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      1 /* $NetBSD: rwalld.c,v 1.23 2011/09/16 16:13:17 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 1.23 2011/09/16 16:13:17 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 
     62 static int from_inetd = 1;
     63 
     64 static void cleanup(int);
     65 static void wallprog_1(struct svc_req *, SVCXPRT *);
     66 
     67 __dead static void
     68 cleanup(int n)
     69 {
     70 
     71 	(void)rpcb_unset(WALLPROG, WALLVERS, NULL);
     72 	exit(0);
     73 }
     74 
     75 int
     76 main(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 
    134 void *
    135 wallproc_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 
    148 static void
    149 wallprog_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 	}
    187 leave:
    188 	if (from_inetd)
    189 		exit(0);
    190 }
    191