KSSL configuration

Configuration of KSSL instance

ksslcfg(1M) is used to configure kssl proxy. while ksslcfg is mainly a SMF wrapper
(it creates new instance of kssl service) /usr/lib/kssladm is used for sending
commands to kssl module in kernel and receiving answers. This is done via
cmd/cmd-inet/usr.sbin/kssl/kssladm/kssladm.c:kssl~_send~_command() which is called
e.g. from src/cmd/cmd-inet/usr.sbin/kssl/kssladm/kssladm~_create.c:do_create()
when new instance of kssl proxy is created.

The communication with kssl kernel module is done via /dev/kssl and ioctl().
When new instance of kssl proxy is created an entry is added to table
kssl~_entry~_tab. This array is defined as global variable in
src/uts/common/inet/kssl/ksslioctl.c. The kernel counterpart for the ioctl()
interface is in src/uts/common/inet/kssl/ksslioctl.c. So when creating new
instance via ksslcfg create it goes like this:

    kssladm create
      kssl~_send~_command()
         ioctl() // /dev/kssl
          (kernel)
             src/uts/common/inet/kssl/kssl.c:kssl~_ioctl()
                src/uts/common/inet/kssl/ksslioctl.c:kssl~_add~_entry() 
                   create~_kssl~_entry()

kssl kernel module extracts all data provided by userland (certificate,
private key, etc.) via src/uts/common/inet/kssl/ksslioctl.c:extract_certificate(),
extract_private_key etc. and grows the kssl_entry_tab table in kssl~_add~_entry()
if needed. (yes, the table has static size)