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 #include <sys/cdefs.h> 33 34 __FBSDID("$FreeBSD$"); 35 36 #ifndef lint 37 static const char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 38 #endif 39 40 #include <sys/types.h> 41 #include <sys/socket.h> 42 #include <protocols/talkd.h> 43 44 #include <errno.h> 45 #include <string.h> 46 #include <unistd.h> 47 48 #include "talk_ctl.h" 49 #include "talk.h" 50 51 /* 52 * See if the local daemon has an invitation for us. 53 */ 54 int 55 check_local(void) 56 { 57 CTL_RESPONSE response; 58 CTL_RESPONSE *rp = &response; 59 struct sockaddr addr; 60 61 /* the rest of msg was set up in get_names */ 62 #ifdef MSG_EOR 63 /* copy new style sockaddr to old, swap family (short in old) */ 64 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 65 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 66 #else 67 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 68 #endif 69 /* must be initiating a talk */ 70 if (!look_for_invite(rp)) 71 return (0); 72 /* 73 * There was an invitation waiting for us, 74 * so connect with the other (hopefully waiting) party 75 */ 76 current_state = "Waiting to connect with caller"; 77 do { 78 if (rp->addr.sa_family != AF_INET) 79 p_error("Response uses invalid network address"); 80 (void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr)); 81 addr.sa_family = rp->addr.sa_family; 82 addr.sa_len = sizeof(addr); 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(CTL_RESPONSE *rp) 109 { 110 current_state = "Checking for invitation on caller's machine"; 111 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 112 /* the switch is for later options, such as multiple invitations */ 113 switch (rp->answer) { 114 115 case SUCCESS: 116 msg.id_num = htonl(rp->id_num); 117 return (1); 118 119 default: 120 /* there wasn't an invitation waiting for us */ 121 return (0); 122 } 123 } 124