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 #include <sys/cdefs.h> 35 36 __FBSDID("$FreeBSD$"); 37 38 #ifndef lint 39 static const char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 40 #endif 41 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #include <protocols/talkd.h> 45 46 #include <errno.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 #include "talk_ctl.h" 51 #include "talk.h" 52 53 /* 54 * See if the local daemon has an invitation for us. 55 */ 56 int 57 check_local(void) 58 { 59 CTL_RESPONSE response; 60 CTL_RESPONSE *rp = &response; 61 struct sockaddr addr; 62 63 /* the rest of msg was set up in get_names */ 64 #ifdef MSG_EOR 65 /* copy new style sockaddr to old, swap family (short in old) */ 66 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 67 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 68 #else 69 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 70 #endif 71 /* must be initiating a talk */ 72 if (!look_for_invite(rp)) 73 return (0); 74 /* 75 * There was an invitation waiting for us, 76 * so connect with the other (hopefully waiting) party 77 */ 78 current_state = "Waiting to connect with caller"; 79 do { 80 if (rp->addr.sa_family != AF_INET) 81 p_error("Response uses invalid network address"); 82 (void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr)); 83 addr.sa_family = rp->addr.sa_family; 84 addr.sa_len = sizeof(addr); 85 errno = 0; 86 if (connect(sockt, &addr, sizeof(addr)) != -1) 87 return (1); 88 } while (errno == EINTR); 89 if (errno == ECONNREFUSED) { 90 /* 91 * The caller gave up, but his invitation somehow 92 * was not cleared. Clear it and initiate an 93 * invitation. (We know there are no newer invitations, 94 * the talkd works LIFO.) 95 */ 96 ctl_transact(his_machine_addr, msg, DELETE, rp); 97 close(sockt); 98 open_sockt(); 99 return (0); 100 } 101 p_error("Unable to connect with initiator"); 102 /*NOTREACHED*/ 103 return (0); 104 } 105 106 /* 107 * Look for an invitation on 'machine' 108 */ 109 int 110 look_for_invite(CTL_RESPONSE *rp) 111 { 112 current_state = "Checking for invitation on caller's machine"; 113 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 114 /* the switch is for later options, such as multiple invitations */ 115 switch (rp->answer) { 116 117 case SUCCESS: 118 msg.id_num = htonl(rp->id_num); 119 return (1); 120 121 default: 122 /* there wasn't an invitation waiting for us */ 123 return (0); 124 } 125 } 126