+/*
+ * 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.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: rwalld.c,v 1.2 1993/08/02 17:50:55 mycroft Exp $";
+#endif /* not lint */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <rpc/rpc.h>
+#include <rpcsvc/rwall.h>
+
+#ifdef OSF
+#define WALL_CMD "/usr/sbin/wall"
+#else
+#define WALL_CMD "/usr/bin/wall -n"
+#endif
+
+void wallprog_1();
+void possess();
+void killkids();
+
+int nodaemon = 0;
+int from_inetd = 1;
+
+main(argc, argv)
+ int argc;
+ char *argv[];
+{
+ SVCXPRT *transp;
+ int s, salen;
+ struct sockaddr_in sa;
+ int sock = 0;
+ int proto = 0;
+
+ if (argc == 2 && !strcmp(argv[1], "-n"))
+ nodaemon = 1;
+ if (argc != 1 && !nodaemon) {
+ printf("usage: %s [-n]\n", argv[0]);
+ exit(1);
+ }
+
+ if (geteuid() == 0) {
+ struct passwd *pep = getpwnam("nobody");
+ if (pep)
+ setuid(pep->pw_uid);
+ else
+ setuid(getuid());
+ }
+
+ /*
+ * See if inetd started us
+ */
+ if (getsockname(0, (struct sockaddr *)&sa, &salen) < 0) {
+ from_inetd = 0;
+ sock = RPC_ANYSOCK;
+ proto = IPPROTO_UDP;
+ }
+
+ if (!from_inetd) {
+ if (!nodaemon)
+ possess();
+
+ (void)pmap_unset(WALLPROG, WALLVERS);
+ if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
+ perror("socket");
+ exit(1);
+ }
+ bzero((char *)&sa, sizeof sa);
+ if (bind(s, (struct sockaddr *)&sa, sizeof sa) < 0) {
+ perror("bind");
+ exit(1);
+ }
+
+ salen = sizeof sa;
+ if (getsockname(s, (struct sockaddr *)&sa, &salen)) {
+ perror("getsockname");
+ exit(1);
+ }
+
+ pmap_set(WALLPROG, WALLVERS, IPPROTO_UDP, ntohs(sa.sin_port));
+ if (dup2(s, 0) < 0) {
+ perror("dup2");
+ exit(1);
+ }
+ (void)pmap_unset(WALLPROG, WALLVERS);
+ }
+
+ (void)signal(SIGCHLD, killkids);
+
+ transp = svcudp_create(sock);
+ if (transp == NULL) {
+ (void)fprintf(stderr, "cannot create udp service.\n");
+ exit(1);
+ }
+ if (!svc_register(transp, WALLPROG, WALLVERS, wallprog_1, proto)) {
+ (void)fprintf(stderr, "unable to register (WALLPROG, WALLVERS, udp).\n");
+ exit(1);
+ }
+ svc_run();
+ (void)fprintf(stderr, "svc_run returned\n");
+ exit(1);
+
+}
+
+void possess()
+{
+ daemon(0, 0);
+}
+
+void killkids()
+{
+ while(wait4(-1, NULL, WNOHANG, NULL) > 0)
+ ;
+}
+
+void *wallproc_wall_1(s)
+ char **s;
+{
+ /* 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);
+ }
+ }
+}
+
+void
+wallprog_1(rqstp, transp)
+ 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, xdr_void, (char *)NULL);
+ goto leave;
+
+ case WALLPROC_WALL:
+ xdr_argument = xdr_wrapstring;
+ xdr_result = xdr_void;
+ local = (char *(*)()) wallproc_wall_1;
+ break;
+
+ default:
+ svcerr_noproc(transp);
+ goto leave;
+ }
+ bzero((char *)&argument, sizeof(argument));
+ if (!svc_getargs(transp, xdr_argument, &argument)) {
+ svcerr_decode(transp);
+ goto leave;
+ }
+ result = (*local)(&argument, rqstp);
+ if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
+ svcerr_systemerr(transp);
+ }
+ if (!svc_freeargs(transp, xdr_argument, &argument)) {
+ (void)fprintf(stderr, "unable to free arguments\n");
+ exit(1);
+ }
+leave:
+ if (from_inetd)
+ exit(0);
+}
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