/* ntp_clockdev.c - map clock instances to devices

 *

 * Written by Juergen Perlinger (perlinger@ntp.org) for the NTP project.

 * The contents of 'html/copyright.html' apply.

 * ---------------------------------------------------------------------

 * The runtime support for the 'device' configuration statement.  Just a

 * simple list to map refclock source addresses to the device(s) to use

 * instead of the builtin names.

 * ---------------------------------------------------------------------

 */

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#ifdef HAVE_NETINFO

# include <netinfo/ni.h>

#endif

#include <stdio.h>

#include <isc/net.h>

#include "ntp.h"

#include "ntpd.h"

#include "ntp_clockdev.h"

/* In the windows port 'refclock_open' is in 'libntp' (windows specific

 * 'termios.c' source) and calling a function located in NTPD from the

 * library is not something we should do.  Therefore 'termios.c' now

 * provides a hook to set a callback function used for the lookup, and

 * we have to populate that when we have indeed device name

 * redirections...

 */

#ifdef SYS_WINNT

extern const char * (*termios_device_lookup_func)(const sockaddr_u*, int);

#endif

/* What we remember for a device redirection */

typedef struct DeviceInfoS DeviceInfoT;

struct DeviceInfoS {

  DeviceInfoT *next;  /* link to next record    */

  int      ident; /* type (byte1) and unit (byte0)*/

  char      *ttyName; /* time data IO device    */

  char      *ppsName; /* PPS device     */

};

/* Our list of device redirections: */

static DeviceInfoT * InfoList = NULL;

/* Free a single record: */

static void freeDeviceInfo(

  DeviceInfoT *item

  )

{

  if (NULL != item) {

    free(item->ttyName);

    free(item->ppsName);

    free(item);

  }

}

/* Get clock ID from pseudo network address. Returns -1 on error. */

static int

getClockIdent(

  const sockaddr_u *srcadr

  )

{

  int clkType, clkUnit;

  /*

   * Check for valid address and running peer

   */

  if (!ISREFCLOCKADR(srcadr))

    return -1;

  clkType = REFCLOCKTYPE(srcadr);

  clkUnit = REFCLOCKUNIT(srcadr);

  return (clkType << 8) + clkUnit;

}

/* Purge the complete redirection list. */

void

clockdev_clear(void)

{

  DeviceInfoT * item;

  while (NULL != (item = InfoList)) {

    InfoList = item->next;

    freeDeviceInfo(item);

  }

}

/* Remove record(s) for a clock.

 * returns number of removed records (maybe zero) or -1 on error

 */

int

clockdev_remove(

  const sockaddr_u *addr_sock

  )

{

  DeviceInfoT *item, **ppl;

  int      rcnt  = 0;

  const int    ident = getClockIdent(addr_sock);

  if (ident < 0)

    return -1;

  ppl = &InfoList;

  while (NULL != (item = *ppl)) {

    if (ident == item->ident) {

      *ppl = item->next;

      freeDeviceInfo(item);

      ++rcnt;

    } else {

      ppl = &item->next;

    }

  }

  return rcnt;

}

/* Update or create a redirection record for a clock instace */

int /*error*/

clockdev_update(

  const sockaddr_u *addr_sock,

  const char   *ttyName,

  const char   *ppsName

  )

{

  DeviceInfoT *item;

  const int   ident = getClockIdent(addr_sock);

  if (ident < 0)

    return EINVAL;

  /* make sure Windows can use device redirections, too: */

#   ifdef SYS_WINNT

  termios_device_lookup_func = clockdev_lookup;

#   endif

  /* try to update an existing record */

  for (item = InfoList;  NULL != item;  item = item->next)

    if (ident == item->ident) {

      msyslog(LOG_INFO, "Update IO devices for %s: timedata='%s' ppsdata='%s'",

        refnumtoa(addr_sock),

        ttyName ? ttyName : "(null)",

        ppsName ? ppsName : "(null)");

      free(item->ttyName);

      free(item->ppsName);

      item->ttyName = ttyName ? estrdup(ttyName) : NULL;

      item->ppsName = ppsName ? estrdup(ppsName) : NULL;

      return 0;

    }

  /* seems we have to create a new entry... */

  msyslog(LOG_INFO, "Add IO devices for %s: timedata='%s' ppsdata='%s'",

    refnumtoa(addr_sock),

    ttyName ? ttyName : "(null)",

    ppsName ? ppsName : "(null)");

  item = emalloc(sizeof(*item));

  item->next    = InfoList;

  item->ident   = ident;

  item->ttyName = ttyName ? estrdup(ttyName) : NULL;

  item->ppsName = ppsName ? estrdup(ppsName) : NULL;

  InfoList = item;

  return 0;

}

/* Lookup a redirection for a clock instance. Returns either the name

 * registered for the device or NULL if no redirection is found.

 */

const char*

clockdev_lookup(

  const sockaddr_u *addr_sock,

  int     getPPS

  )

{

  const DeviceInfoT *item;

  const int   ident = getClockIdent(addr_sock);

  if (ident < 0)

    return NULL;

  for (item = InfoList;  NULL != item;  item = item->next)

    if (ident == item->ident)

      return getPPS ? item->ppsName : item->ttyName;

  return NULL;

}