/* * 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 1.1.1.1 1994/08/28 14:58:36 csgr Exp $"; #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include #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 */ salen = sizeof(sa); 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); }