This is a port of dp-3.1.3 to SunOS 4.  It is known to compile and work on
SunOS 4.1.3_U1 ("Solaris 1.1.1") and SunOS 5.3 ("Solaris 2.3").

I have made the following changes:

ppp/

  mostly replaced with a version adapted from ppp-2.1.2

dpd/

  the Solaris 2 dlpi kernel interfaces are emulated in SunOS 4
  (by routines in misc.c and a big ifdef in dpd.c's main loop).

  a malloc error in access.c is fixed.

dpconfig/

  moved from the conf directory - this is only used in Solaris 2

h/

  dp_str.h (only used in SunOS 4) has acquired bits of dpio.h
  (which is only used in Solaris 2) and the Solaris 2 <sys/dlpi.h>

sys-sunos5/

  is the former dp-3.1.3 "sys" directory.  The Solaris 2 adb
  scripts have been moved here.

sys-sunos4/

  is the former dp-2.3.2 "sys" directory, together with the
  dp-2.3.2 header files only used in the kernel code

conf/

  dpctl and install updated for SunOS 4.

  The SunOS4 startup sequence is

    dpctl -l
    dpctl -c
    dpctl -s

  (dpctl needs a little more tidying up)

  /etc/init.d/dpconfig is linked to /etc/rc2.d/S47dpconfig to match
  Sun's S47asppp.  This allows /etc/defaultrouter to point at a dp
  interface.

*/Makefile

  each subdirectory has separate Makefiles for sunos4 and sunos5
  
  I was lazy, this is horrid.

Tim Rylance <tkr@puffball.demon.co.uk> 27th February 1995
