xref: /freebsd-10.1-release/contrib/ntp/ntpd/ntp_io.c

/*
 * ntp_io.c - input/output routines for ntpd.	The socket-opening code
 *		   was shamelessly stolen from ntpd.
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdio.h>
#include <signal.h>
#include <sys/types.h>
#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif /* HAVE_SYS_PARAM_H */
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_SOCKIO_H	/* UXPV: SIOC* #defines (Frank Vance <fvance@waii.com>) */
# include <sys/sockio.h>
#endif
#include <arpa/inet.h>

#if _BSDI_VERSION >= 199510
# include <ifaddrs.h>
#endif

#include "ntp_machine.h"
#include "ntpd.h"
#include "ntp_io.h"
#include "iosignal.h"
#include "ntp_refclock.h"
#include "ntp_if.h"
#include "ntp_stdlib.h"

#if defined(VMS)		/* most likely UCX-specific */

#include <UCX$INETDEF.H>

/* "un*x"-compatible names for some items in UCX$INETDEF.H */
#define ifreq		IFREQDEF
#define ifr_name	IFR$T_NAME
#define ifr_addr		IFR$R_DUMMY.IFR$T_ADDR
#define ifr_broadaddr	IFR$R_DUMMY.IFR$T_BROADADDR
#define ifr_flags		IFR$R_DUMMY.IFR$R_DUMMY_1_OVRL.IFR$W_FLAGS
#define IFF_UP		IFR$M_IFF_UP
#define IFF_BROADCAST	IFR$M_IFF_BROADCAST
#define IFF_LOOPBACK	IFR$M_IFF_LOOPBACK

#endif /* VMS */


#if defined(VMS) || defined(SYS_WINNT)
/* structure used in SIOCGIFCONF request (after [KSR] OSF/1) */
struct ifconf {
	int ifc_len;			/* size of buffer */
	union {
		caddr_t ifcu_buf;
		struct ifreq *ifcu_req;
	} ifc_ifcu;
};
#define ifc_buf ifc_ifcu.ifcu_buf	/* buffer address */
#define ifc_req ifc_ifcu.ifcu_req	/* array of structures returned */

#endif /* VMS */

#if defined(USE_TTY_SIGPOLL) || defined(USE_UDP_SIGPOLL)
# if defined(SYS_AIX) && defined(_IO) /* XXX Identify AIX some other way */
#  undef _IO
# endif
# include <stropts.h>
#endif

/*
 * We do asynchronous input using the SIGIO facility.  A number of
 * recvbuf buffers are preallocated for input.	In the signal
 * handler we poll to see which sockets are ready and read the
 * packets from them into the recvbuf's along with a time stamp and
 * an indication of the source host and the interface it was received
 * through.  This allows us to get as accurate receive time stamps
 * as possible independent of other processing going on.
 *
 * We watch the number of recvbufs available to the signal handler
 * and allocate more when this number drops below the low water
 * mark.  If the signal handler should run out of buffers in the
 * interim it will drop incoming frames, the idea being that it is
 * better to drop a packet than to be inaccurate.
 */


/*
 * Other statistics of possible interest
 */
volatile u_long packets_dropped;	/* total number of packets dropped on reception */
volatile u_long packets_ignored;	/* packets received on wild card interface */
volatile u_long packets_received;	/* total number of packets received */
u_long packets_sent;	/* total number of packets sent */
u_long packets_notsent; /* total number of packets which couldn't be sent */

volatile u_long handler_calls;	/* number of calls to interrupt handler */
volatile u_long handler_pkts;	/* number of pkts received by handler */
u_long io_timereset;		/* time counters were reset */

/*
 * Interface stuff
 */
struct interface *any_interface;	/* pointer to default interface */
struct interface *loopback_interface;	/* point to loopback interface */
static	struct interface inter_list[MAXINTERFACES];
static	int ninterfaces;

#ifdef REFCLOCK
/*
 * Refclock stuff.	We keep a chain of structures with data concerning
 * the guys we are doing I/O for.
 */
static	struct refclockio *refio;
#endif /* REFCLOCK */

/*
 * File descriptor masks etc. for call to select
 */
fd_set activefds;
int maxactivefd;

static	int create_sockets	P((u_int));
static	int open_socket		P((struct sockaddr_in *, int, int));
static	void	close_socket	P((int));
static	void	close_file	P((int));
static	char *	fdbits		P((int, fd_set *));

/*
 * init_io - initialize I/O data structures and call socket creation routine
 */
void
init_io(void)
{
#ifdef SYS_WINNT
	WORD wVersionRequested;
	WSADATA wsaData;
	init_transmitbuff();
#endif /* SYS_WINNT */

	/*
	 * Init buffer free list and stat counters
	 */
	init_recvbuff(RECV_INIT);

	packets_dropped = packets_received = 0;
	packets_ignored = 0;
	packets_sent = packets_notsent = 0;
	handler_calls = handler_pkts = 0;
	io_timereset = 0;
	loopback_interface = 0;

#ifdef REFCLOCK
	refio = 0;
#endif

#if defined(HAVE_SIGNALED_IO)
	(void) set_signal();
#endif

#ifdef SYS_WINNT
	wVersionRequested = MAKEWORD(1,1);
	if (WSAStartup(wVersionRequested, &wsaData))
	{
		msyslog(LOG_ERR, "No useable winsock.dll: %m");
		exit(1);
	}
#endif /* SYS_WINNT */

	/*
	 * Create the sockets
	 */
	BLOCKIO();
	(void) create_sockets(htons(NTP_PORT));
	UNBLOCKIO();

#ifdef DEBUG
	if (debug)
	    printf("init_io: maxactivefd %d\n", maxactivefd);
#endif
}

/*
 * create_sockets - create a socket for each interface plus a default
 *			socket for when we don't know where to send
 */
static int
create_sockets(
	u_int port
	)
{
#if _BSDI_VERSION >= 199510
	int i, j;
	struct ifaddrs *ifaddrs, *ifap;
	struct sockaddr_in resmask;
#if 	_BSDI_VERSION < 199701
	struct ifaddrs *lp;
	int num_if;
#endif
#else	/* _BSDI_VERSION >= 199510 */
# ifdef STREAMS_TLI
	struct strioctl ioc;
# endif /* STREAMS_TLI */
	char	buf[MAXINTERFACES*sizeof(struct ifreq)];
	struct	ifconf	ifc;
	struct	ifreq	ifreq, *ifr;
	int n, i, j, vs, size = 0;
	struct sockaddr_in resmask;
#endif	/* _BSDI_VERSION >= 199510 */

#ifdef DEBUG
	if (debug)
	    printf("create_sockets(%d)\n", ntohs( (u_short) port));
#endif

