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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)look_up.c 8.1 (Berkeley) 6/6/93 30 * $FreeBSD: src/usr.bin/talk/look_up.c,v 1.5 1999/08/28 01:06:14 peter Exp $ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/socket.h> 35 #include <protocols/talkd.h> 36 #include <netinet/in.h> 37 #include <errno.h> 38 #include <string.h> 39 #include "talk_ctl.h" 40 #include "talk.h" 41 42 /* 43 * See if the local daemon has an invitation for us. 44 */ 45 int 46 check_local(void) 47 { 48 CTL_RESPONSE response; 49 CTL_RESPONSE *rp = &response; 50 51 /* the rest of msg was set up in get_names */ 52 #ifdef MSG_EOR 53 /* copy new style sockaddr to old, swap family (short in old) */ 54 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 55 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 56 #else 57 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 58 #endif 59 /* must be initiating a talk */ 60 if (!look_for_invite(rp)) 61 return (0); 62 /* 63 * There was an invitation waiting for us, 64 * so connect with the other (hopefully waiting) party 65 */ 66 current_state = "Waiting to connect with caller"; 67 do { 68 struct sockaddr_in addr; 69 struct sockaddr_in *raddr; 70 71 if (rp->addr.sa_family != AF_INET) 72 p_error("Response uses invalid network address"); 73 raddr = (struct sockaddr_in *)&rp->addr; 74 memset(&addr, 0, sizeof(addr)); 75 addr.sin_family = AF_INET; 76 addr.sin_port = raddr->sin_port; 77 addr.sin_addr = raddr->sin_addr; 78 errno = 0; 79 if (connect(sockt, 80 (struct sockaddr *)&addr, sizeof(addr)) != -1) 81 return (1); 82 } while (errno == EINTR); 83 if (errno == ECONNREFUSED) { 84 /* 85 * The caller gave up, but his invitation somehow 86 * was not cleared. Clear it and initiate an 87 * invitation. (We know there are no newer invitations, 88 * the talkd works LIFO.) 89 */ 90 ctl_transact(his_machine_addr, msg, DELETE, rp); 91 close(sockt); 92 open_sockt(); 93 return (0); 94 } 95 p_error("Unable to connect with initiator"); 96 /*NOTREACHED*/ 97 return (0); 98 } 99 100 /* 101 * Look for an invitation on 'machine' 102 */ 103 int 104 look_for_invite(CTL_RESPONSE *rp) 105 { 106 current_state = "Checking for invitation on caller's machine"; 107 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 108 /* the switch is for later options, such as multiple invitations */ 109 switch (rp->answer) { 110 111 case SUCCESS: 112 msg.id_num = htonl(rp->id_num); 113 return (1); 114 115 default: 116 /* there wasn't an invitation waiting for us */ 117 return (0); 118 } 119 } 120