizeof(SOCKADDR_STORAGE) + 16, /* Remote address length + 16
+						    */
+		    (LPDWORD)&lpo->received_bytes, /* Bytes Recved */
+		    (LPOVERLAPPED)lpo		   /* Overlapped structure */
+	);
+
+	InterlockedDecrement(&nsock->manager->iocp_total);
+	iocompletionport_update(nsock);
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * This is the I/O Completion Port Worker Function. It loops forever
+ * waiting for I/O to complete and then forwards them for further
+ * processing. There are a number of these in separate threads.
+ */
+static isc_threadresult_t WINAPI
+SocketIoThread(LPVOID ThreadContext) {
+	isc_socketmgr_t *manager = ThreadContext;
+	DWORD nbytes;
+	IoCompletionInfo *lpo = NULL;
+	isc_socket_t *sock = NULL;
+	int request;
+	struct msghdr *messagehdr = NULL;
+	int errval;
+	char strbuf[ISC_STRERRORSIZE];
+	int errstatus;
+
+	REQUIRE(VALID_MANAGER(manager));
+
+	/*
+	 * Set the thread priority high enough so I/O will
+	 * preempt normal recv packet processing, but not
+	 * higher than the timer sync thread.
+	 */
+	if (!SetThreadPriority(GetCurrentThread(),
+			       THREAD_PRIORITY_ABOVE_NORMAL))
+	{
+		errval = GetLastError();
+		strerror_r(errval, strbuf, sizeof(strbuf));
+		FATAL_ERROR(__FILE__, __LINE__, "Can't set thread priority: %s",
+			    strbuf);
+	}
+
+	/*
+	 * Loop forever waiting on I/O Completions and then processing them
+	 */
+	while (TRUE) {
+		BOOL bSuccess;
+
+	wait_again:
+		bSuccess = GetQueuedCompletionStatus(
+			manager->hIoCompletionPort, &nbytes, (PULONG_PTR)&sock,
+			(LPWSAOVERLAPPED *)&lpo, INFINITE);
+		if (lpo == NULL) { /* Received request to exit */
+			break;
+		}
+
+		REQUIRE(VALID_SOCKET(sock));
+
+		request = lpo->request_type;
+
+		if (!bSuccess) {
+			errstatus = GetLastError();
+		} else {
+			errstatus = 0;
+		}
+		if (!bSuccess && errstatus != ERROR_MORE_DATA) {
+			isc_result_t isc_result;
+
+			/*
+			 * Did the I/O operation complete?
+			 */
+			isc_result = isc__errno2result(errstatus);
+
+			LOCK(&sock->lock);
+			CONSISTENT(sock);
+			switch (request) {
+			case SOCKET_RECV:
+				INSIST(sock->pending_iocp > 0);
+				sock->pending_iocp--;
+				INSIST(sock->pending_recv > 0);
+				sock->pending_recv--;
+				if (!sock->connected &&
+				    ((errstatus == ERROR_HOST_UNREACHABLE) ||
+				     (errstatus == WSAENETRESET) ||
+				     (errstatus == WSAECONNRESET)))
+				{
+					/* ignore soft errors */
+					queue_receive_request(sock);
+					break;
+				}
+				send_recvdone_abort(sock, isc_result);
+				if (isc_result == ISC_R_UNEXPECTED) {
+					UNEXPECTED_ERROR(__FILE__, __LINE__,
+							 "SOCKET_RECV: Windows "
+							 "error code: %d, "
+							 "returning ISC error "
+							 "%d",
+							 errstatus, isc_result);
+				}
+				break;
+
+			case SOCKET_SEND:
+				INSIST(sock->pending_iocp > 0);
+				sock->pending_iocp--;
+				INSIST(sock->pending_send > 0);
+				sock->pending_send--;
+				if (senddone_is_active(sock, lpo->dev)) {
+					lpo->dev->result = isc_result;
+					socket_log(__LINE__, sock, NULL, EVENT,
+						   "canceled_send");
+					send_senddone_event(sock, &lpo->dev);
+				}
+				break;
+
+			case SOCKET_ACCEPT:
+				INSIST(sock->pending_iocp > 0);
+				INSIST(sock->pending_accept > 0);
+
+				socket_log(__LINE__, sock, NULL, EVENT,
+					   "Accept: errstatus=%d isc_result=%d",
+					   errstatus, isc_result);
+
+				if (acceptdone_is_active(sock, lpo->adev)) {
+					if (restart_accept(sock, lpo) ==
+					    ISC_R_SUCCESS)
+					{
+						UNLOCK(&sock->lock);
+						goto wait_again;
+					} else {
+						errstatus = GetLastError();
+						isc_result = isc__errno2result(
+							errstatus);
+						socket_log(__LINE__, sock, NULL,
+							   EVENT,
+							   "restart_accept() "
+							   "failed: "
+							   "errstatus=%d "
+							   "isc_result=%d",
+							   errstatus,
+							   isc_result);
+					}
+				}
+
+				sock->pending_iocp--;
+				sock->pending_accept--;
+				if (acceptdone_is_active(sock, lpo->adev)) {
+					closesocket(lpo->adev->newsocket->fd);
+					lpo->adev->newsocket->fd =
+						INVALID_SOCKET;
+					isc_refcount_decrementz(
+						&lpo->adev->newsocket
+							 ->references);
+					free_socket(&lpo->adev->newsocket,
+						    __LINE__);
+					lpo->adev->result = isc_result;
+					socket_log(__LINE__, sock, NULL, EVENT,
+						   "canceled_accept");
+					send_acceptdone_event(sock, &lpo->adev);
+				}
+				break;
+
+			case SOCKET_CONNECT:
+				INSIST(sock->pending_iocp > 0);
+				sock->pending_iocp--;
+				INSIST(sock->pending_connect == 1);
+				sock->pending_connect = 0;
+				if (connectdone_is_active(sock, lpo->cdev)) {
+					socket_log(__LINE__, sock, NULL, EVENT,
+						   "canceled_connect");
+					send_connectdone_abort(sock,
+							       isc_result);
+				}
+				break;
+			}
+			maybe_free_socket(&sock, __LINE__);
+
+			if (lpo != NULL) {
+				HeapFree(hHeapHandle, 0, lpo);
+			}
+			continue;
+		}
+
+		messagehdr = &lpo->messagehdr;
+
+		switch (request) {
+		case SOCKET_RECV:
+			internal_recv(sock, nbytes);
+			break;
+		case SOCKET_SEND:
+			internal_send(sock, lpo->dev, messagehdr, nbytes,
+				      errstatus, lpo);
+			break;
+		case SOCKET_ACCEPT:
+			internal_accept(sock, lpo, errstatus);
+			break;
+		case SOCKET_CONNECT:
+			internal_connect(sock, lpo, errstatus);
+			break;
+		}
+
+		if (lpo != NULL) {
+			HeapFree(hHeapHandle, 0, lpo);
+		}
+	}
+
+	/*
+	 * Exit Completion Port Thread
+	 */
+	manager_log(manager, TRACE, "SocketIoThread exiting");
+	return ((isc_threadresult_t)0);
+}
+
+/*
+ * Create a new socket manager.