	/*
	 * create pseudo-interface with wildcard address
	 */
	inter_list[0].sin.sin_family = AF_INET;
	inter_list[0].sin.sin_port = port;
	inter_list[0].sin.sin_addr.s_addr = htonl(INADDR_ANY);
	(void) strncpy(inter_list[0].name, "wildcard",
		       sizeof(inter_list[0].name));
	inter_list[0].mask.sin_addr.s_addr = htonl(~ (u_int32)0);
	inter_list[0].received = 0;
	inter_list[0].sent = 0;
	inter_list[0].notsent = 0;
	inter_list[0].flags = INT_BROADCAST;

#if _BSDI_VERSION >= 199510
#if 	_BSDI_VERSION >= 199701
	if (getifaddrs(&ifaddrs) < 0)
	{
		msyslog(LOG_ERR, "getifaddrs: %m");
		exit(1);
	}
	i = 1;
	for (ifap = ifaddrs; ifap != NULL; ifap = ifap->ifa_next)
#else
	    if (getifaddrs(&ifaddrs, &num_if) < 0)
	    {
		    msyslog(LOG_ERR, "create_sockets: getifaddrs() failed: %m");
		    exit(1);
	    }

	i = 1;

	for (ifap = ifaddrs, lp = ifap + num_if; ifap < lp; ifap++)
#endif
	{
		struct sockaddr_in *sin;

		if (!ifap->ifa_addr)
		    continue;

		if (ifap->ifa_addr->sa_family != AF_INET)
		    continue;

		if ((ifap->ifa_flags & IFF_UP) == 0)
		    continue;

		if (ifap->ifa_flags & IFF_LOOPBACK)
		{
			sin = (struct sockaddr_in *)ifap->ifa_addr;
			if (ntohl(sin->sin_addr.s_addr) != 0x7f000001)
			{
				continue;
			}
		}

		inter_list[i].flags = 0;
		if (ifap->ifa_flags & IFF_BROADCAST)
		    inter_list[i].flags |= INT_BROADCAST;

		(void)strcpy(inter_list[i].name, ifap->ifa_name);

		sin = (struct sockaddr_in *)ifap->ifa_addr;
		inter_list[i].sin = *sin;
		inter_list[i].sin.sin_port = port;

		if (ifap->ifa_flags & IFF_LOOPBACK)
		{
			inter_list[i].flags = INT_LOOPBACK;
			if (loopback_interface == NULL
			    || ntohl(sin->sin_addr.s_addr) != 0x7f000001)
			    loopback_interface = &inter_list[i];
		}

		if (inter_list[i].flags & INT_BROADCAST)
		{
			sin = (struct sockaddr_in *)ifap->ifa_broadaddr;
			inter_list[i].bcast = *sin;
			inter_list[i].bcast.sin_port = port;
		}

		if (ifap->ifa_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
		{
			inter_list[i].mask.sin_addr.s_addr = 0xffffffff;
		}
		else
		{
			sin = (struct sockaddr_in *)ifap->ifa_netmask;
			inter_list[i].mask = *sin;
		}
		inter_list[i].mask.sin_family = AF_INET;
		inter_list[i].mask.sin_len = sizeof *sin;

		/*
		 * look for an already existing source interface address.  If
		 * the machine has multiple point to point interfaces, then
		 * the local address may appear more than once.
		 *
		 * A second problem exists if we have two addresses on
		 * the same network (via "ifconfig alias ...").  Don't
		 * make two xntp interfaces for the two aliases on the
		 * one physical interface. -wsr
		 */
		for (j=0; j < i; j++)
		    if (inter_list[j].sin.sin_addr.s_addr &
			inter_list[j].mask.sin_addr.s_addr ==
			inter_list[i].sin.sin_addr.s_addr &
			inter_list[i].mask.sin_addr.s_addr)
		    {
			    if (inter_list[j].flags & INT_LOOPBACK)
				inter_list[j] = inter_list[i];
			    break;
		    }
		if (j == i)
		    i++;
		if (i > MAXINTERFACES)
		    break;
	}
	free(ifaddrs);
#else	/* _BSDI_VERSION >= 199510 */
# ifdef USE_STREAMS_DEVICE_FOR_IF_CONFIG
	if ((vs = open("/dev/ip", O_RDONLY)) < 0)
	{
		msyslog(LOG_ERR, "create_sockets: open(/dev/ip) failed: %m");
		exit(1);
	}
# else /* not USE_STREAMS_DEVICE_FOR_IF_CONFIG */
	if (
		(vs = socket(AF_INET, SOCK_DGRAM, 0))
#  ifndef SYS_WINNT
		< 0
#  else /* SYS_WINNT */
		== INVALID_SOCKET
#  endif /* SYS_WINNT */
		) {
		msyslog(LOG_ERR, "create_sockets: socket(AF_INET, SOCK_DGRAM) failed: %m");
		exit(1);
	}
# endif /* not USE_STREAMS_DEVICE_FOR_IF_CONFIG */

	i = 1;
# if !defined(SYS_WINNT)
	ifc.ifc_len = sizeof(buf);
# endif
# ifdef STREAMS_TLI
	ioc.ic_cmd = SIOCGIFCONF;
	ioc.ic_timout = 0;
	ioc.ic_dp = (caddr_t)buf;
	ioc.ic_len = sizeof(buf);
	if(ioctl(vs, I_STR, &ioc) < 0 ||
	   ioc.ic_len < sizeof(struct ifreq))
	{
		msyslog(LOG_ERR, "create_sockets: ioctl(I_STR:SIOCGIFCONF) failed: %m - exiting");
		exit(1);
	}
#  ifdef SIZE_RETURNED_IN_BUFFER
	ifc.ifc_len = ioc.ic_len - sizeof(int);
	ifc.ifc_buf = buf + sizeof(int);
#  else /* not SIZE_RETURNED_IN_BUFFER */
	ifc.ifc_len = ioc.ic_len;
	ifc.ifc_buf = buf;
#  endif /* not SIZE_RETURNED_IN_BUFFER */

# else /* not STREAMS_TLI */
	ifc.ifc_len = sizeof(buf);
	ifc.ifc_buf = buf;
#  ifndef SYS_WINNT
	if (ioctl(vs, SIOCGIFCONF, (char *)&ifc) < 0)
#  else
 	if (WSAIoctl(vs, SIO_GET_INTERFACE_LIST, 0, 0, ifc.ifc_buf, ifc.ifc_len, &ifc.ifc_len, 0, 0) == SOCKET_ERROR)
#  endif /* SYS_WINNT */
{
		msyslog(LOG_ERR, "create_sockets: ioctl(SIOCGIFCONF) failed: %m - exiting");
		exit(1);
}

# endif /* not STREAMS_TLI */

	for(n = ifc.ifc_len, ifr = ifc.ifc_req; n > 0;
	    ifr = (struct ifreq *)((char *)ifr + size))
	{
		extern int listen_to_virtual_ips;

		size = sizeof(*ifr);

