socket.c 95.2 KB
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/*
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 * Copyright (C) 2004-2009  Internet Systems Consortium, Inc. ("ISC")
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 * Copyright (C) 2000-2003  Internet Software Consortium.
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 *
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 * Permission to use, copy, modify, and/or distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
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 */

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/* $Id: socket.c,v 1.80 2009/09/25 23:48:11 tbox Exp $ */
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/* This code uses functions which are only available on Server 2003 and
 * higher, and Windows XP and higher.
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 *
 * This code is by nature multithreaded and takes advantage of various
 * features to pass on information through the completion port for
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 * when I/O is completed.  All sends, receives, accepts, and connects are
 * completed through the completion port.
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 *
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 * 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.
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 *
 * XXXPDM 5 August, 2002
 */
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#define MAKE_EXTERNAL 1
#include <config.h>

#include <sys/types.h>

#ifndef _WINSOCKAPI_
#define _WINSOCKAPI_   /* Prevent inclusion of winsock.h in windows.h */
#endif

#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <io.h>
#include <fcntl.h>
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#include <process.h>
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#include <isc/buffer.h>
#include <isc/bufferlist.h>
#include <isc/condition.h>
#include <isc/list.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/msgs.h>
#include <isc/mutex.h>
#include <isc/net.h>
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#include <isc/once.h>
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#include <isc/os.h>
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#include <isc/platform.h>
#include <isc/print.h>
#include <isc/region.h>
#include <isc/socket.h>
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#include <isc/stats.h>
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#include <isc/strerror.h>
#include <isc/syslog.h>
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#include <isc/task.h>
#include <isc/thread.h>
#include <isc/util.h>
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#include <isc/win32os.h>
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#include <mswsock.h>

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#include "errno2result.h"
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/*
 * 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;

/*
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 * Run expensive internal consistency checks.
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 */
#ifdef ISC_SOCKET_CONSISTENCY_CHECKS
#define CONSISTENT(sock) consistent(sock)
#else
#define CONSISTENT(sock) do {} while (0)
#endif
static void consistent(isc_socket_t *sock);

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/*
 * 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.
 */
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#ifndef SIO_UDP_CONNRESET
#define SIO_UDP_CONNRESET _WSAIOW(IOC_VENDOR,12)
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#endif

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/*
 * Some systems define the socket length argument as an int, some as size_t,
 * some as socklen_t.  This is here so it can be easily changed if needed.
 */
#ifndef ISC_SOCKADDR_LEN_T
#define ISC_SOCKADDR_LEN_T unsigned int
#endif

/*
 * Define what the possible "soft" errors can be.  These are non-fatal returns
 * of various network related functions, like recv() and so on.
 */
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#define SOFT_ERROR(e)	((e) == WSAEINTR || \
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			 (e) == WSAEWOULDBLOCK || \
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			 (e) == EWOULDBLOCK || \
			 (e) == EINTR || \
			 (e) == EAGAIN || \
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			 (e) == 0)

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/*
 * 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 */
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#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 */
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#define DOIO_PENDING	  4       /* status when i/o is in process */
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#define DOIO_NEEDMORE	  5       /* IO was processed, but we need more due to minimum */
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#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;

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/*
 * 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 */
};

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#define SOCKET_MAGIC		ISC_MAGIC('I', 'O', 'i', 'o')
#define VALID_SOCKET(t)		ISC_MAGIC_VALID(t, SOCKET_MAGIC)
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/*
 * 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.
 */
#ifdef ISC_PLATFORM_HAVEIPV6
#ifndef USE_CMSG
#define USE_CMSG	1
#endif
#endif

/*
 * We really  don't want to try and use these control messages. Win32
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 * doesn't have this mechanism before XP.
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 */
#undef USE_CMSG

/*
 * Message header for recvmsg and sendmsg calls.
 * Used value-result for recvmsg, value only for sendmsg.
 */
struct msghdr {
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	SOCKADDR_STORAGE to_addr;	/* UDP send/recv address */
	int      to_addr_len;		/* length of the address */
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	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 */
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	int	msg_totallen;		/* total length of this message */
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} msghdr;
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/*
 * The size to raise the receive buffer to.
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 */
#define RCVBUFSIZE (32*1024)

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/*
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 * The number of times a send operation is repeated if the result
 * is WSAEINTR.
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 */
#define NRETRIES 10

