1 /* $OpenBSD: look_up.c,v 1.10 2004/03/02 21:04:42 tedu 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 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 36 #endif 37 static const char rcsid[] = "$OpenBSD: look_up.c,v 1.10 2004/03/02 21:04:42 tedu Exp $"; 38 #endif /* not lint */ 39 40 #include "talk.h" 41 #include <errno.h> 42 #include <unistd.h> 43 #include "talk_ctl.h" 44 45 /* 46 * See if the local daemon has an invitation for us. 47 */ 48 int 49 check_local(void) 50 { 51 CTL_RESPONSE response; 52 53 /* the rest of msg was set up in get_names */ 54 #ifdef MSG_EOR 55 /* copy new style sockaddr to old, swap family (short in old) */ 56 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 57 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 58 #else 59 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 60 #endif 61 /* must be initiating a talk */ 62 if (!look_for_invite(&response)) 63 return (0); 64 /* 65 * There was an invitation waiting for us, 66 * so connect with the other (hopefully waiting) party 67 */ 68 current_state = "Waiting to connect with caller"; 69 do { 70 if (ntohs(response.addr.sa_family) != AF_INET) 71 quit("Response uses invalid network address", 1); 72 errno = 0; 73 if (connect(sockt, (struct sockaddr *)&response.addr, 74 sizeof (response.addr)) != -1) 75 return (1); 76 } while (errno == EINTR); 77 if (errno == ECONNREFUSED) { 78 /* 79 * The caller gave up, but his invitation somehow 80 * was not cleared. Clear it and initiate an 81 * invitation. (We know there are no newer invitations, 82 * the talkd works LIFO.) 83 */ 84 ctl_transact(his_machine_addr, msg, DELETE, &response); 85 close(sockt); 86 open_sockt(); 87 return (0); 88 } 89 quit("Unable to connect with initiator", 1); 90 /*NOTREACHED*/ 91 return (0); 92 } 93 94 /* 95 * Look for an invitation on 'machine' 96 */ 97 int 98 look_for_invite(CTL_RESPONSE *rp) 99 { 100 current_state = "Checking for invitation on caller's machine"; 101 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 102 /* the switch is for later options, such as multiple invitations */ 103 switch (rp->answer) { 104 105 case SUCCESS: 106 msg.id_num = htonl(rp->id_num); 107 return (1); 108 109 default: 110 /* there wasn't an invitation waiting for us */ 111 return (0); 112 } 113 } 114