libexec/talkd/talkd.c

   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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY 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  * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)talkd.c  8.1 (Berkeley) 6/4/93
  31  * $FreeBSD: src/libexec/talkd/talkd.c,v 1.11.2.1 2001/10/18 12:30:42 des Exp $
  32  */
  33
  34 /*
  35  * The top level of the daemon, the format is heavily borrowed
  36  * from rwhod.c. Basically: find out who and where you are;
  37  * disconnect all descriptors and ttys, and then endless
  38  * loop on waiting for and processing requests
  39  */
  40 #include <sys/types.h>
  41 #include <sys/socket.h>
  42 #include <sys/param.h>
  43 #include <protocols/talkd.h>
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <paths.h>
  47 #include <signal.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <syslog.h>
  52 #include <time.h>
  53 #include <unistd.h>
  54
  55 #include "extern.h"
  56
  57 CTL_MSG         request;
  58 CTL_RESPONSE    response;
  59
  60 int     sockt;
  61 int     debug = 0;
  62 long    lastmsgtime;
  63
  64 char    hostname[MAXHOSTNAMELEN];
  65
  66 #define TIMEOUT 30
  67 #define MAXIDLE 120
  68
  69 int
  70 main(int argc, char *argv[])
  71 {
  72         CTL_MSG *mp = &request;
  73         int cc;
  74
  75 #ifdef NOTDEF
  76         /*
  77          * removed so ntalkd can run in tty sandbox
  78          */
  79         if (getuid())
  80                 errx(1, "getuid: not super-user");
  81 #endif
  82         openlog("talkd", LOG_PID, LOG_DAEMON);
  83         if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
  84                 syslog(LOG_ERR, "gethostname: %m");
  85                 _exit(1);
  86         }
  87         hostname[sizeof(hostname) - 1] = '\0';
  88         if (chdir(_PATH_DEV) < 0) {
  89                 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
  90                 _exit(1);
  91         }
  92         if (argc > 1 && strcmp(argv[1], "-d") == 0)
  93                 debug = 1;
  94         signal(SIGALRM, timeout);
  95         alarm(TIMEOUT);
  96         for (;;) {
  97                 cc = recv(0, (char *)mp, sizeof (*mp), 0);
  98                 if (cc != sizeof (*mp)) {
  99                         if (cc < 0 && errno != EINTR)
 100                                 syslog(LOG_WARNING, "recv: %m");
 101                         continue;
 102                 }
 103                 lastmsgtime = time(0);
 104                 process_request(mp, &response);
 105                 /* can block here, is this what I want? */
 106                 mp->ctl_addr.sa_family = htons(mp->ctl_addr.sa_family);
 107                 cc = sendto(sockt, (char *)&response,
 108                     sizeof (response), 0, (struct sockaddr *)&mp->ctl_addr,
 109                     sizeof (mp->ctl_addr));
 110                 if (cc != sizeof (response))
 111                         syslog(LOG_WARNING, "sendto: %m");
 112         }
 113 }
 114
 115 void
 116 timeout(int sig __unused)
 117 {
 118         int save_errno = errno;
 119
 120         if (time(0) - lastmsgtime >= MAXIDLE)
 121                 _exit(0);
 122         alarm(TIMEOUT);
 123         errno = save_errno;
 124 }