1/* $NetBSD: rwalld.c,v 1.22 2011/08/30 17:06:20 plunky 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. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *          This product includes software developed for the
18 *          NetBSD Project.  See http://www.NetBSD.org/ for
19 *          information about NetBSD.
20 * 4. The name of the author may not be used to endorse or promote products
21 *    derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
35 */
36
37#include <sys/cdefs.h>
38#ifndef lint
39__RCSID("$NetBSD: rwalld.c,v 1.22 2011/08/30 17:06:20 plunky Exp $");
40#endif /* not lint */
41
42#include <unistd.h>
43#include <stdlib.h>
44#include <sys/types.h>
45#include <pwd.h>
46#include <stdio.h>
47#include <string.h>
48#include <syslog.h>
49#include <errno.h>
50#include <sys/socket.h>
51#include <signal.h>
52#include <sys/wait.h>
53#include <rpc/rpc.h>
54#include <rpcsvc/rwall.h>
55
56#ifdef OSF
57#define WALL_CMD "/usr/sbin/wall"
58#else
59#define WALL_CMD "/usr/bin/wall -n"
60#endif
61
62static int from_inetd = 1;
63
64static void cleanup(int);
65static void wallprog_1(struct svc_req *, SVCXPRT *);
66
67__dead static void
68cleanup(int n)
69{
70
71	(void)rpcb_unset(WALLPROG, WALLVERS, NULL);
72	exit(0);
73}
74
75int
76main(int argc, char *argv[])
77{
78	SVCXPRT *transp;
79	struct sockaddr_storage from;
80	socklen_t fromlen;
81
82	if (geteuid() == 0) {
83		struct passwd *pep = getpwnam("nobody");
84		if (pep)
85			setuid(pep->pw_uid);
86		else
87			setuid(getuid());
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
97	if (!from_inetd) {
98		daemon(0, 0);
99
100		(void) rpcb_unset(WALLPROG, WALLVERS, NULL);
101
102		(void) signal(SIGINT, cleanup);
103		(void) signal(SIGTERM, cleanup);
104		(void) signal(SIGHUP, cleanup);
105	}
106
107	openlog("rpc.rwalld", LOG_PID, LOG_DAEMON);
108
109	if (from_inetd) {
110		transp = svc_dg_create(0, 0, 0);
111		if (transp == NULL) {
112			syslog(LOG_ERR, "cannot create udp service.");
113			exit(1);
114		}
115		if (!svc_reg(transp, WALLPROG, WALLVERS, wallprog_1, NULL)) {
116			syslog(LOG_ERR, "unable to register "
117			    "(WALLPROG, WALLVERS).");
118			exit(1);
119		}
120	} else {
121		if (!svc_create(wallprog_1, WALLPROG, WALLVERS, "udp")) {
122			syslog(LOG_ERR, "unable to create "
123			    "(WALLPROG, WALLVERS.)");
124			exit(1);
125		}
126	}
127
128	svc_run();
129	syslog(LOG_ERR, "svc_run returned");
130	exit(1);
131
132}
133
134void *
135wallproc_wall_1_svc(char **s, struct svc_req *rqstp)
136{
137	FILE *pfp;
138
139	pfp = popen(WALL_CMD, "w");
140	if (pfp != NULL) {
141		fprintf(pfp, "\007\007%s", *s);
142		pclose(pfp);
143	}
144
145	return (*s);
146}
147
148static void
149wallprog_1(struct svc_req *rqstp, SVCXPRT *transp)
150{
151	union {
152		char *wallproc_wall_1_arg;
153	} argument;
154	char *result;
155	xdrproc_t xdr_argument, xdr_result;
156	char *(*local) __P((char **, struct svc_req *));
157
158	switch (rqstp->rq_proc) {
159	case NULLPROC:
160		(void)svc_sendreply(transp, (xdrproc_t)xdr_void, NULL);
161		goto leave;
162
163	case WALLPROC_WALL:
164		xdr_argument = (xdrproc_t)xdr_wrapstring;
165		xdr_result = (xdrproc_t)xdr_void;
166		local = (char *(*) __P((char **, struct svc_req *)))
167			wallproc_wall_1_svc;
168		break;
169
170	default:
171		svcerr_noproc(transp);
172		goto leave;
173	}
174	memset((char *)&argument, 0, sizeof(argument));
175	if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
176		svcerr_decode(transp);
177		goto leave;
178	}
179	result = (*local)((char **)&argument, rqstp);
180	if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
181		svcerr_systemerr(transp);
182	}
183	if (!svc_freeargs(transp, xdr_argument, (caddr_t)&argument)) {
184		syslog(LOG_ERR, "unable to free arguments");
185		exit(1);
186	}
187leave:
188	if (from_inetd)
189		exit(0);
190}
191