# ifdef HAVE_SA_LEN_IN_STRUCT_SOCKADDR
		if (ifr->ifr_addr.sa_len > sizeof(ifr->ifr_addr))
		    size += ifr->ifr_addr.sa_len - sizeof(struct sockaddr);
# endif
		n -= size;

# if !defined(SYS_WINNT)
		/* Exclude logical interfaces (indicated by ':' in the interface name)	*/
		if (debug)
			printf("interface <%s> ", ifr->ifr_name);
		if ((listen_to_virtual_ips == 0)
		    && (strchr(ifr->ifr_name, (int)':') != NULL)) {
			if (debug)
			    printf("ignored\n");
			continue;
		}
		if (debug)
		    printf("OK\n");

		if (
#  ifdef VMS /* VMS+UCX */
			(((struct sockaddr *)&(ifr->ifr_addr))->sa_family != AF_INET)
#  else
			(ifr->ifr_addr.sa_family != AF_INET)
#  endif /* VMS+UCX */
			) {
			if (debug)
			    printf("ignoring %s - not AF_INET\n",
				   ifr->ifr_name);
			continue;
		}
# endif /* SYS_WINNT */
		ifreq = *ifr;
		inter_list[i].flags = 0;
		/* is it broadcast capable? */
# ifndef SYS_WINNT
#  ifdef STREAMS_TLI
		ioc.ic_cmd = SIOCGIFFLAGS;
		ioc.ic_timout = 0;
		ioc.ic_dp = (caddr_t)&ifreq;
		ioc.ic_len = sizeof(struct ifreq);
		if(ioctl(vs, I_STR, &ioc)) {
			msyslog(LOG_ERR, "create_sockets: ioctl(I_STR:SIOCGIFFLAGS) failed: %m");
			continue;
		}
#  else /* not STREAMS_TLI */
		if (ioctl(vs, SIOCGIFFLAGS, (char *)&ifreq) < 0) {
			if (errno != ENXIO)
			    msyslog(LOG_ERR, "create_sockets: ioctl(SIOCGIFFLAGS) failed: %m");
			continue;
		}
#  endif /* not STREAMS_TLI */
		if ((ifreq.ifr_flags & IFF_UP) == 0) {
			if (debug)
			    printf("ignoring %s - interface not UP\n",
				   ifr->ifr_name);
			continue;
		}
		inter_list[i].flags = 0;
		if (ifreq.ifr_flags & IFF_BROADCAST)
		    inter_list[i].flags |= INT_BROADCAST;
# endif /* not SYS_WINNT */
# if !defined(SUN_3_3_STINKS)
		if (
#  if defined(IFF_LOCAL_LOOPBACK) /* defined(SYS_HPUX) && (SYS_HPUX < 8) */
			(ifreq.ifr_flags & IFF_LOCAL_LOOPBACK)
#  elif defined(IFF_LOOPBACK)
			(ifreq.ifr_flags & IFF_LOOPBACK)
#  else /* not IFF_LOCAL_LOOPBACK and not IFF_LOOPBACK */
			/* test against 127.0.0.1 (yuck!!) */
			(inter_list[i].sin.sin_addr.s_addr == inet_addr("127.0.0.1"))
#  endif /* not IFF_LOCAL_LOOPBACK and not IFF_LOOPBACK */
			)
		{
#  ifndef SYS_WINNT
			inter_list[i].flags |= INT_LOOPBACK;
#  endif /* not SYS_WINNT */
			if (loopback_interface == 0)
			{
				loopback_interface = &inter_list[i];
			}
		}
# endif /* not SUN_3_3_STINKS */

#if 0
# ifndef SYS_WINNT
#  ifdef STREAMS_TLI
		ioc.ic_cmd = SIOCGIFADDR;
		ioc.ic_timout = 0;
		ioc.ic_dp = (caddr_t)&ifreq;
		ioc.ic_len = sizeof(struct ifreq);
		if (ioctl(vs, I_STR, &ioc))
		{
			msyslog(LOG_ERR, "create_sockets: ioctl(I_STR:SIOCGIFADDR) failed: %m");
			continue;
		}
#  else /* not STREAMS_TLI */
		if (ioctl(vs, SIOCGIFADDR, (char *)&ifreq) < 0)
		{
			if (errno != ENXIO)
			    msyslog(LOG_ERR, "create_sockets: ioctl(SIOCGIFADDR) failed: %m");
			continue;
		}
#  endif /* not STREAMS_TLI */
# endif /* not SYS_WINNT */
#endif /* 0 */
# if defined(SYS_WINNT)
		{int TODO_FillInTheNameWithSomeThingReasonble;}
# else
  		(void)strncpy(inter_list[i].name, ifreq.ifr_name,
  			      sizeof(inter_list[i].name));
# endif
		inter_list[i].sin = *(struct sockaddr_in *)&ifr->ifr_addr;
		inter_list[i].sin.sin_family = AF_INET;
		inter_list[i].sin.sin_port = port;

# if defined(SUN_3_3_STINKS)
		/*
		 * Oh, barf!  I'm too disgusted to even explain this
		 */
		if (SRCADR(&inter_list[i].sin) == 0x7f000001)
		{
			inter_list[i].flags |= INT_LOOPBACK;
			if (loopback_interface == 0)
			    loopback_interface = &inter_list[i];
		}
# endif /* SUN_3_3_STINKS */
# if !defined SYS_WINNT && !defined SYS_CYGWIN32 /* no interface flags on NT */
		if (inter_list[i].flags & INT_BROADCAST) {
#  ifdef STREAMS_TLI
			ioc.ic_cmd = SIOCGIFBRDADDR;
			ioc.ic_timout = 0;
			ioc.ic_dp = (caddr_t)&ifreq;
			ioc.ic_len = sizeof(struct ifreq);
			if(ioctl(vs, I_STR, &ioc)) {
				msyslog(LOG_ERR, "create_sockets: ioctl(I_STR:SIOCGIFBRDADDR) failed: %m");
				exit(1);
			}
#  else /* not STREAMS_TLI */
			if (ioctl(vs, SIOCGIFBRDADDR, (char *)&ifreq) < 0) {
				msyslog(LOG_ERR, "create_sockets: ioctl(SIOCGIFBRDADDR) failed: %m");
				exit(1);
			}
#  endif /* not STREAMS_TLI */

#  ifndef ifr_broadaddr
			inter_list[i].bcast =
			    *(struct sockaddr_in *)&ifreq.ifr_addr;
#  else
			inter_list[i].bcast =
			    *(struct sockaddr_in *)&ifreq.ifr_broadaddr;
#  endif /* ifr_broadaddr */
			inter_list[i].bcast.sin_family = AF_INET;
			inter_list[i].bcast.sin_port = port;
		}

