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Re: Enhance ptyfs to handle multiple instances.
Hello!
This patch introduces subject.
Some code refactoring, because we have more stronger ptm - ptyfs binding.
BSD pty compatibility improvement.
Main explanation you can see in comments inside.
Also I am not sure about, how, correctly release unused vnode and return it
for system and call reclaim. Before anybody call for it getnewvnode.
fs/ptyfs/ptyfs.h | 21 +++++++++++++++++++++
fs/ptyfs/ptyfs_subr.c | 2 --
fs/ptyfs/ptyfs_vfsops.c | 37 +++++++++++++++++++++++++++++--------
fs/ptyfs/ptyfs_vnops.c | 26 ++++++++++++++++++++++++--
kern/tty_bsdpty.c | 4 ++--
kern/tty_ptm.c | 31 +++++++++++++++++++++++--------
sys/pty.h | 21 ---------------------
7 files changed, 99 insertions(+), 43 deletions(-)
Ilya.
Index: fs/ptyfs/ptyfs.h
===================================================================
RCS file: /cvsil/nbcur/src/sys/fs/ptyfs/ptyfs.h,v
retrieving revision 1.6
diff -u -p -r1.6 ptyfs.h
--- fs/ptyfs/ptyfs.h 24 Mar 2014 20:48:08 -0000 1.6
+++ fs/ptyfs/ptyfs.h 1 Apr 2014 19:00:15 -0000
@@ -106,6 +106,8 @@ struct ptyfsnode {
};
struct ptyfsmount {
+ LIST_ENTRY(ptyfsmount) pmnt_le;
+ struct mount *pmnt_mp;
gid_t pmnt_gid;
mode_t pmnt_mode;
int pmnt_flags;
@@ -113,6 +115,25 @@ struct ptyfsmount {
#define VFSTOPTY(mp) ((struct ptyfsmount *)(mp)->mnt_data)
+LIST_HEAD(ptyfs_lhmp, ptyfsmount);
+
+/*
+ * Ptm_pty is used for switch ptm{x} driver between BSDPTY, PTYFS.
+ * Functions' argument (struct mount *) is used only PTYFS,
+ * in the case BSDPTY can be NULL, and arg must be NULL.
+ */
+struct ptm_pty {
+ int (*allocvp)(struct mount *, struct lwp *, struct vnode **, dev_t,
+ char);
+ int (*makename)(struct mount *, struct lwp *, char *, size_t, dev_t,
char);
+ void (*getvattr)(struct mount *, struct lwp *, struct vattr *);
+ struct ptyfs_lhmp *arg;
+};
+
+dev_t pty_makedev(char, int);
+int pty_vn_open(struct vnode *, struct lwp *);
+struct ptm_pty *pty_sethandler(struct ptm_pty *);
+
#endif /* _KERNEL */
struct ptyfs_args {
Index: fs/ptyfs/ptyfs_subr.c
===================================================================
RCS file: /cvsil/nbcur/src/sys/fs/ptyfs/ptyfs_subr.c,v
retrieving revision 1.6
diff -u -p -r1.6 ptyfs_subr.c
--- fs/ptyfs/ptyfs_subr.c 28 Mar 2014 10:53:57 -0000 1.6
+++ fs/ptyfs/ptyfs_subr.c 1 Apr 2014 19:00:15 -0000
@@ -86,8 +86,6 @@ __KERNEL_RCSID(0, "$NetBSD: ptyfs_subr.c
#include <sys/namei.h>
#include <sys/filedesc.h>
#include <sys/select.h>
-#include <sys/tty.h>
-#include <sys/pty.h>
#include <sys/kauth.h>
#include <sys/lwp.h>
Index: fs/ptyfs/ptyfs_vfsops.c
===================================================================
RCS file: /cvsil/nbcur/src/sys/fs/ptyfs/ptyfs_vfsops.c,v
retrieving revision 1.13
diff -u -p -r1.13 ptyfs_vfsops.c
--- fs/ptyfs/ptyfs_vfsops.c 28 Mar 2014 10:53:57 -0000 1.13
+++ fs/ptyfs/ptyfs_vfsops.c 1 Apr 2014 19:00:15 -0000
@@ -54,8 +54,6 @@ __KERNEL_RCSID(0, "$NetBSD: ptyfs_vfsops
#include <sys/syslog.h>
#include <sys/select.h>
#include <sys/filedesc.h>
-#include <sys/tty.h>
-#include <sys/pty.h>
#include <sys/kauth.h>
#include <sys/module.h>
@@ -83,12 +81,13 @@ static void ptyfs__getvattr(struct mount
*/
struct ptm_pty *ptyfs_save_ptm;
static int ptyfs_count;
+static struct ptyfs_lhmp mph;
struct ptm_pty ptm_ptyfspty = {
ptyfs__allocvp,
ptyfs__makename,
ptyfs__getvattr,
- NULL
+ &mph
};
static const char *
@@ -130,6 +129,7 @@ ptyfs__makename(struct mount *mp, struct
{
size_t len;
const char *np;
+ struct cwdinfo *cwdi = l->l_proc->p_cwdi;
switch (ms) {
case 'p':
@@ -137,6 +137,15 @@ ptyfs__makename(struct mount *mp, struct
len = snprintf(tbuf, bufsiz, "/dev/null");
break;
case 't':
+ /*
+ * We support traditional ptys, so we can get here,
+ * if pty had been opened before PTYFS was mounted,
+ * or was opened through /dev/ptyXX devices.