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struct isc_socket {
	/* Not locked. */
	unsigned int		magic;
	isc_socketmgr_t	       *manager;
	isc_mutex_t		lock;
	isc_sockettype_t	type;
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	/* Pointers to scatter/gather buffers */
	WSABUF			iov[ISC_SOCKET_MAXSCATTERGATHER];
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	/* Locked by socket lock. */
	ISC_LINK(isc_socket_t)	link;
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	unsigned int		references; /* EXTERNAL references */
	SOCKET			fd;	/* file handle */
	int			pf;	/* protocol family */
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	char			name[16];
	void *			tag;

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	/*
	 * 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;

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	ISC_LIST(isc_socketevent_t)		send_list;
	ISC_LIST(isc_socketevent_t)		recv_list;
	ISC_LIST(isc_socket_newconnev_t)	accept_list;
	isc_socket_connev_t		       *connect_ev;

	isc_sockaddr_t		address;  /* remote address */

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	unsigned int		listener : 1,	/* listener socket */
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				connected : 1,
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				pending_connect : 1, /* connect pending */
				bound : 1;	/* bound to local addr */
	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)

/*
 * Buffer structure
 */
typedef struct buflist buflist_t;

struct buflist {
	void			*buf;
	unsigned int		buflen;
	ISC_LINK(buflist_t)	link;
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};

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/*
 * I/O Completion ports Info structures
 */

static HANDLE hHeapHandle = NULL;
typedef struct IoCompletionInfo {
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	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;
	ISC_LIST(buflist_t)	bufferlist;	/*%< list of buffers */
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} IoCompletionInfo;

/*
 * Define a maximum number of I/O Completion Port worker threads
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 * to handle the load on the Completion Port. The actual number
 * used is the number of CPU's + 1.
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 */
#define MAX_IOCPTHREADS 20

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#define SOCKET_MANAGER_MAGIC	ISC_MAGIC('I', 'O', 'm', 'g')
#define VALID_MANAGER(m)	ISC_MAGIC_VALID(m, SOCKET_MANAGER_MAGIC)

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struct isc_socketmgr {
	/* Not locked. */
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	unsigned int			magic;
	isc_mem_t		       *mctx;
	isc_mutex_t			lock;
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	isc_stats_t		       *stats;

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	/* Locked by manager lock. */
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	ISC_LIST(isc_socket_t)		socklist;
	isc_boolean_t			bShutdown;
	isc_condition_t			shutdown_ok;
	HANDLE				hIoCompletionPort;
	int				maxIOCPThreads;
	HANDLE				hIOCPThreads[MAX_IOCPTHREADS];
	DWORD				dwIOCPThreadIds[MAX_IOCPTHREADS];
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	/*
	 * Debugging.
	 * Modified by InterlockedIncrement() and InterlockedDecrement()
	 */
	LONG				totalSockets;
	LONG				iocp_total;
};

enum {
	SOCKET_RECV,
	SOCKET_SEND,
	SOCKET_ACCEPT,
	SOCKET_CONNECT
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};

/*
 * send() and recv() iovec counts
 */
#define MAXSCATTERGATHER_SEND	(ISC_SOCKET_MAXSCATTERGATHER)
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#define MAXSCATTERGATHER_RECV	(ISC_SOCKET_MAXSCATTERGATHER)
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static isc_threadresult_t WINAPI SocketIoThread(LPVOID ThreadContext);
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static void maybe_free_socket(isc_socket_t **, int);
static void free_socket(isc_socket_t **, int);
static isc_boolean_t senddone_is_active(isc_socket_t *sock, isc_socketevent_t *dev);
static isc_boolean_t acceptdone_is_active(isc_socket_t *sock, isc_socket_newconnev_t *dev);
static isc_boolean_t 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 queue_receive_event(isc_socket_t *sock, isc_task_t *task, isc_socketevent_t *dev);
static void queue_receive_request(isc_socket_t *sock);
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/*
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 * This is used to dump the contents of the sock structure
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 * 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;
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#if 0
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	isc_sockaddr_t addr;
	char socktext[256];

