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 34 #ifndef lint 35 static char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 36 #endif /* not lint */ 37 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 #include <netinet/in.h> 41 #include <protocols/talkd.h> 42 #include <errno.h> 43 #include "talk_ctl.h" 44 #include "talk.h" 45 46 /* 47 * See if the local daemon has an invitation for us. 48 */ 49 int 50 check_local() 51 { 52 CTL_RESPONSE response; 53 register CTL_RESPONSE *rp = &response; 54 55 /* the rest of msg was set up in get_names */ 56 #ifdef MSG_EOR 57 /* copy new style sockaddr to old, swap family (short in old) */ 58 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 59 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 60 #else 61 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 62 #endif 63 /* must be initiating a talk */ 64 if (!look_for_invite(rp)) 65 return (0); 66 /* 67 * There was an invitation waiting for us, 68 * so connect with the other (hopefully waiting) party 69 */ 70 current_state = "Waiting to connect with caller"; 71 do { 72 if (rp->addr.sa_family != AF_INET) 73 p_error("Response uses invalid network address"); 74 errno = 0; 75 if (connect(sockt, 76 (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1) 77 return (1); 78 } while (errno == EINTR); 79 if (errno == ECONNREFUSED) { 80 /* 81 * The caller gave up, but his invitation somehow 82 * was not cleared. Clear it and initiate an 83 * invitation. (We know there are no newer invitations, 84 * the talkd works LIFO.) 85 */ 86 ctl_transact(his_machine_addr, msg, DELETE, rp); 87 close(sockt); 88 open_sockt(); 89 return (0); 90 } 91 p_error("Unable to connect with initiator"); 92 /*NOTREACHED*/ 93 return (0); 94 } 95 96 /* 97 * Look for an invitation on 'machine' 98 */ 99 int 100 look_for_invite(rp) 101 CTL_RESPONSE *rp; 102 { 103 struct in_addr machine_addr; 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