1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 33 34 #include <arpa/inet.h> 35 36 #include <errno.h> 37 #include <poll.h> 38 39 #include "talk.h" 40 #include "talk_ctl.h" 41 42 #define CTL_WAIT 2 /* time to wait for a response, in seconds */ 43 44 /* 45 * SOCKDGRAM is unreliable, so we must repeat messages if we have 46 * not received an acknowledgement within a reasonable amount 47 * of time 48 */ 49 void 50 ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp) 51 { 52 struct pollfd pfd[1]; 53 int nready = 0, cc; 54 55 lmsg.type = type; 56 daemon_addr.sin_addr = target; 57 daemon_addr.sin_port = daemon_port; 58 pfd[0].fd = ctl_sockt; 59 pfd[0].events = POLLIN; 60 61 /* 62 * Keep sending the message until a response of 63 * the proper type is obtained. 64 */ 65 do { 66 /* resend message until a response is obtained */ 67 do { 68 cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0, 69 (struct sockaddr *)&daemon_addr, 70 sizeof (daemon_addr)); 71 if (cc != sizeof (lmsg)) { 72 if (errno == EINTR) 73 continue; 74 p_error("Error on write to talk daemon"); 75 } 76 nready = poll(pfd, 1, CTL_WAIT * 1000); 77 if (nready < 0) { 78 if (errno == EINTR) 79 continue; 80 p_error("Error waiting for daemon response"); 81 } 82 } while (nready == 0); 83 /* 84 * Keep reading while there are queued messages 85 * (this is not necessary, it just saves extra 86 * request/acknowledgements being sent) 87 */ 88 do { 89 cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0); 90 if (cc < 0) { 91 if (errno == EINTR) 92 continue; 93 p_error("Error on read from talk daemon"); 94 } 95 nready = poll(pfd, 1, 0); 96 } while (nready > 0 && (rp->vers != TALK_VERSION || 97 rp->type != type)); 98 } while (rp->vers != TALK_VERSION || rp->type != type); 99 rp->id_num = ntohl(rp->id_num); 100 rp->addr.sa_family = ntohs(rp->addr.sa_family); 101 } 102