1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 33 #ifndef lint 34 static const char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 35 #endif 36 37 #include <sys/types.h> 38 #include <sys/socket.h> 39 #include <protocols/talkd.h> 40 41 #include <errno.h> 42 #include <string.h> 43 #include <unistd.h> 44 45 #include "talk_ctl.h" 46 #include "talk.h" 47 48 /* 49 * See if the local daemon has an invitation for us. 50 */ 51 int 52 check_local(void) 53 { 54 CTL_RESPONSE response; 55 CTL_RESPONSE *rp = &response; 56 struct sockaddr addr; 57 58 /* the rest of msg was set up in get_names */ 59 /* copy new style sockaddr to old, swap family (short in old) */ 60 msg.ctl_addr = *(struct tsockaddr *)&ctl_addr; 61 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 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 (void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr)); 74 addr.sa_family = rp->addr.sa_family; 75 addr.sa_len = sizeof(addr); 76 errno = 0; 77 if (connect(sockt, &addr, sizeof(addr)) != -1) 78 return (1); 79 } while (errno == EINTR); 80 if (errno == ECONNREFUSED) { 81 /* 82 * The caller gave up, but his invitation somehow 83 * was not cleared. Clear it and initiate an 84 * invitation. (We know there are no newer invitations, 85 * the talkd works LIFO.) 86 */ 87 ctl_transact(his_machine_addr, msg, DELETE, rp); 88 close(sockt); 89 open_sockt(); 90 return (0); 91 } 92 p_error("Unable to connect with initiator"); 93 /*NOTREACHED*/ 94 return (0); 95 } 96 97 /* 98 * Look for an invitation on 'machine' 99 */ 100 int 101 look_for_invite(CTL_RESPONSE *rp) 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