remote_cmds/talkd.tproj/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. 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 #if 0
  36 static char sccsid[] = "@(#)announce.c  8.3 (Berkeley) 4/28/95";
  37 #endif
  38 __attribute__((__used__))
  39 static const char rcsid[] =
  40   "$FreeBSD: src/libexec/talkd/announce.c,v 1.16 2003/04/03 05:13:27 jmallett Exp $";
  41 #endif /* not lint */
  42
  43 #include <sys/cdefs.h>
  44
  45 #include <sys/types.h>
  46 #include <sys/uio.h>
  47 #include <sys/stat.h>
  48 #include <sys/time.h>
  49 #include <sys/wait.h>
  50 #include <sys/socket.h>
  51
  52 #include <protocols/talkd.h>
  53
  54 #include <errno.h>
  55 #include <paths.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include <syslog.h>
  60 #include <unistd.h>
  61 #include <vis.h>
  62
  63 #ifdef __APPLE__
  64 #include <util.h>
  65 #else
  66 #include "ttymsg.h"
  67 #endif
  68 #include "extern.h"
  69
  70 extern char hostname[];
  71
  72 /*
  73  * Announce an invitation to talk.
  74  */
  75
  76 /*
  77  * See if the user is accepting messages. If so, announce that
  78  * a talk is requested.
  79  */
  80 int
  81 announce(CTL_MSG *request, const char *remote_machine)
  82 {
  83         char full_tty[32];
  84         struct stat stbuf;
  85
  86         (void)snprintf(full_tty, sizeof(full_tty),
  87             "%s%s", _PATH_DEV, request->r_tty);
  88         if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&020) == 0)
  89                 return (PERMISSION_DENIED);
  90         return (print_mesg(request->r_tty, request, remote_machine));
  91 }
  92
  93 #define max(a,b) ( (a) > (b) ? (a) : (b) )
  94 #define N_LINES 5
  95 #define N_CHARS 256
  96
  97 /*
  98  * Build a block of characters containing the message.
  99  * It is sent blank filled and in a single block to
 100  * try to keep the message in one piece if the recipient
 101  * in in vi at the time
 102  */
 103 int
 104 print_mesg(const char *tty, CTL_MSG *request,
 105     const char *remote_machine)
 106 {
 107         struct timeval now;
 108         time_t clock_sec;
 109         struct timezone zone;
 110         struct tm *localclock;
 111         struct iovec iovec;
 112         char line_buf[N_LINES][N_CHARS];
 113         int sizes[N_LINES];
 114         char big_buf[N_LINES*N_CHARS];
 115         char *bptr, *lptr, *vis_user;
 116         int i, j, max_size;
 117
 118         i = 0;
 119         max_size = 0;
 120         gettimeofday(&now, &zone);
 121         clock_sec = now.tv_sec;
 122         localclock = localtime(&clock_sec);
 123         (void)snprintf(line_buf[i], N_CHARS, " ");
 124         sizes[i] = strlen(line_buf[i]);
 125         max_size = max(max_size, sizes[i]);
 126         i++;
 127         (void)snprintf(line_buf[i], N_CHARS,
 128                 "Message from Talk_Daemon@%s at %d:%02d on %d/%.2d/%.2d ...",
 129                 hostname, localclock->tm_hour , localclock->tm_min,
 130                 localclock->tm_year + 1900, localclock->tm_mon + 1,
 131                 localclock->tm_mday);
 132         sizes[i] = strlen(line_buf[i]);
 133         max_size = max(max_size, sizes[i]);
 134         i++;
 135
 136         vis_user = malloc(strlen(request->l_name) * 4 + 1);
 137         strvis(vis_user, request->l_name, VIS_CSTYLE);
 138         (void)snprintf(line_buf[i], N_CHARS,
 139             "talk: connection requested by %s@%s", vis_user, remote_machine);
 140         sizes[i] = strlen(line_buf[i]);
 141         max_size = max(max_size, sizes[i]);
 142         i++;
 143         (void)snprintf(line_buf[i], N_CHARS, "talk: respond with:  talk %s@%s",
 144             vis_user, remote_machine);
 145         sizes[i] = strlen(line_buf[i]);
 146         max_size = max(max_size, sizes[i]);
 147         i++;
 148         (void)snprintf(line_buf[i], N_CHARS, " ");
 149         sizes[i] = strlen(line_buf[i]);
 150         max_size = max(max_size, sizes[i]);
 151         i++;
 152         bptr = big_buf;
 153         *bptr++ = '\007'; /* send something to wake them up */
 154         *bptr++ = '\r'; /* add a \r in case of raw mode */
 155         *bptr++ = '\n';
 156         for (i = 0; i < N_LINES; i++) {
 157                 /* copy the line into the big buffer */
 158                 lptr = line_buf[i];
 159                 while (*lptr != '\0')
 160                         *(bptr++) = *(lptr++);
 161                 /* pad out the rest of the lines with blanks */
 162                 for (j = sizes[i]; j < max_size + 2; j++)
 163                         *(bptr++) = ' ';
 164                 *(bptr++) = '\r';       /* add a \r in case of raw mode */
 165                 *(bptr++) = '\n';
 166         }
 167         *bptr = '\0';
 168         iovec.iov_base = big_buf;
 169         iovec.iov_len = bptr - big_buf;
 170         /*
 171          * we choose a timeout of RING_WAIT-5 seconds so that we don't
 172          * stack up processes trying to write messages to a tty
 173          * that is permanently blocked.
 174          */
 175         if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
 176                 return (FAILED);
 177
 178         return (SUCCESS);
 179 }