	isc_socket_getpeername(sock, &addr);
	isc_sockaddr_format(&addr, socktext, sizeof(socktext));
	printf("Remote Socket: %s\n", socktext);
	isc_socket_getsockname(sock, &addr);
	isc_sockaddr_format(&addr, socktext, sizeof(socktext));
	printf("This Socket: %s\n", socktext);
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#endif
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	printf("\n\t\tSock Dump\n");
	printf("\t\tfd: %u\n", sock->fd);
	printf("\t\treferences: %d\n", sock->references);
	printf("\t\tpending_accept: %d\n", sock->pending_accept);
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	printf("\t\tconnecting: %d\n", sock->pending_connect);
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	printf("\t\tconnected: %d\n", sock->connected);
	printf("\t\tbound: %d\n", sock->bound);
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	printf("\t\tpending_iocp: %d\n", sock->pending_iocp);
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	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);
	}
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	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);
	}
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	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);
	}
}
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static void
socket_log(int lineno, isc_socket_t *sock, isc_sockaddr_t *address,
	   isc_logcategory_t *category, isc_logmodule_t *module, int level,
	   isc_msgcat_t *msgcat, int msgset, int message,
	   const char *fmt, ...) ISC_FORMAT_PRINTF(9, 10);
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/*  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];

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	REQUIRE(VALID_MANAGER(manager));
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	for (i = 0; i < manager->maxIOCPThreads; i++) {
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		if (!PostQueuedCompletionStatus(manager->hIoCompletionPort,
						0, 0, 0)) {
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			errval = GetLastError();
			isc__strerror(errval, strbuf, sizeof(strbuf));
			FATAL_ERROR(__FILE__, __LINE__,
				isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKET,
				ISC_MSG_FAILED,
				"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];
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	int i;
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	INSIST(total_threads > 0);
	REQUIRE(VALID_MANAGER(manager));
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	/*
	 * We need at least one
	 */
	for (i = 0; i < total_threads; i++) {
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		manager->hIOCPThreads[i] = CreateThread(NULL, 0, SocketIoThread,
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						manager, 0,
						&manager->dwIOCPThreadIds[i]);
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		if (manager->hIOCPThreads[i] == NULL) {
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			errval = GetLastError();
			isc__strerror(errval, strbuf, sizeof(strbuf));
			FATAL_ERROR(__FILE__, __LINE__,
				isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKET,
				ISC_MSG_FAILED,
				"Can't create IOCP thread: %s"),
				strbuf);
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			exit(1);
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		}
	}
}

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/*
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 *  Create/initialise the I/O completion port
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 */
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void
iocompletionport_init(isc_socketmgr_t *manager) {
	int errval;
	char strbuf[ISC_STRERRORSIZE];
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	REQUIRE(VALID_MANAGER(manager));
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	/*
	 * Create a private heap to handle the socket overlapped structure
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	 * The minimum number of structures is 10, there is no maximum
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	 */
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	hHeapHandle = HeapCreate(0, 10 * sizeof(IoCompletionInfo), 0);
	if (hHeapHandle == NULL) {
		errval = GetLastError();
		isc__strerror(errval, strbuf, sizeof(strbuf));
		FATAL_ERROR(__FILE__, __LINE__,
			    isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKET,
					   ISC_MSG_FAILED,
					   "HeapCreate() failed during "
					   "initialization: %s"),
			    strbuf);
		exit(1);
	}

	manager->maxIOCPThreads = min(isc_os_ncpus() + 1, MAX_IOCPTHREADS);
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	/* Now Create the Completion Port */
	manager->hIoCompletionPort = CreateIoCompletionPort(
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			INVALID_HANDLE_VALUE, NULL,
			0, manager->maxIOCPThreads);
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	if (manager->hIoCompletionPort == NULL) {
		errval = GetLastError();
		isc__strerror(errval, strbuf, sizeof(strbuf));
		FATAL_ERROR(__FILE__, __LINE__,
				isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKET,
				ISC_MSG_FAILED,
				"CreateIoCompletionPort() failed "
				"during initialization: %s"),
				strbuf);
		exit(1);
	}
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	/*
	 * Worker threads for servicing the I/O
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	 */
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	iocompletionport_createthreads(manager->maxIOCPThreads, manager);
}
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/*
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 * 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.
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 */
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void
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iocompletionport_update(isc_socket_t *sock) {
	HANDLE hiocp;
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	char strbuf[ISC_STRERRORSIZE];
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	REQUIRE(VALID_SOCKET(sock));
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	hiocp = CreateIoCompletionPort((HANDLE)sock->fd,
		sock->manager->hIoCompletionPort, (ULONG_PTR)sock, 0);

	if (hiocp == NULL) {
		DWORD errval = GetLastError();
		isc__strerror(errval, strbuf, sizeof(strbuf));
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		isc_log_iwrite(isc_lctx,
				ISC_LOGCATEGORY_GENERAL,
				ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
				isc_msgcat, ISC_MSGSET_SOCKET,
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				ISC_MSG_TOOMANYHANDLES,
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				"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__,
				isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKET,
				ISC_MSG_FAILED,
				"CreateIoCompletionPort() failed "
				"during initialization: %s"),
				strbuf);
		exit(1);
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	}