+ */
+isc_result_t
+isc_socketmgr_create(isc_mem_t *mctx, isc_socketmgr_t **managerp) {
+	return (isc_socketmgr_create2(mctx, managerp, 0, 1));
+}
+
+isc_result_t
+isc_socketmgr_create2(isc_mem_t *mctx, isc_socketmgr_t **managerp,
+		      unsigned int maxsocks, int nthreads) {
+	isc_socketmgr_t *manager;
+
+	REQUIRE(managerp != NULL && *managerp == NULL);
+
+	if (maxsocks != 0) {
+		return (ISC_R_NOTIMPLEMENTED);
+	}
+
+	manager = isc_mem_get(mctx, sizeof(*manager));
+
+	InitSockets();
+
+	manager->magic = SOCKET_MANAGER_MAGIC;
+	manager->mctx = NULL;
+	manager->stats = NULL;
+	ISC_LIST_INIT(manager->socklist);
+	isc_mutex_init(&manager->lock);
+	isc_condition_init(&manager->shutdown_ok);
+
+	isc_mem_attach(mctx, &manager->mctx);
+	if (nthreads == 0) {
+		nthreads = isc_os_ncpus() + 1;
+	}
+	manager->maxIOCPThreads = min(nthreads, MAX_IOCPTHREADS);
+
+	iocompletionport_init(manager); /* Create the Completion Ports */
+
+	manager->bShutdown = false;
+	manager->totalSockets = 0;
+	manager->iocp_total = 0;
+	manager->maxudp = 0;
+
+	*managerp = manager;
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_socketmgr_getmaxsockets(isc_socketmgr_t *manager, unsigned int *nsockp) {
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(nsockp != NULL);
+
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+void
+isc_socketmgr_setstats(isc_socketmgr_t *manager, isc_stats_t *stats) {
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(ISC_LIST_EMPTY(manager->socklist));
+	REQUIRE(manager->stats == NULL);
+	REQUIRE(isc_stats_ncounters(stats) == isc_sockstatscounter_max);
+
+	isc_stats_attach(stats, &manager->stats);
+}
+
+void
+isc_socketmgr_destroy(isc_socketmgr_t **managerp) {
+	isc_socketmgr_t *manager;
+
+	/*
+	 * Destroy a socket manager.
+	 */
+
+	REQUIRE(managerp != NULL);
+	manager = *managerp;
+	*managerp = NULL;
+	REQUIRE(VALID_MANAGER(manager));
+
+	LOCK(&manager->lock);
+
+	/*
+	 * Wait for all sockets to be destroyed.
+	 */
+	while (!ISC_LIST_EMPTY(manager->socklist)) {
+		manager_log(manager, CREATION, "sockets exist");
+		WAIT(&manager->shutdown_ok, &manager->lock);
+	}
+
+	UNLOCK(&manager->lock);
+
+	/*
+	 * Here, we need to had some wait code for the completion port
+	 * thread.
+	 */
+	signal_iocompletionport_exit(manager);
+	manager->bShutdown = true;
+
+	/*
+	 * Wait for threads to exit.
+	 */
+	for (int i = 0; i < manager->maxIOCPThreads; i++) {
+		isc_thread_join((isc_thread_t)manager->hIOCPThreads[i], NULL);
+	}
+	/*
+	 * Clean up.
+	 */
+
+	CloseHandle(manager->hIoCompletionPort);
+
+	(void)isc_condition_destroy(&manager->shutdown_ok);
+
+	isc_mutex_destroy(&manager->lock);
+	if (manager->stats != NULL) {
+		isc_stats_detach(&manager->stats);
+	}
+	manager->magic = 0;
+	isc_mem_putanddetach(&manager->mctx, manager, sizeof(*manager));
+}
+
+static void
+queue_receive_event(isc_socket_t *sock, isc_task_t *task,
+		    isc_socketevent_t *dev) {
+	isc_task_t *ntask = NULL;
+
+	isc_task_attach(task, &ntask);
+	dev->attributes |= ISC_SOCKEVENTATTR_ATTACHED;
+
+	/*
+	 * Enqueue the request.
+	 */
+	INSIST(!ISC_LINK_LINKED(dev, ev_link));
+	ISC_LIST_ENQUEUE(sock->recv_list, dev, ev_link);
+
+	socket_log(__LINE__, sock, NULL, EVENT,
+		   "queue_receive_event: event %p -> task %p", dev, ntask);
+}
+
+/*
+ * Check the pending receive queue, and if we have data pending, give it to this
+ * caller.  If we have none, queue an I/O request.  If this caller is not the
+ * first on the list, then we will just queue this event and return.
+ *
+ * Caller must have the socket locked.
+ */
+static isc_result_t
+socket_recv(isc_socket_t *sock, isc_socketevent_t *dev, isc_task_t *task,
+	    unsigned int flags) {
+	isc_result_t result = ISC_R_SUCCESS;
+
+	dev->ev_sender = task;
+
+	if (sock->fd == INVALID_SOCKET) {
+		return (ISC_R_EOF);
+	}
+
+	/*
+	 * Queue our event on the list of things to do.  Call our function to
+	 * attempt to fill buffers as much as possible, and return done events.
+	 * We are going to lie about our handling of the ISC_SOCKFLAG_IMMEDIATE
+	 * here and tell our caller that we could not satisfy it immediately.
