Subject: README: pppd filter changes
To: None <>
From: Jason Thorpe <>
List: current-users
Date: 05/12/1999 12:03:58
Hi folks... I've made some changes to the pppd filter code.  Here is the
log message.  The reason for the change is explained there.  This is a
heads-up for all of you who will be running -current once the SUP tree
goes back to the trunk.  I've tested this w/ my Ricochet wireless modem,
but if you encounter any problems, please send-pr(1) them and I'll take
a look.

Module Name:    src
Committed By:   thorpej
Date:           Wed May 12 18:50:56 UTC 1999

Modified Files:
        src/sys/net: if_ppp.c if_ppp.h if_pppvar.h
        src/usr.sbin/pppd/pppd: auth.c demand.c options.c pppd.8 pppd.h
Log Message:
Decouple inbound and outbound filters.  Now instead of using "active-filter"
and "pass-filter" and "inbound" and "outbound" qualifiers in the filter
expression, use new "active-filter-in", "active-filter-out", "pass-filter-in",
and "pass-filter-out" without these qualifiers.

This is necessary due to the horrible, awful way "inbound" and "outbound"
were specified for the filter programs when a packet was passed through them.
Basically, the "address" byte in the serial PPP header was overwritten with
a value to indicate the direction.  However, the "address" byte doesn't even
exist on PPP headers for all other PPP encaps!  So, this old method worked
only for serial encaps, and corrupted packets for all others (PPPoE, ATM, etc.)

        -- Jason R. Thorpe <>