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