xref: /netbsd/libexec/talkd/announce.c (revision 6550d01e)
1 /*	$NetBSD: announce.c,v 1.25 2009/03/16 01:13:38 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 1.25 2009/03/16 01:13:38 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 }
167