+	 */
+	queue_receive_event(sock, task, dev);
+	if ((flags & ISC_SOCKFLAG_IMMEDIATE) != 0) {
+		result = ISC_R_INPROGRESS;
+	}
+
+	completeio_recv(sock);
+
+	/*
+	 * If there are more receivers waiting for data, queue another receive
+	 * here.  If the
+	 */
+	queue_receive_request(sock);
+
+	return (result);
+}
+
+isc_result_t
+isc_socket_recv(isc_socket_t *sock, isc_region_t *region, unsigned int minimum,
+		isc_task_t *task, isc_taskaction_t action, void *arg) {
+	isc_socketevent_t *dev;
+	isc_socketmgr_t *manager;
+	isc_result_t ret;
+
+	REQUIRE(VALID_SOCKET(sock));
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+	REQUIRE(action != NULL);
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+
+	INSIST(sock->bound);
+
+	dev = allocate_socketevent(manager->mctx, sock, ISC_SOCKEVENT_RECVDONE,
+				   action, arg);
+	if (dev == NULL) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_NOMEMORY);
+	}
+
+	ret = isc_socket_recv2(sock, region, minimum, task, dev, 0);
+	UNLOCK(&sock->lock);
+	return (ret);
+}
+
+isc_result_t
+isc_socket_recv2(isc_socket_t *sock, isc_region_t *region, unsigned int minimum,
+		 isc_task_t *task, isc_socketevent_t *event,
+		 unsigned int flags) {
+	isc_result_t ret;
+
+	REQUIRE(VALID_SOCKET(sock));
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	event->result = ISC_R_UNEXPECTED;
+	event->ev_sender = sock;
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	event->region = *region;
+	event->n = 0;
+	event->offset = 0;
+	event->attributes = 0;
+
+	/*
+	 * UDP sockets are always partial read.
+	 */
+	if (sock->type == isc_sockettype_udp) {
+		event->minimum = 1;
+	} else {
+		if (minimum == 0) {
+			event->minimum = region->length;
+		} else {
+			event->minimum = minimum;
+		}
+	}
+
+	ret = socket_recv(sock, event, task, flags);
+	UNLOCK(&sock->lock);
+	return (ret);
+}
+
+/*
+ * Caller must have the socket locked.
+ */
+static isc_result_t
+socket_send(isc_socket_t *sock, isc_socketevent_t *dev, isc_task_t *task,
+	    const isc_sockaddr_t *address, struct in6_pktinfo *pktinfo,
+	    unsigned int flags) {
+	int io_state;
+	int send_errno = 0;
+	int cc = 0;
+	isc_task_t *ntask = NULL;
+	isc_result_t result = ISC_R_SUCCESS;
+
+	dev->ev_sender = task;
+
+	set_dev_address(address, sock, dev);
+	if (pktinfo != NULL) {
+		socket_log(__LINE__, sock, NULL, TRACE,
+			   "pktinfo structure provided, ifindex %u (set to 0)",
+			   pktinfo->ipi6_ifindex);
+
+		dev->attributes |= ISC_SOCKEVENTATTR_PKTINFO;
+		dev->pktinfo = *pktinfo;
+		/*
+		 * Set the pktinfo index to 0 here, to let the kernel decide
+		 * what interface it should send on.
+		 */
+		dev->pktinfo.ipi6_ifindex = 0;
+	}
+
+	io_state = startio_send(sock, dev, &cc, &send_errno);
+	switch (io_state) {
+	case DOIO_PENDING: /* I/O started. Enqueue completion event. */
+	case DOIO_SOFT:
+		/*
+		 * We couldn't send all or part of the request right now, so
+		 * queue it unless ISC_SOCKFLAG_NORETRY is set.
+		 */
+		if ((flags & ISC_SOCKFLAG_NORETRY) == 0 ||
+		    io_state == DOIO_PENDING)
+		{
+			isc_task_attach(task, &ntask);
+			dev->attributes |= ISC_SOCKEVENTATTR_ATTACHED;
+
+			/*
+			 * Enqueue the request.
+			 */
+			INSIST(!ISC_LINK_LINKED(dev, ev_link));
+			ISC_LIST_ENQUEUE(sock->send_list, dev, ev_link);
+
+			socket_log(__LINE__, sock, NULL, EVENT,
+				   "socket_send: event %p -> task %p", dev,
+				   ntask);
+
+			if ((flags & ISC_SOCKFLAG_IMMEDIATE) != 0) {
+				result = ISC_R_INPROGRESS;
+			}
+			break;
+		}
+
+	case DOIO_SUCCESS:
+		break;
+	}
+
+	return (result);
+}
+
+isc_result_t
+isc_socket_send(isc_socket_t *sock, isc_region_t *region, isc_task_t *task,
+		isc_taskaction_t action, void *arg) {
+	/*
+	 * REQUIRE() checking is performed in isc_socket_sendto().
+	 */
+	return (isc_socket_sendto(sock, region, task, action, arg, NULL, NULL));
+}
+
+isc_result_t
+isc_socket_sendto(isc_socket_t *sock, isc_region_t *region, isc_task_t *task,
+		  isc_taskaction_t action, void *arg,
+		  const isc_sockaddr_t *address, struct in6_pktinfo *pktinfo) {
+	isc_socketevent_t *dev;
+	isc_socketmgr_t *manager;
+	isc_result_t ret;
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+	REQUIRE(region != NULL);
+	REQUIRE(task != NULL);
+	REQUIRE(action != NULL);
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+
+	INSIST(sock->bound);
+
+	dev = allocate_socketevent(manager->mctx, sock, ISC_SOCKEVENT_SENDDONE,
+				   action, arg);
+	if (dev == NULL) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_NOMEMORY);
+	}
+	dev->region = *region;
+
+	ret = socket_send(sock, dev, task, address, pktinfo, 0);
+	UNLOCK(&sock->lock);
+	return (ret);
+}
+
+isc_result_t
+isc_socket_sendto2(isc_socket_t *sock, isc_region_t *region, isc_task_t *task,
+		   const isc_sockaddr_t *address, struct in6_pktinfo *pktinfo,
+		   isc_socketevent_t *event, unsigned int flags) {
+	isc_result_t ret;
+
+	REQUIRE(VALID_SOCKET(sock));
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	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;
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+	event->region = *region;
+	event->n = 0;
+	event->offset = 0;
+	event->attributes = 0;
+
+	ret = socket_send(sock, event, task, address, pktinfo, flags);
+	UNLOCK(&sock->lock);
+	return (ret);
+}
+
+isc_result_t
+isc_socket_bind(isc_socket_t *sock, const isc_sockaddr_t *sockaddr,
+		isc_socket_options_t options) {
+	int bind_errno;
+	char strbuf[ISC_STRERRORSIZE];
+	int on = 1;
+
+	REQUIRE(VALID_SOCKET(sock));
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	INSIST(!sock->bound);
+	INSIST(!sock->dupped);
+
+	if (sock->pf != sockaddr->type.sa.sa_family) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_FAMILYMISMATCH);
+	}
+	/*
+	 * Only set SO_REUSEADDR when we want a specific port.
