talkd.c revision 1593
1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#ifndef lint 35static char copyright[] = 36"@(#) Copyright (c) 1983, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38#endif /* not lint */ 39 40#ifndef lint 41static char sccsid[] = "@(#)talkd.c 8.1 (Berkeley) 6/4/93"; 42#endif /* not lint */ 43 44/* 45 * The top level of the daemon, the format is heavily borrowed 46 * from rwhod.c. Basically: find out who and where you are; 47 * disconnect all descriptors and ttys, and then endless 48 * loop on waiting for and processing requests 49 */ 50#include <sys/types.h> 51#include <sys/socket.h> 52#include <protocols/talkd.h> 53#include <signal.h> 54#include <syslog.h> 55#include <time.h> 56#include <errno.h> 57#include <unistd.h> 58#include <stdio.h> 59#include <stdlib.h> 60#include <string.h> 61#include <paths.h> 62 63CTL_MSG request; 64CTL_RESPONSE response; 65 66int sockt; 67int debug = 0; 68void timeout(); 69long lastmsgtime; 70 71char hostname[32]; 72 73#define TIMEOUT 30 74#define MAXIDLE 120 75 76main(argc, argv) 77 int argc; 78 char *argv[]; 79{ 80 register CTL_MSG *mp = &request; 81 int cc; 82 83 if (getuid()) { 84 fprintf(stderr, "%s: getuid: not super-user\n", 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 signal(SIGALRM, timeout); 99 alarm(TIMEOUT); 100 for (;;) { 101 extern int errno; 102 103 cc = recv(0, (char *)mp, sizeof (*mp), 0); 104 if (cc != sizeof (*mp)) { 105 if (cc < 0 && errno != EINTR) 106 syslog(LOG_WARNING, "recv: %m"); 107 continue; 108 } 109 lastmsgtime = time(0); 110 process_request(mp, &response); 111 /* can block here, is this what I want? */ 112 cc = sendto(sockt, (char *)&response, 113 sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr, 114 sizeof (mp->ctl_addr)); 115 if (cc != sizeof (response)) 116 syslog(LOG_WARNING, "sendto: %m"); 117 } 118} 119 120void 121timeout() 122{ 123 124 if (time(0) - lastmsgtime >= MAXIDLE) 125 _exit(0); 126 alarm(TIMEOUT); 127} 128