1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)look_up.c 8.1 (Berkeley) 6/6/93 34 * $FreeBSD: src/usr.bin/talk/look_up.c,v 1.5 1999/08/28 01:06:14 peter Exp $ 35 * $DragonFly: src/usr.bin/talk/look_up.c,v 1.4 2004/08/19 23:32:02 joerg Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/socket.h> 40 #include <protocols/talkd.h> 41 #include <errno.h> 42 #include "talk_ctl.h" 43 #include "talk.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 register CTL_RESPONSE *rp = &response; 53 54 /* the rest of msg was set up in get_names */ 55 #ifdef MSG_EOR 56 /* copy new style sockaddr to old, swap family (short in old) */ 57 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 58 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 59 #else 60 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 61 #endif 62 /* must be initiating a talk */ 63 if (!look_for_invite(rp)) 64 return (0); 65 /* 66 * There was an invitation waiting for us, 67 * so connect with the other (hopefully waiting) party 68 */ 69 current_state = "Waiting to connect with caller"; 70 do { 71 if (rp->addr.sa_family != AF_INET) 72 p_error("Response uses invalid network address"); 73 errno = 0; 74 if (connect(sockt, 75 (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1) 76 return (1); 77 } while (errno == EINTR); 78 if (errno == ECONNREFUSED) { 79 /* 80 * The caller gave up, but his invitation somehow 81 * was not cleared. Clear it and initiate an 82 * invitation. (We know there are no newer invitations, 83 * the talkd works LIFO.) 84 */ 85 ctl_transact(his_machine_addr, msg, DELETE, rp); 86 close(sockt); 87 open_sockt(); 88 return (0); 89 } 90 p_error("Unable to connect with initiator"); 91 /*NOTREACHED*/ 92 return (0); 93 } 94 95 /* 96 * Look for an invitation on 'machine' 97 */ 98 int 99 look_for_invite(CTL_RESPONSE *rp) 100 { 101 struct in_addr machine_addr; 102 103 current_state = "Checking for invitation on caller's machine"; 104 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 105 /* the switch is for later options, such as multiple invitations */ 106 switch (rp->answer) { 107 108 case SUCCESS: 109 msg.id_num = htonl(rp->id_num); 110 return (1); 111 112 default: 113 /* there wasn't an invitation waiting for us */ 114 return (0); 115 } 116 } 117