+	 */
+	if ((options & ISC_SOCKET_REUSEADDRESS) != 0 &&
+	    isc_sockaddr_getport(sockaddr) != (in_port_t)0 &&
+	    setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on,
+		       sizeof(on)) < 0)
+	{
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "setsockopt(%d) failed",
+				 sock->fd);
+		/* Press on... */
+	}
+	if (bind(sock->fd, &sockaddr->type.sa, sockaddr->length) < 0) {
+		bind_errno = WSAGetLastError();
+		UNLOCK(&sock->lock);
+		switch (bind_errno) {
+		case WSAEACCES:
+			return (ISC_R_NOPERM);
+		case WSAEADDRNOTAVAIL:
+			return (ISC_R_ADDRNOTAVAIL);
+		case WSAEADDRINUSE:
+			return (ISC_R_ADDRINUSE);
+		case WSAEINVAL:
+			return (ISC_R_BOUND);
+		default:
+			strerror_r(bind_errno, strbuf, sizeof(strbuf));
+			UNEXPECTED_ERROR(__FILE__, __LINE__, "bind: %s",
+					 strbuf);
+			return (ISC_R_UNEXPECTED);
+		}
+	}
+
+	socket_log(__LINE__, sock, sockaddr, TRACE, "bound");
+	sock->bound = 1;
+
+	UNLOCK(&sock->lock);
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_socket_filter(isc_socket_t *sock, const char *filter) {
+	UNUSED(sock);
+	UNUSED(filter);
+
+	REQUIRE(VALID_SOCKET(sock));
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+/*
+ * Set up to listen on a given socket.  We do this by creating an internal
+ * event that will be dispatched when the socket has read activity.  The
+ * watcher will send the internal event to the task when there is a new
+ * connection.
+ *
+ * Unlike in read, we don't preallocate a done event here.  Every time there
+ * is a new connection we'll have to allocate a new one anyway, so we might
+ * as well keep things simple rather than having to track them.
+ */
+isc_result_t
+isc_socket_listen(isc_socket_t *sock, unsigned int backlog) {
+	char strbuf[ISC_STRERRORSIZE];
+#if defined(ENABLE_TCP_FASTOPEN) && defined(TCP_FASTOPEN)
+	char on = 1;
+#endif /* if defined(ENABLE_TCP_FASTOPEN) && defined(TCP_FASTOPEN) */
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	REQUIRE(!sock->listener);
+	REQUIRE(sock->bound);
+	REQUIRE(sock->type == isc_sockettype_tcp);
+
+	if (backlog == 0) {
+		backlog = SOMAXCONN;
+	}
+
+	if (listen(sock->fd, (int)backlog) < 0) {
+		UNLOCK(&sock->lock);
+		strerror_r(WSAGetLastError(), strbuf, sizeof(strbuf));
+
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "listen: %s", strbuf);
+
+		return (ISC_R_UNEXPECTED);
+	}
+
+#if defined(ENABLE_TCP_FASTOPEN) && defined(TCP_FASTOPEN)
+	if (setsockopt(sock->fd, IPPROTO_TCP, TCP_FASTOPEN, &on, sizeof(on)) <
+	    0)
+	{
+		strerror_r(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "setsockopt(%d, TCP_FASTOPEN) failed with %s",
+				 sock->fd, strbuf);
+		/* TCP_FASTOPEN is experimental so ignore failures */
+	}
+#endif /* if defined(ENABLE_TCP_FASTOPEN) && defined(TCP_FASTOPEN) */
+
+	socket_log(__LINE__, sock, NULL, TRACE, "listening");
+	sock->listener = 1;
+	_set_state(sock, SOCK_LISTEN);
+
+	UNLOCK(&sock->lock);
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * This should try to do aggressive accept() XXXMLG
+ */
+isc_result_t
+isc_socket_accept(isc_socket_t *sock, isc_task_t *task, isc_taskaction_t action,
+		  void *arg) {
+	isc_socket_newconnev_t *adev;
+	isc_socketmgr_t *manager;
+	isc_task_t *ntask = NULL;
+	isc_socket_t *nsock;
+	isc_result_t result;
+	IoCompletionInfo *lpo;
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	REQUIRE(sock->listener);
+
+	/*
+	 * Sender field is overloaded here with the task we will be sending
+	 * this event to.  Just before the actual event is delivered the
+	 * actual ev_sender will be touched up to be the socket.
+	 */
+	adev = (isc_socket_newconnev_t *)isc_event_allocate(
+		manager->mctx, task, ISC_SOCKEVENT_NEWCONN, action, arg,
+		sizeof(*adev));
+	ISC_LINK_INIT(adev, ev_link);
+
+	result = allocate_socket(manager, sock->type, &nsock);
+	if (result != ISC_R_SUCCESS) {
+		isc_event_free((isc_event_t **)&adev);
+		UNLOCK(&sock->lock);
+		return (result);
+	}
+
+	/*
+	 * AcceptEx() requires we pass in a socket.
+	 */
+	nsock->fd = socket(sock->pf, SOCK_STREAM, IPPROTO_TCP);
+	if (nsock->fd == INVALID_SOCKET) {
+		free_socket(&nsock, __LINE__);
+		isc_event_free((isc_event_t **)&adev);
+		UNLOCK(&sock->lock);
+		return (ISC_R_FAILURE); /* XXXMLG need real error message */
+	}
+
+	/*
+	 * Attach to socket and to task.