#  ifdef STREAMS_TLI
		ioc.ic_cmd = SIOCGIFNETMASK;
		ioc.ic_timout = 0;
		ioc.ic_dp = (caddr_t)&ifreq;
		ioc.ic_len = sizeof(struct ifreq);
		if(ioctl(vs, I_STR, &ioc)) {
			msyslog(LOG_ERR, "create_sockets: ioctl(I_STR:SIOCGIFNETMASK) failed: %m");
			exit(1);
		}
#  else /* not STREAMS_TLI */
		if (ioctl(vs, SIOCGIFNETMASK, (char *)&ifreq) < 0) {
			msyslog(LOG_ERR, "create_sockets: ioctl(SIOCGIFNETMASK) failed: %m");
			exit(1);
		}
#  endif /* not STREAMS_TLI */
		inter_list[i].mask                 = *(struct sockaddr_in *)&ifreq.ifr_addr;
# else
		/* winnt here */
		inter_list[i].bcast                = ifreq.ifr_broadaddr;
		inter_list[i].bcast.sin_family	   = AF_INET;
		inter_list[i].bcast.sin_port	   = port;
		inter_list[i].mask                 = ifreq.ifr_mask;
# endif /* not SYS_WINNT */

		/*
		 * look for an already existing source interface address.  If
		 * the machine has multiple point to point interfaces, then
		 * the local address may appear more than once.
		 */
		for (j=0; j < i; j++)
		    if (inter_list[j].sin.sin_addr.s_addr ==
			inter_list[i].sin.sin_addr.s_addr) {
			    break;
		    }
		if (j == i)
		    i++;
		if (i > MAXINTERFACES)
		    break;
	}
	closesocket(vs);
#endif	/* _BSDI_VERSION >= 199510 */

	ninterfaces = i;
	maxactivefd = 0;
	FD_ZERO(&activefds);
	for (i = 0; i < ninterfaces; i++) {
		inter_list[i].fd =
		    open_socket(&inter_list[i].sin,
				inter_list[i].flags & INT_BROADCAST, 0);
	}

	/*
	 * Now that we have opened all the sockets, turn off the reuse flag for
	 * security.
	 */
	for (i = 0; i < ninterfaces; i++) {
		int off = 0;

		/*
		 * if inter_list[ n ].fd  is -1, we might have a adapter
		 * configured but not present
		 */
		if ( inter_list[ i ].fd != -1 ) {
			if (setsockopt(inter_list[i].fd, SOL_SOCKET,
				       SO_REUSEADDR, (char *)&off,
				       sizeof(off))) {
				msyslog(LOG_ERR, "create_sockets: setsockopt(SO_REUSEADDR,off) failed: %m");
			}
		}
	}

#if defined(MCAST)
	/*
	 * enable possible multicast reception on the broadcast socket
	 */
	inter_list[0].bcast.sin_addr.s_addr = htonl(INADDR_ANY);
	inter_list[0].bcast.sin_family = AF_INET;
	inter_list[0].bcast.sin_port = port;
#endif /* MCAST */

	/*
	 * Blacklist all bound interface addresses
	 */
	resmask.sin_addr.s_addr = ~ (u_int32)0;
	for (i = 1; i < ninterfaces; i++)
	    hack_restrict(RESTRICT_FLAGS, &inter_list[i].sin, &resmask,
			  RESM_NTPONLY|RESM_INTERFACE, RES_IGNORE);

	any_interface = &inter_list[0];
#ifdef DEBUG
	if (debug > 2) {
		printf("create_sockets: ninterfaces=%d\n", ninterfaces);
		for (i = 0; i < ninterfaces; i++) {
			printf("interface %d:  fd=%d,  bfd=%d,  name=%.8s,  flags=0x%x\n",
			       i,
			       inter_list[i].fd,
			       inter_list[i].bfd,
			       inter_list[i].name,
			       inter_list[i].flags);
			/* Leave these as three printf calls. */
			printf("              sin=%s",
			       inet_ntoa((inter_list[i].sin.sin_addr)));
			if (inter_list[i].flags & INT_BROADCAST)
			    printf("  bcast=%s,",
				   inet_ntoa((inter_list[i].bcast.sin_addr)));
			printf("  mask=%s\n",
			       inet_ntoa((inter_list[i].mask.sin_addr)));
		}
	}
#endif
#if defined (HAVE_IO_COMPLETION_PORT)
	for (i = 0; i < ninterfaces; i++) {
		io_completion_port_add_socket(&inter_list[i]);
	}
#endif
	return ninterfaces;
}

/*
 * io_setbclient - open the broadcast client sockets
 */
void
io_setbclient(void)
{
	int i;

	for (i = 1; i < ninterfaces; i++)
	{
		if (!(inter_list[i].flags & INT_BROADCAST))
		    continue;
		if (inter_list[i].flags & INT_BCASTOPEN)
		    continue;
#ifdef	SYS_SOLARIS
		inter_list[i].bcast.sin_addr.s_addr = htonl(INADDR_ANY);
#endif
#ifdef OPEN_BCAST_SOCKET /* Was: !SYS_DOMAINOS && !SYS_LINUX */
		inter_list[i].bfd = open_socket(&inter_list[i].bcast, INT_BROADCAST, 1);
		inter_list[i].flags |= INT_BCASTOPEN;
#endif
	}
}


/*
 * io_multicast_add() - add multicast group address
 */
void
io_multicast_add(
	u_int32 addr
	)
{
#ifdef MCAST
	struct ip_mreq mreq;
	int i = ninterfaces;	/* Use the next interface */
	u_int32 haddr = ntohl(addr);
	struct in_addr iaddr;
	int s;
	struct sockaddr_in *sinp;

	iaddr.s_addr = addr;

	if (!IN_CLASSD(haddr))
	{
		msyslog(LOG_ERR,
			"cannot add multicast address %s as it is not class D",
			inet_ntoa(iaddr));
		return;
	}

	for (i = 0; i < ninterfaces; i++)
	{
		/* Already have this address */
		if (inter_list[i].sin.sin_addr.s_addr == addr) return;
		/* found a free slot */
		if (inter_list[i].sin.sin_addr.s_addr == 0 &&
		    inter_list[i].fd <= 0 && inter_list[i].bfd <= 0 &&
		    inter_list[i].flags == 0) break;
	}
	sinp = &(inter_list[i].sin);

	memset((char *)&mreq, 0, sizeof(mreq));
	memset((char *)&inter_list[i], 0, sizeof inter_list[0]);
	sinp->sin_family = AF_INET;
	sinp->sin_addr = iaddr;
	sinp->sin_port = htons(123);

	s = open_socket(sinp, 0, 1);
	/* Try opening a socket for the specified class D address */
	/* This works under SunOS 4.x, but not OSF1 .. :-( */
	if (s < 0)
	{
		memset((char *)&inter_list[i], 0, sizeof inter_list[0]);
		i = 0;
		/* HACK ! -- stuff in an address */
		inter_list[i].bcast.sin_addr.s_addr = addr;
		msyslog(LOG_ERR, "...multicast address %s using wildcard socket",
			inet_ntoa(iaddr));
	}
	else
	{
		inter_list[i].fd = s;
		inter_list[i].bfd = -1;
		(void) strncpy(inter_list[i].name, "multicast",
			       sizeof(inter_list[i].name));
		inter_list[i].mask.sin_addr.s_addr = htonl(~(u_int32)0);
	}

