1 /* $OpenBSD: talkd.c,v 1.9 2001/07/08 21:18:12 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1983 Regents of the University of California. 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #ifndef lint 37 char copyright[] = 38 "@(#) Copyright (c) 1983 Regents of the University of California.\n\ 39 All rights reserved.\n"; 40 #endif /* not lint */ 41 42 #ifndef lint 43 /*static char sccsid[] = "from: @(#)talkd.c 5.8 (Berkeley) 2/26/91";*/ 44 static char rcsid[] = "$Id: talkd.c,v 1.9 2001/07/08 21:18:12 deraadt Exp $"; 45 #endif /* not lint */ 46 47 /* 48 * The top level of the daemon, the format is heavily borrowed 49 * from rwhod.c. Basically: find out who and where you are; 50 * disconnect all descriptors and ttys, and then endless 51 * loop on waiting for and processing requests 52 */ 53 #include <sys/param.h> 54 #include <sys/types.h> 55 #include <sys/socket.h> 56 #include <protocols/talkd.h> 57 #include <signal.h> 58 #include <syslog.h> 59 #include <time.h> 60 #include <errno.h> 61 #include <unistd.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <paths.h> 66 #include "talkd.h" 67 68 int sockt; 69 int debug = 0; 70 void timeout(); 71 long lastmsgtime; 72 73 char hostname[MAXHOSTNAMELEN]; 74 75 #define TIMEOUT 30 76 #define MAXIDLE 120 77 78 int 79 main(argc, argv) 80 int argc; 81 char *argv[]; 82 { 83 if (getuid()) { 84 fprintf(stderr, "%s: getuid: not super-user", argv[0]); 85 exit(1); 86 } 87 openlog("talkd", LOG_PID, LOG_DAEMON); 88 if (gethostname(hostname, sizeof (hostname) - 1) < 0) { 89 syslog(LOG_ERR, "gethostname: %m"); 90 _exit(1); 91 } 92 if (chdir(_PATH_DEV) < 0) { 93 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV); 94 _exit(1); 95 } 96 if (argc > 1 && strcmp(argv[1], "-d") == 0) 97 debug = 1; 98 init_table(); 99 signal(SIGALRM, timeout); 100 alarm(TIMEOUT); 101 for (;;) { 102 CTL_MSG request; 103 CTL_RESPONSE response; 104 int cc; 105 int len = sizeof(response.addr); 106 107 cc = recvfrom(0, (char *)&request, sizeof (request), 0, 108 (struct sockaddr *)&response.addr, &len); 109 if (cc != sizeof (request)) { 110 if (cc < 0 && errno != EINTR) 111 syslog(LOG_WARNING, "recvfrom: %m"); 112 continue; 113 } 114 /* Force NUL termination */ 115 request.l_name[NAME_SIZE-1] = '\0'; 116 request.r_name[NAME_SIZE-1] = '\0'; 117 request.r_tty[TTY_SIZE-1] = '\0'; 118 119 lastmsgtime = time(0); 120 process_request(&request, &response); 121 /* can block here, is this what I want? */ 122 cc = sendto(sockt, (char *)&response, 123 sizeof (response), 0, (struct sockaddr *)&request.ctl_addr, 124 sizeof (request.ctl_addr)); 125 if (cc != sizeof (response)) 126 syslog(LOG_WARNING, "sendto: %m"); 127 } 128 } 129 130 void 131 timeout() 132 { 133 int save_errno = errno; 134 135 if (time(0) - lastmsgtime >= MAXIDLE) 136 _exit(0); 137 alarm(TIMEOUT); 138 errno = save_errno; 139 } 140