xref: /openbsd/usr.bin/talk/invite.c (revision 89ee293f)
1 /*	$OpenBSD: invite.c,v 1.11 2003/09/26 04:41:48 deraadt Exp $	*/
2 /*	$NetBSD: invite.c,v 1.3 1994/12/09 02:14:18 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1983, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)invite.c	8.1 (Berkeley) 6/6/93";
36 #endif
37 static char rcsid[] = "$OpenBSD: invite.c,v 1.11 2003/09/26 04:41:48 deraadt Exp $";
38 #endif /* not lint */
39 
40 #include "talk.h"
41 #include <arpa/inet.h>
42 #include <sys/time.h>
43 #include <netdb.h>
44 #include <errno.h>
45 #include <setjmp.h>
46 #include <unistd.h>
47 #include "talk_ctl.h"
48 
49 #define STRING_LENGTH 158
50 
51 /*
52  * There wasn't an invitation waiting, so send a request containing
53  * our sockt address to the remote talk daemon so it can invite
54  * him
55  */
56 
57 /*
58  * The msg.id's for the invitations
59  * on the local and remote machines.
60  * These are used to delete the
61  * invitations.
62  */
63 int	local_id, remote_id;
64 jmp_buf invitebuf;
65 
66 void
67 invite_remote(void)
68 {
69 	int new_sockt;
70 	struct itimerval itimer;
71 	CTL_RESPONSE response;
72 	struct sockaddr rp;
73 	int rplen = sizeof(struct sockaddr);
74 	struct hostent *rphost;
75 	char rname[STRING_LENGTH];
76 
77 	itimer.it_value.tv_sec = RING_WAIT;
78 	itimer.it_value.tv_usec = 0;
79 	itimer.it_interval = itimer.it_value;
80 	if (listen(sockt, 5) != 0)
81 		quit("Error on attempt to listen for caller", 1);
82 #ifdef MSG_EOR
83 	/* copy new style sockaddr to old, swap family (short in old) */
84 	msg.addr = *(struct osockaddr *)&my_addr;  /* XXX new to old  style*/
85 	msg.addr.sa_family = htons(my_addr.sin_family);
86 #else
87 	msg.addr = *(struct sockaddr *)&my_addr;
88 #endif
89 	msg.id_num = htonl(-1);		/* an impossible id_num */
90 	invitation_waiting = 1;
91 	announce_invite();
92 	/*
93 	 * Shut off the automatic messages for a while,
94 	 * so we can use the interrupt timer to resend the invitation.
95 	 * We no longer turn automatic messages back on to avoid a bonus
96 	 * message after we've connected; this is okay even though end_msgs()
97 	 * gets called again in main().
98 	 */
99 	end_msgs();
100 	setitimer(ITIMER_REAL, &itimer, (struct itimerval *)0);
101 	message("Waiting for your party to respond");
102 	signal(SIGALRM, re_invite);
103 	(void) setjmp(invitebuf);
104 	while ((new_sockt = accept(sockt, &rp, &rplen)) < 0) {
105 		if (errno == EINTR || errno == ECONNABORTED)
106 			continue;
107 		quit("Unable to connect with your party", 1);
108 	}
109 	close(sockt);
110 	sockt = new_sockt;
111 
112 	/*
113 	 * Have the daemons delete the invitations now that we
114 	 * have connected.
115 	 */
116 	msg.id_num = htonl(local_id);
117 	ctl_transact(my_machine_addr, msg, DELETE, &response);
118 	msg.id_num = htonl(remote_id);
119 	ctl_transact(his_machine_addr, msg, DELETE, &response);
120 	invitation_waiting = 0;
121 
122 	/*
123 	 * Check to see if the other guy is coming from the machine
124 	 * we expect.
125 	 */
126 	if (his_machine_addr.s_addr !=
127 	    ((struct sockaddr_in *)&rp)->sin_addr.s_addr) {
128 		rphost = gethostbyaddr((char *) &((struct sockaddr_in
129 		    *)&rp)->sin_addr, sizeof(struct in_addr), AF_INET);
130 		if (rphost)
131 			snprintf(rname, STRING_LENGTH,
132 			    "Answering talk request from %s@%s", msg.r_name,
133 			    rphost->h_name);
134 		else
135 			snprintf(rname, STRING_LENGTH,
136 			    "Answering talk request from %s@%s", msg.r_name,
137 			    inet_ntoa(((struct sockaddr_in *)&rp)->sin_addr));
138 		message(rname);
139 	}
140 }
141 
142 /*
143  * Routine called on interupt to re-invite the callee
144  */
145 void
146 re_invite(int dummy)
147 {
148 	message("Ringing your party again");
149 	/* force a re-announce */
150 	msg.id_num = htonl(remote_id + 1);
151 	announce_invite();
152 	longjmp(invitebuf, 1);
153 }
154 
155 static	char *answers[] = {
156 	"answer #0",					/* SUCCESS */
157 	"Your party is not logged on",			/* NOT_HERE */
158 	"Target machine is too confused to talk to us",	/* FAILED */
159 	"Target machine does not recognize us",		/* MACHINE_UNKNOWN */
160 	"Your party is refusing messages",		/* PERMISSION_REFUSED */
161 	"Target machine can not handle remote talk",	/* UNKNOWN_REQUEST */
162 	"Target machine indicates protocol mismatch",	/* BADVERSION */
163 	"Target machine indicates protocol botch (addr)",/* BADADDR */
164 	"Target machine indicates protocol botch (ctl_addr)",/* BADCTLADDR */
165 };
166 #define NANSWERS (sizeof (answers) / sizeof (answers[0]))
167 
168 /*
169  * Transmit the invitation and process the response
170  */
171 void
172 announce_invite(void)
173 {
174 	CTL_RESPONSE response;
175 
176 	current_state = "Trying to connect to your party's talk daemon";
177 	ctl_transact(his_machine_addr, msg, ANNOUNCE, &response);
178 	remote_id = response.id_num;
179 	if (response.answer != SUCCESS)
180 		quit(response.answer < NANSWERS ? answers[response.answer] : NULL, 0);
181 	/* leave the actual invitation on my talk daemon */
182 	ctl_transact(my_machine_addr, msg, LEAVE_INVITE, &response);
183 	local_id = response.id_num;
184 }
185 
186 /*
187  * Tell the daemon to remove your invitation
188  */
189 void
190 send_delete(void)
191 {
192 
193 	msg.type = DELETE;
194 	/*
195 	 * This is just a extra clean up, so just send it
196 	 * and don't wait for an answer
197 	 */
198 	msg.id_num = htonl(remote_id);
199 	daemon_addr.sin_addr = his_machine_addr;
200 	if (sendto(ctl_sockt, &msg, sizeof (msg), 0,
201 	    (struct sockaddr *)&daemon_addr,
202 	    sizeof (daemon_addr)) != sizeof(msg))
203 		warn("send_delete (remote)");
204 	msg.id_num = htonl(local_id);
205 	daemon_addr.sin_addr = my_machine_addr;
206 	if (sendto(ctl_sockt, &msg, sizeof (msg), 0,
207 	    (struct sockaddr *)&daemon_addr,
208 	    sizeof (daemon_addr)) != sizeof (msg))
209 		warn("send_delete (local)");
210 }
211