/*      $OpenBSD: invite.c,v 1.17 2016/03/16 15:41:11 krw Exp $ */
/*      $NetBSD: invite.c,v 1.3 1994/12/09 02:14:18 jtc Exp $   */

/*
 * Copyright (c) 1983, 1993
 *      The 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. 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.
 */

#include <sys/socket.h>
#include <arpa/inet.h>

#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <setjmp.h>
#include <unistd.h>

#include "talk.h"
#include "talk_ctl.h"

#define STRING_LENGTH 158

/*
 * There wasn't an invitation waiting, so send a request containing
 * our sockt address to the remote talk daemon so it can invite
 * him
 */

/*
 * The msg.id's for the invitations
 * on the local and remote machines.
 * These are used to delete the
 * invitations.
 */
int     local_id, remote_id;
jmp_buf invitebuf;

void
invite_remote(void)
{
        int new_sockt;
        struct itimerval itimer;
        CTL_RESPONSE response;
        struct sockaddr rp;
        socklen_t rplen = sizeof(struct sockaddr);
        struct hostent *rphost;
        char rname[STRING_LENGTH];

        itimer.it_value.tv_sec = RING_WAIT;
        itimer.it_value.tv_usec = 0;
        itimer.it_interval = itimer.it_value;
        if (listen(sockt, 5) != 0)
                quit("Error on attempt to listen for caller", 1);
#ifdef MSG_EOR
        /* copy new style sockaddr to old, swap family (short in old) */
        msg.addr = *(struct osockaddr *)&my_addr;  /* XXX new to old  style*/
        msg.addr.sa_family = htons(my_addr.sin_family);
#else
        msg.addr = *(struct sockaddr *)&my_addr;
#endif
        msg.id_num = htonl(-1);         /* an impossible id_num */
        invitation_waiting = 1;
        announce_invite();
        /*
         * Shut off the automatic messages for a while,
         * so we can use the interrupt timer to resend the invitation.
         * We no longer turn automatic messages back on to avoid a bonus
         * message after we've connected; this is okay even though end_msgs()
         * gets called again in main().
         */
        end_msgs();
        setitimer(ITIMER_REAL, &itimer, NULL);
        message("Waiting for your party to respond");
        signal(SIGALRM, re_invite);
        (void) setjmp(invitebuf);
        while ((new_sockt = accept(sockt, &rp, &rplen)) == -1) {
                if (errno == EINTR || errno == EWOULDBLOCK ||
                    errno == ECONNABORTED)
                        continue;
                quit("Unable to connect with your party", 1);
        }
        close(sockt);
        sockt = new_sockt;

        /*
         * Have the daemons delete the invitations now that we
         * have connected.
         */
        msg.id_num = htonl(local_id);
        ctl_transact(my_machine_addr, msg, DELETE, &response);
        msg.id_num = htonl(remote_id);
        ctl_transact(his_machine_addr, msg, DELETE, &response);
        invitation_waiting = 0;

        /*
         * Check to see if the other guy is coming from the machine
         * we expect.
         */
        if (his_machine_addr.s_addr !=
            ((struct sockaddr_in *)&rp)->sin_addr.s_addr) {
                rphost = gethostbyaddr((char *) &((struct sockaddr_in
                    *)&rp)->sin_addr, sizeof(struct in_addr), AF_INET);
                if (rphost)
                        snprintf(rname, STRING_LENGTH,
                            "Answering talk request from %s@%s", msg.r_name,
                            rphost->h_name);
                else
                        snprintf(rname, STRING_LENGTH,
                            "Answering talk request from %s@%s", msg.r_name,
                            inet_ntoa(((struct sockaddr_in *)&rp)->sin_addr));
                message(rname);
        }
}

/*
 * Routine called on interrupt to re-invite the callee
 */
void
re_invite(int dummy)
{
        message("Ringing your party again");
        /* force a re-announce */
        msg.id_num = htonl(remote_id + 1);
        announce_invite();
        longjmp(invitebuf, 1);
}

static  char *answers[] = {
        "answer #0",                                    /* SUCCESS */
        "Your party is not logged on",                  /* NOT_HERE */
        "Target machine is too confused to talk to us", /* FAILED */
        "Target machine does not recognize us",         /* MACHINE_UNKNOWN */
        "Your party is refusing messages",              /* PERMISSION_REFUSED */
        "Target machine can not handle remote talk",    /* UNKNOWN_REQUEST */
        "Target machine indicates protocol mismatch",   /* BADVERSION */
        "Target machine indicates protocol botch (addr)",/* BADADDR */
        "Target machine indicates protocol botch (ctl_addr)",/* BADCTLADDR */
};
#define NANSWERS (sizeof (answers) / sizeof (answers[0]))

/*
 * Transmit the invitation and process the response
 */
void
announce_invite(void)
{
        CTL_RESPONSE response;

        current_state = "Trying to connect to your party's talk daemon";
        ctl_transact(his_machine_addr, msg, ANNOUNCE, &response);
        remote_id = response.id_num;
        if (response.answer != SUCCESS)
                quit(response.answer < NANSWERS ? answers[response.answer] : NULL, 0);
        /* leave the actual invitation on my talk daemon */
        ctl_transact(my_machine_addr, msg, LEAVE_INVITE, &response);
        local_id = response.id_num;
}

/*
 * Tell the daemon to remove your invitation
 */
void
send_delete(void)
{

        msg.type = DELETE;
        /*
         * This is just a extra clean up, so just send it
         * and don't wait for an answer
         */
        msg.id_num = htonl(remote_id);
        daemon_addr.sin_addr = his_machine_addr;
        if (sendto(ctl_sockt, &msg, sizeof (msg), 0,
            (struct sockaddr *)&daemon_addr,
            sizeof (daemon_addr)) != sizeof(msg))
                warn("send_delete (remote)");
        msg.id_num = htonl(local_id);
        daemon_addr.sin_addr = my_machine_addr;
        if (sendto(ctl_sockt, &msg, sizeof (msg), 0,
            (struct sockaddr *)&daemon_addr,
            sizeof (daemon_addr)) != sizeof (msg))
                warn("send_delete (local)");
}