libexec/talkd/talkd.c

   1 /*      $NetBSD: talkd.c,v 1.20 2008/07/20 01:09:07 lukem Exp $ */
   2
   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 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)talkd.c     8.1 (Berkeley) 6/4/93";
  41 #else
  42 __RCSID("$NetBSD: talkd.c,v 1.20 2008/07/20 01:09:07 lukem Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 /*
  47  * The top level of the daemon, the format is heavily borrowed
  48  * from rwhod.c. Basically: find out who and where you are;
  49  * disconnect all descriptors and ttys, and then endless
  50  * loop on waiting for and processing requests
  51  */
  52 #include <sys/types.h>
  53 #include <sys/socket.h>
  54 #include <sys/param.h>
  55
  56 #include <protocols/talkd.h>
  57
  58 #include <errno.h>
  59 #include <paths.h>
  60 #include <signal.h>
  61 #include <stdio.h>
  62 #include <stdlib.h>
  63 #include <string.h>
  64 #include <syslog.h>
  65 #include <time.h>
  66 #include <unistd.h>
  67
  68 #include "extern.h"
  69
  70 CTL_MSG         request;
  71 CTL_RESPONSE    response;
  72
  73 int     sockt = STDIN_FILENO;
  74 int     debug = 0;
  75 int     logging = 0;
  76 time_t  lastmsgtime;
  77
  78 char    hostname[MAXHOSTNAMELEN + 1];
  79
  80 #define TIMEOUT 30
  81 #define MAXIDLE 120
  82
  83 static void timeout(int);
  84 int     main(int, char *[]);
  85
  86 int
  87 main(int argc, char *argv[])
  88 {
  89         CTL_MSG *mp = &request;
  90         int cc, ch;
  91         struct sockaddr ctl_addr;
  92
  93         openlog("talkd", LOG_PID, LOG_DAEMON);
  94         while ((ch = getopt(argc, argv, "dl")) != -1)
  95                 switch (ch) {
  96                 case 'd':
  97                         debug = 1;
  98                         break;
  99                 case 'l':
 100                         logging = 1;
 101                         break;
 102                 default:
 103                         syslog(LOG_ERR, "Usage: %s [-dl]", getprogname());
 104                         exit(1);
 105                 }
 106
 107         if (gethostname(hostname, sizeof hostname) < 0) {
 108                 syslog(LOG_ERR, "gethostname: %m");
 109                 _exit(1);
 110         }
 111         hostname[MAXHOSTNAMELEN] = '\0';  /* ensure null termination */
 112         if (chdir(_PATH_DEV) < 0) {
 113                 syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
 114                 _exit(1);
 115         }
 116         signal(SIGALRM, timeout);
 117         alarm(TIMEOUT);
 118         for (;;) {
 119                 memset(&response, 0, sizeof(response));
 120                 cc = recv(0, (char *)mp, sizeof (*mp), 0);
 121                 if (cc != sizeof (*mp)) {
 122                         if (cc < 0 && errno != EINTR)
 123                                 syslog(LOG_WARNING, "recv: %m");
 124                         continue;
 125                 }
 126
 127                 mp->l_name[sizeof(mp->l_name) - 1] = '\0';
 128                 mp->r_name[sizeof(mp->r_name) - 1] = '\0';
 129                 mp->r_tty[sizeof(mp->r_tty) - 1] = '\0';
 130
 131                 lastmsgtime = time(0);
 132                 process_request(mp, &response);
 133
 134                 tsa2sa(&ctl_addr, &mp->ctl_addr);
 135                 if (ctl_addr.sa_family != AF_INET)
 136                         continue;
 137
 138                 /* can block here, is this what I want? */
 139                 cc = sendto(sockt, (char *)&response, sizeof (response), 0,
 140                     &ctl_addr, sizeof (ctl_addr));
 141                 if (cc != sizeof (response))
 142                         syslog(LOG_WARNING, "sendto: %m");
 143         }
 144 }
 145
 146 void
 147 timeout(int n)
 148 {
 149         int save_errno = errno;
 150
 151         if (time(0) - lastmsgtime >= MAXIDLE)
 152                 _exit(0);
 153         alarm(TIMEOUT);
 154         errno = save_errno;
 155 }
 156
 157 void
 158 tsa2sa(struct sockaddr *sa, const struct talkd_sockaddr *tsa)
 159 {
 160         (void)memcpy(sa, tsa, sizeof(*tsa));
 161         sa->sa_len = sizeof(*tsa);
 162         sa->sa_family = tsa->sa_family;
 163 }