freebsd-dev/usr.bin/talk/ctl_transact.c
Pedro F. Giffuni 7880fc113f talk(1): Replace select(2) with poll(2)
Hinted by:	OpenBSD and NetBSD
2016-02-25 19:06:44 +00:00

106 lines
3.4 KiB
C

/*
* 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.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#ifndef lint
static const char sccsid[] = "@(#)ctl_transact.c 8.1 (Berkeley) 6/6/93";
#endif
#include <arpa/inet.h>
#include <errno.h>
#include <poll.h>
#include "talk.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 received an acknowledgement within a reasonable amount
* of time
*/
void
ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
{
struct pollfd pfd[1];
int nready = 0, cc;
lmsg.type = type;
daemon_addr.sin_addr = target;
daemon_addr.sin_port = daemon_port;
pfd[0].fd = ctl_sockt;
pfd[0].events = POLLIN;
/*
* Keep sending the message until a response of
* the proper type is obtained.
*/
do {
/* resend message until a response is obtained */
do {
cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
(struct sockaddr *)&daemon_addr,
sizeof (daemon_addr));
if (cc != sizeof (lmsg)) {
if (errno == EINTR)
continue;
p_error("Error on write to talk daemon");
}
nready = poll(pfd, 1, CTL_WAIT * 1000);
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");
}
nready = poll(pfd, 1, 0);
} 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);
}