1 /* $OpenBSD: look_up.c,v 1.7 2001/07/17 02:23:58 pvalchev 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 40 #endif 41 static char rcsid[] = "$OpenBSD: look_up.c,v 1.7 2001/07/17 02:23:58 pvalchev Exp $"; 42 #endif /* not lint */ 43 44 #include "talk.h" 45 #include <errno.h> 46 #include <unistd.h> 47 #include "talk_ctl.h" 48 49 /* 50 * See if the local daemon has an invitation for us. 51 */ 52 int 53 check_local() 54 { 55 CTL_RESPONSE response; 56 57 /* the rest of msg was set up in get_names */ 58 #ifdef MSG_EOR 59 /* copy new style sockaddr to old, swap family (short in old) */ 60 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 61 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 62 #else 63 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 64 #endif 65 /* must be initiating a talk */ 66 if (!look_for_invite(&response)) 67 return (0); 68 /* 69 * There was an invitation waiting for us, 70 * so connect with the other (hopefully waiting) party 71 */ 72 current_state = "Waiting to connect with caller"; 73 do { 74 if (ntohs(response.addr.sa_family) != AF_INET) 75 quit("Response uses invalid network address", 1); 76 errno = 0; 77 if (connect(sockt, (struct sockaddr *)&response.addr, 78 sizeof (response.addr)) != -1) 79 return (1); 80 } while (errno == EINTR); 81 if (errno == ECONNREFUSED) { 82 /* 83 * The caller gave up, but his invitation somehow 84 * was not cleared. Clear it and initiate an 85 * invitation. (We know there are no newer invitations, 86 * the talkd works LIFO.) 87 */ 88 ctl_transact(his_machine_addr, msg, DELETE, &response); 89 close(sockt); 90 open_sockt(); 91 return (0); 92 } 93 quit("Unable to connect with initiator", 1); 94 /*NOTREACHED*/ 95 return (0); 96 } 97 98 /* 99 * Look for an invitation on 'machine' 100 */ 101 int 102 look_for_invite(rp) 103 CTL_RESPONSE *rp; 104 { 105 current_state = "Checking for invitation on caller's machine"; 106 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 107 /* the switch is for later options, such as multiple invitations */ 108 switch (rp->answer) { 109 110 case SUCCESS: 111 msg.id_num = htonl(rp->id_num); 112 return (1); 113 114 default: 115 /* there wasn't an invitation waiting for us */ 116 return (0); 117 } 118 } 119