+ * Return it only outside chroot for more security :).
+ */
+ if (cwdi->cwdi_rdir == NULL && ptyfs_save_ptm != NULL &&
+ ptyfs_used_get(PTYFSptc, minor(dev), mp, 0) ==
NULL)
+ return (*ptyfs_save_ptm->makename)(mp, l, tbuf, bufsiz,
dev, ms);
np = ptyfs__getpath(l, mp);
if (np == NULL)
return EOPNOTSUPP;
@@ -188,7 +197,7 @@ ptyfs__getvattr(struct mount *mp, struct
void
ptyfs_init(void)
{
-
+ LIST_INIT(ptm_ptyfspty.arg);
malloc_type_attach(M_PTYFSMNT);
malloc_type_attach(M_PTYFSTMP);
ptyfs_hashinit();
@@ -218,7 +227,7 @@ ptyfs_mount(struct mount *mp, const char
{
struct lwp *l = curlwp;
int error = 0;
- struct ptyfsmount *pmnt;
+ struct ptyfsmount *pmnt, *pmnt_next;
struct ptyfs_args *args = data;
if (*data_len != sizeof *args && *data_len != OSIZE)
@@ -274,10 +283,16 @@ ptyfs_mount(struct mount *mp, const char
return error;
}
- /* Point pty access to us */
+ pmnt->pmnt_mp = mp;
if (ptyfs_count == 0) {
- ptm_ptyfspty.arg = mp;
+ LIST_INSERT_HEAD(ptm_ptyfspty.arg, pmnt, pmnt_le);
+ /* Point pty access to us */
ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty);
+ } else {
+ pmnt_next = LIST_FIRST(ptm_ptyfspty.arg);
+ while(LIST_NEXT(pmnt_next, pmnt_le) != NULL)
+ pmnt_next = LIST_NEXT(pmnt_next, pmnt_le);
+ LIST_INSERT_AFTER(pmnt_next, pmnt, pmnt_le);
}
ptyfs_count++;
return 0;
@@ -296,6 +311,7 @@ ptyfs_unmount(struct mount *mp, int mntf
{
int error;
int flags = 0;
+ struct ptyfsmount *pmnt;
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
@@ -308,7 +324,12 @@ ptyfs_unmount(struct mount *mp, int mntf
/* Restore where pty access was pointing */
(void)pty_sethandler(ptyfs_save_ptm);
ptyfs_save_ptm = NULL;
- ptm_ptyfspty.arg = NULL;
+ }
+ LIST_FOREACH(pmnt, ptm_ptyfspty.arg, pmnt_le) {
+ if (pmnt->pmnt_mp == mp) {
+ LIST_REMOVE(pmnt, pmnt_le);
+ break;
+ }
}
/*
Index: fs/ptyfs/ptyfs_vnops.c
===================================================================
RCS file: /cvsil/nbcur/src/sys/fs/ptyfs/ptyfs_vnops.c,v
retrieving revision 1.5
diff -u -p -r1.5 ptyfs_vnops.c
--- fs/ptyfs/ptyfs_vnops.c 28 Mar 2014 10:53:58 -0000 1.5
+++ fs/ptyfs/ptyfs_vnops.c 1 Apr 2014 19:00:15 -0000
@@ -94,7 +94,6 @@ __KERNEL_RCSID(0, "$NetBSD: ptyfs_vnops.
