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