/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2002 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
 * All Rights Reserved.
 */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California.
 * All Rights Reserved.
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * Invoked by the Internet daemon to handle talk requests
 * Processes talk requests until MAX_LIFE seconds go by with
 * no action, then dies.
 */

#include <stdio.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/systeminfo.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "talkd_impl.h"

static CTL_MSG request;
static CTL_RESPONSE response;

char hostname[HOST_NAME_LENGTH];
int debug = 0;

static CTL_MSG swapmsg(CTL_MSG req);

int
main()
{
        struct sockaddr_in from;
        socklen_t from_size = (socklen_t)sizeof (from);
        int cc;
        int name_length = sizeof (hostname);
        fd_set rfds;
        struct timeval tv;

        (void) sysinfo(SI_HOSTNAME, hostname, name_length);

        for (;;) {
                tv.tv_sec = MAX_LIFE;
                tv.tv_usec = 0;
                FD_ZERO(&rfds);
                FD_SET(0, &rfds);
                if (select(1, &rfds, 0, 0, &tv) <= 0)
                        return (0);
                cc = recvfrom(0, (char *)&request, sizeof (request), 0,
                    (struct sockaddr *)&from, &from_size);

                if (cc != sizeof (request)) {
                        if (cc < 0 && errno != EINTR) {
                                print_error("receive");
                        }
                } else {

                        if (debug) {
                                (void) printf("Request received : \n");
                                (void) print_request(&request);
                        }

                        request = swapmsg(request);
                        process_request(&request, &response);

                        if (debug) {
                                (void) printf("Response sent : \n");
                                print_response(&response);
                        }

                        /*
                         * Can block here, is this what I want?
                         */
                        cc = sendto(0, (char *)&response, sizeof (response), 0,
                            (struct sockaddr *)&request.ctl_addr,
                            (socklen_t)sizeof (request.ctl_addr));

                        if (cc != sizeof (response)) {
                                print_error("Send");
                        }
                }
        }
}

void
print_error(char *string)
{
        FILE *cons;
        char *err_dev = "/dev/console";
        char *sys;
        pid_t val, pid;

        if (debug)
                err_dev = "/dev/tty";

        if ((sys = strerror(errno)) == (char *)NULL)
            sys = "Unknown error";

        /* don't ever open tty's directly, let a child do it */
        if ((pid = fork()) == 0) {
                cons = fopen(err_dev, "a");
                if (cons != NULL) {
                        (void) fprintf(cons, "Talkd : %s : %s(%d)\n\r", string,
                            sys, errno);
                        (void) fclose(cons);
                }
                exit(0);
        } else {
                /* wait for the child process to return */
                do {
                        val = wait(0);
                        if (val == (pid_t)-1) {
                                if (errno == EINTR) {
                                        continue;
                                } else if (errno == ECHILD) {
                                        break;
                                }
                        }
                } while (val != pid);
        }
}

#define swapshort(a) (((a << 8) | ((unsigned short) a >> 8)) & 0xffff)
#define swaplong(a) ((swapshort(a) << 16) | (swapshort(((unsigned)a >> 16))))

/*
 * Heuristic to detect if need to swap bytes.
 */

static CTL_MSG
swapmsg(CTL_MSG req)
{
        CTL_MSG swapreq;

        if (req.ctl_addr.sin_family == swapshort(AF_INET)) {
                swapreq = req;
                swapreq.id_num = swaplong(req.id_num);
                swapreq.pid = swaplong(req.pid);
                swapreq.addr.sin_family = swapshort(req.addr.sin_family);
                swapreq.ctl_addr.sin_family =
                        swapshort(req.ctl_addr.sin_family);
                return (swapreq);
        } else {
                return (req);
        }
}