1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93";
35 #endif
36 static const char rcsid[] =
37 "$FreeBSD$";
38 #endif /* not lint */
39
40 /*
41 * process.c handles the requests, which can be of three types:
42 * ANNOUNCE - announce to a user that a talk is wanted
43 * LEAVE_INVITE - insert the request into the table
44 * LOOK_UP - look up to see if a request is waiting in
45 * in the table for the local user
46 * DELETE - delete invitation
47 */
48 #include <sys/param.h>
49 #include <sys/stat.h>
50 #include <sys/socket.h>
51 #include <netinet/in.h>
52 #include <protocols/talkd.h>
53 #include <ctype.h>
54 #include <err.h>
55 #include <netdb.h>
56 #include <paths.h>
57 #include <stdio.h>
58 #include <string.h>
59 #include <syslog.h>
60 #include <utmpx.h>
61
62 #include "extern.h"
63
64 void
process_request(CTL_MSG * mp,CTL_RESPONSE * rp)65 process_request(CTL_MSG *mp, CTL_RESPONSE *rp)
66 {
67 CTL_MSG *ptr;
68 char *s;
69
70 rp->vers = TALK_VERSION;
71 rp->type = mp->type;
72 rp->id_num = htonl(0);
73 if (mp->vers != TALK_VERSION) {
74 syslog(LOG_WARNING, "bad protocol version %d", mp->vers);
75 rp->answer = BADVERSION;
76 return;
77 }
78 mp->id_num = ntohl(mp->id_num);
79 mp->addr.sa_family = ntohs(mp->addr.sa_family);
80 if (mp->addr.sa_family != AF_INET) {
81 syslog(LOG_WARNING, "bad address, family %d",
82 mp->addr.sa_family);
83 rp->answer = BADADDR;
84 return;
85 }
86 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
87 if (mp->ctl_addr.sa_family != AF_INET) {
88 syslog(LOG_WARNING, "bad control address, family %d",
89 mp->ctl_addr.sa_family);
90 rp->answer = BADCTLADDR;
91 return;
92 }
93 for (s = mp->l_name; *s; s++)
94 if (!isprint(*s)) {
95 syslog(LOG_NOTICE, "illegal user name. Aborting");
96 rp->answer = FAILED;
97 return;
98 }
99 mp->pid = ntohl(mp->pid);
100 if (debug)
101 print_request("process_request", mp);
102 switch (mp->type) {
103
104 case ANNOUNCE:
105 do_announce(mp, rp);
106 break;
107
108 case LEAVE_INVITE:
109 ptr = find_request(mp);
110 if (ptr != (CTL_MSG *)0) {
111 rp->id_num = htonl(ptr->id_num);
112 rp->answer = SUCCESS;
113 } else
114 insert_table(mp, rp);
115 break;
116
117 case LOOK_UP:
118 ptr = find_match(mp);
119 if (ptr != (CTL_MSG *)0) {
120 rp->id_num = htonl(ptr->id_num);
121 rp->addr = ptr->addr;
122 rp->addr.sa_family = htons(ptr->addr.sa_family);
123 rp->answer = SUCCESS;
124 } else
125 rp->answer = NOT_HERE;
126 break;
127
128 case DELETE:
129 rp->answer = delete_invite(mp->id_num);
130 break;
131
132 default:
133 rp->answer = UNKNOWN_REQUEST;
134 break;
135 }
136 if (debug)
137 print_response("process_request", rp);
138 }
139
140 void
do_announce(CTL_MSG * mp,CTL_RESPONSE * rp)141 do_announce(CTL_MSG *mp, CTL_RESPONSE *rp)
142 {
143 struct hostent *hp;
144 CTL_MSG *ptr;
145 int result;
146
147 /* see if the user is logged */
148 result = find_user(mp->r_name, mp->r_tty);
149 if (result != SUCCESS) {
150 rp->answer = result;
151 return;
152 }
153 #define satosin(sa) ((struct sockaddr_in *)(void *)(sa))
154 hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr,
155 sizeof (struct in_addr), AF_INET);
156 if (hp == (struct hostent *)0) {
157 rp->answer = MACHINE_UNKNOWN;
158 return;
159 }
160 ptr = find_request(mp);
161 if (ptr == (CTL_MSG *) 0) {
162 insert_table(mp, rp);
163 rp->answer = announce(mp, hp->h_name);
164 return;
165 }
166 if (mp->id_num > ptr->id_num) {
167 /*
168 * This is an explicit re-announce, so update the id_num
169 * field to avoid duplicates and re-announce the talk.
170 */
171 ptr->id_num = new_id();
172 rp->id_num = htonl(ptr->id_num);
173 rp->answer = announce(mp, hp->h_name);
174 } else {
175 /* a duplicated request, so ignore it */
176 rp->id_num = htonl(ptr->id_num);
177 rp->answer = SUCCESS;
178 }
179 }
180
181 /*
182 * Search utmp for the local user
183 */
184 int
find_user(const char * name,char * tty)185 find_user(const char *name, char *tty)
186 {
187 struct utmpx *ut;
188 int status;
189 struct stat statb;
190 time_t best = 0;
191 char ftty[sizeof(_PATH_DEV) - 1 + sizeof(ut->ut_line)];
192
193 setutxent();
194 status = NOT_HERE;
195 (void) strcpy(ftty, _PATH_DEV);
196 while ((ut = getutxent()) != NULL)
197 if (ut->ut_type == USER_PROCESS &&
198 strcmp(ut->ut_user, name) == 0) {
199 if (*tty == '\0' || best != 0) {
200 if (best == 0)
201 status = PERMISSION_DENIED;
202 /* no particular tty was requested */
203 (void) strcpy(ftty + sizeof(_PATH_DEV) - 1,
204 ut->ut_line);
205 if (stat(ftty, &statb) == 0) {
206 if (!(statb.st_mode & 020))
207 continue;
208 if (statb.st_atime > best) {
209 best = statb.st_atime;
210 (void) strcpy(tty, ut->ut_line);
211 status = SUCCESS;
212 continue;
213 }
214 }
215 }
216 if (strcmp(ut->ut_line, tty) == 0) {
217 status = SUCCESS;
218 break;
219 }
220 }
221 endutxent();
222 return (status);
223 }
224