+	 */
+	isc_task_attach(task, &ntask);
+	if (isc_task_exiting(ntask)) {
+		free_socket(&nsock, __LINE__);
+		isc_task_detach(&ntask);
+		isc_event_free(ISC_EVENT_PTR(&adev));
+		UNLOCK(&sock->lock);
+		return (ISC_R_SHUTTINGDOWN);
+	}
+	isc_refcount_increment0(&nsock->references);
+
+	adev->ev_sender = ntask;
+	adev->newsocket = nsock;
+	_set_state(nsock, SOCK_ACCEPT);
+
+	/*
+	 * Queue io completion for an accept().
+	 */
+	lpo = (IoCompletionInfo *)HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY,
+					    sizeof(IoCompletionInfo));
+	RUNTIME_CHECK(lpo != NULL);
+	lpo->acceptbuffer =
+		(void *)HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY,
+				  (sizeof(SOCKADDR_STORAGE) + 16) * 2);
+	RUNTIME_CHECK(lpo->acceptbuffer != NULL);
+
+	lpo->adev = adev;
+	lpo->request_type = SOCKET_ACCEPT;
+
+	ISCAcceptEx(sock->fd, nsock->fd,	   /* Accepted Socket */
+		    lpo->acceptbuffer,		   /* Buffer for initial Recv */
+		    0,				   /* Length of Buffer */
+		    sizeof(SOCKADDR_STORAGE) + 16, /* Local address length + 16
+						    */
+		    sizeof(SOCKADDR_STORAGE) + 16, /* Remote address length + 16
+						    */
+		    (LPDWORD)&lpo->received_bytes, /* Bytes Recved */
+		    (LPOVERLAPPED)lpo		   /* Overlapped structure */
+	);
+	iocompletionport_update(nsock);
+
+	socket_log(__LINE__, sock, NULL, TRACE, "accepting for nsock %p fd %d",
+		   nsock, nsock->fd);
+
+	/*
+	 * Enqueue the event
+	 */
+	ISC_LIST_ENQUEUE(sock->accept_list, adev, ev_link);
+	sock->pending_accept++;
+	sock->pending_iocp++;
+
+	UNLOCK(&sock->lock);
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_socket_connect(isc_socket_t *sock, const isc_sockaddr_t *addr,
+		   isc_task_t *task, isc_taskaction_t action, void *arg) {
+	char strbuf[ISC_STRERRORSIZE];
+	isc_socket_connev_t *cdev;
+	isc_task_t *ntask = NULL;
+	isc_socketmgr_t *manager;
+	IoCompletionInfo *lpo;
+	int bind_errno;
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(addr != NULL);
+	REQUIRE(task != NULL);
+	REQUIRE(action != NULL);
+
+	manager = sock->manager;
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(addr != NULL);
+
+	if (isc_sockaddr_ismulticast(addr)) {
+		return (ISC_R_MULTICAST);
+	}
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	/*
+	 * Windows sockets won't connect unless the socket is bound.
+	 */
+	if (!sock->bound) {
+		isc_sockaddr_t any;
+
+		isc_sockaddr_anyofpf(&any, isc_sockaddr_pf(addr));
+		if (bind(sock->fd, &any.type.sa, any.length) < 0) {
+			bind_errno = WSAGetLastError();
+			UNLOCK(&sock->lock);
+			switch (bind_errno) {
+			case WSAEACCES:
+				return (ISC_R_NOPERM);
+			case WSAEADDRNOTAVAIL:
+				return (ISC_R_ADDRNOTAVAIL);
+			case WSAEADDRINUSE:
+				return (ISC_R_ADDRINUSE);
+			case WSAEINVAL:
+				return (ISC_R_BOUND);
+			default:
+				strerror_r(bind_errno, strbuf, sizeof(strbuf));
+				UNEXPECTED_ERROR(__FILE__, __LINE__, "bind: %s",
+						 strbuf);
+				return (ISC_R_UNEXPECTED);
+			}
+		}
+		sock->bound = 1;
+	}
+
+	cdev = (isc_socket_connev_t *)isc_event_allocate(
+		manager->mctx, sock, ISC_SOCKEVENT_CONNECT, action, arg,
+		sizeof(*cdev));
+	ISC_LINK_INIT(cdev, ev_link);
+
+	if (sock->connected) {
+		INSIST(isc_sockaddr_equal(&sock->address, addr));
+		cdev->result = ISC_R_SUCCESS;
+		isc_task_send(task, ISC_EVENT_PTR(&cdev));
+
+		UNLOCK(&sock->lock);
+		return (ISC_R_SUCCESS);
+	}
+
+	if ((sock->type == isc_sockettype_tcp) && !sock->pending_connect) {
+		/*
+		 * Queue io completion for an accept().
+		 */
+		lpo = (IoCompletionInfo *)HeapAlloc(hHeapHandle,
+						    HEAP_ZERO_MEMORY,
+						    sizeof(IoCompletionInfo));
+		lpo->cdev = cdev;
+		lpo->request_type = SOCKET_CONNECT;
+
+		sock->address = *addr;
+		ISCConnectEx(sock->fd, &addr->type.sa, addr->length, NULL, 0,
+			     NULL, (LPOVERLAPPED)lpo);
+
+		/*
+		 * Attach to task.
+		 */
+		isc_task_attach(task, &ntask);
+		cdev->ev_sender = ntask;
+
+		sock->pending_connect = 1;
+		_set_state(sock, SOCK_CONNECT);
+
+		/*
+		 * Enqueue the request.