	/*
	 * enable reception of multicast packets
	 */
	mreq.imr_multiaddr = iaddr;
	mreq.imr_interface.s_addr = htonl(INADDR_ANY);
	if (setsockopt(inter_list[i].fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
		       (char *)&mreq, sizeof(mreq)) == -1)
	    msyslog(LOG_ERR,
		    "setsockopt IP_ADD_MEMBERSHIP fails: %m for %x / %x (%s)",
		    mreq.imr_multiaddr.s_addr, mreq.imr_interface.s_addr,
		    inet_ntoa(iaddr));
	inter_list[i].flags |= INT_MULTICAST;
	if (i >= ninterfaces) ninterfaces = i+1;
#else /* MCAST */
	struct in_addr iaddr;

	iaddr.s_addr = addr;
	msyslog(LOG_ERR, "cannot add multicast address %s as no MCAST support",
		inet_ntoa(iaddr));
#endif /* MCAST */
}

/*
 * io_unsetbclient - close the broadcast client sockets
 */
void
io_unsetbclient(void)
{
	int i;

	for (i = 1; i < ninterfaces; i++)
	{
		if (!(inter_list[i].flags & INT_BCASTOPEN))
		    continue;
		close_socket(inter_list[i].bfd);
		inter_list[i].bfd = -1;
		inter_list[i].flags &= ~INT_BCASTOPEN;
	}
}


/*
 * io_multicast_del() - delete multicast group address
 */
void
io_multicast_del(
	u_int32 addr
	)
{
#ifdef MCAST
	int i;
	struct ip_mreq mreq;
	u_int32 haddr = ntohl(addr);
	struct sockaddr_in sinaddr;

	if (!IN_CLASSD(haddr))
	{
		sinaddr.sin_addr.s_addr = addr;
		msyslog(LOG_ERR,
			"invalid multicast address %s", ntoa(&sinaddr));
		return;
	}

	/*
	 * Disable reception of multicast packets
	 */
	mreq.imr_multiaddr.s_addr = addr;
	mreq.imr_interface.s_addr = htonl(INADDR_ANY);
	for (i = 0; i < ninterfaces; i++)
	{
		if (!(inter_list[i].flags & INT_MULTICAST))
		    continue;
		if (!(inter_list[i].fd < 0))
		    continue;
		if (addr != inter_list[i].sin.sin_addr.s_addr)
		    continue;
		if (i != 0)
		{
			/* we have an explicit fd, so we can close it */
			close_socket(inter_list[i].fd);
			memset((char *)&inter_list[i], 0, sizeof inter_list[0]);
			inter_list[i].fd = -1;
			inter_list[i].bfd = -1;
		}
		else
		{
			/* We are sharing "any address" port :-(  Don't close it! */
			if (setsockopt(inter_list[i].fd, IPPROTO_IP, IP_DROP_MEMBERSHIP,
				       (char *)&mreq, sizeof(mreq)) == -1)
			    msyslog(LOG_ERR, "setsockopt IP_DROP_MEMBERSHIP fails: %m");
			/* This is **WRONG** -- there may be others ! */
			/* There should be a count of users ... */
			inter_list[i].flags &= ~INT_MULTICAST;
		}
	}
#else /* not MCAST */
	msyslog(LOG_ERR, "this function requires multicast kernel");
#endif /* not MCAST */
}


/*
 * open_socket - open a socket, returning the file descriptor
 */
static int
open_socket(
	struct sockaddr_in *addr,
	int flags,
	int turn_off_reuse
	)
{
	int fd;
	int on = 1, off = 0;

	/* create a datagram (UDP) socket */
	if (  (fd = socket(AF_INET, SOCK_DGRAM, 0))
#ifndef SYS_WINNT
	      < 0
#else
	      == INVALID_SOCKET
#endif /* SYS_WINNT */
	      )
	{
		msyslog(LOG_ERR, "socket(AF_INET, SOCK_DGRAM, 0) failed: %m");
		exit(1);
		/*NOTREACHED*/
	}

	/* set SO_REUSEADDR since we will be binding the same port
	   number on each interface */
	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
		       (char *)&on, sizeof(on)))
	{
		msyslog(LOG_ERR, "setsockopt SO_REUSEADDR on fails: %m");
	}

	/*
	 * bind the local address.
	 */
	if (bind(fd, (struct sockaddr *)addr, sizeof(*addr)) < 0) {
		char buff[160];
		sprintf(buff,
			"bind() fd %d, family %d, port %d, addr %s, in_classd=%d flags=%d fails: %%m",
			fd, addr->sin_family, (int)ntohs(addr->sin_port),
			ntoa(addr),
			IN_CLASSD(ntohl(addr->sin_addr.s_addr)), flags);
		msyslog(LOG_ERR, buff);
		closesocket(fd);

		/*
		 * soft fail if opening a class D address
		 */
		if (IN_CLASSD(ntohl(addr->sin_addr.s_addr)))
		    return -1;
#if 0
		exit(1);
#else
		return -1;
#endif
	}
#ifdef DEBUG
	if (debug)
	    printf("bind() fd %d, family %d, port %d, addr %s, flags=%d\n",
		   fd,
		   addr->sin_family,
		   (int)ntohs(addr->sin_port),
		   ntoa(addr),
		   flags);
#endif
	if (fd > maxactivefd)
	    maxactivefd = fd;
	FD_SET(fd, &activefds);

	/*
	 * set non-blocking,
	 */

#ifdef USE_FIONBIO
	/* in vxWorks we use FIONBIO, but the others are defined for old systems, so
	 * all hell breaks loose if we leave them defined
	 */
#undef O_NONBLOCK
#undef FNDELAY
#undef O_NDELAY
#endif

