announce.c revision 262435 
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
30#ifndef lint
31#if 0
32static char sccsid[] = "@(#)announce.c	8.3 (Berkeley) 4/28/95";
33#endif
34static const char rcsid[] =
35  "$FreeBSD: stable/10/libexec/talkd/announce.c 262435 2014-02-24 08:21:49Z brueffer $";
36#endif /* not lint */
37
38#include <sys/types.h>
39#include <sys/uio.h>
40#include <sys/stat.h>
41#include <sys/time.h>
42#include <sys/wait.h>
43#include <sys/socket.h>
44
45#include <protocols/talkd.h>
46
47#include <errno.h>
48#include <paths.h>
49#include <stdio.h>
50#include <stdlib.h>
51#include <string.h>
52#include <syslog.h>
53#include <unistd.h>
54#include <vis.h>
55
56#include "ttymsg.h"
57#include "extern.h"
58
59/*
60 * Announce an invitation to talk.
61 */
62
63/*
64 * See if the user is accepting messages. If so, announce that
65 * a talk is requested.
66 */
67int
68announce(CTL_MSG *request, const char *remote_machine)
69{
70	char full_tty[32];
71	struct stat stbuf;
72
73	(void)snprintf(full_tty, sizeof(full_tty),
74	    "%s%s", _PATH_DEV, request->r_tty);
75	if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&020) == 0)
76		return (PERMISSION_DENIED);
77	return (print_mesg(request->r_tty, request, remote_machine));
78}
79
80#define max(a,b) ( (a) > (b) ? (a) : (b) )
81#define N_LINES 5
82#define N_CHARS 256
83
84/*
85 * Build a block of characters containing the message.
86 * It is sent blank filled and in a single block to
87 * try to keep the message in one piece if the recipient
88 * in vi at the time
89 */
90int
91print_mesg(const char *tty, CTL_MSG *request,
92    const char *remote_machine)
93{
94	struct timeval now;
95	time_t clock_sec;
96	struct tm *localclock;
97	struct iovec iovec;
98	char line_buf[N_LINES][N_CHARS];
99	int sizes[N_LINES];
100	char big_buf[N_LINES*N_CHARS];
101	char *bptr, *lptr, *vis_user;
102	int i, j, max_size;
103
104	i = 0;
105	max_size = 0;
106	gettimeofday(&now, NULL);
107	clock_sec = now.tv_sec;
108	localclock = localtime(&clock_sec);
109	(void)snprintf(line_buf[i], N_CHARS, " ");
110	sizes[i] = strlen(line_buf[i]);
111	max_size = max(max_size, sizes[i]);
112	i++;
113	(void)snprintf(line_buf[i], N_CHARS,
114		"Message from Talk_Daemon@%s at %d:%02d on %d/%.2d/%.2d ...",
115		hostname, localclock->tm_hour , localclock->tm_min,
116		localclock->tm_year + 1900, localclock->tm_mon + 1,
117		localclock->tm_mday);
118	sizes[i] = strlen(line_buf[i]);
119	max_size = max(max_size, sizes[i]);
120	i++;
121
122	vis_user = malloc(strlen(request->l_name) * 4 + 1);
123	strvis(vis_user, request->l_name, VIS_CSTYLE);
124	(void)snprintf(line_buf[i], N_CHARS,
125	    "talk: connection requested by %s@%s", vis_user, remote_machine);
126	sizes[i] = strlen(line_buf[i]);
127	max_size = max(max_size, sizes[i]);
128	i++;
129	(void)snprintf(line_buf[i], N_CHARS, "talk: respond with:  talk %s@%s",
130	    vis_user, remote_machine);
131	sizes[i] = strlen(line_buf[i]);
132	max_size = max(max_size, sizes[i]);
133	i++;
134	(void)snprintf(line_buf[i], N_CHARS, " ");
135	sizes[i] = strlen(line_buf[i]);
136	max_size = max(max_size, sizes[i]);
137	i++;
138	bptr = big_buf;
139	*bptr++ = '\007'; /* send something to wake them up */
140	*bptr++ = '\r';	/* add a \r in case of raw mode */
141	*bptr++ = '\n';
142	for (i = 0; i < N_LINES; i++) {
143		/* copy the line into the big buffer */
144		lptr = line_buf[i];
145		while (*lptr != '\0')
146			*(bptr++) = *(lptr++);
147		/* pad out the rest of the lines with blanks */
148		for (j = sizes[i]; j < max_size + 2; j++)
149			*(bptr++) = ' ';
150		*(bptr++) = '\r';	/* add a \r in case of raw mode */
151		*(bptr++) = '\n';
152	}
153	*bptr = '\0';
154	iovec.iov_base = big_buf;
155	iovec.iov_len = bptr - big_buf;
156	/*
157	 * we choose a timeout of RING_WAIT-5 seconds so that we don't
158	 * stack up processes trying to write messages to a tty
159	 * that is permanently blocked.
160	 */
161	if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
162		return (FAILED);
163
164	return (SUCCESS);
165}
166