#include <sys/resourcevar.h>
#include <sys/stat.h>
#include <sys/conf.h>
-#include <sys/tty.h>
#include <sys/pty.h>
#include <sys/kauth.h>
@@ -140,6 +139,7 @@ int ptyfs_kqfilter (void *);
int ptyfs_readdir (void *);
#define ptyfs_readlink genfs_eopnotsupp
#define ptyfs_abortop genfs_abortop
+int ptyfs_inactive (void *);
int ptyfs_reclaim (void *);
#define ptyfs_lock genfs_lock
#define ptyfs_unlock genfs_unlock
@@ -192,7 +192,7 @@ const struct vnodeopv_entry_desc ptyfs_v
{ &vop_readdir_desc, ptyfs_readdir }, /* readdir */
{ &vop_readlink_desc, ptyfs_readlink }, /* readlink */
{ &vop_abortop_desc, ptyfs_abortop }, /* abortop */
- { &vop_inactive_desc, spec_inactive }, /* inactive */
+ { &vop_inactive_desc, ptyfs_inactive }, /* inactive */
{ &vop_reclaim_desc, ptyfs_reclaim }, /* reclaim */
{ &vop_lock_desc, ptyfs_lock }, /* lock */
{ &vop_unlock_desc, ptyfs_unlock }, /* unlock */
@@ -225,6 +225,28 @@ ptyfs_reclaim(void *v)
return ptyfs_freevp(ap->a_vp);
}
+int
+ptyfs_inactive(void *v)
+{
+ struct vop_inactive_args /* {
+ struct vnode *a_vp;
+ bool *a_recycle;
+ } */ *ap = v;
+ struct vnode *vp = ap->a_vp;
+ struct ptyfsnode *ptyfs = VTOPTYFS(vp);
+
+ switch (ptyfs->ptyfs_type) {
+ case PTYFSpts:
+ case PTYFSptc:
+ /* Emulate file deletion for call reclaim(). */
+ *ap->a_recycle = true;
+ break;
+ default:
+ break;
+ }
+ return spec_inactive(v);
+}
+
/*
* Return POSIX pathconf information applicable to special devices.
*/
Index: kern/tty_bsdpty.c
===================================================================
RCS file: /cvsil/nbcur/src/sys/kern/tty_bsdpty.c,v
retrieving revision 1.5
diff -u -p -r1.5 tty_bsdpty.c
--- kern/tty_bsdpty.c 28 Mar 2014 10:53:58 -0000 1.5
+++ kern/tty_bsdpty.c 1 Apr 2014 19:00:15 -0000
@@ -39,7 +39,6 @@ __KERNEL_RCSID(0, "$NetBSD: tty_bsdpty.c
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/lwp.h>
-#include <sys/tty.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/uio.h>
@@ -50,9 +49,10 @@ __KERNEL_RCSID(0, "$NetBSD: tty_bsdpty.c
#include <sys/filedesc.h>
#include <sys/conf.h>
#include <sys/poll.h>
-#include <sys/pty.h>
#include <sys/kauth.h>
+#include <fs/ptyfs/ptyfs.h>
+
/*
* pts == /dev/tty[pqrs]?
* ptc == /dev/pty[pqrs]?
