remote_cmds/talkd.tproj/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 __attribute__((__used__))
  36 static const char copyright[] =
  37 "@(#) Copyright (c) 1983, 1993\n\
  38         The Regents of the University of California.  All rights reserved.\n";
  39 #endif /* not lint */
  40
  41 #ifndef lint
  42 #if 0
  43 static char sccsid[] = "@(#)talkd.c     8.1 (Berkeley) 6/4/93";
  44 #endif
  45 __attribute__((__used__))
  46 static const char rcsid[] =
  47   "$FreeBSD: src/libexec/talkd/talkd.c,v 1.17 2004/06/14 22:44:13 bms Exp $";
  48 #endif /* not lint */
  49
  50 #include <sys/cdefs.h>
  51
  52 /*
  53  * The top level of the daemon, the format is heavily borrowed
  54  * from rwhod.c. Basically: find out who and where you are;
  55  * disconnect all descriptors and ttys, and then endless
  56  * loop on waiting for and processing requests
  57  */
  58 #include <sys/types.h>
  59 #include <sys/socket.h>
  60 #include <sys/param.h>
  61 #include <netinet/in.h>
  62 #include <protocols/talkd.h>
  63 #include <err.h>
  64 #include <errno.h>
  65 #include <paths.h>
  66 #include <signal.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #include <syslog.h>
  71 #include <time.h>
  72 #include <unistd.h>
  73
  74 #include "extern.h"
  75
  76 CTL_MSG         request;
  77 CTL_RESPONSE    response;
  78
  79 int     debug = 0;
  80 long    lastmsgtime;
  81
  82 char    hostname[MAXHOSTNAMELEN + 1];
  83
  84 #define TIMEOUT 30
  85 #define MAXIDLE 120
  86
  87 int
  88 main(int argc, char *argv[])
  89 {
  90         register CTL_MSG *mp = &request;
  91         int cc;
  92         struct sockaddr ctl_addr;
  93
  94         /*
  95          * removed so ntalkd can run in tty sandbox
  96          */
  97         if (getuid())
  98                 errx(1, "getuid: not super-user");
  99
 100         openlog("talkd", LOG_PID, LOG_DAEMON);
 101         if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
 102                 syslog(LOG_ERR, "gethostname: %m");
 103                 _exit(1);
 104         }
 105         hostname[sizeof(hostname) - 1] = '\0';
 106         if (chdir(_PATH_DEV) < 0) {
 107                 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
 108                 _exit(1);
 109         }
 110         if (argc > 1 && strcmp(argv[1], "-d") == 0)
 111                 debug = 1;
 112         signal(SIGALRM, timeout);
 113         alarm(TIMEOUT);
 114         for (;;) {
 115                 cc = recv(0, (char *)mp, sizeof(*mp), 0);
 116                 if (cc != sizeof (*mp)) {
 117                         if (cc < 0 && errno != EINTR)
 118                                 syslog(LOG_WARNING, "recv: %m");
 119                         continue;
 120                 }
 121                 lastmsgtime = time(0);
 122                 (void)memcpy(&ctl_addr, &mp->ctl_addr, sizeof(ctl_addr));
 123                 ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
 124                 ctl_addr.sa_len = sizeof(ctl_addr);
 125                 process_request(mp, &response);
 126                 /* can block here, is this what I want? */
 127                 cc = sendto(STDIN_FILENO, (char *)&response,
 128                     sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
 129                 if (cc != sizeof (response))
 130                         syslog(LOG_WARNING, "sendto: %m");
 131         }
 132         /* NOTREACHED */
 133         return 0;
 134 }
 135
 136 void
 137 timeout(int sig __unused)
 138 {
 139         int save_errno = errno;
 140
 141         if (time(0) - lastmsgtime >= MAXIDLE)
 142                 _exit(0);
 143         alarm(TIMEOUT);
 144         errno = save_errno;
 145 }