Date: 18 Feb 2001 08:35:47 +0100 From: Cyrille Lefevre <clefevre@poboxes.com> To: "Steve O'Hara-Smith" <steveo@eircom.net> Cc: clefevre@poboxes.com, bobb+freebsd-stable@redbrick.dcu.ie, freebsd-stable@FreeBSD.ORG Subject: Re: More than 256 pty's (revised) Message-ID: <puggtpd8.fsf_-_@gits.dyndns.org> In-Reply-To: "Steve O'Hara-Smith"'s message of "Sat, 17 Feb 2001 18:01:39 %2B0100" References: <20010216172854.A67979@enigma.redbrick.dcu.ie> <20010216202737.1807da64.steveo@eircom.net> <66i9w8zd.fsf@gits.dyndns.org> <20010217180139.5269c474.steveo@eircom.net>
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"Steve O'Hara-Smith" <steveo@eircom.net> writes:
> On 17 Feb 2001 17:49:10 +0100
> Cyrille Lefevre <clefevre@poboxes.com> wrote:
>
> Seems to take it up to 704 ptys (now try explaining quickly how *that*
> number comes up). Don't you also need to disable the test in ptsopen() on
in fact, I made a small mistake in calculation of this magic number
since /dev/tty[vxyzR]* shouldn't be counted. the magic number really
is, using the first pty letter :
((('z' - 'p' + 1) * 2) - 5) * 32 = 17 * 32 = 544 ptys
^ ^ ^^ 0-9a-v
|- p-z plus P-Z
|- less vxyzR
after that, you have to play w/ the second pty letter by extending
the set from 0-9a-v to 0-9a-zA-Z, in that case, the limit is :
17 * 62 = 1054 ptys
[snip, forgive my first quick, dirty and wrong (sorry) patch which
didn't handle well the minor number, see bellow for something much
better, but untested, yet, you're welcome to do it :)]
> I was contemplating something with a /dev/pty/* and /dev/tty/* and
> a really mindless naming convention that wouldn't ever bottom out. I hadn't
> even started working on it.
same about /dev/dsk/*, /dev/rmt/*, etc.
the problem would be the compatibility w/ programs using ptys.
xterm, as an example, only knowns ptys as :
/dev/[tp]ty[pqrstuvwxyzPQRSTUVWXYZ][0123456789abcdefghijklmnopqrstuv]
Index: etc/MAKEDEV
===================================================================
RCS file: /home/ncvs/src/etc/MAKEDEV,v
retrieving revision 1.243.2.20
diff -u -r1.243.2.20 MAKEDEV
--- etc/MAKEDEV 2001/02/03 16:16:40 1.243.2.20
+++ etc/MAKEDEV 2001/02/18 07:23:03
@@ -225,6 +225,19 @@
echo $m
}
+# Convert pty (class,instance) to minor number
+# Handle pty minor numbers greater than 256
+ptyminor()
+{
+ echo $(( (( ($1 + $2) &~ 255) << 8) | (($1 + $2) & 255) ))
+}
+
+# *MUST* be the same as in sys/kern/tty_pty.c and lib/libutil/pty.c
+ptyclassnames=pqrstuwPQSTUVWXYZ
+ptyinstancenames=0123456789abcdefghijklmnopqrstuv
+nptyclass=${#ptyclassnames}
+nptyinstance=${#ptyinstancenames}
+
# Raw partition for disks
dkrawpart=2
@@ -701,34 +714,25 @@
done
;;
pty*)
- class=`expr $i : 'pty\(.*\)'`
- case $class in
- 0) offset=0 name=p;;
- 1) offset=32 name=q;;
- 2) offset=64 name=r;;
- 3) offset=96 name=s;;
-# Note that xterm (at least) only look at p-s.
- 4) offset=128 name=P;;
- 5) offset=160 name=Q;;
- 6) offset=192 name=R;;
- 7) offset=224 name=S;;
- # This still leaves [tuTU].
- *) echo bad unit for pty in: $i;;
- esac
umask 0
- case $class in
- 0|1|2|3|4|5|6|7)
+ class=`expr $i : 'pty\(.*\)'`
+ if [ -n "$class" -a "$class" -lt $nptyclass ]; then
+ name=$(echo $ptyclassnames |
+ dd bs=1 skip=$class count=1 2>/dev/null)
+ offset=$(($class * 32))
i=0
while [ $i -lt 32 ]; do
# This was an awk substr() before.
- c=$(echo 0123456789abcdefghijklmnopqrstuv |
+ c=$(echo $ptyinstancenames |
dd bs=1 skip=$i count=1 2>/dev/null)
- mknod tty$name$c c 5 $(($offset + $i))
- mknod pty$name$c c 6 $(($offset + $i))
+ minor=$(ptyminor $offset $i)
+ mknod tty$name$c c 5 $minor
+ mknod pty$name$c c 6 $minor
i=$(($i + 1))
done
- ;;
- esac
+ else
+ echo bad unit for pty in: $i
+ fi
umask 77
;;
Index: lib/libutil/pty.c
===================================================================
RCS file: /home/ncvs/src/lib/libutil/pty.c,v
retrieving revision 1.10
diff -u -r1.10 pty.c
--- lib/libutil/pty.c 1999/08/28 00:05:51 1.10
+++ lib/libutil/pty.c 2001/02/18 07:23:18
@@ -53,6 +53,10 @@
#include <unistd.h>
#include <libutil.h>
+/* *MUST* be the same as in sys/kern/tty_pty.c and etc/MAKEDEV */
+#define ptyclassnames "pqrstuwPQSTUVWXYZ"
+#define ptyinstancenames "0123456789abcdefghijklmnopqrstuv"
+
int
openpty(amaster, aslave, name, termp, winp)
int *amaster, *aslave;
@@ -70,9 +74,9 @@
else
ttygid = -1;
- for (cp1 = "pqrsPQRS"; *cp1; cp1++) {
+ for (cp1 = ptyclassnames; *cp1; cp1++) {
line[8] = *cp1;
- for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) {
+ for (cp2 = ptyinstancenames; *cp2; cp2++) {
line[5] = 'p';
line[9] = *cp2;
if ((master = open(line, O_RDWR, 0)) == -1) {
Index: share/man/man4/pty.4
===================================================================
RCS file: /home/ncvs/src/share/man/man4/pty.4,v
retrieving revision 1.8.2.1
diff -u -r1.8.2.1 pty.4
--- share/man/man4/pty.4 2000/12/08 14:59:07 1.8.2.1
+++ share/man/man4/pty.4 2001/02/18 07:17:36
@@ -191,10 +191,10 @@
is required.