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	InterlockedIncrement(&sock->manager->iocp_total);
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}
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/*
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 * Routine to cleanup and then close the socket.
 * Only close the socket here if it is NOT associated
 * with an event, otherwise the WSAWaitForMultipleEvents
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 * may fail due to the fact that the Wait should not
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 * be running while closing an event or a socket.
 * The socket is locked before calling this function
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 */
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void
socket_close(isc_socket_t *sock) {
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	REQUIRE(sock != NULL);
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	if (sock->fd != INVALID_SOCKET) {
		closesocket(sock->fd);
		sock->fd = INVALID_SOCKET;
		_set_state(sock, SOCK_CLOSED);
		InterlockedDecrement(&sock->manager->totalSockets);
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	}
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}
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static isc_once_t initialise_once = ISC_ONCE_INIT;
static isc_boolean_t initialised = ISC_FALSE;
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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;
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	/* Need Winsock 2.2 or better */
	wVersionRequested = MAKEWORD(2, 2);

	err = WSAStartup(wVersionRequested, &wsaData);
	if (err != 0) {
		char strbuf[ISC_STRERRORSIZE];
		isc__strerror(err, strbuf, sizeof(strbuf));
		FATAL_ERROR(__FILE__, __LINE__, "WSAStartup() %s: %s",
			    isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
					   ISC_MSG_FAILED, "failed"),
			    strbuf);
		exit(1);
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	}
	/*
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	 * 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.
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	 */
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	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);
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	err = WSAIoctl(sock,  SIO_GET_EXTENSION_FUNCTION_POINTER,
		 &GUIDAcceptEx, sizeof(GUIDAcceptEx),
		 &ISCAcceptEx, sizeof(ISCAcceptEx),
		 &dwBytes, NULL, NULL);
	INSIST(err == 0);
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	err = WSAIoctl(sock,  SIO_GET_EXTENSION_FUNCTION_POINTER,
		 &GUIDGetAcceptExSockaddrs, sizeof(GUIDGetAcceptExSockaddrs),
		 &ISCGetAcceptExSockaddrs, sizeof(ISCGetAcceptExSockaddrs),
		 &dwBytes, NULL, NULL);
	INSIST(err == 0);
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	closesocket(sock);
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	initialised = ISC_TRUE;
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}
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/*
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 * Initialize socket services
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 */
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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)
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{
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	int Result;
	DWORD BytesSent;
	DWORD Flags = flags;
	int total_sent;
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	*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);
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			break;
		}
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	} else {
		sock->pending_iocp++;
		sock->pending_send++;
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	}
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	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 total_bytes = 0;
	int Result;
	int Error;
	WSABUF iov[1];
	IoCompletionInfo *lpo;
	isc_result_t isc_result;

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	/*
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	 * If we already have a receive pending, do nothing.
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	 */
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	if (sock->pending_recv > 0)
		return;
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	/*
	 * If no one is waiting, do nothing.
	 */
	if (ISC_LIST_EMPTY(sock->recv_list))
		return;
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	INSIST(sock->recvbuf.remaining == 0);
	INSIST(sock->fd != INVALID_SOCKET);
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	iov[0].len = sock->recvbuf.len;
	iov[0].buf = sock->recvbuf.base;
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	lpo = (IoCompletionInfo *)HeapAlloc(hHeapHandle,
					    HEAP_ZERO_MEMORY,
					    sizeof(IoCompletionInfo));
	RUNTIME_CHECK(lpo != NULL);
	lpo->request_type = SOCKET_RECV;
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	sock->recvbuf.from_addr_len = sizeof(sock->recvbuf.from_addr);
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	Error = 0;
	Result = WSARecvFrom((SOCKET)sock->fd, iov, 1,
			     &NumBytes, &Flags,
			     (SOCKADDR *)&sock->recvbuf.from_addr,
			     &sock->recvbuf.from_addr_len,
			     (LPWSAOVERLAPPED)lpo, NULL);
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	/* Check for errors. */
	if (Result == SOCKET_ERROR) {
		Error = WSAGetLastError();
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		switch (Error) {
		case WSA_IO_PENDING:
			sock->pending_iocp++;
			sock->pending_recv++;
			break;
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		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);
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			break;
		}
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	} 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++;
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		sock->pending_recv++;
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	}
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	socket_log(__LINE__, sock, NULL, IOEVENT,
		   isc_msgcat, ISC_MSGSET_SOCKET,
		   ISC_MSG_DOIORECV,
		   "queue_io_request: fd %d result %d error %d",
		   sock->fd, Result, Error);

