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. 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
  35 static const 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
  41 #if 0
  42 static char sccsid[] = "@(#)talkd.c     8.1 (Berkeley) 6/4/93";
  43 #endif
  44 static const char rcsid[] =
  45   "$FreeBSD$";
  46 #endif /* not lint */
  47
  48 /*
  49  * The top level of the daemon, the format is heavily borrowed
  50  * from rwhod.c. Basically: find out who and where you are;
  51  * disconnect all descriptors and ttys, and then endless
  52  * loop on waiting for and processing requests
  53  */
  54 #include <sys/types.h>
  55 #include <sys/socket.h>
  56 #include <sys/param.h>
  57 #include <netinet/in.h>
  58 #include <protocols/talkd.h>
  59 #include <err.h>
  60 #include <errno.h>
  61 #include <paths.h>
  62 #include <signal.h>
  63 #include <stdio.h>
  64 #include <stdlib.h>
  65 #include <string.h>
  66 #include <syslog.h>
  67 #include <time.h>
  68 #include <unistd.h>
  69
  70 #include "extern.h"
  71
  72 CTL_MSG         request;
  73 CTL_RESPONSE    response;
  74
  75 int     debug = 0;
  76 long    lastmsgtime;
  77
  78 char    hostname[MAXHOSTNAMELEN];
  79
  80 #define TIMEOUT 30
  81 #define MAXIDLE 120
  82
  83 int
  84 main(int argc, char *argv[])
  85 {
  86         register CTL_MSG *mp = &request;
  87         int cc;
  88         struct sockaddr ctl_addr;
  89
  90 #ifdef NOTDEF
  91         /*
  92          * removed so ntalkd can run in tty sandbox
  93          */
  94         if (getuid())
  95                 errx(1, "getuid: not super-user");
  96 #endif
  97         openlog("talkd", LOG_PID, LOG_DAEMON);
  98         if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
  99                 syslog(LOG_ERR, "gethostname: %m");
 100                 _exit(1);
 101         }
 102         hostname[sizeof(hostname) - 1] = '\0';
 103         if (chdir(_PATH_DEV) < 0) {
 104                 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
 105                 _exit(1);
 106         }
 107         if (argc > 1 && strcmp(argv[1], "-d") == 0)
 108                 debug = 1;
 109         signal(SIGALRM, timeout);
 110         alarm(TIMEOUT);
 111         for (;;) {
 112                 cc = recv(0, (char *)mp, sizeof(*mp), 0);
 113                 if (cc != sizeof (*mp)) {
 114                         if (cc < 0 && errno != EINTR)
 115                                 syslog(LOG_WARNING, "recv: %m");
 116                         continue;
 117                 }
 118                 lastmsgtime = time(0);
 119                 (void)memcpy(&ctl_addr, &mp->ctl_addr, sizeof(ctl_addr));
 120                 ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
 121                 ctl_addr.sa_len = sizeof(ctl_addr);
 122                 process_request(mp, &response);
 123                 /* can block here, is this what I want? */
 124                 cc = sendto(STDIN_FILENO, (char *)&response,
 125                     sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
 126                 if (cc != sizeof (response))
 127                         syslog(LOG_WARNING, "sendto: %m");
 128         }
 129 }
 130
 131 void
 132 timeout(int sig __unused)
 133 {
 134         int save_errno = errno;
 135
 136         if (time(0) - lastmsgtime >= MAXIDLE)
 137                 _exit(0);
 138         alarm(TIMEOUT);
 139         errno = save_errno;
 140 }