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authorEd Schouten <ed@FreeBSD.org>2008-09-22 19:25:14 +0000
committerEd Schouten <ed@FreeBSD.org>2008-09-22 19:25:14 +0000
commita1215e37a4a98f22c84d4512dd380761376e8231 (patch)
treeb0edacd4932fd8b74d222a3adf26ec514131733e
parent9545354ed523b2155638c43d4c2cc60498cfad4e (diff)
downloadsrc-a1215e37a4a98f22c84d4512dd380761376e8231.tar.gz
src-a1215e37a4a98f22c84d4512dd380761376e8231.zip
Introduce a hooks layer for the MPSAFE TTY layer.
One of the features that prevented us from fixing some of the TTY consumers to work once again, was an interface that allowed consumers to do the following: - `Sniff' incoming data, which is used by the snp(4) driver. - Take direct control of the input and output paths of a TTY, which is used by ng_tty(4), ppp(4), sl(4), etc. There's no practical advantage in committing a hooks layer without having any consumers. In P4 there is a preliminary port of snp(4) and thompsa@ is busy porting ng_tty(4) to this interface. I already want to have it in the tree, because this may stimulate others to work on the remaining modules. Discussed with: thompsa Obtained from: //depot/projects/mpsafetty/...
Notes
Notes: svn path=/head/; revision=183276
-rw-r--r--sys/kern/tty.c90
-rw-r--r--sys/kern/tty_ttydisc.c101
-rw-r--r--sys/sys/tty.h10
-rw-r--r--sys/sys/ttydevsw.h4
-rw-r--r--sys/sys/ttydisc.h34
-rw-r--r--sys/sys/ttyhook.h147
-rw-r--r--usr.sbin/pstat/pstat.82
-rw-r--r--usr.sbin/pstat/pstat.c1
8 files changed, 341 insertions, 48 deletions
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index cd6a246f8fa1..863b6ce923f1 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
+#include <sys/file.h>
#include <sys/filio.h>
#ifdef COMPAT_43TTY
#include <sys/ioctl_compat.h>
@@ -59,6 +60,7 @@ __FBSDID("$FreeBSD$");
#include <sys/ttydefaults.h>
#undef TTYDEFCHARS
#include <sys/ucred.h>
+#include <sys/vnode.h>
#include <machine/stdarg.h>
@@ -855,7 +857,7 @@ tty_alloc(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
tp->t_devsw = tsw;
- tp->t_softc = sc;
+ tp->t_devswsoftc = sc;
tp->t_flags = tsw->tsw_flags;
tty_init_termios(tp);
@@ -923,7 +925,7 @@ tty_rel_free(struct tty *tp)
tty_lock_assert(tp, MA_OWNED);
if (tp->t_sessioncnt != 0 ||
- (tp->t_flags & (TF_GONE|TF_OPENED)) != TF_GONE) {
+ (tp->t_flags & (TF_GONE|TF_OPENED|TF_HOOK)) != TF_GONE) {
/* TTY is still in use. */
tty_unlock(tp);
return;
@@ -1653,6 +1655,89 @@ tty_hiwat_in_unblock(struct tty *tp)
ttydevsw_inwakeup(tp);
}
+static int
+ttyhook_defrint(struct tty *tp, char c, int flags)
+{
+
+ if (ttyhook_rint_bypass(tp, &c, 1) != 1)
+ return (-1);
+
+ return (0);
+}
+
+int
+ttyhook_register(struct tty **rtp, struct thread *td, int fd,
+ struct ttyhook *th, void *softc)
+{
+ struct tty *tp;
+ struct file *fp;
+ struct cdev *dev;
+ struct cdevsw *cdp;
+ int error;
+
+ /* Validate the file descriptor. */
+ if (fget(td, fd, &fp) != 0)
+ return (EINVAL);
+
+ /* Make sure the vnode is bound to a character device. */
+ error = EINVAL;
+ if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR ||
+ fp->f_vnode->v_rdev == NULL)
+ goto done1;
+ dev = fp->f_vnode->v_rdev;
+
+ /* Make sure it is a TTY. */
+ cdp = dev_refthread(dev);
+ if (cdp == NULL)
+ goto done1;
+ if ((cdp->d_flags & D_TTY) == 0)
+ goto done2;
+ tp = dev->si_drv1;
+
+ /* Try to attach the hook to the TTY. */
+ error = EBUSY;
+ tty_lock(tp);
+ MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
+ if (tp->t_flags & TF_HOOK)
+ goto done3;
