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 30 #ifndef lint 31 static char rcsid[] = "/b/source/CVS/src/usr.sbin/rwalld/rwalld.c,v 1.2 1993/04/10 17:59:30 cgd Exp"; 32 #endif 33 34 #include <unistd.h> 35 #include <sys/types.h> 36 #include <pwd.h> 37 #include <stdio.h> 38 #include <string.h> 39 #include <errno.h> 40 #include <sys/socket.h> 41 #include <signal.h> 42 #include <sys/wait.h> 43 #include <rpc/rpc.h> 44 #include <rpcsvc/rwall.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 56 int nodaemon = 0; 57 int from_inetd = 1; 58 59 main(argc, argv) 60 int argc; 61 char *argv[]; 62 { 63 SVCXPRT *transp; 64 int s, salen; 65 struct sockaddr_in sa; 66 int sock = 0; 67 int proto = 0; 68 69 if (argc == 2 && !strcmp(argv[1], "-n")) 70 nodaemon = 1; 71 if (argc != 1 && !nodaemon) { 72 printf("usage: %s [-n]\n", argv[0]); 73 exit(1); 74 } 75 76 if (geteuid() == 0) { 77 struct passwd *pep = getpwnam("nobody"); 78 if (pep) 79 setuid(pep->pw_uid); 80 else 81 setuid(getuid()); 82 } 83 84 /* 85 * See if inetd started us 86 */ 87 if (getsockname(0, (struct sockaddr *)&sa, &salen) < 0) { 88 from_inetd = 0; 89 sock = RPC_ANYSOCK; 90 proto = IPPROTO_UDP; 91 } 92 93 if (!from_inetd) { 94 if (!nodaemon) 95 possess(); 96 97 (void)pmap_unset(WALLPROG, WALLVERS); 98 if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) { 99 perror("socket"); 100 exit(1); 101 } 102 bzero((char *)&sa, sizeof sa); 103 if (bind(s, (struct sockaddr *)&sa, sizeof sa) < 0) { 104 perror("bind"); 105 exit(1); 106 } 107 108 salen = sizeof sa; 109 if (getsockname(s, (struct sockaddr *)&sa, &salen)) { 110 perror("getsockname"); 111 exit(1); 112 } 113 114 pmap_set(WALLPROG, WALLVERS, IPPROTO_UDP, ntohs(sa.sin_port)); 115 if (dup2(s, 0) < 0) { 116 perror("dup2"); 117 exit(1); 118 } 119 (void)pmap_unset(WALLPROG, WALLVERS); 120 } 121 122 (void)signal(SIGCHLD, killkids); 123 124 transp = svcudp_create(sock); 125 if (transp == NULL) { 126 (void)fprintf(stderr, "cannot create udp service.\n"); 127 exit(1); 128 } 129 if (!svc_register(transp, WALLPROG, WALLVERS, wallprog_1, proto)) { 130 (void)fprintf(stderr, "unable to register (WALLPROG, WALLVERS, udp).\n"); 131 exit(1); 132 } 133 svc_run(); 134 (void)fprintf(stderr, "svc_run returned\n"); 135 exit(1); 136 137 } 138 139 void possess() 140 { 141 daemon(0, 0); 142 } 143 144 void killkids() 145 { 146 while(wait4(-1, NULL, WNOHANG, NULL) > 0) 147 ; 148 } 149 150 void *wallproc_wall_1(s) 151 char **s; 152 { 153 /* fork, popen wall with special option, and send the message */ 154 if (fork() == 0) { 155 FILE *pfp; 156 157 pfp = popen(WALL_CMD, "w"); 158 if (pfp != NULL) { 159 fprintf(pfp, "\007\007%s", *s); 160 pclose(pfp); 161 exit(0); 162 } 163 } 164 } 165 166 void 167 wallprog_1(rqstp, transp) 168 struct svc_req *rqstp; 169 SVCXPRT *transp; 170 { 171 union { 172 char *wallproc_wall_1_arg; 173 } argument; 174 char *result; 175 bool_t (*xdr_argument)(), (*xdr_result)(); 176 char *(*local)(); 177 178 switch (rqstp->rq_proc) { 179 case NULLPROC: 180 (void)svc_sendreply(transp, xdr_void, (char *)NULL); 181 goto leave; 182 183 case WALLPROC_WALL: 184 xdr_argument = xdr_wrapstring; 185 xdr_result = xdr_void; 186 local = (char *(*)()) wallproc_wall_1; 187 break; 188 189 default: 190 svcerr_noproc(transp); 191 goto leave; 192 } 193 bzero((char *)&argument, sizeof(argument)); 194 if (!svc_getargs(transp, xdr_argument, &argument)) { 195 svcerr_decode(transp); 196 goto leave; 197 } 198 result = (*local)(&argument, rqstp); 199 if (result != NULL && !svc_sendreply(transp, xdr_result, result)) { 200 svcerr_systemerr(transp); 201 } 202 if (!svc_freeargs(transp, xdr_argument, &argument)) { 203 (void)fprintf(stderr, "unable to free arguments\n"); 204 exit(1); 205 } 206 leave: 207 if (from_inetd) 208 exit(0); 209 } 210