1 /* $NetBSD: look_up.c,v 1.5 2001/09/27 14:43:31 christos Exp $ */ 2 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 40 #endif 41 __RCSID("$NetBSD: look_up.c,v 1.5 2001/09/27 14:43:31 christos 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 CTL_RESPONSE *rp = &response; 57 struct sockaddr addr; 58 59 /* the rest of msg was set up in get_names */ 60 #ifdef MSG_EOR 61 /* copy new style sockaddr to old, swap family (short in old) */ 62 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 63 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 64 #else 65 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 66 #endif 67 /* must be initiating a talk */ 68 if (!look_for_invite(rp)) 69 return (0); 70 /* 71 * There was an invitation waiting for us, 72 * so connect with the other (hopefully waiting) party 73 */ 74 current_state = "Waiting to connect with caller"; 75 do { 76 if (rp->addr.sa_family != AF_INET) 77 p_error("Response uses invalid network address"); 78 79 (void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr)); 80 addr.sa_family = rp->addr.sa_family; 81 addr.sa_len = sizeof(addr); 82 83 errno = 0; 84 if (connect(sockt, &addr, sizeof(addr)) != -1) 85 return (1); 86 } while (errno == EINTR); 87 if (errno == ECONNREFUSED) { 88 /* 89 * The caller gave up, but his invitation somehow 90 * was not cleared. Clear it and initiate an 91 * invitation. (We know there are no newer invitations, 92 * the talkd works LIFO.) 93 */ 94 ctl_transact(his_machine_addr, msg, DELETE, rp); 95 close(sockt); 96 open_sockt(); 97 return (0); 98 } 99 p_error("Unable to connect with initiator"); 100 /*NOTREACHED*/ 101 return (0); 102 } 103 104 /* 105 * Look for an invitation on 'machine' 106 */ 107 int 108 look_for_invite(rp) 109 CTL_RESPONSE *rp; 110 { 111 current_state = "Checking for invitation on caller's machine"; 112 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 113 /* the switch is for later options, such as multiple invitations */ 114 switch (rp->answer) { 115 116 case SUCCESS: 117 msg.id_num = htonl(rp->id_num); 118 return (1); 119 120 default: 121 /* there wasn't an invitation waiting for us */ 122 return (0); 123 } 124 } 125