1 /* $OpenBSD: rusersd.c,v 1.24 2023/03/08 04:43:06 guenther Exp $ */
2
3 /*-
4 * Copyright (c) 1993 John Brezak
5 * 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. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
27 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <sys/types.h>
32 #include <sys/socket.h>
33
34 #include <fcntl.h>
35 #include <stdio.h>
36 #include <signal.h>
37 #include <unistd.h>
38 #include <stdlib.h>
39 #include <pwd.h>
40 #include <syslog.h>
41 #include <rpc/rpc.h>
42 #include <rpcsvc/rusers.h> /* New version */
43 #include <rpcsvc/rnusers.h> /* Old version */
44 #include <rpc/pmap_clnt.h>
45 #include <utmp.h>
46
47 extern void rusers_service(struct svc_req *, SVCXPRT *);
48
49 int from_inetd = 1;
50 int utmp_fd;
51
52 static void
cleanup(int signo)53 cleanup(int signo)
54 {
55 (void) pmap_unset(RUSERSPROG, RUSERSVERS_3); /* XXX signal races */
56 (void) pmap_unset(RUSERSPROG, RUSERSVERS_IDLE);
57 (void) pmap_unset(RUSERSPROG, RUSERSVERS_ORIG);
58 _exit(0);
59 }
60
61 int
main(int argc,char * argv[])62 main(int argc, char *argv[])
63 {
64 int sock = 0, proto = 0;
65 socklen_t fromlen;
66 struct sockaddr_storage from;
67 struct passwd *pw;
68 SVCXPRT *transp;
69
70 if ((utmp_fd = open(_PATH_UTMP, O_RDONLY)) == -1) {
71 syslog(LOG_ERR, "cannot open %s", _PATH_UTMP);
72 exit(1);
73 }
74
75 openlog("rpc.rusersd", LOG_NDELAY|LOG_CONS|LOG_PID, LOG_DAEMON);
76
77 pw = getpwnam("_rusersd");
78 if (!pw) {
79 syslog(LOG_ERR, "no such user _rusersd");
80 exit(1);
81 }
82
83 if (unveil("/dev", "r") == -1) {
84 syslog(LOG_ERR, "unveil /dev");
85 exit(1);
86 }
87 if (unveil(NULL, NULL) == -1) {
88 syslog(LOG_ERR, "unveil");
89 exit(1);
90 }
91
92 setgroups(1, &pw->pw_gid);
93 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid);
94 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid);
95
96 /*
97 * See if inetd started us
98 */
99 fromlen = sizeof(from);
100 if (getsockname(0, (struct sockaddr *)&from, &fromlen) == -1) {
101 from_inetd = 0;
102 sock = RPC_ANYSOCK;
103 proto = IPPROTO_UDP;
104 }
105
106 if (!from_inetd) {
107 daemon(0, 0);
108
109 (void) pmap_unset(RUSERSPROG, RUSERSVERS_3);
110 (void) pmap_unset(RUSERSPROG, RUSERSVERS_IDLE);
111 (void) pmap_unset(RUSERSPROG, RUSERSVERS_ORIG);
112
113 (void) signal(SIGINT, cleanup);
114 (void) signal(SIGTERM, cleanup);
115 (void) signal(SIGHUP, cleanup);
116 }
117
118 transp = svcudp_create(sock);
119 if (transp == NULL) {
120 syslog(LOG_ERR, "cannot create udp service.");
121 exit(1);
122 }
123 if (!svc_register(transp, RUSERSPROG, RUSERSVERS_3, rusers_service, proto)) {
124 syslog(LOG_ERR,
125 "unable to register (RUSERSPROG, RUSERSVERS_3, %s).",
126 proto ? "udp" : "(inetd)");
127 exit(1);
128 }
129 if (!svc_register(transp, RUSERSPROG, RUSERSVERS_IDLE, rusers_service, proto)) {
130 syslog(LOG_ERR,
131 "unable to register (RUSERSPROG, RUSERSVERS_IDLE, %s).",
132 proto ? "udp" : "(inetd)");
133 exit(1);
134 }
135 if (!svc_register(transp, RUSERSPROG, RUSERSVERS_ORIG, rusers_service, proto)) {
136 syslog(LOG_ERR,
137 "unable to register (RUSERSPROG, RUSERSVERS_ORIG, %s).",
138 proto ? "udp" : "(inetd)");
139 exit(1);
140 }
141
142 svc_run();
143 syslog(LOG_ERR, "svc_run returned");
144 exit(1);
145 }
146