libexec/talkd/announce.c

   1 /*      $NetBSD: announce.c,v 1.24 2009/03/16 01:04:32 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 #if 0
  35 static char sccsid[] = "@(#)announce.c  8.3 (Berkeley) 4/28/95";
  36 #else
  37 __RCSID("$NetBSD: announce.c,v 1.24 2009/03/16 01:04:32 lukem Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <sys/types.h>
  42 #include <sys/uio.h>
  43 #include <sys/stat.h>
  44 #include <sys/time.h>
  45 #include <sys/wait.h>
  46 #include <sys/socket.h>
  47 #include <protocols/talkd.h>
  48 #include <errno.h>
  49 #include <syslog.h>
  50 #include <unistd.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <time.h>
  55 #include <vis.h>
  56 #include <paths.h>
  57 #include <util.h>
  58 #include "extern.h"
  59
  60 extern char hostname[];
  61
  62 /*
  63  * Announce an invitation to talk.
  64  */
  65
  66 /*
  67  * See if the user is accepting messages. If so, announce that
  68  * a talk is requested.
  69  */
  70 int
  71 announce(CTL_MSG *request, const char *remote_machine)
  72 {
  73         char full_tty[32];
  74         struct stat stbuf;
  75
  76         (void)snprintf(full_tty, sizeof(full_tty),
  77             "%s%s", _PATH_DEV, request->r_tty);
  78         if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&S_IWGRP) == 0)
  79                 return (PERMISSION_DENIED);
  80         return (print_mesg(request->r_tty, request, remote_machine));
  81 }
  82
  83 #define max(a, b) ((a) > (b) ? (a) : (b))
  84 #define N_LINES 5
  85 #define N_CHARS 256
  86
  87 /*
  88  * Build a block of characters containing the message.
  89  * It is sent blank filled and in a single block to
  90  * try to keep the message in one piece if the recipient
  91  * is in vi at the time.
  92  */
  93 int
  94 print_mesg(const char *tty, CTL_MSG *request, const char *remote_machine)
  95 {
  96         struct timeval clocktv;
  97         time_t clocktime;
  98         struct tm *localclock;
  99         struct iovec iovec;
 100         char line_buf[N_LINES][N_CHARS];
 101         int sizes[N_LINES];
 102         char big_buf[(N_LINES + 1) * N_CHARS];
 103         char *bptr, *lptr, vis_user[sizeof(request->l_name) * 4];
 104         int i, j, max_size;
 105
 106         i = 0;
 107         max_size = 0;
 108         (void)gettimeofday(&clocktv, NULL);
 109         clocktime = clocktv.tv_sec;
 110         localclock = localtime(&clocktime);
 111         (void)snprintf(line_buf[i], N_CHARS, " ");
 112         sizes[i] = strlen(line_buf[i]);
 113         max_size = max(max_size, sizes[i]);
 114         i++;
 115
 116         (void)snprintf(line_buf[i], N_CHARS,
 117             "Message from Talk_Daemon@%s at %d:%02d ...",
 118             hostname, localclock->tm_hour, localclock->tm_min);
 119         sizes[i] = strlen(line_buf[i]);
 120         max_size = max(max_size, sizes[i]);
 121         i++;
 122         if (strlen(request->l_name) + 1 > sizeof(vis_user) / 4)
 123                 return (FAILED);
 124         strvis(vis_user, request->l_name, VIS_CSTYLE);
 125         (void)snprintf(line_buf[i], N_CHARS,
 126             "talk: connection requested by %s@%s.", vis_user, remote_machine);
 127         sizes[i] = strlen(line_buf[i]);
 128         max_size = max(max_size, sizes[i]);
 129         i++;
 130         (void)snprintf(line_buf[i], N_CHARS,
 131             "talk: respond with:  talk %s@%s", vis_user, remote_machine);
 132         sizes[i] = strlen(line_buf[i]);
 133         max_size = max(max_size, sizes[i]);
 134         i++;
 135         (void)snprintf(line_buf[i], N_CHARS, " ");
 136         sizes[i] = strlen(line_buf[i]);
 137         max_size = max(max_size, sizes[i]);
 138         i++;
 139         bptr = big_buf;
 140         *bptr++ = '\a';                 /* send something to wake them up */
 141         *bptr++ = '\r';                 /* add a \r in case of raw mode */
 142         *bptr++ = '\n';
 143         for (i = 0; i < N_LINES; i++) {
 144                 /* copy the line into the big buffer */
 145                 lptr = line_buf[i];
 146                 while (*lptr != '\0' && lptr < (line_buf[i] + N_CHARS))
 147                         *(bptr++) = *(lptr++);
 148                 /* pad out the rest of the lines with blanks */
 149                 for (j = sizes[i]; j < max_size + 2; j++)
 150                         *(bptr++) = ' ';
 151                 *(bptr++) = '\r';       /* add a \r in case of raw mode */
 152                 *(bptr++) = '\n';
 153         }
 154         *bptr = '\0';
 155         iovec.iov_base = big_buf;
 156         iovec.iov_len = bptr - big_buf;
 157         /*
 158          * we choose a timeout of RING_WAIT-5 seconds so that we don't
 159          * stack up processes trying to write messages to a tty
 160          * that is permanently blocked.
 161          */
 162         if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
 163                 return (FAILED);
 164
 165         return (SUCCESS);
 166 }