announce.c revision 211056 
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
36static char sccsid[] = "@(#)announce.c	8.3 (Berkeley) 4/28/95";
37#endif
38static const char rcsid[] =
39  "$FreeBSD: head/libexec/talkd/announce.c 211056 2010-08-08 02:45:48Z ed $";
40#endif /* not lint */
41
42#include <sys/types.h>
43#include <sys/uio.h>
44#include <sys/stat.h>
45#include <sys/time.h>
46#include <sys/wait.h>
47#include <sys/socket.h>
48
49#include <protocols/talkd.h>
50
51#include <errno.h>
52#include <paths.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <syslog.h>
57#include <unistd.h>
58#include <vis.h>
59
60#include "ttymsg.h"
61#include "extern.h"
62
63extern char hostname[];
64
65/*
66 * Announce an invitation to talk.
67 */
68
69/*
70 * See if the user is accepting messages. If so, announce that
71 * a talk is requested.
72 */
73int
74announce(CTL_MSG *request, const char *remote_machine)
75{
76	char full_tty[32];
77	struct stat stbuf;
78
79	(void)snprintf(full_tty, sizeof(full_tty),
80	    "%s%s", _PATH_DEV, request->r_tty);
81	if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&020) == 0)
82		return (PERMISSION_DENIED);
83	return (print_mesg(request->r_tty, request, remote_machine));
84}
85
86#define max(a,b) ( (a) > (b) ? (a) : (b) )
87#define N_LINES 5
88#define N_CHARS 256
89
90/*
91 * Build a block of characters containing the message.
92 * It is sent blank filled and in a single block to
93 * try to keep the message in one piece if the recipient
94 * in vi at the time
95 */
96int
97print_mesg(const char *tty, CTL_MSG *request,
98    const char *remote_machine)
99{
100	struct timeval now;
101	time_t clock_sec;
102	struct tm *localclock;
103	struct iovec iovec;
104	char line_buf[N_LINES][N_CHARS];
105	int sizes[N_LINES];
106	char big_buf[N_LINES*N_CHARS];
107	char *bptr, *lptr, *vis_user;
108	int i, j, max_size;
109
110	i = 0;
111	max_size = 0;
112	gettimeofday(&now, NULL);
113	clock_sec = now.tv_sec;
114	localclock = localtime(&clock_sec);
115	(void)snprintf(line_buf[i], N_CHARS, " ");
116	sizes[i] = strlen(line_buf[i]);
117	max_size = max(max_size, sizes[i]);
118	i++;
119	(void)snprintf(line_buf[i], N_CHARS,
120		"Message from Talk_Daemon@%s at %d:%02d on %d/%.2d/%.2d ...",
121		hostname, localclock->tm_hour , localclock->tm_min,
122		localclock->tm_year + 1900, localclock->tm_mon + 1,
123		localclock->tm_mday);
124	sizes[i] = strlen(line_buf[i]);
125	max_size = max(max_size, sizes[i]);
126	i++;
127
128	vis_user = malloc(strlen(request->l_name) * 4 + 1);
129	strvis(vis_user, request->l_name, VIS_CSTYLE);
130	(void)snprintf(line_buf[i], N_CHARS,
131	    "talk: connection requested by %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, "talk: respond with:  talk %s@%s",
136	    vis_user, remote_machine);
137	sizes[i] = strlen(line_buf[i]);
138	max_size = max(max_size, sizes[i]);
139	i++;
140	(void)snprintf(line_buf[i], N_CHARS, " ");
141	sizes[i] = strlen(line_buf[i]);
142	max_size = max(max_size, sizes[i]);
143	i++;
144	bptr = big_buf;
145	*bptr++ = '\007'; /* send something to wake them up */
146	*bptr++ = '\r';	/* add a \r in case of raw mode */
147	*bptr++ = '\n';
148	for (i = 0; i < N_LINES; i++) {
149		/* copy the line into the big buffer */
150		lptr = line_buf[i];
151		while (*lptr != '\0')
152			*(bptr++) = *(lptr++);
153		/* pad out the rest of the lines with blanks */
154		for (j = sizes[i]; j < max_size + 2; j++)
155			*(bptr++) = ' ';
156		*(bptr++) = '\r';	/* add a \r in case of raw mode */
157		*(bptr++) = '\n';
158	}
159	*bptr = '\0';
160	iovec.iov_base = big_buf;
161	iovec.iov_len = bptr - big_buf;
162	/*
163	 * we choose a timeout of RING_WAIT-5 seconds so that we don't
164	 * stack up processes trying to write messages to a tty
165	 * that is permanently blocked.
166	 */
167	if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
168		return (FAILED);
169
170	return (SUCCESS);
171}
172