usr/src/usr.bin/talk/ctl_transact.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)ctl_transact.c      5.8 (Berkeley) 3/1/91";
#endif /* not lint */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <protocols/talkd.h>
#include <errno.h>
#include "talk_ctl.h"

#define CTL_WAIT 2      /* time to wait for a response, in seconds */

/*
 * SOCKDGRAM is unreliable, so we must repeat messages if we have
 * not recieved an acknowledgement within a reasonable amount
 * of time
 */
ctl_transact(target, msg, type, rp)
        struct in_addr target;
        CTL_MSG msg;
        int type;
        CTL_RESPONSE *rp;
{
        int read_mask, ctl_mask, nready, cc;
        struct timeval wait;

        msg.type = type;
        daemon_addr.sin_addr = target;
        daemon_addr.sin_port = daemon_port;
        ctl_mask = 1 << ctl_sockt;

        /*
         * Keep sending the message until a response of
         * the proper type is obtained.
         */
        do {
                wait.tv_sec = CTL_WAIT;
                wait.tv_usec = 0;
                /* resend message until a response is obtained */
                do {
                        cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
                            (struct sockaddr *)&daemon_addr,
                            sizeof (daemon_addr));
                        if (cc != sizeof (msg)) {
                                if (errno == EINTR)
                                        continue;
                                p_error("Error on write to talk daemon");
                        }
                        read_mask = ctl_mask;
                        nready = select(32, &read_mask, 0, 0, &wait);
                        if (nready < 0) {
                                if (errno == EINTR)
                                        continue;
                                p_error("Error waiting for daemon response");
                        }
                } while (nready == 0);
                /*
                 * Keep reading while there are queued messages
                 * (this is not necessary, it just saves extra
                 * request/acknowledgements being sent)
                 */
                do {
                        cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
                        if (cc < 0) {
                                if (errno == EINTR)
                                        continue;
                                p_error("Error on read from talk daemon");
                        }
                        read_mask = ctl_mask;
                        /* an immediate poll */
                        timerclear(&wait);
                        nready = select(32, &read_mask, 0, 0, &wait);
                } while (nready > 0 && (rp->vers != TALK_VERSION ||
                    rp->type != type));
        } while (rp->vers != TALK_VERSION || rp->type != type);
        rp->id_num = ntohl(rp->id_num);
        rp->addr.sa_family = ntohs(rp->addr.sa_family);
}