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 30 #include <sys/cdefs.h> 31 32 __FBSDID("$FreeBSD$"); 33 34 #ifndef lint 35 static const char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93"; 36 #endif 37 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 #include <protocols/talkd.h> 41 42 #include <errno.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #include "talk_ctl.h" 47 #include "talk.h" 48 49 /* 50 * See if the local daemon has an invitation for us. 51 */ 52 int 53 check_local(void) 54 { 55 CTL_RESPONSE response; 56 CTL_RESPONSE *rp = &response; 57 struct sockaddr addr; 58 59 /* the rest of msg was set up in get_names */ 60 #ifdef MSG_EOR 61 /* copy new style sockaddr to old, swap family (short in old) */ 62 msg.ctl_addr = *(struct osockaddr *)&ctl_addr; 63 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); 64 #else 65 msg.ctl_addr = *(struct sockaddr *)&ctl_addr; 66 #endif 67 /* must be initiating a talk */ 68 if (!look_for_invite(rp)) 69 return (0); 70 /* 71 * There was an invitation waiting for us, 72 * so connect with the other (hopefully waiting) party 73 */ 74 current_state = "Waiting to connect with caller"; 75 do { 76 if (rp->addr.sa_family != AF_INET) 77 p_error("Response uses invalid network address"); 78 (void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr)); 79 addr.sa_family = rp->addr.sa_family; 80 addr.sa_len = sizeof(addr); 81 errno = 0; 82 if (connect(sockt, &addr, sizeof(addr)) != -1) 83 return (1); 84 } while (errno == EINTR); 85 if (errno == ECONNREFUSED) { 86 /* 87 * The caller gave up, but his invitation somehow 88 * was not cleared. Clear it and initiate an 89 * invitation. (We know there are no newer invitations, 90 * the talkd works LIFO.) 91 */ 92 ctl_transact(his_machine_addr, msg, DELETE, rp); 93 close(sockt); 94 open_sockt(); 95 return (0); 96 } 97 p_error("Unable to connect with initiator"); 98 /*NOTREACHED*/ 99 return (0); 100 } 101 102 /* 103 * Look for an invitation on 'machine' 104 */ 105 int 106 look_for_invite(CTL_RESPONSE *rp) 107 { 108 current_state = "Checking for invitation on caller's machine"; 109 ctl_transact(his_machine_addr, msg, LOOK_UP, rp); 110 /* the switch is for later options, such as multiple invitations */ 111 switch (rp->answer) { 112 113 case SUCCESS: 114 msg.id_num = htonl(rp->id_num); 115 return (1); 116 117 default: 118 /* there wasn't an invitation waiting for us */ 119 return (0); 120 } 121 } 122