+
+ tp->t_flags |= TF_HOOK;
+ tp->t_hook = th;
+ tp->t_hooksoftc = softc;
+ *rtp = tp;
+ error = 0;
+
+ /* Maybe we can switch into bypass mode now. */
+ ttydisc_optimize(tp);
+
+ /* Silently convert rint() calls to rint_bypass() when possible. */
+ if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
+ th->th_rint = ttyhook_defrint;
+
+done3: tty_unlock(tp);
+done2: dev_relthread(dev);
+done1: fdrop(fp, td);
+ return (error);
+}
+
+void
+ttyhook_unregister(struct tty *tp)
+{
+
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(tp->t_flags & TF_HOOK);
+
+ /* Disconnect the hook. */
+ tp->t_flags &= ~TF_HOOK;
+ tp->t_hook = NULL;
+
+ /* Maybe we need to leave bypass mode. */
+ ttydisc_optimize(tp);
+
+ /* Maybe deallocate the TTY as well. */
+ tty_rel_free(tp);
+}
+
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
@@ -1686,6 +1771,7 @@ static struct {
{ TF_EXCLUDE, 'X' },
{ TF_BYPASS, 'l' },
{ TF_ZOMBIE, 'Z' },
+ { TF_HOOK, 's' },
{ 0, '\0' },
};
diff --git a/sys/kern/tty_ttydisc.c b/sys/kern/tty_ttydisc.c
index 693b480d5340..0d7dd7f33d93 100644
--- a/sys/kern/tty_ttydisc.c
+++ b/sys/kern/tty_ttydisc.c
@@ -79,6 +79,8 @@ SYSCTL_LONG(_kern, OID_AUTO, tty_nout, CTLFLAG_RD,
#define CTL_ALNUM(c) (((c) >= '0' && (c) <= '9') || \
((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
+#define TTY_STACKBUF 256
+
void
ttydisc_open(struct tty *tp)
{
@@ -100,6 +102,9 @@ ttydisc_close(struct tty *tp)
ttydevsw_inwakeup(tp);
ttydevsw_outwakeup(tp);
}
+
+ if (ttyhook_hashook(tp, close))
+ ttyhook_close(tp);
}
static int
@@ -433,7 +438,7 @@ ttydisc_write_oproc(struct tty *tp, char c)
int
ttydisc_write(struct tty *tp, struct uio *uio, int ioflag)
{
- char ob[256];
+ char ob[TTY_STACKBUF];
char *obstart;
int error = 0;
unsigned int oblen = 0;
@@ -557,11 +562,12 @@ ttydisc_optimize(struct tty *tp)
{
tty_lock_assert(tp, MA_OWNED);
- if (!CMP_FLAG(i, ICRNL|IGNCR|IMAXBEL|INLCR|ISTRIP|IXON) &&
+ if ((!CMP_FLAG(i, ICRNL|IGNCR|IMAXBEL|INLCR|ISTRIP|IXON) &&
(!CMP_FLAG(i, BRKINT) || CMP_FLAG(i, IGNBRK)) &&
(!CMP_FLAG(i, PARMRK) ||
CMP_FLAG(i, IGNPAR|IGNBRK) == (IGNPAR|IGNBRK)) &&
- !CMP_FLAG(l, ECHO|ICANON|IEXTEN|ISIG|PENDIN)) {
+ !CMP_FLAG(l, ECHO|ICANON|IEXTEN|ISIG|PENDIN)) ||
+ ttyhook_hashook(tp, rint_bypass)) {
tp->t_flags |= TF_BYPASS;
} else {
tp->t_flags &= ~TF_BYPASS;
@@ -818,6 +824,9 @@ ttydisc_rint(struct tty *tp, char c, int flags)
tty_lock_assert(tp, MA_OWNED);
atomic_add_long(&tty_nin, 1);
+
+ if (ttyhook_hashook(tp, rint))
+ return ttyhook_rint(tp, c, flags);
if (tp->t_flags & TF_BYPASS)
goto processed;
@@ -1045,6 +1054,9 @@ ttydisc_rint_bypass(struct tty *tp, const void *buf, size_t len)
atomic_add_long(&tty_nin, len);
+ if (ttyhook_hashook(tp, rint_bypass))
+ return ttyhook_rint_bypass(tp, buf, len);
+
ret = ttyinq_write(&tp->t_inq, buf, len, 0);
ttyinq_canonicalize(&tp->t_inq);
@@ -1057,12 +1069,38 @@ ttydisc_rint_done(struct tty *tp)
tty_lock_assert(tp, MA_OWNED);
+ if (ttyhook_hashook(tp, rint_done))
+ ttyhook_rint_done(tp);
+
/* Wake up readers. */
tty_wakeup(tp, FREAD);
/* Wake up driver for echo. */
ttydevsw_outwakeup(tp);
}
+size_t
+ttydisc_rint_poll(struct tty *tp)
+{
+ size_t l;
+
+ tty_lock_assert(tp, MA_OWNED);
+
+ if (ttyhook_hashook(tp, rint_poll))
+ return ttyhook_rint_poll(tp);
+
+ /*
+ * XXX: Still allow character input when there's no space in the
+ * buffers, but we haven't entered the high watermark. This is
+ * to allow backspace characters to be inserted when in
+ * canonical mode.
