1 /* $NetBSD: process.c,v 1.14 2009/03/16 01:13:38 lukem Exp $ */
2
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 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93";
36 #else
37 __RCSID("$NetBSD: process.c,v 1.14 2009/03/16 01:13:38 lukem Exp $");
38 #endif
39 #endif /* not lint */
40
41 /*
42 * process.c handles the requests, which can be of three types:
43 * ANNOUNCE - announce to a user that a talk is wanted
44 * LEAVE_INVITE - insert the request into the table
45 * LOOK_UP - look up to see if a request is waiting in
46 * in the table for the local user
47 * DELETE - delete invitation
48 */
49
50 #include <sys/param.h>
51 #include <sys/stat.h>
52 #include <sys/socket.h>
53
54 #include <netinet/in.h>
55
56 #include <protocols/talkd.h>
57
58 #include <netdb.h>
59 #include <syslog.h>
60 #include <stdio.h>
61 #include <string.h>
62 #include <paths.h>
63
64 #include "extern.h"
65
66 #include "utmpentry.h"
67
68 void
process_request(CTL_MSG * mp,CTL_RESPONSE * rp)69 process_request(CTL_MSG *mp, CTL_RESPONSE *rp)
70 {
71 CTL_MSG *ptr;
72
73 rp->vers = TALK_VERSION;
74 rp->type = mp->type;
75 rp->id_num = htonl(0);
76 mp->id_num = ntohl(mp->id_num);
77 mp->addr.sa_family = ntohs(mp->addr.sa_family);
78 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
79 mp->pid = ntohl(mp->pid);
80 if (mp->vers != TALK_VERSION) {
81 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers);
82 rp->answer = BADVERSION;
83 return;
84 }
85 if (mp->addr.sa_family != AF_INET) {
86 syslog(LOG_WARNING, "Bad address, family %d",
87 mp->addr.sa_family);
88 rp->answer = BADADDR;
89 return;
90 }
91 if (mp->ctl_addr.sa_family != AF_INET) {
92 syslog(LOG_WARNING, "Bad control address, family %d",
93 mp->ctl_addr.sa_family);
94 rp->answer = BADCTLADDR;
95 return;
96 }
97 if (debug || logging)
98 print_request("request", mp);
99 switch (mp->type) {
100
101 case ANNOUNCE:
102 do_announce(mp, rp);
103 break;
104
105 case LEAVE_INVITE:
106 ptr = find_request(mp);
107 if (ptr != (CTL_MSG *)0) {
108 rp->id_num = htonl(ptr->id_num);
109 rp->answer = SUCCESS;
110 } else
111 insert_table(mp, rp);
112 break;
113
114 case LOOK_UP:
115 ptr = find_match(mp);
116 if (ptr != (CTL_MSG *)0) {
117 rp->id_num = htonl(ptr->id_num);
118 rp->addr = ptr->addr;
119 rp->addr.sa_family = htons(ptr->addr.sa_family);
120 rp->answer = SUCCESS;
121 } else
122 rp->answer = NOT_HERE;
123 break;
124
125 case DELETE:
126 rp->answer = delete_invite(mp->id_num);
127 break;
128
129 default:
130 rp->answer = UNKNOWN_REQUEST;
131 break;
132 }
133 if (debug)
134 print_response("process_request done", rp);
135 }
136
137 void
do_announce(CTL_MSG * mp,CTL_RESPONSE * rp)138 do_announce(CTL_MSG *mp, CTL_RESPONSE *rp)
139 {
140 CTL_MSG *ptr;
141 int result;
142 char hostname[NI_MAXHOST];
143 struct sockaddr sa;
144
145 tsa2sa(&sa, &mp->ctl_addr);
146
147 /* see if the user is logged */
148 result = find_user(mp->r_name, mp->r_tty, sizeof(mp->r_tty));
149 if (result != SUCCESS) {
150 rp->answer = result;
151 return;
152 }
153 if (getnameinfo(&sa, sa.sa_len, hostname, sizeof(hostname), NULL,
154 0, 0)) {
155 rp->answer = MACHINE_UNKNOWN;
156 return;
157 }
158 ptr = find_request(mp);
159 if (ptr == (CTL_MSG *) 0) {
160 insert_table(mp, rp);
161 rp->answer = announce(mp, hostname);
162 return;
163 }
164 if (mp->id_num > ptr->id_num) {
165 /*
166 * This is an explicit re-announce, so update the id_num
167 * field to avoid duplicates and re-announce the talk.
168 */
169 ptr->id_num = new_id();
170 rp->id_num = htonl(ptr->id_num);
171 rp->answer = announce(mp, hostname);
172 } else {
173 /* a duplicated request, so ignore it */
174 rp->id_num = htonl(ptr->id_num);
175 rp->answer = SUCCESS;
176 }
177 }
178
179 /*
180 * Search utmp for the local user
181 */
182 int
find_user(const char * name,char * tty,size_t ttysize)183 find_user(const char *name, char *tty, size_t ttysize)
184 {
185 int status;
186 struct stat statb;
187 struct utmpentry *ep;
188 char ftty[sizeof(_PATH_DEV) + sizeof(ep->line)];
189 time_t atime = 0;
190 int anytty = 0;
191
192 (void)getutentries(NULL, &ep);
193
194 status = NOT_HERE;
195 (void) strlcpy(ftty, _PATH_DEV, sizeof(ftty));
196
197 if (*tty == '\0')
198 anytty = 1;
199
200 for (; ep; ep = ep->next) {
201 if (strcmp(ep->name, name) != 0)
202 continue;
203 if (anytty) {
204 /* no particular tty was requested */
205 (void)strlcpy(ftty + sizeof(_PATH_DEV) - 1, ep->line,
206 sizeof(ftty) - sizeof(_PATH_DEV) + 1);
207 if (stat(ftty, &statb) != 0)
208 continue;
209
210 if (!(statb.st_mode & S_IWGRP)) {
211 if (status != SUCCESS)
212 status = PERMISSION_DENIED;
213 continue;
214 }
215 if (statb.st_atime > atime &&
216 strlcpy(tty, ep->line, ttysize) < ttysize) {
217 atime = statb.st_atime;
218 status = SUCCESS;
219 }
220 } else if (strcmp(ep->line, tty) == 0) {
221 status = SUCCESS;
222 break;
223 }
224 }
225 return (status);
226 }
227