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
  30 #ifndef lint
  31 static const char copyright[] =
  32 "@(#) Copyright (c) 1983, 1993\n\
  33         The Regents of the University of California.  All rights reserved.\n";
  34 #endif /* not lint */
  35
  36 #ifndef lint
  37 #if 0
  38 static char sccsid[] = "@(#)talkd.c     8.1 (Berkeley) 6/4/93";
  39 #endif
  40 static const char rcsid[] =
  41   "$FreeBSD$";
  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 <sys/param.h>
  53 #include <netinet/in.h>
  54 #include <protocols/talkd.h>
  55 #include <err.h>
  56 #include <errno.h>
  57 #include <paths.h>
  58 #include <signal.h>
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62 #include <syslog.h>
  63 #include <time.h>
  64 #include <unistd.h>
  65
  66 #include "extern.h"
  67
  68 static CTL_MSG          request;
  69 static CTL_RESPONSE     response;
  70
  71 int                     debug = 0;
  72 static long             lastmsgtime;
  73
  74 char                    hostname[MAXHOSTNAMELEN];
  75
  76 #define TIMEOUT 30
  77 #define MAXIDLE 120
  78
  79 int
  80 main(int argc, char *argv[])
  81 {
  82         register CTL_MSG *mp = &request;
  83         int cc;
  84         struct sockaddr ctl_addr;
  85
  86 #ifdef NOTDEF
  87         /*
  88          * removed so ntalkd can run in tty sandbox
  89          */
  90         if (getuid())
  91                 errx(1, "getuid: not super-user");
  92 #endif
  93         openlog("talkd", LOG_PID, LOG_DAEMON);
  94         if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
  95                 syslog(LOG_ERR, "gethostname: %m");
  96                 _exit(1);
  97         }
  98         hostname[sizeof(hostname) - 1] = '\0';
  99         if (chdir(_PATH_DEV) < 0) {
 100                 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
 101                 _exit(1);
 102         }
 103         if (argc > 1 && strcmp(argv[1], "-d") == 0)
 104                 debug = 1;
 105         signal(SIGALRM, timeout);
 106         alarm(TIMEOUT);
 107         for (;;) {
 108                 cc = recv(0, (char *)mp, sizeof(*mp), 0);
 109                 if (cc != sizeof (*mp)) {
 110                         if (cc < 0 && errno != EINTR)
 111                                 syslog(LOG_WARNING, "recv: %m");
 112                         continue;
 113                 }
 114                 lastmsgtime = time(0);
 115                 (void)memcpy(&ctl_addr, &mp->ctl_addr, sizeof(ctl_addr));
 116                 ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
 117                 ctl_addr.sa_len = sizeof(ctl_addr);
 118                 process_request(mp, &response);
 119                 /* can block here, is this what I want? */
 120                 cc = sendto(STDIN_FILENO, (char *)&response,
 121                     sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
 122                 if (cc != sizeof (response))
 123                         syslog(LOG_WARNING, "sendto: %m");
 124         }
 125 }
 126
 127 void
 128 timeout(int sig __unused)
 129 {
 130         int save_errno = errno;
 131
 132         if (time(0) - lastmsgtime >= MAXIDLE)
 133                 _exit(0);
 134         alarm(TIMEOUT);
 135         errno = save_errno;
 136 }