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rwalld.c revision 1.15 
      1 /*	$NetBSD: rwalld.c,v 1.15 2000/06/03 20:31:25 fvdl 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 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __RCSID("$NetBSD: rwalld.c,v 1.15 2000/06/03 20:31:25 fvdl Exp $");
     35 #endif /* not lint */
     36 
     37 #include <unistd.h>
     38 #include <stdlib.h>
     39 #include <sys/types.h>
     40 #include <pwd.h>
     41 #include <stdio.h>
     42 #include <string.h>
     43 #include <syslog.h>
     44 #include <errno.h>
     45 #include <sys/socket.h>
     46 #include <signal.h>
     47 #include <sys/wait.h>
     48 #include <rpc/rpc.h>
     49 #include <rpcsvc/rwall.h>
     50 
     51 #ifdef OSF
     52 #define WALL_CMD "/usr/sbin/wall"
     53 #else
     54 #define WALL_CMD "/usr/bin/wall -n"
     55 #endif
     56 
     57 static int from_inetd = 1;
     58 
     59 static void cleanup(int);
     60 static void wallprog_1(struct svc_req *, SVCXPRT *);
     61 
     62 int main(int, char *[]);
     63 
     64 static void
     65 cleanup(int n)
     66 {
     67 
     68 	(void)rpcb_unset(WALLPROG, WALLVERS, NULL);
     69 	exit(0);
     70 }
     71 
     72 int
     73 main(int argc, char *argv[])
     74 {
     75 	SVCXPRT *transp;
     76 	struct sockaddr_in from;
     77 	int fromlen;
     78 
     79 	if (geteuid() == 0) {
     80 		struct passwd *pep = getpwnam("nobody");
     81 		if (pep)
     82 			setuid(pep->pw_uid);
     83 		else
     84 			setuid(getuid());
     85 	}
     86 
     87 	/*
     88 	 * See if inetd started us
     89 	 */
     90 	fromlen = sizeof(from);
     91 	if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0)
     92 		from_inetd = 0;
     93 
     94 	if (!from_inetd) {
     95 		daemon(0, 0);
     96 
     97 		(void) rpcb_unset(WALLPROG, WALLVERS, NULL);
     98 
     99 		(void) signal(SIGINT, cleanup);
    100 		(void) signal(SIGTERM, cleanup);
    101 		(void) signal(SIGHUP, cleanup);
    102 	}
    103 
    104 	openlog("rpc.rwalld", LOG_PID, LOG_DAEMON);
    105 
    106 	if (from_inetd) {
    107 		transp = svc_dg_create(0, 0, 0);
    108 		if (transp == NULL) {
    109 			syslog(LOG_ERR, "cannot create udp service.");
    110 			exit(1);
    111 		}
    112 		if (!svc_reg(transp, WALLPROG, WALLVERS, wallprog_1, NULL)) {
    113 			syslog(LOG_ERR, "unable to register "
    114 			    "(WALLPROG, WALLVERS).");
    115 			exit(1);
    116 		}
    117 	} else {
    118 		if (!svc_create(wallprog_1, WALLPROG, WALLVERS, "udp")) {
    119 			syslog(LOG_ERR, "unable to create "
    120 			    "(WALLPROG, WALLVERS.)");
    121 			exit(1);
    122 		}
    123 	}
    124 
    125 	svc_run();
    126 	syslog(LOG_ERR, "svc_run returned");
    127 	exit(1);
    128 
    129 }
    130 
    131 void *
    132 wallproc_wall_1_svc(char **s, struct svc_req *rqstp)
    133 {
    134 	FILE *pfp;
    135 
    136 	pfp = popen(WALL_CMD, "w");
    137 	if (pfp != NULL) {
    138 		fprintf(pfp, "\007\007%s", *s);
    139 		pclose(pfp);
    140 	}
    141 
    142 	return (*s);
    143 }
    144 
    145 static void
    146 wallprog_1(struct svc_req *rqstp, SVCXPRT *transp)
    147 {
    148 	union {
    149 		char *wallproc_wall_1_arg;
    150 	} argument;
    151 	char *result;
    152 	xdrproc_t xdr_argument, xdr_result;
    153 	char *(*local) __P((char **, struct svc_req *));
    154 
    155 	switch (rqstp->rq_proc) {
    156 	case NULLPROC:
    157 		(void)svc_sendreply(transp, xdr_void, (char *)NULL);
    158 		goto leave;
    159 
    160 	case WALLPROC_WALL:
    161 		xdr_argument = (xdrproc_t)xdr_wrapstring;
    162 		xdr_result = (xdrproc_t)xdr_void;
    163 		local = (char *(*) __P((char **, struct svc_req *)))
    164 			wallproc_wall_1_svc;
    165 		break;
    166 
    167 	default:
    168 		svcerr_noproc(transp);
    169 		goto leave;
    170 	}
    171 	memset((char *)&argument, 0, sizeof(argument));
    172 	if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
    173 		svcerr_decode(transp);
    174 		goto leave;
    175 	}
    176 	result = (*local)((char **)&argument, rqstp);
    177 	if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
    178 		svcerr_systemerr(transp);
    179 	}
    180 	if (!svc_freeargs(transp, xdr_argument, (caddr_t)&argument)) {
    181 		syslog(LOG_ERR, "unable to free arguments");
    182 		exit(1);
    183 	}
    184 leave:
    185 	if (from_inetd)
    186 		exit(0);
    187 }
    188