+		 */
+		INSIST(!ISC_LINK_LINKED(cdev, ev_link));
+		ISC_LIST_ENQUEUE(sock->connect_list, cdev, ev_link);
+		sock->pending_iocp++;
+	} else if (sock->type == isc_sockettype_tcp) {
+		INSIST(sock->pending_connect);
+		INSIST(isc_sockaddr_equal(&sock->address, addr));
+		isc_task_attach(task, &ntask);
+		cdev->ev_sender = ntask;
+		INSIST(!ISC_LINK_LINKED(cdev, ev_link));
+		ISC_LIST_ENQUEUE(sock->connect_list, cdev, ev_link);
+	} else {
+		REQUIRE(!sock->pending_connect);
+		WSAConnect(sock->fd, &addr->type.sa, addr->length, NULL, NULL,
+			   NULL, NULL);
+		cdev->result = ISC_R_SUCCESS;
+		isc_task_send(task, (isc_event_t **)&cdev);
+	}
+	CONSISTENT(sock);
+	UNLOCK(&sock->lock);
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_socket_getpeername(isc_socket_t *sock, isc_sockaddr_t *addressp) {
+	isc_result_t result;
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(addressp != NULL);
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	if (sock->connected) {
+		*addressp = sock->address;
+		result = ISC_R_SUCCESS;
+	} else {
+		result = ISC_R_NOTCONNECTED;
+	}
+
+	UNLOCK(&sock->lock);
+
+	return (result);
+}
+
+isc_result_t
+isc_socket_getsockname(isc_socket_t *sock, isc_sockaddr_t *addressp) {
+	socklen_t len;
+	isc_result_t result;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(VALID_SOCKET(sock));
+	REQUIRE(addressp != NULL);
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	if (!sock->bound) {
+		result = ISC_R_NOTBOUND;
+		goto out;
+	}
+
+	result = ISC_R_SUCCESS;
+
+	len = sizeof(addressp->type);
+	if (getsockname(sock->fd, &addressp->type.sa, (void *)&len) < 0) {
+		strerror_r(WSAGetLastError(), strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__, "getsockname: %s", strbuf);
+		result = ISC_R_UNEXPECTED;
+		goto out;
+	}
+	addressp->length = (unsigned int)len;
+
+out:
+	UNLOCK(&sock->lock);
+
+	return (result);
+}
+
+/*
+ * Run through the list of events on this socket, and cancel the ones
+ * queued for task "task" of type "how".  "how" is a bitmask.
+ */
+void
+isc_socket_cancel(isc_socket_t *sock, isc_task_t *task, unsigned int how) {
+	REQUIRE(VALID_SOCKET(sock));
+
+	/*
+	 * Quick exit if there is nothing to do.  Don't even bother locking
+	 * in this case.
+	 */
+	if (how == 0) {
+		return;
+	}
+
+	LOCK(&sock->lock);
+	CONSISTENT(sock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return;
+	}
+
+	/*
+	 * All of these do the same thing, more or less.
+	 * Each will:
+	 *	o If the internal event is marked as "posted" try to
+	 *	  remove it from the task's queue.  If this fails, mark it
+	 *	  as canceled instead, and let the task clean it up later.
+	 *	o For each I/O request for that task of that type, post
+	 *	  its done event with status of "ISC_R_CANCELED".
+	 *	o Reset any state needed.
+	 */
+
+	if ((how & ISC_SOCKCANCEL_RECV) != 0) {
+		isc_socketevent_t *dev;
+		isc_socketevent_t *next;
+		isc_task_t *current_task;
+
+		dev = ISC_LIST_HEAD(sock->recv_list);
+		while (dev != NULL) {
+			current_task = dev->ev_sender;
+			next = ISC_LIST_NEXT(dev, ev_link);
+			if ((task == NULL) || (task == current_task)) {
+				dev->result = ISC_R_CANCELED;
+				send_recvdone_event(sock, &dev);
+			}
+			dev = next;
+		}
+	}
+	how &= ~ISC_SOCKCANCEL_RECV;
+
+	if ((how & ISC_SOCKCANCEL_SEND) != 0) {
+		isc_socketevent_t *dev;
+		isc_socketevent_t *next;
+		isc_task_t *current_task;
+
+		dev = ISC_LIST_HEAD(sock->send_list);
+
+		while (dev != NULL) {
+			current_task = dev->ev_sender;
+			next = ISC_LIST_NEXT(dev, ev_link);
+			if ((task == NULL) || (task == current_task)) {
+				dev->result = ISC_R_CANCELED;
+				send_senddone_event(sock, &dev);
+			}
+			dev = next;
+		}
+	}
+	how &= ~ISC_SOCKCANCEL_SEND;
+
+	if (((how & ISC_SOCKCANCEL_ACCEPT) != 0) &&
+	    !ISC_LIST_EMPTY(sock->accept_list))
+	{
+		isc_socket_newconnev_t *dev;
+		isc_socket_newconnev_t *next;
+		isc_task_t *current_task;
+
+		dev = ISC_LIST_HEAD(sock->accept_list);
+		while (dev != NULL) {
+			current_task = dev->ev_sender;
+			next = ISC_LIST_NEXT(dev, ev_link);
+
+			if ((task == NULL) || (task == current_task)) {
+				isc_refcount_decrementz(
+					&dev->newsocket->references);
+				closesocket(dev->newsocket->fd);
+				dev->newsocket->fd = INVALID_SOCKET;
+				free_socket(&dev->newsocket, __LINE__);
+
+				dev->result = ISC_R_CANCELED;
+				send_acceptdone_event(sock, &dev);
+			}
+
+			dev = next;
+		}
+	}
+	how &= ~ISC_SOCKCANCEL_ACCEPT;
+
+	if (((how & ISC_SOCKCANCEL_CONNECT) != 0) &&
+	    !ISC_LIST_EMPTY(sock->connect_list))
+	{
+		isc_socket_connev_t *dev;
+		isc_socket_connev_t *next;
+		isc_task_t *current_task;
+
+		INSIST(sock->pending_connect);
+
+		dev = ISC_LIST_HEAD(sock->connect_list);
+
+		while (dev != NULL) {
+			current_task = dev->ev_sender;
+			next = ISC_LIST_NEXT(dev, ev_link);
+			if ((task == NULL) || (task == current_task)) {
+				dev->result = ISC_R_CANCELED;
+				send_connectdone_event(sock, &dev);
+			}
+			dev = next;
+		}
+		closesocket(sock->fd);
+		sock->fd = INVALID_SOCKET;
+		_set_state(sock, SOCK_CLOSED);
