Date: Tue, 27 Jun 1995 08:40:02 -0700 From: Christopher Sean Hilton <chris@vindaloo.com> To: freebsd-bugs Subject: bin/569: Slattach behaviour inconsistant Message-ID: <199506271540.IAA18543@freefall.cdrom.com> In-Reply-To: Your message of Tue, 27 Jun 1995 09:51:23 -0500 <199506271451.JAA00314@dagobah.vindaloo.com>
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>Number: 569
>Category: bin
>Synopsis: Slattach behaviour inconsistant
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs (FreeBSD bugs mailing list)
>State: open
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Tue Jun 27 08:40:01 1995
>Originator: Christopher Sean Hilton
>Organization:
>Release: FreeBSD 2.1.0-Development i386
>Environment:
>Description:
Slattach's behaviour when configuring the the slip interface through
the -u option is inconsistant and can cause problems when using
multiple slip interfaces. In it's current form slattach does nothing
to cleanup the interface on Termination. With my setup, SLIP to my
internet provider and SLIP to my laptop, this can lead to having both
slip interfaces set up with the same address pairs.
>How-To-Repeat:
Put up my SLIP internet connection with no active slip interfaces:
slattach -a -h -u slipconfig -s 57600 /dev/cua01
This assigns and configures sl0 to my slip - to internet
connection.
Attach my laptop to my main machine.
slattach -a -h -u laptopconfig -s 57600 /dev/cua00
This assigns and configures sl1 to connect my laptop to my
desktop machine.
Kill the slip connection to my Internet Provider.
This detaches the interface sl0 but doesn't provide a mechanism
for reflecting that change in the interface (e.g. I'd have to
manually ifconfig sl0 delete down here to remove it's routing
and addresses.)
Kill the slip connection to my laptop.
Same as above.
Reestablish the connection to my laptop.
This won't work because sl0 and sl1 are now programmed for the
same address pairs with the same routing metric. In order for
this to work I'd have to manually delete the configuration in
sl1.
>Fix:
Change slattach to run the configure script with parameters
current_unit -1 upon termination of the slattach daemon. (E.g.
slattach -u slipconfig
runs:
slipconfig 0 -1
on termination if it has slip interface #0.
Further, the scripts to configure interfaces would be more symetric if
on startup the configuration script was called with a parameter of -1
for the old interface on startup. This call on interface startup:
slipconfig -1 0
makes the script to configure the interfaces look like this:
old_unit=$1
new_unit=$2
if [ $old_unit != -1 ]; then
ifconfig sl$old_unit delete down
if [ $new_unit == -1 ]; then
route delete default
fi
fi
if [ $new_unit != -1]; then
ifconfig sl$new_unit address1 address2 mtu 1006
if [ $old_unit == -1 ]; then
route add default address2
fi
fi
Here are the diff's to the current slattach to make this all happen:
-------------------------
358,364d357
<
< /*
< * I don't like this behaviour. It removes some symetry that would make
< * writing a little clearer. E.g. on the first call you go from no
< * slip interface (-1) to some slip interface.
< */
< #if 0
367d359
< #endif
461,476d452
<
< /*
< * Send the configure interface command with a new unit of -1
< * This way the script can delete the interface after use.
< */
<
< if (config_cmd) {
< char *s;
< s = (char*) malloc(strlen(config_cmd) + 32);
< sprintf (s, "%s %d %d", config_cmd, unit, -1);
< syslog(LOG_NOTICE, "Configuring %s (sl%d):", dev, unit);
< syslog(LOG_NOTICE, " '%s'", s);
< system(s);
< free (s);
< unit = -1;
< }
-------------------------
I've been using this for the past couple of days and I'm sold.
C.
=~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~=
"Never tell me the odds." | Chris Hilton <chris@chilton.chi.il.us>
-Han Solo | For PGP Key: finger chilton@mcs.net
-~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~--~~==~~-
>Audit-Trail:
>Unformatted:
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