/*
 * msg.c
 *
 * Written by Archie Cobbs <archie@freebsd.org>
 * Copyright (c) 1995-1999 Whistle Communications, Inc. All rights reserved.
 * See ``COPYRIGHT.whistle''
 */

#include "ppp.h"
#include "msg.h"

/*
 * DEFINITIONS
 */

/* Which pipe file descriptor is which */

  #define PIPE_READ		0
  #define PIPE_WRITE		1

  struct mpmsg
  {
    long	type;
    void	(*func)(int type, void *arg);
    void	*arg;
    Bund	bund;
    Link	lnk;
  };
  typedef struct mpmsg	*Msg;

  struct msghandler
  {
    int		prio;
    void	(*func)(int type, void *arg);
    Bund	bund;
    Link	lnk;
  };

  int		msgpipe[2];
  EventRef	msgevent;

/*
 * INTERNAL FUNCTIONS
 */

  static void	MsgEvent(int type, void *cookie);
  static void	MsgReregister(void);

/*
 * MsgRegister()
 */

MsgHandler
MsgRegister(void (*func)(int type, void *arg), int prio)
{
  MsgHandler	m;
  
  m = Malloc(MB_UTIL, sizeof(*m));
  m->prio = prio;
  m->func = func;
  m->bund = bund;
  m->lnk = lnk;

  if ((msgpipe[0]==0) || (msgpipe[1]==0)) {
    if (pipe(msgpipe) < 0)
    {
	Perror("%s: Can't create message pipe", 
	    __FUNCTION__);
	DoExit(EX_ERRDEAD);
    }
    fcntl(msgpipe[PIPE_READ], F_SETFD, 1);
    fcntl(msgpipe[PIPE_WRITE], F_SETFD, 1);
    MsgReregister();
  }
  return(m);
}

/*
 * MsgUnRegister()
 */

void
MsgUnRegister(MsgHandler *m)
{
  Freee(MB_UTIL, *m);
  *m = NULL;
}

/*
 * MsgEvent()
 */

static void
MsgEvent(int type, void *cookie)
{
  int		nread, nrode;
  struct mpmsg	msg;

  for (nrode = 0; nrode < sizeof(msg); nrode += nread)
  {
    if ((nread = read(msgpipe[PIPE_READ],
      (u_char *) &msg + nrode, sizeof(msg) - nrode)) < 0)
    {
      Perror("%s: Can't read from message pipe", __FUNCTION__);
      DoExit(EX_ERRDEAD);
    }
    if (nread == 0)
    {
      Log(LG_ERR, ("%s: Unexpected EOF on message pipe!", __FUNCTION__));
      DoExit(EX_ERRDEAD);
    }
  }
  lnk = msg.lnk;
  bund = msg.bund;
  (*msg.func)(msg.type, msg.arg);
  MsgReregister();
}

/*
 * MsgSend()
 */

void
MsgSend(MsgHandler m, int type, void *arg)
{
  struct mpmsg	msg;
  int		nw, nwrote, retry;

  if (m == NULL)
    return;
  msg.type = type;
  msg.func = m->func;
  msg.arg = arg;
  msg.bund = m->bund;
  msg.lnk = m->lnk;
  for (nwrote = 0, retry = 10; nwrote < sizeof(msg) && retry > 0; nwrote += nw, retry--)
    if ((nw = write(msgpipe[PIPE_WRITE],
      (u_char *) &msg + nwrote, sizeof(msg) - nwrote)) < 0)
    {
      Perror("%s: Message pipe write error", __FUNCTION__);
      DoExit(EX_ERRDEAD);
    }
  if (nwrote < sizeof(msg)) {
      Log(LG_ERR, ("%s: Can't write to message pipe, fatal pipe overflow!", __FUNCTION__));
      DoExit(EX_ERRDEAD);
  }
}

/*
 * MsgReregister()
 */

static void
MsgReregister()
{
  if (EventRegister(&msgevent, EVENT_READ,
    msgpipe[PIPE_READ], 0, MsgEvent, NULL) < 0)
  {
    Perror("%s: Can't register event!", __FUNCTION__);
    DoExit(EX_ERRDEAD);
  }
}

/*
 * MsgName()
 */

const char *
MsgName(int msg)
{
  switch (msg)
  {
    case MSG_OPEN:
      return("OPEN");
    case MSG_CLOSE:
      return("CLOSE");
    case MSG_UP:
      return("UP");
    case MSG_DOWN:
      return("DOWN");
    default:
      return("???");
  }
}