+	}
+	how &= ~ISC_SOCKCANCEL_CONNECT;
+	UNUSED(how);
+
+	maybe_free_socket(&sock, __LINE__);
+}
+
+isc_sockettype_t
+isc_socket_gettype(isc_socket_t *sock) {
+	isc_sockettype_t type;
+
+	REQUIRE(VALID_SOCKET(sock));
+
+	LOCK(&sock->lock);
+
+	/*
+	 * make sure that the socket's not closed
+	 */
+	if (sock->fd == INVALID_SOCKET) {
+		UNLOCK(&sock->lock);
+		return (ISC_R_CONNREFUSED);
+	}
+
+	type = sock->type;
+	UNLOCK(&sock->lock);
+	return (type);
+}
+
+void
+isc_socket_ipv6only(isc_socket_t *sock, bool yes) {
+#if defined(IPV6_V6ONLY)
+	int onoff = yes ? 1 : 0;
+#else  /* if defined(IPV6_V6ONLY) */
+	UNUSED(yes);
+#endif /* if defined(IPV6_V6ONLY) */
+
+	REQUIRE(VALID_SOCKET(sock));
+
+#ifdef IPV6_V6ONLY
+	if (sock->pf == AF_INET6) {
+		(void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_V6ONLY,
+				 (char *)&onoff, sizeof(onoff));
+	}
+#endif /* ifdef IPV6_V6ONLY */
+}
+
+void
+isc_socket_dscp(isc_socket_t *sock, isc_dscp_t dscp) {
+#if !defined(IP_TOS) && !defined(IPV6_TCLASS)
+	UNUSED(dscp);
+#else  /* if !defined(IP_TOS) && !defined(IPV6_TCLASS) */
+	if (dscp < 0) {
+		return;
+	}
+
+	dscp <<= 2;
+	dscp &= 0xff;
+#endif /* if !defined(IP_TOS) && !defined(IPV6_TCLASS) */
+
+	REQUIRE(VALID_SOCKET(sock));
+
+#ifdef IP_TOS
+	if (sock->pf == AF_INET) {
+		(void)setsockopt(sock->fd, IPPROTO_IP, IP_TOS, (char *)&dscp,
+				 sizeof(dscp));
+	}
+#endif /* ifdef IP_TOS */
+#ifdef IPV6_TCLASS
+	if (sock->pf == AF_INET6) {
+		(void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_TCLASS,
+				 (char *)&dscp, sizeof(dscp));
+	}
+#endif /* ifdef IPV6_TCLASS */
+}
+
+void
+isc_socket_cleanunix(const isc_sockaddr_t *addr, bool active) {
+	UNUSED(addr);
+	UNUSED(active);
+}
+
+isc_result_t
+isc_socket_permunix(const isc_sockaddr_t *addr, uint32_t perm, uint32_t owner,
+		    uint32_t group) {
+	UNUSED(addr);
+	UNUSED(perm);
+	UNUSED(owner);
+	UNUSED(group);
+	return (ISC_R_NOTIMPLEMENTED);
+}
+
+void
+isc_socket_setname(isc_socket_t *socket, const char *name, void *tag) {
+	/*
+	 * Name 'socket'.
+	 */
+
+	REQUIRE(VALID_SOCKET(socket));
+
+	LOCK(&socket->lock);
+	strlcpy(socket->name, name, sizeof(socket->name));
+	socket->tag = tag;
+	UNLOCK(&socket->lock);
+}
+
+const char *
+isc_socket_getname(isc_socket_t *socket) {
+	return (socket->name);
+}
+
+void *
+isc_socket_gettag(isc_socket_t *socket) {
+	return (socket->tag);
+}
+
+int
+isc_socket_getfd(isc_socket_t *socket) {
+	return ((short)socket->fd);
+}
+
+void
+isc_socketmgr_setreserved(isc_socketmgr_t *manager, uint32_t reserved) {
+	UNUSED(manager);
+	UNUSED(reserved);
+}
+
+isc_socketevent_t *
+isc_socket_socketevent(isc_mem_t *mctx, void *sender, isc_eventtype_t eventtype,
+		       isc_taskaction_t action, void *arg) {
+	return (allocate_socketevent(mctx, sender, eventtype, action, arg));
+}
+
+bool
+isc_socket_hasreuseport() {
+	return (false);
+}
+
+#ifdef HAVE_LIBXML2
+
+static const char *
+_socktype(isc_sockettype_t type) {
+	switch (type) {
+	case isc_sockettype_udp:
+		return ("udp");
+	case isc_sockettype_tcp:
+		return ("tcp");
+	case isc_sockettype_unix:
+		return ("unix");
+	default:
+		return ("not-initialized");
+	}
+}
+
+#define TRY0(a)                     \
+	do {                        \
+		xmlrc = (a);        \
+		if (xmlrc < 0)      \
+			goto error; \
+	} while (0)
+int
+isc_socketmgr_renderxml(isc_socketmgr_t *mgr, void *writer0) {
+	isc_socket_t *sock = NULL;
+	char peerbuf[ISC_SOCKADDR_FORMATSIZE];
+	isc_sockaddr_t addr;
+	socklen_t len;
+	int xmlrc;
+	xmlTextWriterPtr writer = (xmlTextWriterPtr)writer0;
+
+	LOCK(&mgr->lock);
+
+	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "sockets"));
+	sock = ISC_LIST_HEAD(mgr->socklist);
+	while (sock != NULL) {
+		LOCK(&sock->lock);
+		TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "socket"));
+
+		TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "id"));
+		TRY0(xmlTextWriterWriteFormatString(writer, "%p", sock));
+		TRY0(xmlTextWriterEndElement(writer));
+
+		if (sock->name[0] != 0) {
+			TRY0(xmlTextWriterStartElement(writer,
+						       ISC_XMLCHAR "name"));
+			TRY0(xmlTextWriterWriteFormatString(writer, "%s",
+							    sock->name));
+			TRY0(xmlTextWriterEndElement(writer)); /* name */
+		}
+
+		TRY0(xmlTextWriterStartElement(writer,
+					       ISC_XMLCHAR "references"));
+		TRY0(xmlTextWriterWriteFormatString(
+			writer, "%" PRIuFAST32,
+			isc_refcount_current(&sock->references)));
+		TRY0(xmlTextWriterEndElement(writer));
+
+		TRY0(xmlTextWriterWriteElement(
+			writer, ISC_XMLCHAR "type",
+			ISC_XMLCHAR _socktype(sock->type)));
+
+		if (sock->connected) {
+			isc_sockaddr_format(&sock->address, peerbuf,
+					    sizeof(peerbuf));
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "peer-address",
+				ISC_XMLCHAR peerbuf));
+		}
+
+		len = sizeof(addr);
+		if (getsockname(sock->fd, &addr.type.sa, (void *)&len) == 0) {
+			isc_sockaddr_format(&addr, peerbuf, sizeof(peerbuf));
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "local-address",
+				ISC_XMLCHAR peerbuf));
