This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
easier to use in mixed environments:
- Add three new members to the request structure:
- a filename specification
- a database type specification
- a system byte prder specification
These allow the client to ask the server for a particular type of
database (Berkeley DB hash/btree/recno, GNU GDBM, dbm, ndbm, etc...)
and get back a meaningful error if the server doesn't support it.
The byte order spec is needed if the database type is byte order
sensntive. You don't, for example, want to read an ndbm database
from a big endian machine on a little endian machine (the ndbm code
will explode). The filename spec lets the client handle things like
ndbm which uses two seperate files per database (foo.dir and foo.pag).
The client can ask for each half, one at a time.
- Add a list of database types and byte order values. Each list has
a wildcard 'ANY' entry which lets the client ask for whatever the
server supports. (XFR_ENDIAN_ANY is useful with the Berkeley DB hash
method for instance, since it isn't byte order sensitive.)
- Add two newserver failure codes: XFR_DB_TYPE_MISMATCH and
XFR_DB_ENDIAN_MISMATCH. The server uses these to tell the client
that it doesn't support the requested type/byte order.
These changes were made at the suggestion of Thorsten Kukuk, the
current maintainer of the Linux ypserv distribution. This allows
Linux and FreeBSD NIS servers to use the same ypxfrd protocol and
avoid accidentally exchanging incompatible map files.
Import a my own little ypxfrd protocol. Note that this protocol is
_NOT_ the same as Sun's, which is proprietary.
This basically impliments an RPC-based file transfer protocol which
lets a slave server suck over a raw map database file from the master.
This is many times faster than the normal method, which requires reading
the records from ypserv via yp_all() and then creating a new database
on the fly, particularly when you have many tens of thousands of
records in a map (e.g. a huge passwd database).
The protocol number I chose falls within the 'user-specified' range.
Maybe we should register it with Sun so we can get an official vendor
number for it. :)
