xref: /freebsd/libexec/talkd/announce.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)announce.c	8.3 (Berkeley) 4/28/95";
35 #endif
36 static const char rcsid[] =
37   "$FreeBSD$";
38 #endif /* not lint */
39 
40 #include <sys/types.h>
41 #include <sys/uio.h>
42 #include <sys/stat.h>
43 #include <sys/time.h>
44 #include <sys/wait.h>
45 #include <sys/socket.h>
46 
47 #include <protocols/talkd.h>
48 
49 #include <errno.h>
50 #include <paths.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <syslog.h>
55 #include <unistd.h>
56 #include <vis.h>
57 
58 #include "ttymsg.h"
59 #include "extern.h"
60 
61 /*
62  * Announce an invitation to talk.
63  */
64 
65 /*
66  * See if the user is accepting messages. If so, announce that
67  * a talk is requested.
68  */
69 int
70 announce(CTL_MSG *request, const char *remote_machine)
71 {
72 	char full_tty[32];
73 	struct stat stbuf;
74 
75 	(void)snprintf(full_tty, sizeof(full_tty),
76 	    "%s%s", _PATH_DEV, request->r_tty);
77 	if (stat(full_tty, &stbuf) < 0 || (stbuf.st_mode&020) == 0)
78 		return (PERMISSION_DENIED);
79 	return (print_mesg(request->r_tty, request, remote_machine));
80 }
81 
82 #define max(a,b) ( (a) > (b) ? (a) : (b) )
83 #define N_LINES 5
84 #define N_CHARS 256
85 
86 /*
87  * Build a block of characters containing the message.
88  * It is sent blank filled and in a single block to
89  * try to keep the message in one piece if the recipient
90  * in vi at the time
91  */
92 int
93 print_mesg(const char *tty, CTL_MSG *request,
94     const char *remote_machine)
95 {
96 	struct timeval now;
97 	time_t clock_sec;
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*N_CHARS];
103 	char *bptr, *lptr, *vis_user;
104 	int i, j, max_size;
105 
106 	i = 0;
107 	max_size = 0;
108 	gettimeofday(&now, NULL);
109 	clock_sec = now.tv_sec;
110 	localclock = localtime(&clock_sec);
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 	(void)snprintf(line_buf[i], N_CHARS,
116 		"Message from Talk_Daemon@%s at %d:%02d on %d/%.2d/%.2d ...",
117 		hostname, localclock->tm_hour , localclock->tm_min,
118 		localclock->tm_year + 1900, localclock->tm_mon + 1,
119 		localclock->tm_mday);
120 	sizes[i] = strlen(line_buf[i]);
121 	max_size = max(max_size, sizes[i]);
122 	i++;
123 
124 	vis_user = malloc(strlen(request->l_name) * 4 + 1);
125 	strvis(vis_user, request->l_name, VIS_CSTYLE);
126 	(void)snprintf(line_buf[i], N_CHARS,
127 	    "talk: connection requested by %s@%s", vis_user, remote_machine);
128 	sizes[i] = strlen(line_buf[i]);
129 	max_size = max(max_size, sizes[i]);
130 	i++;
131 	(void)snprintf(line_buf[i], N_CHARS, "talk: respond with:  talk %s@%s",
132 	    vis_user, remote_machine);
133 	sizes[i] = strlen(line_buf[i]);
134 	max_size = max(max_size, sizes[i]);
135 	i++;
136 	(void)snprintf(line_buf[i], N_CHARS, " ");
137 	sizes[i] = strlen(line_buf[i]);
138 	max_size = max(max_size, sizes[i]);
139 	i++;
140 	bptr = big_buf;
141 	*bptr++ = '\007'; /* send something to wake them up */
142 	*bptr++ = '\r';	/* add a \r in case of raw mode */
143 	*bptr++ = '\n';
144 	for (i = 0; i < N_LINES; i++) {
145 		/* copy the line into the big buffer */
146 		lptr = line_buf[i];
147 		while (*lptr != '\0')
148 			*(bptr++) = *(lptr++);
149 		/* pad out the rest of the lines with blanks */
150 		for (j = sizes[i]; j < max_size + 2; j++)
151 			*(bptr++) = ' ';
152 		*(bptr++) = '\r';	/* add a \r in case of raw mode */
153 		*(bptr++) = '\n';
154 	}
155 	*bptr = '\0';
156 	iovec.iov_base = big_buf;
157 	iovec.iov_len = bptr - big_buf;
158 	/*
159 	 * we choose a timeout of RING_WAIT-5 seconds so that we don't
160 	 * stack up processes trying to write messages to a tty
161 	 * that is permanently blocked.
162 	 */
163 	if (ttymsg(&iovec, 1, tty, RING_WAIT - 5) != NULL)
164 		return (FAILED);
165 
166 	return (SUCCESS);
167 }
168