	CONSISTENT(sock);
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}
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static void
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manager_log(isc_socketmgr_t *sockmgr, isc_logcategory_t *category,
	    isc_logmodule_t *module, int level, const char *fmt, ...)
{
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	char msgbuf[2048];
	va_list ap;

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	if (!isc_log_wouldlog(isc_lctx, level))
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		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);
}

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static void
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socket_log(int lineno, isc_socket_t *sock, isc_sockaddr_t *address,
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	   isc_logcategory_t *category, isc_logmodule_t *module, int level,
	   isc_msgcat_t *msgcat, int msgset, int message,
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	   const char *fmt, ...)
{
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	char msgbuf[2048];
	char peerbuf[256];
	va_list ap;

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	if (!isc_log_wouldlog(isc_lctx, level))
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		return;

	va_start(ap, fmt);
	vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
	va_end(ap);

	if (address == NULL) {
		isc_log_iwrite(isc_lctx, category, module, level,
			       msgcat, msgset, message,
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			       "socket %p line %d: %s", sock, lineno, msgbuf);
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	} else {
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		isc_sockaddr_format(address, peerbuf, sizeof(peerbuf));
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		isc_log_iwrite(isc_lctx, category, module, level,
			       msgcat, msgset, message,
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				   "socket %p line %d peer %s: %s", sock, lineno,
				   peerbuf, msgbuf);
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	}
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}
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/*
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 * Make an fd SOCKET non-blocking.
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 */
static isc_result_t
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make_nonblock(SOCKET fd) {
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	int ret;
	unsigned long flags = 1;
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	char strbuf[ISC_STRERRORSIZE];
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	/* Set the socket to non-blocking */
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	ret = ioctlsocket(fd, FIONBIO, &flags);
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	if (ret == -1) {
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		isc__strerror(errno, strbuf, sizeof(strbuf));
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		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "ioctlsocket(%d, FIOBIO, %d): %s",
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				 fd, flags, strbuf);
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		return (ISC_R_UNEXPECTED);
	}

	return (ISC_R_SUCCESS);
}
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/*
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 * Windows 2000 systems incorrectly cause UDP sockets using WASRecvFrom
 * 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.
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 */
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isc_result_t
connection_reset_fix(SOCKET fd) {
	DWORD dwBytesReturned = 0;
	BOOL  bNewBehavior = FALSE;
	DWORD status;

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	if (isc_win32os_majorversion() < 5)
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		return (ISC_R_SUCCESS); /*  NT 4.0 has no problem */

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	/* disable bad behavior using IOCTL: SIO_UDP_CONNRESET */
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	status = WSAIoctl(fd, SIO_UDP_CONNRESET, &bNewBehavior,
			  sizeof(bNewBehavior), NULL, 0,
			  &dwBytesReturned, NULL, NULL);
	if (status != SOCKET_ERROR)
		return (ISC_R_SUCCESS);
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	else {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "WSAIoctl(SIO_UDP_CONNRESET, oldBehaviour) %s",
				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED, "failed"));
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		return (ISC_R_UNEXPECTED);
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	}
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}

/*
 * 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,
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		  struct msghdr *msg, char *cmsg, WSABUF *iov,
		  IoCompletionInfo  *lpo)
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{
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	unsigned int iovcount;
	isc_buffer_t *buffer;
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	buflist_t  *cpbuffer;
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	isc_region_t used;
	size_t write_count;
	size_t skip_count;

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	memset(msg, 0, sizeof(*msg));
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	memcpy(&msg->to_addr, &dev->address.type, dev->address.length);
	msg->to_addr_len = dev->address.length;
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	buffer = ISC_LIST_HEAD(dev->bufferlist);
	write_count = 0;
	iovcount = 0;