.El
.Sh FILES
-.Bl -tag -width /dev/tty[p-sP-S][0-9a-v]x -compact
-.It Pa /dev/pty[p-sP-S][0-9a-v]
+.Bl -tag -width /dev/tty[p-uwPQS-Z][0-9a-v]x -compact
+.It Pa /dev/pty[p-uwPQS-Z][0-9a-v]
master pseudo terminals
-.It Pa /dev/tty[p-sP-S][0-9a-v]
+.It Pa /dev/tty[p-uwPQS-Z][0-9a-v]
slave pseudo terminals
.El
.Sh DIAGNOSTICS
Index: sys/kern/tty_pty.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/tty_pty.c,v
retrieving revision 1.74
diff -u -r1.74 tty_pty.c
--- sys/kern/tty_pty.c 2000/02/09 03:32:11 1.74
+++ sys/kern/tty_pty.c 2001/02/18 07:32:05
@@ -127,33 +127,46 @@
#define PF_NOSTOP 0x40
#define PF_UCNTL 0x80 /* user control mode */
+#define ptyminor(x) ((((x) &~ 255) << 8) | ((x) & 255))
+/* *MUST* be the same as in lib/libutil/pty.c and etc/MAKEDEV */
+#define ptyclassnames "pqrstuwPQSTUVWXYZ"
+#define ptyinstancenames "0123456789abcdefghijklmnopqrstuv"
+#define nptyclass (sizeof(ptyclassnames)-1)
+#define nptyinstance (sizeof(ptyinstancenames)-1)
+#define npty (nptyclass*nptyinstance)
+
/*
* This function creates and initializes a pts/ptc pair
+ *
+ * pts == /dev/tty[pqrstuwPQSTUVWXYZ][0123456789abcdefghijklmnopqrstuv]
+ * ptc == /dev/pty[pqrstuwPQSTUVWXYZ][0123456789abcdefghijklmnopqrstuv]
*
- * pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
- * ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
+ * don't use the following master/slave pairs since they names clash w/
+ * other drivers (maybe this should be the reverse?) :
*
- * XXX: define and add mapping of upper minor bits to allow more
- * than 256 ptys.
+ * ttyv == syscons
+ * tty[xyz] == Cronyx/Sigma
+ * ttyR == Rocketport
+ *
*/
static void
ptyinit(n)
int n;
{
dev_t devs, devc;
- char *names = "pqrsPQRS";
+ char *names = ptyclassnames;
struct pt_ioctl *pt;
- /* For now we only map the lower 8 bits of the minor */
- if (n & ~0xff)
+ /* be safe */
+ if (n > npty)
return;
pt = malloc(sizeof(*pt), M_PTY, M_WAITOK);
bzero(pt, sizeof(*pt));
pt->devs = devs = make_dev(&pts_cdevsw, n,
- 0, 0, 0666, "tty%c%r", names[n / 32], n % 32);
+ 0, 0, 0666, "tty%c%r", names[n / nptyinstance], n % nptyinstance);
pt->devc = devc = make_dev(&ptc_cdevsw, n,
- 0, 0, 0666, "pty%c%r", names[n / 32], n % 32);
+ 0, 0, 0666, "pty%c%r", names[n / nptyinstance], n % nptyinstance);
devs->si_drv1 = devc->si_drv1 = pt;
devs->si_tty = devc->si_tty = &pt->pt_tty;
@@ -169,7 +182,7 @@
{
register struct tty *tp;
int error;
- int minr;
+ int minr, nextminr;
dev_t nextdev;
struct pt_ioctl *pti;
@@ -179,14 +192,15 @@
* next one too, so people can open it.
*/
minr = lminor(dev);
- if (minr < 255) {
- nextdev = makedev(major(dev), minr + 1);
+ nextminr = minr+1;
+ if (nextminr < npty) {
+ nextdev = makedev(major(dev), ptyminor(nextminr));
if (!nextdev->si_drv1) {
- ptyinit(minr + 1);
+ ptyinit(nextminr);
}
}
if (!dev->si_drv1)
- ptyinit(minor(dev));
+ ptyinit(minr);
if (!dev->si_drv1)
return(ENXIO);
pti = dev->si_drv1;
@@ -349,9 +363,9 @@
struct pt_ioctl *pti;
if (!dev->si_drv1)
- ptyinit(minor(dev));
+ ptyinit(lminor(dev));
if (!dev->si_drv1)
- return(ENXIO);
+ return(ENXIO);
tp = dev->si_tty;
if (tp->t_oproc)
return (EIO);
Cyrille.
--
home: mailto:clefevre@poboxes.com UNIX is user-friendly; it's just particular
work: mailto:Cyrille.Lefevre@edf.fr about who it chooses to be friends with.
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