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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Modified Sun Mar 12 10:39:22 1995, faith@cs.unc.edu for Linux
*
*/
/* 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
* - added Native Language Support
* Sun Mar 21 1999 - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
* - fixed strerr(errno) in gettext calls
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <signal.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <paths.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "nls.h"
#include "closestream.h"
#include "pathnames.h"
#include "ttymsg.h"
#define ERR_BUFLEN (MAXNAMLEN + 1024)
/*
* Display the contents of a uio structure on a terminal. Used by wall(1),
* syslogd(8), and talkd(8). Forks and finishes in child if write would block,
* waiting up to tmout seconds. Returns pointer to error string on unexpected
* error; string is not newline-terminated. Various "normal" errors are
* ignored (exclusive-use, lack of permission, etc.).
*/
char *
ttymsg(struct iovec *iov, size_t iovcnt, char *line, int tmout) {
static char device[MAXNAMLEN];
static char errbuf[ERR_BUFLEN];
size_t cnt, left;
ssize_t wret;
struct iovec localiov[6];
int fd, forked = 0;
ssize_t len = 0;
if (iovcnt > ARRAY_SIZE(localiov)) {
snprintf(errbuf, sizeof(errbuf), _("internal error: too many iov's"));
return errbuf;
}
/* The old code here rejected the line argument when it contained a '/',
saying: "A slash may be an attempt to break security...".
However, if a user can control the line argument here
then they can make this routine write to /dev/hda or /dev/sda
already. So, this test was worthless, and these days it is
also wrong since people use /dev/pts/xxx. */
len = snprintf(device, sizeof(device), "%s%s", _PATH_DEV, line);
if (len < 0 || (size_t)len >= sizeof(device)) {
snprintf(errbuf, sizeof(errbuf), _("excessively long line arg"));
return errbuf;
}
/*
* open will fail on slip lines or exclusive-use lines
* if not running as root; not an error.
*/
if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) {
if (errno == EBUSY || errno == EACCES || errno == ENOENT)
return NULL;
len = snprintf(errbuf, sizeof(errbuf), "%s: %m", device);
if (len < 0 || (size_t)len >= sizeof(errbuf))
snprintf(errbuf, sizeof(errbuf), _("open failed"));
return errbuf;
}
for (cnt = left = 0; cnt < iovcnt; ++cnt)
left += iov[cnt].iov_len;
for (;;) {
wret = writev(fd, iov, iovcnt);
if (wret >= (ssize_t) left)
break;
if (wret >= 0) {
left -= wret;
if (iov != localiov) {
memmove(localiov, iov,
iovcnt * sizeof(struct iovec));
iov = localiov;
}
for (cnt = 0; wret >= (ssize_t) iov->iov_len && iovcnt > 0; ++cnt) {
wret -= iov->iov_len;
++iov;
--iovcnt;
}
if (wret) {
iov->iov_base = (char *) iov->iov_base + wret;
iov->iov_len -= wret;
}
continue;
}
if (errno == EWOULDBLOCK) {
int cpid, flags;
sigset_t sigmask;
if (forked) {
close(fd);
_exit(EXIT_FAILURE);
}
cpid = fork();
if (cpid < 0) {
len = snprintf(errbuf, sizeof(errbuf), _("fork: %m"));
if (len < 0 || (size_t)len >= sizeof(errbuf))
snprintf(errbuf, sizeof(errbuf), _("cannot fork"));
close(fd);
return errbuf;
}
if (cpid) { /* parent */
close(fd);
return NULL;
}
forked++;
/* wait at most tmout seconds */
signal(SIGALRM, SIG_DFL);
signal(SIGTERM, SIG_DFL); /* XXX */
sigemptyset(&sigmask);
sigprocmask (SIG_SETMASK, &sigmask, NULL);
alarm((u_int)tmout);
flags = fcntl(fd, F_GETFL);
fcntl(flags, F_SETFL, (long) (flags & ~O_NONBLOCK));
continue;
}
/*
* We get ENODEV on a slip line if we're running as root,
* and EIO if the line just went away.
*/
if (errno == ENODEV || errno == EIO)
break;
if (close_fd(fd) != 0)
warn(_("write failed: %s"), device);
if (forked)
_exit(EXIT_FAILURE);
len = snprintf(errbuf, sizeof(errbuf), "%s: %m", device);
if (len < 0 || (size_t)len >= sizeof(errbuf))
snprintf(errbuf, sizeof(errbuf),
_("%s: BAD ERROR, message is "
"far too long"), device);
return errbuf;
}
close(fd);
if (forked)
_exit(EXIT_SUCCESS);
return NULL;
}
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