+		}
+
+		TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "states"));
+		if (sock->pending_recv) {
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "state",
+				ISC_XMLCHAR "pending-receive"));
+		}
+		if (sock->pending_send) {
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "state",
+				ISC_XMLCHAR "pending-send"));
+		}
+		if (sock->pending_accept) {
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "state",
+				ISC_XMLCHAR "pending_accept"));
+		}
+		if (sock->listener) {
+			TRY0(xmlTextWriterWriteElement(writer,
+						       ISC_XMLCHAR "state",
+						       ISC_XMLCHAR "listener"));
+		}
+		if (sock->connected) {
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "state",
+				ISC_XMLCHAR "connected"));
+		}
+		if (sock->pending_connect) {
+			TRY0(xmlTextWriterWriteElement(
+				writer, ISC_XMLCHAR "state",
+				ISC_XMLCHAR "connecting"));
+		}
+		if (sock->bound) {
+			TRY0(xmlTextWriterWriteElement(writer,
+						       ISC_XMLCHAR "state",
+						       ISC_XMLCHAR "bound"));
+		}
+
+		TRY0(xmlTextWriterEndElement(writer)); /* states */
+
+		TRY0(xmlTextWriterEndElement(writer)); /* socket */
+
+		UNLOCK(&sock->lock);
+		sock = ISC_LIST_NEXT(sock, link);
+	}
+	TRY0(xmlTextWriterEndElement(writer)); /* sockets */
+
+error:
+	if (sock != NULL) {
+		UNLOCK(&sock->lock);
+	}
+
+	UNLOCK(&mgr->lock);
+
+	return (xmlrc);
+}
+#endif /* HAVE_LIBXML2 */
+
+#ifdef HAVE_JSON_C
+#define CHECKMEM(m)                              \
+	do {                                     \
+		if (m == NULL) {                 \
+			result = ISC_R_NOMEMORY; \
+			goto error;              \
+		}                                \
+	} while (0)
+isc_result_t
+isc_socketmgr_renderjson(isc_socketmgr_t *mgr, void *stats0) {
+	isc_result_t result = ISC_R_SUCCESS;
+	isc_socket_t *sock = NULL;
+	char peerbuf[ISC_SOCKADDR_FORMATSIZE];
+	isc_sockaddr_t addr;
+	socklen_t len;
+	json_object *obj, *array = json_object_new_array();
+	json_object *stats = (json_object *)stats;
+
+	CHECKMEM(array);
+
+	LOCK(&mgr->lock);
+
+#ifdef USE_SHARED_MANAGER
+	obj = json_object_new_int(mgr->refs);
+	CHECKMEM(obj);
+	json_object_object_add(stats, "references", obj);
+#endif /* USE_SHARED_MANAGER */
+
+	sock = ISC_LIST_HEAD(mgr->socklist);
+	while (sock != NULL) {
+		json_object *states, *entry = json_object_new_object();
+		char buf[255];
+
+		CHECKMEM(entry);
+		json_object_array_add(array, entry);
+
+		LOCK(&sock->lock);
+
+		snprintf(buf, sizeof(buf), "%p", sock);
+		obj = json_object_new_string(buf);
+		CHECKMEM(obj);
+		json_object_object_add(entry, "id", obj);
+
+		if (sock->name[0] != 0) {
+			obj = json_object_new_string(sock->name);
+			CHECKMEM(obj);
+			json_object_object_add(entry, "name", obj);
+		}
+
+		obj = json_object_new_int(
+			isc_refcount_current(&sock->references));
+		CHECKMEM(obj);
+		json_object_object_add(entry, "references", obj);
+
+		obj = json_object_new_string(_socktype(sock->type));
+		CHECKMEM(obj);
+		json_object_object_add(entry, "type", obj);
+
+		if (sock->connected) {
+			isc_sockaddr_format(&sock->address, peerbuf,
+					    sizeof(peerbuf));
+			obj = json_object_new_string(peerbuf);
+			CHECKMEM(obj);
+			json_object_object_add(entry, "peer-address", obj);
+		}
+
+		len = sizeof(addr);
+		if (getsockname(sock->fd, &addr.type.sa, (void *)&len) == 0) {
+			isc_sockaddr_format(&addr, peerbuf, sizeof(peerbuf));
+			obj = json_object_new_string(peerbuf);
+			CHECKMEM(obj);
+			json_object_object_add(entry, "local-address", obj);
+		}
+
+		states = json_object_new_array();
+		CHECKMEM(states);
+		json_object_object_add(entry, "states", states);
+
+		if (sock->pending_recv) {
+			obj = json_object_new_string("pending-receive");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		if (sock->pending_send) {
+			obj = json_object_new_string("pending-send");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		if (sock->pending_accept) {
+			obj = json_object_new_string("pending-accept");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		if (sock->listener) {
+			obj = json_object_new_string("listener");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		if (sock->connected) {
+			obj = json_object_new_string("connected");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		if (sock->pending_connect) {
+			obj = json_object_new_string("connecting");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		if (sock->bound) {
+			obj = json_object_new_string("bound");
+			CHECKMEM(obj);
+			json_object_array_add(states, obj);
+		}
+
+		UNLOCK(&sock->lock);
+		sock = ISC_LIST_NEXT(sock, link);
+	}
+
+	json_object_object_add(stats, "sockets", array);
+	array = NULL;
+	result = ISC_R_SUCCESS;
+
+error:
+	if (array != NULL) {
+		json_object_put(array);
+	}
+
+	if (sock != NULL) {
+		UNLOCK(&sock->lock);
+	}
+
+	UNLOCK(&mgr->lock);
+
+	return (result);
+}
+#endif /* HAVE_JSON_C */
+
+void
+isc_socketmgr_maxudp(isc_socketmgr_t *manager, unsigned int maxudp) {
+	REQUIRE(VALID_MANAGER(manager));
+
+	manager->maxudp = maxudp;
+}