libexec/talkd/announce.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  * @(#)announce.c       8.3 (Berkeley) 4/28/95
  30  * $FreeBSD: src/libexec/talkd/announce.c,v 1.11.2.3 2001/10/18 12:30:42 des Exp $
  31  */
  32
  33 #include <sys/types.h>
  34 #include <sys/uio.h>
  35 #include <sys/stat.h>
  36 #include <sys/time.h>
  37 #include <sys/wait.h>
  38 #include <sys/socket.h>
  39
  40 #include <protocols/talkd.h>
  41
  42 #include <errno.h>
  43 #include <paths.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <syslog.h>
  48 #include <unistd.h>
  49 #include <vis.h>
  50
  51 #include "extern.h"
  52 #include "ttymsg.h"
  53
  54 extern char hostname[];
  55
  56 /*
  57  * Announce an invitation to talk.
  58  */
  59
  60 /*
  61  * See if the user is accepting messages. If so, announce that
  62  * a talk is requested.
  63  */
  64 int
  65 announce(CTL_MSG *request, const char *remote_machine)
  66 {
  67         char full_tty[32];
  68         struct stat stbuf;
  69
  70         (void)snprintf(full_tty, sizeof(full_tty),
  71             "%s%s", _PATH_DEV, request->r_tty);
  72         if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&020) == 0)
  73                 return (PERMISSION_DENIED);
  74         return (print_mesg(request->r_tty, request, remote_machine));
  75 }
  76
  77 #define max(a,b) ( (a) > (b) ? (a) : (b) )
  78 #define N_LINES 5
  79 #define N_CHARS 256
  80
  81 /*
  82  * Build a block of characters containing the message.
  83  * It is sent blank filled and in a single block to
  84  * try to keep the message in one piece if the recipient
  85  * in vi at the time
  86  */
  87 int
  88 print_mesg(const char *tty, CTL_MSG *request, const char *remote_machine)
  89 {
  90         struct timeval now;
  91         time_t clock_sec;
  92         struct tm *localclock;
  93         struct iovec iovec;
  94         char line_buf[N_LINES][N_CHARS];
  95         int sizes[N_LINES];
  96         char big_buf[N_LINES*N_CHARS];
  97         char *bptr, *lptr, *vis_user;
  98         int i, j, max_size;
  99
 100         i = 0;
 101         max_size = 0;
 102         gettimeofday(&now, NULL);
 103         clock_sec = now.tv_sec;
 104         localclock = localtime(&clock_sec);
 105         (void)snprintf(line_buf[i], N_CHARS, " ");
 106         sizes[i] = strlen(line_buf[i]);
 107         max_size = max(max_size, sizes[i]);
 108         i++;
 109         (void)snprintf(line_buf[i], N_CHARS,
 110                 "Message from Talk_Daemon@%s at %d:%02d on %d/%.2d/%.2d ...",
 111                 hostname, localclock->tm_hour , localclock->tm_min,
 112                 localclock->tm_year + 1900, localclock->tm_mon + 1,
 113                 localclock->tm_mday);
 114         sizes[i] = strlen(line_buf[i]);
 115         max_size = max(max_size, sizes[i]);
 116         i++;
 117
 118         vis_user = malloc(strlen(request->l_name) * 4 + 1);
 119         strvis(vis_user, request->l_name, VIS_CSTYLE);
 120         (void)snprintf(line_buf[i], N_CHARS,
 121             "talk: connection requested by %s@%s", vis_user, remote_machine);
 122         sizes[i] = strlen(line_buf[i]);
 123         max_size = max(max_size, sizes[i]);
 124         i++;
 125         (void)snprintf(line_buf[i], N_CHARS, "talk: respond with:  talk %s@%s",
 126             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         sizes[i] = strlen(line_buf[i]);
 132         max_size = max(max_size, sizes[i]);
 133         bptr = big_buf;
 134         *bptr++ = '\007'; /* send something to wake them up */
 135         *bptr++ = '\r'; /* add a \r in case of raw mode */
 136         *bptr++ = '\n';
 137         for (i = 0; i < N_LINES; i++) {
 138                 /* copy the line into the big buffer */
 139                 lptr = line_buf[i];
 140                 while (*lptr != '\0')
 141                         *(bptr++) = *(lptr++);
 142                 /* pad out the rest of the lines with blanks */
 143                 for (j = sizes[i]; j < max_size + 2; j++)
 144                         *(bptr++) = ' ';
 145                 *(bptr++) = '\r';       /* add a \r in case of raw mode */
 146                 *(bptr++) = '\n';
 147         }
 148         *bptr = '\0';
 149         iovec.iov_base = big_buf;
 150         iovec.iov_len = bptr - big_buf;
 151         /*
 152          * we choose a timeout of RING_WAIT-5 seconds so that we don't
 153          * stack up processes trying to write messages to a tty
 154          * that is permanently blocked.
 155          */
 156         if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
 157                 return (FAILED);
 158
 159         return (SUCCESS);
 160 }