1 /* 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY 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 /* 33 * The top level of the daemon, the format is heavily borrowed 34 * from rwhod.c. Basically: find out who and where you are; 35 * disconnect all descriptors and ttys, and then endless 36 * loop on waiting for and processing requests 37 */ 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 #include <sys/param.h> 41 #include <netinet/in.h> 42 #include <protocols/talkd.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <paths.h> 46 #include <signal.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <syslog.h> 51 #include <time.h> 52 #include <unistd.h> 53 54 #include "extern.h" 55 56 static CTL_MSG request; 57 static CTL_RESPONSE response; 58 59 int debug = 0; 60 static long lastmsgtime; 61 62 char hostname[MAXHOSTNAMELEN]; 63 64 #define TIMEOUT 30 65 #define MAXIDLE 120 66 67 int 68 main(int argc, char *argv[]) 69 { 70 register CTL_MSG *mp = &request; 71 int cc; 72 struct sockaddr ctl_addr; 73 74 #ifdef NOTDEF 75 /* 76 * removed so ntalkd can run in tty sandbox 77 */ 78 if (getuid()) 79 errx(1, "getuid: not super-user"); 80 #endif 81 openlog("talkd", LOG_PID, LOG_DAEMON); 82 if (gethostname(hostname, sizeof(hostname) - 1) < 0) { 83 syslog(LOG_ERR, "gethostname: %m"); 84 _exit(1); 85 } 86 hostname[sizeof(hostname) - 1] = '\0'; 87 if (chdir(_PATH_DEV) < 0) { 88 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV); 89 _exit(1); 90 } 91 if (argc > 1 && strcmp(argv[1], "-d") == 0) 92 debug = 1; 93 signal(SIGALRM, timeout); 94 alarm(TIMEOUT); 95 for (;;) { 96 cc = recv(0, (char *)mp, sizeof(*mp), 0); 97 if (cc != sizeof (*mp)) { 98 if (cc < 0 && errno != EINTR) 99 syslog(LOG_WARNING, "recv: %m"); 100 continue; 101 } 102 lastmsgtime = time(0); 103 (void)memcpy(&ctl_addr.sa_data, &mp->ctl_addr.sa_data, 104 sizeof(ctl_addr.sa_data)); 105 ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 106 ctl_addr.sa_len = sizeof(ctl_addr); 107 process_request(mp, &response); 108 /* can block here, is this what I want? */ 109 cc = sendto(STDIN_FILENO, (char *)&response, 110 sizeof(response), 0, &ctl_addr, sizeof(ctl_addr)); 111 if (cc != sizeof (response)) 112 syslog(LOG_WARNING, "sendto: %m"); 113 } 114 } 115 116 void 117 timeout(int sig __unused) 118 { 119 int save_errno = errno; 120 121 if (time(0) - lastmsgtime >= MAXIDLE) 122 _exit(0); 123 alarm(TIMEOUT); 124 errno = save_errno; 125 } 126