+ */
+ l = ttyinq_bytesleft(&tp->t_inq);
+ if (l == 0 && (tp->t_flags & TF_HIWAT_IN) == 0)
+ return (1);
+
+ return (l);
+}
+
static void
ttydisc_wakeup_watermark(struct tty *tp)
{
@@ -1093,9 +1131,15 @@ ttydisc_getc(struct tty *tp, void *buf, size_t len)
if (tp->t_flags & TF_STOPPED)
return (0);
+ if (ttyhook_hashook(tp, getc_inject))
+ return ttyhook_getc_inject(tp, buf, len);
+
len = ttyoutq_read(&tp->t_outq, buf, len);
- ttydisc_wakeup_watermark(tp);
+ if (ttyhook_hashook(tp, getc_capture))
+ ttyhook_getc_capture(tp, buf, len);
+
+ ttydisc_wakeup_watermark(tp);
atomic_add_long(&tty_nout, len);
return (len);
@@ -1104,22 +1148,63 @@ ttydisc_getc(struct tty *tp, void *buf, size_t len)
int
ttydisc_getc_uio(struct tty *tp, struct uio *uio)
{
- int error;
+ int error = 0;
int obytes = uio->uio_resid;
+ size_t len;
+ char buf[TTY_STACKBUF];
tty_lock_assert(tp, MA_OWNED);
if (tp->t_flags & TF_STOPPED)
return (0);
- error = ttyoutq_read_uio(&tp->t_outq, tp, uio);
- ttydisc_wakeup_watermark(tp);
+ /*
+ * When a TTY hook is attached, we cannot perform unbuffered
+ * copying to userspace. Just call ttydisc_getc() and
+ * temporarily store data in a shadow buffer.
+ */
+ if (ttyhook_hashook(tp, getc_capture) ||
+ ttyhook_hashook(tp, getc_inject)) {
+ while (uio->uio_resid > 0) {
+ /* Read to shadow buffer. */
+ len = ttydisc_getc(tp, buf,
+ MIN(uio->uio_resid, sizeof buf));
+ if (len == 0)
+ break;
+
+ /* Copy to userspace. */
+ tty_unlock(tp);
+ error = uiomove(buf, len, uio);
+ tty_lock(tp);
+
+ if (error != 0)
+ break;
+ }
+ } else {
+ error = ttyoutq_read_uio(&tp->t_outq, tp, uio);
- atomic_add_long(&tty_nout, obytes - uio->uio_resid);
+ ttydisc_wakeup_watermark(tp);
+ atomic_add_long(&tty_nout, obytes - uio->uio_resid);
+ }
return (error);
}
+size_t
+ttydisc_getc_poll(struct tty *tp)
+{
+
+ tty_lock_assert(tp, MA_OWNED);
+
+ if (tp->t_flags & TF_STOPPED)
+ return (0);
+
+ if (ttyhook_hashook(tp, getc_poll))
+ return ttyhook_getc_poll(tp);
+
+ return ttyoutq_bytesused(&tp->t_outq);
+}
+
/*
* XXX: not really related to the TTYDISC, but we'd better put
* tty_putchar() here, because we need to perform proper output
diff --git a/sys/sys/tty.h b/sys/sys/tty.h
index 54d487cb495f..2250cbc2b1fd 100644
--- a/sys/sys/tty.h
+++ b/sys/sys/tty.h
@@ -80,6 +80,7 @@ struct tty {
#define TF_EXCLUDE 0x1000 /* Exclusive access. */
#define TF_BYPASS 0x2000 /* Optimized input path. */
#define TF_ZOMBIE 0x4000 /* Modem disconnect received. */
+#define TF_HOOK 0x8000 /* TTY has hook attached. */
unsigned int t_revokecnt; /* (t) revoke() count. */
/* Buffering mechanisms. */
@@ -112,13 +113,15 @@ struct tty {
struct termios t_termios_lock_out; /* cua%s.lock. */
struct ttydevsw *t_devsw; /* (c) Driver hooks. */
+ struct ttyhook *t_hook; /* (t) Capture/inject hook. */
/* Process signal delivery. */
struct pgrp *t_pgrp; /* (t) Foreground process group. */
struct session *t_session; /* (t) Associated session. */
unsigned int t_sessioncnt; /* (t) Backpointing sessions. */
- void *t_softc; /* (c) Soft config, for drivers. */
+ void *t_devswsoftc; /* (c) Soft config, for drivers. */