#if defined(O_NONBLOCK) /* POSIX */
	if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
	{
		msyslog(LOG_ERR, "fcntl(O_NONBLOCK) fails: %m");
		exit(1);
		/*NOTREACHED*/
	}
#elif defined(FNDELAY)
	if (fcntl(fd, F_SETFL, FNDELAY) < 0)
	{
		msyslog(LOG_ERR, "fcntl(FNDELAY) fails: %m");
		exit(1);
		/*NOTREACHED*/
	}
#elif defined(O_NDELAY) /* generally the same as FNDELAY */
	if (fcntl(fd, F_SETFL, O_NDELAY) < 0)
	{
		msyslog(LOG_ERR, "fcntl(O_NDELAY) fails: %m");
		exit(1);
		/*NOTREACHED*/
	}
#elif defined(FIONBIO)
	if (
# if defined(VMS)
		(ioctl(fd,FIONBIO,&1) < 0)
# elif defined(SYS_WINNT)
		(ioctlsocket(fd,FIONBIO,(u_long *) &on) == SOCKET_ERROR)
# else
		(ioctl(fd,FIONBIO,&on) < 0)
# endif
	   )
	{
		msyslog(LOG_ERR, "ioctl(FIONBIO) fails: %m");
		exit(1);
		/*NOTREACHED*/
	}
#elif defined(FIOSNBIO)
	if (ioctl(fd,FIOSNBIO,&on) < 0)
	{
		msyslog(LOG_ERR, "ioctl(FIOSNBIO) fails: %m");
		exit(1);
		/*NOTREACHED*/
	}
#else
# include "Bletch: Need non-blocking I/O!"
#endif

#ifdef HAVE_SIGNALED_IO
	init_socket_sig(fd);
#endif /* not HAVE_SIGNALED_IO */

	/*
	 *	Turn off the SO_REUSEADDR socket option.  It apparently
	 *	causes heartburn on systems with multicast IP installed.
	 *	On normal systems it only gets looked at when the address
	 *	is being bound anyway..
	 */
	if (turn_off_reuse)
	    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
			   (char *)&off, sizeof(off)))
	    {
		    msyslog(LOG_ERR, "setsockopt SO_REUSEADDR off fails: %m");
	    }

#ifdef SO_BROADCAST
	/* if this interface can support broadcast, set SO_BROADCAST */
	if (flags & INT_BROADCAST)
	{
		if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST,
			       (char *)&on, sizeof(on)))
		{
			msyslog(LOG_ERR, "setsockopt(SO_BROADCAST): %m");
		}
	}
#endif /* SO_BROADCAST */

#if !defined(SYS_WINNT) && !defined(VMS)
# ifdef DEBUG
	if (debug > 1)
	    printf("flags for fd %d: 0%o\n", fd,
		   fcntl(fd, F_GETFL, 0));
# endif
#endif /* SYS_WINNT || VMS */

	return fd;
}


/*
 * close_socket - close a socket and remove from the activefd list
 */
static void
close_socket(
	int fd
	)
{
	int i, newmax;

	(void) closesocket(fd);
	FD_CLR( (u_int) fd, &activefds);

	if (fd >= maxactivefd)
	{
		newmax = 0;
		for (i = 0; i < maxactivefd; i++)
		    if (FD_ISSET(i, &activefds))
			newmax = i;
		maxactivefd = newmax;
	}
}


/*
 * close_file - close a file and remove from the activefd list
 * added 1/31/1997 Greg Schueman for Windows NT portability
 */
static void
close_file(
	int fd
	)
{
	int i, newmax;

	(void) close(fd);
	FD_CLR( (u_int) fd, &activefds);

	if (fd >= maxactivefd)
	{
		newmax = 0;
		for (i = 0; i < maxactivefd; i++)
		    if (FD_ISSET(i, &activefds))
			newmax = i;
		maxactivefd = newmax;
	}
}


/*
 * findbcastinter - find broadcast interface corresponding to address
 */
struct interface *
findbcastinter(
	struct sockaddr_in *addr
	)
{
#if defined(SIOCGIFCONF) || defined(SYS_WINNT)
	register int i;
	register u_int32 netnum;

	netnum = NSRCADR(addr);
	for (i = 1; i < ninterfaces; i++)
	{
		if (!(inter_list[i].flags & INT_BROADCAST))
		    continue;
		if (NSRCADR(&inter_list[i].bcast) == netnum)
		    return &inter_list[i];
		if ((NSRCADR(&inter_list[i].sin) & NSRCADR(&inter_list[i].mask))
		    == (netnum & NSRCADR(&inter_list[i].mask)))
		    return &inter_list[i];
	}
#endif /* SIOCGIFCONF */
	return any_interface;
}


/* XXX ELIMINATE sendpkt similar in ntpq.c, ntpdc.c, ntp_io.c, ntptrace.c */
/*
 * sendpkt - send a packet to the specified destination. Maintain a
 * send error cache so that only the first consecutive error for a
 * destination is logged.
 */
void
sendpkt(
	struct sockaddr_in *dest,
	struct interface *inter,
	int ttl,
	struct pkt *pkt,
	int len
	)
{
	int cc, slot;
#ifdef SYS_WINNT
	DWORD err;
#endif /* SYS_WINNT */

	/*
	 * Send error cache. Empty slots have port == 0
	 * Set ERRORCACHESIZE to 0 to disable
	 */
	struct cache {
		u_short port;
		struct	in_addr addr;
	};

#ifndef ERRORCACHESIZE
#define ERRORCACHESIZE 8
#endif
#if ERRORCACHESIZE > 0
	static struct cache badaddrs[ERRORCACHESIZE];
#else
#define badaddrs ((struct cache *)0)		/* Only used in empty loops! */
#endif

	/*
	 * check if the source address is a multicast address - replace
	 * interface with any-interface if so.
	 */
	if (IN_MULTICAST(ntohl(inter->sin.sin_addr.s_addr)))
	    inter = any_interface;
#ifdef DEBUG
	if (debug > 1)
	    printf("%ssendpkt(fd=%d dst=%s, src=%s, ttl=%d, len=%d)\n",
		   (ttl >= 0) ? "\tMCAST\t*****" : "",
		   inter->fd, ntoa(dest),
		   ntoa(&inter->sin), ttl, len);
#endif

#ifdef MCAST
	/* for the moment we use the bcast option to set multicast ttl */
	if (ttl >= 0 && ttl != inter->last_ttl)
	{
		char mttl = ttl;

		/* set the multicast ttl for outgoing packets */
		if (setsockopt(inter->fd, IPPROTO_IP, IP_MULTICAST_TTL,
			       &mttl, sizeof(mttl)) == -1)
		{
			msyslog(LOG_ERR, "setsockopt IP_MULTICAST_TTL fails: %m");
		}
		else inter->last_ttl = ttl;
	}
#endif /* MCAST */

	for (slot = ERRORCACHESIZE; --slot >= 0; )
	    if (badaddrs[slot].port == dest->sin_port &&
		badaddrs[slot].addr.s_addr == dest->sin_addr.s_addr)
		break;

