GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/wall/ttymsg.c Lines: 0 75 0.0 %
Date: 2017-11-07 Branches: 0 52 0.0 %

Line Branch Exec Source
1
/*	$OpenBSD: ttymsg.c,v 1.17 2015/11/05 22:20:11 benno Exp $	*/
2
/*	$NetBSD: ttymsg.c,v 1.3 1994/11/17 07:17:55 jtc Exp $	*/
3
4
/*
5
 * Copyright (c) 1989, 1993
6
 *	The Regents of the University of California.  All rights reserved.
7
 *
8
 * Redistribution and use in source and binary forms, with or without
9
 * modification, are permitted provided that the following conditions
10
 * are met:
11
 * 1. Redistributions of source code must retain the above copyright
12
 *    notice, this list of conditions and the following disclaimer.
13
 * 2. Redistributions in binary form must reproduce the above copyright
14
 *    notice, this list of conditions and the following disclaimer in the
15
 *    documentation and/or other materials provided with the distribution.
16
 * 3. Neither the name of the University nor the names of its contributors
17
 *    may be used to endorse or promote products derived from this software
18
 *    without specific prior written permission.
19
 *
20
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30
 * SUCH DAMAGE.
31
 */
32
33
#include <sys/types.h>
34
#include <sys/stat.h>
35
#include <sys/uio.h>
36
#include <signal.h>
37
#include <fcntl.h>
38
#include <dirent.h>
39
#include <errno.h>
40
#include <paths.h>
41
#include <unistd.h>
42
#include <stdio.h>
43
#include <string.h>
44
#include <stdlib.h>
45
#include <err.h>
46
47
char *ttymsg(struct iovec *, int, char *, int);
48
49
/*
50
 * Display the contents of a uio structure on a terminal.  Used by wall(1)
51
 * and talkd(8).  Forks and finishes in child if write would block,
52
 * waiting up to tmout seconds.  Returns pointer to error string on unexpected
53
 * error; string is not newline-terminated.  Various "normal" errors are
54
 * ignored (exclusive-use, lack of permission, etc.).
55
 */
56
char *
57
ttymsg(iov, iovcnt, line, tmout)
58
	struct iovec *iov;
59
	int iovcnt;
60
	char *line;
61
	int tmout;
62
{
63
	static char device[MAXNAMLEN] = _PATH_DEV;
64
	static char errbuf[1024];
65
	int cnt, fd, left, wret;
66
	struct iovec localiov[6];
67
	int forked = 0;
68
	struct stat st;
69
	sigset_t mask;
70
71
	if (iovcnt > sizeof(localiov) / sizeof(localiov[0]))
72
		return ("too many iov's (change code in wall/ttymsg.c)");
73
74
	/*
75
	 * Ignore lines that start with "ftp" or "uucp".
76
	 */
77
	if ((strncmp(line, "ftp", 3) == 0) ||
78
	    (strncmp(line, "uucp", 4) == 0))
79
		return (NULL);
80
81
	(void) strlcpy(device + sizeof(_PATH_DEV) - 1, line,
82
	    sizeof(device) - (sizeof(_PATH_DEV) - 1));
83
	if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) {
84
		/* A slash is an attempt to break security... */
85
		(void) snprintf(errbuf, sizeof(errbuf), "'/' in \"%s\"",
86
		    device);
87
		return (errbuf);
88
	}
89
90
	if (getuid()) {
91
		if (stat(device, &st) < 0)
92
			return (NULL);
93
		if ((st.st_mode & S_IWGRP) == 0)
94
			return (NULL);
95
	}
96
97
	/*
98
	 * open will fail on slip lines or exclusive-use lines
99
	 * if not running as root; not an error.
100
	 */
101
	if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) {
102
		if (errno == EBUSY || errno == EACCES)
103
			return (NULL);
104
		(void) snprintf(errbuf, sizeof(errbuf),
105
		    "%s: %s", device, strerror(errno));
106
		return (errbuf);
107
	}
108
109
	for (cnt = left = 0; cnt < iovcnt; ++cnt)
110
		left += iov[cnt].iov_len;
111
112
	for (;;) {
113
		wret = writev(fd, iov, iovcnt);
114
		if (wret >= left)
115
			break;
116
		if (wret >= 0) {
117
			left -= wret;
118
			if (iov != localiov) {
119
				bcopy(iov, localiov,
120
				    iovcnt * sizeof(struct iovec));
121
				iov = localiov;
122
			}
123
			for (cnt = 0; wret >= iov->iov_len; ++cnt) {
124
				wret -= iov->iov_len;
125
				++iov;
126
				--iovcnt;
127
			}
128
			if (wret) {
129
				char *base = iov->iov_base;
130
131
				iov->iov_base = base + wret;
132
				iov->iov_len -= wret;
133
			}
134
			continue;
135
		}
136
		if (errno == EWOULDBLOCK) {
137
			int off = 0;
138
			pid_t cpid;
139
140
			if (forked) {
141
				(void) close(fd);
142
				_exit(1);
143
			}
144
			cpid = fork();
145
			if (cpid < 0) {
146
				(void) snprintf(errbuf, sizeof(errbuf),
147
				    "fork: %s", strerror(errno));
148
				(void) close(fd);
149
				return (errbuf);
150
			}
151
			if (cpid) {	/* parent */
152
				(void) close(fd);
153
				return (NULL);
154
			}
155
156
			if (pledge("stdio flock rpath cpath wpath", NULL) == -1)
157
				err(1, "pledge");
158
159
			forked++;
160
			/* wait at most tmout seconds */
161
			(void) signal(SIGALRM, SIG_DFL);
162
			(void) signal(SIGTERM, SIG_DFL); /* XXX */
163
			(void) sigemptyset(&mask);
164
			(void) sigprocmask(SIG_SETMASK, &mask, NULL);
165
			(void) alarm((u_int)tmout);
166
			(void) fcntl(fd, O_NONBLOCK, &off);
167
			continue;
168
		}
169
		/*
170
		 * We get ENODEV on a slip line if we're running as root,
171
		 * and EIO if the line just went away.
172
		 */
173
		if (errno == ENODEV || errno == EIO)
174
			break;
175
		(void) close(fd);
176
		if (forked)
177
			_exit(1);
178
		(void) snprintf(errbuf, sizeof(errbuf),
179
		    "%s: %s", device, strerror(errno));
180
		return (errbuf);
181
	}
182
183
	(void) close(fd);
184
	if (forked)
185
		_exit(0);
186
	return (NULL);
187
}