1 /* $OpenBSD: rwalld.c,v 1.12 2004/06/02 02:21:15 brad Exp $ */
2
3 /*
4 * Copyright (c) 1993 Christopher G. Demetriou
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
16 * products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
20 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
23 * 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 static char rcsid[] = "$OpenBSD: rwalld.c,v 1.12 2004/06/02 02:21:15 brad Exp $";
34 #endif /* not lint */
35
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <sys/wait.h>
39 #include <pwd.h>
40 #include <stdlib.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <syslog.h>
44 #include <errno.h>
45 #include <unistd.h>
46 #include <signal.h>
47 #include <rpc/rpc.h>
48 #include <rpcsvc/rwall.h>
49
50 #ifdef OSF
51 #define WALL_CMD "/usr/sbin/wall"
52 #else
53 #define WALL_CMD "/usr/bin/wall -n"
54 #endif
55
56 void wallprog_1(struct svc_req *, SVCXPRT *);
57
58 int from_inetd = 1;
59
60 static void
cleanup(int signo)61 cleanup(int signo)
62 {
63 (void) pmap_unset(WALLPROG, WALLVERS); /* XXX signal race */
64 _exit(0);
65 }
66
67 int
main(int argc,char * argv[])68 main(int argc, char *argv[])
69 {
70 int sock = 0, proto = 0;
71 socklen_t fromlen;
72 struct sockaddr_storage from;
73 SVCXPRT *transp;
74
75 if (geteuid() == 0) {
76 struct passwd *pw = getpwnam("nobody");
77
78 if (pw) {
79 setgroups(1, &pw->pw_gid);
80 setegid(pw->pw_gid);
81 setgid(pw->pw_gid);
82 seteuid(pw->pw_uid);
83 setuid(pw->pw_uid);
84 } else {
85 seteuid(getuid());
86 setuid(getuid());
87 }
88 }
89
90 /*
91 * See if inetd started us
92 */
93 fromlen = sizeof(from);
94 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) {
95 from_inetd = 0;
96 sock = RPC_ANYSOCK;
97 proto = IPPROTO_UDP;
98 }
99
100 if (!from_inetd) {
101 daemon(0, 0);
102
103 (void) pmap_unset(WALLPROG, WALLVERS);
104
105 (void) signal(SIGINT, cleanup);
106 (void) signal(SIGTERM, cleanup);
107 (void) signal(SIGHUP, cleanup);
108 }
109
110 openlog("rpc.rwalld", LOG_CONS|LOG_PID, LOG_DAEMON);
111
112 transp = svcudp_create(sock);
113 if (transp == NULL) {
114 syslog(LOG_ERR, "cannot create udp service.");
115 exit(1);
116 }
117 if (!svc_register(transp, WALLPROG, WALLVERS, wallprog_1, proto)) {
118 syslog(LOG_ERR, "unable to register (WALLPROG, WALLVERS, %s).",
119 proto ? "udp" : "(inetd)");
120 exit(1);
121 }
122
123 svc_run();
124 syslog(LOG_ERR, "svc_run returned");
125 exit(1);
126
127 }
128
129 void *
wallproc_wall_1_svc(char ** s,struct svc_req * rqstp)130 wallproc_wall_1_svc(char **s, struct svc_req *rqstp)
131 {
132 FILE *pfp;
133
134 pfp = popen(WALL_CMD, "w");
135 if (pfp != NULL) {
136 fprintf(pfp, "\007\007%s", *s);
137 pclose(pfp);
138 }
139
140 return (*s);
141 }
142
143 void
wallprog_1(struct svc_req * rqstp,SVCXPRT * transp)144 wallprog_1(struct svc_req *rqstp, SVCXPRT *transp)
145 {
146 char *(*local)(char **, struct svc_req *);
147 xdrproc_t xdr_argument, xdr_result;
148 union {
149 char *wallproc_wall_1_arg;
150 } argument;
151 char *result;
152
153 switch (rqstp->rq_proc) {
154 case NULLPROC:
155 (void)svc_sendreply(transp, xdr_void, (char *)NULL);
156 goto leave;
157
158 case WALLPROC_WALL:
159 xdr_argument = (xdrproc_t)xdr_wrapstring;
160 xdr_result = (xdrproc_t)xdr_void;
161 local = (char *(*)(char **, struct svc_req *))
162 wallproc_wall_1_svc;
163 break;
164
165 default:
166 svcerr_noproc(transp);
167 goto leave;
168 }
169 bzero((char *)&argument, sizeof(argument));
170 if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
171 svcerr_decode(transp);
172 goto leave;
173 }
174 result = (*local)((char **)&argument, rqstp);
175 if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
176 svcerr_systemerr(transp);
177 }
178 if (!svc_freeargs(transp, xdr_argument, (caddr_t)&argument)) {
179 syslog(LOG_ERR, "unable to free arguments");
180 exit(1);
181 }
182 leave:
183 if (from_inetd)
184 exit(0);
185 }
186