1 /* 2 * Copyright (c) 1993 Christopher G. Demetriou 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote 14 * products derived from this software without specific prior written 15 * permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: src/libexec/rpc.rwalld/rwalld.c,v 1.8 1999/08/28 00:09:57 peter Exp $ 30 */ 31 32 #include <err.h> 33 #include <pwd.h> 34 #include <signal.h> 35 #include <stdio.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <syslog.h> 39 #include <rpc/rpc.h> 40 #include <rpcsvc/rwall.h> 41 #include <sys/socket.h> 42 #include <sys/types.h> 43 #include <sys/wait.h> 44 #include <unistd.h> 45 46 #ifdef OSF 47 #define WALL_CMD "/usr/sbin/wall" 48 #else 49 #define WALL_CMD "/usr/bin/wall -n" 50 #endif 51 52 void wallprog_1(); 53 void possess(); 54 void killkids(); 55 static void usage (void); 56 57 int nodaemon = 0; 58 int from_inetd = 1; 59 60 int 61 main(int argc, char *argv[]) 62 { 63 SVCXPRT *transp; 64 int ok, salen; 65 struct sockaddr_storage sa; 66 67 if (argc == 2 && !strcmp(argv[1], "-n")) 68 nodaemon = 1; 69 if (argc != 1 && !nodaemon) 70 usage(); 71 72 if (geteuid() == 0) { 73 struct passwd *pep = getpwnam("nobody"); 74 if (pep) 75 setuid(pep->pw_uid); 76 else 77 setuid(getuid()); 78 } 79 80 /* 81 * See if inetd started us 82 */ 83 salen = sizeof(sa); 84 if (getsockname(0, (struct sockaddr *)&sa, &salen) < 0) { 85 from_inetd = 0; 86 } 87 88 if (!from_inetd) { 89 if (!nodaemon) 90 possess(); 91 92 (void)rpcb_unset(WALLPROG, WALLVERS, NULL); 93 } 94 95 (void)signal(SIGCHLD, killkids); 96 97 openlog("rpc.rwalld", LOG_CONS|LOG_PID, LOG_DAEMON); 98 99 /* create and register the service */ 100 if (from_inetd) { 101 transp = svc_tli_create(0, NULL, NULL, 0, 0); 102 if (transp == NULL) { 103 syslog(LOG_ERR, "couldn't create udp service."); 104 exit(1); 105 } 106 ok = svc_reg(transp, WALLPROG, WALLVERS, 107 wallprog_1, NULL); 108 } else 109 ok = svc_create(wallprog_1, 110 WALLPROG, WALLVERS, "udp"); 111 if (!ok) { 112 syslog(LOG_ERR, "unable to register (WALLPROG, WALLVERS, %s)", (!from_inetd)?"udp":"(inetd)"); 113 exit(1); 114 } 115 svc_run(); 116 syslog(LOG_ERR, "svc_run returned"); 117 exit(1); 118 } 119 120 static void 121 usage(void) 122 { 123 fprintf(stderr, "usage: rpc.rwalld [-n]\n"); 124 exit(1); 125 } 126 127 void 128 possess(void) 129 { 130 daemon(0, 0); 131 } 132 133 void 134 killkids(void) 135 { 136 while(wait4(-1, NULL, WNOHANG, NULL) > 0) 137 ; 138 } 139 140 void * 141 wallproc_wall_1_svc(wrapstring *s, struct svc_req *rqstp) 142 { 143 static void *dummy = NULL; 144 145 /* fork, popen wall with special option, and send the message */ 146 if (fork() == 0) { 147 FILE *pfp; 148 149 pfp = popen(WALL_CMD, "w"); 150 if (pfp != NULL) { 151 fprintf(pfp, "\007\007%s", *s); 152 pclose(pfp); 153 exit(0); 154 } 155 } 156 return(&dummy); 157 } 158 159 void 160 wallprog_1(struct svc_req *rqstp, SVCXPRT *transp) 161 { 162 union { 163 char *wallproc_wall_1_arg; 164 } argument; 165 char *result; 166 bool_t (*xdr_argument)(), (*xdr_result)(); 167 char *(*local)(); 168 169 switch (rqstp->rq_proc) { 170 case NULLPROC: 171 (void)svc_sendreply(transp, (xdrproc_t)xdr_void, NULL); 172 goto leave; 173 174 case WALLPROC_WALL: 175 xdr_argument = xdr_wrapstring; 176 xdr_result = xdr_void; 177 local = (char *(*)()) wallproc_wall_1_svc; 178 break; 179 180 default: 181 svcerr_noproc(transp); 182 goto leave; 183 } 184 bzero((char *)&argument, sizeof(argument)); 185 if (!svc_getargs(transp, (xdrproc_t)xdr_argument, (caddr_t)&argument)) { 186 svcerr_decode(transp); 187 goto leave; 188 } 189 result = (*local)(&argument, rqstp); 190 if (result != NULL && 191 !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) { 192 svcerr_systemerr(transp); 193 } 194 if (!svc_freeargs(transp, (xdrproc_t)xdr_argument, (caddr_t)&argument)) { 195 syslog(LOG_ERR, "unable to free arguments"); 196 exit(1); 197 } 198 leave: 199 if (from_inetd) 200 exit(0); 201 } 202