1 /* $OpenBSD: look_up.c,v 1.13 2016/02/01 07:29:25 mestre Exp $ */ 2 /* $NetBSD: look_up.c,v 1.3 1994/12/09 02:14:21 jtc Exp $ */ 3 4 /* 5 * Copyright (c) 1983, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/socket.h> 34 35 #include <errno.h> 36 #include <unistd.h> 37 38 #include "talk.h" 39 #include "talk_ctl.h" 40 41 /* 42 * See if the local daemon has an invitation for us. 43 */ 44 int 45 check_local(void) 46 { 47 CTL_RESPONSE response; 48 49 /* the rest of msg was set up in get_names */ 50 #ifdef MSG_EOR 51 /* copy new style sockaddr to old, swap family (short in old) */ 52 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 53 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 54 #else 55 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 56 #endif 57 /* must be initiating a talk */ 58 if (!look_for_invite(&response)) 59 return (0); 60 /* 61 * There was an invitation waiting for us, 62 * so connect with the other (hopefully waiting) party 63 */ 64 current_state = "Waiting to connect with caller"; 65 do { 66 if (ntohs(response.addr.sa_family) != AF_INET) 67 quit("Response uses invalid network address", 1); 68 errno = 0; 69 if (connect(sockt, (struct sockaddr *)&response.addr, 70 sizeof (response.addr)) != -1) 71 return (1); 72 } while (errno == EINTR); 73 74 if (errno == ECONNREFUSED) { 75 /* 76 * The caller gave up, but his invitation somehow 77 * was not cleared. Clear it and initiate an 78 * invitation. (We know there are no newer invitations, 79 * the talkd works LIFO.) 80 */ 81 ctl_transact(his_machine_addr, msg, DELETE, &response); 82 close(sockt); 83 open_sockt(); 84 return (0); 85 } 86 quit("Unable to connect with initiator", 1); 87 return (0); 88 } 89 90 /* 91 * Look for an invitation on 'machine' 92 */ 93 int 94 look_for_invite(CTL_RESPONSE *rp) 95 { 96 current_state = "Checking for invitation on caller's machine"; 97 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 98 /* the switch is for later options, such as multiple invitations */ 99 switch (rp->answer) { 100 case SUCCESS: 101 msg.id_num = htonl(rp->id_num); 102 return (1); 103 default: 104 /* there wasn't an invitation waiting for us */ 105 return (0); 106 } 107 } 108