NetBSD/lib/libc/gen/ttyname.c

170 lines
4.4 KiB
C

/* $NetBSD: ttyname.c,v 1.23 2006/03/22 00:05:01 christos Exp $ */
/*
* 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. 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94";
#else
__RCSID("$NetBSD: ttyname.c,v 1.23 2006/03/22 00:05:01 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <assert.h>
#include <db.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>
#ifdef __weak_alias
__weak_alias(ttyname,_ttyname)
__weak_alias(ttyname_r,_ttyname_r)
#endif
static int oldttyname(const struct stat *, char *, size_t);
int
ttyname_r(int fd, char *buf, size_t len)
{
struct stat sb;
struct termios ttyb;
DB *db;
DBT data, key;
struct {
mode_t type;
dev_t dev;
} bkey;
struct ptmget ptm;
#define DEVSZ (sizeof(_PATH_DEV) - 1)
_DIAGASSERT(fd != -1);
if (len <= DEVSZ) {
errno = ERANGE;
return -1;
}
/* If it is a pty, deal with it quickly */
if (ioctl(fd, TIOCPTSNAME, &ptm) != -1) {
if (strlcpy(buf, ptm.sn, len) >= len) {
errno = ERANGE;
return -1;
}
return 0;
}
/* Must be a terminal. */
if (tcgetattr(fd, &ttyb) == -1)
return -1;
/* Must be a character device. */
if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
return -1;
(void)memcpy(buf, _PATH_DEV, DEVSZ);
if ((db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) != NULL) {
(void)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)) {
if (len - DEVSZ <= data.size) {
errno = ERANGE;
return -1;
}
(void)memcpy(buf + DEVSZ, data.data, data.size);
(void)(db->close)(db);
return 0;
}
(void)(db->close)(db);
}
return oldttyname(&sb, buf, len);
}
static int
oldttyname(const struct stat *sb, char *buf, size_t len)
{
struct dirent *dirp;
DIR *dp;
struct stat dsb;
size_t dlen;
_DIAGASSERT(sb != NULL);
if ((dp = opendir(_PATH_DEV)) == NULL)
return -1;
while ((dirp = readdir(dp)) != NULL) {
if (dirp->d_fileno != sb->st_ino)
continue;
dlen = dirp->d_namlen + 1;
if (len - DEVSZ <= dlen) {
/*
* XXX: we return an error if *any* entry does not
* fit
*/
errno = ERANGE;
(void)closedir(dp);
return -1;
}
(void)memcpy(buf + DEVSZ, dirp->d_name, dlen);
if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
sb->st_ino != dsb.st_ino)
continue;
(void)closedir(dp);
return 0;
}
(void)closedir(dp);
/*
* XXX: Documented by TOG to return EBADF or ENOTTY only; neither are
* applicable here.
*/
errno = ENOENT;
return -1;
}
char *
ttyname(int fd)
{
static char buf[MAXPATHLEN];
return ttyname_r(fd, buf, sizeof(buf)) == -1 ? NULL : buf;
}