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/*
* Copyright (c) 1993 Christopher G. Demetriou
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <err.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <arpa/inet.h>
#include <rpc/rpc.h>
#include <rpcsvc/rwall.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#ifdef OSF
#define WALL_CMD "/usr/sbin/wall"
#else
#define WALL_CMD "/usr/bin/wall -n"
#endif
void wallprog_1(struct svc_req *rqstp, SVCXPRT *transp);
void possess(void);
void killkids(int sig);
static void usage(void);
int nodaemon = 0;
int from_inetd = 1;
int
main(int argc, char *argv[])
{
SVCXPRT *transp;
socklen_t salen;
int ok;
struct sockaddr_storage sa;
if (argc == 2 && !strcmp(argv[1], "-n"))
nodaemon = 1;
if (argc != 1 && !nodaemon)
usage();
if (geteuid() == 0) {
struct passwd *pep = getpwnam("nobody");
if (pep)
setuid(pep->pw_uid);
else
setuid(getuid());
}
/*
* See if inetd started us
*/
salen = sizeof(sa);
if (getsockname(0, (struct sockaddr *)&sa, &salen) < 0) {
from_inetd = 0;
}
if (!from_inetd) {
if (!nodaemon)
possess();
(void)rpcb_unset(WALLPROG, WALLVERS, NULL);
}
(void)signal(SIGCHLD, killkids);
openlog("rpc.rwalld", LOG_CONS|LOG_PID, LOG_DAEMON);
/* create and register the service */
if (from_inetd) {
transp = svc_tli_create(0, NULL, NULL, 0, 0);
if (transp == NULL) {
syslog(LOG_ERR, "couldn't create udp service.");
exit(1);
}
ok = svc_reg(transp, WALLPROG, WALLVERS,
wallprog_1, NULL);
} else
ok = svc_create(wallprog_1,
WALLPROG, WALLVERS, "udp");
if (!ok) {
syslog(LOG_ERR, "unable to register (WALLPROG, WALLVERS, %s)", (!from_inetd)?"udp":"(inetd)");
exit(1);
}
svc_run();
syslog(LOG_ERR, "svc_run returned");
exit(1);
}
static void
usage(void)
{
fprintf(stderr, "usage: rpc.rwalld [-n]\n");
exit(1);
}
void
possess(void)
{
daemon(0, 0);
}
void
killkids(int sig __unused)
{
while(wait4(-1, NULL, WNOHANG, NULL) > 0)
;
}
void *
wallproc_wall_1_svc(wrapstring *s, struct svc_req *rqstp __unused)
{
static void *dummy = NULL;
/* fork, popen wall with special option, and send the message */
if (fork() == 0) {
FILE *pfp;
pfp = popen(WALL_CMD, "w");
if (pfp != NULL) {
fprintf(pfp, "\007\007%s", *s);
pclose(pfp);
exit(0);
}
}
return(&dummy);
}
void
wallprog_1(struct svc_req *rqstp, SVCXPRT *transp)
{
union {
char *wallproc_wall_1_arg;
} argument;
char *result;
bool_t (*xdr_argument)(), (*xdr_result)();
char *(*local)();
switch (rqstp->rq_proc) {
case NULLPROC:
(void)svc_sendreply(transp, (xdrproc_t)xdr_void, NULL);
goto leave;
case WALLPROC_WALL:
xdr_argument = xdr_wrapstring;
xdr_result = xdr_void;
local = (char *(*)()) wallproc_wall_1_svc;
break;
default:
svcerr_noproc(transp);
goto leave;
}
bzero(&argument, sizeof(argument));
if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
svcerr_decode(transp);
goto leave;
}
result = (*local)(&argument, rqstp);
if (result != NULL &&
!svc_sendreply(transp, (xdrproc_t)xdr_result, result)) {
svcerr_systemerr(transp);
}
if (!svc_freeargs(transp, (xdrproc_t)xdr_argument, &argument)) {
syslog(LOG_ERR, "unable to free arguments");
exit(1);
}
leave:
if (from_inetd)
exit(0);
}
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