NetBSD/sys/fs/ptyfs/ptyfs_subr.c

266 lines
8.1 KiB
C

/* $NetBSD: ptyfs_subr.c,v 1.34 2020/11/27 14:43:57 christos Exp $ */
/*
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
* @(#)ptyfs_subr.c 8.6 (Berkeley) 5/14/95
*/
/*
* Copyright (c) 1994 Christopher G. Demetriou. All rights reserved.
* Copyright (c) 1993 Jan-Simon Pendry
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
* @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ptyfs_subr.c,v 1.34 2020/11/27 14:43:57 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/filedesc.h>
#include <sys/select.h>
#include <sys/tty.h>
#include <sys/pty.h>
#include <sys/kauth.h>
#include <sys/lwp.h>
#include <fs/ptyfs/ptyfs.h>
static kmutex_t ptyfs_hashlock;
static SLIST_HEAD(ptyfs_hashhead, ptyfsnode) *ptyfs_node_tbl;
static u_long ptyfs_node_mask; /* size of hash table - 1 */
/*
* allocate a ptyfsnode/vnode pair. the vnode is referenced.
*
* the pty, ptyfs_type, and mount point uniquely
* identify a ptyfsnode. the mount point is needed
* because someone might mount this filesystem
* twice.
*/
int
ptyfs_allocvp(struct mount *mp, struct vnode **vpp, ptyfstype type, int pty)
{
struct ptyfskey key;
memset(&key, 0, sizeof(key));
key.ptk_pty = pty;
key.ptk_type = type;
return vcache_get(mp, &key, sizeof(key), vpp);
}
/*
* Initialize ptyfsnode hash table.
*/
void
ptyfs_hashinit(void)
{
ptyfs_node_tbl = hashinit(16, HASH_SLIST, true, &ptyfs_node_mask);
mutex_init(&ptyfs_hashlock, MUTEX_DEFAULT, IPL_NONE);
}
/*
* Free ptyfsnode hash table.
*/
void
ptyfs_hashdone(void)
{
mutex_destroy(&ptyfs_hashlock);
hashdone(ptyfs_node_tbl, HASH_SLIST, ptyfs_node_mask);
}
/*
* Get a ptyfsnode from the hash table, or allocate one.
*/
struct ptyfsnode *
ptyfs_get_node(ptyfstype type, int pty)
{
struct ptyfs_hashhead *ppp;
struct ptyfsnode *pp;
ppp = &ptyfs_node_tbl[PTYFS_FILENO(type, pty) & ptyfs_node_mask];
mutex_enter(&ptyfs_hashlock);
SLIST_FOREACH(pp, ppp, ptyfs_hash) {
if (pty == pp->ptyfs_pty && pp->ptyfs_type == type) {
mutex_exit(&ptyfs_hashlock);
return pp;
}
}
mutex_exit(&ptyfs_hashlock);
pp = malloc(sizeof(struct ptyfsnode), M_TEMP, M_WAITOK);
pp->ptyfs_pty = pty;
pp->ptyfs_type = type;
pp->ptyfs_fileno = PTYFS_FILENO(type, pty);
if (pp->ptyfs_type == PTYFSroot)
pp->ptyfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|
S_IROTH|S_IXOTH;
else
pp->ptyfs_mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|
S_IROTH|S_IWOTH;
pp->ptyfs_uid = pp->ptyfs_gid = 0;
pp->ptyfs_status = PTYFS_CHANGE;
PTYFS_ITIMES(pp, NULL, NULL, NULL);
pp->ptyfs_birthtime = pp->ptyfs_mtime =
pp->ptyfs_atime = pp->ptyfs_ctime;
pp->ptyfs_flags = 0;
mutex_enter(&ptyfs_hashlock);
/*
* XXX We have minimum race condition when opening master side
* first time, if other threads through other mount points, trying
* opening the same device. As follow we have little chance have
* unused list entries.
*/
SLIST_INSERT_HEAD(ppp, pp, ptyfs_hash);
mutex_exit(&ptyfs_hashlock);
return pp;
}
/*
* Mark this controlling pty as active.
*/
void
ptyfs_set_active(struct mount *mp, int pty)
{
struct ptyfsmount *pmnt = VFSTOPTY(mp);
KASSERT(pty >= 0);
/* Reallocate map if needed. */
if (pty >= pmnt->pmnt_bitmap_size * NBBY) {
int osize, nsize;
uint8_t *obitmap, *nbitmap;
nsize = roundup(howmany(pty + 1, NBBY), 64);
nbitmap = kmem_alloc(nsize, KM_SLEEP);
mutex_enter(&pmnt->pmnt_lock);
if (pty < pmnt->pmnt_bitmap_size * NBBY) {
mutex_exit(&pmnt->pmnt_lock);
kmem_free(nbitmap, nsize);
} else {
osize = pmnt->pmnt_bitmap_size;
obitmap = pmnt->pmnt_bitmap;
pmnt->pmnt_bitmap_size = nsize;
pmnt->pmnt_bitmap = nbitmap;
if (osize > 0)
memcpy(pmnt->pmnt_bitmap, obitmap, osize);
memset(pmnt->pmnt_bitmap + osize, 0, nsize - osize);
mutex_exit(&pmnt->pmnt_lock);
if (osize > 0)
kmem_free(obitmap, osize);
}
}
mutex_enter(&pmnt->pmnt_lock);
setbit(pmnt->pmnt_bitmap, pty);
mutex_exit(&pmnt->pmnt_lock);
}
/*
* Mark this controlling pty as inactive.
*/
void
ptyfs_clr_active(struct mount *mp, int pty)
{
struct ptyfsmount *pmnt = VFSTOPTY(mp);
KASSERT(pty >= 0);
mutex_enter(&pmnt->pmnt_lock);
if (pty >= 0 && pty < pmnt->pmnt_bitmap_size * NBBY)
clrbit(pmnt->pmnt_bitmap, pty);
mutex_exit(&pmnt->pmnt_lock);
}
/*
* Lookup the next active controlling pty greater or equal "pty".
* Return -1 if not found.
*/
int
ptyfs_next_active(struct mount *mp, int pty)
{
struct ptyfsmount *pmnt = VFSTOPTY(mp);
KASSERT(pty >= 0);
mutex_enter(&pmnt->pmnt_lock);
while (pty < pmnt->pmnt_bitmap_size * NBBY) {
if (isset(pmnt->pmnt_bitmap, pty)) {
mutex_exit(&pmnt->pmnt_lock);
return pty;
}
pty++;
}
mutex_exit(&pmnt->pmnt_lock);
return -1;
}