Index: kern/tty_ptm.c
===================================================================
RCS file: /cvsil/nbcur/src/sys/kern/tty_ptm.c,v
retrieving revision 1.7
diff -u -p -r1.7 tty_ptm.c
--- kern/tty_ptm.c 28 Mar 2014 10:53:58 -0000 1.7
+++ kern/tty_ptm.c 1 Apr 2014 19:00:15 -0000
@@ -38,7 +38,6 @@ __KERNEL_RCSID(0, "$NetBSD: tty_ptm.c,v
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
-#include <sys/tty.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/uio.h>
@@ -53,6 +52,7 @@ __KERNEL_RCSID(0, "$NetBSD: tty_ptm.c,v
#include <sys/pty.h>
#include <sys/kauth.h>
+#include <fs/ptyfs/ptyfs.h>
#include <miscfs/specfs/specdev.h>
#ifdef COMPAT_60
@@ -94,6 +94,7 @@ int
ptyfs_getmp(struct lwp *l, struct mount **mpp) {
struct cwdinfo *cwdi = l->l_proc->p_cwdi;
struct mount *mp;
+ struct ptyfsmount *pmnt;
if (ptm == NULL)
return EOPNOTSUPP;
@@ -103,14 +104,14 @@ ptyfs_getmp(struct lwp *l, struct mount
return 0;
}
- mp = ptm->arg; /* PTYFS */
-
- if (cwdi->cwdi_rdir == NULL)
- goto ok;
-
- if (vn_isunder(mp->mnt_vnodecovered, cwdi->cwdi_rdir, l))
- goto ok;
+ LIST_FOREACH(pmnt, ptm->arg, pmnt_le) { /* PTYFS */
+ mp = pmnt->pmnt_mp;
+ if (cwdi->cwdi_rdir == NULL)
+ goto ok;
+ if (vn_isunder(mp->mnt_vnodecovered, cwdi->cwdi_rdir, l))
+ goto ok;
+ }
*mpp = NULL;
return EOPNOTSUPP;
ok:
@@ -193,6 +194,19 @@ retry:
error = EOPNOTSUPP;
goto bad;
}
+ /*
+ * XXX Since PTYFS has multiple instance support. If we have mounted it
more than
+ * one time, maybe, we must check here ptyfs_used_tbl, on the subject
of occupancy
+ * appropriate ptyfsnode and skip this dev number in this case, because,
+ * pty could has been released, but ptyfs_reclaim hasn't released
appropriate
+ * ptyfsnode, from other mount point yet.
+ * It's important have only one mount point's ptyfsnode for
appropriate device in
+ * ptyfs_used_tbl, else we will have security problem, because every
entry
+ * will have access to this device.
+ * Also we can have not effective vnode use and memory leak in
ptyfs_free_tbl,
+ * where we will accumulate more and more ptyfsnode for the same device.
+ * See ptyfs_free_get.
+ */
if ((error = (*ptm->allocvp)(mp, l, &vp, *dev, 'p')) != 0) {
DPRINTF(("pty_allocvp %d\n", error));
goto bad;
@@ -340,6 +354,7 @@ ptmattach(int n)
if ((ptc_major = cdevsw_lookup_major(&ptc_cdevsw)) == -1)
panic("ptmattach: Can't find pty master in cdevsw");
#ifdef COMPAT_BSDPTY
+ extern struct ptm_pty ptm_bsdpty;
ptm = &ptm_bsdpty;
#endif
}
Index: sys/pty.h
===================================================================
RCS file: /cvsil/nbcur/src/sys/sys/pty.h,v
retrieving revision 1.4
diff -u -p -r1.4 pty.h
--- sys/pty.h 28 Mar 2014 10:53:58 -0000 1.4
+++ sys/pty.h 1 Apr 2014 19:00:15 -0000
@@ -38,28 +38,7 @@ int pty_check(int);
void ptmattach(int);
int pty_fill_ptmget(struct lwp *, dev_t, int, int, void *, struct mount *);
int pty_grant_slave(struct lwp *, dev_t, struct mount *);
-dev_t pty_makedev(char, int);
-int pty_vn_open(struct vnode *, struct lwp *);
-struct ptm_pty *pty_sethandler(struct ptm_pty *);
int ptyfs_getmp(struct lwp *, struct mount **);
-
-/*
- * Ptm_pty is used for switch ptm{x} driver between BSDPTY, PTYFS.
- * Functions' argument (struct mount *) is used only PTYFS,
- * in the case BSDPTY can be NULL, and arg must be NULL.
- */
-struct ptm_pty {
- int (*allocvp)(struct mount *, struct lwp *, struct vnode **, dev_t,
- char);
- int (*makename)(struct mount *, struct lwp *, char *, size_t, dev_t,
char);
- void (*getvattr)(struct mount *, struct lwp *, struct vattr *);
- void *arg;
-};
-
-#ifdef COMPAT_BSDPTY
-extern struct ptm_pty ptm_bsdpty;
-#endif
-
#endif /* NO_DEV_PTM */
extern int npty;
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