	/*
	 * Single buffer I/O?  Skip what we've done so far in this region.
	 */
	if (buffer == NULL) {
		write_count = dev->region.length - dev->n;
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		cpbuffer = HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY, sizeof(buflist_t));
		RUNTIME_CHECK(cpbuffer != NULL);
		cpbuffer->buf = HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY, write_count);
		RUNTIME_CHECK(cpbuffer->buf != NULL);

		socket_log(__LINE__, sock, NULL, TRACE,
		   isc_msgcat, ISC_MSGSET_SOCKET, ISC_MSG_ACCEPTLOCK,
		   "alloc_buffer %p %d %p %d", cpbuffer, sizeof(buflist_t),
		   cpbuffer->buf, write_count);

		memcpy(cpbuffer->buf,(dev->region.base + dev->n), write_count);
		cpbuffer->buflen = write_count;
		ISC_LIST_ENQUEUE(lpo->bufferlist, cpbuffer, link);
		iov[0].buf = cpbuffer->buf;
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		iov[0].len = write_count;
		iovcount = 1;

		goto config;
	}

	/*
	 * Multibuffer I/O.
	 * Skip the data in the buffer list that we have already written.
	 */
	skip_count = dev->n;
	while (buffer != NULL) {
		REQUIRE(ISC_BUFFER_VALID(buffer));
		if (skip_count < isc_buffer_usedlength(buffer))
			break;
		skip_count -= isc_buffer_usedlength(buffer);
		buffer = ISC_LIST_NEXT(buffer, link);
	}

	while (buffer != NULL) {
		INSIST(iovcount < MAXSCATTERGATHER_SEND);

		isc_buffer_usedregion(buffer, &used);

		if (used.length > 0) {
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			int uselen = used.length - skip_count;
			cpbuffer = HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY, sizeof(buflist_t));
			RUNTIME_CHECK(cpbuffer != NULL);
			cpbuffer->buf = HeapAlloc(hHeapHandle, HEAP_ZERO_MEMORY, uselen);
			RUNTIME_CHECK(cpbuffer->buf != NULL);

			socket_log(__LINE__, sock, NULL, TRACE,
			   isc_msgcat, ISC_MSGSET_SOCKET, ISC_MSG_ACCEPTLOCK,
			   "alloc_buffer %p %d %p %d", cpbuffer, sizeof(buflist_t),
			   cpbuffer->buf, write_count);

			memcpy(cpbuffer->buf,(used.base + skip_count), uselen);
			cpbuffer->buflen = uselen;
			iov[iovcount].buf = cpbuffer->buf;
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			iov[iovcount].len = used.length - skip_count;
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			write_count += uselen;
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			skip_count = 0;
			iovcount++;
		}
		buffer = ISC_LIST_NEXT(buffer, link);
	}

	INSIST(skip_count == 0);

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	msg->msg_iov = iov;
	msg->msg_iovlen = iovcount;
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	msg->msg_totallen = write_count;
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}

static void
set_dev_address(isc_sockaddr_t *address, isc_socket_t *sock,
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		isc_socketevent_t *dev)
{
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	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;
	}
}

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static void
destroy_socketevent(isc_event_t *event) {
	isc_socketevent_t *ev = (isc_socketevent_t *)event;

	INSIST(ISC_LIST_EMPTY(ev->bufferlist));

	(ev->destroy)(event);
}

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static isc_socketevent_t *
allocate_socketevent(isc_socket_t *sock, isc_eventtype_t eventtype,
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		     isc_taskaction_t action, const void *arg)
{
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	isc_socketevent_t *ev;

	ev = (isc_socketevent_t *)isc_event_allocate(sock->manager->mctx,
						     sock, eventtype,
						     action, arg,
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						     sizeof(*ev));
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	if (ev == NULL)
		return (NULL);

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	ev->result = ISC_R_IOERROR; // XXXMLG temporary change to detect failure to set
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	ISC_LINK_INIT(ev, ev_link);
	ISC_LIST_INIT(ev->bufferlist);
	ev->region.base = NULL;
	ev->n = 0;
	ev->offset = 0;
	ev->attributes = 0;
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	ev->destroy = ev->ev_destroy;
	ev->ev_destroy = destroy_socketevent;
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	return (ev);
}

#if defined(ISC_SOCKET_DEBUG)
static void
dump_msg(struct msghdr *msg, isc_socket_t *sock) {
	unsigned int i;

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	printf("MSGHDR %p, Socket #: %u\n", msg, sock->fd);
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	printf("\tname %p, namelen %d\n", msg->msg_name, msg->msg_namelen);
	printf("\tiov %p, iovlen %d\n", msg->msg_iov, msg->msg_iovlen);
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	for (i = 0; i < (unsigned int)msg->msg_iovlen; i++)
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		printf("\t\t%d\tbase %p, len %d\n", i,
		       msg->msg_iov[i].buf,
		       msg->msg_iov[i].len);
}
#endif

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/*
 * 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: