/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

# include       <stdarg.h>
# include       <limits.h>
# include       <sys/types.h>
# include       <poll.h>
# include       <stropts.h>
# include       <unistd.h>
#include <syslog.h>

# include       "lpsched.h"

#define TURN_OFF(X,F)   (void)Fcntl(X, F_SETFL, (Fcntl(X, F_GETFL, 0) & ~(F)))


static void     conn_shutdown();

extern int              Filter_Status;
extern void             dispatch();
extern int              Waitrequest;
void                    shutdown_messages();
static char             *Message;
static int              MaxClients              = 0,
                        do_msg();
extern int              Reserve_Fds;
extern int              Shutdown;

MESG                    *Net_md;

/*
** take_message() - WAIT FOR INTERRUPT OR ONE MESSAGE FROM USER PROCESS
*/

void take_message(void)
{
    int         bytes;
    int         i;
    MESG *      md;

    for (EVER) {        /* not really forever...returns are in the loop */
        if ((md = mlisten()) == NULL)
            switch(errno) {
              case EAGAIN:
              case EINTR:
                return;

              case ENOMEM:
                mallocfail();
                /* NOTREACHED */

              default:
                fail ("Unexpected streams error in mlisten (%s).\n" , PERROR);
            }

        /*
         * Check for a dropped connection to a child.
         * Normally a child should tell us that it is dying
         * (with S_SHUTDOWN or S_SEND_CHILD), but it may have
         * died a fast death. We'll simulate the message we
         * wanted to get so we can use the same code to clean up.
         */
        if ((md->event & POLLHUP) && !(md->event & POLLIN) ||
            (md->event & (POLLERR|POLLNVAL))) {
                switch (md->type) {

                case MD_CHILD:
                        /*
                         * If the message descriptor is found in the
                         * exec table, it must be an interface pgm,
                         * notification, etc. Otherwise, it must be
                         * a network child.
                         */
                        for (i = 0; Exec_Table[i] != NULL; i++)
                                if (Exec_Table[i]->md == md)
                                        break;

                        if (Exec_Table[i] != NULL) {
                                (void) putmessage(Message, S_CHILD_DONE,
                                        Exec_Table[i]->key, 0, 0);
                        } else {
                                (void) putmessage(Message, S_SHUTDOWN, 1);
                        }
                        bytes = 1;
                        break;

                default:
                        bytes = -1;
                        break;

                }

        } else {
                if (md->readfd == -1) { /* something happened to the readfd */
                        syslog(LOG_DEBUG, "take_message: readfd is -1");
                        return;
                }
                bytes = mread(md, Message, MSGMAX);
        }

        switch (bytes) {
          case -1:
            if (errno == EINTR)
                return;
            else
                fail ("Unexpected streams error (%s).\n" , PERROR);
            break;

          case 0:
            break;

          default:
            if (do_msg(md))
                return;
            break;
        }
    }
}

/*
** do_msg() - HANDLE AN INCOMING MESSAGE
*/

static int
do_msg(MESG *md)
{
    int                 type = mtype(Message);

    if (type != S_GOODBYE) {
            md->wait = 0;
            dispatch (type, Message, md);
            /*
             * The message may have caused the need to
             * schedule something, so go back and check.
             */
            return(1);
    }
    return(0);
}

/*
** calculate_nopen() - DETERMINE # FILE DESCRIPTORS AVAILABLE FOR QUEUES
*/

static void
calculate_nopen(void)
{
    int         fd, nopen;

    /*
     * How many file descriptorss are currently being used?
     */
    for (fd = nopen = 0; fd < OpenMax; fd++)
        if (fcntl(fd, F_GETFL, 0) != -1)
            nopen++;

    /*
     * How many file descriptors are available for use
     * as open FIFOs? Leave one spare as a way to tell
     * clients we don't have any to spare (hmmm....) and
     * one for the incoming fifo.
     */

    MaxClients = OpenMax;
    MaxClients -= nopen;        /* current overhead */
    MaxClients -= Reserve_Fds;
    MaxClients -= 2;            /* incoming FIFO and spare outgoing */
    MaxClients--;               /* the requests log */
    MaxClients--;               /* HPI routines and lpsched log */

    return;
}

static void conn_shutdown ( )
{
    if (!Shutdown) {
        note ("The public connection \"%s\", has failed.\n", Lp_FIFO);
        lpshut(1);
    }
}

/*
** init_messages() - INITIALIZE MAIN MESSAGE QUEUE
*/

void
init_messages(void)
{
    char        *cmd;
    MESG *      md;

    (void) signal(SIGPIPE, SIG_IGN);

    calculate_nopen ();

    Message = (char *)Malloc(MSGMAX);

    (void) Chmod(Lp_Tmp, 0711);

    if ((md = mcreate(Lp_FIFO)) == NULL)
        fail ("Can't create public message device (%s).\n", PERROR);
    mon_discon(md, conn_shutdown);

    if (mlisteninit(md) != 0)
        if (errno == ENOMEM)
            mallocfail();
        else
            fail ("Unexpected streams error (%s).\n" , PERROR);

    (void) Chmod(Lp_FIFO, 0666);
    return;
}


void
shutdown_messages(void)
{
    MESG        *md;

    (void) Chmod(Lp_Tmp, 0700);
    (void) Chmod(Lp_FIFO, 0600);
    md = mlistenreset();
    mdestroy(md);
}