+ void *t_hooksoftc; /* (t) Soft config, for hooks. */
struct cdev *t_dev; /* (c) Primary character device. */
};
@@ -181,7 +184,7 @@ void tty_hiwat_in_unblock(struct tty *tp);
dev_t tty_udev(struct tty *tp);
#define tty_opened(tp) ((tp)->t_flags & TF_OPENED)
#define tty_gone(tp) ((tp)->t_flags & TF_GONE)
-#define tty_softc(tp) ((tp)->t_softc)
+#define tty_softc(tp) ((tp)->t_devswsoftc)
#define tty_devname(tp) devtoname((tp)->t_dev)
/* Status line printing. */
@@ -192,8 +195,9 @@ int pts_alloc_external(int fd, struct thread *td, struct file *fp,
struct cdev *dev, const char *name);
/* Drivers and line disciplines also need to call these. */
-#include <sys/ttydevsw.h>
#include <sys/ttydisc.h>
+#include <sys/ttydevsw.h>
+#include <sys/ttyhook.h>
#endif /* _KERNEL */
#endif /* !_SYS_TTY_H_ */
diff --git a/sys/sys/ttydevsw.h b/sys/sys/ttydevsw.h
index 842143d6d911..e2278c3ab432 100644
--- a/sys/sys/ttydevsw.h
+++ b/sys/sys/ttydevsw.h
@@ -97,9 +97,7 @@ ttydevsw_outwakeup(struct tty *tp)
MPASS(!tty_gone(tp));
/* Prevent spurious wakeups. */
- if (tp->t_flags & TF_STOPPED)
- return;
- if (ttyoutq_bytesused(&tp->t_outq) == 0)
+ if (ttydisc_getc_poll(tp) == 0)
return;
tp->t_devsw->tsw_outwakeup(tp);
diff --git a/sys/sys/ttydisc.h b/sys/sys/ttydisc.h
index aeaabc6602f6..2ea54666c56a 100644
--- a/sys/sys/ttydisc.h
+++ b/sys/sys/ttydisc.h
@@ -54,8 +54,10 @@ void ttydisc_modem(struct tty *tp, int open);
int ttydisc_rint(struct tty *tp, char c, int flags);
size_t ttydisc_rint_bypass(struct tty *tp, const void *buf, size_t len);
void ttydisc_rint_done(struct tty *tp);
+size_t ttydisc_rint_poll(struct tty *tp);
size_t ttydisc_getc(struct tty *tp, void *buf, size_t len);
int ttydisc_getc_uio(struct tty *tp, struct uio *uio);
+size_t ttydisc_getc_poll(struct tty *tp);
/* Error codes for ttydisc_rint(). */
#define TRE_FRAMING 0x01
@@ -81,36 +83,4 @@ ttydisc_write_poll(struct tty *tp)
return ttyoutq_bytesleft(&tp->t_outq);
}
-static __inline size_t
-ttydisc_rint_poll(struct tty *tp)
-{
- size_t l;
-
- tty_lock_assert(tp, MA_OWNED);
-
- /*
- * XXX: Still allow character input when there's no space in the
- * buffers, but we haven't entered the high watermark. This is
- * to allow backspace characters to be inserted when in
- * canonical mode.
- */
- l = ttyinq_bytesleft(&tp->t_inq);
- if (l == 0 && (tp->t_flags & TF_HIWAT_IN) == 0)
- return (1);
-
- return (l);
-}
-
-static __inline size_t
-ttydisc_getc_poll(struct tty *tp)
-{
-
- tty_lock_assert(tp, MA_OWNED);
-
- if (tp->t_flags & TF_STOPPED)
- return (0);
-
- return ttyoutq_bytesused(&tp->t_outq);
-}
-
#endif /* !_SYS_TTYDISC_H_ */
diff --git a/sys/sys/ttyhook.h b/sys/sys/ttyhook.h
new file mode 100644
index 000000000000..7a0a0bc13f52
--- /dev/null
+++ b/sys/sys/ttyhook.h
@@ -0,0 +1,147 @@
+/*-
+ * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_TTYHOOK_H_
+#define _SYS_TTYHOOK_H_
+
+#ifndef _SYS_TTY_H_
+#error "can only be included through <sys/tty.h>"
+#endif /* !_SYS_TTY_H_ */
+
+struct tty;
+
+/*
+ * Hooks interface, which allows to capture and inject traffic into the
+ * input and output paths of a TTY.
