freebsd-dev/lib/libc/gen/ttyname.c

223 lines
5.8 KiB
C

/*
* Copyright (c) 1988, 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <db.h>
#include <string.h>
#include <paths.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
static struct pthread_mutex _ttyname_lockd = PTHREAD_MUTEX_STATIC_INITIALIZER;
static pthread_mutex_t ttyname_lock = &_ttyname_lockd;
static pthread_key_t ttyname_key;
static int ttyname_init = 0;
char *
ttyname(int fd)
{
char *ret;
if (_FD_LOCK(fd, FD_READ, NULL) == 0) {
ret = __ttyname_basic(fd);
_FD_UNLOCK(fd, FD_READ);
} else {
ret = NULL;
}
return (ret);
}
char *
__ttyname_r_basic(int fd, char *buf, size_t len)
{
register struct dirent *dirp;
register DIR *dp;
struct stat dsb;
struct stat sb;
char *rval;
int minlen;
rval = NULL;
/* Must be a terminal. */
if (!isatty(fd))
return (rval);
/* Must be a character device. */
if (_thread_sys_fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
return (rval);
/* Must have enough room */
if (len <= sizeof(_PATH_DEV))
return (rval);
if ((dp = opendir(_PATH_DEV)) != NULL) {
memcpy(buf, _PATH_DEV, sizeof(_PATH_DEV));
for (rval = NULL; (dirp = readdir(dp)) != NULL;) {
if (dirp->d_fileno != sb.st_ino)
continue;
minlen = (len - (sizeof(_PATH_DEV) - 1)) < (dirp->d_namlen + 1) ?
(len - (sizeof(_PATH_DEV) - 1)) : (dirp->d_namlen + 1);
memcpy(buf + sizeof(_PATH_DEV) - 1, dirp->d_name, minlen);
if (stat(buf, &dsb) || sb.st_dev != dsb.st_dev ||
sb.st_ino != dsb.st_ino)
continue;
rval = buf;
break;
}
(void) closedir(dp);
}
return (rval);
}
char *
__ttyname_basic(int fd)
{
char *buf;
pthread_mutex_lock(&ttyname_lock);
if (ttyname_init == 0) {
if (pthread_key_create(&ttyname_key, free)) {
pthread_mutex_unlock(&ttyname_lock);
return (NULL);
}
ttyname_init = 1;
}
pthread_mutex_unlock(&ttyname_lock);
/* Must have thread specific data field to put data */
if ((buf = pthread_getspecific(ttyname_key)) == NULL) {
if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) {
if (pthread_setspecific(ttyname_key, buf) != 0) {
free(buf);
return (NULL);
}
} else {
return (NULL);
}
}
return (__ttyname_r_basic(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN));
}
char *
ttyname_r(int fd, char *buf, size_t len)
{
char *ret;
if (_FD_LOCK(fd, FD_READ, NULL) == 0) {
ret = __ttyname_r_basic(fd, buf, len);
_FD_UNLOCK(fd, FD_READ);
} else {
ret = NULL;
}
return (ret);
}
#else
static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV;
static char *oldttyname __P((int, struct stat *));
char *
ttyname(fd)
int fd;
{
struct stat sb;
struct termios ttyb;
DB *db;
DBT data, key;
struct {
mode_t type;
dev_t dev;
} bkey;
/* Must be a terminal. */
if (tcgetattr(fd, &ttyb) < 0)
return (NULL);
/* Must be a character device. */
if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
return (NULL);
if ( (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) ) {
memset(&bkey, 0, sizeof(bkey));
bkey.type = S_IFCHR;
bkey.dev = sb.st_rdev;
key.data = &bkey;
key.size = sizeof(bkey);
if (!(db->get)(db, &key, &data, 0)) {
bcopy(data.data,
buf + sizeof(_PATH_DEV) - 1, data.size);
(void)(db->close)(db);
return (buf);
}
(void)(db->close)(db);
}
return (oldttyname(fd, &sb));
}
static char *
oldttyname(fd, sb)
int fd;
struct stat *sb;
{
register struct dirent *dirp;
register DIR *dp;
struct stat dsb;
if ((dp = opendir(_PATH_DEV)) == NULL)
return (NULL);
while ( (dirp = readdir(dp)) ) {
if (dirp->d_fileno != sb->st_ino)
continue;
bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1,
dirp->d_namlen + 1);
if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
sb->st_ino != dsb.st_ino)
continue;
(void)closedir(dp);
return (buf);
}
(void)closedir(dp);
return (NULL);
}
#endif