#if defined(HAVE_IO_COMPLETION_PORT)
        err = io_completion_port_sendto(inter, pkt, len, dest);
	if (err != ERROR_SUCCESS)
#else
	cc = sendto(inter->fd, (char *)pkt, len, 0, (struct sockaddr *)dest,
		    sizeof(struct sockaddr_in));
	if (cc == -1)
#endif
	{
		inter->notsent++;
		packets_notsent++;
#if defined(HAVE_IO_COMPLETION_PORT)
		if (err != WSAEWOULDBLOCK && err != WSAENOBUFS && slot < 0)
#else
		if (errno != EWOULDBLOCK && errno != ENOBUFS && slot < 0)
#endif
		{
			/*
			 * Remember this, if there's an empty slot
			 */
			for (slot = ERRORCACHESIZE; --slot >= 0; )
			    if (badaddrs[slot].port == 0)
			    {
				    badaddrs[slot].port = dest->sin_port;
				    badaddrs[slot].addr = dest->sin_addr;
				    break;
			    }
			msyslog(LOG_ERR, "sendto(%s): %m", ntoa(dest));
		}
	}
	else
	{
		inter->sent++;
		packets_sent++;
		/*
		 * He's not bad any more
		 */
		if (slot >= 0)
		{
			msyslog(LOG_INFO, "Connection re-established to %s", ntoa(dest));
			badaddrs[slot].port = 0;
		}
	}
}

#if !defined(HAVE_IO_COMPLETION_PORT)
/*
 * fdbits - generate ascii representation of fd_set (FAU debug support)
 * HFDF format - highest fd first.
 */
static char *
fdbits(
	int count,
	fd_set *set
	)
{
	static char buffer[256];
	char * buf = buffer;

	count = (count < 256) ? count : 255;

	while (count >= 0)
	{
		*buf++ = FD_ISSET(count, set) ? '#' : '-';
		count--;
	}
	*buf = '\0';

	return buffer;
}

/*
 * input_handler - receive packets asynchronously
 */
extern void
input_handler(
	l_fp *cts
	)
{
	register int i, n;
	register struct recvbuf *rb;
	register int doing;
	register int fd;
	struct timeval tvzero;
	int fromlen;
	l_fp ts;			/* Timestamp at BOselect() gob */
	l_fp ts_e;			/* Timestamp at EOselect() gob */
	fd_set fds;
	int select_count = 0;
	static int handler_count = 0;

	++handler_count;
	if (handler_count != 1)
	    msyslog(LOG_ERR, "input_handler: handler_count is %d!", handler_count);
	handler_calls++;
	ts = *cts;

	for (;;)
	{
		/*
		 * Do a poll to see who has data
		 */

		fds = activefds;
		tvzero.tv_sec = tvzero.tv_usec = 0;

		/*
		 * If we have something to do, freeze a timestamp.
		 * See below for the other cases (nothing (left) to do or error)
		 */
		while (0 < (n = select(maxactivefd+1, &fds, (fd_set *)0, (fd_set *)0, &tvzero)))
		{
			++select_count;
			++handler_pkts;

#ifdef REFCLOCK
			/*
			 * Check out the reference clocks first, if any
			 */
			if (refio != 0)
			{
				register struct refclockio *rp;

				for (rp = refio; rp != 0 && n > 0; rp = rp->next)
				{
					fd = rp->fd;
					if (FD_ISSET(fd, &fds))
					{
						n--;
						if (free_recvbuffs() == 0)
						{
							char buf[RX_BUFF_SIZE];

#ifndef SYS_WINNT
							(void) read(fd, buf, sizeof buf);
#else
							(void) ReadFile((HANDLE)fd, buf, (DWORD)sizeof buf, NULL, NULL);
#endif /* SYS_WINNT */
							packets_dropped++;
							goto select_again;
						}

						rb = get_free_recv_buffer();

						i = (rp->datalen == 0
						     || rp->datalen > sizeof(rb->recv_space))
						    ? sizeof(rb->recv_space) : rp->datalen;
#ifndef SYS_WINNT
						rb->recv_length =
						    read(fd, (char *)&rb->recv_space, (unsigned)i)
#else  /* SYS_WINNT */
						    ReadFile((HANDLE)fd, (char *)&rb->recv_space, (DWORD)i,
							     (LPDWORD)&(rb->recv_length), NULL)
#endif /* SYS_WINNT */
						    ;

						if (rb->recv_length == -1)
						{
							msyslog(LOG_ERR, "clock read fd %d: %m", fd);
							freerecvbuf(rb);
							goto select_again;
						}

						/*
						 * Got one.  Mark how and when it got here,
						 * put it on the full list and do bookkeeping.
						 */
						rb->recv_srcclock = rp->srcclock;
						rb->dstadr = 0;
						rb->fd = fd;
						rb->recv_time = ts;
						rb->receiver = rp->clock_recv;

						if (rp->io_input)
						{
							/*
							 * have direct input routine for refclocks
							 */
							if (rp->io_input(rb) == 0)
							{
								/*
								 * data was consumed - nothing to pass up
								 * into block input machine
								 */
								freerecvbuf(rb);
#if 1
								goto select_again;
#else
								continue;
#endif
							}
						}

						add_full_recv_buffer(rb);

						rp->recvcount++;
						packets_received++;
					}
				}
			}
#endif /* REFCLOCK */

			/*
			 * Loop through the interfaces looking for data to read.
			 */
			for (i = ninterfaces - 1; (i >= 0) && (n > 0); i--)
			{
				for (doing = 0; (doing < 2) && (n > 0); doing++)
				{
					if (doing == 0)
					{
						fd = inter_list[i].fd;
					}
					else
					{
						if (!(inter_list[i].flags & INT_BCASTOPEN))
						    break;
						fd = inter_list[i].bfd;
					}
					if (fd < 0) continue;
					if (FD_ISSET(fd, &fds))
					{
						n--;

						/*
						 * Get a buffer and read the frame.  If we
						 * haven't got a buffer, or this is received
						 * on the wild card socket, just dump the
						 * packet.
						 */
						if (
#ifdef UDP_WILDCARD_DELIVERY
				/*
				 * these guys manage to put properly addressed
				 * packets into the wildcard queue
				 */
							(free_recvbuffs() == 0)
#else
							((i == 0) || (free_recvbuffs() == 0))
#endif
							)
	{
		char buf[RX_BUFF_SIZE];
		struct sockaddr from;

		fromlen = sizeof from;
		(void) recvfrom(fd, buf, sizeof(buf), 0, &from, &fromlen);
#ifdef DEBUG
		if (debug)
		    printf("%s on %d(%lu) fd=%d from %s\n",
			   (i) ? "drop" : "ignore",
			   i, free_recvbuffs(), fd,
			   inet_ntoa(((struct sockaddr_in *) &from)->sin_addr));
#endif
		if (i == 0)
		    packets_ignored++;
		else
		    packets_dropped++;
		goto select_again;
	}

	rb = get_free_recv_buffer();

	fromlen = sizeof(struct sockaddr_in);
	rb->recv_length = recvfrom(fd,
				   (char *)&rb->recv_space,
				   sizeof(rb->recv_space), 0,
				   (struct sockaddr *)&rb->recv_srcadr,
				   &fromlen);
	if (rb->recv_length == 0
#ifdef EWOULDBLOCK
		 || errno==EWOULDBLOCK
#endif
#ifdef EAGAIN
		 || errno==EAGAIN
#endif
		 ) {
		freerecvbuf(rb);
	    continue;
	}
	else if (rb->recv_length < 0)
	{
		msyslog(LOG_ERR, "recvfrom() fd=%d: %m", fd);
#ifdef DEBUG
		if (debug)
		    printf("input_handler: fd=%d dropped (bad recvfrom)\n", fd);
#endif
		freerecvbuf(rb);
		continue;
	}
#ifdef DEBUG
	if (debug > 2)
	    printf("input_handler: fd=%d length %d from %08lx %s\n",
		   fd, rb->recv_length,
		   (u_long)ntohl(rb->recv_srcadr.sin_addr.s_addr) &
		   0x00000000ffffffff,
		   inet_ntoa(rb->recv_srcadr.sin_addr));
#endif