+ */
+
+typedef int th_rint_t(struct tty *tp, char c, int flags);
+typedef size_t th_rint_bypass_t(struct tty *tp, const void *buf, size_t len);
+typedef void th_rint_done_t(struct tty *tp);
+typedef size_t th_rint_poll_t(struct tty *tp);
+
+typedef size_t th_getc_inject_t(struct tty *tp, void *buf, size_t len);
+typedef void th_getc_capture_t(struct tty *tp, const void *buf, size_t len);
+typedef size_t th_getc_poll_t(struct tty *tp);
+
+typedef void th_close_t(struct tty *tp);
+
+struct ttyhook {
+ /* Character input. */
+ th_rint_t *th_rint;
+ th_rint_bypass_t *th_rint_bypass;
+ th_rint_done_t *th_rint_done;
+ th_rint_poll_t *th_rint_poll;
+
+ /* Character output. */
+ th_getc_inject_t *th_getc_inject;
+ th_getc_capture_t *th_getc_capture;
+ th_getc_poll_t *th_getc_poll;
+
+ th_close_t *th_close;
+};
+
+int ttyhook_register(struct tty **, struct thread *, int,
+ struct ttyhook *, void *);
+void ttyhook_unregister(struct tty *);
+#define ttyhook_softc(tp) ((tp)->t_hooksoftc)
+#define ttyhook_hashook(tp,hook) ((tp)->t_hook != NULL && \
+ (tp)->t_hook->th_ ## hook != NULL)
+
+static __inline int
+ttyhook_rint(struct tty *tp, char c, int flags)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ return tp->t_hook->th_rint(tp, c, flags);
+}
+
+static __inline size_t
+ttyhook_rint_bypass(struct tty *tp, const void *buf, size_t len)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ return tp->t_hook->th_rint_bypass(tp, buf, len);
+}
+
+static __inline void
+ttyhook_rint_done(struct tty *tp)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ tp->t_hook->th_rint_done(tp);
+}
+
+static __inline size_t
+ttyhook_rint_poll(struct tty *tp)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ return tp->t_hook->th_rint_poll(tp);
+}
+
+static __inline size_t
+ttyhook_getc_inject(struct tty *tp, void *buf, size_t len)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ return tp->t_hook->th_getc_inject(tp, buf, len);
+}
+
+static __inline void
+ttyhook_getc_capture(struct tty *tp, const void *buf, size_t len)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ tp->t_hook->th_getc_capture(tp, buf, len);
+}
+
+static __inline size_t
+ttyhook_getc_poll(struct tty *tp)
+{
+ tty_lock_assert(tp, MA_OWNED);
+ MPASS(!tty_gone(tp));
+
+ return tp->t_hook->th_getc_poll(tp);
+}
+
+static __inline void
+ttyhook_close(struct tty *tp)
+{
+ tty_lock_assert(tp, MA_OWNED);
+
+ tp->t_hook->th_close(tp);
+}
+
+#endif /* !_SYS_TTYHOOK_H_ */
diff --git a/usr.sbin/pstat/pstat.8 b/usr.sbin/pstat/pstat.8
index 2770cb7afeab..5474f8ba19a6 100644
--- a/usr.sbin/pstat/pstat.8
+++ b/usr.sbin/pstat/pstat.8
@@ -202,6 +202,8 @@ output stopped (ixon flow control)
block mode input routine in use
.It Z
connection lost
+.It s
+i/o being snooped
.El
.Pp
The
diff --git a/usr.sbin/pstat/pstat.c b/usr.sbin/pstat/pstat.c
index 51828cbca705..a1e81b3f43eb 100644
--- a/usr.sbin/pstat/pstat.c
+++ b/usr.sbin/pstat/pstat.c
@@ -312,6 +312,7 @@ static struct {
{ TF_EXCLUDE, 'X' },
{ TF_BYPASS, 'l' },
{ TF_ZOMBIE, 'Z' },
+ { TF_HOOK, 's' },
{ 0, '\0' },
};