1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 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__FBSDID("$FreeBSD$"); 34 35#include <err.h> 36#include <pwd.h> 37#include <signal.h> 38#include <stdio.h> 39#include <stdlib.h> 40#include <string.h> 41#include <syslog.h> 42#include <arpa/inet.h> 43#include <rpc/rpc.h> 44#include <rpcsvc/rwall.h> 45#include <sys/socket.h> 46#include <sys/types.h> 47#include <sys/wait.h> 48#include <unistd.h> 49 50#ifdef OSF 51#define WALL_CMD "/usr/sbin/wall" 52#else 53#define WALL_CMD "/usr/bin/wall -n" 54#endif 55 56void wallprog_1(struct svc_req *rqstp, SVCXPRT *transp); 57void possess(void); 58void killkids(int sig); 59static void usage(void); 60 61int nodaemon = 0; 62int from_inetd = 1; 63 64int 65main(int argc, char *argv[]) 66{ 67 SVCXPRT *transp; 68 socklen_t salen; 69 int ok; 70 struct sockaddr_storage sa; 71 72 if (argc == 2 && !strcmp(argv[1], "-n")) 73 nodaemon = 1; 74 if (argc != 1 && !nodaemon) 75 usage(); 76 77 if (geteuid() == 0) { 78 struct passwd *pep = getpwnam("nobody"); 79 if (pep) 80 setuid(pep->pw_uid); 81 else 82 setuid(getuid()); 83 } 84 85 /* 86 * See if inetd started us 87 */ 88 salen = sizeof(sa); 89 if (getsockname(0, (struct sockaddr *)&sa, &salen) < 0) { 90 from_inetd = 0; 91 } 92 93 if (!from_inetd) { 94 if (!nodaemon) 95 possess(); 96 97 (void)rpcb_unset(WALLPROG, WALLVERS, NULL); 98 } 99 100 (void)signal(SIGCHLD, killkids); 101 102 openlog("rpc.rwalld", LOG_CONS|LOG_PID, LOG_DAEMON); 103 104 /* create and register the service */ 105 if (from_inetd) { 106 transp = svc_tli_create(0, NULL, NULL, 0, 0); 107 if (transp == NULL) { 108 syslog(LOG_ERR, "couldn't create udp service."); 109 exit(1); 110 } 111 ok = svc_reg(transp, WALLPROG, WALLVERS, 112 wallprog_1, NULL); 113 } else 114 ok = svc_create(wallprog_1, 115 WALLPROG, WALLVERS, "udp"); 116 if (!ok) { 117 syslog(LOG_ERR, "unable to register (WALLPROG, WALLVERS, %s)", (!from_inetd)?"udp":"(inetd)"); 118 exit(1); 119 } 120 svc_run(); 121 syslog(LOG_ERR, "svc_run returned"); 122 exit(1); 123} 124 125static void 126usage(void) 127{ 128 fprintf(stderr, "usage: rpc.rwalld [-n]\n"); 129 exit(1); 130} 131 132void 133possess(void) 134{ 135 daemon(0, 0); 136} 137 138void 139killkids(int sig __unused) 140{ 141 while(wait4(-1, NULL, WNOHANG, NULL) > 0) 142 ; 143} 144 145void * 146wallproc_wall_1_svc(wrapstring *s, struct svc_req *rqstp __unused) 147{ 148 static void *dummy = NULL; 149 150 /* fork, popen wall with special option, and send the message */ 151 if (fork() == 0) { 152 FILE *pfp; 153 154 pfp = popen(WALL_CMD, "w"); 155 if (pfp != NULL) { 156 fprintf(pfp, "\007\007%s", *s); 157 pclose(pfp); 158 exit(0); 159 } 160 } 161 return(&dummy); 162} 163 164void 165wallprog_1(struct svc_req *rqstp, SVCXPRT *transp) 166{ 167 union { 168 char *wallproc_wall_1_arg; 169 } argument; 170 char *result; 171 bool_t (*xdr_argument)(), (*xdr_result)(); 172 char *(*local)(); 173 174 switch (rqstp->rq_proc) { 175 case NULLPROC: 176 (void)svc_sendreply(transp, (xdrproc_t)xdr_void, NULL); 177 goto leave; 178 179 case WALLPROC_WALL: 180 xdr_argument = xdr_wrapstring; 181 xdr_result = xdr_void; 182 local = (char *(*)()) wallproc_wall_1_svc; 183 break; 184 185 default: 186 svcerr_noproc(transp); 187 goto leave; 188 } 189 bzero(&argument, sizeof(argument)); 190 if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) { 191 svcerr_decode(transp); 192 goto leave; 193 } 194 result = (*local)(&argument, rqstp); 195 if (result != NULL && 196 !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) { 197 svcerr_systemerr(transp); 198 } 199 if (!svc_freeargs(transp, (xdrproc_t)xdr_argument, &argument)) { 200 syslog(LOG_ERR, "unable to free arguments"); 201 exit(1); 202 } 203leave: 204 if (from_inetd) 205 exit(0); 206} 207