	/*
	 * Got one.  Mark how and when it got here,
	 * put it on the full list and do bookkeeping.
	 */
	rb->dstadr = &inter_list[i];
	rb->fd = fd;
	rb->recv_time = ts;
	rb->receiver = receive;

	add_full_recv_buffer(rb);

	inter_list[i].received++;
	packets_received++;
	goto select_again;
					}
					/* Check more interfaces */
				}
			}
		select_again:;
			/*
			 * Done everything from that select.  Poll again.
			 */
		}

		/*
		 * If nothing more to do, try again.
		 * If nothing to do, just return.
		 * If an error occurred, complain and return.
		 */
		if (n == 0)
		{
			if (select_count == 0) /* We really had nothing to do */
			{
				if (debug)
				    msyslog(LOG_DEBUG, "input_handler: select() returned 0");
				--handler_count;
				return;
			}
			/* We've done our work */
			get_systime(&ts_e);
			/*
			 * (ts_e - ts) is the amount of time we spent processing
			 * this gob of file descriptors.  Log it.
			 */
			L_SUB(&ts_e, &ts);
			if (debug > 3)
			    msyslog(LOG_INFO, "input_handler: Processed a gob of fd's in %s msec", lfptoms(&ts_e, 6));

			/* just bail. */
			--handler_count;
			return;
		}
		else if (n == -1)
		{
#ifndef SYS_WINNT
			int err = errno;
#else
			DWORD err = WSAGetLastError();
#endif /* SYS_WINNT */

			/*
			 * extended FAU debugging output
			 */
			msyslog(LOG_ERR, "select(%d, %s, 0L, 0L, &0.000000) error: %m",
				maxactivefd+1, fdbits(maxactivefd, &activefds));
			if (
#ifndef SYS_WINNT
				(err == EBADF)
#else
				(err == WSAEBADF)
#endif /* SYS_WINNT */
				)
			{
				int j, b;

				fds = activefds;
				for (j = 0; j <= maxactivefd; j++)
				    if (
#ifndef SYS_WINNT
					    (FD_ISSET(j, &fds) && (read(j, &b, 0) == -1))
#else
					    (FD_ISSET(j, &fds) && (!ReadFile((HANDLE)j, &b, 0, NULL, NULL)))
#endif /* SYS_WINNT */
					    )
					msyslog(LOG_ERR, "Bad file descriptor %d", j);
			}
			--handler_count;
			return;
		}
	}
	msyslog(LOG_ERR, "input_handler: fell out of infinite for(;;) loop!");
	--handler_count;
	return;
}

#endif

/*
 * findinterface - utility used by other modules to find an interface
 *		   given an address.
 */
struct interface *
findinterface(
	struct sockaddr_in *addr
	)
{
	register int i;
	register u_int32 saddr;

	/*
	 * Just match the address portion.
	 */
	saddr = addr->sin_addr.s_addr;
	for (i = 0; i < ninterfaces; i++)
	{
		if (inter_list[i].sin.sin_addr.s_addr == saddr)
		    return &inter_list[i];
	}
	return (struct interface *)0;
}


/*
 * io_clr_stats - clear I/O module statistics
 */
void
io_clr_stats(void)
{
	packets_dropped = 0;
	packets_ignored = 0;
	packets_received = 0;
	packets_sent = 0;
	packets_notsent = 0;

	handler_calls = 0;
	handler_pkts = 0;
	io_timereset = current_time;
}


#ifdef REFCLOCK
/*
 * This is a hack so that I don't have to fool with these ioctls in the
 * pps driver ... we are already non-blocking and turn on SIGIO thru
 * another mechanisim
 */
int
io_addclock_simple(
	struct refclockio *rio
	)
{
	BLOCKIO();
	/*
	 * Stuff the I/O structure in the list and mark the descriptor
	 * in use.	There is a harmless (I hope) race condition here.
	 */
	rio->next = refio;
	refio = rio;

	if (rio->fd > maxactivefd)
	    maxactivefd = rio->fd;
	FD_SET(rio->fd, &activefds);
	UNBLOCKIO();
	return 1;
}

/*
 * io_addclock - add a reference clock to the list and arrange that we
 *				 get SIGIO interrupts from it.
 */
int
io_addclock(
	struct refclockio *rio
	)
{
	BLOCKIO();
	/*
	 * Stuff the I/O structure in the list and mark the descriptor
	 * in use.	There is a harmless (I hope) race condition here.
	 */
	rio->next = refio;
	refio = rio;

# ifdef HAVE_SIGNALED_IO
	if (init_clock_sig(rio))
	{
		refio = rio->next;
		UNBLOCKIO();
		return 0;
	}
# elif defined(HAVE_IO_COMPLETION_PORT)
	if (io_completion_port_add_clock_io(rio))
	{
		refio = rio->next;
		UNBLOCKIO();
		return 0;
	}
# endif

	if (rio->fd > maxactivefd)
	    maxactivefd = rio->fd;
	FD_SET(rio->fd, &activefds);

	UNBLOCKIO();
	return 1;
}

/*
 * io_closeclock - close the clock in the I/O structure given
 */
void
io_closeclock(
	struct refclockio *rio
	)
{
	/*
	 * Remove structure from the list
	 */
	if (refio == rio)
	{
		refio = rio->next;
	}
	else
	{
		register struct refclockio *rp;

		for (rp = refio; rp != 0; rp = rp->next)
		    if (rp->next == rio)
		    {
			    rp->next = rio->next;
			    break;
		    }

		if (rp == 0)
		{
			/*
			 * Internal error.	Report it.
			 */
			msyslog(LOG_ERR,
				"internal error: refclockio structure not found");
			return;
		}
	}

	/*
	 * Close the descriptor.
	 */
	close_file(rio->fd);
}
#endif	/* REFCLOCK */

void
kill_asyncio(void)
{
	int i;

	BLOCKIO();
	for (i = 0; i <= maxactivefd; i++)
	    (void)close_socket(i);
}